Technical Guide to SRAN Network Design (GO Applicable to SRAN10.0 & GBSS17.0 & BSC6910)-20140902-A-1.0

Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) Product Name Confidentiality Level GSM BSC6910 Internal Public Product Version Total 258 pages V900R017C00 Technical Guide to SRAN Network Design (GO Applicable to SRAN10.0 & GBSS17.0 & BSC6910) (For internal use only) Prepared By fuqiang (employee ID:00283077) Date 2014-07-18 Reviewed By lishuanghua (employee ID: 00101863) Date 2014-07-28 Date 2014-09-03 Li Yongqing (employee ID: 00141602) chenyin (employee ID: 00179448) Hu Chunhua (employee ID: 00257638) Approved By hepeng (employee ID: 00110002) Huawei Technologies Co., Ltd. All rights reserved CONFIDENTIAL CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) Change History Version Prepared/Revie wed By Date Description Approved By V0.1 Li Bo 2012-11-30 Initial draft Mei Weifeng, Huang Yanzhong V0.2 Li Bo 2012-12-07 The document is modified according to comments of the delivery department. Mei Weifeng V0.3 Li Bo 2012-12-15 The document is modified according to comments of the network information service (NIS) department. Mei Weifeng V0.4 Li Bo 2012-12-22 The document is modified according to review comments. Mei Weifeng V0.5 Li Bo 2013-2-4 Section 18.2.2"Design Examples" is modified. Songruining V0.6 Li Bo 2013-5-7 Add a note about the relationship between traffic model and BSC specification in the contract: Songruining Specifications and capacity configuration of the BSC must be based on a certain traffic model, all contracts must be established on a given traffic model to ensure the accuracy of the contract. If you are 2015-11-13 Huawei Confidential Page 2 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) Version Prepared/Revie wed By Date Description Approved By unable to obtain accurate traffic model, we recommend using the default Huawei traffic model for the contract traffic model. V0.7 Tang Xiaoli 2013-06-19 Deleted eGSM and used the eGBTS to replace independent NE. Songruining V0.8 Tang Xiaoli 2013-07-30 Added section 19.3"A Interface Design (TDM)" and section 19.6"Abis Interface Design (IP over E1)." Songruining V0.9 Tang Xiaoli 2013-11-22 Updated the document to adapt to the GBSS16.0 version. Songruining V1.0 Tang Xiaoli 2014-03-03 Revised the document based on TR5 review comments. Songruining V1.1 Liuqi 2014-05-06 Add 22.5.2 Constraints Songruining V1.2 付强 2014.07.18 Add VAMOS FR Songruining Add 16.4 source IP route 2015-11-13 Huawei Confidential Page 3 of 258 Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) CONFIDENTIAL Contents Foreword....................................................................................... 19 1.1 Objectives.....................................................................................................................................................................19 1.2 Scope............................................................................................................................................................................20 1.3 Constraints....................................................................................................................................................................20 1.4 Dependency..................................................................................................................................................................20 2 Overview of Network Design........................................................21 3 Overall Guidance Principles.........................................................22 4 Overview of Key NEs...................................................................23 5 Overview of the Network Design Tool...........................................24 6 Important Reference Document...................................................25 7 Product Specifications.................................................................26 7.1 BSC Specifications.......................................................................................................................................................26 7.1.1 Hardware Capacity....................................................................................................................................................26 7.1.2 Estimation of BSC Configuration Capacity..............................................................................................................27 7.2 Board Specifications.....................................................................................................................................................28 7.2.1 BSC6910 Board Specifications.................................................................................................................................28 7.2.2 Service Processing Modules......................................................................................................................................28 7.2.3 Interface Modules......................................................................................................................................................31 8 BOQ Review Guide......................................................................34 8.1 Design Overview..........................................................................................................................................................34 8.1.1 Purpose of the Design................................................................................................................................................34 8.1.2 Input of the Design....................................................................................................................................................34 8.1.3 Contents of the Design..............................................................................................................................................34 8.1.4 Design Reference.......................................................................................................................................................34 8.2 Overview of Pre-sales Network Design.......................................................................................................................34 8.3 BOQ Review Principles...............................................................................................................................................35 8.4 CS Traffic Models........................................................................................................................................................36 8.5 PS Traffic Models.........................................................................................................................................................38 8.6 Relationship Between Traffic Model and Traffic Statistics..........................................................................................40 2015-11-13 Huawei Confidential Page 4 of 258 Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) CONFIDENTIAL 9 Parameters for Capacity Calculation.............................................42 10 Capacity Calculation..................................................................42 11 Design of Resource Allocation....................................................44 11.1 Design Overview........................................................................................................................................................44 11.1.1 Purpose of the Design..............................................................................................................................................44 11.1.2 Input of the Design..................................................................................................................................................45 11.2 BSC Load Allocation..................................................................................................................................................45 11.2.1 Signaling Storm.......................................................................................................................................................46 11.3 BSC Board Layout Design.........................................................................................................................................52 11.3.1 Design Guide...........................................................................................................................................................52 12 Naming Rules Design.................................................................58 12.1 Design Overview........................................................................................................................................................58 12.1.1 Purpose of the Design..............................................................................................................................................58 12.1.2 Input of the Design..................................................................................................................................................58 12.2 NE Naming Rules.......................................................................................................................................................58 12.2.1 Naming Rules of Areas............................................................................................................................................58 12.2.2 Naming Rules of Offices.........................................................................................................................................59 12.2.3 Naming Rules of Manufacturers.............................................................................................................................59 12.2.4 Naming Rules of NEs..............................................................................................................................................60 12.2.5 Naming Rules of Signaling Points..........................................................................................................................61 12.3 NE Numbering Rules.................................................................................................................................................61 12.3.1 Numbering Rules of Entity IDs...............................................................................................................................61 12.3.2 Numbering Rules of BTS IDs.................................................................................................................................62 12.3.3 Numbering Rules of Cell IDs..................................................................................................................................62 12.3.4 Numbering Rules of LACs......................................................................................................................................62 12.3.5 Numbering Rules of MCCs and MNCs...................................................................................................................62 12.3.6 Numbering Rules of SPXs and DPXs.....................................................................................................................62 13 BSC6910 Networking Principles..................................................63 13.1 Technical Principles....................................................................................................................................................63 13.1.1 Overview.................................................................................................................................................................63 13.1.2 Technical Specifications..........................................................................................................................................67 13.1.3 Technical Description..............................................................................................................................................68 14 Optical Interface MSP................................................................70 14.1 MSP Design Guide.....................................................................................................................................................70 14.1.1 STM-1 Tributary Mode Selection...........................................................................................................................70 14.1.2 MSP Mode Selection...............................................................................................................................................70 14.1.3 Parameter Configuration.........................................................................................................................................71 14.1.4 S1 Configuration.....................................................................................................................................................72 14.1.5 C2 Configuration.....................................................................................................................................................73 14.1.6 MSP Support Capabilities of Boards.......................................................................................................................73 2015-11-13 Huawei Confidential Page 5 of 258 ..............4 Signaling Bandwidth Calculation.....................................................138 2015-11-13 Huawei Confidential Page 6 of 258 ...74 15 Detection Mechanism.................................................................................................................................8 Routing Planning (A over IP)..........................................................................................................................................................................................................................................86 16......................................................118 19..........................................................................119 19.........5 Signaling Configuration Principles..........1 Purpose of the Design.......................................................................................................4 IP PM Detection...................89 17 Network Topology Design............118 19..86 16...................................1...........136 19......6 QoS Design.................................................................................................118 19.................................................................91 17................102 18.......2....................................................................................87 16......................................................................................................................................0 & GBSS17................................................................0 & BSC6910) CONFIDENTIAL 14................................................102 18................1 IP Planning on the BSC Side..........................2...2 MSP Technical Description.............................................................2..........................1.........2 Networking Design...........................................................................................................................................135 19............................................1 Design Overview.........................................................6 Traffic Bandwidth Calculation...........................................................................................................................................................................84 16 IP Interworking Design...................................................................................................................................................................................................2 BFD Detection...............................Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.......................1 Design Overview..........91 17..................................................................................................................................2...................1 Purpose of the Design...................118 19.....................2......................2 Input of the Design...............................1 Interface Description.84 15..........................................................................................................................................................................................................2......................................................5 VLAN Design...............................................................................................................................................................................................103 19 Transmission Interface Design............................................135 19.................92 18 Reliability Design...........................................................................................................................1 Purpose of the Design.......................................118 19.135 19...............2.................1.......................................................................4 Routing Design on the BTS Side..80 15..................................................91 17.....................................................................................................................................................................................................................................91 17.....................118 19.......91 17...............................................................102 18.......................................1 Design Guide....7 IP Address Planning (A over IP).................................102 18.....2.........................3 Routing Design on the BSC Side........................................................82 15..............................2 A Interface Design..............................2 Typical Networking...2 Network Reliability Design.......................................................................................2 Design Examples..............................2 Input of the Design................................................................................................................80 15.............91 17..........2 Network Structure Design...................................1........................................................................................2 IP Planning on the BTS Side......3 SCTP Multi-Homing Design..............................................................................................................................................................................2...........................................129 19.......................................................2............................................................................2 Input of the Design................88 16...................................................................................................................2..........................1....................................3 ARP Detection..............................................1 Design Overview.........102 18..................................................................................88 16...........................88 16.....................................................................................................................................................1 Restrictions of the Design........................................................................................................................1 Design Guide............................................................................102 18......1..................................................2......................................................................................................... ..................7.....6..............................................................................................150 19.....................................................................................................145 19...............1 Interface Description........................2..............5.........6 QoS Design (Gb over IP)......................2 Networking Design.............................................................4.............................194 19...................1 Interface Description.......................5.......................................6 Route Planning..........3 Constraints and Limitations..................................................1 Interface Description..................................................................194 19.........................................7...................................5..................................197 19.......................6................6...............................................196 19...............................................................7 Parameter Design..............................................................................................................................................192 19..........................................................................................................2 Function Interaction...3 Transmission Bandwidth Design.................................9 QoS Design (A over IP)...................................2.......................................................183 19........................................................144 19.........................................................................................................................................................................1 Interface Description..............................................Technical Guide to SRAN Network Design (GO Applicable to the SRAN10...........................................................4 Signaling Configuration Principles.....148 19.................................................................................................................6........................195 19........................................................................................................192 19...................................................................................................3.......................................................................161 19.........................................................................................................................................................................................................................................1 Interface Description............2 Networking Design...........4 IP Address Planning.....6.............................7..................................................................................................................................................4 Gb Interface Design.................................157 19................4..........................................6.......3...................159 19...........................................................................................................................................................................3 Bandwidth Calculation.........................................195 19....................................6.......................7...165 19........................194 19.........6 QoS Design.0 & BSC6910) CONFIDENTIAL 19........................................................................................................................................................................................................................................................................0 & GBSS17..........169 19.................................3..139 19..................................................................................6 Abis Interface Design (IP over E1)......5.................4...................................................................5 Positioning Modes.........4 Networking Design.......................................7...198 2015-11-13 Huawei Confidential Page 7 of 258 ...............191 19............................................................................................................160 19.194 19.................4.................................................................168 19........................................148 19...................8 Interface Interworking.............4.......196 19...195 19..........................187 19......................................................................5..............................6..........................................................196 19................................................................................................2 Networking Design.............................................4...................................................198 19...............................................................................................................146 19...........................................................188 19..........................................................7.............................................................................7 Lb Interface Design......................................4.................142 19.........................................................5.............................................................................................................................4...........................................................................................9 Interworking Instances...............8 Clock Synchronization...............144 19................................194 19........................................................3 Bandwidth Calculation...............4 Configuration Principles.....7.....................5.........................................5 Abis Interface Design......................5 Routing Planning........5 Routing Planning (Gb over IP)............................................2 Networking Design.....................3 A Interface Design (TDM)......................................6 Bandwidth Calculation.............................180 19.............................................................................161 19..............................7 QoS Planning...3.................................................................................5 IP Planning....................3 Transmission Bandwidth Design............................7 Abis Port Allocation Design............................................................4..........................................................................................................................................192 19...............................................................................................................................................................................................................146 19.............................................................................157 19...10 Interface Interworking..................168 19......................7 Configuration Principles...........4 IP Address Planning............................................................................................................................................ ................1 Purpose of the Design....................................1 Design Overview.....................5 Transmission Mode...........3 IEEE 1588 V2..........1.............................................201 20................................................2 Input of the Design...........209 21 Time Synchronization Design..................7 Typical Application........................................................2 Networking Design.............................................................................................................................................201 20.......2............................................................................4 Selection of a Time Synchronization Source.224 22................................................................3........................................................................................................2......0 & BSC6910) CONFIDENTIAL 19......................................................................5 QoS Requirements of Clock Protocols.........................................................................................................................................3 Clock Source Selection.............................................................2.........................................3 MOCN II Design..........................................................227 22...201 20.........................227 22......................................................2.....................2..............224 22..................201 20..1.214 21...........................................................................................................6 Typical Networking.................216 22 Function Design............199 20 Clock Synchronization Design...........................................................2...............................................2.........................................................................................................................2 Clock Description........................................................................223 22..............................214 21.........................................................................................................201 20......................................201 20............................................................206 20................2..................................................................................................................................207 20......................................................................................................................2 Design of Radio Measurement Data Interface for Navigation (TOM-TOM)..........................................................................3 Limitations on Specifications.......................................................1 Overview.........................................................................214 21..205 20.....................................................................................................................................................................1 Standard Broadcast.............................................................215 21................................215 21...................................................................4 Software and Hardware Configuration...................202 20....................................................................................................................................................................................................................................................202 20..................................3 Capacity Planning.........................................................228 22.............................................214 21...................................................201 20...............................................3 NTP...........................................................................2 Input of the Design...........................................................................6 Design of the IP Clock Server..........................................................224 22...................................................................................................................................................................217 22................2...........................................................228 2015-11-13 Huawei Confidential Page 8 of 258 ............................................................................................................................2 SyncE....................................................................................3......................................................0 & GBSS17.......1...............................1 Design of Broadcast Solutions for Cells.............7 Time Synchronization..............................217 22..........................6 Bandwidth Design......................................................................................................................1 Purpose of the Design.........................................................................1 Definition of Synchronization..................................2........................217 22.....214 21...........................2...............................2....2 Description of Time Synchronization.....................................................1..........................................................................223 22.................................................................................................5 Clock Design in Abis over IP Mode....8 BTS Homing Allocation..........................................................................1 Design Overview..........................5 Networking Design..............................................227 22...........................................................................214 21............................................................................215 21.....222 22...........227 22.........................1 Overview......................................................................2 Simple Cell Broadcast...................................224 22....................Technical Guide to SRAN Network Design (GO Applicable to the SRAN10...................................................................................................4 Clock Design in Abis over TDM Mode...........4 Advantages and Disadvantages of Clock Protocols.............................2 Reference Document...........1...................................................................................................................................................................................................................................1.....3...............................................................205 20.......... .........256 2015-11-13 Huawei Confidential Page 9 of 258 ....................................................1..................................................................................................3 OM Networking Design................243 23... 243 23...4 Networking Instances.......3 eGBTS Networking................................................................................................................0 & BSC6910) CONFIDENTIAL 22...................233 22......248 24..................................................3.................248 24...........................................................................................................................4................228 22.......................................................................................................................254 24.................................................................255 24............................................4...................................................................................................6 Impact of eGBTS on the O&M..............................................................................................................1 Overview......................................1.........250 24.......1..............................................243 23....................256 24.........................................2 Design Tool of the BTS Cable Diagram........................................................................................................2 Constraints......................................................................................................................................................................................................249 24..3 IP Networking..............250 24......................................................................................................0 & GBSS17.............................................................243 23.........2 Entire E1/T1 Networking...............................................239 23 BTS Design..............4 Interface Design.................................1 Design Overview................2 Introduction to OMU......................................2 Dual OMU.........................................1 Purpose of the Design.....................233 22................................................................................3....................................................................................1...................................243 23.................................................2 Input of the Design....1 Purpose of the Design...............................4.1 BTS Cable Design.............................................................................................................................246 24 OM Networking Design.........1 Networking for Part of E1/T1 Timeslots...4 OM IP Address Planning.....2.................................................248 24...................................................................................................................................3 Networking Design..............................4 Capacity Planning..........................................................4...............................................3.......................Technical Guide to SRAN Network Design (GO Applicable to the SRAN10..................................................................................................................................................................................................230 22...........................................................................2 BTS Transmission...................................................................................................................................................5 Route Planning........5 Interface Design..........................................243 23...........................................................................229 22.......................1 Standalone OMU.......................................................................................................1 Input of the Design...............................5 LCS Function Design..............................................3......252 24..4 Design of BSC Node Redundancy.................3.................3 BTS Transmission Design...........................................................................................................................243 23.................................................................229 22.................3 Reference..2 Design Content...............................................................................................................................................................................................234 22..................................................................................248 24...............................248 24..........................................................................248 24..................................3.........................................................1...............................................................................................................................................3................................253 24..........................................................................243 23....4.......................2.....................................248 24..............................................................................................................................3............................................................................................................................. ...........................................................................................................101 Figure 17-8 Hybrid networking...................................................................................................96 Figure 17-2 BSC/MGW multi-homing networking.....103 Figure 17-11 Physical networking of the transmission pool with independent boards......................................................................................................................106 Figure 18-2 Reliability design of the Gb interface..........................97 Figure 17-3 MSC Pool networking mode 1...........................................................................0 & GBSS17..................................................................................................................................................................................................................112 Figure 18-9 IP networking topology of A interface boards based on the dynamic loading balancing...............................................................................110 Figure 18-7 MSC Pool networking mode 2......108 Figure 18-4 Reliability design of IP transmission routes...........................................................72 Figure 15-1 Diagram of the promoted commercial solution......98 Figure 17-4 MSC Pool networking mode 2................................................................111 Figure 18-8 Typical networking diagram of the SGSN pool.................................................................................................................................................................................................................................104 Figure 18-1 Improving reliability by active/standby links on ports........................................................................................................102 Figure 17-9 Logical networking of the transmission resource pool................................0 & BSC6910) CONFIDENTIAL Figures Figure 2-1 Position of the BSS network design in the entire network construction process........................................................21 Figure 11-1 Average service duration................................86 Figure 17-1 Networking of the BSC connected to a single MGW...................109 Figure 18-6 MSC Pool networking mode 1....................................................................................................................................................51 Figure 13-1 Port switchover............................................................71 Figure 13-2 Board switchover...............100 Figure 17-6 All-IP networking.............................Technical Guide to SRAN Network Design (GO Applicable to the SRAN10............................................................112 Figure 18-10 Standalone EOMU.101 Figure 17-7 Typical IP-based networking.............................................................................107 Figure 18-3 Reliability design of IP transmission routes...113 2015-11-13 Huawei Confidential Page 10 of 258 .............................................................................103 Figure 17-10 Physical networking of the transmission pool with active/standby boards................................................................................................................................................99 Figure 17-5 Typical networking of the SGSN pool......................................................................................................................................108 Figure 18-5 BSC/MGW multi-homing networking.............................................................................................................................................................................................................................. ...0 & GBSS17.................................117 Figure 18-15 Inter-board link aggregation in the inter-board pool networking scenario................. 128 Figure 19-7 Typical A over IP networking mode (pool of active/standby boards+manual active/standby LAGs) .........................................................Technical Guide to SRAN Network Design (GO Applicable to the SRAN10..............................................118 Figure 18-16 Manual active/standby LAGs on the BSC side+router adopting the VRRP networking mode..............................................................115 Figure 18-13 BSC belonging to two layer-2 transmission devices in the dual-homing mode...........................................177 Figure 19-26 IP networking when the Abis adopts data network transmission..............................................................................126 Figure 19-6 Typical A over IP networking mode (pool of active/standby interface boards+dual-active ports)...............................................................156 Figure 19-18 Direction connection (Gb over IP)...........................157 Figure 19-20 Typical Gb over IP networking mode (active/standby boards+manual active/standby LAGs)..................................................................................................................................................................................................................137 Figure 19-13 IP network topology of the BSC.....................................................................................................122 Figure 19-2 Reference protocol model on the user plane of the A interface................0 & BSC6910) CONFIDENTIAL Figure 18-11 Dual EOMUs...............................141 Figure 19-14 Promoted detection mode in active/standby mode.................................................120 Figure 19-1 Reference protocol model on the control plane of the A interface...........................................177 Figure 19-25 IP networking when the Abis adopts MSTP transmission..........................................................................................................................................................................................................................................................................................................122 Figure 19-3 BSC/MGW multi-homing networking.........................................124 Figure 19-5 Typical A over IP networking mode (pool of standalone boards).................158 Figure 19-21 Typical Gb over IP networking mode (active/standby boards+dual-active ports)........................................177 2015-11-13 Huawei Confidential Page 11 of 258 ........................123 Figure 19-4 Typical A over IP networking mode (pool of standalone boards)...........133 Figure 19-9 Two M3UA links and SCTP four-homing between the BSC and the MSC server.....................129 Figure 19-8 SCTP four-homing between the BSC and the MSC server.............................................134 Figure 19-10 SCTP dual-homing on the MSC server side and SCTP single-homing on the BSC side (1)................................................148 Figure 19-16 Gb over IP protocol stack.......135 Figure 19-11 SCTP dual-homing on the MSC server side and SCTP single-homing on the BSC side (2)....................................119 Figure 18-17 LAG of the active/standby board+router adopting the VRRP networking mode....................................................155 Figure 19-17 Embedded PCU networking.................................................................................161 Figure 19-22 Logical connection between the NS layer and the SSGP layer...169 Figure 19-23 Abis over HDLC interface protocol..........114 Figure 18-12 Clock subsystem of the BSC6910..........................................................................................................................175 Figure 19-24 TDM networking when the Abis interface adopts STM-1 transmission..117 Figure 18-14 BSC belonging to one layer-2 transmission device in the single-homing mode......................136 Figure 19-12 SCTP single-homing on the MSC server side and SCTP dual-homing on the BSC side.........................................156 Figure 19-19 IP transmission network connection (Gb over IP)..........143 Figure 19-15 Reference protocol model on the control plane of the A interface..................................................... ................................................247 Figure 24-4 Networking for part of E1/T1 timeslots..243 Figure 24-1 Standalone OMU......225 Figure 22-2 Cable connection diagram between the interface board and the CBC........................232 Figure 22-5 Physical networking on the VNP interface..................233 Figure 22-6 Networking of the active/standby OMUs with a single port and directly connected routers.........................204 Figure 20-1 Clock networking instance 1........................................................................................................................................................245 Figure 24-2 Dual OMUs...........................230 Figure 22-4 Logical networking for the TOM-TOM..................................233 Figure 22-7 Networking for time synchronization.....................................................178 Figure 19-28 Two E1s connected to different interface boards........................................................................................................................................................................................................................................................................................................0 & GBSS17.......................................................................................................................................................................................................238 Figure 23-1 Networking topology change of the eGBTS......................184 Figure 19-32 SMLC-based network topology for the Lb interface.................................................249 2015-11-13 Huawei Confidential Page 12 of 258 ..234 Figure 22-8 Logical structure of the LCS system on the GSM network.....................................216 Figure 20-4 IP Clock synchronization networking...................................................................237 Figure 22-10 Logical structure of the BSS-based SMLC............................................................................................................0 & BSC6910) CONFIDENTIAL Figure 19-27 BTS networking diagram.............................................................................................................................................................................248 Figure 24-5 Entire E1/T1 Networking........................................................................................................................................235 Figure 22-9 Logical structure of the NSS-based SMLC................243 Figure 23-2 Change of northbound and southbound interfaces of the eGBTS...................................204 Figure 19-34 Connection through STP................................................................................................................182 Figure 19-31 Typical A over IP networking mode (pool of active/standby boards+dual-active ports+single IP address)...................................Technical Guide to SRAN Network Design (GO Applicable to the SRAN10...........203 Figure 19-33 Direct connection between the BSC and the SMLC.....................................................................................................................................................................226 Figure 22-3 Topology of the simple cell broadcast system..........................................................................................................................................................................................................246 Figure 24-3 25-pin D model interface...........................................237 Figure 22-11 LCS flow initiated by an external LCS client......................................................................................................................222 Figure 22-1 Network topology of the cell broadcast................249 Figure 24-6 OM network topology.........................................................217 Figure 21-1 Typical networking for time synchronization........................................................................181 Figure 19-29 Two E1s connected to different ports on the same interface board...............................................................................................................................................213 Figure 20-2 Clock networking instance 2..........................................................................................213 Figure 20-3 MSTP-based GSM IP solution................................................................................................................................................................................181 Figure 19-30 Typical A over IP networking mode (pool of active/standby boards+manual active/standby LAGs+single IP address)........................................................................................................................ ..........................................250 Figure 24-9 OM E1 networking instance 2.......................252 2015-11-13 Huawei Confidential Page 13 of 258 ....................251 Figure 24-10 Change of the OM structure..........................................0 & BSC6910) CONFIDENTIAL Figure 24-7 IP networking in dual OMU mode............................................................................................................0 & GBSS17...................Technical Guide to SRAN Network Design (GO Applicable to the SRAN10......................250 Figure 24-8 OM E1 networking instance 1............................................................................................................................................. ...70 Table 13-1 Restrictions of the fault detection mechanism of the controller..........................................................................................................136 2015-11-13 Huawei Confidential Page 14 of 258 ........32 Table 8-4 Performance counters corresponding to basic procedures...............................................................................................................................................................................................................................69 Table 12-4 Optical interface interworking parameters...................................................................................................................................................................................................................................................................................................................................................................................................................................31 Table 8-2 PS user model...........................................................22 Table 7-5 Board specifications...................................................44 Table 12-1 MSP advantages and disadvantages....................................................129 Table 17-4 Design principles of A interface networking...........................................73 Table 13-2 Restrictions of the fault detection mechanism of the base station............................21 Table 7-2 Typical maximum configuration of HW69 R13 boards in BSC6900 GSM where the BM and TC are separated.......24 Table 8-1 Basic PS traffic model (new in the R13).............................................................................................................................22 Table 7-4 Typical maximum configuration of HW69 R13 boards in BSC6900 GSM where the Abis over IP or A over IP is adopted.......................................................121 Table 17-2 Calculation result of A interface bandwidth in IP transmission mode................0 & GBSS17............................................................................0 & BSC6910) CONFIDENTIAL Tables Table 7-1 Typical maximum configuration of HW69 R13 boards in BSC6900 GSM where the BM and TC are integrated...................74 Table 17-1 Calculation result of A interface bandwidth in TDM transmission mode..................43 Table 10-2 NE short names...............................................................133 Table 17-5 Configuration of O&M links for the Ater interface.................136 Table 17-6 Configuration of signaling links for the Ater interface..............32 Table 9-1 BSC capacity planning table.............................................................................22 Table 7-3 Typical maximum configuration of HW69 R13 boards in BSC6900 GSM where the Abis over TDM or A over IP is adopted...........................................................Technical Guide to SRAN Network Design (GO Applicable to the SRAN10........................................................................................35 Table 10-1 Manufacturer short names...................................................................................................................................................................................................................................................................................................................53 Table 12-2 MSP support capabilities of the boards of the controller..........................................................................................................................................................................31 Table 8-3 PS coding ratio and average rate..........................................56 Table 12-3 Framing mode comparison..........................................................................121 Table 17-3 A interface interworking parameters............................................................................................................................................................................... ...................................................................151 Table 17-8 Gb over IP interworking parameters............... c.................170 Table 17-10 Estimates of data related to parameters a.......... c..........................................................0 & BSC6910) CONFIDENTIAL Table 17-7 Gb over IP interworking parameters....................................170 Table 18-1 Support for 2G-based 1588v2 clocks............... and d.............................189 2015-11-13 Huawei Confidential Page 15 of 258 ............................ b...................................................................... b.153 Table 17-9 Performance test results of parameters a...0 & GBSS17..........Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.......................................................... and d....................... the CIC of A interface. without any Ater interface. EIUb. The BSC6910 R15 has less networking scenarios than the BSC6900. and FG2d boards. and DPUa/c/d/e/f/g. FG2c. the CIC of A interface and Ater interface. remote TC subracks. without any Pb interface. the BSC CS BHCA. POUc.  The A interface does not support IP over E1/T1. the BSC CS BHCA. for example. TNU boards. the number of PDCH. or local independent TC subracks.0.0. the networking is enhanced. IWF resources. OIUa. IWF resources.0&BSC6910) Keywords: network design Abstract: The BSC6910 is introduced in the GBSS15. see this document. FG2a. Contents considering the deleted networking scenarios are removed from this document. The following table lists the differences in network design between the GBSS17. Calculation of the BSC6910 capacity does not require calculation of Ater or HDLC transmission. Capacity Supports the calculation of the CS traffic volume.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the number of BSC subscribers. TNU boards. GOUd.0 BSC6900 and BSC6910: 2015-11-13 Item BSC6900 BSC6910 Resource allocation Not supports the EXOUa in 10 GE or EGPUa. In GBSS17. and the Gb interface throughput. Overall capacity calculati on of the BSC Huawei Confidential Page 16 of 258 . GOUd. the number of PDCH. PEUc. OIUb. FG2d. the number of BSC subscribers. and the Gb interface throughput. the BSC6910 (configured with the POUc) supports A over TDM networking. the TDM&IP and IP&IP using the IWF. GOUc. GOUc. GOUa.0&GBSS17. Specifically. Supports the calculation of the CS traffic volume. Supports the EXOUa in 10 GE and EGPUa. XPUb. Supports TDM exchange.  The BSC6910 does not support TC. TC Pool and local switching. and TC subracks. Not supports TDM exchange. Not supports the CIC calculation of Ater interface. the TDM&IP and IP&IP using the IWF. PEUa.  The BSC6910 does not support Abis over HDLC. XPUa. The following describes the networking scenarios of the BSC6910:  The BSC6910 does not support an external PCU. FG2c.0 & BSC6910) Technical Guide to SRAN Network Design (GO Applicable to SRAN10. GOUe.0 & GBSS17. For details. EIUa. GOUe. Pb interface Supports the bandwidth calculation of Pb interface circuits and the calculation of the bandwidth occupied by Pb interface links. IP networking Supports the IP design on the BSC and BTS sides. A over IP over STM1. Not supports the bandwidth calculation of A over IP over 10 GE(optical). Supports bandwidth calculation of Abis over TDM over STM1 and Abis over IP over FE/GE(electrical)/GE(optical)/1 0GE(optical). Abis over TDM over STM1. and Ater over IP over STM1. Supports Gb over IP over FE/GE(electrical)/GE(optical)/1 0GE(optical). Abis over IP over E1. Not supports this interface. Abis over IP over FE/GE(electrical)/GE(optical).0 & GBSS17. Ater over TDM over STM1. Abis over IP over STM1. Not supports Gb over FR over TDM E1 or Gb over FR over TDM STM1. and the QoS design. Not supports the bandwidth calculation of 10GE(optical) interface. the VLAN design. the route design on the BSC and BTS sides. Ater interface Supports the bandwidth calculation of Ater over TDM over E1. Not supports the bandwidth calculation of Gb over IP over 10 GE(optical). A over IP over E1. Bandwid th calculati on of A interface Supports the bandwidth calculation of A over TDM over E1. Huawei Confidential Page 17 of 258 . and Gb over IP over FE/GE(electrical)/GE(optical). the VLAN design. Naming rules The value of both BTS ID and CELL ID ranges from 0 to 2047. A over TDM over STM1.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. and the QoS design. Not supports the IP path design. The value of both BTS ID and CELL ID ranges from 0 to 7999. The value of DPX (integer) ranges from 0 to 186. and A over IP over FE/GE(electrical)/GE(optical). and the calculation of the number of M3UA links over IP. Supports the calculation of the number of M3UA links over IP.0 & BSC6910) 2015-11-13 Bandwid th calculati on of Abis interface Supports the bandwidth calculation of Abis over TDM over E1. Not supports this interface. Supports the IP design on the BSC and BTS sides. GB over FR over TDM STM1. Gb interface Supports the bandwidth calculation of GB over FR over TDM E1. Supports bandwidth calculation of A over IP over FE/GE(electrical)/GE(optical)/1 0GE(optical). and Abis over HDLC over E1. the route design on the BSC and BTS sides. The value of DPX (integer) ranges from 0 to 427. Reliability Supports the reliability design of active/standby port links. A over IP over FE/GE(electrical)/GE(optical).0 & GBSS17. data configuration. Supports Gb over IP. clock. all-IP networking. Gb interface Supports Gb over FR and Gb over IP. Abis over TDM over E1. and Abis over HDLC. Not supports the TDM networking or TC subracks. the OM. loadbalancing. the BSC and MGW multi-homing networking. networking in the BM and TC separated mode does not exist. the MSC pool. multiple transmission channels. the SCTP multi-homing. Supports the reliability design of active/standby port links. Transmis sion interface 2015-11-13 Huawei Confidential Page 18 of 258 .0 & BSC6910) Network topology Supports the TDM networking. loadbalancing. the SGSN pool networking. the VRRP in IP networking.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. A interface Supports A over TDM. and A over IP over E1. the transmission resource pool over A interface. the MSC Pool networking. hybrid networking. the SGSN pool networking. Not supports the reliability design of the TC pool. hybrid networking. the SGSN pool. clock. the SCTP multi-homing. Therefore. Supports the BSC and MGW single-homing networking. Not supports A over IP over E1. the SGSN pool. the OM. the BSC and MGW singlehoming networking. the VRRP in IP networking. and the transmission resource pool networking. the BSC multi-homing MGWs. data configuration. Abis Interface Supports Abis over TDM over STM1. multiple transmission channels. all-IP networking. Abis over IP. Supports A over IP over FE/GE(electrical)/GE(optical)/1 0GE(optical). the MSC pool. and Ethernet link aggregation. Not supports Gb over FR. and Ethernet link aggregation. the transmission resource pool over A interface. Supports Abis over TDM over STM1 and Abis over IP over EF/GE(electrical)/10GE(Optical ). the MSC Pool networking. the BSC multi-homing MGWs. the BSC and MGW multi-homing networking. and the transmission resource pool networking. and time synchronization.1 Objectives This document guides global system for mobile communications (GSM) base station subsystem (BSS) network design engineers through the network design and delivery of GSM BSS establishment. interfaces. cable connections. The LLD is intended for engineering guidance. a GSM BSS network design engineer can use high-level design (HLD) and low-level design (LLD) templates for GSM BSS network design to work out a final GSM BSS network design report for a customer. and external clock. The HLD provides the customer with the design of the network topology.0 & GBSS17.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. BITS clock. With the help of this document. BITS clock. networking. resource capacity. operation and maintenance (O&M). A network design report consists of the HLD and LLD. expansion. and external clock. Clock synchronization Foreword 1. You can use the network equipment planning (NEP) tool to generate the LLD. clock. transmission. and optimization. Supports GPS. This document covers all the guidance principles. migration. Not supports line clock. and provides the design of the device board layout. and key data configuration.0 & BSC6910) Ater interface Supported Not supported Pb interface Supported Not supported Supports line clock. GPS. 2015-11-13 Huawei Confidential Page 19 of 258 . function services. com. you need to effectively communicate with the operator and core network engineers to ensure that the required information is accurate and the change causes and change results are recorded.0 BSC6910 and is applicable to the GSM Only mode of the BSC6910.  The network design personnel must be global technical service (GTS) engineers who are familiar with the BSC6910 and are engaged in engineering or maintenance for more than one year.0 & GBSS17. serving GPRS support node (SGSN).3 Constraints This document is developed based on GBSS17. and BTS.2 Scope This document describes the design principles. and local maintenance terminal (LMT). and the involved interface NEs are the mobile switching center (MSC) server. and output formats of the BSS networking. and O&M. M2000. you must collect the required data based on the information collection template for network design. You can obtain the latest version of the guide from the following path: Documentation > Wireless > Wireless Public > Wireless Professional Services Product > Technical Guides 2015-11-13 Huawei Confidential Page 20 of 258 . 1. interfaces.  The network design guide is updated based on changes in the BSC and application scenarios and is available at http://support.huawei.0&GBSS17. packet control unit (PCU). services.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The GU mode is described in the Single RAN network design guide. During the network design. Network design of the BSC6900 is described in Technical Guide to Single RAN Network Design V100R003 (GO applicable to SRAN10.4 Dependency  Before the network design.0 & BSC6910) 1. transmission. The core network elements (NEs) involved in BSS network design are the base station controller (BSC). media gateway (MGW). design methods. 1.0&BSC6910). 0 & GBSS17.1 Position of the BSS network design in the entire network construction process The GSM BSS network design service involves the overall designs of the networking. O&M. the GSM BSS network design provides guidance for engineering and construction and guarantees highquality network operation for operators. balance. interfaces. transmission. functional services.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.1 shows the position of the BSS network design in the entire network construction process: Figure 1. The network planning (NP) provided by the network design department of Sales & Services. and extensibility of the network. resource capacity.0 & BSC6910) 2 Overview of Network Design The BSS network design service is provided in the engineering preparation and delivery stage. the network development planning provided by the operator. Focusing on the security. and clock of the network. and the radio network plan provided by the network planner are the input of the HLD and LLD. Figure 1. The BSS network design guides the follow-up network deployment design and engineering. 2015-11-13 Huawei Confidential Page 21 of 258 .  Principle of interface independence The A.  Principle of interworking The BSS network design and core network design are closely related. The BSS network design principles are as follows:  Principle of area-based design The BSS network design is implemented based on the network construction plan of the operator. and the interface interworking is complicated. and device capacity. and stages in engineering. In this way. such as NE homing. That is. a physical board can be configured with only one type of logical interfaces. and then the new BTSs result in hybrid networking and require re-homing. the design work can be simplified. design is implemented in a "cakecutting" manner with an MSC and all the BSCs mounted to the MSC as a cluster. numerous NEs are involved.  Principle of proper utilization of resources The design principle of resources on a network varies with the development stage of the network. Generally. areas. and Abis interfaces are physically independent. and Gb interfaces on the same interface board because of the inconvenience for follow-up maintenance and expansion and the greater impact from board faults. Therefore. after the network is constructed. Otherwise.0 & GBSS17. Abis. or new TRXs cannot be added for capacity expansion due to capacity limitation of the BSC after resources are used up. during the BSS network design. For example. the resource usage cannot be designed too high. if the number of users on a network rapidly increases. 2015-11-13 Huawei Confidential Page 22 of 258 . the scale of GSM BSS network construction is large. Do not configure the A. interface interworking.Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Gb.0 & BSC6910) 3 CONFIDENTIAL Overall Guidance Principles Generally.  Principle of security in network design The purpose of network design is to provide the customer with an available and reliable network that can handle burst traffic and can recover quickly in the event of network faults. designers must effectively communicate with core network designers on issues. new BSCs may be required. and the design process is lengthened so that the design workload can be distributed properly based on the engineering schedule. controls power. and implements channel coding. measures the quality of the radio network.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. session management. data packet routing and forwarding. and quality of service (QoS) management. and supplementary services for mobile subscribers. bearer services. charging. and radio network performance measurement. such as mobility management. controls packet calls. the BTS transmits and receives radio signals. The BTS/eGBTS provides radio functions in the BSS. handover control.0 & GBSS17. customized applications for mobile network enhanced logic (CAMEL).  BTS The BTS/eGBTS connects to the BSC through the Abis interface and communicates with mobile stations (MSs) through the radio interface. The PCU is introduced in the BSS so that the BSS supports the general packet radio service (GPRS) packet service. For example. interleaving. radio network configuration. and encrypting for radio channels.  PCU The built-in PCU connects to the SGSN through the Gb interface. and transmits data packets on the radio interface and Gb interface  MSC server The MSC server provides switching functions and implements call switching between the public land mobile network (PLMN) and the public switched telephony network (PSTN).  SGSN The SGSN is a core network device in the GSM packet switched (PS) domain.0 & BSC6910) 4  Overview of Key NEs BSC The BSC connects to the MSC and BTS through the A interface and Abis interface respectively. BTS management. A PCU is embedded to implement radio resource management. It implements functions. 2015-11-13 Huawei Confidential Page 23 of 258 . The PCU manages packet radio resources. power control. SMS. The MSC server provides telecom services. 0 & GBSS17. contact Li Yongqing (employee ID: 00141602). the efficiency can be greatly improved.Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & BSC6910) 5 CONFIDENTIAL Overview of the Network Design Tool The NEP tool is developed to improve the efficiency of network design delivery. This tool can complete most network designs automatically. For detailed information. network design delivery representative of Network Integration Service (NIS). If you use the NEP tool in network design. 2015-11-13 Huawei Confidential Page 24 of 258 . do? actionFlag=getAllJsonData&colID=ROOTWEB|CO0000000064&level=4&itemId=20300051453&itemId0=29-7&itemId1=3-154&itemId2=1-632&itemId3=20200051452&itemId4=20300051453&itemId5=&itemId6=&itemId7=&itemId8=&itemId9=&materialType=1232&isHedexDocType=&pageSize=20 2015-11-13 Huawei Confidential Page 25 of 258 .0 & GBSS17.com/support/pages/navigation/gotoKBNavi.0 & BSC6910) 6 Important Reference Document The Transmission Configuration Specifications describes the specifications of IP planning. QoS parameters.0) Wireless > Wireless Public > Wireless Professional Services Product > Technical Guides http://support.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.com:  A&GB Interface Configuration Specification_IP(GBSS17.huawei. Related links are available at http://support.huawei. and VLAN planning used for IP transmission. 7.1 lists the typical maximum configuration of R16 boards in BSC6910 GSM.1 Hardware Capacity Table 1. Specifications of a BSC adopting an all-IP network change as follows: The number of TRXs increases from 8192 in the BSC6900 to 24000 in the BSC6910.1 BSC Specifications For details about BSC specifications.0 & BSC6910) 7 Product Specifications The specifications vary with the product version. Table 1. see BSC6910 GU Product Description in the Hedex BSC6910 GU product documentation. all contracts must be established on a given traffic model to ensure the accuracy of the contract. If you are unable to obtain accurate traffic.) 2015-11-13 Specification and Subrack Name 1 MPS+2 EPS Number of cabinets 1 Maximum BHCA (M) 15 Traffic volume (Erlang) 43750 Number of TRXs 7000 Number of PDCHs that can be activated (MCS-9) 28000 Huawei Confidential Page 26 of 258 .1. Specifications and capacity configuration of the BSC must be based on a certain traffic model. The GBSS15.0 & GBSS17. For details about the capacity specifications of the BSC of a certain version. 7.0 does not support A over TDM.0 BSC6910 has a maximum configuration of one cabinet and three subracks in the GO mode and supports A over TDM. see the officially released documents of that version. but it cannot be configured in BM/TC separated mode.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.1 Typical maximum configuration of R16 boards in BSC6910 GSM (Abis over TDM and A over IP are adopted. The GBSS17. 2 Typical maximum configuration traffic volume of R16 boards in BSC6900 GSM (all-IP mode used) Specification and Subrack Name 1 MPS+2 EPS (Number of Subracks Can Be Changed) Number of cabinets 1 Maximum BHCA (M) 52 Traffic volume (Erlang) 150000 Number of TRXs 24000 Number of PDCHs that can be activated (MCS-9) 96000 Gb throughput (G) 8 7.2 lists the typical maximum configuration of traffic volume of R16 boards in BSC6900 GSM where the BM and TC are separated. The following describes how to calculate the maximum number of BHCA and maximum traffic volume:  2015-11-13 The method for calculating the maximum number of BHCA allowed by the current configuration is as follows: − If all interfaces adopt the IP transmission mode. 52.2 Estimation of BSC Configuration Capacity BSC configuration capacity is estimated based on two key BSC counters: Busy Hour Call Attempts (BHCA) and traffic volume. the maximum number of BHCA allowed by the current configuration is calculated as follows: Maximum number of BHCA = MIN ((Number of EGPUa(GCUP) pairs on the current BSC x Number of BHCA supported by a pair of EGPUa(GCUP)s x 80%.000) − If all Abis interfaces adopt the TDM transmission mode.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. however.000.000) − If the Abis interfaces adopt the TDM/IP hybrid transmission mode.688 Table 1.000) Huawei Confidential Page 27 of 258 . is based on the number of EGPUa(GCUP) boards. 21. the maximum number of BHCA allowed by the current configuration is calculated as follows: Maximum number of BHCA = MIN ((Number of EGPUa(GCUP) pairs on the current BSC x Number of BHCA supported by a pair of EGPUa(GCUP)s x 80%. Table 1. The actual configuration capacity is related to the number of interface boards and the number of service processing boards and is the minimum capacity calculated based on each board.0 & BSC6910) Gb throughput (G) 2. the maximum number of BHCA allowed by the current configuration is calculated as follows: Maximum number of BHCA = MIN ((Number of EGPUa(GCUP) pairs on the current BSC x Number of BHCA supported by a pair of EGPUa(GCUP)s x 80%. This section describes a simple method for estimating BSC configuration capacity based on the number of EGPUa(GCUP) boards.000.1.0 & GBSS17.000. 52. The estimation of the configuration capacity conducted currently. the POUc supports 512 TRXs and can be used in the BSC6910.000) − If all Abis interfaces adopt the TDM transmission mode. the maximum traffic volume allowed by the current configuration is calculated as follows: Maximum traffic volume = MIN ((Number of EGPUa(GCUP) pairs on the current BSC x Traffic volume supported by a pair of EGPUa(GCUP)s. DPUf boards must be configured to process user-plane CS data. 150. 150.0 & GBSS17. The POUc supports 1024 TRXs (without extra license control).0) where MaxACICPerBSCTDM indicates the maximum number of required A CICs on a BSC and is calculated based on the traffic model. The DPUf supports N+1 backup mode. POUc boards support TDM and IP over E1 transmission.000) 7. In the BSC6910. see Boards in BSC6910 GSM Hardware Description in the BSC6910 documentation package. In the BSC6900.1 BSC6910 Board Specifications For details about board specifications. the maximum traffic volume allowed by the current configuration is calculated as follows: Maximum traffic volume = MIN ((Number of EGPUa(GCUP) pairs on the current BSC x Traffic volume supported by a pair of EGPUa(GCUP)s. 62. only the POUc boards support Abis over TDM and A over TDM.2. Hardw are Versio n Involved Board HW6910 R15 SCUb、GCGa、GCUa、GCUb、GCGb、FG2c、GOUc、EGPUa、EXOUa、EOMUa 、ESAUa、ENIUa、EXPUa HW6910 R16 SCUb、GCUb、GCGb、FG2c、GOUc、EGPUa、EXOUa、EOMUa、ESAUa、ENI Ua、GOUe、EXPUa HW6910 R17 SCUb、FG2c、EGPUa、EXOUa、EOMUa、ESAUa、ENIUa. In A over TDM transmission mode. Number of Configured DPUf = RoundUp(MaxACICPerBSCTDM/ TCNoPerDPUf. 2015-11-13 Huawei Confidential Page 28 of 258 . the maximum traffic volume allowed by the current configuration is calculated as follows: Maximum traffic volume = MIN ((Number of EGPUa(GCUP) pairs on the current BSC x Traffic volume supported by a pair of EGPUa(GCUP)s. This document is officially issued to customers.0 & BSC6910)  The simplified method for calculating traffic (expressed in Erlang) is as follows: − If all interfaces adopt the IP transmission mode.500) − If the Abis interfaces adopt the TDM/IP hybrid transmission mode. The number of configured DPUf boards is determined according to the number of CICs.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.2 Board Specifications 7. SPUc 、GCGb 、GCUb、GOUe、EXPUa In the BSC6910. it can calculate using the Interference Based Channel Allocation (IBCA) algorithm.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.2. This board (GCUP) processes services of control plane and user plane integration. A BSC is configured with a pair of EGPUa boards.1 lists the specifications of service processing boards.0 & BSC6910) 7. None The GMCP needs to be configured if the IBCA feature is enabled. This board processes services of control plane and user plane integration. processing GCUP 2015-11-13 GSM BSC control plane and user plane processing 600 BTSs 600 CELLs 3000 PDCHs. NASP Network assisted service process Network assisted service processing unit None The NASP needs to be configured if Intelligent WiFi Detection and Selection is enabled. it supports CS and PS services of the standard TRX.2 Service Processing Modules Table 1. Table 1.1 Specifications of service processing boards Boar d Logical Functi on Full Name of Logical Function Descriptio n Specificati ons Condition EGPUa RMP Resource management Resource management processing This board is for resource management of the system. Huawei Confidential Page 29 of 258 . The specification is: 1000 TRXs The BHCA is based on Huawei default traffic model. In addition.0 & GBSS17. GMCP GSM BSC mathematics calculation processing If the board is used for GSM BSC mathematics calculation processing. 0 & GBSS17. and periodically sending it to Nastar. A BSC is configured with a pair of EXPUa boards. A BSC is configured with only one ESAUa board. GCUP GSM BSC control plane and user plane processing This board (GCUP) processes services of control plane and user plane integration.0 & BSC6910) EXPUa RMP Resource management processing Resource management processing board. The specification is: The BHCA is based on Huawei default traffic model. The ENIUa needs to be configured if the Evolved Deep Packet Inspection function is enabled. If the board is used for GSM BSC mathematics calculation processing. In addition. The SAU needs to be configured on the BSC.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. This board processes services of control plane and user plane integration. ESAUa SAU Evolved service aware unit Evolved service aware unit The SAU board is for collecting. filtering. GMCP GSM BSC mathematics calculation processing 1000 TRXs 600 BTSs 600 CELLs 3000 PDCHs.0. it can calculate using the IBCA algorithm None The GMCP needs to be configured if the IBCA feature is enabled. and gathering data of the service board. 2015-11-13 Huawei Confidential Page 30 of 258 . ENIUa NIU Evolved network intelligence unit Evolved network intelligence unit An ENIUa board has a capacity of 8000 M PS throughput in the RAN15. This board is for resource management of the system. it supports CS and PS services of the standard TRX. if a user purchases Nastar. the number of supported CICs is halved. 7. Optical) IP: A/Abis/Lb/Gb/Iur-g EXOUa Evolved 10GE Optical interface Unit IP: A/Abis/Lb/Gb/Iur-g POUc TDM Interface Unit(4 STM1.0 & GBSS17. the board capability required by WB AMR calls is two times greater than that required by common calls. Table 1. the DPUf supports 1920 CICs.0 & BSC6910) DPUf DPU CS Data Processing Unit (1920 CICs) This board provides the TC function to process CS data and works in N+1 backup mode. That is.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.1 Interfaces applicable to the boards Board Name Description Applicable Interface FG2c IP Interface Unit (12 FE/4 GE.1 lists the interfaces applicable to the boards. This board provides the TC function (supporting 1920 CICs) in A over TDM mode.3 Interface Modules Table 1.2 Specifications of interface boards over different interfaces 2015-11-13 Huawei Confidential Page 31 of 258 .2. If common AMR is used.2 lists the specifications of interface boards over different interfaces. If WB AMR is used. Table 1. Electric) IP: A/Abis/Lb/Gb/Iur-g GOUc IP Interface Unit(4 GE. channelized) TDM: Abis Table 1. concern the following aspects: 2. If the Abis uses TDM over E1/T1 transmission on the BSC side.  Calculation of the number of A interface boards Select appropriate transmission ports based on the network plan. In Abis over TDM transmission mode. 2015-11-13 Huawei Confidential Page 32 of 258 . Instead. The BSC does not support BM/TC separated mode and is not configured with the Ater interface. and Gb share an interface board. Gb.0) When configuring Abis interface boards. the BSC6910 only supports the POUc and does not support the TDM over E1/T1 interface board. 4. it can only be configured with the FG2 or GOUc working as the GE interface board when both of the following conditions are met: − The BTS uses IP over E1 transmission. The BSC6910 cannot be configured with a 10GE EXOUa interface board. − The BSC uses IP transmission. and then select the maximum value. Number of Abis interface boards = 2 x RoundUp(MAX(Number of TRXs in the transmission mode/Number of TRXs supported by the interface board. Only the POUc board of the BSC6910 supports IP over E1 transmission.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. it is not recommended that the A.  Calculation of the number of Abis interface boards Select appropriate transmission ports based on the network plan. Abis. optical or electrical switching devices. number of ports in the transmission mode/number of ports supported by the interface board). TRX A CIC (64 kbit/s) Ater CIC (16 kbit/s) Gb Through put(Mbit /s) WP1D000FG201 (FG2c) IP FE/GE electrical port 12/4 2048 23040 N/A 2000 WP1D000GOU01 (GOUc) IP GE optical port 4 2048 23040 N/A 2000 QM1D00EXOU00 (EXOUa) IP 10 GE optical port 2 8000 75000 N/A 8000 WP1D000GOU03 (GOUe) IP GE optical port 4 2048 23040 N/A 2000 WP1D000POU01 (POUc) TDM CSTM-1 port 4 1024 7680 N/A 488 IP IP CSTM-1 4 2048 N/A N/A N/A The total number of required interface boards is the sum of interface boards over all interfaces. Calculate the number of required A interface boards based on the service capability (CIC support capability). 3.0 & BSC6910) Model Trans missi on Mode Port Type Port No. and Abis interfaces must be configured on the BM subrack side. On a GSM network.0 & GBSS17. Interface boards are configured over different interfaces. The A. such as Huawei OSN device. are required to perform switching between E1/T1 and STM-1. Interface boards work in 1+1 backup mode. Calculate the number of required Abis interface boards based on the service capability (TRX support capability) and port requirements. 0)  Calculation of the total number of required interface boards The total number of required interface boards is calculated as follows: Total number of interface boards = Number of Abis interface boards + Number of A interface boards + Number of Gb interface boards 2015-11-13 Huawei Confidential Page 33 of 258 . If the Abis uses incoming TDM over E1/T1 transmission.0 & GBSS17. are required to perform switching between E1/T1 and STM-1.0 & BSC6910) Number of A interface boards = 2 x RoundUp(A CIC Number/Support capability of the A interface board.0) When configuring A interface boards. Number of Gb interface boards = 2 x RoundUp(Gb throughput/Support capability of the Gb interface board.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.  Calculation of the number of Gb interface boards Select appropriate transmission ports based on the network plan. such as Huawei OSN device. Calculate the number of required Gb interface boards based on the service capability (bandwidth support capability). optical or electrical switching devices. the BSC6910 only supports the POUc interface board (TDM over STM-1) and does not support the TDM over E1/T1 interface board. concern the following aspects: In A over TDM transmission mode. predicted number of subscribers. traffic.2 Input of the Design  Device BOQ  Network planning information (obtain the information. or transmission of the customer.4 Design Reference GSM BSC Configuration Manual 8. 2015-11-13 The pre-sales network planner plans the number of TRXs and the number of BTSs in the areas based on the capacity. and special requirements of the customer 8. the pre-sales network design procedures are as follows: 1.)  Information about the equipment room. including the BSC coverage. In the network deployment scenario.0 & GBSS17.0 & BSC6910) 8 BOQ Review Guide 8.3 Contents of the Design  BOQ review result  Defects in the BOQ and solution (suggestions) 8. and traffic per subscriber.1 Design Overview 8.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. power supply.2 Overview of Pre-sales Network Design This section describes the pre-sales network planning and design as well as BOQ principles and process to guide network design personnel through BOQ review. 8. and BTS homing from the on-site network planning department.1. and information. such as coverage.1. Huawei Confidential Page 34 of 258 . location area code (LAC) partitioning.1.1 Purpose of the Design Review the pre-sales bill of quantities (BOQ) configuration based on accurate network planning information to ensure that the BOQ meets network construction requirements. provided by the customer.1. coverage. and check the number against the pre-sales expansion BOQ. The BOQ and interface bandwidth data of the core network are obtained directly based on the number of subscribers. In BOQ review. The pre-sales network designer confirms the BSC locations and network topology based on the transmission conditions. In the new network construction and migration scenarios. The pre-sales network designer uses the design tool to calculate the subrack and board BOQ configuration of each BSC based on the number of TRXs of each BSC. 2015-11-13 Huawei Confidential Page 35 of 258 . number of BTSs. and number of BSCs. half-rate ratio. and frequency planning of the live network. use the GSM NEP tool to calculate the required BSC hardware based on the number of BTSs. In the network expansion scenario. and core network of the customer. The BSS planning does not involve bandwidth bottleneck and facilitates follow-up network development. the calculation result of the core network is smaller. Generally. use the GSM NEP tool to calculate the required BSC hardware based on the number of BTSs. Therefore. and then generates the BSC device BOQ. check with marketing personnel whether to change the delivery. equipment room resources. The pre-sales network planner plans the number of sites and carriers to be added based on the congestion rate.0 & BSC6910) 2. especially the number of Abis interface boards. is reviewed. the number of pre-sales configured boards. If spare BOQ hardware is configured. In terms of BTS distribution. number of TRXs. number of TRXs. the review is successful. half-rate ratio. and check the requirements against the pre-sales BOQ. This facilitates follow-up TRX expansion or BTS addition. Traffic model parameters The following content is quoted from the GBSS15. The pre-sales network designer calculates the number of pieces of BSC hardware required based on the number of sites.0 & GBSS17. If the BOQ hardware is insufficient. and traffic model. the actual number of pieces of hardware in BOQ delivery is far greater than the actual required number of pieces of hardware. The pre-sales planning of the core network is different from that of the BSS.0 BSC6910 system capacity calculation manual. transmission type.3 BOQ Review Principles Use the GSM NEP tool for BOQ review. and certain redundancy. and this causes the interface bandwidth inconsistency. and transmission type. 8. number of TRXs. coverage. In the expansion scenario. interface bandwidth inconsistency may occur. deducts the number of pieces of existing hardware from the number of pieces of BSC hardware required to obtain the number of pieces of hardware to be added. and traffic model after expansion. 3. deduct the existing BSC hardware to obtain the number of pieces of hardware to be added. 2. To meet the special requirements of some operators. the pre-sales network design procedures are as follows: 1. the following principles are recommended (you communicate with the operator to learn the follow-up expansion plan): BTSs are evenly distributed to subracks and Abis interface boards based on a certain redundancy ratio. traffic per subscriber. Ensure that the following content is for internal use only.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. you can use it.4 CS Traffic Models The circuit switched (CS) traffic model affects the BSC system capacity in the following aspects:  CS traffic on the control plane in the system.0 & GBSS17. Different colors in tables convey different meanings as follows: Parameter Title TRX Number Parameter name 0. more device resources are required. which is entered based on the network planning and design result. It is measured by the BHCA. the result calculated based on the default value is larger. parameters are described in tables. It is measured in Erlang. If the traffic on the air interface in the system is specified. That is. 300 It is an advanced parameter. Generally.02 Average busy-hour CS traffic per subscriber Average Call Duration(Second) CSCallDuration 60 Average busy-hour conversation duration per subscriber Percent of Mobile originated calls CSMOCRatio 50% Average busy-hour MOC ratio Percent of Mobile terminated calls CSMTCRatio 50% Average busy-hour MTC ratio Huawei Confidential Page 36 of 258 .02 It is an input parameter. but you must ensure that the modification is correct. the traffic model affects the BHCA traffic on the control plane in the system. The calculation result based on the default value is different from the actual situation.1 CS traffic model parameters Parameter 2015-11-13 Name Defau lt Value Description Average voice traffic CSErlPerSub per subscriber@BH(Erlang) 0. the traffic model affects the traffic on the user plane in the system.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Do not change this value unless you are absolutely confident of the new value.0 & BSC6910) In this document. 8. If you can provide the dimension result. 98% Automatically calculated result. You can enter a value or directly use the default value. Table 1. If the number of subscribers on the network is specified. You can use the default value (if available) of an input parameter if the entered value cannot be obtained.  CS traffic on the user plane in the system. 2 Number of busy-hour location updates per subscriber Average IMSI Attach/sub/BH CSAttachPerSubinBH 0.3 GoS-related parameters 2015-11-13 Parameter Name Defau lt Value Description Grade of Service (GoS) on Um interface UmBlockRatio 0.0 & BSC6910) Parameter Name Defau lt Value Description Average LUs/sub/BH CSLUPerSubinBH 1.2 Busy-hour 64K signaling load 2M SS7 signaling links load 2MSS7SigLinkLoad 0.0 & GBSS17.6 Average busy-hour sent SMSs per subscriber Average MT-SMSs /sub/BH CSMTSMSPerSubinB H 1 Average busy-hour received SMSs per subscriber Average intra-BSC HOs CSIntraHOPerSubinB /sub/BH H 1.2 CS signaling load parameters Parameter Name Defau lt Value Description 64k SS7 signaling links load 64kSS7SigLinkLoad 0.15 Average busy-hour IMSI detachments per subscriber Average MO-SMSs /sub/BH CSMOSMSPerSubinB H 0.15 Average busy-hour IMSI attachments per subscriber Average IMSI Detach/sub/BH CSDetachPerSubinBH 0.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.1 Average busy-hour intraBSC handovers per subscriber Average inter-BSC HOs /sub/BH CSInterHOPerSubinB H 0.1 Average busy-hour interBSC handovers per subscriber Paging Retransfer Ratio PagingRetransferRatio 35% Ratio of paging retries on the A interface in busy hours Table 1.02 Um interface block ratio Huawei Confidential Page 37 of 258 .2 Busy-hour 2M signaling load Table 1. 001 Device block ratio Table 1. Its weight in BHCA is zero. Relationship between CSErlPerSub.0 & GBSS17. and CSMTCPerSubinBH: CSMOCPerSubinBH = (CSErlPerSub x 3600/CSCallDuration) x CSMOCRatio CSMTCPerSubinBH = (CSErlPerSub x 3600/CSCallDuration) x CSMTCRatio 4.0 & BSC6910) Grade of Service (GoS) on A interface ABlockRatio 0.4 Other related parameters Parameter Name Defau lt Value Description Average MOCs/sub/BH CSMOCPerSubinBH 0. Relationship between CSMTCRatio and CSMOCRatio: CSMTCRatio = 1 – CSMOCRatio 3. CSMOCPerSubinBH. the MRs that are not reported in the call stage. the MRs reported in the short message service (SMS) and signaling connection stages. are not included. Paging retransfer /sub/BH CSRetransferPagingPe rSubinBH 0. CSCallDuration. For example.6 Number of busy-hour calling times per subscriber = CSErlPerSub x 3600/CSCallDuration x CSMOCRatio Average MTCs/sub/BH CSMTCPerSubinBH 0.6 Number of busy-hour called times per subscriber = CSErlPerSub x 3600/CSCallDuration x CSMTCRatio MR report/sub/BH CSMRPerSubinBH 144 Average number of MRs reported by each subscriber in busy hours. CSMOCPerSubinBH. Calculation of CSMRPerSubinBH: CSMRPerSubinBH = (CSMTCPerSubinBH + CSMOCPerSubinBH) x CSCallDuration x2 In the preceding formula. 5. Relationship between CSRetransferPagingPerSubinBH and PagingRetransferRatio: CSRetransferPagingPerSubinBH = (CSMTCPerSubinBH + CSMTSMSPerSubinBH) x PagingRetransferRatio 2015-11-13 Huawei Confidential Page 38 of 258 . Parameter relationship in the CS traffic model 2.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.56 Average number of paging retransmission times per subscriber in busy hours on the A interface. It is used only for reference. CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) 8.5 PS Traffic Models The packet switched (PS) traffic model affects the BSC system capacity in the following aspects: If the number of subscribers in the system is specified, the PS traffic model determines the total traffic of PS services in the BSC. The PS traffic model consists of the following:  Basic PS traffic model (This model is new in the R13. In R12 and earlier versions, only the PS user model is available.)  PS user model (For details about this model, see Table 1.2.) Table 1.1 Basic PS traffic model Parameter Name Value Description Uplink TBF Est & Rel / Second/TRX TBFUpPerSec PerTRX 1.75 It indicates the average number of uplink TBFs per second for each TRX in peak hours. Its default value is 1.75 for common networks and is 3.5 for PS networks with heavy traffic. Downlink TBD Est & Rel / Second/TRX TBFDownPerS ecPerTRX 0.9 It indicates the average number of downlink TBFs per second for each TRX in peak hours. Its default value is 0.9 for common networks and is 1.8 for PS networks with heavy traffic. PS Paging / Sub/BH PSPagingPerS ub 1.25 It indicates the number of received peak-hour pagings for each PS subscriber. Its default value is 1.25 for common networks and is 2.5 for PS networks with heavy traffic. Table 1.2 PS user model 2015-11-13 Parameter Name Valu e Description GPRS Active Sub PSSubAct 10000 Number of online GPRS/EGPRS subscribers average traffic per sub in busy hour (bit/s) PSTrafficPerSubinBH 300 Average GPRS/EGPRS traffic per online subscriber in busy hours (application layer) PS Traffic Peak Ratio PSPeakRatio 25% Ratio of the difference between the PS peak traffic and the average traffic to the average traffic. Do not use this parameter if it is not required. Huawei Confidential Page 39 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) average IP packet data length in Gb (Bytes) PayloadLenGb 300 Average packet length on the Gb interface. Do not use this parameter if it is not required. Table 1.3 PS coding ratio and average rate code scheme Ratio CS1 0% CS2 0% CS3 0% CS4 0% MCS1 0% MCS2 0% MCS3 0% MCS4 0% MCS5 0% MCS6 100% MCS7 0% MCS8 0% MCS9 0% The sum of the preceding coding rate ratios must be 100%. Generally, the customer cannot provide the ratios of coding rates during calculation. You can use the customer-expected average rate to replace the inputs. For example, the customerexpected average rate is about 30 kbit/s. According to the preceding table, this average rate is within the rate range of the MCS6 coding mode. In this case, you can simply enter 100% as the ratio of the MCS6 coding mode. 8.6 Relationship Between Traffic Model and Traffic Statistics Traffic model indicates the average number of typical subscriber behaviors for a subscriber. The total number of these subscriber behaviors can be obtained from the traffic statistics. The traffic model for a subscriber equals the total number divided by the number of subscribers. The number of subscribers (SubPerBSC) served by a BSC must be available and accurate in the calculation of the traffic model. Table 1.1 lists the performance counters corresponding to basic procedures. 2015-11-13 Huawei Confidential Page 40 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) Table 1.1 Performance counters corresponding to basic procedures 2015-11-13 Basic Procedure (Subscriber Operation) Performance Counters (Sum of Cell Performance) CS LUs (Location Update) A300F: Channel Requests (Location Updating) Average IMSI Attachs (IMSI Attachs) From MSC Average IMSI Detachs (IMSI Detachs) From MSC CS calls A300A: Channel Requests (MOC) + A300C: Channel Requests (MTC) – CA334A: Total Uplink Point-to-Point Short Messages – CA334B: Total Downlink Point-to-Point Short Messages MR Reports S329: Number of Power Control Messages per Cell CS SMS (sending and receiving) CA334A: Total Uplink Point-to-Point Short Messages + CA334B: Total Downlink Point-to-Point Short Messages Intra-Hos (intra BSC) CH310: Number of Outgoing Internal Inter-Cell Handover Requests Inter-HOs (Inter BSC) CH330: Outgoing External Inter-Cell Handover Requests + CH340: Incoming External Inter-Cell Handover Requests CS Paging A330: Delivered Paging Messages for CS Service Uplink TBF Est A9201: Number of Uplink EGPRS TBF Establishment Attempts + A9001: Number of Uplink GPRS TBF Establishment Attempts Downlink TBF Est A9301: Number of Downlink EGPRS TBF Establishment Attempts + A9101: Number of Downlink GPRS TBF Establishment Attempts PS Paging A331: Delivered Paging Messages for PS Service Huawei Confidential Page 41 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) 9 Parameters for Capacity Calculation Please refer to the latest BSC6900 Capacity Calculation Manual which you can download from http://3ms.huawei.com. http://3ms.huawei.com/mm/docMaintain/mmMaintain.do? method=showMMDetail&f_id=GSM14040308540024 10 Capacity Calculation Please refer to the latest BSC6900 Capacity Calculation Manual which you can download from http://3ms.huawei.com. http://3ms.huawei.com/mm/docMaintain/mmMaintain.do? method=showMMDetail&f_id=GSM14040308540024 Reference: Impact on Interface Transmission Bandwidth After VLAN Is Deployed VLAN is a data exchange technology derived from traditional LAN. VLAN allows LAN devices to be logically grouped into multiple network segments (that is, smaller LANs) to implement virtual workgroups. The hosts in the same VLAN communicate 2015-11-13 Huawei Confidential Page 42 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) with each other through VLAN switches. The hosts in different VLANs are separated from each other and they only communicate with each other through routers. A VLAN is a broadcast domain, that is, a host in a VLAN can receive broadcast packets from the other hosts in the same VLAN but cannot receive any broadcast packets from other VLANs. The advantages of VLAN are as follows:  Suppresses broadcast storm  Improves transmission security  Provides differentiated services VLAN Frame Format The VLAN frame format is defined in IEEE 802.1Q. Compared with a standard Ethernet frame, the VLAN frame is added with a four-byte VLAN tag in its header, as shown below. The fields of the VLAN tag are described as follows:  TPID: specifies the VLAN tag protocol identifier defined by IEEE. If a VLAN frame complies with IEEE 802.1Q, TPID is permanently set to 0x8100.  VLAN priority: specifies the priority of a VLAN frame. The priority ranges from 0 to 7. Ethernet provides differentiated services based on the VLAN priority.  Canonical Format Indicator (CFI): specifies the format of a frame that is exchanged between the bus Ethernet and a Fiber Distributed Data Interface (FDDI) or between the bus Ethernet and the token ring network.  VLAN ID: specifies the VLAN to which a frame is to be sent. Each VLAN is identified by a VLAN ID. Application scenario: Only Ethernet IP networks. The related BSC6910 parameters are as follows:  VLANID: This parameter specifies the identifier of a VLAN. The VLAN ID mapping should be preconfigured in the BSC6910. According to the VLAN ID mapping, the BSC6910 determines the VLAN ID to send a VLAN frame. The BSC6910 supports two VLAN configuration modes: − Configuring VLAN by next hop: The VLAN ID is determined according to the preconfigured mapping between the next-hop IP address and the VLAN ID. The related parameters are IPADDR and VLANID. 2015-11-13 Huawei Confidential Page 43 of 258 a four-byte (32-bit) VLAN tag is added to a 20-ms voice (data) frame. a four-byte (32-bit) VLAN tag is added to voice (data) frames that are transmitted at an interval of 20 ms. VLAN tag resources are saved if MUX is in use. with the increasing deployment of VLAN networking on IP networks. IP path.5%. and VLANID. PATHID. in particular.  The Ater interface supports configuring VLAN by next hop or data flow when IP over E1 is not in use. and VLAN ID. Detailed calculation method: If IP multiplexing (MUX) is not in use. Therefore. and the average impact is about 3.0 & BSC6910) − Configuring VLAN by data flow The VLAN ID is determined according to the preconfigured mapping between the SCTP link. VLAN tags have certain impact on IP transmission bandwidth over the Abis interface. The parameters related to SCTP link are SCTPLNKN. The actual impact varies according to different compresses and transmission rate.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.  The Gb interface supports configuring VLAN by next hop. 2015-11-13 Huawei Confidential Page 44 of 258 . If MUX is in use.  VLANPRI: This parameter specifies the priority of a VLAN frame. Impact assessment: With the increasing deployment of IP networking. VLAN configuration modes supported by different interfaces on the BSC6910 on the GSM networks are as follows:  The A and Abis interfaces support configuring VLAN by next hop or data flow.0 & GBSS17. 1 Purpose of the Design  Review the traffic and BHCA load of each device based on accurate network planning information. If a load risk exists or the traffic exceeds the specifications. traffic.1 Design Overview 11. improve the device resource usage.  TRXs are allocated to subracks evenly to balance the load and reduce signaling transfer between subracks.2 BSC Load Allocation This section assesses the BSC load risks. including the current traffic model and target traffic model based on the current device processing capability. negotiate with the customer and marketing personnel to purchase more devices (under the guidance of marketing personnel).2 Input of the Design  Device BOQ  Network planning information (Obtain the information.1. and improve the anti-attack capability.0 & GBSS17.  Review the specifications information about the MSC. LAC partitioning.  Configure BSC boards in proper slots based on the BSC traffic and BHCA to balance the BSC load.1.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. and lists the percentages of the BHCA and traffic load of each BSC in the design specifications. MGW. 11.  The number of TRXs configured in each subrack needs to be less than 70% (it is for flexible follow-up adjustment and expansion but is Huawei Confidential Page 45 of 258 . and BTS homing from the on-site network planning department. adjust the BTS homing.0 & BSC6910) 11 Design of Resource Allocation 11. If the BTS homing cannot be adjusted.)  Information about the equipment room.2. including the BSC coverage. and special requirements of the customer 11.1.  The predicted BHCA load does not exceed 70% of the design specifications. 11. and SGSN to check whether the capacities are enough and assess the risk. power supply. or transmission of the customer.1 Design Principles 2015-11-13  The predicted BSC traffic load does not exceed 70% of the design specifications. 1 Signaling Storm 11.0 & BSC6910) not mandatory) of the specifications to facilitate follow-up site adjustment and expansion. and improve the overall system capacity by optimizing capacity resource allocation. Under the impact of a large number of signaling messages.  The SS7 link load exceeds 40%. The actual traffic can be obtained from the customer or network planner.1. follow the marketing BOQ.2.  The busy-hour traffic exceeds 70% of the specifications. Output of the design Table 1. It is obtained based on the number of TRXs. congestion rate. and erlang_B table. The BSC traffic calculated by the GSM NEP is the traffic capacity of the BSC. If the preceding principles conflict with the marketing BOQ. Confirm the BSC traffic capacity and BHCA specifications in the current configuration based on the configuration in the marketing BOQ. see section Error: Reference source not found. experts in the Huawei headquarters assess the risk.1 BSC capacity planning table BSC Name BTS Numbe r Traffic BHCA Foreca st Foreca st TRX Numbe r TRX TRX Traffic BHCA Capacit y Perce nt Perce nt Percen t For BHCA calculation note.2 Concept of Signaling Storm Signaling storms first rose on the 3G network.  The busy-hour central processing unit (CPU) usage exceeds 70%.0 & GBSS17. traffic capacity. major signaling processing channels become the bottleneck of the 2015-11-13 Huawei Confidential Page 46 of 258 .7 ERL. 9.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The calculation formula is as follows:  Actual BSC traffic = Predicted number of subscribers x Busy-hour traffic per subscriber  Actual BSC BHCA = Predicted number of subscribers x Busy-hour BHCA per subscriber  Actual BSC traffic load = Actual BSC traffic/BSC traffic specifications  Actual BSC BHCA load = Actual BSC BHCA/BSC BHCA specifications Huawei's recommended expansion standards are as follows:  The number of TRXs configured for the BSC reaches 70% of the capacity specifications. and BTS homing.1.  The busy-hour BHCA exceeds 70% of the specifications.  The CIC traffic per line exceeds 0. number of BTSs. If the traffic load or BHCA load exceeds 60%. Assess whether the BSC resource load meets the requirements based on the traffic model. Moreover. Smart terminals and mobile network services are increasingly popular. have been diversified. a smart terminal sends an SCRI with the cause value being "UE Requested PS Data session end.3 Current State of Signaling Storm As the penetration rate of smart terminals increases. As a result. That is. the already heavy signaling traffic becomes even heavier. To save power. services. which causes a signaling storm. The signaling storm threatens equipment security of both the RNC and NodeB. 11.1.5 Impact of Smart Phones on the 2G Networks Signaling storms in the UMTS network rise from too many signaling messages caused by a large number of smart phones and low-traffic services. and the cycle goes on and on. Some subscribers of StarHub in Singapore had the same problem in 2011. Heartbeat packages are small data packages of hundreds or thousands of bytes sent every dozen seconds or tens of seconds. and performance and reliability of the network were affected for the same reason. a connection to the RRC is re-established. and the UE returns to the connected state. However. including low-traffic services. smart terminals periodically send heartbeat packages to the network server to synchronize the information at the request of such applications as QQ and MSN Messenger. a terminal in the connected state can send a signaling connection release indication (SCRI) to the RNC in some scenarios. some applications on the terminal need to periodically send heartbeat packages to the application server. and CPU usage on the control plane of both the radio network controller (RNC) and NodeB increases sharply. As many as 30 pieces of signaling over the Uu interface and Iub interface are required in every PS data transmission. For example. 11. 11. a smart terminal attempts to access the network at an increasingly short interval. Moreover. Part of the UMTS network has been affected by signaling storms. some subscribers of TELUS in Canada failed to access the network after many signaling messages were discarded by the CN of the X office. Consequently.2.2.1. According to the 3rd Generation Partnership Program (3GPP). Whether signaling storms are likely to 2015-11-13 Huawei Confidential Page 47 of 258 ." to indicate the end of a PS data session. After a small-size heartbeat package is sent.2. the feature of high signaling traffic on smart terminals stands out. For example. After smart phones were introduced. An SCRI carries different cause values in different scenarios.0 & GBSS17. which are caused by the following factors: Smart phone penetration rate increases year on year. and seriously decreases the processing capacity of the system. the RRC connection is released again. Statistics shows that smart terminals have seen an increase in signaling traffic.0 & BSC6910) CONFIDENTIAL network. A typical phenomenon is that the serving capacity of the system decreases. which makes the traffic model change significantly and the packet calling attempts exceed the voice calling attempts.Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. which is 15 times that in traditional terminals. some subscribers of China Unicom in Beijing failed to access the network after the congestion rate increases in the core network (CN) of the X office in Beijing in 2010. high RRC and radio access bearer (RAB) rejection rates occur when the data traffic is low. To provide better user experience.4 Causes of Signaling Storm A signaling storm rises from too many signaling messages. once some signaling messages are discarded. The heartbeats of different applications and the system result in frequent PS calling.1. The greatest bottleneck of an MS lies in the battery. a smart terminal automatically sends an SCRI to the RNC at the end of a data session to release the RRC signaling connection and returns to the idle state. Some subscriber of NTT DoCoMo in Japan failed to access the network. − The state changes from Ready to Standby. the MS returns a correct logical link control (LLC) frame.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & BSC6910) raise in the 2G networks as the penetration rate of smart phones rapidly increases? An analysis is made in multiple dimensions.1. Figure 1. In response.1 Average service duration  Impact of access to the GSM over the core network − When uplink data exists on the MS. As shown in Figure 1. the MS is switched to the Ready state and directly sends the data. signaling interworking does not exist between the GSM service access and the core network.0 & GBSS17.  Impact of the heartbeat service model of smart phones over the average service model in the GSM Use the live network in Hangzhou city of China Mobile Group Zhejiang Company Ltd as an example. − Frequent service triggering does not increase signaling messages other than paging messages over the Gb interface. − When downlink data exists on the network side. 2015-11-13 Huawei Confidential Page 48 of 258 . the Gb interface sends a paging message. if the time when no signaling message exists over the Gb interface exceeds a time prescribed by a timer on the SGSN side. No authorization or encryption is required. To sum up. the heartbeat service model of smart phones is the same as the average service model in the GSM. CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.  2015-11-13 Signaling load on the common control channel (CCCH) − Based on the loading capacity of the base station subsystem (BSS).0 & BSC6910)  Signaling in each access to the GSM When the GSM network is accessed. the number of signaling messages is less than three on the wireless network side. much less than the 25 signaling messages in the UMTS network (not considering interworking with the core network). Huawei Confidential Page 49 of 258 . gives priority to access of voice services. the loading efficiency of the packet data channel (PDCH) is 9 kbit/s when a cell uses a maximum of 64 PDCHs. − Channel management by layer improves signaling resource usage efficiency.0 & GBSS17. Two CCCHs can meet the requirements of the PS signaling load when the cell enables the multi-CCCH function. − The CCCH resources can bear the signaling load and do not form a bottleneck. and prevents the heavy PS load from affecting the CS services. − The CCCH resource usage efficiency can be further improved by multi-layered paging. which affects the CS paging messages. 2015-11-13 Huawei Confidential Page 50 of 258 . In all-IP mode.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The LAPD resources can bear the signaling load and do not form a bottleneck.000 K.0 & BSC6910)  Signaling load on the LAPD resources The load on the LAPD link mainly comes from the load on the B RSL link.0 & GBSS17. PS paging messages. and PS immediate assignment messages. which is much higher than the specification of the BSC6900.  − The number of LAPD links required by the PS service is calculated according to the following specifications: On a 16 kbit/s timeslot. CS immediate assignment messages. the latest product BSC6910 has a BHCA specification of 52. the maximum signaling load has 2000 Bytes/s. Huawei's XPU design specifications can meet the BHCA requirements and do not form a bottleneck. − Number of bytes in paging messages: 21 Bytes − Number of bytes in PS immediate assignment messages: 27 Bytes The eXtensible processing unit (XPU) resources The following figure describes the subsequent networking planning requirements of China Mobile Group. the traffic in the 2G network can increase to 2. Functions of both XPU and DPU boards are integrated in EGPUa boards. − The increase in signaling services caused by the increase in the traffic of the current data services does not have an impact over the XPU of the BSC.35 times that of the current traffic. the BSC6910 does not have a bottleneck in processing capability of the XPU and DPU boards.0 & GBSS17. Based on the above analysis. if non-smart phones are substituted by smart phones.35 times the current traffic. the DPU supports an increasing large number of PDCHs. traffic of smart phone users is 2. An EGPUa (GCUP) board supports 1000 TRXs and 3000 PDCHs. However.Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The total traffic increases to 2.9 times that of non-smart phone users. Huawei Confidential Page 51 of 258 . − The average loading efficiency of the PDCH is 4 kbit/s on the live network. When the loading efficiency of the PDCH increases to 9 kbit/s and the specification of equipment is improved to support more channels. The data processing unit (DPU) resources As the version is updated. In event of sudden increase in signaling messages.  2015-11-13 Impact of smart phones over the 2G network (based on the data of China Mobile Group Zhejiang Company Ltd) − The 2G network subscriber base remains unchanged.0 & BSC6910)  CONFIDENTIAL − Flow control on the XPU of the BSC ensures that the PS paging times in a period and the channel requests by the PS services in a period are controllable. − The BSC BHCA specification of the BSC6910 is 52000 K (all-IP networking mode). almost twice the number of TRXs (512) and PDCHs (1024) supported by the original XPU and DPU boards. The DPU resources can bear the signaling load and do not form a bottleneck. − Market penetration rate of small phones reached 19% in 2011. The BSC6910 does not use the XPU and DPU boards separately. the flow control on the XPU guarantees the loading security on the XPU and deals with the impact of the PS services over the CS services. a server to send notification messages to such terminals as iPhone in a secure and timely manner.2.0 & GBSS17.1 Design Guide Design board layout between subracks for the BSC based on the BOQ for load balancing and work out the board configuration figure.0 & BSC6910)   Heartbeat duration of application services is adjusted to reduce the impact over the network − Tencent increases the heartbeat duration of its program QQ (30 to 180s) to reduce the impact over the network. signaling storms do not occur on the 2G network. configuration for the BTS degrades in the GSM.1.  Balance the load between subracks to improve the anti-attack capability. 11. Huawei Confidential Page 52 of 258 . As a result. Purpose of board layout design: 2015-11-13  Decrease the number of messages forwarded between subracks to improve the BSC performance.3. to manage heartbeats and increase heartbeat duration. The conclusion may be updated depending on the future development.3 BSC Board Layout Design 11. Development trend View of the operator (VF): The GSM network will evolve to be a low-cost and low-traffic network for the following reasons: − The spectrum resources of the GSM will decrease because part of the resources is given to the UMTS and LTE in spectrum refarming. 11. − The legacy UE evolves towards smart phones and the traffic becomes increasingly low.6 Conclusion of Impact of Smart Phones over the 2G Network Based on the analysis above.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. − Apple launched APNS.  Balance the load between the subracks of the BSC. Deployment of 10G Slots in the BSC6910 2015-11-13 Huawei Confidential Page 53 of 258 . Therefore. and the priorities of slots are 2 to 7.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. board layout is important. The system can be configured with a maximum of 15 ENIUa boards. 11. Ensure that the processing capabilities of the Abis interface board. Abis interface board. The ENIUa board can only be configured in 10 G slot.3. An ESAUa board occupies two slots.  When a customer purchases and uses Huawei's Nastar. Therefore. Configure the ESAUa board in the active subrack.  Deploy optical interface boards and electrical interface boards on different sides in the subrack. The XPU load is relatively high. such as operation and maintenance (O&M). Deploy the A interface board.  The ENIU board (data service identification board with a specification of 1000 Mbit/s over the Gb interface) can be inserted in slots that do not hold the OMU and GGCU of the BM subrack. preferentially install service processing boards in front slots. the ESAUa boards need to be inserted in the BSC6910. and embedded packet control unit (PCU) in the same subrack match each other.1.  Use different boards to provide 2G and 3G services to reduce the impact of software upgrade and board adjustment on services. and Gb interface board separately. The recommended slots are slots 2 and 3. and alarms.  Deploy electrical interface boards on one side and optical interface boards on the other side to facilitate cable connection. A interface board. and improve the antiattack capability of the device. Do not deploy them on the same side. In an office where traffic is heavy.  Deploy logical boards of the same type in a centralized manner to reduce interleaving with boards of different types. balance the load.0 & BSC6910)  Reserve certain port redundancy to facilitate site adjustment and expansion.  Deploy boards of the same type (physical boards or logical boards) from the middle to sides in the subrack to facilitate follow-up board expansion.  Install interface boards in rear slots and service processing boards in non-fixed slots. traffic measurement. and the following principles are only for your reference)  Reduce inter-subrack signaling transfer. and Gb interface board) together.0 & GBSS17. The GMPS needs to process data. The number of TRXs configured in the GMPS subrack is relatively small. and deploy logical interface boards of the same type (A interface board.  Allocate slots properly to maximize the board processing capability (the switching capability of the slots on the backplane differs).1 BSC6910 Design Principles Design Principles (Use the NEP Tool to automatically generate the board layout figure. The ESAUa board may be inserted in other idle slots other than the fixed slots. ENIU boards are preferably configured with the same subracks of the Gb interface board (to reduce traffic between subracks). Abis interface board. in the case of Abis interface board imbalance between BM subracks. the number of Abis interface boards configured for the GMPS is small. Proper board resource allocation can maximize the processing capability of the device. ESAUa boards are required in the BSC6910. The following assignment is recommended for GOUc/FG2c/EXOUa/POUc boards: − EXOUa boards can only be assigned to slot 16 to 19 and slot 22 to 25.0 & GBSS17. Huawei Confidential Page 54 of 258 .0 & BSC6910) The following describes a method for configuring a main subrack: Every BSC6910 must be configured with only one PCS main subrack.  When a customer purchases Huawei's Nastar. when a GPS clock is required. SCUb boards are assigned to slot 20 and 21.  Assign EOMUa switch boards to slot 10 to 13. The following assignment is recommended:  2015-11-13 − Assign ESAUa boards to slot 0 and 1. Configure the BSC6910 with two PCS GCGa boards. when a GPS clock is not required.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. and EGPUa boards for resource management are assigned to slot 8 and 9.  Configure the BSC6910 with two PCS GCUa boards. − Preferred slots for EGPUa boards are slot 2 to 7. Assign GCUa/GCGa boards to slot 14 and 15. they are assigned to slot 26 to 27. When these slots are inadequate. − Preferred slots for GOUc/FG2c/POUc boards are slot 16 to 19 and slot 22 to 25.  EGPUa/ESAUa boards can be inserted in other idle slots other than the fixed slots. 0 & BSC6910) The following describes a method for configuring an extended processing sub rack:  SCUb switch boards are assigned to slot 20 and 21. When these slots are inadequate. The recommended slots are slot 0 to 13. ESAUa boards are required.  EXOUa/POUc boards can only be assigned to slot 16 to 19 and slot 22 to 25.  GOUc/FG2c/EXOUa/POUc boards are interface boards.  If a customer purchases Huawei's Nastar.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.  EGPUa boards can be assigned to other idle slots other than slot 20 and 21. Principles of EGPUa/EXPUa configuration 2015-11-13 Huawei Confidential Page 55 of 258 .  Preferred slots for GOUc/FG2c boards are slot 16 to 19 and slot 22 to 25. Configure ESAUa boards in the main subrack. assign GOUc/FG2c boards to slot 26 and 27. cell number. Divide the site-planned overall specification by the basic specifications above respectively. the RMP can only use EGPUa boards. Table 1. the EGPUa boards are used. one active and one standby board.0 & GBSS17. Logical types of service processing boards are RMP. In the GU/UO mode. The greatest of these numbers is the number of boards to be configured. the RMP can use EXPUa or EGPUa boards.  In the UO mode. to obtain several board numbers. only EGPUa boards can be configured. EXPUa boards are used in the GSM other than the Universal Mobile Telecommunications System (UMTS). GMCP. For boards on the control plane. comprehensive BHCA. In the BSC6910. number of PDCHs. the GMCP can use XPUa or EGPUa boards. Principles of GCUP configuration Service processing boards are configured according to the BSC capacity planning. and DPUc/DPUf boards on the CS user plane are calculated differently. By default. By default. the RMP uses the same board as the GCUP. instead of EXPUa boards. In the BSC6900.1 describes the specifications of the EGPUa boards. For boards on the CS user plane. DPUd/DPUg boards on the PS user plane. numbers of XPUa/XPUb boards on the control plane. instead of EXPUa boars.0 & BSC6910) Service processing boards used by the BSC6910 include EGPUa and EXPUa boards. By default. Different calculation methods are applied for the BSC6910 and BSC6900.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Principles of RMP configuration The system is configured with only one RMP pair in the MSP subrack. GCUP. and traffic volume.  Principles of EGPUa/EXPUa configuration for GMCP: In the GO/GU mode. TRX number. the GMCP uses the same board as the GCUP. Each GCUP board has the following specifications: BTS number. 2015-11-13 Huawei Confidential Page 56 of 258 .  EXPUa and EGPUa boards can be configured in both GO and GU mode. EXPUa boards are configured in GO mode and EXPUa in GU mode.  Principles of EGPUa/EXPUa configuration for the NASP: The NASP can only use EGPUa boards. the number is calculated based on the predicated traffic volume. the number is calculated based on the number of PDCHs. or NASP. the number is the larger value calculated based on the planned TRX number and the comprehensive BHCA.  Principles of EGPUa/EXPUa configuration for the RMP: In the GO mode. For boards on the PS user plane. 25 Erlang per TRX on average PDCH 3000 3 PDCHs per TRX on average PS throug hput 300 Mbit/s 3000 × 100 kbit/s. A BSC is configured with only one ESAUa board. another GCUP board is configured.0 & GBSS17. a BSC is configured with only once NASP board. The PS BHCA is based on the comprehensive BHCA of Huawei's default traffic model. Principles of ESAUa configuration If a customer purchases the Nastar. If this feature is enabled. Principles of ENIUa configuration If the feature of intelligent service identification is enabled.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. EGRPS2A Compre hensive BHCA 2200 K The value is based on the actual benchmark weights and considers the PS BHCA. the ESAUa board needs to be configured in the BSC. Each BSC is configured with at least two redundant boards. if the number of GCUP boards required is X in capacity calculation. By default.0 & BSC6910) Table 1.1 Specifications of the EGPUa board TRX 1000 Cell 600 BTS 600 Traffic volume 6250 6. If the IBCA function is enabled. A BSC is configured with only one ENIUa board. one GMCP board supports 2048 TRXs. ENIUa boards are required. The number of redundant boards can be manually specified in the redundancy configuration. 2015-11-13 Huawei Confidential Page 57 of 258 . GCUP boards do not support the active/standby mode. GMCP boards do not support the active/standby mode. Principles of NASP configuration NASP boards are configured according to the deployment requirement of network assisted WLAN identification. Principles of GMCP configuration GMCP boards are configured according to the IBCA deployment requirements. In actual applications. In the high-level design (HLD). For a geographical name in China.  Standard numbering and naming facilitate maintenance. naming rules of NEs are determined based on naming conventions and planning requirements of the customer. This document describes the naming and numbering rules recommended by Huawei. 12. Directly locate faults by using alarm information to improve maintenance efficiency. However.1 Naming Rules of Areas Network design is performed based on areas. area names. Nigeria is LOS.1.0 & BSC6910) 12 Naming Rules Design 12.0 & GBSS17. 12. 2015-11-13 Huawei Confidential Page 58 of 258 .2. Use LOS as the name of Lagos. For example. the publicly known short name of Lagos.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Therefore.2 Input of the Design  Information.1 Purpose of the Design  This section designs the numbering and naming rules for all the NEs on the network to make network topology clear and facilitate network management. use the capital letters in the full pinyin name. communicate with the customer and then determine the naming and numbering rules based on the customer requirements and the rules recommended in this document.1. Use the short name of the geographical name of an area to name the area. office names. and Huawei's naming rules.1 Design Overview 12. such as geographical distribution and the number of NEs.2 NE Naming Rules 12. it is necessary to name the areas. most customers use their own NE naming rules. and NE types  NE naming specifications and requirements of the customer. use the capital letters in the full pinyin name. Use the commonly used manufacturer short names in the telecom field. two BSC offices are located in Okuno and Okuani in Nigeria. For example. and it is important for locating NEs quickly.0 & BSC6910) For example. and this document lists only the commonly known ones. For a geographical name in China. 12. Use OKUN and OKUA as the names of the offices in Okuno and Okuani respectively. 12. a BSC office is located in Adekula in Nigeria. Naming the manufacturers and using the manufacturer names in NE naming can help quickly distinguish the manufacturer of an NE. For example. office naming is part of NE naming. Use GZ as the name of Guangzhou. a BSC office is located in Dian Xin Guang Chang in Xi'an.2. Use the first three letters in the full English geographical name of an office. For example.2 Naming Rules of Offices Devices are installed in offices. Use DXGC as the name of the Dian Xin Guang Chang office.2.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.1 Manufacturer short names Manufacturer Short Name Huawei HW Ericsson ERI ZTE ZTE Nortel NOR Motorola MOT Samsung SAM Alcatel-Lucent AL UTSTARCOMM UT UT Nokia-Siemens NSN Cisco CIS There are numerous manufacturers. the capital letters of the full pinyin name of Guangzhou is GZ. 2015-11-13 Huawei Confidential Page 59 of 258 . lengthen the short name of one office to distinguish them. Therefore. Table 1. If the short names of two are the same.0 & GBSS17. Use ADE as the name of the Adekula office.3 Naming Rules of Manufacturers The network of an operator may use the devices of multiple manufacturers. 2.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. For example. The short names of the NEs are as follows: Table 1. E stands for the sequence number in the area where the NE is located. and the BSC is named as follows: 2015-11-13 Huawei Confidential Page 60 of 258 .4 Naming Rules of NEs This document describes the naming rules only of the NEs on the radio side and the NEs closely related to the radio side. D stands for the short name of the NE.1 NE short names Network Element Type Description BTS Base transceiver station eGBTS Evolved GSM Base Transceiver Station BSC Base station BSC AN Access network OMU Operation and maintenance unit MSC Mobile switching center MSCe Mobile switching center emulation MGW Media gateway HLR Home location register STP Signaling transfer point SGSN Serving GPRS support node GGSN Gateway GPRS support node DNS Domain name server BG Border gateway NE08. the second BSC (manufactured by Huawei) in Xi'an is located in Dian Xin Guang Chang. NE40 RT Router LSW LAN switch FW Firewall M2K M2000 server Huawei recommends the following naming rules for NEs other than the BTS: <A>_<B>_<C><D><E> A stands for the short name of the area where the NE is located.0 & GBSS17. C stands for the short name of the manufacturer of the NE.0 & BSC6910) 12. B stands for the short name of the office where the NE is located. 12. It is used to identify BSCs. or the name of the property company that manages the area where the BTS is located. The value range is 0 to 65535. they are independent NEs in terms of GSM network structure.3. name them independently. The OMU and PCU are embedded in the BSC. the second DPC of XA_DXGC_HWBSC2 is named as follows: XA_DXGC_HWBSC2_DPC2 An OPC or DPC consists of 1 to 49 characters. B stands for the BTS ID.0 & BSC6910) XA_DXGC_HWBSC2 For example. Name BTSs as follows: <A><B> A stands for the name of area where the BTS is located.3 NE Numbering Rules 12. see 12.5 Naming Rules of Signaling Points A signaling point refers to the originating signaling point code (OPC) or destination signaling point code (DPC) of the BSC.2. 2015-11-13 Huawei Confidential Page 61 of 258 ." For example. The OMU and the PCU are named based on the BSC. the first PDSN (manufactured by ZTE) in Lagos in Nigeria is located in Adekula.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. and the PDSN is named as follows: LOS_ADE_ZTEPDSN1 This document recommends this naming rule. Generally. 12. Each BSC ID in the same MSC must be unique. if the devices on the operator's network are all provided by Huawei. However. see 12.2"Numbering Rules of BTS IDs.1 Numbering Rules of Entity IDs An entity ID is a BSC ID. The DPC naming rule is as follows: The DPC naming rule is as follows: <A>_OPC<B> The DPC naming rule is as follows: <A>_DPC<B> A stands for the name of the BSC to which the DPC belongs. omit the manufacturer name to simplify the NE names." B stands for the sequence number of the DPC in the BSC to which the DPC belongs.0 & GBSS17. For example. Engineers can determine the specific naming rule based on actual conditions.4"Naming Rules of NEs. For example.3. Therefore. the number of BTSs is large.2. Therefore. For details about BTS IDs. The combination of MSC ID+BSC ID can uniquely identify a BSC in the system. simplify the BTS names. BTS2 in Parkview in Nigeria is named Parkview2. For details about BSC names. Each country has multiple mobile network codes (MNCs). Each BTS ID in the BSC must be unique. that is. Provide this numbering rule after you communicate with the RF network planner.3. A DPX uniquely identifies a destination signaling point. 12.3. The operator provides the MNC.2 Numbering Rules of BTS IDs A BTS ID is used to uniquely number a BTS in the BSC. 12. 12. 2015-11-13 Huawei Confidential Page 62 of 258 .0 & GBSS17. The value range is 0 to 4. MCC+MNC+LAC+CI comprise the cell global identifier (CGI) of a cell.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.5 Numbering Rules of MCCs and MNCs Each country has a mobile country code (MCC).3. Name BTSs based on geographical areas. The indexes range from 0 to 427.0 & BSC6910) Number the BSCs with the entity IDs starting from 1 based on the order in which the BSCs are launched in commercial use.3 Numbering Rules of Cell IDs A cell ID is used to uniquely number a cell in the BSC.4 Numbering Rules of LACs In actual applications. the maintenance personnel can learn the geographical area where the BTS is located from the BTS ID (BTS name). there can be up to 428 destination signaling points. A CGI can uniquely identify a cell. Then. The operator provides the MCC. 12. The BSC allocates indexes to all destination signaling points.3. The value range is 0 to 7999. Provide this numbering rule after you communicate with the RF network planner. the RF network planner determines the LAC numbers.6 Numbering Rules of SPXs and DPXs An SPX uniquely identifies an originating signaling point. Each cell ID in the BSC must be unique. 12.3. That is. The value range is 0 to 7999. Configure up to five originating signaling points. Use four originating signaling points for GSM and reserve one for universal mobile telecommunications system (UMTS) for follow-up GU convergence expansion. allocate a consecutive number range to a geographical area. 1 lists the advantages and disadvantages when the GBSS15.0 & GBSS17. thereby generating a 1:N protection.  Low maintenance 2015-11-13 Huawei Confidential Disadvantages The reliability is low.  Low hardware cost: Multiple interface boards work independently to dynamically balance the load. Table 1.1 Technical Principles 13.  Basic reliability: The BTS is homed to BSC's multiple interface boards that provide resource pool. 13.0 & BSC6910) 13 BSC6910 Networking Principles This chapter describes the principles. and disadvantages of the mainstream networking of the IP interface of the BSC6900.0 BSC6910 adopts the typical networking mode of IP transmission resource pool.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.1. Page 63 of 258 . thereby providing the highest usage. resulting call drop for the ongoing calls instead of the newly connected subscribers. The independent BSC interface boards form the resource pool.0 BSC6910 adopts the typical networking mode of IP transmission resource pool Networking Scheme Description Advantages Promoted scheme: Pool of independent interface boards Each port of the router works in load-sharing mode.1 Overview Table 1.1 Advantages and disadvantages when the GBSS15. The SCTP is configured to multihoming. advantages. The ports of the router work in pairs using the Virtual Router  High adaptability: This scheme has no special requirements on network device configuration.  Compared with the solution with independent boards. The ports work independently. In addition. The BSC interface boards form the resource pool. IP address can be added on the core network device without changing the configuration on the BSC.0 & GBSS17. IP address can be added on the core network device without changing the configuration on the BSC.  High reliability: Fault of port or board does not Huawei Confidential  After a switchover in case of a fault. affecting those excess services.  High reliability: Fault of port or board does not affect services. the data processing and connection capabilities decreases by half.  Low maintenance cost: The maintenance is IPpath-free configuration.0 & BSC6910) cost: The maintenance is IPpath-free configuration. Optional scheme 1: Pool of active/standby interface boards+dualactive ports Optional scheme 2: Pool of active/standby interface boards+manual 2015-11-13 Each port of the router works in load-sharing mode.  Low hardware cost: Multiple pairs of interface boards dynamically balance the load. The configuration of the network device is simple and ports can be easily added to a board. for example.  High hardware cost: The number of port and interface boards doubles Page 64 of 258 .CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. one port takes over the services from another. thereby providing the highest usage.  There are special requirements on the configuration of network devices. The gateways also work in active/standby mode. in which the interface boards with dual-active ports work in active/standby mode. the 1:N protection of resource pool is configured between multiple pairs of interface boards. active/standby route policies are required. services are congested. The Huawei Confidential Selection Principle (SubScenario) The promoted solution is the default solution.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. compared with other two resource pool solutions. and the application technology is proven. The BSC requires the configuration of dual BFD+ARP detection. services may be affected. thereby providing the highest usage. and layer-2 interface.0 & BSC6910) active/standby link aggregation groups (LAGs) Redundancy Protocol (VRRP). If the bandwidth is insufficient. VLANIF. and layer-2 interface. Multiple pairs of interface boards dynamically balance the load. The ports work in active/standby mode. Table 1.  2015-11-13 The ports of the router work in pairs using the VRRP. In addition. Only small changes are required on the BSC. the hardware cost is lower. The ports work independently. for example. Try your best to recommend this Page 65 of 258 .  Compared with nonpool solutions.  The trunk connection between routers may not be reliable and affects the bandwidth. VLANIF.  Complicated configuration: This scheme has special requirements on the configuration of network devices. the router requires the configuration of VRRP. The BSC interface boards work in active/standby Complicated configuration: The router requires the configuration of VRRP.  Reconstruction from the solution of active/standby interface boards with dual-active ports requires few changes.  Low maintenance cost: The maintenance is IPpath-free configuration. affect services. the 1:N protection of resource pool is configured between multiple pairs of interface boards. If the trunk is disconnected. The BSC interface boards working in active/standby mode form the resource pool. Table 1.2 Advantages and disadvantages when the BSC6910 does not adopt the typical networking mode of IP transmission resource pool Networ Description king Scheme Advantages Disadvantages Promoted scheme: Pool of active/stan dby The implementation is simple.0 & GBSS17.2 lists the advantages and disadvantages when the BSC6910 does not adopt the typical networking mode of IP transmission resource pool. Transmission capacity expansion and adjustments do not require migration. CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Different route priorities are configured for each group.0 & BSC6910) interface boards+ma nual active/stan dby LAGs (pool of independe nt IP addresses) mode with manual active/standby LAG. services may be affected. Two independent boards are connected to two routers. The router and network path usage is increased. Furthermore. In addition. Each port provided by the active and standby boards of the BSC is dual-homed to one router. If the bandwidth is insufficient. the two routes work in backup mode. The Huawei Confidential The customer requires load-sharing networking which satisfies the following requirements:  Services address in pairs must be configured for core network devices. Either the active or standby port bears the data streams. which provides good maintainability and helps fault location and QoS monitoring. an endto-end deployment can be implemented. In addition.0 & GBSS17. that is. Ports of routers work in load-sharing mode. If the trunk is disconnected.  The data flow path is clear and consistent in sending and receiving. Complicated planning and configuration: IP addresses need to be divided to two groups. interboard dual-homing BSC requires the configuration of dual BFD+ARP detection. respectively. in which one group of IP is routed to the left path and another group of IP is routed to the right path through the highpriority route configuration. The ports are set to LAG mode. solution to the customer. services are congested. The trunk connection between routers may not be reliable and affects the bandwidth.  Active/standby route policies are required. Not recommen ded: independe nt interface board 2015-11-13 Divide the signaling and IP addresses of the local and peer ends into two groups.   Load sharing is implemented. The BTS is Services are affected if the homed to BSC's board is faulty. thereby generating a 1:N protection.  Basic reliability: The reliability is low. thereby achieving load sharing. multiple interface boards that provide resource pool. Optional scheme 1: Pool of active/stan dby interface boards+du al-active ports (pool of independe nt IP addresses) Ports of routers work in load-sharing mode. Not recommended Page 66 of 258 .  Effective load sharing: The load both in the sending and receiving directions are shared. improving reliability. dual-path protection is configured for intermediate networks. Best: 100 ms Remote Same as local fault detection Failure Note: The switchover duration is related to the number of routes.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.  Low maintenance cost: The configuration is simple.  High adaptability: This scheme has no special requirements on network device configuration. it is shorter than 1 second. Immediate Worst: 2 seconds transmission Generally. and CPU usage of the interface board/SCU.1 Technical specifications Fault Detection Port Failure Detection on the Physical Layer BFD ARP (100 ms x 3) (300 ms x 3) Best: 300 ms Best: 200 ms Worst: 600 ms Worst: 300 ms Best: 6 seconds Switchover ARP Message Total Sending Best: 100 ms Immediate transmission Generally.2 Technical Specifications Table 1.0 & BSC6910) needs to be configured on the bearer plane. it is shorter than 3 seconds. LAG protection is configured for intra-board ports.1. Expansion can be easily implemented. Worst: 1 second Worst: 9 seconds Board Failure The fault NA detection duration varies with the component where the fault occurs. 2015-11-13 Huawei Confidential Page 67 of 258 . The data path is clear. 13. number of IP paths/SCTP links. services are not interrupted. 2015-11-13 Huawei Confidential Page 68 of 258 . The BSC supports 1:1 active/standby link mode.3 Technical Description 1.0 & GBSS17.0 & BSC6910) These specifications are internally used. This is known as a port active/standby mode based on link aggregation. the active port transmits and receives data. the standby link takes over the data sending and receiving from the active link. In addition. the active port can be on the active board or standby board. and the standby port is generally not used or is used only for link detection. If the active link is faulty. Figure 2.2 describes the board switchover. Port 0 of the active and standby boards are switched over. but only internal configuration varies with flexible change. IP1 moves to port 0 in the standby board. the reliability of the IP pool is improved and use this scheme on the A interface. improve transmission reliability. Link aggregation means to aggregate multiple physical links of the active and standby boards to a logical link. − Pool of dual-active ports of active/standby boards: An IP pool is added to a network that has load-sharing ports and active/standby boards.1. Networking schemes in GBSS15.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. If the active link is available. Therefore.1. after switchover. and transmit data streams of users over multiple links at the same time. The LAG can increase bandwidth. Figure 2. 13. it sends and receives data. There are multiple detection modes. − Pool of active/standby boards+manual active/standby LAGs: It is an alternative for the solution of active/standby boards+active /standby ports.1 describes the port switchover. the active/standby port can be inconsistent with the active/standby board. That is. In port active/standby mode. Do not promise these to the customer unless it is necessary.1 Port switchover As shown in Figure 2. Furthermore. Networking changes are invisible to customers. Principle description of active/standby boards+manual active/standby LAGs Manual active/standby LAGs are adopted on active/standby boards. if an Ethernet port in an LAG is faulty. thereby generating an LAG. Figure 2. 2.0: − Pool of independent interface boards: An IP pool is added to a network that has independent dual-active interface boards. active and standby boards remain unchanged. The actual switchover duration is determined by the quickest detection mode. 0 & GBSS17. manual active/standby LAG. Different ports belong to different network segments. and the default IP subnet mask is 32-bit subnet mask.0 & BSC6910) Figure 2. Recommended detection mode: Dual BFD detection on the active port. which cannot be configured.2 Board switchover Use networking based on active/standby boards. generally no IP address is configured. Layer-3 networking. In the ARP detection on the standby port.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. In this mode. router VRRP. the destination addresses are the port IP addresses corresponding to the two routers. ETHIP: Each port is configured with an IP address. the destination addresses are the VRRP IP addresses of the two routers. and device IP for communication. and uses the 29-bit subnet mask. If ARP detection is not enabled on the standby port. Typical configuration: Device IP address: The active and standby boards share the same device IP address. 2015-11-13 Huawei Confidential Page 69 of 258 . In the case of interworking with network devices. and this mode is known as the sequence-based mode. The VC-12 is numbered based on TUG-3. Instead.0 & BSC6910) 14 Optical Interface MSP This chapter describes the optical interface (STM-1 interworking design). then based on TUG-2.1 MSP Design Guide Optical interface interworking mainly describes the optical interface boards on the BSC side and the directly connected optical interface NEs (including the design of interworking between transmission devices). the E1T1 number on the BSC is not the same as the VC-12 number of the network device even if the numbering modes are the same.1. find out the mode used at the peer end. use the MSP 1+1 single-end non-recovery mode. then based on TUG-2. the VC-12 numbers of network devices start from 1 generally.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. and then configure the mode at the local end accordingly. In addition. and the E1T1 numbers of BSCs start from 0. the ITU standard does not clearly specify the mode in which timeslots are sequenced in the VC-4. The VC-12 is numbered based on TU-12.2 MSP Mode Selection By default. E1T1 number = VC-12 number – 1. the VC-12 numbering rules in the VC4 of different manufacturers are different. Three modes are available based on the numbering rules: Huawei mode: In this mode. and finally based on TUG-3. and finally based on TUG-3. Alcatel Mode: This mode is seldom used. 14. 2015-11-13 Huawei Confidential Page 70 of 258 .1 STM-1 Tributary Mode Selection For channelized optical interfaces. In this mode. then based on TU-12. numbering is implemented based on timeslot numbers.1. 14. the VC-12 is numbered based on TUG-2. Therefore. The optical interface of the BSC supports the preceding modes. numbering is implemented based on line numbers. Lucent mode: In this mode. 14. Therefore. and finally based on TU-12.0 & GBSS17. and this mode is known as the insertion mode. complicated. 64 The user can enter 62 The receiving The remote end does not Huawei Confidential Page 71 of 258 . The detailed contents are negotiated with the remote end. and protocol compatibility is required.  The remote device or the customer requires this mode. Negotiation between the two ends is not required. J1.0 & GBSS17. The detailed contents are negotiated with the remote end. The bytes are checked one by one. and the compatibility is high. and J2 configuration 2015-11-13 Length Mode (Byte) Sending Receiving Selection Principle 16 The user can enter 15 bytes (the most significant bit cannot be 1).1. The remote end does not support the 16-byte mode.1 MSP advantages and disadvantages Solution Advantage Disadvantage MSP 1+1 single-end nonrecovery mode A number of It is the default mode and boards/backplanes of is promoted. the most significant bit is 1). 14.1 J0. The receiving end adopts the same algorithm for comparison. 1 The single bytes set by the user are sent consecutively. the bytes are sent. MSP 1+1 double-end nonrecovery mode Negotiation between the two ends is required. Negotiation between the two ends is required. and the first byte is automatically generated (15-byte CRC7 check value. Selection Principle (Sub-Scenario) The paths in the two The self-healing rate is high directions are inconsistent. The paths in the two directions must be the same for easy understanding and fault location. and the when multi-point faults implementation is occur. The default SBS 155 is converted into hexadecimal 0X534253203135352020202 020202020. Huawei's BSC do not support the single-end mode. Then. The switchover speed is high. It is the standard mode and promoted by default.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & BSC6910) Table 1. MSP 1:1 double-end recovery mode  The boards/backplanes that do not support the 1+1 single-end mode use this mode. The remote device does not support MSP 1+1 protection and only supports 1:1 protection.3 Parameter Configuration Table 1. In interworking. 14. Table 1. ensure that the padding modes (ZERO/SPACE) at the two ends are the same. Two configuration modes. the bytes are sent. zeros or spaces are padded automatically (this can be configured by running Set OPT: JAUTOADD=ZERO/SPACE. The most significant four bits are reserved. Then. the J byte does not provide the continuity check function and do not use it as the default configuration. By default. The J2 of the AOUa and POUa does not support the 1-byte mode. end adopts the same algorithm for comparison.1.1 Definition of the S1 in G.4 S1 Configuration The S1 byte is in the first column and the ninth row in MSOH of the SDH frame structure. Generally.1 describes the definition of the S1 in G.707. that is. spaces are padded. and San4 Synchronization Quality Level 0 0000 The quality is unknown (on the existing synchronization network). no alarm is generated regardless of the format set at the local end. Table 1. A check is not performed.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.812 transit exchange) 8 1000 SSU-B (G. or the formats at the two ends do not match.707 2015-11-13 Quality Level San1. All zeros without a format are sent consecutively.811 recommended clock 4 0100 SSU-A (G.0 & GBSS17. San2. If all zeros are received. The remote configuration cannot be known.812 local office) 11 1011 Synchronous equipment timing source (SETS) Huawei Confidential Page 72 of 258 . The detailed contents are negotiated with the remote end. the character mode and the hexadecimal number mode.). The least significant four bits (bits 5 to 8) transmit the synchronization status information (SSM). are available. San3. If the number of bytes/characters that the user enters is smaller than the required number. 2 0010 G. Use the character mode because it is clear and not prone to errors.0 & BSC6910) Length Mode (Byte) NULL Sending Receiving Selection Principle bytes (0D0A cannot be present). support the 16-byte mode. The larger value indicates the lower clock quality. In NULL mode. Huawei network devices expand the most significant four bits so that they can be used to transmit the clock ID. the S1 byte refers to the least significant four bits. and the last two bytes 0D0A are automatically generated. 1. for example. If the interface is a channelized optical interface. and San4 Synchronization Quality Level 15 1111 Synchronization is unavailable.5 C2 Configuration On the BSC. In special cases. Table 1. The BSC selects the clock based on the configured priority and does not process the S1 byte sent by the remote end of the optical interface. the clock is obtained from the optical interface on the core network side. the SDH may trace the clock of the BSC.1.1 describes the MSP support capabilities of boards. the C2 byte does not need to be configured by the user but is determined by the board application type. The synchronous digital hierarchy (SDH) network of the Iub/Abis interface possesses its own clock and seldom obtains the clock from the BSC. if the interface is a non-channelized optical interface. Table 1. 14. San3.1 lists the details of the C2 configuration.0 & BSC6910) Quality Level San1.0 & GBSS17.  The BSC does not have a requirement for the S1 byte of the remote device. San2.1 Details of the C2 configuration Board Function C2 Value C2 Interpretation POUc TDM+FR 0X02 TUG structure It is required that the remote configuration be the same as the local configuration. 14. Table 1. That is. that is. Generally. Conclusion:  Set S1 to the default value 11 on the BSC. the SETS.6 MSP Support Capabilities of Boards Table 1. Huawei Confidential Page 73 of 258 . the SDH network is the small-scale network dedicated for BTS backhaul.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the C2 byte is 0X02 (TUG structure). The requirement for the clock of the BSC is stratum 3 and category A.1 MSP support capabilities of the boards of the BSC 2015-11-13 Board Function MSP 1:1 MSP 1+1 single-end MSP 1+1 double-end Remarks POUc TDM+FR Y Y(*) Y It supports the singleend mode only after it is inserted in the new backplane. the optical interface of the BSC seldom works as the clock source of the SDH devices. the C2 byte can be 0X13 (ATM mapping) or 0X16 (PPP Mapping). The arrangement of the 63 PCMs on the optical interface varies with the framing mode. They are Huawei mode (X increments first. and finally X).0 & BSC6910) The new backplane refers to the backplane whose version is VER.C or later. then Z. and finally Z).2 MSP Technical Description Technical Description of the BSC Optical Interfaces Framing mode In optical interface interworking. Lucent mode. then Y.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. and finally X). the first E1s in the three modes are the same. and Alcatel mode. Lucent mode (Z increments first. see Table 1. This makes the communication between the technical personnel difficult for interworking negotiation. are available. 2015-11-13 Huawei Confidential Page 74 of 258 . However. three framing modes. Three SDH optical interface framing modes are available. the following describes the three modes and provides a reference for the communication between technical personnel. The backplanes in the subracks delivered after about April 2008 are new backplanes.1. 14. that is. Huawei mode. The names of the three modes are different from the names that partners use. and Alcatel mode (Y increments first.0 & GBSS17. then Y. For details. Therefore. 1 Framing mode comparison 2015-11-13 Huawei Confidential Page 75 of 258 .0 & GBSS17.Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & BSC6910) CONFIDENTIAL Table 1. 0 & BSC6910) 2015-11-13 Huawei Confidential CONFIDENTIAL Page 76 of 258 .Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17. Character String) Negotiated with the peer end This byte is used to repeatedly send the segment access point identifier so that the receiving end can determine based on this byte that the receiving end and the specified sending end are in the continuous connection state. J0 trace mismatch alarm switch Negotiated with the peer end It indicates whether RTIM is reported if TX J0 Byte (Hexadecimal. The J0 byte lengths of the optical interface devices provided by different manufacturers are different.0 & GBSS17. and Alcatel mode. the maximum length of TX J0 Byte (Hexadecimal. Character String) or Expect RX J0 Byte (Hexadecimal. Character String) on both ends are inconsistent in optical interface interworking. The value is a character string of 0 to 15 characters. Character String) on both ends are inconsistent in optical Huawei Confidential Page 77 of 258 . Character String) or Expect RX J1 Byte (Hexadecimal. J1 trace mismatch alarm switch 2015-11-13 Negotiated with the peer end It indicates whether HPTIM is reported if TX J1 Byte (Hexadecimal. Character String) Negotiated with the peer end This byte is used to repeatedly send the segment access point identifier so that the receiving end can determine based on this byte that the receiving end and the specified sending end are in the continuous connection state. Optional values: YES and NO. The value is a character string of 0 to 15 characters. Character String) can be adjusted so that Huawei's device can interwork with the optical interface devices of other manufacturers and can be compatible with the earlier versions. The setting of this parameter must be consistent with the corresponding parameter on the peer optical interface device. TX J0 Byte (Hexadecimal. Character String). Optional modes: Lucent mode.2 Optical interface interworking parameters Parameter Name Recommended Value Description Tributary Numbering Negotiated with the peer end It indicates the tributary arrangement sequence in an SDH frame. Expect RX J0 Byte (Hexadecimal. Character String) and Expect RX J0 Byte (Hexadecimal. Huawei mode.0 & BSC6910) Names and description of the optical interface interworking parameters: Table 1. Character String) and Expect RX J0 Byte (Hexadecimal.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. J0 Mode Negotiated with the peer end It indicates the maximum length of TX J0 Byte (Hexadecimal. Therefore. Character String). Therefore. Character String) and Expect RX J1 Byte (Hexadecimal. Huawei Confidential Page 78 of 258 . 16 bytes. Set TX S1 Byte Negotiated with the peer end It indicates whether the S1 byte is enabled. Character String) Negotiated with the peer end The J1 byte is used to repeatedly send the higher order path access point identifier so that the receiving end of the path can determine based on this byte that the receiving end and the specified sending end are in the continuous connection (the path is continuously connected) state. Character String) Negotiated with the peer end The J1 byte is used to repeatedly send the higher order path access point identifier so that the receiving end of the path can determine based on this byte that the receiving end and the specified sending end are in the continuous connection (the path is continuously connected) state. 2015-11-13 Expect RX J1 Byte (Hexadecimal. The optional lengths are 1 byte. and 64 bytes.0 & GBSS17. the maximum length of TX J1 Byte (Hexadecimal. The value is a character string of 0 to 15 characters. Character String) and Expect RX J1 Byte (Hexadecimal. Optional values: YES and NO. The J1 byte lengths of the optical interface devices provided by different manufacturers are different. Character String) can be adjusted so that Huawei's device can interwork with the optical interface devices of other manufacturers and can be compatible with the earlier versions. J1Mode Negotiated with the peer end It indicates the maximum length of TX J1 Byte (Hexadecimal. Expect RX J1 Byte (Hexadecimal. The value is a character string of 0 to 15 characters.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The setting of this parameter must be consistent with the corresponding parameter on the peer optical interface device. The value is a character string of 0 to 15 characters. TX J1 Byte (Hexadecimal. Character String) Negotiated with the peer end The J1 byte is used to repeatedly send the higher order path access point identifier so that the receiving end of the path can determine based on this byte that the receiving end and the specified sending end are in the continuous connection (the path is continuously connected) state.0 & BSC6910) Parameter Name Recommended Value Description interface interworking. Character String) on the BSC side must be consistent with Expect RX J0 Byte (Hexadecimal.  The S1 synchronization state flag must be consistent with the flag on the MSC side. J2.0 & GBSS17. Otherwise. Character String) on the MSC side. Character String) on the BSC side must be consistent with Expect RX J1 Byte (Hexadecimal. only SUPER_FRAME and EXTENDED_SUPER_FRAME are supported. Otherwise. ALM-20225 is generated. TX Frame Format Negotiated with the peer end In E1 working mode. right-click the corresponding OIUa and select Query Interface Board Port State to check the C2 value sent by the remote end. J1.  The sending and receiving framing formats on the two sides must be consistent. The values on the two sides must be consistent.  TX J1 Byte (Hexadecimal. Expect RX J0 Byte (Hexadecimal. Expect RX J1 Byte (Hexadecimal. Character String) on the BSC side must be consistent with TX J1 Byte (Hexadecimal. Expect RX J2 Byte (Hexadecimal. 2015-11-13 Huawei Confidential Page 79 of 258 . In T1 working mode.  TX J0 Byte (Hexadecimal. check whether this parameter is set to 0x02 on the MSC side. ALM-20243 is generated. and the default value is 0x02. the interworking fails. Character String) on the BSC side must be consistent with Expect RX J2 Byte (Hexadecimal. and the K1 and K2 parameters must be consistent with the parameters on the MSC side. only DOUBLE_FRAME and CRC4_MULTIFRAME are supported. Character String) on the MSC side. Character String) on the MSC side. Character String) on the MSC side. Character String) on the BSC side must be consistent with TX J2 Byte (Hexadecimal. pay attention to the preceding parameters and configure the tributary numbering mode. and C2. In T1 working mode. If it cannot be confirmed.  TX J2 Byte (Hexadecimal. frame format. Character String) on the BSC side must be consistent with TX J0 Byte (Hexadecimal. Configuration principles of the optical interface interworking data If optical interface interworking is adopted. The C2 parameter cannot be configured on the BSC6000. ALM-20234 is generated. only DOUBLE_FRAME and CRC4_MULTIFRAME are supported. only SUPER_FRAME and EXTENDED_SUPER_FRAME are supported.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Therefore. J0. The configuration principles are as follows:  Tributary Numbering on the BSC side must be consistent with Tributary Numbering on the MSC side. Character String) on the MSC side. S1. It is a character string of 0 to 15 characters. Character String) on the MSC side. RX Frame Format Negotiated with the peer end In E1 working mode. Otherwise. This parameter is set internally in the software. Otherwise.0 & BSC6910) Parameter Name Recommended Value Description TX S1 Byte Negotiated with the peer end It indicates the synchronization state byte. 0 & GBSS17.1 Restrictions of the fault detection mechanism of the BSC 2015-11-13 Huawei Confidential Page 80 of 258 .Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.1 Restrictions of the Design Table 1.0 & BSC6910) 15 CONFIDENTIAL Detection Mechanism 15. Default: 30 ms x 3 times One IP address can perform either SBFD or ARP detection. Set the period to one second.0 & BSC6910) Physical detection Fixed: 300 ms x 2 times ETH EFM It is associated with the port status. 16/board (SBFD+MBFD). One port cannot perform BFD and ARP detections at the same time. The number of detections on a port is not limited. The GB IP interface does not support ETH OAM. Detection PPP Default: 10 seconds x 5 times Status Detection Default: 300 ms x 3 times ARP Detection 16/board. Otherwise. The number of detections on a port is not limited. ARP does not support flow-based VLAN tagging and supports only nexthop-based tagging. The standby port supports only one ARP detection. ETH CFM The GB IP interface does not support ETH OAM. The SBFD and MBFD distinguish sessions based on the source and destination IP addresses. The ARP automatically associates the next-hop route and sets the port as the key detection association port. The route or path is considered faulty if any detection fails. Only the FE and GE ports support BFD. A 10-second delay is introduced in the case of path faults. After you enable the negotiation switch (by running SET BFDPROTOSW). and the POS interface does not BFD Detection support BFD. MBFD. They do not support multiple BFD detections on the same address pair or VLAN-based BFD. but the two detections cannot be performed at the same time. The port becomes Down only if all the detections fail.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The route and path can be associated with multiple detections (ARP/SBFD. negotiation fails. The standby port does not support the BFD detection and supports only the ARP detection.0 & GBSS17. the 2015-11-13 Huawei Confidential Page 81 of 258 . The active port can be associated with multiple detections (multiple ARP and BFD detections). The EFM of the RNC requires that the PDU packet sending period of the remote end be the same as the period of the local end. It can trigger an active/standby port Detection switchover but cannot trigger a trunk switchover. The SBFD automatically associates the next-hop route and sets the port as the key detection association port. The detected IP address of the standby port and the IP address of the active port can be in the same network segment. The MBFD uses port 4784 by default (stipulated in the new draft). 512/board (only the AIU). Configure the MBFD associated IPRT and IP path. and ping). Path max retrans = 2 N/A Huawei Confidential Page 82 of 258 . SCTP Default: MinRTO = 1000 ms. the data is switched back to the active route. The MBFD does not detect the standby route. the applications with and without BFD are different. therefore.0 & GBSS17. MaxRTO = 3000 ms.2 Restrictions of the fault detection mechanism of the base station NodeB Restrictions (RAN12. Association max retrains = 4. Detection Association max retrains = 4. 2 BFDs/board The MBFD automatically associates the single-point route of the BFD destination address and does not associate with ports or other routes. if the active route is recovered. SCTP Detection 2015-11-13 Does the SBFD automatically associate the route whose next hop is The BFD destination address? In the active/standby route scenario. After the active route fails and the data is switched to the standby route.0 & BSC6910) local port number can be automatically adjusted to the same port number as the remote end. the active route is available but the system still uses the standby route.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0) GBTS Restrictions (GBSS9. Enable the MBFD to associate the IP route. MaxRTO = 3000 ms. HB interval = 1000 ms. Path max retrans = 2 Table 1. then: 1) If the BFD is not configured.0) Physical Detection No smoothness on the upper layer NA ETH EFM Detection NA NA ETH CFM Detection NA NA PPP Status Detection NA NA ARP Detection Not supported Not supported BFD Detection The SBFD automatically associates the route whose next hop is the BFD destination address and does not associate with ports or other routes. It can be used for the interworking with Huawei's router of an earlier version (the port number is 3784). Default: MinRTO = 1000 ms. 2) If the BFD is configured. HB interval = 1000 ms. Same as the RNC. the priority of the active route is higher than that of the standby router. the ARP detection is implemented on the standby port.0 & GBSS17.0 & BSC6910) 15. 2015-11-13 Huawei Confidential Page 83 of 258 . If both BFD sessions on the active port detect a fault but the ARP probe on the standby port indicates no abnormality. The BFD can be used on the top layer of any data protocol to detect multiple network layers. Enable two BFD sessions on the active port. One port can enable either the ARP or BFD detection at a time. and associated objects are ports. The detection time and payload ranges are wide. data link faults. Recommended commercial solution: In the most recommended solution. the dual BFD detection is implemented on the active port. One BFD session detects the physical IP address of the active router. The BFD provides an independent mechanism to detect any media or protocol layer in real time. The BFD can detect faults on any type of channel between systems. It can implement rapid detection and switchover in a short time and can help to locate link faults. Set both BFDs to key detections. The BFD completes detection in milliseconds. and forwarding engine faults. and to enable automatic switchover of the active/standby ports when two BFDs are interrupted simultaneously. Enable one ARP probe session on the standby port to detect virtual IP addresses of the two VRRP routers. The BFD is implemented on the service layer of the system and the detection is specific to the connectivity for service packet forwarding. and the other detects the physical IP address of the standby router. ensuring that only the BFD is used and avoiding conflicts with other detections.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the switchover between the active port and the standby port is triggered automatically. Such faults include interface faults.2 BFD Detection BFD definition: The BFD can detect channel faults between forwarding engines with light load and quick response. BFD is short for bidirectional forwarding detection. therefore.  The number of routers is small. On the BSC side. Currently. Therefore. and the routers of other suppliers may not support the BFD detection. and then static routes are introduced into the dynamic routing protocol to ensure rapid convergence of downlink routes. but the VRRP address of Huawei's router does not support the BFD detection. such as VLAN separation. When the active port is normal. the multi-hop BFD cannot be completed quickly. the intermediate network provides the dynamic routing protocol and rapid switchover mechanisms for protection. Huawei proposes the dual BFD detection solution. The active port on the BSC side determines the status of the two BFD detections.1 Diagram of the promoted commercial solution Application analysis: The BFD application in the current VRRP networking is defective: If the BFD is enabled on the active and standby ports. Therefore. the remote address in the BFD after the active and standby ports are switched over remains unchanged. rapid switchover can be implemented. Hence. the multi-hop BFD is used only in the following scenarios: 2015-11-13  The redundant path is independent on the network. and the remote ends are the interface addresses of the two routers. and use the ARP detection. therefore.0 & BSC6910) Figure 1.0 & GBSS17. Application scenario of the multi-hop BFD (do not use): Generally. the remote address must be a fixed virtual address. and no dynamic routing protocol is used between routers. and increases the network load. If the scale of the bearer network is large. The end-to-end detection is required. The active port considers the link down only when the status of both BFD detections is Down. rapid detection and switchover are not required. two BFD detections are initiated on the active port. The network is not protected. A service NE requires only the protection between the NE and the access router instead of the protection across the intermediate network. On the router side. Huawei Confidential Page 84 of 258 . In this way. a fault on the standby port does not affect services.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the BFD is associated with static routes. In VRRP networking. the VRRP virtual address mode cannot be used. the E2E multi-hop BFD is not required. the VLAN interface addresses are used for implementing solutions. Therefore. this address can only be a VRRP virtual address. 0 & GBSS17. The purpose of the ARP detection is to detect the connectivity of gateways. the bandwidth usage is improved. If the bandwidth is increased. Generally. One port can enable either the ARP or BFD detection at a time. the standby port adopts the ARP detection. − Obtains the packet loss and delay of all the IP paths of a logical port. Therefore. Forward monitoring (FM) and backward reporting (BR) are used to detect the packet loss condition along the path. the ARP detection does not require support from the peer end. 15. Then. After receiving the FM messages.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the addresses detected in the ARP detection are VRRP virtual addresses. dynamically adjusts the bandwidth of the logical port. the ARP detection is slow and completed in seconds. If the bandwidth is reduced. broadcast packets are used and only the FE/GE addresses in the same network segment can be detected. IP PM provides the following functions:  − Detects the delay. jitter. Then.  The ARP detection is used independently. The IP transmission QoS detection is the basis for the RAN system to perform flow control and admission control. In the ARP detection.4 IP PM Detection  Functions of IP PM IP performance monitor (PM) is an IP transmission QoS detection solution. the remote end replies with BR responses to report the number of received packets. based on a certain algorithm module. and the ARP detection is seldom used. One end sends FM messages periodically to indicate the number of packets sent by this end. If the current networking mode is VRRP. 15. and packet loss in IP transmission. − Detects the IP path connectivity and uses alarms to report the detection result to users.3 ARP Detection Compared with the BFD detection.0 & BSC6910)  The access router does not run the dynamic routing protocol. The main scenarios of the ARP detection in the recommended networking solution are as follows:  When the dual BFD detection is configured on the active port. Any gateway can respond to ARP requests. the BFD detection is preferred. The period can be specified to an interval or the number of sent packets. the transmitting end measures the packet loss condition based on the BR responses. Basic principles of IP PM IP PM is similar to ATM OAM PM. packet loss is reduced and the efficiency is improved. One port can enable either the ARP or BFD detection at a time. The basic process is as follows: 2015-11-13 Huawei Confidential Page 85 of 258 . the PM initiator enables the FM function from the PM initiator to the PM receiver. When the jitter or packet loss ratio of the detected link is increased. GBSS14.0 & BSC6910) When the PM initiator needs to start the PM function. set up PM sessions in the directions from A to B and from B to A. Then. 2015-11-13 Huawei Confidential Page 86 of 258 . disable IP PM. the PM receiver enables the BR function from the PM receiver to the PM initiator and replies the PM initiator with an ACT ACK frame. If the queue threshold is reached. the PM initiator sends an ACT frame to the PM receiver.0 & GBSS17. and the output rate of the logical interface of a BTS cannot exceed the measured bottleneck bandwidth of the logical interface. when the boards work in active/standby mode and the ports work in load-sharing mode). use dynamic bandwidth adjustment for the logical interface. Currently. IP PM closed loop adjustment is used externally and closed loop adjustment of congestion back pressure is used internally. ensure that the versions of both ends support this function.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the system informs the radio service processing board of the queue congestion in back pressure mode. In this case.  Scenarios that require IP PM In the scenario where the quality of an IP transmission link fluctuates a lot (for example. the PM initiator sends FM frames periodically to the PM receiver. and the PM receiver replies the PM initiator with BR frames after receiving the FM frames. only the Abis IP path supports IP PM. the detection data and subscriber data may travel along different paths. To enable the bidirectional link QoS detection. and therefore the IP PM result is not reliable. Basic principle: The closed loop control system is used to eliminate packet loss in the BSC. ADSL). This function must be used with the BTS. enable IP PM. The adjustment of the rate of the logical interface inevitably affects the queue of the logical interface. After receiving the ACT frame. end-to-end congestion avoidance is implemented externally and internally in a joint manner. The service processing board reduces the pressure. the closed loop control system adjusts the output rate of the logical interface of the link to reduce the link load and relieve the link congestion. In this way.  Recommended IP PM solution on the BSC side If IP paths require the IP PM detection and statistics to monitor the link quality. In this case.0 supports only the BSC providing FE and BTS providing E1. For the multiple flows whose source and destination addresses are the same (for example. Therefore.  Requirements of IP PM for the transmission network The DSCP value cannot be modified on the transmission network. After receiving the ACT ACK frame. IP PM must be enabled so that the currently available bandwidth can be adjusted based on the detection result. The closed loop control system detects the jitter or packet loss ratio of a detected flow on the transmission link from the BSC to the BTS. Description of the IP addresses of interface boards Interface board FG2c/GOUc/EXOUa that supports Ethernet ports: Each interface board supports up to 16 device IP addresses (DEVIP. 2015-11-13 Restrictions of IP address planning − IP addresses are determined by the customer based on the actual network conditions and belong to the A/B/C category. including IP technical solutions. such as layer-2 and layer-3 networking design in IP networking. Each port can be configured with one active Ethernet port address (ETHIP) and up to five ETHIPs (configured only for the active port in port backup).0 & BSC6910) 16 IP Interworking Design This section describes the IP interworking design. 16. the selected IP address cannot be an invalid address in the A/B/C category). Each port being used must be configured with at least the active Ethernet address. and address planning for the maintenance channel. A device IP address cannot be the same as or in the same network segment as any configured IP address in the BSC (it can be an IP address of the Ethernet port or remote address of the SCTP link). IP address planning. However. − The network segment of the planned IP address and the network segment of the BAM internal network address cannot partially or totally overlap. in IP RAN networking. VLAN planning. The network segments of the active and standby IP addresses of the Huawei Confidential Page 87 of 258 . and the device IP addresses configured for different interface boards cannot be the same.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.1 IP Planning on the BSC Side 1.0 & GBSS17. An IP address consists of a network segment and a host segment. CBS or MDSP cannot use this device IP address. logical IP address in the board). The device IP addresses configured on the same BSC cannot be in the same subnet. When a service other than CBS and MDSP uses a device IP address. the services other than CBS and MDSP can share the same device IP address. 2. − ETHIP: The network segments of different Ethernet port IP addresses cannot partially or totally overlap. When the CBS or MDSP service uses a device IP address. The host segment cannot be all 0s or all 1s (when CIDR is used. other services (such as the SCTP link) cannot use this device IP address. The first byte of an IP address cannot be 0 or 127. − Device IP address: The network segment of a device IP address and the network segment of the BAM internal network address cannot partially or totally overlap. the length of the subnet mask is determined by the number of BTSs in the same network segment. − In IP layer-3 networking. use port IP communication. the gateway requires one virtual IP addresses and two real IP addresses. In this case. They need to be implemented jointly. and services for the BTS.255). − In network segment planning. the length of the subnet mask of the address on the BSC side is irrelevant to the number of BTSs but is determined by the number of required addresses.  In layer-2 networking. The signaling. One BTS uses one port IP address. and 29-bit subnet masks can be used. two valid addresses are required. further network segment separation is required. For example. − The addresses on the BTS side are planned independently.255. If the O&M and service are separated on the bearer network. Use port IP communication for the BTS. signaling. The 30-bit or 32-bit subnet mask can be used (the 32-bit subnet mask is 255. Same as in the layer-2 networking. the port IP address of the BTS is in the same network segment as the port IP address on the corresponding interface board on the BSC. Use the simplest possible configuration for the remote router. Principles of IP address planning − On the BSC side. Huawei Confidential Page 88 of 258 .CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the ETHIPs of the ports on the BSC interface board are in the same network segment as the FE port IP addresses of the BTS. and 30-bit subnet masks can be used. Use the 32-bit subnet mask. Whether an independent NE adopts separate O&M IP address and service IP address depends on whether the O&M and service are separated on the bearer network. IP addresses must be sufficient.  In layer-3 networking.255. an ETHIP must be in the same network segment as its gateway. If the gateway uses only one IP address. and O&M share the same IP address. Generally.0 & BSC6910) same port cannot partially or totally overlap. − The device IP addresses of interface boards are in different network segments. The default 32-bit and 29bit subnet masks are used for the device IP address and port IP address respectively.0 & GBSS17. use the port IP address.2 IP Planning on the BTS Side The IP address planning of the BTS is related to the IP address planning of the BSC. and consider reservation for extensibility. use the device IP communication mode. 3. Principles of IP address planning 2015-11-13  On the BTS side. services. the port IP address of the BTS is in the same network segment as the port IP address of the next-hop gateway. An Ethernet port IP address cannot be the same as or in the same network segment as any configured IP address in the BSC (it can be a device IP address). One BTS uses one IP address. − In IP layer-2 (FE) networking. 16. the NE adopts separate logical O&M IP address and service IP address. If the gateway adopts VRRP. Device IP address: logical IP address of the BTS (DevIP) Port IP address: port IP address of the TMU The same IP address works for O&M. mask. the next-hop IP addresses are the same. the eNodeB source IP routes are not recommended. as shown in the following figure. the static routes form equivalent routes.4 Routing Design on the BTS Side The principles are as follows:  In layer-3 networking.0 & GBSS17. the port sending packets and the gateway IP address are queried based on the source IP address in the IP packets. and there are multiple destination IP addresses on the peer end. The eNodeB source IP routes configure different priorities to achieve active and standby routes.1 Scenario where the eNodeB source IP route is recommended If there are multiple IP addresses on the eNodeB side. configure the route from the BTS to the corresponding interface on the BSC and the route from the BTS to the IP CLK server. If only one IP address is available on the eNodeB side. route load balancing is not supported. Packet routes can forward packets based on the flows or packets. For IP routes based on the source IP address. Figure 1. as shown in the following figure.  In layer-2 networking. or configure a network segment route for the network segment where the BTS resides.3 Routing Design on the BSC Side It is required in IP layer-3 networking.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the next-hop IP addresses are different. However. 16. and there is only one destination IP address on the peer end. and priority but different next-hop IP addresses. Routes are added on the interface board. The ADD SRCIPRT command is used to configure the routing entries. eNodeB source IP routes are recommended to simplify the route configuration on the eNodeB side. if the routes have the same source IP address. 2015-11-13 Huawei Confidential Page 89 of 258 . a route is not required. Add a host route for each BTS.0 & BSC6910) 16. and Huawei radio devices support only flow-based route forwarding. Configure a network segment route. For static route configurations. 2 Scenario where the eNodeB source IP route is not recommended If there is only one IP address on the eNodeB side. A field in the VLAN tag indicates the priority. If the BSC is directly connected to the layer-2 interface of the router: 2015-11-13 Huawei Confidential Page 90 of 258 . as shown in the following figure. and there are multiple destination IP addresses on the peer end.0 & BSC6910) CONFIDENTIAL Figure 1. This prevents broadcast storm. The broadcast traffic in one VLAN is not forwarded to another VLAN. This can distinguish priorities in layer-2.1Q). the next-hop IP addresses are different.5 VLAN Design The VLAN technology partitions a physical LAN into different broadcast domains (based on IEEE 802.0 & GBSS17. The VLAN technology increases the security because any two VLANs cannot visit each other in layer-2.Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.3 Scenario where the eNodeB source IP route is not supported 16. the eNodeB source IP routes are not supported. Figure 1. If sub-interfaces are used.1 Specifications of the VLAN on the interface board Single Subrack VLAN ID 8192 ETH board FG2c/FG2d GOUc/GOU d EXOUa VLAN /PORT 4094 4094 4094 VLAN /BOARD 4094 4094 4094 16. use the number of BTSs that are connected to one board or one optical interface of the transmission device (for example. Table 1. Only VLAN tagging based on the next hop is supported. no tag is used if sub-interfaces are not used. Therefore. Planning principles:  In principle. 2G and 3G services use VLAN values in different ranges.1% Huawei Confidential Page 91 of 258 . Sub-interfaces share the MAC address.  To make VLAN planning logically clear and simplify the configuration. the proper number of BTSs recommended for one VLAN is 20 to 100. and different interfaces use different VLAN values. use VLAN values segment by segment.  In VLAN planning. the VLAN tags are not added on both the BSC and BTS.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. VLAN tags are required to distinguish flows. maintenance. and expansion.1 Abis IP bearer network QoS requirement Abis IP 2015-11-13 Delay (ms) Jitter (ms) Packet Loss Rate (%) Suggestio n Value Max Value Suggesti on Value Max Value Suggesti on Value Max Value < 15 ms < 40 ms < 8 ms < 15 ms < 0. VLAN tags can be added on the transmission device side. as listed in Table 1.0 & GBSS17.6 QoS Design QoS requirements of interfaces for IP transmission: Table 1. but are added on the intermediate devices. the OSN) at the level-1 convergence point (nearest to the BTS side) as the number of BTSs that belong to the same VLAN. The router cannot distinguish flows based on the MAC address or based on the IP addresses in the received IP packets (the IP address in an IP packet is the destination IP address but not the source IP address). This facilitates follow-up management.05% < 0.0 & BSC6910) Generally. VLAN tags are required by default.  VLAN tags can be added based on the next hop or based on the service flow. For example.1.  Generally. If the number of DSCP values provided by an operator is smaller than the number of DSCP values recommended by Huawei.3 IPCLK and BTS/NodeB Input Clock Precision Requirement IPCLK < 0. Basic principles:  The priority of signaling is the highest. 2015-11-13 Huawei Confidential Page 92 of 258 . DSCP convergence can be implemented.05% Table 1. use the same DSCP for the voice service and the real-time data service.  The priority of the real-time data service is lower than that of the voice service. In GSM IP layer-3 network.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.  The priority of the voice service is lower than that of signaling.2 A/Gb IP bearer network QoS requirement A/Gb IP Delay (ms) Jitter (ms) Packet Loss Rate (%) < 15 ms < 8 ms < 0.016 ppm BTS/NodeB < 0.  The priority of the non-real-time data service is lower than that of the real-time data service. For example.0 & BSC6910) Table 1.05 ppm QoS design principles: For details. different DSCP values are set for different services to ensure the QoS in IP transmission. The IP networks of different operators are different.0 & GBSS17. see the Configuration Recommendation of a specific version. 1 Purpose of the Design  The network topology design is based on the unit of area (or city). BSC. such as geographical distribution and the number of NEs. and geographical location and can guide engineers through network construction. for example. the topology details are designed.  Design a detailed network topology figure that can help learn the connections between NEs.1 Design Guide The network structure design is based on the unit of area. location relationship between the MSC server. whether the capacities of the MSC server and SGSN meet the requirements. The input is the pre-sales target network. locations.1.1.  Design the network topology to optimize the resource usage and reduce the invalid load. and backbone transmission network. transmission types. and transmission distribution) 17.2.0 & BSC6910) 17 Network Topology Design 17. Design principles: 2015-11-13 Huawei Confidential Page 93 of 258 .0 & GBSS17.1 Design Overview 17. 17. Within the unit. area names. MGW. In the design. consider the geographical distribution of NEs. transmission quantity.  Obtain information about the capacities. MGW.2 Input of the Design  Information. equipment room names. and NE types  Subscriber transmission information (transmission type. This is different from the design of the entire target network. Details are designed.2 Network Structure Design 17. and SGSN. and manufacturers of the interface NEs related to the MSC server. and analyze the possible networking risks. and BTS.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. transmission type. Select the equipment room where the power supply is stable and air conditioners/ESD floor are available. inter-MSC signaling load.0 & GBSS17. and this facilitates maintenance.  Plan the BSCs in the same area in the same MSC server. connect one BSC to more than two MGWs that belong to the same MSC server (non-MSC Pool mode).  The SGSN capacity meets the data service requirements of the corresponding PCU. Drawing requirements:  The networking diagram must be drawn based on the standard radio icons.0 & BSC6910)  The transportation to the equipment room is convenient. BSC.2.  Different types of lines must be used in the networking diagram to indicate different transmission types.  The networking diagram must include the MSC server.2.  Abis transmission cost control is important for the network where the number of sites is large.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. 17.  To improve the network security. Avoid discontinuous BSC networking because it increases inter-MSC handovers. See Figure 1.2 Typical Networking 17. Use the existing transmission nodes to save the investment.1.  The networking diagram must clearly mark the geographical homing areas of the NEs. MGW.  Consider the distribution of existing transmission nodes when designing the BSC locations. Ensure that the BSC location and Abis networking are good for transmission convergence.1 Networking of the BSC connected to a single MGW 2015-11-13 Huawei Confidential Page 94 of 258 . The networking design needs to collect the information about the capacity and manufacturer of the SGSN connected to the PCU. one BSC is connected to one MGW and belongs to one MSC server. and reduces the handover success ratio.  Group the sites under the BSC based on geographical areas to facilitate LAC planning. Figure 1. and BTS and must clearly show the connections between the NEs. and the configuration difficulty.2.1 BSC/MGW Single-Homing Networking Generally. BSC/MGW multi-homing requires the support of the core network and does not have requirements for the BSC. and the negotiation with the core network indicates that the STP needs to be configured for the BSC. the MSC Pool planning is simplified a lot.1 BSC/MGW multi-homing networking 17. To use this networking mode.0 & GBSS17. In the past.2. If the MGW possesses signaling points. See Figure 1. This facilitates follow-up expansion and maintenance. even if one MGW is faulty. Figure 1. and you need only to specify the STP of the MSC server as the destination STP. physical interconnection is required. configure multiple STPs (signaling points of the connected MGW) for the BSC. one RNC/BSC can connect to multiple MSC servers at the same time. Advantage: The reliability is high and the networking is simple. confirm that the core network supports this mode.2.3 MSC Pool Networking Different from traditional networking.2. the BSC can provide service continuously. to improve the network reliability. When one MSC server is faulty.0 & BSC6910) 17. nowadays. If the MGW does not possess a signaling point and the SS7 signaling is transparently transmitted to the MSC server. assign the A interface transmission and signaling to different MGWs. Then. routing configuration is used. This significantly improves the network reliability.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. 2015-11-13 Huawei Confidential Page 95 of 258 .2 BSC/MGW Multi-Homing Networking If two or more MGWs are connected to the same MSC server. in MSC Pool networking. After IP transmission is widely used. the services of the BSC are automatically switched to another MSC server. This implements the MSC-level backup mechanism. you do not need to configure the signaling transfer point (STP) for SS7 on the BSC.1. It is predicted that the MSC Pool networking will be widely used after 2011.2. Advantage: The reliability is high. 0 & GBSS17.  The networking and expansion are complicated. Huawei Confidential Page 96 of 258 . Figure 1. The BSC does not require special configuration. the reliability of the entire network is significantly improved.  The BSCs are connected to multiple MGWs.1 MSC Pool networking mode 1 MSC Pool networking mode 2 2015-11-13  The BSC implements the NNSF function. and the design and implementation workload is heavy.0 & BSC6910) Disadvantage: The networking on the core network is complicated. Use this mode. the MSC servers in the pool work as a large-capacity MSC server. and do not use this mode.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. MSC Pool networking mode 1  The MGW implements the A-Flex function.  The MGW implements the NNSF function.  The BSC configuration does not need to be changed. For the BSC. In addition. The SGSN pool area contains the area served by a group of SGSN nodes. Figure 1.0 & BSC6910) Figure 1.2 MSC Pool networking mode 2 17.0 & GBSS17.2. multiple SGSNs run concurrently and share the service traffic in the pool area.1 shows the typical networking of the SGSN pool based on Gb over IP: 2015-11-13 Huawei Confidential Page 97 of 258 . In the pool area.4 SGSN Pool Networking The SGSN pool is based on the Gb Flex technology. another SGSN in the pool can provide services.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. If a single SGSN node is faulty. This significantly improves the network reliability.2. 2 show the typical networking diagrams.Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.1 and Figure 1.0 & BSC6910) CONFIDENTIAL Figure 1.1 Typical networking of the SGSN pool 17. use layer-3 networking for all-IP networking.5 All-IP Networking The all-IP networking saves the transmission cost a lot and provides better evolution capability to implement GU and GUL evolution.0 & GBSS17. 2015-11-13 Huawei Confidential Page 98 of 258 . Generally.2.2. Figure 1. 1.6 Hybrid Networking The common networking mode is A interface over IP+Abis interface over TDM.2 Typical IP-based networking 17.2. 2015-11-13 Huawei Confidential Page 99 of 258 . as shown in Figure 1.0 & GBSS17.1 All-IP networking Figure 1.0 & BSC6910) CONFIDENTIAL Figure 1.2.Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Figure 1. For details.2.1 shows the logical networking of the transmission resource pool.  Mode 2: The A interface boards work independently. thereby simplifying the configuration. When A interface boards are faulty. The transmission resource pool over the A interface can work in the following modes:  Mode 1: The A interface boards work in active/standby mode.0 & GBSS17. if IP addresses on the MGW are added or modified. but ongoing calls are disconnected once an interface board is faulty. In addition. the MGW can communicate with the BSC through any board in the pool.7 Transmission Resource Pool Networking If multiple A interface boards of the BSC form a transmission resource pool.2. Mode 1 provides high reliability. IP route and IP path configurations on the BSC do not need to be changed. Mode 2 provides high board usage. the system automatically allocates the newly connected calls to other interface boards. 2015-11-13 Huawei Confidential Page 100 of 258 . If an interface board in the pool is overloaded. the BSC implements the source IP-based route and IP-path-free configuration.0 & BSC6910) Figure 1.1 Hybrid networking 17. The SCTP links on the control plane are deployed on two different interface boards in the transmission resource pool by dual-homing to improve data protection on the control plane. This solution requires a three-layer networking between the BSC and the MGW to ensure interconnection between the MGW and all interface boards of the BSC. ongoing calls are not dropped. see A Interface Transmission Pool. in other words. The transmission resource pool is used on the A interface over IP network.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. 2 Physical networking of the transmission pool with active/standby boards As shown in Figure 1.1 Logical networking of the transmission resource pool As shown in Figure 1. Figure 1. the BSC selects an IP address from the service IP address pool to carry the call in a way that ensures load balance.0 & BSC6910) Figure 1.3. These device IP addresses form a service IP address pool. Each board is configured with a logical board IP (DEVIP) address as the service IP address.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. During a call setup. four independent FG2c/GOUc boards form a pool. Each board is configured with a logical board IP (DEVIP) address as the service IP address to comprise a 2015-11-13 Huawei Confidential Page 101 of 258 .2.0 & GBSS17. two pairs of active/standby FG2c/GOUc boards form a pool. − The router configuration is simple. this networking has the following advantages and disadvantages:   2015-11-13 Advantages − The maximum payload throughput rate and the connection capability of the interface board are doubled. Compared with the networking of transmission pool with active/standby boards. the interface boards can be evenly distributed to each frame. ongoing calls are dropped. Therefore.0 & BSC6910) service IP address pool.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Figure 1. no static routes with different levels of priorities are required. During a call setup.0 & GBSS17.3 Physical networking of the transmission pool with independent boards In this networking mode. − The interface board can be independently added. the BSC selects an IP address from the service IP address pool to carry the call in a way that ensures load balance. Use this networking. that is. configure two or more ports for an interface board to form an LAG to avoid ongoing call drop in case of a port fault. − There are no restrictions on the slot configuration of the active/standby board. Disadvantages: if the interface board is faulty. Huawei Confidential Page 102 of 258 . 2 Network Reliability Design 18. Abis interface. 2. Implement port protection on the transmission device to improve reliability. board active/standby feature and link active/standby feature of the A interface. For example.0 & GBSS17.1 Design Overview 18. For example. if you need to improve reliability but do not want to increase investment in backbone transmission. Implement the network reliability design based on the board active/standby feature of the product. and Gb interface.1.1 Purpose of the Design  The design is based on product features and transmission routes to improve the network reliability. Huawei Confidential Page 103 of 258 .CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.  Design a detailed network topology figure that can help learn about the connections between NEs. you can implement transmission port backup by using the timeslot cross device on designed backbone transmission interfaces.2.0 & BSC6910) 18 Reliability Design 18.1. 18. transmission type.2 Input of the Design  Network structure diagram  Transmission routing information 18.1 Design Guide The reliability design of the radio network is based on the following:  Active/standby feature of boards  Active/standby feature of links  Active/standby feature of transmission resources  MSC pool  SGSN pool  Flow control policy  Device load balancing  Proper data configuration Design principles: 2015-11-13 1. and geographical location. 4. and Abis interface can be implemented to improve the network reliability.0 & BSC6910) 3. Design the networking structure to improve the network reliability. If the core network supports the active/standby configuration of the A interface.1 Improving reliability by active/standby links on ports 2015-11-13 Huawei Confidential Page 104 of 258 . and SGSN pool networking.1 Reliability of Active/standby Links on Ports Based on product features. 18.1. 5. Learn the port distribution of the remote device. use the active/standby configuration function of the A interface of the BSC6910.2.2 Design Examples 18. Distribute transmission resources properly and use proper configuration principles to improve the network reliability. For example. Use BSC/MGW cross networking. If the core network does not support the active/standby configuration of the A interface. Figure 1. Distribute the transmission resources of the same BSC to different interface boards to improve the network reliability.2. see Figure 1. distribute signaling and calls evenly to different routes to reduce node cross-connection and avoid concurrent service interruption.0 & GBSS17. For details about APS 1+1.2.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. MSC pool networking. the A interface board of the BSC6910 is configured to work in standalone mode. active/standby links and active/standby boards of the A interface. Gb interface. 2 Reliability of Load Balancing Evenly distribute BTSs. As shown in Figure 1.2 Reliability design of the Gb interface 18. BTSs.4 Reliability of Multiple Transmission Routes Configure transmission routes to improve the reliability.  Configure SS7 links to different transmission resources and boards to reduce node crossconnection and improve the network reliability.2. The principles are as follows:  Evenly distribute BTSs and TRXs to the modules of the BSC.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. A interface boards. 18.2. Balanced load can improve the anti-shock capability of the BSC in the case of burst traffic. the balance of SS7 links.2.0 & GBSS17.  Evenly distribute SS7 links (with the same bandwidth) to the modules. 18. and backbone transmission channels. and RSI links on different CPUs is adjusted to further design the load balancing.  For example. and SS7 links to the modules of the BSC to balance the load between the modules.2.  If the traffic of a single BSC reaches 70% of the design specifications. the GOUc of the BSC6910 provides four physical transmission links destined for the remote NEs through two CEs. This implements reliability of multiple transmission links and prevents service interruption caused by the faults in a single transmission node.0 & BSC6910) Figure 1. configure SS7 links to different MGW boards. The minimum number of SS7 links is 2. A interface physical transmission channels.3 Reliability of Data Configuration  Evenly distribute SS7 links and bandwidth to the modules of the BSC. You can apply for R&D support. Configure the transmission resources of the same NE to different transmission nodes and routes to reduce the possibility of service interruption caused by the faults in a single transmission node and to improve the network reliability. TRXs.2. 2015-11-13 Huawei Confidential Page 105 of 258 .1.2. 1 Reliability design of IP transmission routes 18. Figure 1. 2015-11-13 Huawei Confidential Page 106 of 258 .2.0 & BSC6910) Figure 1. The master router forwards the packets destined for the virtual router.1. a reliable transmission route is established to improve the network reliability. and the active/standby Gb interface boards are configured for the BSC.1 Reliability design of IP transmission routes The VRRP protocol is used to dynamically select a master router from a group of VRRP routers and associate the router to a virtual router as the default gateway of the connected network segment. The VRRP router that is selected to associate with the IP address of a virtual router is the master router.2. the VRRP technology is used to implement the active/standby mechanism of the routers AR1 and AR2. In this manner.0 & GBSS17. If the master router is faulty. in Gb over IP mode.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. VRRP selects another VRRP router as the master router to forward the packets destined for the virtual router.5 Reliability of the IP Networking VRRP Technology As shown in Figure 1. 2.0 & GBSS17.2.2. one BSC is connected only to one MSC server. the MSC pool network has the following advantages: 2015-11-13  Load sharing: Multiple MSC servers share the network load to improve the resource usage of the entire core network and save the device investment. the M3UA SCTP multi-homing design implements highly reliable SS7 design. 18. If a single MSC server is faulty. and the bandwidth needs to be twice higher than the service traffic. Compared with the traditional network. trunks must be configured between routers.7 Reliability of BSC Multi-Homing (Connected to Multiple MGWs) The BSC6910 supports the configuration of multiple DSPs and STPs.  Disaster tolerance: The MSC-level redundancy is implemented. if a single MGW is faulty. the services of the BSC are not interrupted. one BSC can be connected to multiple MSC servers.8 Reliability Based on the MSC POOL For details. In VRRP configuration.2.2.1 BSC/MGW multi-homing networking 18. On the GBSS side.3"SCTP Multi-Homing Design. Huawei Confidential Page 107 of 258 .6 SCTP Multi-Homing Design In A over IP mode.0 & BSC6910) The advantage of VRRP is that the reliability of the default gateway is improved for the host. see the GSM MSC Pool Network Design Guide.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the services of the BSC are not interrupted. This improves the BSC reliability.2. only the A interface supports the SCTP configuration. For details.1 shows the typical networking. see section 19. Figure 1. In the traditional mobile communication network. In the MSC pool network. Figure 1. The transmission links of the A interface of the BSC are connected to two or more MGWs (the MGWs belong to the same MSC server). Then.2." 18. At least two physical links must be configured. Use this networking mode for the IP networking. Use this MSC pool networking mode because no special BSC configuration is required and the reliability of the entire network is improved. For the BSC.1 MSC Pool networking mode 1 The BSC provides the NNSF function. In the office that requires high reliability. Figure 1. the MSC servers in the pool work as a large-capacity MSC server. use the MSC pool solution. and the quality of subscriber calls is improved.  Inter-office handovers are reduced. the signaling traffic on the C/D interface is reduced. The BSC configuration does not need to be changed. 2015-11-13 Huawei Confidential Page 108 of 258 .CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. BSCs are interconnected with multiple MGWs. The commonly used networking solution is as follows: The MGW implements the A-Flex function and NNSF function.0 & BSC6910)  Inter-office location updates are reduced.0 & GBSS17. and the MSC capacity gain is obtained. Networking and capacity expansion are complicated. This solution can be used based only on Gb over IP.2. If a single SGSN node is faulty.Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. This improves the network reliability. another SGSN in the pool can provide services. see the GSM SGSN Pool Network Design Guide.2 MSC Pool networking mode 2 18.0 & GBSS17.0 & BSC6910) CONFIDENTIAL Figure 1.1 shows the typical networking diagram.2. For details. In the pool area. 2015-11-13 Huawei Confidential Page 109 of 258 . The SGSN pool area contains the area served by a group of SGSN nodes.9 Reliability Based on the SGSN Pool The SGSN pool is based on the Iu Flex technology. multiple SGSNs run concurrently and share the service traffic in the pool area. Figure 1. the BSC implements the free configurations on IP routes and IP paths.1 shows the IP networking topology of A interface boards based on the dynamic loading balancing. the MGW can communicate with the BSC through any board in the pool.0 & BSC6910) Figure 1. 2015-11-13 Huawei Confidential Page 110 of 258 .2. the BSC does not need to change the configuration of the corresponding IP path or IP route.1 IP networking topology of A interface boards based on the dynamic loading balancing If multiple A interface boards of the BSC form a transmission resource pool. In addition. This simplifies the configurations.0 & GBSS17.2.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the BSS automatically distributes calls to interface boards with light traffic. That is. Figure 1. when the IP address is added or modified on the MGW.10 Reliability Based on Dynamic Load Balancing of A Interface Boards Figure 1. When the load of an interface board in the pool is high.1 Typical networking diagram of the SGSN pool 18. Mode 2 provides high board usage. but ongoing calls are disconnected once an interface board is faulty. ongoing calls are not dropped.3 show the typical networking modes. Mode 1 provides high reliability. When A interface boards are faulty.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The transmission resource pool over the A interface can work in the following modes: Mode 1: The A interface boards work in active/standby mode. This solution requires a three-layer networking between the BSC and the MGW to ensure interconnection between the MGW and all interface boards of the BSC. OM Reliability The OM reliability design of the BSS is implemented through the active/standby EOMU configurations and the active/standby EOMU port configurations. Mode 2: The A interface boards work independently.0 & BSC6910) The SCTP links on the control plane are deployed on two different interface boards in the transmission resource pool by dual-homing.0 & GBSS17.2 and Figure 1. Figure 1. Figure 1.2 Standalone EOMU 2015-11-13 Huawei Confidential Page 111 of 258 . the BSC does not need a clock. GCGa boards have satellite cards and can obtain signals of GPS clock sources.0 & GBSS17.4 shows the clock subsystem of the BSC6910.3 Dual EOMUs Clock Reliability Clock reliability of the BSC6910 The design of the clock system reliability of the BSC6910 is simple. They are located at slots 14 and 15 of the GMPS subrack to form the active/standby relationship.0 & BSC6910) Figure 1. On an all-IP network. Clock signals provided by the BITS are transmitted to the GCUa/GCGa boards through panel interfaces. Either GCUa boards or GCGa boards can be installed on the BSC6910 based on the clock type. Figure 1.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. This section describes the principle and reliability mechanism of the clock system for better communication with operators. Clock sources of the BSC6910 system are as follows:  Building Integrated Timing Supply System (BITS) clock  External 8 kHz clock  GPS clock The GCUa/GCGa boards support plane input of the clock sources. 2015-11-13 Huawei Confidential Page 112 of 258 . GCUa/GCGa boards provide clock information for the BSC6910 system. 4 Clock subsystem of the BSC6910 Clock information generated by the GCUa/GCGa boards is processed as follows: The clock information is sent to the SCUb board of the local subrack through the backplane and then the SCUb board of the local subrack sends the clock information to service boards in the subrack.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the system traces other available reference sources. The clock system of the BSC6910 has the following characteristics: 2015-11-13  Clock holdover function: When external clocks are faulty.  The BSC clock adopts international standard layer-3 clocks to provide stable and reliable clock sources for the system. local free-run clocks can continue providing stable clocks for the system.0 & GBSS17. If the system does not detect that frequency deviation is great during this process.0 & BSC6910) Figure 1. You can set internal parameters of the clock on the maintenance terminal.  The clock system of the BSC adopts the digital phase-locked loops and reliable software phase-locked loops to ensure that the clock of the BSC is synchronized with clock reference sources. The clock information is sent to SCUb boards of GEPS subracks through plane interfaces and then the GSCU boards of the GEPS subracks send the clock information to service boards in the subrack.  The clock system provides complete display. If no clock sources are available and the system has traced other reference sources for 10 minutes. the system is in the holdover state.  If configured clock reference sources are lost. alarm. software phase-locked loops are Huawei Confidential Page 113 of 258 . and operation and maintenance functions. such as the Optical Switch Node (OSN)/Packet Transport Network (PTN) device. Although the system provides high-precision holdover function. The local equipment does not need to interwork with peer equipment through the static LACP.0 & GBSS17. Reliability of Ethernet Link Aggregation In link aggregation. Therefore. The manual active/standby LAG networking mode apples to more scenarios and is more convenient to interwork with peer equipment.  If the active/standby board has multiple ports.  Reliability and check mechanism for the manual active/standby LAG networking mode and the active/standby port networking mode are the same. two FE/GE links on the active/standby board of the BSC form an LAG and are respectively connected to two transmission devices. Multiple links are aggregated to an LAG. which is the same as that of multiple active/standby ports. It supports flexible networking mode. multiple physical links are aggregated to form a logical link. 2015-11-13 Huawei Confidential Page 114 of 258 . services are not interrupted. time specifications of affected services cannot be determined. improve transmission reliability.5. but active/standby ports must be on active/standard boards respectively. enable multiple manual active/standby LAGs.0 & BSC6910) retained for 10 days and then the system is in the free-run state. For example. the active/standby LAG can be located on one board. This LAG crosses two transmission devices. The Ethernet link aggregation matches the MRFD-210103 Link aggregation feature. The external networking of the manual active/standby LAG mode and the active/standby port mode are the same. services are affected due to the free-run state. When an Ethernet port in the LAG is faulty. The Ethernet link aggregation can increase the bandwidth. and ensures that traffic is distributed to different links for transmission. Application of the link aggregation Typical application scenarios of link aggregation on the BSC side are as follows:  BSC belonging to two layer-2 transmission devices in the dual-homing mode  BSC belonging to one layer-2 transmission device in the single-homing mode  Inter-board link aggregation in the inter-board pool networking scenario  Link aggregation on the BSC side and the interworking router adopting the VRRP networking mode BSC belonging to two layer-2 transmission devices in the dual-homing mode As shown in Figure 1. In the synchronization networking (non-IP clock sources) mode. quick restoration of references sources is also required.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The Ethernet link aggregation implemented by Huawei aims to:  Replace the active/standby port mode. 5 BSC belonging to two layer-2 transmission devices in the dual-homing mode The LAG that crosses two transmission devices is named Multi-Chassis Link Aggregation Group (MC-LAG) on the network side.0 & GBSS17. the working mode of the aggregation group on the BSC side must be set to the active/standby mode. This ensures that the active/standby properties of links that transmission devices use to interwork with the BSC through the LACP protocol are consistent. the aggregation group ensures that links are reliable and the active/standby board on the BSC side ensures that boards are reliable. BSC belonging to one layer-2 transmission device in the single-homing mode As shown in Figure 1. In addition.6 BSC belonging to one layer-2 transmission device in the single-homing mode In this application: 2015-11-13  When an aggregation group works in the active/standby mode. the MC-LAG works in only the active/standby mode.0 & BSC6910) Figure 1. the aggregation mode on the BSC side needs to be set to static aggregation. Currently. Huawei Confidential Page 115 of 258 . the aggregation group not only ensures that links/ports/boards are reliable but also expands the capacity of the link bandwidth. Figure 1.6. Therefore.  When an aggregation group works in the load sharing mode. multiple FE/GE links on the active/standby board of the BSC form an aggregation group and are connected to one layer-2 transmission device.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Link aggregation on the BSC side and the interworking router adopting the VRRP networking mode 2015-11-13 Huawei Confidential Page 116 of 258 .  The two routers adopt the VRRP to ensure reliability.  On primary links of an aggregation group. The working mode of the aggregation group must be active/standby mode.  On secondary links of an aggregation group.8:  Two FE/GE links on a board on the BSC side are configured into an aggregation group that connects to two routers. In this scenario.7 Inter-board link aggregation in the inter-board pool networking scenario Manual active/standby link aggregation on the BSC side and the interworking router adopting the VRRP networking mode As shown in Figure 1.  The aggregating mode of the aggregation group must be manual mode.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. enable the BFD check for two actual port IP addresses of the VRRP device and the ARP check for virtual IP address of the VRRP device. Figure 1.7:  Multiple interface boards form the transmission pool to implement the load balancing between interface boards.0 & BSC6910) Inter-board link aggregation in the inter-board pool networking scenario As shown in Figure 1.  Multiple FE/GE link groups on interface boards form an aggregation group to implement the load balancing among multiple interfaces on boards. enable the ARP check for virtual IP address of the VRRP device. the aggregation group needs to work in the load balancing mode.0 & GBSS17. Figure 1. use the transmission resource pool networking mode. Two FE/GE links on the active/standby board form an aggregation group that connects to VRRP devices. Two FE/GE links on the active/standby board form an aggregation group that connects to VRRP devices. GOUc/FG2c boards support the transmission resource pool networking mode.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.8 Manual active/standby LAGs on the BSC side+router adopting the VRRP networking mode Link aggregation on the BSC side has the following two scenarios:  Two FE/GE links on a board form a link aggregation group and interwork with the VRRP device. Two FE/GE links on the interface boards form a link aggregation group. This implements the load sharing for the interface boards and ensures reliability.0 & GBSS17. As shown in Figure 1. Multiple independent boards share the load. Therefore. two FE/GE links on the active/standby board form an aggregation group that connects to VRRP devices.0 & BSC6910) Figure 1.  Interface boards form a pool. This networking mode mainly applies to the A interface and GOUa/FG2a boards are used interface boards.9 LAG of the active/standby board+router adopting the VRRP networking mode 2015-11-13 Huawei Confidential Page 117 of 258 .9. 1 and Figure 1.1. 2015-11-13 Huawei Confidential Page 118 of 258 .  Specify interface configuration principles to guide LLD design and implementation. and the user plane uses the RTP protocol.2 describe the bearer protocol on the A interface.  Negotiate interface interworking parameters for follow-up interface interworking to improve the interworking success ratio.2 Input of the Design  Device BOQ  Networking diagram of the device  Terms about transmission resources in the contract  Transmission type and interface protocol  Feature function application.1 Interface Description The A interface is between the BSS and the MSC server. the core network (CN) side uses the softswitch architecture.1 Design Overview 19.2 A Interface Design 19.1 Purpose of the Design  Properly design the interface networking solution based on the NE geographical locations and transmission conditions to ensure the reliability and save resources. 19. including the MSC Pool. the control plane uses the SIGTRAN protocol.  Calculate the interface bandwidth and plan the number of transmission links based on the traffic model and transmission type. If A over IP is in use. 19. Figure 1. and it implements the interworking of the products provided by multiple manufacturers.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.2.0 & BSC6910) 19 Transmission Interface Design 19.0 & GBSS17.1. 2. provides the TC function. and the MGW provides the TC function. Use the existing transmission nodes to save the investment. Layer-3 router-based networking is preferred. Therefore. The BSC and the MSC server can be connected through a LAN or WAN based on the locations of the BSC and the MSC server.2 Reference protocol model on the user plane of the A interface IP transmission on the A interface allows an operator to construct the IP network between the BSC and the MSC server. and this facilitates maintenance. The A interface protocol is the standardized A interface protocol. Because the A interface supports only the IP bearer. The supported protocol is IPv4. Huawei Confidential Page 119 of 258 . the BSS does not provide the TC function.2 Networking Design Design principles: 2015-11-13  The transportation to the equipment room is convenient.1 Reference protocol model on the control plane of the A interface Figure 1. 19. Select the equipment room where the power supply is stable and air conditioners/ESD floor are available.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. confirm the A interface protocol supported by the MSC server. Huawei's BSS expands the A interface protocol to support the TrFO function to reduce the number of coding times and improve the voice quality.  The A interface supports only the IP bearer and the MGW.  Consider the distribution of existing transmission nodes when designing the BSC locations. in the interworking with the MSC server. The networking mode can be direct connection or router-based networking.0 & BSC6910) Figure 1. instead of the BSS.0 & GBSS17. IP transmission on the A interface provides two types of interfaces: FE and GE. and therefore can interwork only with the softswitch devices that also use the standardized A interface protocol. the transmission links of the A interface are connected to two or more MGWs (the MGWs belong to the same MSC server). the TC function is provided by the MGW.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. 19. if a single MGW is faulty. route-based active/standby in standalone mode. that is. and layer-3 networking can be used. Design guide: Step 1 Determine the networking mode based on the networking scale and the requirements of the customer for A interface networking. and the configuration difficulty. inter-MSC signaling load. design the networking reliability of the router. Step 4 Determine whether the signaling and service are separated on the A interface on the bearer network.2.0 & BSC6910)  Plan the BSCs in the same area in the same MSC server. Avoid discontinuous BSC networking because it increases inter-MSC handovers. The optional modes are as follows:  2015-11-13 The signaling and service share the same port. Step 3 If layer-3 networking is in use. or routebased load sharing in standalone mode is used. connect one BSC to more than two MGWs that belong to the same MSC server (non-MSC Pool mode).2. This improves the BSC reliability. layer-3 networking is preferred. The inter-board active/standby networking mode is preferred. Generally. Then. determine whether interboard active/standby. that is.  To improve the network security. (Recommended) Huawei Confidential Page 120 of 258 .2 Networking Design of IP Transmission on the A Interface After an A over IP construction.1 BSC/MGW multi-homing networking In BSC/MGW multi-homing mode. determine whether to use VRRP-based route active/standby networking. the services of the BSC are not interrupted. Direct connection networking. layer-2 networking. load sharing. Figure 1. and reduces the handover success ratio. Step 2 Design the networking reliability of the interface board based on the support capability of the interworking device and the requirements of the customer.0 & GBSS17. services on the faulty links are allocated to other pooled IP addresses. they are mapped to different virtual private networks (VPNs) based on different ports. use different ports for the signaling and service.0 & GBSS17. instead of the configuration of peer IP addresses. If the ICMP ping detection of a pooled IP address fails. IP pool fault detection and switchover triggering mechanism: Each address in the IP pool on the BSC side automatically starts the ICMP ping detection. Then. service logical IP addresses form an IP pool. signaling and service separation on the bearer network is implemented. (Recommended)  Configure multiple IP addresses for the physical port. The BSC does not require the configuration of IP path. Figure 1. the network construction cost is low.1 Typical A over IP networking mode (pool of standalone boards) On the bearer network side: Layer-3 router networking is in use and a pair of independent routers is deployed. It requires the configuration of a local end IP pool.0 & BSC6910)  If the customer requires the signaling and service to be separated. the signaling and service are mapped to different VPNs based on different IP addresses.1 shows the typical networking. and pooled interface boards work in load-sharing mode. In this way.  Direct connection networking without routers (not recommended) Advantages: − 2015-11-13 If no datacom device is used. Then. (Not recommended) ----End Figure 1. pooled interface boards in multiple pairs and pooled ports in multiple pairs protect each other.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. IP route: The next hop is the IP address of the router. On the BSC side: Independent interface boards are used. the reliability is improved. In this way. Detection mechanism After a transmission resource pool is deployed on the A interface. and the maintenance is simple. signaling and service separation on the bearer network is implemented. Huawei Confidential Page 121 of 258 . Intra-board port active/standby: Configure active and standby routes (with different priorities) from different ports to the same destination address to implement route-based port active/standby within the board. or route-based load sharing in standalone mode). (Not recommended) The requirements of the customer and the capability of the interworking device determine the networking reliability mode on the A interface (the active/standby mode. design the networking reliability. the QoS can be easily guaranteed to facilitate bandwidth call access control. − It is not applicable to large-scale networking.0 & GBSS17. Disadvantages: − The best effort feature of the IP network causes low QoS. If no datacom device is used. The router networking mode is preferred. Promoted networking schemes for the GBSS15.0 & BSC6910) − The datacom device is uncontrollable in some aspects. This means that certain investment is required. After you determine the networking mode. Disadvantages:  − The networking is not open. and the evolution capability is low. − In this solution. − The compatibility problem can be prevented in the interworking with the devices provided by other manufacturers. − The networking is open and supports large-scale networking. − This solution meets the requirements for the transmission bearer network in GSM network evolution. the operator must provide an IP bearer network (that consists of devices such as routers) as the transmission bearer network. If A over IP (FE/GE) is in use. load-sharing mode.0 BSC6910:  2015-11-13 Promoted scheme 1: using a transmission resource pool Huawei Confidential Page 122 of 258 . if only one interface board is used (that is. Router networking (recommended) Advantages: − This solution provides a high bandwidth and reliable transmission bearer for the A interface.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. In addition. port active/standby or port load-sharing can be implemented on the interface board using route configuration on condition that the interface adopts the device IP communication mode. route-based active/standby in standalone mode. and the end-to-end QoS mechanism is required to ensure the QoS. Adopt the mode recommended by Huawei. the standalone mode). Networking reliability design Analyze and design the networking scenario based on the requirements of the customer and the project condition. the active/standby and load-sharing modes are supported for the reliability of A interface networking. − This solution can protect the network from burst data services. Use either or both of the direct connection networking mode (without a router) and the router networking mode. − Follow-up expansion is inconvenient. (Not recommended) Intra-board port load sharing: Configure equivalent routes (with the same priority) from different ports to the same destination address to implement route-based port load sharing within the board. 0 & GBSS17.0 & BSC6910) Networking: Pool of standalone boards Interface boards on the BSC side are standalone and are divided into two groups to connect to two routers.2). Route configuration examples Devic Source e IP Next Hop BSC IP150 IP110 IP170 IP130 IP160 IP120 IP180 IP140 Standby Next Hop Detection mechanism 2015-11-13 Huawei Confidential Page 123 of 258 .2 Typical A over IP networking mode (pool of standalone boards) On the bearer network side: Layer-3 router networking is in use and a pair of independent routers is deployed. Packets on the control plane and the service plane are transmitted and received through the port on the active board. It requires the configuration of a local end IP pool. The BSC does not require the configuration of IP path. Each SCTP link on the control plane is configured with inter-board dual-homing protection (two IP addresses such as IP150 and IP160 in Figure 1.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. On the BSC side: Interface boards adopt the IP pool comprised by logical IP addresses of the independent service plane of the board.2) of multiple interface boards of the BSC form an IP pool. and loads are evenly distributed among the pooled interface boards. instead of the configuration of peer IP addresses. Figure 1. Logical IP addresses (such as IP170 and IP180 in Figure 1. Device IP addresses are used for communication. pooled interface boards in multiple pairs and pooled ports in multiple pairs protect each other.0 & BSC6910) After a transmission resource pool is deployed on the A interface. SCTP links must be configured to inter-board dual-homing mode to provide inter-board protection in the IP pool. Device IP addresses are configured only on the logical active board. The pooled interface boards work in load-sharing mode. that is. the interface board on which IP170 is configured is faulty. The BSC is directly connected to the dual routers through two independent ports on the active/standby interface boards. If the ICMP ping detection of a pooled IP address fails. IP150. so that the ports of the active/standby boards can protect each other. On the control plane: Packet receiving by the SCTP links times out and the packets are resent through the standby path. Packets on the control plane and the service plane are transmitted and received through the port on the active board. With the active/standby MGW features of the source IP enabled. IP170. On the user plane: ICMP ping detection on IP170 in the IP pool fails (5 x 5s). the active/standby paths are bound to the outgoing ports of the active/standby boards to achieve active/standby routes of the active/standby boards. 2015-11-13 Huawei Confidential Page 124 of 258 . and IP180 are configured only on the active board.  Optional scheme 1: using a transmission resource pool Networking: Pool of active/standby interface boards+dual-active ports Logical IP addresses on the service plane of the active/standby interface boards on the BSC side form a pool. Analysis of the fault switchover mechanism (only on single-fault scenarios) Fault 1: On the BSC side. services on the faulty links are allocated to other pooled IP addresses.0 & GBSS17. The SCTP working links switch to the standby path about 15s after the packets are resent. IP170 is blocked and subsequent services are provided through IP180. Local IP addresses instead of IP paths are configured on the BSC. IP pool fault detection and switchover triggering mechanism: Each address in the IP pool on the BSC side automatically starts the ICMP ping detection. Upper layer signaling indicates that no packets are lost but a time delay of about 1s occurs. IP160. the outgoing port routes of the active/standby boards are configured and active/standby routes are configured for routers.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Besides. 3 Typical A over IP networking mode (pool of active/standby interface boards+dualactive ports) In actual application. The BSC performs a BFD detection every 100 ms for three times. Device IP addresses are used for communication. If BFD is deployed between interface boards and the peer routers.0 & BSC6910) Figure 1. If the ICMP ping detection of a pooled IP address fails. the 2015-11-13 Huawei Confidential Page 125 of 258 . the BSC triggers a switchover of the active/standby gateways in the source IP address routing table. IP pool fault detection and switchover triggering mechanism: Each address in the IP pool on the BSC side automatically starts the ICMP ping detection. On the BSC side: Interface boards adopt the IP pool comprised by logical IP addresses of the active/standby service planes of the board.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. pooled interface boards in multiple pairs and pooled ports in multiple pairs protect each other. On the bearer network side: Layer-3 router networking is in use and a pair of independent routers is deployed.0 & GBSS17. Route configuration examples Devic Source e IP Next Hop Standby Next Hop BSC IP150 IP110 IP120 IP170 IP130 IP140 IP160 IP120 IP110 IP180 IP140 IP130 Detection mechanism After a transmission resource pool is deployed on the A interface. services on the faulty links are allocated to other pooled IP addresses. IP addresses of more than two boards form an IP pool. Configure the delay enabling BFD on CE1 and CE2 to avoid service interruption of CE1 and CE2 due to a reset upon power-off. The BSC can detect board faults and if it detects a board fault. The active port of each board enables two BFD sessions to detect the IP addresses of the two routers. because the ports on the interface boards of the BSC side do not support adding ports to the boards of the LAG. new IP addresses must be configured and added to the pool. MSC server. Accordingly. If an IP pool is deployed on the BSC side. and separate ETHIP for the user plane: IP141 and the mapping VLAN). New IP addresses and new VRRP IP addresses must be also configured on peer devices. CE1 functions as the high priority router of VRRP1 and CE2 functions as the high priority router of VRRP2. All data is sent and received through the active port. the interface board on which IP170 is configured is faulty. The SCTP working links switch to the standby path about 15s after the packets are resent. The BSC.2. the bearer network adopts different VPN isolation for the control plane and the user plane of the A interface. The MSC server and the MGW connect to the BSC in loose coupling mode and the BSC can be configured to work in either active/standby mode or load-sharing mode. which function as the next hops of the BSC.1Step 5Figure 1.  Optional scheme 2: using a transmission resource pool Networking: Pool of active/standby boards+manual active/standby LAGs The BSC is directly connected to the dual routers through the active/standby ports on the active/standby interface boards. Heartbeat messages are transmitted over the trunk between CE1 and CE2. configure separate ETHIP for the control plane on the other pair of interface boards: IP121 and the mapping VLAN. However.0 & GBSS17. The control plane and the user plane use the same physical port. Upper layer signaling indicates that no packets are lost but a time delay of about 1s occurs.1.0 & BSC6910) active/standby boards of the BSC switch over. and separate ETHIP for the user plane: IP131 and the mapping VLAN.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.4 Typical A over IP networking mode (pool of active/standby boards+manual active/standby LAGs) 2015-11-13 Huawei Confidential Page 126 of 258 . Multiples pairs of active/standby ports of a pair of active/standby boards form a pool. Analysis of the fault switchover mechanism (only on single-fault scenarios) Fault 1: On the BSC side. contact peer maintenance engineers to configure the peer device to work in load-sharing mode. VRRP IP addresses are configured between the dual routers. As shown in 19. Logical IP addresses of multiple pairs of active/standby interface boards of the BSC form an IP pool.1. The destination is reachable all the time. On the user plane: ICMP ping detection on IP170 in the IP pool fails (5 x 5s).7. Configure multiple VRRP IP addresses between CE1 and CE2 to share loads. which is consistent with the IP pool on the BSC side. In this networking. On the control plane: Packet receiving by the SCTP links times out and the packets are resent through the standby path. the source IP address route mapping the logical IP address is switched between the active/standby gateways. IP170 is blocked and subsequent services are provided through IP180. and the MGW are deployed in layer-3 networking mode. Therefore. Figure 1. and the logical IP address is migrated to a normal board from the faulty board. different VLANs and ETHIPs must be designed on the BSC side (configure separate ETHIP for the control plane on one pair of interface boards: IP111 and the mapping VLAN. The standby port of a certain pair of active/standby interface boards on the BSC enables an ARP detection session to detect the VRRP virtual IP addresses (IP114 and IP124 are configured when the ARP detection is enabled). a pair of active/standby interface boards is faulty. SACK message receiving by data blocks on the active path of the SCTP links times out and the SACK messages are resent through the standby path. If faults are detected during both BFD sessions and the ARP detection indicates that the standby port is normal.0 & BSC6910) Route configuration examples Devic Source e IP Next Hop BSC IP150 IP110 IP170 IP130 IP160 IP120 IP180 IP140 Standby Next Hop Transmission fault detection scheme After a transmission resource pool is deployed on the A interface. 2015-11-13 Huawei Confidential Page 127 of 258 . If the ICMP ping detection of a pooled IP address fails.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Then SACK messages are not resent. IP pool fault detection and switchover triggering mechanism: Each address in the IP pool on the BSC side automatically starts the ICMP ping detection. ICMP ping detection on an IP address in the IP pool fails (5 * 5s). Upper layer signaling indicates that no SACK messages are lost but a time delay of about 1s occurs. The active port of a certain pair of active/standby interface boards on the BSC enables two BFD sessions to detect the physical IP addresses (IP110 and IP112) of the two routers. and Whether affect the port swapping is set to YES.0 & GBSS17. the active/standby ports switch over. This IP address is blocked and subsequent services are provided through other IP addresses. pooled interface boards in multiple pairs and pooled ports in multiple pairs protect each other. Fault 1: On the BSC side. The SCTP working links switch to the standby path about 15s (1 + 2 + 3 + 3 + 3 + 3) after the SACK messages are resent. services on the faulty links are allocated to other pooled IP addresses. 0.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. use the GOUc/GOUd/EXOUa interface boards. Therefore. only FG2c/FG2d/GOUd/GOUc/EXOUa interface boards support the transmission interface Pool feature. Impact and constrains: The load-sharing boards in the pool and the boards that have logical ports configured are mutually exclusive.  Only the FG2c/FG2d/GOUd/GOUc/EXOUa interface boards support the transmission interface Pool feature. If the FG2c/FG2d interface boards are in use.  Interfaces of different systems cannot share the transmission pool. However. If boards with logical ports are configured. these boards are preferentially selected. the network where the GOUc/GOUd/EXOUa interface boards are deployed has no limitation on transmission distance and the networking is more flexible. Config ure All Max Trans fer Unit Auto Negotiat ion Mode Port Rate( M) Dupl ex Mod e Parameter description:  2015-11-13 Board Type: board type. other boards are selected. Output: A over IP networking design BSC Subr Nam ack e No. Huawei Confidential Page 128 of 258 . if the peer end has sufficient GE optical interfaces. Device IP addresses without source IP routing cannot be added to the IP address pool. Compared with the network where the FG2c interface boards are in use. use the GOUc/GOUd/EXOUa interface boards. If these boards are faulty or the CPU of these boards is overloaded.0 & GBSS17. only GE/FE electrical interfaces are available and the transmission distance is less than 100 meters (328 ft).0 & BSC6910) The processing after a pair of active/standby interfaces on the BSC side is faulty is similar to the processing after a pair of active/standby interface boards on the BSC side is faulty. Restrictions and Constrains of the Transmission Pool Network Requirements and specification for the transmission pool networking:  The transmission pool can be used only on layer-3 Ethernet network (an layer-3 route is deployed before the BSC).  The IP addresses in an IP address pool must be device IP addresses and be configured with the source IP routing.  Each IP address can be in only one pool. Boa rd Typ e Net Mo de Po rt Ty pe P or t N o. IP Interface Boards For GBSC15. If the peer end has GE optical interfaces. the peer end must support GE optical interfaces. Sl ot No . 2. one physical interface board provides two physical ports for signaling. On the BSC side.  Max Transfer Unit. or standalone mode). 19. on the MSC server side. Port Rate(M).Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. 2015-11-13 Huawei Confidential Page 129 of 258 . Two IP addresses (Local IP1 and Local IP2) are allocated to the two physical ports. and Duplex Mode: must be consistent with those of the directly connected devices. The peer MSC server provides two pairs of IP interface boards and two IP addresses (Peer IP1 and Peer IP2) to implement SCTP multihoming with the BSC. multiple IP addresses on the local and peer end are configured to form multiple IP paths. one physical board provides two physical ports for signaling. the BSC is configured with two pairs of A interface boards in subrack 0 and subrack 1. The service and signaling are separated on physical ports.1 Scenario 1 In A over IP mode. Each pair works in active/standby mode.  Port Type: port type (GE/10 GE or FE port). A router is deployed between the BSC and the MSC server. and each pair provides one physical port for signaling. the following networking mode shown in Figure 1.0 & GBSS17. On each pair of boards. Each pair of interface boards on the BSC must be configured with routes destined for both pairs of interface boards on the peer MSC server to implement four-homing.3 SCTP Multi-Homing Design In SCTP multi-homing mode.2. two pairs of interface boards are available.3. The scenarios are as follows (scenario 1 is the most recommended one): 19. On the peer MSC server side. This can improve the networking reliability and is used in A interface signaling networking (IP over FE/GE). that is.1 can be used to implement SCTP multi-homing. In both of the preceding cases. Implement SCTP multi-homing design based on the networking plan and configuration of the peer MSC server. totally two physical ports are allocated for signaling. inter-board load-sharing mode.0 & BSC6910) CONFIDENTIAL  Net Mode: inter-board mode (inter-board active/standby mode. one port is allocated for signaling. Alternatively. Auto Negotiation Mode. and two paths are available. System 2015-11-13 Related Software Parameter None. two source IP addresses. Impact on the None. = 1: The new path management mechanism is used. two paths are formed. that is. Public or Not For internal use only Huawei Confidential Page 130 of 258 .1 SCTP four-homing between the BSC and the MSC server If bit 1 of P42 on the MSC server is set to 1 (default value).0 & GBSS17. two source IP addresses. Set bit 1 of P42 to 0 to implement four-homing. = 0: The original path management mechanism is used. that is. two destination IP addresses.0 & BSC6910) Figure 1. that is. Bit Bit 1 Description It controls whether to enable the new path management mechanism. and four paths are available.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. two destination IP addresses. dual-homing can be implemented. Default value: 1 Application Scenario It is used to select a path management mechanism in SCTP multihoming. 19. Set bit 1 of P42 to 0 to implement four-homing. the BSC is configured with a pair of A interface boards that work in active/standby mode. dual-homing can be implemented.2. One physical port is allocated for signaling. 2015-11-13 Huawei Confidential Page 131 of 258 .2 Scenario 2 An M3UA link is added compared with the networking in scenario 1. two paths are formed. The signaling and service are separated on physical ports. A router is deployed between the BSC and the MSC server.2. and peer address 2 to Peer IP1. see the parameter description in scenario 1. Figure 1. The other configurations remain unchanged.3.0 & GBSS17.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Configure local address 1 to Local IP1.3. and one IP address is allocated to this physical port.1 Two M3UA links and SCTP four-homing between the BSC and the MSC server If bit 1 of P42 on the MSC server is set to 1 (default value). For detailed information about P42.3 Scenario 3 In A over IP mode. peer address 1 to Peer IP2.0 & BSC6910) 19. that is. The peer MSC server provides two pairs of IP interface boards and two IP addresses to implement SCTP dual-homing on the MSC server side. local address 2 to Local IP2. 4 Scenario 4 In A over IP mode.2. 19. For detailed information about P42. One physical port is allocated for signaling. The signaling and service are separated on physical ports.1 SCTP dual-homing on the MSC server side and SCTP single-homing on the BSC side (1) Bit 1 of P42 on the MSC server is set to 1 by default. see the parameter description in scenario 1.3. 2015-11-13 Huawei Confidential Page 132 of 258 . A router is deployed between the BSC and the MSC server.0 & GBSS17.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & BSC6910) Figure 1. and two IP addresses are allocated to this physical port (multiIP function on the port). Set bit 1 of P42 to 0 to implement SCTP multihoming on the MSC server side. the BSC is configured with a pair of A interface boards that work in active/standby mode. The peer MSC server provides two pairs of IP interface boards and two IP addresses to implement SCTP dual-homing on the MSC server side. Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) CONFIDENTIAL Figure 1.1 SCTP dual-homing on the MSC server side and SCTP single-homing on the BSC side (2) 19.2.3.5 Scenario 5 In A over IP mode, the BSC provides two pairs of A interface boards, and each pair works in active/standby mode. The service and signaling are separated on physical ports. Each pair of interface boards provides one port for the signaling, that is, two IP addresses (in different network segments) are configured to the two pairs of interface boards on the BSC. The peer MSC server provides one pair of IP interface boards and one IP address to implement SCTP dual-homing on the BSC side. A router is deployed between the BSC and the MSC server. 2015-11-13 Huawei Confidential Page 133 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) Figure 1.1 SCTP single-homing on the MSC server side and SCTP dual-homing on the BSC side Summary By default, the duration of detection on a single-homing link is 3s during data services and 7s when no service is being processed. The detection duration doubles for a dual-homing link. For GBSS15.0: The RTO min value can be set to 50 ms. However, if the system performs detection frequently, the SCTP links may repeatedly switch over if transmission condition is poor. First local IP address and Second local IP address of an SCTP link must be service IP addresses (device IP addresses are recommended). Two pairs of the A interface boards provide a port respectively to implement SCTP multi-homing. Output: SCTP link Linkset name Local Port No. Local Address 1 Local Address 2 Peer Address 1 Peer Addres s2 Peer Port No. Parameter description: 2015-11-13  Linkset name: name of the link set to which the M3UA link belongs. It is planned on the BSC internally.  Local Port No.: local port number. It must be negotiated with the peer end.  Local Address 1: first local IP address. It must be negotiated with the peer end.  Local Address 2: second local IP address. It is required only when SCTP multi-homing is enabled. It must be negotiated with the peer end. Huawei Confidential Page 134 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910)  Peer Address 1: first peer IP address. It must be negotiated with the local end.  Peer Address 2: second peer IP address. It is required only when SCTP multi-homing is enabled. It must be negotiated with the local end.  Peer Port No.: peer port number. It is planned on the BSC internally. 19.2.4 Signaling Bandwidth Calculation Calculation method Use the GSM NEP tool to calculate the bandwidth. For details, see section Error: Reference source not found. Output of the design BSC Traffi Name c 7000 Signaling link type Bandwidth per link Signaling quantity Subrac k Numbe r0 Subrac k Numbe r1 Subrac k Numbe r2 64 kbit/s/2 Mbit/s 64 kbit/s/256/512/1 024/2 Mbit/s 6 2 2 2 19.2.5 Signaling Configuration Principles If the A interface adopts IP transmission, M3UA signaling links are used, and broadband signaling and narrowband signaling are not distinguished. Each SCTP/M3UA link supports a maximum of 4,000 Erlang (it is an experience-based estimated value and not presented to the customer) traffic. Each SCTP link maps an M3UA link. In signaling design, configure one SCTP link to bear 4,000 Erlang traffic. In terms of reliability, configure at least two links regardless of the traffic load. If the A interface adopts IP transmission, M3UA signaling links are used, and broadband signaling and narrowband signaling are not distinguished. Take the signaling balance and reliability of the BSC into account when configuring signaling links. The principles are as follows: 2015-11-13  In A over IP mode, bandwidth for M3UA links needs not to be configured. Each M3UA link supports about 4,000 Erlang traffic. To improve reliability, configure an M3UA link set for each BSC, and the M3UA link set contains at least four M3UA links that are distributed to boards in different subracks.  In A over IP mode, use the SCTP multi-homing for signaling links to improve reliability. For details, see section 19.2.3"SCTP Multi-Homing Design." Huawei Confidential Page 135 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) 19.2.6 Traffic Bandwidth Calculation This chapter provides engineers with a guide to the calculation of the number of CICs and transmission bandwidth of the A interface. For calculation methods, see section Error: Reference source not found. Use the GSM NEP tool to calculate the bandwidth. Methods and principles of bandwidth calculation Method 1: Cell channel configuration -> Checking the ErlangB table -> Cell traffic -> Sum of the traffic of all the cells in the BSC -> Total BSC traffic -> Checking the ErlangB table -> Number of CICs of the A interface Method 2: Traffic per subscriber x Number of subscribers -> Total BSC traffic -> Dividing by 0.7 (traffic per CIC) -> Number of CICs of the A interface Generally, the network design tool uses the first calculation method (this method is adopted in pre-sales marketing). The redundancy of A interface bandwidth calculated using this method is sufficient, and this method does not cause transmission bottleneck of the BSC. The result obtained using the second calculation method is precise, and the second method is applicable to the scenario where transmission resources are insufficient to meet the minimum transmission requirements. Output of the design Table 1.1 Calculation result of A interface bandwidth in IP transmission mode BSC Name Traffic (Erlan g) System Congestion Ratio 7000 10-6 Number of CICs of the A Interface IP Transmission Bandwidth 19.2.7 IP Address Planning (A over IP) The IP addresses of the interface boards of the BSC include device IP addresses (logical IP addresses) and physical port IP addresses. Physical ports support the configuration of multiple IP addresses. In the GBSS9.0 and later versions, the IP interface board supports multiple device IP addresses. The following uses the PIU as the common name of the A interface board, Gb interface board, and Abis interface board. The device IP communication mode is in use. The device IP address uses the 32-bit mask to save IP resources. Design principles: 2015-11-13  The planned IP addresses must facilitate follow-up maintenance.  The planned IP addresses must meet the expansion requirements in a certain period in future.  Plan VLAN tagging based on the next hop or service type to facilitate follow-up maintenance and expansion. Huawei Confidential Page 136 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) Design guide: Step 1 Allocate device IP addresses based on the A interface networking design and number of FE/GE/10 GE ports calculated in the bandwidth design. Step 2 Allocate port IP addresses. In the active/standby boards+manual active/standby LAGs, configure an IP address for the active port. Configure an IP address for the standby port only when the ARP detection is performed on the standby port. The IP addresses of the active/standby ports must be in the same network segment. Step 3 If layer-3 networking is used and the device IP address is used for communication, configure a route from the intermediate router to the device IP address of the BSC. If layer-3 networking is used and the port IP address is used for communication, a route from the intermediate router to the port IP address of the BSC is not required. Step 4 If the end-to-end solution requires that VLAN tags be added on the BSC side based on different destination IP addresses, add VLAN tags based on the next hop or service type on the BSC side. Step 5 If the control plane and the user plane are separated using multiple IP addresses on the physical port, configure the BSC to add different VLAN tags based on different next hops. ----End Principles of IP address planning  The device IP address of a board is the logical IP address that the board uses for communication. The device IP address is valid for all the port IP addresses of the board. Use the pool of independent board networking mode.  For the FG2c board, if the FE interface mode is adopted, one board can be configured with 12 port IP addresses that are in different network segments. If the GE interface mode is adopted, one board can be configured with four port IP addresses. In addition, the port IP addresses and the device IP address must be in different network segments. If the PIU adopts the active/standby configuration, only the port on the active board is allocated with an IP address.  The gateway IP address must be in the same network segment as the port IP address of the PIU.  One physical port can be configured with a maximum of six IP addresses. The multiple IP function is supported. The IP addresses of the same physical port must be in different network segments.  The BSC can add VLAN tags based on the next hop or service type. The VLAN ID ranges from 2 to 4094. If the interface communication mode is device IP communication, the port IP address works as the gateway IP address used to communicate with other external devices. If the interface communication mode is port IP communication, the port IP address works as the IP address used to communicate with other external devices. In addition, each PIU can be configured with a maximum of eight service logical IP addresses. A service logical IP address works as the source or destination IP address used to communicate with other external devices. For the PIU, the 12 FE ports and four GE ports adopt the router mode, that is, the IP addresses of the FE ports must be in different network segments. In addition, to simplify the implementation, the device IP address (logical IP address) of each PIU and the port IP address of the PIU must be in different network segments. The PIU interface board of the BSC adopts the routing mode. The IP addresses of the FE ports on the same interface board must be in different network segments. In addition, the IP addresses of the FE ports on different interface boards must be in different network segments. 2015-11-13 Huawei Confidential Page 137 of 258 and current IP address planning of the A over IP interface board.8 Routing Planning (A over IP) Design guide: Step 1 Plan BSC routing based on the A interface networking design. IP address of the MGW. IP1 to IP8 are the port IP addresses that need to be planned on the BSC side. routes to the device IP address of the BSC need to be configured on the MGW and MSC server.2.1 shows the IP network topology of the BSC.1: IP_1 to IP_4 (in yellow) are the IP addresses used only for the internal communication in the BSC.0 & BSC6910) Example: Figure 1. Each PIU can be configured with a maximum of eight logical IP addresses. The port IP addresses must be in different network segments. routes to the device IP address of the BSC need to be configured on the intermediate router. Figure 1.1 IP network topology of the BSC In Figure 1. Step 2 If the A interface adopts the device IP address for communication. IP_L1 and IP_L2 are the device IP addresses (logical IP addresses) to be planned for the PIU on the BSC side. Step 3 If the A interface adopts the device IP address for communication and layer-3 networking is used. ----End Principles of routing planning: 2015-11-13 Huawei Confidential Page 138 of 258 .CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Users do not sense and do not need to pay attention to this type of IP address. 19. IP address of the MSC server.0 & GBSS17. This type of address is generated automatically and does not need to be configured. The BSC needs to be configured with routes to the MGW and MSC server. Destinati on IP Address Subn et Mask Gatew ay To MSC/MG W Parameter description:  Outgoing Port No.9 QoS Design (A over IP) Design principles:  Port link detection − 2015-11-13 The BFD detection and ARP link detection cannot be enabled at the same time on the interface board.: port number of the outgoing port from the A interface board of the BSC to the peer MGW or MSC server. The network IP address is obtained by performing the AND operation on the device IP address (or port IP address if no device IP address is available) of the MGW or MSC server and the subnet mask.  Gateway: port IP address of the device directly connected to the outgoing port (indicated by Outgoing Port No. this parameter indicates the network IP address of the port IP address. In layer-3 networking mode. configure routes only on the active board to the MGW and MSC server. configure a route on the intermediate router to the device IP address of the BSC. In load-sharing mode. Outgoi ng Port No. The BFD detection supports SBFD detection (single-hop BFD detection.2. This IP address must be in the same network segment as the IP address of the outgoing port of the A interface board. Huawei Confidential Page 139 of 258 . but takes only tens of milliseconds to detect a fault in the BFD detection.0 & GBSS17. (The function that the ARP link detection implements is similar to the single-hop BFD detection. Generally. and the BFD detection requires the next-hop device to support the BFD detection.  Routes to the MGW and MSC server need to be configured on the BSC.  In BSC active/standby mode. however.0 & BSC6910)  If the router adopts the VRRP+VLANIF networking mode.  Subnet Mask: subnet mask of the IP address of the peer MGW or MSC server. configure routes on the MGW and MSC server to the device IP address of the BSC regardless of whether the layer-3 or layer-2 networking mode is used.  If the A interface of the BSC adopts the device IP address for communication. Subra ck No.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the gateway IP address in the routing information configured for the A interface board of the BSC is the VRRP IP address or the port IP address of the device directly connected to the port.) of the A interface board of the BSC.  To MSC/MGW: The routes to the MSC server and MGW need to be configured separately because the control plane and service plane are separated for the A interface. Output: Inde x No.  Destination IP Address: network IP address of the device IP address of the peer MGW/MSC server (destination of the data from the A interface board of the BSC). In layer-2 networking mode. Sl ot No . 19. it takes several seconds to detect a fault in the ARP link detection. routes to the MGW and MSC server are not required. recommended) and MBFD detection (multiple-hop BFD detection). If the peer MGW or MSC server does not have a device IP address (logical IP address). configure routes on both load-sharing boards to the MGW and MSC server. 0 & GBSS17. BFD detection on the active port and physical-layer detection on the standby port. Figure 1. the Huawei headquarters need to work out a solution. The physical-layer detection does not require data configuration. − The commonly used detections are the ARP detection and physical-layer detection. the ARP link detection can be implemented as long as one end supports the ARP detection. − The following detection modes are supported: BFD detection on the active port and ARP detection on the standby port (the standby port does not support BFD detection).CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. interval: 300 ms. ARP link detection on the active and standby ports. but the BFD detection can be implemented only if both ends support the BFD detection. For the logical port bandwidth.1 Promoted detection mode in active/standby mode   Logical port − The logical port bandwidth is different from other types of bandwidth. Figure 1. − Reserved bandwidth of the logical port = Reserved bandwidth threshold of the logical port x Logical port bandwidth − Congestion bandwidth of the logical port = Congestion bandwidth threshold of the logical port x Logical port bandwidth − Congestion clearance bandwidth of the logical port = Congestion clearance threshold of the logical port x Logical port bandwidth QoS parameters See the Configuration Recommendation of the specific version. the physical-layer detection is adopted by default.) − One port can be configured with only one detection mode.0 & BSC6910) However. ARP detection on the active port and physical-layer detection on the standby port. and physical-layer detection on the active and standby ports. The configurations recommended for the ARP detection are as follows: number of retries: 3. 1 represents 64 bit/s. If the customer requires the MBFD detection. and the ports support this detection by default.  2015-11-13 VLAN Huawei Confidential Page 140 of 258 . Do not use the MBFD detection.1 shows the promoted detection mode. If a port is not configured with the BFD detection or ARP link detection. VLAN is not necessary. only several pairs of boards are used. Output: A over IP QoS design ARP link detection Subra ck No. and do not change the value. BFD detection Subrack No. Huawei Confidential Page 141 of 258 . If the VLAN function is enabled on the device port that possesses the gateway IP address of the route configured on the port.  VLAN Flag: whether VLAN tags are added to ARP packets when the BSC implements ARP detection.0 & BSC6910) In A over IP mode. Therefore.: port number of the A interface board that requires the physical link detection.  VLAN ID: VLAN ID in the ARP detection packets when VLAN Flag is set to Enable. The default value is 3.  Arp Retry Attempts: number of ARP detection times in a period.  Peer IP Address of the Standby Board: physical IP address of the peer port directly connected to the physical port of the standby board. and the volume of broadcast packets is small.  IP Address Index indicates the IP address index. The system supports the configuration of multiple IP addresses for a port. Slo t No.  Peer IP Address: port IP address of the device that is directly connected to the physical port.  ARP Timeout: ARP response timeout interval (after an ARP request is sent) in the ARP detection. The default timeout interval is 3 seconds. Slo t No. Add VLAN tags based on the next hop or add VLAN tags on the intermediate transmission devices. Use the default value 3. the route is unreachable. IP Addre ss Index Peer IP Addre ss Arp Retry Attemp ts Arp Timeo ut VLA N Flag VLA N ID Peer IP Address of the Standby Board Parameter description:  Port No. Port No. otherwise. The software has a bug. IP Addres s Index Peer IP Addre ss MinTxIn terval( ms) MinRxI nterval (ms) Dete ct Mult Peer IP Address of the Standby Board Parameter description:  2015-11-13 Peer IP Address: peer IP address in the BFD session. Por t No. The BFD detection supports only the next hop detection. Therefore. and the VLAN ID must be the same as the VLAN ID configured for the device port that possesses the gateway address. the peer IP address in the BFD session is the port IP address of the device that is directly connected to the port. this parameter must be enabled.0 & GBSS17.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.  MinRxInterval(ms): minimum interval between the BFD control packets that the local system receives.0 & BSC6910)  MinTxInterval(ms): minimum interval between the BFD control packets that the local system sends.2. see the parameter description in "IP Path. Bandwidth of the Logical Port(32Kpb s) Reserved Bandwidth Threshold (%) Congestio n Bandwidth Threshold (%) Congestion Clear Bandwidth Threshold(%) Parameter description:  Physical Port No. For details about the other parameters.0 & GBSS17. Sl ot No ." 19. It ranges from 32 kbit/s to 64 kbit/s. and whether to adopt a single signaling point or multiple signaling points The preceding information needs to be negotiated between the core network personnel and the customer.: physical port number of the interface board to which the logical port belongs.  Bandwidth of the Logical Port(32Kpbs): fixed bandwidth of the logical port. see the parameter description in "ARP link detection. the following must be taken into consideration:  Protocol type  Protocol phase identifier (Phase2. that is. The sum of the bandwidths of all the logical ports bound to the same physical port cannot exceed the bandwidth of the physical port. Table 1. the link is considered disconnected after the detection fails for the specified number of times. GSM_PHASE_2+ is recommended)  OSP  DSP  Whether to use signaling point transfer. Huawei Confidential Page 142 of 258 . Physi cal Port No." Logical port Subra ck No.  Detect Mult: number of detection times. or Phase2+.10 Interface Interworking In interface interworking.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Log ic Por t No.1 A interface interworking parameters 2015-11-13 Parameter Name Recommende d Value Description OSP Name BSC It is consistent with the BSC name in the BSC attribute. For details about the other parameters. OSP Code None Set it to the hexadecimal signaling point code (SPC) that is actually planned by the customer. . Encryption type Negotiated with the peer end The bits. Network ID None Set it to the actual network indicator of the country. the A interface phase identifier must be set to GSM_PHASE_2+. enable this switch. half-rate version 1. it is set to GSM_PHASE_2+ . STP MGW Use MGW as the name or use the actual NE name. For example. 2015-11-13 Speech Version Negotiated with the peer end Full-rate version 1. The value range is 000 to 999. it is NATB. Value:  GSM_PHASE_1  GSM_PHASE_2  GSM_PHASE_2+ If the system supports the GPRS and AMR services. In China. The value 1 indicates that the BSS Huawei Confidential Page 143 of 258 . The value range is 0 to 7999. CI Planned on the customer network It indicates the cell identification. STP Code None Set it to the hexadecimal SPC of the signaling transfer MGW. disable this switch. and A5/7 algorithms are supported.. Set it based on the actual voice version. The value range is 000 to 999. The value range is 0 to 65535. DSP Name MSC Use MSC as the name or use the actual NE name. and half-rate version 3 are supported. MCC Planned on the customer network It uniquely identifies the country to which the mobile subscribers belong. Is using STP? None If the interworking is implemented using the MGW. from the most significant bit to the least significant bit..0 & BSC6910) Parameter Name Recommende d Value Description OSP Code Bit None Set it to the actual encoding rule of the country. Generally. respectively indicate whether the A5/0. A interface tag Negotiated with the peer end It indicates the GSM protocol phase identifier supported by the A interface. A5/1. full-rate version 3.. MNC Planned on the customer network It identifies the public land mobile network (PLMN) to which the mobile subscribers belong. Set it based on the A interface phase identifier provided by the MSC server. if the BSC interworks with the MSC server directly. A5/2.0 & GBSS17. it is 14bit.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the MCC of China is 460. In China. DSP Code None Set it to the hexadecimal SPC of the interworking MSC server. LAC Planned on the customer network It indicates the local area code. the BSC6910 also supports A over TDM transmission (only the optical interface is supported. In versions earlier than BSC6910 V100R015C01. the A interface is a trunk circuit and trunk interface between the BSS and the MSC.0 & GBSS17. A over IP (A interface active/standby+VRRP). and the interface board is POUc). TDM-based Interface Physically.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. 2015-11-13 Huawei Confidential Page 144 of 258 .1 Interface Description The A interface is between the BSS and the MSC. the A5/0 algorithm must be supported. The following figure illustrates the reference protocol model on the control plane over the A interface.3 A Interface Design (TDM) 19. The most significant bit must be set to 1.0 & BSC6910) Parameter Name Recommende d Value Description supports the encryption algorithm. In BSC6910 V100R015C01 and later. Confirm the supported encryption algorithms.xls 19. The value 0 indicates that the BSS does not support the encryption algorithm.3. It cannot be set to all 0s. A over IP interworking instance in the P project on the live network: The following document provides the interworking parameter planning of the BSC in A over IP transmission mode on the live network. The protocols over the A interface are as follows: 1. the BSC6910 only supports A over IP transmission. that is.  SCCP: complies with ITU-T Q. 2015-11-13 Huawei Confidential Page 145 of 258 . and G.008.706. and 3GPP TS 44. 19.701-Q. remote TC.714 and Q.2 Networking Design The A over TDM transmission is a traditional networking mode over the A interface on a GSM network.0 & GBSS17.  BSSAP: complies with 3GPP TS 48.  TDM/IP dual-stack is not supported.704. and Q. That is. BM/TC separated mode. TC pool.704.  The control plane can use IP transmission and the user plane can use TDM transmission.  The Ater interface is not supported.1 Reference protocol model on the control plane of the A interface BSSAP: Base Station Subsystem Application Part BSSMAP: Base Station Subsystem Management Application Part DTAP: Direct Transfer Application Part MTP: Message Transfer Part SCCP: Signaling Connection Control Part Protocol and specifications that the A interface complies with are as follows:  Physical layer: complies with ITU-T G.716.3.018. Q. G.703.705.008. BSC6910 V100R015C01 has the following restrictions:  Only the POUc interface board is supported in A over TDM transmission mode. and Ater over IP are not supported. G. 3GPP TS 24.732. The following figure shows a typical topology.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.707.0 & BSC6910) Figure 1.  MTP: complies with ITU-T Q.711-Q. see section 10.1 BSCs connected to an MGW Generally. Figure 1.3 Transmission Bandwidth Design For details about how to calculate the transmission bandwidth. 2015-11-13 Huawei Confidential Page 146 of 258 .0 & BSC6910) Figure 1. as shown in the following figure. To improve network reliability.3.0 & GBSS17. This enables the BSC to properly provide services even if any of the MGWs is faulty.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.3. a BSC is connected to an MGW and both of them are homed to the same MSC.2 BSCs connected to multiple MGWs 19. distribute A interface traffic and signaling on the BSC to different MGWs if two or more MGWs are available under an MSC.2.  Using 2 Mbit/s signaling links: The maximum bandwidth for each 2 Mbit/s signaling link can reach 1984 kbit/s. The maximum number of signaling links that can be configured over the A interface increases to 64. 2 Mbit/s signaling link: The bandwidth of each signaling link is 2 Mbit/s.704. As stipulated in GSM protocols Q. the configuration is appropriate. and a BSC can be configured with a maximum of 64 (16 x 4) narrowband signaling links.0 & BSC6910) 19. The maximum bandwidth for a single signaling point is 16 Mbit/s. Otherwise. the configuration is inappropriate. If the maximum number of signaling links contained in the signaling link set is 2. A BSC can be configured with 32 2 Mbit/s signaling links. That is. Assume that the number of digits 1 in the signaling link mask (in binary) for the signaling link set is n. the maximum bandwidth for signaling links between two signaling points can be 1 Mbit/s (16 x 64 kbit/s).3. the BSC6900 supports the following two methods for increasing the capacity of signaling links:  Using local multiple signaling points: The BSC6900 supports a maximum of four local signaling points. The MTP3 signaling link set and signaling route mask are designed as follows:  Check whether the signaling link mask for the MTP3 signaling link set is appropriately configured. The bandwidth of a narrowband signaling link is 64 kbit/s while that of a high-speed signaling link is N x 64 kbit/s (N ranges from 2 to 31). the configuration is inappropriate.4 Signaling Configuration Principles In an SS7 network.0 & GBSS17. the maximum bandwidth for the BSC is 64 Mbit/s. Specifications of signaling points: A BSC can be configured with a maximum of four local signaling points. Specifications of SS7 signaling links: Narrowband signaling link: The bandwidth of each signaling link is 64 kbit/s. Huawei Confidential Page 147 of 258 . assume that the signaling link mask is B0001 (the digits after B are binary numbers). If 2n is greater than or equal to the number of signaling links contained in the signaling link set.703 and Q. the configuration is appropriate. two types of signaling links are used: 64 kbit/s links and 2 Mbit/s highspeed signaling links. If 64 kbit/s signaling links are used. and the signaling link mask must be reconfigured. If the maximum number of signaling links contained in the signaling link set is greater than 2. A single signaling point can be configured with a maximum of 16 narrowband signaling links. In A over TDM transmission mode. For example. a maximum of 16 signaling links can be configured between two signaling points. The 2-Mbit/s signaling links consist of the standard signaling links at the rate of 2048 kbit/s and signaling links at the rate of N x 64 kbit/s (N ranges from 2 to 31). The bandwidth calculation method and processing for a narrowband signaling link are the same as those for a high-speed signaling link.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The only difference between a narrowband signaling link (64 kbit/s) and a high-speed signaling link (2 Mbit/s) lies in the bandwidth.  2015-11-13 Check whether the signaling route mask for the destination signaling point is appropriately configured. the result of the "and" operation performed between the signaling route mask and signaling link mask must be 0. and the total bandwidth for each GMPS/GEPS cannot exceed 4 Mbit/s.0 & GBSS17. source signaling points are no longer bound to the subracks. and the signaling route mask must be reconfigured.  High-speed signaling links and 64 kbit/s signaling links cannot be simultaneously configured between the BSC and the same destination signaling point. If the maximum number of routes contained in the destination signaling point is 2. signaling load may be unbalanced. the signaling links are M3UA links which do not distinguish wideband and narrowband signaling links.  A maximum of 32 2-Mbit/s signaling links can be configured. assume that the signaling route mask is B0001 (the digits after B are binary numbers).  The BSC6900 supports simultaneous configuration of high-speed signaling links and local multiple signaling points. In GBSS14.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. a minimum of two SCTP links must be configured regardless of traffic volume. In TDM transmission mode. Therefore. During the signaling design. this restriction does not apply. in GBSS9. Otherwise. In GBSS9. the configuration is appropriate. When local multiple signaling points are configured. A maximum of eight high-speed signaling links can be configured in each GMPS/GEPS. In GBSS8. It is equivalent to the number of speech channels supported by 16 64 kbit/s SS7 signaling links. If the maximum number of routes contained in the destination signaling point is greater than 2. It is recommended that cells be homed to different signaling points based on their areas. Therefore. Each 64 kbit/s signaling link supports 256 CIC speech channels). In versions earlier than GBSS14. this restriction applies. (The inter-cell handover procedure between different signaling points is similar with the inter-BSC handover procedure. the configuration is inappropriate. Local signaling points of the BSC6900 are not bound to the BM subrack.0 and later. the signaling point binding relationship between cells and CICs must be configured. In A over IP transmission mode. To ensure reliability. this restriction no longer applies. Otherwise.) In A over IP transmission mode. Huawei Confidential Page 148 of 258 . Each SCTP or M3UA link supports maximum traffic volume of 4000 Erlang (this value is based on experience and not provided for customers. For example.0 and later.0 and later. If the CN does not support wideband signaling.0. it is recommended that local multiple signaling points are configured for the BSC (in version earlier than GBSS9. source signaling points are bound to the BM subrack and TCS. cell homing based on areas can decrease the number of such handovers. a single subrack can be configured with multiple source signaling points even if only an A interface board is available). you are advised to set an SCTP link per 4000 Erlang. the configuration is appropriate. the restrictions on the number of signaling links and bandwidth supported by the PARC platform must be considered. and the default signaling route mask is B1111. the configuration is inappropriate.0 & BSC6910) Assume that the number of digits 1 in the signaling route mask (in binary) for the destination signaling point is n.0. If 2n is greater than or equal to the number of routes contained in the destination signaling point. a single subrack can be configured with four local signaling points. the configuration of signaling links must comply with the following rules to ensure the signaling load balancing and reliability: 2015-11-13  When high-speed signaling links are used. Therefore.1 and earlier versions. the signaling links are M3UA links which do not distinguish wideband and narrowband signaling links. therefore. the same bandwidth can be set for multiple SS7 high-speed signaling links. A BSC can be connected to multiple MSCs.  2015-11-13 Network service layer (NS) Huawei Confidential Page 149 of 258 .4. the embedded PCU is used.1 shows the protocol model of the Gb interface.  Any combination of timeslots (except timeslot 0) on an E1 link can form a high-speed signaling link. and manages sessions.  Physical-layer protocol L1 The physical-layer configurations and protocols defined in GSM 08. at least two high-speed signaling links must be configured. In TDM transmission mode.  The BSC supports MSC Pool. 19. manages the mobility. Figure 1.  Under the same signaling point.0 BSC6910 supports only IP networking mode. The Gb interface of the GBSS15. Physical resources are configured in the O&M process.1 Gb over IP protocol stack The Gb interface implements the communication between the SGSN and the BSS system and between the SGSN and MSs.14 can be used. The two signaling links are distributed to different STM-1 ports of an A interface board or to different A interface boards to improve the reliability. transmits packet data. the SS7 configuration is determined according to the proportion of the number of A CICs between the BSC and MSC to the total number of A CICs. the external PCU solution is not taken into consideration in the Gb interface design. and it is the standard interface defined in the protocol.0 & GBSS17.1 Interface Description The Gb interface connects the BSC (including the PS service) and the SGSN after the PCU is embedded.0 & BSC6910)  Different bandwidths can be configured for each high-speed signaling link.4 Gb Interface Design In new offices of the BSC6910. 19. Figure 1. Since the SS7 signaling links use load sharing.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The Gb interface is mandatory in GPRS networking. Figure 1. The NS-layer protocol transmits service data unit (SDU) data.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The BSSGP transmits signaling information and subscriber data. and provides the report of network congestion status indication and the network status report for the upper-layer service module. dynamically configures and manages the BVC.2 Embedded PCU networking 2015-11-13 Huawei Confidential Page 150 of 258 . the BSSGP is the interface between the LLC frame and the RLC/MAC block.0 & GBSS17. shares subscriber data in load-sharing mode. With the Gb over IP function. After the Gb over IP function is used. IP headers are compressed. Generally. Figure 1. In the SGSN. The BSSGP provides radio-related data. The IP transmission module implements the interworking between sub-networks so that the PCU and the SGSN can directly connect to each other (direct connection mode) or connect to each other through the IP transmission network (routing mode). and the maintenance work is simplified. performs flow control for downlink data.2 shows the logical networking diagram of the embedded PCU. the BSSGP is the interface between the RLC-/MAC-originated information and the LLC frame. the Gb interface uses the IP protocol to provide the lower-layer transmission service for the NS. and routing information to meet the requirements for subscriber data transmission between the BSS and the SGSN. the Gb interface maintenance commands are simplified.0 & BSC6910) NS refers to the network service control part in the NS protocol.  BSSGP protocol layer In the BSS. the Gb interface adopts IP transmission. QoS. and the data on the Gb interface can share the transmission bandwidth to improve the transmission efficiency and save the transmission cost. manages NS-VC links. and detects errors in interface messages. blocks and unblocks the BVC. In the Gb over IP function. Figure 1. Use the active/standby boards+active/standby ports.2 IP transmission network connection (Gb over IP) Design guide: Step 1 Determine the networking mode (direction connection networking or layer-2/layer-3 networking) based on the requirements of the customer for the Gb interface networking. In this connection mode.2 Networking Design In IP networking mode. Figure 1. the PCU and the SGSN are connected through an intermediate IP network. Step 3 If the layer-2/layer-3 networking is adopted. route-based active/standby boards in standalone mode. routers are used to provide the layer-3 routing service for the PCU and the SGSN. Do not use the layer-2 networking or direct connection mode. the PCU and the SGSN can be connected in either of the following modes:  Direct connection (direct connection mode)  IP transmission network connection (routing mode) In Gb over IP direct connection mode. In this connection mode.0 & GBSS17. Step 2 Design the networking reliability of the interface boards based on the capability of the interworking device and the requirements of the customer. The networking reliability of the Gb interface is the same as that of the A interface.2.1 Direction connection (Gb over IP) In Gb over IP routing connection mode. a switch can be deployed to provide the layer-2 switching service for the PCU and the SGSN. the PCU and the SGSN are directly connected to each other without any intermediate IP network. design the layer-2/layer-3 networking reliability and use layer-3 router VRRP+VLANIF to ensure the router reliability. and route-based boards load sharing in standalone mode.1. The active/standby boards and manual active/standby LAGs+layer-3 router VRRP networking mode is recommended. The optional modes are active/standby boards.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. as shown in Figure 1.0 & BSC6910) 19. as shown in Figure 1. ----End Design principles: 2015-11-13 Huawei Confidential Page 151 of 258 .4. 1 Typical Gb over IP networking mode (active/standby boards+manual active/standby LAGs) Ports configured on the two routers CE1 and CE2 and used by the VRRP IP addresses must be configured to layer-2 networking mode. If peer devices are configured with the STP protocol. If peer devices are configured with the RSTP/MSTP. this facilitates follow-up expansion and SGSN pool implementation. mode of the ports connecting to the BSC must be modified. and peer devices are not required to be configured with the STP protocol. Heartbeat messages are transmitted over the trunk between CE1 and CE2. The SGSN connects to the BSC in loose coupling mode and the BSC can be configured to work in either active/standby mode or load-sharing mode.0 & BSC6910)  If the IP transmission conditions are met.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. set the port mode to STP Disable.  In IP transmission mode. If peer devices are configured with the STP (802. If peer devices do not support the preceding modes. use IP transmission because the IP transmission bandwidth is sufficient. Bandwidth of trunks must be greater than 50% of the total data volume of the BSC and at least two GE interfaces must be converged. All data is sent and received through the active port. including the ports connecting the BSC and the trunk ports between routers. VRRP IP addresses are configured between the dual routers.1D-1998). set the port mode to PortFast. configure the Gb interface boards to work in active/standby mode. 2015-11-13 Huawei Confidential Page 152 of 258 .0 & GBSS17. Ports of the BSC do not support layer-2 exchange. which function as the next hops of the BSC. Figure 1. The ports in even-numbered slots of the BSC connect to a high-priority VRRP router. which improves the probability that the same active path is used by the BSC and the router. The typical Gb over IP networking modes are as follows: Gb interface networking schemes for GBSS15. The BSC and the SGSN are deployed in layer-3 networking mode. set the port mode to the STP edge port.  Connect the active and standby ports to the two VRRP routers respectively.0 BSC6910:  Promoted scheme Networking: Pool of active/standby boards+manual active/standby LAGs The BSC is directly connected to the dual routers through the active/standby ports on the active/standby interface boards. the active/standby ports are not switched over. the BSC and the SGSN exchange messages through CE2.0 & BSC6910) Route configuration examples Devic Destination Next e IP Hop Priorit y BSC IP311 IP119 Default CE1 IP150 IP111 Default CE2 IP150 IP111 Default Transmission fault detection scheme The active ports of the active/standby interface boards on the BSC enable two BFD sessions to detect the physical IP addresses of the two routers. If the BSC sends packets to the SGSN through CE1. When the active/standby ports switch over. That is. the original path remains unchanged. − Connection between two routers is faulty: BFD detection of heartbeat messages on VRRP1 fails and the standby port on CE2 becomes active. In this case. packet sending is interrupted. manual active/standby LAGs switch over. packets are sent to the BSC through CE1 and CE2. it then sends packets through CE2: The two BFD sessions on the active port of the BSC fail. then the active/standby ports are not switched over. packet sending is not interrupted. In this case.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. services are not interrupted and the switchover duration is less than 1s. Configure the delay enabling BFD on CE1 and CE2 to avoid service interruption of CE1 and CE2 due to a reset upon power-off. and the BSC sends packets to the SGSN through CE2. the active/standby ports switch over. Regardless of whether the BSC sends packets to the SGSN through CE1 or CE2.0 & GBSS17. the OSPF re-converges. the two BFD detections detect faults. One BFD detection on the active port of the BSC succeeds and the other BFD detection fails. and the SGSN sends packets to the BSC through CE2. After CE1 is faulty. The SGSN sends packets to the BSC through CE2. and the path of uplink packets of the BSC is BSC => CE2 => CE1 => SGSN. then the BSC sends packets to the SGSN through CE2: BSC <=> CE2 <=> SGSN. Huawei Confidential Page 153 of 258 . packet sending from the BSC to the SGSN is not interrupted. If the BSC sends packets to the SGSN through CE1. If the BSC sends packets to the SGSN through CE1. Analysis of the fault switchover mechanism (only on single-fault scenarios) 2015-11-13 − CE1 is faulty (suspended or powered off): Heartbeat detection on the VRRP port of CE2 fails and the standby VRRP port of CE2 becomes active. there is 50% probability that packet sending from the SGSN to the BSC may be interrupted (see the following Note). only the standby port is faulty. If the BSC sends packets to the SGSN through CE2. and the original path remains unchanged. then VRRP1 has two active ports. − Connection between the BSC and CE1 is faulty: Heartbeat communication on the VRRP ports is correct and the VRRP ports are not switched over. The BSC performs a BFD detection every 100 ms for three times and performs an ARP detection every 10s for three times. the BSC sends free ARP to update the ARP entries on CE1 and CE2. If the BSC sends packets to the SGSN through CE2. If the SGSN sends packets to the BSC through CE1. only one BFD session on the BSC fails and the active/standby ports are not switched over. In this case. The standby ports of active/standby interface boards on the BSC enable an ARP detection session. If the BSC sends packets to the SGSN through CE1. If the BSC sends packets to the SGSN through CE2. services are not interrupted and the switchover duration is less than 1s. IP address reachable rarely occurs on VRRP network. contact R&D engineers if the value of the weight parameter needs to be modified. When the active/standby ports switch over. and the switchover duration is less than 1s. In actual commercial deployment. That is. all services on this interface are interrupted. In this case. In this case. If the Gb interface on the BSC has more than one IP address but services on one IP address are interrupted. Modifying the value of the weight parameter affects the load-sharing effect of this scheme. service access success rate is low within 25s but services restore after 25s. modify the value of the weight parameter. − Intermediate network is faulty. NSVC configuration  NSVC BSC IP Addr BSC UDP Port No SGSN IP Addr SGSN UDP Port No NSVC 1 IP150 Port 1 IP311 Port 2 Optional scheme Networking: Active/standby boards+dual-active ports 2015-11-13 Huawei Confidential Page 154 of 258 . if the Gb interface on the BSC has only one IP address. services are not interrupted.0 & BSC6910) − Connection between CE1 and the intermediate network is faulty: The OSPF reconverges. In this case. services are not interrupted and the switchover duration is less than 1s. and the default value 100 is used (the same for each NSVL). − Manual switchover of ports on the BSC: VRRP routes and intermediate network routes are not affected. − Interface boards of the BSC are faulty: The active/standby boards switch over. This problem can be ignored. no redundancy service IP address is available.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. because the intermediate network has self-healing function.0 & GBSS17. The SGSN sends packets to the BSC through CE2. only one service IP address is configured by default). services are not interrupted and the switchover duration is 1 to 3s. and the active/standby ports switch over. which causes a service IP address of the BSC unreachable (rarely occurs): If only one service IP address is configured on the BSC (if only a pair of ports is configured. the value range is from 1 to 255. the BSC allocates subsequent services to another IP address. multiple pairs of ports are configured on the BSC to bearer multiple service IP addresses. and one pair of ports can bearer multiple service IP addresses. all services on this interface are interrupted. In this case. the BSC sends free ARP to update the ARP entries on CE1 and CE2. Logical link configuration: NSVL configuration Devic NSVL IP e Addr UDP Port No Weight BSC NSVL 1 IP150 Port 1 100 (see the following Note) SGSN NSVL 1 IP311 Port 2 100 (see the following Note) The weight here is not a percentage. if ping detection indicates that the network service virtual connection (NSVC) of an IP address is faulty (service restoration requires 5s x 5 = 25s by default). If the bandwidth of intermediate paths is different or the multiple SGSNs are configured on the peer end. However. Therefore. 2 Typical Gb over IP networking mode (active/standby boards+dual-active ports) On the bearer network side: Layer-3 router networking is in use and a pair of independent routers is deployed. no VLAN needs to be configured. which facilitates route combination and simplifies intermediate network route. The Gb interface occupies an Ethernet port. The control plane and user plane are not distinguished.0 & BSC6910) The BSC is directly connected to the dual routers through two independent ports on the active/standby interface boards. Figure 1.0 & GBSS17. service IP addresses of the BSC use logical IP addresses (device IP addresses). Besides. Route configuration examples Devic Destination Next e IP Hop Priorit y BSC CE1 CE2 2015-11-13 IP311/32 IP110 High IP331/32 IP130 High IP311/32 IP130 Low IP331/32 IP110 Low IP150/32 IP111 High IP170/32 IP111 Low IP150/32 IP131 Low IP170/32 IP131 High Huawei Confidential Page 155 of 258 . Configure IP addresses in the same network segment for each sub-interface. With the active/standby MGW features of the source IP enabled. Device IP addresses are configured on the logical active board. the active/standby paths are bound to the outgoing ports of the active/standby boards to achieve active/standby routes of the active/standby boards. therefore.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the outgoing port routes of the active/standby boards are configured and active/standby routes are configured for routers. so that the ports of the active/standby boards can protect each other. To facilitate network expansion. The next hop of the route between intermediate network to IP150 switches to CE2 from CE1 and the SGSN sends packets to the BSC only through CE2.0 & BSC6910) Local service IP addresses and peer service IP addresses are grouped in two. services are not interrupted and the switchover duration is less than 1s. The board switchover triggering mechanism is similar to that when the intermediate network is faulty. the source IP address route mapping the logical IP address is switched between the active/standby gateways. and the active/standby routes switch over. the active/standby boards of the BSC switch over. and the OSPF reconverges. − Main interface boards of the BSC are faulty: In most cases. At the same time. the BSC cannot detect board faults. With route priority configuration. Then the active/standby routes switch over. The next hop of the route between intermediate network to IP150 switches to CE2 from CE1 and the SGSN sends packets to the BSC only through CE2.0 & GBSS17. − Intermediate network is faulty. The BSC performs a BFD detection every 100 ms for three times. services are not interrupted and the switchover duration is less than 1s. Then the active/standby routes switch over. In this case. In this case. The standby route whose next hop is IP130 becomes valid and services migrated to this route. Accordingly. If BFD is deployed between interface boards and the peer routers. Analysis of the fault switchover mechanism (only on single-fault scenarios) 2015-11-13 − Connection between the BSC and CE1 is faulty: SBFD detection on the route from the BSC to IP110 of CE1 fails and the active route whose next hop is IP110 becomes invalid. Dynamic route protocols (OSPF/ISIS) need to be configured between CE1 or CE2 and intermediate bearer networks. the BSC can detect board faults and if it detects a board fault. In addition. In this case. and the route from CE2 toIP170 has higher priority than the route from CE1 to IP170. The standby route whose next hop is IP130 becomes valid and services migrated to this route. Static routes also need to be configured. IP addresses in the two groups have different priorities. the active/standby boards of the BSC switch over. the active/standby boards of the BSC switch over. In addition. In this case. Detection mechanism The active port of each board enables two BFD sessions to detect the IP addresses of the two routers. route priorities need to be configured to ensure that the route from CE1 to IP150 has higher priority than the route from CE2 to IP150. the BSC triggers a switchover of the active/standby gateways in the source IP address routing table. backup routes are configured to ensure reliability.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Configure the delay enabling BFD on CE1 and CE2 to avoid service interruption of CE1 and CE2 due to a reset upon power-off. The BSC can detect board faults and if it detects a board fault. In rare cases. At the same time. thereby implementing load-sharing. and the logical IP address is migrated to a normal board from the faulty board. data is sent to IP150 through CE1 and sent to IP170 through CE2. the BSC switches the uplink data on this NSVC to a normal NSVC (the BSC replaces only local NSVL) and informs the peer end of the NSVC fault in any of the following ways: Huawei Confidential Page 156 of 258 . which causes a service IP address of the BSC unreachable (rarely occurs): An NSVC detection takes 15s (3s x 5 = 15s) to 45s (30s + 15s = 45s) (The BSC starts NSVC detection after the Tns-test times out and the system determines that the NSVL is faulty after NS-ALIVE sends an NS-ALIVERETRIES message for five times). and the OSPF re-converges. − CE1 is faulty (suspended or powered off): SBFD detection on the route from the BSC to CE1 fails and the active route whose next hop is IP110 becomes invalid. services are not interrupted and the switchover duration is less than 1s. After the BSC detects an NS-VC fault. the BFD for OSPF detection on the intermediate network indicates that CE1 is faulty. If NSVC detection detects a board fault. the static route that bound to the SBFD on CE1 becomes invalid. b) The NS BLOCK blocks the NSVC. the assumed convergence time of the intermediate network is less than 1s. Auto Negotiation Mode. The following uses the PIU as the common name of the A interface board. inter-board load-sharing mode.0 & GBSS17.4. Output: Gb over IP bandwidth design BSC Nam e Configur ed BTS Number active subscribe rs Average traffic in BH/sub (bps) Gb IP throughp ut (Mbps) GE Link Numbe r Board Numbe r IP Segmen t Number 19. 2015-11-13 Huawei Confidential Page 157 of 258 . Boar d Type Net Mod e Por t Typ e Po rt No .3 Bandwidth Calculation Use the GSM NEP tool to calculate the bandwidth. Port Rate(M). data on the faulty path and to be sent to the BSC is sent through a normal NSVL (source NSVL in NS UNITDATA).4 IP Address Planning The BSC interface boards mainly contain the device IP address (logical IP address) and physical port IP address. That is. and Duplex Mode: must be consistent with those of the directly connected devices.4. In this scheme. 19. services over the Gb interface restore after 15 to 45s.  Net Mode: inter-board mode (inter-board active/standby mode. requesting the SGSN to replace the peer NSVL.  Port Type: port type (GE or FE port). and Abis interface board. Gb interface board. Capacity restriction after the switchover is not taken into consideration. In this case.  Flow Control: whether the flow control is enabled.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.  Max Transfer Unit. c) R-BIT in NS UNITDATA of uplink data is set to 1. Slo t No . A physical port can be configured with multiple IP addresses. or standalone mode). Configu re All Max Transf er Unit Auto Negotiati on Mode Port Rate( M) Flow Contr ol Duple x Mode Parameter description:  Board Type: board type. Output: Gb over IP networking design Subrac k No.0 & BSC6910) a) The NS STATUS informs the peer end of the local NSVL fault. on the router that connects to the BSC. The system automatically identifies the communication mode (port IP communication or device IP communication). The network address is the AND result of the peer IP address and subnet mask. For example. Therefore. On the SGSN.2 and the subnet mask is 255.168.  The planned IP addresses must facilitate follow-up maintenance. and the port address is used to forward data for the communication between the external device and the service address. the device IP addresses of the active and standby boards must be the same.  When you configure a BSC route. When the ARP detection is enabled on the standby port. The processing of the A interface is the same as the processing of the Abis interface. configure a route on the intermediate router to the device IP address of the BSC. the standby port does not require an IP address.  If one board is configured with different port IP addresses. the destination IP address is invalid. Huawei Confidential Page 158 of 258 . 2015-11-13  When you configure a BSC route.  The Gb interface supports VLAN tagging based on the next hop. and number of boards and number of FE/GE ports calculated in the bandwidth design provided by the customer. Principles of IP address planning  The service address and port address are separated on the Gb interface board of the BSC6910. In other cases.  The IP address cannot be all 0s or all 255s. Step 3 In layer-3 networking mode.255.x. Design guide: Step 1 The device IP address communication mode (recommended) or port IP address communication mode can be used. Configure and use the port IP address or device IP address. the destination IP address must be configured to the network address and cannot be in the same network segment as the port IP address of the board. configure an IP address for the standby port. configure the active port IP address. configure a route destined for the service address of the Gb interface board. The IP addresses of the active/standby ports must be in the same network segment. In addition.255.  The IP address cannot be a loopback address whose network number is 127.128. the AND result of them is 192. In active/standby configuration mode. Use device IP addresses. configure a route whose destination address is the service address of the Gb interface and the next hop is the port IP address on the Gb interface board. Add VLAN tags on the intermediate transmission devices. the gateway IP address must be in the same network segment as the port IP address of the board. The NSVL uses the service address. Step 2 Allocate port IP addresses and device IP addresses based on the available IP address resources.0 & GBSS17. the peer IP address is 192.0 (network address).x.80. the port IP addresses must be in different network segments.255.255. A network address refers to an address that is used for addressing the peer device when two devices communicate with each other.0 & BSC6910) Design principles:  The planned IP addresses must meet the expansion requirements in a certain period (determined by the customer) in future. the port IP addresses and the device IP address must be in different network segments.80. Otherwise.  In active/standby mode.x.168.  The subnet mask of the device IP address can be 255. Network address is a technical term.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.255. Gb over IP networking design.  The designed routing solution must facilitate follow-up expansion.255. Design guide: Step 1 Plan BSC routing based on the Gb interface networking design. that is. that is.0 & GBSS17. The routing information configured on the BSC includes the destination IP address.255. 19.0. Subnet Mask is the subnet mask of the network where the service address of the SGSN resides.0. Step 3 In layer-3 networking mode. Output: Gb over IP routing design NE name Boar d Type Board Numb er Po rt ID SGS N Nam e Destinati on IP Subn et Mask Next Gateway Parameter description:  2015-11-13 Destination IP Address: network IP address of the destination IP address of the peer SGSN (destination of the data from the Gb interface board of the BSC).5 Routing Planning (Gb over IP) Design principles:  The designed routing solution must facilitate follow-up maintenance.0 to 239.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. address in the range of 240. The network IP address is obtained by performing the AND operation on the device IP address (or port IP address if no device IP address is available) of the SGSN and the subnet mask.4.0 to 247.255. configure a route to the network segment of the control-plane address based on the preceding principle. if the control-plane address and service address of the SGSN are not in the same network segment.255. ----End Principles of routing planning:  On the Gb interface board. this parameter indicates the network IP address of the port IP address. subnet mask. Huawei Confidential Page 159 of 258 .255. Step 2 On the SGSN.0.255. this address must be in the same network segment as the port IP address connected to the BSC.  The IP address cannot be the reserved IP address of category E. Destination IP is the network address of the service address of the SGSN. configure a route on the intermediate router to the device IP address of the BSC.0 & BSC6910)  The IP address cannot be the multicast IP address of category D. plan a route to the service IP address of the SGSN. The gateway configuration in control-plane route configuration is the same as the gateway configuration in service-plane route configuration. On the BSC. If the peer SGSN does not have a device IP address (logical IP address).0. add a BSC route. address in the range of 224. configure a route to the SGSN. that is. and gateway address.  When the IP subnet configuration mode is dynamic configuration. Next Gateway is the IP address of the port (connected to the BSC) on the first router on the way from the BSC to the SGSN. configure a route to the device IP address of the BSC. BFD detection on the active port and physical-layer detection on the standby port. This IP address must be in the same network segment as the IP address of the outgoing port of the Gb interface board.: port number of the Abis interface board that requires the physical link detection.6 QoS Design (Gb over IP) Design principles: Port link detection  The BFD detection and ARP link detection cannot be enabled at the same time on the interface board.4. Sl ot No . the physical-layer detection is adopted by default. IP Addres s Index Peer IP Addre ss Arp Retry Attempt s Arp Timeo ut VLA N Flag VLA N ID Peer IP Address of the Standby Board Parameter description: 2015-11-13  Port No. If a port is not configured with the BFD detection or ARP link detection.  Peer IP Address: port IP address of the device that is directly connected to the physical port.  IP Address Index: IP address index.  The following detection modes are supported: BFD detection on the active port and ARP detection on the standby port (the standby port does not support BFD detection). The physical detection is supported by default and does not require configuration.0 & BSC6910)  Subnet Mask: subnet mask of the IP address of the peer SGSN.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. or physical detection) based on the capability of the interworking device. and physical-layer detection on the active and standby ports.  Gateway: port IP address of the device directly connected to the outgoing port of the Gb interface board on the BSC. ARP detection on the active port and physical-layer detection on the standby port. ARP link detection on the active and standby ports. and the default value is 1. The system supports the configuration of multiple IP addresses for a port.0 & GBSS17. The default value is 3.  Route Priority: route priority. Po rt No . Step 2 Determine the port link detection mode (BFD detection. Design guide: Step 1 Design the port QoS attribute parameters based on the capability of the interworking device. Huawei Confidential Page 160 of 258 . ARP link detection. ----End Output: Gb over IP QoS design ARP link detection Subra ck No.  Arp Retry Attempts: number of ARP detection times in a period. 19.  One port can be configured with only one detection mode. Use the default value 3. The default timeout interval is 3 seconds.7 Configuration Principles  One BSC can connect to multiple SGSNs. but all point-to-point BSSGP virtual connections (PTP BVCs) in an NSE can provide services only for one SGSN.  MinRxInterval(ms): minimum interval between the BFD control packets that the local system receives. The software has a bug.0 & BSC6910)  ARP Timeout: ARP response timeout interval (after an ARP request is sent) in the ARP detection. and the VLAN ID must be the same as the VLAN ID configured for the device port that possesses the gateway address. 19. and precautions to improve the interworking efficiency.  Peer IP Address of the Standby Board: physical IP address of the peer port directly connected to the physical port of the standby board. One SGSN can correspond to multiple NSEs in a BSC. prepare the template of interface interworking parameters.  Detect Mult: number of detection times.  NSEs belong to the same SGSN must be different. the link is considered disconnected after the detection fails for the specified number of times. parameter description. and do not change the value.  One BSC can be configured with multiple network service entities (NSEs). t No . In the negotiation. IP Addre ss Index Peer IP Addre ss MinT xInt erva l(ms ) Min RxIn terv al(m s) Dete ct Mult Peer IP Address of the Standby Board Parameter description:  Peer IP Address: peer IP address in the BFD session.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Por t No.  One cell corresponds to one PTP BVC (except for the SGSN pool scenario). that is. otherwise.  VLAN ID: VLAN ID in the ARP detection packets when VLAN Flag is set to Enable.4. networking diagram.8 Interface Interworking The Gb interface interworking needs to be negotiated with the SGSN. this parameter must be enabled.  One BSC can belong to different SGSN cells. If the VLAN function is enabled on the device port that possesses the gateway IP address of the route configured on the port.0 & GBSS17." 19. The BFD detection supports only the next hop detection. BFD detection Subrac Slo k No.4. the peer IP address in the BFD session is the port IP address of the device that is directly connected to the port. the route is unreachable. For details about the other parameters.  VLAN Flag: whether VLAN tags are added to ARP packets when the BSC implements ARP detection. Therefore.  MinTxInterval(ms): minimum interval between the BFD control packets that the local system sends. 2015-11-13 Huawei Confidential Page 161 of 258 . see the parameter description in "ARP link detection. an IP NSVC is uniquely identified a quadruple of the local IP address. The number of NSVLs must be equal to or larger than the number of physical transmission links. the NSE functions as a BVC collection. The NSVL is used in Gb over IP mode. and it is equivalent to the NSVC in Gb over FR mode. Table 1. local port number. SGSN pool networking: The number of NSEs is equal to the number of SGSNs in the SGSN pool to which the BSC belongs. the NSE functions as an IP NSVC collection. Use logical IP addresses (device IP addresses) as the IP addresses of NSVL. Each NSE must be configured with at least two NSVLs. local NSVL. and PTP BVC objects. remote NSVL. that is.0 & BSC6910) If the Gb interface adopts the IP protocol. Local and remote NSVLs The local NSVL determines the location information about the Gb interface board. Each cell corresponds to one PTP BVC. Non-SGSN pool networking: Configure each BSC with an NSE (or multiple NSEs). SGSN pool networking: A PTP BVC must be configured between each cell and each SGSN in the Pool. 2015-11-13 Huawei Confidential Page 162 of 258 . Select the IP protocol for the NSE. The remote NSVL establishes mappings between NSEs and device IP addresses/port numbers on the SGSN side and determines the ports through which the NSE cell data is transmitted. On the IP network. Configure the local and remote NSVL objects. The NSEIs configured on the BSC are the same as the NSEIs configured on the SGSN. the NSEs at the two ends must be consistent. peer IP address. Non-SGSN pool networking: One cell corresponds to one PTP BVC.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. establishes mappings between NSEs and device IP addresses/port numbers. and peer port number. the Gb interface link needs to be configured with the NSE.1 Parameters of Gb interface link configuration Object Description Recommended Configuration NSE On the BSSGP layer. on the NS layer.0 & GBSS17. The NSEs on the BSC map the NSEs on the SGSN based on the one-to-one relationship. PTP BVC The PTP BVC establishes the point-to-point virtual connection on the BSSGP layer. An NSEI uniquely identifies an NSE. and determines the ports through which the NSE cell data is transmitted. The NS layer provides data transmission channels for the BSSGP layer.0 & BSC6910) Figure 1.0 & GBSS17. IP address on the server (control plane) and UDP port number on the server This parameter needs to be negotiated when Huawei Confidential Page 163 of 258 . It is the same as the NSEI on the SGSN. The channel selection principle is that the traffic between IP NSVCs is balanced. on the NS layer. Service address of the BSC (device IP address) It indicates the IP address and subnet mask of the local NSVL. In Gb over IP mode.2.1 Gb over IP interworking parameters 2015-11-13 Parameter Description NSEI Value range: 0 to 65534. The channel used to transmit the data of the cells in the same NSE must be an IP NSVC in the IP NSVC collection of the NSE. Figure 1.2 Logical connection between the NS layer and the SSGP layer As shown in Figure 1. The device must inform the SGSN of this parameter. Service address of the SGSN It indicates the IP address and subnet mask of the remote NSVL. the NSE functions as an IP NSVC group (IP NSVC collection).CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the user needs to configure IP NSVCs by using the local NSVL and remote NSVL objects Key interworking parameters in IP networking mode: Table 2. on the BSSGP layer. the NSE functions as a BVC collection (equivalent to a cell collection).2 shows the logical connection at the NS layer and BSSGP layer between the BSC and the SGSN. Subnet configuration mode Static or Dynamic.  IP: indicates the IP address. The routing gateway IP address on the SGSN side is the port IP address of the BSC when the networking mode is direct connection. the remote NSVL is not required. set Subnet configure mode to Dynamic and configure Server IP and Server UDP Port. Port IP address IP address of the port on the board.  NSEI: indicates the NSE ID. Address and UDP port number of the remote NSVL This parameter needs to be negotiated when the subnet configuration mode is Static. The value range is 0 to 65534. The value range is 0 to 65534. It needs to be negotiated with the SGSN. configure the remote NSVL. IP address and UDP port number of the local NSVL The device needs to inform the SGSN of this parameter when the subnet configuration mode is Static.  NSEI: indicates the NSE ID. The value range is 0 to 65534. The value range is 0 to 65534. The value range is 0 to 65534.  UDPPN: indicates the UDP port number. This parameter needs to be negotiated with the SGSN. The main differences between the dynamic configuration process and the static configuration process are as follows: When you configure the NSE in dynamic configuration mode.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. This parameter needs to be negotiated with the SGSN. The NSEs of the same SGSN are numbered in a unified manner. In Gb over IP mode. the remote NSVL is configured by using the local maintenance terminal (LMT) or man-machine language (MML) commands. In static configuration mode. It needs to be negotiated with the SGSN. It needs to be negotiated with the SGSN.  IP: indicates the IP address. The value must comply with IPv4.0 & BSC6910) (control plane) of the SGSN the subnet configuration mode is Dynamic. set Subnet configure mode to Static. Remote NSVL: 2015-11-13  NSVLI: indicates the local NSVL ID. In dynamic configuration mode. It needs to be negotiated with the SGSN. In static configuration mode. Huawei Confidential Page 164 of 258 . In static configuration mode. The value must comply with IPv4. Local NSVL:  NSVLI: indicates the local NSVL ID. It needs to be negotiated with the SGSN. the NSVL configuration modes are static configuration and dynamic configuration. The NSEs of the same SGSN are numbered in a unified manner. Server IP and Server UDP Port specify the interface corresponding to the remote NSVL (used to communicate with the BSC) on the SGSN. the remote NSVL is obtained from the SGSN by using the subnet service process (SNS process) in the 48018 protocol.  UDPPN: indicates the UDP port number. whereas in dynamic configuration mode. The value range is 0 to 65534.0 & GBSS17. It needs to be negotiated with the SGSN. the subscriber data and signaling data of the Gb interface are transmitted in UDP packets. Determine a protocol type Gb over IP for an NSE. Subnet protocol type In Gb over IP mode. the SGSN cannot provide access for new users. causing some SGSNs overloaded. The three SGSN management states are uninstalled.1 SGSN node parameters SGSN Node Parameter Description SGSN Node ID It indicates the SGSN number. in the prohibited state. Subrack Number It indicates the number of the subrack where the end-to-end communication NSE is located. the remote NSVL can be configured on the LMT. Table 1.4. In IP mode. it is a collection of the BVC and the IP NSVC.9 Interworking Instances Gb over IP instances Design the basic Gb over IP parameters that need to be negotiated with the SGSN based on the Gb over IP networking design and IP address planning. Configure Capacity It indicates the number of subscribers that can access the NSE. in the normal state. Subnetwork Configure Mode It indicates the IP subnet configuration mode. The IP network in Gb over IP mode takes the place of the FR connections in Gb over FR mode. An NSE manages a group of NSVCs. the remote NSVL can be obtained from the SGSN by Huawei Confidential Page 165 of 258 . the functions of the protocol stacks of the NS and upper layers are completely the same as the functions in Gb over FR mode.0 & BSC6910) An NSE specifies a network service entity. a subscriber determines the SGSN to access based on the NSE capacity. In the uninstalled state. SGSN Management Status It indicates that when an MS accesses the network initially. The basic negotiation parameters are as follows: Table 1. the Gb interface is connected to the IP network. In Gb over IP mode. the SGSN can be used normally. In static configuration mode. normal. In dynamic configuration mode. the SGSN cannot be used.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.2 NSE attribute parameters 2015-11-13 NSE Attribute Parameter Description NSE Identifier It indicates the NSE ID. 19. The two optional modes are static configuration and dynamic configuration. the MS selects the SGSN randomly. In Gb over IP mode. In the case that one BSC can connect to multiple SGSNs. configure the local and remote NSVL objects. and prohibited.0 & GBSS17. the uplink signaling message load sharing involves the selection of the local IP endpoint and the remote IP endpoint. User Data load weight The service data load sharing involves the selection of the local IP endpoint and the remote IP endpoint. An NSVL ID uniquely identifies an NSVL. Huawei Confidential Page 166 of 258 . the server UDP port number is not required.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. UDP Port It indicates the UDP port number. Table 1. If the IP subnet configuration mode is static configuration. NSE Index It indicates the NSE index. Server UPD Port It indicates the UDP port number of the SGSN. the SIGBVC needs to be reset. configure the server UDP port number. If the RIM function is enabled. The PFC function can be implemented only if the SGSN also supports the PFC function. All local IP endpoints are polled to select a local IP endpoint. The RIM function can be implemented only if the SGSN also supports the RIM function. If the IP subnet configuration mode is dynamic configuration. IP Address It indicates the IP address in the dotted decimal format of the Gb interface board. Server IP It indicates the IP address of the SGSN.3 Local NSVL parameters (configured on the Gb interface board) 2015-11-13 Local NSVL Parameter Description Local NSVL ID It indicates the NSVL ID on the BSC side. the server IP address is not required. The protocol does not describe the selection of the local IP endpoint in detail. Signaling load weight It indicates the signaling data load sharing. An NSVL is a network service virtual link.0 & BSC6910) NSE Attribute Parameter Description using the protocol process. If the IP subnet configuration mode is dynamic configuration. PFC Support It indicates whether the NSE supports the PFC function. If the PFC function is enabled. In Gb over IP mode. RIM Support It indicates whether the NSE supports the RIM function.0 & GBSS17. and this process is simplified. Default value: NO. configure the server IP address. Default value: NO. The value range is 0 to 255. the SIGBVC needs to be reset. If the IP subnet configuration mode is static configuration. It must be consistent with the UDP port number configured on the SGSN. All the available local signaling endpoints are evenly polled to select a local signaling endpoint. All the available local signaling endpoints are evenly polled to select a local signaling endpoint. PTP BVC Identifier It identifies a unique PTP BVC with NSE. Huawei Confidential Page 167 of 258 .6 SGSN attribute parameters: 2015-11-13 SGSN Attribute Parameter Description SGSN Name It indicates the SGSN name. and this process is simplified. if it is set to Dynamic. All local IP endpoints are polled to select a local IP endpoint. Table 1.0 & BSC6910) Table 1. You need to specify the peer IP address only when configuring the remote NSVL. The service data load sharing involves the selection of the local IP endpoint and the remote IP endpoint. The protocol does not describe the selection of the local IP endpoint in detail. IP Address It indicates the IP address of the remote NSVL. Cell Name It indicates the BSC cell name. configure the remote NSVL.5 PTP BVC attribute parameters PTP BVC Attribute Parameter Description NSE Index It indicates the NSE ID. NSE Index It indicates the NSE index.0 & GBSS17.4 Remote NSVL parameters Remote NSVL parameter Description Remote NSVL ID It indicates the NSVL ID on the SGSN side. User Data load weight It indicates the service data load sharing. In Gb over IP mode. Table 1. It must be consistent with the UDP port number configured on the SGSN. Signaling load weight It indicates the signaling data load sharing. The value range is 0 to 255. the uplink signaling message load sharing involves the selection of the local IP endpoint and the remote IP endpoint. If the NSE attribute Subnet configure mode is set to Static. UDP Port It indicates the UDP port number. do not configure the remote NSVL. An NSVL ID uniquely identifies an NSVL.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Each CS service channel. Therefore. the PS and service service/signaling messages are transmitted in IP over FE/GE mode. the IP address of the standby board must be in the same network segment as the IP address of the active board. The BSC6910 supports only BTS3012 and BTS3900. a fixed UDP port number is used. The interface bandwidth and networking mode are closely related to the interface type. each TRX is allocated with a UDP port number.054  Data link layer: 3GPP 48.0 & GBSS17. On the BSC side. the BSC6910 can interwork only with Huawei's BTS. and the UDP port number on the BTS side is used to distinguish CS and PS signaling/O&M messages. and TDM over STM1. or the BTSs of BTS3X serials.052  Physical layer: 3GPP 48.5 Abis Interface Design 19. RSL. and O&M messages.021  BSC code converter/rate adaptation in-band control protocol: 3GPP 48.5.060 The Abis interface of the GBSS15. IP transmission mode Basic principle: UDP/IP bears the CS and PS service. 19. The protocols and standards that the Abis interface complies with are as follows:  Basic principles of the Abis interface: 3GPP 48. signaling. 2015-11-13 Huawei Confidential Page 168 of 258 . In active/standby mode. Implementation method: Packet interfaces boards are added to the BTS and the BSC.0 BSC6910 supports IP over FE/GE.0 & BSC6910) IP Address It indicates the IP address of the SGSN.058  O&M message transfer mechanism: 3GPP 52. For the PS service. in terms of Abis interface interworking. Each BTS is configured with an independent logical IP address.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. and ESL is allocated with a UDP port number. The BTS that are provided by different manufacturers cannot interwork through the Abis interface. On the Abis interface. but does not support the co-locate deployment of BTS3012 and BTS3900. OML.056  Layer 3 signaling procedure: 3GPP 48.1 Interface Description The Abis interface in an internal interface.  For some VIP BTSs where transmission resources are sufficient and the security requirements are high. 19.5.0 & BSC6910) Figure 1.2 Transmission Mode The Abis interface supports two transmission modes: Abis over TDM and Abis over IP.5. Networking design Design the networking based on the site configuration.1 Abis over HDLC interface protocol 19. use the ring networking.2.2.  For the operator who purchases the BTS local exchange and Flex Abis functions and adopts TDM transmission.5. Transmission mode selection Abis over TDM Abis over IP 2.  For the operator who provides sufficient TDM transmission resources. number of transmission resources of the operator. use the simple star networking.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. 2015-11-13 Huawei Confidential Page 169 of 258 .0 & GBSS17. use the star or chain (determined by the technical personnel based on the onsite conditions) networking. Transmission type selection STM-1 IP or FE 3. and distribution of the transmission backbone network.1 Basic Procedure 1.2 Networking Design 19. The operator can fully use the existing PDH/SDH transmission resources. Disadvantage: The cost of this solution is higher than the cost of the IP transmission solution. and XDSL transmission. Step 2 If the layer-2/layer-3 networking mode is used. Do not use the layer-2 or direct connection mode. Step 3 Design the networking reliability of the interface board based on the capability of the interworking device and the customer requirements.1. 2015-11-13 Huawei Confidential Page 170 of 258 .0 & GBSS17.  Abis over IP In Abis over IP mode. and Figure 1. layer 2 of the protocol stack of the Abis interface complies with the IP protocol. Advantages: The bandwidth is sufficient. Disadvantage: The QoS is difficult to guarantee. In this mode. Figure 1. layer-2/layer-3 data network transmission. The Abis interface board of the BSC6910 is the FG2c/GOUc/EXOUa/FG2d/GOUd. the cost is low.3 show the typical networking diagrams. Figure 1.2.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The optional transmission modes are MSTP transmission. and do not use the load sharing+router VRRP mode. ----End The Abis over IP mode supports two application scenarios: direct connection and switch/router networking. and the IP network is deployed between the BSC and the BTS to provide the transmission service. The following is the design guide to the Abis over IP mode: Design guide: Step 1 Determine the networking mode (direction connection networking or layer-2/layer-3 networking) based on the requirements of the customer for the Abis interface networking and the adopted transmission backbone network (MSTP and MPLS/IP).0 & BSC6910)  Abis over TDM In Abis over TDM mode. and the SDH/PDH network is deployed between the BSC and the BTS to provide the transmission service. Advantages: The networking solution is proven with the perfect QoS guarantee mechanism. Use the mode of active/standby boards+manual active/standby LAGs (Pool of single IP address) for the Abis interface networking. the evolution capability is high. the Abis interface adopts the traditional TDM mode for transmission. Use the active/standby boards+manual active/standby LAGs (Pool of single IP address)+layer-3 router networking mode. the Abis interface board of the BSC6910 is the POUc. determine the transmission mode. determine whether to enable the router to adopt VRRP+VLANIF to improve the reliability in the mode of active/standby boards. This mode is secure and reliable. Step 4 If the layer-3 data transmission networking mode is used. satellite link transmission. 2.5.0 & BSC6910) Figure 1.1 TDM networking when the Abis interface adopts STM-1 transmission Figure 1. 2015-11-13 Huawei Confidential Page 171 of 258 .3 IP networking when the Abis adopts data network transmission 19.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. star.2 IP networking when the Abis adopts MSTP transmission Figure 1.0 & GBSS17. ring. and tree.3 Networking Design (TDM) The main BTS networking types are chain. 1 BTS networking diagram Each networking type has its own advantages and disadvantages. If a transmission fault occurs on a BTS in the chain. Disadvantage: Expansion is inconvenient.0 & BSC6910) Figure 1. and the reliability is low. and the last BTS is connected back to the BSC.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the services of the downstream BTSs are affected. the highway). Therefore. the BTS that is directly connected to the BSC is the parent BTS. expansion is convenient. Chain networking If the coverage area is in the form of a band (for example. Therefore. and the traffic in the coverage area is light. and the Huawei Confidential Page 172 of 258 . for small-scale BTSs. the BTSs form an ordinary chain. Timeslot interchange can be controlled by using the LMT. The tree networking combines the characteristics of the star networking and chain networking. the chain networking can be used because if the star networking is used in such a coverage area. the BTSs are cascaded. the star networking is widely used. the number of cascading levels cannot be too large.0 & GBSS17. Ring networking 2015-11-13 The ring networking is a special chain networking. The parent BTS completes timeslot interchange of the children BTSs. the networking mode of the upstream BTSs before the faulty BTS does not change. If a transmission fault occurs on a BTS on the ring. and the BTSs subordinated to the parent BTS are children BTSs. and this may degrade the BTS performance. which causes inconvenience for expansion and maintenance. the other BTSs are not affected. the reliability is high. The clock preciseness decreases with the number of cascading levels. and the reliability of the tree networking is between these two networking modes. transmission resources are wasted. a ring is formed. Tree networking In tree networking mode. The timeslot consolidation device can be used to address this issue. The disadvantage is that the structure is complicated. In normal cases. the transmission usage of the star networking is low. If one BTS is faulty. However. Configure the networking based on the requirements of the operator based on the following principles: Star networking Advantages: The network structure is simple. In this way. A BTS on a cascading link processes only its own timeslots and transparently transmits the timeslots of downstream BTSs. In chain networking. the multi-chain cascading mode can be used.   Star networking and configuration principles − In star networking mode. this root can connect to a maximum of 15 TRXs. each root can possess a maximum of seven branches (in the case that two TMUs that work in active/standby mode are configured for the root BTS). A BTS supports a maximum of eight E1 ports. therefore. each root can possess a maximum of six branches (in the case that two TMUs that work in active/standby mode are configured for the root BTS). the networking mode of the upstream BTSs before the faulty BTS does not change. the number of TRXs that can connect to this root is determined by the number of E1 timeslots. each BTS receives information from the upper-level BTS and transmits the information to the lower-level BTS in cascading mode. If a BTS is faulty. − A transmission-optimized BTS is directly connected to the Abis interface board on the BSC through fiber and does not need another BTS for transfer. It is recommended for some VIP sites.1. − If the number of TRXs of each BTS is great (greater than six). The tree networking mode combines the characteristics of the star and chain networking modes. Ring networking and configuration principles In ring networking mode. Due to the E1 port restriction (each TMU provide only eight E1 ports) of the TMU on the BTS. − If a BTS adopts the single-chain mode to connect to the Abis interface board directly. the BTSs form a ring network.0 & GBSS17. the networking mode is the tree networking mode. Chain networking and configuration principles In chain networking mode.0 & BSC6910) downstream BTSs after the faulty BTS form a new chain in a reverse manner.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. as shown in Figure 1. − TDM BTSs are directly connected to the Abis interface board on the BSC through fiber. − An IP BTS is connected to the router or switch through one or two FE ports and does not need another BTS for forwarding. Due to the E1 port restriction (each TMU provide only eight E1 ports) of the TMU on the BTS. − TDM BTSs are directly connected to the Abis interface board on the BSC through E1 links. − Multi-chain cascading: If the total number of cascading BTSs is less than 5 and the total number of TRXs is greater than 15. and the 2015-11-13 Huawei Confidential Page 173 of 258 . Tree networking and configuration principles − If two BTSs are subordinated to another BTS. the single-chain cascading mode can be used. but the transmission resource cost is high. In normal cases. The number of TRXs allowed in multi-chain cascading mode is greater than that in single-chain cascading mode. − If a BTS adopts the multi-chain mode to connect to the Abis interface board directly. the Abis interface board and the BTSs form a ring. The chain networking mode can be single-chain cascading or multi-chain cascading:   − Single-chain cascading: If the total number of cascading BTSs is less than 5 and the total number of TRXs is less than 15. any TDM BTS is directly connected to the Abis TDM interface board (POUc) on the BSC through fiber and does not need another BTS for transfer. the multi-chain cascading mode supports a maximum of eight active/standby links. the chain networking mode can be used. The reliability is high. However. In the OML backup function. all the carriers. this OML link is always used unless the BTS is reset or the OML link is disconnected. − The OML backup function is mutually exclusive with the ring network and Abis bypass functions. channels. Each BTS on the ring can support tributary BTSs. the interface boards are counted in single-board mode instead of active/standby mode. Then. Restrictions: 2015-11-13 − The new BTS types (such as the 3900 series) later than the BTS3012 series of double-density BTSs support this function. the ports of the Abis interface may be insufficient. in the V900R011 version. − One ring supports the BTS cascading of a maximum of five levels. the OML link can be configured only on the timeslot of port 0. If the ring is disconnected at a point. the BTS automatically switches to the other port and attempts to establish a link on that port. switchovers are not performed. This networking mode is the same as the tree networking mode. In this case. Compared with the chain networking mode. configure the Abis interface boards of the BSC6910 to work in non-active/standby mode. that is. link switchovers can be performed. the BSC triggers an OML link switchover and switches the related ESL/EML links to the port where the currently available OML link is located. the services of the entire site are interrupted. the ring networking mode is more robust. if the BSC6910 is connected to BTSs through active/standby Abis interface boards. If the link is established successfully. if the port where the currently available OML link is established is faulty. the OML backup function is planned. each interface board is counted (not recommended). Therefore. the BTS attempts to establish a link on the two ports one by one. service channels. The IP networking mode does not support this function.0 & BSC6910) downstream BTSs after the faulty BTS form a new chain in a reverse manner. If the user uses the OML backup function when configuring the BTS. − The two mutually backup OML links (including EML/ESL) between the BSC and the BTS cannot be located on the same E1/T1 (or on the same E1/T1 on the upper-level Huawei Confidential Page 174 of 258 . the processing of OML/EML/ESL links is similar to the processing on the ring network.0 & GBSS17. OML backup networking Principles: On Huawei's 2G site. After the BTS is reset.  − In ring networking mode. it is automatically split into two chains. that is. and monitoring timeslots is different from the processing on the ring network. the BSC configures an OML link on timeslot 31 of port 0 and port 1. idle timeslots. The BTSs on the ring and their tributary BTSs form a tree network. and the BTSs before and after the faulty point can work properly. for port 0 and 1 of the BTS. that is. If the OML link fails. idle timeslots. the processing of carrier RSLs. The number of BTS cascading levels between a tributary BTS and the BSC cannot exceed five. Once the OML link is established on either port. In other words. − OML backup can be implemented only between port 0 and port 1 in the primary cabinet group and cannot be implemented between other ports or between the primary cabinet group and the secondary cabinet group. whereas the OML/ESL/EML links can be switched over to the other port to ensure that the BTS is not out-of-service and that the normal port can provide services. If the established OML link is disconnected.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. and monitoring timeslots configured on this port become invalid. − Only the TDM (including the 16 kbit/s and Flex Abis scenarios) supports this function. Therefore.3 show the typical networking diagrams. which function as the next 2015-11-13 Huawei Confidential Page 175 of 258 . the OML backup function can be used only if either of the following conditions is met: − A secondary link to the upper-level BTS is added. do not connect the E1s of the BTS to the interface boards in different subracks.2. if the upper-level BTS has only one E1/T1 connected to the BSC.5.0 & BSC6910) BTS).3 Two E1s connected to different ports on the same interface board The reliability of the networking mode where the E1s of a BTS are connected to two pairs of interface boards is high. − A secondary link (directly connected to the BSC) to the lower-level BTS is added. use this mode.2 and Figure 1. Figure 1. That is.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. 19. All data is sent and received through the active port.0:  Promoted scheme Networking: Pool of active/standby boards+manual active/standby LAGs+single IP address The BSC is directly connected to the dual routers through the active/standby ports on the active/standby interface boards. VRRP IP addresses are configured between the dual routers.0 & GBSS17.4 Networking Design (IP) Interface networking schemes for GBSS15.2 Two E1s connected to different interface boards Figure 1. Figure 1. However. The BSC 2015-11-13 Huawei Confidential Page 176 of 258 . new IP addresses must be added. The active ports of the active/standby interface boards on the BSC enable two BFD sessions to detect the physical IP addresses of the two routers. Figure 1. Heartbeat messages are transmitted over the trunk between CE1 and CE2.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The BSC uses layer-3 networking. The BTS is connected to the Ethernet network through a single Ethernet port. and the BSC does not require VLAN tags.1 Typical A over IP networking mode (pool of active/standby boards+manual active/standby LAGs+single IP address) Layer-2 ports connecting CE1 and the BSC and connecting CE2 and the BSC are configured to the Access mode. Logical IP addresses of each pair of active/standby interface boards of the BSC form an IP pool.0 & GBSS17. New IP addresses and VRRPs must be also configured on peer devices. The standby ports of active/standby interface boards on the BSC enable an ARP detection session.0 & BSC6910) hops of the BSC. O&M data and service data is separated on the interface and a logical IP address must be configured for O&M data. Route configuration examples Devic Destination Next e IP Hop Priorit y BSC IP151 IP19 Default BTS IP200 IP119 Default CE1 IP200 IP11 Default CE2 IP200 IP11 Default Transmission fault detection scheme IP pool fault detection and switchover triggering mechanism: The IP pool on the BSC side starts the UDP ping detection. Non-standalone NEs do not have this requirement. When ports are added to the internal interface boards of the BSC in this networking mode. For standalone NEs. the BSC sends free ARP to update the ARP entries on CE1 and CE2. Besides. − Manual switchover of ports on the BSC: VRRP routes and intermediate network routes are not affected. the two BFD detections detect faults. The BTS sends packets to the BSC through CE2. In this case. Optional scheme Networking: Pool of active/standby boards+dual-active ports+single IP address Logical IP addresses of each pair of active/standby interface boards of the BSC form an IP pool. When the active/standby ports switch over. If the BSC sends packets to the BTS through CE1. the BSC and the BTS exchange messages through CE2. then the active/standby ports are not switched over. In this case. then the BTS sends packets to the BSC through CE2 and CE3: BSC <=> CE2 <=> CE3 <=> BTS. then VRRP1 has two active ports. the original path remains unchanged. After CE1 is faulty. services are not interrupted.0 & BSC6910) performs a BFD detection every 100 ms for three times and performs an ARP detection every 10s for three times. packet sending from the BTS to the BSC is not interrupted. With the active/standby MGW features of the source IP enabled. If the BSC sends packets to the BTS through CE2. and services are not interrupted. If the BTS sends packets to the BSC through CE2. That is. the OSPF re-converges. In this case. and the active/standby ports switch over. − Connection between the BSC and CE1 is faulty: Heartbeat communication on the VRRP ports is correct and the VRRP ports are not switched over. the active/standby ports switch over. the outgoing port routes of the active/standby boards are 2015-11-13 Huawei Confidential Page 177 of 258 . packet sending is interrupted. the active/standby ports are not switched over. only one BFD session on the BSC fails and the active/standby ports are not switched over. When the active/standby ports switch over.0 & GBSS17. and the path of uplink packets of the BSC is BSC => CE2 => CE1 => BTS. there is 50% probability that packet sending from the BTS to the BSC may be interrupted (see the following Note). packets are sent to the BSC through CE1 and CE2. Analysis of the fault switchover mechanism (only on single-fault scenarios)  − CE1 is faulty (suspended or powered off): Heartbeat detection on the VRRP port of CE2 fails and the standby VRRP port of CE2 becomes active. Regardless of whether the BSC sends packets to the BTS through CE1 or CE2. If the BTS sends packets to the BSC through CE1. the active/standby paths are bound to the outgoing ports of the active/standby boards to achieve active/standby routes of the active/standby boards. If the BSC sends packets to the BTS through CE1. and the original path remains unchanged. If the BTS sends packets to the BSC through CE1. If the BSC sends packets to the BTS through CE2. In this case. packet sending is not interrupted. One BFD detection on the active port of the BSC succeeds and the other BFD detection fails. and the BTS sends packets to the BSC through CE2. In this case. manual active/standby LAGs switch over. Configure the delay enabling BFD on CE1 and CE2 to avoid service interruption of CE1 and CE2 due to a reset upon power-off. − Interface boards of the BSC are faulty: The active/standby boards switch over. the BSC sends free ARP to update the ARP entries on CE1 and CE2. − Connection between two routers is faulty: BFD detection of heartbeat messages on VRRP1 fails and the standby port on CE2 becomes active. The BTS sends packets to the BSC through CE2. and services are not interrupted. only the standby port is faulty. − Connection between CE1 and the intermediate network is faulty: The OSPF reconverges.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. it then sends packets through CE2: The two BFD sessions on the active port of the BSC fail. and the BSC sends packets to the BTS through CE2. services are not interrupted. Device IP addresses are configured on the logical active board. If the BTS sends packets to the BSC through CE2. The BSC is directly connected to the dual routers through two independent ports on the active/standby interface boards. services are not interrupted. new IP addresses must be added. so that the ports of the active/standby boards can protect each other. thereby 2015-11-13 Huawei Confidential Page 178 of 258 . New IP addresses and VRRPs must be also configured on peer devices. When ports are added to the internal interface boards of the BSC in this networking mode. service IP addresses of the BSC use logical IP addresses (device IP addresses). which facilitates route combination and simplifies intermediate network route. Route configuration examples Devic Destination IP e Next Hop Priority BSC IP151 IP10 High IP151 IP20 Low IP161 IP20 High IP161 IP10 Low BTS1 IP210 IP119 Default BTS6 IP220 IP129 Default CE1 IP210 IP11 High IP220 IP11 Low IP210 IP21 Low IP220 IP21 High CE2 Local service IP addresses and peer service IP addresses are grouped in two. Figure 1.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.2 Typical A over IP networking mode (pool of active/standby boards+dual-active ports+single IP address) Configure IP addresses in the same network segment for each sub-interface.0 & GBSS17. To facilitate network expansion. With route priority configuration.0 & BSC6910) configured and active/standby routes are configured for routers. IP addresses in the two groups have different priorities. The standby route whose next hop is IP20 becomes valid and the BTS sends packets to the BSC through CE2. the BSC sends packets to the BTS through this path: BSC -> CE1 -> CE2 -> CE3 -> BTS1. services are not interrupted. − CE1 is faulty (suspended or powered off): SBFD detection on the route from the BSC to CE1 fails and the active route whose next hop is IP10 becomes invalid. The next hop of the route between CE3 and IP210 switches to CE2 from CE1 and the BTS sends packets to the BSC only through CE2. The IP PM function can be used correctly. In this case. backup routes are configured to ensure reliability. Accordingly. route priorities need to be configured to ensure that the route between CE1 and IP150 has higher priority than the route between CE2 and IP150. services are not interrupted. Configure the delay enabling BFD on CE1 and CE2 to avoid service interruption of CE1 and CE2 due to a reset upon power-off. − Connection between two routers is faulty: Services are not affected because no data is transmitted between CE1 and CE2 in normal cases. the source IP address route mapping the logical IP address is switched between the active/standby gateways. and the logical IP address is migrated to a normal board from the faulty board. the static route that bound to the SBFD on CE1 becomes invalid. Data transmission path in normal cases for BTS6: BSC -> CE2 -> CE4 -> BTS6. the assumed convergence time of the intermediate network is less than 1s. In this case. Then the active/standby routes switch over. 2015-11-13 Huawei Confidential Page 179 of 258 . At the same time. data is sent to CE1 through IP150 and sent to CE2 through IP170. In this case. In addition.0 & GBSS17. Analysis of the fault switchover mechanism (only on single-fault scenarios) Data transmission path in normal cases for BTS1: BSC -> CE1 -> CE3 -> BTS1. If BFD is deployed between interface boards and the peer routers. In this scheme. In addition. That is. data sent to and received by one BTS is always through a certain port.0 & BSC6910) implementing load-sharing. The next hop of the route between CE3 and IP210 switches to CE2 and the next hop of the route between CE1 and IP111 switches to CE3 from CE2. Dynamic route protocols (OSPF/ISIS) need to be configured between CE1 or CE2 and intermediate bearer networks.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. and the OSPF reconverges. At the same time. In this case. Therefore. The BSC performs a BFD detection every 100 ms for three times. and the route between CE2 and IP170 has higher priority than the route between CE1 and IP170. − Connection between the BSC and CE1 is faulty: SBFD detection on the route from the BSC to IP10 of CE1 fails and the active route whose next hop is IP10 becomes invalid. Then the active/standby routes switch over. Static routes also need to be configured. and the OSPF re-converges. Capacity restriction after the switchover is not taken into consideration. the BFD for OSPF detection on CE3 indicates that CE1 is faulty. The standby route whose next hop is IP20 becomes valid and services migrated to this route. services are not interrupted. the active/standby boards of the BSC switch over. the BSC triggers a switchover of the active/standby gateways in the source IP address routing table. The BSC can detect board faults and if it detects a board fault. The next hop of the route to IP210 switch to CE2 from CE1 and the BTS sends packets to the BSC through CE2. Detection mechanism IP pool fault detection and switchover triggering mechanism: The IP pool on the BSC side starts the UDP ping detection. − Connection between CE1 and CE3 is faulty: The OSPF re-converges. The active port of each board enables two BFD sessions to detect the IP addresses of the two routers.  Each idle timeslot is 16 kbit/s.0 & GBSS17.  Configure the ARP sessions for the two next hops of the BTS.0 & BSC6910) Active/standby scheme on the BTS side (do not use this scheme unless it is approved by the R&D department): Basic principle:  In IP transmission mode. and configure active and standby routes for the uplink outgoing interface of the BTS.1 Abis over TDM For the detailed bandwidth calculation formula.  A PDCH occupies a 16 kbit/s timeslot.3 Bandwidth Calculation When designing Abis interface bandwidth. use the logical IP address for BTS communication. Multiple links share the 64 kbit/s bandwidth. configure two FE/GE ports on the TMU of the BTS to work in active/standby mode. The following description will help you understand timeslot allocation principles for the Abis interface. and set the session type to reliable session (enabling and disabling the related route based on the ARP session).5.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Use a redundancy capacity of about 20%. Huawei Confidential Page 180 of 258 .5. see section Error: Reference source not found.  Signaling timeslots and service timeslots (TCH timeslot. Determine the redundancy with the operator. 19. and idle timeslot) are multiplexed on a 64 kbit/s timeslot. This scheme is specific to the customer who has high reliability requirements.  In the active/standby port mode.3. 19. take certain redundancy into consideration for subsequent expansion. PDCH timeslot. Basic principles are as follows: 2015-11-13  A TCH occupies a 16 kbit/s timeslot. The formula for calculating interface bandwidth is as follows: Total BTS bandwidth = OML bandwidth + RSL bandwidth + TCH bandwidth + PDCH bandwidth + idle timeslot bandwidth Timeslot multiplexing of the Abis interface belongs to statistical multiplexing. Configure two IP addresses for the Ethernet ports. Design of the Multiplex Ratio of Abis Signaling Links (TDM) Aiming to improve the utilization rate of transmission resources over the Abis interface.3. 19. For example.2 Abis over IP For the detailed bandwidth calculation formula.)  16 kbit/s mode: OML = 16 kbit/s RSL = 16 kbit/s For the detailed timeslot distribution. The ratio of the number of multiplexed RSLs to the number of actually occupied LAPD links is called the multiplex ratio. the bandwidth calculation formulas are as follows:  1:1 OML = 64 kbit/s RSL = 64 kbit/s  2:1 OML + RSL = 64 kbit/s 2 x RSL = 64 kbit/s Remaining RSL = 64 kbit/  3:1 OML + 2 x RSL = 64 kbit/s 3 x RSL = 64 kbit/s Remaining RSLs (less than 3) = 64 kbit/s  4:1 OML + 3 x RSL = 64 kbit/s 4 x RSL = 64 kbit/s Remaining RSLs (less than 4) = 64 kbit/s  5:1 OML + 2 x RSL + ESL = 64 kbit/s 5 x RSL = 64 kbit/s Remaining RSLs (less than 5) = 64 kbit/s (the Flex Abis function must be enabled. The multiplex ratio is configured as a parameter for the BTS. see the BTS timeslot distribution on the LMT.5. The ratio of the multiplex ratio to the multiplex ratio related to the BTS is called the BTS multiplex ratio. the multiplex ratio is N:1. use the GSM ENP to calculate Abis transmission timeslots.0 & BSC6910) Based on different multiplex ratios of the Abis interface. 2015-11-13 Huawei Confidential Page 181 of 258 . see section Error: Reference source not found.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. For a single site.0 & GBSS17. This technology allows signals over multiple RSLs to be multiplexed into one LAPD link for transmission. if signals over N RSLs are transmitted over one LAPD link.)  6:1 OML + 2 x RSL + ESL = 64 kbit/s 6 x RSL = 64 kbit/s Remaining RSLs (less than 6) = 64 kbit/s (the Flex Abis function must be enabled. statistical multiplexing is introduced to Abis RSLs. 0 & GBSS17. − Average number of peak-hour messages for a TRX = [a x (Number of bytes in peakhour call-related messages + Number of bytes in handover-related messages + Number of peak-hour messages for call measurement reports) + b x Number of bytes in peak-hour messages for location updates + c x Number of bytes in received and sent peak-hour messages + d x Average number of bytes in peak-hour pagings] x Number of subscribers supported by each TRX − Number of bytes in peak-hour call-related messages = Number of originating peakhour calls x Average number of bytes in messages for an originating call + Number of received peak-hour calls x Average number of bytes in messages for a received call − Number of bytes in handover-related messages = Number of intra-BSC handovers x Average number of bytes in messages for an intra-BSC handover + Number of interBSC handovers x Average number of bytes in messages for an inter-BSC handover − Number of peak-hour messages for call measurement reports = (Number of originating peak-hour calls + Number of received peak-hour calls) x Average number of measurement reports for a call x Average number of bytes in a measurement report − Number of bytes in peak-hour messages for location updates = Number of peak-hour location updates x Average number of bytes in messages for a location update − Number of bytes in received and sent peak-hour messages = Number of sent peakhour short messages x Average number of bytes in messages for a mobile originating short message + Number of received peak-hour short messages x Average number of bytes in messages for a mobile terminating short message − Average number of bytes in peak-hour pagings = Number of received peak-hour calls + Number of received peak-hour short messages + Average number of re-pagings) x Average number of bytes in messages for a paging − Number of subscribers supported by each TRX = Traffic volume of the site/Peakhour traffic volume for each subscriber/Number of TRXs for a site − Average number of measurement reports for a call = Average duration of a call/0. The following describes the fields in the preceding formula: 2015-11-13  The number 64 indicates that the bandwidth of each LAPD link is 64 kbit/s.  The payload rate of LAPD links ranges from 70% to 75%. the BTS multiplex ratio is 2:1.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Note that when 16 kbit/s signaling links are used on the Abis interface.6.  If the half-rate transmission is enabled. The result is the BTS multiplex ratio.0 & BSC6910) The multiplex ratio of Abis signaling links determines the bandwidth of each Abis signaling link. and the multiplex ratio is fixedly 1. To calculate the multiplex ratio.  The number 1024 indicates that 1024 bits equal to one k. The recommended BTS multiplex ratio used in common situations is as follows:  If the half-rate transmission is disabled.  The number 8 indicates that eight bits equal to one byte. if the calculation result value obtained is 2. the recommended ratio is 4:1 or 2:1. the recommended ratio is 2:1 or 1:1.5 Huawei Confidential Page 182 of 258 .  The RSL bandwidth is calculated as follows: RSL bandwidth = Average number of peakhour messages for a TRX/3600. For example. multiplexing is not applicable. A proper multiplex ratio for a network helps improve the utilization rate of transmission bandwidth. use the following formula: BTS multiplex ratio = 64 x 1024 x Payload rate of LAPD links/8/RSL bandwidth Round off the calculation result of the preceding formula to the nearest integer. 0 & GBSS17.4 and the most used value is 0. Multiple port IP addresses can be configured. b. The value of the average ratio of re-pagings to total pagings ranges from 0. b.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Table 1.  The planned IP addresses are added with different VLAN tags based on different destination IP addresses for easy maintenance and expansion.2 lists estimates of data related to parameters a. Table 1.2 Estimates of data related to parameters a. The packet interface unit (PIU) is the common name of the A-interface board. c. Design guide: 2015-11-13 Huawei Confidential Page 183 of 258 . and d Service a: Call (No Paging) b: Location Update c: Short Message (No Paging) d: Paging Weight 100% 60% 80% 1% Table 1.5. c.4 IP Address Planning The interface board of the BSC is configured with the device IP address (also called logical IP address) and port IP address. Gb interface board.2 to 0.0 & BSC6910) − Average number of re-pagings = (Number of received peak-hour calls + Number of received peak-hour short messages) x Average ratio of re-pagings to total pagings. and d. Design principles:  IP addresses can facilitate future maintenance. and d. b.  The planned IP addresses can meet future expansion requirements. b.35. c. and Abis interface board. and d Parameter Value Average number of bytes in messages for an originating call 230 Average number of bytes in messages for a received call 240 Average number of bytes in messages for an intra-BSC handover 80 Average number of bytes in messages for an inter-BSC handover 80 Average number of bytes in a measurement report 60 Average number of bytes in messages for a location update 90 Average number of bytes in messages for a mobile originating short message 220 Average number of bytes in messages for a mobile terminating short message 220 Average number of bytes in messages for a paging 16 19.1 Performance test results of parameters a. Table 1.1 describes the performance test results of parameters a. c. When the GE interface is used. Step 3 Allocate port IP addresses. configure a group IP address (IP address of the active port) for the trunk. If the layer-3 networking and port IP communication are adopted.0 & GBSS17. In active/standby boards+manual active/standby LAGs. Step 4 If the layer-3 networking and device IP communication are adopted.  When the FE interface is used.  If the physical address of the PIU on the BSC side is in the same network segment as that of the PTU/GTMU on the BTS side.  If the physical address of the PIU on the BSC side is in a different network segment from that of the PTU/GTMU on the BTS side. layer-2 interworking is not supported.x. layer-3 switch or router) is required for routing.  One physical port can be configured with a maximum of six IP addresses that must be in different network segments. configure a route to the device IP address of the BSC for the intermediate router. Port IP addresses must be in different network segments from device IP addresses. For the best results.  The IP address cannot be a loopback address whose network number is 127. Step 5 If the BSC is required to add VLAN tags according to the next hop or service type in the E2E solution. Configure and use the port IP address or device IP address. the port IP addresses of the active and standby PIUs must be in the same network segment. The system automatically identifies the communication mode (port IP communication or device IP communication). This is called layer-3 networking. do not configure a route to the port IP address of the BSC for the intermediate device.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Huawei Confidential Page 184 of 258 .  The gateway IP address must be in the same network segment as the port IP address of the board.x.0 & BSC6910) Step 1 Select a communication mode (port IP communication or device IP communication). layer-2 interworking is allowed. The processing of the A interface and Gb interface is the same as the processing of the Abis interface. configure the function of adding VLAN tags according to the next hop or service type on the BSC side.  The IP address cannot be all 0s or all 255s. and a layer-3 device (for example. configure an IP address for the standby port during ARP detection. adopt device IP communication for the Abis interface board on the BSC side (if a device IP address is configured) and port IP communication for the interface board (TMU board) on the BTS side. ----End Principles of IP address planning 2015-11-13  The device IP address is a logical IP address that a board uses for communication. The device IP address is valid for all the port IP addresses of the board. In addition. Step 2 Allocate device IP addresses according to the networking design scheme for the Abis interface and the calculated number of FE/GE ports of the Abis interface on the BSC side in the bandwidth design. one board can be configured with eight port IP addresses that are in different network segments. When the PIU works in active/standby mode. Use the active/standby board networking mode. The IP address of the active port must be in the same network segment as that of the standby port. Use the device IP communication mode for the Abis interface board on the BSC side.x. one board can be configured with two port IP addresses. and the port IP communication mode for the Abis interface board on the BTS side. 255. VLAN ID carried in the IP packet. Dest IP Address VLAN ID Parameter description:  Dest IP Address: next hop IP address of the destination BTS. Sub System No.255. BTS Information 2015-11-13 Huawei Confidential Page 185 of 258 .0 & BSC6910)  The IP address cannot be the multicast IP address of category D. Device IP Address Subnet Mask Ethernet port IP of BSC side board Subra ck No.255. Slot No.255. Slot No.0 & GBSS17.255.  The IP address cannot be the reserved IP address of category E.0 to 247. Slot No. Output: IP address planning in Abis over IP mode BSC Attribute (for Abis over IP communication method) Abis IP Type Parameter description: Abis IP Type: communication mode (logical IP communication or port IP communication) that the Abis interface adopts in Abis over IP mode.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0. Por t No. Device IP (logical IP) of BSC side board Subrack No. that is. address in the range of 224.0. address in the range of 240. that is.0.  VLAN ID: VLAN ID of the next hop of the BSC port corresponding to the destination IP address.0.255.0 to 239. IP Address Index Port IP Addres s Port Standby IP Address Subnet Mask IP VLAN Subrack No. that is. When the BTS functions as the client.(BSC): slot number of the interface board of the BSC connected to the BTS. Huawei Confidential Page 186 of 258 .0 & GBSS17.  BTS Bar Code: electronic label of the BTS.  IP Clock Port: indicates that the BTS uses the IP clock server as the clock source.  Site IP Address: IP address allocated to a site. In Abis over IP mode. (BSC) MTU BSC IP BTS Bar Code Reference Clock Source type BSC IP Mask Activity State IP Clock Port Subrac k No. Trace Transport Clock.  Site Name: name of a site. Port Rate(M).  Auto Negotiation Mode.  Upper-level Port No: upper-level port number. Clock. Duplex Mode. (BSC) Longitu de Latit ude Parameter description: 2015-11-13  Site Index: index number of a site. (BSC) Dupl ex Mode Port No. This parameter must be correctly set. this parameter is constantly set to 33003 and cannot be modified.  Reference Clock Source type: type of the reference clock source of the BTS. In Abis over IP mode. only the star networking is supported.  Site IP Subnet Mask: subnet mask allocated to a site. and MTU: must be negotiated with the device directly connected to the IP interface board of the BTS. this parameter is set to IP.  Service Mode: service type.(BSC): subrack number of the interface board of the BSC connected to the BTS. and therefore this parameter is set to the outgoing port number of the directly connected BSC. the BTS cannot be started. This parameter uniquely identifies a site in a BSC. Transport Clock.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & BSC6910) Site Inde x Site Nam e Site Typ e Upperlevel Port No Servi ce Mode Site IP Addre ss Site IP Subne t Auto Negotiati on Mode Mask Port Rate(M) Slot No. Internal Clock. Values are IP Time. otherwise. External sync.  Site Type: BTS type of a site.  Slot No.  Subrack No. Set this parameter to IP Time if the IP clock server is used to provide clocks and Trace GPS Clock if the GPS is used to provide clocks. and Trace GPS Clock. ----End Principles of routing planning:  When the BTS adopts port IP addresses to provide services.5. Design principles:  The designed routing solution must facilitate follow-up maintenance. All routes need to be configured manually. one logical IP address (that is. and a route from the BSC to the logical IP address of the BTS.(BSC): port number of the interface board of the BSC connected to the BTS. The BTS calculates the route to the BSC according to the information delivered by the BSC. no route to the BTS needs to be configured on the BSC.  BSC IP: port IP addresses (destination IP address) of the interface board of the BSC connected to the BTS.0 & BSC6910)  Port No. Design guide: Step 1 Plan routes for the BSC according to the networking design scheme for the Abis interface and the reliability design. and the port IP address is the same as the logical IP address. configure two FE port IP addresses (they must be in different network segments). During communication.  Set Destination IP to a network address in the network segment of the IP address of the BTS. In this case. The network address is obtained by performing the AND operation on the peer IP address and 2015-11-13 Huawei Confidential Page 187 of 258 . only one FE port IP address can be configured. the BTS can be configured with two FE port IP addresses for load sharing. no route to the BTS needs to be configured on the BSC because the physical address of the FE port of the PIU (IP interface board on the BSC side) is in the same network segment as that of the FE port of the PTU (IP interface board on the BTS side).CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Instead. the BTS does not support load sharing. In layer-2 networking. a route to the BTS needs to be configured on the BSC. the IP address of the BTS). only static routes are supported. configure the route to the device IP address of the BTS on the intermediate router.  The route to the BSC cannot be configured on the BTS.  When the BTS adopts the device IP address for communication. Step 3 If the layer-3 networking is adopted and the BTS uses the device IP address for communication. with the next hop being the physical IP address and the destination address being the logical address of the PTU.  When the BTS adopts the port IP address for communication and the layer-3 networking is available.  The route to the BTS needs to be configured on the BSC. configure the route to the device IP address of the BSC on the intermediate router.0 & GBSS17.  When the BTS is configured with logical IP addresses for providing services.  When the BTS adopts the port IP address for communication and the layer-2 networking is available. 19. a network address is used to address the peer device. Step 2 If the layer-3 networking is adopted and the BSC uses the device IP address for communication. a route to the BTS needs to be configured on the BSC.5 Routing Planning In Abis over IP mode.  Gateway: port IP address of the device directly connected to the outgoing port of the Gb interface board on the BSC. Slot No.255. if the peer IP address is 192.  ARP link detection and physical layer detection are mainly used.168. When a port is configured with neither BFD detection nor ARP link detection. physical layer detection is adopted. 2015-11-13 Huawei Confidential Page 188 of 258 . Destination IP Address Subnet Mask Gateway Route Priority Parameter description:  Destination IP Address: network IP address of the destination IP address of the peer BTS (destination of the data from the Abis interface board of the BSC). The IP address specified by this parameter must be in the same network segment as the IP address of the outgoing port of the Gb interface board on the BSC.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. ARP link detection for the active port and physical layer detection for the standby mode. Design guide: Step 1 Design the port QoS attribute parameters based on the capability of the interworking device. 19.80.  Subnet Mask: subnet mask of the IP address of the BTS of the peer device. Output: Abis over IP routing design Subrack No.  Route Priority: route priority. The default value is 1.255.  The DHCP relay is configured on the router connected to the BTS.0 & BSC6910) the subnet mask.  Set Subnet Mask to the subnet mask of the destination device.128.0.  One port can be configured with only one detection mode.6 QoS Design Design principles: Port link detection  The BFD detection of the interface and ARP link detection cannot be enabled at the same time. Physical layer detection does not need to be configured and is supported by all ports by default. the network address is 192. ARP link detection for both active and standby ports. The network IP address is obtained by performing the AND operation on the device IP address (or port IP address if no device IP address is available) of the BTS and the subnet mask. BFD detection for the active port and physical layer detection for the standby mode.  Set Gateway Address to an address that is in the same network segment as the IP address of the related port of the interface board on the BSC side.80. this parameter indicates the network IP address of the port IP address.  The following detection modes are supported: BFD detection for the active port. and no configuration is required on the BSC port.2 and the subnet mask is 255.5. Configure the retry attempts for ARP link detection to 3 with 300 ms per attempt. If the peer BTS does not have a device IP address (logical IP address). For example.168.0 & GBSS17. and physical layer detection for both active and standby ports. Huawei GBSS provides the same QoS assurance mechanism for Abis over IP transmission and A over IP transmission to provide E2E QoS assurance.  ARP Timeout: ARP response timeout interval (after an ARP request is sent) in the ARP detection.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The system supports the configuration of multiple IP addresses for a port. and application layer. Step 4 Design VLAN priorities and DSCP mappings. and do not change the value.0 & BSC6910) Step 2 Determine the port link detection mode (BFD detection. Slo t No . including the physical layer. If the VLAN function is enabled on the device port that possesses the gateway IP address of the route configured on the port. Por t No.  Peer IP Address: port IP address of the device that is directly connected to the physical port. otherwise. link layer. IP layer.  VLAN ID: VLAN ID in the ARP detection packets when VLAN Flag is set to Enable.  Arp Retry Attempts: number of ARP detection times in a period.: port number of the Abis interface board that requires the physical link detection.0 & GBSS17. the route is unreachable.  VLAN Flag: whether VLAN tags are added to ARP packets when the BSC implements ARP detection. or physical layer detection) according to the support capabilities of the interconnected device. this parameter must be enabled. ARP link detection.  Peer IP Address of the Standby Board: physical IP address of the peer port directly connected to the physical port of the standby board. BFD detection 2015-11-13 Huawei Confidential Page 189 of 258 .  IP Address Index: index of an IP address. ----End Output: Abis over IP QoS design ARP link detection Subrac k No. and the VLAN ID must be the same as the VLAN ID configured for the device port that possesses the gateway address. The default value is 3. The default timeout interval is 3 seconds. The software has a bug. Use the default value 3. Step 3 Design IP addresses and VLANs. IP Addre ss Index Peer IP Addre ss Arp Retry Attem pts Arp Timeo ut VLA N Flag VLA N ID Peer IP Address of the Standby Board Parameter description:  Port No. " Logic Port Subrac Slo k No. The BFD detection supports only the next hop detection.0 & BSC6910) Subrac k No.  MinTxInterval(ms): minimum interval between the BFD control packets that the local system sends. Slot No.0 & GBSS17. t No .  Congestion Bandwidth Threshold(%): congestion threshold of the logical port. The sum of the bandwidths of all the logical ports bound to the same physical port cannot exceed the bandwidth of the physical port. The default value is 95. that is. Bandwidt h of the Logical Port(32Kp bs) Reserved Bandwidth Threshold( %) Congestio n Bandwidth Threshold( %) Congestion Clear Bandwidth Threshold( %) Parameter description:  Physical Port No.  MinRxInterval(ms): minimum interval between the BFD control packets that the local system receives. that is. the percentage of the congestion clearance bandwidth to the logical port bandwidth. Physic al Port No. Logi c Port No. It ranges from 32 kbit/s to 64 kbit/s.  Bandwidth of the Logical Port(32Kpbs): fixed bandwidth of the logical port. the percentage of the logical port reserved bandwidth to the logical port bandwidth. the link is considered disconnected after the detection fails for the specified number of times. The default value is 75.  Congestion Clear Bandwidth Threshold(%): congestion clearance threshold of the logical port. that is. that is. For details about the other parameters. Port No.: physical port number of the interface board to which the logical port belongs.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. IP Addres s Index Peer IP Addres s MinTx Interv al(ms) MinRx Interv al(ms) Detec t Mult Peer IP Address of the Standby Board Parameter description:  Peer IP Address: peer IP address in the BFD session. Therefore.  Detect Mult: number of detection times. the percentage of the logical port congestion bandwidth to the logical port bandwidth. see the parameter description in "ARP link detection. BSC ABIS MUX 2015-11-13 Huawei Confidential Page 190 of 258 . the peer IP address in the BFD session is the port IP address of the device that is directly connected to the port. The default value is 85.  Reserved Bandwidth Threshold(%): reserved threshold of the logical port. 7 Abis Port Allocation Design  Subrack-based Abis port planning by LAC To minimize the inter-subrack signaling traffic caused due to inter-cell handover and paging forwarding.  Site ID: ID of a site. 1ms) Parameter description:  ABIS MUX State: whether to enable the Abis MUX function. CS voice service. Service types are as follows: OML service. excluding the IP/UDP header. adjacent BTSs are distributed to different Abis interface boards. If the packet length after the multiplexing exceeds this parameter value. the packet is directly sent and no subracks are added. ESL service. Slo t No. PS service (high priority). This can minimize the impacts of board faults. EML service. Overlapping coverage exists between adjacent cells.  Discontinuous BTS distribution in a subrack (optional) The BTSs in a subrack can be distributed between boards in a discontinuous manner. The more the number of packets to be multiplexed. the PTU of the BTS is configured with the BTS Abis MUX function. their multiplexing types must be the same and the packet length before the multiplexing cannot exceed the multiplexing subframe threshold. the longer the duration of the timer.  Multiplexing Packet Length Threshold: threshold for the length of the multiplexed packet. BSC ABIS MUX is optional. The packet length after the multiplexing cannot exceed this parameter value.1ms): maximum multiplexing waiting time. When no content is added to the multiplexed packet within the time specified by this parameter. If the data streams on the same MUX channel are multiplexed. Sit e ID Servi ce Type Multiplexi ng SubFrame Threshold Multiplexi ng Packet Length Threshold Time Out(0. the timer expires and the packet is directly sent. the BTS under it is out of service but the overlapping coverage of the peripheral cells can still ensure services to a certain degree.  Time Out(0. When a board is faulty. Based on discontinuous BTS distribution. plan the BTSs in the same LAC to the same BM subrack as possible as you can.  Service Type: service type of the Abis MUX function on the IP-based interface board. The parameters for the BTS Abis MUX function are the same as those for the BSC Abis MUX function. RSL service. The Abis MUX function is available when only the GFGUB board is configured with the BTS supporting IP transmission.  Multiplexing SubFrame Threshold: multiplexing subframe threshold.5. and the GFGUB board is configured with the BSC Abis MUX function.0 & BSC6910) ABIS MUX Stat e Subr ack No. 19. Set it when the Abis MUX technology is adopted to improve the IP transmission efficiency of the Abis interface. The Abis MUX function is valid only when the Abis MUX function is enabled on the BSC and BTS sides at the same time. and PS service (low priority). This parameter value refers to the payload. CS data service.0 & GBSS17. 2015-11-13 Huawei Confidential Page 191 of 258 . The duration of the timer depends on the average number of packets to be multiplexed within the timer.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. which is unique in a BSC. The BTS must be evenly distributed to different interface boards based on the station module to ensure load balance among boards.6.  Continuous BTS distribution in a subrack BTSs are continuously distributed in a BM subrack according to the longitude and latitude.2 Networking Design The IP over E1 networking over the Abis interface can be classified into two types: noncascading IP over E1 networking and cascading IP over E1 networking.6.0 & BSC6910) The BTS must be evenly distributed to different interface boards based on the station module to ensure load balance among boards. the site distribution strategy can be adjusted. Based on special requirements. This networking includes the following scenarios:  2015-11-13 Direct connection between the BTS and BSC using IP over E1 (the BTS is considered directly connected to the BSC although an SDH network is deployed between the BTS and BSC) Huawei Confidential Page 192 of 258 .1 Interface Description The interface description is the same as that in section 19.1"Interface Description.0 & GBSS17.  Batch site establishment For certain projects. 19. 19. engineering implementation capabilities and customer requirements.5.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. For the best results." Only the POUc board (IP over STM-1) of the BSC6910 supports IP over E1 over the A interface. Non-Cascading IP over E1 Networking In the non-cascading IP over E1 networking mode. sites need to be established in batches due to transmission providing capabilities.6 Abis Interface Design (IP over E1) 19. the BTS directly uses the IP over E1 transmission to communicate with the BSC. Select this principle or the principle of discontinuous BTS distribution in a subrack according to the actual situation. abide by the principle of subrack-based Abis port planning by LAC.  2015-11-13 Tree networking when all the BTSs use IP over E1 transmission Huawei Confidential Page 193 of 258 .CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.1 Direction connection between the BTS and BSC using IP over E1 Channelized STM-1 ports are the only available physical ports on the BSC side. and the routes to destination IP addresses of all BTSs must be configured on the BSC. Cascading IP over E1 Networking In the cascading IP over E1 networking mode. This networking includes the following scenarios:  Chain networking when all the BTSs use IP over E1 transmission Figure 1. The intermediate BTSs work as the routes for forwarding the traffic of lower-level BTSs to the BSC.2 Chain networking when all the BTSs use IP over E1 transmission PPP links are terminated between two BTSs. BTSs in IP over E1 mode may be cascaded with those in TDM mode.0 & BSC6910) Figure 1. Multiple E1 links can be configured as an MP.0 & GBSS17. the upper-level BTSs must work as the routes for forwarding packets of lower-level BTSs. E1 links can be configured as PPP links or an MP. Generally. This helps subsequent capacity expansion adjustment. A single E1 link which may be expanded subsequently can be configured as an MP. The BTSs that use IP over E1 over the Abis interface can be cascaded.3 Transmission Bandwidth Design For details about how to calculate the transmission bandwidth. In this situation. 2015-11-13 Huawei Confidential Page 194 of 258 . the upper-level BTSs must provide the DHCP relay function for lower-level BTSs so that device IP addresses (logical IP addresses) can be obtained using the DHCP and used for communication after PPP or MP negotiation is successful.2 Abis Interface. The intermediate BTSs work as the routes for forwarding the traffic of lower-level BTSs to the BSC. Otherwise.4 Configuration Principles In IP over E1 mode.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. 19. and the routes to destination IP addresses of all BTSs must be configured on the BSC.0 & BSC6910) Figure 1. The Abis on the BSC6900 uses a resource pool and therefore IP paths are not required. when the BTSs are cascaded. see 10. a single E1 link can be configured as a PPP link.6. leaf or intermediate BTSs cannot establish communications with the BSC.2. Among cascaded BTSs using IP over E1. 19.3 Tree networking when all the BTSs use IP over E1 transmission PPP links are terminated between two BTSs.6. 6. 2015-11-13 Huawei Confidential Page 195 of 258 .0) and A&GB Interface Configuration Specification_IP(GBSS17. the BTS can extract a line clock from E1 links.com/support/pages/kbcenter/view/product. Routes are not required on both the uplink and downlink. the BSC must be configured with a route from the BTS to the logical IP address (the next-hop IP address is the PPP or MP IP address on the BTS side). If the BSC IP address is the same as a specified DEVIP.6.6.7 QoS Planning For details. If the BTS uses a logical IP address for communication.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.5 IP Planning In IP over E1 transmission mode. The port IP address is recommended on the BTS.6. 19.huawei. and the line clock is used as the clock reference source.0 & BSC6910) 19. see Abis Interface Configuration Specification_IP(GBSS17.0). http://support.do? actionFlag=detailProductSimple&web_doc_id=SC0000783702&doc_type=1232&doc_type=123-2/support/pages/kbcenter/view/product.6 Route Planning The BSC is directly connected to the BTS over the PPP/MP.do? actionFlag=detailProductSimple&web_doc_id=SC0000783702&doc_type=123-2 19. The device IP address is recommended on the BSC side (the MP or PPP links use the local device IP).0 & GBSS17. This saves IP addresses. If the BTS IP address and the BSC IP address are included in the MP group. both the BTS and BSC support the device IP (using the local device IP) and port IP addresses. the BTS must be configured with a route to the BSC DEVIP by running the ADD BTSIPRT command with Route Type set to OUTIF. 19.8 Clock Synchronization In IP over E1 transmission mode. The SMLC selects a positioning mode. LCSs include weather forecasts.7. Huawei BSS supports flow control on LCS services.1 shows the SMLC-based network topology for the Lb interface. trip scheduling. Figure 1. 3GPP TS 44. Figure 1.1 SMLC-based network topology for the Lb interface Huawei's BSS supports message tracing over the Lb interface and can provide LCS performance measurement entities. stock information. emergency assistance. or AGPS mode.031. and transportation information.0 & BSC6910) 19.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. 2015-11-13 Huawei Confidential Page 196 of 258 .2 Function Interaction The LCS service is mutually exclusive with the following functions:  GBFD-115401 NSS-Based LCS (Cell ID+TA)  GBFD-115402 BSS-Based LCS (Cell ID+TA)  GBFD-115403 Simple Mode LCS(Cell ID+TA) The AGPS positioning method requires the support the cell phone and the core network must support the LCS service.71.031. Huawei GSM BSS equipment can be connected to the SMLC and LMU (TypeB) of other vendors to provide the LCS in CellID+TA. LCSs can increase operators' revenues. 3GPP TS 49. When the external SMLC is overloaded or the number of LCS requests received by the BSC exceeds the maximum limit.1 Interface Description Lb is a standard interface between the BSC and the Serving Mobile Location Center (SMLC). the BSC rejects some LCS requests to ensure the correct running of the GPS. Operators can provide various LCSs for subscribers based on subscribers' locations. and 3GPP TS 03. manages the positioning process. The Lb interface complies with the 3GPP TS 48. The BSC provides the LCS for subscribers over the Lb interface by using the external SMLC. and estimates the location of an MS based on the measurement results reported by the MS. With the Lb Interface feature.7 Lb Interface Design 19. 19.071.7.0 & GBSS17. business planning. 4 Networking Design The SMLC and BSC use IP to communicate with each other. The SMLC can be connected to the BSC either directly or through the signaling transfer point (STP).  When the Lb interface uses the IP transmission mode.3 Constraints and Limitations  When the external SMLC uses the IP transmission mode.  Each SMLC can be configured with at most one DSP or M3UA destination entity.  Direct connection The BSC is directly connected to the SMLC in IP transmission mode. and set DESTSSN to specify the subsystem number of the peer SMLC.  When the Lb interface uses the IP transmission mode and the STP. each BSC can be connected to only one SMLC. The Lb interface and the A interface must use the same network indicator.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.  When the BSC uses RAN Sharing. each SMLC can be configured with a maximum of 16 MTP3-User Adaptation Layer (M3UA) links.7.  The Lb interface on the BSC must be configured in the same subrack as the inter-BSC connection if the BSC is configured with the IP-based Lb interface and the IP-based inter-BSC connection. set DPCT of the destination signaling point (DSP) to LB(LB). 19. In IP transmission mode.  When the BSC does not use RAN Sharing.0 & BSC6910) 19. One operator can be configured with only one SMLC. as shown in Figure 1. each BSC can be connected to a maximum of four SMLCs. the Lb interface can be configured only on an IP-based A or Abis interface board because the A interface of the BSC6910 supports only the IP transmission mode.0 & GBSS17.1. Figure 1.1 Direct connection between the BSC and the SMLC 2015-11-13 Huawei Confidential Page 197 of 258 . set OPNAME to specify the name of the operator to which the SMLC belongs.7. the Lb interface must use a different STP from the A interface. The signaling interaction procedure is as follows:  AGPS mode In the AGPS positioning method.0 & GBSS17.6 Bandwidth Calculation When the Lb interface uses the IP transmission mode. Calculation formula for reference only: Lb interface bandwidth (kbit/s) = Average signaling traffic per LCS service (byte) x 8 x Number of LCS services per second/1024 2015-11-13 Huawei Confidential Page 198 of 258 .2 Connection through STP 19. Figure 1. the number of M3UA links need to be configured. The LCS service is initiated and controlled by the SMLC. the SMLC locates an MS by using GPS and exchanges the positioning assistance information with the MS.7.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. and IP can be used for the intermediate transmission. the SMLC needs to exchange BSSAP-LE-layer signaling with the BSC. 19.5 Positioning Modes  CellID+TA mode The CellID+TA positioning method estimates the location of an MS based on the timing advance (TA) value reported by the MS.0 & BSC6910)  Connection through STP The BSC is connected to the SMLC through the STP. such as the number of LCS services. as shown in Figure 1.7. each SMLC can be configured with a maximum of 16 M3UA links. and the positioning method.2. In CellID+TA mode. The peer SMLC provides the bandwidth required by the Lb interface. Specifically.1 lists the data to be planned and negotiated for the Lb interface (in IP bearer mode). because the link bandwidth is small. and the number of initiated LCS services varies. Table 1. The digit 8 in the preceding formula indicates that one byte consists of eight bits.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.  Without adding an Lb interface board If the Lb interface uses the IP bearer. establish the relationship between the signaling points and the SMLCs and configure related link and route information for the signaling points and the SMLCs.0 & BSC6910) However.1 Parameters to be planned for the Lb interface (in IP bearer mode) Parameter Example Value How to Obtain OSP Code 1 Negotiated with the peer end DSP Code 2 Negotiated with the peer end Network ID NATB(NATB) Negotiated with the peer end OSP code bits BIT14 Negotiated with the peer end SS7 protocol type ITUT(ITUT) Negotiated with the peer end Local entity type M3UA_IPSP(M 3UA_IPSP) Negotiated with the peer end Destination Entity Type M3UA_IPSP(M 3UA_IPSP) Negotiated with the peer end Traffic mode M3UA_OVERR IDE_MOD(Acti ve/Standby Mode) Negotiated with the peer end Work mode M3UA_IPSP(M 3UA_IPSP) Negotiated with the peer end In multiple local signaling points scenarios. 19.7 Parameter Design A BSC can be connected to an SMLC in the following ways:  By adding an Lb interface board IP bearer can be used over the Lb interface.0 & GBSS17.7. Table 1. design the bandwidth with a redundancy capacity of about 50%. Average signaling traffic per LCS service is about 120 bytes. 2015-11-13 Huawei Confidential Page 199 of 258 . configure the Lb interface according to the following operations. the Lb interface must be configured on the A interface board or Abis interface board of the BM subrack. Avoid discontinuous BTS distribution in different BSCs.  Plan the BTSs connected to the BSC continuously in the coverage area (unless transmission conditions do not permit).  For an office that is constructed by phase.  The number of TRXs needs to meet the required board processing specification.  In a multi-chain site (ring networking). To balance the processing capabilities of various BSC modules and improve anti-impact and anti-risk capabilities. network planning personnel plan the allocation of BTSs and TRXs in various BSCs but do not complete the module-level planning.8 BTS Homing Allocation BTS homing and TRX homing are designed according to the network planning design made by network planning personnel. distribute multiple chains to different boards to prevent the entire site from being out of service due to board faults.0 & GBSS17. Therefore.2. allocate the sites that have such a re-homing requirement to several Abis interface boards in a module and adopt centralized cabling on the DDF to reduce the workload during re-homing." 19. there may be many site re-homing requirements. otherwise inter-MSC handovers increase. Design principles:  The number of TRXs needs to meet the designed specifications of GMPS and GEPS subracks. Therefore. Output of the design HLD output BSC Name Module No BSC1 0 BTS quantity TRX quantity 1 2 3 2015-11-13 Huawei Confidential Page 200 of 258 .  Allocate the VIP sites (hot-spot areas with heavy traffic) in an area to different Abis interface boards in a subrack in a discontinuous manner. When performing network planning. this allocation mode can minimize the impacts due to out-of-service of partial VIP sites in the same area. distribute BTSs in a continuous manner between BSCs but distribute BTSs in a discontinuous manner within a BSC and between boards in large sites. during initial site allocation.5"Signaling Configuration Principles.  Allocate the BTSs in the same LAC to the same subrack to reduce inter-module signaling traffic. Whether to adopt this mode depends on the actual situation.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & BSC6910) For details about signaling link design of the Lb interface. The recommended redundancy is 20%.  The traffic carried by each module and BHCA do not exceed 60% of the designed specification. see section 19. and the actual redundancy depends on the BOQ. That is.  Certain redundant ports and capacity need to be reserved for each Abis interface board for subsequent small-scale adjustment and expansion. allocate BTSs among modules properly to implement load balancing. Overlapping coverage exists between adjacent cells. CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & BSC6910) LLD output (work out LLD based on the LLD template) BTS name BTS configuration Module No Board No Port No S2/2/2 2015-11-13 Huawei Confidential Page 201 of 258 .0 & GBSS17.  Design a networking diagram and a proper clock synchronization route according to the clock source position.2 Input of the Design Type of the clock source 20.  Design a clock connection diagram. indicating an absolute time synchronization.2.  Time synchronization is also called moment synchronization. NE position.1 Purpose of the Design  Select a proper clock source according to the situation of the customer.  Clock synchronization generally refers to frequency synchronization. Initial moment does not require consistency.2. the phase difference or frequency difference of two or more signals at the same moment keeps within a tolerable range.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.1 Definition of Synchronization  Synchronization indicates that two or more signals keep a specific relationship in frequency or phase. 20.2 SyncE  2015-11-13 The SyncE technology is defined in the ITU-T G. 20.1 Design Overview 20.1.2 Clock Description 20. The downstream NEs obtain and trace the clock of the upstream NEs by restoring the clock from the serial Huawei Confidential Page 202 of 258 .0 & BSC6910) 20 Clock Synchronization Design 20.1. and transmission environment. instructing project implementation.8262 protocol. This technology inherits the basic clock synchronization theory of the SDH and PDH networks. This means that the initial moment of a signal is consistent with the Universal Time Coordinated (UTC). That is. The frequency of a signal is on the reference frequency.0 & GBSS17. CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. but does not support interworking with servers of other vendors. The clock is extracted and restored from the Ethernet physical layer.1 and IEEE 1588 V2.8265. Huawei's clock over IP proprietary protocol is not described here.1 is released by the ITU for the synchronization of the layer-3 unicast frequency in IEEE 1588. It supports interworking with servers of other vendors.3 IEEE 1588 V2  The initial edition of the IEEE 1588 (Precision Time Protocol (PTP) used in measurement and control systems) was developed by John Edison from the Agilent Laboratories and 12 persons from other companies and organizations.  The IEEE 1588 defines the PTP protocol for the standard Ethernet.  SyncE is compliant with the constraints and requirements of SyncE specified in the G. This protocol applies to the IP RAN and can implement high-precision frequency synchronization even time synchronization between the clock server (for example.0 & GBSS17. G.2.0 or later. IP Clock 3000) and the NodeB. The IP Clock 1000 serves as a clock server and the NodeB/BTS 2015-11-13 Huawei Confidential Page 203 of 258 . and G. Intermediate transmission devices are required to support the SyncE.2.  SyncE is available for commercial usage in GBSS15.8262.8261. 20. It was approved by the IEEE in November 2002.8265. In 2008. the second edition of PTP focused on improving the accuracy of frequency synchronization and minimizing forward delay between the intermediate devices. Do not use it. The accuracy reaches microsecond level. 20.8264 protocols.4 Advantages and Disadvantages of Clock Protocols Clock Source The following clock sources are available:  Building Integrated Timing Supply System (BITS) clock  Clock obtained from the A interface  Local free-run clock  Clock over IP (Huawei proprietary protocol)  SyncE  IEEE 1588 V2 Comparison of synchronization technologies Technolo gy Frequen cy Synchro nization Time Synchro nization Advantage Disadvantage Remarks Clock over IP (Huawei proprietary √ × Supports transparent transmission Not support time synchronization. irrelevant to the specific service of the upstream NEs.  The second edition of the IEEE 1558 is compliant with the G.  The IEEE 1588 is intended to synchronize the independent clocks running in measurement and control systems. The G. The IEEE 1588 V2.0 & BSC6910) data streams received on the physical layer. max: 50 kbit/s. The BTS3012 still supports this function.0 do not support this function. The Ethernet physical media conversion devices or packet switched (PS) devices located between the Ethernet clock source and the NodeB/BTS (namely. Not support time synchronization. irrelevant to upper layer services. and packet loss on the bearer network. Besides network QoS. Not recommende d serves as a client. Normal. SyncE 2015-11-13 √ × This clock is obtained from the physical layer. This technology is mature and clock recovery quality is good and is not vulnerable to packet loss and In addition to the RNC and NodeB. the RAN network also requires intermediate devices. use the IEEE 1588 V2. 30 kbit/s. TGW1000) support SyncE.0 & BSC6910) Technolo gy Frequen cy Synchro nization Time Synchro nization protocol) Advantage Disadvantage across the bearer network and has low requirements on the intermediate devices. In the same condition. such as the hub and LAN The NodeB/BTS and other intermediate NEs (for example.0 & GBSS17. Remarks The clock recovery quality is vulnerable to delay. the Clock over IP does not have other special requirements on the IP bearer network and therefore network reconstruction is not required. This technology is mature and application in market is in a long time. Otherwise.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Connectivity is good. Clock information can be transmitted on the IP bearer network. 3900 series base stations later than GBSS9. interruption occurs and the clock cannot be allocated to the lower layer NEs. reflecting high adaptability. Occupies Iub downlink bandwidth resource. The NodeB/BTS supports not only hub cascade on Huawei Confidential Page 204 of 258 . the client) must support SyncE. jitter. This protocol is a Huawei proprietary protocol and does not support time synchronization. CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) Technolo gy Frequen cy Synchro nization Time Synchro nization Advantage Disadvantage Remarks jitter. switch to support clock transparent transmission on the physical layer or clock regeneration. the Iub interface but also allocation of the SyncE downstream clock. However, if other NEs exist between the NodeB/BTS and the downstream clock, the intermediate NEs must support SyncE. Not occupy radio bandwidth. IEEE 1588 V2 2015-11-13 √ √ SyncE is not supported when the transmission rate is set to 10 Mbit/s. If frequency synchronization is used, transparent transmission across the bearer network is supported and the requirement on the intermediate devices is low. If time synchronization is used, all intermediate devices must be upgraded to support IEEE 1588. The clock server (for example, Huawei IP Clock 1000) that supports IEEE 1588 V2 serves as a clock source and the NodeB/BTS serves as a client. If frequency synchronization is used, either the clock server or the NodeB/BTS needs to support IEEE 1588 V2. Besides network QoS, the IEEE 1588 V2 does not have other special requirements on the IP bearer network and therefore network reconstruction is not required. Supports frequency synchronization and time synchronization and meets the requirements of the LTE TDD on clock. The clock recovery quality is vulnerable to delay, jitter, and packet loss on the bearer network. If time synchronization needs to be used, in addition to the clock server and NodeB/BTS, all intermediate devices (including microwave devices, routers, and L2 switches) must support IEEE 1588 V2. IEEE 1588 V2 is a standard protocol, supporting interconnection Occupies Iub downlink bandwidth resource. Normal, 20 kbit/s; max: 40 Time synchronization is not planned for the NodeB/BTS. Huawei Confidential Page 205 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) Technolo gy Frequen cy Synchro nization Time Synchro nization Advantage Disadvantage of devices of manufacturers. kbit/s. Remarks 20.2.5 QoS Requirements of Clock Protocols Table 1.1 Requirements on clock accuracy Clock Synchronizati on Over IP Index Index Value Remarks Clock over IP (Huawei proprietary protocol) Jitter < 20 ms - Packet loss rate < 1% - SyncE Frequency accuracy of the input clock (+ 4.6 ppm, – 4. 6 ppm) Similar to E1/T1, SyncE is obtained from the physical layer and therefore SyncE does not have special requirements on the QoS of the data bearer network. According to the G.8262 protocol, the frequency accuracy of the input SyncE clock must be between + 4.6 ppm and – 4.6 ppm. IEEE 1588 V2 Jitter ≤ 20 ms Packet loss rate ≤ 1% If the jitter is great, the frequency deviation of the BTS and the clock source is great. When the frequency deviation is greater than 0.05 ppm, the clock is unlocked. 1. When the packet loss rate is great, clock packets of the timestamp are lost. This results in great frequency deviation. 2. When the packet loss rate is great, negotiated packets and the great period packet are lost. This results in interruption of clock links. 2015-11-13 Huawei Confidential Page 206 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) Clock Synchronizati on Over IP Index Index Value Remarks Delay ≤ 60 ms No impact 20.3 Clock Source Selection Clock source selection is subject to the requirements of operators. Select a clock source as follows:  In A over IP, the BTS can obtain only the BITS clock because it cannot obtain the line clock on the A interface.  In Abis over IP, the BTS adopts IEEE 1588 V2, SyncE, or IP Clock. 20.4 Clock Design in Abis over TDM Mode A clear networking diagram of a clock source and the BSC needs to be drawn. To use a BITS clock, connect the clock cable from the BITS to the clock interface on the panel of the GGCU board. Clock networking in this mode is simple. If an operator puts forward a special clock source, you need to confirm the principle of the special clock source with the operator and make a drawing specific to the special clock source. Figure 1.1 shows how to obtain a clock over the A interface. Figure 1.1 Clock networking instance 1 Figure 1.2 shows how to obtain a clock on the backbone network. 2015-11-13 Huawei Confidential Page 207 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) Figure 1.2 Clock networking instance 2 20.5 Clock Design in Abis over IP Mode Design Principles  Determine a clock in Abis over IP mode according to the BSC, BTS, and bearer information.  In Abis over MSTP, the BTS obtains the line clock over MSTP to implement clock synchronization.  In Abis over FE/GE, the BTS adopts IEEE 1588 V2 or SyncE to implement clock synchronization.  In Abis over microwave, if the microwave device has clock information, the BTS obtains a line clock through microwave. Otherwise, adopt IEEE 1588 V2 or SyncE.  In Abis over satellite, the BTS adopts GPS to implement clock synchronization. Design Guidelines  Determine a clock in Abis over IP mode according to the BSC, BTS, and bearer information. See section "Scheme of Interface Clock Synchronization."  In Abis over MSTP, the BTS obtains the line clock over MSTP to implement clock synchronization.  In Abis over FE/GE, the BTS adopts Clock over IP to implement clock synchronization.  In Abis over microwave, if the microwave device has clock information, the BTS obtains a line clock through microwave. Otherwise, the BTS adopts Clock over IP.  In Abis over satellite, the BTS adopts GPS to implement clock synchronization. Scheme of Interface Clock Synchronization All radio data services require frequency accuracy. The BTS guarantees stable RF by means of clock synchronization. Currently, the GSM requires 0.05 ppm frequency accuracy. After the GSM network is constructed into an IP network, the BTS cannot obtain a clock through a physical link. This is because the IP network is an asynchronous network. Therefore, the clock needs to be obtained in a new mode for the BTS to ensure clock synchronization on the air interface. Furthermore, the BSC does not lock the clock and therefore the BSC does not require clock synchronization after IP construction. Table 1.1 lists the schemes recommended for clock synchronization under GSM IP construction. 2015-11-13 Huawei Confidential Page 208 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) Table 1.1 Schemes recommended for clock synchronization under GSM IP construction Networking Clock Synchronization Scheme Recommended for the BTS Clock Synchronization Scheme Recommended for the BSC Abis over MSTP/PTN The BTS obtains a line clock over MSTP/PTN to implement clock synchronization. The BSC does not require clock synchronization. Abis over FE/GE The BTS adopts IEEE 1588 V2 or SyncE to implement clock synchronization. Abis over microwave If the microwave device has clock information, the BTS obtains a line clock through microwave. Otherwise, the BTS adopts IEEE 1588 V2 or SyncE. Abis over satellite The BTS adopts GPS to implement clock synchronization. GSM BSS A interface IP construction Abis over TDM The BTS traces the BSC clock. The BSC adopts the BITS clock to provide a line clock for downstream BTSs. GSM BSS Gb interface IP construction A over TDM The BTS traces the BSC clock. The BSC adopts a line clock and locks the clock that serves the SGSN. GSM BSS all IP construction (IP over FE) The following section uses the MSTP-based IP networking as an example. Figure 1.2 shows the MSTP-based Abis IP solution. In this solution, the BSC and BTS connect to the MSTP device over the FE interface. The MSTP device encapsulates Ethernet frames into the VC trunk, whose bandwidth is shared by multiple BTSs. This solution is applicable to a GSM network that an SDH network or MSTP network operator is constructing. The operator can upgrade the SDH network into an MSTP network, therefore providing Ethernet access. If the BTS and MSTP reside in the same site, the BTS connects to the MSTP over an electrical FE interface and obtains the clock from the MSTP. If the BTS and MSTP reside in different sites, the BTS connects to the MSTP over an optical FE interface and obtains the external clock of the MSTP through an E1 link free of services. 2015-11-13 Huawei Confidential Page 209 of 258 2015-11-13 Huawei Confidential Page 210 of 258 . 20. see Figure 1.05 ppm frequency accuracy within 90 days and periodically send IP clock packets. the transmission bearer network supports MSTP. or L2/L3 networking. the BTS adopts Clock over IP (supporting the IEEE 1588 V2) to implement clock synchronization of the BTS. operators can customize the time of sending IP clock packets to ensure that IP clock packets are sent during light network load. The IP Clock Server obtains the reference clock source from other devices.0 & BSC6910) CONFIDENTIAL Figure 1.6 Design of the IP Clock Server Introduction to Clock over IP (Supporting the IEEE 1588 V2) The Clock over IP (supporting the IEEE 155 V2) is a solution for BTS clock synchronization.2 MSTP-based GSM IP solution Currently.Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. For details. and delivers the clock information to the BTS (namely. The Clock over IP can be classified into IP Clock Server and IP Clock Client. PSTN.2.1 shows the networking of Clock over IP. In the GBSS system. not only reducing bandwidth use but also preventing BTS out-of-sync. Figure 1.0 & GBSS17. The BTS of the GBSS system can retain 0. The following section describes Clock over IP and the design principle. The BTS performs adaptive processing of the IP clock packet to obtain the clock information. continuously sending IP clock packets may increase transmission cost and even affect services in busy hours of the network. such as the GPS or BITS. In Abis over L2/L3 networking. In Abis over MSTP. the IP Clock Client) by using a clock packet on the IP network. the BTS obtains the line clock over MSTP to implement clock synchronization. Each IP clock packet occupies a certain bandwidth. On a rent network or in satellite transmission. The clock mode widely used on the live network is 1588v2 Layer-3 unicast.  You can run the SET BTSIPCLKPARA command on the maintenance console to set Clock Protocol Type to HW_DEFINED(Huawei User-defined) or PTP(PTP Protocol).1 IP Clock synchronization networking Table 1.0 & BSC6910) Figure 1.  You can run the SET BTSCLK command on the maintenance console to set Clock Type to IP_TIME(IP Clock).1 describes the support for 2G-based 1588v2 clocks.1 Support for 2G-based 1588v2 clocks Syste m IP Clock Type Support Clock Redundanc y Backup or Not Address 1 Address 2 Synchroniz ation Mode 2G 1588v2 Layer-3 unicast Yes IP address of the IP clock server IP address of the IP clock server Intermittent synchronization (command: SET BTSIPCLKPA RA) 1588v2 Layer-2 multicast Yes MAC address of the IP clock server MAC address of the IP clock server Default continuous synchronization  2G networks support 1588v2 Layer-3 unicast and 1588v2 Layer-2 multicast. supports only the PTP clock mode currently. The BTS.0 & GBSS17.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Table 1. however. Design principle of the IP Clock Server (Huawei's IP Clock Server product is IPCLK3000) 2015-11-13 Huawei Confidential Page 211 of 258 . 016 ppm)  Network topology Layer-3 networking. The IP clock server accesses the network through a layer-3 router.  IPCLK3000 clock performance indicators Table 1.0 & BSC6910) For details about the IPCLK3000 product and the configuration guide.2 IPCLK3000 clock performance indicators Name Value Maximum number of supported clients Frequency synchronization: 512 NodeBs. layer-2 networking of the private network.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. add VLAN tags to intermediate transmission devices. or BTSs Time synchronization: 512 WiMAX BTSs Maximum picket sending frequency IEEE 1588 V2: 128 packet per second (pps) Maximum bandwidth occupied by each signal IEEE 1588 V2: Frequency synchronization: normal: 12 kbit/s. eNodeBs. Table 1. – 0.2 lists IPCLK3000 clock performance indicators. and the Internet public networking are supported. 2015-11-13 Huawei Confidential Page 212 of 258 . The IP clock server accesses the network through a layer-2 switch. max: 190 kbit/s Time synchronization: normal: 14 kbit/s.huawei.  IPCLK3000 supports the following clock sources: − BITS clock − External 8 kHz clock provided by external devices − Global Positioning System (GPS)/Global Navigation Satellite System (GLONASS) satellite clock − External 1 pulse per second (1PPS) clock A built-in satellite card can be installed in IPCLK3000 to obtain GPS clock signals.0 & GBSS17.com and http://3ms. max: 210 kbit/s Frequency retention hour after clock sources are lost 7 days Frequency retention precision after clock sources are lost (+ 0. Use the layer-3 networking. add VLAN tags to intermediate transmission devices.com. GPS clock signals generated by external satellite cards can also be obtained through clock signal interfaces on the panel.huawei. If VLAN tags need to be configured.016 ppm. If VLAN tags need to be configured. obtain the IPCLK3000 Description and IPCLK3000 User Guide at http://support. Table 1. IP addresses of two IPCLK3000 clock servers need to be configured on the BTS side.  − Run the SET ETHIP command on the IP clock LMT to configure service IP addresses of IPCLK3000 for matching service ports with Port Type set to SERVICE. the synchronization time needs to be set during peak hours and the clock needs to be locked during off-peak hours. or BTSs. On the BTS side. You can plan IP addresses based on the IP address schemes for the layer-3 and layer-2 networking modes.0 & GBSS17. 500 BTSs share one IPCLK3000. clock sources are still available when an IPCLK3000 is faulty. the number of base stations needs to be less than 50 for a VLAN. They are configured to be the primary and secondary clock server on the BTS side. Use the intermittent synchronization on the live network.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.  Capacity planning In frequency synchronization.3 describes whether the IP clock server adaptive synchronization protocols are supported on the hardware platform or the old hardware platform. Reliability To implement 1+1 backup of reference clock sources.3 Whether the IP clock server adaptive synchronization protocols are supported on the hardware platform or the old hardware platform IP Clock Server IP Clock (Customized by Huawei) V100R001 2015-11-13 √ 1588 V2 (L3 Transparent Transmission) Hardware Platform Old hardware Huawei Confidential Page 213 of 258 . Generally. − Run the SET ETHIP command on the IP clock LMT to configure operation and maintenance IP addresses of IPCLK3000 for matching operation and maintenance ports with Port Type set to DEBUG. The two IPCLK3000 clock servers are independent. Intermittent synchronization only applies to the 1588v2 Layer-3 unicast packet mode. IPCLK3000 is an independent case-shaped device. The actual number of IPCLK3000s to be deployed depends on the number of Clients and the backup relationship between IPCLK3000s. one IPCLK3000 can support 512 NodeBs.0.  Synchronization mode on the BTS The support for continuous and intermittent synchronizations is introduced to the MBTS in SRAN5. eNodeBs.  IP address planning IP addresses of IP clock servers need to be configured on the radio BTS side. two IP addresses are planned. Generally. (Intermittent synchronization helps save the bandwidth. Intermittent synchronization is used in the following scenarios: − The transmission bandwidth is limited.) − If the network QoS is poor in peak hours and good in off-peak hours. Matching Version of the IP Clock Server Table 1. A maximum of 512 VLANs can be configured on the IP clock server.0 & BSC6910) The IP clock server supports VLAN configurations. With enhanced reliability. 4 Whether the GSM products support the IP adaptive synchronization protocols IP Clock (Customized by Huawei) GBSS15.4 describes whether the GSM products support the IP adaptive synchronization protocols. Table 1.  V100R002 is a non-productive version and is an upgrade version of V100R001. IP clock version under various GSM scenarios Create an IP clock server.0 1588 V2 (L3 Transparent Transmission) 1588 V2 over MAC √ √ Because the hardware logic resource of the GSM BTS3900 is limited. All devices to be delivered have used this version since August 1. If an IP clock server is required.0 supports only 1588 V2.0 & GBSS17. Table 1.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. 2009. 2015-11-13 Huawei Confidential Page 214 of 258 . the GBSS15.  V200R002 applies on the new hardware platform.0 & BSC6910) IP Clock Server IP Clock (Customized by Huawei) 1588 V2 (L3 Transparent Transmission) Hardware Platform V100R002 √ platform √ New hardware platform V200R002 √  V100R001 and V100R002 apply only on the old hardware platform and they cannot be upgraded to V200R002. V200R002 is delivered. specific to microsecond. and position and IP address of the M2000 server 21.1 Purpose of the Design  Select a proper time synchronization source. Normally.1. The NTP can be used in two modes: broadcast and 2015-11-13 Huawei Confidential Page 215 of 258 .CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.1. facilitating fault analysis and performance analysis. time synchronization means that the NMS synchronizes with BSS NEs.  Design IP addresses for time synchronization.2 Input of the Design Type of time synchronization.3 NTP Network Time Protocol (NTP) is a complex time synchronization protocol across WAN and LAN.2 Description of Time Synchronization Time synchronization indicates that the time of communication devices or computer devices on the communication network is UTC-based and the time offset is small enough. 21. the NMS can record the time of generating alarms and events of each NE.0 & BSC6910) 21 Time Synchronization Design 21. A time synchronization network works in client/server mode and adopts a leveled time server to implement time synchronization. In this way. 21.1 Design Overview 21.  Design a networking scheme of time synchronization according to transmission information and NE position.0 & GBSS17. for example. 100 ms. On a BSS network. a time synchronization source is obtained from the standard time source. DCN is used in mobile networks for time synchronization.5 Transmission Mode Transmission mode is classified into wireless transmission and wired transmission (DCN and DDN).4 Selection of a Time Synchronization Source Currently. the following time synchronization sources are used:  GPS time synchronization source.1 Typical networking for time synchronization 2015-11-13 Huawei Confidential Page 216 of 258 . Therefore. requires high cost. NTP uses UDP transmission and adopts the standard port number 123. this mode is widely used in network time transmission.1 shows a typical networking for BSS time synchronization. You can access the servers to implement time synchronization.0 & BSC6910) client/server.  Internet-based time synchronization source.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. It features convenient networking. to obtain the time offset between the NTP server and the NEs. high security. Figure 1. DDN. 21. In client/server mode. Selection of a time synchronization source is subject to the time source provided by an operator. The client/server mode has 1 to 10 ms accuracy.0 & GBSS17. Therefore. DCN is a TCP/IP-based network for internal transmission. 21. little investment.6 Typical Networking Figure 1. a private transmission network. Simple Network Time Protocol (SNTP) is a simplified NTP protocol. 21. and high reliability. The Internet provides many NTP-based time servers. the NTP server needs to exchange NTP packets with NEs requiring tine synchronization. The later mode has higher accuracy than the former one. 2015-11-13 ZONET DST SM SMONTH GMT+1 YES Week March SDAY SWSEQ SWEEK ST Last Sunday 02:00:00 EM EMONTH Week October EDAY EWSEQ Last EWEEK ET TO Sunday 03:00:00 60 Huawei Confidential Page 217 of 258 .0.0 & GBSS17. The following table lists the NTP servers and the port number.5 123 BRBSC10 10. One BSC can be configured with addresses of multiple NTP servers.4 123 BRBSC10 10.123. The NTP time is obtained from the M2000. The following tables describe the DST configuration of a north European country.123. with the port number being 123.123.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. BSC Name NTP Server Port No BRBSC10 10.0 & BSC6910) 21.0.7 Typical Application The NTP server of the OMU of the BSC is configured with the IP address of the M2000.6 123 The configuration of daylight saving time (DST) varies with areas.0. Table 1.1 Standard Broadcast The cell broadcast is a broadcast short message (SM) service specific to the GSM system. The simple cell broadcast provides the simple cell broadcast service without the CBC system. Within a same period. the cell broadcast uses radio CBCH channels to send messages to a specific coverage area in a single direction under certain conditions.  The CBC collects and stores formatted cell broadcast information from the CBE and then sends the broadcast information to specific BSCs based on scheduling information Huawei Confidential Page 218 of 258 . In this way.1.1 Design of Broadcast Solutions for Cells 22. BSC.0 & GBSS17. weather information. all MSs on a network can receive messages and do not need to respond to the received messages. Each NE provides the following functions: 2015-11-13  The CBE is an interface connecting external message sources and the GSM network.1 NEs involved in the cell broadcast system Acronyms and Abbreviations Full Name BTS Base transceiver station BSC Base station controller CBC Cell broadcast center CBS Cell broadcast server CBT Cell broadcast terminal CBE Cell broadcast entity The cell broadcast system comprises the CBE. CBC. It records cell broadcast information and encodes and formats the cell broadcast information. and social commonweal information.0 & BSC6910) 22 Function Design 22.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. BTS. and MS. The broadcast information includes the cell name. the CBCH channel can be configured in the following two ways:  SDCCH/8+CBCH: used for a cell whose channel type is set to the non-combined BCCH channel  BCCH+CCCH+SDCCH/4+CBCH: used for a cell whose channel type is set to the combined BCCH channel For the SDCCH/8+CBCH configuration mode. if the CBCH channel is configured on the time slot involved in frequency hopping. For the BCCH+CCCH+SDCCH/4+CBCH configuration mode. When CCCH Blocks Reserved for AGCH is not set to 0. if a paging message for the MS is reported over the PCH channel.0 & BSC6910) in the broadcast information. deleting outdated information and querying the status of broadcasting information in a cell. set CCCH Blocks Reserved for AGCH to 0. For the SDCCH+CBCH channel configuration. CCCH Blocks Reserved for AGCH needs not to be set to a value other than 0. Figure 1. The network design needs to consider the location of the CBC and BSC and transmission resources. select BCCH+CBCH for Channel Type. In addition. Figure 1.  The BTS distributes cell broadcast information over the Um interface. The XPU board of the BSC connects to the CBC over the Ethernet network interface. For the BCCH+CBCH channel configuration. the CBC manages broadcast information on the BSC. The CBC connects to the BSC over the CB interface. It also needs to maintain the CBCH status.  The MS receives and displays cell broadcast information. The CBCH channel is a logical channel and occupies the same physical channel with the SDCCH. In this case.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. To enable the cell broadcast. a CBCH channel needs to be configured on a cell.2 Network topology of the cell broadcast 2015-11-13 Huawei Confidential Page 219 of 258 . The SDCCH+CBCH channel can be configured only on any of timeslots 0 to 3 of the carrier. Network design: The network design of the cell broadcast is simple. the MS cannot receive this paging message. the number of frequencies of frequency hopping configured on the time slot needs to be less than 32. the MS can receive information over the CBCH channel within the AGCH channel period and can receive all paging messages.0 & GBSS17. This is because the MS needs to temporarily stop monitoring the PCH channel and to receive contents over the CBCH channel so that the MS can receive cell broadcast information. Due to codec constraints. The BCCH+CBCH channel can be configured only on time slot 0 of the carrier. select SDCCH+CBCH for Channel Type. for example.2 shows the network design diagram.  The BSC schedules and maintains broadcasting information. Therefore. Figure 1.3 shows the physical cable connection diagram.1 Key parameter configurations 2015-11-13 IP address of the CBC Negotiated with peer equipment Subnet mask Negotiated with peer equipment MAC address Negotiated with peer equipment Huawei Confidential Page 220 of 258 .3 Cable connection diagram between the interface board and the CBC Configure cell broadcast data based on the product feature configuration guide without additional data configuration for the IP interface board. Figure 1.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Table 3.0 & BSC6910) The BSC directly interwork with the CBC over the IP network. Specifically. the BSC accesses the CBC network using a network cable from the port on the IP interface board (depending on the port enabled in Configure boards attributes on the IP interface board.0 & GBSS17. because the combined BCCH is configured by default. the value of this parameter indicates the actual seizure rates of the AGCHs and the PCHs over the CCCHs. a scheduling message contains the description of each short message to be broadcast and the position of each broadcast message in the scheduling period.0 & GBSS17. SET BTSCHNFALLBACK (Mandatory) BTS CCCH Blocks Reserved for AGCH BS-AG-BLKS-RES.2 Parameter configurations 2015-11-13 Name Description Command Impact NE Channel Type This parameter specifies the channel type of the timeslot on the TRX. MSs supporting the DRX can consume less power to receive interested broadcast messages. indicating the number of the CCCH message blocks reserved for the AGCH. The period occupied by broadcast messages that are contained in a scheduling message is called a scheduling period.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. SET GCELLIDLEBASIC (Optional) Cell SMCBC DRX This parameter specifies whether to support the discontinuous reception mechanism (DRX). the DRX is introduced into the GSM Specification.0 & BSC6910) Table 3. After the CCCHs are configured. To reduce the power consumption. The channel type of timeslot 0 must not be set. This prolongs the service time of MS batteries. SET GCELLOTHEXT (Optional) Cell Support Cell Broadcast This parameter specifies whether the BSC6910 supports the cell broadcast function. ADD GCNOPERATOR (Optional) BSC6910 Huawei Confidential Page 221 of 258 . The channel type of other timeslots can be set to full-rate TCH or half-rate TCH. BSCs supporting the DRX must send scheduling messages to MSs so that the MSs can use the DRX function. In the sending sequence. SET GCELLSBC CBC Port Broadcast Content 2015-11-13  (Optional) Huawei Confidential (Mandatory) BSC6910 (Mandatory) Cell (Optional) Page 222 of 258 . The following describes each bit of the value: ADD GCBSADDR BSC6910 Bit 0: phase flag  Bit 1: message type flag  Bit 2: cell-list flag  Bit 3: whether to carry a recovery indication  Bit 4: whether to carry the cell flag  Bit 5: whether to carry a recovery indication during the reset procedure Support Cell Broadcast Name This parameter specifies whether to broadcast the cell name.0 & GBSS17. ADD GCBSADDR (Mandatory) BSC6910 BSC Port This parameter specifies the port number used for the communication between the BSC6910 and the CBC.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. ADD GCBSADDR (Mandatory) BSC6910 CBC ITF Para The value of this parameter must be translated into binary digits.0 & BSC6910) BSC IP This parameter specifies the IP address for the communication between the BSC and the CBC. ADD GCBSADDR (Mandatory) BSC6910 BSC GateWay IP When the BSC supports the standard cell broadcast function. ADD GCBSADDR This parameter specifies contents of a cell broadcast message. it sends cell broadcast messages using the IP address specified by this parameter. It must be consistent with the configured IP address of the CPU board. SET GCELLSBC (Optional) Cell CBC IP This parameter specifies the IP address of a CBC. ADD GCBSADDR BSC6910 This parameter specifies the port number at the CBC side in the communication with the BSC6910. The BSC will keep sending the one-page-long message. This function equates to the simple location service. You can obtain the value of this parameter using DSP GSMSCB. SET GCELLSBC (Optional) This parameter specifies the time interval for a cell broadcast message. Coding Scheme. and Broadcast Interval. Geography Scope. The maximum size of the cell broadcast message that can be sent through the MML command is 15 pages. the MS can obtain and display the cell name.0 & BSC6910) Geography Scope Chan ID Coding Scheme Broadcast Interval This parameter specifies the geographic scope of a simple cell broadcast message. Chan ID.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. SET GCELLSBC (Optional) Cell (Optional) ADD GSMSCB (Mandatory) Cell (Optional) ADD GSMSCB (Mandatory) Cell ADD GSMSCB (Mandatory) Cell 22. The broadcast information includes the cell name. It specifies the channel ID of a simple cell broadcast message. 2015-11-13 Huawei Confidential Page 223 of 258 . first set Support Cell Broadcast Name to Yes and then specify parameters. but MS users can disable this function on the MS to stop the receiving of this message.0 & GBSS17. It specifies the coding scheme of message contents. The simple cell broadcast provides two types of functions: cell name broadcast and cell broadcast. weather information.1. Geography Scope. Code. when a roaming MS enters a new cell where the simple cell broadcast function is enabled. A cell can save a maximum of 63 pages of cell broadcast messages. such as Broadcast Content (this parameter is set to the cell name by default). If you send the cell broadcast message in such a way. SET GCELLSBC This is a key parameter for adding a simple cell broadcast message. specify ST and ET of the period during which the cell broadcast message is broadcast. set Support Cell Broadcast to Support Simple CB. You can obtain the value of this parameter using DSP GSMSCB. SET GCELLSBC This is a key parameter for identifying a simple cell broadcast message. The text message contains the cell name. The ADD GSMSCB command can be run to send a cell broadcast message to the BSC. and social commonweal information. The cell name broadcast enables the BSC to send a one-page-long text message to the MSs in a cell under the BSC. To enable the simple cell broadcast service.2 Simple Cell Broadcast The simple cell broadcast provides the simple cell broadcast service without the CBC system. Therefore. To enable the cell name broadcast function. and Update uniquely identify a cell broadcast message. 1 Topology of the simple cell broadcast system The simple cell broadcast cannot be used with the cell broadcast provided by the CBC. you can also run the RMV GSMSCB command to stop the broadcast of a cell broadcast message. For details about the function of the TOM-TOM. (The MS-related radio data includes whether the MS is within the BTS coverage area of the highway.) The CU processes the reported. see the BSC6910 GSM Product Documentation. The TOM-TOM cannot be used if the switch is disabled.1 shows the topology of the simple cell broadcast system. You can also configure the IP address of the VNP on the BSC. the movement speed of the MS. The TOM-TOM sends MS-related radio data collected by the BSC to the VNP. selects a proper path. 2015-11-13 Huawei Confidential Page 224 of 258 . collected information.0 & GBSS17. You can configure an ENTSWITCH on the BSC. Figure 1. and sends the path information to the GPS end user for providing guidance for the user to bypass the congested road. They are mutually exclusive. and the VNP reports the data to the third-party collection unit (CU).CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.2 Design of Radio Measurement Data Interface for Navigation (TOM-TOM) 22. The BSC and VNP used during the entire navigation are provided by the device manufacturer and the CU is from a third party. and the movement direction of the MS. 22. The standard cell broadcast system is recommended for the dynamic information that is frequently changed.2.0 & BSC6910) In addition.1 Overview The radio measurement data interface for navigation (TOM-TOM) is used for real-time navigation on highways. the DSP GSMSCB command can be used to query the cell broadcast messages saved in a cell. Figure 1. The simple cell broadcast provides only simple cell broadcast services. The VNP interface uses the EOMU board of the BSC6910.1 shows the logical networking for the TOM-TOM.  VLANs cannot be configured based on the service flow. Before using the feature.2 Reference Document Deployment Guide: The deployment guide of this feature is available on the deployment guide named BSC6910 GSM Product Documentation. 2015-11-13 Huawei Confidential Page 225 of 258 .2.3 Limitations on Specifications The TOM-TOM has the following limitations on specifications:  A BSC can connect to only one VNP. 22.  Neither IP paths nor logical ports can be configured.2.  The IP PM function is not supported. use different next hops for the OM and the TOM-TOM.  Priorities of DSCP values and VLANs cannot be configured.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.2.  Neither ARP nor BFD is supported. To differentiate the OM service flow from the TOM-TOM service flow.  A VNP can connect to a maximum of five BSCs.2.0 & BSC6910) 22.0 & GBSS17. This feature is supported in BSC6910 V900R015 and later. you need to apply for a license.4 Software and Hardware Configuration No new hardware configuration is added to the BSC. 22. Then configure VLANs based on the next hops.5 Networking Design 22.2. 22.5.1 Logical Networking Figure 1. however.1 Logical networking for the TOM-TOM The logical networking shows only the logical connection. and Traffic server obtain the synchronization time from the NTP server.2.1 shows the physical networking over the VNP interface.5. Subscriber events generated on the BSC are reported to the VNP over the TCP/IP (the BSC provides TCP 6200 port).1 Physical networking on the VNP interface 2015-11-13 Huawei Confidential Page 226 of 258 . Two VRRP routers are configured. The EOMUs are configured in active/standby mode. Then. CU. A VNP. and the BSC and VNP obtain the synchronization time from the M2000.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. but not the actual physical connection between network elements. A BSC can connect and report events to only one VNP. The M2000. can connect to multiple BSCs simultaneously.0 & GBSS17.2 VNP Interface Networking Design The VNP interface uses the EOMU board of the BSC6910.0 & BSC6910) Figure 1. the VNP sends the data to a third-party server for calculation. Figure 1. Figure 1. 22. The Ethernet interfaces 0 and 1 of each EOMU are connected to different LAN switch ports. The BSC interworks with the VNP using the IP bearer. 2.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.6 Bandwidth Design None. This networking is used only by some operators. because the networking has lower reliability.1).0 & BSC6910) The use of the TOM-TOM feature does not cause a change to the original OMU interface networking generally. In addition.0 & GBSS17. because the interface of the OMU adopts the IP transmission networking. although it saves two LAN switches as compared with the networking in Figure 1. and in the same network segment or different network segments with the IP address of the OM. A new logical IP address of the OMU. If the local IP address of the VNP is a logical IP address. The local IP address of the VNP must be different from the virtual IP address of the external network of the OMU or the fixed IP address of the external network.1. the IP address of the peer VPN needs to be configured as the destination IP address.2. (This configuration is optional. 22.2.2 Networking of the active/standby OMUs with a single port and directly connected routers 22.3 VLAN Planning You can configure different VLANs to distinguish the OM service flow from the TOM-TOM service flow. 2015-11-13 Huawei Confidential Page 227 of 258 . Figure 1. it can be configured as a 32-bit mask.5.) 22. however.2 shows the networking of the active/standby OMUs with a single port and directly connected routers. is required as a communication address of the VPN interface (see VPN logical IP address in Figure 1.5.4 QoS Planning Priorities of DSCP values and VLANs cannot be configured. Figure 1. 3 MOCN II Design 22. and the BSC and VNP obtain the synchronization time from the M2000. such as IP addresses and routes.1 shows the networking for time synchronization. MOCN II achieves RAN equipment sharing.3.1 Overview The principles. BTS. and feature activation have been described in the MOCN II Feature Parameter Description.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. and Traffic server obtain the synchronization time from the NTP server. CU.2 Networking Design For details.7 Time Synchronization The M2000. specifications.2.3. This section only describes the planning and design related to this feature.1 Networking for time synchronization 22. 22.0 & GBSS17. Abis transmission resources. parameter settings. networking. including BSC.0 & BSC6910) 22. Figure 1. The core network resources cannot be shared. 2015-11-13 Huawei Confidential Page 228 of 258 . The A and Gb interfaces can share interface boards and transmission on the BSC but use different logical resources. see section "Network Topology" in MOCN II Feature Parameter Description. Figure 1. The MOCN networking can be classified into operator-based independent configuration and configuration sharing among multiple operators for A interface boards. Then.3. Mode Operator-based Independent Configuration of A interface Boards (Recommended) Configuration Sharing of A Interface Boards Among Multiple Operators Pooled with operators distinguished Pooled according to the number of operators or pooled with the boards belonging to the same operator. Therefore.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the interfaces use the following configurations:  Operators use different interface boards. the bandwidths over the A and Gb interfaces are planned according to the need of each operator. the traditional networking modes over each interface still apply in MOCN II-enabled scenarios.4 Interface Design The interface networking does not change during the implementation of MOCN II. During the planning. The A and Gb interfaces must be connected to CNs of different operators. but multiple device IP addresses are used to distinguish operators.0 & GBSS17. The physical networking in this situation is the same as the traditional one. Configure certain number of device IP addresses for all boards and form multiple pools where physical ports can be shared or independently used and port IP addresses can be shared or independently used (in this situation.3 Capacity Planning The MOCN II networking does not affect capacity planning of RAN resources. 2015-11-13 Huawei Confidential Page 229 of 258 . Pooled with all boards. The following table lists the designed specifications in the transmission resource pool mode. For details. obtain the total amount of resources required by different operators.3. transfer services to CNs of different operators according to the destination IP addresses. see chapter 19 "Transmission Interface Design. MOCN II does not allow operator-based configuration of Abis transmission resources.0 & BSC6910) 22." Since the A and Gb interfaces are connected to the CNs of different operators in MOCNenabled scenarios. RAN resources are planned in the same way as in traditional networking mode. 22. Abis transmission resources are shared and therefore the method for planning the resources is the same as the traditional one. but the interface networking modes are the same as the traditional ones. configure multiple port IP addresses). Transmission resource pool is a network networking mode. Therefore.  Operators share interface boards. 0 & BSC6910) Pooled without distinguishing operators N/A Boards in active/standby mode.0 & GBSS17. and a BTS is connected to both BSCs.4 Design of BSC Node Redundancy 22.4. 22. or an independent board can form a pool.1 Overview The BSC Node Redundancy feature allows two BSCs to form a redundancy group. 2015-11-13 Huawei Confidential Page 230 of 258 .CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The following figure shows the networking diagram of two BSCs working in a redundancy group. Two BSCs in a redundancy group work in 1+1 backup mode. If one BSC fails or all the signaling links on the A interface of one BSC are disconnected. Services are transferred to CNs of different operators according to the destination IP addresses. two ports in load sharing mode. Under normal circumstances. the BTSs controlled by each BSC operate properly. the other BSC takes over services from the failed BSC. and feature activation have been described in BSC Node Redundancy Feature Parameter Description. the BSC Node Redundancy feature recovers services without adjusting the transmission data over interfaces or reconfiguring data. but new services will not be affected. networking. This section only describes the planning and design related to this feature. However.0 & GBSS17. The principles.4.2 Constraints The design of BSC node redundancy is subject to the following constraints: 2015-11-13 Huawei Confidential Page 231 of 258 . this feature is neither hot standby nor warm standby.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. specifications. In this sense. if a BSC switchover is triggered. but a redundancy between the warm standby and cold standby. 22. parameter configurations.0 & BSC6910) Unlike cold standby. all ongoing services will be interrupted because no backup data is available. execute a configuration synchronization task. − Then. reminding you to take the following measures to rectify the situation: Manually modify the parameters that do not support configuration synchronization on the secondary-homed BSC so that the parameter settings are consistent with those on the primary-homed BSC.  When you reconstruct single-homed BTSs to dual-homed BTSs under an existing BSC. and the BSC interface board connecting BSC 1 to the BTS supports IP transmission.  The cascaded BTSs working in IP over E1 mode must have the same homing attributes under one BSC. When you first perform data synchronization for the BSC Node Redundancy feature during networking configuration. perform an immediate synchronization task and then perform periodic synchronization tasks.0 & GBSS17. perform a configuration synchronization task. a report is displayed on the CME. but the interface board in the slot with the same slot No. For example. − Synchronize in batches the BTS-level radio parameter settings on the primary-homed BSC to the secondary-homed BSC.0 & BSC6910)  The settings of the parameters that do not support configuration synchronization must be consistent between two BSCs. Rectification measures: − Install an IP interface board in the slot with the same No. and Sharing Allow is set to NO(NO) in the SET BTSSHARING command. BSC radio parameter. upgrade them to the same software version. the synchronization of parameter settings may fail. the parameters that do not support synchronization must be configured first.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. run the ADD BRD command to add data configurations. Rectification measures: On BSC 2 LMT. a configuration synchronization task fails.  Two BSCs support the configuration synchronization function only when they run the same software version (VxxxRxxxCxx). run the SET BSCBASIC command with Support RAN Sharing set to NO(No). manually trigger a configuration synchronization task.  If the settings of parameters that do not support configuration synchronization on the secondary-homed BSC conflict with those on the primary-homed BSC. a configuration synchronization task fails. Support RAN Sharing is set to NO(No) in the SET BSCBASIC command. Support RAN Sharing is set to YES(Yes) in the SET BSCBASIC command. on BSC 2 is not an IP interface board. the radio parameter settings for a dual-homed BTS can be synchronized only after Abis transmission data has been configured on the secondary-homed BSC. To enable two BSCs running different software versions to support this function. Example 1: Problem description: A BTS under BSC 1 uses IP transmission. If the configuration synchronization fails. Then.  To enable successful configuration synchronization. Then. However. These parameters include equipment parameters. Huawei Confidential Page 232 of 258 . Example 2: Problem description: For BSC 1. As a result. for BSC 2. perform the following steps:  2015-11-13 − Configure Abis-interface transmission data for multiple BTSs (≤ 50). on BSC 2. − On BSC 2 LMT. As a result. and transmission-related parameters (excluding IP address-related parameters). configuration synchronization cannot be implemented by running this command.  The ADD PTPBVC command used to configure the Gb interface includes the NSEI parameter. It is recommended that you configure data for primary-homed BTSs and then use immediate synchronization to generate the configuration data for secondary-homed BTSs. and TrafficCpuNo corresponding to TrafficType equal to 3 indicate the XPU/SPU's CPU where the main control AICP module resides. manually configure parameters on the peer BSC. 2015-11-13 Huawei Confidential Page 233 of 258 . TrafficSlotNo. the main control AICP module is used for managing heartbeat links of the primary and secondary BSCs. configuration synchronization cannot be implemented by running the ADD BTSEXTOPIP command in the Abis Independent Transmission feature. As shown in the following figure. ALM-21829 BSC Node Redundancy Configuration Exception is reported because a periodic synchronization task is executed on the CME on a daily basis. The XPU/SPU that accommodates the main control AICP module of the backup BSC must be normal. but the listed parameters do not support synchronization. In this situation. Otherwise.  The MML commands listed in the following table support configuration synchronization. manually configure the parameters on the peer BSC. node redundancy is unavailable because links cannot be synchronized. To query the number of the XPU/SPU where the main control AICP module resides. In node redundancy scenarios. To change the values of these parameters. run the DSP FAMDATA command with Data Table set to CCENTRALTRAFFICCPU.0 & BSC6910)  If you configure data for primary-homed BTSs and then use the configuration synchronization function to generate the configuration data for secondary-homed BTSs. In this situation. TrafficSubrackNo.  If the configuration synchronization parameters include BSCIP.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. manually configure parameters on the peer BSC. the main control AICP module is located on CPU 2 of the board in slot 0 of subrack 0. Therefore. In the command output. MML Command Parameter ID ADD BTS BTSTYPE SET BTSALM BTSTYPE SET BTSAUTOPLANCFG BTSTYPE ADD BTS SEPERATEMODE ADD BTS RFUCFGBYSLOT ADD BTS SRANMODE ADD BTSCABINET SRANMODE  All boards on the backup BSC must be normal.0 & GBSS17. 4. PS throughput. the XPU of each BSC supports 4000 TRXs. For details. 22.4 Capacity Planning Capacity planning can be performed in terms of control plane. To check the status of an SCTP link. number of cells. The control-plane capacity planning includes BHCA. The transmission-plane capacity planning includes CS traffic volume (Erlang). number of subscribers who are processing services. and transmission. number of activated subscribers. Each BSC in a redundancy group is configured with a specified number of boards that can meet the total specifications of two BSCs. number of cells.4.Heartbeat messages are transmitted over SCTP links on the inter-BSC interface.0 & GBSS17. one BSC reserves certain capacity for the other BSC in a redundancy group. The capacity planning for the BSCs in a redundancy group is the same as that for an independent BSC. 2015-11-13 Huawei Confidential Page 234 of 258 . and number of activated subscribers. The user-plane capacity planning includes CS traffic volume (Erlang). The number of purchased boards for each BSC in a redundancy group can meet the total specifications of two BSCs. The two scenarios have been described in the BSC Node Redundancy Feature Parameter Description. and number of call connections. see section "Network Topologies" in the BSC Node Redundancy Feature Parameter Description in GBSS17.0 & BSC6910)  Fault detection is implemented between two BSCs in a redundancy group by checking the heartbeat messages periodically transmitted from the peer end over the inter-BSC interface. run the DSP SCTPLNK command. user plane.3 Networking Design The BSC Node Redundancy feature is used in two typical scenarios: load sharing mode and active/standby mode.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. The BEATSENDINGDISparameter specifies the interval for sending heartbeat messages between two BSCs.0. As shown in the following figure. 22. For example. number of BTSs. This rule also applies to other boards. and number of subscribers who are processing services. if the BSCa supports 3000 TRXs and the BSCb supports 1000 TRXs. CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) As shown in the following figure, the BSCs support dual-homed BTSs. Therefore, some BTSs serving VIP subscribers can be configured as dual-homed BTSs and required service processing boards are purchased for the BSCs. The remaining BTSs are configured as singlehomed BTSs. After a BSC is faulty, services of the BTSs serving VIP subscribers can recover, but services of the remaining BTSs are interrupted. For example, the BSCa supports 3000 TRXs of which 1000 TRXs are configured for dual-homed BTSs; the BSCb supports 1000 TRXs of which 500 TRXs are configured for dual-homed BTSs. In this situation, the XPU of the BSCa can support 3500 TRXs and that of the BSCb can support 2000 TRXs. This rule also applies to other boards. If the active BSC has been configured with the SAU, NIU, NASP, or GCG, the standby BSC must also be configured with the same board to ensure that related functions and features can recover after services on the standby BSCs are recovered. The inter-BSC detection link interface used in the BSC Node Redundancy feature is a Huawei-customized interface which carries necessary equipment information for inter-BSC interaction, such as heartbeat messages. When the inter-BSC SCTP detection link is configured, the inter-BSC interface can only use IP transmission. Therefore, an IP interface board is required or the existing IP interface board is used. The GOUc or GOUe on the BSC6900 can carry the inter-BSC detection link interface. The traffic on the inter-BSC detection link can be neglected. Therefore, capacity planning is not required for the traffic. 22.4.5 Interface Design The following table describes the requirements for transmission modes used by different interfaces during the implementation of BSC Node Redundancy. 2015-11-13 Huawei Confidential Page 235 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) A Interface C o n t r o l P l a n e A Interface User Plane Abis Interface Support BSC Node Redundancy IP over ETH IP over ETH IP over ETH Manual switchover/automatic switchover IP over ETH IP over ETH (E1/T1 transmission terminated at the router) Manual switchover/automatic switchover IP over ETH IP over ETH (the BTS directly connected to the BSC) Manual switchover TDM TDM TDM Not support For details about transmission modes used by different interfaces, see section "Network Topologies." 2015-11-13 Huawei Confidential Page 236 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) According to the GSM 03.71, Figure 1.1 shows the logical structure of the LCS system on the GSM network. Figure 1.1 Logical structure of the LCS system on the GSM network LMU Type A CBC BTS (LMU Type B) Abis Abis SMLC SMLC HLR CBC-BSC Um MS Lp CBC-SMLC Ls Lb Lh A BSC MSC/VLR Lg Le GMLC Gb Gs External LCS client Lc Lg SGSN LMU Type B gsmSCF GMLC Other PLMN Table 1.1 NEs involved in the LCS service 2015-11-13 NE Function Description LCS Client The LCS client is a logical function entity that requests location information of one or multiple MSs from the LCS server. The location request message contains the QoS parameter. The LCS client can reside in entities on the PLMN (including MSs) or entities out of the PLMN. MS The LCS server can provide location information for an MS. For the network-based LCS, a destination MS does not need to support the LCS. For an MS-assistant or MS-based LCS, an MS needs to support the LCS. For all LCSs, the MS privacy can be controlled through registration in each location request. On the LCS client, a destination MS can be identified using MSISDN. On the PLMN network, a destination MS can be identified using MSISDN, IMSI, or an internal flag of the PLMN network. In emergency calls, a destination MS can be identified using MSISDN, IMSI, or NAESRK+IMEI. Huawei Confidential Page 237 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) NE Function Description SMLC The serving mobile location center (SMLC) coordinates and schedules resources required for the LCS and calculates location estimation results and precision. Two SMLCs are available: NSS-based SMLC and BSS-based SMLC. The NSS-based SMLC interworks with one or multiple MSC servers over the Ls interface to support the LCS and manage the LMU. The BSS-based SMLC interworks with one or multiple BSCs over the Lb interface to support the LCS and manage the LMU. Both NSS-based SMLC and BSS-based SMLC can obtain resources and information of other SMLCs over the Lp interface. The SMLC and the gateway mobile location center (GMLC) can be integrated into one physical node or can reside in different physical nodes. When the CBC connects to the BSC, the SMLC needs to interwork with the CBC to perform assistance data broadcast using the cell broadcast function of an existing cell. GMLC One PLMN network can have multiple GMLCs. The GMLC is the first node through which an external LCS client accesses the GSM network. After the GMLC receives an LCS request from an LCS subscriber, it queries route information of a destination MS from the HLR over the Lh interface. After the GLMC authenticates an LCS subscriber, it sends the LCS request to the VMSC over the Lg interface. After the LCS flow ends, the GMLC obtains the location estimation result from the VMSC. LMU The LMU is a logical network entity. Its LCS measurement function can support one or multiple LCS methods. The LMU measurement is classified into the following two measurements:  LCS measurement for an MS: is used to calculate the location estimation result of an MS.  Assistance measurement for all MSs in a specific geographic area: is used to perform periodic measurement over radio interfaces, such as Absolute Time Differences (ATD) and Real Time Differences (RTD). Each LMU is controlled and managed by an SMLC on the network. Measurement parameters and relevant commands of the LMU can be provided by this SMLC or preset in the LMU. All measurement results of the LMU are reported to the SMLC through an LCS request. The LMU is classified into the A-type and B-type LMUs: 2015-11-13  The A-type LMU is identified with the IMSI. It adopts the same frequency with an MS and accesses the BTS over the Um interface. It does not connect to any NE. It has an independent subscription profile in the HLR and supports the mobility management function of all radio resources and interfaces. The HLR differentiates the A-type LMU and an MS based on settings in the subscription profile.  The B-type LMU accesses the BSC over the Abis interface. It can be deployed independently or be integrated into the BTS. Huawei Confidential Page 238 of 258 CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.0 & BSC6910) NE Function Description MSC/VLR The MSC/VLR registers and authenticates an MS and manages LCS requests relevant or irrelevant to GSM calls. The MSC server accesses the GMLC over the Lg interface and the SMLC over the Ls interface. If the MSC server connects to the SGSN over the Gs interface, the MSC server checks whether an MS is in the GPRS attach status to determine whether it pages the MS over the A interface or the Gs interface. SGSN The SGSN transfers paging requests in the CS domain received over the Gs interface to the BSS. BSC The BSC connects to the SMLC over the Lb interface. It provides system operation capability and LCS assistance function in the LCS flow. HLR The HLR stores LCS subscription data and route information of an MS. It connects to the GMLC over the Lh interface. For a roaming MS, the HLR serving the MS and the SMLC may reside in different PLMN networks. CBC The CBC connects to or is embedded the broadcast entity of the BSC. It broadcasts LCS assistance information specified by the SMLC to cells managed by the BSC using the signaling between the CBC and the SMLC. gsmSCF The gsmSCF connects to the GMLC over the Lc interface and can visit the LCS using the CAMEL III. Huawei BSC supports the LCS service only in the CELL+TA mode. It supports NSS-based SMLC and BSS-based SMLC and does not support the LMU. 22.5.1.1.1Step 1Figure 1.2 shows the logical structure of the NSS-based SMLC. 22.5.1.1.1Step 1Figure 1.3 shows the logical structure of the BSS-based SMLC. In this scenario, Huawei BSC and the SMLC are integrated. Figure 1.2 Logical structure of the NSS-based SMLC 2015-11-13 Huawei Confidential Page 239 of 258 0 & BSC6910) Figure 1. configure the LCS function data on the BSC and longitude and latitude information of each cell.0 & GBSS17. Figure 1.4 shows the LCS flow initiated by an external LCS client.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.3 Logical structure of the BSS-based SMLC Figure 1. 2015-11-13 Huawei Confidential Page 240 of 258 .4 LCS flow initiated by an external LCS client For the A interface in the LCS design. 0 & BSC6910) CONFIDENTIAL 22. the MS privacy can be controlled through registration in each location request.1 shows the logical structure of the LCS system on the GSM network. Huawei Confidential Page 241 of 258 . MS The LCS server can provide location information for an MS. but can meet the requirements of those services requiring low precision. On the PLMN network. For an MS-assistant or MS-based LCS.1 Logical structure of the LCS system on the GSM network CBC BTS (LMU Type B) Abis Abis SMLC SMLC HLR CBC-BSC Um MS Lp CBC-SMLC LMU Type A Ls Lb Lh A BSC MSC/VLR Lg Le GMLC Gb Gs External LCS client Lc Lg SGSN LMU Type B gsmSCF GMLC Other PLMN Table 1. On the LCS client. Figure 1. Figure 1. For the network-based LCS. or NA-ESRK+IMEI. For all LCSs. The LCS service provides MSs with the weather report. or an internal flag of the PLMN network. The precision of the LCS service implemented on the GSM network is low. IMSI. an MS needs to support the LCS.71. IMSI. According to the GSM 03. and traffic conditions based on the location of MSs.Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. a destination MS can be identified using MSISDN. The LCS client can reside in entities on the PLMN (including MSs) or entities out of the PLMN.5 LCS Function Design The location service (LCS) is a special service specific to the GSM network. The location request message contains the QoS parameter. a destination MS does not need to support the LCS. a destination MS can be identified using MSISDN. emergency aid. tour arrangement.1 NEs involved in the LCS service 2015-11-13 NE Function Description LCS Client The LCS client is a logical function entity that requests location information of one or multiple MSs from the LCS server. a destination MS can be identified using MSISDN.0 & GBSS17. In emergency calls. If the MSC server connects to the SGSN over the Gs interface. The LMU measurement is classified into the following two measurements:  LCS measurement for an MS: is used to calculate the location estimation result of an MS. Both NSS-based SMLC and BSSbased SMLC can obtain resources and information of other SMLCs over the Lp interface. GMLC One PLMN network can have multiple GMLCs. It has an independent subscription profile in the HLR and supports the mobility management function of all radio resources and interfaces.0 & GBSS17.  Assistance measurement for all MSs in a specific geographic area: is used to perform periodic measurement over radio interfaces. The BSS-based SMLC interworks with one or multiple BSCs over the Lb interface to support the LCS and manage the LMU. it queries route information of a destination MS from the HLR over the Lh interface. Measurement parameters and relevant commands of the LMU can be provided by this SMLC or preset in the LMU. Its LCS measurement function can support one or multiple LCS methods. It adopts the same frequency with an MS and accesses the BTS over the Um interface. All measurement results of the LMU are reported to the SMLC through an LCS request. the MSC server checks whether an MS is in the GPRS attach status to determine whether it pages the MS over the A interface or the Gs interface. When the CBC connects to the BSC. The GMLC is the first node through which an external LCS client accesses the GSM network. Two SMLCs are available: NSS-based SMLC and BSS-based SMLC. the SMLC needs to interwork with the CBC to perform assistance data broadcast using the cell broadcast function of an existing cell. The SMLC and the gateway mobile location center (GMLC) can be integrated into one physical node or can reside in different physical nodes.0 & BSC6910) SMLC The serving mobile location center (SMLC) coordinates and schedules resources required for the LCS and calculates location estimation results and precision. After the GMLC receives an LCS request from an LCS subscriber. The MSC server accesses the GMLC over the Lg interface and the SMLC over the Ls interface. The MSC/VLR registers and authenticates an MS and manages LCS requests relevant or irrelevant to GSM calls. Huawei Confidential Page 242 of 258 . such as Absolute Time Differences (ATD) and Real Time Differences (RTD).CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. It can be deployed independently or be integrated into the BTS. The NSS-based SMLC interworks with one or multiple MSC servers over the Ls interface to support the LCS and manage the LMU. Each LMU is controlled and managed by an SMLC on the network. After the GLMC authenticates an LCS subscriber. It does not connect to any NE. LMU The LMU is a logical network entity. After the LCS flow ends. the GMLC obtains the location estimation result from the VMSC. it sends the LCS request to the VMSC over the Lg interface. The HLR differentiates the A-type LMU and an MS based on settings in the subscription profile. The LMU is classified into the A-type and B-type LMUs: MSC/VLR 2015-11-13  The A-type LMU is identified with the IMSI.  The B-type LMU accesses the BSC over the Abis interface. It supports NSS-based SMLC and BSS-based SMLC and does not support the LMU. Figure 1. It provides system operation capability and LCS assistance function in the LCS flow.2 shows the logical structure of the NSS-based SMLC.3 Logical structure of the BSS-based SMLC Figure 1. HLR The HLR stores LCS subscription data and route information of an MS. Huawei BSC and the SMLC are integrated. It broadcasts LCS assistance information specified by the SMLC to cells managed by the BSC using the signaling between the CBC and the SMLC.2 Logical structure of the NSS-based SMLC Figure 1. the HLR serving the MS and the SMLC may reside in different PLMN networks.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17. In this scenario. Figure 1. gsmSCF The gsmSCF connects to the GMLC over the Lc interface and can visit the LCS using the CAMEL III. It connects to the GMLC over the Lh interface. 2015-11-13 Huawei Confidential Page 243 of 258 . CBC The CBC connects to or is embedded the broadcast entity of the BSC. BSC The BSC connects to the SMLC over the Lb interface.0 & BSC6910) SGSN The SGSN transfers paging requests in the CS domain received over the Gs interface to the BSS. For a roaming MS. Figure 1. Huawei BSC supports the LCS service only in the CELL+TA mode.3 shows the logical structure of the BSS-based SMLC.4 shows the LCS flow initiated by an external LCS client. 0 & BSC6910) Figure 1. configure the LCS function data on the BSC and longitude and latitude information of each cell.0 & GBSS17. 2015-11-13 Huawei Confidential Page 244 of 258 .4 LCS flow initiated by an external LCS client For the A interface in the LCS design.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. see section 19. carrier quantity. tools are available for the cable connection design for major BTS types.com. 23. Onsite TSD personnel can obtain the tool at http://support.2 Input of the Design Network plan data of a cell (BTS type.2 Design Tool of the BTS Cable Diagram Currently. The TDM supports a maximum of 126 carriers and the IP over FE supports a maximum of 60 carriers.3.0 & GBSS17. and frequency) 23.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. 23. design BTS transmission networking methods under different transmission conditions to provide guidance for engineers in construction and improve work efficiency.1.3 BTS Transmission Design 23. SXXX.1 BTS Cable Design 23.1 Purpose of the Design Design the internal cable diagram of the BTS in different BSC types and configurations to provide guidance for engineers in construction and improve work efficiency.0 & BSC6910) 23 BTS Design 23.1 Purpose of the Design For the Huawei's third and fourth generation of BTSs with the most installed base in the market. For details about networking.2 BTS Transmission Huawei's third and fourth generation of BTSs support the TDM and IP over FE/GE. 23.1.5"Abis Interface Design. The carrier quantity supported by different transmission protocols varies.3." 2015-11-13 Huawei Confidential Page 245 of 258 .huawei. UIEB. DPTU TDM. IP over FE E1/T1. FE No BTS3006C DMCM TDM E1/T1. BTS3900B PICO IP over FE FE N/A BTS3900A GTMU. DPTU TDM. FE/GE Hybrid usage of TDM and IP is not supported. IP over FE E1/T1. UTRPC TDM. BTS3900E MICRO TDM. 2015-11-13 Huawei Confidential Page 246 of 258 .0 & GBSS17. UIEB.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. STM-1 N/A BTS3900 GTMU. BTS Type Transmission Board Supported Transmission Mode Supported Transmission Interface Hybrid Usage of Transmission Interface Supported? BTS3012 DTMU. IP over FE/GE E1/T1. UTRPC TDM. IP over FE/GE E1/T1. UTRPC TDM. UIEB. transmission interface boards of GSM BTSs are DTMU and GTMU.0 & BSC6910) Constraints on usage of different transmission media (E1 and FE): Currently. IP over FE/GE E1/T1. IP over FE/GE E1/T1. UTRPC TDM. FE/GE Hybrid usage of TDM and IP is not supported. UIEB. FE No BTS3900L GTMU. FE/GE Hybrid usage of TDM and IP is not supported. The DTMU does not support hybrid usage of E1 and FE interfaces. BTS3900AL GTMU. FE No BTS3012AE DTMU. IP over FE E1/T1. FE/GE Hybrid usage of TDM and IP is not supported. the IP address needs to be configured on port 1. In an upgrade of an installed site. The BTS communicates with the BSC either in the port IP communication mode or in the logical IP communication mode. The following table shows advantages and disadvantages of these two communication modes. BTSIP needs to be the same as the device IP address of Ethernet port 1. The following table describes comparison of two versions.  Comparison of GBSS9.0 and later versions when the BTS adopts the port IP communication mode Configuration of the Port IP Communication Mode GBSS9. add VLAN tags based on the IP address of the next hop. For new sites.0. VLAN tags can be added based on the service type. If the BTS adopts the port IP communication mode. When the BTS adopts the port IP communication mode and only the electrical interface is used. the BTS adopts the logical IP communication mode.0 and Later Version FE0 configured FE1 not configured Support Support FE0 configured FE1 configured Not support Support FE0 not configured FE1 configured Not support Support If BTSIP configured on the BSC side is the same as the device IP address of any port configured on the BTS. IP over FE/GE E1/T1.0 is the same as that in GBSS9.  2015-11-13 Advantages and disadvantages of the port IP communication mode and the logical IP communication mode Huawei Confidential Page 247 of 258 . When the BTS adopts the port IP communication mode and only the optical interface is used. only configurations of port 0 are supported in GBSS9.0 and configurations of the FE optical interface are added to support the GU transmission backup scenario in GBSS12. BTSIP needs to be the same as the device IP address of Ethernet port 0.0 & GBSS17.0 and later versions. see the deployment guide of the BSC6910.0 & BSC6910) DBS3900 GTMU. That is. the IP address needs to be configured on port 0. FE/GE Hybrid usage of TDM and IP is not supported.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. UTRPC TDM. The BSC communicates with the BTS either in the port IP communication mode or in the logical IP communication mode. the BTS adopts the port IP communication mode. UIEB. except for the GTMUa board. If BTSIP differs from the device IP configured on the BTS. The logical IP communication in GBSS14. That is.0 GBSS12.0 and GBSS12. For details about configuration methods. The eGBTS has the following characteristics: 2015-11-13  The BTS provides the southbound interface and OM channels.  The BSC supports the hybrid networking of non-eGBTS and GBTS. BTS3900 eGSM. Port IP addresses are used as service IP addresses. but does not support hybrid cascading.  When intermediate layer-3 transmission devices are available. which is the same as that of the UMTS. which requires less IP addresses.  When physical links are faulty.  The original Abis interface is adjusted to the Abis 2. which requires more IP addresses.0. BTS3900A eGSM. The M2000/CME can directly manage the eGBTS. BTS3900L eGSM. Logical IP Communication Mode  Logical IP addresses are used as service IP addresses. The original OML changes to CSL and the message flow also changes.3. cooperation of links is difficult to be implemented to ensure that services are not affected. cooperation of links is easy to be implemented to ensure that services are not affected. which has high requirements on transmission networks. routes of this logical IP address need to be identified. Disadvantage   When physical links are faulty.  Static routes to logical IP addresses need to be configured. 3900 series base stations support the eGBTS and matching BTS types are DBS3900 eGSM.0 interface.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17. and BTS3900AL eGSM.  The BTS LMT maintains and manages local and remote eGBTSs.0 & BSC6910) Advantage/Disadva ntage Port IP Communication Mode Advantage  The configuration is simple.  The BTS license file is added and the file is directly loaded on the BTS. 23.  The layer-2 LAPD over the original Abis interface changes to the SCTP. Huawei Confidential Page 248 of 258 .  Port addresses of intermediate transmission networks are visible. Compared with the transmission GBTS.3 eGBTS Networking The eGBTS is introduced in the GBSS15. Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & BSC6910) CONFIDENTIAL Figure 1.2 Change of northbound and southbound interfaces of the eGBTS 2015-11-13 Huawei Confidential Page 249 of 258 .0 & GBSS17.1 Networking topology change of the eGBTS Figure 1. Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. BSC.2 Design Content  Networking of the BSS and the NMS  Calculation of NMS bandwidth 24.1 Design Overview 24. The ETH0 and ETH1 are network cards for external communication. Download the BSC GOMU Management Guide at http://support.1 Standalone OMU The ETH5-SCU6 and ETH4-SCU7 are network cards for internal communication.huawei.3 Reference M2000 Commissioning Guide 24.1. 2015-11-13 Huawei Confidential Page 250 of 258 .0 & BSC6910) 24 CONFIDENTIAL OM Networking Design 24.1. connecting to the LMT through the LAN switch or hub.2.1. The OMU connects to the SCU using the cards to obtain the performance and alarm information of the BSC board.1 Input of the Design  Physical position of the MSC.com. and PCU and the topology  Number of BTSs 24.2 Introduction to OMU 24.0 & GBSS17. connecting to the LMT through the LAN switch or hub. The active and standby OMUs are configured with the same IP address. Download the BSC GOMU Management Guide at http://support. 2015-11-13 Huawei Confidential Page 251 of 258 . The active and standby OMUs connect four LAN cables to the hub or LAN switch.huawei.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & BSC6910) Figure 1.2 Dual OMU The ETH5-SCU6 and ETH4-SCU7 are network cards for internal communication.0 & GBSS17. The OMU connects to the SCU using the cards to obtain the performance and alarm information of the BSC board. The ETH0 and ETH1 are network cards for external communication.1 Standalone OMU 24.2. The ETH3-UPDATE is a network card used to connect two OMUs working in active/standby mode. to implement data synchronization and software update.com. The timeslot extraction principle (specific to Mercury3600) is as follows: 2015-11-13 Huawei Confidential Page 252 of 258 . networking for part of E1 timeslots is recommended.1 Dual OMUs 24.3. If the existing network is TDM-based. MSC.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. the following devices are required: router. The peer end cross-connects the NMS information and provides the information to the NMS by using a router. entire E1 networking is preferred. and Mercury3600.0 & GBSS17. That is. use the IP networking.1 Networking for Part of E1/T1 Timeslots In this mode. If the existing network is TDM-based and the customer has high requirements on cost.0 & BSC6910) Figure 1. some of timeslots of the E1 link are used as operation and maintenance channels. 24.3 OM Networking Design If the network of a customer is IP-based. The core of networking for part of E1 timeslots is as follows: Cross-connect the NMS information to the idle timeslots of the existing E1 link by using the Mercury3600 for transmitting the information to the peer end. Cross connection of any timeslot can be performed on any two ports.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.2 shows a typical OM networking. Figure 1. In the current OM networking.1 25-pin D model interface For details.0 & BSC6910) In the networking mode of part of E1 timeslots. see the Mercury 3600 Manual. Any port can use the near loop or remote loop to implement performance monitor and system maintenance. Mercury3600 uses a 4-E1 interface card (with 25-pin D model). Figure 1. 2015-11-13 Huawei Confidential Page 253 of 258 . timeslot cross-connect devices. such as Mercury3600 are used.0 & GBSS17. A maximum of 16 E1 channels can be provided. The four universal slots of a Mercury3600 can be inserted with 4-E1 interface cards and 2-V35 interface cards.1 shows the pins. Figure 1. Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Figure 1. routers and MSCs are required. applicable to a network requiring abundant transmission resources and large data volume. Figure 1. entire E1 networking does not require cross-connect devices for timeslot extraction and exchange.2 Networking for part of E1/T1 timeslots 24.0 & BSC6910) CONFIDENTIAL Figure 1.1 Entire E1/T1 Networking 2015-11-13 Huawei Confidential Page 254 of 258 .3. In this mode. An entire 2 Mbit/s E1 link can be used for information transmission.0 & GBSS17.1 shows a typical OM networking.2 Entire E1/T1 Networking Compared with networking for part of E1 timeslots. 2015-11-13 Huawei Confidential Page 255 of 258 . Each OMU is configured with a physical IP address. the NMS device only needs to provide a network interface because the routes of the IP network and remote end are completed. Therefore.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.0 & GBSS17.1 and Figure 1.0 & BSC6910) 24. Figure 1. The bandwidth for IP networking is allocated by the operator as required.2 IP networking in dual OMU mode In dual OMU mode. In an IP network.3.3 IP Networking Usually. The three IP addresses are in the same network segment. A private IP network requires private transmission resource. three IP addresses need to be planned.2 show typical OM networking. With high reliability and high transmission efficiency. Figure 1. this networking mode is preferred in the area where the operator has constructed a private IP network. IP networking is used in the private network of an operator. cost is high. Two OMUs share a logical IP address.1 OM network topology Figure 1. switch is performed on ports of the same board.1 OM E1 networking instance 1 To facilitate M2000 maintenance.2 show an office adopting E1 networking.4 Networking Instances Figure 1.3.Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. Figure 1.0 & BSC6910) CONFIDENTIAL Preferentially. 24. Mercury3600s in this networking provide port conversion and timeslot adjustment functions. The BSCs in other cities are remotely connected to this equipment room. 2015-11-13 Huawei Confidential Page 256 of 258 .1 and Figure 1. E1 transmission is used.0 & GBSS17. three M2000s are placed in an equipment room. 4 OM IP Address Planning Negotiate with operators how to plan IP addresses.  Divide a large network segment into small subnets based on the subnet masks of IP addresses and allocate the IP addresses of the subnets to LANs.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10. 24. 2015-11-13 Huawei Confidential Page 257 of 258 .5 Route Planning The network between the network card of extranet of the GOMU and the LMT/M2000 is defined as the extranet. to save IP network segment.0 & BSC6910) Figure 1.2 OM E1 networking instance 2 24.0 & GBSS17.  Ensure the WAN ports of routers with different office directions in different network segments. When planning IP addresses.  Ensure the WAN ports of two routers connecting and communicating with each other in different network segments.  Assess the number of IP addresses that can be allocated and the extension space in future when allocating IP addresses of subnets. The GOMU can connect to the LMT/M2000 directly or through multiple routers (gateways). pay attention to the following:  Ensure the IP addresses of the LANs connected to a WAN in different network segments.  Ensure the LAN port and the WAN port of a router in an office in different network segments. transmission.CONFIDENTIAL Technical Guide to SRAN Network Design (GO Applicable to the SRAN10.  For the eGBTS. The northbound model of this NE type differs from that of the non-eGBTS.0. This OM management function is implemented by the M2000 and the BTS LMT currently. rather than the IP address of the master server and the slave server of the M2000. The OM management channel and the southbound interface are added between the OSS and the eGBTS and are managed by the M2000 as the new NE type. routs between the OMU and M2000 need to be added. the OMU must connect to the master server and the slave server of the M2000. In the eGBTS. BTSs are managed by the BSC and access the OSS. BTSs do not have independent southbound interfaces. a route to the newly added slave server of the M2000 is added on the OMU. 24. and local logical objects of the BTS. On a hybrid network.1 Change of the OM structure 2015-11-13  The OM model and function of the non-eGBTS are deployed on the BSC side. If multiple the M2000 has multiple network segments. The OSS manages the OM of physical devices. The BSC implements only the logical model and service processing. Huawei Confidential Page 258 of 258 . Operation and maintenance can be performed on the local eGBTS or by remotely connecting to the eGBTS through the communication network. a set of northbound interfaces are available and can be differentiated through the NE type. Figure 1.0 & BSC6910) When the OMU communicates with the M2000 through routers (gateways). relevant models and functions of physical devices and transmissions of the BTS are adjusted from the BSC to the BTS.0 & GBSS17.1 shows the change of the OM structure. a new NE type is added on the OSS northbound interface. Ensure that when a slave server of the M2000 is added. In this case.  The BSC6910 LMT is removed with the OM management function of public physical devices and transmission of the eGBTS. Set the destination IP address of the OMU route to the network segment address of M2000 by running ADD OMUIPRT. Figure 1.  The BTS LMT is added for the eGBTS. set the destination IP address to multiple network segment addresses.  The local maintenance tool SMT of the non-eGBTS is removed in the eGBTS and its function is migrated to the BTS LMT.6 Impact of eGBTS on the O&M The eGBTS is introduced in the GBSS15.