High Capacity Base Station Controller, BSC2i, BSCi.pdf

2003282Nokia BSC S10.5 ED, Product Documentation High Capacity Base Station Controller, BSC2i (ETSI/ANSI), BSCi dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 1 (68) High Capacity Base Station Controller, BSC2i (ETSI/ANSI), BSCi The information in this document is subject to change without notice and describes only the product defined in the introduction of this documentation. This document is intended for the use of Nokia's customers only for the purposes of the agreement under which the document is submitted, and no part of it may be reproduced or transmitted in any form or means without the prior written permission of Nokia. The document has been prepared to be used by professional and properly trained personnel, and the customer assumes full responsibility when using it. Nokia welcomes customer comments as part of the process of continuous development and improvement of the documentation. The information or statements given in this document concerning the suitability, capacity, or performance of the mentioned hardware or software products cannot be considered binding but shall be defined in the agreement made between Nokia and the customer. However, Nokia has made all reasonable efforts to ensure that the instructions contained in the document are adequate and free of material errors and omissions. Nokia will, if necessary, explain issues which may not be covered by the document. Nokia's liability for any errors in the document is limited to the documentary correction of errors. NOKIA WILL NOT BE RESPONSIBLE IN ANY EVENT FOR ERRORS IN THIS DOCUMENT OR FOR ANY DAMAGES, INCIDENTAL OR CONSEQUENTIAL (INCLUDING MONETARY LOSSES), that might arise from the use of this document or the information in it. This document and the product it describes are considered protected by copyright according to the applicable laws. NOKIA logo is a registered trademark of Nokia Corporation. Other product names mentioned in this document may be trademarks of their respective companies, and they are mentioned for identification purposes only. Copyright © Nokia Corporation 2003. All rights reserved. 2 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en Contents Contents Contents 3 Summary of changes 5 1 1.1 1.2 1.3 1.4 High Capacity Base Station Controller Overview 7 Use of the terms BSC, BSCE, BSCi, BSC2E/A, BSC2i and BSC3i The GSM/EDGE Product Family 9 The Nokia Base Station Controller Product upgrades 10 Features of the BSC platform 10 2 Functionality of the High Capacity BSC 13 3 Architecture of the High Capacity Base Station Controller, BSC2i (ETSI/ANSI), BSCi 23 General design of the GSM/EDGE BSC 23 Bit Group Switch 25 Call Control Computers 25 Marker and Cellular Management Unit (MCMU) 26 BSC Signalling Unit (BCSU) 27 Operation and Maintenance Unit (OMU) 30 Message Bus (MB) 32 Exchange Terminal (ET) 33 Clock and Synchronisation Unit (CLS) 34 Peripheral devices 34 Disk units 35 DAT (optional) 35 Printer (optional) 35 Visual display unit (optional) 35 Alarm lamp panel (optional) 36 Cable Conduit with Cabling Rack for raised floor installations 36 Applicable NEBS3 compliance (optional) 36 3.1 3.2 3.3 3.3.1 3.3.2 3.4 3.5 3.6 3.7 3.8 3.8.1 3.8.2 3.8.3 3.8.4 3.8.5 3.8.6 3.8.7 4 8 4.1 4.2 4.3 4.4 4.5 Interfaces relating to the High Capacity Base Station Controller, BSC2i (ETSI/ANSI), BSCi 37 A interface 37 Abis interface 38 Gb interface 39 Q3 interface 40 CBC interface (BSC-CBC) 41 5 5.1 5.2 5.3 5.4 High Capacity BSC Software 43 Platform architecture 43 Layers 44 Databases 44 Description and programming languages 6 6.1 Configurations and capacity of the High Capacity BSC 47 General description of configuration 47 dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 45 3 (68) 3.2 Mechanical design and power supply of the High Capacity BSC 51 Mechanical design 51 Plug-in units 51 Cartridges 51 Racks 54 Cabling 57 Dimensioning of the GSM/EDGE BSC 58 Power supply 58 Structure of power supply 58 Power consumption 58 8 8.1.4 7.3 7.2 7.3 8.2.2 7.1.2 9.2 Capacity of the BSC 47 7 7.5 Reliability of the High Capacity Base Station Controller 61 Fault management 61 Overload protection 62 Redundancy principles 62 System availability 62 Planned downtime 63 9 9.4 8.2 8.2. BSCi 4 (68) 6.2.2.4 High Capacity BSC Operating environment 65 Equipment room 65 Environmental conditions 66 General 66 Climatogram 67 Cooling of racks 67 Electromagnetic environment 68 © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en .High Capacity Base Station Controller.3.1 7.2 9.3 9.1 8.1 9. BSC2i (ETSI/ANSI).1 7.1 7.1.1.3 7.1 9. Changes made between issues 4 and 3 The information has been updated to software release S10. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 5 (68) . no changes have been made to the content. The chapter High Capacity BSC Software has been moved to just before the chapter Configurations and capacity of the High Capacity BSC . Added references to BSC3i. The chapter Reliability of the High Capacity Base Station Controller has been moved to after the chapter Mechanical design and power supply of the High Capacity BSC . the latest document issue contains all changes made to previous issues. EDGE/EGPRS and MS Location Services . BSCi . Therefore. section The Nokia Base Station Controller Product Family Added Second PCU upgrade delivery and SMLC (Serving Mobile Location Centre) upgrade delivery . Chapter Functionality of the High Capacity BSC Added new sections Adaptive Multi Rate Codec . Changes made between issues 4a and 4 Only minor structural changes have been made. Changes made between issues 3 and 2 Chapter Architecture of the High Capacity Base Station Controller.Summary of changes Summary of changes Summary of changes Changes between document issues are cumulative. section Peripheral devices Added two new sections: Cable Conduit with Cabling Rack for raised floor installations and Applicable NEBS3 compliance (optional) .5 level. Changes made between issues 2 and 1 Chapter Introduction to the DX 200 High Capacity Base Station Controller . BSC2i (ETSI/ ANSI). Chapters About the High Capacity Base Station Controller and Introduction to the DX 200 High Capacity Base Station Controller combined to High Capacity Base Station Controller Overview. section Power consumption Power consumption figures have been updated. section Racks ET5C 7 and 8 have been added to the figure Rack layouts of the DX 200 BSC2i first deliveries Chapter Mechanical design and power supply of the High Capacity BSC . Chapter Reliability of the High Capacity Base Station Controller The availability figures have been updated. 6 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . BSCi Chapter Configurations and capacity of the High Capacity BSC .High Capacity Base Station Controller. BSC2i (ETSI/ANSI). Chapter Mechanical design and power supply of the High Capacity BSC . section Capacity of the BSC The paragraph of different types of connections contains updated figures. the specific name BSCi. configurations and capacity. DX200 BSCi. Here are described the functionality at S10. the architecture. They also control signalling to the BTS. There are different types of S10. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 7 (68) . The software features are described elsewhere in the GSM/EDGE BSC documentation library. The Nokia GSM/EDGE BSC product family provides the operator with the means to control terrestrial and radio channels. DX200 BSC2i. BSC2i or BSC3i variant. BSC2i or BSC3i is used. and the high capacity version of the first generation DX200 Base Station Controller for ETSI environment.High Capacity Base Station Controller Overview 1 High Capacity Base Station Controller Overview The following is an overview of the high capacity version of the second generation GSM/EDGE Base Station Controller for ETSI and ANSI environment. When the information is applicable only to the BSCi. Another important function of the BSC is to have an operation and maintenance interface towards NetAct. interfaces.5 level.5 Release deliveries: " upgrade deliveries of the BSCE (BSCE to BSCi) " upgrade deliveries of the BSC2E/A (BSC2E/A to BSC2i) " upgrade deliveries of the BSC2i " GPRS upgrades to all of the above " SMLC upgrade " first deliveries of the BSC2i " first deliveries of the BSC3i In addition to the above. extension deliveries are available for the BSC2i and BSC3i. reliability and operating environment of the High Capacity BSC. BSC is used here as the general term for the Nokia GSM/EDGE Base Station Controller. ANSI version American National Standards Institute (ANSI) High Capacity version of the Nokia DX 200 BSC2   BSC2i.High Capacity Base Station Controller. The Nokia GSM/EDGE BSC product family BSC Base Station Controller. BSC2i and BSC3i The terms BSC. External PCM lines (lines which go out of the BSC) are 1. BSCE. both internal and external lines are 2 Mbit/s lines of E1 ETSI hierarchy. a general term for all Nokia GSM/EDGE BSC versions General name Product name Explanation BSCE BSCE First generation Nokia DX 200 BSC BSCi BSCi High Capacity (upgraded and improved) version of the first generation Nokia DX  200 BSC BSC2 BSC2A American National Standards Institute (ANSI) version of the second generation Nokia DX 200 BSC2   BSC2E European Telecommunications Standards Institute (ETSI) version of the second generation Nokia DX 200 BSC2 BSC2i BSC2i. Table 1. BSCi PCM lines are mentioned frequently here.1 Use of the terms BSC.5 Mbit/s lines of T1 ANSI hierarchy. BSC2E/A. In the ETSI version. ETSI version European Telecommunications Standards Institute (ETSI) High Capacity version of the Nokia DX 200 BSC2 BSC3i BSC3i. BSC2E/A. BSC2i (ETSI/ANSI). There are two types of PCM lines in the BSC2: internal or external. 1. BSC2i and BSC3i are explained in the table below. BSCE. internal PCM lines (lines which run within the BSC) are 2 Mbit/s lines of E1 ETSI hierarchy. ANSI version American National Standards Institute (ANSI) High Capacity version of the Nokia GSM/EDGE BSC3i 8 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . In the ANSI (US) BSC2. BSCi. BSCi. 1. The Nokia BSC is a stable. such as Base Station Controller (BSC). the BSC is designed for efficient use of radio resources and is easy to operate and maintain.High Capacity Base Station Controller Overview Table 1. mature and highly reliable product. the name of that specific version or application is used. Based on Nokia's long experience in cellular networks. The Nokia GSM/EDGE BSC product family (cont. Together with the functionally distributed modular architecture of the DX 200 Computing Platform and the latest commercially available industry standard hardware components. The Nokia BSC is based on modular software and hardware architecture.) BSC3i. Transcoder Submultiplexer (TCSM2). The DX 200 product family contains products for digital mobile applications. One major feature of the BSC is its field-proven multivendor functionality. The distributed architecture of the Nokia BSC is implemented with a high-capacity and redundant multiprocessor system . dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 9 (68) . and when the text is applicable to all versions and applications.2 The GSM/EDGE Product Family The Nokia GSM/EDGE Base Station Controller is a modern fault-tolerant system for GSM 800/GSM 900/GSM 1800/GSM 1900 networks. Mobile Switching Centre (MSC). The system enables the distribution of processing capacity to several computer units with dedicated tasks. The main function of the BSC is to control and manage the Base Station Subsystem (BSS) and the radio channels. Home Location Register (HLR) and 2G Serving GPRS Support Node (SGSN). the BSC is easily expandable and cost-efficient and has high capacity. ETSI version European Telecommunications Standards Institute (ETSI) High Capacity version of the Nokia GSM/ EDGE BSC3i Note When the information in the text is only applicable to one of the versions or applications.the DX 200 Computing Platform. the general term BSC is used. The DX 200 product family covers a wide application area in GSM/EDGE mobile networks and fixed telephone networks. BSCi 1. BSC2i (ETSI/ANSI).5 release consists of High Capacity upgrade deliveries. The 2nd PCU upgrade is available for the BSC2E/A and BSC2i. SMLC (Serving Mobile Location Centre) upgrade delivery The SMLC upgrade delivery is available for all BSC versions. High capacity configurations up to 512 TRXs with hardware upgrade. High capacity configurations up to 512 TRXs with hardware upgrade.3 The Nokia Base Station Controller Product upgrades The S10. BSCE upgrade delivery The existing BSCE can be upgraded to BSCi. 1. BSC to BSCi and BSC2E to BSC2i and a new BSC2i delivery.4 Features of the BSC platform The main features of the BSC platform are: Reliable platform: " distributed processing " modular structure " fault tolerance " upgradable processors (Intel family) Easy operability: 10 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . GPRS upgrade deliveries and capacity extensions are also possible. The second PCU is upgraded to all configured BCSUs as GPRS/EGPRS extension. BSC2E/A upgrade delivery The existing BSC2E/A can be upgraded to BSC2i.High Capacity Base Station Controller. The GPRS upgrade delivery is available for all BSC versions. (E)GPRS upgrade deliveries All the deliveries above can include the GPRS upgrade as optional hardware. and it also reduces the cost of surplus capacity and enables new facilities to be readily added.High Capacity Base Station Controller Overview " good online operability " OSI protocol model for O & M functions " user-friendly MML interface according to ITU-T (International Telecommunication Union) recommendations Flexible configuration: " expandability in 64 TRX steps from 64 TRXs to up to 512 TRXs in High Capacity BSC configurations " the modular architecture allows you to build economically dimensioned switching systems according to your needs. No special room requirements: dn99558545 Issue 4a-0 en " BSCs are small and compact and low on power consumption " the cooling of the BSC is implemented by means of natural convection © Nokia Corporation Nokia Proprietary and Confidential 11 (68) . BSCi 12 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en .High Capacity Base Station Controller. BSC2i (ETSI/ANSI). The BSC manages a variety of tasks ranging from channel administration to short message service. Management of radio channels " Management of channel configurations. The tasks are explained in brief below. The most common solution is to locate the BSC remotely to the MSC near the BTSs it controls and install the TransCoder SubMultiplexer (TCSM) at the MSC site. half rate and high speed circuit switched data. for example. Management of terrestrial channels " indication of blocking on the A interface channels between the BSC and the MSC " allocation of traffic channels between the BSC and the BTSs " pool support for A interface circuits " concept support for flexible channel assignments. on the same site as the Base Transceiver Station (BTS) it controls. or at a remote location. that is. which can be either co-located or non-co-located with the MSC. how many traffic channels and signalling channels can be used in the BSS.Functionality of the High Capacity BSC 2 Functionality of the High Capacity BSC The GSM/EDGE BSC can be located flexibly in the GSM network. " Management of traffic channels (TCH) and stand-alone dedicated control channels (SDCCH). Submultiplexing can then be used between the BSC and TCSM to reduce transmission costs. This is done in connection with radio network configuration. This function can be subdivided into the following tasks: - dn99558545 Issue 4a-0 en resource management channel allocation link supervision channel release power control © Nokia Corporation Nokia Proprietary and Confidential 13 (68) . It can be installed as stand-alone. High Capacity Base Station Controller. inter-cell. There are two types of LAPD channels: TRXSIG (connection for TRX signalling per TRX) and OMUSIG (BCFSIG) (connection for BTS Operation and Maintenance). " Handovers The frequency of the mobile is changed in connection with handovers which are executed and controlled by the BSC. which means that the handover takes place within the area controlled by the BSC and the mobile stays in the same cell intra-BSC. intra-cell (both intra-TRX and inter-TRX). which means that the mobile stays in the area of the BSC but moves from one cell to another inter-BSC. This function can be subdivided into the following tasks: - " channel management random access access grant paging management of PCCCH/PBCCH for (E)GPRS Management of frequency hopping: The BSC is in charge of frequency hopping management which enables effective use of radio resources and enhanced voice quality for a GSM subscriber. BSCi " Management of broadcast control channels (BCCH) and common control channels (CCCH). 32 or 64 kbit/s permanent point-to-point LAPD signalling connections. Such a handover can be one of the following three types: - - intra-BSC. both outgoing and incoming. which means that the mobile moves into the area of another BSC Management of signalling channels between the BSC and the BTSs The BSC supervises all 16. BSC2i (ETSI/ANSI). Maintenance The BSC offers the possibility for the following maintenance procedures: 14 (68) " fault localisation for the BSC " reconfiguration of the BSC © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 15 (68) . In addition. which are easy to learn and use.25 and a LAN connection to NetAct. This user interface complies with the recommendations of the International Telecommunication Union (ITU-T). TCSM2 and BTS Operation During normal operation. This interface enables the following events: " file transfer capability for downloading software and data into the BSC and the BTSs " file transfer capability for measurement and observation results User interface The BSC has a user-friendly interface with plain-text messages and commands. Interface for NetAct The BSC has an X. The interface between the BSC and the CBC is based on the OSI layer 4 protocol. The interface between these two network elements is based on the OSI protocol.Functionality of the High Capacity BSC " reconfiguration support to the BTS " updating of the software in the BSC. The CBC can also request information on the amount of transmission for each CB. the Cell Broadcast Interface offers improved tools for requesting and reporting of CBCH-related loading and error conditions. the BSC offers various possibilities for the operator: " modification of the parameters of the BSC and the BTS " modification of the radio network parameters " configuration of the BSC hardware " administration of the BSC equipment Interface for the CBC The BSC has an X. The CBC interface offers operators a centralised means of operating Cell Broadcast.25 and a LAN connection to the Cell Broadcast Centre (CBC). you need information on the performance and service level of the BSC and the radio network. and traces a specific call. is there congestion on the SDCCH or TCH channels. you are able to forecast the time when new resources or extensions must be introduced into the network. Traffic measurements provide this information. to minimise costs and maximise service quality to the subscriber. The input is MMI. does the network have both heavily and lightly loaded parts. observes signalling events. Optionally CBC can be used as the input for CB messages. The SMSCB is a basic teleservice that is used for broadcasting short messages to mobile stations in a specified area within the PLMN. BSC measurements are independent of each other even though they are handled via the same user interface. BSCi Measurements and observations In order to run the network effectively. defined in GSM Specification ETS 300 904 with applicable ETSI/3GPP specifications: 16 (68) " Data Circuit Duplex (300-9600 kbit/s) Transparent/Non transparent " High Speed Circuit Switched Data " 14. When you observe certain traffic characteristics over a period of time.High Capacity Base Station Controller. how much traffic different cells carry. Useful information is. that is. It then forwards these results to Nokia NetAct for further processing. and how many handovers are successful and how many fail. for example. you can.4 kbits/s Data Traffic Channel © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . or remote. Circuit Switched Data Services The BSC supports the following bearer services. If the load distribution is not even you can make changes to the dimensioning of the network in order to balance it and to improve performance. Short Message Service (SMS) The BSC forwards mobile originating and mobile terminating short messages transparently. When you analyse the information. including both transparent and non transparent data services. Cell Broadcast Messages (CB) Cell Broadcast provides the BSC with the short message service cell broadcast (SMSCB) capabilities defined by GSM recommendations. The measurements are grouped together to allow better functionality and handling. that is. This gives you an easier selection of the measurements you need at a particular time. find out if the load is distributed evenly or are there problems in load distribution. BSC2i (ETSI/ANSI). local. The BSC measures traffic. for example. and Enhanced Full Rate traffic channels. but can be used. The Dual Band operation supports dual band mobiles able to perform handovers between the GSM 900 and GSM 1800 bands as well as between 800 and 1900 bands during a call. For a GSM operator. the circuit pool is not needed. Dual Band GSM/EDGE 900/1800 and GSM/EDGE 800/1900 The BSC supports the Dual Band network. the area of 880-890 MHz uplink and 925-935 MHz downlink where available. the MSC must support the circuit pool. If the network includes both first generation transcoders (TCSM) and second generation transcoders (TCSM2). Transparent " Short Message Service Functionality Full Rate/Half Rate/EFR The BSC supports Full Rate traffic channels. the E-GSM900 extension band can represent the most cost-effective way of adding capacity to his system if the Primary GSM spectrum is used. The Adaptive Multi Rate (AMR) codec consists of a family of codecs (source and channel codecs with different trade-off bit-rates) operating in the GSM FR and HR channels. With AMR we can achieve very good speech quality in full rate (FR) mode even in low C/I conditions or increase the speech capacity by using the half rate (HR) mode and still maintain the quality level of current FR calls. Half Rate traffic channels. Tri-Band The Tri-Band feature supports the use of the ETSI-specified GSM900 frequency band extension. This means that a total of 50 radio frequency channels are included in this E-GSM900 band. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 17 (68) . Optimal interworking with power control and handover algorithms together with enhanced quality measurements (FER Measurement feature) will provide full benefits and interworking with prior Nokia top-of-theworld capacity features including Intelligent Frequency Hopping (IFH). If the network includes only second generation transcoders. The idea behind the AMR codec concept is that it is capable of adapting its operation optimally according to the prevailing channel conditions.Functionality of the High Capacity BSC " Telefax Automatic Group 3. Adaptive Multi Rate Codec Adaptive Multi Rate Codec (AMR) introduces a new set of codecs and adaptive algorithm for codec changes and thus can provide significantly better speech quality and more capacity on air interface. A multiple set of basic resources is reserved for one HSCSD call. The Common BCCH feature is also supported for GSM/EDGE 800/1900 frequency bands. HSCSD supports both transparent and non-transparent data services. in other words provides the operator both improved quality and capacity. Advanced Multilayer Handling The Nokia Advanced Multilayer Handling (AMH) concept is a part of the Soft Capacity features. The overlay network uses regular frequencies and offers a continuous coverage area. AMH provides the network operator with the tools to relief load of the congested cells and smooth out the load over the network. BSC2i (ETSI/ANSI). BSCi Common BCCH There is an option to allow GSM 900 and GSM 1800 TRXs to share the same BCCH in the same cell. Intelligent Underlay Overlay The Intelligent Underlay-Overlay (IUO) feature allows the operator to reuse frequencies more intensively and hence achieve a higher radio network capacity. Intelligent Frequency Hopping The Intelligent Frequency Hopping (IFH) feature provides the benefits of IUO and frequency hopping at the same time: the operator can enjoy powerful radio spectrum efficiency and the quality benefits of frequency hopping. This functionality could be considered a progression from the integrated dual band BTS and EGSM 900 frequency band support (Tri Band). In IUO the operating spectrum of a network is divided into regular frequencies and super-reuse frequencies.High Capacity Base Station Controller. 18 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . General Packet Radio Service (GPRS) Data and internet services will be the areas of future growth in the mobile communications. avoiding frequency-dependent fading in the radio path. It is used to redistribute traffic to the appropriate layer or frequency band according to the prevailing load of the network. and up to four time slots can be used for a HSCSD call. The underlay network uses the super-reuse frequencies which are reused very intensively to provide the extended capacity. Mobile data is the key to open the door to the high revenue corporate sector and to value-added services for consumers.4 kbit/s data service for higher data speed rates. HSCSD can be combined with 14. High Speed Circuit Switched Data The optional high speed circuit switched data (HSCSD) feature provides accelerated data rates for end-user applications. The Dynamic Abis transmission solution saves up to 70% in the Abis transmission expansion cost as it allows Abis dimensioning to be performed near to the average data rates instead of peak rates. The sharing of resources together with a very fast method of reserving radio channels makes the air interface usage even more efficient. will be up to 473 kbps. GPRS provides packet radio access for a GSM/GPRS mobile. EDGE offers an evolution path for GSM to support medium rate multimedia applications. It gives customers the benefits of instant IP connectivity on-the-move and being continuously connected. In EGPRS. enables gross data rate of 69. This means that one mobile uses the resources only for a short period of time. that is. The basic concept.Functionality of the High Capacity BSC GPRS is a major step forward in mobile data. The pool can be shared by a number of transceivers.2 kbps. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 19 (68) . is to provide a higher data rate on the 200kHz carrier. and a dynamic pool for data.8 and 59. the maximum standardised data rate per time slot will triple and the peak throughput. EDGE. As data rates per radio time slot can vary between 8. The Dynamic Abis functionality allocates Abis transmission capacity to cells when needed instead of reserving a full fixed transmission link per TRX. GPRS provides the possibility of being charged only for transferred data in addition to more efficient use of limited air interface resources. The Dynamic Abis feature uses existing Abis more efficiently by splitting PCMs into permanent time slots for signalling and voice or data. traditional static Abis allocation does not use transmission resources efficiently. The benefit of GPRS is that it can use the same resources that circuit-switched connections do by sharing the overhead capacity. with all eight time slots in the radio interface. EDGE (EGPRS) Enhanced Data Rates for Global Evolution (EDGE) provides services such as Enhanced GPRS (EGPRS) allowing much higher data rates than current GPRS configurations. The user can send more data per radio time slot with the same amount of air time used and operators do not need to invest in another frequency band and license to offer higher data rate services like mobile multimedia. therefore. This also applies to the number of 2M BSC interfaces needed. when there is data to be sent or received.2 kbps per radio time slot by transmitting 3-bits/symbol with the existing symbol rate. Dynamic Abis Allocation Dynamic Abis allocation is a solution for higher data rates of EGPRS to ensure cost efficient and flexible Abis transmission capacity addition. using 8-PSK modulation. With multi-slot reservation. C31/C32 provide a more general tool to make cell planning for GPRS as similar to existing planning in GSM as possible. the one among all cells with the highest C32 value shall be selected. Quality of service is improved by the Dynamic Abis method. for example: 20 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . and so on. The following common control channels are available: " PRACH is used by MS to initiate uplink transfer for sending data or signalling information.High Capacity Base Station Controller. PCCCH comprises logical channels for packet common control signalling. the cell with highest priority class shall be selected. Support of PCCCH/PBCCH This feature will bring dedicated CCCH capacity for (E)GPRS services. service profiles. the network. MS Location Services MS Location Services allows a GSM subscriber and/or valid mobile equipment to be positioned with a certain Quality of Service. PPCH uses paging groups in order to allow usage of DRX mode. Important applications of Location Services are. If no cell fulfils the C31 criterion. PBCCH broadcasts packet data specific System Information (for example C31 and C32 cell selection criteria). The new cell re-selection criteria C31 and C32 are provided as a complement to the current GSM cell re-selection criteria. PPCH can be used for paging of both circuit switched and packet data services. For cells that fulfil the C31 criterion. The implementation of shared transmission channel connection pools is supported by Nokia cellular transmission cross connection products and made easy with the Nokia NPS/10 transmission network planning tool. which uses allocation of circuit switched connections under real time centralised control. C31 is a signal strength criterion used to decide whether prioritised cell reselection shall be used. BSCi Dynamic Abis is implemented as a software feature. security. the one of those with the highest C32 value shall be selected. " PPCH is used to page an MS prior to downlink packet transfer. Packet Access burst and Extended Packet Access burst are used on PRACH. or an external party utilising the Mobile Positioning Function. Positioning may be initiated by the subscriber. Positioning is subject to various restrictions based on capability. " PAGCH is used in the packet transfer establishment phase to send a resource assignment to an MS prior to packet transfer. BSC2i (ETSI/ANSI). If more than one cell has the highest priority. LCS will allow the location of a GSM mobile station (MS) to be determined at any time whilst the MS is within the radio coverage area of the GSM HPLMN or VPLMN. All methods calculate 2dimension location estimation. for example RxLev. an inter-system handover from GSM to WCDMA can be made in order to relieve the traffic load in the GSM system.Functionality of the High Capacity BSC " Government Applications: - " Operator Applications: - " Emergency calls (E911 requirement by FCC in US) location of emergency calls with the RMS accuracy 125m Electronic surveillance Home zone calls Commercial Services: - Fleet management. MS speed information. A 3-dimension location calculation is for further development. GSM-WCDMA Interworking GSM-WCDMA Interworking in GSM means Inter-System handover from GSM BSS to WCDMA RAN and the same vice versa. No single method is suitable for all applications. petrol station and so on Car Navigation Emergency roadside service Search for stolen property Different MS Location methods have different benefits and drawbacks. Additionally. In order for an operator to provide seamless coverage in areas where WCDMA is not available. including: dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 21 (68) . tracking packages Information on the nearest hotel. The method includes location calculation using radio interface measurements. inter-system handovers provide a method of extending the radio network coverage area by making a handover from the WCDMA network to the GSM network. for example in rural areas. That means that TA correction will be done to improve legacy MS location accuracy.5 includes the E-OTD method. The signalling between SMLC and MS is similar for E-OTD and stand-alone GPS method. Support for the standalone GPS method is also implemented. in situations where the WCDMA network and GSM network overlap. and improved cell ID + TA method for legacy phones with Enhanced TA (E-TA). Nokia BSS10. There are quite substantial benefits of having inter-system handovers in place. " 3G services to all dual-mode subscribers. The above-mentioned BSC functionalities consist of basic and optional functionalities. " capacity extension for GSM with load sharing between 3G and GSM.High Capacity Base Station Controller. Both the circuit switched (handover and MS cell re-selection) and packet switched (MS cell re-selection) modes will be supported. These functionalities and options are described in more detail in BSS feature descriptions. BSC2i (ETSI/ANSI). 22 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . BSCi " seamless coverage extension for 3G with existing GSM network (or vice versa). The MCMU also acts as a BSC SYM (system maintenance) unit in case of OMU failure. " Marker and Cellular Management Unit (MCMU). new functions can easily be added without changing the architecture of the system. BSC2i (ETSI/ANSI). The optional Packet Control Units (PCUs) are included in every BCSU. Call handling capacity depends on the number of Call Control Computer Units. © Nokia Corporation Nokia Proprietary and Confidential 23 (68) . The distributed architecture of the GSM/EDGE BSC is implemented by a multiprocessor system.1 Architecture of the High Capacity Base Station Controller. and connecting signalling circuits. The capacity of the BSC can easily be increased by adding more Call Control Computer Units to the BSC. In a multiprocessor system the data processing capacity is divided among several computer units. BSC2i (ETSI/ANSI). Figure 1 shows the block structure of the GSM/EDGE BSC. Because there are exact specifications for the interfaces between different modules. " Base Station Controller Signalling Unit (BCSU). being responsible for cells and radio channels. Thus. BSCi 3 3. The most important functional units of the BSC are: dn99558545 Issue 4a-0 en " Group Switch (GSWB). which is used for switching speech and data. which handles the BSC signalling functions. the GSM/EDGE BSC can have a long operational lifespan and still always have up-to-date features. BSCi General design of the GSM/EDGE BSC The GSM/EDGE BSC is based on a modular software (SW) and hardware (HW) structure. each of which has a microcomputer of its own. when the (E)GPRS service is implemented. which controls and supervises the GSWB and implements radio resource management (RRM) functions.Architecture of the High Capacity Base Station Controller. please refer to the TCSM2 user documentation). though a separate network element usually installed on the MSC site. which interconnects the call control computers and the OMU.High Capacity Base Station Controller. BTS A bis SGSN Gb ET ET ET MSC A ter CLS GSWB X. which generates the clock signals for the BSC. Functional units (FU) are composed of individual HW and SW modules. The units and cartridges are presented in alphabetical order. " Clock and Synchronisation Unit (CLS). Block diagram of the GSM/EDGE BSC with Bit Group Switch The functional units and cartridge types used in the GSM/EDGE BSC are described in the following sections. BSC2i (ETSI/ANSI). which serves as an interface between the user and the BSC. BSCi " Operation and Maintenance Unit (OMU). " The high-speed Message Bus (MB). but also works as a SYM unit of BSC and automatically supervises the BSC. 24 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . which provide the information on both the basic configurations of the functional units (or cartridges) and the extension possibilities. " Exchange Terminals (ET).25 / LAN PCU BCSU MCMU OMU Hard disk Disk drive DAT drive MB Figure 1. " Transcoder (TCSM2) which. is normally viewed as a functional unit of the BSC (for further information. which connect transmission systems to the GSWB. 32. there must be an additional AFS plug-in unit in the BCSU to control the ET1E plug-in units. 192 or 256 PCMs. The only difference is the following: since the original ET1C cartridges (that accept only ET1E plug-in units) are not replaced by ET5C cartridges. consists of power supply (PSC1) and from two to four SW64B plug-in units. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 25 (68) . BSCi In principle.3 Call Control Computers In the GSM/EDGE BSC. Its great advantage is simplicity. BSC2i (ETSI/ANSI). 3.Architecture of the High Capacity Base Station Controller. which is based on the most suitable commercially available Intel microprocessors. one-staged. called Call Control Computers. and non-blocking time switch with full availability. The operation of the Bit Group Switch is controlled and supervised by the Marker and Cellular Management Unit (MCMU. 3. and 64 kbit/s level. The Bit Group Switch Cartridge. The MCMU performs all necessary connecting and releasing functions. which all have 32 4 Mbit/s interfaces. The Bit Group Switch also establishes the needed connections to the signalling units and the internal data transmission channels. The Call Control Computers have an identical Central Processing Unit (CPU). The Bit Group Switch switches on 8. The CPU board contains a microprocessor and a local Random Access Memory (RAM). The Bit Group Switch of the GSM/EDGE BSC is a fully digital. the BSCi consists of the same functional units as the BSC2 and BSC2i. Each Call Control Computer also contains the additional units that are required for performing specific tasks. SWCOP). and is responsible for the submultiplexing functions of the BSC. the call control functions are executed by microcomputers. The capacity of the GSWB is 128. After the Bit Group Switch has identified the correct time slots.2 Bit Group Switch The Bit Group Switch conveys the traffic passing through the BSC and switches the tones to the subscribers of the exchange and to the trunk circuits. 16. SW1C. it can always connect them in a uniform manner without using a special search path. The DMC processor bus is independent of component technology evolution. through the message bus. GROUP SWITCH MCMU clock control interface microcomputer equipment DMC BUS message bus interface 1 MB Figure 2. OMU and BCSU. The hardware of the MCMU consists of three modules: a microcomputer. a Switch Control Interface. The DMC processor bus operates according to the specifications of the internal communication of the Control Computers. the DMC processor bus facilitates further development of the plug-in units. The MCMU is connected to the other computer units of the exchange. and a Message Bus Interface (see Figure 2 ). connecting and releasing of the switching network circuits. BSC2i (ETSI/ANSI).High Capacity Base Station Controller. Consequently. The range of the tasks it handles makes up a combination of general marker functions and radio resource management functions.3. 26 (68) 0 Structure of the MCMU © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . resulting in an up-to-date and cost-effective BSC with high capacity.1 Marker and Cellular Management Unit (MCMU) The Marker and Cellular Management Unit (MCMU) controls and supervises the Bit Group Switch and performs the hunting. 3. BSCi All the different plug-in units of each Call Control Computer are interconnected by a DMC processor bus. It performs the control functions of a switching matrix and the BSC-specific management functions of the radio resources. The switch control interface also performs various tests on the switching network. When the MCMU performs the marker functions.Architecture of the High Capacity Base Station Controller. The MCMU reserves and keeps track of the radio resources requested by the MSC and the handover procedures of the BSC. The MCMU also manages the configuration of the cellular network.3. This responsibility is centralised in the MCMU. It consists of two parts. These control functions include the connection and the release of the circuits of the switching matrix. defined by the microcomputer. The cellular management functions of the MCMU are responsible for cells and radio channels that are controlled by the BSC. the active MCMU to the active GSWB and the passive MCMU to the passive GSWB. The BCSU is housed in a cartridge of its own. In case the optional MS locationing with E-OTD method is used.2 BSC Signalling Unit (BCSU) The BSC Signalling Unit (BCSU) performs those BSC functions that are highly dependent on the volume of traffic. The cellular management functions of the MCMU do not require any specific hardware in addition to the standard microcomputer and a Message Bus Interface Unit (MBIF). 3. BSCi The marker functions of the MCMU control the Bit Group Switch. the SMLC calculation algorithm is handled in the MCMU. The optional Packet Control Units (PCUs) are included in the BCSU. BSC2i (ETSI/ANSI). The Switch Control Interface writes the required connections into the switch control memory and reads its contents. BSSAP) " performing all message handling and processing functions of the signalling channels connected to it. © Nokia Corporation Nokia Proprietary and Confidential 27 (68) . which correspond to the A and Abis interfaces. it exchanges messages with other Call Control Computers via the Message Bus (MB). and generates the required timing signals. The A interface part of the BCSU is responsible for the following tasks: dn99558545 Issue 4a-0 en " performing the distributed functions of the Message Transfer Part (MTP) and the Signalling Connection Control Part (SCCP) of SS7 " controlling the mobile and base station signalling (Base Station Subsystem Application Part. One GSM/EDGE BSC always includes two MCMUs that are permanently connected to the duplicated pair of the Bit Group Switches. High Capacity Base Station Controller. BSC2i (ETSI/ANSI). The hardware of the BCSU consists of the following modules (see Figure 3 ): " a microcomputer " an SS7 (Signalling System No. 7) interface " a LAPD (Link Access Protocol on the D-Channel) interface " a LAPD interface for control of the ET " the Message Bus interface " the Packet Control Unit GROUP SWITCH BCSU SS7 interface LAPD interface DMC BUS microcomputer message bus interface LAPD interface 1 MB Figure 3. the SS7 and the LAPD protocols. are connected to the switching network via PCM connections 28 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . The handover and power control algorithms reside in this functional unit. Every speech circuit on the Abis interface is mapped one-to-one to a GSM-specific speech/data channel on the Radio interface. BSCi The Abis interface part of the BCSU controls the Radio interface channels associated with transceivers (TRXs) and Abis signalling channels. that is. 0 ET Structure of the BCSU The interface units. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 29 (68) .Architecture of the High Capacity Base Station Controller. BSCi The SS7 interface module is for the A interface. A similar principle applies to the optional second PCU unit. Gb load sharing (uplink) and flow control (downlink). but only the activated ones are to be used. The layer 2 LAPD functions are performed by the signalling terminal. It implements both packet switched traffic oriented Gb and Abis interfaces in the BSC. MS uplink power control. BSC2i (ETSI/ANSI). The signalling terminal is semipermanently connected to the time slots used for signalling. It contains a preprocessor. but application-specific messages are handled by the microcomputer of the BCSU. The bit rate of a single link can be either 16 kbit/s. which is capable of handling a maximum of four signalling channels (64. The main functions are GPRS traffic radio resource management. The BCSU is equipped with LAPD interface terminals. Packet Control Unit (PCU) The PCU unit performs all the data processing tasks that are related to the (E) GPRS traffic. One BCSU can handle traffic in a maximum of 64 transceivers (TRXs) in High Capacity BSC configuration. The BCSU uses the LAPD Interface to supervise the 2 Mbit/s circuits (time slot 0 handling) connected to the Bit Group Switch. and one for the A interface. Each LAPD signalling terminal can handle a maximum of 64 LAPD links. for example connection establishment and management. there is one extra BCSU compared to the number set by the dimensioning rules. According to the N+1 redundancy principle (see the section Redundancy principles ). resource allocation. or 64 kbit/s. The additional unit is used only if one of the active units fails. scheduling. PCUs must be configured to every BCSU installed. 128 and 256 kbit/s). The standard equipment of the BCSU includes two terminals for LAPD interfaces for signalling towards BTSs and towards ET2Es. 32 kbit/s. This requirement comes from the general N+1 redundancy principle of the fault tolerant DX 200 Computing Platform. data transfer. A PCU includes a microprocessor and digital signal processors integrated to the same plug-in-unit to handle the tasks. Recovery can also be activated by the MCMU if the OMU is lost. The OMU receives fault indications from the BSC. In the event of a fault.25 interface (time-slot-based O & M interface) " Ethernet interface © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . the OMU contains I/O interfaces for local operation. The Operation and Maintenance Unit (OMU) consists of the following modules (see Figure 4 ): 30 (68) " microcomputer " alarm interface " Message Bus Interface " peripheral device interface " analog X. In addition. BSC2i (ETSI/ANSI). The OMU can also be used for local operations and maintenance. the OMU automatically activates appropriate recovery and diagnostics procedures within the BSC. The tasks of the Operation and Maintenance Unit (OMU) can be divided into four groups: " traffic control functions " maintenance functions " system configuration administration functions " system management functions The OMU consists of microcomputers similar to the Call Control Computers.High Capacity Base Station Controller. It can produce local alarm printouts to the user or send the fault indications to NetAct.4 Operation and Maintenance Unit (OMU) The Operation and Maintenance Unit (OMU) is an interface between the BSC and a higher-level network management system (like Nokia NetAct) and/or the user.25 interface (modem to PSPDN or LAN) " digital X. BSCi 3. The OMU communicates with the Call Control Computers of the BSC via the Message Bus.25 modem or LAN interface DMC BUS 1 MB Figure 4. V. visual display unit. power supply. which houses both hard disk and floppy disk units. a DAT tape drive. and printer to the OMU. which is used to connect disk units.Architecture of the High Capacity Base Station Controller. The visual display unit and printer interfaces are standard asynchronous serial interfaces complying with the ITU-T Recommendation V.24 restricted.25 Data Terminating Equipment (DTE) interface for the packet switched network (PSPDN) with a physical layer of V. air conditioning equipment. The analog X. BSCi GROUP SWITCH X. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 31 (68) .25. or X. PSPDN or LAN OMU X.35.24. The disk units are installed in a separate cartridge. The CPU controls the peripheral device interface module. A mirrored pair of Winchester disk units. PCM interface alarm interface message bus interface peripheral device interface microcomputer X. 0 Structure of the OMU The alarm interface module connects internal wired alarms to the OMU from the BSC cartridges. V. BSC2i (ETSI/ANSI).25 modem interface module provides an X.24.21. This module provides both input and output interfaces for external alarms to NetAct. and one 3. etc.25.5" disk unit can be controlled by the OMU. BSCi The digital X. The LAN interface module provides an ethernet interface according to IEEE802. 3. This module provides an X. which carry the actual data and also control the information required for the message transfer. or it can be a group of microcomputers specified by the broadcast address. The length of each message is determined individually by a message length parameter at the beginning of the message.25 connection via the A interface time slot. In the event of a failure.5 Message Bus (MB) A duplicated high-speed Message Bus (MB) is used for data transfer between the OMU and the Call Control Computers of the GSM/EDGE BSC (see Figure 5 ). The sender and the receiver of the message are indicated in the address field of the message. The receiver can be a single microcomputer. The hardware of the Message Bus consists of several parallel twisted pairs.25 PCM-based O & M interface module is used for the network management interfaces implemented in time slots.3. It also provides an O & M interface for the transcoders and the transmission equipment. The OMU of the GSM/EDGE BSC is located in a cartridge of its own. 32 (68) Structure of the Message Bus system © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . This interface is located at the CPU. microcomputer DMC BUS interface unit 0 interface unit 1 message bus interface 1 MESSAGE BUS 0 Figure 5. BSC2i (ETSI/ANSI).High Capacity Base Station Controller. the hot standby Message Bus takes over the functions of the active bus without interfering with the ongoing calls. All 2.048 Mbit/s (in the ETSI environment) or 1.6 Exchange Terminal (ET) The ET performs the electrical synchronisation and adaptation of external PCM lines.048 Mbit/s (ETSI) or 1. The ET1C cartridges of the first generation BSC house Exchange Terminal plugin units (ET1E). inserts the alarm bits in the outgoing direction and produces PCM frame structure. The resulting signal is converted into a line code (HDB3 in the ETSI environment. the ET2 decodes the 2. The ETs are also connected to the LAPD interface via a LAPD link. Each ET is connected to the switching network and the Clock Unit of the GSM/ EDGE BSC via permanent. wired connections. on the other hand. the ET2 receives a binary PCM signal from the switching network and generates the PCM frame structure. B8ZS or AMI in the ANSI environment) into binary form. can contain only two ET5C cartridges (as an option.544 Mbit/s (ANSI) signal of a circuit into data signals. The ET1 plug-in units are housed in the ET1C cartridge and the ET2 plug-in units are housed in the ET5C cartridge. BSC2i (ETSI/ANSI). B8ZS or AMI in the ANSI environment) and transmitted further onto the 2. The decoder decodes the line code (HDB3 in the ETSI environment. the BCBE rack can contain up to two ET5C cartridges and the BCEE rack up to seven. are available for the ET1Es and ET2Es. Two types of connectors.544 Mbit/s (in the ANSI environment) interfaces for the MSC and the BTSs are connected to the Exchange Terminals. symmetrical and coaxial (75/120 SL). or B8ZS or AMI (ET2A) coding and decoding. At the same time. The ETs are located in Exchange Terminal cartridges. In the incoming direction. In the BSC2i application.048 Mbit/s (ETSI) or 1.544 Mbit/s (ANSI) circuit. All ET2 plug-in units contain two separate ETs but the ET1E plug-in units of the first generation BSC contain only one ET. The BSCi application. the ET2 is synchronised to the bit rate of the incoming signal. The Exchange Terminals adapt the external PCM circuits to the GSWB and synchronise to the system clock. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 33 (68) .Architecture of the High Capacity Base Station Controller. It performs the HDB3 (ET2E). Synchronisation is included in the bit frame. in addition to the seven original ET1C cartridges): one in the BCBE rack and the other in the BCEE rack. In the outgoing direction. The BCBE rack contains two ET1C cartridges and the BCEE rack five ET1C cartridges. Each ET1C cartridge contains eight ET1E plug-in units and two PSC3 plug-in units. BSCi 3. if the temperature of the environment does not vary. The Clock & Tone Generator (CL1TG) plug-in unit meets the requirements of the ITU-T Q. through a PCM line. It can operate plesiochronously or synchronously with the timing references it receives from the digital PCM trunks. 34 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . with external synchronised input is also available. and the transfer function. the jitter.High Capacity Base Station Controller. usually an MSC.8 Peripheral devices The peripheral O & M devices of the GSM/EDGE BSC are: " disk units " Digital Audio Tape unit (DAT) tape drive " printer " visual display unit " alarm lamp panel Other peripheral devices of the GSM/EDGE BSC are: " Cable Conduit with Cabling Rack for raised floor installations " Applicable NEBS3 compliance There are two types of Storage Device cartridges: the WDDC in the BSC2E/A and the SD3C-S in the BSCi (optional) and BSC2i (standard in first deliveries). BSCi 3. Three PCM reference inputs with priority order are provided for the timing reference signals. the frequency shift of the CL1TG is 2 * 10-8 within each 24hour period. Up to two additional PCM inputs are provided for redundancy. the wander. In the plesiochronous operation mode. 3.500 Series Recommendation with respect to the Time Interval Error (TIE).7 Clock and Synchronisation Unit (CLS) The Clock and Synchronisation Unit (CLS) distributes timing reference signals to the functional units of the GSM/EDGE BSC. CL3TG. When the system consists of two racks. The oscillator of the CLS is normally synchronised to an external source. An optional Clock & Tone Generator plug-in unit. BSC2i (ETSI/ANSI). the timing reference signals are buffered for the extension rack by a duplicated Clock and Alarm Buffer (CLAB) plug-in unit. Architecture of the High Capacity Base Station Controller.3 Printer (optional) A printer can be connected to the OMU.8. a visual display unit is used as a user interface. 3.4 Visual display unit (optional) In the BSC. the DAT is used for loading software locally to the BSC and also as a software backup medium. The system disk units contain the operative software as well as fallback software of the BSC and BTS software including the BTS HW database.24. With a VDU terminal. The software can be loaded locally to the BSC by using 3. because it has high capacity and is easy to use.2 DAT (optional) The GSM/EDGE BSC can have a Digital Audio Tape (DAT) tape drive as an option.1 " two hard disk units (WDU) " one floppy disk unit (FDU) " one cartridge tape unit (CTU) / (DAT) " two power supplies for the disk units (PSC4-S) Disk units The GSM/EDGE BSC has a duplicated system disk unit (Winchester) and 3.5" disks or DAT tape.8. Traffic measurements are also stored on the system disks. the user can perform normal operational functions with MML commands and diagnostic tests on various units. The basic configuration of a SD3C-S cartridge is the following: 3.8. In the BSC. The DAT is a recommended solution for software backups and for other additional disk storage.5" disk drive. 3. which controls the system disk units.8. All the disk drives are connected to the OMU. 3. The interface complies with the ITU-T Recommendation V. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 35 (68) . BSCi The BSCi contains one SD3C-S cartridge (optional) and the BSC2i contains one SD3C-S cartridge (standard in first deliveries) housing the floppy and hard disk units and the CTU (DAT). BSC2i (ETSI/ANSI). See the section DAT . TRANSM. depending on the predefined urgency and equipment type (SWITCH.8.6 Cable Conduit with Cabling Rack for raised floor installations If there is a raised floor in the equipment room. O/M. or between two equipment racks. Furthermore there are dedicated cable conduit and cabling rack items for raised floor installations when BSC2i is upgraded to meet applicable NEBS level 3 compliance. the incoming and outgoing cables can be placed under the floor and connected to the equipment racks through a vertical cable conduit and a cable rack. It can be installed to a place where the observations of alarms can be noticed easily.8. which can be placed at either end of the rack row. BSCi Visual display units can be connected to the OMU in the same way as printers by using interfaces that comply with the ITU-T Recommendation V. 3.7 Applicable NEBS3 compliance (optional) The BSC can be upgraded to meet applicable NEBS level 3 compliance. The floor mounting in this case should be based on rails.High Capacity Base Station Controller. 36 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . EXTERNAL).24. 3.5 Alarm lamp panel (optional) The alarm lamp panel shows BSC alarms.8. 3. BSC2i (ETSI/ANSI). This is achieved by fitting the rack with alternative doors and side plates including hinge bars as well as by installing fire protection plates and earth bonding-point bracket. POWER. 703. which is similar to the layered OSI protocol model. NetAct. then the following sections explain them in more detail. based on the ITU-T Recommendation G. if the NSS supports them. BSS. and the Cell Broadcast Centre (CBC). At least two signalling links are normally provided between the BSS and the MSC for both capacity and reliability reasons. OSI Layer 1 represents the physical layer. The GSM/EDGE BSC provides interfaces for the MSC. The interfaces are first briefly described. providing a 64 kbit/s transmission rate on each channel. Because the A interface is open. Layered interface structure in A interface The interface between the DX 200 MSC and the Base Station Subsystem. the Serving GPRS Support Node (SGSN).Interfaces relating to the High Capacity Base Station Controller. BSC2i (ETSI/ANSI). It is a digital interface at 2048 kbit/s (ETSI) or 1544 kbit/s (ANSI). BSCi 4 Interfaces relating to the High Capacity Base Station Controller. BSCi The policy of open standard interfaces has been adopted for the design of the GSM/EDGE BSC. The Message Transfer Part (MTP) and the Signalling Connection Control Part (SCCP) provide the signalling network functions required to carry the messages of the Base Station Subsystem Application Part (BSSAP) layer. OSI Layer 2 is based on the MTP level 2 of SS7. the Nokia GSM/EDGE BSC can be used with switching centres from other suppliers. the Base Transceiver Stations (BTSs).1 A interface The A interface between the MSC and the GSM/EDGE BSC is implemented according to the GSM standards. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 37 (68) . Additionally. This interface is normally used as an A interface between the MSC and the BSS. BSC2i (ETSI/ ANSI). 4. is defined in accordance with the Signalling System No. The MTP level 2 provides a mechanism for reliable transfer of signalling messages between the MSC and the BSS. wide SS7 links (128 or 256 kbit/s) can be configured.7 (SS7). 32 kbit/s and 64 kbit/s. and BTS database management. based on the ITU-T Recommendation G. the MTP and the SCCP functions provide both connectionless and connection-oriented network services. Together. The LAPD protocol is implemented to provide the data link functions required to carry layer 3 messages. These services are used to transfer circuitrelated and non-circuit-related signalling information and other types of information between the MSC and the BSS. 4. Connection between the BSC and the BTS have to be unrestricted digital 2 x 64 kbit/s. which are in accordance with GSM standards. The Abis O & M part is Nokia property which supports additional features like the Site Test Monitoring unit. BSCi OSI Layer 3 of the signalling network includes the SCCP and MTP level 3. Functions of the application parts of the A interface The Base Station Subsystem Application Part (BSSAP) provides procedures for the A interface. Functions of the telecom application parts The following procedures are provided for the Abis interface: 38 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . The interface between the BSC and the ISDN network is based on ITU-T's Digital Subscriber Signalling System No. 1 (DSS1) Network layer Q. The GSM/ EDGE BSC can handle LAPD signalling links with the bit rates of 16 kbit/s. alarm consistency. because each speech channel reserves only 16 kbit/s (FR channel or DR channel) or 8 kbit/s (HR channel) in the ETSI environment.703. Layer 1 represents the physical layer. remote transmission equipment management.High Capacity Base Station Controller. ISDN connections can also be used as the bearer for the Abis interface. 16 kbit/s in the ANSI environment. Layer 2 is based on the LAPD protocol. BSC2i (ETSI/ANSI).931 (03/93) and Data link layer Q. It is a digital interface at 2048 kbit/s (ETSI) or 1544 kbit/s (ANSI).921.2 Abis interface The Abis interface telecommunication part between the GSM/EDGE BSC and the BTS is implemented according to the 08. Submultiplexing is used on the Abis interface as a standard solution. Layered interface structure in Abis interface The interface between the GSM/EDGE BSC and the BTS is defined in accordance with the OSI protocol model.5X Series of GSM Recommendations. Interfaces relating to the High Capacity Base Station Controller. Network Service layer further divides into two: Sub-network Service and Network Service Control.3 " fault management " fault reporting " BTS recovery " BTS test handling " configuration management " software configuration management " radio network management including extensions and parameters " performance management Gb interface The Gb interface between the BSC (PCU) and Serving GPRS Support Node (SGSN) is implemented according to 08. The Sub-network Service uses either Frame Relay or UDP/IP-based protocol. is defined in accordance with the OSI protocol model. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 39 (68) . BSCi " radio link management procedures " dedicated channel management procedures " common channel management procedures " TRX management procedures Functions of the O & M application parts on Abis Interface The application parts of the Abis interface contain the following O & M functions: 4. BSC2i (ETSI/ANSI). BSS.1X Series of GSM Recommendations.703 interface. On top of the physical layer in the Gb interface direct point-to-point Frame Relay connections or intermediate Frame Relay network can be used. It is an open interface connecting the BSS and GPRS core network. Sub-network Service Layer The physical layer is implemented as one or several PCM lines with G. and L1. Network Service layer including Frame Relay (FR). Layered interface structure in Gb interface The interface between the SGSN and the Nokia Base Station Subsystem. The protocol stack comprises BSSGP. 703. BSSGP is a layer 3 protocol for delivering data packets and associated control information. In the case of PSPDN connections. the physical interface can be V.25 interface. which maps cells to virtual connections.25 protocol is used on the interface between the GSM/EDGE BSC and Nokia NetAct. BSCi GMM/SM GMM/SM LLC LLC Relay BSSGP BSSGP MAC Network Service Network Service GSM RF L1bis L1bis RLC RLC MAC GSM RF Um MS Figure 6.21 and in the case of PCM time slot connections. 40 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . depending on the network operator's requirements: " an X. The implementation of this interface is based on the O & M framework of the ITU-T and the International Standards Organization (ISO). 4.High Capacity Base Station Controller. Network interface The X.35 or X. the physical interface is G. connected via the LAN Switch The Nokia NetAct interface is of the Q3 type. PSPDN " a LAN interface.25 connection via a semipermanent time slot on the A interface " an X. BSC2i (ETSI/ANSI). V. BSS Gb SGSN The protocol stack on the Gb interface Network Service Control is responsible for virtual circuit management and GPRS-specific addressing. connected directly or via the Packet Switched Public Data Network. Either the PSPDN or the PCM-time-slot-based connection can be used.24.4 Q3 interface The GSM/EDGE BSC provides the following types of interfaces between NetAct and the BSC. access and management (FTAM). X.25 protocol or LAN as a subnetwork. using the ACSE and the ROSE. The connections can be made redundant as an option. The upper layers use the X. The implementation is according to GSM Specification 03. The following protocols are implemented: " transport protocol. above the network layer. TP2 and TP4) " session protocol. The X. X. The CMISE protocol. using ACSE. are implemented in the GSM/EDGE BSC.229 " file transfer.Interfaces relating to the High Capacity Base Station Controller.225 " presentation protocol.224 (TP0.227 " remote operations service element (ROSE). is used for transferring files between the GSM/EDGE BSC and Nokia NetAct. X. The physical interface supported is Ethernet IEEE802. X.226 " association control service element (ACSE). ISO 8571 " common management information service element (CMISE). dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 41 (68) . X. ISO 9596 The FTAM protocol.25 software in the GSM/EDGE BSC can be configured to function as the DTE or the DCE. Interface with a full OSI Stack The upper layers of the OSI model.3. BSC2i (ETSI/ANSI). is used for Network Management. BSCi The BSC also supports the LAN interface.41 and permits the open interconnection between BSC and CBC. 4.5 CBC interface (BSC-CBC) The BSC Cell Broadcast Centre Interface provides an interconnection between the BSC and Cell Broadcast Centre (CBC). The CBC Application can be developed using the XTI Application Programming Interface (X/Open Transport Interface) to interconnect the application to the OSI Transport Layer. The XTIinterface uses the services of the OSI Transport Layer. Interface with OSI layer 4 The protocol used between the BSC and the CBC is the XTI-interface. 42 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . the CBC connection is made through the OMU using current Q3 interface plug-in units AC25 and AS7. The CBC connection shares the same transport media as Q3.High Capacity Base Station Controller. Network interface The interface between the BSC and the CBC is similar to the interface between the BSC and NetAct. only a new logical connection is introduced. If a nonredundant Q3 connection is used. BSC2i (ETSI/ANSI). more transmit capacity can be gained by using a dedicated plug-in unit for the CBC. BSCi In the BSC. This uniform system software provides a standard.1 Platform architecture The BSC is based on a Fault Tolerant Computing Platform. The uniform operating environment facilitates the development and maintenance of the application software and helps the user understand the operation of the software. which constitutes a base for the switching and offers a wide range of cellular and fixed network applications. The most significant functions of the operating system are: dn99558545 Issue 4a-0 en " scheduling the processor time " synchronisation of processes " exchange of messages between processes located in one computer or in separate computers " time supervision " creation and deletion of processes " memory allocation and protection " observation of message traffic and processor load " initialisation of the operating system © Nokia Corporation Nokia Proprietary and Confidential 43 (68) . easy-to-use operating environment for the application software. The operating system is a platform for other system level software and all the application software. each Computer Unit has common system software. 5.High Capacity BSC Software 5 High Capacity BSC Software In the BSC. In the case of the BSC the database includes. 44 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en .3 Databases The base systems contain different types of data. the files are RAM memory arrays. Layers can be developed relatively independently. 5. reduced routing and cellular data. for example. 5. The database also includes data needed for the control and operation of the BSC.2 The BSC conceptual model Layers A layer is an up-level hierarchy level of the system platform. BSCi Base Station Controller Application Common Switching Platform Fault Tolerant Computing Platform Modular and Scalable Hardware Platform Figure 7. In this context.High Capacity Base Station Controller. Some files are loaded from a disk unit after restarting the control computer. BSC2i (ETSI/ANSI). It divides the monolithic platform into smaller modules. Other files are updated on the disk when the contents are changed. 4 Description and programming languages In the design and documentation of the BSC software. readability and visual quality of the programs are enhanced by using special description languages in addition to the actual programming language. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 45 (68) .High Capacity BSC Software 5. These description languages also facilitate effective software design and enable the use of automatic tools for development and testing. BSC2i (ETSI/ANSI).High Capacity Base Station Controller. BSCi 46 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . Engineering Descriptions for a description of the configurations.2 Capacity of the BSC With the reference model below. the GSM/EDGE BSC is a stand-alone network element that is connected to the surrounding network elements by means of standard PCM interfaces. The High Capacity BSCi and BSC2i can be equipped with: " 1-rack configuration: - " a maximum of 128 TRXs a maximum of 128 BTSs a maximum of 62 BCFs 2-rack configuration: - a maximum of 512 TRXs a maximum of 248 BTSs (256 PrimeSites) a maximum of 248 BCFs. See Base Station Controller. 6.Configurations and capacity of the High Capacity BSC 6 6. There are two basic configurations of the BSCi/BSC2i: 1-rack and 2-rack. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 47 (68) . Both of them can be equipped flexibly with a number of TRXs and trunk circuits. giving full support to 512 FR TRXs.1 Configurations and capacity of the High Capacity BSC General description of configuration In the BSS. the maximum processing capacity of a GSM/ EDGE BSC2i is 3040 Erl/91000 BHCA. /1 hour The above-mentioned traffic processing capacity of the BSC can be achieved with S10. BSC2i (ETSI/ANSI)./subs. a maximum of 128. BSCi Table 2. Different types of connections are provided as follows: 48 (68) " in BSC2i. For example. some future features might have an influence on the capacity of the BSC. 56 or a maximum of 88 PCM connections used on A and Abis interfaces " in BSC2i. The maximum traffic processing capacity of the BSC2i supports 512 full rate TRXs in the ANSI version. PCM connections connected to the nonblocking switching matrix © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en .5 HOs per call Proportions of location updates (LUs) 2 LUs per call Proportion of IMSI detaches 0. a maximum of 256 PCM connections. and in BSCi. upgradable to 192.1 detaches per call For terminating call attempts.4 kbit/s) the call is seen as two mobile originating or terminating calls. based on how many time slots are reserved for the call. Circuit switched processing capacity of the BSC2i Reference model of call traffic (call mix and parameters): Mean holding time 120s Proportion of MS originated calls 70% Proportion of MS terminated calls 30% Proportion of handovers (HOs) 1.High Capacity Base Station Controller. if two time slots are reserved (2 x 14. and in BSCi. 512 full rate TRXs or 256 half rate TRXs in the ETSI version. However. Circuit switched data calls are taken into account in the reference model of call traffic in the following way: " one data call with one radio time slot is seen as one mobile originating or terminating call " one full rate data call is seen as one mobile originating or terminating call " one high speed circuit switch data (HSCSD) call with two or more radio time slots is seen as several calls. a maximum of 144 PCM connections.5level features activated and with the new BSC hardware environment. the proportion of no-answer call attempts to paging requests 63% SMS call rate 1 req. Introduction of HR will enable TRX configurations of more than 18 radio channels which leads to increased load in measurement reporting. - maximum capacity with full configuration (8 PCUs) is 256 x 8 = 2048 traffic channels (16 kbit/s) per BSCi for GPRS/EDGE use maximum capacity with full configuration (16 PCUs) is 256 x 16 = 4096 traffic channels (16 kbit/s) per BSC2i for GPRS/EDGE use The above-mentioned packet handling capacity can be achieved with the new HW environment. the capacity of a 16 kbit/s signalling link is not sufficient in all cases.Configurations and capacity of the High Capacity BSC " a maximum of 16 SS7 signalling links. some future features might have an influence on the packet handling capacity of the BSC. and in BSCi. and 256 traffic channels (16 kbit/s) for GPRS/ EDGE use. With TRX configurations of more than 18 radio channels a 32 kbit/s LAPD link is highly recommended for supporting the telecom signalling which half rate requires. Optionally wider 128 or 256 kbit/s signalling links can be configured instead of standard 64 kbit/s links " in BSC2i. Therefore it is recommended that also with HR the TRX configurations should be restricted to the maximum of 18 radio channels if 16 kbit/s signalling links are used. Because of this. 32 or 64 kbit/s speeds. The overload of the signalling link can be monitored by the Telecom LAPD link supervision with a possibility to set an alarm in an overload situation. In GSM/EDGE BSC the packet handling capacity is provided by Packet Control Units (PCUs). a maximum of 936 LAPD protocol links LAPD signalling links can be configured to 16. 128 TRXs. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 49 (68) . a maximum of 992 LAPD protocol links. Packet handling capacity and connectivity per each PCU is 64 BTSs. However. BSC2i (ETSI/ANSI). BSCi 50 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en .High Capacity Base Station Controller. 1 Plug-in units The BSC2i is constructed by using a total of 15 plug-in unit types. The printed circuit boards (PCBs) of plug-in units are multilayered.1. The cartridges of the BSC2i are of the following types: dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 51 (68) . The connectors are of the Euro-connector type. 7. A fixed rack position has been assigned to the cartridge of each functional unit. The dimensions of different units and cartridges are in accordance with the recommendations of the IEC (International Electrotechnical Commission).2 Cartridges Most of the functional units consist of one cartridge that contains a selection of PCBs. 7. They are covered with a protective coating that makes the PCBs easy to handle and protects the foils from scratches. based on plugin units. cartridges and racks. and maintain.4 mm x 160 mm. including the DC/DC converters.1.1 Mechanical design and power supply of the High Capacity BSC Mechanical design The mechanical structure of the GSM/EDGE BSC is hierarchical. The size of these plug-in units is either 233. or 110 mm x 220 mm.4 mm x 220 mm. Both surface-mounted and hole-mounted components are used on the PCBs. 233. Special attention has been paid to thermal resistance and immunity to various types of interference. The GSM/EDGE BSC is easy to install. operate. 100 mm x 220 mm.Mechanical design and power supply of the High Capacity BSC 7 7. OMU. BSCi " MC1C cartridge for MCMU. DAT and Floppy Disk drives or " SD3C-S cartridge for Winchester units. CLOC. and BCSU " CLAC cartridge for the Clock and Alarm Buffer Unit " CLOC cartridge for the Clock and Synchronisation Unit " ET1C and ET5C cartridges for Exchange Terminals " SW1C cartridge for the Bit Group Switch " WDDC cartridge for Winchester units. DAT and Floppy Disk drives. The cartridges of the BSCi are of the following types (see Figure 8 ): " MC1C cartridge for MCMU. BSC2i (ETSI/ANSI). DAT and Floppy Disk drives.High Capacity Base Station Controller. and BCSU " CLAC cartridge for the Clock and Alarm Buffer Unit " CLOC cartridge for the Clock and Synchronisation Unit " ET5C cartridge for Exchange Terminals " SW1C cartridge for the Bit Group Switch " SD3C-S cartridge for Winchester units. © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . WDDC: - 52 (68) 262 mm x 120 mm x 230 mm type SW1C: - " 262 mm x 240 mm x 230 mm type ET5C : - " 262 mm x 260 mm x 170 mm type ET1C : - " 262 mm x 260 mm x 170 mm 262 mm x 120 mm x 230 mm. OMU. The size of each cartridge type is given below: " type SD3C-S: - " type MC1C: - " 262 mm x 180 mm x 230 mm types CLAC. Mechanical design and power supply of the High Capacity BSC 2 6 9 ET2E ET2E ET2E ET2E ET2E ET2E ET2E ET1C 1 2 3 OMU 4 5 6 7 8 USY PSC4 CTU TAPE TAPE STATUS STATUS :::::::::::::::::::::::::::::::::: HDU CTU USY 0 0 0 4 5 7 8 9 PSC3 AS7-X AS7-X 6 AS7-X HWAT PSC4 3 MBIF-UA SERO-T MBIF-UA CP6MX dn99558545 Issue 4a-0 en 0 EJECT EJECT 0 Figure 8. excluding BCSU © Nokia Corporation Nokia Proprietary and Confidential 53 (68) . 9 SD3C-S HDU 2 PSC3 PSC3 ET1E ET1E ET1E ET1E ET1E ET1E ET1E 0 :::::::::::::::::::::::::::::::::: ET2E 10 CL1TG CL1TG PSC3 SWCOP 4 CLAC CLAB CLOC 3 MBIF-UA MBIF-UA :::::::::::::::::::::::::::::::::: CP6MX PSC1 SW64B 4 4 ET5C ET1E 3 MCMU CLAB 2 SW64B SW64B SW64B :::::::::::::::::::::::::::::::::: SW1C with GSWB ( 4 SW64B cards) 10 0 Cartridges and functional units of the BSC2i and BSCi with GSWB. High Capacity Base Station Controller, BSC2i (ETSI/ANSI), BSCi Note 00 05 06 07 08 09 10 00 PCU 01 02 03 04 05 06 07 08 PSC3 AFS-T AS7-X AS7-X AS7-X MBIF-UA MBIF-UA :::::::::::::::::::::::::::::::::: :::::::::::::::::::::::::::::::::: CP6MX PSC3 AS7-X AS7-X AS7-X MBIF-UA 04 PCU PCU 01 02 03 Figure 9. 7.1.3 MBIF-UA :::::::::::::::::::::::::::::::::: CP6MX :::::::::::::::::::::::::::::::::: The BSC2i does not include the ET1C cartridge. 09 10 BCSU in BSC2i and BSCi including Packet Control Unit Racks All the racks are of a standard type. The frame of a rack consists of side rails, made of plated steel sheet, that support an upper shelf and a lower shelf with adjustable legs. Only two types of racks are used in the BSC2i: BCBE and BCEE (see Figures 10 and 11 ). In the case of a 2-rack configuration, the two frames are connected to each other in order to create a closed space and reduce the possibility of interference. The closed space in both 1-rack and 2-rack configurations is surrounded by the side plates, the doors, the upper cable conduit, and the baseboard. The doors are perforated to facilitate cooling. The height, width and depth of a standard BSCi rack are (with cabling and doors): 2200 mm x 600 mm x 500 mm 54 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en Mechanical design and power supply of the High Capacity BSC The height, width and depth of a standard BSC2i rack are (with cabling and doors): 2020 mm x 600 mm x 500 mm Each installed BSC has side plates on its both sides. Each side plate is 40 mm wide, which must be taken into account when estimating the total width of the racks. If more than one BSC2i is located on the same site, the racks can be connected to each other. In this case, each row of racks constitutes a closed EMC-shielded space. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 55 (68) High Capacity Base Station Controller, BSC2i (ETSI/ANSI), BSCi CPLAN-S 1 CPLAN-S 0 CPLAN-S 3 CPLAN-S 2 BCBE BCEE PSA20_0 PSA20_1 PSA20_2 PSA20_3 PSFP0 PSFP1 PSFP2 PSFP3 GSWB 0 GSWB 1 SW1C0 SW1C1 CLS CLS CLOC CLAC ET 5C 2 ET 5C 3 ET 5C 4 CDB 8 MCMU 0 MCMU 1 BCSU 3 BCSU 4 MC1C MC1C MC1C MC1C SD3C-S ET 5C 0 BCSU 5 BCSU 6 MC1C MC1C BCSU 0 4 BCSU 7 BCSU 8 MC1C MC1C MC1C BCSU 1 BCSU 2 MC1C MC1C Figure 10. 56 (68) ET 5C 1 OMU MC1C ET 5C 5 ET 5C 6 ET 5C 7 ET 5C 8 Rack layouts of the BSC2i first deliveries © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en the cabling is installed from each cartridge to the next one.1. Within a rack.4 ET1C 0 ET1C 1 Rack layouts of the BSCi: 56 and 88 PCM versions Cabling Standard length cables are used for the internal cabling of the GSM/EDGE BSC. Each rack in the row is connected to the next rack by cables. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 57 (68) . In the 2-rack configuration the connecting cables between the racks are also factory-installed from the other end to ensure easy and fast installation at site. The internal cables of the racks are installed at the factory.Mechanical design and power supply of the High Capacity BSC BCBE BCBE BCEE BCEE PSA20_2 PSA20_3 PSA20_2 PSA20_3 PSA20_0 PSA20_1 PSA20_2 PSA20_3 PSFP2 PSFP3 PSFP2 PSFP3 PSFP0 PSFP1 PSFP2 PSFP3 SW1C0 MCMU 0 MC1C SW1C1 MCMU 1 MC1C CLACWDDC BCSU 0 MC1C OMU WDDC MC1C ET1C 6 SW1C0 MCMU 0 ET1C 4 ET1C 5 SW1C1 MCMU 1 ET1C 2 ET1C 3 CLAC MC1C MC1C CLAC ET5C BCSU 3 BCSU 4 OMU MC1C MC1C MC1C BCSU 0 MC1C SD3C-S CLAC ET5C ET1C 6 ET1C 4 ET1C 5 ET1C 2 ET1C 3 BCSU 3 BCSU 4 MC1C MC1C BCSU 1 BCSU 2 BCSU 5 BCSU 6 BCSU 1 BCSU 2 BCSU 5 BCSU 6 MC1C MC1C MC1C MC1C MC1C MC1C MC1C MC1C BCSU 7 BCSU 8 BCSU 7 BCSU 8 MC1C MC1C MC1C MC1C ET1C 0 ET1C 1 Figure 11. 7. BSC2i (ETSI/ANSI).3. Table 3. 7. These cables are attached to the connectors on the front panels of plug-in units.2 Power consumption The power consumption values for the cartridge types used in the BSC are shown in the table below. it is possible to use a direct floating battery. the main battery voltage of the GSM/EDGE BSC can be 48 V or 60 V. BSCi The PCM trunks and other station cables (external alarm cables.2 Dimensioning of the GSM/EDGE BSC The dimensioning rules of the GSM/EDGE BSC equipment are described in other documents of the GSM/EDGE BSC (see for example Engineering for BSC. and easy maintenance have been the main objectives in the design of the power supply system of the GSM/EDGE BSC. easy installation. Plan Network ). 7.3.5 V and 72 V. The power supply cables are terminated to the power supply connector on top of the rack. X. All the voltages required for the GSM/EDGE BSC are generated from the DC voltage by high frequency transformers using chopper technique.1 Structure of power supply Reliability. Power consumption of the BSC cartridges. In both cases. The input voltage is between 41. Because the range is wide.High Capacity Base Station Controller.25 cables) of the GSM/EDGE BSC enter the exchange room via a cable conduit and they enter the rack via earthing elements on top of the racks. The figures are for maximum equipment configurations. 7. the BCSU includes the PCU Application Cartridge type Power consumption BSCi CLAC 15 W   CLOC 20 W 58 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . LAN cables enter the rack via connector panels on top of the rack.3 Power supply 7. the BCSU includes the PCU (cont.Mechanical design and power supply of the High Capacity BSC Table 3. The figures are for maximum equipment configurations. Power consumption of the BSC cartridges. Table 4.) Application Cartridge type Power consumption   ET1C 25 W   ET5C 29 W   MCMU 44 W   OMU 69 W   BCSU 79 W   SW1C with GSWB application 65 W   SD3C-S 45 W BSC2i CLAC 15 W   CLOC 20 W   ET5C 29 W   MCMU 44 W   OMU 70 W   BCSU 93 W   SW1C with GSWB application 87 W   SD3C-S 45 W The power consumption values for the BCBE and BCEE racks are shown in the table below. Power consumption of the BSCi and BSC2i racks Application Rack type Power consumption BSCi BCBE 660 W   BCEE 620 W BSC2i BCBE 730 W dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 59 (68) . ) Application Rack type Power consumption   BCEE 770 W 60 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . BSC2i (ETSI/ANSI). BSCi Table 4.High Capacity Base Station Controller. Power consumption of the BSCi and BSC2i racks (cont. preprocessor. a restart in a program block.1 Fault management The DX 200 system is a loosely coupled. The control computer states are controlled from a centralised point which can be dynamically reallocated from the OMU to a pair of control computers when. control computers control their own software and are able to restart on their own by asking for the appropriate loading services. fault-tolerant distributed system with some centralised functions. The preprocessors run under the control of a master computer.Reliability of the High Capacity Base Station Controller 8 Reliability of the High Capacity Base Station Controller The simplicity and the fast speed of the maintenance procedures are the prerequisites for the availability of the Nokia BSC. or a single control computer is enough. The DX 200 System Maintenance functions conform with the idea of loose coupling of autonomous control computers. that state control mechanisms do not depend on any centralised hardware. Only the control computers are autonomous as described above. In most cases. This means that this centralised function has 3N redundancy. This means. and an individual program block failure or an individual hardware failure has a minor effect on the overall operation of the whole system. an OMU with no redundancy fails. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 61 (68) . and by the elimination of downtime by using a hot standby unit in the event of a failure. for example. for example. Maintenance is improved by the modular structure of the equipment. 8. The fault situation is hardly ever so bad or complex that the whole system has to be restarted. automatic fault detection procedures. in addition to what is required by the correct dimensioning. Power supply and the distribution of the basic timing signal are arranged so that the units backing each other up get their supply from different or redundant DC/ DC converters and their basic timing signals from different distribution lines. 8. BSCi 8. including an active unit and a spare unit. however. The Exchange Terminals of the PCM trunk circuits and the terrestrial channels are not critical. active or reserve. because the failure of a single terminal does not prevent service. Table 5. BSC2i (ETSI/ANSI). The main cause of this kind of load might be related to special end-user behaviour and is mainly related to radio network planning and dimensioning according to the required level.4 System availability The BSC2i is designed to meet the availability requirements of the ITU-T. All the critical parts of the switching system have an appropriate type of redundancy. The following design objectives have been adopted to ensure that the unavailability of the BSC is very low. so that preventive actions can be taken. Availability of the BSC2i in maximum configuration MTBF 62 (68) © Nokia Corporation Nokia Proprietary and Confidential 25 770 000 h dn99558545 Issue 4a-0 en .3 Redundancy principles When the BSC was designed.High Capacity Base Station Controller. 8. " N+1 or N+m redundancy principle for provision of one or more units.2 Overload protection The BSC overload protection handles excessive traffic or signalling load by limiting the load level of the BSC's main CPUs and preprocessors. the Exchange Terminals are without redundancy. There are usually several PCM circuits available in each direction. and also provides information of excessive load. great attention was paid to the reliability of operation. Thus. The following redundancy methods are used for various units: " 2N principle for duplicated units. BSC software can be downloaded without any disturbance to user data traffic.) Mean down time 0. the spare units are switched into active state and vice versa. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 63 (68) . software upgrades. 8. and finally the new software is loaded into the primary units. The trial configuration means that first the new software is loaded into spare units. for example.Reliability of the High Capacity Base Station Controller Table 5. but the activation of new software requires computer unit restarts. then a unit switchover is performed. the mean time to recovery for 512 TRXs has been assumed to be 1. the possible downtime can be minimised. Availability of the BSC2i in maximum configuration (cont. that is.5 Planned downtime The BSC is based on the DX 200 Computing Platform that makes it possible to minimise the downtime caused by.999 999 961 The above calculations have been based on plug-in unit failure statistics with the complete configuration of the BSC2i (for example. The following general design objectives have been established for the maintenance of the BSC: " mean active repair time less than half an hour " fault localisation with the accuracy of a plug-in unit for 70 % of the faults " fault localisation with the accuracy of four plug-in units for 95 % of the faults For more detailed information see BSC2i Availability Performance Prediction.0 hours). Thanks to the trial configuration.02 min/year Availability 0. High Capacity Base Station Controller. BSC2i (ETSI/ANSI). BSCi 64 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 65 (68) . take the following points into consideration when planning where to locate the BSC: " future expansion of the BSC " standard lengths of the cables between the racks " location of other equipment on the same site " air-conditioning of the equipment room " sufficient working space around the racks. This ensures that there is almost 500 mm of open working space above the cable troughs on top of the racks.High Capacity BSC Operating environment 9 9. No raised floor is needed. However.1 High Capacity BSC Operating environment Equipment room The mechanical structure of the GSM/EDGE BSC does not place any special requirements on the ceiling. Engineering Descriptions . Location of the racks is discussed in more detail in Base Station Controller. the walls. Figure 12 shows examples of equipment layouts of the GSM/EDGE BSC. or the floor. The racks of the GSM/EDGE BSC can be located in many different ways in the equipment room. The height of the room should be at least 2500 mm. Environmental conditions and environmental tests for telecommunications equipment Part 1-2. Environmental conditions and environmental tests for telecommunications equipment Part 1-1. 1992: Equipment Engineering (EE). Storage " ETS 300 019-1-2. Classification of environmental conditions. Typical layout of a BSC site 9.1 General The internationally recognised and comprehensive description of the environmental conditions is covered by the following ETS standards: 66 (68) " ETS 300 019-1-1. 1992: Equipment Engineering (EE).2.2 Environmental conditions 9. Classification of environmental conditions. BSCi 500 1000 600 RACK 2 600 1000 300 RACK 1 WORKING AREA Figure 12. Classification of environmental conditions. Stationary use at weatherprotected locations © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . 1992: Equipment Engineering (EE). BSC2i (ETSI/ANSI). Environmental conditions and environmental tests for telecommunications equipment Part 1-3. Transportation " ETS 300 019-1-3.High Capacity Base Station Controller. no special fans or other extra equipment are needed in the racks. the temperature of the air in the equipment room must naturally be within the limits of the recommendations (see Figure 13 ).2. the air warms up and rises. B 10 0 C -10 0 20 40 60 80 100% RELATIVE HUMIDITY Climatogram of the GSM/EDGE BSC Cooling of racks Because the power consumption of the BSC2i is low. performance and the environment is defined in the climatogram in Figure 13 . Inside the cartridge. No start-up below 0 °C temperature is allowed. The duration of these conditions is limited to 1 % of time or 48 h consecutively. TEMPERATURE °C 60 A B C 40 30 Exceptional conditions: The main functions of the equipment are not jeopardized. A 20 Normal conditions: The equipment meets the functional requirements in accordance with the product specifications.3 50 Nominal conditions: The equipment meets the functional reliability and life cycle requirements in accordance with the product specifications.High Capacity BSC Operating environment 9. When natural convection is used for cooling purposes.2. These conditions must be maintained 85 % of time. In this case. the cooling of the equipment can be implemented by means of natural convection.2 Climatogram Changes of temperature and relative humidity affect the reliability of the equipment. Cool air is directed into the cartridges from the room. Figure 13. dn99558545 Issue 4a-0 en © Nokia Corporation Nokia Proprietary and Confidential 67 (68) . The functional ambient temperature is -5 to +45 °C. The relationship between the availability. 9. High Capacity Base Station Controller. 68 (68) © Nokia Corporation Nokia Proprietary and Confidential dn99558545 Issue 4a-0 en . Equipment Engineering (EE).2.4 (FCC Rules in Title 47. 1997. Part 2: Product family standard. Class A. 2001). Subpart B.4 Electromagnetic environment EN 300 386-2. BSC2i (ETSI/ANSI). Electromagnetic Compatibility (EMC) requirements. BSCi 9. Part 15. Telecommunication network equipment. ANSI C63.