Security Level3G Cluster Packet Service Optimization Kickoff REPORT DATE: 28-June-2012 Table of Contents 2016-02-11 Huawei Proprietary - Restricted Distribution Page1, Total72 Security Level 1 Introduction............................................................................................................................................................................3 2 Tools.......................................................................................................................................................................................3 3 Contact Information...............................................................................................................................................................3 4 Analysis Procedure.................................................................................................................................................................3 4.1 PS CSSR Optimization.......................................................................................................................................................4 4.1.1 Pre Analysis....................................................................................................................................................................4 4.1.2 PS CSSR Optimization...................................................................................................................................................5 4.2 PS CDR Optimization......................................................................................................................................................19 4.2.1 Introduction..................................................................................................................................................................19 4.2.2 FACH Congestion........................................................................................................................................................19 4.2.3 F3 Strategy Modification.............................................................................................................................................20 4.3 PS Throughput Optimization...........................................................................................................................................21 4.3.1 Fundamental Check......................................................................................................................................................21 4.3.2 RTWP Optimization.....................................................................................................................................................21 4.3.3 TCP Accelerator...........................................................................................................................................................32 4.3.4 CQI Adjustment Based on Dynamic BLER Target.....................................................................................................36 4.3.5 HSUPA Adaptive Re-Transmission..............................................................................................................................37 5 Smart Phone Optimization...................................................................................................................................................38 5.1 Enhanced Fast Dormancy.................................................................................................................................................38 5.2 Multi-RAB Optimization.................................................................................................................................................46 5.3 Call Re-establishment......................................................................................................................................................59 6 Summary and Conclusion....................................................................................................................................................61 7 Schedule...............................................................................................................................................................................66 2016-02-11 Huawei Proprietary - Restricted Distribution Page2, Total72 Security Level 1 Introduction According to Ongoing Service contract for 2012, Cluster Packet Service Optimization is one of the defined work packages for which Huawei will take the responsibilities. PP12 was selected for 3G packet service optimization as an example. The Analysis and recommendations will be provided to improve PS CSSR, CDR and throughput, etc. Meantime, some improvement might be obtained on Circuit Switching Domain as well. As agreed, the best practices and experiences verified in PP12 will be rollout in entire network by Vodacom. This document is intended to explain the contracted 3G cluster packet service optimization process, tools & the deliverables attached with this service. The RF design related issues and optimizations are out of the scope of this activity. 2 Tools 1) Huawei Configuration Management Express (CME) for configuration data collection – Integrated on M2000 2) Huawei PRS (Performance Reporting System) 3) Sonar 3 Contact Information Following will be the contact person from Huawei for this work package: NO. Name Mail Cell Phone 1 Sagar
[email protected] +27 715172241 2 Bob Sun
[email protected] +27 763186113 4 Analysis Procedure This activity is divided into 4 categories: 2016-02-11 PS Call Setup Success Rate Optimization PS Call Drop Rate Success Rate Optimization PS Throughput Optimization Smart Phone Optimization Huawei Proprietary - Restricted Distribution Page3, Total72 Security Level 4.1 PS CSSR Optimization 4.1.1 Pre Analysis CSSR (Call Setup Success Rate) = RRC Setup Success Rate (Service) * RAB Setup Success Rate The PS CSSR is around 99%. The RRC Setup Success Rate (service) is around 99.8%, so no big room for further optimization. So the CSSR optimizations will be focusing on PS RAB Setup Success Rate. 2016-02-11 Huawei Proprietary - Restricted Distribution Page4, Total72 Security Level From the graphs above, we can see the main contributor to the PS RAB failures are congestions. On Huawei RAN, the congestions are pegged during “Admission” stage, admission failures caused by Code, Uplink/Downlink power, Uplink/Downlink Channel Element, Iub bandwidth should be 2016-02-11 Huawei Proprietary - Restricted Distribution Page5, Total72 Security Level checked. The pie chart above indicates that about 85% of the congestions are caused by UL Channel Element and Uplink Power. These two aspects should be the main optimization targets. 4.1.2 PS CSSR Optimization a) Fundamental Check Before any fine tunings on some parameters, some fundamental checks as per the project parameter baseline are required. Items: All Co-antenna cells should be configured with Blind Handover Inter Frequency Neighbors (BlindHoFlag=TRUE) Non Co-antenna cells can’t be configured with Blind Handover Inter Frequency Neighbors (BlindHoFlag=FALSE) The EcNo threshold for candidate target DRD cell is -13dB (DRDEcN0Threshhold). MO UINTERFREQNCELL Parameter ID DRDEcN0Threshhold Parameter Name Drd Ec/No Threshold NE BSC6900 MML Command ADD UINTERFREQNCELL MOD UINTERFREQNCELL Meaning DRD Ec/No threshold for determining whether to perform the blind handover. If the measured Ec/No of the current cell is greater than this parameter, this cell can be the candidate cell for DRD. IsKey NO Mandatory NO Feature ID WRFD-02040001 Feature Name Intra System Direct Retry Value Type Interval Type 2016-02-11 Huawei Proprietary - Restricted Distribution Page6, Total72 Security Level GUI Value Range -24~0 Enumeration Number/Bit Not involved Unit dB Actual Value Range -24~0 Default Value -18 Recommended Value -18 Impact Cell Parameter Relationship None Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved Interruption Duration(Min) Not involved Caution None Validation of Modification The parameter modification has no impact on the equipment. Impact on Radio Network Performance None Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio SIB11 should be ON MO UINTERFREQNCELL Parameter ID SIB11Ind 2016-02-11 Huawei Proprietary - Restricted Distribution Page7, Total72 Security Level Parameter Name SIB11 Indicator NE BSC6900 MML Command ADD UINTERFREQNCELL MOD UINTERFREQNCELL Meaning Indicates whether to send the system information block 11 (SIB11) including neighboring cell information. The value "FALSE" indicates that the neighboring information is not included in the SIB11. The value "TRUE" indicates that the neighboring information is included in the SIB11. IsKey NO Mandatory NO Feature ID WRFD-010801 WRFD-010802 Feature Name Intra RNC Cell Update Inter RNC Cell Update Value Type Enumeration Type GUI Value Range FALSE(Do not send), TRUE(Send) Enumeration Number/Bit FALSE~0, TRUE~1 Unit None Actual Value Range FALSE, TRUE Default Value TRUE Recommended Value TRUE Impact Cell Parameter Relationship None Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved 2016-02-11 Huawei Proprietary - Restricted Distribution Page8, Total72 Security Level Interruption Duration(Min) Not involved Caution None Validation of Modification The parameter modification has no impact on the equipment. Impact on Radio Network Performance None Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio The Priority for Coverage based interfreq handover between Co-antenna cells is “0” MO UINTERFREQNCELL Parameter ID HOCovPrio Parameter Name Priority of Coverage-Based Inter-Frequency Handover NE BSC6900 MML Command ADD UINTERFREQNCELL MOD UINTERFREQNCELL Meaning Priority for neighboring cell supporting coverage-based inter-frequency handover. The value "0" indicates that the coverage-based inter-frequency handover is not supported. The value "1" indicates that the cell is assigned with the highest priority for the handover. The value "3" indicates that the cell is assigned with the lowest priority for the handover. If a higher priority is assigned to a cell, the probability for selecting the cell as the measurement object and the target cell for the handover increases. For example, the cell with priority 1 has more chance to select as the measurement object and the target cell for the handover than the cell with priority 2. IsKey NO Mandatory NO Feature ID WRFD-020302 Feature Name Inter Frequency Hard Handover Based on Coverage 2016-02-11 Huawei Proprietary - Restricted Distribution Page9, Total72 Security Level Value Type Interval Type GUI Value Range 0~3 Enumeration Number/Bit Not involved Unit None Actual Value Range 0~3 Default Value 2 Recommended Value 2 Impact Cell Parameter Relationship None Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved Interruption Duration(Min) Not involved Caution None Validation of Modification The parameter modification has no impact on the equipment. Impact on Radio Network Performance None Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio Findings on PP12: 2016-02-11 2 cells are not configured with Blind Handover Neighbors. 10 neighbors SIB11 are OFF. Huawei Proprietary - Restricted Distribution Page10, Total72 Security Level 38 cells: The Priority for Coverage based interfreq handover between Co-antenna cells is “2”. 40 cells: The EcNo threshold for candidate target DRD cell is -18dB. Benchmark: Slight improvement is seen on PS CSSR after implementation on these cells. b) UL Power Congestion Optimization As default, uplink power admission is based on equivalent user number (ENU): ALGORITHM_SECOND. MO UCELLALGOSWITCH Parameter ID NBMUlCacAlgoSelSwitch Parameter Name Uplink CAC algorithm switch NE BSC6900 MML Command ADD UCELLALGOSWITCH MOD UCELLALGOSWITCH Meaning The algorithms with the above values represent are as follow: ALGORITHM_OFF: Disable uplink call admission control algorithm. ALGORITHM_FIRST: The load factor prediction algorithm will be used in uplink CAC. ALGORITHM_SECOND: The equivalent user number algorithm will be used in uplink CAC. ALGORITHM_THIRD: The loose call admission control algorithm will be used in uplink CAC. IsKey NO Mandatory YES Feature ID WRFD-020101 2016-02-11 Huawei Proprietary - Restricted Distribution Page11, Total72 Security Level Feature Name Admission Control Value Type Enumeration Type GUI Value Range ALGORITHM_OFF, ALGORITHM_FIRST, ALGORITHM_SECOND, ALGORITHM_THIRD Enumeration Number/Bit ALGORITHM_OFF~0, ALGORITHM_FIRST~1, ALGORITHM_SECOND~2, ALGORITHM_THIRD~3 Unit None Actual Value Range ALGORITHM_OFF, ALGORITHM_FIRST, ALGORITHM_SECOND, ALGORITHM_THIRD Default Value None Recommended Value None Impact Cell Parameter Relationship None Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved Interruption Duration(Min) Not involved Caution None Validation of Modification The parameter modification has no impact on the equipment. Impact on Radio Network Performance None Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio ENU Calculations: 2016-02-11 Huawei Proprietary - Restricted Distribution Page12, Total72 Security Level ENU Counter: Counter “VS.RAC.UL.EqvUserNum” can indicate the real ENU for each cell. Worst performing cells in PP12 with Uplink Power congestion: Recommendations: 2016-02-11 F3 Upgrade if possible Huawei Proprietary - Restricted Distribution Page13, Total72 Security Level Increase admission threshold (impact all types of admission control) Disable uplink CAC (Call Admission Control) Benchmark for disabling UL power CAC on severe congested cells: Uplink Power Congestions are cleared, and PS CSSR is around 99.5% for these cells. CE, Iub, Code and DL power admission controls are still valid. Practices to relieve UL power congestion in SGA region: In SGC region, current CAC algorithm parameters were fine tuned in order to relieve the congestion problem. Please note, in this study, the algorithm itself is still active and the triggering conditions have been optimized only. For this study, most congested 16 sites were selected as candidate sites from entire region. The changes were implemented for 49 cells from 5 different RNCs. Candidate cells were selected according to the UL Power Congestion rates. It was the key measure that cell has major UL Power Congestion. In current network policy, the max allowed ENU percentage is set 65, which is equal to 130 ENU out 2016-02-11 Huawei Proprietary - Restricted Distribution Page14, Total72 Security Level of total allowed 200 for PS service in UL direction for all cells. With fine tuning of parameters, allowed UL ENU percentage is set to 90, which increased the total allowed number from 130 ENU to 180 ENU. In case of sudden traffic increase, since algorithm is still active but with an optimized set of thresholds, in case of high load, required CAC actions will be triggered and system stability will be kept constant. Below are old and new values regarding to the change. Please note, the threshold values for Conv and non-Conv AMR services have been changed to satisfy the UlNonCtrlThdForHo > UlNonCtrlThdForAMR; UlNonCtrlThdForAMR > UlNonCtrlThdForOther The rejects due to other types of congestion (i.e. Code, CE and Iub) have been monitored. In case of an excessive load (because of the increased threshold) actions are expected to be triggered by this algorithm. It is possible to increase the thresholds further, but LDM parameters also have to be modified to do so (because of parameter relation) Results: 2016-02-11 Huawei Proprietary - Restricted Distribution Page15, Total72 Security Level c) UL CE Optimization CE congestions are mostly on uplink as on downlink the dedicated Mac-hs element processes HSDPA traffic. As per Huawei equipment specifications, one Resource Group can support 6 cells, for S333 sites, 9 cells have to be divided into 2 Groups. CE resources can’t be shared between different Uplink Resource Groups, so there is a possibility that one group is congesting and another one is not fully utilized. Furthermore, as congestions are only pegged during “admission” stage, so it’s possible that the overall NodeB CE utilization is not high but the CE congestions are seen due to data service behavior (resource is always reserved for each user). Worst performing cells in PP12: Top 3 sites are already configured with 4*WBBP, but only one for F3. Many congestions are seen on F3 cells. It is recommended to move one WBBP to Group1 (configuration). RED Line: Uplink resource group reconfiguration 2016-02-11 Huawei Proprietary - Restricted Distribution Page16, Total72 Security Level GREEN Line: Disable cell level CE CAC After Uplink resource group adjustment, congestions moved from F3 to F1&F2 (even more). The root cause is still that the different uplink resource groups can’t be shared. Disabling Cell level credit (CE) CAC (NodeB level CE CAC still valid), CE congestion reduced. The graph above shows very low CE utilization for these sites. 2016-02-11 Huawei Proprietary - Restricted Distribution Page17, Total72 Security Level Conclusion: For 4*WBBP sites, disabling cell level CE CAC is a better solution. The UL CE congestion can’t be cleared after disabling cell level CAC as NodeB level CE CAC is still valid. Some other features and functions can be considered to reduce CE congestion, such as Fast Dormancy, HSUPA TTI reconfigurations and HSUPA GBR adjustment. HSUPA GBR Adjustment: The main contributor to the uplink CE congestion is HSUPA traffic. According to the statistics, the average HSUPA throughput per user is <40kbps. The GBR (Guaranteed Bit Rate) for HSUPA is 64kbps in live network, so some resources are wasted for admission. GBR is only used for admission control, users can get higher throughput via DCCC (Dynamic Channel Configuration Control) Recommendation: Change the HSUPA GBR from 64kbps to 32kbps. Less PS congestions after GBR changed from 64kbps to 32kbps. d) Enable “DRD Failure Rollback” function DRD (Direct Retry Decision): If the UE requests a service setup or channel reconfiguration in an area covered by multiple frequencies, the RNC sets up the service on a carrier with a light load to balance out the load among the cells on the different frequencies. Current PP12’s DRD Successful Rate is around 99%. 2016-02-11 Huawei Proprietary - Restricted Distribution Page18, Total72 Security Level Recommendation: Enable “DRD failure rollback” function to avoid some RAB setup failures. MML command: SET URRCTRLSWITCH:PROCESSSWITCH2=RNC_RBRECFG_DRD_FAIL_ROLLBACK_SWITCH1&RNC_RBSETUP_DRD_FAIL_ROLLBACK_SWITCH-1; Description: RNC_RBRECFG_DRD_FAIL_ROLLBACK_SWITCH (RB Reconfiguration DRD Rollback Switch): When the switch is turned on, the RNC supports rollback caused by failed DRDs of RB reconfiguration. When the switch is turned off, the RNC does not support rollback caused by failed DRDs of RB reconfiguration. RNC_RBSETUP_DRD_FAIL_ROLLBACK_SWITCH (RB Establishment DRD Rollback Switch) : When the switch is turned on, the RNC supports rollback caused by failed DRDs of RB establishment. When the switch is turned off, the RNC does not support rollback caused by failed DRDs of RB establishment. Benchmark on PP12: Slight improvement on PS RAB Setup Success Rate 2016-02-11 Huawei Proprietary - Restricted Distribution Page19, Total72 Security Level 4.2 PS CDR Optimization 4.2.1 Introduction Besides of some RF design issues, there are two main contributors to the PS Call Drop Rate in live network: FACH Congestion – causing PS Call Drops on Common channels Correlation between PS CCH drop rate and FACH congestion: F3 idle barred strategy As Cell_FACH and Cell_PCH is enabled, if F3 is idle barred, when UE transit to Cell_FACH on F3, it will reselect back to F1&F2 (SIB12 is not enabled). Ping-pong reselections between different layers increase the possibility of drops, negatively impact subscriber’s perception as well. 4.2.2 FACH Congestion As default, only one SCCPCH (Secondary Common Control Physical Channel) is configured for each cell. Paging channel (PCH) and FACH are mapped onto the same physical channel SCCPCH as per 3GPP specifications. And, PCH has higher priority to occupy this channel comparing with FACH. To expand FACH capacity, 2nd SCCPCH dedicated for FACH is recommended. 2nd SCCPCH addition has already been rolled out in entire network. 4.2.3 F3 Strategy Modification Current F3 Strategy: 2016-02-11 Huawei Proprietary - Restricted Distribution Page20, Total72 Security Level Randomly camping on F1&F2 F3 is idle barred DRD algorithm based on User Number Load based blind handover between different layers Proposed Strategy for PP12 (non-continuous F3 footprint): Change from F3 barred to inclined camping on F1&F2 in case F3 is not continuous. - Set a big Qoffset2 between (F1,F2) & F3 to make idle UE mainly camp on F1&F2 to reduce the mobility CS drops on F3. Inclined camping on F1&F2 F3 is not idle barred DRD algorithm based on User Number Load based blind handover between different layers Benchmark for F3 strategy modification: Improvement on F3 PS CDR after implementation (from 1.9% to 1.3%) 2016-02-11 Huawei Proprietary - Restricted Distribution Page21, Total72 Security Level As for the areas with continuous F3 footprint such as SGS region, the proposed strategy is: 4.3 Randomly camping on F1&F2&F3 F3 is not idle barred DRD algorithm based on User Number Load based blind handover between different layers PS Throughput Optimization 4.3.1 Fundamental Check Items: HSDPA/HSUPA function should be activated. 64QAM, Downlink Enhanced Layer2, Dual-Carrier HSDPA should be activated. 4.3.2 RTWP Optimization These section only targets at high RTWP caused by high traffic, abnormalities caused by external interference, engineering issues need specific inspections. a) Background Noise Alignment As default, the background noise is 61, which means -112+61/10=-105.9dBm. 2016-02-11 Huawei Proprietary - Restricted Distribution Page22, Total72 Security Level As default, the maximum target load is 75%, means 6dB lift. Under these settings, when RTWP=-105.9dBm+6dB=-99.9dBm, the uplink load has already 2016-02-11 Huawei Proprietary - Restricted Distribution Page23, Total72 Security Level reached maximum load target. Consequently, the HUSPA throughput can’t be scheduled more. In the live network during the peak hours, many RTWP spikes can exceed this value which are causing low HSUPA throughput. This activity is to align the configured background noise with actual RTWP. We can regard the minimum RTWP during the early morning (02h00-03h00) as real background noise. b) CQI Feedback Period Optimization More and more HSDPA connections are active according to the traffic growth trend. HSDPA uplink feedback channel HS-DPCCH generated a big part of uplink interference which limits the uplink capacity and HSUPA throughput as well. Huawei Lab test result: 2016-02-11 Huawei Proprietary - Restricted Distribution Page24, Total72 Security Level Highest “HSDPA User Number” vs “Mean RTWP” in PP12: High RTWP caused by HSDPA traffic. Recommendation: Prolong “CQI Feedback period” from 2ms to 8 ms Pros: Improve the RTWP, uplink capacity and HSUPA throughput Cons: HSDPA scheduling will be slower in fast fading scenario MML command: ADD UCELLHSDPCCH:CELLID=11111,CQIFBCK=D8,CQIFBCKFORSHO=D8; Benchmark for CQI feedback period change on PP12: 2016-02-11 Huawei Proprietary - Restricted Distribution Page25, Total72 Security Level About 3dB improvement on average RTWP during peak hours, which means we have almost 50% gains on uplink capacity. c) RACH Access Parameter Optimization RACH access preamble adopts open-loop power control method, when the coverage is not so good or with massive RRC attempts, UE TX power will increase quickly, lead to RTWP spikes. In order to reduce RTWP spikes caused by this, RAC access parameters could be optimized. Top cells with highest RRC attempts in PP12, the average RTWP is also high: Recommendations: 2016-02-11 Huawei Proprietary - Restricted Distribution Page26, Total72 Security Level Parameter Description: MO UPRACHUUPARAS Parameter ID Constantvalue Parameter Name Constant Value for Calculating Initial TX Power NE BSC6900 MML Command MOD UPRACHUUPARAS Meaning This parameter specifies a constant used at calculation of the initial transmit power of the first preamble, to be used in the random access procedure. The formula is as follows: Preamble_Initial_Power = Primary CPICH DL TX power-CPICH_RSCP + UL interference + Constant Value. Where, Preamble_Initial_Power is the preamble initial TX power, Primary CPICH DL TX power is the downlink transmit (TX) power of PCPICH, CPICH_RSCP is the receive signaling code power of the PCPICH measured by UEs, and UL interference is the uplink interference. For detailed information of this parameter, refer to 3GPP TS 25.211. IsKey NO Mandatory NO Feature ID WRFD-020501 Feature Name Open Loop Power Control Value Type Interval Type GUI Value Range -35~-10 Enumeration Not involved Number/Bit Unit dB 2016-02-11 Huawei Proprietary - Restricted Distribution Page27, Total72 Security Level Actual Value Range -35~-10 Default Value -20 Recommended Value -20 Impact Cell Parameter None Relationship Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved Interruption Not involved Duration(Min) Caution None Validation of The parameter modification has no impact on the equipment. Modification Impact on Radio None Network Performance Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio MO UPRACHUUPARAS Parameter ID PreambleRetransMax Parameter Name Max Preamble Retransmission NE BSC6900 MML Command MOD UPRACHUUPARAS Meaning The maximum number of preambles transmitted in a preamble ramping cycle. For detailed information of this parameter, refer to 3GPP TS 25.211. IsKey NO Mandatory NO 2016-02-11 Huawei Proprietary - Restricted Distribution Page28, Total72 Security Level Feature ID WRFD-020501 Feature Name Open Loop Power Control Value Type Interval Type GUI Value Range 1~64 Enumeration Not involved Number/Bit Unit None Actual Value Range 1~64 Default Value 20 Recommended Value 20 Impact Cell Parameter None Relationship Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved Interruption Not involved Duration(Min) Caution None Validation of The parameter modification has no impact on the equipment. Modification Impact on Radio If the value of Max preamble retransmission is too small, the preamble power may fail to ramp Network Performance to the required value. This may result in UE access failure. If it is too large, the UE will repeatedly increase the power and make access attempts, which may result in interference to other UEs. Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio MO 2016-02-11 UPRACHUUPARAS Huawei Proprietary - Restricted Distribution Page29, Total72 Security Level Parameter ID PowerRampStep Parameter Name Power Increase Step NE BSC6900 MML Command MOD UPRACHUUPARAS Meaning The power ramp step of the random access preambles transmitted before the UE receives the acquisition indicator in the random access process. For detailed information of this parameter, refer to 3GPP TS 25.211. IsKey NO Mandatory NO Feature ID WRFD-020501 Feature Name Open Loop Power Control Value Type Interval Type GUI Value Range 1~8 Enumeration Not involved Number/Bit Unit dB Actual Value Range 1~8 Default Value 2 Recommended Value 2 Impact Cell Parameter None Relationship Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved Interruption Not involved Duration(Min) Caution None 2016-02-11 Huawei Proprietary - Restricted Distribution Page30, Total72 Security Level Validation of The parameter modification has no impact on the equipment. Modification Impact on Radio If the value of Power ramp step is too large, the access procedure will be shortened, but it is Network Performance more likely to cause power waste. If it is too small, the access procedure will be extended in time, but transmit power resources will be saved. This parameter must be set carefully. In addition, the higher the parameter value is, the smaller impact "Constant Value for Calculating Initial TX Power" has on the network performance. Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio Benchmark: 2016-02-11 Huawei Proprietary - Restricted Distribution Page31, Total72 Security Level Significant RTWP improvement on High RRC Attempts sites, HSUPA throughput improved as well. No degradation on RRC Setup Success Rate. d) Adaptive PO for HSUPA Traffic Channel Current HSUPA power parameter configuration is more reasonable for high speed transmission, in order to adapt to the scenario with many low throughput online users, this feature enables the RNC to configure an optimal power offset for HSUPA 10 ms TTI UEs with a small target number of retransmissions based on the rate of the UEs. If the data rate is lower than 300 kbit/s, a large power offset of E-DPDCH and DPCCH can be configured. Configuring a larger offset decreases power on the DPCCH and reduces power consumption on the uplink control channel. In this way, more power can be used to transmit user data in the uplink, thereby increasing capacity of HSUPA cells. If the data rate is higher than 300 kbit/s, a low power offset of E-DPDCH and DPCCH can be configured. Configuring a smaller offset increases power on the DPCCH, thereby meeting power requirements in cases of multipath searching and channel assessment and improving performance of HSUPA services. MML command: SET UCORRMALGOSWITCH: PcSwitch=PC_HSUPA_DATA_CH_PO_ADAPTIVE_ADJ_SWITCH-1; Benchmark: 2016-02-11 Huawei Proprietary - Restricted Distribution Page32, Total72 Security Level No obvious improvement on statistics, as the main gain is obtained when the HSUPA throughput is greater than 300kbps as per the feature description. In the live network, this scenario could have a small proportion. Field HSUPA test should be getting more benefit. 4.3.3 TCP Accelerator The Transmission Control Protocol (TCP) is a reliable transport layer protocol to provide reliable end-to-end streams of bytes for the Internet. It is widely used in email and file transfer services. The TCP was initially designed for wired communications. After the TCP is introduced in wireless communications, the original TCP mechanism cannot well adapt to the wireless network's characteristics such as high bit error rate and long delay, which leads to dissatisfactory transmission performance. To improve the performance, the TCP Performance Enhancer (TPE) is introduced. The TPE is also known as TCP accelerator or TCP proxy. The TPE is a functional entity in the RNC. It works as a proxy between the sender and the receiver. It buffers and processes data to accelerate data transmission and to improve transmission performance. The position of the TPE entity on the TCP connection is shown as below. In uplink transmission, the server is the receiver and the UE is the sender. In downlink 2016-02-11 Huawei Proprietary - Restricted Distribution Page33, Total72 Security Level transmission, the UE is the receiver and the server is the sender. The TPE works independently of other network elements (NEs). The TPE must be implemented before Packet Data Convergence Protocol (PDCP) header compression. After the TPE function is activated, only the new TCP connections can benefit from the feature. TCP Terms: Term MSS Definition The maximum segment size (MSS) is the largest amount of data (excluding TCP headers) sent through TCP from the source end to the peer end in a single segment. The MSS is negotiated when a TCP connection is established between two ends. Receive The receive window (rwnd for short) specifies the largest amount of data that can be received window by the receiver. Congestion The congestion window (cwnd for short) limits the total amount of data that can be sent by a window TCP connection. It frequently changes throughout the communication process of the TCP connection. Offered The offered window indicates the largest amount of data that can be received at a moment by window the receiver. It is used to limit the largest amount of unacknowledged data allowed by the sender. Send The send window indicates the largest amount of data that can be sent by the sender at a window moment. It is equal to the minimum value of cwnd and offered window. Slow start When cwnd is larger than or equal to the slow start threshold (ssthresh for short), the TCP threshold connection enters the congestion avoidance phase. RTT The round trip time (RTT) is the time during which the sender sends a packet to the receiver and the receiver returns an acknowledgement (ACK). DupACK The duplicate acknowledgement (DupACK) is an ACK whose sequence number is the same as that of the previous ACK. When packet misordering or packet loss occurs during transmission, the receiver responds the sender with a DupACK. TCP Reno Data can be transmitted in sequence only after a TCP connection is established through three 2016-02-11 Huawei Proprietary - Restricted Distribution Page34, Total72 Security Level handshakes. During the transmission, congestion is controlled through transmission rate adjustment. The adjustment is based on three variables: cwnd, rwnd, and ssthresh. When the sender detects packet loss due to retransmission timeout or repeat reception of DupACK, it adjusts the transmission rate. The TCP Reno is the most widely used TCP protocol version. It consists of four phases: slow start, congestion avoidance, fast recovery, and fast retransmission. Here, assume that ssthresh is set to 64 KB. Slow start and congestion avoidance: Fast retransmission and fast recovery: In the slow start phase, cwnd is set to the two times the MSS. Each time an ACK is received, the 2016-02-11 Huawei Proprietary - Restricted Distribution Page35, Total72 Security Level value of cwnd is incremented by one MSS (unit: byte). In addition, the TCP connection maintains the threshold ssthresh. When the value of cwnd reaches this threshold, the TCP connection enters the congestion avoidance phase. RTT Timeout In this case, the sender sets ssthresh to max {cwnd /2, 2 x MSS} and then sets cwnd to 2 x MSS. The TCP connection enters the slow start phase again. Repeat reception of DupACK In this case, the TCP connection enters the fast retransmission and fast recovery phases. The sender sets ssthresh and cwnd to max {cwnd/2, 2 x MSS}. Each time a DupACK is received, the value of cwnd is incremented by one MSS. This process is accomplished until the retransmitted packets are received. Then, the sender sets cwnd to the value of ssthresh. The TCP connection enters the congestion avoidance phase again. TPE Technologies The TPE module function is in the RNC. When establishing a TCP connection, the TPE module sets up a TPE entity for the TCP connection to process TCP packets. In uplink transmission, the server is the receiver and the UE is the sender. In downlink transmission, the UE is the receiver and the server is the sender. In downlink transmission, the TPE adopts the following technologies to improve the transmission performance: ACK Splitting DupACK Duplication Downlink Packet Sorting In uplink transmission, the TPE adopts technologies such as “ACK Splitting” and “Uplink Packet Sorting”. The working principles of uplink transmission are the same as those of downlink transmission. ACK Splitting: In TCP, the congestion window is updated according to the number of received ACK messages and is expanded by increasing the number of ACK messages. When a slow startup occurs at the transmitting end, ACK splitting can quickly recover the congestion window; when the transmitting end works in congestion avoidance mode, ACK splitting can accelerate the 2016-02-11 Huawei Proprietary - Restricted Distribution Page36, Total72 Security Level expansion of the congestion window. DupACK Duplication: In TCP, a lost TCP packet is retransmitted after three DupACK are received. With this feature, after the TPE receives the ACK message from the UE, the TPE immediately duplicates three DupACK messages and sends them to the Server if it detects that the packets requested by the ACK are not in the buffer. This shortens the time for packet retransmission. Downlink Packet Sorting: The TPE sorts and transmits the disordered DL packets to avoid unnecessary transmission of DupACKs in the uplink and to prevent TPE local retransmission caused by disordered packets. In this way, transmission resources are saved. Uplink Packet Sorting: The TPE sorts the UL packets and transmits them to the core network (CN) in sequence. This avoids the deterioration of the UL data transmission performance caused by the disordered UL packets. TCP Accelerator was enabled on 20th June. Slight improvement is seen on throughput statistically. 2016-02-11 Huawei Proprietary - Restricted Distribution Page37, Total72 Security Level 4.3.4 CQI Adjustment Based on Dynamic BLER Target Without this feature, the NodeB determines a transmission block size (TBS) based on the channel quality indicator (CQI) reported by the UE, system resources, and the transport format and resource combination (TFRC) policy. If the reported CQI and related conditions remain the same, the NodeB does not change the TBS because it does not consider the ever-changing radio environments. The constant changes in radio environments, caused by multipath effects and UE mobility, lead to fluctuating channel quality. Under these circumstances, choosing a TBS based on the reported CQI makes it difficult to always achieve the optimum downlink throughput. With this feature, the NodeB monitors the channel quality fluctuations for HSDPA users in a cell in real time and dynamically selects a proper BLER target based on the monitoring result. The NodeB then uses the BLER target to adjust the CQI reported by the UE. Based on the adjusted CQI, the NodeB determines an appropriate TBS to achieve higher downlink throughput for HSDPA users and higher cell throughput. 2016-02-11 Huawei Proprietary - Restricted Distribution Page38, Total72 Security Level Note: This feature needs NodeB license support. 4.3.5 HSUPA Adaptive Re-Transmission HARQ retransmission number is used as the target value of HSUPA uplink outer loop power control. When UE signal quality is good and uplink transmission power is not limited, a small retransmission can improve single user throughput. However, when capacity is limited and cell uplink power becomes a bottleneck, increasing retransmission number can improve cell throughput. Increasing retransmission number can also boost user cell edge throughput, where UE uplink power is limited. Therefore there’s a need to realize the adaptive adjustment of retransmission number. With comprehensive considerations of cell uplink power load, CE resources, and limited uplink coverage, this feature enables the adaptive adjustment of the number of target uplink retransmissions to improve the throughput per user and cell uplink capacity. Pros: In a limited uplink coverage scenario, a user’s uplink cell edge throughput can be increased, in order to enhance user experience. According to simulation results, single user throughput has been show to increase by 15%-60%. In a scenario where the cell uplink power load is limited, increasing the retransmission number can 2016-02-11 Huawei Proprietary - Restricted Distribution Page39, Total72 Security Level improve cell throughput and cell uplink capacity. Simulation results have shown an increase of 53% in cell throughput under multi-user scenarios. Cons: UL CE consumption will increase MML Command: //RNC MML command SET URRCTRLSWITCH: PROCESSSWITCH=NODEB_PRIVATE_INTERFACE_SWITCH-1; SET UCORRMALGOSWITCH: PcSwitch=PC_HSUPA_HARQNUM_AUTO_ADJUST_SWITCH-1; // NodeB MML command (execute on all the NodeBs under PP12) SET ADPRETRANSSWTCH: SWITCH =OPEN; 5 Smart Phone Optimization 5.1 Enhanced Fast Dormancy Some intelligent UEs on a live network send a Signaling Connection Release Indication (SCRI) message to the RNC after PS data transmission is complete. By sending the SCRI message, intelligent UEs request for a transition to idle mode or the CELL_PCH or URA_PCH state to reduce battery consumption. Upon receiving the SCRI, the RNC can release the signaling connection and put the UE into idle mode, or the RNC can maintain the signaling connection and put the UE to CELL_FACH or CELL_PCH/URA_PCH state. RSVDBIT1_BIT29 of the RsvdPara1 parameter in the SET URRCTRLSWITCH command controls the UE through CELL_FACH to CELL_PCH/URA_PCH or directly to CELL_PCH/URA_PCH. These procedures can reduce battery consumption, depending on the UE capability and feature activation on the RNC. By default, the RNC puts the UE into idle mode. A UE setting up PS services in idle mode consumes more signaling resources than that in the CELL_PCH or URA_PCH state. If there are a large number of UEs transited between idle mode and CELL_DCH state, signaling storms may occur. The EFD feature puts UEs into the CELL_FACH or CELL_PCH state to reduce signaling resource consumption and eliminate signaling storms. Huawei provides a comprehensive end-to-end solution based on network characteristics to respond to network challenges. EFD is one component of the solution. This feature alone is not enough to eliminate signaling storms caused by intelligent UEs. However, when applied with professional 2016-02-11 Huawei Proprietary - Restricted Distribution Page40, Total72 Security Level services, EFD can be used to optimize the quality of service (QoS) for the entire network. The UEs on a live network can be divided into three types: UEs that do not send SCRI messages because there is no PS data to be transmitted. Pre fast dormancy UEs. This type of UE does not read the T323 information element (IE) carried in the system information block type 1 (SIB1) message. After PS data transmission is complete, this type of UE sends an SCRI message to the RNC, but the SCRI message does not carry the IE Signaling Connection Release Indication Cause. Both T323 and Signaling Connection Release Indication Cause are introduced in 3GPP Release 8. R8 fast dormancy UEs. This type of UE reads the T323 IE carried in the SIB1 message and sends an SCRI message to the RNC after PS data transmission is complete. The SCRI message carries the IE Signaling Connection Release Indication Cause that is set to "UE Requested PS Data session end." The T323 IE carried in the SIB1 message controls the frequency at which the R8 fast dormancy UEs send SCRI messages with the IE Signaling Connection Release Indication Cause set to "UE Requested PS Data session end". The T323 timer starts after an SCRI message is sent by the R8 fast dormancy UEs, and the second SCRI message with the IE Signaling Connection Release Indication Cause set to "UE Requested PS Data session end" can be sent only after the T323 timer expires. The EFD feature applies only to the pre fast dormancy UEs and R8 fast dormancy UEs. Users can configure EFD to be enabled for only the pre fast dormancy UEs or R8 fast dormancy UEs. When this feature is disabled, the RNC releases the signaling connection and puts the UE into idle mode after receiving the SCRI message regardless the UE types. When this feature is enabled, the RNC performs different processing based on the UE type: For the pre fast dormancy UEs, the RNC checks for compatibility issues after receiving an SCRI message. If there are no compatibility issues, the RNC puts the UE into the CELL_FACH or PCH state. If there is a compatibility issue, the RNC puts the UE into idle mode. For the R8 fast dormancy UEs, the RNC puts the UE into the CELL_FACH or PCH state after receiving an SCRI message. Note: 2016-02-11 Huawei Proprietary - Restricted Distribution Page41, Total72 Security Level Some pre fast dormancy UEs may have compatibility issues after moving to the CELL_FACH, CELL_PCH, or URA_PCH state. As a result, new services cannot be initiated. This feature has been tested by using iPhones and no compatibility issue occurred. When there is no PS data to be transmitted, the intelligent UE sends the RNC an SCRI message to request the UTRAN to release the signaling connection. This procedure saves power. In addition, the UE periodically sends heartbeat messages to the core network, for example, to check for new mails on the mail server. If the EFD feature is disabled, the RNC releases the signaling connection and puts the UE into the idle state. In this case, sending heartbeat messages leads to the procedures for RRC connection setups, authentication, encryption, and RAB setups. These procedures increase the RNC signaling processing load. EFD addresses this problem. With EFD, the RNC transits a UE to the CELL_FACH or PCH state instead of idle mode upon receiving an SCRI message from the UE. In this case, when the UE periodically sends heartbeat messages, the signaling procedure between the UE and RNC is simplified because the RRC connection is maintained. As the number of signaling exchange messages decreases, significant CPU resources can be saved for the RNC, and the UE consumes about the same low amount of battery power as a UE in idle mode. Signaling processing procedures for pre fast dormancy UEs and R8 fast dormancy UEs before and after EFD is enabled 2016-02-11 Huawei Proprietary - Restricted Distribution Page42, Total72 Security Level Identifying Fast Dormancy UEs The RNC identifies the pre fast dormancy UEs and R8 fast dormancy UEs using the following mechanisms: R8 fast dormancy: The T323 parameter that can be set in the SET UCONNMODETIMER command is sent to the UE by the SIB1 message. The R8 fast dormancy UEs send an SCRI message with the IE Signaling Connection Release Indication Cause set to "UE Requested PS Data session end" after PS data transmission is complete. The RNC identifies the R8 fast dormancy UEs by reading the value of IE Signaling Connection Release Indication Cause. This mechanism is standardized by 3GPP Release 8. Pre fast dormancy: The RNC identifies the pre fast dormancy UEs using the Type Allocation Codes (TACs). This mechanism, which is not standardized, is used for the early proprietary implementations of fast dormancy. The international mobile equipment identity (IMEI), which consists of 14 decimal digits and one check digit, contains TAC and SNR. TAC indicates a particular type of device that has been approved by a national GSM/WCDMA approval body. SNR is the serial number identifying the UE. The structure of the IMEI, which is shown as follows, is specified in 3GPP TS 23.003. 2016-02-11 Huawei Proprietary - Restricted Distribution Page43, Total72 Security Level To identify pre fast dormancy UEs, FD_TAC_MATCH_SWITCH of the PROCESSSWITCH parameter on the RNC side needs to be turned on. The TAC parameter has been set for the pre fast dormancy UEs by the ADD UIMEITAC command. The RNC checks the TAC of the IMEI in the IDENTITY REQUEST message. If the TAC is included in the EFD list, the UE can use EFD. State Transition for Fast Dormancy UE When EFD is disabled, upon receiving an SCRI message from a UE, the RNC releases the UE’s RRC connection. The EFD switches are specified by the RNC-level sub-parameter FAST_DORMANCY_SWITCH of the parameter PROCESSSWITCH. When EFD is enabled, state transition procedures vary according to the UE type as follows: For R8 fast dormancy UEs and pre fast dormancy UEs in EFD list: - If the RNC received the SCRI, The RNC transfers the UE to CELL_FACH or CELL_PCH/URA_PCH. The RSVDBIT1_BIT29 sub-parameter of the RsvdPara1 parameter in the SET URRCTRLSWITCH command controls whether the UE moves to CELL_FACH or CELL_PCH/URA_PCH. - After PS data transmission is complete, If UE is in CELL_DCH, the PS inactivity timer (PsInactTmrForFstDrmDch) for EFD in CELL_DCH is started. If the PS inactivity timer for EFD in CELL_DCH expires, the RNC transfers the UE to CELL_FACH or CELL_PCH/URA_PCH. - After PS data transmission is complete, If UE is in CELL_FACH, the PS inactivity timer (PsInactTmrForFstDrmFach) for EFD in CELL_FACH is started. If the PS inactivity timer for EFD in CELL_FACH expires, the RNC transfers the UE to CELL_PCH/URA_PCH. - If UE is transferred to CELL_PCH/URA_PCH, the PS inactivity timer (PsInactTmrForPreFstDrm) is started. If the PS inactivity timer for EFD in CELL_PCH expires, the RNC transfers the UE to IDLE. - If UE is in CELL_PCH/URA_PCH and has something to send and the condition for P2D is not satisfied, the RNC instructs the UE to enter the CELL_FACH state. 2016-02-11 Huawei Proprietary - Restricted Distribution Page44, Total72 Security Level - If UE is in CELL_FACH and send messages whose traffic volume is higher than FastDormancyF2DHTvmThd, The RNC will transfer the UE from CELL_FACH to CELL_DCH. - When the switch RSVDBIT1_BIT20 of RsvdPara1 in the SET URRCTRLSWITCH command is turned on and the UE tries to originate or terminate a CS service and the FACH is congested, the RNC instructs the UE to perform a P2D (instead of P2F) state transition. - When the switch FACH_DTCH_CONGEST_P2D of PROCESSSWITCH2 in the SET URRCTRLSWITCH command is turned on and the UE tries to originate or terminate a PS service and the FACH is congested, the RNC instructs the UE to perform a P2D (instead of P2F) state. For pre fast dormancy UEs not in EFD list: - If the RNC received the SCRI, the RNC transfers the UE to IDLE state. - The D2F/F2P/P2F/F2D/P2D state transition for pre fast dormancy UEs not in EFD list is the same to ordinary UEs. 2016-02-11 Huawei Proprietary - Restricted Distribution Page45, Total72 Security Level Data configuration for state transitions for a fast dormancy UE: Typ e Description D2P D2P indicates a transition from CELL_DCH to CELL_PCH, F2P from CELL_FACH to CELL_PCH, and D2F from CELL_DCH to CELL_FACH. The RNC starts the PS inactivity timer for fast dormancy when inactivity on PS data is detected. - PsInactTmrForFstDrmDch specifies the PS inactivity timer for CELL_DCH. - PsInactTmrForFstDrmFach specifies the PS inactivity timer for CELL_FACH. - PsInactTmrForPreFstDrm specifies the PS inactivity timer for CELL_PCH. D2F F2P If the UE is a fast dormancy UE and is not processing CS services, when the PS inactivity timer for fast dormancy expires or the RNC receives an SCRI message or 4B event from the UE, the UE changes states as follows: 1) For a UE in the CELL_DCH state: − If RSVDBIT1_BIT29 of RsvdPara1 in the SET URRCTRLSWITCH command is turned off, the RNC triggers a D2F state transition. − If RSVDBIT1_BIT29 of RsvdPara1 in the SET URRCTRLSWITCH command is turned on, the RNC triggers a D2P state transition. Note: The D2F and F2P state transitions are recommended for the following reasons: - During an IOT test, some terminal issues occur. Occasionally, terminals fail to establish services after a transition from CELL_DCH to CELL_PCH/URA_PCH. This failure has a bad impact on user experience. - Compare with a state transition from CELL_DCH to CELL_FACH and then to CELL_PCH/URA_PCH, the state transition from CELL_DCH to CELL_PCH/URA_PCH does not improve the network performance or user experience. - Some terminals send CELL UPDATE message to transfer data immediately after a state transition from CELL_DCH to CELL_PCH/URA_PCH, which increases the signaling messages and leads to a heavy load on the Uu interface. 2) For a UE in the CELL_FACH state, the RNC trigger an F2P state transition. 2016-02-11 Huawei Proprietary - Restricted Distribution Page46, Total72 Security Level D2I D2I indicates a transition from CELL_DCH to idle. When the FACH is congested, D2F is not triggered for inactive CELL_DCH users. Instead, the RNC triggers a D2I transition to release the UE's RRC connection. The switch for D2I is turned off by default. Run the following command to switch it on: SET UCORRMALGOSWITCH: ReservedSwitch0=RESERVED_SWITCH_0_BIT16-1; P2I P2I indicates a transition from CELL_PCH to idle. If the UE is in the CELL_PCH state, when the PS inactivity timer for fast dormancy (specified by PsInactTmrForPreFstDrm) expires, the RNC releases the UE's RRC connection and then the UE enters idle mode. P2D P2D indicates a transition from CELL_PCH to CELL_DCH. When the switch RSVDBIT1_BIT20 of RsvdPara1 in the SET URRCTRLSWITCH command is turned on and the UE tries to originate or terminate a CS service and the FACH is congested, the RNC instructs the UE to perform a P2D (instead of P2F) state transition. When the switch FACH_DTCH_CONGEST_P2D of PROCESSSWITCH2 in the SET URRCTRLSWITCH command is turned on and the UE tries to originate or terminate a PS service and the FACH is congested, the RNC instructs the UE to perform a P2D (instead of P2F) state transition. P2F P2F indicates a transition from CELL_PCH to CELL_FACH. When the UE has something to send and the condition for P2D is not satisfied, the RNC instructs the UE to enter the CELL_FACH state. For details about conditions for P2D, see above P2D description. F2D F2D indicates a transition from CELL_FACH to CELL_DCH. When a fast dormancy UE is in the CELL_FACH state, When the fast dormancy UE sends messages whose traffic volume is higher than FastDormancyF2DHTvmThd, The RNC will transfer the UE from CELL_FACH to CELL_DCH. The FastDormancyF2DHTvmThd is a new threshold of event 4a for fast dormancy UE, This threshold is set to bigger than traffic volume of most heartbeat messages so that to prevent state transitions from being triggered by a small number of heartbeat messages. Benchmark for PP12: 2016-02-11 Huawei Proprietary - Restricted Distribution Page47, Total72 Security Level About 20% reductions on RRC and RAB attempts, which reduce the signaling load significantly Less congestions are observed as well. 5.2 Multi-RAB Optimization The Multi-RAB (mainly for CS+PS) services increased as smart phone penetration is increasing. The trend of Multi-RAB attempts in NGA region: 2016-02-11 Huawei Proprietary - Restricted Distribution Page48, Total72 Security Level The live network statistics shows that the Call Drop Rate in Multi-RAB scenario is much higher than single RAB service. General cause of drop rate of Multi-RAB higher than single CS RAB: Higher RF signal quality requirement comparing with CS Single RAB More complicated signaling procedure comparing with Single RAB To improve the CS call drop: Reduce the PS RF signal quality requirement for multi-RAB Reduce the loss probability due to complicated signaling process. Optimize the signaling procedures 10 parameter tunings were rollout in NPI 2011, some more activities are proposed in 2012 Parameter Change (MML) Remark 3G_PP12_PPQ_ NGA SET UCORRMALGOSWITCH: Initiative in 2012: ON ReservedSwitch0=RESERVED_SWITCH_0_BIT1 Downlink HSDPA to R99 reconfiguration 5-1; on Multi RAB SET UCORRMALGOSWITCH: Initiative in NPI 2011 ON SET UFRC:ULDCHBEUPPERLIMITFORAMR=D64, Initiative in NPI 2011 D64 SET UFRC:DLDCHBEUPPERLIMITFORAMR=D8; Initiative in NPI 2011 D8 SET URRCTRLSWITCH: Initiative in NPI 2011 OFF SET USTATETIMER:RBSETUPRSPTMR=10000; Initiative in NPI 2011 10000 SET USTATETIMER:HOASUTMR=10000; Initiative in NPI 2011 10000 SET Initiative in NPI 2011 10000 SET USTATETIMER:RBRECFGRSPTMR=10000; Initiative in NPI 2011 10000 SET USTATETIMER:RBRELRSPTMR=10000; Initiative in NPI 2011 10000 SET USTATETIMER: Initiative in NPI 2011 10000 ReservedSwitch0=RESERVED_SWITCH_0_BIT1 1-1; RsvdPara1=RsvdBit1_BIT26-0; USTATETIMER:HOPHYCHRECFGTMR=10000; 2016-02-11 Huawei Proprietary - Restricted Distribution Page49, Total72 Security Level HoCellUpdateRspTmr=10000; SET URRCTRLSWITCH: Initiative in 2012: RsvdPara1=RsvdBit1_BIT20-0; When Cell_Fach&PCH is enabled, avoid SET URRCTRLSWITCH: CS RAB failures caused by the RsvdPara1=RsvdBit1_BIT21-0; procedure overlap between cell update OFF OFF and CS RAB establishment Parameter Description: MO UCORRMALGOSWITCH Parameter ID ReservedSwitch0 Parameter Name CORRM Algorithm Reserved Switch 0 NE BSC6900 MML Command SET UCORRMALGOSWITCH Meaning CORRM algorithm reserved switch 0. RESERVED_SWITCH_0_BIT11: When the switch is turned on, the PS service must be carried by DCHs in the uplink if both CS and PS services exist. RESERVED_SWITCH_0_BIT15: When the switch is turned on, the PS service must be carried by DCHs in the downlink if both CS and PS services exist. IsKey NO Mandatory NO Feature ID NA Feature Name NA Value Type Bit Field Type GUI Value Range RESERVED_SWITCH_0_BIT11, RESERVED_SWITCH_0_BIT15 Enumeration RESERVED_SWITCH_0_BIT11~10, RESERVED_SWITCH_0_BIT15~14 Number/Bit Unit None Actual Value Range RESERVED_SWITCH_0_BIT11, RESERVED_SWITCH_0_BIT15 Default Value None Recommended Value RESERVED_SWITCH_0_BIT11:OFF, RESERVED_SWITCH_0_BIT15:OFF 2016-02-11 Huawei Proprietary - Restricted Distribution Page50, Total72 Security Level Impact RNC Parameter None Relationship Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved Interruption Not involved Duration(Min) Caution None Validation of Not involved Modification Impact on Radio None Network Performance Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio MO UFRC Parameter ID UlDchBeUpperLimitforAmr Parameter Name Upper limit of UL BE data rate in AMR services NE BSC6900 MML Command SET UFRC Meaning This parameter specifies the upper limit of uplink BE service rate in combined AMR services. Combined AMR services consist of only AMR services and BE services. If there is a member of a different traffic class, the combined services are regarded as combined non-AMR services. IsKey NO Mandatory NO Feature ID None 2016-02-11 Huawei Proprietary - Restricted Distribution Page51, Total72 Security Level Feature Name None Value Type Enumeration Type GUI Value Range D8, D16, D32, D64, D128, D144, D256, D384 Enumeration D8~1, D16~2, D32~3, D64~4, D128~5, D144~6, D256~7, D384~8 Number/Bit Unit kbit/s Actual Value Range 8, 16, 32, 64, 128, 144, 256, 384 Default Value D384 Recommended Value D384 Impact RNC Parameter None Relationship Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved Interruption Not involved Duration(Min) Caution None Validation of The parameter modification has no impact on the equipment. Modification Impact on Radio None Network Performance Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio MO UFRC Parameter ID DlDchBeUpperLimitforAmr Parameter Name Upper limit of DL BE data rate in AMR services 2016-02-11 Huawei Proprietary - Restricted Distribution Page52, Total72 Security Level NE BSC6900 MML Command SET UFRC Meaning This parameter specifies the upper limit of downlink BE service rate in combined AMR services. Combined AMR services consist of only AMR services and BE services. If there is a member of a different traffic class, the combined services are regarded as combined non-AMR services. IsKey NO Mandatory NO Feature ID None Feature Name None Value Type Enumeration Type GUI Value Range D8, D16, D32, D64, D128, D144, D256, D384 Enumeration D8~1, D16~2, D32~3, D64~4, D128~5, D144~6, D256~7, D384~8 Number/Bit Unit kbit/s Actual Value Range 8, 16, 32, 64, 128, 144, 256, 384 Default Value D384 Recommended Value D384 Impact RNC Parameter None Relationship Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved Interruption Not involved Duration(Min) Caution None Validation of The parameter modification has no impact on the equipment. Modification 2016-02-11 Huawei Proprietary - Restricted Distribution Page53, Total72 Security Level Impact on Radio None Network Performance Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio MO Parameter ID Parameter Name NE URRCTRLSWITCH RsvdPara1 Reserved parameter 1 BSC6900 MML Command SET URRCTRLSWITCH Meaning RSVDBIT1_BIT20 (Reserved Parameter 1 Bit 20) When the switch is turned on, for UEs that support fast dormancy and are in the CELL_PCH state, the RNC performs the CELL_PCH-toCELL_FACH (P2F for short) procedure if the UEs perform cell update with the cause value "uplink data transmission" or "paging response." When the switch is turned off, for UEs that support fast dormancy and are in the CELL_PCH state, the RNC performs the P2D procedure if the UEs perform cell update with the cause value "uplink data transmission" or "paging response." RSVDBIT1_BIT21 (Reserved Parameter 1 Bit 21) When the switch is turned on, for UEs that are establishing AMR services and shifting from the CELL_FACH state to the CELL_DCH state, the RNC stops establishing AMR services to handle cell update if the RNC receives from the UEs a cell update message containing the cause value "cell reselection." When the switch is turned off, for UEs that are establishing AMR services and shifting from the CELL_FACH state to the CELL_DCH state, if the RNC receives from the UEs a cell update message containing the cause value "cell reselection," the RNC stops establishing AMR services to handle cell update and resumes AMR services only after cell update is completed. RSVDBIT1_BIT26 (Reserved Parameter 1 Bit 26) When the switch is turned on, the RNC does not reestablish radio links for a UE if the UE reports to the RNC cell update caused by SRB reset. When the switch is turned off, the RNC reestablishes radio links for a UE if the UE reports to the RNC cell update caused by SRB reset. IsKey NO Mandatory NO Feature ID WRFD-010101 2016-02-11 Huawei Proprietary - Restricted Distribution Page54, Total72 Security Level Feature Name 3GPP Specifications Value Type Bit Field Type GUI Value Range RSVDBIT1_BIT20, RSVDBIT1_BIT21, RSVDBIT1_BIT26 Enumeration RSVDBIT1_BIT20~19, RSVDBIT1_BIT21~20, RSVDBIT1_BIT26~25 Number/Bit Unit None Actual Value Range This parameter is set to 0 or 1 according to the related domains. Default Value None Recommended Value None Impact RNC Parameter None Relationship Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved Interruption Not involved Duration(Min) Caution None Validation of Not involved Modification Impact on Radio None Network Performance Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio MO USTATETIMER Parameter ID RbSetupRspTmr Parameter Name Wait RB setup response timer 2016-02-11 Huawei Proprietary - Restricted Distribution Page55, Total72 Security Level NE BSC6900 MML Command SET USTATETIMER Meaning A timer to RNC wait for the RB setup response from UE in the RB procedure. Refer to the Note. IsKey NO Mandatory NO Feature ID WRFD-010101 Feature Name 3GPP Specifications Value Type Interval Type GUI Value Range 300~300000 Enumeration Not involved Number/Bit Unit ms Actual Value Range 300~300000 Default Value 5000 Recommended Value 5000 Impact RNC Parameter None Relationship Access Read & Write Service Interrupted No (No impact on the UE in idle mode) After Modification Interruption Scope Not involved Interruption Not involved Duration(Min) Caution The retransmit mechanism is used if the signaling is sent by adopting RLC UM on Uu interface during channel handover. In this case, the setting of the corresponding waiting response timer for UE setup does not work. (For example, when the channel change form DCH to FACH or the channel change from FACH to DCH, the timer does not work.) The retransmit timer is 2 second. The RB reconfiguration message may retransmit three times when the timer expires. The parameter modification has no impact on the equipment. 2016-02-11 Huawei Proprietary - Restricted Distribution Page56, Total72 Security Level Validation of Not involved Modification Impact on Radio None Network Performance Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio MO USTATETIMER Parameter ID HoAsuTmr Parameter Name HO active set update response timer NE BSC6900 MML Command SET USTATETIMER Meaning A timer to RNC wait for the response to active set update in soft handover procedure. IsKey NO Mandatory NO Feature ID WRFD-020202 WRFD-020203 Feature Name Intra Node B Softer Handover Inter RNC Soft Handover Value Type Interval Type GUI Value Range 1~300000 Enumeration Not involved Number/Bit Unit ms Actual Value Range 1~300000 Default Value 5000 Recommended Value 5000 Impact RNC 2016-02-11 Huawei Proprietary - Restricted Distribution Page57, Total72 Security Level Parameter None Relationship Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved Interruption Not involved Duration(Min) Caution None Validation of Not involved Modification Impact on Radio None Network Performance Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio MO USTATETIMER Parameter ID HoPhychRecfgTmr Parameter Name HO PhyCh reconfiguration timer NE BSC6900 MML Command SET USTATETIMER Meaning A timer to RNC wait for the response to physical channel reconfiguration in hard handover procedure. IsKey NO Mandatory NO Feature ID WRFD-020302 WRFD-020304 WRFD-020301 2016-02-11 Huawei Proprietary - Restricted Distribution Page58, Total72 Security Level Feature Name Inter Frequency Hard Handover Based on Coverage Inter Frequency Hard Handover Based on DL QoS Intra Frequency Hard Handover Value Type Interval Type GUI Value Range 1~300000 Enumeration Not involved Number/Bit Unit ms Actual Value Range 1~300000 Default Value 5000 Recommended Value 5000 Impact RNC Parameter None Relationship Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved Interruption Not involved Duration(Min) Caution None Validation of Not involved Modification Impact on Radio None Network Performance Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio 2016-02-11 Huawei Proprietary - Restricted Distribution Page59, Total72 Security Level MO 2016-02-11 USTATETIMER Huawei Proprietary - Restricted Distribution Page60, Total72 Security Level Parameter ID RbRecfgRspTmr Parameter Name Wait RB reconfiguration response timer NE BSC6900 MML Command SET USTATETIMER Meaning A timer used to wait for the RB reconfiguration response from UE in the RB procedure. Refer to the Note. IsKey NO Mandatory NO Feature ID WRFD-010101 Feature Name 3GPP Specifications Value Type Interval Type GUI Value Range 300~300000 Enumeration Not involved Number/Bit Unit ms Actual Value Range 300~300000 Default Value 5000 Recommended Value 5000 Impact RNC Parameter None Relationship Access Read & Write Service Interrupted No (No impact on the UE in idle mode) After Modification Interruption Scope Not involved Interruption Not involved Duration(Min) Caution The retransmit mechanism is used if the signaling is sent by adopting RLC UM on Uu interface during channel handover. In this case, the setting of the corresponding waiting response timer 2016-02-11 Huawei Proprietary - Restricted Distribution Page61, Total72 Security Level for UE reconfiguration does not work. (For example, when the channel change form DCH to FACH or the channel change from FACH to DCH, the timer does not work.) The retransmit timer is 2 second. The RB reconfiguration message may retransmit three times when the timer expires. The parameter modification has no impact on the equipment. Validation of Not involved Modification Impact on Radio None Network Performance Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio MO USTATETIMER Parameter ID RbRelRspTmr Parameter Name Wait RB release response timer NE BSC6900 MML Command SET USTATETIMER Meaning A timer to RNC wait for the RB release response from UE in the RB procedure. Refer to the Note. IsKey NO Mandatory NO Feature ID WRFD-010101 Feature Name 3GPP Specifications Value Type Interval Type GUI Value Range 300~300000 Enumeration Not involved Number/Bit Unit ms Actual Value Range 300~300000 Default Value 5000 2016-02-11 Huawei Proprietary - Restricted Distribution Page62, Total72 Security Level Recommended Value 5000 Impact RNC Parameter None Relationship Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved Interruption Not involved Duration(Min) Caution The retransmit mechanism is used if the signaling is sent by adopting RLC UM on Uu interface during channel handover. In this case, the setting of the corresponding waiting response timer for UE release does not work. (For example, when the channel change form DCH to FACH or the channel change from FACH to DCH, the timer does not work.) The retransmit timer is 2 second. The RB reconfiguration message may retransmit three times when the timer expires. The parameter modification has no impact on the equipment. Validation of Not involved Modification Impact on Radio None Network Performance Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio MO USTATETIMER Parameter ID HoCellUpdateRspTmr Parameter Name HO cell update response timer NE BSC6900 MML Command SET USTATETIMER Meaning A timer to RNC wait for the response to the cell update confirm from UE in forward handover procedure. IsKey NO 2016-02-11 Huawei Proprietary - Restricted Distribution Page63, Total72 Security Level Mandatory NO Feature ID WRFD-010801 WRFD-010802 Feature Name Intra RNC Cell Update Inter RNC Cell Update Value Type Interval Type GUI Value Range 1~10000 Enumeration Not involved Number/Bit Unit ms Actual Value Range 1~10000 Default Value 5000 Recommended Value 5000 Impact RNC Parameter None Relationship Access Read & Write Service Interrupted No After Modification Interruption Scope Not involved Interruption Not involved Duration(Min) Caution None Validation of Not involved Modification Impact on Radio None Network Performance Introduced in Version Versions earlier than BSC6900 V900R011 Attribute Radio 2016-02-11 Huawei Proprietary - Restricted Distribution Page64, Total72 Security Level 5.3 Call Re-establishment The drop calls mostly are caused by “Radio link failure”, “RLC reset” and “SRB reset”. Utran can initiate a “Cell Update” procedure to re-establish the Radio Link in a new cell to save some drops. Parameter Change (MML Description command) SET URRCTRLSWITCH: When the switch is turned off, the RNC RsvdPara1=RSVDBIT1_BIT22-0; triggers cell update with the cause value Current Setting Proposed on PP12 Setting ON OFF ON OFF ON OFF ON OFF OFF OFF "RL Failure" and reestablishes radio links if the RNC detects interrupted downlink transmission on SRB2. SET URRCTRLSWITCH: When the switch is turned off, the RNC RsvdPara1=RSVDBIT1_BIT23-0; triggers cell update with the cause value "RL Failure" reported by a UE and reestablishes radio links, if the associated NodeB reports to the RNC that all radio links for the UE experience synchronization loss. SET URRCTRLSWITCH: When the switch is turned off, for UEs using RsvdPara1=RSVDBIT1_BIT24-0; CS services, the RNC triggers cell update with the cause value "RL Failure" reported by a UE and reestablishes radio links, if the RNC detects interrupted downlink transmission on SRB2, or if the associated NodeB reports to the RNC that all radio links for the UE experience synchronization loss. SET URRCTRLSWITCH: When the switch is turned off, for UEs using RsvdPara1=RSVDBIT1_BIT25-0; PS services only, the RNC triggers cell update with the cause value "RL Failure" reported by a UE and reestablishes radio link, if the RNC detects interrupted downlink transmission on SRB2, or if the associated NodeB reports to the RNC that all radio links for the UE experience synchronization loss. SET URRCTRLSWITCH: When the switch is turned off, the RNC RsvdPara1=RSVDBIT1_BIT26-0; reestablishes radio links for a UE if the UE reports to the RNC cell update caused by SRB reset. 2016-02-11 Huawei Proprietary - Restricted Distribution Page65, Total72 Security Level SET Timer for CS 0 15000 Timer for PS 0 30000 URRRSVDPARA:RSVDPARA1=15000 ; SET URRRSVDPARA:RSVDPARA2=30000 ; Pros: The subscriber perception has been improved from dropped calls point of view. There are less dropped calls compared to before KPIs. Improvement in mobility KPIs makes users have more continuous service. Cons: While executing cell update procedure, transmission gaps may occur. The improvement in user experience is not as much as gained in KPIs, some network problems may be hidden. The user experience has been improved after the change, but the change in subscriber perception is not as big as reflected to the KPIs. After the change, there are less dropped subscribers in the network, but some of the subscribers are experiencing bad quality disconnections where it is not possible to recover RL by repeated cell updates. Benchmark: Significant improvement is seen on CS Call Drop rate and PS Call drop rate has a slight improvement. 2016-02-11 Huawei Proprietary - Restricted Distribution Page66, Total72 Security Level 6 Summary and Conclusion Totally 19 Jo’s were implemented, some individual benchmark evaluations in the previous slides might be some combined operation affect. So to conclude some parameter tunings or features, some separate trials in other RNC’s are required. Total Improvement PS CSSR is improved from 99% to 99.5% CS CSSR is improved from 98% to 98.7% 2016-02-11 Huawei Proprietary - Restricted Distribution Page67, Total72 Security Level CS CDR is improved from 0.65% to 0.3%. PS CDR increase is caused by EFD feature (only statistical impact) Significant improvement on average RTWP 2016-02-11 Huawei Proprietary - Restricted Distribution Page68, Total72 Security Level Improvement on HSDPA throughput: Improvement on HSUPA throughput: Improvement on UL PS384 throughput: 2016-02-11 Huawei Proprietary - Restricted Distribution Page69, Total72 Security Level Further Actions: N Category Item o 1 Implementa tion PS CSSR Blind Handover 29-May Optimizatio Fundamental Check 2 Remark n Disable uplink CAC for 11-Jun high congesting cells Rollout Scenario Slight improvement on PS CSSR on Rollout in these cells entire network Uplink Power Congestions cleared, Only for the and PS CSSR is around 99.5%. Need cells with high to monitor the uplink power "VS.RAC.UL.EqvUserNum" to congestions evaluate the impact. CAC threshold adjustment can be the 1st step. 3 CE resource group 10-Jun After Uplink resource group Resource group reconfiguration for 3 CE adjustment, congestions moved from configuration congestion sites F3 to F1&F2 (even more). The root audit for all cause is still that the different uplink sites resource groups can’t be shared. 4 Disable CE admission 13-Jun CE Congestion reduced Not control on recommended 3G_Mooikloof_Ridge_NG to rollout A 5 HSUPA GBR change 4-Jul PS Congestion reduced from 64kbps to 32kbps Not recommended to rollout 6 Enable DRD Failure 27-Jun PS RAB Setup Success Rate has Rollout in slight improvement entire network Just parameter standardization for Rollout in Optimizatio cells are not these sites (most of them are new entire network n sites). Rollback function 7 PS CDR 8 2nd SCCPCH audit (24 implemented) F3 Strategy Modification 2016-02-11 13-Jun 8-Jun Improvement on F3 PS CDR after Rollout in non- implementation (from 1.9% to 1.3%) continuous F3 Huawei Proprietary - Restricted Distribution Page70, Total72 Security Level coverage 9 PS No obvious change on stats as it is Rollout in Throughput sites were not enabled related to the DC-HSDPA capable entire network Optimizatio with DC-HSDPA handset penetration and user n behavior. 10 Fundamental Check: 4 Background noise 7-Jun 11-Jun adjustment 11 CQI Feedback Period 11-Jun Slight improvement on HSUPA Rollout in throughput on stats. entire network About 3dB improvement on average Implement on optimization from 2ms RTWP, which means we have almost high RTWP to 8ms 50% gain on uplink capacity. caused by high HSDPA traffic 12 RACH Access Parameter 13-Jun Optimization Significant RTWP improvement on Implement on High RRC Attempts sites, HSUPA high RTWP throughput improved as well. caused by high RRC attempts 13 Adaptive Power Offset 18-Jun for HSUPA No obvious improvement on Need a statistics, as the main gain is separate trial obtained when the HSUPA in another RNC throughput is greater than 300kbps as per the feature description. In the live network, this scenario could have a small proportion. Field HSUPA test should be getting more benefit. 14 TCP Accelerator 20-Jun Slight improvement on throughput Need a on statistics. separate trial in another RNC 15 CQI Adjustment Based 9-Jul on Dynamic BLER Implemented on 9-July, no obvious Need a improvement on statistics. separate trial Target 16 HSUPA Adaptive Retransmission in another RNC 4-July & 5- Implemented on 4-July (DBS sites) July Need a and 5-July (BTS sites), no separate trial improvement is seen after in another RNC implementation. 17 Smart Multi-RAB Optimization 31-May CS CSSR is improved from 98.2% to Rollout in Phone 99.0%, CS CDR is improved from Optimizatio 0.7% to 0.55% after Multi-RAB n optimization parameter entire network standardization. 18 Enhanced Fast Dormancy 20-Jun About 20% reduction on RRC and Rollout in RAB attempts, which reduce the entire network signaling load significantly. Less 2016-02-11 Huawei Proprietary - Restricted Distribution Page71, Total72 Security Level congestions as well. 19 Call re-establishment 11-Jul Significant improvement on CS CDR, Rollout in slight improvement on PS CDR entire network 7 Schedule According to the project plan, Huawei will conduct 2*run cluster packet service optimization in 2012. Meanwhile, the best practices and experiences verified in PP12 will be rollout in entire network. THE END 2016-02-11 Huawei Proprietary - Restricted Distribution Page72, Total72