data performance optimization guidelines

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Document Type Author Unit/Dept.

Document Title Date, Version For internal use only

Nokia Siemens Networks

Data/MBB Performance Optimisation Guide

For Internal Use Only

NPO/NSO Capability Management Date: 175.110.2010

Data Performance Optimisation Guide for RU10/RU20

Version 2.10

Copyright Nokia Siemens Networks 2008 Company confidential Page 2 (123)

Revision History

Date Rev. Summary of Change

25.9.2008 v.0.1 Document created

23.12.2008 v.0.6 First draft for review

19.1.2009 v.0.7 Initial reviewed version for RAS06

28.7.2009 v.1.0 First version for RAS06/RU10

31.12.2009 v. 1.1 Updated for RU10

15.10.2010 V.2.0 Updated for RU20

17.11.2010 v.2.1 Small updates; DC HSDPA etc.

Editor/s: Jarkko Itkonen, Kirsi Tervinen, Pekka Ranta

Date: 1517.110.2010

Version: v.2.10

Copyright Nokia Siemens Networks. This material, including documentation and any related computer programs, is protected by copyright controlled by Nokia Siemens Networks. All rights are reserved. Copying, including reproducing, storing, adapting or translating, any or all of this material requires the prior written consent of Nokia Siemens Networks. This material also contains confidential information which may not be disclosed to others without the prior written consent of Nokia Siemens Networks



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Table of contents

1 Introduction............................................................................................... 128

2 PS Data connection signalling ................................................................. 149

2.1 RRC Setup .......................................................................................................................... 149 2.2 SRB on HSPA ................................................................................................................... 1712 2.3 Fast Dormancy .................................................................................................................. 1813 2.4 Packet data connection setup ............................................................................................ 1914 2.4.1 GPRS Attach .................................................................................................................. 1914 2.4.2 Service Request ............................................................................................................. 1914 2.4.3 PDP context setup .......................................................................................................... 2015 2.4.4 Data flow setup ............................................................................................................... 2217 2.4.5 Direct Resource Allocation for HSPA ............................................................................. 2419 2.4.6 RRC state transitions ...................................................................................................... 2520 2.4.7 Packet data connection mobility ..................................................................................... 2823

3 PS RAB QoS parameters ...................................................................... 3126

3.1 Specification ...................................................................................................................... 3126 3.2 Definition of PS RAB QoS in connection setup .................................................................. 3126

4 UE Categories and Monitoring ............................................................... 3227

5 NRT PS RAB performance .................................................................... 3631

5.1 Accessibility ....................................................................................................................... 3631 5.2 Retainability ....................................................................................................................... 3833

6 HSPA bearer performance ..................................................................... 4338

6.1 Accessibility ....................................................................................................................... 4338 6.1.1 HSDPA accessibility ....................................................................................................... 4338 6.1.2 HSDPA UL Return Channel ............................................................................................ 4944 6.1.3 HSUPA Accessibility ....................................................................................................... 5146 6.2 HSPA Throughput and RTT (incl. MIMO and DC).............................................................. 5651 6.2.1 HSDPA throughput Optimisation .................................................................................... 5651 6.2.1.1 HSDPA peak performance and configurations ............................................................. 5651 6.2.1.2 HSDPA throughput Monitoring and troubleshooting ..................................................... 6256 6.2.1.3 MIMO throughput performance & monitoring ............................................................... 7671 6.2.1.4 DC HSDPA throughput and Performance .................................................................... 7974 6.2.2 HSUPA throughput optimisation ..................................................................................... 8378 6.2.2.1 HSUPA Peak performance and configuration .............................................................. 8378 6.2.2.2 HSUPA throughput monitoring and troubleshooting ..................................................... 8883 6.2.3 Round Trip Time (RTT) ................................................................................................... 9893 6.3 Mobility .............................................................................................................................. 9994 6.4 Retainability ..................................................................................................................... 10297

7 HSPA & R99 bearer interworking ...................................................... 105100

7.1 Power, Code and CE (HSUPA) sharing ......................................................................... 106101 7.1.1 DL power sharing ....................................................................................................... 106101



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7.1.2 Channelisation code tree sharing ............................................................................... 110105 7.1.3 WBTS resource sharing .............................................................................................. 116111 7.2 Effect of HSPA on R99 performance ............................................................................. 121116

References .............................................................................................. 123118

1 Introduction....................................................................................................8

2 PS Data connection signalling ......................................................................9

2.1 RRC Setup .............................................................................................................................. 9 2.2 SRB on HSPA ....................................................................................................................... 12 2.3 Fast Dormancy ...................................................................................................................... 13 2.4 Packet data connection setup ................................................................................................ 14 2.4.1 GPRS Attach ...................................................................................................................... 14 2.4.2 Service Request ................................................................................................................. 14 2.4.3 PDP context setup .............................................................................................................. 15 2.4.4 Data flow setup ................................................................................................................... 17 2.4.5 Direct Resource Allocation for HSPA ................................................................................. 19 2.4.6 RRC state transitions .......................................................................................................... 20 2.4.7 Packet data connection mobility ......................................................................................... 23

3 PS RAB QoS parameters .......................................................................... 26

3.1 Specification .......................................................................................................................... 26 3.2 Definition of PS RAB QoS in connection setup ...................................................................... 26

4 UE Categories and Monitoring ................................................................... 27

5 NRT PS RAB performance ........................................................................ 31

5.1 Accessibility ........................................................................................................................... 31 5.2 Retainability ........................................................................................................................... 33

6 HSPA bearer performance ......................................................................... 38

6.1 Accessibility ........................................................................................................................... 38 6.1.1 HSDPA accessibility ........................................................................................................... 38 6.1.2 HSDPA UL Return Channel ................................................................................................ 44 6.1.3 HSUPA Accessibility ........................................................................................................... 46 6.2 HSPA Throughput and RTT (incl. MIMO and DC).................................................................. 51 6.2.1 HSDPA throughput Optimisation ........................................................................................ 51 6.2.1.1 HSDPA peak performance and configurations ................................................................. 51 6.2.1.2 HSDPA throughput Monitoring and troubleshooting ......................................................... 57 6.2.1.3 MIMO throughput performance & monitoring ................................................................... 71 6.2.2 HSUPA throughput optimisation ......................................................................................... 74 6.2.2.1 HSUPA Peak performance and configuration .................................................................. 74 6.2.2.2 HSUPA throughput monitoring and troubleshooting ......................................................... 80 6.2.3 Round Trip Time (RTT) ....................................................................................................... 90 6.3 Mobility .................................................................................................................................. 91 6.4 Retainability ........................................................................................................................... 94

7 HSPA & R99 bearer interworking .............................................................. 97

7.1 Power, Code and CE (HSUPA) sharing ................................................................................. 98



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7.1.1 DL power sharing ............................................................................................................... 98 7.1.2 Channelisation code tree sharing ..................................................................................... 101 7.1.3 WBTS resource sharing .................................................................................................... 107 7.2 Effect of HSPA on R99 performance ................................................................................... 112

References .................................................................................................... 114



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List of Figures

Figure 1. RRC connection setup signalling................................................................................................ 149 Figure 2. F-DCPCH signalling example, when FDPCHSetup (1) RRC Connection Setup message moves the UE into Cell_FACH. F-DPCH is then allocated immediately after receiving the RRC connection setup complete message ................................................................................................................................... 1813 Figure 3. GPRS Attach procedure ........................................................................................................... 1914 Figure 4. Service Request procedure. ..................................................................................................... 2015 Figure 5. PDP context setup procedure. .................................................................................................. 2015 Figure 6. Capacity request and resource allocation signalling for packet data call. HSDPA+HSUPA ... 2217 Figure 7. Comparison of Normal NRT RAB Setup and Direct Resource allocation for HSPA ................ 2419 Figure 8. RRC states and transitions. RU10 Introduce possibility to use URA_PCH state and fast call setup directly from URA_PCH/CELL_PCH to Cell_DCH. New transitions supported by RU10, are shown with black lines. ........................................................................................................................................ 2520 Figure 9. Transition from CELL_DCH to CELL_FACH with Radio Bearer Reconfiguration procedure. . 2621 Figure 10. Transition from CELL_FACH to CELL_PCH (URA_PCH) with Radio Bearer Reconfiguration procedure. ................................................................................................................................................ 2621 Figure 11. Transfer of the UE to CELL_DCH and reactivation of the data connection (cause UL data transmission). ........................................................................................................................................... 2722 Figure 12. Fast call setup with direct transition from URA_PCH/CELL_PCH to CELL_DCH. ................ 2823 Figure 13. Serving HS-DSCH cell change triggered by periodical EcNo measurements. ...................... 2924 Figure 14. Serving cell change triggered by Event 1B on the serving HSDSCH cell (no NBAP signalling presented). ............................................................................................................................................... 3025 Figure 15. Inter-RNC serving HS-DSCH cell change with hard handover (no NBAP signalling presented). ................................................................................................................................................................. 3025 Figure 16 HSDPA and HSUPA UE utilisation within last 100 weeks. ..................................................... 3429 Figure 17 HSDPA UE category distribution within last 100 weeks. ......................................................... 3429 Figure 18. HSUPA UE category distribution within last 100 weeks. ........................................................ 3530 Figure 19 PS RAB setup failure rate statistics (RU10/RU20) ................................................................. 3833 Figure 20. PS RAB Access failure rate statistics (RU10/RU20) .............................................................. 3833 Figure 21. NRT PS RAB retainability analysis ......................................................................................... 4136 Figure 22 Example of PS NRT RAB Active fail change due to BTS (RU10/RU20)................................. 4136 Figure 23 Example of PS setup failure rates (RU10/RU20) .................................................................... 4237 Figure 24 HSDPA Accessibility Failure Analysis .................................................................................. 4439 Figure 25. Example HSDPA performance (RU10/RU20) PIs. ................................................................. 4641 Figure 26. Example HSDPA accessibility failure causes (RU10/RU20). ................................................. 4641 Figure 27. HSDPA accessibility with optimisation. .................................................................................. 4843 Figure 28. HSDPA accessibility failure analysis with optimisation steps. ................................................ 4843 Figure 29. Effect of PrxLoadMarginMaxDCH on HSDPA return channel accessibility. .......................... 4944 Figure 30. Relation between UL CE usage and HS-DSCH setup failures (RAS06) ............................... 5045 Figure 31. Activation of TBO and 16 kbps return channel (RAS06) ........................................................ 5146 Figure 32. HSUPA Accessibility failure analysis ...................................................................................... 5247 Figure 33. Example of HSUPA performance (RU10/RU20). ................................................................... 5348 Figure 34. Example of HSUPA setup failure causes (RAS06/RU10) ...................................................... 5449 Figure 35. Relation between CE usage and HSUPA setup and selection failures.................................. 5550 Figure 36. Max Achieved HSDPA application level throughputs for different category UEs ................... 5752 Figure 37. Example of HSDPA link adaption parameters. ....................................................................... 5954 Figure 38. 64QAM throughput measured in the lab and in the field. ( 5 x 100M file downloads) ............ 5954 Figure 39. HSDPA 64QAM result showing TBS and retransmission rate. Vepro is measured in the lab and Ahvenatie case is measured in the field. (5x100M file downloads) ......................................................... 6054 Figure 40. RSCP vs. DL application throughput, drive test Comparison of 16QAM and 64QAM - Test is done in NSN test network under isolated cell without any other traffic to ensure that conditions remains unchanged between testing. .................................................................................................................... 6055 Figure 41. Comparison of DC-HSDPA, MIMO and 64QAM DL application level throughputs in the field (RSCP around -60 dBm in measurement location) ................................................................................. 6155 Figure 42. Throughput per allocated HS-DSCH [8] ................................................................................. 6257 Figure 43. General flow chart to analyse HSDPA throughput [8] ............................................................ 6358 Figure 44. HSDPA throughput measurement from BTS and drive test log. ............................................ 6560 Figure 45 Example of throughput measurements included to M1027 ..................................................... 6560



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Figure 46. Buffers with data Example (RNC_726b_number of HSDPA users per cell) ......................... 6762 Figure 47. Example of RNC_1879b HSDPA end used throughput formula vs. average active cell throughput RNC_722b ............................................................................................................................. 6762 Figure 48. Example of differences between the Compensated CQI and Reported CQI ......................... 6863 Figure 49 Air Interface bitrate estimation using reported CQI .............................................................. 6863 Figure 50. Average CQI vs. TBS with different CPICH Tx Powers from drive test logs. ......................... 7065 Figure 51. CQI comparison between RAS06 and RU10 ......................................................................... 7165 Figure 52. The relation of Average reported CQI vs. HSDPA cell throughput in live network (RU10) .... 7166 Figure 53. The relation of Average reported CQI and HSDPA User throughput in live network. ............ 7266 Figure 54. Number of codes and used modulation when RSCP drops HSDPA 5 code feature .......... 7267 Figure 55. Number of codes and used modulation when RSCP drops HSDPA 10 Code feature ....... 7368 Figure 56. New usage of 16QAM codes transmission in RU10 due the unevenly distributed codes between the users. ................................................................................................................................... 7368 Figure 57. RNC_2093a Average reserved SF16 codes for HSDPA and RNC_722b Active HSDPA throughput. ............................................................................................................................................... 7570 Figure 58. MIMO peak performance. .................................................................................................... 7671 Figure 59 . MIMO drive test under NSN test network. Above chart show modulation for main stream and RSCP along the drive route. Chart below show modulation for secondary stream and also DL application throughput along the route. ...................................................................................................................... 7772 Figure 60. Example of CQI report cycle. .................................................................................................. 7873 Figure 61. Example of MIMO CQI counters distribution .......................................................................... 7974 Figure 62. Example of DC HSDPA throughput in lab .............................................................................. 7974 Figure 63. throughput in case there is simultaneously DC HSDPA and 64QAM users. ......................... 8075 Figure 64. HS-SCCH usage for both DC HSDPA and 64 QAM UE ........................................................ 8176 Figure 65. Example of TTI counters for scheduled DC HSDPA user for Primary and Secondary cells . 8277 Figure 66. Example of HSUPA link adaption parameters. ....................................................................... 8479 Figure 67. HSUPA throughput when 2ms TTI and 5.8 Mbps was activated. (100M file uploaded) ........ 8580 Figure 68. HSUPA throughput (yellow) and Noise rise with different PrxMaxTargetBTS values ............ 8580 Figure 69. HSUPA performance with R99 load. PrxMaxTargetBTS =6 dB (default) .............................. 8681 Figure 70. HSUPA throughput with HSUPA 2 Mbps feature ................................................................... 8681 Figure 71. HSUPA Cell UL application level throughput with different number of HSUPA UEs and with different PrxTargetMaxBTS values (changed in case of 3 HSUPA UE) ................................................. 8782 Figure 72. UL application level throughput of 1 HSUPA UE when there is different number of UEs in the cell. ........................................................................................................................................................... 8782 Figure 73. Uplink PrxTotal with different number of HSUPA UEs ........................................................... 8883 Figure 74. Uplink Load with different number of HSUPA UEs ................................................................. 8883 Figure 75. HSUPA throughput PIS and drive test tool measurement. .................................................... 9085 Figure 76. HSUPA throughput KPI comparison, example from NSN test network ................................. 9186 Figure 77. Example of Active HSUPA TTI throughput (both 2ms and 10ms) and Average number of HSUPA 10ms & 2ms TTI users. Example is from NSN test networks ................................................... 9287 Figure 78. HSUPA selections and throughput. ........................................................................................ 9287 Figure 79. BTS CE HSUPA Usage and HSUPA Maximum Mac-d Throughput (RAS06) ....................... 9388 Figure 80. BTS resource status counters ................................................................................................ 9489 Figure 81. HSUPA congestion control and HW overload CC Frame loss counter .................................. 9590 Figure 82. Function of Iub congestion Control ......................................................................................... 9590 Figure 83. Function of Iub congestion control for throughput with different symbol rate ......................... 9691 Figure 84. HSUPA congestion control decrease the HSUPA bit rate by decreasing the Serving grant with too high spreading code configuration ..................................................................................................... 9691 Figure 85. Uplink throughput with 1 x E1 for HSPA and different Parameter values .............................. 9792 Figure 86. UE tx Power limitation vs. HSUPA throughput ....................................................................... 9893 Figure 87. RU20 RTT values in NSN test network .................................................................................. 9994 Figure 88. Example of SCC Performance (RU10/RU20) ......................................................................10196 Figure 89. HSDPA SCC performance compared to HSDPA retainability. ............................................10297 Figure 90. HSPA retainability failure analysis ........................................................................................10398 Figure 91 Example of HSDPA release failure (RU10/RU20) .................................................................10499 Figure 92 Example of E-DCH release reasons (RU10/RU20) .............................................................105100 Figure 93. Effect of DCH power on HSDPA throughput. .....................................................................106101 Figure 94. HS-PDSCH code reservation. ............................................................................................106101 Figure 95. DL power sharing between HSDPA and NRT PS traffic. ...................................................107102 Figure 96. DL power sharing analysis. ................................................................................................108103



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Figure 97. Average HSDPA power vs. HSDPA Utilisation ..................................................................109104 Figure 98. Average UL and DL load as a function of HSDPA power ..................................................110104 Figure 99. HSDPA Code downgrade due to AMR with HSPDSCHMarginSF128=0 ...........................111106 Figure 100. Example of HSDPA code allocation and spreading code occupancy [8]. ........................112107 Figure 101. Example of HSDPA & NRT code allocation duration with different UEs ..........................113108 Figure 102. Code tree occupancy. .......................................................................................................114109 Figure 103. Code tree blocking, with code downgrade due to congestion. .........................................115110 Figure 104. Code downgrade due to NRT with DPCHOverHSPDSCHThreshold=0. .........................116111 Figure 105. Setup fails with DPCHOverHSPDSCHThreshold=0. .......................................................116111 Figure 106. Example of WBTS resource sharing with HSDPA (RAS06) ............................................120115 Figure 107. Example of WBTS resource sharing with HSUPA (RAS06) ............................................121116 Figure 108. Effect of increased HSDPA traffic on CS RAB and HSPA bearer performance. .............122117 Figure 1. RRC connection setup signalling.................................................................................................... 9 Figure 2. F-DCPCH signalling example, when FDPCHSetup (1) RRC Connection Setup message moves the UE into Cell_FACH. F-DPCH is then allocated immediately after receiving the RRC connection setup complete message ....................................................................................................................................... 13 Figure 3. GPRS Attach procedure ............................................................................................................... 14 Figure 4. Service Request procedure. ......................................................................................................... 15 Figure 5. PDP context setup procedure. ...................................................................................................... 15 Figure 6. Capacity request and resource allocation signalling for packet data call. HSDPA+HSUPA ....... 17 Figure 7. Comparison of Normal NRT RAB Setup and Direct Resource allocation for HSPA .................... 19 Figure 8. RRC states and transitions. RU10 Introduce possibility to use URA_PCH state and fast call setup directly from URA_PCH/CELL_PCH to Cell_DCH. New transitions supported by RU10, are shown with black lines. ............................................................................................................................................ 20 Figure 9. Transition from CELL_DCH to CELL_FACH with Radio Bearer Reconfiguration procedure. ..... 21 Figure 10. Transition from CELL_FACH to CELL_PCH (URA_PCH) with Radio Bearer Reconfiguration procedure. .................................................................................................................................................... 21 Figure 11. Transfer of the UE to CELL_DCH and reactivation of the data connection (cause UL data transmission). ............................................................................................................................................... 22 Figure 12. Fast call setup with direct transition from URA_PCH/CELL_PCH to CELL_DCH. .................... 23 Figure 13. Serving HS-DSCH cell change triggered by periodical EcNo measurements. .......................... 24 Figure 14. Serving cell change triggered by Event 1B on the serving HSDSCH cell (no NBAP signalling presented). ................................................................................................................................................... 25 Figure 15. Inter-RNC serving HS-DSCH cell change with hard handover (no NBAP signalling presented). ..................................................................................................................................................................... 25 Figure 16 HSDPA and HSUPA UE utilisation within last 100 weeks. ......................................................... 29 Figure 17 HSDPA UE category distribution within last 100 weeks. ............................................................. 29 Figure 18. HSUPA UE category distribution within last 100 weeks. ............................................................ 30 Figure 19 PS RAB setup failure rate statistics (RU10/RU20) ..................................................................... 33 Figure 20. PS RAB Access failure rate statistics (RU10/RU20) .................................................................. 33 Figure 21. NRT PS RAB retainability analysis ............................................................................................. 36 Figure 22 Example of PS NRT RAB Active fail change due to BTS (RU10/RU20)..................................... 36 Figure 23 Example of PS setup failure rates (RU10/RU20) ........................................................................ 37 Figure 24 HSDPA Accessibility Failure Analysis ...................................................................................... 39 Figure 25. Example HSDPA performance (RU10/RU20) PIs. ..................................................................... 41 Figure 26. Example HSDPA accessibility failure causes (RU10/RU20). ..................................................... 41 Figure 27. HSDPA accessibility with optimisation. ...................................................................................... 43 Figure 28. HSDPA accessibility failure analysis with optimisation steps. .................................................... 43 Figure 29. Effect of PrxLoadMarginMaxDCH on HSDPA return channel accessibility. .............................. 44 Figure 30. Relation between UL CE usage and HS-DSCH setup failures (RAS06) ................................... 45 Figure 31. Activation of TBO and 16 kbps return channel (RAS06) ............................................................ 46 Figure 32. HSUPA Accessibility failure analysis .......................................................................................... 47 Figure 33. Example of HSUPA performance (RU10/RU20). ....................................................................... 48 Figure 34. Example of HSUPA setup failure causes (RAS06/RU10) .......................................................... 49 Figure 35. Relation between CE usage and HSUPA setup and selection failures...................................... 50 Figure 36. Max Achieved HSDPA application level throughputs for different category UEs ....................... 52 Figure 37. Example of HSDPA link adaption parameters. ........................................................................... 54 Figure 38. 64QAM throughput measured in the lab and in the field. ( 5 x 100M file downloads) ................ 54 Figure 39. HSDPA 64QAM result showing TBS and retransmission rate. Vepro is measured in the lab and Ahvenatie case is measured in the field. (5x100M file downloads) ............................................................. 54



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Figure 40. RSCP vs. DL application throughput, drive test Comparison of 16QAM and 64QAM - Test is done in NSN test network under isolated cell without any other traffic to ensure that conditions remains unchanged between testing. ........................................................................................................................ 55 Figure 41. Comparison of DC-HSDPA, MIMO and 64QAM DL application level throughputs in the field (RSCP around -60 dBm in measurement location) ..................................................................................... 55 Figure 42. DC-HSDPA, MIMO and 64QAM drive test comparison under empty, isolated cell. .................. 56 Figure 43. Throughput per allocated HS-DSCH [8] ..................................................................................... 57 Figure 44. General flow chart to analyse HSDPA throughput [8] ................................................................ 58 Figure 45. HSDPA throughput measurement from BTS and drive test log. ................................................ 60 Figure 46 Example of throughput measurements included to M1027 ......................................................... 60 Figure 47. Buffers with data Example (RNC_726b_number of HSDPA users per cell) ............................. 62 Figure 48. Example of RNC_1879b HSDPA end used throughput formula vs. average active cell throughput RNC_722b ............................................................................................................................... 62 Figure 49. Example of differences between the Compensated CQI and Reported CQI ............................. 63 Figure 50 Air Interface bitrate estimation using reported CQI .................................................................. 63 Figure 51. Average CQI vs. TBS with different CPICH Tx Powers from drive test logs. ............................. 65 Figure 52. CQI comparison between RAS06 and RU10 ............................................................................. 65 Figure 53. The relation of Average reported CQI vs. HSDPA cell throughput in live network (RU10) ........ 66 Figure 54. The relation of Average reported CQI and HSDPA User throughput in live network. ................ 66 Figure 55. Number of codes and used modulation when RSCP drops HSDPA 5 code feature .............. 67 Figure 56. Number of codes and used modulation when RSCP drops HSDPA 10 Code feature ........... 68 Figure 57. New usage of 16QAM codes transmission in RU10 due the unevenly distributed codes between the users. ....................................................................................................................................... 68 Figure 58. RNC_2093a Average reserved SF16 codes for HSDPA and RNC_722b Active HSDPA throughput. ................................................................................................................................................... 70 Figure 59. MIMO peak performance. ........................................................................................................ 71 Figure 60 . MIMO drive test under NSN test network. Above chart show modulation for main stream and RSCP along the drive route. Chart below show modulation for secondary stream and also DL application throughput along the route. .......................................................................................................................... 72 Figure 61. Example of CQI report cycle. ...................................................................................................... 73 Figure 62. Example of MIMO CQI counters distribution .............................................................................. 74 Figure 63. Example of HSUPA link adaption parameters. ........................................................................... 75 Figure 64. HSUPA throughput when 2ms TTI and 5.8 Mbps was activated. (100M file uploaded) ............ 76 Figure 65. HSUPA throughput (yellow) and Noise rise with different PrxMaxTargetBTS values ................ 77 Figure 66. HSUPA performance with R99 load. PrxMaxTargetBTS =6 dB (default) .................................. 77 Figure 67. HSUPA throughput with HSUPA 2 Mbps feature ....................................................................... 78 Figure 68. HSUPA Cell UL application level throughput with different number of HSUPA UEs and with different PrxTargetMaxBTS values (changed in case of 3 HSUPA UE) ..................................................... 78 Figure 69. UL application level throughput of 1 HSUPA UE when there is different number of UEs in the cell. ............................................................................................................................................................... 79 Figure 70. Uplink PrxTotal with different number of HSUPA UEs ............................................................... 79 Figure 71. Uplink Load with different number of HSUPA UEs ..................................................................... 80 Figure 72. HSUPA throughput PIS and drive test tool measurement. ........................................................ 82 Figure 73. HSUPA throughput KPI comparison, example from NSN test network ..................................... 83 Figure 74. Example of Active HSUPA TTI throughput (both 2ms and 10ms) and Average number of HSUPA 10ms & 2ms TTI users. Example is from NSN test networks ....................................................... 83 Figure 75. HSUPA selections and throughput. ............................................................................................ 84 Figure 76. BTS CE HSUPA Usage and HSUPA Maximum Mac-d Throughput (RAS06) ........................... 85 Figure 77. BTS resource status counters .................................................................................................... 85 Figure 78. HSUPA congestion control and HW overload CC Frame loss counter ...................................... 86 Figure 79. Function of Iub congestion Control ............................................................................................. 87 Figure 80. Function of Iub congestion control for throughput with different symbol rate ............................. 87 Figure 81. HSUPA congestion control decrease the HSUPA bit rate by decreasing the Serving grant with too high spreading code configuration ......................................................................................................... 88 Figure 82. Uplink throughput with 1 x E1 for HSPA and different Parameter values .................................. 89 Figure 83. UE tx Power limitation vs. HSUPA throughput ........................................................................... 90 Figure 84. RU20 RTT values in NSN test network ...................................................................................... 91 Figure 85. Example of SCC Performance (RU10/RU20) ............................................................................ 93 Figure 86. HSDPA SCC performance compared to HSDPA retainability. .................................................. 94 Figure 87. HSPA retainability failure analysis .............................................................................................. 94



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Figure 88 Example of HSDPA release failure (RU10/RU20) ....................................................................... 96 Figure 89 Example of E-DCH release reasons (RAS06/RU10) .................................................................. 96 Figure 90. Effect of DCH power on HSDPA throughput. ............................................................................. 97 Figure 91. HS-PDSCH code reservation. .................................................................................................... 97 Figure 92. DL power sharing between HSDPA and NRT PS traffic. ........................................................... 98 Figure 93. DL power sharing analysis. ........................................................................................................ 99 Figure 94. Average HSDPA power vs. HSDPA Utilisation ........................................................................ 100 Figure 95. Average UL and DL load as a function of HSDPA power ........................................................ 101 Figure 96. HSDPA Code downgrade due to AMR with HSPDSCHMarginSF128=0 ................................. 102 Figure 97. Example of HSDPA code allocation and spreading code occupancy [8]. ................................ 103 Figure 98. Example of HSDPA & NRT code allocation duration with different UEs .................................. 104 Figure 99. Code tree occupancy. ............................................................................................................... 105 Figure 100. Code tree blocking, with code downgrade due to congestion. ............................................... 106 Figure 101. Code downgrade due to NRT with DPCHOverHSPDSCHThreshold=0. ............................... 107 Figure 102. Setup fails with DPCHOverHSPDSCHThreshold=0. ............................................................. 107 Figure 103. Example of WBTS resource sharing with HSDPA (RAS06) .................................................. 111 Figure 104. Example of WBTS resource sharing with HSUPA (RAS06) .................................................. 112 Figure 105. Effect of increased HSDPA traffic on CS RAB and HSPA bearer performance. ................... 113 List of Tables

Table 1. Packet data connection related information elements in RRC Connection Setup Request message................................................................................................................................................... 1510 Table 2. Feature related information elements in RRC Connection Setup Request message ............... 1510 Table 3. Packet data connection related information elements in RRC connection setup message ...... 1510 Table 4. Packet data connection related information elements in RRC Connection Setup Complete message................................................................................................................................................... 1611 Table 5. Packet data connection related information elements in Activate PDP Context Request message ................................................................................................................................................................. 2015 Table 6. Packet data connection related information elements in Radio Bearer Reconfiguration message ................................................................................................................................................................. 2217 Table 7. 64QAM, MIMO parameter and secondary cell info can be added to Radio Bearer reconfiguration message................................................................................................................................................... 2318 Table 8. UMTS QoS attributes ................................................................................................................. 3126 Table 9 QoS negotiation at PDP context setup. ...................................................................................... 3126 Table 10. QoS values for different traffic classes. ................................................................................... 3227 Table 11. Reports and PIs related NRT PS RAB accessibility ................................................................ 3732 Table 12. Reports and PIs related NRT PS RAB retainability ................................................................. 4035 Table 13. Reports and PIs related HSDPA accessibility ......................................................................... 4439 Table 14. RNC parameters related to CELL_DCH state selection and release. ..................................... 4742 Table 15. Reports and PIs related HSUPA accessibility ......................................................................... 5247 Table 16. Maximum user bit rates with different RAS features (RU20) ................................................... 5752 Table 17. HSDPA traffic and throughput KPIs and counters ................................................................... 6358 Table 18. Mobile Power Offset Calculation (MPO) for different Cell power setting PtxMaxHSDPA is set to same value as PtxCellMax .................................................................................................................. 6964 Table 19. HSDPA performance comparison with different CPICH Tx Power values. ............................. 7064 Table 20. Maximum throughput that can be sent by shared HSDPA scheduler for BB efficiency in one TTI. (This table does not include MIMO or DC HSDPA users) ....................................................................... 7469 Table 21. DC HSDPA functionality and throughput with different carrier spacing. Currently there is no UE in the market which supports 5.2 MHz carrier spacing. ........................................................................... 8075 Table 22. Example of RNC_722d Average Active HSDPA throughput ................................................... 8176 Table 23. HSUPA bitrates with different MaxTotalUplinkSymbolRate settings ....................................... 8378 Table 24. HSUPA congestion control parameters. .................................................................................. 8479 Table 25. HSUPA traffic and throughput KPIs and counters ................................................................... 8984 Table 26. HSPA mobility counters and KPIs .........................................................................................10095 Table 27. HSPA retainability counters and KPIs (Report: Service/Session Retainability Analysis RSRAN079) ...........................................................................................................................................10398 Table 28. PIs related power sharing between HSPA and R99 traffic ..................................................107102

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Table 29. PIs related to channelisation code sharing between HSPA and R99 traffic. .......................110105 Table 30. WBTS CE reservation of DCH bearers. In RU10, less CE needed with high bitrate (384 kbps) with Flexi Rel2 HW system module. Less CE also needed for HSDPA users in Uplink (return channel) if 384 kbps is used. .................................................................................................................................117112 Table 31 UL/DL CE reservation example for HSUPA when Flexi Rel2 SM is used with 10ms TTI. (RU20) .............................................................................................................................................................117112 Table 32. PIs related power sharing between HSPA and R99 traffic ..................................................118113 Table 1. Packet data connection related information elements in RRC Connection Setup Request message....................................................................................................................................................... 10 Table 2. Feature related information elements in RRC Connection Setup Request message ................... 10 Table 3. Packet data connection related information elements in RRC connection setup message .......... 10 Table 4. Packet data connection related information elements in RRC Connection Setup Complete message....................................................................................................................................................... 11 Table 5. Packet data connection related information elements in Activate PDP Context Request message ..................................................................................................................................................................... 15 Table 6. Packet data connection related information elements in Radio Bearer Reconfiguration message ..................................................................................................................................................................... 17 Table 7. 64QAM, MIMO parameter and secondary cell info can be added to Radio Bearer reconfiguration message....................................................................................................................................................... 18 Table 8. UMTS QoS attributes ..................................................................................................................... 26 Table 9 QoS negotiation at PDP context setup. .......................................................................................... 26 Table 10. QoS values for different traffic classes. ....................................................................................... 27 Table 11. Reports and PIs related NRT PS RAB accessibility .................................................................... 32 Table 12. Reports and PIs related NRT PS RAB retainability ..................................................................... 35 Table 13. Reports and PIs related HSDPA accessibility ............................................................................. 39 Table 14. RNC parameters related to CELL_DCH state selection and release. ......................................... 42 Table 15. Reports and PIs related HSUPA accessibility ............................................................................. 47 Table 16. Maximum user bit rates with different RAS features (RU20) ....................................................... 52 Table 17. HSDPA traffic and throughput KPIs and counters ....................................................................... 58 Table 18. Mobile Power Offset Calculation (MPO) for different Cell power setting PtxMaxHSDPA is set to same value as PtxCellMax ...................................................................................................................... 64 Table 19. HSDPA performance comparison with different CPICH Tx Power values. ................................. 64 Table 20. Maximum throughput that can be sent by shared HSDPA scheduler for BB efficiency in one TTI. (This table does not include MIMO or DC HSDPA users) ........................................................................... 69 Table 21. HSUPA bitrates with different MaxTotalUplinkSymbolRate settings ........................................... 75 Table 22. HSUPA congestion control parameters. ...................................................................................... 75 Table 23. HSUPA traffic and throughput KPIs and counters ....................................................................... 80 Table 24. HSPA mobility counters and KPIs ............................................................................................... 92 Table 25. HSPA retainability counters and KPIs (Report: Service/Session Retainability Analysis RSRAN079) ................................................................................................................................................. 94 Table 26. PIs related power sharing between HSPA and R99 traffic .......................................................... 98 Table 27. PIs related to channelisation code sharing between HSPA and R99 traffic. ............................. 101 Table 28. WBTS CE reservation of DCH bearers. In RU10, less CE needed with high bitrate (384 kbps) with Flexi Rel2 HW system module. Less CE also needed for HSDPA users in Uplink (return channel) if 384 kbps is used. ....................................................................................................................................... 108 Table 29 UL/DL CE reservation example for HSUPA when Flexi Rel2 SM is used with 10ms TTI. (RU20) ................................................................................................................................................................... 108 Table 30. PIs related power sharing between HSPA and R99 traffic ........................................................ 109

1 Introduction

The purpose of this guideline is to give guidance for packet data performance optimisation tasks. The main focus is in HSPA (HSDPA and HSUPA) performance but also interworking with



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Rel99 NRT services is covered. Basic HSPA functionality and parameters is not described here but in HSPA planning guide [2][2][2]. Some performance related signalling charts are included

here also basic QoS information, which will be updated with RU10 features later. NRT feature optimization is not described here but in Packet Scheduler Optimization document [7][7][7].

There is also not info about different HSPA layers which is covered in HSPA layering guide [5][5][5]. It is recommended to look at separate capacity management guide for detailed capacity analysis [8][8][8]. From KPI guarantee document [13][13][13] main KPI definitions with target

values are explained, also for HSPA. This guide can be used for MBB projects also.

The structure of the document is following the data call flow. In the beginning there is chapter for PS signalling showing different packet call setup cases and mobility both in RNC level and at UE side. Then there is a chapter for PS RAB QoS introduction. Then there is chapter for NRT PS RAB performance covering traditional service level KPIs related to NRT PS RAB. After that there is chapter for HSPA bearer performance optimization covering accessibility, throughout, mobility and retainability related to HSDPA and HSUPA. The last chapter is covering the HSPA and Rel99 interworking related mainly to WBTS resource sharing.

The performance KPIs shown in the document is structured based on the the latest RU20 reporting suite reports. In RU10, there are several updated KPIs due the introducing of Streaming class.

Using reporting suite Content browser functionality, the user can also create own report based on counters, KPIs or existing reports so it is not necessary to follow reporting suite report content. Reporting suite KPI creator tool make it possible to create own KPIs also.



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2 PS Data connection signalling

Packet data connection related signalling information is exchanged in different phases of the packet call. This section describes the main signalling information.

2.1 RRC Setup

RRC connection setup procedure is performed when UE moves from Idle mode to RRC Connected mode. RRC connection is required for any signalling from UE to the network and the setup information contains also information related to packet data connection. The RRC connection setup signalling is presented in Figure 1Figure 1Figure 1.

RRC: RRC Connection Request (RACH)

UE RNCNode B

NBAP: Radio Link Setup Request

NBAP: Radio Link Setup Response

ALCAP: Establish Request

ALCAP: Establish Confirm

FP: Downlink Sync

FP: Uplink Sync

NBAP: Synchronisation Indication

RRC: RRC Connection Setup (FACH)

L1 Synchronisation

RRC: RRC Connection Setup Complete (DCH)

Figure 1. RRC connection setup signalling.

The fist message from UE is the RRC Connection Setup Request which mainly indicates the RNC that the UE wants to establish signalling connection with the RAN. This message contains these information elements that can be related to packet data connection establishment.

A) Rel-5 UE B) Rel-6 UE C) Rel-8 UE

File 1. Examples of RRC Connection Setup Request messages

IE: Establishment cause which gives RNC an indication of the service that the UE is requesting. Establishment cause depends also on UE implementation. Cause value Registration is used to initiate GPRS Attach signalling and Measurement quantity about the quality of the pilot signal. IE Access stratum release indicator indicates the RNC on the release of the specification the UE



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supports. Release 6 UEs are capable of sending also the IE UE capability indication to indicate the HSDPA and/or HSUPA capability of the UE.

Table 1. Packet data connection related information elements in RRC Connection Setup Request message

Information element Value Description

Establishment cause Registration For GPRS Attach

Originating High Priority Signalling

For PDP Context Setup

Measurement Quantity Ec/No = -24 + IE / 2

EcNo used for initial UL and DL power calculation

Access stratum release indicator (Absence = R99), Rel-4 / Rel-5 / Rel-6 / Rel7 / Rel8

Release of the RRC functionality supported by UE

UE capability indication Absence = No HSPA, HS-DSCH, HSDSCH+EDCH

IE available only from R6 UEs

Optionally, UE signal its supports for different features in RRC Connection request message. NSN support only Rel7 version of F-DPCH (Enhanced F-DPCH). Mac-ehs allows the support of flexible RLC PDU sizes. Table 2. Feature related information elements in RRC Connection Setup Request message

Information element Value Description Release

Support for F-DCPCH OP TRUE The IE shall be present and set to TRUE in this version of specification Rel-6

Support for Enhanced F-DPCH OP TRUE The IE shall be present and set to TRUE in this version of specification Rel-7

MAC-ehs support OP TRUE The absence of this IE indicates that the UE does not support MAC-ehs Rel-7

EPCCH Discontinuous Transmission support OP TRUE

The absence of this IE indicates that the UE does not support DPCCH DTX Rel-7

Multi Cell Support OP TRUE The absence of this IE indicates that the UE does not support Multi-Cell Rel-8

The RRC Connection Setup is received from RNC as reply to the request message. This message mainly contains the configuration of the signalling radio bearers that will be used for the signalling. It also contains information defining the next RRC state and a request for UE capability. RRC connection establishment is normally performed directly to the Cell_DCH state or optionally on common channels (Cell_FACH). RU10 feature, Common Channel Setup allows also connections to be established in CELL_FACH rather than CELL_DCH, i.e. using RRC Idle to CELL_FACH transition. Parameter SRBMapRRCSetupEC defines the establishment causes which prefer SRB mapping to the common channels in the RRC connection setup. With F-DPCH feature (RU20) different options can be selected with parameter FDPCHSetup.

Table 3. Packet data connection related information elements in RRC connection setup message


RRC state indicator Cell-DCH Signalling continues typically



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in DCH channel type in NSN RAN

Capability update requirement True Set true for FDD

UARFCN uplink Channel number UL IE is provided if the frequency is changed (can be done due to DRRC procedure)

UARFCN downlink Channel number DL IE is provided if the frequency is changed (can be done due to DRRC procedure)

If RU20 feature fast L1 synchronisation feature is enabled, the RNC sets the Post Verification Period information element to TRUE when signaling to a release 6 or newer UE. This IE can be included RRC Connection Setup, Radio Bearer Reconfiguration, Radio Bearer Setup or Cell Update Confirm messages

The RRC Connection Setup Complete message contains mainly the UE radio access capability information. There is range of information related to UE data connection capability, e.g. HSDPA an HSUPA physical layer category and UE power class.

The UE signals also whether or not it benefits from network based battery power consumption optimization within the RRC Connection Setup Complete message (This is related to CPC feature)

A) Rel-5 UE B) Rel-6 UE C) Rel-8 UE

File 2. Example of RRC Connection Setup Complete message from Rel-5, Rel-6 and Rel-8 UEs.

Table 4. Packet data connection related information elements in RRC Connection Setup Complete message


HS-DSCH physical layer

Category

1-64 (16-64 are spares)

Note 8

Rel-5 and later

HS-DSCH physical layer category extension

OP 1-64 (used when DC-HSDPA is disabled) Note 9

Rel-8

HS_DSCH physical layer category extension2

OP 21..24 (used when DC_HSDPA is enabled)

Rel-8

E-DCH physical layer

Category

1-16 Rel-6

UE power class 1-4

Note 8: All UEs supporting HS_DSCH should signal a category between 1 and 15 for this IE even if the UE physical capability category is above 15. This IE corresponds to the HS_DSCH category supported by UE when MAC-ehs is not configured.

Note 9: This is IE corresponds to the HS_DSCH category supported by the UE when MAC-ehs is configured.



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2.2 SRB on HSPA

In RU20, there are 2 features which map SRB to HSPA/HSUPA. HSUPA 2ms TTI feature require that SRB is mapped to HSUPA in Uplink. Requirement for F-DPCH allocation is that SRB can be mapped to HSPA in both Uplink and Downlink. With F-DPCH, following two configurations are possible:

HSDPA & HSUPA 10 ms TTI

HSDPA & HSUPA 2 ms TTI (Require that HSUPA 2ms TTI is enabled)

If allocation of HS-DSCH in downlink for SRB is not possible, that is SRB on HSPA is not possible, packet scheduler is able to allocate only E- DCH/DCH for SRB with 2ms TTI. Channel type selection algorithm for SRBs proceeds together with downlink and uplink channel type selection algorithm for HSDPA and HSUPA when there is setup RB simultaneous with SRBs on HSPA.

Rel99 DCH shall be allocated for SRBs if the establishment cause received from the UE is defined to use DCH for SRBs by FDPCHSetupEC parameter. Otherwise it shall follow the allocation of F-DPCH controlled by the FDPCHSetup parameter. This parameter have 3 different options

(0) RRC Connection Setup message configures F-DPCH and UE is moved into CELL_DCH with an HSDPA SRB

(1) RRC Connection Setup message moves the UE into Cell_FACH. F-DPCH is then allocated immediately after receiving the RRC connection setup complete message

(2) RRC Connection setup message moves the UE into CELL_DCH and allocates a DCH connection for the standalone SRB. F-DPCH is then allocated a the same time as user plane resources

When SRB are already on HSPA during the initial NRT-RAB setup phase, the Direct Resource Allocation for HSPA (DRA) is used as a default, i.e. the MAC-d flow for NRT-RAB is allocated during the RB setup without DCH-0/0 allocation and waiting for UL/DL capacity request first. If there arent the required resources (radio, BTS, transport, DMCU, ) for an immediate u-plane setup available, the NRT-RB shall be mapped to DCH-0/0 as in the classic NRT-RAB setup scenario and the RAB Assignment Request is acknowledged to the SGSN. After this the (next) UL/DL capacity request triggers the next resource allocation attempt F-DPCH -related decision making and signaling concerns only those call-types for which Cell_DCH is the preferred RRC state. All NAS signaling transactions (registrations, LAU, RAU, SMS etc.) are still fully executed in Cell_FACH if so parameterized. If the established service doesnt allow the usage of F-DPCH the SRBs on HSPA need to be mapped to DCH/DCH and UE/BTS must be reconfigured accordingly. One such service would be AMR on DCH when CS voice over HSPA isnt allowed (or any service requiring DCH), and thus the F-DPCH=>DPCH reconfiguration will be executed in RB Setup/RL Reconfiguration procedures when setting up the AMR-RAB



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Figure 2. F-DCPCH signalling example, when FDPCHSetup (1) RRC Connection Setup message moves the UE into Cell_FACH. F-DPCH is then allocated immediately after receiving the RRC connection setup complete message

2.3 Fast Dormancy

Fast dormancy is functionality that UE vendors have introduced to save UE battery life, by forcing them to RRC idle mode. After completing data transfer, UE send signaling connection release indicator, which RNC has to obey and release the UE to RRC idle mode. This can increase network signaling load as polls and keep alives can cause UE to continuously setup and release RRC connection.

In Rel8 specification is modified so that RNC can keep the UE in RRC connected mode after receiving Signaling connection release indicator with new cause value UE Requested PS Data Session End.

RRC Connection Request (RACH)

RRC Connection Setup (FACH)

RRC Connection Setup Complete

UE RNC CN BTS

RRC: Initial UE message RANAP: Initial DIRECT transfer

[Support for F-DPCH=TRUE]

[Enhanced F-DPCH support=TRUE] UE support REL7 F-DPCH

NBAP: RL Setup Request [F-DPCH information]

NBAP: RL Setup Response [F-DPCH capacity

information] AAL2 Setup

RRC: Radio Bearer Reconfiguration [RRC State Indicator: CELL_DCH; DL F-DPCH Info common for all RL; DL F-DPCH info for each RL]

NBAP: RL Restore Indication RRC: Radio bearer Reconfiguration

complete UE in CELL_DCH state

NAS Signalling Connection; UE CN Signalling Continued

RANAP: Security mode command RRC: Security mode

Command RRC: Security mode Complete RANAP: Security mode

complete RANAP: RAB Assignment Request

F-DPCH can be used with established service, DRA is used and all resources immediately

available NBAP: RL reconfiguration prepare NBAP: RL Reconfiguration

ready NBAP:RL Reconfiguration Commit RRC: Radio Bearer Setup

RRC: Radio Bearer Setup Complete RANAP: RAB Assignment

Response

UE in CELL_FACH State

RNC establishes RRC connection on RACH/FACH and waits for RRC

Conn. Setup Complete from the UE

F-DPCH setup

DRA



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Fast Dormancy feature is included to RU20 MP1 without parameter control, Parameter control is coming with RU30 (FD is originally planned to be RU30 feature). In RU20, the fast dormancy is activated by default (RU30 this can be handled with parameter) which results T323 being broadcasted within SIB1. T323 within SIB1 allow a UE to detect that the network supports fast dormancy. By default the value of T323 is 0s.

After receiving a Signalling Connection Release Indication message with cause value UE Requested PS Data Session End, Fast dormancy functionality overrides inactivity timers and RNC instructs UE to make state change to CELL_PCH/URA_PCH.

if RNC receives signaling Connection Release Indication message without a cause value then the existing legacy functionality is applied and the UE is moved to RRC Idle mode

2.4 Packet data connection setup

2.4.1 GPRS Attach After the RRC connection setup procedure the UE has established a dedicated communication link with UTRAN, it is in a position to send a message to the core network (PS core in this case). With the GPRS attach the UE establishes a GPRS mobility management context with SGSN.

Figure 3. GPRS Attach procedure

The purpose of the Security Mode procedure is to trigger the start or ciphering for the radio bearers of one core network domain and for all signalling bearers. It is also used to start integrity protection for all signalling radio bearers.

The PS core may optionally request the UE to provide its identity, e.q. IMEI. This is done using the Identity Request message.

2.4.2 Service Request The Service Request procedure is initiated prior to PDP context setup to form a secure connection between the SGSN and the UE for user data. This is required if no other signalling with SGSN has preceded the PDP context setup. This could be the case with MT packet call, but it is not supported by NSN.



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Figure 4. Service Request procedure.

2.4.3 PDP context setup PDP context forms the user data connection between the UE and internet or private network. An IP address is allocated to the UE in the procedure. PDP Context Setup procedure includes Radio Access Bearer (RAB) setup and Radio Bearer setup procedures. This is done to DCH 0/0 if Directed Resource Allocation for HSPA is not enabled. If DRA for HSPA is enabled, then HSPA UEs can establish connection directly without allocating DCH 0/0.

Figure 5. PDP context setup procedure.

The Activate PDP Context Request message includes information related to the requested service type and quality, connection end point (Access point name) and requested IP address. Access point name can be used to request a connection to operator specific services like WAP or to internet if this is allowed by the operator.

Table 5. Packet data connection related information elements in Activate PDP Context Request message


Requested QoS See Section 333.

Requested IP address By default IP address is allocated automatically.

Access Point Name Access points are defined in the GGSN configuration and UE request a connection to/via specific access point

Requested service type and quality is defined in the Requested QoS information. Section 333

describes more in detail the QoS definition parameters and procedure. The PDP context setup



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procedure is completed with the Activate PDP Context Accept message, which contains mainly the negotiated QoS and IP/PDP address allocated for the UE.

A) Activate PDP Context Request B) Activate PDP Context Accept

File 3. Examples of Activate PDP Context Request and Activate PDP Context Accept messages.

The Activate PDP Context Request message triggers the SGSN to start the RAB setup procedure. This is initiated when SGSN sends the RAB Assignment Request message to the RNC, this message is sent over the Iu-PS interface and it contains the QoS of the RAB. The reception of the RAB Assignment Request message triggers the admission control (AC) procedure in RNC and the following radio bearer setup procedure. The AC algorithm defines the maximum bit rate of the radio bearer, target BLER and other bearer parameters.

In NSN RAN, Prior to RU20 the initial bit rate allocated in the RAB setup procedure of the NRT RAB is always zero (RAB 0/0). Thus there is no need for resource reservations in this phase. The Radio Bearer Setup message sent from RNC to UE contains the next state (in NSN RAN cell-DCH) some Radio Bearer information (RLC, TrCH), but no bit rate allocations. There is also no radio link setup with Node B at this phase, i.e. no transport and CE resources are reserved. With RU20 feature, Direct Resource allocation for HSPA (DRA for HSPA), HSPA is allocated already during RAB establishment which replaces the allocation of a 0/0 kbps DCH. When SRB are already on HSPA during the initial NRT-RAB setup phase (F-DPCH), the Direct Resource Allocation for HSPA (DRA) is used as a default,

File 4. Example of Radio Bearer Setup message.

Once the RAB has been established the RNC sends a measurement control messages to the UE in order to initiate the traffic volume measurements (UE internal) together with intra and inter frequency measurements. Measurement control initiates the traffic volume measurements and defines the reporting thresholds for traffic volume measurements which are used for the UL capacity requests.

File 5. Example of Measurement Control message.



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2.4.4 Data flow setup The data flow over the air interface is setup after a capacity request from either UE or internally RNC. Typically UE initiates the connection to the server and the capacity request comes from the UE. The data flow setup involves packet scheduling, channel type selection and resource reservation for the selected connection type.

Figure 6. Capacity request and resource allocation signalling for packet data call. HSDPA+HSUPA

UE sends the Measurement Report message for Event 4A indicating that there is some data in the buffers. This measurement report is handled as capacity request by the packet scheduler in the RNC, which schedules the capacity request. The scheduling operation starts with channel type selection procedure, where the RNC makes a selection between HSPA, HSDPA, DCH or common channel usage. Scheduling includes also allocation of bit rates for DCH bearers (allowed transport format set) based on RNC parameters and load conditions.

File 6. Example of Measurement Report message.

The selected radio bearer configuration is sent in the Radio Bearer Reconfiguration message to the UE and with the following Radio Link Reconfiguration Prepare message to the Node B.

Table 6. Packet data connection related information elements in Radio Bearer Reconfiguration message


RRC state indicator cell-DCH, cell-FACH The initial bit rate allocation is typically done to DCH channel at packet call setup

Uplink transport channel

Type

DCH, RACH, E-DCH Selected UL the channel type

Downlink transport channel

Type

DCH, FACH, HS-DSCH, DCH + HSDSCH

Selected DL the channel type



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MAC-d PDU size Fixed (336 or 656) or Flexible

336 used as default in NSN RAN, 656 used for higher HSDPA data rates. From RU20 onwards, Flexible RLC used for higher HSDPA rata rates.

Maximum channelisation codes sf4, 2sf4, 2sf2and2sf4 Maximum Channelisation code configuration for HSUPA.

Serving Grant value 0-37, 38 Initial grant value for HSUPA, 38 means no grant. Value is defined by BTS and signalled to RNC and to UE in this IE.

Spreading factor (UL) 4-128 Minimum spreading factor of the UL DCH channel.

Measurement Power Offset -6..13 dB Measurement power offset indicating the current available HSDPA power relative to pilot. UE utilises the value in CQI reporting.

UARFCN uplink Channel number UL IE is provided if the frequency is changed (not done in packet call setup)

UARFCN downlink Channel number DL IE is provided if the frequency is changed (not done in packet call setup)

A) Rel-5 UE B) Rel-6 UE C) Rel-7 MIMO UE C) Rel-8 DC-HSDPA UE

File 7. Example of Radio Bearer Reconfiguration message.

Table 7. 64QAM, MIMO parameter and secondary cell info can be added to Radio Bearer reconfiguration message.

Information element Value Description Release

Downlink 64QAM Configured OP TRUE

This allows UE the determine which TBS table to use, and which HS-SCCH format to use. Absence of this IE means that the HS-SCCH does not use the 64QAM format Rel-7

MIMO Parameters OP TRUE Absence of this IE means that the HS-SCCH does not support MIMO Rel-7

dl-SecondaryCellInfoFDD IE OP TRUE

DL optional parameters relevant to reception of secondary serving HS-DSCH cell Rel-8

The UE acknowledges the Radio Bearer Reconfiguration message with a Radio Bearer Reconfiguration Complete message.



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RNC orders the UE with the Measurement Control message to stop the traffic volume measurements, if the UE has been allocated the maximum available bit rate of HSPA channel type, as there is no use for the UEs to request higher bit rate. If the UE is allocated a lower than maximum bit rate, then the RNC modifies the Event 4A reporting threshold according to the allocated bit rate (Flexible Upgrade feature provides possibility to define bit rate specific thresholds).

A) Rel-5 UE, initial UL rate B) Rel-6 UE, HSPA allocated

File 8. Example of Measurement Control message used to modify/release the Ul traffic volume measurement.

2.4.5 Direct Resource Allocation for HSPA Direct resource allocation for HSPA allocates HSPA during RAB setup establishment which replaces the allocation of a 0/0 kbps. Direct resource allocation is applicable to full HSPA connections using PS NRT Interactive or Background traffic classes. Direct resource allocation for HSPA can be applied only for CELL_DCH or CELL_FACH or for both, depending on settings of parameter RABDRAEnabled. If RABDRAEnabled is disabled, then direct resource allocation for HSPA shall not be applied but RB is mapped to DCH 0/0 kbps and traffic volume measurements are started according to existing principles.

In case HSPA allocation is not possible due to BTS, TRS or DSP congestion, no further attempt shall be made and DCH 0/0 shall be allocated and TVM started as per existing principles.

Figure 7. Comparison of Normal NRT RAB Setup and Direct Resource allocation for HSPA



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2.4.6 RRC state transitions The RNC can order the UE to change the RRC state during the packet call. This is typically performed due to packet connection inactivity or start of data transmission (see Figure 8Figure 8Figure 8). When the UE is transferred from CELL_DCH to CELL_FACH state, the radio bearer is reconfigured to use common channels (RACH/FACH) with Radio Bearer Reconfiguration procedure. The Physical Layer Reconfiguration procedure is used to transfer the UE to/from the CELL_PCH and URA_PCH (RU10 feature) states. In this procedure the physical layer and transport channel resources are released but RB (could be with SRB only), RAB and PDP context remain active towards Iu-interface.

Figure 8. RRC states and transitions. RU10 Introduce possibility to use URA_PCH state and fast call setup directly from URA_PCH/CELL_PCH to Cell_DCH. New transitions supported by RU10, are shown with black lines.

The transition of the UE from CELL_DCH to CELL_FACH is performed with the Radio Bearer Reconfiguration message (see Figure 9Figure 9Figure 9 and File 9File 9File 9 A). It is initiated by the RNC in basis of data transmission inactivity both in UL and DL or low measured throughput. This transition included the release of the BTS and Iub resources reserved for the connection. The common channel resources are used in CELL_FACH for the data and signalling.

CELL_PCH URA_PCH

CELL_FACH CELL_DCH

UTRA RRC Connected Mode

Fast call setup from URA_PCH

IDLE Mode

Fast call setup from CELL_PCH

After RT call with inactive PS RABs

After RT call with inactive PS RABs & high mobility in

CELL_DCH

RRC Setup / Release

Phys. Reconfiguration UL/DL activation timer

Phys. Reconfiguration

Cell Update, UL data, paging

Phys. Reconfiguration

Frequent cell updates Phys. Reconfiguration

URA Update, UL data, Paging

RB. Reconfiguration

Traffic Volume, RACH load RB. Reconfiguration

Inactivity Timer, Overload



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Figure 9. Transition from CELL_DCH to CELL_FACH with Radio Bearer Reconfiguration procedure.

The transition of the UE from CELL_FACH to CELL_PCH is performed with the Physical Channel Reconfiguration message (see Figure 10Figure 10Figure 10 and File 9File 9File 9 B) is initiated by the RNC in basis of data transmission inactivity both in UL and DL. In CELL_PCH state the UE is receiving the paging messages. Transition to URA_PCH is performed with the same signalling procedure.

Figure 10. Transition from CELL_FACH to CELL_PCH (URA_PCH) with Radio Bearer Reconfiguration procedure.

A) RB reconfiguration from CELL_DCH to CELL_FACH

B) Physical channel reconfiguration from CELL_FACH to CELL_PCH

File 9. Example of Radio Bearer reconfiguration and Physical channel reconfiguration messages used in the RRC state transitions.

When URA_PCH is enabled, to reduce the unnecessary signalling (cell updates) the UE is moved to the URA_PCH state if UE has been moving fast (in CELL_DCH state) or when too frequent execution of cell reselection procedure is observed (in CELL_FACH state). In CELL_DCH state, UE location is known in cell level and handover process (HA3) can calculate the velocity of the UE by active set changes needed for the UE. If the number of complete active set changes during the time period FastUEPeriod is equal or exceeds the threshold FastUEThreshold, the RNC (HA3) shall inform RRC signalling entity (MCC via CCM) about UE which is moving fast. This is used for deciding Cell_PCH or URA_PCH state transitions after inactivity is detected. Low moving UEs go to CELL_PCH state.

In CELL_FACH state, transition to URA_PCH is performed for high mobility UEs if amount of cell reselections/updates exceed predefined threshold set by parameter MaxCellReselections within time defined with parameter CellReselectionObservingTime. If MaxCellReselections is set to 0, URA_PCH is not possible



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In case of the UE is not supporting URA_PCH state, following handling is used: When RRC entity has tried to switch the UE to URA_PCH state and the UE has responded by sending RRC: PHYSICAL CHANNEL CONFIGURATION FAILURE message (cause: unsupported configuration). There will be second trying to the CELL_PCH state and the non-URA UE flag is set.

The re-activation of the data connection can be initiated by the UE by using the Cell Update message (cause UL data transmission, see Figure 11Figure 11Figure 11 and File 10File 10File 10A) or by the RNC by paging the UE. The RNC either keeps the UE in CELL_FACH or moves it to CELL_DCH with the Radio Bearer Reconfiguration procedure.

Figure 11. Transfer of the UE to CELL_DCH and reactivat

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