Ultra-FlashCSFB-r5_CSFB和VOLTESRVCC的融合

1、HUAWEI TECHNOLOGIES CO., LTDHuawei Ultra-Flash CSFBHuawei Ultra-Flash CSFBContentsContentsuStandard CSFB, VoLTE/SRVCC introductionuHuawei Ultra-Flash CSFB IntroductionuHuawei Ultra-Flash CSFB DeploymentuSummary Page 3HUAWEI TECHNOLOGIES CO., LTD.MMEMSCLTEG/UCS RABRRC24Target cell RRC/CS RAB establis

2、hment1Redirection to target cell3Authentication/ encryption /call procedureRead Cell informationR8 CSFBMMEMSCLTEG/UTriggerPS HORRCCell measurement123Target cell RRC/CS RAB establishment4PSHO to target cellSGSNPS RAB5Authentication/ encryption /call procedureCS RAB6PS HO CSFB3GPP standard CSFB introd

3、uction1MSCUpgrade all MSCor Proxy MSC(additional 12s delay)2TA/LA PlanningStrictly planning is needed, otherwise it will lead to additional delay and MT failure in TA/LA mismatch area3Roaming Retry/Roaming ForwardingAll MSC must be upgradedProxy CSFB (Non-Standard)MMEMSCLTEG/UCS RABRRC4Target cell R

4、RC/CS RAB establishment2Redirection to target cell3Authentication/ encryption /call procedureRIM procedure1R9 CSFB (Flash CSFB)Issues and limitation of standard CSFBPage 4HUAWEI TECHNOLOGIES CO., LTD.3GPP standard (e)SRVCC introductionATCF/ATGWContentsContentsuStandard CSFB, VoLTE/SRVCC introduction

5、uHuawei Ultra-Flash CSFB IntroductionuHuawei Ultra-Flash CSFB DeploymentuSummary Page 6HUAWEI TECHNOLOGIES CO., LTD.Issue 1: E2E call setup time is too longFallback to GSMwithout Proxy4G call 4G 12s R84G call 4G 8s R92G call 2G 6s Legacywith Proxy4G call 4G 14s 4G call 4G 10s R8R9mLAB test resultLiv

6、e network test result Operator A test result: (to GSM without Proxy)： R8 : 1216s R9 : 8sFallback to UMTS without Proxy4G call 4G 7s R84G call 4G 6s R93G call 3G 5s Legacywith Proxy4G call 4G 9.5s 4G call 4G 9s R8R9mLAB test resultLive network test resultMiddle east operator A (to UMTS with Proxy)： R

7、8 + Proxy : 1012sEuropean operator BUMTS with Proxy)： R8 + Proxy : 1012sR9 = Flash CSFBPage 7HUAWEI TECHNOLOGIES CO., LTD.Issue2： Deployment difficulties, planning complexPlanning complexTA List = TA1 + TA2 + TA3 Good planning：TA List in one LATA1TA2TA3LA1TA1TA2TA3LA1LA2Bad planning：TA List cross mu

8、lti-LAMTRF：MT Roaming Forwarding MTRR：MT Roaming Retry Bad Planning will lead to: MT failure when UE fallback to LA2 MSC and calling from LA1 MSC MT Supplementary services failure (refer to issue 6) Current solution in bad planning MT failure when ：MTRF/MTRR deployment in MSC MT Supplementary servic

9、es failure: No solution MTRF/MTRR issues: All MSC and HLR must be upgradedAdditional 12s call latencyDeployment difficultiesu Impacted NEs for R9 CSFB deploymentMMEeNBMSCBSCRNCSGSNUpgradedNewu Impacted NEs for R8 CSFB deploymentMMEMSCeNBUpgradedNewuFuture VoLTE / SRVCC need to continue to invest in

10、NEsNewIMS CoreMSCUpgradedMMEeNBu Impacted NEs for PSHO deploymentMMEMSCeNBBSCRNCUpgradedNewPage 8HUAWEI TECHNOLOGIES CO., LTD.Issue3：Limitation of Proxy in Standard CSFBProblems from Proxy DeploymentCSFB Proxy Deployment Reduce TCO Proxy is not the serving MSC to handle service Additional LAU is man

11、datory to forward UE to serving MSC Additional 12s latency was caused by LAUAdditional 12s latency in voice call Proxy could not to be service anchor Serving MSC could not initiate MT supplementary services （refer to issue 6）Supplementary Services Failure SGs and Sv interfaces must be in same MSC, o

12、therwise supplementary service will fail when VoLTE is ongoing(refer to issue 6) If SRVCC IWF was adapted, CSFB must use Proxy deployment in the same MSCSGs and Sv interface must be in same MSCCSFB Proxy DeploymentCSFB ProxyMMESGs3. LAU1.LCS Request 2.Paging via SGsFailure 4 .LCS RequestPage 9HUAWEI

13、 TECHNOLOGIES CO., LTD.Issue4: Blind redirection decrease call success rate Blind Redirection for standard CSFBBlind Redirection is often used in standard CSFBBlind Redirection: without Signal Measurement, select cell to fallback randomlyLTEG/URedirectionMSCMMECell selectionProblem of blind redirect

14、ion Without Signal Measurement in redirection Blind redirection was used in standard CSFB eNB indicate 2G neighbor cell list or 3G frequency to UE based on configuration. eNB could not get 2G/3G load status In edge of G/U coverage, UE have to try cells one by one, it may lead to success rate decreas

15、ing and In edge of G/U coverage, blind redirection may further lead to both EPS and CSFB service unreachable for certain time when UE is back to LTE. Call success rate decreased in complex radio scenarioPage 10HUAWEI TECHNOLOGIES CO., LTD.Issue5: Problems of LTE only operators Operator A and B share

16、 LTE radio network Rent Operator B G/U network for CSFBSoftware upgrade is mandatory both OP A LTE and OP B 2/3G networksComplex charging in 2 operators to decrease customer satisfactionUE could not return to Operator A LTE network after CSFB Return issues after CSFB call is hung up Logo of UE will

17、change to rented operators UE could not return to OP A LTE network after CSFB MMEMSCG/UMMELTECSFBPLMN1PLMN2OP A CSFB UE to OP B G/U networkMMEMSCG/UMMELTEReturnPLMN1PLMN2OP A CSFB UE back to OP B LTE network after CSFBLTE Operator A2/3G Operator BLTE Operator A2/3G Operator BPage 11HUAWEI TECHNOLOGI

18、ES CO., LTD.Issue 6: Supplementary services problem in CSFBTA1TA2TA3LA1LA2MSC1MSC2LCS requestTA List across multiple LA planning, resulting in failure of Mobile Terminated supplementary servicesCSFB to MSC2CSFB Proxy scenario, Mobile Terminated supplementary services failProxyMMESGs3. LAU1.LCS reque

19、st 2.Paging via SGsFailure 4 .LCS request Already deployed VoLTE, but still with CSFB provide supplementary services, SGs and Sv separated deployment scenario, Mobile Terminated supplementary services failSRVCC IWFMMESvLCS requestFailure SGs MSCSRVCC HO SGsVoLTE ongoingIMSSeparated SGs, SvSGs/Sv anc

20、horing in same MSC and MME is best optionPage 12HUAWEI TECHNOLOGIES CO., LTD.Issue 7: Emergency Call of IMS is not readyIMSEPCLTEG/UCSFB emergency callVoLTE call CS Core VoLTE EMC is not ready, CSFB must be used Emergency call is mandatory in many countries IMS emergency call is difficulty to deploy

21、 in short term Standard CSFB EMC call setup time could not meet regulatory requirements EMC: Emergency CallPage 13HUAWEI TECHNOLOGIES CO., LTD.LTEG/USGs MSCSGSNMMERedirectionWhat is Ultra-Flash CSFB ? (SRVCC supported UE Scenario)MSCSGSNMMEIMSSRVCC Session TransferLTEG/USvSRVCC Inter RAT Handover SR

22、VCC IRAT HOSvSRVCC Inter RAT Handover SRVCC IRAT HOCSFBVoLTEw/ SRVCCUltra-Flash CSFB is a solution used SRVCC IRAT handover to accelerate CSFBLTEG/USGs MSCSGSNMMERedirectionUltra-Flash CSFBUltra-Flash CSFB, SRVCC Session Transfer is not needed as it is a CS call setup procedure rather than VoLTE to

23、2/3G hand over . Ultra-Flash CSFB requires UE to support standard SRVCC feature.Page 14HUAWEI TECHNOLOGIES CO., LTD. Ultra Flash CSFB with SRVCC capable UEPer UEs SRVCC capability, eNB triggers SRVCC HO during CSFBMME sends PS to CS HO request to MSC upon receiving SRVCC HO from eNB during CSFB(1)SR

24、VCC MSC triggers CS HO and prepare CS RAB(2)SRVCC MSC proceed with normal CS call Page 15HUAWEI TECHNOLOGIES CO., LTD. Ultra Flash CSFB with SRVCC capable UE - MOPage 16HUAWEI TECHNOLOGIES CO., LTD.Huawei Analysis As shown in green lines, the UE start CS call and CC sublayer allocate (TI=0,TI Flag=0

25、) CS voice session.The MM sublayer find out the UE in E-UTRAN side and indicate EMM sublayer to initiate ESR procedureThe LTE AS layer forward HO CMD to GERAN/UTRAN AS layerGERAN/UTRAN AS layer access the GERAN/UTRAN and SRVCC handling is triggeredMM sublayer gives an indication to the CC sublayer t

26、o establish CS call(TI=0,TI Flag=0)due to SRVCC per step b6.And derives GERAN/GERAN security contexts for the CS domain from the current EPS security contextUpon receiving step b6, CC sublayer allocates(TI=0, TI Flag=1) for SRVCC and proceed with (TI=0,TI Flag=0) call setup procedure by sending CM S

27、ervice Request and Setup with TI=0. MSC send disconnect(TI=0,TI Flag=1) to clear the dummy call object (TI=0, TI Flag = 1) in UE side.Page 17HUAWEI TECHNOLOGIES CO., LTD.Ultra Flash CSFB with L-U SRVCC - MTPer UEs SRVCC capability, eNB triggers SRVCC HO during CSFBMME sends PS to CS HO request to MS

28、C upon receiving SRVCC HO from eNB during CSFB(1)SRVCC MSC triggers CS HO and prepare CS RAB(2)SRVCC MSC send setup(TI=1) to the UE(3) SRVCC send Disconnect(TI=0) to the UEPage 18HUAWEI TECHNOLOGIES CO., LTD. Ultra Flash CSFB with SRVCC capable UE - MTPage 19HUAWEI TECHNOLOGIES CO., LTD.Huawei Analy

29、sis As shown in green lines, the UE(LTE part) receive CSFB paging call and trigger the CSFB procedure accordingly.The LTE AS layer forward HO CMD to GERAN/UTRAN AS layerGERAN/UTRAN AS layer access the GERAN/UTRAN and SRVCC handling is triggeredMM sublayer gives an indication to the CC sublayer to es

30、tablish CS call with TI =0 due to SRVCC per step b6.And derives GERAN/GERAN security contexts for the CS domain from the current EPS security contextCC sublayer allocate TI=0 CS session per step b6 MM sublayer sends paging response to MSC and MSC sends setup(TI=1) to the UE as TI=0 is already in CC

31、sublayer. MSC further sends Disconnect(TI=0) to the UE in order to release the TI=0 CS sessionPage 20HUAWEI TECHNOLOGIES CO., LTD.UltraUltra-FLASH CSFBFLASH CSFB優(yōu)勢優(yōu)勢（1 1）：時延低）：時延低n主被叫均為主被叫均為FLASH CSFB終端，雙端呼叫建立時延低于標(biāo)準(zhǔn)終端，雙端呼叫建立時延低于標(biāo)準(zhǔn)GSM打打GSM時延時延SRVCC IRAT HOUltra-Flash CSFB to GSMR8R9(Flash)Ultra-Flash

32、 call Ultra-FlashGSM CallUltra-Flash CSFB2G call 2GSRVCC/PS HOAuthentication/encryption/UE Capacity identifyCS RAB establishmentUE access to 2G cellRead SIBasic call procedure注：1、基于Huawei實驗室測試數(shù)據(jù)分析，帶異系統(tǒng)測量和帶異系統(tǒng)測量和DRX優(yōu)化優(yōu)化 2、采用高通、采用高通FFAPage 21HUAWEI TECHNOLOGIES CO., LTD.DRX based LTE-GERAN measurement

33、u36300-840 10.2.3.1Inter-RAT handovers from E-UTRANMeasurements to be performed by a UE for inter-RAT mobility can be controlled by E-UTRAN, using broadcast or dedicated control. In RRC_CONNECTED state, a UE shall follow the measurement parameters specified by RRC or MAC commands (FFS) directed from

34、 the E-UTRAN (e.g. as in UTRAN MEASUREMENT_CONTROL).UE performs inter-RAT neighbour cell measurements during DL/UL idle periods that are provided by the network through suitable DRX/DTX period or packet scheduling if necessary.uDRX based L-G discussionuHuawei analysisAccording to our testing L2G SRV

35、CC on 8960 platform, LTE-GSM measurement takes about 1700ms. Back to Ultra-Flash CSFB, UE usually is in idle mode when initiating CSFB i.e. no data transmission at that time.If use gap+B1:700-800ms where gag is 40ms/6ms.As there is no data transmission, it seem beneficial to use DRX+B1. The real mea

36、surement time is (800/40)*6=120ms that can be done in DRX 256ms with short active time.If DRX based measurement is used, L-G measurement could takes about 200msPage 22HUAWEI TECHNOLOGIES CO., LTD.Ultra-FLASH CSFBUltra-FLASH CSFB相比相比CSFBCSFB呼叫時延呼叫時延優(yōu)優(yōu)勢勢原因分析原因分析同時支持同時支持SGsSGs、SvSv接口，使用接口，使用SRVCC SRVCC

37、 IRAT HOIRAT HO來提高來提高CSFBCSFB呼叫性能呼叫性能BSC/RNCeNBSRVC MSCMMESvSGs1234CSFB R8/R9Ultra-Flash CSFB1小區(qū)選擇重定向流程選擇目標(biāo)小區(qū)SRVCC IRAT切換流程選擇目標(biāo)小區(qū)2CS承載建立小區(qū)選擇完成后，再啟動CS承載建立過程在SRVCC切換過程中，提前建立好CS承載3鑒權(quán)/加密/UE能力獲取單獨流程完成切換流程提前完成4信令傳輸信道(Only GSM)8個用戶共享SD信道單用戶獨占TCH信道Ultra-Flash CSFB在以下在以下4 4個階段節(jié)省了時間個階段節(jié)省了時間Page 23HUAWEI TECHN

38、OLOGIES CO., LTD.Call Setup Time Comparison(Fall back to GSM)SRVCC IRAT HOUltra-Flash CSFB to GSMR8R9(Flash)Ultra-Flash call Ultra-FlashGSM CallUltra-Flash CSFB2G call 2GSRVCC/PS HOAuthentication/encryption/UE Capacity identifyCS RAB establishmentUE access to 2G cellRead SIBasic call procedureBased

39、on Huawei Lab testingLTE call LTE, both MO/MT fall backThe Data for Ultra-Flash CSFB is per DRX based measurementContentsContentsuStandard CSFB, VoLTE/SRVCC introductionuHuawei Ultra-Flash CSFB IntroductionuHuawei Ultra-Flash CSFB DeploymentuSummary Page 25HUAWEI TECHNOLOGIES CO., LTD.EPCCSIMSSGsSvC

40、SFBCSFB PhasePhase CSFBPre-VoLTEPre-VoLTE PhasePhase Ultra-Flash CSFBVoLTEVoLTE PhasePhaseVoLTE/CSFBEPCCSSvSGsEPCCSSGsLTE Data + 2G/3G VoiceLTE Data + Ultra-Flash CSFB voice（improved user experience）LTE Data+ Ultra-Flash CSFB voice（supplementary to VoLTE）+ VoLTE voiceCSFBUltra-Flash CSFBVoLTE/SRVCC

41、Trial VoLTE/SRVCC commercial 2012201320142015Redefine LTE Voice RoadmapPage 26HUAWEI TECHNOLOGIES CO., LTD.Ultra-FLASH CSFBUltra-FLASH CSFB優(yōu)勢優(yōu)勢（1 1）：）：網(wǎng)絡(luò)配置要求網(wǎng)絡(luò)配置要求低低MSC1LAnTA1=LA1nTA4=LA4nTA5=LA5nTA3nLA3nLA6nLA52/3G LALTE TAnTA2nLA22nLA23nLA2 TA-LA不對應(yīng)場景二TA不在LA覆蓋范圍內(nèi)回落后LA不同，但回落后MSC POOL未改變 TA-LA不對應(yīng)場景一

42、TA跨MSC POOL邊界，回落后MSC不同 場景一的測試驗證結(jié)果 由于青島現(xiàn)場均未開啟MTRF，當(dāng)測試LTE終端回落后對應(yīng)的LA已經(jīng)跨出原有的TA時，呼叫建立均失敗場景二的測試驗證結(jié)果通過對4G主叫單端撥打的場景進行驗證，平均增加時延1.44s，各呼叫約增加 12s 的LAU 時延Ultra-Flash CSFB to GSMCSFB R8/R9 to GSM場景場景GSM LA和和TD-LTE TA無需嚴(yán)格映射，呼叫性能不受影響，大幅降低無線網(wǎng)絡(luò)規(guī)劃、優(yōu)化復(fù)雜度無需嚴(yán)格映射，呼叫性能不受影響，大幅降低無線網(wǎng)絡(luò)規(guī)劃、優(yōu)化復(fù)雜度Page 27HUAWEI TECHNOLOGIES CO., L

43、TD.Ultra-FLASH CSFBUltra-FLASH CSFB優(yōu)勢優(yōu)勢（2 2）：）：投資被投資被VoLTEVoLTE/SRVCC/SRVCC復(fù)用復(fù)用現(xiàn)有現(xiàn)有GSM無線網(wǎng)和核心網(wǎng)無需改動無線網(wǎng)和核心網(wǎng)無需改動改造投資CSFBUltra-Flash CSFB1GSM MSC所有MSC升級，或使用E-MSC（顯著增加呼叫時延）使用Proxy無需升級MSC（不會增加呼叫時延）2現(xiàn)網(wǎng)MSC必須升級支持MTRF，否則會導(dǎo)致被叫失敗無需部署，不會導(dǎo)致被叫失敗3TD-LTE現(xiàn)有CSFB投資無法被VoLTE/SRVCC復(fù)用Ultra-Flash CSFB投資可直接被VoLTE/SRVCC復(fù)用eNode

44、BSRVCC MSCBSCVMSCMMESvSGsIMS CoreEPC使使用用SRVCC MSC，進一步減少對已有網(wǎng)進一步減少對已有網(wǎng)絡(luò)影響絡(luò)影響無需改動無需改動GSMGSM現(xiàn)網(wǎng)現(xiàn)網(wǎng)疊加疊加IMS直接支持直接支持VoLTE/SRVCC，已有網(wǎng)絡(luò)無需二次投資已有網(wǎng)絡(luò)無需二次投資軟件升級軟件升級Page 28HUAWEI TECHNOLOGIES CO., LTD.Ultra-FLASH CSFBUltra-FLASH CSFB產(chǎn)業(yè)鏈支持情況產(chǎn)業(yè)鏈支持情況2013H22014H12014H22015芯片進展終端進展即將商用發(fā)布SRVCC芯片SRVCC即將可測，商用待定VoLTE+SRVCC研發(fā)中

45、已發(fā)布VoLTE商用手機，但不含SRVCC預(yù)計將發(fā)布VoLTE+SRVCC終端iPhone6可能支持VoLTE+SRVCCiPhone5/C/S僅支持CSFBiPhone5 支持CSFB支支持持CSFB+SRVCC終終端端, 即即可支持可支持Ultra FLASH CSFB，催熟，催熟TD-LTE到到GSM芯片產(chǎn)業(yè)鏈，芯片產(chǎn)業(yè)鏈，海思海思2013年年10月，高通月，高通2013年年12月，因此月，因此2014年年Ultra-FLASH CSFB可以商用可以商用 Page 29HUAWEI TECHNOLOGIES CO., LTD.VoLTEVoLTE手機配置支持手機配置支持Ultra-Fla

46、sh CSFBMMEMSCSGWPGWVoLTEUltra-Flash CSFBUE配置成 IMS PS語音優(yōu)先，CS語音其次1.若已經(jīng)部署IMS，MME指示 UE IMS Voice over PS session supported 2.若沒有部署IMS，MME指示IMS Voice over PS session NOT supported UE根據(jù)MME指示決定使用VoLTE還是Ultra-Flash CSFB價值：價值：1.在沒有部署IMS的場景下，可以使用VoLTE/SRVCC手機做Ultra-Flash CSFB2.IMS部署后，手機可以直接使用VoLTE，無需重新配置n配置成配置成VoLTE優(yōu)先的手機無需修改配置即支持優(yōu)先的手機無需修改配置即支持Ultra-Flash CSFBContentsContentsuStandard CSFB, VoLTE/SRVCC introductionuHuawei Ultra-Flash CSFB IntroductionuHuawei Ultra-Flash CSFB DeploymentuSummary Page 31HUA