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Wujie-LTENEAJuly24th,2015VOLTEE2EArchitecture,CallFlowsCopyright©2014Alcatel-Lucent,2|FeatureValidation|LA3.0.2-L108258-PCIAllocation1VoLTEIntroductionCopyright©2014Alcatel-Lucent,3VoLTEIntroducitonLTETypicalVoiceSolutionsinLTEnetworkNon-typicalVoiceSolutionsVoLGA,IMSMSC,OTT,etc.Copyright©2014Alcatel-Lucent,4VoLTEIntroducitonVoLTEFREESYOUR2G/3GSPECTRUMFORLTEDATAYouhavemorecapacityforLTEdataandcandeliverhigherqualityvoiceatalowercost,becauseLTE’sspectralefficiency&VoLTE’soptimizationsenableanincreasedvoice&datacombinedcapacity.Andyoucanre-farm2G/3GvoicespectrumtoLTEdata:•~3xUMTScircuitswitchedvoice(~2x)•~6xGSMcircuitswitchedvoice(~3x)MORESPECTRUMFORLTEHELPSYOU:1.Sellmoredata,becauseyouhavemorecapacity2.Reuseyourexistingspectrum•AvoidspendingUSD$180M-$490M,whichisotherwiseneededforspectrumpurchasessupporting50Msubscribersin10Ksites3.Servemobiledata’sgrowthwithmoreplentifulLTE•FarlesscostlytoaddLTEcapacitythan3GHSPA+•SimplifyoperationsbyusinganLTEoverlay•PutsyouontoaneasierpathtoLTE-Advanced(avoidconvergedRANcomplications)VoLTEenablesefficiency,unlikeCSFBCopyright©2014Alcatel-Lucent,5VoLTEIntroductionQCIBearerTypePriorityPacketdelaybudgetPacketLossRate1GBR2100ms10-22GBR3150ms10-33GBR450ms10-34GBR5300ms10-65NGBR1100ms10-66NGBR6300ms10-67NGBR7100ms10-38NGBR8300ms10-69NGBR9300ms10-6•NineQoSclassesarestandardizedforLTE•AgivenQoSClassensuresthatapplications/servicesmappedtothatClassreceivetheminimumlevelofQoS.•ThePacketDelayBudgetcorrespondstotheend-to-enddelaybetweentheUEandtheP-GWwithaconfidencelevelof98%.•ParameterTrafficRadioBearerConf::packetDelayBudgetconfiguresthecorrespondingradiodelaybetweentheUEandtheeNBandisderivedbysubtracting20msfromtheend-to-enddelayinthe3GPPtable.Copyright©2014Alcatel-Lucent,6ROCH-Therobustheadercompressionprotocol(ROHC)islocatedinthePDCPlayer.ItisusedtocompresstheheadersofIPpacketstoreduceoverallpacketsize,therebyimprovingcapacity.Copyright©2014Alcatel-Lucent,7RTCPProfile(110000000)Copyright©2014Alcatel-Lucent,8SPSIntroductionSemi-PersistentScheduling(SPS)wasdefinedin3GPPRelease8withthegoalofreducingcontrolchanneloverheadinhandlingVoIPcallsWithDynamicScheduling(DS),physicalresourceblocksareallocatedonaperrequestbasis–soaUEneedstosendaresourcerequestforeveryVoIPpacketTypically,oneVoIPpacket(small)issentat20msintervalsduringtalkingandaSilenceInsertionDescriptor(SID)every160msduringsilentperiodsOnaverage,VoIPusersareactive(talking)halfthetimeandtheotherhalfsilentToreducethecontrolchanneltraffic,SPSisusedtoallocateapersistentsequenceofresourcesforactivestatesTheUEsendsarequestatthestartofeachactiveperiodandtheeNodeBallocatesasequenceofresourcesforVoIPevery20ms,aslongasspeechpacketskeeparrivingThediagramattherightshowstherelationshipbetweenthenumberofuserspercellsectorandthenumberofcontrolchannelsperTransmissionTimeInterval(TTI)(1ms)TransmissionsinLTEaredoneonaTTIbasisAsusersincrease,thenumberofchannelsfordynamicschedulingrisessharply,whileforSPSitrisesmoreslowlyNotethatSPScouldbeusedforSIDpacketsinsilentstate(pinkline)ordynamicscheduling(blue)9COPYRIGHT©2013ALCATEL-LUCENT.ALLRIGHTSRESERVED.•WhenauseronanactiveVoLTEcall(Figure1)movesintoanareawithoutLTEcoverage,thehandoverofthecalltotheCSnetworkisaccomplishedwithtwosteps:IRAThandoverandsessiontransfer.IRAThandoveristhetraditionalhandoveroftheuser’sdevicefromLTEradioaccesstoWCDMA/GSMradioaccess.SessiontransferisanewmechanismtomoveaccesscontrolandvoicemediaanchoringfromtheLTEEvolvedPacketCore(EPC)tothelegacyCScore.•DuringtheentirevoicehandoverprocessfromLTEto2G/3G,theIMSretainscontroloftheuser.ThehandoverprocessisinitiatedbyasessiontransferrequesttotheIMS(showninFigure2).SRVCC–FeatureDescriptionVolteCallinprogress-Fig.1SessionTransferReqFig.210COPYRIGHT©2013ALCATEL-LUCENT.ALLRIGHTSRESERVED.•TheIMSrespondssimultaneouslywithtwocommands,(Figure3)onetotheLTEnetworkandonetothe2G/3Gnetwork.TheLTEnetwork,receivesanIRAThandoverexecutioncommandthroughtheMMEandtheLTERANtotheinstructtheuser’sdevicetopreparetomovetotheCSnetworkforthevoicecall.TheCSnetworkreceivesasessiontransferresponse,preparingittoacceptthecallinprogress.•Withacknowledgementsthatthecommandshavebeenexecuted,theuser’sdeviceandtheIMS,stillincontroloftheuser’svoicecallinprogress,switchtotheCSnetworktocontinuethecall.(Figure4)SRVCC–FeatureDescriptionFigure4Figure311COPYRIGHT©2013ALCATEL-LUCENT.ALLRIGHTSRESERVED.SRVCC–FeatureDescriptionCopyright©2014Alcatel-Lucent,VoLTEMOSVoiceperformanceevaluationMOS:MeanOptionScore1.GSMalsousethis2.Subjective3.ITU-TP.8004.Relatedtovoicesource5.Ourfieldtestalsousemosvalueasvoicequalityevaluationmethod6.Someothercriterion(packetloss,jitter…)scouldhaveequivalentMOSvaluesTDDvoicequalityevaluationmethod:AllthesemetricscouldhaveequivalentMOSvaluesCopyright©2014Alcatel-Lucent,PESQVs.POLQAscouldhaveequivalentMOSvaluesVolte-VoltecallusesAMR-WBcodecandthereforeonlyPOLQAisusedCopyright©2014Alcatel-Lucent,VoLTEMonitoringPerformanceMonitoring---KPIdashboardscouldhaveequivalentMOSvaluesCopyright©2014Alcatel-Lucent,15|FeatureValidation|LA3.0.2-L108258-PCIAllocation2Vo