LTEbasicIntroduction-LTE英文介紹課件

3GPPLongTermEvolution

IntroductionLTETIS2009-12Agenda1.LTE&3GPPStandard2.LTENetworkSystem3.LTEKeyTechnologies4.LTETDDCharacteristics21.LTE&3GPPStandard3About3GPPLTESinceNovember2004,3GPPhasbeenworkingontheLongTermEvolution(LTE)forenhancementstotheUniversalMobileTelecommunicationsSystem(UMTS),andfocusonadopting4Gtechnology.Specs(Rel-8)werefinalizedandapprovedinJanuary2008.LTE-Advancedstudyphaseinprogress.Targetondeploymentin2010.By2015,subscriptionscouldexceed400million,andrevenuesfromLTEcouldrepresentmorethan15%ofallmobilerevenues.4LTEMilestonein3GPPStandardEvolution3GPPReleaseRel’99Rel’4Rel’5Rel’6Rel’7Rel’8UMTSFDDDCHupto2MbpsCoreNetw.EvolutionFDDrepeaters1.28McpsTDDHSDPAMultimediasub-systemHSUPAMBMSHSPA+i.e.MIMO,CPC,DL64-QAM,UL16-QAMLTERel’9/1053GPPRequirementsForLTESpectrumefficiencyDL:3-4timesHSDPAforMIMO(2,2)UL:2-3timesE-DCHforMIMO(1,2)FrequencySpectrum:Scalablebandwidth:1.4,3,5,10,15,20MHzTocoverallfrequenciesofIMT-2000:450MHzto2.6GHzPeakdatarate

(scalinglinearlywiththespectrumallocation)

DL:>100Mb/sfor20MHzspectrumallocationUL:>50Mb/sfor20MHzspectrumallocation

Capacity200usersfor5MHz,400usersinlargerspectrumallocations(activestate)LatencyC-plane:<100mstoestablishU-planeU-plane:<10msfromUEtoserver

CoveragePerformancetargetsupto5km,slightdegradationupto30kmMobilityLTEisoptimizedforlowspeeds0-15km/hbutconnectionmaintainedforspeedsupto350or500km/hHandoverbetween3G&3GLTEReal-time<300msNon-real-time<500ms6IncreasedPerformances&ReducedCostswithLTELatencyThroughputCostperMegabyte**Source:AnalysisResearch,2006MobilityRoamingLTEEDGEHSPAUMTS384kbpsDL128kbpsUL14.4Mb/sDL5.7Mb/sUL0.06€

0.03€220kbpsDL120ms60ms750msH/OwithGSM0.005€

>100Mb/sDL>50Mb/sUL<10msH/OwithGSM,UMTS,CDMA…7LTElandscape82.LTENetworkSystem93GPPLTEsystemarchitectureeNodeBcellsitenodeS1-MME:controlplanebetweeneNodeBandMMES1-U:userplanebetweeneNodeBandSAEGWS1:interfacebetweenaneNBandanEPC,providinganinterconnectionpointbetweentheE-UTRANandtheEPC.Itisalsoconsideredasareferencepoint.X2:logicalinterfacebetweentwoeNBs.WhilstlogicallyrepresentingapointtopointlinkbetweeneNBs,thephysicalrealizationneednotbeapointtopointlink.10EUTRANNetworkArchitectureLTE-UuLTE-UuX2CX2UX2CX2UX2CX2US1-MMES1-MMES1-MMES1US1US1UUEUEeNBeNBeNBMMEAGWIPTransportNetwork(IPCloud)X2C-X2CplaneS1U-S1UplaneX2U-X2UplaneS1-MME-S1CplaneAP-AccessPoint(forIPcloud)eUTRANEPCAPAPAPAPAP11FlatArchitectureLowlatency

RTT:10msinsteadof60msforHSPAShortTTI(1msinsteadof2msforHSPA)andtheflatarchitectureBackhaulbasedfromday1onIP/MPLStransportNode-BNode-BNode-BMSCRNCSGSNPSTNInternetGGSNaGWeNode-BeNode-BInternetPSTNeNode-B12NetworkSimplification:From3GPPto3GPPLTE3GPParchitecture4functionalentitiesonthecontrolplaneanduserplane3standardizedUP&CPinterfaces3GPPLTEarchitecture2functionalentitiesontheuserplane:eNodeBandASGWSGSNcontrolplanefunctions=>ASGW&MMERNCcontrolplanefunctions=>MME&eNodeBLessinterfaces,somefunctionswilldisappear4layersinto2layersEvolveGGSNintegratedASGWMovingSGSNfunctionalitiestoASGW.RNCevolutionstoRRMDBonaIPdistributednetworkforenhancingmobilitymanagement.PartofRNCmobilityfunctionbeingmovedtoASGW&eNodeBGGSNSGSNRNCNodeBASGWeNodeBMMFGGSNSGSNRNCNodeBControlplaneUserplaneASGWeNodeBMMFAGWeNodeBMMEControlplaneUserplane133GPPSystemArchitectureEvolution

Mobilityby“SingleGw”orMobileIPPCRF–PolicyandChargingRulesFunctionGERANOtherIPAccess3GPPornon-3GPP(e.g.I-WLAN,3GPP2,LTEalso)GGSNMIPHAPS&EvolvedPSCoreASGWIMSL3AAA(e.g.PCRF)MultimediaStratumAccessSystemStratumNetworkStratum(AIPN)UTRANGANEvolvedUTRAN14S1ArchitectureKeypointsFlexArchitectureforbothinterfacesS1-UandS1-MMEMMEandSAEGWcanbesplitintwologicalnodesorcombinedinthesameAGW2entitiesforcontrolplane:eNB&MME(S1-MMEinterface)eNB:UMTSNodeBplusUMTSRNC(RRC,RadioBearerManagement…)MME:UMTSMMandSMfunctions2entitiesforuserplane:eNB&SAEGW(S1-Uinterface)eNB:UMTSNodeBplusUMTSRNC(PDCP/RLC/MAC…)SAEGTW:(ServingGateway)UMTSpacketcoreuserplaneNoMacro-diversity15FunctionalMapping(fromTR25.813)MMEFunctionsIdlemodemobilityTrackingareaupdateMaintenanceofequivalenttrackingareasIdlemodeaccessrestrictionsSecurityKeymanagementS1connectionestablishmentIdletoactivemodetransitionSessionmanagementRABandQoSS1handlingduringHOSAEGWradiorelatedfunctionalityIdleS1GTPbearerendpoint

QoShandling&tunnelmgtS1pathswitchduringHandover16FunctionalMapping(fromTR25.813)

LTEfunctionsineNode-B

SelectionofaGWatUEattachmentRoutingtowardsaGWatUEinitialaccessNASmessagingencapsulatedbyRRCfortxoverradioSchedulingandtransmissionofpagingmessagesSchedulingandtransmissionofSystemInformationDynamicallocationofresourcestoUEsinbothULandDLConfigurationandprovisionofeNBmeasurementsRadioBearerControlRadioAdmissionControlAccessrestrictionsinActivestateConnectionMobilityControlinLTE_ACTIVEstateActivemodeHandoverhandlingRRC,headercompression,encryption,RLC,MAC,PHYSecurityofUserplaneandRRCEncryptionofbothinPDCP,integritycheckofRRCSchedulingandassociatedQoShandling17RRMFunctions(1/3)Inter-CellInterferenceCoordination(ICIC):Managingtheradioresources(notablytheradioresourceblocks)suchthatinter-cellinterferenceiskeptundercontrolLoadBalancing(LB):InfluencethetrafficloaddistributioninsuchamannerthatradioresourcesremainhighlyutilizedandtheQoSofin-progresssessionsaremaintainedtothepossibleextent(mayresultinhandoverdecisions)Inter-RATRadioResourceManagement:Inconnectionwithinter-RATmobility(takingintoaccounttheinvolvedRATresourcesituation,UEcapabilities&operatorpolicies)18RRMFunctions(2/3)ConnectionMobilityControl(CMC):ManagementofradioresourcesinconnectionwithidleoractivemodeMobilityofradioconnections:handoverdecisionsbasedonUE&e-NodeBmeasurements+potentially:neighbourcellload,trafficdistribution,transport&HWresources&operatordefinedpoliciesRadioBearerControl(RBC):Establishment,maintenance&releaseofRadioBearersTakingintoaccountoverallresourcesituation,QoSrequirementsofin-progresssessionsandofthenewservice)RadioAdmissionControl(RAC):Admitorrejecttheestablishmentrequestsfornewradiobearers(takingintoaccountoverallresourcesituation,QoSrequirements&prioritylevels)19RRMFunctions(3/3)PacketScheduling(PSC)Allocate/De-allocateresources(includingbuffer,processingresources&resourceblocks)toUP&CPpacketsincluding:SelectionofRB,whosepacketsaretobescheduledManagingthenecessaryresources(e.g.powerlevels,specificresourceblocks)20LTEARCHITECTURE–ControlPlaneLayoutoverS1UEeNode-BMME21LTEARCHITECTURE–ControlPlaneLayoutoverS1UEeNode-BMMERRCsub-layerperforms:BroadcastingPagingConnectionMgtRadiobearercontrolMobilityfunctionsUEmeasurementreporting&controlPDCPsub-layerperforms:Integrityprotection&cipheringNASsub-layerperforms:AuthenticationSecuritycontrolIdlemodemobilityhandlingIdlemodepagingorigination22LTEARCHITECTURE–UserPlaneLayoutoverS1UEeNode-BMMESAEGateway23LTEARCHITECTURE–UserPlaneLayoutoverS1UEeNode-BMMESAEGatewayRLCsub-layerperforms:TransferringupperlayerPDUsIn-sequencedeliveryofPDUsNoerrorcorrectionthroughARQDuplicatedetectionFlowcontrolConcatenation/re-assemblyofpacketsPDCPsub-layerperforms:HeadercompressionCipheringMACsub-layerperforms:SchedulingErrorcorrectionthroughHARQPriorityhandlingacrossUEs&logicalchannelsIn-sequencedeliveryofRLCPDUsMultiplexing/de-multiplexingofRLCradiobearersinto/fromPhCHsonTrCHsPhysicalsub-layerperforms:DL:ODFMA,UL:SC-FDMAHARQULpowercontrolMulti-streamtransmission&reception(i.e.MIMO)24FromUEPower-uptoActiveConnectionAcquisitionPower-upIdleAccessRegistrationTrafficLTENetworkFrequency/Timingacquisitionp-SCH,s-SCH&ReferenceSignalCellIddeterminationCellsearchprocedureSIBmessageCCPCH/PDSCHMessagefromUE(origination,registration,…)PRACH/PUSCHRegistrationprocedurePDSCH/PUSCHDLtrafficPDSCHULtrafficPUSCH253.LTEKeyTechnologies26InnovativeTechnologiesEmerginginStandards1stCommerciallaunches20082007Beyond20062009

3GLTEAll-IPOFDMMIMOAASWiMAX802.16mAll-IP

OFDMMIMOWiMAX802.16e-2005All-IPOFDMMIMOAASAASCDMA2000EV-DORev.AIPtransport

EV-DORev.CAll-IPOFDMMIMOAASHSDPA/HSUPAIPTransportHSPA+MIMOAll-IPOFDM,All-IP,MIMO&AASarethekeycornerstonesofnew&futurewirelessstandards27KeyLTEFeaturestoOvercomeChallengesOFDMAIncreasedspectralefficiencySimplifiedRxdesignCheaperUEScalable-Gobeyond5MHzlimitationMIMO:antennatechnologyMultiple-input,multiple-outputOvercomemulti-pathinterferencePeakratebreakthroughIPCore:flat,scalableLowlatency:10ms(60msforHSPA)ShortTTI:1ms(2msforHSPA)BackhaulbasedonIP/MPLStransportFitswithIMS,VoIP,SIPMobileLocalFixedUMTS/HSDPACDMA/EVDOWiMAX16e802.11,MeshWiMAX16dDSL/CablePSTNInternetCorporatePOTSIPEthernetOFDMMIMOMobilityAccessIMSVoIPSIPCoreSISO,10Mbps/5MHzMIMO2x2,20Mbps/5MHz16QAM28WhyOFDMA?SuitableforMIMOimplementationEaseTime&FrequencyschedulingLessreceivercomplexityRobusttofrequency-selectivefadingRobusttoInter-SymbolInterference(i.e.ISI)HighdataratestMobileenvironmentt+ISItMulti-pathHighdelayspreadShortsymboldurationHigh-ordermodulationsLowinter-symboldistance29FrequencyOFDMAPrincipleSub-carrierspacing=ΔfPowerTimeN-OFDMSymboldurationBandwidthUser#1User#2User#3User#430LTEAccessTechnologiesOFDMeNode-BLTEUEOFDMAOFDMASC-FDMASC-FDMAFDDULBdwDLBdwFrequenceduplexTDDTimeduplexTimeDLslotULslot……Frame31UMTSLTESC-FDMATransmitter/receiver32OFDMAdvantages&DrawbacksAdvantagesCaneasilyadapttoseverechannelconditionswithoutcomplexequalizationRobustagainstnarrow-bandco-channelinterferenceRobustagainstIntersymbolinterference(ISI)andfadingHighspectralefficiencyEfficientimplementationusingFFTLowsensitivitytotimesynchronizationerrorsTunedsub-channelreceiverfiltersarenotrequired(unliketraditionalFDM)FacilitatesSingleFrequencyNetworksDrawbacksSensitivetoDopplershiftandtofrequencysynchronizationproblemsHighPeak-to-AveragePowerRatio33MIMOPrincipleTransmissionOfseveralindependentdatastreamsinparallelOveruncorrelatedantennas(i.e.separatedby10)ReceptionOverNTxxNRx(ideally)uncorrelatedpathsTheoreticalmaximumrateincreasefactor=Min(NTx,NRx)Inarichscatteringenvironment;nogaininLOSenvironmentPracticalgaininurbanareas=1.2to1.5for2x2MIMOBoostingcapacity(DLandUL)andpeakburstrate(DL),SensitivetoSINR34MIMOin3GPPRel’8InDL:1,2or4TXantennasand1,2or4RXantennasAllowingmulti-layertransmissionswithuptofourstreamsMU-MIMO:allocation

ofdifferentstreamstodifferentusersMU-MIMOSU-MIMOInUL:onlyMU-MIMOnoSU-MIMOChoiceforMIMOmodeattheNodeBsideRestrictedbytheUEcapability(e.g.numberofRXantennas)Adaptedslowly(e.g.onceinacom,oreveryxipleof100ms)Rankadaptation(and/orantennasubsetselection)issupportedforevaluationThenumberofcodewordstransmittedtoaUEiscontrolledthroughrankadaptationMU-MIMOtoaUEisdeterminedeitherdynamicallyorsemi-staticallyCandidatesfortheUEfeedbackinformationMIMOchannelstateinformationChannelqualityindicator(CQI),whichmaybeusedbytheNodeBtodecideaMCSlevel(s).35Combining

Rxpackets

Hybrid-ARQPrinciplePackettransmissionH-ARQACKH-ARQRe-TxH-ARQNACKRLCACKServing

RNCNode-BUEPackettransmissionRLCRe-TransmissionRLCNACKRLCACKServing

RNCNode-BUER99onaDCHchannel

Theerroneousblockisdeleted!R5onthe

HS-DSCHchannel

TheerroneousblockisstoredforrecombinationCombining

RxpacketsPackettransmissionH-ARQACKH-ARQRe-TxH-ARQNACKeNode-BUELTEH-ARQ

TheRTTisshorterduetoeNode-Bconcentration36LTERRCStatesRRC_Idle(Idlestate)RRC_CONNECTED(activestate)RRC_NULL(detachedstate)Activeconnection(i.e.traffic)InactivityDe-registration/PLMNchangeRegistrationPeriodicTAUpdatetime-outTraffic/HO

Cellre-selectionPagingTAupdateNoMMcontextofUEineNB/Corenetwork374.LTETDDCharacteristics38TD-LTEEmergingfromtheFDDShadowTD-LTEwasakeypartofoverallLTEstandardtopreventrepeatof3GTDDfailureAlignmentachievedtobothEuropeTDDandChinaTD-SCDMA,achievedtoensureeasyevolutionandspectrumaccessStandard/LSTI:thoughTD-LTEstandardstartedlaterthanLTEFDD,ChinaMobilehassuccessfullyacceleratedtheTDDIOTtimelinetobeinlinewithFDDTD-LTEledbyChinaMobileTD-LTEisanimportantpartof“NextGenerationBBWirelessNetwork”identifiedbystateM&LProjects,whichisalignedwithChina’sInnovationPolicytobe“InnovationCountry”CMCCdrivingTD-LTEasitsnextgenerationbroadbandwireless-IPnetworktoreplaceGSMandTD-SCDMAandcompetewithWCDMA/LTEFDDoperatorsUniqueGlobalAlignmentVodafone,CMCC,VerizonhaveajointagreementtopromotethesuccessofTD-LTEUnitedtodrivesuccessofecosystemOtheroperatorgroupsaskingforRFxandTrialstoevaluate

TD-LTEtoallowuseofunusedspectrumassets39

CommonalitiesbetweenTD-LTEandLTEFDDTheLTEinfrastructureincludes…Terminal,eNB,MME,PCRF,sGWandPDNGWTD-LTEandLTEFDDaremainlydifferentbydedicatedrealizationofphysicallayerHence,theyareinvisibletothehigherlayers(exceptforparameterconfigurations).TheMME,PCRFandxGWarevirtuallyidenticalforFDDandTDDsystemsDifferencesareineNBandterminalswithrespecttoFDDandTDDduetothedifferenceinairinterfacedesign/physicallayer.Therefore,itisbeneficialtoexploitthissimilaritytobuildonesystemthatcansupportFDDand/orTDD.MMEPCRFSGWPDNGW40MainDifferencesbetweenTD-LTEandLTEFDDSummary

TD-LTEneedstosupportvariousTDDUL/DLallocations&needstosupportcoexistencewithotherTDDsystemsResultingTD-LTEdifferencesFramestructure(3GPPTS36.300/TS36.211)Introductionof“framestructure2”forTD-LTEIntroductionofspecialsubframeforswitchingfromDLtoULandcoexistencewithotherTDDsystemsSysteminformationCellbroadcaststheTDDUL/DLconfigurationinformationRandomAccessAdditionalshortrandomaccessformatforspecialsubframe/UpPTSMultiplerandomaccesschannelsinasubframeULmultiTTIschedulingMulti-subframeschedulingforULForheavyULconfigurationstosaveDLcontroloverheadACK/NACKbundling/multiplexingonULcontrolchannelForheavyDLconfigurationstosaveULcontroloverheadH-ARQprocessnumber&timingVariablenumberofH-ARQprocessesdependingontheUL/DLallocationPowercontroltimingSRSconfigurationDifferentTD-LTEspectrumallocation(3GPPTS36.101)41LTERadioFrameStructureTwotypesofradioframeType1ApplicabletobothFDDandTDDType2ApplicabletoTDDonlyDwPTS:PilotforDLUpPTS:Specialuplinktimeslot42TD-LTEFrameStructure-UplinkandDownlinkConfiguration–3GPPTS36.211Configuration1issupportedinfirstrelease.Configuration2isplannedinTLA2.1(2010Q2).43H-ARQUnlikeFDD,wherethenumberofHARQprocessesisalways8,inTDDthenumberofHARQprocesesdependsonth