GPRS优化方法、案例培训资料(MOTO)

MotorolaConfidentialProprietary!!!MOTOROLAandtheStylizedMLogoareregisteredintheUSPatent&TrademarkOffice.Allotherproductorservicenamesarethepropertyoftheirrespectiveowners.©Motorola,Inc.2002.中国移动GPRS无线优化课题交流会SolutionCenterGTSSChinaMotorola2019年9月15日星期日MotorolaConfidentialProprietary!Page21.GPRS业务模型分析2019年9月15日星期日MotorolaConfidentialProprietary!Page3MotorolaUSTMViewofUserServicesUSTMconsidersserviceactivityfromtheGPRS/UMTSuser’spointofview:(USTMstandsforUnifiedSimpleTrafficModels)UserApplicationTelecommunicationsNetworkUserApplicationApplicationLevelServiceActivityAtthisleveltheapplicationservicebehaviourisrelativelynetworkimplementationindependent.However,asthetrafficistransportedoverthenetwork,trafficbehaviourwithinthenetworkwilldependonthenetworkimplementationandconfiguration2019年9月15日星期日MotorolaConfidentialProprietary!Page4Example:Application-ProtocolsInteractionAstheapplicationinteractswithdifferentprotocolsinthenetworkimplementation,applicationtrafficbecomespackets.ApplicationApplicationUMTSNetworkUTRANCoreNetworkInternetTCP/IPPacketActivityApplication-levelActivityPacketbehaviourmaybedifferentindifferentprotocollayers,andpartsofthenetwork,i.e:•UTRAN•UMTSCoreNetwork•ExternalPacketDataNetwork•TCP&IPpackets•RLCSDU•Radioframes2019年9月15日星期日MotorolaConfidentialProprietary!Page5LayeredTrafficModellingApproachThetrafficcharacteristicsofaservicecanbeverycomplex.Itisoftendescribedbyalayeredserviceworkloadmodel–dataapplicationmodelinUSTM.ThefollowingisaviewoftheFTPservice:SessionBurst(File)Packetttt2019年9月15日星期日MotorolaConfidentialProprietary!Page6DefinitionofASessionAservicesessionisalogicalentity.Independentoftransmissiondirection.Itisbasicallydescribedastheperiodwhereauserisactivelyusingtheservice.Duringanactiveservicesession,thenetworkmustmaintainconnectivitybetweentheusersinthatsession.ServiceDefinitionofSessionTelephony:Telephonecallduration(difficulttodeterminefinish)FTP:PerioddownloadingfromsingleserverEmail(download):FromconnectingtoemailservertodisconnectionSessionsaredescribedby:•SessionDuration(D)•SessionInter-arrivaltime(I)DIt2019年9月15日星期日MotorolaConfidentialProprietary!Page7DefinitionofABurstServiceExampleofBurstTelephony:Activetalkspurt:TransferofafilebetweenserverclientEmail(download):AfilecontainingsingleemailwithMIMEencodedattachmentsSMS:OnetextmessageBurstsdescribedby:•BurstSize/Duration()•Inter-bursttime(T)TtTheBurstrepresentsablockofrealtrafficthattheapplicationsends/receives.TheBurstistheactivitythatthebearerchannelsinthenetworksee.Formanyservices,aburstequatestothetransferofafileormessage.Theburstisuni-directional(uplinkanddownlinkburstsaredifferent).Note:Burstdurationmaybedrivenbydatasize/linkspeed/load2019年9月15日星期日MotorolaConfidentialProprietary!Page8MoreExamplesofBurstTelephony:SpeechburstsUplinkDownlink:MessageBurstUplinkSpeechsamplesencodedintospeechframes.Whilstoriginatoristalking,speechframeactivitygeneratesthespeechburst.Complex年9月15日星期日MotorolaConfidentialProprietary!Page9AcompleteView–Example:TD-SessiondurationI-Sessioninter-arrivaltime-BurstdurationT-Inter-bursttimeS-PacketsizeA-Packetinter-arrivaltime2019年9月15日星期日MotorolaConfidentialProprietary!Page10PDPContextsAPDPcontextisalogicalpipethatprovidesthetransferofuserdataacrosstheUMTSnetwork.UMTSExternalNetworkApplicationPDPContextApplicationFromeitherend,thePDPcontextwilllooklikeanIPtermination(IPaddress/port)thatoffersagivenlevelofIPQoS(e.g.actsasaDiffServcodepoint).Note:ThePDPcontextdoesnotreallyseetheuserapplication,butonlyseestheIPQoSrequirements.UMTSUserLANPDPExt.IPTETETETEUMTSlookslikeanIProuterRealNetwork=MSModemGGSNUEUERemoteHost2019年9月15日星期日MotorolaConfidentialProprietary!Page11PDPContextsvs.SessionsinUSTMAservicesessionneedsaconnectionacrosstheIPnetworkstooperate.ThusaservicesessionneedsaPDPcontextoverUMTSforitsduration.However,aPDPcontextmayexistbeforeandafteraparticularservicesession.MorethanoneservicesessioncanuseasinglePDPcontext.DifferentservicessessionsmayshareasinglePDPcontext.PDPcontextsmaychangestates(active,standby).Thisistransparenttotheservice.ServiceAsessionsServiceBsessionsPDPContextst2019年9月15日星期日MotorolaConfidentialProprietary!Page12DataCollectionpointsRANCorePDNGbMDTTPCtcpdump/windumpTcptrace/EtherrealNetsenseGiGbConsultantRadComGbLinkAnalysisEnd-to-EndAnalysisPerformanceBenchmarkingtcpdump/windumpTcptrace/EtherrealNetsenseEnd-to-EndAnalysisEndUser(DataandRFStats)K1205GbSnoopGDSScriptsBOTGiLinkAnalysistcpdumpWindumpTcptraceEtherrealNetsenseTCPAnalyzerTEMS2019年9月15日星期日MotorolaConfidentialProprietary!Page13用户数据流与协议栈用户数据(IP包)从终端出发跨过GPRS承载到达因特网,途中进行了大量的协议封装和解封装,传输完成后,在GGSN还原成原来的用户数据(IP包),从GGSN经Gi接口进入因特网,我们选择Gi接口作为用户数据流的侦听和分析点.BSS/PCUSGSN因特网GGSNPPPIPTC