中國(guó)移動(dòng)GPRS無(wú)線優(yōu)化專業(yè)培訓(xùn)資料

中國(guó)移動(dòng)GPRS無(wú)線優(yōu)化課題交流會(huì)SolutionCenterGTSSChinaMotorola1.GPRS業(yè)務(wù)模型分析MotorolaUSTMViewofUserServicesUSTMconsidersserviceactivityfromtheGPRS/UMTSuser’spointofview:(USTMstandsforUnifiedSimpleTrafficModels)UserApplicationTelecommunicationsNetworkUserApplicationApplicationLevelServiceActivityAtthisleveltheapplicationservicebehaviourisrelativelynetworkimplementationindependent.However,asthetrafficistransportedoverthenetwork,trafficbehaviourwithinthenetworkwilldependonthenetworkimplementationandconfigurationExample:Application<->ProtocolsInteractionAstheapplicationinteractswithdifferentprotocolsinthenetworkimplementation,applicationtrafficbecomespackets.ApplicationApplicationUMTSNetworkUTRANCoreNetworkInternetTCP/IPPacketActivityApplication-levelActivityPacketbehaviourmaybedifferentindifferentprotocollayers,andpartsofthenetwork,i.e:UTRANUMTSCoreNetworkExternalPacketDataNetworkTCP&IPpacketsRLCSDURadioframesLayeredTrafficModellingApproachThetrafficcharacteristicsofaservicecanbeverycomplex.Itisoftendescribedbyalayeredserviceworkloadmodel–dataapplicationmodelinUSTM.ThefollowingisaviewoftheFTPservice:SessionBurst(File)PackettttDefinitionofASessionAservicesessionisalogicalentity.Independentoftransmissiondirection.Itisbasicallydescribedastheperiodwhereauserisactivelyusingtheservice.Duringanactiveservicesession,thenetworkmustmaintainconnectivitybetweentheusersinthatsession.Service

DefinitionofSessionTelephony: TelephonecalldurationWWW: Webbrowsingsession(difficulttodeterminefinish)FTP: PerioddownloadingfromsingleserverEmail(download): FromconnectingtoemailservertodisconnectionSessionsaredescribedby:SessionDuration(D)SessionInter-arrivaltime(I)DItDefinitionofABurstService

ExampleofBurstTelephony: ActivetalkspurtWWW: HTTPobjectsinaWWWpagedownloadFTP: Transferofafilebetween

serverclientEmail(download): AfilecontainingsingleemailwithMIMEencodedattachmentsSMS: OnetextmessageBurstsdescribedby:BurstSize/Duration()Inter-bursttime(T)TtTheBurstrepresentsablockofrealtrafficthattheapplicationsends/receives.TheBurstistheactivitythatthebearerchannelsinthenetworksee.Formanyservices,aburstequatestothetransferofafileormessage.Theburstisuni-directional(uplinkanddownlinkburstsaredifferent).Note:Burstdurationmaybedrivenbydatasize/linkspeed/loadMoreExamplesofBurstTelephony:SpeechburstsUplinkDownlinkWWW:FileburstsUplinkDownlinkPageDownloadsSMSMO:MessageBurstUplinkSpeechsamplesencodedintospeechframes.Whilstoriginatoristalking,speechframeactivitygeneratesthespeechburst.ComplexWWWpagesmaycontainmultipleobjectslocatedondifferentservers.DownloadinganobjectisanHTTPrequest/responsetransaction.UnidirectionaltransmissionoftheSMSpacket.AcompleteView–Example:WWWTrafficModelSAWWWApplicationSummary:SessionObjectstDItBurststULDLBurstPacketTD - SessiondurationI - Sessioninter-arrivaltime - BurstdurationT - Inter-bursttimeS - PacketsizeA - Packetinter-arrivaltimePDPContextsAPDPcontextisalogicalpipethatprovidesthetransferofuserdataacrosstheUMTSnetwork.UMTSExternalNetworkApplicationPDPContextApplicationFromeitherend,thePDPcontextwilllooklikeanIPtermination(IPaddress/port)thatoffersagivenlevelofIPQoS(e.g.actsasaDiffServcodepoint).Note:ThePDPcontextdoesnotreallyseetheuserapplication,butonlyseestheIPQoSrequirements.UMTSUserLANPDPExt.IPTETETETEUMTSlookslikeanIProuterRealNetwork=MSModemGGSNUEUERemoteHostPDPContextsvs.SessionsinUSTMAservicesessionneedsaconnectionacrosstheIPnetworkstooperate.ThusaservicesessionneedsaPDPcontextoverUMTSforitsduration.However,aPDPcontextmayexistbeforeandafteraparticularservicesession.MorethanoneservicesessioncanuseasinglePDPcontext.DifferentservicessessionsmayshareasinglePDPcontext.PDPcontextsmaychangestates(active,standby).Thisistransparenttotheservice.ServiceAsessionsServiceBsessionsPDPContextstDataCollectionpointsRANCorePDNGbMDTTPCtcpdump/windumpTcptrace/EtherrealNetsenseGiGbConsultantRadComGbLinkAnalysisEnd-to-EndAnalysisPerformanceBenchmarkingtcpdump/windumpTcptrace/EtherrealNetsenseEnd-to-EndAnalysisEndUser(DataandRFStats)K1205GbSnoopGDSScriptsBOTGiLinkAnalysistcpdumpWindumpTcptraceEtherrealNetsenseTCPAnalyzerTEMS用戶數(shù)據(jù)流與協(xié)議棧用戶數(shù)據(jù)(IP包)從終端出發(fā)跨過(guò)GPRS承載到達(dá)因特網(wǎng),途中進(jìn)行了大量的協(xié)議封裝和解封裝,傳輸完成后,在GGSN還原成原來(lái)的用戶數(shù)據(jù)(IP包),從GGSN經(jīng)Gi接口進(jìn)入因特網(wǎng),我們選擇Gi接口作為用戶數(shù)據(jù)流的偵聽(tīng)和分析點(diǎn).BSS/PCUSGSN因特網(wǎng)GGSNPPPIPTCP/UDPHTTPetc.L2L1IPTCP/UDPHTTPetc.L2L1Gi接口用戶數(shù)據(jù)的封裝WAP數(shù)據(jù)從GGSN出發(fā)封裝到GRE隧道協(xié)議中去WAP網(wǎng)關(guān),WAP網(wǎng)關(guān)作為代理訪問(wèn)服務(wù)站點(diǎn)WWW服務(wù),電子郵件服務(wù)以及其它因特網(wǎng)服務(wù)經(jīng)過(guò)TCP/UDP封裝后,直接進(jìn)入因特網(wǎng)去服務(wù)站點(diǎn)因特網(wǎng)GGSNWapGWGRETCP/UDPwwwserverOtherAppsMailserviceIPTCP/UDP/GREHTTP/WAP/POP3&SMTP/etc.L2L1NetworkTransportApplicationDataLinkPhysical協(xié)議棧與分析內(nèi)容ApplicationPresentationSessionTransportNetworkDataLinkPhysicalApplicationPresentationSessionTransportNetworkDataLinkPhysical封裝后的應(yīng)用層報(bào)文和實(shí)際傳輸?shù)臄?shù)據(jù),如FTPDataApplicationApplication應(yīng)用層報(bào)文(控制消息等),如FTPControl在應(yīng)用層只能看到“應(yīng)用消息”,它被封裝到傳輸層和網(wǎng)絡(luò)層與數(shù)據(jù)一起被傳輸,在應(yīng)用層的話務(wù)量分析沒(méi)有意義.應(yīng)用層做會(huì)話分析,傳輸層做連接分析和話務(wù)分析.傳輸協(xié)議分析應(yīng)用協(xié)議分析應(yīng)用會(huì)話分析傳輸連接分析傳輸流量分析網(wǎng)絡(luò)流量分析分析內(nèi)容分析內(nèi)容CaseStudyin2003fromaEuropeanNetworkDetailedAnalysis–General

TotalFiguresTotalFigures AllSessions +10kByteSessionsTotalTraffic: 440MByte 330MByteDL/ULRatio: 4,75 32,55Sessions: 64778 6936TCPSessions: 80% 100%SessionDuration(Avg): <10s(85%) 1min50secTrafficperTCPSession(Avg): 7,1kB 47kBTrafficperUDPSession(Avg): 1,1kB N/AAverageSegmentSize(DL/UL): 320/N/ABytes 780/330Bytes+10kByteSessionsAllsessionswithmorethan10kBytetrafficindownlinkarecounted.Source:TCPDump/TCPTraceDetailedAnalysis–General

ApplicationUsage(intermofsessions)Source:TCPDump/TCPTraceAllSessions1%~650Sessions+10kBSessions(inDL)1%~70SessionsDetailedAnalysis–General

ApplicationUsage(intermofbytes)Source:TCPDump/TCPTraceAllSessions1%~650Sessions+10kBSessions(inDL)1%~70SessionsDetailedAnalysis–General

TransportProtocolUsageMajorTrafficTCPHTTPEmailSource:TCPDump/TCPTraceUDPWAPDNSBytesSessionsAllSessionsDetailedAnalysis–General

PacketSize(ULandDL)Source:TCPDump/NetSenseAllSessionsDetailedAnalysis–TCPParameterSegmentSizeRequestedAppliedWindowSizeInitial,Avg/StdDev/Min/MaxAppliedSelectiveACKUsageOutofOrderPacketsSource:TCPDump/TCPTraceDetailedAnalysis–TCPParameter

SelectiveAcknowledge/OutofOrder(onGi)Source:TCPDump/TCPTraceSelectiveAcknowledge AllSessions +10kByteSessions(DL)DL: 24% 0,04% UsedinX%oftheTCPSessionsUL: 24% 2% UsedinX%oftheTCPSessionsOutofOrderPacketsDL: 0,16% 2,93% TCPSessionswithOoOPacketsUL: 0,07% 0,22% TCPSessionswithOoOPacketsConclusion&RecommendationsSystemOptimisationHW/SWDimensioningFeaturePriorizationConclusion&Recommendations

SystemOptimisationShortSessions-GeneralHTTP1.1isusedCausesLowThroughputLowSACKusageforlargetransfers3%outoforderpacketforlargetransfersonGi!Recommendation:TCPStackTuningProxySelectiveACK,RetransmissionsTCPClientWindowSizeTuning(viaDriverInstallation?)ImportantforCS3-4FurtherAnalysison?Whysomanyshort(HTTP)sessions?“Conclusion&RecommendationsHardware/SoftwareDimensioningSegmentSize+60%ofpacketsare+500BytesRecommendation:MaximumLLClengthoptimisation(Max.Improvement~1%)HardwareDimensioningTrafficDistribution,BusyHour@2pmwith1/3aboveminimumConclusion&RecommendationsFeaturePriorizationSessionDurationSessionsaremainlyveryshortRecommendation:OverlappingTBFandRapidInterleavingareveryimportantSessionIntervalTypicallybelow5seconds.ShowsbenefitofSuper-CoattailRecommendation:SCTParametersaresetwellConclusion&RecommendationsFeaturePriorizationApplicationUsage97%ofthetrafficisTCPUDPtrafficisWAP(isconnectionoriented)andDNSRecommendation:LLCAcknowledgementnotnecessary案例：引入新應(yīng)用(PushtoTalk)CaseStudyFive-Introductionofnewapplication&understandingitsimpactCustomTelemetryapplicationwasmodelledandsimulatedbyGSMS8GPRSTimeslotswereconsideredpercell250,500&750usersinacellweresimulated250Users500Users750UsersNewChallengeswithPTToverGPRSPTTisthefirstalways-onapplicationtobedeployedoverGPRSNetworkPDPcontextisalwaysonandTBFissetupduringconversations–couldbeacapacityconstraintRequirementsonGPRSNetworkMinimallatencyOptimalbandwidthtosupportPTTtrafficCellReselection&RoutingAreaUpdatedelaysshouldbeminimalUplink/downlinkTBFreleasedurationshouldbeoptimal,toenablePTTconversationtousethesameTBFandavoidsettingupanewTBF,forevery‘push’OptimiseSGSNReadyTimerValueInSTANDBYnodatareceptionispossible.TogetbacktoREADYstate,themobileneedstobepaged,thusincreasingtheset-uptime,forthefirstpush.Benefit:ByincreasingtheReadyTimerontheSGSN,themobilesstaylongerinREADYstate.Drawback:IncreasedreadytimerincreasesthenumberGMMsignalingmessagesandcauseshigherbatteryconsumption.STANDBYIDLEREADYGPRSattachGPRSdetachREADYtimerexpiryorforcedtoSTANDBYPDUtrans-missionOptimiseduseofPBCCH/PCCHfeaturePBCCH/PCCCHprovidesmoresignallingcapabilitiesforbothGSMvoiceandGPRSservicebymovingallGPRSsignallingontothePBCCH/PCCCH.ItreducesinternalsignallingtrafficovertheGSLandRSLsincetherearefewerrequests,assignmentsorpagingmessagesoverGSLandRSL.ThisisduetoGPRSsignallingtrafficshallbecarriedovertheTRAUGDSOptimiseduseofPBCCH/PCCHfeatureBenefitsforPTTIncreasedsignallingcapacitytosupportPTTtypeapplicationSeparatedsignallingforGPRS(PTT)andGSMFasterpagingShorterTBFset-uptimesinheavilyloadednetworks(cells)comparedtothesituationwithoutthePBCCH/CCCHfeature.DrawbacksByreservingatimeslotforaPBCCH/PCCCH,capacitywillbelostforGPRS,thoughitshouldbenotedthataPBCCH/PCCCHtimeslotmaystillbeusedforuserdata(onlyPPCH&PAGCHi.e.downlink,nouplink).IfacellisRACboundary,theresourceonthecellwillbeusedforlocationareaupdatesandsoleavelessresourceforuserdata.NotallexistingGPRSMSssupportPBCCHandtheseMSswontbeabletoattachwhenPBCCHispresentinthecellOptimisingDRXtimerThegprs_drx_timer_maxparametercontrolshowlongthemobilestationstaysinnon-DRXmode,whenithasleftthepackettransfermodeandentersthepacketidlemode.Themaximumvalueofthisparameteris3seconds.BenefitforPTTDecreasingset-uptimesforconsecutive“pushes”,whendonewithin3seconds(orwhateverdurationisset)afterlastdatatransmission/reception.DrawbackOptimizingthenon-DRXtimerisimportanttoincreaseMSbatterylifetimeOnePhaseaccessOnePhaseaccessisrecommendedforGPRSNetworktoreduceTBFset-uptimes,thisworkswellforlightlyloadednetwork.Foracongestednetwork,thismayresultintoRSLcongestion.ToavoidusingtheRSLtonotifythePCUofanaccess,theBTSforcesthemobiletoperformatwo-phaseaccess,withthemobilesendingaPRRonthereservedblock.SincethisreservedblockisonaPDCH,thissignallingiscarriedoutonGPRSTRAUandnottheRSL,therebyreducingRSLload.(ThisrequiresthatuplinkblocksarereservedforonlyPACKETRESOURCEREQUESTS)ByreservingblocksforPRRsandforcingtwophasepacketaccessRSLcongestionisreduced,butthetradeoffisthattwophasepacketaccessresultsinamuchslowerTBFestablishmenttimethanbothonephaseandenhancedonephase.PTTPerformanceEnhancementGPRS網(wǎng)絡(luò)無(wú)線優(yōu)化原則及案例分析GPRS網(wǎng)絡(luò)結(jié)構(gòu)無(wú)線環(huán)境核心網(wǎng)SGSNGi頻率計(jì)劃UmConf天線PCUPIXDNSCom-HubGGSNGnGb網(wǎng)管系統(tǒng)數(shù)據(jù)鏈路DHCPNTPOMC-ROMC-GNTOMC-GUnixISSGPRS優(yōu)化所涉及的網(wǎng)絡(luò)單元GrFRAME協(xié)議族路由協(xié)議隧道協(xié)議FRLLC/MACTCP/IPGsAirIPCircuit載干比吞吐量誤碼率延遲傳輸速率NetworkCMCC主要統(tǒng)計(jì)重傳率CS比率無(wú)線參數(shù)時(shí)鐘

終端應(yīng)用測(cè)試路測(cè)數(shù)據(jù)GPRS優(yōu)化所涉及的改善指標(biāo)GPRS的優(yōu)化方式SnifferHP37907接口測(cè)試MDTT手段工具路測(cè)CTPSwordFishgNPMTcpdump/Tcptrace終端用戶測(cè)試性能測(cè)試IP包監(jiān)測(cè)數(shù)據(jù)庫(kù)審計(jì)應(yīng)用層傳輸層MSPCUBTSBSCCorporate

VPNWAP

GatewayRadiusDHCPDNSFRBillingLIANSGSNGGSNISSIOSGPRS測(cè)試環(huán)境MaxisIntranetAntennaInternetGGSN100bTHub"Radius-Server"(Solaris)BenchmarkServer(Solaris)RSM1RSM2CommHubGn-Desktop(Win2000)SGSNHP37907PCUVLAN20GnLaptop-Testexecution(Win2000)Laptop-MDTT(Win2000)VLAN10GGSN-GiVLAN30WANBorderRouterGi-Trace:Tool:tcpdumpBmServer-Logs/Trace:Tool:tcpdump

log-filesGn-Trace:Tool:windumpSGSN-Logs:Tool:log-filesGb-Trace:Tool:HP37907PCU-Logs:Tool:PCU-LogsMS-Logs/Trace:Tool:log-file

CommView

Perf.MonitorMDTT-Logs:Tool:MDTTMobileOMC-RCallTrace-Logs:Tool:IOSCTP設(shè)備鏈路測(cè)試鏈路GPRS

無(wú)線優(yōu)化原則—數(shù)據(jù)分析E2E性能—通過(guò)DT/CQT對(duì)終端性能分析，包括：Attachsuccessrate;PDPactivesuccessrate;RAUsuccessrate;CSusage;Cellreselect;Networklatency,throughput,bandwith;BLERGPRS

無(wú)線優(yōu)化原則—數(shù)據(jù)分析統(tǒng)計(jì)方向系統(tǒng)容量分析

PCU/PRPload分析；

熱點(diǎn)地區(qū)GPRS時(shí)隙分配；

Switch時(shí)隙對(duì)GSM影響；上下行吞吐量分析；BLER分析；擁塞分析；各信令層丟包分析；GPRS

無(wú)線優(yōu)化原則—數(shù)據(jù)分析硬件告警分析PCU，RXCDR，BSC，BTS，TCU告警分析；傳輸信令告警；天饋線系統(tǒng)；

GPRS

無(wú)線優(yōu)化原則—數(shù)據(jù)分析數(shù)據(jù)庫(kù)分析功率控制分析；小區(qū)重選分析；鄰區(qū)拓?fù)浣Y(jié)構(gòu)分析；GPRS接入及信令Timer;GPRS

無(wú)線優(yōu)化原則—數(shù)據(jù)分析無(wú)線環(huán)境分析上下行質(zhì)量分布；上下行電平分布；C/I分布；Pathbalance分布；TA分布；GPRS

無(wú)線優(yōu)化原則—問(wèn)題總結(jié)系統(tǒng)問(wèn)題總結(jié)系統(tǒng)硬件告警及問(wèn)題頻率干擾問(wèn)題覆蓋問(wèn)題數(shù)據(jù)庫(kù)問(wèn)題信令配合系統(tǒng)資源問(wèn)題GPRS

無(wú)線優(yōu)化原則—問(wèn)題處理無(wú)線環(huán)境優(yōu)化系統(tǒng)C/I、BLER分析頻率調(diào)整覆蓋/天線調(diào)整相鄰小區(qū)優(yōu)化GPRS

無(wú)線優(yōu)化原則—問(wèn)題處理系統(tǒng)容量與負(fù)荷分析PDCH擁塞跟蹤及處理；GBL信令鏈路穩(wěn)定性跟蹤及處理；GBL帶寬及配置優(yōu)化；GSL負(fù)荷分析；熱點(diǎn)區(qū)域負(fù)荷分析；核心網(wǎng)容量規(guī)模，區(qū)域UDBI、USPU負(fù)荷趨勢(shì)

GPRS

無(wú)線優(yōu)化原則—問(wèn)題處理數(shù)據(jù)庫(kù)參數(shù)調(diào)整針對(duì)小區(qū)重選，C1/C2調(diào)整GPRS接入定時(shí)器計(jì)數(shù)器調(diào)整；GPRS釋放定時(shí)器調(diào)整；Gb及小區(qū)GPRS容量調(diào)整；功率控制調(diào)整，功率控制窗及快慢；GPRS

無(wú)線優(yōu)化原則—問(wèn)題處理GPRS功能問(wèn)題排查GPRS附著過(guò)程GPRS激活過(guò)程；路由區(qū)域更新過(guò)程；異地漫游；P-TMSI重新分配；認(rèn)證與加密過(guò)程；識(shí)別過(guò)程；尋呼過(guò)程；GPRS

無(wú)線優(yōu)化重點(diǎn)GPRS無(wú)線網(wǎng)絡(luò)調(diào)整，包含無(wú)線資源管理的配置以避免擁塞、載干比優(yōu)化、在不同編碼方式下(CS1,CS2)的覆蓋優(yōu)化等.

1根據(jù)GPRS數(shù)據(jù)用戶的實(shí)際分布，調(diào)整無(wú)線接入網(wǎng)的參數(shù)和GPRS小區(qū)切換調(diào)整。PCU數(shù)據(jù)庫(kù)參數(shù)、Gb接口配置參數(shù)的優(yōu)化。解決系統(tǒng)瓶頸，保證GPRS的提供，重點(diǎn)區(qū)域的數(shù)據(jù)業(yè)務(wù)質(zhì)量應(yīng)作為目前優(yōu)化的重點(diǎn).

2

3

4GPRS網(wǎng)絡(luò)無(wú)線優(yōu)化實(shí)例優(yōu)化實(shí)施實(shí)例—統(tǒng)計(jì)項(xiàng)使用GBLPlanning/TrafficVolumeCalculationGBL_<UL/DL>_DATA_THRPUT_HIST

everye.g.5secondsthePCUgeneratesasnapshot.ThecounteroftheappropriateBINisincremented.However,atthemomenttheBINsexistonlyPCUinternallyandonlytheMean/MaxarereportedtotheOMC.TheMean/Maxvaluesarecomputedbasedonthesamplesgenerated.

Usedto(assoonasBINsareavailableontheOMC–in16.50.f)seethenormaldistributionwithinthelaststatisticinterval(e.g.30min).IncasetheGbtrafficisveryburstytheMeanmightbemisleadingandshownmuchlowervaluesasperiodswithverylowtrafficareconsideredaswell.However,theGbmustcopewiththemeaninbusyperiodsandnotwiththeaverageacrossthe30min.peggingperiod.GBL_<UL/DL>_DATA_THRPUT

thehistorystatsgetonlyasampleseverye.g.5seconds.ThisstatsusesthesampleswithinthisintervalaswellandcalculatestheMean/Max/Minvalues.

Usedto

getaclearpictureoftherealMean/MaxthroughputontheGblink優(yōu)化實(shí)施實(shí)例—統(tǒng)計(jì)項(xiàng)使用PlanningGPRS_32k_channels_switched,GPRS_channels_switched

eachswitchcosts<800msthatthetimeslotisnotavailableforCSanPS.However,iftheQoS(CSSR,DCR)isn‘treducedletthealgorithmwork.Ifreducedtrytoincreasegprs_reconfig_thresh_idle_tch.Thisdoesn‘treducetheswitchingnumberbutitgivesthesoftwaremoretimetoreact(doesreducePDCHbandwidth).Gbl_Paging_Reqs

howmanypercentofallthepaginggoesthroughtheGPRSnetwork.HowfrequentisthemobilepagedifitisinGPRSactivetransfermode(rightnetworkmodeneedstobeset)MS_Class_<x>_<x>_Req

whatisthecapabilityofthemobilesinthefield.HowmanyPDCHshouldbeequippedtoofferthemax.PerformancetotheuserIMM_Assign_Cause whatforistheAGCHbandwidthused優(yōu)化實(shí)施實(shí)例—統(tǒng)計(jì)項(xiàng)使用PlanningGPRS_access_per_AGCH,_PCH,_RACH

requestingGPRSaccessonAGCHGPRS_pch_agch_q_length

areadditionalchannelsrequiredGPRS_dynet_failures,_res_reqs,_swi_reqs

dynamicallocationofGDSresources(featurenotusedbyMaxis)優(yōu)化實(shí)施實(shí)例—統(tǒng)計(jì)項(xiàng)使用MobilityActivityCell_Flush_Reqs

indicatorforoutgoingcellreselections.

Whatfor?Microcellandmovingmobilesarehandedin?Gprs_cell_reselection_attampt,Gprs_cell_reselection_fail onlyforNC2available.SameuseasinGSMthehandoverstatistic.Gprs_ms_neighbor_strong

networkcontrolledreselectionsduetostrongerneighborandnotduetocongestionCoding_scheme_change

calculatethenumberofCSchangesperTBF(otherstats).AnidealTBFhasonly2CSchanges(CS2=>CS3=>CS4).However,itdoesn‘tmeanthatahighCSchangeratepointstowardsaproblem.The/amobilecouldmoveacrossareaswithdifferentRFconditionsandthenCSchangesarerequired.優(yōu)化實(shí)施實(shí)例—統(tǒng)計(jì)項(xiàng)使用CongestionStatusonCell/PRP<UL/DL>_PDTCH_Q_Length

congestionseverity<UL/DL>_PDTCH_Congestion

howlongisthecellcongested<UL/DL>_PDTCH_Seizure

countsthenumberofTBFs

whatfor?Isoneuser/sessioncausingtheRLCtraffic<UL/DL>_Busy_PDTCH

howmanyPDCHareoccupiedforhowlong(BINsfornumberofPDCHsnotavailableincurrentOMC-R–butinPCU.SameasGBL_<UL/DL>_DATA_THRPUT_HISTstatistic)PRPLoad

howloadedisthePRP優(yōu)化實(shí)施實(shí)例—統(tǒng)計(jì)項(xiàng)使用AvailabilityCell/PCUAvailable_PDTCH

areallequippedcellsavailable?No_PDTCH_Availmin/max/meanTimeGbl_Unavailable

timenotavailableGPRS_32k_<UL/DL>_Not_AvailGbl_Link_Ins

timeGblinservice優(yōu)化實(shí)施實(shí)例—統(tǒng)計(jì)項(xiàng)使用AccessibilityChannel_Req_Recvs.Channel_Req_Rej

channel_req_rejispegedfore.g.IA-Rejectincaseof1PhaseaccessandPR-Reject.

MotorolaBSSdoesn‘tsendIA-Reject(forGPRS)asworkaroundimplementationassomemobilesaren‘tcompliantanddon‘tinterpretthemessageproperly.Thus,IA-Rejectwasremovedfromthecode.

TocomputetherejectrateinGSR6theChannel_Req_Sucstatisticwasaddedtocounttherealrejectrate(received–granted)優(yōu)化實(shí)施實(shí)例—統(tǒng)計(jì)項(xiàng)使用PerformanceTheperformancedoesn‘tonlydependingonRFQuality(thismustbecheckedwithGSMstats–ifTCHsareequippedonthatcell-).Lowcellutilisationcouldbethecase,notproperlyworkingmobiles,mobilityorsomemore)CS12_on_32k_chan

isitworthtokeepthatcarrier32kenabled?Air_<UL/DL>_Data_Blks

computethetransferedbytes,RLCdatathroughput,etc.Air_<UL/DL>_Control_Blks

howefficientarethechannelsused,i.e.percentofcontrolmessages.

TocorrecttheRLCbandwidthandmakeisclosertouserbandwidth優(yōu)化實(shí)施實(shí)例—統(tǒng)計(jì)項(xiàng)使用Gbl_Flow_Ctrl_Sent

flowcontrolmessagesaresentbeforethePCUbuffergetsflooded.Thiscouldbebecausetheairleakrateisreducedforthatmobile/cellorthedataratereceivedfromtheSGSNisincreased.

Whatfor?

Extremelyhighnumbers(againstthehistoryasusual)couldindicateamobileiskickedbackonRLCbandwidth,PDTCHbandwidthreduced,etc.

IDLE_PDTCH_Intf_Band0

samplestakenonIDLEframeforinterferenceband0(samebandsasinGSM)優(yōu)化實(shí)施實(shí)例—Attach信令流程Figure22.Authenticate1.GPRSAttachVLR3.UpdateLocationtoSGSNandVLR4.AttachAcceptHLR1234567890MSBSCSGSNMSC優(yōu)化實(shí)施實(shí)例—Attach信令流程Gs優(yōu)化實(shí)施實(shí)例—PDP激活信令流程Figure61.ActivatePDPContext1234567890MSBSCSGSNGGSNVLRMSCggsna.b.c.d.bj.zjmnc000.mcc460.gprscmnetsgsnsgsnDNSRootDNSDNSAPN:cmnetcmnet.mnc000.mcc460.gprsggsne.f.g.hAPN:cmnetcmnet.mnc000.mcc460.gprs優(yōu)化實(shí)施實(shí)例—PDP激活信令流程GGSNpathtoPDNggsn.bjMnc000.mcc460.gprsbj-DNS1Zj-DNS2cmnetsgsnDNS1RootDNS.zjtestggsna.b.c.dsgsnDNS2APN:test.zjTest.zj.Mnc000.mcc460.gprsTest.zja.b.c.d優(yōu)化實(shí)施實(shí)例—PDP激活信令流程GGSNpathtoPDN優(yōu)化實(shí)施實(shí)例—PDP激活信令流程Figure62.CreatePDPContext1234567890MSBSCSGSNGGSNVLRMSCDHCP–getsIPaddressBSCPCUMS1MS2Loopback154Loopback2WapGateway72MSAPN12CMNETCMWAPVirtualTemplate4GGSNGGSN44DHCPProxy

4

4MsIPaddress

SGSNDHCPServerCMnetInetnetLoopback354Corp3Corp4

優(yōu)化實(shí)施實(shí)例—PDP激活信令流程優(yōu)化實(shí)施實(shí)例—PDP激活信令流程Figure63.ActivatePDPContextAccept1234567890MSBSCSGSNGGSNVLRMSC

SGSNGGSNHLRDNSPDNGrGnGiGbBSSActivePDPContextRequestAPNResolutiontoDNSServerAPNResolutionResult-GGSNVTAddressCreatePDPContextRequestAssignIPtoMSCreatePDPContextResponseActivatePDPContextAccept優(yōu)化實(shí)施實(shí)例—PDP激活信令流程優(yōu)化實(shí)施實(shí)例—GPRS數(shù)據(jù)傳輸流程TLLI+NSAPITID優(yōu)化實(shí)施實(shí)例—PING性能分析PING的信令解析

上行TBF的建立（channelrequest到立即支配IA）上行傳送PCU處理，ULForward到SGSNSGSN處理，及對(duì)方服務(wù)器的響應(yīng)下行傳送MS，OS，COMPUTER的處理及系統(tǒng)接入（RACHACCESS）優(yōu)化實(shí)施實(shí)例—PING性能分析GPRS系統(tǒng)中PING流程優(yōu)化實(shí)施實(shí)例—PING性能分析Motorola系統(tǒng)PING分析

測(cè)試手機(jī)MotorolaT720測(cè)試環(huán)境按照CMCC的測(cè)試規(guī)范，完成間隔8秒，payload為500bytes的共10次Ping。

GSN版本：

BSS版本：1670.ClientOS：WindowsXPServeOS：Linux優(yōu)化實(shí)施實(shí)例—PING性能分析PING測(cè)試時(shí)長(zhǎng)各個(gè)階段時(shí)間分布優(yōu)化實(shí)施實(shí)例—PING性能分析各個(gè)階段標(biāo)準(zhǔn)偏差各個(gè)階段時(shí)間占用比例分析

根據(jù)波動(dòng)性和耗時(shí)比例確定重點(diǎn)問(wèn)題

使沒(méi)步的時(shí)間達(dá)到最短應(yīng)用時(shí)長(zhǎng)

確定影響時(shí)長(zhǎng)的相關(guān)因素優(yōu)化實(shí)施實(shí)例—PING性能分析改善Ping建議RACH接入保證

繁忙小區(qū)RACH碰撞后下次接入時(shí)延—

tx_integer

IA保證AGCH資源—bs_ag_blks_res

PDCH資源分配

?DL/UL_PD_Con_TOT確認(rèn)小區(qū)產(chǎn)生擁塞時(shí)長(zhǎng)

?SDCCH擁塞情況

?IA中LU比重

?Totalcall無(wú)線環(huán)境及系統(tǒng)資源

Rxlev；RxQual；C/I；Gprs_cell_reselection；Gb；PRPLoading。。。優(yōu)化實(shí)例測(cè)試手機(jī)Attach問(wèn)題在使用測(cè)試手機(jī)+MDTT測(cè)試中出現(xiàn)Attach異常的信令流程—手機(jī)在發(fā)出AttachRequest約1秒后MDTT顯示手機(jī)收到DetachAccept消息，而后大約6秒鐘后才收到IdentifyRequest消息，造成Attach時(shí)長(zhǎng)為8秒

從L3層信令流程中看出：DetachAccept消息的接收時(shí)間為14:04:20.406IdentifyRequest消息的接收時(shí)間為14:04:26.715優(yōu)化實(shí)施實(shí)例—終端問(wèn)題舉例測(cè)試手機(jī)Attach問(wèn)題所有手機(jī)接收到的下行L3層的信令消息必然對(duì)應(yīng)著一組時(shí)間與其相對(duì)應(yīng)的RLC/MAC層數(shù)據(jù)包在RLC/MAC層消息中我們可以找到和IdentifyRequest時(shí)間相對(duì)應(yīng)的DownlinkDataBlock，但確無(wú)法找到和DetachAccept相對(duì)應(yīng)的DownlinkDataBlock。由此得出結(jié)論：此問(wèn)題為手機(jī)內(nèi)部錯(cuò)誤造成未響應(yīng)系統(tǒng)第一次

IdentifyRequest消息，而響應(yīng)了第二次IdentifyRequest消息，造成了Attach時(shí)長(zhǎng)長(zhǎng)達(dá)8秒。優(yōu)化實(shí)施實(shí)例—終端問(wèn)題舉例OT96PING問(wèn)題采用集團(tuán)公司新的間隔8秒PING測(cè)試方法，OT96的丟包率為10%—15%。遠(yuǎn)遠(yuǎn)高于其他手機(jī)的相同測(cè)試結(jié)果，及OT96在原有的連續(xù)PING的結(jié)果。PING失敗原因手機(jī)未發(fā)ChannelRequest消息，PING超時(shí)手機(jī)晚發(fā)送ChannelRequest消息，造成PING超時(shí)優(yōu)化實(shí)施實(shí)例—終端問(wèn)題舉例成功PING的手機(jī)信令流程手機(jī)未發(fā)送ChannelRequest消息的信令流程手機(jī)遲8秒發(fā)送ChannelRequest消息的信令流程GPRSQoSFundamentalsQoSintroduction隨著數(shù)據(jù)業(yè)務(wù)發(fā)展,不斷增長(zhǎng)的互聯(lián)網(wǎng)應(yīng)用及其它寬帶需求業(yè)務(wù)(如視頻和音樂(lè))需求的增長(zhǎng),增加帶寬和購(gòu)買更快的設(shè)備開(kāi)銷很大而效率低.單一的QoS級(jí)別是無(wú)法解決不同業(yè)務(wù)的QoS需求的矛盾,它將影響用戶的感受度和多種業(yè)務(wù)的推廣,尤其是那些基于IP的視頻和話音業(yè)務(wù).

QoS提供質(zhì)量是可預(yù)知的,并且是可控的服務(wù).QoS是分段承載的端到端的服務(wù).QoS端到端的分層體系結(jié)構(gòu)QoS的實(shí)施一定是端到端的,參考下圖,我們可以了解到QoS的這種端到端的分層的體系結(jié)構(gòu).

GPRSQoSversionGPRSQoS的版本

GPRSR97/98QoSGPRSR99QoS

GPRSR97/98QoS屬性

服務(wù)優(yōu)先等級(jí)可靠性等級(jí)時(shí)延等級(jí)數(shù)據(jù)吞吐量等級(jí)（平均數(shù)據(jù)吞吐量和峰值數(shù)據(jù)吞吐量）

GPRSQoSversionGPRSR99QoS屬性

Trafficclass('conversational','streaming','interactive','background')

Maximumbitrate(kbps)Guaranteedbitrate(kbps)Deliveryorder(y/n)MaximumSDUsize(octets)SDUformatinformation(bits)SDUerrorratioResidualbiterrorratioDeliveryoferroneousSDUs(y/n/-)Transferdelay(ms)TraffichandlingpriorityAllocation/RetentionPriority不同版本QoS的映射在現(xiàn)網(wǎng)中,MS,SGSN,GGSN和HLR可能支持不同的QoS版本(R97/98或R99),為了互通,在3GPP規(guī)范23.107中定義了不同版本QoS的映射原則.MOTOROLAGSN3.0基于GPRSR99QoS并支持不同QoS版本之間的映射.可能出現(xiàn)的不同版本的QoS互連情景如下表所示:

情景編號(hào)

MSSGSNGGSNIR97/98R99

R97/98IIR97/98R99

R99

IIIR99

R99

R97/98IVR99

R99

R99

R99QoS規(guī)范是基于DiffServ框架,支持會(huì)話級(jí),流級(jí),交互級(jí),和背景級(jí)等QoS級(jí)別以適應(yīng)不同的業(yè)務(wù)性質(zhì)及不同的流量需求.DiffServFundamentalsDifferentiatedServicesArchitecturalModelThedifferentiatedservicesarchitectureisbasedonasimplemodelwheretrafficenteringanetworkisclassifiedandpossiblyconditionedattheboundariesofthenetwork,andassignedtodifferentbehavioraggregates.EachbehavioraggregateisidentifiedbyasingleDScodepoint.Withinthecoreofthenetwork,packetsareforwardedaccordingtotheper-hopbehaviorassociatedwiththeDScodepoint.

DifferentiatedServicesDomainADSdomainisacontiguoussetofDSnodeswhichoperatewithacommonserviceprovisioningpolicyandsetofPHBgroupsimplementedoneachnode.ADSdomainhasawell-definedboundaryconsistingofDSboundarynodeswhichclassifyandpossiblyconditioningresstraffictoensurethatpacketswhichtransitthedomainareappropriatelymarkedtoselectaPHBfromoneofthePHBgroupssupportedwithinthedomain.NodeswithintheDSdomainselecttheforwardingbehaviorforpacketsbasedontheirDScodepoint,mappingthatvaluetooneofthesupportedPHBsusingeithertherecommendedcodepoint->PHBmappingoralocallycustomizedmapping[DSFIELD].DSBoundaryNodesandInteriorNodesBothDSboundarynodesandinteriornodesmustbeabletoapplytheappropriatePHBtopacketsbasedontheDScodepoint.Inaddition,DSboundarynodesmayberequiredtoperformtrafficconditioningfunctionsasdefinedbyatrafficconditioningagreement(TCA)betweentheirDSdomainandthepeeringdomainwhichtheyconnectto.DSIngressNodeandEgressNodeDSboundarynodesactbothasaDSingressnodeandasaDSegressnodefordifferentdirectionsoftraffic.ADSingressnodeisresponsibleforensuringthatthetrafficenteringtheDSdomainconformstoanyTCAbetweenitandtheotherdomaintowhichtheingressnodeisconnected.ADSegressnodemayperformtrafficconditioningfunctionsontrafficforwardedtoadirectlyconnectedpeeringdomain,dependingonthedetailsoftheTCAbetweenthetwodomains.DifferentiatedServicesRegionAdifferentiatedservicesregion(DSRegion)isasetofoneormorecontiguousDSdomains.DSregionsarecapableofsupportingdifferentiatedservicesalongpathswhichspanthedomainswithintheregion.TrafficClassificationandConditioningDifferentiatedservicesareextendedacrossaDSdomainboundarybyestablishingaSLAbetweenanu