Gsm呼叫流程(基本)

GSM呼叫流程目的和内容目的介绍GSM正常的呼叫流程（空中接口、A-bis接口和A接口）内容GSM网络协议介绍无线链路建立流程（RadioandLinkEstablishmentProcedure）TCH正常分配流程（NormalAssignmentProcedure）主叫流程（OriginatingCall）被叫流程（TerminatingCall）位置更新流程（LocationUpdating）切换流程（HandoverProcedure）呼叫释放流程（CallReleaseProcedure）信道释放流程（ChannelReleaseProcedure）GSM协议层数无线网络优化主要关心第三层的信令无线网络优化主要关心DTAP、RSL的信令无线网络优化主要关心DTAP、BSSMAP和部分SCCP的信令DTAPRSLOMLGSM网络协议GSM网络协议信令解码介绍信令流程的主要阶段信令流程的主要阶段信令信道(SDCCH)建立阶段鉴权,身份识别,加密阶段(OPTION)业务信道建立阶段振铃,通话阶段释放阶段切换(OPTION)Layer3介绍RR:无线资源管理（RadioResourceManagement）由MS、BTS和BSC控制功能举例Paging管理（PagingManagement）加密管理（CipheredModeManagement）频点分配（FrequencyRedefinition）信道分配（DedicatedChannelAssignment）切换（HandoverManagement）测量和功率控制（MeasuresandPowerControl）MM:移动性管理（MobilityManagement）由MS和MSC/VLR控制功能举例鉴权和身份识别（Authentication/IdentificationProcedures）位置更新（LocationUpdating）IMSIAttach/DetachGSM网络协议CC:呼叫控制（CallControl）由MS和MSC控制功能举例呼叫处理和路由（Callprocessingandrouting）双音多频（DTMFFacilities）短消息服务（ShortMessageService）附加服务（SupplementaryService）GSM网络协议定义手机与网络间建立一个无线链路，用于信令传送包括以下四个步骤Paging过程（PagingProcedure）（仅用于被叫流程中）随机接入过程（RandomAccessProcedure）立即分配过程（ImmediateAssignmentProcedure）SCCP联接建立过程（SCCPConnectionEstablishmentProcedure）当手机需要与网络发生联系时，必须要先建立无线链路和A接口的信令连接无线链路建立流程MSBTSBSCMSCChannelRequestChannelRequiredChannelActivation（SD）ChannelActAck（SD）ImmediateAssignmentCommandUIImmAssignment/ImmAssExtST9103ET9103ST3126ET3126ST3101SABM[L3Info]EstInd[L3Info]SCCPConRqrd[L3]SCCPConnConfirmET3101ST9105ET9105UA[L3Info]（RACH）（EstCause，RndNbr）（EstCause，RndNbr，TA）RACH_TA_Filtering（TA，BS/MS_TxPwr-->Max，Chann）空中接口Abis接口A接口（RndNbr随机序列码，TDMAFrameNbr，Chan，TA）（AGCH）同时对两个MS分配SDCCH（SDCCH）无线链路建立流程MSBTSBSCMSCAuthenticationReqCipheringModeCmdAuthenticationReqAuthenticationReqAuthenticationRespAuthenticationRespAuthenticationRespEncryptionCommandCipheringModeCmdCipheringModeCmpCipheringModeCmpCipheringModeCmpTMSIReallocCmdTMSIReallocCmdTMSIReallocCmdTMSIReallocCmpTMSIReallocCmpTMSIReallocCmpAuthenticationCipheringTMSIReallocST3260ET3260*AuthenticationReject*IdentificationIdentificationRequestST3270ET3270IdentificationRequestIdentificationRequestIdentificationResponseIdentificationRespIdentificationResponseST3250ET3250（RAND）（SRES）RAND与Ki经过A3算法得到SRES；经过A8算法得到Kc比较SRES（IMSI）选择加密算法（PermittedAlg，Kc）准备解密接收（Alg，Kc）（Alg（A5算法））开始加密发射和解密接收如正确解密接收，则下条消息加密发射已加密的消息（TMSI）VLR从HLR处得到RAND/SRES/Kc鉴权、身份识别、加密、TMSI重新分配过程定义分配TCH的过程特殊情况排队（Queuing）直接重试（DirectedRetry）TCH分配过程MSBTSBSCMSCChannelActivationTCHSABM(FACCH)ChannelActivationAck.AssignmentCommandAssignmentCommandAssignmentRequestPhysicalContextRequestPhysicalContextConfirmEstablishIndicationUAAssignmentCompleteAssignmentCompleteAssignmentCmpRFChannelRelease(SD)RFChannelReleaseAck.STrr1ETrr1ST9108ET9108ST9103ET9103ST3107ET3107（ChnType，Priority，CIC，DLDTX，QueuingFlag）（TA，MS/BS_TxPwr）（SDCCH）（TA，MS/BS_TxPwr）（MA，TS，HSN，MAIO，MS_TxPwr）占用TCH时，如需传送信令，则通过StealingFlag将TCH转换成FACCH一般情况下，在RF信道释放前都有PhysicalContextReq过程TCH分配过程MSBTSBSCMSCSABM(FACCH)ChannelActivationHOCMDAssignmentRequestPhysicalConReqChan.Act.Ack.HODetectionUAPhys.InfoAssignmentCmpST11ST3103QueuingIndicationET11Atthistime,aTCHbecomefreeTCH拥塞和排队AssignmentRequestST11QueuingIndicationET11AHandoveralarmisraised.AtargetBTSisselectedHOCMDHOAccessST9103ET9103TTSTTEstablishIndicationTTHOCMPTHOCMPST3124ET3124ET3103直接重试如果QueuingInd=True或Queuing_Anyway=True。（当Queuing_Anyway时T11_Forced取代T11TCH分配过程——排队和直接重试主叫过程MSBTSBSCMSCRRConnectionEstablishmentRRConnectionEstablishmentRRConnectionEstablishmentAuthenticationProcedureCipheringProcedureAuthenticationProcedureAuthenticationProcedureCipheringProcedureCipheringProcedureTMSIReallocProcedureTMSIReallocProcedureTMSIReallocProcedureCallProceedingSETUPSETUPSETUPCallProceedingCallProceedingAssignmentProcedureAssignmentProcedureAssignmentProcedure（calledpartynbr）ESTIN(CM_Serv_Req)CM_Serv_Req(CMServiceType)SDCCHAlertingAlertingAlertingConnectConnectConnectConnectAck.ConnectAck.ConnectAck.Speech先建立TCH，再接通B侧信道。Alerting在FACCH上发送TCHCMSERVICEACCEPTCMSERVICEACCEPTCMSERVICEACCEPTCLASSMARKUPDAECLASSMARKCHANGECLASSMARKUPDAEMSBTSBSCMSCCallConfirmedESTIN(PagingResp)RRConnectionEstablishmentRRConnectionEstablishmentRRConnectionEstablishmentAuthenticationProcedureAuthenticationProcedureAuthenticationProcedureCipheringProcedureCipheringProcedureCipheringProcedureTMSIReallocProcedureTMSIReallocProcedureTMSIReallocProcedureSETUPSETUPSETUPCallConfirmedCallConfirmedAssignmentProcedureAssignmentProcedureAssignmentProcedureAlertingAlertingAlertingConnectConnectConnectConnectAck.ConnectAck.ConnectAck.Speech被叫过程只有主叫号码，主叫过程只有被叫号码PagingResponsePagingPagingCommandPagingRequestST3113ET3113PagingGroup的个数（N）：由BS_AG_BLKS_RES和BS_PA_MFRMS决定;MS的PagingGroup=(IMSImod1000)modN;MS只监听自己对应的PagingGroup的PagingReq消息（MSID（TMSI/IMSI），CellID（LAC/LAC+CI））（MSID（TMSI/IMSI），PagingGroup）（MSID（TMSI/IMSI））（最多可同时发4个TMSI）（MobileID，Classmark2，Priority，）（callingpartynbr）被叫过程MSBTSBSCMSCClearCMDESTIN(LocUpReq)RRConnectionEstablishmentRRConnectionEstablishmentRRConnectionEstablishmentAuthenticationProcedureAuthenticationProcedureAuthenticationProcedureCipheringProcedureCipheringProcedureCipheringProcedureTMSIReallocProcedureTMSIReallocProcedureTMSIReallocProcedureLocUpAcceptChannelReleaseDeactivateSACCHDISCReleaseIndicationUARFChReleaseLocUpReqLocUpAcceptLocUpAcceptChannelReleaseRFChReleaseAckClearCMPST3210ET3210（LUType，MSID，LAI，Classmark1，）位置更新过程MSBTSservingBSCMSCBTStargetHOAlarm&CandidateCellChannelActivationChannelActAck.HOCommandHOCommandHOAccessHODetectionSABMEstablishIndUAHandoverCompleteHandoverCompleteHandoverPerformedRFChannelReleaseRFChannelRel.Ack.ST9103ET9103ST3103ST3103ST3105ET3105PhysicalInfoST3124ET3124ST200ET200ST_RCR_ACKET_RCR_ACKPhysContextReqPhysContextConfST9108ET9108MeasReportMeasResult没有PhysicalContReq过程，原信道上的TA不能被沿用到新的信道上测量TA（TA）（TA被采用）在RF信道释放前，有PhysicalContextReq过程InternalInterCell切换过程——异步切换ClearCommand如果带有HO成功则表示切换成功ET3124ST3124ST200ET200ExternalInterCell切换过程——异步切换MSBTSservingBSCservingMSCBTStargetMeasReportMeasResultHOAlarm&CandidateCellChannelActivationChannelActAck.HOCommandHOCommandHOAccessHODetectionSABMEstablishIndUAHandoverCompleteHandoverCompleteHOCompleteRFChannelReleaseRFCh.Rel.Ack.BSCtargetHORequired要求切出HORequest要求切入HORequestAck.HOCommandPhysInformation（SCCPConRequired）（SCCPConConf）.ClearCompleteSCCPReleasedSCCPRel.Cmp.STrr2ETrr2ST_HO_REQ_LostST9103ST9103ST9113ST3103ET3103ST3106ET3106ST8ET8ET9113ET_HO_REQ_LostMSBTSBSCMSCDisconnectDisconnectDisconnectReleaseReleaseReleaseReleaseCompleteReleaseCompleteReleaseComplete手机触发的呼叫释放DisconnectDisconnectDisconnectReleaseReleaseReleaseReleaseCompleteReleaseCompleteReleaseComplete网络触发的呼叫释放呼叫释放过程信道释放时空中接口和A接口的释放过程是同时、独立进行的空中接口的信道释放过程BSC发ChannelRelease消息给手机无线链路