Gsm呼叫流程(基本)

1、目的和内容目的和内容t目的p介绍GSM正常的呼叫流程（空中接口、A-bis接口和A接口）t内容pGSM网络协议介绍p无线链路建立流程（Radio and Link Establishment Procedure）pTCH正常分配流程（Normal Assignment Procedure） p主叫流程（Originating Call）p被叫流程（Terminating Call）p位置更新流程（Location Updating）p切换流程（Handover Procedure）p呼叫释放流程（Call Release Procedure）p信道释放流程（Channel Release Pr

2、ocedure）GSMGSM协议协议层数层数无线网络优化主要关心第三层的无线网络优化主要关心第三层的信令信令无线网络优化主要关心无线网络优化主要关心DTAPDTAP、RSLRSL的信令的信令无线网络优化主要关心无线网络优化主要关心DTAPDTAP、BSSMAPBSSMAP和部分和部分SCCPSCCP的信令的信令DTAPRSLOMLGSM网络协议网络协议GSM网络协议网络协议t信令解码介绍信令流程的主要阶段信令流程的主要阶段t信令流程的主要阶段tLayer 3介绍pRR : 无线资源管理（Radio Resource Management）由MS、BTS和BSC控制功能举例 Paging管理（P

3、aging Management） 加密管理（Ciphered Mode Management） 频点分配（Frequency Redefinition） 信道分配（Dedicated Channel Assignment） 切换（Handover Management ） 测量和功率控制（Measures and Power Control）pMM : 移动性管理（Mobility Management）由MS和MSC / VLR控制功能举例 鉴权和身份识别（Authentication / Identification Procedures） 位置更新（Location Updating）

4、 IMSI Attach / DetachGSM网络协议网络协议pCC : 呼叫控制（Call Control）由MS和MSC控制功能举例 呼叫处理和路由（Call processing and routing） 双音多频（DTMF Facilities） 短消息服务（Short Message Service） 附加服务（Supplementary Service）GSM网络协议网络协议t定义p手机与网络间建立一个无线链路，用于信令传送p包括以下四个步骤Paging过程（Paging Procedure）（仅用于被叫流程中）随机接入过程（Random Access Procedure）立即分

5、配过程（Immediate Assignment Procedure）SCCP联接建立过程（SCCP Connection Establishment Procedure） 当手机需要与网络发生联系时，必须要当手机需要与网络发生联系时，必须要先建立无线链路和先建立无线链路和A A接口的信令连接接口的信令连接无线链路建立流程无线链路建立流程MSBTSBSCMSCChannel RequestChannel RequiredChannel Activation（SD）Channel Act Ack （SD）Immediate AssignmentCommandUI Imm Assignment /

6、 Imm Ass ExtST9103ET9103ST3126ET3126ST3101SABM L3 InfoEst Ind L3 InfoSCCP Con Rqrd L3SCCP Conn ConfirmET3101ST9105ET9105UA L3 Info（RACH）（）（Est Cause，Rnd Nbr）（Est Cause，Rnd Nbr，TA）RACH_TA_FilteringRACH_TA_Filtering（TA，BS/MS_TxPwr -Max，Chann）空中接口空中接口AbisAbis接口接口A A接口接口（Rnd Nbr随机序列码随机序列码，TDMA Frame Nbr

7、，Chan ，TA）（AGCH）同时对两个同时对两个MSMS分配分配SDCCHSDCCH（SDCCH）无线链路建立流程无线链路建立流程MSBTSBSCMSCAuthentication ReqCiphering Mode CmdAuthentication ReqAuthentication ReqAuthentication RespAuthentication RespAuthentication RespEncryption CommandCiphering Mode CmdCiphering Mode CmpCiphering Mode CmpCiphering Mode CmpTMS

8、I Realloc CmdTMSI Realloc CmdTMSI Realloc CmdTMSI Realloc CmpTMSI Realloc CmpTMSI Realloc CmpAuthenticationCipheringTMSI ReallocST3260ET3260*Authentication Reject*IdentificationIdentification RequestST3270ET3270Identification RequestIdentification RequestIdentification ResponseIdentification RespIde

9、ntification ResponseST3250ET3250（RAND）（SRES）RANDRAND与与KiKi经过经过A3A3算法算法得到得到SRESSRES；经过经过A8A8算算法得到法得到KcKc比较比较SRESSRES（IMSI）选择加密算法选择加密算法（Permitted Alg，Kc）准备解密接收准备解密接收（Alg，Kc）（Alg（A5算法）算法）开始加开始加密发射密发射和解密和解密接收接收如正确解密接收，则下条如正确解密接收，则下条消息加密发射消息加密发射已加密的消息已加密的消息（TMSI）VLRVLR从从HLRHLR处得处得到到RAND/SRRAND/SRES/KcES/

10、Kc鉴权、身份识别、加密、鉴权、身份识别、加密、TMSI重重新分配过程新分配过程t定义p分配TCH的过程p特殊情况排队（Queuing）直接重试（Directed Retry）TCH分配过程分配过程MSBTSBSCMSCChannel Activation TCHSABM (FACCH)Channel Activation Ack.Assignment CommandAssignment CommandAssignment RequestPhysical Context RequestPhysical Context ConfirmEstablish IndicationUAAssignmen

11、t CompleteAssignment CompleteAssignment CmpRF Channel Release (SD)RF Channel Release Ack.STrr1ETrr1ST9108ET9108ST9103ET9103ST3107ET3107（Chn Type，Priority，CIC，DL DTX，Queuing Flag）（TA，MS/BS_TxPwr）（SDCCH）（TA，MS/BS_TxPwr）（MA，TS，HSN，MAIO，MS_TxPwr）占用占用TCHTCH时，如需传送信令，则通过时，如需传送信令，则通过Stealing FlagStealing Fl

12、ag将将TCHTCH转换成转换成FACCHFACCH一般情况下，在一般情况下，在RFRF信道释放前都有信道释放前都有Physical Context ReqPhysical Context Req过程过程TCH分配过程分配过程MSBTSBSCMSCSABM (FACCH)Channel ActivationHO CMDAssignment RequestPhysical Con ReqChan. Act. Ack.HO DetectionUAPhys. InfoAssignment CmpST11ST3103Queuing IndicationET11At this time, a TCH b

13、ecome freeTCH拥塞和排队Assignment RequestST11Queuing IndicationET11A Handover alarm is raised. A target BTS is selectedHO CMDHO AccessST9103ET9103TTSTTEstablish IndicationTTHO CMPTHO CMPST3124ET3124ET3103直接重试如果如果Queuing Ind=TrueQueuing Ind=True或或Queuing_Anyway=TrueQueuing_Anyway=True。（。（当当Queuing _Anyway

14、Queuing _Anyway时时T11_ForcedT11_Forced取代取代T11T11TCH分配过程分配过程排队和直接重试排队和直接重试主叫过程主叫过程MSBTSBSCMSCRR Connection EstablishmentRR Connection EstablishmentRR Connection EstablishmentAuthentication ProcedureCiphering ProcedureAuthentication ProcedureAuthentication ProcedureCiphering ProcedureCiphering Procedur

15、eTMSI Realloc ProcedureTMSI Realloc ProcedureTMSI Realloc ProcedureCall ProceedingSETUPSETUPSETUPCall ProceedingCall ProceedingAssignment ProcedureAssignment ProcedureAssignment Procedure（called party nbr）ESTIN (CM_Serv_Req)CM_Serv_Req(CM Service Type)SDCCHAlertingAlertingAlertingConnectConnectConne

16、ctConnect Ack.Connect Ack.Connect Ack.Speech先建立先建立TCHTCH，再再接通接通B B侧信道。侧信道。AlertingAlerting在在FACCHFACCH上发送上发送TCHCM SERVICE ACCEPTCM SERVICE ACCEPTCM SERVICE ACCEPTCLASSMARK UPDAECLASSMARK CHANGECLASSMARK UPDAEMSBTSBSCMSCCall ConfirmedESTIN (Paging Resp)RR Connection EstablishmentRR Connection Establi

17、shmentRR Connection EstablishmentAuthentication ProcedureAuthentication ProcedureAuthentication ProcedureCiphering ProcedureCiphering ProcedureCiphering ProcedureTMSI Realloc ProcedureTMSI Realloc ProcedureTMSI Realloc ProcedureSETUPSETUPSETUPCall ConfirmedCall ConfirmedAssignment ProcedureAssignmen

18、t ProcedureAssignment ProcedureAlertingAlertingAlertingConnectConnectConnectConnect Ack.Connect Ack.Connect Ack.Speech 被叫过程只有主叫号码，主叫过程只有被叫号码Paging ResponsePagingPaging CommandPaging RequestST3113ET3113Paging GroupPaging Group的个数（的个数（N N）：）：由由BS_AG_BLKS_RESBS_AG_BLKS_RES和和BS_PA_MFRMSBS_PA_MFRMS决定决定;

19、;MSMS的的Paging Group = (IMSI mod 1000) mod Paging Group = (IMSI mod 1000) mod N;MSN;MS只监听自己对应的只监听自己对应的Paging GroupPaging Group的的Paging ReqPaging Req消息消息（MS ID（TMSI/IMSI），），Cell ID（LAC/LAC+CI）（MS ID（TMSI/IMSI），），Paging Group）（MS ID（TMSI/IMSI）（最多可同时发最多可同时发4个个TMSI）（Mobile ID，Classmark2，Priority，），）（call

20、ing party nbr）被叫过程被叫过程MSBTSBSCMSCClear CMDESTIN (Loc Up Req)RR Connection EstablishmentRR Connection EstablishmentRR Connection EstablishmentAuthentication ProcedureAuthentication ProcedureAuthentication ProcedureCiphering ProcedureCiphering ProcedureCiphering ProcedureTMSI Realloc ProcedureTMSI Rea

21、lloc ProcedureTMSI Realloc ProcedureLoc Up AcceptChannel ReleaseDeactivate SACCHDISCRelease IndicationUARF Ch ReleaseLoc Up ReqLoc Up AcceptLoc Up AcceptChannel ReleaseRF Ch Release AckClear CMPST3210ET3210（LU Type，MS ID，LAI，Classmark1，），）位置更新过程位置更新过程MSBTSservingBSCMSCBTStargetHO Alarm & Candida

22、te CellChannel ActivationChannel Act Ack.HO CommandHO CommandHO AccessHO DetectionSABMEstablish IndUAHandover CompleteHandover CompleteHandover PerformedRF Channel ReleaseRF Channel Rel. Ack.ST9103ET9103ST3103ST3103ST3105ET3105Physical InfoST3124ET3124ST200ET200ST_RCR_ACKET_RCR_ACKPhys Context ReqPh

23、ys Context ConfST9108ET9108Meas ReportMeas Result没有没有Physical Cont Physical Cont ReqReq过程，原信道上的过程，原信道上的TATA不能被沿用到新的信不能被沿用到新的信道上道上测量测量TATA（TA）（TA被采用）被采用）在在RFRF信道释放前，有信道释放前，有Physical Physical Context ReqContext Req过程过程Internal Inter Cell切换过程切换过程异异步切换步切换Clear Command如果带有HO成功则表示切换成功ET3124ST3124ST200ET20

24、0External Inter Cell切换过程切换过程异步切换异步切换MSBTSservingBSCservingMSCBTStargetMeas ReportMeas ResultHO Alarm & Candidate CellChannel ActivationChannel Act Ack.HO CommandHO CommandHO AccessHO DetectionSABMEstablish IndUAHandover CompleteHandover CompleteHO CompleteRF Channel ReleaseRF Ch. Rel. Ack.BSCtar

25、getHO Required要求切出HO Request要求切入HO Request Ack.HO CommandPhys Information（SCCP Con Required）（SCCP Con Conf）.Clear CompleteSCCP ReleasedSCCP Rel. Cmp.STrr2ETrr2ST_HO_REQ_LostST9103ST9103ST9113ST3103ET3103ST3106ET3106ST8ET8ET9113ET_HO_REQ_LostMSBTSBSCMSCDisconnectDisconnectDisconnectReleaseReleaseReleaseRelease CompleteRelease CompleteRelease Complete手机触发的呼叫释放DisconnectDisconnectDisconnectReleaseReleaseReleaseRelease CompleteRelease CompleteRelease Complete网络触发的呼叫释放呼叫释放过程呼叫释放过程t信