【正文】 seDISCDeactivate SACCHRF Channel release ackRelease IndicationUADisconnect Data Ind.(Disconnect)Data Req.(Release)Data Ind.(Release Complete)Data Req.(Channel Release)6被叫流程（一）MS BSCBTSChannel activation ackChannel activationChannel requiredCall confirmSABM(pag_resp)Immediate assign mandestablish indicationChannel requestUA(pag_resp)Immediate assignment SetupCM service acceptPaging CommandPaging RequestData req.(CM service accept)Data req.(Setup)Data ind.(Call confirm)7被叫流程（二）MS BSCBTSChannel activation ackAssignment mandestablish indicationAssignment CompleteDeactivate SACCHRelease requestRelease confirmRF Channle releaseRF Channel release ackAlertingConnectConnect acknowledgeSABMUAChannel activationData req.(Assignment mand)Data ind.(Assignment Complete)Data ind.(Alerting)Data ind.(Connect)Data req.(Connect acknowledge)8小區(qū)間切換MS BSCBTS1 BTS2Channel activationChannel activation ackMeasurement resultHandover mandMeasurement reportHandover accessHandover pleteSABMUAData ind.(HO plete)Physical informationestablish indicationHandover detectionRelease Request(local)Release ConfirmationRF Channel Release ACKRF Channel ReleaseData req.(HO mand)9A 接接 口口 信信 令令10A接口信令11A接口信令MS BSS MSCASSIGNMENT REQUESTASSIGNMENT COMMANDASSIGNMENT COMPLETEASSIGNMENT COMPLETEASSIGNMENT REQUESTChannel TypePriorityCircuit Identity Code(MSC Allocate)Downlink DTX FlagInterference Band To Be UsedClassmark Information 2ASSIGNMENT COMPLETERR CauseCircuit Identity CodeCell IdentifierChosen ChannelCircuit PoolSpeech Version(Chosen)Channel TypeSpeech/data indicator:Speech/Data/SignalingChannel rate and type:Full rate(Half rate)/SDCCHPermitted speech version indication:FRV1/FRV2(EFR)PriorityPreemption Capability IndicatorPriority Level:1~14Queueing Allowed Indicator:Allowed/not AllowedPreemption Vulnerability IndicatorCircuit Identity Codeak:PCM No.,max 2048xxxxx:timeslot No.Interference Band To Be Usedbitmap format for band1~band5RR CauseNormalCircuit PoolNo1:FRV1。FR Data 12/6/No4:FRV2。FRV2。A5/3Classmark 3 T1012A接口信令MS BSS MSCASSIGNMENT REQUESTASSIGNMENT COMMANDASSIGNMENT FAILURE ASSIGNMENT FAILUREASSIGNMENT FAILURECauseRR CauseCircuit PoolCircuit Pool ListCauseRequested terrestrial resource unavailableRequested transcoding/rate adaption availableRequested speech version unavailableCircuit pool mismatchSwitch circuit pool/Terrestrial circuit already allocatedEquipment failure/No radio resource available/OM intervention Radio interface message failureRadio interface failure,reversion to old channelT10ASSIGNMENT FAILUREASSIGNMENT FAILURE13A接口信令MS BSS MSCClear RequestCauseCauseRadio interface message failureOM interventionProtocol error between BSS and MSCPreemptionCLEAR COMMANDCLEAR REQUESTCLEAR COMPLETEClear CommandCall controlEquipment failureHandover successfulProtocol error between BSS and MSC14A接口信令Handover RequiredCauseResponse RequestCell Identifier List(Preferred)Circuit Pool ListCurrent ChannelSpeech Version(Used)Queueing IndicatorCauseUplink Quality Uplink StrengthDownlink Quality Downlink StrengthDistance Better CellTraffic Response toMSC InvocationDirected Retry Switch Circuit PoolPreemption OM InterventionResponse RequestRequest HANDOVER REQUIRED REJECT if result in no handover Cell Identifier ListMax n,which is set by OM,from 1 to 16, list is given in order of preferenceOM interventionEquipment failureRequested terrestrial resource unavailableInvalid message contentsRequested transcoding/rate adaptation unavaliableCauseRequested terrestrial resource unavailable Ciphering algorithm not supported Requested transcoding/rate adaptation unavaliable Requested Speech version unavailable Circuit pool mismatch Switch circuit poolOM intervention Equipment failureNo radio resource available Invalid cellRadio interface failure,reversion to old channelTerrestrial resource already allocatedHandover RequestChannel Type Encryption InformationClassmark Information 1 or 2 Cell Identifier(Serving)Priority Circuit Identity CodeDownlink DTX Flag Cell Identifier(Target)Interference Band To Be Used CauseClassmark Information 3 Current ChannelSpeech version(Used) Config. Evolution IndChosen Encryption Algorithm(Serving)Configuration Envolution IndicationSMI:Subsequent Modification Indication,whether modification is allowed or notClassmark Information 1Phase1/Phase2 MSControlled Early Classmark Sending RF Power CapabilityA5/1 Classmark Information 3Multibands supported,EGSM/DCS1800/RGSMRF Power Capability for each bandA5/4,A5/5,A5/6,A5/7UCS2Handover FailureRR CauseCircuit PoolHandover Required RejectHandover Request ACKLayer3 InformationChosen ChannelChosen Encryption AlgorithmCircuit PoolCircuit Identity CodeHandover CommandCell IdentifierMS BSS MSCHANDOVER REQUIREDHANDOVER REQUIED(1)T7HANDOVER COMMANDHANDOVER REQUIRED REJECTHANDOVER REQUESTBSSHANDOVER FAILUREHANDOVER REQUEST ACKT8HANDOVER COMMANDHANDOVER ACCESSHANDOVER DETECTHANDOVER COMPLETEHANDOVER COMPLETECLEAR COMMANDCLEAR COMPLETECLEAR REQUESTHANDOVER FAILURE CLEAR COMMANDCLEAR COMPLETEHANDOVER FAILUREHandover DetectNo information element except for message typeHandover CompleteRR Cause15A接口信令Handover PerformedCauseCell IdentifierChosen ChannelChosen Encryption AlgorithmSpeech Version(Chosen)MS BSS MSCT8HANDOVER COMMANDCLEAR COMMANDCLEAR COMPLETECLEAR REQUESTHANDOVER FAILUREHANDOVER ACCESSHANDOVER COMPLETE HANDOVER PERFORMEDCauseUplink Quality Uplink StrengthDownlink Quality Downlink StrengthDistance Better CellTraffic Directed