GSM信令流程分析

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1、...GSM信令流程分析一、常见业务流程1.移动主叫流程MSCBSCBTSMS1ChannelRequest(RACH) 2ChannelRequired3ChannelActivation4ChannelActivationAck56ImmediateAssigment(AGCH)ImmediateAssigmentCommand7CMServiceRequest(SDCCH) 8CMServiceRequest9CMServiceRequestEstableishIndication10UA(SDCCH)1112AuthenticationRequest(SDCCH)

2、AuthenticationRequest13AuthenticationReponse(SDCCH) 14AuthenticationReponse15CipheringModeCommand16CipheringModeCommand17CipheringModeCommand(SDCCH)18CipheringModeComplete(SDCCH) 19CipheringModeComplete20TMSIReallocationCommand21TMSIReallocationCommand(SDCCH)22TMSIReallocationComplete(SDC

3、CH) 23TMSIReallocationComplete24Setup(SDCCH) 25Setup26CallProceeding27CallProceeding(SDCCH)28AssignmentRequest 29ChannelActivation30ChannelActivationAck31AssignmentCommand(SDCCH)32SABM(FACCH) 33EstablishIndication34UA(FACCH)35AssignmentComplete(FACCH) 36AssignmentComplete37ChannelRelease3

4、8DeactiveSACCH39ReleaseIndication40RFChannelRelease41RFChannelReleaseAck42Alerting43Alerting(FACCH) 44Connect45Connect(FACCH)46ConnectAck(FACCH) 47ConnectAck48MeasurementReport(SACCH) 49Prep_MeasurementResult50Disconnect(FACCH) 51Disconnect52Release53Release(FACCH)54ReleaseComplete(FACCH)

5、 55ReleaseComplete56ClearCommand57ChannelRelease(FACCH)58DeactivateSACCH 59DISC(FACCH)60UA(SACCH) 61ReleaseIndication62RFChannelRelease63RFChannelReleaseAck 64ClearComplete65SCCPRelease66SCCPReleaseAck......移动主叫流程图1.信道请求MS通过动态地在RACH信道（随机接入信道）上发送一个随机接入脉冲向一个BTS申请一条信道。在信道请求消息中包括了建立的原因，这个原因可能

6、是“寻呼响应”、“紧急呼叫”、“移动主叫”、“短消息业务”或“其他”，比如“位置更新”。此外，这条消息还包括随机参数，移动台（MS）随机的选5个比特作为随机参数。这些参数的作用是：当两个移动台同时接入网络时，网络能运用这些参数来区分这些移动台。Randomreference有5位，最多可同时区分32个MS，但不保证两个同时发起呼叫的MS的RAND值一定不同。要进一步区别同时发起请求的MS，还要根据Um接口上的应答消息下面是一个ChannelRequest信令的举例MS1ChannelRequestTime:15:44:04.16Framenumber:742632Fram

7、enumber:742630ReadfromARFCNChannelnumber:(GSM900)72RandomAccessInformationEstablishmentcause:(6)OriginatingcallandTCH/Fisneeded,ororiginatingcallandthenetworkdoesnotsetNECIbitto1,orproceduresthatcanbecompletedwithaSDCCHandthenetworkdoesnotsetNECIbitto1Randomreferenc