呼叫流程及信令.docx

1、呼叫流程及信令位置更新及呼叫流程位置更新操作(一)_位置更新仅涉及本VLR2.1.2位置更新操作(二)_位置更新涉及本VLR和HLR(当MS进入新的VLR或MS首次登录,或相关网络数据丢失后,MS都使用IMSI来标识自己) 3.1.1呼叫接续信号流程_移动用户呼叫移动用户(主被叫MS在同一MSC内)(一)3.1.2呼叫接续信号流程_移动用户呼叫移动用户(主被叫MS在同一MSC中)(二)3.1.3呼叫接续流程_挂机过程切换控制流程_同MSC内基站间切换4.2.1切换控制流程_基本切换处理4.2.2切换控制流程_后续切换流程(MS离开MSCb漫游到MSCb)附：消息说明DTAP消息移动管理MM消息

2、消息名传递方向功能鉴权拒绝 Authentication rejectTo MS向MS指明鉴权已经失败鉴权请求 Authentication requestTo MS网络启动MS鉴权鉴权响应 Authentication responseTo Network将计算出的鉴权响应SERS传送到网络CM重建请求 CM Re-establishment requestTo Network若前一个连接失败,MS请求重建一个连接CM业务接受 CM service acceptTo MS网络向MS指明已经接受请求的业务CM业务拒绝 CM service rejectTo MS网络向MS指明不能提供请求的业务

3、CM业务请求 CM service request To NetworkMS请求连接管理(CM)子层实体业务识别请求 Identity requestTo MS网络请求MS提供标识识别响应 Identity responseTo NetworkMS提供标识给网络IMSI分离指示 IMSI detach indicationTo Network在网络中设置此MS处于非活动状态位置更新接受 Location updating acceptTo MS网络通知MS位置更新或IMSI附着已经完成位置更新拒绝 Location updating rejectTo MS网络通知MS位置更新或IMSI附着失败

4、位置更新请求 Location updating requestTo NetworkMS请求位置更新或IMSI附着MM状态 MM-Status双向向另一方报告错误状况TMSI再分配 TMSI reallocation commandTo MS网络再分配一个新的TMSI给MSTMSI再分配完成 TMSI reallocation completeTo NetworkMS通知网络一个新的TMSI再分配已经发生DTAP 消息呼叫控制(CC)消息消息名传递方向功能提醒 Alerting 被叫MS到网络或网络到主叫MS通知对方已经提醒被叫用户呼叫证实 Call confirmed被叫MS到网络被叫用户证

5、实一个来话请求呼叫进行 Call proceeding 网络到主叫MS网络表明主叫用户所请求的呼叫建立信息已经接收到连接 Connect被叫MS到网络或网络到主叫MS表明被叫用户已经接收呼叫连接证实 Connect acknowledge网络到被叫MS或主叫MS到网络表明MS已经获得呼叫紧急建立 Emergency setupMS到网络MS启动紧急呼叫的建立进展 Progress网络到MS表明一个呼叫的进展建立 Setup双向启动呼叫建立修改 Modify 双向请求改变一个呼叫的负载能力修改完成 Modify complete双向表明呼叫负载能力的改变已经完成修改拒绝 Modify rejec

6、t双向表明呼叫负载能力的改变已经失败用户信息 User information 双向MS发送到远端用户的信息或网络发送远端用户的信息断连 Disconnect双向MS请求清除端对端连接或网络指明端对端连接被清除释放 Release双向表明发送方准备释放业务标识符TI释放完成 Release complete双向表明发送方已经释放TI,且接收方将释放TI拥塞控制 Congestion control 双向表明在发送用户信息消息时流量控制的建立和终止通知 Notify双向指明关于一个呼叫的信息启动DTMF Start DTMFMS到网络网络请求将包含的数字转变成DTMF音调启动DTMF证实 Sta

7、rt DTMF ack网络到MS指明网络已经成功地将包含的数字转变成DTMF音调启动DTMF拒绝 Start DTMF rej网络到MS表明网络不接收将包含的数字转变成DTMF音调的请求状态 Status双向报告错误状况状态查询 Status enquiry双向请求同层的层3实体发送Status消息停止DTMF Stop DTMFMS到网络停止发送DTMF音调到远端用户停止DTMF证实 Stop DTMF ack网络到MS表明DTMF音调的发送已经停止BSSMAP 消息 无连接消息消息名传递方向功能阻塞 BLOCKBSS=MSC向MSC指明特定的陆地资源阻塞阻塞证实 BLOCKING ACKN

8、OWLEDGEMSC=BSS指明相关电路中的业务已经被移去解闭 UNBLOCKBSS=MSC指明特定的陆地资源可恢复服务解闭证实 UNBLOCKING ACKNOWLEDGEMSC=BSS指明相关电路已经恢复服务切换已执行 HANDOVER PERFORMEDBSS=MSC指明BSS已经执行了一个内部切换切换候选者询问 HANDOVER CANDIDATE ENQUIREMSC=BSSMSC查询正在某小区中工作的MS是否可以切换到其它小区切换候选者询问响应 HANDOVER CANDIDATE RES.BSS=MSC指明候选MS的数目资源请求 RESOURCE REQUESTMSC=BSSBS

9、S请求当前特定小区中的空闲资源资源指示 RESOURCE INDICATIONBSS=MSC响应资源请求消息寻呼 PAGING MSC=BSS通知BSS在正确的小区发送寻呼消息复位 RESET双向指明发送方发生了故障复位证实 RESET ACKNOWLEDGE双向指明发送方已经发生了复位,等待恢复业务过载 OVERLOAD双向表明发送方过载复位电路 RESET CIRCUIT双向由于故障发送方特定的电路状态不明复位电路证实 RESET CIRCUIT ACKNOWLEDGE双向表明发送方已清除了可能有关的呼叫,等待恢复服务BSSMAP 消息面向连接消息消息传递方向功能指配请求 ASSIGNME

10、NT REQMSC=BTS请求BSS指配无线资源,消息中包括资源的特性和地面信道指配完成 ASSIGNMENT COMPLETEBSS=MSC指出所请求的指配已经正确完成指配故障 ASSIGNMENT FAILUREBSS=MSC指出在BSS指配过程中出现故障,指配程序已终止切换请求 HO REQUESTMSC=BTS某MS要切换到该BSS所属的小区切换要求 HO REQUIRED BSS=MSC指出已有专用无线资源的某一MS请求切换,原因在消息中给出切换请求证实 HO Required AcknowledgeBSS=MSC指出BSS可以支持请求的切换,并指示MS应切换到的信道切换命令 HO

11、CommandMSC=BTS包含MS应重新调谐的目标信道切换完成 HO CompleteBSS=MSC指出正确的MS已经成功地接入目标小区切换故障 HO FailureBSS=MSC指出在对资源分配过程中出现故障,已放弃切换切换要求拒绝 HO Required rejectMSC=BTS指出BSS要求的切换没能执行切换执行 HO PerformedBSS=MSC指出BSS已完成了一个内部切换,包括小区识别清除请求 Clear RequestBSS=MSC指出BSS希望释放相关的专用资源清除命令 Clear CommandMSC=BTS指示BSS释放相关专用资源清除完成 Clear Comple

12、teBSS=MSCBSS通知相关专用资源已释放MSC调用跟踪 MSC Invoke TraceMSC=BTS指示BSS开始跟踪记录级别更新 Classmark Updated双向更新相关的MS的级别加密模式命令 Cipher Mode CommandMSC=BTS要求更新相关的MS加密参数加密模式完成 Cipher Mode CompleteBSS=MSC指出通过无线接口已达到成功的加密同步完全层3消息 Complete L3 MessageBSS=MSC寻呼响应,位置更新请求,CM请求重建,CM业务请求,IMSI分离BSS执行SCCP连接建立时,MS发出的第一个层3消息排队指示 Queryi

13、ng IndicationBSS=MSC指出所需的TCH的指配会有延时SAPIn拒绝 SAPIn RejectBSS=MSC指出SAPI!=0的一个消息被拒绝了寻呼 PagingMSC=BTS该消息包含足够的信息以使寻呼在正确的时间和正确的小区发送切换检测 HO DetectedBSS=MSC指出正确的MS已成功地接入目标小区BSS调用跟踪 BSS Invoke Trace双向发端指示收端开始跟踪记录级别请求 Classmark RequestMSC=BTS请求为对应的MS更新级别参数加密模式拒绝 Cipher Mode RejectBSS=MSC七号信令：GSM信令分层： BSSAP BSS

14、 Application Part BSSMAP BSS Management Application Part DTAP Direct Transfer Application Part MM Mobility Managemert CM Connection Management CC Call Control SMS Short Message Services SS SCCP Signalling Connection Control Part MTP Message Transfer Part RR Radio Resourses BTSM BTS Management LapD L

15、ink Access Protocol on the D channel LapDm Link Access Protocol on the D channel modified Layer 1 (Physical Layer) The physical layer is responsible for the error free transfer of physical data units. This layer defines the electrical and mechanical characteristics of the transmission path. Layer 2

16、(Link Layer) The function of the link layer is to transfer frames, error free, between two stations using the bit transfer connection created by the physical layer. The tasks of this layer include opening, maintaining, and closing a connection between two stations. In GSM, the data link layer is imp

17、lemented with the standard LapD (Link Access Protocol on D channel) protocol on the BTS-BSC link, and with a GSM specific LapDm protocol on the BTS-MS (radio interface) link. Layer 3 (Network Layer) The network layer isolates the higher levels from routing and connection tasks. It is responsible for

18、 getting the message to its destination through an arbitrary network topology. In GSM, this layer is hierarchically divided into three sublayers; CM (Connection Management), MM (Mobility Management), and RR (Radio Resource) layers. The Radio Resource layer, RR, produces services for the Mobility Man

19、agement layer. The functions of this layer include establishing, maintaining, and releasing physical connections (i.e. RF traffic and control channels). The main part of this function is located in the BSC, although some of the functions are performed by the BTS. The Mobility Management layer, MM, c

20、ontrols the registration of subscriber equipment in the network and identification of users. This function is located in the MSC. The Connection Management layer, CM is the highest layer in the GSM implementation of the OSI model. This is indicated by its location (top of the protocol stack in both

21、MSC and MS). This layer is basically the interface to the user in the GSM system. The connection management layer is subdivided into three segments; Call Control segment, CC, which is responsible for establishing, maintaining and releasing calls, Suplementary Services segment, SS, and Short Message

22、Service segment, SMS. 呼叫建立过程：呼叫建立过程说明：1. CHANNEL_REQUESTThe MS requests a channel by sending a random access burst on a RACH channel via one BTS. Channel request -message contains the establishment cause. This can be Answer for paging, emergency call, other services (Mobile Originated Call, Short Me

23、ssage Service) or Other, like location update. In addition to, this message contains Random Reference. This is 5 bits randomly selected by MS. The usage of random reference is: when two MSs are accessing to the network exactly the same time, the network can separate these Mobile Stations by using th

24、is random reference.2. IMMEDIATE_ASSIGNMENTThe BSS informs the MS on AGCH channel about the SDCCH channel to be used. In practice, this message is an order from the network to the MS to move to the SDCCH -channel defined before. Page mode, SDCCH channel description, associated SACCH and hopping freq

25、uency are included as parameters. In addition, request reference (same as establishment cause), initial timing advance and frequency allocation if frequency hopping applies are also included.3. AUTHENTICATION_RESPONSEThe MS responds to the Authentication Request with the Signed Response SRES. The Au

26、thentication Response is sent to the BSC via the BTS.In the MS Authentication procedure, two algorithms, A3 and A8 are used. In the SIM -card (In MS), both of these algorithms and 32 -digit key are stored) and the very same information can be found in Authentication Centre (AuC) also. When MS Authen

27、tication is requested by the network, AuC/VLR sends 32 -digit RANDom Number to the MS. MS calculates then Signed Response (SRES and returns that back to the VLR. VLR makes a comparison if received SRES is same than it has received inside of the Authentication triplet from the AuC before. If these tw

28、o SRESs are the same, authentication went OK and MS can continue the call setup.Should you notice, the first 8 digits of the KI are used for Authentication and SRES calculation, the rest 24 are reserved for Ciphering Key calculation. 4. SETUPAfter authentication, Identification and Ciphering, the MS

29、 is in the SDCCH channel and ready to start real call setup signaling. The MS sends a Setup message to the BSC to be forwarded to the MSC. 5. ASSIGNMENT_COMMAND The BTS delivers received information further on towards the MS. Contents: channel description, power levels, cell channel description, channel mode (Full / Half) and mobile allocation.位置更新