callflow1.pptVIP

呼叫流程 CP、RSS简介 Um结构 控制信道 主被叫呼叫流程 Call Processing (CP) The purpose of CP is controlling communication between the MSC, BSC, BTS and MS. CP and RSS interact to control call setup and clearing, handover, encryption and movement of Direct Transfer Application (DTAP) messages between the MSC and MS. CP has been split into 2 levels connected by the Motorola A-bis link: Call Processing (CP) CPBSC Connectionless Manager (CLM) Message Transfer Part L3 (MTPL3) Signalling Connection Control Part (SCCP) preprocessor SCCP State Machine (SSM) CPBTS Radio Resource State Machine (RRSM) Cell Resource Manager (CRM) Cell Broadcast Scheduler (CBS) Call Processing (CP) BSS Radio Subsystem (RSS) The Radio Subsystem (RSS) is a collection of application processes whose purpose is to manage the BSS RF hardware to the MSs The RSS comprises of five components: RSS configuration and Fault Management (CFM) Layer 1 interface Layer 2 protocol RSS A-bis interface Handover detection and power control Radio Subsystem (RSS) Ladder Diagrams Signalling Model GSM Burst Types Control Channels MS主叫流程(MO) MS被叫流程(MT) System infomation System information type 1 System information type 2 System information type 2bis System information type 2ter System information type 3 System information type 4 System information type 5 System information type 5bis System information type 5ter System information type 6 System information type 7/8 System information 1 System information 2 System information 3 PCH计算 Number of paging groups = (number of CCCH block - bs_ag_blks_res) * (bs_pa_mfrms + 2 ) 以 ccch_conf = 0，bs_ag_blks_res = 1，bs_pa_mfrms=2为例讲解三个参数之间的关系（bs_pa_mfrms=2表示有2+2=4个51复帧作为一个寻呼组） Transmission of Paging Messages System information 4 System information 5 System information 6 Channel request Channel Establishment Immediate assignment SDCCH信道相关信息 RAND 缩减帧号 T 时间提前量TA RAND与T值都与请求信道的MS有关，用于减少MS之间的请求冲突。 Channel Request Immediate Assignment: SABM帧/CM SERVER REQUEST CM SERVER REQUEST 请求的服务类型 MS类别 （CLASSMA