是空中接口Clear command消息，Abis接口对它进行透明传输。 66. Data request(clear complete)：该消息在Abis接口上由BTS发往BSC，其中包含的是空
中接口Clear complete消息，Abis接口对它进行透明传输。 67. Clear complete：BSC向MSC发送该消息来通知MSC相关的专用资源已经被成功的清
除。
1.2 移动用户呼叫移动用户被叫侧完整过程（被叫释放）
MSBTSBSC1 PagingMSCVLR2 Paging command3 Paging request4 Channel request5 Channel required6 Channel activation7 Channel activation ack8 Immediate assign command9 Immediate assign10 Paging response11 Estind(paging response)12a UA12b Paging response CR13 CC14 Map_process_access_request15 Map_authenticate16 Authenticate request17 Data request(authenticate)18 Authenticate request19 Authenticate response20 Data ind(authenticate)21 Authenticate response22 Map_authenticate ack23 Map_set_Ciphering_mode24 Ciphermod cmd25 Encr cmd 26 Ciphermod cmd27 Ciphermod com28 Data ind(ciphermod com)29 Ciphermod com30 Map_process_access_request_ack31 Map_forward _new_TMSI32 TMSI real cmd33 Data request(TMSI real cmd)34 TMSIi real cmd35 TMSI real com36 Data ind(TMSI real com)37 TMSIi real com38 Map_forward_new_TMSI ack39 Map_complete_call40 Set_up41 Data request(set up)42 Set_up43 Call confirmed44 Data ind(call confirmed)45 Call confirmed46 Assign request47 Phys CTX request48 Phys CTX confirmed49a Channel activation50 Channel activation ack51 Data request(assign cmd)49b Queuing
