本课程的重点是介绍GSM系统的协同工作过程，涉及内容包含：呼叫、位置更新、切换、短消息。对流程的介绍突出了移动特征，具体的信令细节本课程不做描述，可以参考ETSI的GSM规范获得更加详细的内容-The focus of this course is to introduce the GSM system in the process of collaborative work, involving the contents include: call, location update, switch, short message. Highlighted on the process of mobile features, the specific signaling not describe the details of this course, you can refer to the GSM specification ETSI to obtain more detailed content