Research And Realization On CM Layer Of UMTS Switch Center Software

With the rapid development of mobile communication,people need more communication services. So it is necessary to introduce more services,especially multimedia service with graphics,text,sound,pictures and access to the Internet. In addition,it is the development of communication services and the lack of channel resources that drive the produce of the third generation mobile communication.According to experiences while working on the product of UMSC in HuaWei company,the author designs the functions of CM ( Connection Management ) layer in the switch center of UMTS(Universal Mobile Telecommunication System),and realizes them with the means of state machine,which can be used for reference to a certain extent.The author presents the background knowledge,status quo and intending trend of mobile communication in brief. The structure of UMTS is also described,which educe the author's work. According to the protocols and the company's GSM code ,the author analyzes the functions of CM layer,and partitions them in the point of realization,and adds software modules to make the whole system easy to be realized,maintained. The software modules must abide by the rule of high cohesion and low coupling. This is the emphasis and difficulties of the paper. On the basis of the designs above,the author describes the realization of the basic functions of CC(Call Control) service in CM layer. The functions are mobile originating call,mobile terminated call,normal connection release and some abnormal conditions. The test procedure is very important during the project. The author introduces the requests and steps of unit test and integrated test,and illustrates the test method with examples. In addition,some services not realized are also mentioned.