Design And Implement Of Soft-Switch System Based On Circuit Domain Of WCDMA Corenet

With the rapid development of the information technology, people can not be satisfied with the existing GSM network which can only provide a narrow-band single voice services, and demand more and more broadband, intelligent and personalized mobile multimedia services. In this case, 3G system has become the goal that people looking forword to.3G system will provide multi-media communications at any time through the personal mobile terminal, enable more and more people enjoying the pleasure of the communication. The WCDMA, as the 3G system evolving from GSM, has the most mature technology and the most popular applications.The Softswitch system built in IP-Center, can support voice, data and multimedia services, is a integrated network platform, occupies a very important position in 3G.The WCDMA system project studied in this paper adopts R4 network technique, its corenet includes two parts.One is the part of circuit domain, it changes dramatically comparing with the second-generation network.The traditional MSC is divided to MSC Server and MGW, realizes the separation of signaling control and circuit carrying, and changes in related interface. The other is the part of packet domain.,it holds on using the infrastructure of GSM GPRS network,changes nearly nothing. Therefore,the emphasis of this paper is the system principles of corenet elements MGW and MSC Server,explains the call flow in detail.The part of packet domain will not be related.In the 3G Softswitch reconstucting project of China unicom Lanzhou Branch, I'm in charge of relevant debugging work on the software and hardware equipments, system entire testing and troubleshooting. During more than three months in the works,I have comprehended the Softswitch system of WCDMA cornet through studing with an effort and operating constantly. In the last part of this paper,combines with the practice of my job,relates the designing ideas and implementing methods of this project in detail.And then, the prospect of 3G networks are given. The contents that the paper relates adapt to the development and updating of the current communication technologies,it has a certain practical value.