Call Access Design & Implementation In IP-Based GSM Base Station

All-IP mobile communication network makes various wireless air interface standards and voice,video,data and signaling of the means to access to be routed and transmitted through the harmonization of the all-IP packet switching platform. All-IP mobile network is natural product through combining IP technology of the Internet and mobile communication technology. Now, GSM system still occupies the dominant position in the global wireless mobile market, and its users are still rapid growing.After considering the mobile communication network of IP and GSM system will be long-standing together, and the full account of the development trend of base station, this paper introduces an IP-based GSM base subsystem. Making a combination of traditional GSM base subsystem and IP technology, to reduce the cost of transmission and increase system flexibility. Highlighting the points of IP transmission in internal system and voice,data and signaling to be transmitted through different routes. And the paper also makes a detail description of the two important parts of the subsystem: base station and base station controller.In the part of design and implement, the paper divides traffic subsystem into various function modules, and makes a detailed description of them according to the process of call handling process. The paper gives emphasis to the core module of call access process– Random Access Channel Module, makes a detail introduce of call admission process, including the initialization of random access channel module,initialization failure and the access handling of new call. The paper presents the key data structure model of the design according various processes. Considering various unusual cases, the entire process of random access communication is divided into different processes, detailed presentation on the related handling and uses flow charts to express. Finally, making tests to the various common cases of call admission process and confirming the feasibility of the design through setting test stakes.