Research And Implementation Of Call Control Protocol Based On The Geo Satellite Mobile Communication System

As a necessary complement to the ground mobile communication system, the satellite mobile communication system has become a important development direction of personal mobile communication in the future, and due to its advantages of simple system construction, the GEO satellite mobile communication systems with large diameter multi-beam antenna technology has a broader prospects. The technology of mobile satellite communication system of our country is still lag seriously, so the development of our country’s independent civil satellite mobile communication system is the key factor affecting the quality of individual mobile communication, as well as the realization of the air interface protocol stack is the core part of system implementation. Previous communication protocols development follow the steps of software engineering, the detailed design stage mainly rely on the programmer to write code by hand, which is low efficiency and lack of the guarantee of correctness, a little error in understanding of the protocol can lead to a lot of useless work, so it needs a development method with integration and standardization to realize protocols. Protocol engineering and formal description technology is the method.Under this technology background, this dissertation researched the GEO satellite mobile communication system protocol architecture and call control protocol, designed the call control process of the single jump call mode and the state transition process of the CC entity, considering the complexity of signaling interaction in GEO satellite mobile communication system high-level protocol, on the basis of the method using SDL language to realize the simulation of the OSI reference model in the past, a new modeling method of high-level protocol has been proposed in this dissertation. With the method of multi-level mapping protocol entity to the SDL system module, service primitives is mapping for signal, which is more clear hierarchy. Besides, a set of direct and facilitate process is designed to implement the codec of messages, by using operators of Octetstring data structure to deal with messages.In the meantime, this dissertation completed the call control sub-layer implementation and system simulation. The results show that according to this method, we can establish SDL model of high-level protocol whose functions are correct and consistent with the specification.At the same time, the steps and methods introduced in this dissertation are also appropriate for the implementation for other sub-layers of GEO satellite mobile communication system. It is easier to implement effective, which can improve the productivity, reliability and maintainability of satellite mobile communication protocol software, promote the realization of standardization.