| MF-TDMA/CWTDM(Multi-frequency Time division Multiple Access/Continuous Wave Time Division Multiplexing) system is a new satellite communications system proposed by the research group which the author affiliates with. The system has some advantages such as: it can make the satellite onboard equipments compact, compose networks inflexibly, the networks based on this system are easy to extend and so on. It is a novel and advanced system. The main work in this thesis is to study and design a gateway of a satellite system based on the proposed system, so as to enable it constitute a perfect system with the user terminals and on-board equipment. The main contributions of the author are as follows:1. A system scheme is proposed. It uses a from top to down modular design method. The whole gateway is divided into several units according to the types of their processing service. The block diagrams of all the units are given with necessary description of every module in each diagram.2. An Internet Access Gateway in the gateway system is designed in detail. The detailed signaling procedure and the signaling frame structure is given, and a simple and convenient method for IP allocating and route table updating is proposed.3. Simulations of the designed Internet Access Gateway have been done on the OPNET simulation platform, including the simulation of the signaling system, the simulation of the Internet access module, the simulation of their joint system, and the simulation of the IP allocating and route table updating method. The simulation result shows that they can work well to realize the function of Internet accessing. |
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