Routing Algorithm Research Of Satellite Network Based On Timeslot Communication

Recent years, thanks to the rapid development of wireless communication and mobile communication, people can exchange all kinds of information with any others at any time and in any place. Among them, satellite communication has become one of the most important communication modes in mobile communication technology owing to its rapid development. Routing algorithm is the key in satellite network technology, which has a significant influence on the performance of the whole satellite network system in a large part.In the paper, aiming at MEO satellite network system communicating according to time slots, the routing algorithm in network layer is the focus in research. The satellite network system communicating according to time slots, namely there is directional antenna assembled in each satellite node in the satellite network, which switches its direction according to a fixed time slot table. This mechanism makes the satellite network system has a defined link scheduling in a determined time. As a result, a periodical dynamic network topology is formed in the satellite network system.In the paper, based on OPNET network simulation platform, a MEO satellite network system communicating according to time slots is established. And the massive structure of the satellite network and the inner structure of each satellite node are studied and modeled. On this basis, the characteristic of periodical dynamic network topology in the satellite network system communicating according to time slots is studied in the paper, and then the graph theory is introduced. Evolution graph modeling is carried out to the satellite network topology, and Dijkstra shortest path algorithm is applied in the evolution graph model. Therefore, the optimal path of the information from any source satellite node to any destination satellite node can be worked out in the satellite network.In the paper, the storage structure based on adjacency list applied in the traditional Dijkstra shortest path algorithm is studied as a focus of research. The shortcomings and problems are analyzed, and a modified time evolving graph shortest path algorithm based on heap structure is proposed. The storage structure of Fibonacci Heap and Pairing Heap are applied in the shortest path algorithm respectively, and their construction, operation steps, and time complexity are analyzed and contrasted. The experiment results show that the routing algorithm applying time evolving graph based on Pairing Heap proposed in the paper has a good performance in MEO satellite network system communicating according to time slots. Moreover, the algorithm can improve the network throughout, reduce the packet loss rate and decrease the time complexity of routing computing obviously.