Research On Routing Algorithm Of Space Network Based On SDN

With the development of Space-Ground integrated network,and the base station in the traditional ground mobile cellular network cannot be deployed to the particularly complex geographical environment,so the research of low earth orbit satellite network technology has become a hot topic.In order to realize the real-time access of small power mobile terminals and the seamless global coverage of satellite signals,there are more and more satellite nodes in the LEO satellite network being deployed,so the study of LEO satellite network characteristics and related routing algorithms has become an urgent issue to be solved.Firstly,the characteristics of LEO satellite networks are studied,and a LEO satellite network model is built by using STK software,the inter-satellite link characteristics in the model are analyzed,and it can provide reference for the study of routing algorithms for LEO satellites.As the satellites increase,the topological structure of the satellite network changes faster and faster,and the routing calculation becomes more difficult.When considering the routing algorithm,this paper adopts the routing algorithm based on the idea of virtual topology.The algorithm decomposes the operating period of the satellite into continuous time slices,so that the satellite topology can be regarded as a fixed static topology in the period of time as long as the time slice is short enough.When routing the static topology within each time slice,we introduce the Depth-First-Search(DFS)algorithm and Dijkstra algorithm,and integrated use two algorithms to improve the computational efficiency and the reliability of the calculation results.Because of the large number of nodes in the network and the complexity of the network deployment,it is difficult to control the distribution of data traffic in the network,so as to the management of the network.We introduce the new network architecture of the software defined network(SDN),and the basic communication process is simulated,the core idea is to separate the control part of the network from the underlying switches,the control layer is monitoring the whole network,a comprehensive analysis of the real-time information on the network traffic distribution and the network node load is underway,according to the information,the optimal path is calculated.The control layer controls the equipment in the network to transmit data and provides real-time management and maintenance to the network to improve the operating efficiency and the stability of the network.Therefore,SDN network is a dynamic,controllable,cost-effective and adaptable network system.It is suitable for communication networks with high bandwidth and high dynamic characteristics.Therefore,combining SDN ideas with the new generation of LEO satellite networks can achieve more flexible monitoring and management of the network,and can make the network expansion more convenient.At the end of this paper,we combine SDN with space-based network,and the communication performance of space-based network based on SDN and traditional space-based network is compared and analyzed.The results show that the SDN network architecture breaks through the performance limitations of the traditional network architecture,and can better improve the performance of the network.