Research On Routing Technology Of Satellite Networks

With the development of the social economy and a growing demand of communications, we have more requirements for quality of communications. The ideal communication goal is to achieve "point to point" communication; namely we can communications with anyone in a timely information at any time, any place. As a kind of wireless communication, satellite communication plays an irreplaceable role in contemporary society.In recent years, satellite networks receive more and more attention around the world, for global coverage, easy access,extensibility, strong communication capacity and bandwidth allocated on demand and so on. In satellite networks, routing technology has an important position and determines the system performance. Whether in single-layer satellite networks or in multi-layer satellite networks, flexible and effective routing technology can achieve network load balancing,improve the utilization rate of network resources, and guarantee the quality of service (QoS) for the network.Due to uneven population distribution and economic development,global data traffic is also unevenly distributed. The paper proposed a congestion-based Random-encountering routing strategy in LEO satellite networks. The main purpose of the strategy is to allocate the traffic that needs to be transmitted to local congested satellites to the relatively unoccupied satellites, making full use of resources in single-layer satellite network. The strategy uses the agent in the field of artificial intelligence, which can move freely to explore a relatively good path from the source satellite node to the destination satellite node, and it can update the data routing table according to the congestion of the path, the communication delay between the satellite and the satellite. The strategy proposed in the thesis focuses on the congestion of satellite to determine the data forwarding, more effectively achieves load balancing, improving the overall performance of the network.Considering traffic in satellite networks will continue to increase in the future,the thesis proposed a routing strategy based on load balancing in a multi-layer satellite network. The network consists of GEO layer,MEO layer and LEO layer three-layer satellite network. By setting a unified cost function, different types of traffic change the weight of the cost function according to their characteristics. According to the result of the cost function, different traffic chooses path in different satellite network layers. The high-orbit satellites share the traffic for the low-earth orbit satellites, realizing the load balance. And it more effectively utilizes the resources of the satellite network, which has satisfied the QoS of each traffic.