Routing Algorithm On Space-based Network And Sensitivity Analysis

With the rapid development and application of space technology, accelerating the development and utilization of space resources has become an important strategic orientation of countries all over the world. The space-based network is a real-time multi-dimensional information network system in which all kinds of satellites connected by inter-satellite links(ISL) form the backbone of the system. Due to the characteristics of working in all-weather, real-time, global coverage and the capability of obtaining and distributing information quickly, the space-based network is the main part of the future integrated space-ground information networks, in which the information transmission and exchange mechanism will be simplified and the construction plan of space facilities will be optimized. The development of space-based network will have a great impact in economic,social and military field, etc.Routing technology is one of the key problems in satellite network. Based on the analysis of parameters which influencing the performance of routing in space-based network, this thesis concentrates on the questions brought by various qualities of service(QoS)with different architectures in designing routing algorithms for space-based network. The major work of this dissertation includes: 1). First analyzed the influence of network routing strategy caused by the invalidation of the ISL. Then a novel algorithm is proposed to reconfigure the shortest path between the source satellite and destination satellite based on result of the previous analysis. The algorithm, which computed on-board, ensures the minimum hops of new route and the configuration occoured only in the area of the invalid ISL. 2). Taking the characteristics of the LEO satellite network into consideration,a multi-QoS objective optimization routing algorithm is proposed for the discrete topology of the dynamic LEO satellite network. In the meantime, a fast reconfiguration routing algorithm is proposed to deal with the case of ISLs become invalid, which is local optimum. 3). First a minimum-cost flow model for LEO satellite network is established.Focusing on the effect of route cost brought by the change of QoS, sensitivity analysis method is introduced to solve the problem. At last a boundary condition, in which the cost of the optimized route does not change, is given. 4). A LEO/MEO coverage model is given based on the analysis of the architecture of LEO/MEO satellite network. A minimum-cost model in LEO/MEO satellite is established in which cost is defined by multi-QoS constraints. A routing strategy based on probability formulated by different QoS parameters is proposed, which also concerns the balance of the dataflow distribution in LEO/MEO satellite network.