Research On QoS-based Routing Algorithm And Handover Strategy For Space-based Integrated Information Networks

Both the development of global communication technology and growth of demands in military area drive the satellite communication system develop in the direction of network, in which satellites are capable of computing and switching onboard. The satellites connecting one another through inter-satelli te-links(ISL), can reduce the dependence on earth-gate-station and fulfil the fast information transmission. Space-based Integrated Information Network (SIIN), which based on satellite networks, can utilize spacial information resources comprehensively , and enable a variety of satellite systems in different orbits to interconnect and constitute an organic intelligent system. SIIN has become a critical strategy project due to its special function and role in space spying, environment and disaster monitoring, navigation and positioning, communications and broadcasting, space defense and confrontation,etc.There still exsits a number of key issues need in-depth study on satellite constellation interconnecting to form a network through ISLs. This paper focues on issues related to architectture of SIIN, QoS routing in satellite networks and re-routing after satellite handover.Aiming at the characteristics of the geographic location and future communications needs, a SIIN structure model based on LEO/MEO double-layered Walker satellite constellation is proposed. Simulation analysis of satellite constellation coverage performance and relevant parameters of inter-satellite link shows that the SIIN model can satisfy the country's coverage and communication needs , and also has scalability.Aiming at architecture characteristics of double-layered Walker satellite constellation and traffic distributing characteristics, a novel Traffic-adaptive Hybrid Routing Algorithm(THRA) is proposed. Simulation analysis shows that algorithm can meet business QoS requirements and optimize overall network resources utilization efficiency to a certain extent.Aiming at two types of handover in double-layered satellite networks(DLSN), a Re-routing Strategy Based on Candidate Satellite Sets(RSCSS) is proposed, which takes full advantage of overlapped coverage characteristic of DLSN. Preliminary simulation results show that RSCSS strategy is effective.