Study On QoS-based Routing Algorithm For Satellite Networks

Satellite networks(SN), as one important networking communication method, have merits of global coverage, mobile well, good expansibility and so on, so not only is profitable supplement to ground networks, but also have its own performance and predominance. These traits of SN make them apply successfully to global voice operation, television relay operation and data translation operation. With the rapid development of internet, SN have been considered as one part of next generation internet and to provide broadband access, thus broadband SN have special important status in information infrastructure of our nation.Networking layer which locates in middle station in protocol stack and in highest layer of communication subnet, provides service for translation layer and implication layer, as routing protocol is kernel technology of network layer, routing protocol becomes one of key technologies of satellite communication network. Recently SN routing protocol becomes one of hot research article, at the same time existing SN routing protocol is difficult to provide QoS.Because of particularity of SN itself, cost of hardware examination was high, and development period was long. Thus, software simulation was adopted by worldwide countries, which overcomes above shortcomings, can be deployed vary scale SN topology conveniently, realized different candidates flexibly, and controlled test schedule in real-time. Therefore, software simulation was in application to double-layered satellite constellation design, analysis performance and design protocol and so on.Firstly this paper introduced vary parameters of SN, analyzed their possible effect to routing, and designed one space information communication system composed of double satellite constellation. Moreover, SN QoS mechanism was analyzed, satellite grouping method was introduced to reduce system complication and proposed one new QoS Routing Algorithm for the Double-layered Satellite Networks.Secondly, satellite simulation software and network protocol simulation software were introduced. STK and NS were choosen as SN protocol simulation software, according to SN researching requirement and those software functions. Then NS modules was modified and expanded, and realized simulation of QRAS.Lastly, the performance of QRAS was evaluated, realized simulations in 2 scenes of vary satellite constellation topologies, including mono-layer and double-layer satellite constellation composed of LEO satellites and MEO satellites. And vary guide of non-QoS operations and QoS operations were analyzed and compared. Simulation results show that the proposed routing algorithm results in low delay, small delay jitter and low drop ratio, and provides excellent performance for QoS requirement.