Reasearch On The Routing Algorithm Of Space Satellate Network

In recent years,with the rapid development of as wireless communication technology,mobile communication and Internet network,network becomes the essential infrastructure for people to get information and and communication information in daily life.Among them,the satellite communication become an integral part of the next generation network due to the rapid development of the satellite network.If the satellite network can work as the ground network such as the Internet,it can effectively make full use of the satellite resources,make good technology promotion at the same time,and bring huge economic value.If you want to achieve such a satellite network,routing algorithm is the key in satellite network technology,which also has greatly influences on the whole performance of the satellite network system even the whole next generation network.In this paper,aiming at the non-geostationary(NGEO)satellite network system,the routing algorithm in the network layer is the key research.NGEO satellite network system itself has some structural challenges.The node moves fast relative to the slow-moving or fixed users,which will lead to network topology changes frequently.So it decides that the traditional QoS routing algorithm on the ground is not suitable for NGEO satellite network.Therefore,the routing algorithm that meet the user's QoS demands is the focus in the study of this papar.In this paper,based on STK network simulation platform,we build a polar orbit and a Walker satellite constellation network system.Accoding to the structure of the satellite network,the internal properties of each node is modeled and researched.On this basis,this paper studies the content of designing the satellite constellation.According to the simulations of polar orbit and Walker constellation,we explore the characteristics of the constellation from coverage and satellite orbit changes and so on.Based on the characteristics of NGEO Iridium satellite system,this paper design NGEO satellite routing algorithm based on fuzzy theory.The routing algorithm uses Fuzzy Satellate Congestion Indicator(FSCI)to indicate the characterization of congestion in each satellite node.What's more,the Fuzzy Routing Determination(FRD)is used to make the decision of the routing algorithm.The FSCI combines multiple indicators of satellite nodes and it is more suitable to reflect the congestion of the satellite than the single queuing delay.Secondly,FRD is combied by multiple perspectives to realize the QoS requirements of satellite network including the queuing delay,propagation delay and bandwidth.Finally,the proposed routing algorithm can not only effectively deal with satellite node congestion due to the optimization method of detours,but alse can achieve network load balancing at the same time can.What's more,based on the NS2 simulation platform,the proposed algorithm and the related DSP,ELB algorithm are simulated.Experimental results show that the proposed routing algorithm based on fuzzy theory in NGEO satellite network system has a good performance.It can improve the network throughput,reduce the packet loss rate and the end-to-end delay.