LEO Satellite Network Routing Strategy Design And Performance Analysis

In recent years,with the rapid development of satellite telecommunications technology,the satellite already has the ability of packets processing and data forwarding.Compared with traditional terrestrial networks,satellite networks have the advantages of long communication distance,wide coverage ability,and no interference by terrain factors.The satellite network is becoming more and more critical in today's communication systems.For satellite communication systems,compared to high-orbit(GEO)satellite systems and medium-orbit(MEO)satellite systems,low-orbit(LEO)satellite systems have the advantages of achieving global seamless coverage,lower transmission delay,and good inter-satellite link quality.The LEO satellite communication system has become a hotspot of satellite network research.The topology dynamics of LEO satellite network communication and the uneven distribution of ground services cause congestion in the network.Therefore,designing a more effective routing algorithm to avoid congestion is an essential problem for satellite networks.This thesis mainly researches on LEO satellite routing strategies.First of all,this thesis studies the satellite routing algorithm,analyzes and summarizes the congestion status of the LEO network system,and provides a basis for subsequent research and design work.Secondly,we put forward the design scheme of the LEO network simulation platform based on OPNET,and implement the construction of specific node models and process models according to the scheme.The work uses the built LEO network simulation platform to simulate and verify the effectiveness of the proposed algorithm in this thesis.Finally,on the basis of analyzing the satellite routing algorithm,a multipath routing algorithm based on link load prediction is proposed.For network congestion,this thesis considers three factors:link transmission delay,link queue delay,and predicted link queue delay.The link performs a "penalty" mechanism to derive routing tables based on congestion control and congestion prediction over a period of time,respectively.After receiving the data packet,the satellite node selects the routing table according to the link congestion status of the local node and the next-hop node to better avoid the congested link and reduce the packet loss rate of the network.