Research On The Routing Problem Of Inclined Orbit Constellations

Satellite networks,especially the Low Earth Orbit(LEO)satellite networks,have unique advantages in communications and navigation,resource exploration,environment and disaster monitoring.Due to the low orbital position and low communication delay,the LEO satellite is a viable way to build a global mobile wireless network in the future.LEO satellite networks need tens or even hundreds of satellites to build satellite constellations covering the world.The topology structure of LEO satellite networks changes rapidly,resulting in that the traditional routing algorithms for terrestrial networks can not be applied directly to LEO s atellite constellations.Traditional routing algorithms will require extensive routing signaling and computation to maintain the routing table,which consumes a significant amount of bandwidth and energy.LEO satellite constellations can be divided into polar orbit constellations and incline orbit constellations.This paper mainly studies the routing algorithm of inclined orbit constellation.The main contributions of this paper are as follows:1.We proposed a Shortest Path routing algorithm based on Virtual Coordinate(SPVC)to find the shortest path in inclined orbit constellations.The virtual coordinate of a satellite can represent its relative position in the network,but virtual coordinates do not need update after assignment.The shortest path between any two ground terminals can be calculated using the virtual coordinates and orbit phases of the accessing satellites of the source and destination ground terminals.The propagation delay of packets are minimized.2.We proved that the computational complexity of the proposed algorithm is c onstant.The computational complexity of SPVC does not change with the number of satellites in the constellation and the number of ground equipment,which can effectively reduce the computational load of the satellite.3.We built up a variety of delta constellation networks in NS2.The proposed algorithm,geographic routing algorithm and Dijkstra algorithm are applied separately for routing.Through simulations,it is validated that the new algorithm can obtain the shortest path,and its running time is much shorter than that of Dijkstra algorithm.