A Load Balancing Routing Algorithm For LEO

With the development of the communication technology,satellite communication has made breakthrough progress in terms of broadcast television,global communication and mobile communication.Satellite networks make the satellite communication as the important component of the wireless networks.The routing algorithm,as the key point,can affect the performance of the satellite network system to some degree.In this paper,we study the changes of topogoly and the limitation of the satellite capabilities and propose a low complexity probabilistic routing algorithm for polar orbits satellite constellation networks.We adopt the method to utilize the satellite node number instead of the virtual topology algorithms in order to reduce the space complexity.And the proposed algorithm makes full use of the mesh structure of the polar orbits satellite constellation network topology refering to DRA in order to reduce the time complexity.Inspired by ELB,we a link state informing mechanism in the proposed algorithm.Each satellite can send a small-sized high priority packet to neighboring satellites to inform them the link state.By this mechanism each satellite node can choose the next hop according to the link state.Besides,choosing the next hop according to the probability makes a contribution to balance the traffic load.The algorithm takes the link state as a factor when calculate the probability of the candidate next hop.The probility of the candidate next hop changes dynamically with the change of link state,making the node on relatively free link as the next hop with greater possibilities,thus realizing the goal of balancing the traffic load,avoiding the congestion and reducing the packet loss rate.In simulation,the source and destination terminals are dispersed into six continental regions,following a distribution identical to the traffic distribution.Results assessed by NS2 presents the superiority of LCRA in terms of end-to-end delay,throughput and packet loss rate in comparison with other routing algorithms in comparison with DSP and DRA.