Research On Inter-satellite Load Balancing Routing Algorithm For LEO Constellation Network

Compared with MEO communication satellites and GEO communication satellites,LEO satellite networks have many advantages such as short delay,and wide coverage and miniaturization of user terminals,which have been used in multimedia broadcasting,mobile communication,remote Internet of Things and other fields.The LEO satellite communication networks are characterized by non-uniform traffic distribution,unevenly ground station distribution and time-varying network load.Therefore,The data of the LEO satellite network based on the inter-satellite links transmission between satellites and the nearby ground stations may lead to dynamic funnel-type congestion in the space segment.It will result in the congestion of the feeder link congestion and the worse end-to-end characteristics.This article makes a study on the problem of dynamic funnel-type congestion in the space segment of the LEO satellite networks based on inter-satellite links and designs the inter-satellite load balancing routing algorithm for the purpose of alleviating such congestion.This article analyzes the problem of dynamic funnel congestion in the space segment of the LEO satellite networks.Based on the introduction of the LEO satellite network topology and inter-satellite links,this paper discusses the causes and characteristics of the dynamic funnel congestion in the space segment and provides the theoretical basis for routing algorithm design.The Enhanced Practical Distributed Routing Protocol(PDR-e)is proposed in this article to alleviating the dynamic funnel-type congestion.Firstly,PDR-e defined the “station area” to divide the space segment area with the dynamic funnel-type congestion risk of space segment.Then,in order to achieve the reasonable distribution of traffic,PDR-e calculates link weight based on region to obtain multiple routing paths.Finally,PDR-e achieves the distributed forwarding according to local satellite queue status and next-hop satellite status.The OPNET simulation result shows that PDR-e can alleviate the dynamic funnel-type congestion in the space segment and improve the network load balancing capability.Aiming to improve routing algorithm delay sensitivity,the Regional-TrafficDetour Multipath Load Balancing Routing algorithm(RMLBR)is proposed based on the research in Chapter Three.Firstly,RMLBR calculates the transition probability according to satellite network status and the source-to-destination distance to implement the regional-traffic-detouring.Then,under the constraint of path delay,the multipath routing scheme is obtained by the multipath search based on the transition probability to alleviate the dynamic funnel-type congestion.The OPNET simulation shows that RMLBR can alleviate the dynamic funnel-type congestion,reduce the endto-end delay,so this algorithm can be applied to delay-sensitive scenarios.