面向大规模低地球轨道卫星网络的星间链路连接策略

Inter-satellite link connection strategy for large-scale low earth orbit satellite networks

针对大规模低地球轨道(LEO)卫星网络,提出了2类新型星间链路(ISL)连接策略:Grid-V和Grid+,并对传统的Grid连接策略进行改进。所提策略充分利用了次邻轨和跨邻轨星间链路,Grid-V连接策略舍弃了Grid连接策略的轨内链路,利用次邻轨和跨邻轨的星间链路形成网络拓扑;Grid+连接策略在保留Grid连接策略中的星间链路基础上,允许卫星与同轨道或者次邻轨道卫星建立跨星连接。针对Walker-Delta星座构型的大规模LEO卫星网络,设计了基于所提星间链路连接策略的最短距离路由算法,并分别从几何拓扑和数据包层面对路由进行了系统级仿真,以评估各连接策略的性能。仿真结果表明,在几何拓扑层面,所提策略可以有效减少平均路由跳数与路径切换次数;在数据包层面,所提策略在往返时延及抖动、路径占用率、平均吞吐量等方面具有更好的性能。

For large-scale low earth orbit(LEO)satellite networks,two new inter-satellite link(ISL)connection strategies named Grid-V and Grid+were proposed,which improved the traditional Grid connection strategy.The proposed strategies made full use of the ISL connected to adjacent and cross-adjacent orbits.The Grid-V connection strategy abandoned the intra-orbit links of the Grid connection strategy and used ISL of the adjacent and cross-adjacent orbits to form the network topology.The Grid+connection strategy,while retaining the Grid connection strategy,allowed satellites to establish cross-satellite connections with satellites in the same orbit or the cross-adjacent orbits.For the large-scale LEO satellite network with a Walker-Delta constellation configuration,a shortest distance inter-satellite routing algorithm was designed based on the proposed ISL connection strategies,and system-level simulations were conducted from the perspectives of geometric topology and packet respectively to evaluate the performance of each connection strategy.Simulation results show that,from the perspective of geometric topology,the proposed strategies can effectively reduce the average number of routing hops and path switches.At the packet level,the proposed strategies exhibit better performance in terms of round-trip time and jitter,path occupation ratio,average throughput and so on.