一种基于时空等级的LEO卫星网络路由策略

A routing strategy for LEO satellite network based on space⁃time⁃level

随着5G技术的发展和6G技术的研究,低轨卫星网络在未来空天地一体化网络中的地位越发重要,而作为网络核心技术的路由策略仍面临一些挑战,如卫星网络拓扑高动态变化、链路频繁切换、节点计算处理能力有限以及负载流量分布不均衡等。针对卫星所覆盖区域负载不均衡且与时间因素有关,以及星上用户多业务服务质量需求的问题,设计了一种基于时空等级的业务分类负载均衡路由算法。算法考虑了卫星网络流量的分布与时空等级的关系。卫星节点需先根据当前时刻及其所覆盖的地面区域计算其时空等级,并在路由算法的下一跳实时调整阶段加入时空等级作为选路条件之一,同时改进了阈值的计算方式,并在路由时考虑了不同的链路代价以满足多业务服务质量需求。仿真结果表明,相较于DSP、TLR和RMLBR算法,所提算法虽然在总吞吐量表现不及TLR和RMLBR算法,但在时延以及链路利用率方面有所改进,有效降低了平均端到端时延,较好地满足不同业务服务质量需求,均衡网络负载。

With the development of 5G technology and the research of 6G technology,the LEO satellite network will play an increasingly important role in the future integrated air-space-ground network.However,the routing strategy as the core technology of the network still faces some challenges,such as high dynamic changes in satellite network to⁃pology,frequent switching of paths,limited computing and processing capacity of nodes,and unbalanced load and traffic distribution.Aiming at the problem of unbalanced load in the area covered by the satellite and related to time fac⁃tors,and the multi-service QoS requirements of users on the satellite,this paper designs a space-time-level-based service classification load balancing routing algorithm.The algorithm considers the relationship between the distribution of satellite network traffic and the space-time level.The satellite node needs to solve its space-time level according to the current moment and the ground area it covers.In the next hop real-time adjustment stage of the routing algorithm,the space-time level is added as one of the routing conditions.At the same time,the calculation method of the thresh⁃old is improved,and different link weights are considered when routing to meet the multi-service QoS requirements.The simulation results show that,compared with the DSP algorithm,the TLR algorithm and RMLBR algorithm,al⁃though the algorithm in this paper is not as good as the TLR and RMLBR algorithm in terms of total throughput,the de⁃lay and ISL utilization have been improved,which effectively reduces the average end-to-end delay,better meets the QoS requirements of different services,and balances the network load.