星地融合网络中基于多目标优化的星间切换决策方法

Inter-Satellite Handover Method Based Multi-Objective Optimization in Satellite-Terrestrial Integrated Network

低轨通信卫星高速运动使网络拓扑具有高动态性,同时,星地融合网络资源呈现时空非均匀分布。当卫星移动引发多个用户和业务切换时,触发大量切换请求导致网络资源竞争加剧,有限的星上资源无法满足切换请求,导致切换成功率显著下降。针对以上问题,提出一种基于多目标优化的星间切换方法,引入卫星覆盖时空图,将动态连续拓扑划分为静态离散快照,表征卫星节点与用户在不同时间与空间下的连接关系,建立星间切换决策的多目标优化模型,提出自适应加速多目标优化算法对平均数据速率与网络负载进行优化,保证切换成功率,提高网络服务能力。搭建星地融合通信仿真环境,在多星重叠覆盖场景下测试多用户切换性能,分析表明,所提多目标星间切换方法的平均切换成功率提高20%以上。

The high-speed motion of low-earth orbit communication satellites results in a highly dynamic network topology,and the spatio-temporal distribution of resources in the satellite-terrestrial integrated network is non-uniform.When multiple users and services switch between satellites,a large number of handover requests are triggered,leading to intensified network resource competition.As a result,the limited satellite resources cannot meet all the handover requests,leading to a significant decrease in handover success rate.In view of the above problem,the multi-objective optimization based satellite handover method was proposed.It introduced the satellite coverage spatio-temporal graph and transforms the dynamic continuous topology into static discrete snapshots,accurately depicted the connections between satellite nodes and users at different times and locations.The multi-objective optimization model was established for satellite handover decisions,and anadaptive accelerated multi-objective evolutionary algorithm(AAMOEA)was proposed to optimized user data rate and network load simultaneously,ensured handover success rate and enhanced network service capability.It built a STIN communication simulation environment and tested the multi user handover performance in a multi satellite overlapping coverage scenario.The results demonstrated that the multi-objective optimization-based satellite handover method achieved an average handover success rate improvement of over 20%compared to benchmark algorithms.