LEO卫星网络快照序列路由算法优化  

Optimization of Sequent Snapshots Routing Algorithm in LEO Satellite Networks

作　　者：王京林[1,2] 晏坚[1] 曹志刚[1] 

机构地区：[1]清华大学电子工程系,北京100084 [2]海军装备研究院,北京100073

出　　处：《宇航学报》2009年第5期2003-2007,共5页Journal of Astronautics

基　　金：国家自然科学基金资助项目(60672106);国家863高技术项目(2007AA01Z2b6)

摘　　要：快照序列路由算法中时间段的大小影响卫星网络路由性能以及路由表存储和更新代价。提出一种等长时间段快照序列路由改进算法,能够保证时间段内路径不中断。通过分析和仿真,研究了不同时间段划分与丢包率、网络链路利用率、网络端到端延时的关系。结果表明,改进算法能够显著降低丢包率,而且随着时间段的增大,路径切换丢包率呈下降趋势,因此可以兼顾较好的网络性能和较低的存储需求。还提出一种星上存储的改进方法,能够进一步减轻星上存储压力。For sequent snapshots routing algorithm, the length of time interval will impact not only on the routing performance, but also the storage capacity and update cost of routing table in the low earth orbit satellite networks. To support the algorithm with topology snapshots changing over equal-length interval, we proposed an alternative way to guarantee against intra-interval interruption of path. By analysis and simulations, this paper investigated the relations between the length of time interval and the packet loss ratio, link utilization, as well as end-to-end delay. Simulation results show that the proposed method significantly reduces total packet loss rate, hence the packet loss rate caused by path handover delay tends to decrease as the length of interval increases. As a result, the proposed algorithm strikes a good balance between storage requirements and network performance. Besides, the paper presents an improved storage method, which further reduces the demand for storage on-board.

关 键 词：快照序列 时间段 链路中断 存储需求 

分 类 号：TN927[电子电信—通信与信息系统]