适于低轨卫星IP网络的特定源组播算法  

Source-Specific Multicast Algorithms for LEO Satellite IP Networks

作　　者：程连贞[1] 刘凯[1] 张军[1] 宋学贵[1] 

机构地区：[1]北京航空航天大学电子信息工程学院,北京100083

出　　处：《电子学报》2007年第6期1050-1055,共6页Acta Electronica Sinica

基　　金：国家自然科学基金(No60532030;10377005;10577005);航天科技创新基金

摘　　要：为了解决低轨卫星IP网络中现有特定源组播算法的信道资源浪费问题,本文提出了一套新的特定源组播算法,即基于核心群的特定源组播算法(CSSM)和加权的CSSM算法(w-CSSM).CSSM算法以源节点作为初始核心群,通过核心群和剩余组成员的最短路径方法逐步扩展直至整棵组播树构建完成,所得的树代价最小,从而大大提高了网络的带宽利用率和传输效率.在w-CSSM算法中,加权因子可以自适应调整以适度增大树代价、降低端到端传播时延,以支持某些有严格端到端时延要求的实时组播业务.通过与低轨卫星IP网络中典型特定源组播算法MRA的仿真比较,可以看出CSSM和w-CSSM算法的树代价性能比MRA有较大改善,不过端到端传播时延略高.To resolve the channel resources waste problem of current source-specific multicast （SSM） routing algorithm in low earth orbit （LEO） satellite IP networks, a new SSM algorithm called core-cluster-based source-specific multicast （CSSM） algorithm and its improved one （the weighted CSSM algorithm） are presented. The CSSM algorithm takes source node as initial corecluster,and extends it step by step to construct entire multicast tree with the lowest tree cost by a shortest path scheme between newly-generated core-cluster and surplus group member nodes, which can greatly improve transport bandwidth utilization and transport efficiency. In the w-CSSM algorithm,end-to-end propagation delay can be decreased and meanwhile tree cost will be increased a bit by adaptively adjusting the weighted coefficient to meet strict end-to-end delay requirements of some real-time mulficast applications. Finally,performance comparison of the two algorithms with the typical SSM algorithm （i.e.MRA） in LED satellite networks is provided. Simulation results show that their tree cost performance is greatly better than that of MRA at the expense of a bit higher end-to-end propagation delay.

关 键 词：卫星IP网络 低轨 路由 组播 特定源组播 

分 类 号：TN927.3[电子电信—通信与信息系统]