Efficient Multicast Routing for LEO Satellite IP Networks

To resolve the channel resources waste problem of current multicast routing algorithm in low earth orbit (LEO) satellite IP networks, a core-cluster-based source-specific multicast (CSSM) algorithm and its weighted version (i.e. wCSSM algorithm) are presented. The CSSM algorithm takes source node as initial core-cluster, and expands 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 members, which can greatly improve transport bandwidth utilization and transport efficiency. Moreover, the wCSSM algorithm can make tradeoff between end-to-end propagation delay and tree cost by adaptively adjusting the weighted factor to meet strict end-to-end delay requirements of some real-time multicast applications at the expense of a slight increase in tree cost. Finally, performance comparison of the proposed algorithms with the typical SSM algorithm (i.e. MRA) in LEO 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.