Source-based multicast algorithms for LEO satellite IP networks

To resolve the channel resources waste problem of current source-based multicast routing algorithms in low earth orbit (LEO) satellite IP networks, a new source-specific multicast (SSM) algorithm called core-cluster-based source-specific multicast (CSSM) algorithm and its improved one (i.e. the weighted CSSM algorithm) are proposed. The CSSM algorithm takes source node as initial core cluster, and extends it to construct entire multicast tree with the lowest tree cost step by step by a shortest path scheme between newly-generated core cluster and surplus group member nodes, which can greatly improve transport bandwidth utilization and efficient transport capacity. In the w -CSSM algorithm, a weighted approach is proposed to make tradeoff between tree cost and end-to-end propagation delay so that end-to-end propagation delay can be decreased to meet strict end-to-end delay requirements of some real-time multicast applications by adjusting a weighted factor at the expense of a bit increase of tree cost. Compared with a typical SSM algorithm in LEO satellite networks, i.e. multicast routing algorithm (MRA), tree cost performance of the CSSM and w-CSSM algorithms is better than that of MRA at the expense of a bit higher end-to-end propagation delay.