Core-cluster combination-based shared tree algorithm for LEO satellite IP networks

To resolve the channel resources waste problem of the typical source-specific multicast routing algorithm in Low Earth Orbit (LEO) satellite IP networks, a new core-based shared tree algorithm named Core-cluster Combination-based Shared Tree (CCST) algorithm is proposed in this paper. It includes a core selection method named Dynamic Approximate Center (DAC) and a multicast route construction scheme named core-cluster combination. The DAC method selects core node based on virtually static and regular network topology formed by logical locations. The core-cluster combination scheme takes core 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 members, which can greatly improve transport bandwidth utilization and multicast transport efficiency. Finally, the CCST algorithm is compared with several other typical algorithms in LEO satellite IP networks, and simulation results show that its tree cost performance is greatly better than the others at the expense of a bit higher end-to-end propagation delay.