Virtual-Cost-Based Algorithm for Dynamic Multicast Routing in Satellite-Terrestrial Networks

SUMMARY Satellite-terrestrial (ST) networks, in which many nodes are interconnected by both satellite and terrestrial networks, can efficiently support multicast services. This is because satellite broadcasting is suitable for a large multicast group and a terrestrial network is suitable for a small multicast group. An ST network requires a multicast routing algorithm that can select the appropriate satellite and terrestrial routes. Conventional dynamic routing algorithms for terrestrial networks cannot construct an efficient multicast routing tree because they basically select a less-expensive route when a node is added. We have developed a dynamic routing algorithm, a virtual-cost-based algorithm, for ST networks that selects the route to use according to the multicast group size when a node is added to the group. Simulation showed that the proposed algorithm is advantageous when nodes are added to or removed from the multicast group during steady-state simulation.