High Performance IP Multicasting Over Wireless Satellite-Terrestrial Networks

We describe our work on IP multicast extensions to the wireless hybrid network described. We describe effective extensions of IGMP, and asymmetric multicast algorithms that exploit the asymmetry to increase the number of users, scale-up and improve the loading of the terrestrial components. This requires an asymmetric multicast routing mechanism. We describe enhancements to existing multicast routing protocols such as CBT to the hybrid environment described here. We provide results on performance of our proposed hybrid multicast algorithms with respect to the following performance metrics: time to join a group; time for a packet to reach every member of the multicast group; performance with large multicast groups.