On-Demand QoS Multicast Routing for Triple-Layered LEO/HEO/GEO Satellite IP Networks

In this paper, for the sake of better global coverage, we introduce a novel triple-layered satellite network architecture including the Geostationary Earth Orbit (GEO), the Highly Elliptical Orbit (HEO), and the Low Earth Orbit (LEO) satellite layers, which provides the near-global coverage with 24 hour uninterrupted over the areas varying from 75° S to 90° N. On the basis of this satellite network architecture, we propose an on-demand QoS multicast routing protocol (ODQMRP) for satellite IP networks using the concept of logical locations to isolate the mobility of LEO and HEO satellites. In ODQMRP, we present two strategies, i.e., the parallel shortest path tree (PSPT) strategy and the least cost tree (LCT) strategy, to create the multicast trees under the condition that the QoS requirements, containing the delay constraint, and the available bandwidth constraint, are guaranteed. The PSPT and LCT strategy minimize the path delay and the path cost of the multicast trees, respectively. Simulation results demonstrate that the performance benefits of the proposed ODQMRP in terms of the end-to-end tree delay, the tree cost, and the failure ratio of multicasting connections by comparison with the conventional non-QoS shortest path tree (SPT) strategy.