Efficient planning of satellite-terrestrial hybrid networks for multicast applications

As the satellite technology will be one of the main components of the next generation Internet (NGI), a naturally occurring question concerns the feasibility of providing an efficient satellite-based Internet access. In this paper, we are interested in the problem of the planning of satellite-terrestrial hybrid networks for the multicast transfer. We first develop an architectural model for such type of networks, then we define the problem and we propose a planning heuristic that determines the suboptimal positions of satellite uplinks in a given terrestrial network. The proposed method minimizes the mean cost (the number of branches) of multicast trees for the unreliable multicast and the mean packet transfer delay for the reliable multicast. In addition, we develop a configuration policy of PIM-SM in hybrid networks concerning the choice of the list of rendezvous points (RPs) and the switching from the RP-routed tree to the shortest path tree. The obtained results demonstrate the ability of the proposed methods (the planning heuristic and the PIM-SM configuration policy) to improve the multicast performance criteria and to determine effectively the satellite uplink positions using PIM-SM combined with UDLR (unidirectional link routing)