Dynamic routing algorithm for LEO/MEO double-layered satellite networks

Double-Layered satellite networks consisting of LEO (low earth orbit) and MEO (medium earth orbit) satellites have advantages on networking and communication performances. Based on the advantages of MEO and LEO satellites in long-distance and short-distance communications respectively, a hierarchical and distributed dynamic routing algorithm named DLRA (double-layered satellite-network routing algorithm) was proposed. By controlling flood of link state information, LEO satellites could acquire local topology information to route the short-distance traffics. The long-distance traffics were routed in MEO layer. The residual lifetime of the ISL (inter-satellite link) was considered in the path weight calculation in this algorithm. The selected path was optimal in path delay and duration. The simulation results show that DLRA has better performances in end-to-end delay, routing overhead and traffic flow distribution, and is easy to be applied.