ATM-based routing in LEO/MEO satellite networks with intersatellite links

An asynchronous transfer mode (ATM)-based concept for the routing of information in a low earth orbit/medium earth orbit (LEO/MEO) satellite system including intersatellite links (ISL's) is proposed, Specific emphasis is laid on the design of an ATM-based routing scheme for the ISL part of the system, The approach is to prepare a virtual topology by means of virtual path connections (VPC's) connecting all pairs of end nodes in the ISL subnetwork for a complete period in advance, similar to implementing a set of (time dependent) routing tables, The search for available end-to-end routes within the ISL network is based on a modified Dijkstra Shortest Path Algorithm (M-DSPA) capable of coping with the time-variant topology, With respect to the deterministic time variance of the considered ISL topologies, an analysis of optimization aspects for the selection of a path at call setup time is presented, The performance of the path search in combination with a specific optimization procedure is-by means of extensive simulations-evaluated for example LEO and MEO ISL topologies, respectively.