Probabilistic routing protocol for low Earth orbit satellite networks

Low Earth orbit (LEO) satellite networks have dynamic, yet deterministic, topologies. The time-varying connectivity pattern would result in the re-routing of all connections passing through a link that is turned off as a result of the topology change. A routing algorithm called probabilistic routing protocol (PRP) is introduced. The PRP reduces the number of re-routing attempts due to the dynamic topology of the network. During the routing phase of a newly arriving call, the PRP eliminates the links that will be turned off before the call releases the link due to call termination or connection handover. Since the algorithm has no knowledge of the call duration or exact terminal location, route usage time is only known probabilistically. The probability distribution function of the route usage time of the call is determined to realize the algorithm. Since the routing algorithm works in parallel with a handover re-routing algorithm, the application to the footprint handover re-routing protocol (FHRP) is also demonstrated. The performance of the algorithm is investigated using simulation experiments.