DARTING: a cost-effective routing alternative for large space-based dynamic-topology networks

This paper introduces a novel distributed adaptive routing algorithm called DARTING that is devised specifically to achieve cost-effective, yet reliable, message delivery on large space-based dynamic-topology networks (DTNs). Conventional DTN routing schemes (e.g., flooding) require extraneous link resource for sustaining overhead messages, which often drives the overall system cost to an unacceptable level when large number of space-based communication payloads are involved. Two topology-update mechanisms are devised into DARTING, and neither will create overhead messages unless there is a demand for delivering data messages. One of these mechanisms also entails a “loop-breaking” property that is crucial for maintaining reliable message delivery by DARTING on DTNs. This paper also presents the simulation results on the end-to-end performance of DARTING, and contrasts these results against those of conventional flooding. Performance data on end-to-end message delay, minimum buffer sizes, and link usage when instituting either routing scheme on a 64-node DTN are obtained by running parallel simulation programs on NASA/ARC´s iPSC/860 parallel computer. These simulation data indicate a clear cost-saving potential of replacing the conventional flooding algorithm with DARTING on large space-based DTNs