Routing in Space Delay Tolerant Networks under Uncertain Contact Plans

Delay Tolerant Networking (DTN) has been proposed to provide efficient and autonomous store-carry-and-forward data transport in space networks. Since these networks relay on scheduled contact plans, Contact Graph Routing (CGR) can be used to optimize routing and data delivery performance. However, transient or permanent faults can occur in large space networks, thus introducing uncertainties on the original contact plan reducing CGR performance. In this work, we propose alternative CGR metrics and study a novel replication-based CGR formulation that improves data delivery when operating under uncertain contact plans. This proposal is analyzed by means of simulation and compared with other scheduled and opportunistic routing approaches. Results provide a baseline to develop more specialized probabilistic CGR routing strategies that could cope with unplanned and transient faults in future space DTN networks.