An Energy-Efficient Opportunistic Routing Protocol in Delay Tolerant Networks

In delay tolerant networks (DTN), connectivity between nodes is not guaranteed and a message is delivered to a destination node from a source node via opportunistic contacts between intermediate nodes. In DTN, nodes are operated using battery and thus, an energy-efficient operation is crucial, especially for disaster environment. In this paper, we consider PRoPHET protocol as a base protocol since it is the standardized DTN protocol and thus, is regarded as one of the representative DTN routing protocol. Then, we propose an energy-efficient opportunistic routing protocol in DTN, where messages are forwarded based on node's remaining battery and delivery predictability in PRoPHET protocol, analyze the performance of the proposed scheme, and compare the performance with PRoPHET and PRoPHET with periodic sleep in detail, from the aspect of delivery ratio, overhead ratio, delivery latency, and ratio of alive nodes. Simulation results show that the proposed protocol has better delivery probability and overhead ratio, in spite of small increase of delivery latency.