A Utility-based Multi-copy Forwarding Algorithm in Delay Tolerant Networks

In delay tolerant networks (DTNs) with uncertainty in node mobility, message forwarding usually employs a multi-copy, opportunistic forwarding scheme to improve delivery probability. Minimizing the delivery latency (delay) and minimizing the number of forwardings (message copies) have been two conflicting goals. On the other hand, utility-based routing has been proposed in multi-hop wireless networks, where a utility is defined as a compound metric that provides a trade-off between delay and forwarding cost. In this paper, we propose the first multi-copy utility-based opportunistic forwarding algorithm in DTNs. The proposed multi-copy opportunistic utility-based forwarding (MOUF) algorithm is able to improve the overall utility representing a user preferred trade-off between delay and forwarding cost so as to satisfy different requirements. Theoretical analysis and extensive simulations are conducted to verify the improved performance of the proposed algorithm.