An anycast routing strategy with time constraint in delay tolerant networks

Abstract

Delay Tolerant Networks (DTNs) are sparse mobile ad-hoc networks in which there is typically no complete path between the source and destination. Anycast is an important group communication paradigm for numerous DTN applications such as resource discovery and information exchange in emergency or crisis situations. Unlike unicast and multicast, which have been studied extensively in DTNs, few prior works have addressed the DTN anycast routing problem. Furthermore, they do not consider the time constraint in formulating the relay selection strategy. In this work, we propose a single-copy Time Constrained Anycast (TCA) routing, which considers relay node candidates form both current and past contacts to reduce the transmission cost. Furthermore, we derive the one-hop and two-hop delivery probability to an anycast group based on the distribution of inter-contact times (ICTs). Extensive simulation results based on the Cabspotting trace show that our scheme can achieve up to 21% higher delivery rate, 11% lower delay, and 36% lower transmission cost compared to other anycast routing strategies.