Achieving Anycast in DTNs by Enhancing Existing Unicast Protocols ∗

Many DTN environments, such as emergency response networks and pocket-switched networks, are based on human mobility and communication patterns, which naturally lead to groups. In these scenarios, group-based communication is central, and hence a natural and useful routing paradigm is anycast, where a node attempts to communicate with at least one memberof aparticular group. Unfortunately, most existing anycast solutions assume connectivity, and the few specifically for DTNs are single-copyin natureandhaveonly been evaluatedin highlylimited mobility models. In thispaper, we propose a protocol-independent method of enhancing a large number of existing DTN unicast protocols, giving them the ability to perform anycast communication. This method requires no change to the unicast protocols themselves and instead changes their world view by adding a thin layer beneath the routing layer. Through a thorough set of simulations, we also evaluate how different parameters and network conditions affect the performance of these newly transformed anycast protocols. Categories andSubject Descriptor