Price: Hybrid geographic and contact-based forwarding in delay-tolerant networks

Similarity-based techniques relying on contact patterns among nodes have shown to provide high delivery success rate when performing routing in delay-tolerant networks (DTN). Nevertheless, such approaches work well only when nodes exhibit high similarity values. In this paper, we propose Price (Periodicity-based Routing in Intermittently-Connected Environments), an agenda-based greedy forwarding scheme for DTNs that combines geographic-oriented forwarding with contact-based forwarding by relying packets according to predictable patterns of locations and contacts. We define the operation of Price and evaluate the performance of geographic forwarding under the framework of graph navigation to unveil a small-world phenomenon. We then gauge the performance of Price using a real-life mobility data set according to various well-known routing solutions such as Flooding, Prophet, Bubble Rap, and Wait. Simulation results show that Price largely outperforms other solutions, especially in terms of combined cost/delivery ratio. (C) 2011 Elsevier B.V. All rights reserved.