On Exploiting Few Strangers for Data Forwarding in Delay Tolerant Networks

Routing is one of the challenging tasks in Delay Tolerant Networks (DTNs), due to the lack of global knowledge and sporadic contacts between nodes. Most existing works take greedy mechanism to forward messages, i.e., only nodes which have higher quality metrics than current carriers can be selected as relays to final destinations. In this work, we explore the influence of strangers on routing performance under a more challenging scenario of pure darkness. We first present a method to identify the relationship between nodes (i.e., stranger or friend). Second, we explore the optimized number of strangers we can employ. Third, we propose a novel routing scheme which are called STRON in this paper by taking both the STRangers and their Optimized Number into account. We finally compare our routing scheme with the greedy mechanism through synthetical and trace-driven simulations, the results show that our routing strategy achieves a better performance, especially in terms of combined overhead/packet delivery ratio and the average number of hops per message.