One Leader at One Time: OLOT Routing in Delay Tolerant Networks

Routing is a challenge problem in Delay-tolerant networks (DTNs) due to the intermittent connectivity environment. To cope with it, both single-copy and multi-copy routing protocols have been proposed. The difference between them is how to handle with the messages that have been forwarded to the next hop. These messages will be removed from buffer immediately in the single-copy protocols, while be kept and forwarded to other relays in the multi-copy cases. However, there is a gap between the two protocols. In our previous work, we have indicated it and proposed a Snail Crawling(SC) method to fill the gap. In this paper, we indicate that the SC method is just an enhanced method but not a routing protocol. By adopting heuristic strategies in messages distribution of SC, we get a new routing protocol One Leader at One Time(OLOT), in which only one node can forward message to another relay at the same time. Simulation results show that both the delivery rate and the overhead of OLOT are better than the SC method.