Performance of two-hop routing in delay tolerant networks with selfish nodes

Routing in delay tolerant network (DTN) closely depends on the cooperation of nodes. At present, there are many works exploring the impact of the selfish behavior. However, most of these works assume that there is only one source-destination pair, and the source just generates one message. For this reason, this paper studies the impact of selfish behavior when many messages are transmitted at the same time. In particular, there are multiple source-destination pairs, and each source generates the messages according to the Poisson process. Due to the selfish behavior, the nodes may be more willing to forward their own messages. In addition, the nodes may have closer relation with certain nodes (friends). Due to selfishness, the nodes may be more willing to help their friends other than the strangers. In such complex scenario, this paper proposes the theoretical models to evaluate the performance of the two-hop routing algorithm with single-copy and redundancy, respectively. Simulations show the accuracy of the models. Numerical results show that the selfish behavior may significantly increase the average delivery delay. In addition, the selfishness may also decrease the maximal flow.