Mobility similarity-based routing in buffer-limited delay tolerant networks

In delay tolerant networks (DTNs), multiple-copy routing is often adopted to improve the probability of successful message delivery but causes more traffic loads. The excessive increase in multiple messages copies often exhausts the network resources and deteriorates its performance significantly. To solve this problem, a mobility similarity-based routing (SBR) algorithm is proposed in this paper. On one hand, destination similarity is used to help the message carrier node find the appropriate relay nodes with the higher opportunity to meet the destination node in order to improve the delivery ratio. On the other hand, carrier similarity is adopted to avoid sending the same copy to the nodes with mobility similarity so as to reduce the number of message copies. Furthermore, inspired by the law of diminishing marginal utility in economics, a buffer management scheme based on the message transmission status is proposed. Experimental results show that the proposed SBR routing algorithm combined with the buffer management scheme can improve the delivery ratio and has the lower overhead ratio compared to other routing algorithms.