SMART: A selective controlled-flooding routing for delay tolerant networks

Delay-Tolerant network (DTN) is a network in which no simultaneous end-to-end path exists. And the messages delivered in the DTN usually have large delivery latency due to network partition. These special characteristics make DTN routing a challenging problem. In this paper, we propose a DTN routing protocol SMART. SMART uses travel companions of the destinations (i.e. nodes that frequently meet the destination) to increase the delivery opportunities. In the first phase of SMART, a fixed number of copies of a message are injected into the network to forward the message to the companions of the destination. In the second phase of SMART, a companion of the destination only forwards the message to a fixed number of the destination’s companions. Our analysis and simulation results show that SMART has a higher delivery ratio and smaller delivery latency than opportunistically controlled-flooding schemes and has a significantly smaller routing overhead than pure flooding schemes.