An Efficient Message Dissemination Scheme for Minimizing DeliveryDelay in Delay Tolerant Networks

Delay tolerant networks （DTNs） are a kind of sparse and highly mobile wireless networks, where no stableconnectivity guarantee can be assumed. Most DTN users have several points of interest （PoIs）, and they enjoy disseminatingmessages to the other users of the same PoI through WiFi. In DTNs, some time-sensitive messages （disaster warnings, searchnotices, etc.） need to be rapidly propagated among specific users or areas. Therefore, finding a path from the source tothe destination with the shortest delay is the key problem. Taking the dissemination cost into consideration, we proposean efficient message dissemination strategy for minimizing delivery delay （MDMD） in DTNs, which first defines the user＇sactiveness according to the transiting habit among different PoIs. Furthermore, depending on the activeness, an optimaluser in each PoI is selected to constitute the path with the shortest delay. Finally, the MDMD with inactive state （on theway between PoIs） is further proposed to enhance the applicability. Simulation results show that, compared with otherdissemination strategies, MDMD achieves the lowest average delay, and the comparable average hopcounts, on the premisethat the delivery ratio is guaranteed to be 100% by the sufficient simulation time.