Social and Geographical Routing for Vehicular Delay-Tolerant Networks

Vehicular Delay-Tolerant Networks (VDTN) address the communication challenges inherent in vehicular environments characterized by intermittent connectivity and dynamic mobility patterns. This paper investigates the simultaneous use of social and geographical routing mechanisms in VDTNs. Social information can be learned automatically from previous contact history, while geographical information is assumed to be received on each node from a GPS system and exchanged with neighboring nodes. The routing protocol variants studied are variants of the spray-and-wait protocol, where both the spray and wait phases use either social or geographical information. The simulation results show that the mechanism used in the search phase has more impact on the routing performance. GreedySocial, a combination of Greedy spraying of messages followed by Social (dLife-based) search of the destination had the best (higher) delivery probability for higher node density situations, although for lower density scenarios its spray mechanism is not aggressive enough.