Simulation And Study On Routing In Vehicular Delay Tolerant Network

Vehicular delay tolerant network is a new wireless network derived from the combination of delay tolerance network and vehicular ad-hoc network.In the network environment of intermittent connectivity and high delay,the VDTN adopts the strategy of"store-carry-forward" to complete the perception,processing and transmission of messages.Due to the intermittent connectivity of the network and the high change of topology,the routing of the traditional vehicular ad-hoc network is not suitable for vehicular delay tolerant network.How to design routing to reliably complete message transmission is a challenging task and has been one of the research hotspots of vehicular delay tolerant network.In the VDTNs,when the mobile nodes move in the predicted route,the frequency of the nodes meeting increases.Mobile nodes with a history of encountering a particular node can have a significant impact on the decision to forward messages in the future.A node that has encountered the relay node in the past has a higher probability of encountering it again at some time in the future.Based on the characteristics of mobile nodes in vehicular delay tolerant network,this paper proposes a routing algorithm based on node contact history and a routing algorithm based on node contact history and geographic information.The routing algorithm based on node contact history works in two modes:the intersection mode and the road segment mode.In the intersection mode,the transmitted message is forwarded to the road segment with a higher connectivity probability.And in the road segment mode,the optimal relay vehicle is selected through delivery probability.The algorithm based on the node contact history and geographic information adopts the historical strategy and geographical strategy in the selection of the next hop node.The history strategy selects the next hop based on the historical encounter information between nodes to increase the accuracy of message delivery.The geographic strategy is to select the next hop according to the direction of node movement to expand the message coverage.The routing algorithm proposed in this paper is simulated by building a network simulation scenario based on vehicle model under ONE platform.Through algorithm comparison and analysis under multiple routing metric,the results show that the routing algorithm based on node contact history can improve data delivery rate and reduce delay.And the routing algorithm based on contact history and geographic information can predict node movement trend,expand message coverage,and provide better real-time information services for vehicles.