Connective-aware Routing Protocol And Its Implementation For Vehicular Delay Tolerant Network In Urban Scenario

With the rapid development of short-range communication and intelligent transportation technology,and the demand for mobile vehicular services(active safety services and user entertainment services),vehicle delay tolerant network(VDTN)as an emerging technology attracts much more attention by academy and industry.Different from vehicular ad hoc network(VANET),the connections among vehicle nodes are intermittent by opportunistic communication in VDTN,which brings greater challenges to data forwarding in mobile vehicular environments.Hence,the existing storage-forwarding routing mode in VANET is no longer applicable to VDTN.Considering the more intensive demand for vehicular service in urban environment,this paper focus on the research of data dissemination algorithm in urban VDTN,that is to design stable and reliable routing protocol which is appropriated for the characteristics of urban VDTN environment.Therefore,connective-aware routing protocol for VDTN in urban scenario is proposed.In the protocol,data distribution direction is determined by network connectivity-based directional selection.And then the intermediate node is selected for data forwarding by node forwarding capability-based next hop selection mechanism.The main contents of this paper can be summarized as follows:(1)The communication system,characteristics and application of VDTN are elaborated.And routing principle,advantages and disadvantages of various algorithms are summarized by studying the existing routing algorithms in vehicular network.(2)A road network connectivity analysis model is established to realize the direction selection of network connectivity-based routing by studying the traffic flow theory in vehicular network.Simulation of urban mobility(SUMO)is used to verify and analyze the network connectivity and its traffic flow model,by which to analyze the impact on data transmission efficiency;(3)Both wavelet neural network-based flow forecasting model and the calculation of effective connection time between two nodes are created to estimate the node forwarding capability,which is the standard to design the selection method of the routing node.The real traffic data from WiBro network is used to verify the prediction effect of wavelet neural network-based traffic prediction model;(4)Adaptive retransmission times-based data retransmission mechanism is implemented in connection with the failure of message transmission,which makes the data transmission efficiency be further protected.In this paper,the proposed routing algorithm is implemented on the opportunistic network environment simulation(ONE),which can greatly improve the message success delivery rate in VDTN environment,and reduce the data transmission delay and communication overhead to guarantee the stability of data transmission compared with the similar algorithms.The effect of data dissemination will more efficient and reliable by attaching data retransmission mechanism.