Research Data Distribution Method Vehicular Ad Hoc Network

With the rapid development of wireless communication technology, VANET (Vehicular Ad-hoc Network) has attracted great attention, becoming one of the major fields of inquiry in wireless communication research. Since VANET can be applied to a wide range of fields for transportation management, information sharing, as well as music downloading and resource sharing, etc., it has a vast potential for future development. Typologically diversified and dynamic, VANET is a highly mobilized vehicular network featuring unevenly distributed node density, resulting in a highly unstable wireless communication. Although network coding can effectively enhance the reliability and stability during data dissemination, thus promoting the network throughput while reducing network congestion, it is still a fact that network congestion might occur since all the nodes can request and forward an event. Therefore, a clustering-based agent selection approach was adopted to address network congestion caused by broadcasting storm, proposing a PSO based cluster-head election in order to let cluster-head broadcast the encoded blocks. On this basis, a revised algorithm for sparse scene data dissemination strategy RDDR (RSU-aided Data Dissemination based on Random linear network coding) is also proposed to remedy for the DDR.The main research and contribution of this paper are elaborated as follows:(1) A conclusion is drawn that network coding technique should be applied to data dissemination in VANET based on a detailed analysis of network coding mechanism on VANET, featuring great instability, unevenly distribution of vehicle density, and dynamic mobilization of nodes.(2) A VANET data dissemination methodology is proposed based on clustering-based selection. A PSO based cluster-head election is adopted in order to let cluster-head carry out data dissemination as the agent.(3) A DDR is proposed based on network coding mechanism and clustering mechanism. DDR is able to add robustness to data dissemination, easing the broadcasting storm caused by flooding.(4) RDDR is proposed considering the sparse scene. Saving and forwarding encoded packs with RSU promotes the reliability of data dissemination.This paper realizes DDR and RDDR with the simulation software, namely, Network Stimulator2(NS2) and VanetMobiSim, and carries out simulation experiments. The results have shown that compared with existing solutions, DDR better suits the city scenario, for it can maintain a higher delivery rate and throughput and lower transmission delay. More importantly, RDDR is able to provide data dissemination service to a certain extent when applied to a sparse network topology in VANET.