Research On Routing And File Transmission In Vehicular Ad Hoc Networks

As the emerging market of the information industry both from a commercial and scientific view, Internet of things(IoT), has been attracting many institutions and workers all of the world to devote themselves to the related research, while Intelligent Transportation System(ITS) is exactly the significant field supported and promoted by the national Io T applications. Vehicular Ad-hoc Networks(VANETs), one of the core technologies of the Intelligent Transportation System(ITS), lay the foundation for the future mobile Internet of things and draw enormous attention from the academia and industry to the technology research. Based on the Vehicle-to-Vehicle(V2V) communications and the Vehicle-to-Infrastructure(V2I) communications, VANETs are aimed at the applications including the traffic safety, traffic efficiency, infotainment and Internet access services, the realization of which, to some extent, relies on the appropriate and effective transmission mechanism of information. Consequently, it's rather essential to research on the reliable routing protocols and information transmission mechanism to meet the information transmission requirements.Due to vehicles' mobility, Vehicular ad hoc networks(VANETs) are suffering from the highly dynamic network topology and frequent link breakage. The complex communication environment and unreliable wireless communication links make it hard for the existing routing protocols to keep the high packet delivery rate. Besides, as for those current routing protocols based on the receiving nodes' forwarding, they always obtain the higher packet delivery rate at the expense of the redundant broadcast information and affected seriously by the sparse degree of the network. Owing to VANETs' features and restricts, the files, especially audio or video files, are impossible to transmit completely in the limited communication time between two nodes. However, some files such as audio or video will be truly effective only if received completely and the failure of the transmission is also a waste of the network resources. To address the two issues above, we propose a FLRBF routing protocol, which can maintain the higher delivery rate and keep the low network overhead; and a transmission mechanism based on the file integrity and cluster, respectively. FLRBF takes advantage of the fuzzy logic system to process the related parameters, and adopts the timer-based competition strategy to control neighbor nodes to broadcast packets. At the same time, the results of the simulation show FLRBF can obtain a higher delivery ratio and lower network overhead. The file transmission mechanism based on the integrity and cluster, evaluates the amount of information that can be transmitted in the communication time between two nodes by combining the theory with the practice. When the evaluation result is bigger than the amount of information of the files to be transferred, the source node will transfer the files to the destination node directly. Otherwise, the node requesting resource will build a cluster and act as the cluster head. The cluster member nodes download files in the way of the collaboration to realize the files' integrity of transmission and downloading. By the usage of the cluster, this kind of transmission mechanism can not only transmit the bigger size of files when guaranteeing their integrity, but also save the network resources.