The Framework Of Joint Congestion Control For VANET Based On Security Demand

Safety is one of the most important issues in the field about the intelligent transportation, and there are many advantages when active collaborative safety systems absorb the methods from communication. Since the deficiency of the communication protocols, the channel would be congested when communicating in a crowded traffic and that leads the safety applications to a bad performance. In order to more clearly understand the cooperation method between beacons and safety applications and the requirements about beacons from safety applications, the sampling model and the necessary condition based on the Nyquist sampling theorem is given. According to the characteristics of the demand and the channel, a new transmit mode and a related constrained relationship are proposed. The nature of the method of congestion control is cutting down those less important messages, and based on this theory the joint congestion control framework which meets the requirements model of safety applications is proposed. The performance of the joint congestion control framework is evaluated by the simulations running on Veins. The successfully receiving probability of beacons and the average dangerous travelled distance are evaluated during the experiments, and it's proved that compared with traditional mode, the performance about communication and safety is improved a lot when the proposed mode is deployed.