Distributed Beacon Frequency Control Algorithm for VANETs (DBFC)

Two types of safety messages, beacons and event-driven emergency warning messages, are playing a key role in many safety-related applications of Intelligent Transportation System (ITS), which are designed for improving road safety and traffic efficiency. Every vehicle on the road periodically sends safety beacons to notify the neighbors on the road its position, speed, direction and acceleration. When there is an emergency situation, the event-driven warning messages are emitted. As the same Control Channel is used by these two types of messages, in dense network when congestion happens, it is necessary to reduce the beacon load to improve the channel condition by adjusting the transmit parameters. As a solution to the problem of overloading the channel, this paper proposes and evaluates an adaptive congestion control scheme which adjusts the beacon transmission frequency according to the current network condition, while considering the appropriate accuracy of status information updating. To appraise the algorithm, several simulations are performed. Simulation results demonstrate the promising results for the adaptive scheme.