A car following based rate control algorithm for VANET in intelligent transportation systems

Vehicular ac-hoc network (VANET) is a promising technology for intelligent transportation systems (ITS) to improve the safety and efficiency of transportation. Vehicles broadcast status messages periodically containing status information such as velocity, position, etc. The information can be used for road safety and collected by Internet of Things (IoT) elements for traffic management. The mobility of the vehicles will impact the reliability of vehicular communications, which leads to performance degradation especially in high density and highly dynamic scenarios. This paper presents a rate control algorithm based on the widely recognized car following model proposed by Wiedemann, which considers the movement interaction effect of vehicles and the driver's behavior. The car following process is common in high density situations and autonomous vehicles. We analyze the oscillation of vehicle's speed in car following process and derive the theoretical lower bound of message broadcast interval. The proposed algorithm can reduce redundant messages and meet the requirements of vehicle location accuracy. The rate control algorithm is evaluated using the network simulator ns-3 and the microscopic vehicle traffic simulator VISSIM.