POSACC: Position-Accuracy Based Adaptive Beaconing Algorithm for Cooperative Vehicular Safety Systems

Cooperative vehicular safety systems are expected to revolutionize the driving experience by providing road safety applications based on incident detection. Two vital quality parameters for cooperative safety applications are the position accuracy and communication reliability of the status information. The receiver may take erroneous decisions if the received data does not correspond to the latest situation of the transmitter (e.g., position, velocity, and trajectory of the target vehicle). In this paper, we propose and evaluate a POSition-ACCuracy (POSACC) based adaptive beaconing algorithm for cooperative vehicular safety systems. POSACC integrates three different control mechanisms to guarantee specific performance metrics. It adopts the position accuracy and communication reliability as the highest priority metrics, due to their direct impact on the vehicle's systems capability to avoid potential traffic accidents in real-time. In addition, it guarantees the priority metrics, maintaining the vehicle's warning distance, channel load, and end-to-end latency into the operative range of cooperative safety applications. POSACC is compared with three different state-of-the-art adaptive beaconing algorithms; ETSI DMG, LIMERIC, and DC-BTR&P. Extensive evaluation results show that POSACC successfully controls the beacon rate, transmission power, and the size of the minimum contention window. Simulation results also demonstrate that POSACC is more effective than the benchmark algorithms by guaranteeing the operational requirements of cooperative safety applications in a wider range of traffic situations.