A combined fair decentralized message-rate and data-rate congestion control for V2V communication

Channel congestion Is one of the most critical Issues In IEEE 802.11p-based vehicular ad hoc networks as it leads to unreliability of safety applications. As a counter measure, the European Telecommunications Standard Institute (ETSI), proposes a mandatory Decentralized Congestion Control (DCC) framework to control the channel load, by tuning transmission parameters, such as message-rate or data-rate. This paper defines a novel decentralized combined message-rate and data-rate congestion control (MD-DCC) scheme, which provides a fair and effective way of message-rate and data-rate allocation among vehicles to avoid congestion and satisfy application requirements. We discuss several implementation aspects such as the selection of parameters of MD-DCC and their relation with the application requirements. Simulations studies are presented to show the performance of MD-DCC in terms of application reliability and fairness. Our results show that, for various application requirements in a synthetic highway scenario and for various vehicular densities, MD-DCC outperforms other approaches that adapt only message-rate or data-rate. We conclude that MD-DCC takes the best of both message-rate and data-rate algorithms, resulting in superior application reliability as well as a dramatic increase in the maximum supported vehicular density.