Data Rate Based Congestion Control in V2V Communication for Traffic Safety Applications

Vehicle-to-Vehicle (V2V) communication systems intend to increase safety and efficiency of the transportation networks. At high vehicle density, the communication channel may become congested, impairing the reliability of the safety applications. As a counter measure, the European Telecommunications Standard Institute (ETSI), proposes the Decentralized Congestion Control (DCC) framework to control the channel load, by tuning message transmission parameters, such as message rate and transmitting power. In this paper, we analyze a congestion control scheme that follows the DCC framework known as Data Rate-DCC (DR-DCC) for various traffic densities. DR-DCC adjusts the data rate based on channel load measurements thus controlling the air time of packets to avoid congestion. Although tuning the data rate has been proposed before we are not aware of any reported work, where its full potential has been investigated in detail. In this paper we intend to provide more insight on the benefits of this approach by analyzing schemes that aim at optimum data rate for various traffic density cases. The objective is not only to avoid congestion but also to provide optimal support to safety applications. We compare the performance of DR-DCC to another DCC approach based on adjusting transmit power for various traffic density cases. DR-DCC outperforms at various traffic densities providing better support to safety applications.