SRAG: A Priority-Based Rate Adaptation Scheme Using Game Theory for Vehicular Networks

Rate adaptation is critical to the system performance of Wireless Local Area Networks (WLANs). Existing rate adaptation schemes mostly make use of packet statistics or the signal strengths of received packets to adapt transmission rates, regardless of the packet priorities. In this paper, we first find out that it is beneficial for rate adaptation schemes to consider packet priorities when adapting transmission rates. We then propose a novel priority-based rate adaptation scheme for vehicular networks named SRAG (Stackelberg Rate Adaptation Game) which jointly considers channel conditions and packet priorities using game theory. In SRAG, rate adaptation is modeled as a game which consists of different priorities of users and each user tries to select an optimal transmission rate that maximizes its utility regardless of others' utilities. SRAG adopts a Stackelberg game model to regulate behaviors of self-interested users and gives priority to high priority users in order to achieve better overall performance. Extensive ns-2 simulations demonstrate that SRAG can provide much better performance for high priority users than existing rate adaptation schemes, while maintaining good performance for low priority users.