Fair Congestion Control in Vehicular Networks With Beaconing Rate Adaptation at Multiple Transmit Powers

Cooperative intervehicular applications rely on the exchange of broadcast single-hop status messages among vehicles, which are called beacons. The aggregated load on the wireless channel due to periodic beacons can prevent the transmission of other types of messages, which is called channel congestion due to beaconing activity. In this paper, we propose to let vehicles transmit with different transmit power levels, each with a particular beaconing rate. The selection of the rate is modeled as a network utility maximization (NUM) problem. Our goal is to maximize the number of beacons delivered at each transmit power according to a well-defined fairness notion while complying with the maximum allowed beaconing load on the channel. The algorithm parameters can be set per vehicle and dynamically changed, which provides enough flexibility to support multiple applications on top of the control scheme, whereas the NUM model provides a rigorous framework to design a broad family of simple and decentralized algorithms, with proved convergence guarantees to afairallocation solution. Simulation results validate our approach and show that it provides fair rate allocations in realistic multihop and dynamic scenarios with packet losses.