An Adaptive Power Level Control Algorithm for DSRC Congestion Control

Vehicular industries and researchers have invested efforts to reduce avoidable accidents through the means of Vehicle to Vehicle (V2V) wireless communication using Vehicular Ad Hoc Networks (VANETs). Up-to-date information on the location, speed and other important parameters for each vehicle is shared with neighboring vehicles through the periodic exchange of Basic Safety Messages (BSMs). With a high vehicular density, network congestion can quickly arise in the 5.9GHz spectrum, rendering the system as unreliable because safety messages are not delivered and received on time. To alleviate this problem, there has been considerable research, in recent years, on distributed congestion control algorithms for VANETs. These approaches are generally based on rate control or power control of the transmitted packets. In this paper, we propose a novel, adaptive power control algorithm to reduce packet congestion in VANETs. Instead of requiring all vehicles to use the same power level, our approach allows each vehicle to dynamically adjust the transmit power of BSM packets, depending on its current speed. The goal is to prioritize which other vehicles will receive BSM packets from a given vehicle. Our simulation results demonstrate the advantages of the proposed algorithm regarding commonly used metrics such as packet loss, Beacon Error Rates(BER), Channel Busy Time(CBT) and Inter-Packet Delay(IPD).