Congestion Control Mechanism based on Power and Rate Adjustments in VANETs

Abstract

Vehicular manufacturers and researchers have invested efforts to reduce road accidents through the Vehicle to Vehicle wireless communication using Vehicular Ad Hoc Networks. Up-to-date information on the location, speed and other important parameters for each vehicle is shared with neighbouring vehicles through the periodic exchange of BSM. 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 solve this problem, there has been considerable research, in recent years, on congestion controlling mechanisms for VANETs. Most of them are generally based on rate or power control of the transmitted packets. In this paper, we propose to combine rate controlling and power altering mechanisms together to reduce packet congestion in VANETs based on the density and speed of vehicles in a standard transmission diameter. Instead of requiring all vehicles to use the same power and rate, our approach allows each vehicle to dynamically adjust the transmit power and data rate of BSM packets, depending on the density and speed of vehicles. Our simulation results demonstrate, packet losing is minimized with 25%, beacon reception rate and channel busy time can be managed up to 50% and beacon error rate is reduced with 30% when using our system, this shows the importance of our algorithm to solve congestion problem that occurred in VANET