Congestion Control in Vehicular Ad-hoc Network by Adapting Transmission Power with Vehicle Density and Speed

Abstract

In a VANET vehicles communicating with each other and infrastructure is the basis of the future of vehicular transportation. There are several applications of a VANET. The most important application in VANETs is safety application. Basic Safety Messages exchanged between vehicles can be lifesaving. Though, if safety messages are not received in a timely or reliable way, a safety application's efficiencies could suffer. One of the main challenges for communication in VANET is well-organized network channel utilization for the transmission of packets. Regularly transmitting packets at a fixed transmission power without taking into consideration the traffic density, current channel load, transmission delay, vehicle speed, etc. is highly inefficient and will lead to a high number of packet collisions on the channels. With the increasing number of vehicles in the vehicular network, the number of safety messages also increases quickly, which results in network channel congestion. This paper introduces a congestion control approach by adapting transmission power based on vehicle density and vehicle speed. By this approach, Vehicles will broadcast packets at suitable transmission powers. The goal is to reduce congestion on the network channel and advance the network’s overall performance. The proposed algorithm was applied in a simulation environment and its performance was validated in various traffic scenarios. The research was conducted using OMNET++, Veins, and SUMO. Our simulation results show that this method can lead to improving performance in terms of reduced packets lost, beacon error rate, and channel busy time thus increasing the performance of VANET.