Volume 14, Number 5

Controlling Adaptive Contention Window to Improve Safe Message Received Rate in VANET


Nguyen Hoang Chien1 and Pham Thanh Giang2, 1University of Economics – Technology for Industries, Vietnam, 2Vietnam Academy of Science and Technology, Vietnam


The primary goal of Vehicular Ad Hoc Networks (VANETs) is to support the secure transmission of applications via vehicles. Broadcasting is an important form of communication in the VANET network. Since there is no recovery for broadcast frames in the VANET network, the rate of receiving safe messages can become very low, especially in dense network conditions. In this paper, we present a new broadcast coordination mechanism with the aim of adaptive control of CW size to improve the received rate of safety messages. Each vehicle in the VANET can identify current local conditions of the network such as collisions or congestion by analyzing recently successfully sent and received frames. Based on the analysis of the received frame rate at each vehicle, the proposed mechanism controls the CW size and uses the EDCA mechanism to prioritize the important data flows. Using a combination of simulation tools in VANET, we build simulation scenarios in different network conditions to evaluate the received rate of safety messages compared to the default mechanism in the 802.11p standard. Simulation results have demonstrated that the proposed mechanism improves the received rate of safety messages better than the default mechanism in the 802.11p standard in all cases.