Home > Published Issues > 2023 > Volume 18, No. 6, June 2023 >
JCM 2023 Vol.18(6): 369-376
Doi: 10.12720/jcm.18.6.369-376

Adaptive Sliding Contention Window Design to Minimize Safe Message Collision Rates with Different Priority Levels in VANET

Nguyen Hoang Chien1,* and Pham Thanh Giang2
1.University of Economics – Technology for Industries, Hanoi, Vietnam
2.Institute of Information Technology, Vietnam Academy of Science and Technology, Hanoi, Vietnam
*Correspondence: nhchien@uneti.edu.vn (N.H.C.)

Manuscript received October 29, 2022; revised December 25, 2022; accepted March 1, 2023.

Abstract—In Vehicular Ad Hoc Networks (VANETs), the broadcast is an important form of communication and occupies the main traffic in the network. However, since there is no recovery for broadcast frames in the VANET network, the collision rate between safe message traffic can become very high, especially in vehicle-dense network conditions. This paper proposes a new coordination mechanism that adaptively controls the Contention Window (CW) size for broadcast to reduce the safe message collision rate with different priority levels. In our mechanism, each vehicle in the VANET can automatically adjust the CW based on the perception of the current network condition by analyzing the percentage of successfully received frames. The algorithm controls the CW size by sliding the window with a dynamic persistence factor according to each type of safe message traffic. Each data traffic chooses a backoff timer dynamically varying in the range [0, CW[AC[i]]], which can overlap the CW range with other data traffic to improve efficient bandwidth depending on the network conditions. Simulation results prove that the proposed mechanism significantly reduces the collision rate for both safe message traffic in high-priority and low-priority in vehicle-dense network conditions.

Keywords—VANET, dedicated short range communication (dsrc), enhanced distributed channel access (EDCA), medium Access control (MAC), adaptive sliding contention window (ASCW)

Cite: Nguyen Hoang Chien and Pham Thanh Giang, "Adaptive Sliding Contention Window Design to Minimize Safe Message Collision Rates with Different Priority Levels in VANET," Journal of Communications, vol. 18, no. 6, pp. 369-376, June 2023. 

Copyright © 2023 by the authors. This is an open access article distributed under the Creative Commons Attribution License (CC BY-NC-ND 4.0), which permits use, distribution and reproduction in any medium, provided that the article is properly cited, the use is non-commercial and no modifications or adaptations are made.