A Discrete-Time Markov Chain Based Comparison of the MAC Layer Performance of C-V2X Mode 4 and IEEE 802.11p

Vehicle-to-vehicle (V2V) communication plays a pivotal role in intelligent transport systems (ITS) with cellular-vehicle to everything (C-V2X) and IEEE 802.11p being the two competing enabling technologies. This paper presents multi-dimensional discrete-time Markov chain (DTMC) based models to study the medium access control (MAC) layer performance of the IEEE 802.11p standard and C-V2X Mode 4, considering periodic cooperative awareness messages (CAMs) and event-driven decentralized environmental notification messages (DENMs). Closed-form solutions for the models’ steady-state probabilities are obtained, which are then utilized to derive expressions for several key performance metrics. Numerical results are provided to draw insights on the performance. In particular, a performance comparison between IEEE 802.11p and C-V2X Mode 4 in terms of the average delay, the collision probability, and the channel utilization is presented. The results show that IEEE 802.11p is superior in terms of average delay, whereas C-V2X Mode 4 excels in collision resolution. The paper also includes design insights on possible future MAC layer performance enhancements of both standards.

Authors:
Wijesiri Geeth P., Haapola Jussi, Samarasinghe Tharaka

Publication type:
A1 Journal article – refereed

Place of publication:

Keywords:
C-V2X Mode 4, discrete-time Markov chain, ETSI ITS-G5, IEEE-802.11p, medium access control, vehicle-to-vehicle communication

Published:
14 December 2020

Full citation:
G. P. W. N.B.A, J. Haapola and T. Samarasinghe, “A Discrete-Time Markov Chain Based Comparison of the MAC Layer Performance of C-V2X Mode 4 and IEEE 802.11p,” in IEEE Transactions on Communications, doi: 10.1109/TCOMM.2020.3044340

DOI:
https://doi.org/10.1109/TCOMM.2020.3044340

Read the publication here:
http://urn.fi/urn:nbn:fi-fe20201216100918