Analytical Model of NR-V2X Mode 2 with Re-Evaluation Mechanism

TL;DR

This paper develops an analytical model for NR-V2X Mode 2 with a re-evaluation mechanism, using DTMC to simulate traffic, and demonstrates its impact on transmission reliability and latency in complex vehicular environments.

Contribution

It introduces an analytical model incorporating the re-evaluation mechanism and traffic simulation, providing insights into its effects on NR-V2X performance.

Findings

Re-evaluation mechanism enhances transmission reliability.

Latency can be further reduced with local improvements.

The model accurately reflects 3GPP recommended traffic patterns.

Abstract

Massive message transmissions, unpredictable aperiodic messages, and high-speed moving vehicles contribute to the complex wireless environment, resulting in inefficient resource collisions in Vehicle to Everything (V2X). In order to achieve better medium access control (MAC) layer performance, 3GPP introduced several new features in NR-V2X. One of the most important is the re-evaluation mechanism. It allows the vehicle to continuously sense resources before message transmission to avoid resource collisions. So far, only a few articles have studied the re-evaluation mechanism of NR-V2X, and they mainly focus on network simulator that do not consider variable traffic, which makes analysis and comparison difficult. In this paper, an analytical model of NR-V2X Mode 2 is established, and a message generator is constructed by using discrete time Markov chain (DTMC) to simulate the traffic pattern recommended by 3GPP advanced V2X services. Our study shows that the re-evaluation mechanism improves the reliability of NR-V2X transmission, but there are still local improvements needed to reduce latency.