# Evaluation of Radio Access Protocols for V2X in 6G Scenario-Based Models
## 1 Introduction
With the evolution of cellular networks, 3 GPP published the NR-V2X, which is a new specification for V2X. This protocol began its initial standardization in Release 15 [12]. NR-V2X offers better performance with advanced services for the new use cases of autonomous driving. This efficiency is being achieved by investing in hardware resources and techniques to achieve high spectral efficiency. With the advent of 6G-based networks, which aim to combine terrestrial and non-terrestrial communication networks, such as satellite and unmanned aerial vehicle (UAV) communication networks, vehicular communications are expected to be greatly improved. The NR-V2X will probably be used in 6G (6G-V2X) but in an improved way. It will allow the deployment of new use cases for V2X communications in the context of autonomous driving [13; 14; 15]. In the pursuit of linking billions of IoT devices, achieving blazingly fast data rates, and minimizing delays, 6G technology aims to fulfil its demanding requirements. 6G is anticipated to deliver the following: (1) speeds surpassing 1 Tbps; (2) an enhanced network capacity, accommodating a significantly greater density of mobile devices per square kilometer; and (3) ultra-low latency, crucial for time-sensitive applications like autonomous driving, online gaming, and remote device control. To achieve this, it employs strategies like block transmission techniques, sophisticated error correction codes, and large intelligence surfaces (LISs). The LIS system can be envisioned as an ultra-advanced MIMO (multiple-input multiple-output) setup, boasting an even greater number of antenna elements, thereby enabling enhanced capacities and data transfer speeds [16]. Furthermore, 6G networks will allow intelligent V2X systems to have significant reliability and enhanced security, high data rates (around 1 Tbps), low latency (<1 ms), and fast access to wireless networks [17]. To supply the needs of the 6G network with its heterogeneous composition of autonomous devices, various connectivity techniques for 6G scenarios are required to enable decision making in future V2X networks. It is envisioned that 6G will work together with machine learning not only to achieve intelligent and autonomous radio signals, but also to bring new features, such as enhanced context awareness, self-aggregation, adaptive coordination, and self-configuration [18]. The aim of this article is to evaluate the performance of emerging protocols for V2X communications, namely 802.11 bd and NR-V2X, and the current 802.11p and LTE-V2X protocols. To determine this comparative performance of the protocols, the following metrics are considered in the analyses: transmission latency, data rate, and packet error rates. In this way, it will be possible to determine which of the protocols would make autonomous driving more reliable and safer, contributing to more adaptable mobility. In the first part of the methodology used in this manuscript, the configuration parameters for calculating the L and DR values are defined, using the established theoretical mathematical model. The second part describes the procedure for calculating the PER using simulations. The article is structured as follows: Section 2 describes V2X communication protocols and related work. Section 3 defines and explains the calculations of the performance metrics analyzed in this paper. Section 4 analyzes the performance results and discusses prospects. Section 5 presents the research conclusions.