## 1 Introduction  
By leveraging the real-time information-sharing capability with the surrounding traffic environment, the Vehicle-to-Everything (V2X) communication technology enables a range of applications in improving traffic safety and efficiency [1; 2; 3; 4]. Additionally, supporting various related services and information sharing will significantly enhance the travel experience [5]. IEEE 802.11p was released in 2010 [6], marking the first V2X communication standard. The standard defines the protocols required for dedicated short-range communication (DSRC) to facilitate highly efficient and low-latency information exchange in V2X [7]. It is specifically designed to enhance the efficiency and robustness of data transmission in the Internet of Vehicles (IoV). Communication devices based on this standard have been widely deployed [8], such as the electronic toll collection (ETC) system in China and the ETC 2.0 system in Japan [9]. Although [10] stated that the IEEE 802.11p standard could reliably support safety applications with end-to-end latency requirements of approximately 100 ms when the vehicle density is not very high, the IEEE 802.11p standard is now struggling to satisfy the increasing quality of service (QoS) requirements due to its limitations in bandwidth, antenna modes, frequency bands, etc. [11]. In response to the urgent need for standard updates to meet the escalating QoS requirements, including faster data transfer speeds, greater data throughput, and higher transmission reliability, a research group has been established. This group aims to develop the next-generation V2X (NGV) standard, 802.11 bd, by integrating the mature and advanced technologies developed within the IEEE 802.11 standard family over the past decade. After eight versions of draft revisions, the official version of the IEEE 802.11 bd standard [12] was formally released on 10 March 2023. Due to the rapid advancement of intelligent transportation systems (ITS), there is a growing demand for a unified standard for advanced vehicular communication. The IEEE 802.11 bd standard, as a strong competitor to NR-V2X for the NGV universal communication standard, has garnered widespread attention from both academia and industry. As the standard for C-V2X, NR-V2X has the potential to interact with 5G-and-beyond cellular technologies, extending vehicular communication beyond V2V and V2I communications [13; 14; 15]. However, due to the extensive safety-related field trials performed worldwide, DSRC still holds an advantage compared with C-V2X, whose effective reliability and scalability are still to be completely verified [16; 17; 18]. To investigate the potential improvement of the NGV standards, several researchers have compared the communication performance of 802.11 bd with that of its predecessor, IEEE 802.11p, and its competitor, NR-V2X [19; 20; 21; 22; 23; 24]. Refs. [19; 20] provided pioneering and preliminary comparative evaluations of the advantages and disadvantages based on the technical characteristics of different standards, which provide some crucial insights from the analytical aspect. To obtain more detailed and realistic comparison results, researchers have utilized simulation tools such as MATLAB ([[https://www2.mathworks.cn/products/matlab.html](https://www2.mathworks.cn/products/matlab.html)]([https://www2.mathworks.cn/products/matlab.html](https://www2.mathworks.cn/products/matlab.html))) [21; 22; 23] and OMNeT++ ([[https://omnetpp.org/](https://omnetpp.org/)]([https://omnetpp.org/](https://omnetpp.org/))) [24] to simulate the performance of the IEEE 802.11 bd standard. The results demonstrate that 802.11 bd outperformed its predecessor, 802.11p, in multiple V2X performance metrics and provide valuable observations and experience in operating the NGV standard. However, as a typical cyber-physical system, the existing study [25] has already verified that the performance of V2X will be affected by traffic scenarios.