## 2 State-of-the-Art V2X Technology  
V2X, as a method for connecting vehicles to the environment first appeared in the late 1980s, and its primary aim was to reduce road accidents and increase traffic safety by information sharing between vehicles and autonomous systems. While the concept has been investigated by automakers and automotive suppliers, with the lack of standardized communication protocol and dedicated bandwidth, the information to be shared and the possible use cases were subjects to debate up until the early 2000s [14]. The first global standard for WLAN-based V2X communication was published by the Institute of Electrical and Electronics Engineers (IEEE) in 2010 [15]. The IEEE 802.11p standard supports a direct Vehicle-to-Vehicle (V2V) communication, as well as its extension to the infrastructure Vehicle-to-Infrastructure (V2I). Appointing a dedicated bandwidth, this standard aimed to provide a direct radio communication between the vehicles and their surroundings, theoretically enabling basic automated driving safety and comfort features, such as blind spot warning, forward collision warning and mitigation and platooning. Since 2010, alternative protocols have been proposed based on cellular networks, which may extend or shift the operation domain of V2X aided autonomous systems. The advantages and disadvantages of using any of these protocols have launched a joint industrial and academic debate since the late 2010s [16]. The two most common V2X communication protocols are Dedicated Short-Range Communication (DSRC) and Cellular Vehicle-to-Everything (C-V2X). However, the underlying technology does not affect the assessment of the contribution of V2X technology to the levels of autonomy. While the discussion of industrial feasibility of these protocols does not form the scope of this paper, a general introduction of the scope of application and use cases are provided in this introductory section. In recent years, V2X communication and development have faced several challenges. This paper does not aim to address the challenges of the underlying technology, rather it aims to focus on the implementation of new methodologies on automated driving use cases. However, some of these challenges are mentioned hereafter, serving as basis for further work and possible future development areas:  
* Interference and Signal Degradation: In urban environments with high-density traffic, buildings and other obstacles, the radio signals can suffer interference or degradation, leading to signal loss or reduced quality of communication [17]. Dynamic Network Topology: The network topology in V2X communication is highly dynamic due to the mobility of vehicles and changing environmental conditions. Maintaining reliable communication paths becomes challenging as vehicles move in and out of range or obstruct each other's signals [18]. * Latency and Delay: The time-sensitive nature of V2X applications, such as collision avoidance systems, requires low latency communication. However, delays in signal transmission or processing can occur due to network congestion, protocol overhead, or computational limitations in onboard systems, compromising reliability [19]. * Scalability: As the number of connected vehicles increases, the scalability of communication systems becomes crucial. Ensuring reliable communication among a large number of vehicles while maintaining network efficiency and avoiding congestion is a significant challenge [20]. * Security and Privacy: V2X communication involves the exchange of sensitive information related to vehicle location, speed and trajectory. Ensuring the security and privacy of these data against malicious attacks, such as spoofing, jamming, or eavesdropping, is essential for maintaining communication reliability and trust among the users [21]. * Harsh Environmental Conditions: V2X communication must operate reliably under various environmental conditions, including adverse weather (e.g., heavy rain, snow), electromagnetic interference and physical obstructions.