C-V2X and 5G-V2X: Challenges and Improvement Strategies

Vehicular networks are at the core of intelligent transportation systems, empowering vehicles to communicate with each other (V2V) and with infrastructure (V2I) to enhance road safety and traffic efficiency. Given the limitations of traditional Dedicated Short Range Communications (DSRC) in deployment and scalability, Cellular Vehicle-to-Everything (C-V2X) has emerged as a promising alternative. In particular, the evolution toward 5G based V2X (5G-V2X) brings improved reliability, higher bandwidth, and ultra-low latency capabilities. This paper provides a comprehensive review of recent trends in vehicular networking, with a focus on developments in C-V2X and 5G-V2X technologies. This study compares these cellular V2X solutions with legacy approaches, highlight their technical merits, and discuss current deployment efforts. Key findings indicate that C-V2X and 5G-V2X significantly advance vehicular communications by extending communication range and enabling advanced applications, yet they also introduce challenges such as stringent latency requirements, network scalability in dense traffic, heterogeneity of devices, and security concerns. This paper further outlines open research challenges and explores potential improvement strategies, including the role of artificial intelligence in adaptive communication protocols, integration of forthcoming 6G capabilities, design of energy efficient (green) V2X networking solutions, development of cooperative perception frameworks, and the use of digital twin environments for testing and optimization. These insights aim to guide researchers and practitioners in advancing robust and efficient vehicular network technologies.