Routing Method for 5G NR-based V2X Single-Hop Communication Using SNR and Communication Failure-Based Metrics

Vehicle-to-everything (V2X), as typified by automated driving, is attracting attention as a highly reliable usage model for the 5th generation (5G) mobile communication system. In particular, V2X using 4G and 5G is called cellular V2X (C-V2X), and it achieves highly reliable communication by establishing a single-hop routing path among nodes of vehicles, roadside units (RSUs), and base stations (BSs). Currently, there is a study of using the signal-to-noise ratio (SNR) to assess the quality of the communication between the vehicle, RSU, and BS and using this as a metric for single-hop routing. However, in this method, vehicles tend to select a BS for a relay node, which raises an issue of an increasing interference inside a specific resource allocated for BS-vehicle communication. In this paper, we propose a new routing method that adds the success or failure of communication carried out by each node to the routing metric to avoid an extensive selection of communication path between vehicles and BSs that is susceptible to interference and is likely to fail in communication. Using computer simulations, we evaluated the packet reception ratio (PRR) characteristics in an environment with many vehicles moving at high speeds using the evaluation model defined by the $3^{\text {rd }}$ generation partnership project, achieving a maximum 5% improvement in PRR and a maximum $4 \%$ reduction in the vehicle-BS occupancy rate.