Performance Evaluation of 5G New Radio V2X Sidelink for Coexisting Traffic

In the last releases, 5G New Radio V2X enabled the Sidelink vehicle-to-vehicle communication to accommodate low-latency and highly reliable vehicular applications. To support the direct vehicle-to-vehicle communication, without the need to rely on the cellular network, dynamic scheduling and random resource selection channel access techniques must be adopted. In this paper, we assess the performance of the 5G NR V2X Sidelink technology, in Mode 2, for the transmission of different traffic types: only broadcast, only unicast, and when both traffic types coexist. We deeply investigate the impact of several PHY layer parameters of the resource allocation procedure, for safety-related broadcast messages, with different message transmission rates and vehicle density. Next, we expand the analysis to include unicast communications. Finally, we assess the impact of this vehicular communication technology when both traffic applications coexist, comparing the results for two scheduling access schemes, in static and mobile setups. The outcomes of the experiments emphasize the importance of optimal resource utilization, achieved through MCS and numerology, for example, when employing dynamic scheduling. For unicast communications, we evaluate the influence of the packet sizes for different application rates, which proves to be minor as the application rates get substantial. The scheduling scheme selection presented clear behavior across the different applications: the dynamic scheme outperformed the semi-persistent scheme for lower densities of unicast vehicles, and vice versa for higher densities. As for the ITS traffic, and considering a coexistence traffic scenario, better results were achieved with the semi-persistent approach.