Advancements in Vehicular Communication Technologies: C-V2X and NR-V2X Comparison

Cellular vehicle-to-everything (C-V2X) is one of the key enabling vehicular communication technologies endorsed by the vehicular industry, scientists, and researchers. Introduced by the 3GPP, LTE device-to-device in Release 12 evolved into C-V2X with mode 3 and mode 4. In mode 4, semi-persistent -scheduling-based sensing is performed by vehicles to select resources. However, when the density of vehicles increases, the performance of C-V2X mode 4 degrades. To address this challenge, 3GPP Release 16 introduced New Radio (NR) for V2X services, also known as NR-V2X. Modes 1 and 2 along with four additional sub-modes were considered in NR-V2X to achieve high reliability and higher throughput with low latency. This article discusses and evaluates the advancements introduced in NR-V2X by comparative analysis with C-V2X. To compare the performance, an NR-V2X simulator based on a network simulator (ns-3) for sub-6 GHz band is also introduced. In addition, feasible practical solutions to resolve resource selection problems are also discussed.