Enhancing Periodic and Non-Periodic Data Transmissions in 3GPP NR V2X Mode 2

The 3rd Generation Partnership Project (3GPP) New Radio (NR) Vehicle-to-Everything (V2X) Mode 2 is a resource allocation mechanism for vehicular networks. By the 3GPP NR V2X Mode 2, vehicles first specify the cycles for radio resources (or say subchannels) they require and then reserve subchannels by themselves. While traveling on the road, vehicles may generate periodic and non-periodic data to support vehicular applications. Since vehicles can obtain subchannels periodically, we can observe that the reserved subchannels may be wasted if vehicles have no data or are not sufficient if vehicles are demanded to disseminate unexpected event packets from the application layer. In this work, we propose a resource reservation interval determination scheme to facilitate data transmissions. Additionally, we design a resource-sharing mechanism for vehicles to share their unused subchannels. Simulation results demonstrate that the proposed methods outperform other approaches in various performance metrics. Specifically, the proposed approach increases subchannel utilization by up to 25% and reduces the packet drop ratio for event-driven traffic to nearly 0%.