A Defensive Scheduling Scheme to Accommodate Random Selection Devices in 5G NR V2X

The newly completed 3GPP Release 16 for 5G New Radio (NR) vehicle-to-everything (V2X) communication assumes that all participating devices can continually sense the channel activities in terms of resource use. However, many non-vehicular devices such as smartphones of vulnerable road users (VRUs) and road-embedded sensors are constrained by battery, and cannot afford such "always-on" sensing. The deficiency will have undesirable impact on the existing resource allocation algorithm in the envisioned NR V2X integrated framework. As we start the efforts towards Release 17, therefore, there is a pressing need to develop a solution to smoothly integrate the limited-sensing devices into the framework. This letter develops a solution based on the new features available in Release 16 NR Sidelink Mode 2, such as resource reservation pointers and resource pre-emption checks. We demonstrate that a defensive transmission strategy employed by the full-sensing devices that jitters their transmissions around the resource double-booked by the limited-sensing devices can significantly mitigate the packet delivery performance degradation for both the full-sensing and the limited-sensing devices.