Full Duplex-driven Resource Reselection in 5G-V2X Sidelink Mode 2 under Mixed Periodic and Aperiodic Traffic Scenarios

In the fifth generation (5G) Vehicle-to-Everything (V2X) autonomous mode, vehicles may select radio resources for their packet transmissions without the support of the base station (BS). For periodic traffic, the same resources can be accessed at consecutive reservation intervals to improve the selection procedure. However, potential collisions occurring during this period may remain undetected and persist over time. Previous studies introduced algorithms leveraging in-band full-duplex (FD) transceivers to detect and react to collisions by performing resource reselection. However, as demonstrated in this paper, in more realistic scenarios where part of the data traffic is not periodic, performing reselections after collisions, regardless of the traffic type, may not be effective and could even be counterproductive. To address this issue, this work introduces two novel alternative schemes, each with its own advantages and drawbacks, both based on FD transceivers. Simulation results demonstrate that both solutions effectively handle scenarios with mixed traffic. Without penalising the aperiodic traffic, the range of periodic traffic is improved by up to 38% over the legacy Mode 2 under heavy traffic conditions.