Enhancing Groupcasting Reliability in the Multi-Platoon Environment Through a Multi-Relay-Vehicle Adjustment Mechanism

In 5G platoon communications, the Platoon Leader (PL) can adopt groupcasting to transmit messages to all Platoon Member (PM) vehicles. However, due to the limited range of transmission, a PM vehicle must act as the Platoon Relay (PR) vehicle to retransmit messages to other PM vehicles that are outside PL's groupcasting range. This work introduces a 2-Step relay vehicle selection method called Platoon Relay Vehicle Selection Achieving the Maximum Groupcasting Reliability (PRVS-MGR). The first Step of PRVS-MGR formulates a tripartite matching problem among the allocated subchannel, the PL or PR vehicle, and the individual entity to ensure efficient resource allocation for groupcasting. In the second Step, PRVSMGR proposes a scheme for selecting PR vehicles to enhance groupcasting reliability. The simulation results show that the proposed method has the better performance in terms of spectral efficiency, transmission latency and overall reliability of platoon groupcasting.