Modeling and Analysis of Intra-platoon Multi-hop Unicast Message Delivery Delay

In this paper, a theoretical model is derived to analyze the intra-platoon message delivery delay (InP-delay) for an autonomous platoon to enable each platoon member to receive a message transmitted from the platoon leader via multi-hop unicast. Both platoon vehicles and non-platoon vehicles employ a carrier sense multiple access (CSMA/CA) mechanism to contend for channel access. Since the delay of delivering a message within a platoon may affect the platoon stability, the effects of major system parameters on the InP-delay are investigated, including the platoon size, the intra-platoon spacing, the density of non-platoon vehicles, the transmission range and carrier sensing range of vehicles. This work is of help to the stability maintenance of an autonomous platoon by providing reference values for system parameter configuration under different use case requirements.