Performance Analysis of IEEE 802.11p DCF for Inter-Platoon Communications with Autonomous Vehicles

Enabling vehicular communications is expected to revolutionize the transport infrastructure and support many traffic management applications such as platooning. Sharing vehicle information such as speed and acceleration wirelessly among platoons plays an effective role in platoon control by maintaining a constant inter-vehicle and inter-platoon distances. However, the performance of (inter and intra-) platoon communications in terms of throughput, transmission delays and packet transmission collisions can undermine the effectiveness of information sharing on platoon control. In this paper, we present probabilistic performance analysis of IEEE 802.11p Distributed Coordination Function (DCF) for inter-platoon communications in a multiplatooning scenario (i.e, a chain of platoons). The expressions for the transmission attempt probability, packet collision probability, network throughput and packet delay are derived accordingly. Numerical results show that the performance of inter-platoon communications depends on the vehicle's role in one platoon and its platoon position within the multiplatoon and that the end-to- end delay of platoons can be reduced by adjusting the contention window size.