Time-Dependent Performance Modeling for Platooning Communications at Intersection

With the development of Internet of Vehicles, the platooning strategy has been widely studied as the potential approach to ensure the safety of autonomous driving. Vehicles in the form of platoon adopt 802.11p to exchange messages through vehicle-to-vehicle (V2V) communications. When multiple platoons arrive at an intersection, the leader vehicle of each platoon adjusts its movement characteristics to ensure that it can cross the intersection, and thus the following vehicles have to adjust their movement characteristics accordingly. In this case, the time-varying connectivity among vehicles leads to the significant nonstationary performance change in platooning communications, which may incur safety issues. In this article, we construct the time-dependent model to evaluate the platooning communication performance at the intersection based on the initial movement characteristics. We first consider the movement behaviors of vehicles at the intersection, including turning, accelerating, decelerating, and stopping as well as the periodic change of traffic lights to construct a movement model and then establish a hearing network to reflect the time-varying connectivity among vehicles. Afterward, we adopt the pointwise stationary fluid flow approximation (PSFFA) to model the nonstationary behavior of the transmission queue. Then, we consider four access categories (ACs) and continuous backoff freezing of 802.11p to construct the models to describe the time-dependent access process of 802.11p. Finally, based on the time-dependent model, the packet transmission delay (PTD) and packet delivery ratio (PDR) are derived. The accuracy of our proposed model is verified by comparing the simulation results with analytical results.