Connectivity Maintenance for Next-Generation Decentralized Vehicle Platoon Networks

Always keeping a certain distance between vehicles in a platoon system is important for collision avoidance. Centralized platoon systems let the leader vehicle determine and notify the velocities of all the vehicles in the platoon. Unfortunately, such a centralized method generates high packet drop rate and communication delay due to the leader vehicle's limited communication capability. Therefore, we propose a decentralized platoon network, in which each vehicle determines its velocity by only communicating with the vehicles in a short range. However, the multiple simultaneous transmissions between different pairs of vehicles may interfere with each other. By leveraging a typical feature of a platoon, we devise a channel allocation algorithm, called the Fast and Lightweight Autonomous channel selection algorithm (FLA), in which each vehicle determines its channel simply based on its distance to the leader vehicle. We also devise a strategy, in which a succeeding vehicle uses its stored common velocity profile when it is disconnected from its preceding vehicle and then adjusts its velocity once the connection is built. We conduct experiments on NS-3 and Matlab to evaluate the performance of our proposed methods and implement a real-world prototype by equipping vehicles with Android mobile devices. The experimental results demonstrate the superior performance of our decentralized platoon network over the previous centralized platoon networks.