Energy Minimization for Infrastructure-to-Vehicle Communications with Multiple Roadside Units

Nowadays, roadside units (RSUs)assisted message propagation in vehicular networks has aroused the widespread concern due to their ability of extending communication coverage or connectivity. This paper considers a vehicular service radio network consisting of multiple RSUs tasked to push traffic information to passing vehicles, and analyzes the energy efficiency of data transmission. Each RSU has a finite storage room, and vehicles entering the coverage of RSUs would receive packets with service rate determined by their downlink channel conditions. We consider the energy consumption minimization problem over multiple RSUs, under average packet loss probability and average system time constraints. Then, a low complexity algorithm is proposed with joint optimization of the number of RSUs, transmission power, and storage room. Simulation results closely corroborate the analytical results and validate the effectiveness of the proposed algorithm in terms of energy minimization and computation complexity. Practically, our proposed approach can help decide proper deployment of RSUs to achieve energy saving.