Scheduling Energy Harvesting Roadside Units in Vehicular Ad Hoc Networks

The use of renewable energy at roadside units (RSUs) in vehicular ad hoc networks is a great alternative to the electric grid, since it lowers the carbon footprint, and the cost of deployment and maintenance. This paper describes a scheduler for serving vehicles by RSUs that use energy harvesting, with the aim to maximize the number of served vehicles. We start by defining an integer linear programming model for finding the optimal offline schedule. The model is shown to be NP-hard and hence we propose a greedy heuristic to solve it. We compare the optimal solution and near- optimal offline heuristic with an energy-efficient scheduler for RSUs. Our simulation results show that the proposed scheduler for energy harvesting RSUs can reduce the service delay of vehicles. It also provides good performance with respect to the percentage of served vehicles, in comparison to energy-efficient scheduler in grid-powered RSUs.