Roadside units deployment for content downloading in vehicular networks

The Vehicular Ad hoc Networks (VANETs) have been recently introduced to provide high-speed Internet access to vehicles by deploying 802.11 enhanced Roadside Units (RSUs) along roads. However, few content downloading oriented RSU deployment strategies have been proposed. In this paper, we propose a new RSU deployment strategy for content downloading in VANETs. The encounters between vehicles and RSUs are modeled as a time continuous homogeneous Markov chain. The optimal inter-meeting time between vehicles and RSUs is analyzed based on the encounter model. Then, the road network is modeled as a weighted undirected graph, and a RSU deployment algorithm is designed based on the depth-first traversal algorithm for edges of a graph. Simulation results show that the proposed RSU deployment algorithm can satisfy the file downloading service requirements with the lowest RSU deployment cost.