Centrality-based Access-Points deployment for vehicular networks

Vehicular Ad hoc Networks appeared as a natural result of the evolution of the communication technology, which becomes able to satisfy the need of users to be connected anytime and anywhere. Providing comfort services such as Internet access or even vehicle traffic monitoring requires the use of road-side units (RSU) as gateways to the requested resources. Today, most of Intelligent Transport Systems (ITS) architectures rely on the integration and use of such gateways. Nevertheless, none of them tried to study the way these should be deployed neither the way they should be organized to achieve best performances. We think that such a study is primordial, in an environment that cannot be fully covered due to the high costs of infrastructure deployment. In this paper we provide a deep analysis of the deployment problem. We show in a first part the benefits of using RSU as support for V2V communications. We then investigate in a second part different approaches and strategies for Access-Points deployment. An objectives-based analysis reveals the role of centrality and equidistant-based deployment in optimizing the end-to-end delay and ensuring a regular and stable service access. Our simulation results confirm that the performances in a cooperative environment (V2I and V2V) get greatly improved. It shows that the use of RSU becomes essential in low density situations and especially in case of long-distance communications. In the context of RSU deployment, simulation results proved that centrality and equidistance are key factors for optimizing end-to-end delays and ensuring stable performances.