Voronoi-based placement of road-side units to improve dynamic resource management in Vehicular Ad Hoc Networks

Vehicular Ad-hoc Networks (VANETs) illustrate mobile P2P networks, which hold significant promise in improving traffic safety and alleviating traffic congestion. Reliable VANETbased services require dynamic resource management due to limited and often fluctuating network connectivity of VANETs that stem from the wireless and mobile nature of vehicleto-vehicle (V2V) communications. To address these needs, a collaboration with Road-Side Units (RSU) have been proposed to complement V2V communication by providing event and data brokering capability in the form of Vehicle-to-Infrastructure (V2I) communications. Deploying RSUs involves upfront investment and maintenance costs, and hence solutions are needed that maximize the benefit of RSUs by placing them effectively in accordance to existing and projected traffic density, and the types of services planned for VANETs. To address these challenges, this paper proposes a novel Voronoi diagram-based algorithm for the effective placement of RSUs using packet delay and loss as a criteria. This approach has two-fold advantages: a significant reduction in the number of RSUs required to cover a geographic region, and increase in the logical coverage area of each RSU irrespective of the dynamic vehicular traffic conditions thereby improving reliability of communications. This algorithm has been evaluated in the context of a road network and traffic conditions for an urban area. When compared with other baseline placement algorithms, communication reliability stemming from our Voronoi diagram-based placement algorithm results in less packet delay and lesser packet loss both of which are important to realize the different VANET-based services.