Strategic deployment of RSUs in urban settings: Optimizing IEEE 802.11p infrastructure

The efficient deployment of Roadside Units (RSUs) in an infrastructure based on IEEE 802.11p is essential for delivering Internet-based services to vehicles. In this paper, we introduce novel strategies that, in contrast to prior works, exclusively rely on the average vehicular density within specific urban areas, and these strategies depend on a performance model of IEEE 802.11p for guidance and decision-making regarding RSU placement. This minimal upfront information contributes to the practicality and ease of implementation of our strategies. We apply our strategies to three real-world urban scenarios, utilizing the ns-3 and sumo simulators for validation. This study contributes to three fundamental aspects. First, we establish that any efficient deployment of RSUs is closely linked to the unique characteristics of the city under consideration such as the street layout and spatial density of vehicles. In other words, the characteristics of an efficient RSU deployment are unique to each city. Second, we show that the optimal strategy is not to place the RSUs at the locations with the highest traffic density. Instead, with the help of an analytical performance model of IEEE 802.11, we propose a more efficient strategy wherein the location of each RSU is determined to maximize the number of vehicles receiving the target QoS. This can lead to a significant drop in the number of RSUs required to equip a city. Finally, we demonstrate that, by preventing the use of the lowest transmission rate of IEEE 802.11p at each RSU, a collective benefit can be achieved, even though each RSU experiences a shorter radio range.