Efficient RSU Selection Scheme for Fog-based Vehicular Software-Defined Network

Efficient traffic control center (TCC) management requires roadside units (RSUs) to frequently update vehicles with traffic messages (TMs). RSUs are costly to road operators in terms of deployment and maintenance. Therefore, vehicular users expect the TCC to deliver high-quality and rapid responses to query requests on TMs through RSUs. This paper presents a novel RSU selection scheme based on a software-defined network (SDN) for traffic message transmission. In the proposed scheme, the RSU selection is determined by comparing the utility function calculated at the SDN controller. The SDN controller discovers the network connectivity topology through a cluster approach in which a cluster head (CH) is elected to report the network topology to the SDN controller. Furthermore, the SDN controller relies on the RSU selection manager to load existing RSU deployment techniques. In addition, a distance vector hop localization algorithm (DV-hop) is used to locate hidden RSUs to control signaling between the SDN controller and local controllers at RSUs. The proposed scheme achieves minimum latency and appropriate RSU management within a higher packet reception rate, which improves the selection of RSUs and traffic message delivery.