RADAR: a rapid discovery algorithm for routes in SDN-based IoV

Link failures are a critical issue that disrupts consistent communications in the fast-evolving Internet-of-Vehicles (IoV) environment. In response to the aforementioned limitation, we introduce the rapid discovery algorithm for routes (RADAR), a novel scheme designed for rapid route discovery in the event of abrupt link failures or topological changes. Built on a heuristic Theta⁎ algorithm, RADAR operates within a three-layered Software-Defined Networking (SDN) architecture to ensure seamless communications. The first layer collects vital vehicle information, including location, speed, direction, and vehicle ID. The second layer uses an SDN edge controller to carry out local and intra-zone path discovery with the Theta⁎ heuristic algorithm. The third layer introduces a global controller that oversees inter-zone route discovery, thereby expanding the network's reach and capabilities. To validate RADAR's effectiveness, we compare its performance to those of Dijkstra-based and A⁎ path planning algorithms across key metrics—Route Discovery Messages (RDM), Path Length (PL), and Route Discovery Time (RDT). Our analysis shows significant improvements with RADAR over Dijkstra, achieving up to an 80% increase in RDM, 20% in PL, and 70% in RDT. It also surpasses A⁎ by up to 70% in RDM and 60% in RDT. These results indicate that RADAR enhances routing reliability in IoV systems, thereby improving overall network performance.