Car Talk: Technologies for Vehicle-to-Roadside Communications

The vision for intelligent transportation systems (ITS) in the near term foresees establishing radio communications between vehicles and the road infrastructure using the 5.9-GHz frequency band to propagate useful information aimed at passenger safety and efficient traffic management [1]-[3]. To date, three classes of applications have been distinguished at the communication application layer: road safety, traffic efficiency, and a catch-all category of other applications. All rely on roadside equipment (RSE) capable of broadcasting either regulatory or contextual information to vehicles, along with onboard units (OBUs) capable of communicating with the RSE and, in some cases, of forwarding the information to other vehicles.