Improving safety message delivery through RSU´s coordination in vehicular networks

Modern society lives surrounded by technology intended for enhancing human commodity, entertainment and safety. The use of novel technological solutions in transportation led to a relatively new field often called Intelligent Transportation Systems (ITS). Due to its highly dynamic nature, wireless communications are applied to implement vehicular communication systems. The concern of reducing road injuries/fatalities is of utmost importance, being nowadays a public health question. This led the development of vehicular communication standards focused in safety-related applications. These, demand typically low channel access delay with a well-defined upper bound, which is mainly addressed in the Medium Access Control (MAC) layer. This paper emphasizes some key points favoring the use of an infrastructural architecture with full Road Side Unit (RSU) coverage, presents an overview of the used time-slotted oriented MAC approach based on the Wireless Access in Vehicular Environment (WAVE) standard, addresses the issue of RSUs´ coordination using beacons, and discusses the vehicle slot choice for the initial broadcast of safety-critical messages, in order to guarantee that they are timely delivered.