Vehicular Communications Using DSRC: Challenges, Enhancements, and Evolution

Dedicated Short-Range Communications (DSRC) has been designed to support vehicular communications. In the U.S., DSRC operates in the 5.9 GHz licensed spectrum band. Its physical (PHY) and medium access control (MAC) layers, defined in the IEEE 802.11p standard, are based on the IEEE 802.11 family of Wi-Fi standards. Vehicular communication environments differ significantly from the sparse and low-velocity nomadic use cases of a typical Wi-Fi deployment. Thus, there are many challenges to adapt Wi-Fi technologies to support the unique requirements of vehicular communications such as achieving high and reliable performance in highly mobile, often densely populated, and frequently non-line-of-sight environments. The automotive and the communications industries, academia, and governments around the world have been devoting tremendous efforts to address these challenges, and significant achievements have been made. Remaining challenges can be addressed by the future versions of DSRC. In this paper, we investigate the current technologies used by DSRC to support vehicle safety communications, analyze existing and possible DSRC performance enhancements that can be realized in the near term, and provide a few initial thoughts on the DSRC evolution path.