  As driving becomes more automated, vehicles are being equipped with more
sensors generating even higher data rates. Radars (RAdio Detection and Ranging)
are used for object detection, visual cameras as virtual mirrors, and LIDARs
(LIght Detection and Ranging) for generating high resolution depth associated
range maps, all to enhance the safety and efficiency of driving. Connected
vehicles can use wireless communication to exchange sensor data, allowing them
to enlarge their sensing range and improve automated driving functions.
Unfortunately, conventional technologies, such as dedicated short-range
communication (DSRC) and 4G cellular communication, do not support the
gigabit-per-second data rates that would be required for raw sensor data
exchange between vehicles. This paper makes the case that millimeter wave
(mmWave) communication is the only viable approach for high bandwidth connected
vehicles. The motivations and challenges associated with using mmWave for
vehicle-to-vehicle and vehicle-to-infrastructure applications are highlighted.
A high-level solution to one key challenge - the overhead of mmWave beam
training - is proposed. The critical feature of this solution is to leverage
information derived from the sensors or DSRC as side information for the mmWave
communication link configuration. Examples and simulation results show that the
beam alignment overhead can be reduced by using position information obtained
from DSRC.
