Dedicated Short-Range Communications (DSRC) utilizes the 5.850-5.925 GHz RF band to facilitate communications in the Transportation sector. 75 MHz spectrum has been reserved for this use by the FCC. It is IEEE standard 802.11 P.
These communications are essential to the operation of V2V and V2I communications which is the critical capability for connected and autonomous vehicles. Each vehicle transmits precise location, speed and acceleration data to other vehicles, stop signs, traffic signals and other infrastructure.
Current trials of Connected Vehicle Technology in Columbus, Tampa, NYC and Wyoming are all being deployed using DSRC.
Here is a look at the architecture of the Tampa deployment using DSRC.
The network was purpose built and required deployment of 46 Roadside Units (RSU’s). An RSU is transceiver mounted along a road or pedestrian path. Vehicles use an Onboard Unit (OBU)(transceiver). Tampa retrofitted over 1000 cars, 10 buses, 8 streetcars and 500 personal devices. www.tampacvpilot.com
Commercial automakers are investing in both Cellular and DSRC with DSRC trials being conducted by Automakers: GM, Volkswagen, Toyota and Renault.
DSRC utilization is being challenged by the current American FCC who believes the band might be better shared for unlicensed applications similar to Wi-Fi.
Current proposals include leaving 30 MHZ in the upper range for the Transportation industry and making 45 MHz unlicensed for other uses such as basic
connectivity. This issue is currently tabled but most believe it will rematerialize.