Dedicated Short Range Communications (DSRC) Service
In 1997, ITS America petitioned the Commission to allocate seventy-five megahertz of spectrum in the
5.9 GHz band for ITS, in particular for DSRC. The following year, in 1998, Congress passed and the
President signed into law the Transportation Equity Act for the 21st Century ("TEA-21"), which directed the
Commission, in consultation with the Department of Transportation (DOT), to consider the spectrum needs
“for the operation of intelligent transportation systems, including spectrum for the dedicated short-range
vehicle-to-wayside wireless standard,” DSRC. TEA-21 also directed DOT to promote, through the National
Architecture, interoperability among ITS technologies implemented throughout the United States. In October
1999, the Commission allocated the 5.9 GHz band for DSRC-based ITS applications and adopted basic
technical rules for DSRC operations.
On December 17, 2003 the Commission adopted a Report and Order establishing licensing and service rules for the
Dedicated Short Range Communications (DSRC) Service in the Intelligent Transportation Systems (ITS) Radio Service in
the 5.850-5.925 GHz band (5.9 GHz band). There is also a co-primary Federal Government radiolocation allocation (for
use by high-powered military services) in the 5.850-5.925 GHz band, a co-primary fixed satellite (earth-to-space) allocation,
and the amateur service has a secondary allocation in the band. Industrial, Scientific and Medical (ISM) equipment may
also operate in the 5.850-5.875 MHz portion of the band.
Equipment in the DSRC Service comprises On-Board Units (OBUs) and Roadside Units (RSUs). An
OBU is a transceiver that is normally mounted in or on a vehicle, or in some instances may be a portable unit. OBUs
mounted in vehicles and portable units are licensed by rule under Part 95 of the Rules. An RSUs is a transceiver that is
mounted along a road or pedestrian passageway. An RSU may also be mounted on a vehicle or hand carried, but it may
only operate when the vehicle or hand-carried unit is stationary. An RSU broadcasts data to OBUs or exchanges data with
OBUs in its communications zone. RSUs operate under Part 90 of the Rules.