Dedicated short-range communication (DSRC) is a wireless communication technology designed to allow automobiles in the intelligent transportation system (ITS) to communicate with other automobiles or infrastructure technology. DSRC technology operates on the 5.9 GHz band of the radio frequency spectrum and is effective over short to medium distances.
DSRC has low latency and high reliability, is secure, and supports interoperability. It receives very little interference, even in extreme weather conditions, because of the short range that it spans. This makes it ideal for communication to and from fast-moving vehicles.
DSRC technology can be used in either a vehicle-to-vehicle (V2V) or vehicle-to-infrastructure (V2I) format, and communicates using transponders known as on-board units (OBUs) or roadside units (RSUs). In V2V, DSRC is used to allow vehicles to communicate with each other through OBUs. This communication is usually for safety reasons, such as to alert the driver of one car that the car in front of it is about to slow down. In V2I, an OBU in or on the vehicle communicates with surrounding infrastructure equipped with an RSU. This can also alert the driver to safety risks, such as that they are approaching a curve too quickly, or can be used to collect tolls and parking payments.
In 1999, the United States Federal Communications Commission (FCC) allocated the 5,725 MHz to 5,875 MHz band of radio frequency for DSRC communication. The ITS Joint Program Office of the US Department of Transportation conducts research on DSRC and other wireless communication technologies and their uses in vehicle safety.
Outside of the US, DSRC is also used for safety and other purposes. The European Telecommunications Standards Institute designated a 30 MHz band of radio frequency for DSRC in 2008, although the technology was used earlier than that for electronic tolling. Other countries, such as Japan, are also using the technology for safety and billing purposes.