Understanding DSRC

Dedicated Short Range Communications (DSRC) is an open-source protocol for wireless communication, similar in some respects to WiFi.  While WiFi is used mainly for wireless Local Area Networks, DSRC is intended for highly secure, high-speed wireless communication between vehicles and the infrastructure.

The key functional attributes of DSRC are:

  • Low latency:  The delays involved in opening and closing a connection are very short—on the order of 0.02 seconds.
  • Limited interference:  DSRC is very robust in the face of radio interference.  Also, its short range (~1000 m) limits the chance of interference from distant sources.  Additionally, DSRC is protected by the Federal Communications Commission (FCC) for transportation applications.  Although purely commercial convenience applications are welcome, transportation safety applications take precedence.
  • Strong performance during adverse weather conditions.

In 2004, the FCC dedicated 75 MHz of bandwidth at 5.9 GHz to be used for vehicle safety and other mobility applications.  DSRC operates in this band, and has been developed for over a decade by a range of stakeholders including automakers, electronics manufacturers, state highway departments, and the federal government.  Most work on DSRC has focused on active safety—crash avoidance using driver alerts based on sophisticated sensing and vehicle communications.

A number of other DSRC applications have been envisioned as well.  For example:

  • Transit signal priority
  • Transit vehicle refueling management
  • Personalized taxi dispatch services
  • Integrated transportation financial transactions:
    • Toll collection
    • Parking payment
    • Rental car payments and processing
  • Enhanced truck roadside inspection
  • Real time freight logistics
  • Pedestrian safety at intersections
  • Routing and scene management for emergency services
  • Advanced highway-rail and highway-transit grade crossings

More information on DSRC is available here.