Like a Wi-Fi connection, DSRC allows for over-the-air data transmission.
Like a Wi-Fi connection, DSRC allows for over-the-air data transmission.
( Source: Adobe Stock)

DSRC What is DSRC dedicated short range communications?

Author / Editor: Jason Unrau / Florian Richert

Have you ever wondered how connected cars would be able to operate driver-assist systems without a cellular connection? It's the same for vehicle-to-vehicle (V2V) or vehicle-to-infrastructure (V2I) communication, designed to enhance road safety. One protocol under development is DSRC—Dedicated Short Range Communications.

When you're exploring the realm of vehicle communications to enhance road safety, one factor has always been at the forefront: speed of communication. High-latency connections over cellular networks leave much to be desired and can leave the connection less reliable and secure.
In 2004, a specific 75 megahertz spectrum was allocated in the 5.9 GHz band for DSRC, dedicated for automotive purposes. It's this bandwidth that opens up options for the automotive sector for safety and convenience.

What is DSRC?

Like a Wi-Fi connection, DSRC allows for over-the-air data transmission. Unlike the broadly-used wireless connection for Local Area Networks, DSRC is assigned for the sole purpose of communication between vehicles and infrastructure. It does not require cellular signal or a Wi-Fi connection, but rather it communicates directly with other vehicles and transportation infrastructure in its vicinity.
Why DSRC rather than other communication methods? Think of it like using walkie-talkies. When someone else on the same frequency is nearby, you can communicate without lag and the signal is stronger the closer you are in proximity. A cell signal, on the other hand, must be sent through the network, resulting in high latency, even if you're standing side by side.

DSRC benefits in three main areas:

  • Low latency – the connection opens and closes in around 0.02 seconds.
  • Limited interference – with its short-range limitations or around 1,000m, interference from surroundings is unlikely. Plus, the band is protected by FCC regulations.
  • Resilience to weather – sun, cloud, or precipitation, DSRC is reliable in all conditions.

How can DSRC be used?

Carmakers are focused on using DSRC technology almost exclusively for advanced driver-assist systems (ADAS) applications. These systems often depend on sensors, cameras, lidar, and radar to identify hazards and other vehicles on the roadway, but line of sight is almost always necessary. With DSRC, a vehicle can essentially see around corners, not to mention operate at high speeds.
In addition to the aspect of active safety, DSRC can also be used to personalize parking payment, toll collection, freight logistics, plus integrate with V2I for traffic signal prioritization. With any V2V or V2I communications, DSRC could be implemented.

Real-World Applications of DSRC

General Motors was the first carmaker to deploy DSRC-based V2V communication in the US market, starting with the 2017 Cadillac CTS and Super Cruise technology. Since that time, development has continued for several carmakers. Notably, Toyota and Lexus stated in 2018 that all vehicles would have DSRC-based V2V beginning in 2021. Toyota later suspended that plan, though.
Honda has also been working with DSRC technology. They've demonstrated the ability for DSRC to communicate with pedestrians' DSRC-enabled smartphones. This would help drivers and vehicles avoid non-vehicle collisions too.

DSRC: Viable and well-developed or in its infancy?

Just as DSRC began to hit its stride and implementation began, 5G wireless technology sprung into the picture. This mobile broadband connection is more than just a cellular connection—it's designed to be an all-encompassing protocol.
DSRC has not been made obsolete and development continues. However, 5G is likely to be the focus for future development.

  • It's way more flexible as it operates on three different spectrum bands.
  • 5G also has extremely low latency, especially in the low-band spectrum, which is where ADAS and V2X technologies would operate most often.
  • 5G will be used for over-the-air updates and other OEM-direct communication anyway, which could make integrating DSRC redundant.
  • With the massive amounts of data that connected vehicles transmit, the incredibly-high data speed 5G affords makes it the preferred choice.

There is likely to be a place for DSRC technology, especially as 5G is years away from widespread implementation. However, you can also expect that mobility options will be apt to wait rolling out new services until 5G is commonplace, if they can.