GM to Congress: We’ll Test Wi-Fi in DSRC Spectrum

Burney Simpson

The role of Congress keeps growing in the battle among driverless transportation proponents over Dedicated Short Range Communications (DSRC) technology.

Last week, a U.S. House committee heard testimony from power houses in the industry regarding the possible expansion of Wi-Fi communications into the DSRC 5.9 GHz range.

General Motors and Cisco Systems plan to test the use of Wi-Fi in the spectrum. GM wants to speed the research as it prepares to launch a Cadillac CTS in the 2017 model year with V2V technology.

On the other side are researchers like the University of Michigan Transportation Research Institute (UMTRI) and safety regulators National Highway Traffic Safety Administration (NHTSA). They want to keep that DSRC spectrum devoted to vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2X) communication.

The researchers believe that allowing Wi-Fi within the DSRC 5.9 GHz range will impact the technology, while GM says that the use of Wi-Fi for V2V should at least be tested.

Both sides agree that DSRC is a technology with proven reliability and the capacity to support a variety of communication speeds in good and bad weather, while also handling message authentication and data privacy demands.

Both sides also agree that implementing V2V communications could greatly reduce traffic accidents. The Department of Transportation estimates the technology could prevent about 81 percent of all vehicle crashes involving non-impaired, i.e. sober, drivers.


The legislative conflict began about a year ago when Sens. Marco Rubio, a Republican from Florida, and Cory Booker, a Democrat from New Jersey, introduced the Wi-Fi Innovation Act that would open parts of the 5.9 spectrum to Wi-Fi use. A companion bill was introduced in the House.

Now, Rep. Dan Lipinski has introduced the Future Transportation Research and Innovation for Prosperity (TRIP) Act (HR 2886), a bill that takes a big-picture view of the development of transportation infrastructure, including driverless technologies, freight shipment and research. Lipinski’s bill is on the side of the DSRC purists.

That view was expressed in testimony to the U.S. House Subcommittee on Commerce, Manufacturing, and Trade last week by Peter Sweatman, director of UMTRI. The research group reviewed DSRC use in V2V communications in a two-year test with 47 companies deploying 2843 vehicles that collected 115 billion messages from 35 million miles of driving.

“Our entire ecosystem of companies (are) committed to (V2V) using 5.9 GHz DSRC,” said Sweatman. “Spectrum must be protected for (V2V) safety performance (which) depends on the absolute reliability of messages, as well as certainty in spectrum availability, in the mode that has been fully tested.”

In comparison, Wi-Fi spectrum sharing was only a theoretical possibility, he said.

Nathaniel Beuse, a NHTSA safety administrator, agreed. He cited a research report finding that “unless … (Wi-Fi) and other unlicensed and licensed technologies are determined not to interfere with DSRC, the potential benefits of the program will be severely compromised.” 


But the GM and Cisco Systems executives set off a minor bomb during their testimony when they revealed that GM will move forward on plans to test V2V communications with technology from Cisco that makes room for Wi-Fi communications in the 5.9 GHz band.

“(GM) is focused upon implementing V2V technology (and) … We are very optimistic about a sharing proposal from Cisco that would operate on a “listen, detect and vacate” basis. We have engaged with Cisco and plan to begin testing their technology as soon as possible,” said the GM exec.

The Cisco exec said it planned to “use a combination of DSRC and wired technologies,” to deliver a “highly secure, mobile, and high availability solution.” 

The sleepy summer in Washington D.C. may have just woken up.


Photo 2015 Protesting by Stephen Melkisethian.