Connected-vehicle spectrum could be tapped for next gen Wi-Fi

This article was updated with a correction and additional material on June 6.

The Federal Communications Commission is considering shifting spectrum currently reserved for smart transportation applications to help accelerate deployment of next-generation Wi-Fi, which will bolster emerging 5G wireless communications.

Unlicensed spectrum used for current Wi-Fi applications is a data transmission workhorse. At a New American Foundation event on June 3, Michael Calabrese, director of the think tank's Wireless Futures Project, said that "70-80% of mobile data traffic" doesn't touch the large commercial wireless providers' networks. Instead Wi-Fi funnels the traffic to licensed wireline networks without jumping over to licensed spectrum.

Wi-Fi 6, which is now available on routers and other devices, can give 5G speeds to consumers and businesses in rural and urban areas alike, sooner and more cheaply than licensed 5G cellular spectrum, Calabrese said.

FCC Chairman Ajit Pai said in speech at the Wi-Fi World Congress on May 24 that the commission wants to open up 1,200 megahertz of spectrum between 5.925 GHz and 7.125 GHz for different types of unlicensed use.

However, 75 MHz of band in 5.9 GHz has been a contentious interagency issue for years. The band is used currently for Dedicated Short Range Communications in vehicle-to-vehicle technology. Spectrum licenses are held locally and the effort to keep the band reserved nationally for traffic safety applications is supported by the Department of Transportation. Advocates for repurposing the band say that DSRC use cases are few, and the band is being underutilized. 

After this article was initially published, a Department of Transportation spokesperson told FCW via email that there were "a significant number of deployments across the country currently utilizing the band."  Those applications, typically implemented by state or local transportation departments, include smart intersection signal control that can prioritize traffic lights for emergency vehicles; systems that can warn of pedestrian in crosswalks; as well as right turn detection for buses, vehicle-to-vehicle collision warnings and other vehicle-to-vehicle and vehicle-to-infrastructure applications.

In his speech, Pai said his agency planned to open a "fresh look" rulemaking process for the spectrum. After that announcement, Transportation Secretary Elaine Chao asked for a 30-day extension on opening up the rulemaking. The FCC is still looking to reclaim the spectrum for communications use.

"It's totally appropriate and reasonable not to strand our policy and take a fresh look at how to use those airwaves," FCC Commissioner Jessica Rosenworcel said at the New America event. "I hope the agency hasn't lost its nerve."

At the same event, Commissioner Michael O'Rielly said the decision to move ahead with the rulemaking is "decided by the chairman."

He added that the spectrum the FCC set aside years ago for DSRC vehicular safety capabilities has been taken up by other technologies that leverage licensed commercial spectrum, such as lidar-based capabilities, that can detect other vehicles and road hazards.

Correction: The Department of Transportation does not hold licenses in the 5.9 GHz band. Licenses for traffic safety applications in that band are held locally.