Safer Roads or Stronger Wi-Fi?

Limited spectrum has connected-car advocates at odds with expanded-Wi-Fi supporters.

Talking cars will one day make the roads safer, but will they come at the expense of Wi-Fi? (National Journal)

Talking cars will one day be mandatory, but in the meantime, some think they're holding back the airwaves for much-needed Wi-Fi.

As Internet access grows, more and more frequency is needed to support Wi-Fi devices. Some of that frequency — the 5.9 GHz band — has been set aside for talking cars. Vehicle-to-vehicle communication, which the Transportation Department says will one day be mandatory, allows cars to alert one another to their presence and to warn drivers if a wreck is imminent.

The National Highway Traffic Safety Administration estimates talking cars could eliminate 80 percent of wrecks not involving driver impairment.

For now, though, the 5.9 GHz band is spectrum that can't be used for Wi-Fi devices. Some see a middle ground in which the frequency is still used for talking cars but shared for some Wi-Fi purposes.

Sens. Marco Rubio and Cory Booker want to see if that's possible. Their Wi-Fi Innovation Act, released Friday, gives the Federal Communications Commission 18 months to test the spectrum to see if it can be shared without interference. "This bill requires the FCC to conduct testing that would provide more spectrum to the public and ultimately put the resource to better use, while recognizing the future needs and important work being done in intelligent transportation," Rubio said in a release.

Some connected-car advocates think that timeline is rushed. At present, there are no firm spectrum-sharing plans in place, said Paul Feenstra of the Intelligent Transportation Society of America. Without plans, the FCC has nothing to test, and giving it a brief timeline to find an answer could be problematic.

"We're concerned about putting deadlines on the testing of the technology that has yet to be introduced," Feenstra said. "We're very concerned about preventing a rush to judgment. [Rushing testing] could potentially put the future of vehicle-to-vehicle communications at risk."¦ Any potential for interference in that band is unacceptable."

Talking cars will have to communicate at a rate of 10 signals per second. For that to work, said Feenstra, the signal must be "high speed, it's got to be secure, reliable, and it's got to work every time." He's concerned Wi-Fi use on that frequency could clog up signals and prevent the technology from being foolproof.

In other words, ceding part of the 5.9 GHz band — without being absolutely sure it can be done interference-free — could endanger what's heralded as one of the greatest auto safety breakthroughs ever. But with the ever-increasing demand for Wi-Fi, it may prove to retain sole possession.