FCC endorses C-V2X mobile network that lets cars talk to each other

The agency's proposal would free airwaves for Wi-Fi, too. But it's bad news for the older DSRC car network technology.

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The Federal Communications Commission on Thursday endorsed new networking technology called C-V2X, which links cars to each other and to traffic signals. In a unanimous decision, the commission voted on a proposal that would carve off some radio airwaves in the 5.9GHz frequency range for use by C-V2X .

The FCC's proposal also would free up some spectrum for unlicensed use. But it casts a shadow on an older rival to C-V2X called DSRC. which for the last two decades has had exclusive rights to use the 5.9GHz band.

Radio spectrum is a precious resource, and fans of many wireless communications technologies are scrapping for as much of it as they can get to promote their different visions for the future. Spectrum is already used for everything from the mobile networks relied on by phones to Wi-Fi, Bluetooth, TV broadcasts, police and fire department networks and long-range telecommunications.

Unlicensed spectrum is something of a free-for-all, with many different uses all chattering at the same time on the same frequency bands, but licensed spectrum used for phone networks, emergency services and car communications is protected for more reliable service.

A 'balanced approach' to radio spectrum

The proposal "seeks to achieve a balanced approach that will both improve automobile safety and unleash more wireless innovation for the benefit of the American people," the FCC said.

The proposal has a good chance of being adopted, in part because it's got bipartisan support, said Todd Daubert, who leads telecommunications and technology work at law firm Dentons. "Chairman [Ajit] Pai's proposal to split the band between unlicensed and transportation uses has support across the aisle, from a significant portion of the auto industry, broadband providers and consumer groups," he said.

The next step for the FCC is to gather and review comments. There's no timeline yet for making the proposed rule final.

The agency has been stewing for years about what to do with the 5.9GHz band, which includes a swath of spectrum 75 megahertz wide. Its proposal would divide that into three chunks. The bottom 45MHz would be for unlicensed use, meaning it's free for anyone to use for radio transmissions. The top 20MHz would be solely for C-V2X.

The middle 10MHz would be for DSRC -- but only if its fans can make a persuasive case in a comment period, and the FCC has been unimpressed with progress so far. Otherwise, it'll be devoted to C-V2X.

The Wi-Fi Alliance, a trade group that helps standardize the Wi-Fi networking technology, cheered the FCC's proposal to keep 45MHz for unlicensed use. That spectrum could be combined with earlier unlicensed spectrum so devices like phones and laptops could use a very wide 160MHz band for faster data transfer.

Others endorsing the unlicensed spectrum use included Comcast and Charter Communications, two large internet service providers. Chipmakers Broadcom and Qualcomm -- the latter a major C-V2X backer -- also voiced support for the FCC's proposal.

Carmakers want more spectrum

Some carmakers, though, are unhappy with the push.

The FCC's proposal "risks lives, slows innovation and runs counter to what the Commission has heard from safety and technical experts," said the Association of Global Automakers and the Alliance of Automobile Manufacturers in a statement Thursday. The groups said carmakers are ready to use all of the 75MHz available and that the FCC must "protect critical safety communications from harmful interference, including unlicensed technologies."

The automaker groups sidestepped the issue of DSRC versus C-V2X.

In a November letter to the FCC, Ford Chief Executive James Hackett said the company is willing to share the 5.9GHz spectrum with unlicensed uses, but only if there is a conclusive demonstration that other uses of the airwaves won't hurt C-V2X.

Qualcomm said 20MHz worth of spectrum is sufficient for C-V2X using today's mainstream network technology, 4G. "In addition to the 20MHz, we requested another 40MHz for 5G-based C-V2X, which will support autonomous vehicles," said Dean Brenner, Qualcomm's senior vice president of spectrum strategy.

FCC concerned about DSRC 'slow adoption'

The FCC pointed to "slow deployment of the DSRC service" as the reason for deciding what to do with the 5.9GHz band. That's a pessimistic signal for DSRC fans like Volkswagen and Toyota.

Toyota declined to comment until it reviews the FCC's proposal in more detail.

The proposal comes as no surprise. "DSRC ... was intended to enable ubiquitous transportation and vehicle-related communications, but results haven't matched that intent," Pai said in November. "Here we are, two decades later, and the situation can at best be described as 'promise unfulfilled.'"

But the stance on C-V2X is good for fans like Ford Motor and Qualcomm. C-V2X stands for "cellular vehicle-to-everything" and covers how cars can link up to each other directly, to infrastructure like traffic signals, and to mobile networks operated by companies like AT&T and Verizon.

C-V2X development began with today's 4G technology, and indeed that's the type Ford plans to build into its cars initially. But it also will extend to 5G networks that offer faster data transfer speeds and more-reliable communications.

Originally published Dec. 12.
Updates, Dec. 12 and 13: Adds further background and comment from the wireless and automotive industries.

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