A Congressional committee is weighing in on a spat between the FCC and parts of the automotive industry over a plan to appropriate a piece of wireless spectrum set aside for connected-cars and instead designate it for Wi-Fi.
The dispute centers on Dedicated Short Range Communications or DSRC, a point-to-point communication standard designated to let vehicles close to each other on roadways share information to improve safety. The go-to example is using it to warn a driver near-instantly if the car ahead suddenly slams on its brakes.
DSR and its 75MHz of spectrum in the 5.9GHz band has been a relatively obscure technology until late last year when the FCC started considering that 45MHz of that spectrum should be made available for unlicensed wireless use such as Wi-Fi
Secretary of Transportation Elaine Chao raised “significant concerns” over the proposal, citing potential harm to public safety because it would more than halve the spectrum available for DSRC. Those concerns were echoed more recently in an open letter signed by 38 members of the House Committee on Transportation and Infrastructure.
But it’s unclear whether the proposed FCC rule would actually have a negative effect on the development of automotive safety systems, particularly in light of the fact that the industry hasn’t moved en masse to adopt DSRC technology at all, despite the spectrum being set aside for that use nearly two decades ago.
DSCR vs. C-V2X
Among the stakeholders themselves the issue boils down mostly to investment. Companies that have actually put money toward making DSRC a reality dislike the idea that their investment could be rendered moot by an FCC-abetted shift to a different technology. Even though both DSRC and a newer standard called C-V2X work in similar ways, they could require different chipsets with different underlying architectures.
Bill Ray, senior research director at Gartner, said that there simply hasn’t been any real urgency in the automotive world to put DSRC to work. “There was a general perception that this would be a useful thing to be able to do in the future,” he said.
While some car companies, including Volkswagen and Toyota, have made an effort to develop DSRC-based connected-car tech, others have moved to develop C-V2X, which boasts most of the same capabilities but would be largely unaffected by the skimming off of some 5.9GHz spectrum for unlicensed use.
IDC research manager Matt Arcaro said that the opportunities presented by either technology are great, but that the industry as a whole simply hasn’t managed to pull itself together and standardize anything.
“There’s a lot of opportunity to advance the technology into making vehicles work better,” he said. “The challenge becomes when you want to cooperate across brands and across highway infrastructure.”
More channels for Wi-Fi
The FCC’s initial notice argues that the demand for mobile broadband services makes for a better use of that 45MHz, noting that some of the most advanced features of Wi-Fi 6 (802.11ax Wi-Fi) require the use of 160MHz-sized channels. The additional unlicensed spectrum freed up under the FCC’s proposal would allow the use of four such channels, instead of the current three.
Yet it’s unclear whether the extra spectrum in the 5.9GHz band will be necessary for such an expansion, according to IDC research director Phil Solis.
“There’s a wider perspective here,” he said. “The argument can be made, ‘Why take from 5.9[GHz] and add it to the 5GHz band when the 6GHz band is going to become available and provide far more spectrum than all of that?’”
C-V2X tests in the works
With Congress, the Department of Transportation and the FCC all now involved, the dispute’s intensity has grown. Qualcomm and Audi on Thursday announced plans to test C-V2X technology in Virginia, using part of the spectrum that the FCC’s proposal has allocated to that system. Deployment is expected in the third quarter of 2020, and the tests will center on frameworks to notify motorists of work-zone warnings and improve signal timing at busy intersections.
According to Forrester analyst Glenn O’Donnell, the issue is essentially a political one at this point, even if it doesn’t break down along partisan lines.
“How far it goes, I don’t know, I’m not a lawyer … [but] there will be legal challenges,” he said. “I think the automotive industry has to really think through what it’s trying to do here.”