Hoping to free up valuable spectrum for WiFi, the NCTA is urging the Federal Communications Commission to take a "fresh look" at the 5.9GHz band, arguing that an expensive, decades-long effort to use it for Dedicated Short Range Communications (DSRC) has "clearly failed."

In a filing (PDF) to the Federal Communications Commission (FCC) and a blog posted earlier this week, NCTA – The Internet & Television Association asserted that the use of DSRC for connected cars has fallen short as vehicle connectivity has gained serious ground in the free market using non-5.9GHz spectrum and existing cellular technologies.

The cable industry wants the FCC to open up a substantial portion of the 75MHz of spectrum in the 5.9GHz band for unlicensed use as WiFi continues to play a major role in its wireless strategy. For that strategy, cablecos leverage a network of hundreds of thousands of WiFi hotspots in metro locations and business venues, as well as inside millions of home-side gateways.

Stressing that the industry is "nearing a WiFi spectrum crisis" in the existing unlicensed bands, with the lower-adjacent 5.8GHz band serving today as WiFi's "workhorse," NCTA suggested it would make sense for the FCC to relocate automotive operations to a band other than 5.9GHz. It also noted that the FCC is already exploring whether to authorize unlicensed use in the upper-adjacent 6GHz spectrum.

Figure 1: Image source: NCTA.

On this issue, cable has a friend in FCC Commissioner Jessica Rosenworcel. She has also been advocating that the time is right to review the 5.9GHz band for new uses that will take fuller advantage of the spectrum. She agrees that the band's use for DSRC to help cars communicate to help reduce accidents has been a non-starter. Though testing on DSRC continues, "just a few thousand vehicles have DSRC on board out of more than 260 million cars on the road," Rosenworcel said in remarks given September 6 to the Silicon Flatirons Conference in Boulder, Colo.

Despite some pilots and early trials, DSRC is not widely used, though Cadillac includes the technology in some models, while Toyota has discussed plans to do so in several models in the coming years, TU-Automotive reports.

However, The Auto Alliance told the publication that the 5.9GHz band should be preserved for its current use, citing research from the National Highway Traffic Safety Administration finding that the technology has the potential to reduce up to 79% of crashes. The group also said unlicensed use should be forbidden unless it can occur without interfering with the incumbent safety systems.

Update: The National Highway Traffic Safety Administration (NHTSA) estimates that safety applications enabled by V2V and V2I could eliminate or mitigate the severity of up to 80% of non-impaired crashes (not all crashes).

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But Rosenworcel doesn't see eye-to-eye with that group with respect to early work around DSRC or its potential. "So, let's be honest: Our bet on DSRC didn't pan out the way we thought it would," Rosenworcel said. "There is no shame in correcting course"

She noted that back in 2013 the FCC started a study on opportunities for WiFi in the 5.9GHz band. The Commission followed with a test and feasibility plan in 2016 in coordination with the National Telecommunications and Information Administration and the Department of Transportation to determine the feasibility of DSRC and WiFi sharing.

The first phase, tests in the FCC lab, is complete, she said, arguing that it's time for the Commission to release those results and update the approach to emphasize co-channel sharing -- an approach that sounds similar to the spectrum-sharing effort underway now for the 3.5GHz CBRS band. (See Proposed CBRS Rules Suit Cable's Cause and Who's Doing What in the CBRS Band?)

The NCTA, meanwhile, is asking the FCC to act in the form of a Further Notice of Proposed Rulemaking (FNPRM) that would make substantial changes in the band, recognize the "market's rejection of DSRC," and designate all or a major portion of the 5.9GHz band for unlicensed use.

— Jeff Baumgartner, Senior Editor, Light Reading