The government’s “talking cars” plans failed. What’s next for the spectrum?

by on March 15, 2018 · 0 comments

In the waning days of the Obama administration, the US Department of Transportation (USDOT) proposed to mandate a government-designed “talking cars” technology–so-called DSRC devices–on all new cars. Fortunately, in part because of opposition from free-market advocates, the Trump administration paused the proposed mandate. The FCC had set aside spectrum in the 5.9 GHz band for DSRC technologies in 1999 but it’s been largely unused since then and these new developments raise the question: What to do with that 75 MHz of fairly “clean” spectrum? Hopefully the FCC will take the opportunity to liberalize the use of the DSRC band so it can be put to better uses.


Since the mid-1990s, the USDOT and auto device suppliers have needed the FCC’s assistance–via free spectrum–to jumpstart the USDOT’s vehicle-to-vehicle technology plans. The DSRC disappointment provides an illustration of what the FCC (and other agencies) should not do. DSRC was one of the FCC’s last major “beauty contests,” which is where the agency dispenses valuable spectrum for free on the condition it be used for certain, narrow uses–in this case, only USDOT-approved wireless systems for transportation. The grand plans for DSRC haven’t lived up to its expectations (USDOT officials in 2004 were predicting commercialization as early as 2005) and the device mandate in 2016–now paused–was a Hail Mary attempt to compel widespread adoption of the technology.

Last year, I submitted public interest comments to the USDOT opposing the proposed DSRC mandate as premature, anticompetitive, and unsafe (researchers found, for instance, that “the system will be able to reliably predict collisions only about 35% of the time”). I noted that, after nearly 20 years of work on DSRC, the USDOT and their hand-selected vendors had made little progress and were being leapfrogged by competing systems, like automatic emergency brakes, to say nothing of self-driving cars. The FCC has noticed the fallow DSRC spectrum and Commissioners O’Rielly and Rosenworcel proposed in 2015 to allow other, non-DSRC wireless technologies, like WiFi, into the band.

The FCC’s Role

These DSRC devices use spectrum in the 5.9 GHz band. The FCC set aside radio spectrum in the band for DSRC applications in 1999 based on a scant 19 comments and reply comments from outside parties. 

Despite the typical flowery language in the 1999 Order, FCC commissioners and Wireless Bureau staff must have had an inkling this was not a good idea. After decades of beauty contests, it was clear the spectrum set-asides were inefficient and anticonsumer, and in 1993 Congress gave the FCC authority to auction spectrum to the highest bidder. The FCC also moved towards “flexible-use” licenses in the 1990s, thus replacing top-down technology choices with market-driven ones. The DSRC set-aside broke from those practices, likely because DSRC in 1999 had powerful backers that the FCC simply couldn’t ignore: the USDOT, device vendors, automakers, and some members of Congress.

The FCC then codified the first DSRC standards in 2003. However, innovation at the speed of government, it turns out, isn’t very speedy at all. The fast-moving connected car industry simply moved ahead without waiting for DSRC technology to catch up. (Government-selected vendors making devices according to 15-year old government-prescribed technical standards on spectrum allocated by the government in 1999. Gee, what could go wrong?)

A Second Chance

So if the DSRC plans didn’t pan out, what should be done with that spectrum? Hopefully the FCC will liberalize the band and, possibly, combine it with the adjacent bands.

The gold standard for maximizing the use of spectrum is flexible-use, licensed spectrum, so the best option is probably liberalizing the DSRC spectrum, combining it with the adjacent higher band (5.925 GHz to 6.425 GHz) and auctioning it. In November 2017, the FCC asked about freeing this latter band for flexible, licensed use.  

The other (probably more popular) option is liberalizing the DSRC band and making it available for free, that is, unlicensed use. Giving away spectrum for free often leads to misallocation but this option is better than keeping it dedicated for DSRC technology. Unlicensed is for flexible uses and allows for many consumer technologies like WiFi, Bluetooth, and unlicensed LTE devices.

Further, because of global technical standards, unlicensed devices in the DSRC band make far more sense, it seems to me, in 5.9 GHz than in the CBRS band* (3.6 GHz), which many countries are using for licensed services like LTE. The FCC is currently trying to simplify the rules in the CBRS band to encourage investment in licensed services, and perhaps that’s a compromise the FCC will reach with those who want more unlicensed spectrum: make 3.6 GHz more accommodating for licensed, flexible uses but in return open the DSRC band to unlicensed devices.

Either way, the FCC has an opportunity to liberalize the use of the DSRC band. Grand plans for DSRC didn’t work out and hopefully the FCC can repurpose that spectrum for flexible uses, either licensed or unlicensed.



*Technically, the GAA devices in the CBRS band are non-exclusive licenses, but the rules intentionally resemble an unlicensed framework.

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