Some Question Potential Benefits of Spectrum Usage NOI

The FCC’s draft notice of inquiry on understanding nonfederal spectrum use “through new data sources, technologies and methods” appears to be generating little official reaction from the wireless industry. Only one party filed comments on the draft in a new docket, 23-232 -- the Institute for the Wireless IoT at Northeastern University. No one reported meetings at the FCC about the draft. Some experts said it's unclear what the NOI will accomplish. Commissioners are expected to approve the item at their Thursday meeting, officials said.

Recon Analytics’ Roger Entner slammed the NOI, saying when the FCC “could do so many things about identifying new spectrum, they are going on a wild goose chase here.”

The NOI seemed to come out of nowhere, said a lawyer with wireless clients. “What exactly is that?” the lawyer asked, suggesting it could be a “Trojan horse,” which “could go so badly” for industry. Industry executives expect concerns from wireless carriers that may not relish a deeper dive into how they’re using spectrum.

The NOI seeks comment on the “capabilities and limitations” of existing commission practices on real-time spectrum usage (see 2307130065). It seeks “feedback on what definitions appropriately capture the extent to which a set of frequencies is being utilized” and on “band-specific considerations” for examining spectrum usage.

The FCC said the NOI “continues the Commission’s efforts to bring next-generation techniques and data-driven analysis to our spectrum management toolkit, building on the Commission’s recent Spectrum Policy Statement regarding the responsibilities of receivers to operate resiliently in congested spectrum bands.” Commissioners approved the receiver statement 4-0 at their April meeting (see 2304200040).

The NOI is “very timely” but should have been extended to federal bands, though that would likely have required coordination with NTIA, said Monisha Ghosh, engineering professor at Notre Dame and former FCC chief technologist.

Ghosh emailed an outtake from an upcoming IEEE article she wrote. The NOI “is a welcome first step, [but] a similar effort towards understanding federal spectrum usage is also necessary, especially since many of the proposed bands for future sharing, for example in 7-24 GHz, have primarily federal incumbents,” Ghosh writes: “There is still no scalable, pervasive methodology that measures spectrum usage in different frequency bands in close to real-time. Hence, every spectrum proceeding that proposes spectrum sharing inevitably faces the same hurdle: how does one share spectrum efficiently if there are almost no measurements of actual spectrum usage?”

Digital Progress Institute President Joel Thayer said the draft is explicit about what the FCC doesn’t want in response to the NOI, but “exactly what the FCC is looking for … is unclear.” The agency appears to want to “mirror proceedings to what NTIA does when looking at the federal use spectrum,” Thayer emailed: “However, these expressed limits on the type of comments it wants are peculiar. Frankly, I don't know what to make of it.”

'Worthwhile'

The NOI could be helpful, predicted Joe Kane, Information Technology and Innovation Foundation director-broadband and spectrum policy. “Productive use of spectrum should be the central goal of spectrum policy, and measuring what use there is will help guide policy toward that goal,” Kane emailed. Kane noted the NOI "explicitly connects itself" to the earlier spectrum policy statement and asks questions about receivers. "Those principles were generally good, and it would be worthwhile for the FCC to work toward their realization," he said: "One could imagine ... the C-band debacle going differently if the FCC knew how wide-open the altimeters were in practice.”

“One reason that there is no agreement about how to quantify spectrum usage is that the best way to measure usage depends on technology and how those measurements will be used,” said Jon Peha, Carnegie Mellon University engineering and public policy professor and former FCC chief technologist. “It matters whether one is trying to figure out whether there are easy opportunities for spectrum sharing in a given band, or whether a license-holder is using its spectrum efficiently to offer services,” Peha said.

The Northeastern University filing notes the FCC started to look at nonfederal spectrum use through the “now mostly forgotten FCC Spectrum Management Task Force of the early 1970s.” A 1977 paper by then-FCC staffer Oleg Efremov, “Measured VHF and UHF Signal Strength and Spectrum Occupancy Versus Antenna Height,” discussed “a key phenomenon in any spectrum usage measurements: due to radio propagation issues the apparent spectrum occupancy increases with the height of the observing antenna,” the institute said: “The NOI should specifically address criteria for determining which antenna height should be used so that measurements can be both meaningful and reproduceable.”

“For occupancy measurements to be both meaningful and reproducible some sort of standardization of the gain characteristics of the antennas used for the measurements is necessary,” the institute said. It noted the problems with taking measurements in an era when most spectrum use is digital rather than analog. “In the 1970s analog case, it was relatively easy to confirm that the radio channel was actually being used for real productive communications” the filing said: “In today’s digital case, an FCC licensee with an incentive to make its license spectrum to appear more heavily utilized than it actually is has options to create meaningless data for transmission and measurement by spectrum measurement equipment.”

The institute said the FCC should consider “adopting regulations … to decrease the likelihood that a licensee could artificially increase its apparent spectrum use for regulatory gain or to avoid a penalty of some sort.”