FCC Inquiry on Receiver Performance Faces 'Complicated Journey'

The FCC could face a tough challenge in looking at possible standards for receivers, as part of a notice inquiry teed up for a commissioner vote April 21 (see 2203310065). Chairwoman Jessica Rosenworcel, working with Commissioner Nathan Simington, circulated a draft NOI last week. Receiver problems figured prominently in recent spectrum fights, most notably the C band, but industry officials said there’s no easy approach for the FCC. In the C band, the FAA and airline industry fought to protect altimeters operating in spectrum more than 200 MHz away.

“Starting with a fresh NOI is a good first step, but it will be a complicated journey,” predicted Cooley’s Robert McDowell. “Receiver issues are among the most important in spectrum public policy,” he said. “But they are sleeper issues that wake up in a variety of ways and can cause tremendous disruption.” McDowell was a commissioner the last time the FCC had a pending NOI on receivers.

The “combination of the inexorable march of spectrum uses with the clear demonstration of problematic receivers” means “there is much more political capital behind doing something,” said New Street’s Blair Levin. “As to what can be done, it's a long-term problem, so it will need a number of new pieces, but that is what the NOI is supposed to determine,” he said.

Rules face opposition. “Commission regulation of receiver designs would be a bad idea from an innovation and market freedom standpoint,’ said Free State Foundation Director-Policy Studies Seth Cooper. “Fortunately,” the draft NOI “appears to recognize this, and it rightly recognizes the importance of voluntary cooperation in the wireless sector for improving receiver interference immunity,” he said.

The issue has been before the commission for more than 20 years, including in a 2003 NOI. NTIA urged standards, in comments that year. “NTIA has seen instances where interference problems have occurred due to a lack of receiver immunity to non-cochannel signals and believes that incorporating receiver standards will eliminate many of these problems,” the agency said.

The FCC suspended the proceeding four years later, saying the record had become outdated and could be better addressed “in proceedings that are frequency band or service specific.” Democratic Commissioners Michael Copps and Jonathan Adelstein said in a concurring joint statement to the order that the FCC “has a statutory duty to encourage more efficient uses of the radio spectrum.”

During a House Commerce Committee hearing last week (see 2203310060), receiver standards came up several times, first during testimony by Rosenworcel and Simington. Rep. Doris Matsui, D-Calif., noted she’s working “on draft legislation that I believe can complement” the FCC’s pending NOI by making receiver standards part of government purchasing decisions.

The FCC can’t look at just transmission if it wants to promote efficiency, Rosenworcel said. “If we want to be efficient, we also have to think about the other end -- we have to think about receiving,” she said. “What you’re raising in legislation is really important,” she told Matsui: “Making receiver efficiency part of government purchasing will change the market for receiver equipment because government purchases at a greater scale than anyone else.”

Joe Kane, Information Technology and Innovation Foundation director-broadband and spectrum policy, said that based on last week’s hearing, he sees “a strong appetite in the FCC and on the Hill to have more oversight” of receivers. “Something like mandating a receiver mask for devices it certifies is a possibility,” Kane said: “The FCC could also work toward asserting authority specifically over altimeters specifically, which are currently not covered by Part 87.”

The agency could publish acceptable receiver standards for different bands and services and then offer receiver testing, Kane said. “If there were a more widely agreed-upon standard that the FCC and FAA agreed on ahead of time, that could go a long way toward avoiding the kind of asymmetric perceptions of acceptable receiver performance that led to the C-band debacle,” he said.

“The FCC can't continue to pack more users into the spectrum if the receivers don't get better in rejecting adjacent channel interference,” emailed TechFreedom General Counsel Jim Dunstan. The more you reduce guard bands, the more efficient spectrum use becomes, he said. But in many services, the receiver “tends to stay out in the field for decades, if not generations -- if we had really tackled this back in 2002, we would JUST be seeing the benefits today,” he said.

Until NTIA and DOD get serious about receiver performance, “you're only tackling a part of the problem,” Dunstan said: “DOD probably has 10 times the legacy systems that the commercial side has, because there's never the same incentive or cost-benefit win for government users to upgrade their communications systems. Bravo to the FCC for taking this one. But they've got to lean on NTIA to undertake a similar (and far more difficult) task for government users.”

Regulation is raised as one possibility in the draft. “We request comment on whether and under what circumstances it might be appropriate for the Commission to consider adopting rules promoting receiver performance or specifying minimal receiver requirements,” the draft NOI says: “We also invite comment on possible regulatory approaches that promote receiver performance without specifying technical requirements.”

The proceeding could help the FCC “establish some basic expectations regarding when receivers will be protected from signal interference from adjacent bands, and when receivers will not receive protection because of the legitimate needs of new services operating in neighboring spectrum,” Cooper said.

“With the spectrum pipeline facing a shortage of new spectrum to auction, licensees will have to look for new ways to become more spectrally efficient,” McDowell said: “Making receivers behave more efficiently and in ways that protect licensees spectral neighbors, will make for a more robust wireless marketplace.”

“This proceeding is important and long overdue,” said Michael Calabrese, director of the Wireless Future Program at New America. “Spectrum sharing and accommodating new wireless technologies will require the FCC to set receiver standards to some degree,” he said: “As the conflicts around Ligado and repurposing C-band spectrum for 5G demonstrate, receivers are too often designed on the assumption that the use and allocation of neighboring frequency bands will remain the same indefinitely. Going forward, receivers should be robust enough to anticipate sharing by new terrestrial broadband uses.”