By Kelly Hill

The Federal Communications Commission plans to hold an auction of spectrum at 3.45-3.55 GHz by the end of this year, putting additional midband spectrum in play for 5G services.

Auction 110, set to begin in early October, will offer up to 100 megahertz of spectrum divided into ten 10-megahertz blocks, licensed by geographic areas known as Partial Economic Areas (PEAs), for a total of 4,060 flexible-use licenses across the contiguous United States.

The commission noted in a release that the 3.45 GHz band, plus the neighboring 3.5 GHz CBRS band and the 3.7 GHz C Band spectrum, represent 530 megahertz of contiguous midband spectrum for 5G. Acting FCC Chairwoman Jessica Rosenworcel said that the build-out requirements for this spectrum are the “most aggressive build-out obligations of any spectrum auctioned for 5G to date. … We insist on getting infrastructure built twice as fast as what the agency has required in other recent 5G bands.”

The move to auction the spectrum gained bipartisan support, with both of the Democrats on the FCC approving the measure and the two Republicans approving in part and concurring in part. The tone struck by both sides was notable in recognizing each other’s work toward consensus.

“While we may disagree on some details from time to time, I know that each one of my colleagues at the Federal Communications Commission is equally committed to ensuring that the United States leads in 5G. I welcome their ideas, their resolve, and their partnership, and I look forward to building this future for the benefit of the American people,” said Rosenworcel.

Commissioner Brendan Carr, a Republican, said that he was pleased that full-power operations and geographic license size for the 3.45 GHz band are aligned with the FCC’s approach to the C Band, rather than with CBRS. Carr did take issue with two aspects of the FCC’s go-forward on 3.45: The imposing of a maximum spectrum aggregation limit of 40 megahertz and the way the Commission is requiring specific, double-masking to avoid out of band emissions. However, Carr added, “Given the good-faith progress we made to find common ground on this item and improve the outcome, I am concurring on these two issues while approving of the rest of today’s decision.”

Rosenworcel framed those two points — the limits on spectrum aggregation and the emphasis on interference prevention — as an effort to diversify the base of bidders (she noted that in the C Band auction, more than 90 per cent of licenses went to the top two bidders) and to take a more holistic approach to spectrum management by recognizing the nature of shared, lower-power operations in the adjacent CBRS band and protecting it adequately.

And there may be more spectrum to come. There are already discussions underway about an auction of 2.5 GHz spectrum, and Carr broached the topic of taking a look at 5.470-5.725 GHz, which he said “contains a large, 255 megahertz-wide swath of unlicensed spectrum that is vastly underutilized today—indeed, equipment manufacturers don’t even bother to include the band in many 5 GHz Wi-Fi devices. This is because we have costly and cumbersome technical restraints on the band that are designed to protect federal operations. We should examine whether advances in technology would allow us to continue to protect federal through a more efficient mechanism, thus creating more opportunities for unlicensed use of this band.”

Last year’s Consolidated Appropriations Act had required the FCC to put 3.45-3.55 GHz up for auction by the end of 2021, and another law, the MOBILE NOW Act, ordered the FCC to work with NTIA to look at the feasibility of commercial network operations all the way down to 3.1 GHz.

Rosenworcel said she has already begun work with federal partners to look put in motion the examination of 3.1-3.45 GHz. “While the law compelled certain outcomes in our decision today, it is my hope that our future efforts to find more spectrum for 5G will enjoy the flexibility to explore every option available to us, including the opportunity to pursue more innovative spectrum sharing policies like we have in the CBRS band,” she said. “I also have instructed the Wireless Telecommunications Bureau to consider opportunities to rationalize the entire 3 GHz band to increase efficiency while also being mindful of the importance of unlicensed use.”