Google, BAC Coalition eye mid-band spectrum at 3.7-4.2 GHz

FCC 2017 (FCC)
The FCC, headed by Chairman Ajit Pai (center) is considering releasing more spectrum for commercial uses. Image: FCC

At its August Open Meeting, the FCC initiated a major inquiry proceeding into what it labels “mid-band spectrum,” namely the frequencies between 3.7 GHz and 24 GHz. It’s eying these for flexible use, including wireless broadband, on both a licensed and unlicensed basis. But it’s one band, the 3.7-4.2 GHz that’s attracting the most interest, including from Google and a coalition looking to close the broadband gap in the U.S.

In adopting its Notice of Inquiry, the commission is looking for input on three specific bands (5.925-6.425 GHz and 6.425-7.125 GHz bands are the other two), and it’s also asking companies to identify other non-federal frequencies that may be suitable for expanded use. But the 3.7-4.2 GHz band it attractive because it’s adjacent to the 3.5 GHz Citizens Broadband Radio Service (CBRS) band, a.k.a. the 3.5 GHz band, which means that those who are also interested in some of the CBRS spectrum have an opportunity to nab contiguous spectrum. Also, it offers another path to providing affordable broadband to the underserved.

There are existing uses in the band, which means the debate around this is likely to be contentious. Satellite for media broadcast and communications backhaul is a major player already, and some carriers use it for fixed services. Nonetheless, the proposals are coming in.

On the contiguous spectrum point, “Two petitions for rulemaking, by CTIA and T-Mobile, for liberalization of certain licensing rules in the 3.5 GHz CBRS band to make operations in that spectrum more attractive to investors and deployment friendly were recently put on public notice,” the law firm of Kelley, Warren & Drye said in a brief. “Proponents smell an opportunity for a larger contiguous band which could bring equipment costs down and harmonize with international initiative in this same portion of the radio frequency spectrum.”

Then there’s the Broadband Access Coalition (BAC), made up of wireless ISPs, educational interests and technology advocacy organizations interested in closing the digital divide. BAC is urging the commission to create a new licensed, point-to-multipoint (P2MP) fixed wireless service in the band, and Google is throwing its hat in with the group.

“Alphabet Access fully supports the larger goal of opening the 3700-4200 MHz band for licensed services and the 6 GHz band for unlicensed services, as contemplated in that NOI, while protecting incumbent systems from harmful interference,” Google’s Alphabet umbrella company said in a letter to the FCC last week. “BAC’s proposals would allow limited deployments of point-to-multipoint systems, which would advance the Commission’s goal of expanding broadband service, especially in the remote and underserved areas where terrestrial service is critical and relatively few [fixed service] sites exist.”

It quoted Mimbres Communications, a fixed wireless broadband provider serving rural Grant County, N.M, as saying that the scheme would “would bring rapid innovation to a currently underutilized band having highly desirable propagation characteristics.”

Interesting, the two areas are rubbing up against each other. CTIA in early August filed a motion to, among other things, have the FCC consider the BAC Petition in consolidation with the Mid-Band NOI overall, so that it wouldn’t be approved separately before all of the comments were in from other interested parties. The FCC denied the request—which is a positive outcome for BAC.

That development came as the commission weighs a proposal from T-Mobile asking the FCC to consider adopting rules that some say make it virtually impossible for smaller operators and WISPs to get a piece of the 3.5 GHz, which is widely seen as prime real estate for 5G. The uncarrier would like to see the FCC auction all 150 megahertz of spectrum in the 3.5 GHz band as PALs, or Priority Access Licenses on a standard 10-year licensed term—a proposition that only larger licensed mobile carriers are likely to afford. A similar scheme for parts of the 3.7-4.2 GHz band would make sense in that context.

Meanwhile, an ad hoc coalition of equipment manufacturers and mobile carriers are also looking to access to the 3.7-4.2 GHz band for licensed mobile services (and to the 5.925-7.125 GHz band for unlicensed usage). But they still have yet to formally file their petition for rulemaking. In a blog post published on the FCC’s website on July 10, Commissioner Mike O’Rielly expressed support for the ad hoc proposal.