T-Mobile eyes GAA use of 3.5 GHz band ahead of licensed availability

BARCELONA, Spain—T-Mobile is pushing hard for rule changes for the licensed portion of the 3.5 GHz spectrum band, but given the chance, it’s not going to turn down the General Authorized Access (GAA) portion of the band.

That’s according to Steve B. Sharkey, vice president, Government Affairs, Technology and Engineering Policy at T-Mobile, who participated in a fireside chat on Monday with FierceWireless Editor-in-Chief Mike Dano as part of the FierceWireless luncheon series here at Mobile World Congress 2018.

The Citizens Broadband Radio Services (CBRS) band, as the 3.5 GHz band is known in the U.S., is very good midband spectrum, Sharkey said. Elsewhere around the world, the 3.5 GHz band has become associated with 5G and countries around the world are designating the 3.5 GHz band for full 5G deployments, he noted.

The U.S. pursued a unique three-tiered structure: one for incumbents like radar and satellites; a second tier for priority access that will have to protect the incumbents; and a third tier, known as GAA, that will have to protect the other two tiers, he explained. All of it will be managed via a database, known as a Spectrum Access System (SAS) administrator, as well as a sensing element to detect where the government users are located in order to protect them from interference.

“We are excited about the band,” Sharkey said. “We’re doing work in it now,” including testing with some of the SAS database providers. “It looks very promising. The technology seems to be working well.”

The FCC is reviewing the band after T-Mobile and CTIA last year petitioned for a review of the rules because when written, the rules didn’t anticipate how much of the world is moving to 3.5 GHz for 5G, for one thing. Sharkey said he doesn’t expect an auction for the Priority Access License (PAL) portion—the second bucket he referenced—until 2019, but the GAA part could get started this year as soon as proper authorizations are done; auctions are not a part of the GAA set-up.

The T-Mobile executive said the initial rules ended up with very short-term license terms and very small license areas based on 74,000 census tracks—an unmanageable number from a wireless carrier perspective.

RELATED: T-Mobile CTO has ‘huge interest’ in 3.5 GHz

“We want at least the licensed spectrum that will be auctioned to look more like what we’re traditionally used to investing in” and that will drive investment, and eventually, investment in technology will drive GAA use, he said. “What we’re looking for is greater certainty.”  

A slew of entities have filed comments critical of the proposed changes, but T-Mobile has stood firm and argues that no investments made in reasonable reliance on the current rules will be stranded as a result of the proposed changes being considered at the FCC.

So just what does T-Mobile intend to do with the spectrum? “We think it will be an important part” of T-Mobile’s rollout, with LTE being the first technology envisioned for the band but it will eventually become part of the 5G ecosystem.

If the regulatory processes forward this year, “I think we’ll be in a good position to start using the band under GAA,” he said, with the usage looking a lot like LAA or LTE-U, technologies that use both licensed and unlicensed spectrum.