T-Mobile asks FCC for two-year 2.7GHz 6G test window

The application is dated 17 September and covers seven test sites: six in and around T-Mobile's headquarters in Bellevue, Washington, and one in Kirkland, Washington. T-Mobile would run up to seven temporary fixed base stations, each with up to six experimental devices. No new towers would be built, and no antenna would sit more than six metres above an existing structure.

T-Mobile told the FCC the tests would generate data on coexistence with in-band and adjacent-band users, including federal radar systems and radio astronomy operations. In the application the carrier said the work will "support the advancement of wireless services without causing harmful interference to others."

T-Mobile filed days after Verizon asked the FCC to test 4GHz midband spectrum for possible 6G use, naming Ericsson as its vendor partner. T-Mobile did not name any vendors for the 2.7GHz tests. The carrier is also looking to test prototypes in the 4.8GHz to 4.9GHz portion of the 4GHz band until the end of October 2028.

Why 2.7GHz is in the filing

The FCC plans to auction 2.7GHz spectrum in 2028, a year after its C-band auction. On T-Mobile's third-quarter earnings call, chief technology officer John Saw said the upper C-band and 2.7GHz auctions would give the carrier capacity for 6G and more uplink bandwidth. He said 2030 traffic would stay downlink heavy but become "increasingly uplink rich," driven by AI wearables, AI agents and physical AI devices. SBA Communications chief executive Brendan Cavanagh said on 3 November that he expects proposed rulemaking for the 2.7GHz and 7GHz bands soon.

Earlier 6GHz tests

The FCC has granted T-Mobile an experimental license to test prototype 6G equipment from Ericsson and MediaTek in the 6425MHz to 6825MHz band around Bellevue. The setup calls for an Ericsson basestation and two mobile devices, one from Ericsson and one from MediaTek, in fixed locations and on moving vehicles. The move follows similar assessments with Nokia gear in the 7125MHz to 7525MHz band.

T-Mobile's aim is to evaluate the operation of "experimental prototype" equipment and the development of "next-generation wireless technologies," according to its FCC application. It said it will explore band segmentation, frequency sharing mechanisms and advanced beamforming. Steve Crowley, a consulting engineer who spotted the application, said this is "what you want to pin down as best as possible before investing in deployment." A T-Mobile spokesperson said the company "routinely" tests new technologies, including early pre-6G testing using readily available spectrum.

What happens next

If the FCC grants the September application as filed, T-Mobile would get two years of prototype data in 2.7GHz. T-Mobile has given no 6G launch date and points to the industry's 2030 timeframe. Saw said 2030 "will see 6G networks being built" and that T-Mobile would be first in the US. He cited integrated sensing and communications, where basestations and radios behave as radars, as one 6G use case.