AT&T doesn't think that the satellite-to-phone service T-Mobile and SpaceX's Starlink are planning should be approved as it is, and it has informed the FCC of its opinion in a filing (PDF). As Bloomberg notes, the carrier has raised concerns that the companies' service, in its current proposed state, could interfere with existing wireless services. "[I]t is paramount that operations do not jeopardize or inhibit the delivery of terrestrial wireless services," AT&T wrote.
In August last year, T-Mobile and SpaceX announced a collaboration that would allow the carrier's subscribers to connect to Starlink's second-gen satellites for coverage even if they're in the most remote locations. The companies are gearing up to begin testing this year, and the FCC started seeking comments (PDF) in April on their request to establish supplemental coverage from space (SCS). AT&T's filing is a response to that call.
The carrier wrote that FCC's rules "do not permit SpaceX’s proposed use of T-Mobile’s terrestrial spectrum" and that the companies "fail to even request — much less justify — rule waivers that would be necessary to authorize their proposed SCS authorizations." It added: "More broadly, the Applicants' technical showings are woefully insufficient regarding the risk of harmful interference posed by their planned SCS deployments. SpaceX and T-Mobile’s applications fall far short of meeting the threshold for waiver and cannot be granted in their current state."
AT&T has plans for a satellite service of its own in partnership with communications specialist AST SpaceMobile. The companies successfully conducted the first two-way satellite audio call on AT&T's network in Texas to a Rakuten number in Japan on a Samsung Galaxy S22 smartphone in April. The carrier assured in its filing that consistent with its comments, "AT&T and AST intend to provide the demonstrations necessary to show that they will not cause interference to any authorized terrestrial system."