AT&T filed some concerns with the Federal Communications Commission (FCC) on Thursday over T-Mobile and Starlink owner SpaceX’s plans to let mobile phones connect to Starlink satellites (via Ars Technica).

In its filing, AT&T argues that SCS, or “supplemental coverage from space,” should not inhibit terrestrial wireless service and that the FCC “must prioritize” protecting terrestrial networks, and that T-Mobile and SpaceX’s proposals don’t have enough information about potential interference. “The Applicants’ technical showings are woefully insufficient regarding the risk of harmful interference posed by their planned SCS deployments,” AT&T said. “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’s filing was part of a call for comments from the FCC on T-Mobile and SpaceX’s plans for the satellite-to-cellular service, which were announced in August 2022. The idea is that you’d be able to connect to SpaceX’s second-generation Starlink satellites set to launch this year from your mobile phone to do things like text or send MMS messages.

T-Mobile and SpaceX’s service isn’t expected to launch in beta until sometime before the end of this year. But if the FCC throws up roadblocks following this call for comments, we might be waiting even longer.