AT&T and Verizon have taken issue with SpaceX and T-Mobile’s upcoming direct-to-cell satellite offering, arguing that SpaceX’s implementation will harm their respective mobile broadband networks. Filings that urge the Federal Communications Commission to reject SpaceX’s request to waive out-of-band emission limits were submitted by AT&T and Verizon this week, joining similar opposition from satellite companies EchoStar and Omnispace.

T-Mobile announced the SpaceX partnership in 2022, pledging to eradicate dead zones by allowing mobile phones to connect to Starlink satellites. SpaceX is now seeking a “ninefold increase” to current power flux-density limits for out-of-band emissions to enact the Supplemental Coverage from Space (SCS) offer, which, according to AT&T, “would cause unacceptable harmful interference” to terrestrial mobile operations.

Specifically, AT&T’s technical analysis shows that SpaceX’s proposal would cause an 18 percent average reduction in network downlink throughput in an operational and representative AT&T PCS C Block market deployment. Primary terrestrial licenses and networks must be protected from SCS interference, and operations under SpaceX’s Waiver Request would fail to do so.

AT&T raised similar concerns in a previous complaint filed with the FCC in May of last year. Both Verizon and AT&T have also announced their own satellite-to-phone services with AST SpaceMobile, which are unlikely to roll out before 2025. The T-Mobile and SpaceX service is expected to launch sometime this fall, provided these complaints don’t create delays.