The Federal Communications Commission will vote on October 29 over a proposal to free up more than 480 MHz of spectrum for direct-to-device satellite connections. This would let satellites send mobile signals straight to smartphones without requiring special equipment. However, the three largest U.S. wireless carriers—AT&T, T-Mobile, and Verizon—have united to block about 60% of that expansion. They claim the plan threatens to disrupt their existing networks.
On October 25, the carriers submitted a 10-page joint petition through the CTIA trade association. They demanded the FCC remove two mid-band frequencies from the Supplemental Coverage from Space (SCS) framework. The contested bands total 290 MHz and include T-Mobile’s core 2.5 GHz holdings and AT&T’s 3.45 GHz spectrum, both purchased in multi-billion-dollar FCC auctions. Their objection stems from a technical incompatibility: these frequencies use Time Division Duplex (TDD), which requires ultra-precise synchronization between transmitters and receivers, measured in microseconds.
A satellite orbiting at 550 kilometers introduces an 1.8-millisecond delay for signals traveling at light speed, a delay 300 times longer than the TDD guard interval. When a smartphone communicates with a satellite on these bands, the satellite’s downlink transmission arrives at nearby terrestrial cell towers during their uplink listening period. The carriers’ interference modeling shows this creates a noise floor elevation capable of degrading or completely blocking uplink service within 1 to 3 miles of any active satellite link.
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The carriers insist this is not a fixable interference problem but an architectural mismatch. Reducing satellite power or tightening FCC limits cannot resolve the timing conflict. Only removing these bands from the SCS expansion would prevent the issue, they argue. Independent technical reviews confirm that the 3GPP NTN timing advance protocol, designed for dedicated satellite spectrum, does not apply in shared TDD bands where terrestrial and orbital networks must operate side by side.
Carriers unite to block satellite spectrum
This dispute marks another clash between the carriers and the FCC over satellite spectrum access. All three companies already operate satellite partnerships: T-Mobile collaborates with SpaceX’s T-Satellite service, while AT&T and Verizon are investors in AST SpaceMobile. Verizon also backs Amazon’s Project Kuiper. Despite their usual rivalry in spectrum auctions, the three have aligned against the SCS proposal, viewing it as a threat to their competitive position.
SpaceX, the most aggressive satellite operator, has spent the last two years assembling a spectrum portfolio that rivals terrestrial carriers. In September 2025, it acquired EchoStar’s mid-band frequencies for $17 billion, ending its dependence on leased spectrum. Two months later, the FCC approved SpaceX’s plan to launch 15,000 next-generation Starlink Mobile satellites, with trials set for late 2026 and full deployment in 2027. On October 6, the company added 800 MHz of low-band spectrum from Grain Management, addressing a key gap in rural coverage. These moves position SpaceX to challenge the carriers not just as a supplementary service but as a standalone mobile provider.
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SpaceX President Gwynne Shotwell has stated the company aims to attract “quite a few” subscribers from Verizon, AT&T, and T-Mobile. Following SpaceX’s earnings presentation outlining its satellite ambitions, the carriers’ stock prices dropped between 2% and 5%. Their petition reflects concerns beyond interference; it also seeks to protect the value of spectrum they purchased at significant cost, now facing potential sharing with an orbital competitor under terms they did not influence.
FCC proposes dedicated satellite auction instead
The October 29 meeting will address two spectrum-related actions. In addition to the 482 MHz SCS expansion, the FCC will vote to auction 25 MHz of mid-band spectrum in the 1675–1695 MHz and 2020–2025 MHz bands. The goal is to create a separate spectrum pool for satellite operators, avoiding the shared-access conflicts that have hindered the broader SCS proposal.
The report designated these bands for satellite use. Unlike the SCS expansion, which relies on secondary access to terrestrial carriers’ licensed frequencies, the auction spectrum would be exclusively licensed to satellite providers. This approach bypasses the TDD interference concerns raised by AT&T, T-Mobile, and Verizon, as the new bands are unpaired and not used for terrestrial 5G.
