SpaceX has offered $8 billion for 13.5 MHz of 800 MHz spectrum, according to the Wall Street Journal. The preliminary agreement with investment firm Grain Management covers paired frequencies at 817-824/862-869 MHz. The licences span 3,224 counties and 100% of the US population.

For practitioners, the price is the first number that matters. Eight billion dollars for 13.5 MHz works out to roughly $593 million per MHz of paired low-band spectrum. That figure will now anchor every future D2D spectrum negotiation in the US market.

Grain bought this block from T-Mobile. That deal closed in September, valued at $2.9 billion, and also saw T-Mobile take 2 x 5 MHz of paired 600 MHz licences from Grain. The 800 MHz licences came with conditions attached by the Federal Communications Commission.

What does the FCC require?

The Commission wants Grain to run a transparent competitive solicitation for satellite partners and complete it by November 5. Grain must find a leasing partner or sell the licences through a competitive process before transferring them. The FCC now has to decide whether Grain completed that process before agreeing to sell to SpaceX.

Republican Senator Ted Cruz wrote to the FCC weeks before approval, calling for stricter deployment requirements amid speculation fears. His intervention signals that congressional scrutiny of satellite spectrum aggregation is not going away.

AST SpaceMobile had been testing in this exact band under a special temporary authorisation. The 30-day permit allowed noncommercial D2D tests on 7 x 7 MHz near Midland, Texas and Lanham, Maryland, using up to 100 commercially available phones. AST had pledged to demonstrate broadband satellite coverage "without harmful interference".

How did the companies react?

David Grain, founder and chief executive of Grain Management, framed the deal as a play on asset value. He said: "Our spectrum expertise allows us to connect the strategic value of these assets with the technologies and operators that can realise their potential."

He added: "This agreement with SpaceX brings that capability to bear at extraordinary scale, with the potential to change where and how Americans connect."

Elon Musk was more direct. "This is the last critical piece of the spectrum puzzle needed for SpaceX to provide complete phone coverage in America," he posted on X. SpaceX Vice President David Goldman tweeted one word: "boom".

Musk's language has revived US operator fears that SpaceX will compete directly for subscribers. The company rebranded its D2D service as Starlink Mobile earlier this year, positioning it as a mobile operator.

Is 13.5 MHz really disruptive?

T-Mobile's President of Technology, John Saw, offers a counterweight. He notes SpaceX holds "roughly 80 MHz of spectrum, some of it uplink-only". Much of that comes from the 65 MHz SpaceX acquired from EchoStar in the AWS-4 and H-block ranges in 2025.

For comparison, the PolicyTracker Spectrum Database puts T-Mobile at 54.7 MHz of low-band and 320.7 MHz of mid-band spectrum. Verizon and T-Mobile each hold thousands of MHz in total. Even at 80 MHz, SpaceX remains far behind the major terrestrial operators.

Saw also raises two structural constraints: indoor coverage and capacity. "More than 70% of mobile traffic takes place indoors," he says, pointing to homes, offices, stores and crowded venues. "Buildings, walls, and other obstacles make it much harder for signals travelling from space to reach customers reliably."

On capacity, he concedes one satellite beam "can cover an area served by hundreds of terrestrial cell sectors" but doubts it can match 5G speeds. "Direct-to-Cell has an important role to play in extending coverage, but it is a complement to terrestrial networks, not a replacement for the capacity of a dense 5G-Advanced network," he says.

Where does this leave AST SpaceMobile?

The deal puts AST SpaceMobile in an awkward position. The operator many expected to pursue this spectrum most aggressively now faces a band it tested going to a rival. CEO Abel Avellan responded: "American operators hold ~1,000 MHz of low- and mid-band spectrum, tunable on the AST SpaceMobile network."

He added: "With our current satellites in orbit and in build, our United States partners will access critical low-band and mid-band spectrum that no one can match."

The transaction now rests with the FCC. Its verdict on whether Grain ran a genuine competitive process, due after the November 5 solicitation deadline, will determine whether SpaceX closes on the spectrum and whether satellite D2D economics shift across the US market.