Cantwell Opposed to Senate GOP’s Spectrum Language
She cited concerns about protecting airplane altimeters and military systems.
WASHINGTON, June 13, 2025 – Sen. Maria Cantwell, D-Wash., continued to criticize the spectrum auction language in Republicans’ budget reconciliation package, saying the 800 megahertz pipeline could disrupt military systems and aircraft altimeters.
The Senate Commerce Committee put forward text that would restore the Federal Communications Commission’s ability to auction off airwaves to the private sector until September 2034. It would exempt the military’s lower 3 GHz band and much of its 7/8 GHz band from being sold off, while requiring at least 800 megahertz to be auctioned in that time. It’s a win for the wireless industry, which has been pushing for a pipeline in the bill.
“The planes that we’re flying today do not have altimeters that are sensitive enough” to mitigate the likely interference, Cantwell said. “I guarantee you no one is telling my colleagues every plane and every DoD asset will need a new altimeter.”
She spoke Thursday at a Center for Strategic and International Studies event with Tom Karako, director of CSIS’s missile defense project.
The bill would mandate an auction of 100 megahertz in the upper C-band within two years, which is adjacent to the band used by airplane altimeters. The FCC has been taking input on how best to put the band to more intensive use, which will likely involve selling it to wireless carriers, and potentially Elon Musk’s SpaceX.
Domestic and international airlines urged the agency to tread lightly and conduct a host of technical studies before instituting any changes to the band. Airlines were up in arms when C-band airwaves were deployed, citing similar interference concerns.
New altimeter equipment standards aimed at protecting against interference are in development, but the airlines said those couldn’t be relied upon, especially in the interim while they upgrade their fleets. They said studies would still need to be done to confirm planes could still fly safely with a given user in the upper C-band.
“By addressing coexistence issues early, the Commission would avoid repeating the disruptive and resource intensive remediations needed to maintain aviation safety following the 2020 proceeding on the” C-band, a trade group for domestic airlines told the agency on May 29.
Cantwell said the protections for military spectrum included in the bill did not go far enough, something some Republicans allied with the Defense Department have also said.
Sen. Ted Cruz, R-Texas, chair of the Commerce Committee where Cantwell is the top Democrat, said earlier this week he wasn’t budging on the pipeline language. Cruz has been pushing hard for a spectrum pipeline of some kind, touting it as a job creator revenue raiser that would help pay for tax cuts.
Cruz said he cut a deal with Sens. Mike Rounds, R-S.D., Deb Fischer, R-Neb., and other defense-focused lawmakers to up the pipeline to 800 megahertz, more than a House-passed version of the bill, in exchange for adding protection for much, but not all, of the military’s 7/8 GHz band.
The DoD proposed earlier this year a plan that would have exempted its lower 3 GHz and 7/8 GHz bands from auction and seen the military vacate other spectrum, but the Senate trying to institute something similar hasn’t satisfied Democrats or defense hawks.
“The DoD in the past has been very clear” that it opposed freeing up military airwaves, Cantwell said. “I'm not sure what's happening of late. I'm not sure Secretary Hegseth understands this technology.”
Users of the shared, lower power CBRS band are also worried about a pipeline pressuring the FCC to consider reallocating it to the wireless carriers. AT&T and the Defense Department have floated moving current users, like wireless ISPs, cable companies, and others, and auctioning the band off.
Salt Typhoon
Later Thursday, Cantwell sent letters to AT&T and Verizon demanding documents related to last year’s Salt Typhoon hack. She said there were concerns that the China-backed hackers were still embedded in the companies’ networks, despite their claims to the contrary.
“Recent reports indicate broad, ongoing doubts among security experts that Salt Typhoon has been fully eradicated from our telecommunications networks,” she wrote. “Experts also noted the sheer scale of any network would likely need a forensic analysis of tens of thousands of endpoints to identify all potential compromises.”
The FCC adopted new cybersecurity rules for telecom providers in the wake of the hack, over the dissent of now-Chairman Brendan Carr. The rules specify that federal wiretapping law creates a legal requirement for telecom carriers to secure their networks generally against hacks. Companies can face fines for infractions of the law.
