FCC Advances Upper C-band Spectrum Auction to Protect Aviation Safety

FCC Advances Strategic Spectrum Auction to Prevent Aviation Conflicts

On Thursday, November 20, 2025, the Federal Communications Commission (FCC) took a decisive step toward expanding the nation’s wireless infrastructure. In a unanimous 3-0 vote, the commission adopted a Notice of Proposed Rulemaking (NPRM) to auction licenses in the Upper C-band, specifically the 3.98–4.2 GHz frequencies. This move is designed to release critical mid-band spectrum essential for next-generation 5G and 6G technologies while simultaneously establishing safeguards to prevent interference with Aviation equipment. The vote marks the beginning of a regulatory process mandated by the “One Big Beautiful Bill Act” (OBBBA), legislation signed in July 2025 that restored the FCC’s auction authority.

The significance of this vote extends beyond simple frequency allocation; it represents a concerted effort to avoid a repeat of the chaotic “aviation standoff” witnessed in 2022. By proactively addressing technical parameters and coordinating with the Federal Aviation Administration (FAA), the FCC aims to balance the aggressive expansion of wireless capabilities with the non-negotiable safety requirements of the airline industry. The proposal seeks to clear a pathway for the auction of at least 100 megahertz (MHz) of spectrum by July 2027, a deadline set by Congress to ensure the United States maintains its competitive edge in global telecommunications.

We observe that this regulatory action is not merely administrative but a direct response to legislative directives and industry needs. The OBBBA not only restored the FCC’s lapsed authority but also set ambitious goals for spectrum identification. As the agency moves forward, the focus shifts to the technical nuances of the proposal, including guard bands and power limits, which will determine how effectively the telecom and aviation sectors can coexist in an increasingly crowded spectral environment.

Technical Safeguards and the Upper C-Band Proposal

The core of the FCC’s proposal revolves around the Upper C-band, a frequency range highly valued for its ability to carry large amounts of data over significant distances. The NPRM seeks public comment on auctioning between 100 MHz, the statutory minimum required by the OBBBA, and a more ambitious 180 MHz. To make this feasible without compromising safety, the commission has proposed a guard band of no more than 20 MHz. This buffer is intended to separate new wireless operations from the 4.2–4.4 GHz band, which is utilized by radio altimeters, the critical instruments that measure an aircraft’s altitude during flight.

In addition to frequency separation, the proposal outlines specific power limitations designed to mitigate interference risks. For non-rural base stations, the FCC proposes a limit of 1640 watts per megahertz (EIRP), while rural base stations would be permitted to operate at 3280 watts per megahertz. This differentiation acknowledges the need for higher power to cover expansive, less-populated areas where interference with airport operations is less likely. These technical parameters are being developed in close coordination with the FAA, which plans to adopt robust performance standards for radio altimeters prior to the auction. This proactive approach ensures that aviation equipment can effectively filter out 5G signals, addressing the root cause of previous operational disruptions.

Furthermore, the FCC is exploring financial mechanisms to support the aviation industry’s transition. The commission is considering utilizing a portion of the auction proceeds to fund the upgrade or replacement of older radio altimeters. This proposal directly addresses the primary financial concerns of airlines, potentially smoothing the path for implementation. By aligning the auction timeline with equipment upgrades, the FCC aims to create a synchronized rollout that benefits both the telecommunications sector and air travel safety.

The proposal includes a “Tribal licensing window,” an amendment championed by Commissioner Anna Gomez, allowing Tribal nations to access spectrum over their lands before commercial bidding begins.

Stakeholder Reactions and Historical Context

The reaction to the FCC’s vote highlights the complex landscape of interests involved in spectrum management. The wireless industry, represented by groups such as CTIA, has expressed strong support for the move. CTIA President Ajit Pai has urged the FCC to pursue the maximum 180 MHz inventory, arguing that maximizing spectrum availability is vital for supporting 5G and future 6G technologies. From this perspective, the proposed technical mitigations are viewed as sufficient to protect aviation operations, and the emphasis is placed on maintaining U.S. leadership in wireless technology.

Conversely, the aviation sector remains cautious. While not opposing the auction outright, organizations like Airlines for America have called for a “deliberate and data-driven process.” Their hesitation stems from the events of early 2022, when the activation of C-band 5G towers led to emergency flight cancellations and a public feud between regulators. The aviation industry demands strict protections for radio altimeters to ensure that the safety fears and operational chaos of the past are not repeated. Simultaneously, broadcasters have voiced concerns that clearing more than the mandated 100 MHz could be costly and disruptive for satellite incumbents who rely on this band for video distribution.

Looking ahead, the process now enters a critical public comment period. Stakeholders will provide feedback on the size of the guard band, the total amount of spectrum to be cleared, and the implementation of the Tribal licensing window. Following this review, the FCC will vote on a final “Report and Order” to establish the official auction rules. With the OBBBA mandating the auction’s completion by July 2027, the timeline is tight, requiring efficient collaboration between government agencies and private sector entities to finalize a framework that accommodates innovation without compromising safety.

Concluding Section

The FCC’s unanimous vote to advance the Upper C-band auction represents a significant milestone in U.S. telecommunications policy. By initiating the rulemaking process now, the commission is adhering to the aggressive timelines set by the One Big Beautiful Bill Act while attempting to navigate the technical and political minefield of spectrum allocation. The proposed safeguards, including guard bands and power limits, alongside the potential funding for altimeter upgrades, suggest a more collaborative approach than previous attempts at spectrum expansion.

As the process moves toward the July 2027 auction deadline, the focus will remain on the interplay between the FCC and the FAA. The success of this initiative depends on the ability to finalize technical rules that satisfy the wireless industry’s hunger for bandwidth while providing the aviation sector with absolute assurance regarding flight safety. If successful, this auction could serve as a blueprint for future inter-agency cooperation in the management of the nation’s finite airwaves.

FAQ

Question: What is the Upper C-band and why is it important?
Answer: The Upper C-band refers to the 3.98–4.2 GHz frequency range. It is considered “mid-band” spectrum, which is ideal for 5G and 6G technologies because it offers a balance of high data capacity and broad geographic coverage.

Question: What was the “aviation standoff” of 2022?
Answer: In early 2022, the FAA warned that 5G signals in the C-band could interfere with radio altimeters, which measure an aircraft’s altitude. This led to emergency flight cancellations and a temporary ban on 5G deployment near airports until a voluntary agreement was reached to reduce power levels.

Question: What is the One Big Beautiful Bill Act (OBBBA)?
Answer: Signed into law in July 2025, the OBBBA restored the FCC’s authority to auction spectrum (which had lapsed in 2023) and mandated the auction of at least 100 MHz of Upper C-band spectrum by July 2027.

Sources: Reuters