Data / Federal rules / 2025-22020

In the Matter of Upper C-band (3.98-4.2 GHz)

The Federal Communications Commission published this proposed rule in the Federal Register on December 5, 2025. Comments closed on January 5, 2026.

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What the agency says

In this Notice of Proposed Rulemaking (NPRM), the Federal Communications Commission (Commission) seeks comment on proposed rule changes that would expand the ecosystem for next generation wireless services in the 3.7-4.2 GHz band (C-band) by making as much as 180, and at least 100, megahertz of the 3.98-4.2 GHz band (Upper C-band) available for terrestrial wireless flexible use via a system of competitive bidding. This action would be in furtherance of Congress' direction in the One Big Beautiful Bill Act (OBBB Act) to "complet[e] a system of competitive bidding not later than 2 years after the date of enactment of this Act for not less than 100 megahertz in the band between 3.98 gigahertz and 4.2 gigahertz." The NPRM seeks comment on options for reconfiguring the Upper C-band in the contiguous United States ranging from 180 megahertz (3.98-4.16 GHz) to the congressionally mandated minimum of 100 megahertz (3.98-4.08 GHz) for terrestrial wireless use. The NPRM seeks comment on how much Upper C- band spectrum--beyond the minimum 100 megahertz required by the OBBB Act--could be repurposed by incumbent fixed satellite service (FSS) space station operators and on how the transition could be effectuated if their existing customers relocate out of the C-band. Under any of the reconfiguration options under consideration, the NPRM's baseline proposition is to apply the existing 3.7 GHz Service rules (applicable in the Lower C-band from 3.7-3.98 GHz) to any newly authorized terrestrial wireless operations. Any other rules and requirements, including those relating to the transition process, would be modeled to the greatest extent possible on those that applied to the Lower C-band transition. The NPRM also seeks comment on a range of issues associated with repurposing some portion of the Upper C-band, including: reallocation of the 4.0-4.2 GHz band; competitive bidding procedures for an eventual auction; licensing, operating, and technical rules for any new wireless services; (4) transitioning incumbent FSS operations; and promoting co-existence with adjacent band radio altimeters.

Key facts

Document number

2025-22020

Type

Proposed rule

Action

Proposed rule

Agency

Federal Communications Commission

Published

December 5, 2025

Comments due

January 5, 2026

Dates

Comments are due on or before January 5, 2026; reply comments are due on or before February 3, 2026. Written comments on the Paperwork Reduction Act (PRA) proposed information collection requirements must be submitted by the public, Office of Management and Budget (OMB), and other interested parties on or before February 3, 2026.

Docket

GN Docket No. 25-59; FCC 25-78; FR ID 319865

Code of Federal Regulations

47 CFR 1; 47 CFR 2; 47 CFR 25; 47 CFR 27

Pages

26

The document on federalregister.gov PDF

Other documents from the Federal Communications Commission

Everything from the Federal Communications Commission · Published in December 2025

Read from the Federal Register API, last updated 2026-10-23. The document on federalregister.gov is the official record; dates and dockets can change through later corrections. Free to reuse with credit to SpecStream under CC BY 4.0.