On April 29, 2025, the FCC adopted a notice of proposed rulemaking (NPRM) to review the decades-old spectrum sharing regime between geostationary (GSO) and non-geostationary (NGSO) satellite systems operating in the 10.7-12.7, 17.3-18.6, and 19.7-20.2 GHz bands. This NPRM features the FCC’s new docket, SB Docket No. 25-157, captioned “Modernizing Spectrum Sharing for Satellite Broadband.”

1. Granting SpaceX’s Petition for Rulemaking

The FCC first grants Space Exploration Technologies Corp.’s (SpaceX) petition for rulemaking, which argued that the equivalent power-flux density (EPFD) limits are based on “flawed and outdated assumptions” that result in inefficient spectrum sharing between GSO and NGSO systems. In granting the petition, the FCC argues that compliance with the EPFD limits significantly limits the services offered by NGSO broadband satellite constellations, requiring NGSO system designers to adjust key operational parameters of their systems. “In total, compliance with the current EPFD limits constrains NGSO systems and directly degrades the efficiency of spectrum use by these systems.”

The FCC notes that the International Telecommunications Union (ITU)’s World Radiocommunication Conference (WRC)-23 considered a proposal from the Inter-American Telecommunication Commission (CITEL) to review the EPFD limits under a future agenda item for WRC-27. However, that review is ongoing, and there is no explicit item on the agenda for WRC-27 to review EPFD limits. The FCC states its is “happy to lead in this way and encourage the international community to modernize their domestic as well as international frameworks.”

2. Notice of Proposed Rulemaking

Seeking to develop a substantial technical record concerning modern and efficient spectrum sharing among NGSO Fixed-Satellite Service (FSS) systems and GSO FSS and Broadcasting-Satellite Services (BSS) networks in the 10.7-12.7, 17.3-18.6, and 19.7-20.2 GHz bands, the NPRM seeks comment on several issues. Some of the topics are listed below:

• How the satellite industry has changed since ITU EPFD limits were adopted in 2000
• Whether current NGSO EPFD limits overprotect modern GSO networks
• Whether current EPFD limits over restrict modern NGSO operations
• GSO Reference Links
• Protection of GSOs that use Adaptive Coding and Modulation (ACM)
• Protection of GSOs that do not use ACM
• Methodology and Modeling Assumptions
• Alternative NGSO-GSO Sharing Frameworks
• Information Sharing
• Aggregate Interference
• Protection of Terrestrial Operations
• Radio Astronomy
• Cross-Border Considerations
• Assessing Compliance
• Costs and Benefits
• Additional Frequency Bands subject to ITU EPFD limits
• Transition to New Rules (i.e., sunset of current GSO protections)

Takeaways:

This new proceeding will enable a strong technical record of how the satellite and space industry can continue to innovate, deliver faster service to the American public, and ultimately, solidify the United States’ leadership in space.

Look for more content on The Digital Docket related to this proceeding as comments are filed!