Consensus Study Report
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Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2025. Views of the U.S. National Academies of Sciences, Engineering, and Medicine on Agenda Items at Issue at the World Radiocommunication Conference 2027. Washington, DC: National Academies Press. https://doi.org/10.17226/28596.
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COMMITTEE ON THE VIEWS ON THE WORLD RADIOCOMMUNICATION CONFERENCE 2027
NATHANIEL J. LIVESEY, Jet Propulsion Laboratory, California Institute of Technology, Chair
SCOTT N. PAINE, Center for Astrophysics, Harvard & Smithsonian, Vice Chair
NANCY L. BAKER, Naval Research Laboratory
LAURA B. CHOMIUK, Michigan State University
KSHITIJA DESHPANDE, Embry-Riddle Aeronautical University
DARA ENTEKHABI (NAE), Massachusetts Institute of Technology
PHILIP J. ERICKSON, Massachusetts Institute of Technology
TOMAS GERGELY, Consultant (retired)
KELSEY JOHNSON, University of Virginia
CHRISTOPHER KIDD, University of Maryland
KAREN L. MASTERS, Haverford College
MAHTA MOGHADDAM (NAE), University of Southern California
JULIO NAVARRO (NAE), The Boeing Company
BANG D. NHAN, National Radio Astronomy Observatory
Study Staff
CHRISTOPHER JONES, Senior Program Officer, Study Director
KRISTEN GAROFALI, Associate Program Officer (from October 14, 2024)
LINDA WALKER, Program Coordinator
COLLEEN N. HARTMAN, Senior Board Director, Space Studies Board, Aeronautics and Space Engineering Board, and Board on Physics and Astronomy (through May 15, 2025)
ARUL MOZHI, Associate Board Director, Space Studies Board, Aeronautics and Space Engineering Board, and Board on Physics and Astronomy (Acting Board Director from May 16, 2025)
BOARD ON PHYSICS AND ASTRONOMY
JILL P. DAHLBURG, Naval Research Laboratory, Chair
MEIGAN ARONSON, University of British Columbia
MIRIAM E. JOHN (NAE), Sandia National Laboratories
ANTHONY M. JOHNSON, University of Maryland, Baltimore County
YOUNG-KEE KIM (NAS), University of Chicago
CHUNG-PEI MA (NAS), University of California, Berkeley
ANDREW J. MILLIS (NAS), Columbia University
DAVID H. REITZE, California Institute of Technology
EDWARD E. THOMAS, JR., Auburn University
ROBERT TYCKO (NAS), National Institutes of Health
RISA H. WECHSLER, Stanford University
AMIR YACOBY (NAS), Harvard University
Staff
ALEXIS BHADHA, Financial Business Partner (until February 2025)
AMISHA JINANDRA, Senior Research Assistant (until April 2025)
CHRIS JONES, Senior Financial Business Partner
TANJA PILZAK, Manager, Program Operations
COLLEEN N. HARTMAN, Senior Board Director, Space Studies Board, Aeronautics and Space Engineering Board, and Board on Physics and Astronomy (through May 15, 2025)
ARUL MOZHI, Associate Board Director, Space Studies Board, Aeronautics and Space Engineering Board, and Board on Physics and Astronomy (Acting Board Director from May 16, 2025)
Reviewers
This Consensus Study Report was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published report as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.
We thank the following individuals for their review of this report:
MICHAEL BETTENHAUSEN, Computational Physics, Inc.
ALISON BROWN (NAE), NAVSYS Corporation
ANDREW CLEGG, Google, Inc.
DALE GARY, New Jersey Institute of Technology
DAVID KUNKEE, The Aerospace Corporation
KAREN O’NEIL, Green Bank Observatory
YAN SOLDO, European Space Agency, Earth Observation Directorate
SUZANNE STAGGS (NAS), Princeton University
LUCY ZIURYS, University of Arizona
Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations of this report nor did they see the final draft before its release. The review of this report was overseen by K.I. KELLERMANN (NAS), National Radio Astronomy Observatory, and JOHN P. STENBIT (NAS), TRW Inc. They were responsible for making certain that an independent examination of this report was carried out in accordance with the standards of the National Academies and that all review comments were carefully considered. Responsibility for the final content rests entirely with the authoring committee and the National Academies.
Dedication
This report is dedicated in memory of Professor Liese van Zee (1970–2024), chair of the Committee on the Views on the World Radiocommunication Conference 2023, and a former member, vice chair, and chair of the National Academies of Sciences, Engineering, and Medicine’s Committee on Radio Frequencies.
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Contents
Earth Exploration-Satellite Service
Agenda Item 1.1: Aeronautical/Marine Earth Stations in Motion Around 50 GHz
Agenda Item 1.2: Fixed Satellite Uplinks in 13.75–14 GHz
Agenda Item 1.3: Fixed Uplinks to Non-Geostationary Satellites at 51.4–52.4 GHz
Agenda Item 1.4: Fixed Satellite Downlinks in 17.3–17.8 GHz
Agenda Item 1.5: Limiting Unauthorized Non-Geostationary Ground Station Operations
Agenda Item 1.6: Equitable Access to Fixed Satellite Service in Selected Bands
Agenda Item 1.7: Allocations to International Mobile Telecommunications
Agenda Item 1.8: Radiolocation from 231.5–700 GHz
Agenda Item 1.10: Power Limits for Satellite Services in 71–76 and 81–86 GHz
Agenda Item 1.11: Space-to-Space Transmissions in 1.5–2.5 GHz
Agenda Item 1.12: Mobile Satellite Services from 1.4–2.025 GHz
Agenda Item 1.13: Direct Satellite to Cellphone Communications in 694 MHz to 2.7 GHz
Agenda Item 1.14: Mobile Satellite Service in 2.0–2.2 GHz
Agenda Item 1.15: Communications in the Lunar Environment
Agenda Item 1.16: Protection of Radio Quiet Zones
Agenda Item 1.17: Allocations for Receive-Only Space Weather Sensors
Agenda Item 1.18: Protection of EESS (Passive) and RAS in Bands Above 76 GHz
Agenda Item 1.19: Allocations to EESS (Passive) in 4.2–4.4 and 8.4–8.5 GHz
Preliminary Agenda Items 2.1 and 2.6: Allocations from 102–275 GHz and Above
Preliminary Agenda Item 2.2: Wireless Power Transmission
Preliminary Agenda Item 2.3: Aeronautical and Marine Ground Stations in 12.75–13.25 GHz
Preliminary Agenda Item 2.4: Space-to-Space Links at 4 and 6 GHz
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Preface
Since the early days of radio’s invention, it has served as an indispensable observational tool for scientists, enabling discoveries in areas ranging from cosmology to the nature and behavior of Earth’s atmosphere, land surface, oceans, and ice. As the frontiers of scientific research continue to advance, so too do the needs to measure ever-smaller signals, whether they be tantalizingly faint patterns in the cosmic microwave background, or small but critical signatures of changes in Earth’s climate. Thankfully, evolving technologies are enabling us to meet such exacting demands. At the same time, many of these new technologies are also enabling other revolutionary uses of the radio spectrum, most notably in recent decades for world-wide communications. These applications bring immense societal benefits of their own but, in the absence of suitable safeguards, the radio transmissions inherent in them will vastly overpower the exceptionally weak natural signals observed by radio astronomy and Earth remote sensing receivers. Balancing the needs of all users of the radio spectrum is a complex challenge that is the focus of a large and established community of government, industrial, legal, and scientific experts. This work is little understood by the scientific research community. Conversely, the unique vulnerabilities of “passive” (observe-only) uses of the radio spectrum are often underappreciated by others in the radiocommunications endeavor.
The National Academies of Sciences, Engineering, and Medicine’s Committee on Radio Frequencies (CORF), established in 1961, has played an important part in efforts to promote continued protection of scientific use of the spectrum within the United States and beyond, and to encourage engagement between the scientific and spectrum management communities. This report of the Committee on the Views on the World Radiocommunication Conference 2027 adds to the body of work from the National Academies on this topic, albeit in a very focused manner, being limited to discussion of issues under consideration at the upcoming 2027 World Radio Communication Conference (WRC-27). Readers seeking a more general introduction to scientific use of the radio spectrum are encouraged to read the National Academies’ report Handbook of Frequency Allocations and Spectrum Protection for Scientific Uses.1
The International Telecommunication Union (ITU) “Radio Regulations” are an internationally agreed treaty that regulates use of the radio spectrum. The regulations consist of more than 2,500 pages of individual articles, appendices, and resolutions (complemented by associated, but typically not regulatory, recommendations and reports). The rapidly evolving nature of radiocommunications technologies, applications, and needs demands that these regulations be updated. However, the large, complex, and intertwined nature of radio spectrum usage necessitates that such updates be very carefully considered, and typically incremental in nature. To enact such updates, the ITU convenes “WRCs,” currently held every 4 years, with specific agenda items considering targeted changes to the regulations. During the years leading up to each WRC, the agenda items are subject to detailed study at the national and international level, with careful consideration given to the implications of each proposed change to potentially affected uses of the radio spectrum. WRCs, and the meetings and negotiations leading up to them, are invariably intense and fast-moving negotiations, and ready access to critical information is a key need for those involved.
This report is intended as a resource for those involved in WRC-27 and its precursor meetings in the coming years. It provides not only a summary of the scientific uses of the regions of the spectrum that may be affected by each agenda item (either directly or indirectly through out-of-band or harmonic emissions) but also carefully considered recommendations from the committee regarding
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1 National Academies of Sciences, Engineering, and Medicine, 2015, Handbook of Frequency Allocations and Spectrum Protection for Scientific Uses: Second Edition, The National Academies Press, https://doi.org/10.17226/21774.
appropriate measures to protect those uses. The WRC-27 agenda is notably replete with items that have the potential to impact radio astronomy, Earth remote sensing, or, in many cases, both.
The report could not have been written without the dedication and expertise of the committee members involved. In many cases, this expertise was honed by previous work of these same individuals on CORF.2 We express our profound thanks to these authors, listed above, as well as to Darrel Emerson who, while serving on CORF, helped shape our thinking on several WRC-27 agenda items, but retired from CORF before work on this report formally commenced. Profound thanks are due also to CORF’s legal counsel, Paul Feldman, whose wisdom has been essential to CORF’s work for more than two decades, and whose work guiding scientists in the ways of spectrum management has benefited this report greatly. We also owe many thanks to Christopher J. Jones for his work to steer us through the report generation process, and to Colleen Hartman for her continual support of this work and the work of CORF more broadly. We are grateful to Kristen Garofali and the National Academies’ editorial and publishing staff for their help in finalizing this report. The report benefited significantly from insightful comments by multiple peer reviewers to whom we extend our thanks also.
Finally, we recognize that we are benefiting from the singular and sustained impetus given to all of us by our much-missed colleague Liese van Zee, who worked tirelessly for the protection of scientific use of the radio spectrum. She was chair of the committee authoring the WRC-23 report and a former chair of CORF. We dedicate this report to her memory.
Nathaniel Livesey, Chair
Scott Paine, Vice Chair
Committee on the Views on the World Radiocommunication Conference 2027
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2 Although the committee authoring this report has a membership that significantly overlaps that of CORF, it is strictly speaking a distinct committee.
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