The Radio Spectrum Is Getting Crowded: Radio Astronomy Sounds a Warning for Amateur Radio
Date :
15 /
10 /
2026
Author :
WIA
As the world prepares for WRC-27, increasing satellite activity and interference are raising serious questions about the future protection of radio spectrum, including the frequencies used by amateur radio operators.
A thought-provoking article published by the International Telecommunication Union (ITU) has highlighted the growing challenges facing radio astronomy as the radio spectrum becomes increasingly congested.
Written by Australian scientist Balthasar Indermuehle, Principal Scientist and Spectrum Manager at CSIRO and Chair of ITU-R Working Party 7D, the article Radio astronomy at the regulatory crossroads: WRC-27 and beyond examines how rapidly expanding satellite networks, unwanted emissions and outdated regulatory protection mechanisms are threatening the ability of radio astronomers to observe the universe.
But the issues raised extend well beyond radio astronomy. They carry an important warning for amateur radio and other spectrum users whose activities depend on access to frequencies that are increasingly subject to interference and competing commercial demands.
More Satellites, More Signals, More Interference
According to the ITU article, the number of active satellites in low Earth orbit has increased approximately tenfold since the 2019 World Radiocommunication Conference, from around 1,500 to more than 15,000.
Proposals before the ITU point towards a future involving more than 100,000 spacecraft.
For radio astronomy, the challenge is no longer simply identifying a single source of interference. Instead, radio telescopes must contend with the combined emissions of thousands of satellites moving continuously across the sky.
Even where individual transmitters comply with existing technical requirements, their unwanted emissions can collectively create interference levels that exceed the limits necessary to protect sensitive scientific receivers.
Recent measurements at Australian radio astronomy facilities have demonstrated that signals can intrude into frequency bands intended to be protected, sometimes exceeding established interference thresholds by many orders of magnitude.
This raises a fundamental question: what value does a protected frequency allocation have if the signals using it can no longer be reliably received?
Amateur Radio Faces Its Own Interference Challenges
While radio astronomy operates with extraordinarily sensitive receiving systems, amateur radio is confronting many of the same broader pressures.
Amateur bands face interference from a variety of sources, including poorly controlled electronic equipment, switching power supplies, solar inverters, broadband communications technologies and unwanted emissions from other radio services.
Radio amateurs also operate in an environment where spectrum allocations are shared, commercial demand is increasing and some existing amateur allocations face continuing regulatory scrutiny.
These challenges are particularly relevant to weak-signal experimentation, satellite communications, Earth-Moon-Earth operation, microwave activities and other applications where even relatively low levels of unwanted interference can make communication difficult or impossible.
For radio amateurs, interference is not simply an inconvenience. It can directly affect the ability to experiment, undertake technical research, communicate over long distances and develop new radio technologies.
The challenge is compounded by the increasing difficulty of influencing decisions in a regulatory environment dominated by major commercial telecommunications and satellite interests.
The Growing Challenge of Regulatory Influence
The ITU article highlights the importance of active participation in international spectrum management processes, particularly in preparation for the 2027 World Radiocommunication Conference (WRC-27), scheduled for Shanghai, China, from 18 October to 12 November 2027.
At WRC-27, governments will consider changes to the international Radio Regulations, including matters involving satellite services, spectrum sharing, unwanted emissions and interference protection.
These decisions can have consequences lasting decades.
For amateur radio, the challenge is that our community does not possess the financial resources, regulatory teams or commercial influence available to major telecommunications operators.
As spectrum becomes more commercially valuable and regulatory issues more technically complex, maintaining an effective voice in national and international decision-making becomes increasingly demanding.
This is why the work of national amateur radio societies, including the Wireless Institute of Australia (WIA), and international representation through the International Amateur Radio Union (IARU), remains essential.
The WIA's role in engaging with the Australian Communications and Media Authority (ACMA), contributing to spectrum policy discussions and supporting international advocacy is not simply administrative. It is fundamental to protecting the future opportunities available to Australian radio amateurs.
Why Amateur Radio Needs a Strong Collective Voice
Individual radio amateurs have limited opportunities to influence complex national and international spectrum decisions.
Collectively, however, the amateur radio community can contribute technical expertise, interference observations, research, practical operating experience and informed regulatory submissions.
Amateur radio has a long history of innovation in communications, antennas, propagation, digital signal processing and weak-signal techniques. Those capabilities remain relevant to modern spectrum management.
But technical expertise alone is not enough.
The amateur radio community must also maintain relationships with regulators, participate in consultations and ensure that the social, educational, scientific and emergency communications benefits of amateur radio are understood.
Without effective representation, there is a risk that the interests of amateur radio will receive progressively less consideration as commercial demands increase.
A Warning Worth Heeding
The experience of radio astronomy illustrates a fundamental weakness in traditional spectrum protection arrangements: regulations developed for a world of relatively few transmitters are increasingly being challenged by large numbers of interconnected, mobile and space-based systems.
The ITU article makes clear that protecting access to usable spectrum requires more than simply preserving allocations in the Radio Regulations. It also requires realistic interference standards, accurate measurements, effective coordination and ongoing regulatory engagement.
For amateur radio, the lesson is equally important.
We cannot assume that because we have access to particular frequencies today, those frequencies will remain usable and available tomorrow.
As preparations for WRC-27 continue, the WIA encourages Australian radio amateurs and affiliated clubs to recognise the importance of spectrum advocacy, support the work of the WIA and IARU, and contribute technical evidence and expertise wherever possible.
The future of amateur radio depends not only on what we build and operate, but also on our ability to protect the radio spectrum that makes experimentation and communication possible.
Further Reading
ITU: Radio astronomy at the regulatory crossroads: WRC-27 and beyond
Link
ITU: World Radiocommunication Conference 2027
Link
International Amateur Radio Union
Link
Wireless Institute of Australia
Link
Australian Communications and Media Authority
Link
Source acknowledgement: Based on the ITU article by Balthasar Indermuehle, CSIRO, published 8 September 2026. Additional commentary concerning amateur radio reflects the wider spectrum management and advocacy challenges facing the amateur radio community.
Page Last Updated: Thursday, 15 Oct 2026 at 10:41 hours by Justin Giles-clark
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