Radio quiet zone (RQZ). The RQZ is defined in section 5 by reference to Schedule 1. It comprises two parts: (a) the area described in columns 2 to 4 of item 1 (inner zone: a circle of 70 km radius) and (b) the area described in columns 2 to 4 of item 2 (outer zone: an annulus from 70 km radius to 150 km radius). Both share the same central coordinate. The inner zone covers about 15,400 square kilometres; the outer annulus adds about 69,000 square kilometres. The zone is thus not a single contiguous area but two separate geometric regions with different regulatory treatment.

Applicable frequency band. Section 6 defines this as a frequency band that is applicable to an area under section 7. Section 7 specifies that for item 1 (inner) the range is 70 MHz - 25.25 GHz, and for item 2 (outer) the same range. Being the same in both items, the “applicable frequency band” is geographically invariant in frequency but spatially tiered. The exclusive lower bound means 70 MHz is not included, so a licence for exactly 70 MHz would not be captured; in practice, most emissions have bandwidth, so this nuance may matter for narrowband systems.

Radio astronomy service. This term has the same meaning as in the Spectrum Plan (section 5). The Spectrum Plan defines it as a radiocommunication service involving the reception of radio waves from celestial sources for scientific purposes. It is a passive service (it transmits nothing), so its protection requires minimising man-made emissions.

Harmful interference. Defined in a determination under section 64 of the ACMA Act. The Plan uses the term but does not redefine it; it relies on the Act’s general prohibition (sections 186-187) against causing harmful interference. The RQZ concept is a pre-emptive tool to prevent harmful interference before it occurs, rather than relying on post-hoc enforcement.

Secondary service. Under section 8(2), for the inner zone, any additional service (other than radio astronomy) that is authorised under an apparatus or class licence is taken to be a secondary service. In the Act’s priority hierarchy, a secondary service must not cause harmful interference to a primary service (radio astronomy) and cannot claim protection from interference caused by the primary service. This imposes a higher burden on non-astronomy users inside the 70 km radius. The outer zone is not so designated; there the additional service may operate on equal priority, subject to the overarching requirement not to cause harmful interference.

Consultation requirement. Section 9(3) imposes a mandatory step for applicants for new apparatus licences: they must consult CSIRO before applying. ACMA may waive this requirement in writing (section 9(4)). The provision does not specify any criteria for waiver, giving ACMA broad discretion. Failure to consult would mean the licence cannot rely on section 9(1) to use the band for additional services, effectively rendering the licence invalid or unworkable for that purpose.

The Plan directly affects any person or entity that wishes to operate a radiocommunication transmitter within 150 km of the central coordinate in the frequency range 70 MHz to 25.25 GHz. This includes:

• Radio astronomers (CSIRO). They are the intended beneficiaries. The Plan gives CSIRO a formal consultative role over new apparatus licences, and they benefit from the secondary service designation in the inner zone.

• Apparatus licence holders. Existing apparatus licences within the RQZ are grandfathered (section 9(1) applies to licences issued before or after commencement). However, for new apparatus licences, the applicant must consult CSIRO. This affects mobile phone carriers, broadcasters, point-to-point microwave links, mining operators with private networks, government agencies, and others who seek new licences. The requirement adds delay and cost to the licensing process and gives CSIRO de facto veto power (since ACMA will likely place conditions on the licence if CSIRO objects). There is no prescribed maximum consultation period, creating uncertainty.

• Class licence users. Individuals and businesses using devices under a class licence (e.g., amateur radio, low-power devices, WiFi in the 2.4 GHz band) are not required to consult CSIRO. However, if such a device causes harmful interference, the Act’s enforcement provisions apply. The Plan does not restrict class licence use per se, but ACMA could later vary class licences for the RQZ.

• Applicants for apparatus licences. Any party (including mining companies, agricultural enterprises, infrastructure providers, research organisations) seeking a new transmit licence in the RQZ must factor in the consultation requirement. If ACMA refuses to waive it, the applicant must engage with CSIRO, which may impose technical conditions (e.g., lower power, antenna screening) or even oppose the licence.

• Landholders and developers. The RQZ covers a large area in the Murchison region of Western Australia. While the Plan does not directly regulate land use, a landholder who wants to install a radiocommunication system (e.g., for remote monitoring, telemetry, broadband) will face additional hurdles. Real estate values in the zone could be affected; a property that is encumbered by restrictions on spectrum use may be less attractive for certain businesses. There is no compensation mechanism.

• ACMA. The regulator gains a new function: managing the consultation process, deciding waiver applications, and coordinating with CSIRO. This imposes administrative costs ultimately borne by licence fee payers.

• Other spectrum users outside the RQZ. The Plan does not affect them directly, but it creates a precedent for establishing radio quiet zones. If used more widely (e.g., for future radio astronomy sites in other states), it could cumulatively reduce available spectrum for commercial users.

Duty not to cause harmful interference. The Plan does not create a standalone duty; it operates within the Act, which prohibits causing harmful interference (section 188 of the Act). Within the RQZ, the Plan reinforces that duty by prioritising radio astronomy. For the inner zone, the secondary service designation (section 8(2)) means that any non-astronomy user must accept interference from radio astronomy and must not cause interference to it. This is a higher standard than the general prohibition because it removes the right to claim protection.

Right to operate radio astronomy services. The Plan grants radio astronomy a preferential right to use the applicable frequency bands within the RQZ free from harmful interference. This right is enforceable at ACMA’s discretion.

Right to consult. CSIRO has a statutory right to be consulted by applicants for new apparatus licences who wish to use the applicable frequency band (section 9(3)). This right is not absolute: ACMA can waive it. But when not waived, CSIRO can influence licence conditions.

Right to apply for waiver. An applicant has a right to request that ACMA waive the consultation requirement (section 9(4)). ACMA’s decision is in writing and is likely a reviewable decision under the Act, though the Plan does not specify that.

Rights of existing licence holders. Licences issued before the Plan commenced are unaffected; they can continue to operate without consultation. The Plan is not retrospective in that sense. However, if a licence is later renewed or varied, ACMA may re-examine conditions, especially if the renewal is considered a new licence.

No right to compensation. Neither the Act nor the Plan provides any compensation to licence holders or landowners whose spectrum rights are diminished by the RQZ. The Plan does not create property rights in spectrum; it is a regulatory overlay.

Secondary service rights. For the inner zone, additional services are secondary. That means they cannot complain if radio astronomy causes them interference; they must take the risk. Conversely, they cannot cause interference to radio astronomy. This asymmetric burden reduces the commercial viability of non-astronomy uses.

Outer zone ambiguity. Section 8(2) only applies to item 1 (inner zone). In the outer zone, additional services are not statutorily designated as secondary. However, the Act’s general harmful interference prohibition still applies, and ACMA could impose licence conditions to achieve protection. This creates legal uncertainty: a user in the outer zone might assume equal priority, but ACMA could later constrain the licence based on CSIRO’s concerns, even without secondary designation.

The Plan itself does not prescribe penalties. Enforcement is through the Radiocommunications Act 1992. Key enforcement tools:

• Operating without a licence. If a transmitter in the RQZ uses the applicable frequency band without the required apparatus licence, and no class licence applies, the operator faces civil penalties (section 133 of the Act) or criminal prosecution (section 135 for unauthorised operation causing interference). Maximum civil penalty for an individual is 20,000 penalty units (currently $4,440 per unit), and for a body corporate 100,000 penalty units. Imprisonment terms apply for concurrent criminal offences.

• Causing harmful interference. Section 188 of the Act makes it an offence to operate a device that causes harmful interference to another radiocommunication service. Penalties are similar. The Plan makes it easier for ACMA to determine that harmful interference has occurred because the RQZ is designed to protect radio astronomy.

• ACMA directions. ACMA can issue a direction under section 189 requiring a person to cease or modify operation to prevent interference. Non-compliance attracts penalties.

• Suspension or cancellation of licences. ACMA has general powers under sections 114-115 of the Act to suspend or cancel an apparatus licence if the licensee fails to comply with conditions or if continued operation would cause interference. The secondary service status in the inner zone may give ACMA an easier basis to act.

• Waiver decisions. ACMA’s written decision under section 9(4) is not reviewable on the merits under the Act; judicial review under the Administrative Decisions (Judicial Review) Act 1977 may apply, but the threshold is high.

• Consultation failure. If an applicant obtains a new apparatus licence without having consulted CSIRO (and no waiver was granted), the licence might be vulnerable. The Plan says section 9(1) “only applies” if consultation occurs, meaning the licence could be considered not authorised for the additional service. ACMA could treat the operation as unauthorised, triggering the penalties above.

• Class licence enforcement. Users under a class licence who cause harmful interference are still subject to the Act. The Plan does not exempt them. So even without consultation, a ham radio operator in the RQZ could face enforcement.

Enforcement depends on ACMA’s resources and detection capability. Radio astronomy observatories can detect interference, but proving the source may be difficult. The Plan shifts the burden of proof toward licensees in the inner zone by making them secondary.

Radiocommunications Act 1992 (the Act). This is the primary legislation. The Plan is made under section 32(1) and must be consistent with the Act. It is subordinate legislation. Existing provisions on licensing, interference, and enforcement apply. The Plan does not displace any part of the Act; it adds spatial and frequency restrictions.

Spectrum Plan. The Plan must be consistent with the Spectrum Plan (section 9(2) requires that additional service use must not be inconsistent with the Spectrum Plan or another frequency band plan). The Spectrum Plan classifies services by frequency and allocation. Radio astronomy is an allocation in many bands; the Plan effectively makes that allocation exclusive in the RQZ.

Other frequency band plans. If another frequency band plan covers part of the RQZ, it may also apply. The Plan’s area is in Western Australia; there may be other plans for the Murchison region (e.g., for the Mid West). Section 9(2) requires consistency.

Australian Communications and Media Authority Act 2005 (ACMA Act). ACMA’s general functions under the ACMA Act include planning, regulating, and allocating spectrum. The Plan is one of ACMA’s tools. Determinations under section 64 of the ACMA Act define terms like “harmful interference”.

State and local laws. The Plan does not directly interact with Western Australian laws. However, land use planning, environmental approvals, and native title may intersect. For example, a mining tenement in the RQZ may require a state licence that depends on ACMA issuing a radiocommunications apparatus licence. The consultation requirement could delay that state approval. No compensation mechanism exists under state law for spectrum restrictions.

International obligations. Australia is a member of the ITU; radio astronomy is a recognised service in the Radio Regulations. The Plan assists Australia in meeting its obligations to protect the Murchison Radio-astronomy Observatory, which hosts the Square Kilometre Array (SKA). International treaties may influence the Plan’s future amendments.

Native Title Act 1993 (Cth). The RQZ may cover areas subject to native title claims. Restrictions on spectrum use could affect native title holders’ ability to operate communications, but the Plan does not address this. ACMA may need to consider native title requirements when issuing licences.

Environmental law. The RQZ is not an environmental protected area, but restrictions could discourage development, indirectly conserving the dark sky qualities. This is not explicit.

The Plan commenced on 1 April 2023 and has not been amended. It was registered on the Federal Register of Legislation before commencement, as noted in section 2. As a legislative instrument, it can be amended by ACMA by making a new instrument. No amendments are listed. The Plan is relatively new; any future amendments would likely involve:

• Changing the central coordinate or radius (e.g., if a new telescope is built).
• Expanding the frequency range (upward or downward) to cover new observation bands.
• Adding or removing zones.
• Adjusting the consultation requirement (e.g., extending it to class licences).
• Reclassifying the outer zone as secondary.

Because the Plan is made under section 32(1), ACMA can vary or revoke it at any time, subject to disallowance by Parliament. The Commonwealth Government may also issue a new Plan for the same area. There is no sunset clause.

There is no known litigation specifically concerning this Plan. It is possible that its predecessor, the Radiocommunications (Australian Radio Quiet Zone Western Australia) Frequency Band Plan 2018 (since replaced), was challenged, but no reported decisions exist in the public record. Potential future litigation could include:

• Judicial review of ACMA’s waiver decision under section 9(4) - for example, if ACMA refuses to waive consultation, the applicant may argue unreasonableness or procedural unfairness.
• Challenge to the validity of the Plan itself - e.g., that it is inconsistent with the Spectrum Plan or goes beyond the authority of section 32(1).
• Disputes over harmful interference - a radio astronomy service may sue a licensee for damages under the Act or common law (nuisance), but the Act largely excludes private actions.
• Native title claims - if the Plan interferes with traditional rights, but unlikely.
• Constitutional challenge - extremely unlikely; the Plan is a lawful exercise of Commonwealth power under the radiocommunications power (section 51(v)).

Until litigation occurs, the Plan’s legal boundaries remain untested. Practitioners should note that ACMA’s broad discretion over waiver and licence conditions may be hard to challenge.

1. Lower frequency exclusive. Section 5(2) means 70 MHz is not included in the applicable band. A narrowband licence at exactly 70.000 MHz would miss the RQZ? Actually it says “greater than but not including the lower frequency, up to and including the higher frequency.” So signals at 70.000 MHz are not captured; emissions with a centre frequency above 70 MHz are captured. This quirk could allow some VHF services just above 70 MHz to avoid the RQZ restrictions. But in practice, most emissions have bandwidth, so the team will include frequencies above 70 MHz.

2. Inner zone secondary outer zone not. Many readers will assume both zones impose equal restrictions. Section 8(2) only applies to item 1. The outer zone has no secondary designation. However, the Act’s harmful interference provisions still apply. ACMA may still condition an outer zone licence to protect radio astronomy, but it lacks the statutory priority. This may lead to legal arguments about ACMA’s power to impose such conditions. The asymmetry is likely intentional (inner zone is more sensitive), but it creates a false sense of security for outer zone users.

3. Consultation requirement only for apparatus licences issued after commencement. Existing licences are grandfathered. But what about a licence renewal? ACMA may treat a renewal as a new licence if the conditions change substantially. There is ambiguity. A prudent licensee should consult CSIRO even on renewal if they want certainty, but the Plan does not require it. Additionally, the waiver provision (s9(4)) has no criteria. ACMA could waive consultation for some applicants and not others arbitrarily. No appeal mechanism except judicial review.

4. No compensation. Landowners and spectrum users bear the cost of lost spectrum access. The RQZ reduces the value of spectrum licences in the zone. For example, a mining company with an existing apparatus licence for telemetry might find that any expansion of that system (requiring a new licence) is subject to CSIRO veto. No compensation is payable.

5. Class licence users not required to consult, but still liable. A farmer using a 900 MHz telemetry system under a class licence may cause interference to the radio telescope. The farmer may not know about the RQZ. If CSIRO detects interference, ACMA can enforce against the farmer, who may have limited ability to modify operations. The consultation requirement only protects CSIRO from new apparatus licences; class licence users are exposed.

6. Geodetic datum. Coordinates are referenced to GDA94. Surveys using GDA2020 or WGS84 may differ slightly (up to ~1 metre). The difference is unlikely to matter for 70 km radius, but for boundary calculations it could matter legally.

7. Secondary service implications. In the inner zone, an additional service cannot claim protection. If radio astronomy introduces interference (e.g., from a calibration transmitter), the additional service must accept it. This could disrupt critical services such as emergency communications or aviation (though those may be excluded by other laws). The Plan does not exempt safety-of-life services.

For parties subject to the Plan, compliance steps depend on the type of spectrum use and location.

Before acquiring or operating any transmitter within the RQZ (inner or outer zone) in the 70 MHz - 25.25 GHz range:

1. Determine if you need an apparatus licence. If you are using a device that operates under a class licence (e.g., amateur, low-power, remote control), no consultation is needed. Ensure compliance with class licence conditions - they may incorporate the secondary service status for the inner zone. Operate at minimum power.

2. If you need a new apparatus licence:

   • Check whether ACMA has waived the consultation requirement for your class of applicant. ACMA may publish a list of waivers. If not, you must consult CSIRO.
   • Contact CSIRO’s radio astronomy team at the Murchison observatory. Provide details: frequency, power, antenna pattern, location, and modulation.
   • CSIRO may respond with requests for shielding, filtering, power limits, or antenna placement (e.g., directional antennas pointing away from the telescope). Negotiate in good faith.
   • After consultation, apply for the apparatus licence with ACMA, attaching evidence of consultation. ACMA may still impose conditions.
   • If CSIRO does not respond or is unreasonable, you can request ACMA to waive the consultation requirement under s9(4). This decision is not merits-reviewable, but you can seek judicial review for procedural failure.

3. If you hold an existing apparatus licence:

   • No immediate action required. But if you want to modify the licence (e.g., change power or frequency), treat it as a new application? ACMA may apply the consultation requirement to variations. Check with ACMA.

Ongoing obligations:

• Ensure your operation does not cause harmful interference to radio astronomy. If you receive an interference complaint from CSIRO, you must cease or modify operation under ACMA direction.
• Keep records of any CSIRO consultation for future licence renewals or variations.
• Monitor ACMA publications for any amendment to the Plan or new class licence conditions.

For the outer zone specifically:

• You are not secondary, but you still must not cause harmful interference. That is a lower standard of protection for radio astronomy, but CSIRO may still advocate for restrictions. Cooperate voluntarily to avoid enforcement action.

Practical tips:

• Budget for consultation time: expect at least 4-8 weeks lead time before applying.
• Consider using frequencies outside 70 MHz - 25.25 GHz, which are not captured by the Plan. (But watch for other quiet zones elsewhere.)
• If you are a class licence user causing interference, consider switching to wired alternatives or directional antennas to reduce emissions toward the observatory.
• Engage a spectrum lawyer or consultant familiar with ACMA processes and CSIRO’s typical requirements.

Non-compliance risks: loss of licence, penalties (see Penalties and enforcement section), and potential liability for damage to CSIRO’s equipment (though rare). The safest path is to treat the RQZ as a de facto exclusion zone: assume any new transmission within 150 km of the observatory at these frequencies will require coordination with CSIRO.