Radiocommunications (Unacceptable Levels of Interference – 2.3 GHz Band) Determination 2024

This Determination centres on a small set of interlocking technical and regulatory concepts. Each is defined or operationalised in the text and in Schedule 1, and these are the concepts practitioners must master to apply the instrument.

Device boundary (Schedule 1 item 1). The device boundary is the locus of end points determined by scanning radials (bearings 0-359) from the transmitter site and finding the first point, moving outward, where the device boundary criterion RP - MP is less than or equal to zero (or where the maximum scanning radius is reached, m = 1010). For groups of transmitters the calculation is carried out "as if for a single radiocommunications transmitter" with the radiated power taken to be equal for each bearing and equal to the maximum horizontally radiated power among the group (Schedule 1 item 1(2)). The scanning increments are m × 100 metres where m ranges from 2 to 1010 (Schedule 1 item 1(1)), meaning the computational grid begins at 200 metres and extends to 101,000 metres along each radial.

Device boundary criterion (Schedule 1 item 2). The core scalar tested along each radial is RP - MP. RP is the horizontally radiated power in dBm EIRP per 5 MHz for the relevant bearing (Schedule 1 item 2). MP is calculated as PL(lmn, Lmn) + LOP − Gr, where PL is the propagation loss for the mth increment on the nth radial (calculated under item 3), LOP is a prescribed level of protection depending on whether the transmitter incorporates an AAS, and Gr is the nominal receiver antenna gain including feeder loss, set to 0 dBi (Schedule 1 item 2).

Radiated power and AAS (Schedule 1 item 2, Note 1). For transmitters with an AAS, RP is defined as the sum of the gain of the antenna towards the horizontal plane and towards the azimuth σn (dB) and the total radiated power (dBm). The Determination explicitly notes an operational assumption: that beam pointing angles and/or power can be controlled dynamically to ensure RP is not exceeded (Schedule 1 item 2, Note 1). For groups, RP is taken as the maximum horizontally radiated power of any of the transmitters (Schedule 1 item 1(2)).

Propagation loss (Schedule 1 item 3). PL(lmn, Lmn) is to be calculated using ITU‑R Recommendation P.525‑4 (calculation of free‑space attenuation) in section 2.2 in all cases, plus either P.526‑15 section 4.5.2 when the transmitter antenna is more than 6 metres above ground level, or P.2108‑0 section 3.2 when the antenna is at 6 metres or lower (Schedule 1 item 3(1)(a),(b)). When using P.526‑15 the Determination fixes the nominal receiver height at 5 metres above ground level and requires the transmitter antenna height and profile points to be expressed in terms of average ground height (Schedule 1 item 3(2); note references to the Radiocommunications (Interpretation - Technical Framework) Determination 2024 for average ground height procedures). Path profiles must be developed at 100‑metre increments along each radial (Schedule 1 item 3(3)).

Level of protection, receiver gain and bandwidth reference (Schedule 1 item 2). LOP is -91.5 dBm per 5 MHz for AAS transmitters and -99.5 dBm per 5 MHz for other transmitters (Schedule 1 item 2). Gr is nominal receiver antenna gain including feeder loss set to 0 dBi (Schedule 1 item 2). RP and MP are expressed in dBm EIRP per 5 MHz, so the test is bandwidth‑referenced at 5 MHz.

Exceptions and transitional rules. Section 8 sets out when a level of interference is unacceptable, with exceptions in section 8(2) for parts of the device boundary lying outside the geographic area but connected to certain radials that do not cross particular land areas or specified HCIS identifiers (section 8(2)(b)(i)-(iii)). Section 10 provides transitional rules for transmitters already in the Register before commencement, preserving the 2013 Determination's test for those transmitters unless certain changes are recorded and the new device boundary distances on each radial are equal to or less than the old distances (section 10(1)-(4)).

Accuracy (section 9). Unless otherwise specified, parameter values in Schedule 1 must be estimated with at least 95 per cent confidence that the true value will remain below the applicable requirement (section 9). This imposes a quantifiable confidence requirement on measurements, models and assumptions used in calculating the device boundary.

References to other instruments (section 7 and section 6). The Determination relies on external material: ITU‑R Recommendations (defined in section 6) and other domestic instruments for technical definitions (for example Radiocommunications (Interpretation - Technical Framework) Determination 2024). Section 7 makes clear that references to other legislative instruments are references to those instruments "as in force from time to time" (section 7(a)), and references to other instruments or writings are to their versions "as in force or existing from time to time" (section 7(b)).

Together, these concepts produce a deterministic, numerically-specified boundary test for unacceptable interference, tied to a small number of fixed parameters (LOP, Gr, receiver height of 5 m for diffraction, scanning grid) and to external technical methods (ITU‑R Recommendations and domestic interpretation instruments).

Primary obligations flow to holders of 2.3 GHz spectrum licences and to prospective registrants of radiocommunications transmitters operating under those licences. The Determination is addressed at devices that require inclusion in the Register under the Act and therefore operates as a precondition to registration: the ACMA may refuse to include transmitter details in the Register where operation could cause unacceptable interference as defined by this Determination (sections 3, 5 and 8; notes to section 5).

Existing registered transmitters are covered by transitional provisions (section 10). If a transmitter was in the Register before commencement, the Determination preserves the 2013 test for that transmitter for the purposes of subsection 145(4) of the Act, subject to exceptions in section 10(3) where a change to recorded details reduces (or does not increase) device boundary distances on each relevant radial (section 10(2)-(3)). Therefore registrants that pre‑date the Determination may retain protection of the previous standard unless their recorded changes enlarge their device boundary distances (section 10).

ACMA is the administrative decision-maker. The Determination is made under s 145(4) and references the ACMA’s role in registration decisions and in taking advisory guidelines into account during settlement of interference disputes (section 3; notes to section 5). The ACMA also issues advisory guidelines under section 262 which the Determination lists; those guidelines are non‑binding but will be considered during dispute settlement (notes to section 5).

Manufacturers, operators and network planners are indirectly affected because the Determination prescribes how device boundaries must be calculated and what inputs are required. Equipment incorporating an AAS is treated differently (LOP -91.5 dBm per 5 MHz; different RP definition, Schedule 1 item 2 and Note 1), which affects transmitter design choices, beam‑forming operation and power management policies. For groups of transmitters (for example, co‑located sectorised sites or MIMO arrays treated as a group), the Determination takes the maximum horizontally radiated power of any transmitter as the group’s RP (Schedule 1 item 1(2)), which may affect arrangements for co‑site coordination and power capping.

Users of spectrum in adjacent geographic areas or adjacent frequency bands are affected because the Determination's test explicitly includes contraventions of core conditions relating to maximum permitted levels of radio emission outside licensed frequencies or geographic area as constituting unacceptable interference (section 8(1)(a)(i)-(ii)). That means licence holders must demonstrate compliance not only within their licensed band and area but also that emissions outside those bounds are below core condition limits.

Operators whose transmitters are exempt from the Register under subsection 69(2) of the Act are not required to meet the device boundary criterion (note to section 8(3)). The Determination therefore affects mainly registered transmitters but recognises that some licence conditions may exempt small or specific classes of devices from registration obligations.

Finally, legal advisers, compliance professionals and technical consultants who prepare registration data will be affected by the Determination's procedural and data‑quality requirements: the device boundary calculation involves scanning 360 radials with up to 1,009 increments each, propagation modelling per ITU recommendations, path profiles at 100‑metre increments and a 95 per cent confidence requirement for parameter estimates (Schedule 1 items 1-3; section 9). These are the parties who will bear the compliance cost of producing registerable detail.

Duties

• Duty to ensure a transmitter will not cause an "unacceptable level of interference" as defined (section 8(1)). The Determination provides the test ACMA will apply when deciding to include a transmitter in the Register under s 145 of the Act (sections 3 and 8; notes to section 5). Licensees or applicants must produce technical evidence sufficient for ACMA to be satisfied a transmitter will not breach the device boundary criterion.
• Duty to calculate the device boundary in accordance with Schedule 1 for any single transmitter or group of transmitters proposed for registration (Schedule 1 item 1). That involves performing the specified steps: scanning radials (bearings 0-359), computing RP - MP at m×100 metre increments where m is 2 through 1010, and locating end points where RP - MP ≤ 0 or m = 1010 (Schedule 1 item 1(1)-(2)).
• Duty to compute propagation loss in accordance with the specified ITU‑R Recommendations and the parameters the Determination fixes (Schedule 1 item 3). For antennas > 6 metres above ground level, the method and parameters in P.525‑4 section 2.2 and P.526‑15 section 4.5.2 apply; for antennas ≤ 6 metres, P.525‑4 section 2.2 and P.2108‑0 section 3.2 apply (Schedule 1 item 3(1)(a),(b)). Path profiles must be developed at 100‑metre increments and average ground height determined per the Interpretation - Technical Framework Determination (Schedule 1 item 3(3); note).
• Duty to meet the accuracy/confidence requirement when estimating parameter values in Schedule 1: a level of confidence not less than 95 per cent that the true value will always remain below the requirement (section 9).
• Duty to measure antenna phase‑centre height within an error of less than five parts in 100 relative to the specified reference point and to use the greatest antenna height for groups (Schedule 1 item 4(1)-(2)).

Rights and defences

• Transitional protection for pre‑existing registered transmitters (section 10). A transmitter included in the Register before commencement is assessed for unacceptability under the 2013 Determination as it applied at the time the transmitter was included in the Register, subject to the caveats in section 10(3). This is a form of grandfathering protected by the Determination.
• Exception for parts of device boundary outside the geographic area where the radial meets specified conditions (section 8(2)). Where that test is satisfied, a part of the device boundary lying outside the geographic area is not, of itself, unacceptable. This narrows the scope of section 8(1)(b) and therefore can be relied on by registrants with coastal or offshore radials that meet the constraints in section 8(2)(b).
• Right to rely on advisory guidelines in disputes: the Determination lists two Radiocommunications Advisory Guidelines issued under section 262 of the Act and states ACMA will take those guidelines into account during settlement of interference disputes, though the guidelines do not prevent licensees from negotiating other compatibility requirements (note to section 5). Practically, this means parties can invoke these advisory guidelines in negotiations and dispute settlement, but they are not binding in the same way as the Determination.

Operational effects of key parameters

• The level of protection (LOP) is fixed and differs by transmitter type: AAS transmitters have LOP -91.5 dBm/5 MHz; others have -99.5 dBm/5 MHz (Schedule 1 item 2). Because MP incorporates LOP, a different LOP alters where the RP - MP criterion crosses zero and therefore changes the device boundary distance. The Determination thus creates different technical burdens for AAS and non‑AAS equipment.
• RP must be expressed in dBm EIRP per 5 MHz and for AAS RP is defined by an explicit operational assumption about beam control (Schedule 1 item 2, Note 1). Registrants of AAS‑equipped transmitters must demonstrate the control capability that underlies that RP assumption.

Administrative effect

• ACMA is empowered to refuse registration under s 145 if it is satisfied the operation of the transmitter could cause an unacceptable level of interference, using the test provided by this Determination (sections 3 and 8; note to section 5). The Determination therefore functions as a gatekeeping standard: compliance with its calculational regime is required to secure registration (and thereby operate under a 2.3 GHz spectrum licence without ACMA refusing registration).

The Determination itself does not create criminal penalties or monetary fines; it is a legislative instrument that prescribes criteria for determining what amounts to an "unacceptable level of interference" for the purposes of registration under the Act. Enforcement occurs through ACMA's administrative powers under the Act:

• Registration refusal under s 145. The immediate enforcement mechanism the Determination feeds into is ACMA's power to refuse to include a transmitter's details in the Register if it is satisfied operation could cause unacceptable interference (notes to section 5 and section 8 in conjunction with subsection 145(1) and subsection 145(4) of the Act as referenced in the instrument). The Determination establishes the test ACMA will use in making that satisfaction decision (section 3; section 8).
• Settlement of interference disputes. The Determination notes ACMA has issued advisory guidelines under section 262 of the Act and that ACMA will take those guidelines into account in interference dispute settlement (notes to section 5). Those guidelines are non‑binding but will inform ACMA’s approach in adjudication or negotiation, potentially affecting outcomes in enforcement or remedial settings.
• Administrative consequences for non‑registration or contravention of licence core conditions. Section 8(1)(a) makes explicit that a transmitter that results in contravention of a core condition relating to maximum permitted level of radio emission outside licensed spectrum or geographic area causes an unacceptable level of interference. While the Determination does not itself specify penalties for contravening core conditions, such contraventions tie back to the Act’s regulatory framework, under which ACMA has available compliance powers in relation to breaches of licence conditions. The instrument therefore operates as an evidentiary and definitional touchstone for those powers, but it does not itself state those powers or penalties.

Practical enforcement pathway. In practice, enforcement is likely to proceed through ACMA’s registration gatekeeping (refusal to register), and through ACMA’s handling of interference complaints and disputes where the Determination’s criteria will be used to determine whether a transmitter's operation is causing unacceptable interference or whether an existing transmitter may need modification, mitigation or removal. The Determination’s explicit reference to advisory guidelines means ACMA’s settlement processes will consider those guidelines alongside the device boundary calculations (note to section 5).

Evidentiary and technical burden. The Determination imposes a technical evidentiary burden on applicants and registrants: to avoid ACMA refusing registration they must demonstrate, via the specified calculations and with the accuracy/confidence standard (section 9), that their transmitters' device boundaries do not produce unacceptable interference. Failing to supply this evidence risks administrative refusal. Section 10’s transitional rule reduces the immediate enforcement risk for pre‑existing registered transmitters by preserving the 2013 test for those transmitters in most circumstances (section 10(2)-(3)).

Interpretation and review risks. Because the Determination relies on external ITU‑R Recommendations and on other domestic specification instruments for definitions and procedures (section 6; section 7), disputes about the correct application of those external methods may arise in enforcement contexts. The Determination’s requirement to compute path profiles at 100‑metre increments, to use specific sections of ITU recommendations, and to meet a 95 per cent confidence standard means enforcement decisions will be technically granular and depend on contested modelling and data inputs.

In short, enforcement is administrative rather than penal in the Determination itself, with ACMA registration decisions and dispute settlement as the principal mechanisms. The Determination supplies the metric and procedures ACMA will use in those mechanisms.

This Determination is an instrument under the Radiocommunications Act 1992 and interacts with that Act and with other legislative instruments referred to within it. The instrument explicitly places itself within the Act’s registration framework and cross‑references the ACMA’s powers and procedural instruments.

Primacy within the Act’s registration regime. The Determination is made under subsection 145(4) of the Act (section 3), and the notes to section 5 and section 8 cross‑reference subsection 145(1) and subsection 69(2) of the Act. Those references show the Determination is a technical implementation of the Act’s registration criterion: ACMA may refuse to register a transmitter if its operation would cause unacceptable interference, and this Determination defines what that unacceptable interference is for 2.3 GHz spectrum licence transmitters (section 8; notes to section 5). The Determination therefore supplies the technical standard ACMA will apply within the Act's administrative procedures concerning the Register.

Dependence on other instruments for definitions and procedures. Section 6 lists several defined terms and notes that many other expressions used in the instrument are defined in the Act or in the Radiocommunications (Interpretation - Technical Framework) Determination 2024 or another instrument made under subsection 64(1) of the Australian Communications and Media Authority Act 2005 to replace it (section 6, Note 3). Section 3 of Schedule 1 also requires average ground height procedures that are provided in Schedule 2 of the Interpretation - Technical Framework Determination 2024 (Schedule 1 item 3(2)-(3), notes). Section 7 makes express that references to other legislative instruments are to be taken as references to those instruments "as in force from time to time" (section 7(a)). This creates a compositional dependency: the Determination’s operation requires correct and current application of other instruments’ definitions and procedures and these may be updated independently, affecting how the Determination is applied.

Interaction with advisory guidelines and dispute settlement. The instrument lists two advisory guidelines issued under section 262 of the Act and states the ACMA will take them into account during settlement of interference disputes, while the guidelines do not prevent licensees negotiating other compatibility requirements (note to section 5). Therefore the Determination interacts functionally with non‑binding guidelines that will influence ACMA’s adjudicative approach in interference disputes.

Transitional interplay with the 2013 Determination. The instrument expressly repeals the 2013 Determination (section 4) and provides transitional rules that keep the 2013 standard applicable to transmitters already in the Register at commencement, except where specified changes occur that have the effect described in section 10(3). Practically, this means that when applying the Act’s registration provisions to existing transmitters ACMA must refer back to the 2013 Determination as it applied at the registration time (section 10(2)). The Determination therefore creates a temporal boundary in the body of applicable law which must be navigated in registration and dispute contexts.

Cross‑references to the Act for licence core conditions. Section 8(1)(a) declares that a transmitter causes an unacceptable level of interference if its operation results in a contravention of a core condition of the licence relating to the maximum permitted level of radio emission outside the authorised spectrum or geographic area. That ties the Determination directly to licence core conditions established under the Act and implies the Determination will be invoked when assessing potential or actual breaches of licence conditions. The Determination does not itself set those core conditions but uses them as part of the unacceptable interference test.

Bandwidth and measurement units. The test is expressed in dBm EIRP per 5 MHz (Schedule 1 item 2). That interacts with the spectrum licensing regime insofar as spectrum licences authorise operation in particular frequency bands and bandwidths; applicants or licensees must convert their emissions to the 5 MHz reference as required by the Determination when preparing documentation for registration or dispute resolution.

In summary, this Determination is integrally linked with the Act’s registration and licence condition framework, depends on definitions and technical procedures in other instruments (with references to the current versions), and is complemented by advisory guidelines that ACMA will consider in dispute settlement. Practitioners must therefore apply the Determination alongside the Act, the Interpretation - Technical Framework Determination 2024, the specified ITU‑R Recommendations and ACMA’s advisory guidelines.

This Determination replaces the earlier instrument that governed unacceptable levels of interference in the 2.3 GHz band. The key amendment events stated in the text are:

• Repeal of the 2013 Determination. Section 4 expressly repeals the Radiocommunications (Unacceptable Levels of Interference - 2.3 GHz Band) Determination 2013 [F2013L02155]. That repeal makes the 2024 Determination the operative instrument for new registration decisions subject to the transitional rules in section 10.
• Commencement. Section 2 states the instrument commences on 31 March 2024. For transmitters included in the Register before that date, transitional provisions in section 10 apply.
• Authority and enabling provision. Section 3 records that the instrument is made under subsection 145(4) of the Act. That locates the Determination within the Act’s registration powers and clarifies its legal source.

Dependencies and future updates. Section 7 provides that references to other legislative instruments are references to those instruments "as in force from time to time" (section 7(a)) and references to other instruments or writings are to their current versions (section 7(b)). This clause means the Determination is explicitly designed to operate with other instruments that may change. The Determination also refers to the Radiocommunications (Interpretation - Technical Framework) Determination 2024 (section 6, Note 3), and to ITU‑R Recommendations whose versions are specified in the Definitions (section 6). Practically, that creates a modular amendment space: later updates to the Interpretation - Technical Framework Determination or to the ACMA’s or ITU's texts may alter how provisions of this Determination are implemented without amending the Determination itself, because the Determination references those texts as in force.

Transitional amendment effect. Section 10 sets out a specific transitional regime for transmitters registered before commencement. Subsection 10(2) preserves the previous test (the 2013 Determination) for relevant transmitters, while subsection 10(3) permits certain recorded changes where device boundary distances do not increase on each radial. These transition rules amount to a temporal amendment effect: although the 2013 Determination is repealed for future registrations, it continues to govern specific pre‑existing registrations until certain changes occur.

No further amendments listed. The instrument contains no schedule of past amendments (other than repeal of the 2013 Determination) and provides no mechanism within the text for its own amendment; amendments would therefore require a subsequent legislative instrument under the same or similar power.

Practitioners must therefore note three key amendment‑related facts in the instrument: the repeal of the 2013 Determination (section 4); the transitional protection for transmitters registered before commencement (section 10); and the Determination’s express reliance on other instruments "as in force from time to time" (section 7). Those facts mean that applying the Determination requires checking the current versions of the referenced Interpretation Determination, ITU Recommendations and any other legislative instruments mentioned.

The text of this Determination does not cite any judicial decisions or litigation. It repeals the 2013 Determination (section 4) and replaces it with a new technical regime, but it contains no reference to past or present cases and no litigation record is included in the instrument itself. Therefore, within the source document there is no litigation history to report.

That said, the Determination explicitly situates ACMA’s use of the instrument within administrative decision‑making contexts that commonly produce disputes: registration decisions under subsection 145(4) of the Act (section 3 and notes to section 5) and the settlement of interference disputes where ACMA will take advisory guidelines into account (note to section 5). These administrative decisions are classically subject to judicial review in the Australian administrative law system, and decisions interpreting whether a transmitter causes "unacceptable level of interference" as defined by this Determination will be susceptible to procedural and merits review in the courts and tribunals. The instrument itself, however, neither cites nor summarises any cases, and it does not create a statutory right of appeal in its text.

Points likely to attract litigation in the future (conceptually grounded in the Determination). While the Determination does not contain a litigation history, its content points to a number of technically-focused issues that are the likely subjects of dispute and hence potential litigation:

• Interpretation or application of the device boundary calculation (Schedule 1 item 1) and the RP - MP criterion where modelling choices (for example, selection of path profile endpoints or the correctness of the 100‑metre increment grid) materially affect whether RP - MP crosses zero within the geographic area.
• Choice and application of ITU‑R methods and parameters (Schedule 1 item 3), including the use of P.526‑15 section 4.5.2 for antennas above 6 metres versus P.2108‑0 for antennas at or below 6 metres; disputes might arise over whether a particular path should be modelled under diffraction or clutter prediction rules, and how average ground heights are computed under the Interpretation - Technical Framework Determination.
• The 95 per cent confidence requirement (section 9) for parameter estimation, which raises technical questions about acceptable methods of statistical estimation, model uncertainty, and whether submitted modelling meets the confidence threshold.
• The operational assumptions regarding AAS (Schedule 1 item 2, Note 1), namely that beam control can ensure RP is not exceeded. Disputes could focus on whether an AAS can, in practice, meet the operational assumption relied upon in the RP calculation.
• Transitional protection under section 10 and whether a recorded change qualifies under section 10(3) as not producing an unacceptable level of interference because the new device boundary distances are equal to or less than the prior distances on each radial.

Because the Determination is detailed and technical, disputes will likely hinge on expert evidence and the specific computational assumptions used by parties and by ACMA. The Determination’s incorporation of external standards (ITU‑R Recommendations and other domestic instruments) means that litigation is likely to involve contested interpretation of those technical materials as well.

In sum, there is no litigation history recorded in the Determination. The instrument creates many points at which administrative decisions under it could be contested and litigated; those are predictable from the Determination’s substantive content even though no cases are named in the source.

Several technical and legal features of the Determination are easy to overlook but have material effects on compliance, risk allocation and the calculation outcome. These are practical "gotchas" drawn directly from the instrument.

Start point for radial scanning (Schedule 1 item 1(1)). The radial scan uses m as integers from 2 through 1010 and evaluates the device boundary criterion at each m × 100 metre increment. That means the scanning grid begins at 200 metres from the transmitter location (m = 2) rather than at 0 or 100 metres. This is an explicit feature (Schedule 1 item 1(1)) and therefore the device boundary calculation does not examine points at 100 metres or within 200 metres under the specified procedure. Practitioners must not assume the Determination requires a near‑field assessment inside 200 metres.

Maximum radius and forced end point (Schedule 1 item 1(2)). If RP - MP never becomes ≤ 0 along a given radial, the end point is at m = 1010, i.e. at 101,000 metres (101 km) from the transmitter. That is the computational cap for each radial and is not open‑ended; registrants must therefore be prepared to report end points at the maximum radius where the inequality is not met.

Bandwidth reference per 5 MHz (Schedule 1 item 2). RP and MP are specified in dBm EIRP per 5 MHz. Applicants or registrants operating with non‑standard channel bandwidths must convert their emissions to the 5 MHz reference to apply the test accurately.

LOP differences for AAS versus non‑AAS (Schedule 1 item 2). The Determination assigns LOP = -91.5 dBm/5 MHz for AAS transmitters and LOP = -99.5 dBm/5 MHz for other transmitters. This 8 dB difference materially affects device boundary distance because MP includes LOP. A less negative LOP (e.g. -91.5) increases MP and therefore can shrink the device boundary (Schedule 1 item 2). The instrument also contains an operational assumption regarding AAS beam control (Schedule 1 item 2, Note 1) which must be demonstrable.

Receiver antenna gain (Gr) fixed to 0 dBi (Schedule 1 item 2). The Determination sets Gr, the nominal receiver antenna gain including feeder loss, to 0 dBi. Parties cannot substitute a different Gr; this fixed parameter will directly affect MP and therefore device boundary distances.

Propagation modelling choices require external documents (Schedule 1 item 3 and section 6). PL is to be calculated using specified sections of ITU‑R Recommendations P.525‑4, P.526‑15 and P.2108‑0 depending on antenna height (Schedule 1 item 3). Average ground height procedures are required per the Radiocommunications (Interpretation - Technical Framework) Determination 2024 (Schedule 1 item 3(2)-(3) notes). Practitioners must ensure they use the exact sections cited, at the correct revision, and that they follow the path profile and average ground height procedures set out in the referenced domestic instrument.

Path profile increments and averaging (Schedule 1 item 3(3)). Where P.526‑15 is used, the path profile must be developed at 100‑metre increments along each radial and average ground height worked out at each increment. This is a computational burden: 360 radials × up to 1,009 increments × path profile computations, including diffraction calculations, will be required in many cases.

P.2108‑0 corrective clamps (Schedule 1 item 3(4)). When P.2108‑0 is used for ≤6 m antenna height, the Determination fixes the percentage of locations at 0.08%, applies the correction at only one end of the path, and clamps the calculated loss between 0 dB and 8 dB. These clamps are non‑intuitive and will matter in short‑range clutter scenarios: if the P.2108 calculation yields less than 0 dB, it must be taken as 0 dB, and if it yields more than 8 dB it must be taken as 8 dB.

Accuracy/confidence requirement (section 9). Parameters in Schedule 1 must be estimated with at least 95% confidence that the true value will remain below the requirement. This is not a simple "best estimate" clause: it requires practitioners to specify and justify the statistical or modelling methodology that produces a 95% confidence bound for quantities such as RP and PL. The Determination does not prescribe particular statistical methods; parties must supply them and show the confidence level is met.

Exceptions for parts of device boundary outside the geographic area (section 8(2)). A part of the device boundary lying outside the geographic area is not unacceptable if it is connected to a radial that (a) is one of the radials used in Schedule 1 item 1, (b) does not cross land outside the geographic area that is permanently above the Australian territorial sea baseline, and (c) does not cross specific HCIS identifiers (IW3E, IW3I, IW3M, IW6A, IW6E, KX9, LX7, LX8, LX9) (section 8(2)). The HCIS list describes areas near Adelaide and in the Bass Strait (note to section 8). Practitioners must check whether their radials cross these identifiers, because crossing them removes the exception and may render a part of the device boundary unacceptable.

Transitional protection conditionality (section 10). The transitional preservation of the 2013 Determination for pre‑existing transmitters is conditional. If, after commencement, a recorded change results in the new device boundary distances being equal to or less than the old distances on each radial, then such a change does not render the transmitter unacceptable (section 10(3)). But if the new device boundary distances increase on any radial, the old protection may not apply. Attention to the exact definition of "change time", "new device boundary" and "old device boundary" in section 10(4) is important (section 10(4)).

Antenna height measurement tolerance (Schedule 1 item 4(1)). The phase centre height must be measured with an error of less than five parts in 100 relative to a specific reference point on the supporting structure. This requires precise surveying and documentation; failure to meet the tolerance could be a determinative compliance failure.

Reference versions of external standards. The Determination names specific ITU‑R Recommendations and particular sections within them (section 6; Schedule 1 item 3). Users must ensure they are using the exact editions listed (for example Recommendation ITU‑R P.526‑15, not a different revision) because the Determination ties its computational rules to those specified sections.

In short, the key gotchas are the particular starting point for radial scanning, the 101 km computational cap, the 5 MHz bandwidth reference, the LOP differences and their mechanical effect on device boundary, the 95% confidence requirement, exact path profile requirements, fixed Gr, measurement tolerances, and the specific HCIS identifiers that remove an otherwise available exception.

This section sets out a practical, source‑grounded compliance checklist aligned to the Determination’s requirements. Each step maps to the relevant section or schedule item and is framed for practitioners preparing registration submissions or compliance evidence for a 2.3 GHz spectrum licence transmitter.

1. Confirm applicability and check definitions (sections 5-7, section 6).

   • Verify the transmitter operates under a 2.3 GHz spectrum licence (section 5; defined in section 6).
   • Check whether the transmitter is exempt from the Register under subsection 69(2) of the Act (note to section 8(3)): exempt transmitters are not required to meet the device boundary criterion.
   • Ensure you are using the current versions of referenced instruments, including the Radiocommunications (Interpretation - Technical Framework) Determination 2024 and the ITU‑R Recommendations named in section 6 and Schedule 1 (section 7).

2. Prepare the technical submission for registration: device boundary calculation (Schedule 1 item 1).

   • For a single transmitter, implement the Step 1-3 procedure in Schedule 1 item 1: compute the device boundary criterion RP - MP at each m × 100 metre increment along each degree radial n (n = 0 to 359), where m = 2 to 1010 (Schedule 1 item 1(1)). The grid begins at 200 metres and extends to 101,000 metres.
   • For each radial, identify the lowest m at which RP - MP ≤ 0, or set the end point at m = 1010 if the inequality is never satisfied (Schedule 1 item 1(2)). Record latitude and longitude of each radial’s end point. These end points comprise the device boundary.

3. Compute RP (Schedule 1 item 2).

   • Express RP in dBm EIRP per 5 MHz for each bearing σn. For transmitters with an AAS, follow the Note 1 definition: RP is the sum of antenna gain towards the horizontal plane and towards azimuth σn (dB), plus the total radiated power (dBm). Document the operational assumption that beam pointing angles and/or power control ensure RP is not exceeded (Schedule 1 item 2, Note 1).
   • For groups, make RP equal for each bearing and equal to the maximum horizontally radiated power in any direction of any transmitter in the group (Schedule 1 item 1(2)).

4. Compute MP components: PL, LOP, Gr (Schedule 1 item 2 and item 3).

   • Set Gr to 0 dBi (Schedule 1 item 2). Do not substitute a different receiver gain.
   • Apply the correct LOP: -91.5 dBm/5 MHz if the transmitter incorporates an AAS; otherwise -99.5 dBm/5 MHz (Schedule 1 item 2). Document which LOP applies and why.
   • Calculate PL(lmn, Lmn) at each increment using the specified ITU‑R methods: use P.525‑4 section 2.2 and P.526‑15 section 4.5.2 if the antenna is > 6 m above ground, or P.525‑4 section 2.2 and P.2108‑0 section 3.2 if antenna height is ≤ 6 m (Schedule 1 item 3(1)(a),(b)). For P.526 use receiver height = 5 m above ground and average ground height for profile points (Schedule 1 item 3(2)); develop path profiles at 100 m increments (Schedule 1 item 3(3)). For P.2108 apply the 0.08% location percentage and clamp loss between 0 dB and 8 dB (Schedule 1 item 3(4)).

5. Antenna height and survey requirements (Schedule 1 item 4).

   • Measure the phase centre height of the transmitter’s antenna relative to the point on the supporting structure that has the lowest elevation on the line of intersection with the surface of the ground or sea, with measurement error less than five parts in 100 (Schedule 1 item 4(1)). Produce survey documentation to substantiate the measurement and error margin.
   • For groups, use the greatest antenna height among the individual transmitters (Schedule 1 item 4(2)).

6. Path profile and terrain procedures (Schedule 1 item 3; section 6 note).

   • Use the average ground height procedure set out in Schedule 2 of the Radiocommunications (Interpretation - Technical Framework) Determination 2024 as required by the Determination (Schedule 1 item 3(2)-(3) notes).
   • Build path profiles at 100 m increments for each radial and for each m increment where diffraction or clutter modelling is required under the specified ITU‑R methods.

7. Meet the 95% confidence accuracy requirement (section 9).

   • Ensure statistical or modelling methods are specified and documented to show parameter estimates meet the requirement that there is at least 95% confidence the true value will remain below the applicable requirement. This includes propagation loss estimates, RP estimates (for AAS beam control), and other inputs that affect RP - MP. Provide the probabilistic analysis and underlying data or assumptions used to generate confidence intervals.

8. Apply section 8 test and exceptions.

   • Having determined the device boundary, check whether the operation would result in a contravention of any licence core condition concerning emission outside authorised band or geographic area (section 8(1)(a)). If so, the interference is unacceptable.
   • For parts of device boundary lying outside the geographic area, verify whether section 8(2) applies. That requires the part to be connected to a radial mentioned in Schedule 1 item 1, and that the radial does not cross land outside the geographic area permanently above the Australian territorial sea baseline, and does not cross specified HCIS identifiers (IW3E, IW3I, IW3M, IW6A, IW6E, KX9, LX7, LX8, LX9) (section 8(2)). If the radial fails any test, that part is not exempt.

9. Transitional checks for pre‑existing registered transmitters (section 10).

   • If the transmitter was included in the Register before commencement, determine the relevant "registration time" and apply the 2013 Determination’s test for the purposes of s 145(4) per section 10(2). If changes are recorded after commencement, confirm whether the new device boundary distances on each radial are equal to or less than the old distances; if so section 10(3) provides that the post‑change level of interference is not unacceptable because of that change. Maintain records of "change time", old and new device boundary computations, and supporting data (section 10(4)).

10. Documentation and submission to ACMA.

• Prepare a technical report that includes: explicit statement of the methods used (including ITU‑R section citations), complete device boundary coordinates, path profile data at 100 m increments, antenna height survey data and error margins, RP calculations (including AAS beam control assumptions where applicable), PL calculations, LOP, Gr, statistical confidence calculations demonstrating 95% confidence for each parameter in Schedule 1, and a table mapping each radial to the end point and whether RP - MP ≤ 0 was reached within the scanning radius.
• If disputing interference or defending a registration, be ready to reference ACMA advisory guidelines listed in the Determination (notes to section 5) as they will be taken into account during settlement (though not binding).

11. Ongoing compliance and monitoring.

• Monitor any changes in the external instruments referenced (ITU‑R Recommendations, Interpretation - Technical Framework Determination) because section 7 makes references to those instruments as in force from time to time. Update modelling and re‑submissions to ACMA if changes to those instruments materially affect device boundary computations.
• For AAS systems, maintain operational logs or technical evidence demonstrating beam pointing/power control work in practice to ensure RP does not exceed the RP used in the device boundary calculation (Schedule 1 item 2, Note 1).

12. Dispute readiness.

• Keep records sufficient to demonstrate adherence to the Determination and to defend any ACMA decision. Because the Determination will be used by ACMA in registration refusals and in settling interference disputes (note to section 5), maintain reproducible models, raw path profile data and statistical analyses supporting the 95% confidence claims.

Following these steps will align submissions to ACMA with the Determination’s procedural and evidentiary standards and will put licensees and applicants in a position to show compliance with the device boundary and unacceptable interference criteria set out in the instrument.