The Determination hangs on a few key technical concepts that determine whether a transmitter will be treated as causing unacceptable interference.

1. 26 GHz band and spectrum licences: The instrument applies only to radiocommunications transmitters operated under a spectrum licence for the 26 GHz band, defined as 25.1-27.5 GHz (s 4(1) 26 GHz band). It is therefore targeted at licensees operating within that band.

2. Device boundary and device boundary criterion: The “device boundary” is a geographic contour calculated by sampling every degree of azimuth (0-359) and stepping along each radial at 100-m increments from 200 m (m = 2) to 53 km (m = 530) unless the device boundary criterion is met earlier (Schedule 2 Part 1). The device boundary criterion is RP − MP, where RP is the horizontally radiated power (dBm EIRP per MHz) oriented to each bearing, and MP is PL + LOP − Gr (Schedule 2 Part 2). The device boundary is the set of end points of those radials where RP − MP ≤ 0 (i.e. where signal falls to the protected level).

3. Horizontally radiated power (RP): RP is defined as the sum of maximum true mean power at the antenna connector in dBm per specified rectangular bandwidth plus antenna gain in the horizontal plane (s 4 definition horizontally radiated power). For devices with an active antenna system (AAS), RP at a particular bearing σn is defined as the sum of antenna gain towards the horizontal plane and towards azimuth σn (dB) and the total radiated power (dBm) (Schedule 2 Part 2 note). The Determination explicitly recognises dynamic beam control in AAS by allowing RP to be defined per-bearing with the implicit assumption that beam pointing and/or power control can ensure RP is not exceeded.

4. Level of protection (LOP) and receiver gain: LOP is a fixed numeric value depending on whether the transmitter uses AAS (−102 dBm/MHz) or not (−110 dBm/MHz) (Schedule 2 Part 2). Nominal receiver antenna gain Gr is set to 0 dBi (Schedule 2 Part 2).

5. Propagation loss and algorithmic standards: Propagation loss PL(lmn,Lmn) is computed using specific ITU-R recommendations. For antennas >6 m above ground, the relevant methods are in P.525-4 (free-space attenuation) and P.526-15 (diffraction) (Schedule 2 Part 3(1)(a)). For antennas at or below 6 m, the calculation additionally uses P.2108-0 (prediction of clutter loss) with the percentage of locations set to 0.0001% and correction applied at only one end (Schedule 2 Part 3(1)(b) and (4)(a)). Path profiles must sample DEM-3S at 100 m increments and average ground heights computed from a 3×3 DEM cell matrix (Schedule 2 Part 3(3) and Schedule 3 Part 2).

6. Emission designator: The Determination requires use of the Radio Regulations’ method to determine an emission designator, interpreting references to “necessary bandwidth” as the transmitter’s occupied bandwidth (s 6, and note at s 6(2)).

7. Grouping: Two or more fixed transmitters can be treated as a group for the device boundary calculation only if they share the same centre frequency, emission designator, are operated to communicate with the same receiver group, have antennas of same type/model/manufacturer, are on the same structure within 20 metres of phase centres, and have the same ACMA antenna identification number (s 7(1)). A transmitter cannot belong to more than one group of transmitters (s 7(2)). Equivalent grouping rules exist for receivers (s 8).

8. Accuracy requirement: Unless otherwise specified, parameter values in Schedules 2 and 3 must be estimated with at least 95% confidence that the true value will always remain below the requirement (s 10).

9. Unacceptable interference triggers: The Determination treats interference as unacceptable if the transmitter causes a breach of a core licence condition relating to maximum permitted radio emission outside authorised spectrum or geographic area, if any part of the device boundary lies outside the licence geographic area (subject to narrow exceptions), or if the device boundary cannot be calculated per Schedule 2 Part 1 (s 9(1)(a)-(c)).

Each of these concepts is expressed in numeric or prescriptive terms in the instrument. That converts a high-level notion of “unacceptable interference” into a reproducible engineering test that ACMA will apply to registration decisions under the Act.

The Determination principally affects holders of spectrum licences for the 26 GHz band and any authorised third parties who operate radiocommunications transmitters under those licences. The text repeatedly references “radiocommunications transmitter operated under a spectrum licence issued for the 26 GHz band” (s 9(1)); definitions in s 4 and the reliance on the Register and ACMA-issued site identifiers (Schedule 1 notes) reinforce that the operative subjects are licensed operators.

More specifically, the instrument imposes obligations or operational constraints on:

• Operators of fixed transmitters and antenna installations whose licence authorises use within the 26 GHz band. Fixed transmitter location, antenna height, emission designator and related data are the inputs for the device boundary calculation (Schedule 1; Schedule 3 Part 1).
• Licensees deploying active antenna systems (AAS). The Determination distinguishes AAS devices in the LOP value used in the protection threshold (−102 dBm/MHz) and in the per-bearing RP definition, which assumes dynamic beamforming/power control (Schedule 2 Part 2). Operators of AAS must therefore compute per-bearing RP in line with the note in Part 2 and are subject to a different protection threshold.
• Licensees deploying low-height installations (antenna height ≤6 m). The propagation modelling method changes when antenna height is at or below 6 m: the Determination adds ITU-R P.2108-0 clutter loss with specific parameters (Schedule 2 Part 3(1)(b) and 4).
• Operators of transmitter groups (multiple panels on a structure) who wish to treat their equipment as a unit for device boundary calculation. Grouping is possible but only if the strict criteria in s 7(1) are met (same centre frequency and emission designator, same antenna type/model/manufacturer, same structure within 20 m of phase centres, same ACMA antenna ID).
• Equipment vendors and integrators supplying antenna identification, antenna gain curves, AAS configuration data, and site surveys. The Determination depends on accurate antenna gain figures, phase-centre coordinates, and measured maximum true mean power (s 4 definitions; Schedule 1; Schedule 2 Part 2).
• Parties preparing Register submissions or contesting registration; ACMA will apply the Determination’s test when deciding whether to refuse to include transmitter details in the Register under s 145(1) of the Act (note to s 9). Conversely, transmitters exempt from registration under s 69(2) of the Act are not required to meet the device boundary criteria, as the Determination notes (s 9 note).

Indirectly, receivers and network designers who expect to operate in the 26 GHz band are affected because the Determination defines protection levels (LOP) and spatial exclusion contours. The instrument also references the ASMG (Australian Spectrum Map Grid 2012) and the hierarchical cell identification scheme (HCIS) as geographic referencing tools (s 4 definitions). The narrow carve-outs in s 9(2)-(4) affect geography-specific outcomes: e.g., areas outside the ASMG or the HCIS cell MW4H6 can produce exceptions for some parts of device boundaries.

Who pays and who decides: licensees bear the measurement, modelling and engineering costs required to demonstrate compliance with the device boundary rules. ACMA decides acceptability when considering inclusion in the Register and will apply the Determination’s numerical thresholds and methods (s 3, s 9 and note referencing s 145(1) of the Act).

The Determination establishes duties in the sense of technical obligations that licensees must meet to avoid ACMA treating emissions as “unacceptable” for registration purposes. It does not confer new property rights in spectrum or change licence conditions directly; it prescribes the test ACMA will use.

Duties imposed on licensees or authorised operators

• Provide accurate transmitter site data: The transmitter location used in calculations must be the phase-centre location referenced to GDA94 and measured with less than 10 m error (Schedule 1 items 1-3). Antenna height must be measured with an error less than 5 parts in 100 relative to the lowest elevation point at the structure’s base (Schedule 3 Part 1 item 1).
• Determine emission designator per Radio Regulations: Occupied bandwidth is to be used as “necessary bandwidth” in the Radio Regulations method (s 6(1)-(2)).
• Compute device boundaries and device boundary criterion: Licensee must be able to calculate the device boundary per Schedule 2 Part 1 (compute RP and MP along all radials at each m increment and identify the end point where RP − MP ≤ 0 or m = 530). If the device boundary cannot be calculated according to that procedure, the Determination deems the level of interference unacceptable (s 9(1)(c); Schedule 2 Part 1).
• Compute propagation loss per named ITU-R recommendations: For antennas above 6 m, apply P.525-4 and P.526-15; for antennas at or below 6 m, also apply P.2108-0 with specified parameters (Schedule 2 Part 3). Path profiling must sample DEM-3S at 100 m increments (Schedule 2 Part 3(3)(a)).
• Respect accuracy requirement: Values in Schedules 2 and 3 are to be estimated with at least 95% confidence that the true value will remain below required thresholds (s 10).
• Grouping conformity: If treating multiple transmitters as a group, they must meet the exact criteria in s 7(1) and cannot belong to more than one group (s 7(2)).

Rights and consequences

• ACMA’s assessment leverage: The Determination clarifies the engineering basis ACMA will use to decide whether to exclude transmitter details from the Register under s 145(1) of the Act (see note to s 9). Licensees have the procedural right to submit Register entries and must expect the ACMA to test those against the Determination’s algorithm.
• Exception rules: The Determination gives limited situations where parts of a device boundary lying outside a licence area are not treated as “unacceptable” (s 9(2)-(4)). These exceptions are tightly framed and depend on geography (outside ASMG, HCIS cell MW4H6) and on radials not crossing other 26 GHz spectrum licence areas or permanently above the territorial sea baseline.
• Emission designator determination method: Operators have a right to use the internationally standard Radio Regulations method to determine emission designators and may treat occupied bandwidth as necessary bandwidth for that purpose (s 6(1)-(2)).

What licensees must not do

• Depend on unspecified models or non-prescribed propagation methods: The Determination prescribes which ITU-R methods to use and the DEM-3S dataset; failure to use those methods could result in ACMA treating the device boundary calculation as invalid (s 4 definitions; Schedule 2 Part 3).
• Create ambiguous grouping claims: A transmitter cannot belong to more than one group (s 7(2)). If a transmitter could belong to multiple groups, the licensee or authorised third party may nominate the group (note to s 7(2)).

Operational constraints that flow from duties

• The per-bearing RP computation and the LOP thresholds impose a maximum spatial reach beyond which a transmitter must not cause protected-level signal, effectively constraining network design and power/beam-forming profiles to avoid device boundaries crossing outside licence geographic areas (Schedule 2 Part 2 and s 9).
• For AAS devices, the Determination assumes dynamic control can be used to keep RP within limits; this creates an operational expectation that AAS vendors and operators will provide and document control capability (Schedule 2 Part 2 note).

The Determination therefore converts technical definitions into duties licensees must satisfy to maintain the right to be registered and to operate without ACMA determining an unacceptable level of interference exists.

This Determination itself does not create new civil or criminal penalties. It is a technical determination made under subsection 145(4) of the Radiocommunications Act 1992 (s 3) and is used by ACMA when exercising regulatory powers under the Act, notably the power to refuse to include transmitter details in the Register under subsection 145(1) of the Act (note to s 9). The enforcement consequences are therefore exercised through the Act’s machinery rather than via fines or separate sanctions contained within the Determination.

Key enforcement mechanisms and triggers

• Registration refusal: The primary enforcement mechanism implied by the Determination is ACMA’s ability to refuse to register a transmitter if its operation could cause an unacceptable level of interference. The Determination defines the circumstances that constitute unacceptable interference for 26 GHz spectrum-licensed transmitters (s 9(1)). The note to s 9 expressly connects the Determination to the s 145(1) power in the Act.
• Validity of device boundary calculations: Section 9(1)(c) treats a transmitter as causing unacceptable interference if the device boundary cannot be calculated in accordance with Part 1 of Schedule 2. That makes the capacity to compute a device boundary (per the specified method) a prerequisite to avoiding the “unacceptable” label for registration decisions.
• Technical evidence and accuracy expectation: The Determination imposes a 95% confidence accuracy requirement for parameter estimates in Schedules 2 and 3 (s 10). ACMA can treat failure to demonstrate that standard as undermining a submission. While the Determination does not specify the evidentiary form, the 95% rule raises the evidentiary bar for compliance demonstrations.
• Data and recordkeeping expectations: The Determination relies on site identifiers, antenna identification numbers, emission designators, and DEM-3S terrain datasets. ACMA will have the practical discretion to accept or query licence-holder submissions and calculations when assessing registration outcomes; refusal to register may follow if calculations do not conform to the instrument.

Matters not specified in the Determination

• No fines, infringement notices or explicit administrative penalty regime is created by the Determination itself. Any financial penalties or notices would derive from other provisions of the Act or regulations, not from this instrument.
• The Determination does not specify procedural timelines, appeal routes or merits review for registration refusals. Those processes are contained in the Act and associated administrative law principles; the Determination only supplies the technical test ACMA will apply.

Practical enforcement implications

• ACMA is the decision-maker that applies the Determination in the registration context (s 3; s 9 note). Operators should expect ACMA to require technical demonstrations that device boundary calculations conform to the specified methods and accuracy thresholds.
• Because the Determination treats failure to produce a device boundary per Schedule 2 as itself a ground for deeming interference unacceptable (s 9(1)(c)), the burden is on the operator to produce compliant calculations; inability to do so is an enforcement trigger.
• The Determination also creates a compliance risk if licensed transmitters operate in ways that breach core licence conditions by emitting outside the authorised spectrum or geographic area - that is a separate statutory ground for unacceptable interference under s 9(1)(a)(i)-(ii).

In short, enforcement envisaged by the Determination is procedural and regulatory, carried out through ACMA’s registration powers under the Act, with technical non‑conformance or failure to calculate device boundaries being explicit triggers for ACMA action.

The Determination references and interacts with the Radiocommunications Act 1992 and a set of international technical instruments and domestic geographic referencing schemes. The cross-references determine both legal authority and the technical baseline to be applied.

Primary statutory interaction

• Made under the Act: The Determination is made under subsection 145(4) of the Radiocommunications Act 1992 (s 3). Subsection 145(4) gives ACMA authority to make determinations for the purposes of subsection 145(1) (refusal to include transmitter details in the Register where operation could cause unacceptable interference). The Determination itself defines what is to be treated as “unacceptable” for the 26 GHz band (s 9).
• Register and registration exemptions: The Determination notes that some transmitters are exempt from Register requirements under s 69(2) of the Act and therefore are not required to meet the device boundary criteria (note to s 9). Thus one must consult the Act to establish whether a particular transmitter is exempt from registration and therefore from the Determination’s tested requirement in practice.

Interaction with international instruments and technical standards

• Radio Regulations and emission designator: The Determination instructs users to use the methods in the ITU Radio Regulations to determine emission designators, interpreting “necessary bandwidth” as the occupied bandwidth (s 6(1)-(2)). The Radio Regulations are international technical prescriptions; the Determination adopts them for domestic application.
• ITU-R Recommendations for propagation loss: The Determination mandates specific ITU-R Recommendations: P.525-4 for free-space attenuation, P.526-15 for diffraction propagation, and P.2108-0 for clutter loss (Schedule 2 Part 3). Using those recommendations ties domestic regulatory outcomes to internationally recognised propagation models; it also prescribes numerical parameters and procedural choices drawn from those documents (for example, sample spacing and how P.2108-0 is applied for low antennas).

Interaction with geographic and cadastral schemes

• ASMG and HCIS: The Determination prescribes use of the Australian Spectrum Map Grid 2012 (ASMG) and its hierarchical cell identification scheme (HCIS), including reference to the HCIS identifier MW4H6 for a specific exception (s 4 definitions; s 9(3)). Where parts of device boundaries lie outside the ASMG, narrow exceptions apply if radials meet specified connectivity tests (s 9(2)-(4)). This binds the device boundary test to defined spatial mapping systems and means outcomes depend on whether the location lies within the ASMG footprint or particular HCIS cells.
• GDA94 and DEM-3S: Coordinates must be referenced to GDA94 (s 4 definitions; Schedule 1), and terrain sampling is required from the DEM-3S dataset published by Geoscience Australia (s 4 definitions; Schedule 2 Part 3(3)). These specifications link the Determination to domestic geodetic and terrain data standards.

Interaction with other Commonwealth laws for maritime baseline

• The Determination borrows the concept of “Australian territorial sea baseline” from the Seas and Submerged Lands Act 1973 in defining an exception for parts of the device boundary connected to radials that do not cross land outside the geographic area permanently above the territorial sea baseline (s 9(4)). This creates an intersection with maritime law concepts in determining spatial exceptions.

Interpretive and administrative law interactions

• Acts Interpretation Act and Legislation Act references: Section 5 includes notes that cross-refer to the Acts Interpretation Act 1901 and Legislation Act 2003 for interpreting references to other Commonwealth Acts and instruments (s 5 notes). Practitioners will need to consult those interpretation statutes where questions of temporal operation or references to instruments arise.
• ACMA operational instruments: The Determination refers to ACMA’s Business Operating Procedure (BOP) - Radiocommunications site data requirements - for advice on site determination (Schedule 1 Note 2). That administrative guidance will interact in practice with the Determination, because it provides implementation detail ACMA expects to inform submissions.

Limits on effect

• The Determination does not amend licence instruments, does not alter core statutory provisions of the Act, and does not in itself impose civil penalties. Its effect is to define a technical decision rule ACMA will apply when exercising registration powers and when assessing whether a transmitter’s operation could cause unacceptable interference.

Overall, the Determination is a technical layer applied within the Act’s registration framework, tied to specified international technical standards and domestic geospatial datasets, and requires practitioners to work across the Act, ITU documents, and ACMA operational guidance.

The Determination itself is short on amendment history. The instrument records:

• Date made: The Determination was signed and dated 23 November 2020 (preamble; top of the instrument).
• Commencement: It commences at the start of the day after registration on the Federal Register of Legislation (s 2). No subsequent amendments or variation notes are present in the instrument text provided.

There are no amendment clauses, transitional provisions, repeal provisions or schedules indicating later variation. The instrument’s s 5 instructs that references to other legislative instruments are to be read as references to those instruments “as in force from time to time” (s 5(a)), but that is a general reference rule and not an amendment of the Determination itself.

For practitioners tracking evolution:

• To identify any later amendments, or whether ACMA has replaced or updated the Determination, consult the Federal Register of Legislation entry for this Determination (the instrument commenced on the day after registration) where versioning, repeal or commencement details appear (s 2 note referencing the Register).
• The Determination explicitly adopts external technical documents (Radio Regulations, ITU-R Recommendations P.525-4, P.526-15, P.2108-0). Those external documents are themselves subject to periodic revision by their publishers (ITU). The Determination specifies the Recommendation editions by number (e.g. P.526-15, P.525-4, P.2108-0); any update to those ITU documents will not automatically alter the Determination unless ACMA amends the Determination or the Determination’s reference language (s 5 clarifies that references to other instruments are to be read as that instrument “as in force from time to time” where applicable, but the Radio Regulations and ITU Recommendations are not legislative instruments in the Commonwealth sense,this nuance means the practitioner should confirm which edition ACMA intended to bind and monitor ACMA guidance).
• The instrument’s definition of DEM-3S and citation is specific (Gallant et al., 2009, persistent identifier 69888). If a new terrain dataset or updated DEM is adopted in practice, that would require either ACMA issuing new guidance or an amendment to the Determination.

Because the instrument text provides no further amendment history, users must check the Federal Register of Legislation and ACMA communications for any subsequent variations, replacements, or interpretative guidance after the 23 November 2020 making date.

The text of this Determination contains no cases, judicial decisions, or references to litigation. It is a technical instrument issued by ACMA under subsection 145(4) of the Radiocommunications Act 1992 and does not record or cite any legal challenges.

Absent additional materials (for example, court or tribunal records, ACAT or Federal Court decisions reviewing ACMA’s exercise of s 145 powers, or litigation about the interpretation of ITU recommendations in Australian administrative law), there is no litigation history to summarise from this instrument alone. Any litigation arising from ACMA’s use of this Determination would appear in separate judicial or administrative review records. Practitioners seeking litigation history should:

• Search ACAT, Federal Court and Federal Circuit Court databases for decisions referencing subsection 145(4) of the Act or for cases challenging ACMA registration refusals in relation to the 26 GHz band.
• Check ACMA’s own register of decisions or public determinations to see whether the Determination has been relied upon in decisions open to review.
• Examine the Federal Register of Legislation and ACMA’s website for any public consultation documents, objections, or recorded disputes that might have led to formal review.

Because the Determination imposes a defined technical test for unacceptable interference, disputes that could lead to litigation include ACMA registration refusals where licensees argue the chosen methodology is inapplicable, or where contested data, modelling assumptions, or accuracy standards produce divergent device boundary results. However, none of those disputes are documented in the instrument itself.

This Determination reads like a prescriptive algorithm; compliance failures commonly arise from implementation details rather than conceptual disagreement. The following are specific “gotchas” drawn directly from the instrument that practitioners, vendors and licensees must watch for.

1. Sampling and radial indexing: Device boundary calculation requires computing RP − MP at each m×100 metre increment where m runs from 2 through 530, for each bearing n from 0 (true north) to 359 (Schedule 2 Part 1 Step 1). That means the calculation does not start at m = 1 (100 m); it starts at m = 2 (200 m). Missing this detail shifts the device boundary calculation and may yield a non‑compliant result or an inability to calculate the boundary (Schedule 2 Part 1).

2. Stopping condition is RP − MP ≤ 0 or m = 530: For each radial, you must find the first increment moving away from the transmitter where RP − MP ≤ 0, otherwise the endpoint is the 53 km limit (m = 530) (Schedule 2 Part 1 Step 2). Implementations must test the RP − MP inequality exactly as stated; any alternative threshold will be treated as non‑conforming.

3. RP definition for AAS: For devices with active antenna systems, RP at bearing σn is defined differently , it is the sum of antenna gain towards the horizontal plane and towards azimuth σn (dB) and the total radiated power (dBm) (Schedule 2 Part 2 note). The Determination explicitly assumes beam pointing and/or power control can be used to ensure RP is not exceeded. Practically, that creates a documentation and operational expectation on AAS controllers to demonstrate that beam and power control constrain actual emissions to the modelled RP.

4. LOP differentiation: Level of protection is −102 dBm/MHz for AAS and −110 dBm/MHz for non‑AAS (Schedule 2 Part 2). A 8 dB difference materially changes device boundary extents. Misclassification of a transmitter as AAS or non‑AAS will produce materially different device boundary outcomes.

5. Gr fixed at 0 dBi: The receiver gain used in the MP calculation is fixed to 0 dBi (Schedule 2 Part 2). Do not substitute a different Gr unless the Determination is amended; using a different receiver gain will alter the MP and device boundary calculation.

6. Propagation model switching at 6 metres: Use P.525-4 and P.526-15 for antennas >6 m; add P.2108-0 for antennas ≤6 m (Schedule 2 Part 3(1)). The inclusion of P.2108-0 introduces clutter correction; the Determination specifies a percentage of locations (0.0001%) and that the correction is applied at only one end of the path (Schedule 2 Part 3(4)(a)). Implementers must ensure the correct models and parameters are applied based on measured antenna height.

7. DEM-3S sampling and averaging: Path profiles must sample the DEM-3S at 100 m increments (Schedule 2 Part 3(3)(a)). Average ground height at each sample point is the mean of the 9 DEM-3S cells in a 3×3 matrix (Schedule 3 Part 2). If a sample coordinate falls exactly on a DEM cell boundary (modulus zero when divided by 0.000833333), the identified DEM‑3S cell is the adjacent cell with minimum height (Schedule 3 Part 2 item 2). These particular rules affect small but material elevation choices used in diffraction loss.

8. DEM-3S dataset must be used as specified: The Determination names a specific dataset citation for DEM-3S (Gallant et al. 2009; persistent identifier 69888) (s 4 DEM-3S). Using a different DEM or a newer version without ACMA direction risks non‑conformity with the Determination.

9. Accuracy expectation is stringent: Values in Schedules 2 and 3 must be estimated with at least 95% confidence that the true value will remain below the requirement (s 10). This is not a “best efforts” clause; it requires either statistical analysis or conservative bounding to demonstrate the 95% confidence. Failing to provide this level of confidence could lead ACMA to treat the device boundary calculation as invalid.

10. Device boundary calculation is a gate: If you cannot calculate the device boundary per Schedule 2 Part 1, the Determination treats interference as unacceptable (s 9(1)(c)). Thus even purely practical or computational failures (e.g. missing DEM data, numerical instability in Vincenty calculations) can trigger the unacceptable label. The Schedule 3 explicit Vincenty instructions require iteration until delta less than 10−12 , accuracy and numerical implementation matter.

11. Grouping requirements are narrow and strict: To treat several transmitters as a group the five conditions in s 7(1) must all be met; a transmitter cannot be in more than one group (s 7(2)). Group RP is taken as the maximum horizontally radiated power of any transmitter in the group for each bearing (Schedule 2 Part 1 item 2). Misapplication of grouping may produce overly conservative or non‑compliant device boundary results.

12. Spatial exceptions are limited: There are narrow exceptions where parts of a device boundary outside a licence area are not unacceptable (s 9(2)-(4)). These exceptions require the part to lie outside ASMG or be inside HCIS MW4H6 or be connected to a permitted radial that does not cross another licence area or land permanently above the territorial sea baseline. Do not assume a general “buffer” outside the licence area is acceptable.

13. Emission designator method: The Determination requires use of the Radio Regulations method and treats “necessary bandwidth” as the transmitter’s occupied bandwidth (s 6(1)-(2)). Practitioners must ensure occupied bandwidth is measured to the 99% true mean power definition used by the Determination (s 4 occupied bandwidth).

14. Antenna height measurement tolerance: Antenna height must be measured with an error less than 5 parts in 100 relative to the base point on the structure (Schedule 3 Part 1 item 1). That is a 5% relative tolerance and must be adhered to in site surveys.

15. Maritime baseline and land crossing test: One exception requires the radial not cross “the land outside the geographic area of the licence that is permanently above the Australian territorial sea baseline” (s 9(4)(b)(ii)). Determining whether a radial crosses land permanently above the baseline requires application of the Seas and Submerged Lands Act 1973 baseline concept.

These operational details are concrete and prescriptive. Failure to attend to any one of them can convert a well‑intentioned calculation into a basis for ACMA to refuse registration on the grounds of unacceptable interference.

Compliance with this Determination requires an engineering and administrative workflow that produces device boundary calculations conforming to the instrument’s specified methods and accuracy rules. The following stepwise approach synthesises the instrument’s requirements into practical tasks. Each step references the applicable provision(s) for practitioners to cross‑check.

1. Assemble required baseline data

• Site coordinates: determine the phase-centre latitude and longitude referenced to GDA94 for each transmitter antenna (Schedule 1 items 1-3). Ensure measurement error is less than 10 metres. Consult ACMA’s site identifier data and the BOP Radiocommunications site data requirements for format (Schedule 1 notes).
• Antenna characteristics: obtain antenna model, type, manufacturer, per‑azimuth horizontal gain pattern expressed for the horizontal plane and phase centre location, and ACMA antenna identification number if applicable (s 7(1)(c), (e)).
• Transmitter power: establish maximum true mean power in the specified rectangular bandwidth within the licence frequency band (s 4 maximum true mean power; horizontally radiated power definition).
• Emission designator / occupied bandwidth: determine the emission designator using the ITU Radio Regulations method, interpreting necessary bandwidth as occupied bandwidth per s 6(1)-(2). Measure occupied bandwidth so that 99% of true mean power is contained (s 4 occupied bandwidth).
• Determine whether the transmitter is an AAS: establish if the antenna is an active antenna system (Definition in s 4) because that affects LOP and RP definition (Schedule 2 Part 2).

2. Compute horizontally radiated power (RP) per bearing

• For each azimuth σn (n = 0..359), determine RP in dBm EIRP per MHz as the sum of maximum true mean power (dBm per specified rectangular bandwidth) and the antenna horizontal gain towards azimuth σn (dBi), in the units required by the Determination (s 4 horizontally radiated power; Schedule 2 Part 2).
• For AAS, the RP is defined as the sum of antenna gain towards the horizontal plane and towards azimuth σn, and the total radiated power (Schedule 2 Part 2 note). Document AAS control and beam limitation mechanisms to demonstrate RP is not exceeded in operation.

3. Prepare terrain and profiling inputs

• Obtain the DEM-3S dataset (Gallant et al. 2009, persistent identifier 69888) as specified (s 4 DEM-3S). Confirm coordinate reference (GDA94 compatibility).
• Implement sampling along each radial at 100 m increments starting at m = 2 (200 m) through m = 530 (53 km) (Schedule 2 Part 1 Step 1). For each sample point compute average ground height using the 3×3 DEM cell mean as specified (Schedule 3 Part 2 Steps 1-4), handling cell-boundary cases per Schedule 3 Part 2 item 2.

4. Apply propagation-loss models

• For antennas higher than 6 m above ground, apply methods and parameters from section 2.2 of ITU-R P.525-4 and section 4.5.2 of ITU-R P.526-15 (Schedule 2 Part 3(1)(a)). For antennas at or below 6 m, also apply P.2108-0 with the percentage of locations set at 0.0001% and correction applied at only one end; if that calculation yields a loss less than 0 dB, replace with 0 dB (Schedule 2 Part 3(1)(b) and (4)(a)-(b)). Use the 100 m sampled path profile in these computations (Schedule 2 Part 3(3)).
• Ensure the nominal receiver height used in ITU-R P.526-15 implementation is 5 m above ground (Schedule 2 Part 3(2)(a)), and determine transmitter height per Schedule 3 Part 1.

5. Calculate MP and device boundary criterion

• For each sample point compute MP = PL(lmn, Lmn) + LOP − Gr where LOP is −102 dBm/MHz for AAS or −110 dBm/MHz for non‑AAS, and Gr = 0 dBi (Schedule 2 Part 2).
• Determine device boundary criterion RP − MP at each sample point and locate, for each radial, the first point moving away from the transmitter where RP − MP ≤ 0, or take the m = 530 point if none is found (Schedule 2 Part 1 Step 2). Record latitude/longitude per Schedule 3 Vincenty direct formulae implementation (Schedule 3 Part 3).

6. Check geographic outcome against licence area and exceptions

• Compare the device boundary polygon to the licence geographic area. If any part lies outside the geographic area, check whether a narrow exception in s 9(2)-(4) applies (outside ASMG and connected to a permissible radial that does not cross another 26 GHz licence area; parts within HCIS MW4H6 under conditions; or connected to a radial that does not cross land permanently above the territorial sea baseline).
• If any part of the device boundary lies outside the licence geographic area and none of the exceptions apply, ACMA will treat that as an unacceptable level of interference for registration purposes (s 9(1)(b)).

7. Demonstrate numerical and statistical accuracy

• Ensure all parameter estimates used in Schedules 2 and 3 are produced with a level of confidence not less than 95% that the true value will always remain below the requirement (s 10). This may require statistical bounding, calibrated measurement uncertainty statements, or conservative assumptions. Document measurement uncertainties for location (<10 m), antenna height measurement error (<5 parts in 100), and instrument measurement protocols for mean power (s 4 definitions and Schedule 1 and 3 notes).

8. Documentation and submission to ACMA

• Prepare a submission to ACMA (for Register inclusion or site notification) that includes: GDA94 coordinates with stated measurement error, antenna height calculations and tolerances, emission designator and occupied bandwidth derivation, per-bearing RP values and antenna patterns, propagation-loss calculations per the enumerated ITU-R methods, DEM-3S usage and averaging details, device boundary polygon coordinates, and an explicit statement demonstrating the 95% confidence requirement for key parameters (s 6, Schedule 2, Schedule 3, s 10, Schedule 1).
• If claiming grouping under s 7(1), include evidence that each criterion is met: same centre frequency and emission designator, same antenna type/model/manufacturer, placement on same structure within 20 m of phase centres, and ACMA antenna identification numbers.

9. Operational controls and recordkeeping

• For AAS devices, maintain operational logs and technical records that show beam-forming and power control parameters are constrained to the modelled RP values. This supports the Determination’s AAS note assumption that beam control ensures RP is not exceeded (Schedule 2 Part 2 note).
• Keep records of DEM-3S dataset versions used, date/time stamps on terrain sampling, and software or tool versions used for propagation modelling and Vincenty calculations in case of ACMA queries.

10. Pre-submission validation

• Run an independent validation or third‑party review of the device boundary calculation, particularly for complex urban deployments or sites near licence area boundaries, because failure to calculate a device boundary per Schedule 2 Part 1 itself gives rise to an “unacceptable” finding (s 9(1)(c)).
• Verify numerical convergence criteria for Vincenty’s Direct Formulae per Schedule 3 Part 3 (iterate until change < 10−12) and ensure your geodetic implementation uses GRS80 parameters consistent with GDA94 (Schedule 3 Part 3 notes).

Adopting this workflow aligns technical procedures with the Determination’s prescriptive requirements and reduces the risk of ACMA treating a transmitter’s emissions as unacceptable when ACMA considers registration. Keep in mind the Determination’s limited and specific exceptions under s 9(2)-(4): do not assume leniency for device boundaries extending beyond licence areas without confirming the narrow statutory exception conditions apply.