Radiocommunications (Unacceptable Levels of Interference – 1800 MHz Band) Determination 2023

The instrument relies on a small set of technical concepts and data sources that determine the legal outcome (whether interference is “unacceptable”). Key concepts are defined in section 5 and in the Schedules; the most operationally important are device boundary, additional device boundary, horizontally radiated power (RP), propagation loss PL, level of protection (LOP), effective antenna height, AAS, and geographic area.

• Device boundary (Schedule 2 item 1): a radial sampling construct around the transmitter. For a single transmitter, the device boundary is the set of end points found by stepping out along every degree bearing (0-359 degrees) in 100‑metre increments (m = 1 to 400), and finding the first point where the device boundary criterion RP − MP ≤ 0 or the maximum sample is reached. RP and MP are defined precisely (Schedule 2 item 2 and item 3). For groups of transmitters, the device boundary is computed as if for a single transmitter but using the maximum horizontally radiated power among the group and treating RP as equal for each bearing (Schedule 2 item 1(2)).

• Device boundary criterion (Schedule 2 item 2): RP − MP, where MP = PL(lmn, Lmn) + LOP − Gr. PL is the propagation loss computed under Schedule 2 item 3; LOP is the level of protection (−107 dBm/30 kHz for AAS; −115 dBm/30 kHz otherwise); Gr is the nominal receiver antenna gain set at 0 dBi (Schedule 2 item 2).

• Additional device boundary (Schedule 2 item 4): similar to the device boundary but sampled at 500‑metre increments and using the additional device boundary criterion HRP − Lb − CR, where HRP is horizontally radiated power per 30 kHz (Schedule 2 item 5), Lb is propagation loss worked out by ITU‑R P.526 using DEM‑3S (Schedule 2 item 6), and CR is a compatibility requirement of −136.5 dBm/30 kHz (Schedule 2 item 5).

• AAS (section 5): active antenna systems are defined; the Determination treats them specially by adjusting LOP and RP definitions to reflect dynamic amplitude/phase control. The instrument’s Note explicitly assumes beam pointing and/or power control can be managed to ensure RP limits are not exceeded (Schedule 2 item 2 Note 1).

• Effective antenna height (Schedule 3): defined using DEM‑3S cell heights and local ground averaging rules, including a special rule where certain DEM cell selection applies when coordinates fall on grid boundaries (Schedule 3 items 1-2). The effective antenna height feeds into propagation-loss calculations.

• Data and methods: the instrument prescribes DEM‑3S as the elevation dataset (section 5, DEM‑3S definition) and ITU‑R Recommendation P.526 for diffraction loss for the additional device boundary (Schedule 2 item 6). Vincenty’s direct formulae are mandated for geodetic computations (Schedule 3 item 3).

• Regulatory linkage: “unacceptable” is defined by reference to the device/additional device boundaries and by explicit rules for high-sited transmitters in the 1800 MHz lower band, especially in areas of high mobile use (section 10(1)(d)-(f)). There are carve outs in section 10(2) and (3) that limit when an out‑of‑area device boundary counts as unacceptable, and a transitional regime in section 12 preserving prior assessment rules for transmitters already registered.

These concepts function together as a mechanistic decision tree. An operator’s measurements and models feed into RP and PL. The computed device boundary and additional device boundary are compared against the licence geographic area and other criteria in s 10. If one of the listed conditions is met, interference is “unacceptable” for the statutory purpose used in s 145(4) of the Act.

The Determination primarily affects holders of 1800 MHz spectrum licences and parties who operate transmitters under those licences, including authorised third parties recorded in the Register. The definitions make that clear: “1800 MHz spectrum licence” and “spectrum licence” are used throughout (section 5 definitions, and the operative tests in section 10), and the instrument was made under the Act’s regulator power in subsection 145(4) (section 3). Practically, affected actors include:

• Spectrum licensees in the 1800 MHz lower band (1710-1785 MHz) and upper band (1805-1880 MHz), because the device and additional device boundary tests and the special high‑site rules apply to operations in those bands (section 5 definitions; section 10).

• Network operators (mobile carriers) and their engineering teams, because the Determination requires detailed RF modelling inputs (EIRP, occupied bandwidth, emission designator per s 7, effective antenna height per Schedule 3), and imposes constraints that may require power reductions, site redesign, or written agreements (section 10(3)(c)(ii)).

• Equipment manufacturers and vendors of Active Antenna Systems (AAS), because the Determination gives AAS a different LOP (−107 dBm/30 kHz) and modifies RP calculation for AAS (Schedule 2 item 2 Note 1). The instrument also assumes dynamic control capability for AAS beamforming.

• Tower and site owners, insofar as measured antenna phase centre location, tower geometry and permitted heights affect effective antenna height calculations (Schedule 3 item 1 and Diagram 1), and because the location accuracy requirements (location measurement error < 10 m, section in Schedule 1) may require surveying.

• Other spectrum licensees whose geographic areas abut or overlap potential device or additional device boundaries, because the Determination treats the presence of other spectrum licences and written agreements between licensees as an exception to unacceptable interference for additional device boundary breaches (section 10(3)).

• The ACMA, which applies the Determination when assessing register inclusion decisions and when enforcing the Act. The Determination operationalises the ACMA’s assessment criteria under subsection 145(4) of the Act (section 3 and the Note to section 10 referencing s 145(1)).

Not directly named but affected are vendors of geospatial and propagation modelling services, who will be hired to produce the PL and Lb calculations using DEM‑3S and ITU‑R P.526. Journalists, compliance professionals and counsel advising carriers will need to understand the formulaic outputs because small changes in EIRP or height can change whether a device boundary crosses a licence boundary and thus whether ACMA will treat interference as “unacceptable” under section 10.

The instrument also affects the legal position of already‑registered transmitters: section 12 creates a transitional rule that preserves the earlier 2012 Determination’s test for interference in relation to transmitters registered before commencement, unless and until registered details change in ways that increase device/additional device boundaries.

Duties

• Ensure operations do not produce an “unacceptable level of interference” as defined in section 10. That requires computing the device boundary and, where relevant, the additional device boundary in accordance with Schedule 2 and ensuring those boundaries lie within the geographic area of the licence or satisfy the carve outs in section 10(2) and 10(3).

• Use specified datasets and methods when calculating propagation loss for device and additional device boundaries. For device boundary PL calculations, the Determination prescribes the use of a nominal frequency (1840 MHz) and the parameters listed in Schedule 2 item 3; for additional device boundary Lb, ITU‑R P.526 with DEM‑3S and an effective earth radius factor of 4/3 is required (Schedule 2 item 6).

• For effective antenna height, compute hgt, hs and he_m(sigma_n) following the process in Schedule 3, which includes averaging DEM‑3S cell heights and applying special rules when site coordinates fall on grid boundaries (Schedule 3 items 1-2).

• For AAS, apply the specific RP definition and use the elevated LOP (−107 dBm/30 kHz) when computing MP for the device boundary (Schedule 2 item 2). The instrument expects licensees to be able to demonstrate that beamforming can be controlled so RP limits are not exceeded (Schedule 2 item 2 Note 1).

• Maintain measurement accuracy standards. Location measurement error must be less than 10 m (Schedule 1 item 3). Effective antenna height vertical measurement error (hgt) must be less than 5 parts in 100 (Schedule 3 item 1). Unless otherwise specified, Schedule 2 and 3 parameter values must be estimated with at least 95% confidence that true values remain below specified requirements (section 11).

• Record changes in the Register and, when changing transmitter details, be aware that certain changes that do not increase device/additional device boundary distances will preserve the prior non‑unacceptable status (section 12(3)-(4)).

Rights and procedural protections

• Transitional protection: For transmitters in the Register before commencement, section 12 protects them by applying the 2012 Determination’s test, unless registrable changes increase device/additional device boundary distances above the prior values. If a change reduces the new device/additional device boundary distances to be equal to or less than the old ones along each radial, the immediate post‑change interference is not unacceptable because of the change (section 12(3)-(4)).

• Ability to nominate group membership: If a transmitter could belong to more than one group of transmitters, the licensee or authorised third party may nominate which group the transmitter belongs to (sections 8(2) and 9(2) notes).

• Exceptions via written agreement: If the additional device boundary for a high‑sited transmitter in the 1800 MHz lower band lies outside the geographic area (section 10(1)(f)), it is not unacceptable provided the additional device boundary is wholly within the geographic area of one or more other spectrum licences and either the licensee is the licensee of the other licences or has the written agreement of the other licensees to exceed the additional device boundary criterion (section 10(3)). This creates an opt‑in coordination route.

Decision‑making authority

• The ACMA applies these criteria when deciding whether to include transmitters in the Register (note to section 10 referencing subsection 145(1) of the Act). The Determination itself is the legal instrument the ACMA will apply under subsection 145(4) of the Act (section 3).

Operational duties therefore squarely fall on spectrum licensees and their technical teams: those parties must perform the prescribed calculations, maintain the accuracy tolerances, document modelling assumptions and, where necessary, coordinate with neighbouring licencees or alter technical parameters to avoid device/additional device boundary exceedances.

The Determination is an instrument made under the Act that defines a statutory criterion the ACMA uses in exercising powers under the Act. It does not itself prescribe civil penalties, criminal offences or administrative fines in its text. Instead, it specifies objective criteria that the ACMA will apply when exercising functions such as refusing to include a transmitter in the Register under subsection 145(1) of the Act (note to section 10) and when acting under subsection 145(4) (authority in section 3). The Act contains enforcement powers; the Determination provides the technical test ACMA uses under those powers.

What the Determination makes enforceable in practice

• Register inclusion decisions. The primary enforcement lever signalled in the Determination is the ACMA’s power to refuse to include a transmitter in the Register if it would cause an “unacceptable level of interference” as determined by the criteria in section 10 and Schedule 2. The instrument operationalises the ACMA’s decision to exclude or require changes to transmitters before registering them.

• Licence core condition compliance. Section 10(1)(a) makes a contravention of a core condition relating to maximum permitted level of radio emission outside licensed spectrum or geographic area a trigger for “unacceptable” interference. Breaches of core licence conditions are managed under the Act and can lead to regulatory responses under the Act’s enforcement regime; the Determination identifies the technical circumstances that constitute such a breach for the 1800 MHz band.

• Administrative measures and coordination. The Determination provides mechanisms for written agreements between licensees to allow additional device boundary exceedances (section 10(3)(c)(ii)). ACMA can require or recognise such agreements in exercising its registration powers.

What the Determination does not do (and thus limits on enforcement claims)

• The instrument does not itself impose monetary penalties, forfeiture, criminal sanctions, or administrative fines; those are matters for the Act and other legislative instruments. The Determination therefore functions as a technical standard and procedural rule for the ACMA’s decision‑making rather than a stand‑alone penalties instrument.

Practical enforcement risks and procedural choices

• Measurement and modelling disputes will be central. Enforcement decisions will turn on computations undertaken under Schedule 2 and Schedule 3 using DEM‑3S, Vincenty’s formulae and ITU‑R P.526. The Determination embeds precise numerical tolerances (e.g., location measurement error <10 m, hgt error <5 parts in 100, 95% confidence requirement for parameters, section 11 and Schedule 1/3). Disputes about adherence to those tolerances, selection of DEM cells (Schedule 3 item 2), and the correctness of PL or Lb computations are likely to be the locus of challenges to ACMA decisions.

• ACMA discretion and procedural review. The ACMA’s refusal to register a transmitter on the basis that it would cause “unacceptable” interference is an administrative decision under the Act. The Determination provides the measurable basis for that decision; affected licensees may seek internal review or merits/ judicial review remedies under the applicable Act and administrative law principles. The Determination itself contains no appeal procedure; appeal or review rights flow from the Act.

In sum, the Determination supplies the technical yardstick the ACMA will apply. The regulatory consequences (refusal to include a transmitter in the Register, enforcement of licence core conditions) are exercised under the Act; the instrument does not itself create new monetary penalties or criminal offences.

The Determination is designed to be interpreted and applied alongside the Radiocommunications Act 1992 and a number of external technical documents and data sources. The instrument itself references those primary legal and technical materials and requires their use where indicated.

Statutory framework

• Radiocommunications Act 1992: The Determination is made under subsection 145(4) of the Act (section 3), and several of its operative provisions are explicitly tied to the Act’s Register and core condition regime (see the note to section 10 referencing subsection 145(1) of the Act and the Register information requirement in the notes to sections 8-9 referencing section 144 of the Act). The Act supplies the ACMA’s power to refuse to include transmitters in the Register and to enforce licence conditions; the Determination supplies the technical test the ACMA will apply under those statutory powers.

References to other statutes

• Seas and Submerged Lands Act 1973: The Determination references the Australian territorial sea baseline for the purposes of deciding whether certain radials cross land that is permanently above that baseline when applying the device boundary carve‑out (section 5 definition of Australian territorial sea baseline; section 10(2)(b)(ii)). That ties the Determination’s spatial tests to maritime baseline law.

• Acts Interpretation Act 1901 and Legislation Act 2003: Section 6 and its notes refer to statutory interpretation rules and the ongoing operation of referenced legislative instruments, signalling that where the Determination refers to other legislative instruments they are to be read as in force from time to time.

Technical instruments and datasets

• Radio Regulations and ITU‑R Recommendations: The Determination adopts Radio Regulations methods for emission designator calculation (section 7) and ITU‑R Recommendation P.526 for diffraction loss in additional device boundary calculations (Schedule 2 item 6). These are not Australian statutes but international technical standards the Determination requires licensees to use.

• DEM‑3S (Geoscience Australia): The elevation dataset DEM‑3S is mandated (section 5 definitions and Schedule 3). The Determination prescribes how to identify DEM‑3S cells and how to average cell heights when computing effective antenna height and propagation loss (Schedule 3 items 1-2 and Schedule 2 item 6).

Interoperation with spectrum licence conditions and the Register

• Core conditions and spectrum licence geographic areas: The Determination links its device/additional device boundary tests to core licence conditions that regulate out‑of‑area emissions and maximum permitted radio emission levels (see section 10(1)(a) and the Note referencing core conditions and section 144 of the Act). It therefore interacts concretely with the licence instrument and the spatial extent recorded for spectrum licences in the Register.

• Register entries and changes: Section 12 sets transitional rules for transmitters already in the Register and conditions under which registered changes are treated as not producing unacceptable interference. The Register processes and the Act’s requirements for content (section 144 of the Act, cited in notes) are therefore relevant compliance touchpoints.

Limits on cross‑legislative interplay

• The Determination does not directly displace other legal regimes (for example, planning or environmental approvals for towers). It is narrowly focused on radiofrequency interference criteria and the ACMA’s radio spectrum regulatory functions. Where tower height, planning approvals or local laws affect the physical siting, those regimes remain applicable, but they are outside the Determination’s scope and are not referenced in the text.

Practical consequence

• To comply with the Determination, licensees must integrate outputs from technical instruments (DEM‑3S, ITU‑R P.526, Radio Regulations) and statutory concepts (licence geographic area, ACMA Register entries) into an interdisciplinary compliance programme that includes RF engineering modelling, geodetic computations (Vincenty’s formulae), and register administration. The Determination thereby formalises cross‑disciplinary interaction between the ACMA’s statutory regime and international and national data/technical resources.

The instrument was originally registered on 17 March 2023 and commenced on 18 March 2023 (Endnote 3). It has since been amended by a variation: Radiocommunications (Unacceptable Levels of Interference , 1800 MHz Band) Determination Variation 2024 (No. 1), which was registered on 19 December 2024 and commenced on 20 December 2024 (Endnote 3). The endnote table (Endnote 4) records specific clause‑level amendments.

Noted amendments recorded in the endnotes

• Sch 2, item 2: amended by F2024L01612 (the 2024 variation). Item 2 in Schedule 2 contains the device boundary criterion formula and the LOP and RP definitions, including the special AAS treatment. The endnote indicates that the 2024 variation changed this item; practitioners must consult the variation instrument on the Federal Register of Legislation for the precise textual differences (Endnote 4).

• Sch 2, item 3, Step 2: amended by F2024L01612. Item 3 of Schedule 2 describes calculation of propagation loss PL for the device boundary criterion and includes Step 2, which sets out the propagation loss calculation steps. The endnote indicates Step 2 was amended in 2024; the amended text will affect how PL is computed in device boundary tests.

• Other historical editorial amendments: The endnote table shows that earlier repeals of provisions (s.2 and s.4 references to legislative interpretation provisions) were effected by amendments to the Legislation Act (referenced in Endnote 4 as rep. LA s.48D and rep. LA s.48C). These reflect editorial and structural changes and are recorded in the instrument’s amendment history.

Practical implications

• Because the Determination is technical and numerical, seemingly minor amendments to Schedule 2 item 2 or item 3 Step 2 can change device/additional device boundary distances and therefore change whether a transmitter is treated by the ACMA as causing unacceptable interference. Licence holders and consultants must therefore track these amendments closely and use the current consolidated instrument (or the original plus variation text) when calculating boundaries.

• The endnotes instruct readers to consult the Federal Register of Legislation for the variation instruments. The amendment history in the endnotes is the canonical record for what changed and when; practitioners should retrieve the variation instrument F2024L01612 and confirm whether the change affects LOP values, propagation models, or the sampling/iteration steps.

• Transitional rules in section 12 interact with the amendment history: for transmitters registered prior to the Determination’s commencement, section 12 preserves the 2012 Determination’s test. But subsequent registered changes to transmitter details will attract the current instrument as in force at the change time; section 12 therefore mediates the practical impact of amendments on existing registered transmitters.

Recommendation for practitioners

• Whenever the ACMA publishes an amending instrument identified in the endnotes, recompute device and additional device boundaries under the new text for any proposed or modified transmitter, especially if earlier calculations were close to licence boundaries. Keep archived records of prior computations so section 12 transitional rules can be applied if needed. The endnotes explicitly point to the registration details (F2023L00245 and F2024L01612) and commencement dates (18 March 2023; 20 December 2024).

The Determination itself contains no citations to case law and the instrument’s endnotes do not record any litigation arising from it. The text includes administrative law references (for example, the ACMA’s Register functions under section 144 of the Act and the ACMA’s powers under subsection 145(1) and subsection 145(4) of the Act are referenced in the instrument), but it does not record judicial review decisions, appeals or other litigation outcomes.

Practical points for counsel and compliance teams

• Absent cases named in the instrument, there is no internal record here of judicial construction of the Determination’s technical rules. The determinative factors when disputes arise are likely to be (a) whether the ACMA correctly applied the formulae in Schedule 2 and Schedule 3, (b) whether the model inputs (DEM‑3S selection, EIRP, occupied bandwidth, effective antenna height) complied with the instrument’s accuracy and confidence requirements (section 11; Schedule 1/3 tolerances), and (c) whether the ACMA correctly applied section 10’s carve outs and transitional rules (section 12).

• Administrative law remedies: challenges to ACMA decisions refusing to include a transmitter in the Register or taking enforcement action under the Act would be pursued under the Act’s internal review mechanisms and, where applicable, by merits review (if available) or judicial review on public law grounds. The Determination will be central to any such review because it supplies the technical standard the ACMA used to make the decision.

• Areas likely to attract dispute: calculation of propagation loss (the Determination requires ITU‑R P.526 and DEM‑3S for the additional device boundary, Schedule 2 item 6), the selection and averaging of DEM cells for effective antenna height (Schedule 3), the handling of AAS where dynamic beamforming assumptions affect RP, and the application of section 10(2) radial carve outs that rely on the Australian territorial sea baseline.

Because the instrument’s endnotes list the registration and variation instruments and do not record litigation, practitioners should not assume precedent exists. Before litigating, counsel should review ACMA decisions made under the Determination, ACMA internal review decisions, and any relevant tribunal or court decisions addressing similar technical tests under prior Determinations (for example, the 2012 Determination) or analogous instruments. The instrument itself contains no case names and the authoring notes prohibit inventing case law; therefore step‑one is to compile administrative records and consider statutory review pathways under the Act and the Judiciary Act and administrative law principles.

This Determination contains a number of technical and procedural traps that can produce materially different compliance outcomes if overlooked. Below are concrete items to watch for, with direct references to the instrument.

1. Lower frequency bound exclusion (section 5(4)). The instrument specifies that in frequency band notational ranges, the lower number is excluded and the upper number included. Practically, if a transmitter’s occupied bandwidth abuts the lower frequency of a band, the instrument treats frequencies strictly greater than the lower frequency as within the band but not equal to it. This subtlety matters for the 1800 MHz lower and upper band boundaries and for adjacent‑spectrum proximity tests in section 10(1)(e).

2. Increment sampling distances and maximum radial extent (Schedule 2 item 1 and item 4). Device boundary calculations use 100‑metre increments up to m = 400 (maximum 40 km per radial); additional device boundary calculations use 500‑metre increments up to m = 400 (maximum 200 km per radial). Practitioners must ensure their modelling grid reflects these exact increments; using coarser sampling or different maxima will produce different end points and potentially different legal outcomes.

3. Different propagation methods for device boundary vs additional device boundary (Schedule 2 items 3 and 6). The device boundary PL calculation (item 3) uses a set of parameters and an embedded iterative formula (the Schedule contains images of the formulaic steps), whereas the additional device boundary requires ITU‑R P.526 with DEM‑3S and an effective earth radius factor of 4/3 (item 6). Mixing methods or substituting simpler path‑loss models will not comply with the instrument.

4. AAS special treatment (Schedule 2 item 2, Note 1, and LOP values). For AAS, RP is defined as the sum of the antenna gain toward the horizontal plane in the azimuth plus the total radiated power, and the LOP is relaxed to −107 dBm/30 kHz rather than −115 dBm/30 kHz for non‑AAS. However, Note 1 makes an explicit assumption that beam pointing/power can be controlled dynamically. If an AAS cannot demonstrate that control in practice, applying the AAS RP/LOP treatment may not be supportable.

5. Tight measurement error tolerances (Schedule 1 and Schedule 3). Location measurement error must be less than 10 m (Schedule 1 item 3). hgt measurements must be less than 5 parts in 100 error (Schedule 3 item 1). These tolerances may require surveyors or validated GNSS measurements; approximate site coordinates from planning documents or base maps may not suffice.

6. 95 percent confidence requirement (section 11). Unless otherwise specified, parameter values in Schedules 2 and 3 must be estimated with at least 95% confidence that the true parameter will remain below the requirement. This is not a simple “best estimate” rule; it imposes a probabilistic quantification (and thus modelling uncertainty analysis) onto power and propagation parameter estimates.

7. Radial carve‑out tied to maritime baseline (section 10(2)). A device boundary part lying outside the geographic area is not unacceptable if connected to a radial mentioned in Schedule 2 item 1 that does not cross over land permanently above the Australian territorial sea baseline. This requires careful maritime baseline checks; coastal radials that briefly cross islands or land features above the baseline will change the carve‑out outcome.

8. Additional device boundary exception requires written agreement or same licensee (section 10(3)). If a high‑sited transmitter in the 1800 MHz lower band would have parts of its additional device boundary outside its licence area, it is not unacceptable only if the additional device boundary is within the area of other licences and either the same licensee holds those licences or has written agreements from the other licensees. Verbal or informal coordination is not enough; the Determination requires written agreement.

9. Grouping rules require identical antenna IDs and close co‑location (sections 8-9). To treat multiple transmitters as a group the antenna identification number assigned by the ACMA must be the same and antennas must be on the same structure within 20 m of the phase centre of other antennas. Administrative mismatches in ACMA antenna IDs or slight structural relocations can prevent grouping and force more conservative device boundary computations.

10. Transitional protection can be lost by registered changes that increase boundaries (section 12). Section 12 preserves the 2012 Determination’s test for transmitters registered before commencement, but if subsequent registered changes increase device or additional device boundary distances on any radial, the changed transmitter is assessed under the instrument as in force at the change time. Licensees making modifications must therefore plan changes knowing transitional protection depends on not increasing radial boundary distances.

11. Emission designator calculation depends on Radio Regulations (section 7). The Determination requires methods in the Radio Regulations to set emission designators and equates “necessary bandwidth” with occupied bandwidth (section 7(2)). If a transmitter’s emission classification is ambiguous, licensees must use ITU Radio Regulations Appendix 1 methods in force at the time of assessment.

12. DEM grid boundary special rules (Schedule 3 item 2). When a sampled point lies on a grid line in DEM‑3S (seconds component plus 1.5 modulo 3 equals zero), the Determination requires using a particular adjacent DEM cell selection rule (the “minimum height” adjacent cell for some steps) rather than the nominal cell. This non‑intuitive rule can produce discontinuities in effective antenna height near grid boundaries.

Failing to observe these specifics will lead to different computed boundaries and therefore different ACMA decisions about whether a transmitter would cause “unacceptable” interference.

Compliance requires an integrated technical, administrative and legal process. Below is a practical compliance checklist mapped to the Determination’s requirements with action steps and evidence to retain.

1. Inventory and classify transmitters

   • Identify all radiocommunications transmitters operated under an 1800 MHz spectrum licence and confirm whether they are fixed transmitters or part of transmitter groups (sections 8-9). Ensure ACMA antenna identification numbers are accurate and consistent.
   • For each transmitter, record: location (phase centre latitude and longitude referenced to GDA94), whether it uses an AAS, occupied bandwidth and emission designator (section 7; section 5 definitions).

2. Ensure measurement accuracy

   • Survey each transmitter location to a measurement error less than 10 m (Schedule 1 item 3).
   • Measure vertical antenna phase centre (hgt) with an error less than 5 parts in 100 (Schedule 3 item 1).
   • Document measurement methodologies, instrumentation and calibration certificates. Retain raw GNSS/survey data for ACMA inspection.

3. Compute effective antenna height

   • Follow Schedule 3 to compute hgt, hs and effective antenna height per increment (he_m(sigma_n)). Use DEM‑3S for cell heights and apply the 3×3 averaging matrix and special grid‑boundary rules where applicable (Schedule 3 items 1-2 and Diagrams).
   • Archive the DEM‑3S cell identifiers used and the averaging computations.

4. Compute emission designator and occupied bandwidth

   • Use the Radio Regulations methods to derive the emission designator (section 7). Treat “necessary bandwidth” as occupied bandwidth per section 7(2).
   • Record canonical occupied bandwidth measurements or designator assignments and the measurement protocol (spectrum analyser/adjacent channel power meter methodology referenced in definition of maximum true mean power in section 5).

5. Model propagation loss for device boundary

   • For device boundary PL calculations, apply Schedule 2 item 3 with nominal frequency 1840 MHz and the specified parameters. Implement the iterative computations as shown in the Schedule and use Vincenty’s Direct Formulae for geodetic computations (Schedule 3 item 3).
   • Sample radials at every integer degree and at 100‑metre increments up to m = 400 (Schedule 2 item 1). Keep intermediate outputs for each m and bearing.

6. Model additional device boundary

   • Use ITU‑R P.526 diffraction loss with DEM‑3S and effective earth radius factor 4/3 for Lb (Schedule 2 item 6). Sample at 500‑metre increments up to m = 400. Adopt the notional receiver height of 30 m indicated for Lb.
   • Archive P.526 implementation details, profile generation and DEM cell selections.

7. Compute RP, MP, HRP and evaluate criteria

   • For each bearing evaluate RP (horizontally radiated power) and MP = PL + LOP − Gr (Schedule 2 item 2). For AAS apply the AAS definition of RP and the AAS LOP (−107 dBm/30 kHz) and document beamforming control assumptions.
   • For additional device boundary evaluate HRP − Lb − CR with CR = −136.5 dBm/30 kHz (Schedule 2 item 5).

8. Apply the unacceptable interference tests (section 10)

   • Check whether any device boundary part lies outside the licence geographic area, whether emission limits or core conditions are breached outside licensed spectrum/geographic area, whether the additional device boundary lies outside and the transmitter is high sited and in the 1800 MHz lower band, or whether proximity tests in section 10(1)(e) apply (occupied bandwidth within 10 MHz of an adjacent licence).
   • For radial carve‑outs under section 10(2), confirm whether the radial crosses land permanently above the Australian territorial sea baseline. Obtain maritime baseline maps if coastal radials are involved.

9. Use coordination and written agreements where needed

   • If an additional device boundary would extend into another licence’s area, negotiate and document written agreements with the other licence holder(s) to permit exceeding the additional device boundary criterion, or acquire the other licence(s) to satisfy section 10(3)(c)(i)-(ii).
   • Keep execution and authority evidence for agreements available for ACMA review.

10. Register and manage changes

    • Ensure transmitter details are correctly recorded in the ACMA Register. Where transmitters were registered pre‑commencement, apply section 12 transitional rules carefully: if a change reduces device/additional device boundary distances on every radial to be less than or equal to the previous values, the immediate post‑change interference is not unacceptable because of the change (section 12(3)-(4)).
    • Before making changes that might increase device or additional device boundary distances, recompute boundaries under the current Determination and assess whether ACMA registration may be refused or whether mitigation is needed.

11. Maintain uncertainty and confidence documentation

    • For parameters covered by the 95% confidence requirement (section 11), maintain uncertainty analyses, statistical confidence intervals or Monte Carlo simulations as appropriate to demonstrate that parameter estimates meet the confidence threshold.
    • Document assumptions about antenna patterns, beamforming control (for AAS), feeder losses, measurement instrument accuracy, and spectrum analyser settings used to derive maximum true mean power (section 5 definitions).

12. Retain reproducible models and audit trails

    • Archive propagation model inputs, DEM‑3S extracts, Vincenty computation logs, per‑bearing RP/MP/HRP outputs, and final device/additional device boundary coordinates. Include the scripts or software versions used to compute PL and Lb. ACMA decisions and audits will require reproducible computations.

13. Keep current with instrument amendments

    • Consult the Federal Register of Legislation for the instrument and any variations (Endnote 3 lists the original registration F2023L00245 and the variation F2024L01612). Recompute boundaries whenever the instrument is amended, particularly where Schedule 2 item 2 or item 3 Step 2 are changed (Endnote 4).

14. Legal and compliance review

    • Involve legal counsel when ACMA signals that inclusion in the Register may be refused or when other licencees refuse written agreements. Prepare administrative review records and, where relevant, consider internal or external review paths under the Act.

By following these concrete steps and retaining a robust technical audit trail, licensees can demonstrate compliance with the Determination’s specific modelling, measurement and documentation requirements and reduce the risk that an ACMA registration decision will treat a transmitter as producing “unacceptable” interference.