Several core technical and legal concepts are defined and then used as deterministic inputs to the device-boundary method.

Band structure and definitions

• The 850/900 MHz band is explicitly the union of four named sub-bands: 850 MHz Lower (814-845 MHz), 850 MHz Upper (859-890 MHz), 900 MHz Lower (890-915 MHz) and 900 MHz Upper (935-960 MHz) (s 5). All subsequent technical rules are applied with reference to those sub-bands.

Device boundary and device boundary criterion

• The device boundary is the geographic locus of end points found on 360 radials (one per degree) at 100 m increments from the transmitter location. For a single transmitter, the end point on each radial is the first increment where RP − MP ≤ 0 (Schedule 2 Part 1). RP − MP is defined in Schedule 2 Part 2: RP is the horizontally radiated power (dBm EIRP per MHz) for each bearing; MP is PL + LOP − Gr (PL is propagation loss in dB, LOP is the level of protection in dBm per MHz, Gr is nominal receiver antenna gain in dBi).
• For a group of transmitters, the device boundary is calculated as for a single transmitter but with RP for the group taken to be equal for each bearing and equal to the maximum horizontally radiated power in any direction of any transmitter in the group (Schedule 2 Part 1.2). Group membership is strictly defined (s 8).

Horizontally radiated power (RP)

• RP is the sum of the maximum true mean power at the antenna connector (in dBm per specified rectangular bandwidth located within the licensed band) and the antenna gain relative to isotropic in the horizontal plane containing the phase centre, in dBi (s 5). For an AAS, RP is defined as the sum of the antenna gain towards the horizontal plane and towards the azimuth and the total radiated power, reflecting the dynamic beam control assumption (Schedule 2 Part 2 note).

Level of protection (LOP) and receiver gain (Gr)

• LOP is set at −92 dBm per MHz for transmitters with an AAS and used specifically for beam-forming, and −100 dBm per MHz for all other transmitters (Schedule 2 Part 2).
• Gr, the nominal receiver antenna gain (including feeder loss set to 0 dBi for the 850/900 Upper Sub-bands and 13 dBi for the Lower Sub-bands), is explicitly specified (Schedule 2 Part 2).

Propagation loss and modelling

• PL is to be calculated using Modified Hata propagation as in ERC Report 068 (Step 1 and Step 2, Schedule 2 Part 3). The instrument references that report for the propagation model and requires the use of DEM-3S terrain data and Vincenty’s Direct Formulae for geodetic calculations (Schedules 2 and 3). This ties the device boundary to internationally-recognised propagation methodology and a specified national DEM product.

Site geometry and effective antenna height

• Location is defined as the latitude and longitude of the antenna phase centre with reference to GDA94 and measurement error less than 10 metres (Schedule 1). Effective antenna height is calculated using the antenna height above the local ground, DEM-3S cell heights, averaging of 3×3 DEM cells for each increment, and specified boundary conditions (Schedule 3 Part 1 and Part 2). There are explicit tolerances for antenna height measurement (measurement error less than 5 parts in 100) (Schedule 3 Part 1.1(a)).

Precision and confidence

• Parameters in Schedules 1-3 must be estimated with at least 95 percent confidence that the true value will always remain below the requirement specified in the instrument (s 11). This is a statistical certainty requirement that will affect modelling, measurement, and reporting practices.

Registration interaction and scope

• The instrument is made under s 145(4) of the Act and is explicitly intended to be used by the ACMA when deciding whether to include transmitter details in the Register under s 145(1) (see s 4, s 10 and the Note to s 10). However, the instrument notes that some transmitters are exempt from the requirement to be registered under s 69(2) of the Act and accordingly those exempt devices are not required to meet the device boundary criteria (Note 1 to s 10).

Special geographic carve-outs

• The instrument treats device boundary portions that lie outside the ASMG or cross particular HCIS-identified areas in a different way: s 10(2) and s 10(3) provide exemptions from being "unacceptable" for device boundary parts that lie outside the ASMG or cross over particular areas relative to the geographic area and the territorial sea baseline, subject to stated conditions.

Together, these concepts transform a legal test (unacceptable interference for the purposes of s 145(4)) into a prescriptive technical regime using specified datasets, numeric thresholds and propagation and geodetic algorithms.

Primary affected parties

• Spectrum licensees who hold licences for operation in the 850/900 MHz band. The instrument is framed around transmitters "operated under a spectrum licence issued for the 850/900 MHz band" (s 10(1)). Licensees are the principal actors who must ensure a transmitter’s operation does not produce an "unacceptable level of interference" under the instrument.
• Operators of radiocommunications transmitters and groups of transmitters: the instrument imposes requirements on individual fixed transmitters and groups (s 8; Schedule 2 Part 1.2). Where transmitters are part of a group (as strictly defined in s 8) the group device boundary method applies and RP is taken from the maximum horizontally radiated power among the group.

Secondary affected parties

• Parties who wish to have transmitter details included in the ACMA Register: the instrument specifies what ACMA will treat as "unacceptable" interference when deciding whether to include a transmitter in the Register under s 145(1) of the Act (see the Note to s 10). Inclusion in the Register is a precondition for many operational and regulatory expectations that depend on record of a site.
• Equipment manufacturers and system designers, particularly those producing active antenna systems (AAS) and beam-forming solutions. The instrument specifically treats AAS differently (Schedule 2 Part 2 note and LOP) and makes concrete demands on how RP is to be calculated for AAS.
• Site surveyors, radio-frequency engineers and consultants engaged to compute device boundaries, perform site location surveys (Schedule 1), estimate effective antenna height (Schedule 3) and compute propagation loss (Schedule 2 Part 3). The instrument mandates use of DEM-3S, Modified Hata (ERC Report 068) and Vincenty formulae , these are inputs to the engineer’s work.
• ACMA as regulator and technical approver, because it will apply these tests to decisions about registration and to whether a transmitter causes unacceptable interference under s 145(4) (s 4 and s 10). The instrument therefore changes ACMA’s technical decision rules.

Entities with limited or no effect

• Transmitters exempt from registration under s 69(2) of the Act are explicitly not required to meet the device boundary criteria (Note 1 to s 10). The instrument therefore leaves some low-impact or otherwise exempt transmitters outside its device-boundary compliance regime.
• Transmitters registered before the commencement of s 12 are subject to the older 2012 Determination for assessing unacceptability (s 12). That transitional rule affects how existing registered transmitters are assessed (s 12(2)).

Key ways behaviour must change

• Pre-deployment modelling and documentation: licensees must implement the device boundary calculation in accordance with Schedule 2 and record inputs (RP, effective antenna height, DEM-3S cells, propagation losses). The 95 percent confidence requirement (s 11) raises the evidentiary standard for modelling results.
• Site selection and equipment configuration: because s 10(1)(c) declares an operation to be unacceptable if it uses the 850/900 Lower Sub-bands with effective antenna height greater than 10 metres, site design (mast height, mounting options) and choice of sub-band are directly constrained for new deployments.
• Use of AAS and beam-forming: AAS are explicitly recognised and treated separately (Schedule 2 Part 2 note), which will affect how beam-forming systems are modelled and how their device boundaries are calculated.

Who pays

• The costs of compliance fall primarily on spectrum licensees and their contractors who must perform the modelling, measurement, site surveys and documentation required to demonstrate that device boundaries are compliant. Costs include acquiring and processing DEM-3S data, implementing Modified Hata and geodetic algorithms, and conducting site surveys to the measurement tolerances (Schedule 1 and Schedule 3).

Who decides

• Licensees decide on network design, antenna height, RP, use of AAS and grouping arrangements. ACMA decides whether a transmitter will be entered onto the Register and whether its operation could cause unacceptable interference for s 145(1) purposes, applying this Determination as the technical rule-set (see s 4 and the Note to s 10).

Duties imposed on licensees and operators

• Ensure transmissions in the 850/900 MHz band do not cause an "unacceptable level of interference" as defined in s 10. That triggers a duty to measure or estimate parameters and to calculate a device boundary in accordance with Schedule 2 (s 10(1), Schedule 2 Part 1).
• Calculate and document the location (phase centre latitude/longitude) with a measurement error less than 10 metres and follow Schedule 1 for the site location (Schedule 1 items 1-3).
• For each transmitter or group, compute the device boundary by evaluating RP − MP along radials and increments as specified (Schedule 2 Part 1). RP must be measured or estimated in the terms set out in s 5 and Schedule 2 Part 2.
• Use the specified propagation model (Modified Hata, ERC Report 068) and DEM-3S for terrain data and apply Vincenty’s Direct Formulae for geodetic calculations (Schedule 2 Part 3 and Schedule 3 Part 3).
• Ensure parameter estimates in Schedules 1-3 are made with at least 95 percent confidence that the true value will remain below the requirement in the instrument (s 11). This is an explicit duty to adopt a statistical standard in modelling and measurement.
• For fixed transmitters in the 850/900 MHz Lower Sub-bands, ensure effective antenna height does not exceed 10 metres, unless the transmitter is subject to the transitional rule in s 12 or otherwise exempt (s 10(1)(c) and s 12).
• If a transmitter incorporates an AAS and is used specifically for beam-forming, apply the LOP of −92 dBm per MHz in the device-boundary calculation; for other transmitters use −100 dBm per MHz (Schedule 2 Part 2).

Rights and operational options

• Grouping: A licensee may choose to nominate which group a transmitter belongs to where it is capable of belonging to more than one group (s 8(2) note). This gives licensees limited operational choice about whether to treat clustered antennas as a group, which will affect RP and the resulting device boundary per Schedule 2 Part 1.2.
• Transitional protection for pre-existing registers: a transmitter included in the Register during the 2012 Determination period is assessed under the 2012 Determination as it stood at the time of registration (s 12). That preserves previously-computed rights for those registered transmitters.
• Exemptions from registration: transmitters exempted from Register inclusion under s 69(2) of the Act are not required to meet device boundary criteria (Note 1 to s 10). That means some small or otherwise exempt transmitters avoid the compliance regime entirely.

Administrative and evidentiary duties

• Parties must be capable of calculating device boundaries in accordance with the instrument; failure to be able to do so is itself ground for an "unacceptable" determination (s 10(1)(d)). That creates a duty to retain the tools, data and technical competence necessary to perform the specified computations.

Decision rights of regulator

• ACMA retains the power to refuse to include transmitter details in the Register where operation could cause unacceptable interference (s 145(1) of the Act, cited in the Note to s 10). The Determination provides ACMA with the technical rule-set that defines what constitutes unacceptable interference for that purpose (s 4 and s 10).

Constraints on licence design and operation

• The instrument places a strict numerical cap on effective antenna height for transmitters operating in the Lower Sub-bands. It also prescribes receiver antenna gains (Gr) by sub-band (Schedule 2 Part 2), which will influence how licence holders design their networks to satisfy the device boundary test.

What the instrument itself provides

• The Determination is a legislative instrument made under subsection 145(4) of the Act (s 4). It does not itself create criminal or civil penalties, nor does it insert new monetary fines or offences in its text. Its enforcement mechanism is regulatory rather than penal in nature: it provides ACMA with the technical criteria to apply when exercising powers under the Act (see s 4 and the Note to s 10).

How enforcement operates under the Act (as referenced by the Determination)

• The Determination is explicitly linked to ACMA’s power under subsection 145(1) of the Act, which allows ACMA to refuse to include transmitter details in the Register if it is satisfied that operation of the transmitter could cause an unacceptable level of interference (Note 1 to s 10). The Determination defines what is to be treated as "unacceptable" for that purpose (s 10).
• The Note to s 10 signals that non-registration or refusal to register is the immediate administrative consequence contemplated by the Act and by the instrument. The instrument therefore functions as a precondition to registration: if a transmitter fails the device boundary test, ACMA may deny Registry inclusion (and any consequences that flow from non-registration will be those established in the Act).

Indirect or consequential enforcement levers

• Refusal to enter a transmitter in the Register can have pragmatic consequences for the licensee: registration is the formal record of authorised radiocommunications devices under a spectrum licence; without entry in the Register, a transmitter’s operation may be limited by legal or administrative constraints or expose a licensee to future compliance action under the Act. The Determination itself does not list those downstream consequences, it provides the standard used by ACMA when exercising existing Act powers.
• The instrument ensures that if licensees cannot calculate a device boundary (s 10(1)(d)), then the transmitter operation is treated as unacceptable; that functions as an enforcement backstop by making computability a compliance prerequisite.

Standards of proof and technical thresholds

• The instrument imposes a technical evidentiary standard: parameters in Schedules 1-3 must be estimated with at least 95 percent confidence that the true value will always remain below the requirement (s 11). This is an unusually explicit statistical burden that affects the evidentiary posture of any licence-holder seeking registration or defending an operational configuration.
• Measurement tolerances are prescribed: location measurement error should be less than 10 metres (Schedule 1 item 3) and antenna vertical height measurement error less than 5 parts in 100 (Schedule 3 Part 1.1(a)). Failure to meet these tolerances could be an enforcement risk when ACMA reviews a registration.

Limitations and practical enforcement notes in the instrument

• The Determination recognises that some transmitters are exempt from Register inclusion under s 69(2) of the Act and therefore are not brought under the device-boundary compliance regime (Note 1 to s 10). That limits the Determination’s reach; enforcement via registration refusal does not apply to exempt transmitters.
• Transitional provisions (s 12) protect transmitters registered in the 2012 period, by applying the 2012 Determination standards to those transmitters. That delays or limits enforcement changes for those existing registrations.

Implementation and capacity considerations

• Effective enforcement will require ACMA to apply numerical modelling and to review third-party modelling and site-measurement evidence. The Determination’s detailed technical prescriptions will create administrative workload and require the regulator to possess (or acquire) the technical competence and systems to replicate or validate licensee calculations, including DEM-3S usage, Modified Hata propagation calculations and Vincenty formulae (Schedules 2 and 3).

Summary

• The Determination creates administrative enforcement via ACMA’s registration power under the Act rather than through new criminal or civil penalties in the instrument itself. Its practical enforcement consequences flow from ACMA’s ability to refuse Register inclusion and from the instrument’s precise technical standards, measurement tolerances and statistical confidence requirement which a licensee must meet to avoid being treated as causing unacceptable interference.

Primary statutory relationship

• The Determination is made under subsection 145(4) of the Radiocommunications Act 1992 and is intended to be used in applying subsection 145(1) of the Act, which concerns ACMA’s discretion to refuse to include transmitter details in the Register where the operation could cause unacceptable interference (s 4; Note to s 10). The Determination therefore functions as an Act-level delegated instrument that supplies technical criteria for an Act power.

Revocation and transition

• It revokes the Radiocommunications (Unacceptable Levels of Interference , 800 MHz Band) Determination 2012 (F2012L01777) (s 3). For transmitters already included in the Register during the 2012 Determination period, s 12 provides that unacceptable interference is to be judged as it would have been under the 2012 Determination at the time of registration. That preserves the legal status of previously-registered transmitters and creates a transition layer between the two Determinations.

Cross-references to other instruments and documents

• The Determination references several external instruments and documents for technical definitions and calculation methods:
  • The Radio Regulations (ITU) are referenced for emission designator methodologies (s 7).
  • ASMG (Australian Spectrum Map Grid 2012) is the geographic grid referenced for mapping and HCIS identifiers (s 5).
  • DEM-3S (Geoscience Australia 3-Second SRTM Derived Digital Elevation Model) is required for terrain height information used in effective antenna height and average ground height calculations (s 5 and Schedule 3).
  • ERC Report 068 (Modified Hata propagation) is mandated for propagation loss calculations (Schedule 2 Part 3).
  • Vincenty’s Direct Formulae (with GRS80 ellipsoid parameters referenced by GDA94) are mandated for geodetic computations (Schedule 3 Part 3).
• Section 6 makes clear that references to other legislative instruments are references to those instruments "as in force from time to time" (s 6), so the Determination’s cross-references track updates to referenced instruments.

Interaction with registration exemptions

• The instrument explicitly acknowledges that some transmitters are exempt from the requirement to be registered under subsection 69(2) of the Act, and therefore those transmitters are not required to meet the device boundary criteria (Note 1 to s 10). That cross-reference limits the Determination’s applicability and ensures it does not override Act-based registration exemptions.

Technical standards and external material

• The Determination incorporates external technical standards and data sources by reference rather than reproducing them. This means the legal standard for "unacceptable interference" is sensitive to external technical material (e.g., ERC Report 068, DEM-3S, ITU Radio Regulations). Section 6 confirms that references to other kinds of instrument or writing are references "as in force or existing from time to time", so changes to those external documents can alter the practical application of the Determination unless further legislative action is taken.

Administrative law considerations

• Because the Determination fixes technical standards that ACMA will use in its s 145 decisions, it interacts with administrative law review of ACMA decisions. The instrument sets the law that a reviewing court or tribunal would apply when assessing ACMA's exercise of discretion under s 145(1), but the Determination itself does not provide internal appeal rights; those remain as provided in the Act and in administrative law generally.

Geographic law interaction

• The Determination refers to the Australian territorial sea baseline as defined in the Seas and Submerged Lands Act 1973 when delineating special cases (s 10(4)). It also uses HCIS identifiers and the ASMG to relate device boundary calculations to mapped geographic areas (s 5 and s 10(2)-(3)). Thus it interacts with maritime baseline measurement law and with spatial grid systems used elsewhere in Commonwealth radiocommunications regulation.

Scope limits

• The Determination does not create offences or penalties itself; enforcement and consequential action will be through the Act (see earlier section). It also does not purport to alter the underlying licensing conditions (core conditions) of spectrum licences themselves; rather it clarifies what counts as an unacceptable interference level for the purposes of ACMA’s registration decision-making powers under the Act (s 10 and s 4).

Revocation and replacement

• The instrument revokes the earlier Radiocommunications (Unacceptable Levels of Interference , 800 MHz Band) Determination 2012 (F2012L01777) (s 3). It is the legislative successor and thus represents the current version of the delegated technical rules for the 850/900 MHz band.

Commencement

• The Determination commences at the start of the day after it is registered on the Federal Register of Legislation (s 2). The instrument itself does not provide the date of registration in its text; the operative date is therefore the day after the registration entry made on the Federal Register.

Transitional regime

• Section 12 creates a specific transition for transmitters that were included in the Register in the period commencing on the day the 2012 Determination commenced and ending at the commencement of s 12. Those transmitters are to be assessed, for the purposes of s 145(4) of the Act, against the 2012 Determination as it applied at the time they were included in the Register (s 12(2)). That is an explicit grandfathering mechanism which preserves the legal and technical expectations of transmitters that were registered under the prior instrument.

References to and dependence on external, updating documents

• Section 6 makes express that references to any other legislative instrument are references to that instrument as in force from time to time and that references to other kinds of instrument or writing are references as in force or existing from time to time. This means the Determination’s operational content is partially elastic, depending on updated versions of the Radio Regulations, ERC Report 068, DEM-3S dataset versions, ASMG, and other referenced documents. Any change to those external technical documents or data sets that are incorporated "as in force from time to time" can alter the way the Determination is applied in practice unless ACMA or the Attorney-General updates the Determination.

No internal amendment history recorded in the text

• The instrument does not list amendments or multiple versions within itself. The only internal historical references are the revocation of the 2012 Determination and the transition provision for pre-existing registered transmitters (s 3 and s 12). Any subsequent amendments to this Determination would be recorded in the Federal Register of Legislation and are not present in the version supplied here.

Operational implications of amendment mechanics

• Because the Determination references external instruments and datasets "as in force", operators and advisers must monitor both (a) whether the Determination itself is amended or remade, and (b) whether the external technical documents it depends upon change. The cross-reference approach reduces drafting friction for the legislator but increases compliance surveillance duties on licensees.

Documented litigation within the instrument

• The Determination contains no references to court or tribunal decisions, and the text does not cite any litigation or adjudicative history. It does not name cases. The instrument therefore provides no internal litigation history.

Practical litigation considerations that arise from the text

• The Determination creates a technical standard that ACMA will apply to registration decisions under s 145 of the Act. That means disputes about ACMA’s decisions may be amenable to administrative review and judicial review channels provided by the Act and administrative law. However, the instrument itself does not describe dispute resolution or appeal pathways; those remain the procedures established by the Act and general administrative law.
• Where a licensee's modelling or measurement is challenged, the deterministic nature of the device-boundary calculation (Schedules 1-3) points litigation or review scrutiny towards:
  • Whether the licensee used the mandated datasets (DEM-3S, ASMG) and models (Modified Hata ERC Report 068) and geodetic formulae (Vincenty);
  • Whether the licensee met the numeric tolerances for measurement error (location <10 m, antenna height <5 parts in 100) and the 95 percent confidence requirement (s 11);
  • How RP, Gr and LOP were determined and whether the AAS-specific RP treatment was properly applied.
• Administrative review would likely focus on whether ACMA correctly applied the Determination to the facts and whether any discretion exercised by ACMA was lawful, rational and procedurally fair. The instrument narrows ACMA’s technical discretion by supplying specific formulae; that may channel judicial review to questions of correct application and of whether underlying technical facts were correctly established.

Evidence and expert testimony likely to be central

• Any dispute about a registration decision based on this Determination will be technical. Expert evidence on DEM-3S interpretation, propagation loss calculations, antenna phase centre location measurement, and implementation of Modified Hata is likely to be decisive. The Determination’s requirement for 95 percent confidence may also raise issues about statistical methodologies and whether modelling assumptions were reasonable.

Absence of precedent in the instrument

• Because the Determination names no cases and lists no adjudications, users must infer likely litigation themes from the technical prescriptions themselves. The deterministic, prescriptive nature of the device-boundary calculations reduces some scope for argument over standards, but increases the technical intensity of disputes.

Precision and statistical requirement

• s 11 requires that parameter values in Schedules 1-3 be estimated "with a level of confidence not less than 95 percent that the true value of the parameter will always remain below the requirement specified in this instrument." This is not a casual precision requirement. It imposes a statistical standard that affects modelling choices, safety margins and reporting. Practical consequence: conservative modelling, additional measurements, and statistical documentation are necessary; ad hoc or single-point estimates will not meet the stated standard.

Uncomputable device boundary equals automatic unacceptability

• Under s 10(1)(d), if the device boundary cannot be calculated in accordance with Part 1 of Schedule 2, the interference is "unacceptable." This creates implementation risk: failure to have the correct terrain data, geodetic computation routines (Vincenty), or the ability to run Modified Hata calculations means a transmitter may be treated as unacceptable irrespective of its actual emissions. Licensees must maintain the computational capability and required datasets.

AAS special treatment may be counter‑intuitive

• The Determination sets LOP at −92 dBm per MHz for AAS used specifically for beam-forming, and −100 dBm per MHz for others (Schedule 2 Part 2). That difference affects the device boundary via MP = PL + LOP − Gr and the comparison RP − MP. Practically, the less negative LOP for AAS (−92) typically reduces the radial distance at which RP − MP ≤ 0 is satisfied, producing a smaller device boundary for AAS beam‑forming sites compared with conventional sites, all else equal. Users must model this carefully; the instrument assumes dynamic beam control can limit RP in a bearing (Schedule 2 Part 2 note).

Receiver antenna gain differences by sub-band

• Gr is set to 0 dBi for Upper sub-bands and 13 dBi for Lower sub-bands (Schedule 2 Part 2). Because Gr enters MP with a minus sign (MP = PL + LOP − Gr), higher Gr increases the device boundary (more protective). The instrument thus treats receivers in the Lower sub-bands as having higher nominal gain, which materially changes device boundary size by sub-band. Operators must not assume uniform receiver characteristics across bands.

Hard cap on effective antenna height in Lower sub-bands

• Section 10(1)(c) defines operation in the 850 MHz Lower or 900 MHz Lower Sub-bands with effective antenna height greater than 10 metres as unacceptable. This is an absolute rule applying to new operations under the Determination (subject to s 12 for pre-registered transmitters). Network design that contemplates elevated base-stations or towers in lower sub-bands must be reworked or justified under the transitional rule. Check Schedule 3 for the detailed effective height calculation; the measurement tolerances are non-trivial (antenna vertical height measurement error less than 5 parts in 100).

Radial and increment discretisation

• Device boundaries are computed on radials at each integer degree (0-359) and increments m = 2 to 530 (m×100 m). That means the device boundary is insensitive to features inside 200 m of the site (m starts at 2) and is limited to 53 km (m = 530). Operators must ensure modelling software respects the increment grid and understand the discrete sampling nature of the test.

DEM-3S cell boundary rules and the 3×3 averaging step

• Average ground height at an increment is the mean of the DEM-3S cell and its eight adjacent cells (Schedule 3 Part 2). Where an increment sits on a DEM-3S cell boundary there are rules about selecting the adjacent cell with minimum height in particular modulus cases (Schedule 3 Part 2.2 and related notes). Small errors in cell referencing or rounding can change effective antenna height calculations; site surveys and DEM handling must be precise.

Group definition is strict and can be operationally constraining

• A "group" of transmitters must meet strict conditions (s 8(1)): same centre frequency and emission designator; same receiver purpose; same antenna type/model/manufacturer; antennas on same structure and within 20 m of each other; same ACMA antenna identification number. A transmitter cannot belong to more than one group (s 8(2)). These rules restrict how operators aggregate power for compliance modelling and create choices about whether to nominate grouping where a transmitter could belong to more than one.

Transitional grandfathering limits immediate disruption but also complicates planning

• s 12 preserves the 2012 Determination standard for transmitters registered during the 2012 instrument period. That creates a mixed-regime where older registered sites are assessed under a different technical standard than new sites, complicating interference negotiations and co-ordination in practice.

Dependency on external documents and data sets

• The Determination requires use of ERC Report 068 (Modified Hata), the ITU Radio Regulations for emission designators, DEM-3S, ASMG and GDA94. These are external to the instrument and (per s 6) are taken "as in force from time to time." Changes in those external documents, updates to DEM-3S releases or revisions to ERC Report 068 practice can materially affect device boundary calculations. Operators must monitor such changes.

Nominal measurement and "good engineering practices"

• The definition of "maximum true mean power" contains a Note that measurement and estimation practices should be "in accordance with good engineering practices." That phrase is not defined in the instrument; it leaves unquantified expectations that may be contested in review processes. Combine this with the 95 percent confidence requirement and the measurement tolerances and operators face a non-trivial evidentiary obligation.

Geographic carve-outs

• s 10(2) and s 10(3) carve out some parts of device boundaries from the "unacceptable" label where the device boundary lies outside the ASMG or crosses certain radials that do not cross specified other licences or land permanently above the territorial sea baseline or particular HCIS areas. These rules are technical and map-dependent. Misapplication can change whether a particular radial endpoint is deemed unacceptable.

Stepwise compliance checklist (practical, document-ready)

1. Confirm legal status and applicability

   • Verify whether the transmitter is subject to the Determination: is it a fixed transmitter operated under a spectrum licence in the 850/900 MHz band (s 10(1))? If it was included in the Register during the 2012 Determination period, read s 12 to determine whether the 2012 standard applies instead (s 12(1)-(2)). If the transmitter is exempt from registration under s 69(2) of the Act, the device-boundary criteria do not apply (Note 1 to s 10).

2. Establish site location and measurement tolerances

   • Determine the phase-centre latitude and longitude (GDA94) for the transmitter site and ensure the measurement error is less than 10 metres (Schedule 1 items 1-3). Use the ACMA site identifier if one is issued and follow ACMA’s Business Operating Procedure for site data if needed (Schedule 1 notes).

3. Determine antenna vertical height and measurement precision

   • Measure antenna vertical height hgt with an error of less than 5 parts in 100 (Schedule 3 Part 1.1(a)). Check Schedule 3 for the reference point (line of intersection between supporting structure and ground/sea surface) and the requirement to use DEM-3S cell heights when computing hs and effective antenna height.

4. Compute effective antenna height

   • Use Schedule 3 Part 1 formulae and Diagram 1 to calculate effective antenna height, applying DEM-3S cell heights and the 3×3 averaging method for average ground height at each increment (Schedule 3 Part 2). Observe special rules when the site coordinates lie on DEM-3S cell boundaries (Schedule 3 Part 1 note and Part 2.2).

5. Check the 10-metre cap for Lower sub-bands

   • If the transmitter will operate in the 850 MHz Lower Sub-band (814-845 MHz) or the 900 MHz Lower Sub-band (890-915 MHz), verify that the effective antenna height is not greater than 10 metres. If it is greater and the transmitter is not grandfathered by s 12, the operation is defined as unacceptable (s 10(1)(c)).

6. Decide grouping and record choices

   • If multiple fixed transmitters might form a group, ensure they meet the strict group definition in s 8(1) (same centre frequency and emission designator, same receiver purpose, identical antenna type/model/manufacturer, antennas on the same structure within 20 m, and same ACMA antenna ID). If a transmitter could belong to more than one group nominate which group it belongs to (s 8(2) note). For groups, RP is the maximum horizontally radiated power among members in any direction (Schedule 2 Part 1.2).

7. Determine RP, Gr and LOP inputs

   • Measure or estimate RP (horizontally radiated power in dBm EIRP per MHz) according to s 5 and Schedule 2 Part 2. For an AAS used specifically for beam-forming, account for RP as the sum of antenna gain toward the horizontal plane and toward azimuth plus total radiated power (Schedule 2 Part 2 note).
   • Set Gr per the sub-band: 0 dBi for 850/900 Upper Sub-bands and 13 dBi for 850/900 Lower Sub-bands (Schedule 2 Part 2).
   • Choose LOP according to whether the transmitter is an AAS used specifically for beam-forming (LOP = −92 dBm/MHz) or not (LOP = −100 dBm/MHz) (Schedule 2 Part 2).

8. Calculate propagation loss PL

   • Use Modified Hata propagation as set out in ERC Report 068, and implement Step 1 and Step 2 in Schedule 2 Part 3. Use the centre frequency f, the effective antenna height, receiver antenna height hgr, and the distance d(lmn, Lmn) as inputs. Ensure computation adheres to the formulae provided and that DEM-3S terrain inputs are correctly used.

9. Compute device boundary per Schedule 2 Part 1

   • For each bearing σn (0-359 degrees) and each increment m = 2..530 (m × 100 m), compute RP − MP where MP = PL(lmn, Lmn) + LOP − Gr. Identify the first increment at which RP − MP ≤ 0 or m = 530. Record the latitude/longitude of each radial endpoint using Vincenty’s Direct Formulae (Schedule 3 Part 3). The endpoints constitute the device boundary.

10. Satisfy the 95% confidence requirement

    • For parameters required by Schedules 1-3, document the statistical methods and uncertainties and demonstrate an estimation confidence of at least 95 percent that the true value remains below the specified requirement (s 11). Keep methodological documentation and the statistical basis for any safety margins.

11. Prepare documentation and evidence for ACMA

    • Retain and submit (if required) the DEM-3S data extracts, Modified Hata computation logs, Vincenty geodetic calculation outputs, antenna phase-centre survey reports, RP measurement protocols and results, and the statistical confidence documentation. Ensure that measurement instruments and protocols align with "good engineering practices" as noted for power measurements (s 5 Note).

12. Pre-empt device boundary calculability issues

    • Confirm that the device boundary can in fact be calculated (access to DEM-3S and ASMG, ability to run Modified Hata and Vincenty routines). If the device boundary cannot be computed, the operation is automatically unacceptable (s 10(1)(d)); resolve data or computational gaps before applying for registration.

13. Account for special geographic and HCIS carve-outs

    • Evaluate radials that lie outside the ASMG or cross land outside the geographic area related to territorial sea baseline or specific HCIS identifiers; apply s 10(2) and s 10(3) where relevant. Map-based checks against ASMG and HCIS are required.

14. Maintain change control and re-evaluate after changes

    • Recompute device boundaries after changes in transmitter power, antenna height, antenna type, installation or after any software, dataset (DEM-3S), or propagation-model updates that are relevant. Because the Determination references external documents "as in force from time to time" (s 6), operators should re-evaluate if referenced datasets or standards are updated.

Operational and procurement implications

• Procurement of modelling tools: Acquire or contract software that implements Modified Hata (ERC Report 068) and Vincenty formulae reliably and supports DEM-3S inputs and the radial/increment sampling described in Schedule 2. Validate tools against known test-cases.
• Site surveys: Commission qualified surveyors to document antenna phase-centre location to the <10 m location error and antenna height to <5 parts in 100 measurement error. Document survey methodology and equipment calibration.
• AAS-specific controls: If using an AAS, ensure the network control logic and documentation support the RP assumptions (dynamic beam control, steering angles and power control) that underlie the Determination’s AAS RP note and LOP choice.
• Record-keeping and readiness for ACMA review: Keep modelling inputs, outputs, measurement certificates, and the 95 percent confidence analysis available for ACMA review during registration processes or compliance checks.

If in doubt

• Use the ACMA resources referenced in the instrument: ASMG and DEM-3S are publicly available (s 5 notes), and ACMA provides guidance such as the Business Operating Procedure for site data requirements (Schedule 1 notes). Where technical judgement is required (e.g., establishing "good engineering practices" for power measurement), document conservative assumptions and the statistical basis for those choices.

Compliance is technical, document-intensive and continuous; a single missing dataset, a computation error, or an inadequate confidence assessment can transform a compliant design into an "unacceptable" operation under the Determination.