{"id":"F2025L01052","name":"Radiocommunications (Unacceptable Levels of Interference – 3.4 GHz Band) Determination 2025","slug":"radiocommunications-unacceptable-levels-of-interference-3-4-ghz-band-determination-2025","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":106790,"registerId":"commonwealth-F2025L01052-current","compilationNumber":null,"startDate":"2026-04-03","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"Name","content":"#### 1 Name\n\n  This is the Radiocommunications (Unacceptable Levels of Interference – 3.4 GHz Band) Determination 2025.","sortOrder":0},{"sectionNumber":"2","sectionType":"section","heading":"Commencement","content":"#### 2 Commencement\n\n  This instrument commences on 23 September 2025.\n\n> Note: The Federal Register of Legislation is available, free of charge, at www.legislation.gov.au.","sortOrder":1},{"sectionNumber":"3","sectionType":"section","heading":"Authority","content":"#### 3 Authority\n\n  This instrument is made under subsection 145(4) of the Act.","sortOrder":2},{"sectionNumber":"4","sectionType":"section","heading":"Repeal of the Radiocommunications (Unacceptable Levels of Interference — 3.4 GHz Band) Determination 2015","content":"#### 4 Repeal of the Radiocommunications (Unacceptable Levels of Interference – 3.4 GHz Band) Determination 2015\n\n  The Radiocommunications (Unacceptable Levels of Interference – 3.4 GHz Band) Determination 2015 \\[F2015L00727\\] is repealed.","sortOrder":3},{"sectionNumber":"5","sectionType":"section","heading":"Definitions","content":"#### 5 Definitions\n\n  (1) In this instrument, unless the contrary intention appears:\n\n> 3.4 GHz band means the frequency band 3400 MHz to 3800 MHz.\n\n> 3.4 GHz spectrum licence means a spectrum licence that authorises the operation of radiocommunications devices in the 3.4 GHz band.\n\n> device boundary: see item 1 of Schedule 1.\n\n> device boundary criterion: see item 2 of Schedule 1.\n\n> earth station protection zone: see Schedule 2.\n\n> Recommendation ITU-R P.525-4 means the ITU-R Recommendation “P.525-4 Calculation of free-space attenuation”.\n\n> Note: The ITU-R Recommendations are available, free of charge, from the International Telecommunication Union’s website at www.itu.int.\n\n> Recommendation ITU-R P.526-15 means the ITU-R Recommendation “P.526-15 Propagation by diffraction”.\n\n> Note: The ITU-R Recommendations are available, free of charge, from the International Telecommunication Union’s website at www.itu.int.\n\n> Recommendation ITU-R P.2108-0 means the ITU-R Recommendation “P.2108-0 Prediction of clutter loss”.\n\n> Note: The ITU-R Recommendations are available, free of charge, from the International Telecommunication Union’s website at www.itu.int.\n\n> urban area: see Schedule 3.\n\n> Note 1: A number of other expressions used in this instrument are defined in the Act, including the following:\n\n    (a) ACMA;\n    (b) core condition;\n    (c) frequency band;\n    (d) interference;\n    (e) radiocommunications device;\n    (f) radiocommunications receiver;\n    (g) radiocommunications transmitter;\n    (h) radio emission;\n    (i) Register;\n    (j) spectrum licence.\n\n> Note 2: A number of other expressions used in this instrument may be defined in the Radiocommunications (Interpretation – Technical Framework) Determination 2024 or another instrument made under subsection 64(1) of the Australian Communications and Media Authority Act 2005 to replace it, including the following:\n\n    (a) AAS;\n    (b) Act;\n    (c) Australian Spectrum Map Grid;\n    (d) Australian territorial sea baseline;\n    (e) average ground height;\n    (f) EIRP;\n    (g) geographic area;\n    (h) group of radiocommunications transmitters;\n    (i) HCIS identifier;\n    (j) horizontally radiated power;\n    (k) ITU-R Recommendation;\n    (l) location;\n    (m) occupied bandwidth.\n  (2) In this instrument, unless otherwise specified, a reference to a part of the spectrum or a frequency band includes all frequencies that are greater than but not including the lower frequency, up to and including the higher frequency.\n\n> Note: This subsection means the lower number in a part of the spectrum or a frequency band is not included in the frequency band.","sortOrder":4},{"sectionNumber":"6","sectionType":"section","heading":"References to other instruments","content":"#### 6 References to other instruments\n\n  In this instrument, unless the contrary intention appears:\n    (a) a reference to any other legislative instrument is a reference to that other legislative instrument as in force from time to time; and\n    (b) a reference to any other kind of instrument or writing is a reference to that other instrument or writing as in force or existing from time to time.\n\n> Note 1: For references to Commonwealth Acts, see section 10 of the Acts Interpretation Act 1901; and see also subsection 13(1) of the Legislation Act 2003 for the application of the Acts Interpretation Act 1901 to legislative instruments.\n\n> Note 2: All Commonwealth Acts and legislative instruments are registered on the Federal Register of Legislation.\n\n> Note 3: See section 314A of the Act.","sortOrder":5},{"sectionNumber":"7","sectionType":"section","heading":"Unacceptable levels of interference","content":"#### 7 Unacceptable levels of interference\n\n  (1) A level of interference caused by a radiocommunications transmitter operated under a 3.4 GHz spectrum licence is unacceptable if:\n    (a) the operation of the transmitter results in a contravention of a core condition of the licence relating to the maximum permitted level of radio emission from the transmitter:\n    (i) outside the parts of the spectrum the use of which is authorised under the licence; or\n    (ii) outside the geographic area of the licence; or\n    (b) subject to subsections (2) to (5), any part of the device boundary of the transmitter lies outside of the geographic area of the licence; or\n    (c) the device boundary of the transmitter cannot be calculated in accordance with item 1 of Schedule 1; or\n    (d) the transmitter is on an aircraft.\n  (2) A level of interference mentioned in paragraph (1)(b) is not unacceptable in relation to a part of the device boundary that:\n    (a) lies outside the Australian Spectrum Map Grid; and\n    (b) is connected to a radial that:\n    (i) is mentioned in item 1 of Schedule 1; and\n    (ii) does not cross over the geographic area of another 3.4 GHz spectrum licence.\n  (3) A level of interference mentioned in paragraph (1)(b) is not unacceptable in relation to a part of the device boundary that:\n    (a) lies outside the geographic area of the licence; and\n    (b) lies inside an earth station protection zone;\n    (c) is connected to a radial that:\n    (i) is mentioned in item 1 of Schedule 1; and\n    (ii) does not cross over the geographic area of another 3.4 GHz spectrum licence.\n  (4) A level of interference mentioned in paragraph (1)(b) is not unacceptable in relation to a part of the device boundary that:\n    (a) lies outside the geographic area of the licence; and\n    (b) is connected to a radial that:\n    (i) is mentioned in item 1 of Schedule 1; and\n    (ii) does not cross over land outside the geographic area of the licence that is permanently above the Australian territorial sea baseline; and\n    (iii) does not cross over any of the following HCIS identifiers: IW3E, IW3I, IW3M, IW6A, IW6E, KX9, LX7, LX8, LX9.\n\n> Note: The HCIS identifiers beginning with IW describe an area near Adelaide. The HCIS identifiers beginning with KX and LX describe an area in the Bass Strait.\n\n  (5) A level of interference mentioned in paragraph (1)(b) is not unacceptable in relation to a part of the device boundary that:\n    (a) lies outside the geographic area of the licence; and\n    (b) lies inside an urban area; and\n    (c) relates to the operation of a radiocommunications transmitter with an occupied bandwidth contained in the 3400 MHz to 3475 MHz frequency band; and\n    (d) is connected to a radial that:\n    (i) is mentioned in item 1 of Schedule 1; and\n    (ii) does not cross over the geographic area of another 3.4 GHz spectrum licence.\n  (6) This section does not apply in relation to a radiocommunications transmitter to which section 9 applies.\n\n> Note: Subsection 145(1) of the Act provides that the ACMA may refuse to include in the Register details of a radiocommunications transmitter if the ACMA is satisfied that operation of the transmitter could cause an unacceptable level of interference to the operation of other radiocommunications devices. However, some radiocommunications transmitters are exempt from the requirement to be registered in the Register under their 3.4 GHz spectrum licence – see subsection 69(2) of the Act. Accordingly, these transmitters are not required to meet the device boundary criterion specified in this instrument.","sortOrder":6},{"sectionNumber":"8","sectionType":"section","heading":"Accuracy","content":"#### 8 Accuracy\n\n  Unless otherwise specified, the value of a parameter in Schedule 1 must 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.","sortOrder":7},{"sectionNumber":"9","sectionType":"section","heading":"Transitional — radiocommunications transmitter registered before commencement of this instrument","content":"#### 9 Transitional – radiocommunications transmitter registered before commencement of this instrument\n\n  (1) If a radiocommunications transmitter was included in the Register in relation to a 3.4 GHz spectrum licence before the commencement of this instrument (relevant transmitter), and is taken to cause an unacceptable level of interference under section 7, this section applies to that transmitter.\n  (2) Subject to subsection (3), for the purposes of subsection 145(4) of the Act, a level of interference caused by a relevant transmitter is unacceptable if it would have been unacceptable under the Radiocommunications (Unacceptable Levels of Interference – 3.4 GHz Band) Determination 2015, as in force at the time the relevant transmitter was included in the Register.\n\n> Note: The Radiocommunications (Unacceptable Levels of Interference – 3.4 GHz Band) Determination 2015 is available, free of charge, from the Federal Register of Legislation at www.legislation.gov.au.\n\n  (3) For the purposes of subsection 145(4) of the Act, if:\n    (a) after the commencement of this instrument, both:\n    (i) a detail of a relevant transmitter changes (relevant change); and\n    (ii) the change to the detail is recorded in the Register; and\n    (b) the distance of the new device boundary of the relevant transmitter is, on each radial mentioned in item 1 of Schedule 1, equal to or less than the distance of the old device boundary of the relevant transmitter on that radial; and\n    (c) but for the effect of this subsection, a level of interference caused by the relevant transmitter, immediately after the change time, would be unacceptable;\n  the level of interference caused by the relevant transmitter, immediately after the change time, is not unacceptable because of the relevant change.\n  (4) In subsection (3):\n\n> change time, for a relevant transmitter, means the time the relevant change is recorded in the Register.\n\n> new device boundary, of a relevant transmitter, means the device boundary of the transmitter immediately after the change time, in accordance with this instrument as in force at the change time.\n\n> old device boundary, of a relevant transmitter, means the device boundary of the transmitter immediately before the change time, in accordance with the Radiocommunications (Unacceptable Levels of Interference – 3.4 GHz Band) Determination 2015, as in force at the registration time.\n\n> registration time, for a relevant transmitter, means the time the transmitter was included in the Register.","sortOrder":8}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":7,"scope_assessment":{"changed":false,"description":"This is a straightforward repeal and replacement of the 2015 Determination with the same core purpose: defining unacceptable interference levels for the 3.4 GHz band. While it updates technical methodologies (incorporating newer ITU recommendations and AAS technology considerations), it does not expand beyond the original scope of regulating interference for this specific spectrum band."},"complexity_factors":["Extensive cross-referencing to three separate ITU-R international technical recommendations (P.525-4, P.526-15, P.2108-0) for propagation loss calculations","Mathematical device boundary criterion formula (RP – MP) with multiple nested variables and conditional logic based on antenna type (AAS vs non-AAS)","Four separate exception provisions in section 7 (subsections 2–5) with overlapping but distinct conditions involving geographic boundaries, HCIS identifiers, urban areas, and earth station protection zones","Transitional provisions in section 9 creating a dual-regime test (old vs new determination) with defined terms specific to the transition ('change time', 'old device boundary', 'new device boundary')","Technical calculation methodology in Schedule 1 requiring 360 radial calculations (0–359 degrees) at 100-metre increments up to 101 km","Multiple defined terms (11 in section 5) plus implicit definitions through references to the Radiocommunications Act and the Radiocommunications (Interpretation – Technical Framework) Determination 2024","Conditional antenna height calculations with 5% error tolerance requirements","Specific HCIS identifier lists for protected zones and urban areas requiring geographic lookup tables"],"plain_english_summary":"This instrument sets technical rules for what counts as \"unacceptable interference\" in the 3.4 GHz (3400–3800 MHz) band used for 5G, applying to spectrum licence holders, the ACMA and anyone operating transmitters under those licences. It updates a 2015 rule, defines device‑boundaries and permitted spillover zones (including certain coastal, satellite‑protection and major urban exceptions), includes transitional protections for existing equipment, and requires 95% confidence in calculations.  \n\nIt matters because it lets telcos build networks while protecting other radio users, satellites and emergency services from harmful interference."},"flash_summary":{"complexity_score":8,"scope_assessment":{"changed":false,"description":"This instrument primarily updates and consolidates technical prescriptions and geographic carve-outs for determining when interference in the 3.4 GHz band is \"unacceptable\". It repeals the 2015 determination and replaces it with more detailed, model-based rules (device boundary algorithm, specific ITU methods, AAS-specific protection level, accuracy standard, and named protection zones). These are technical refinements rather than a substantive expansion of the statutory power: the Act already authorised treating certain interference as unacceptable (s145), and this instrument specifies the measurement and mapping rules. The practical scope (who is regulated — holders of 3.4 GHz spectrum licences — and the legal trigger — unacceptable interference) is unchanged; what changed is the level of technical detail, added exceptions and updated propagation methodology."},"complexity_factors":["Extensive technical prescription for device boundary: 360 radials (0–359 degrees) sampled at 100 m increments m = 2..1010 (Schedule 1, item 1) — up to 101 km per radial","Device boundary criterion combines multiple parameters (RP, PL, LOP, Gr) with different definitions depending on equipment (Schedule 1, item 2)","Different propagation calculation methods depending on antenna height (>6 m vs ≤6 m) with references to three ITU Recommendations (P.525-4, P.526-15, P.2108-0) and multiple sub‑rules (Schedule 1, item 3)","Multiple conditional exceptions to the core rule on out‑of‑area device boundary being \"unacceptable\" (s7(2)–(5)) — geographic-grid, earth station zones, sea/HCIS exclusions, urban-area/sub-band exception","Two different LOP values depending on whether transmitter uses AAS (-90 dBm per MHz) or not (-98 dBm per MHz) (Schedule 1, item 2) and an assumption about dynamic beam control for AAS (note)","Cross-references to the Act, the Radiocommunications (Interpretation – Technical Framework) Determination 2024 and multiple other instruments for definitions and procedures (s5, s6 and notes)","Precision requirements: antenna height measured to <5% error, 95% confidence accuracy requirement for estimated parameters (item 4 and s8)","Schedules contain many HCIS identifiers that map to geographic policy areas (Schedules 2 and 3), increasing mapping and administrative work","Transitional provisions tying treatment of existing registered transmitters to previous (2015) determination with conditional carve‑outs (s9)","Group-of-transmitters rule where RP equals the maximum horizontally radiated power of any transmitter in the group (Schedule 1, item 1(2)) creates aggregation effects and additional calculation complexity"],"plain_english_summary":"**What this instrument does (mechanics)\n\n- Replaces the 2015 \"3.4 GHz band\" interference determination with updated technical rules for when interference from transmitters operating under a 3.4 GHz spectrum licence is treated as \"unacceptable\" (see s7).  The instrument comes into force on 23 September 2025 (s2) and is made under subsection 145(4) of the Radiocommunications Act (s3).\n\n- It defines a mandatory way to draw a \"device boundary\" for each transmitter (Schedule 1, item 1). The device boundary is produced by sampling along every degree of bearing (0–359) in 100 metre steps (m = 2 to 1010), finding the first point on each radial where a numeric test (the device boundary criterion, RP – MP) falls to zero or less, or the sample limit is reached (Schedule 1, item 1(1)–(2)).\n\n- The device boundary criterion is RP – MP, where RP is the horizontally radiated power (dBm EIRP per MHz) and MP is the sum of path loss, a set protection level (LOP), and receiver antenna parameters (Schedule 1, item 2).\n\n- Path loss (PL) is calculated by reference to ITU methods (P.525, P.526, and for low antennas P.2108) with specific parameter choices and sampling (Schedule 1, item 3 and notes). The rules treat antennas above 6 m differently to lower antennas (Schedule 1, item 3(1)). Antenna height measurement rules are provided (item 4).\n\n- The instrument sets different protection levels depending on whether the transmitter uses an adaptive antenna system (AAS): LOP = -90 dBm per MHz for AAS; LOP = -98 dBm per MHz for other transmitters (Schedule 1, item 2).\n\n- The instrument lists specific geographic exceptions where parts of a device boundary outside a licence area are not treated as \"unacceptable\" — for example, portions outside the Australian Spectrum Map Grid, portions inside specified earth station protection zones (Schedule 2), or portions that lie inside defined urban areas for a sub-band (3400–3475 MHz) (s7(2)–(5)).\n\n- There is an accuracy requirement for parameter estimates: values used in the calculations must be estimated with at least 95% confidence that the true value will remain below the requirement (s8).\n\n- Transitional provisions apply to transmitters registered before commencement: generally those continue to be judged under the 2015 rules unless certain post‑commencement changes reduce the new device boundary relative to the old one (s9).\n\nWho this affects and who decides\n\n- Primary compliance obligations fall on holders of 3.4 GHz spectrum licences and operators of radiocommunications transmitters under those licences. They must ensure each transmitter’s device boundary can be calculated and meets the RP–MP test, or else its level of interference is \"unacceptable\" (s7 & Schedule 1).\n\n- The Australian Communications and Media Authority (ACMA) is the decision-maker that may refuse to record or may remove transmitter details from the Register where operation could cause unacceptable interference (note to s7; instrument is made under s145(4) of the Act (s3)).\n\nWhy it matters (stated purpose and practical effects)\n\n- The instrument operationalises the Act’s existing power to treat certain transmitter operation as creating \"unacceptable\" interference (s7), by setting a precise, reproducible algorithm for mapping where a transmitter could cause harmful interference. That creates predictable geographic limits (device boundaries) and a technical compliance test.\n\n- Stated policy effects: to protect other spectrum users, including fixed earth stations (through named earth station protection zones in Schedule 2), and to manage co-existence in the 3.4 GHz band by defining how much radiated power is tolerable at different distances and directions.\n\nCosts, incentives and trade-offs (implementation, compliance and market effects)\n\n- Compliance burden: licensees must perform detailed propagation calculations (ITU procedures), sample every degree of azimuth at 100 m resolution out to up to 101 km per radial, and demonstrate 95% confidence in parameter estimates (Schedule 1; s8). That requires modelling expertise, mapping data, and possibly software or consultant expense.\n\n- Operational incentives: because the device boundary depends on horizontally radiated power and antenna gain/height, licence holders are incentivised to limit horizontally radiated power, control antenna heights, or use beam control (AAS) subject to the tighter LOP for AAS (-90 dBm per MHz) vs -98 dBm per MHz for other transmitters (Schedule 1, item 2). For groups of transmitters the RP is the maximum horizontally radiated power (Schedule 1, item 1(2)), which discourages aggregating many transmitters at different orientations without managing peak emissions.\n\n- Effects on private decision-making: the rules constrain where a transmitter can be operated without being treated as causing unacceptable interference, which may influence site selection, antenna mounting, power settings, and whether to register particular transmitters. Aircraft-mounted transmitters are explicitly treated as unacceptable (s7(1)(d)).\n\n- Concentrated vs diffuse impacts: benefits (reduced interference) accrue to other spectrum users and protected earth stations (Schedules 2 & 3), while costs (modelling, reduced coverage area, equipment/site changes) fall on licence holders. Where exceptions exist (e.g. limited radials that do not cross another licence area), licence holders gain operational flexibility.\n\n- Implementation risks and discretion: the instrument relies on precise inputs (antenna phase centre heights, average ground height, HCIS grid mapping) and external ITU recommendations. Mistakes in inputs or differing interpretations of the external procedures could produce disputes with ACMA. ACMA retains the regulatory power under the Act to refuse or remove Register entries where interference would be unacceptable (note to s7).\n\nSpecific, concrete behavioural changes required\n\n- Licence holders must compute device boundaries per the algorithm and keep Register details accurate; if a transmitter’s device boundary falls outside its licensed geographic area (subject to listed exceptions), the interference is treated as unacceptable and ACMA may refuse registration or require remedial steps (s7, Schedule 1, s9).\n\n- Where transmitters use adaptive antenna systems (AAS), licence holders must account for a different protection level and the instrument assumes dynamic control of beam pointing/power when determining RP (Schedule 1, item 2, Note 1).\n\nLimitations, caveats and official rationale\n\n- The instrument’s stated legal basis is subsection 145(4) of the Act (s3). The document provides technical rules rather than a policy justification; any policy claims in explanatory materials should be tested against the costs and incentives above. The instrument also explicitly preserves a transitional regime for pre-existing registered transmitters (s9), limiting the immediate practical effect of some changes for already-registered sites.\n\nKey sections to consult in the instrument: s7 (definition of unacceptable interference), Schedule 1 items 1–4 (device boundary algorithm, device boundary criterion, propagation loss calculation, antenna height), s8 (accuracy), s9 (transitional), Schedules 2 and 3 (earth station protection zones and urban areas).\n"},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"}},"importantCases":[],"_links":{"self":"/api/acts/radiocommunications-unacceptable-levels-of-interference-3-4-ghz-band-determination-2025","history":"/api/acts/radiocommunications-unacceptable-levels-of-interference-3-4-ghz-band-determination-2025/history","analysis":"/api/acts/radiocommunications-unacceptable-levels-of-interference-3-4-ghz-band-determination-2025/analysis","conflicts":"/api/acts/radiocommunications-unacceptable-levels-of-interference-3-4-ghz-band-determination-2025/conflicts","importantCases":"/api/acts/radiocommunications-unacceptable-levels-of-interference-3-4-ghz-band-determination-2025/important-cases","documents":"/api/acts/radiocommunications-unacceptable-levels-of-interference-3-4-ghz-band-determination-2025/documents"}}