Radiocommunications Advisory Guidelines (Managing Interference to Spectrum Licensed Receivers – 2.5 GHz Band) 2023

Dated: 16 March 2023

Chris Jose

[signed]

Member

Linda Caruso

[signed]

Member/General Manager

Part 1—Preliminary

1  Name

                   These are the Radiocommunications Advisory Guidelines (Managing Interference to Spectrum Licensed Receivers – 2.5 GHz Band) 2023.

2  Commencement

                   This instrument commences at the start of the day after the day it is registered on the Federal Register of Legislation.

Note:    The Federal Register of Legislation may be accessed free of charge at www.legislation.gov.au.

3  Authority

                   This instrument is made under section 262 of the Act.

4  Repeal of the Radiocommunications Advisory Guidelines (Managing Interference to Receivers – 2.5 GHz Band) 2012

                   The Radiocommunications Advisory Guidelines (Managing Interference to Receivers – 2.5 GHz Band) 2012 [F2012L02549] are repealed.

5  Definitions

             (1)  In this instrument:

2.5 GHz band means the 2.5 GHz lower band and the 2.5 GHz upper band.

2.5 GHz lower band means the frequency band 2500 MHz to 2570 MHz.

2.5 GHz receiver means a radiocommunications receiver operated under a 2.5 GHz spectrum licence.

2.5 GHz spectrum licence means a spectrum licence that authorises the operation of radiocommunications devices in the 2.5 GHz band.

2.5 GHz upper band means the frequency band 2620 MHz to 2690 MHz.

Act means the Radiocommunications Act 1992.

adjacent channel, in relation to another channel (the occupied channel), means a channel with a centre frequency offset on either side of the assigned channel frequency of the occupied channel by a specific frequency relation.

adjacent channel selectivity: see item 2 of Schedule 1.

centre frequency, in relation to a radiocommunications transmitter, means the frequency midway between the lower and upper frequency limits of the transmitter’s occupied bandwidth.

compatibility requirement: see Part 5 and Schedule 2.

device boundary criterion has the meaning given by:

                     (a)  the section 145 determination; or

                     (b)  if another instrument replaces that determination – the other instrument.

effective antenna height has the meaning given by:

                     (a)  the section 145 determination; or

                     (b)  if another instrument replaces that determination – the other instrument.

emission buffer zone, in relation to a spectrum licence, means a zone along the frequency or geographic boundary specified in a spectrum licence where emission levels of radiocommunications transmitters are reduced to ensure that significant levels of emissions stay within the geographic areas and frequencies of the licence.

fixed receiver means a radiocommunications receiver:

                     (a)  located at a fixed point on land or sea; and

                     (b)  not designed or intended for use while in motion.

fixed transmitter means a radiocommunications transmitter:

                     (a)  located at a fixed point on land or sea; and

                     (b)  not designed or intended for use while in motion.

frequency adjacent spectrum licence, in relation to a spectrum licence (the first licence), means a spectrum licence that authorises the operation of radiocommunications devices in a part of the spectrum that is adjacent to the parts of the spectrum specified in a core condition of the first licence.

geographic area, for a spectrum licence, means the area within which operation of a radiocommunications device is authorised under the licence.

in-band means:

                     (a)  for a radiocommunications device operated under a spectrum licence – the part of the spectrum within which the operation of radiocommunications devices is authorised under the licence; or

                     (b)  for a radiocommunications device operated under an apparatus licence that specifies a frequency band – the frequencies within the lower frequency limit and the upper frequency limit specified in the licence; or

                     (c)  for a radiocommunications device operated under an apparatus licence that specifies a specific frequency and bandwidth – the frequencies within that bandwidth, when centred on the specific frequency.

intermodulation response rejection: see item 3 of Schedule 1.

mobile device means a radiocommunications device that is used:

                     (a)  while it is in motion on land, on water or in the air; or

                     (b)  in a stationary position at unspecified points on land, on water or in the air.

notional receiver performance level: see subsection 12(2) and item 1 of Schedule 1.

out-of-band, for a radiocommunications device, means a frequency other than an in-band frequency.

receiver blocking, in relation to a radiocommunications receiver, means the measure of the ability of the receiver to receive a wanted signal in the presence of a high level unwanted interferer on frequencies other than those of an adjacent channel.

section 145 determination means the Radiocommunications (Unacceptable Levels of Interference – 2.5 GHz Band) Determination 2023.

Note:          The section 145 determination is available, free of charge, from the Federal Register of Legislation at www.legislation.gov.au.

spectrum space means the three dimensional space consisting of a frequency band and a geographic area.

unwanted signal means a radio emission from a radiocommunications transmitter that is not a wanted signal.

wanted signal means a radio emission from a radiocommunications transmitter that is intended for reception by a radiocommunications receiver protected by this instrument.

wideband unwanted signal means a radio emission that is an unwanted signal and is spread across a bandwidth greater than 4 MHz, with 99 percent of its power contained within a bandwidth of 5 MHz.

Note:          A number of other expressions used in this instrument are defined in the Act, including the following:

(a)    ACMA;

(b)    apparatus licence;

(c)    class licence;

(d)    core condition;

(e)    frequency band;

(f)    interference;

(g)    radiocommunications device;

(h)    radiocommunications receiver;

(i)     radiocommunications transmitter;

(j)     radio emission;

(k)    spectrum licence.

             (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.

Note:          This subsection means the lower number in a part of the spectrum or a frequency band is not included in the part of the spectrum or the frequency band.

6  References to other instruments

                   In this instrument, unless the contrary intention appears:

                     (a)  a reference to any other legislative instrument is a reference to that other legislative instrument as in force from time to time; and

                     (b)  a reference to any other kind of instrument or writing is a reference to that other instrument or writing as in force or existence from time to time.

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.

Note 2:       All Commonwealth Acts and legislative instruments are registered on the Federal Register of Legislation.

Note 3:       See section 314A of the Act.

Part 2—Overview

7  Background

             (1)  A spectrum licence authorises the operation of radiocommunications devices within a part of the spectrum and in a geographic area. Interference occurring between adjacent spectrum licences consists of in-band interference across the geographic boundaries, and out-of-band interference across the frequency boundaries.

             (2)  This interference is managed by creating emission buffer zones along the geographic and frequency boundaries of a spectrum licence, using a number of powers under the Act. Emission buffer zones may be created by, or as a result of, the following:

                     (a)  specifying out-of-area and out-of-band emission limits in the core conditions of the licence, which must be included in all spectrum licences (see section 66 of the Act);

                     (b)  a determination under section 145 of the Act, relating to unacceptable levels of interference and the registration of radiocommunications devices, and related licence conditions (see section 69 of the Act);

                     (c)  advisory guidelines under section 262 of the Act, about managing interference in specific circumstances.

             (3)  This instrument:

                     (a)  provides protection to 2.5 GHz receivers from interference caused by:

                              (i)  radiocommunications transmitters operated under a class licence; or

                             (ii)  fixed transmitters operated under a transmitter licence; or

                            (iii)  fixed transmitters operated under a 2.5 GHz spectrum licence; and

                     (b)  assists in the management of in-band and out-of-band interference by providing compatibility requirements for registered fixed receivers operated under 2.5 GHz spectrum licences; and

                     (c)  sets out minimum receiver performance requirements that the ACMA will assume are met by a radiocommunications receiver, when considering whether to provide protection to the receiver in accordance with this instrument, so that the onus of managing interference is not solely placed upon the operators of radiocommunications transmitters.

             (4)  This instrument is intended to provide guidance on the management and settlement of interference to 2.5 GHz receivers, caused by radiocommunications transmitters operated under another class, apparatus or spectrum licence issued under the Act.

             (5)  This instrument should be used by spectrum licensees, apparatus licensees, and authorised third parties in the planning of services and in the resolution of interference.

             (6)  This instrument does not prevent a person negotiating and implementing other protection requirements with other persons.

Part 3—Managing interference from other services

8  In-band interference

             (1)  In-band interference to a 2.5 GHz receiver, caused by a radiocommunications transmitter operated under an adjacent spectrum licence, is managed by the core conditions imposed on spectrum licences under section 66 of the Act and the device boundary criterion.

             (2)  In-band interference to a 2.5 GHz receiver, caused by a radiocommunications transmitter operated under an apparatus licence is managed as if the transmitter were operated under a spectrum licence. The device boundary criterion should be applied to such radiocommunications transmitters, affording 2.5 GHz receivers the same level of in-band protection from apparatus licensed radiocommunications transmitters as they are afforded from radiocommunications transmitters operated under adjacent spectrum licences.

             (3)  Application of the device boundary criterion manages in-band interference. The device boundary criterion incorporates emission limits that provide reasonable protection within the geographic area of a spectrum licence. Emission limits are also used to manage out-of-band interference, but these do not provide protection along the frequency boundaries of a spectrum licence. Because of the nature of out-of-band interference, emission limits cannot be used to provide protection from out-of-band interference for radiocommunications devices that are located near each other.

Example:    Radiocommunications devices that are located near each other include devices located at multi-operator sites.

             (4)  The ACMA does not intend to act in relation to in-band interference to a 2.5 GHz receiver caused by a radiocommunications transmitter operated under a class licence where the operation complies with all relevant conditions of the class licence.

9  Out-of-band interference

             (1)  Out-of-band interference is difficult to predict, because the levels and frequencies of unwanted emissions depend on both the nearness and the operating frequencies of radiocommunications transmitters and radiocommunications receivers that are spectrally or geographically close. In addition, out-of-band interference:

                     (a)  can extend for many MHz either side of the frequency boundary of a spectrum licence; and

                     (b)  is dependent on the quality of the radiocommunications receiver as well as the levels of the radiocommunications transmitter’s emissions; and

                     (c)  is difficult to model accurately.

             (2)  Emission limits are also used to manage out-of-band interference, but these do not provide protection along the frequency boundaries of a spectrum licence throughout the entire geographic area. Because of the nature of out-of-band interference, emission limits cannot be used to provide protection from out-of-band interference for radiocommunications devices that are located near each other.

Example:    Radiocommunications devices that are located near each other include devices located at multi-operator sites.

             (3)  Emission limits are not the sole mechanism used to manage out-of-band interference for devices in close proximity, because the interference modelling inaccuracy would require large probability margins to be added to those limits. Large probability margins would place severe constraints on the use of the spectrum because the upper and lower frequency limits of a spectrum licence extend throughout the geographic area. Emission limits to manage out-of-band interference throughout the geographic area cannot be used, because they would lead to a severe loss of utility of the spectrum on both sides of the frequency limits.

             (4)  To avoid large probability margins, out-of-band interference is managed through interference management procedures based on a compatibility requirement for radiocommunications receivers. A minimum level of receiver performance is specified in Part 4 in conjunction with the compatibility requirement because the performance level of receivers:

                     (a)  affects the level of interference; and

                     (b)  can vary for receivers operating under spectrum licences.

Note:          The minimum level of receiver performance is specified in Part 4. The compatibility requirement is set out in Part 5.

10  Recording radiocommunications receiver details in the Register

             (1)  In this instrument, for a 2.5 GHz receiver to be afforded protection from interference caused by an apparatus licensed radiocommunications transmitter, the details of the receiver must have been included in the Register before the relevant apparatus licence was first issued under section 100 of the Act.

             (2)  In this instrument, for a 2.5 GHz receiver to be afforded protection from interference caused by a spectrum licensed radiocommunications transmitter, the details of the receiver must have been included in the Register before the details of the relevant transmitter were included in the Register.

Note:          See also Part 5.

11  Mobile devices

                   The compatibility requirement specified in Part 5 does not apply to radiocommunications receivers operated under a 2.5 GHz spectrum licence that are mobile devices, because the transient nature of these devices prevents the use of this requirement as an interference management procedure.

Part 4—Minimum level of receiver performance

12  Notional receiver performance level

             (1)  The level of interference caused by unwanted emissions depends on the interference susceptibility of a radiocommunications receiver and the level of the unwanted signal. Emission levels from radiocommunications transmitters should not have to be reduced below a point where the performance of the radiocommunications receiver is the main cause of the problem.

             (2)  A notional receiver performance level is set out in Schedule 1 and is to be used when setting a compatibility requirement for a radiocommunications receiver. A receiver should meet the notional receiver performance level to gain protection from interference from a radiocommunications transmitter specified in this instrument.

Part 5—Compatibility requirement

13  Compatibility

             (1)  In relation to a fixed receiver specified in subsection (2), the licensee of a fixed transmitter operated under an apparatus licence or a spectrum licence must ensure that the transmitter meets the compatibility requirement in Schedule 2.

             (2)  For the purposes of subsection (1), a fixed receiver is specified if the receiver:

                     (a)  is operated under a spectrum licence; and

                     (b)  has at least the notional receiver performance level; and

                     (c)  was included in the Register before:

                              (i)  if the fixed transmitter mentioned in subsection (1) is operated under a spectrum licence – the fixed transmitter was included in the Register; or

                             (ii)  if the fixed transmitter mentioned in subsection (1) is operated under an apparatus licence – the apparatus licence was issued; and

                     (d)  if the receiver is operated in the 2.5 GHz lower band – has an effective antenna height greater than 20 metres, for any increment 1, ; and

                     (e)  if the receiver is operated in the 2.5 GHz upper band – has an effective antenna height less than 10 metres, for any increment 1, .

             (3)  A radiocommunications transmitter operated under a class licence must comply with the conditions of the class licence.

Schedule 1          Notional receiver performance level

                         (subsections 5(1) and 12(2))

1  Notional receiver performance level

             (1)  A 2.5 GHz receiver meets the notional receiver performance level if the combined performance of duplex filtering and receiver equipment is equal to or greater than the combination of:

                     (a)  adjacent channel selectivity; and

                     (b)  intermodulation response rejection; and

                     (c)  receiver blocking.

Note:          The notional receiver performance level is a product of duplex filtering from the antenna to the receiver and the performance of the receiver equipment.

             (2)  These performance parameters are assessed at the antenna connector port of the radiocommunications receiver unit. All frequency offsets are specified with reference to the upper and lower limits of the frequency bands of the spectrum licence under which the receiver operates.

             (3)  The wanted level signal to be used for testing purposes should be a level equivalent to that specified in subitem 1(1) of Schedule 2.

2  Adjacent channel selectivity

             (1)  In this instrument, adjacent channel selectivity means the measure of the ability of a radiocommunications receiver to receive a wanted signal without exceeding a specified degradation in output quality due to the presence of an unwanted signal from an adjacent channel.

             (2)  The adjacent channel selectivity parameter is expressed as a ratio between the unwanted signal and the compatibility requirement.

             (3)  The minimum adjacent channel selectivity is:

                     (a)  43.5 dB for a wideband unwanted signal operating at offsets equal to or less than 5 MHz from the upper or lower frequency limits of the relevant spectrum licence; or

                     (b)  85 dB for a wideband unwanted signal operating at offsets greater than 5 MHz from the upper or lower frequency limits of the relevant spectrum licence.

3  Intermodulation response rejection

             (1)  In this instrument, intermodulation response rejection means the measure of the ability of a radiocommunications receiver to receive a wanted signal in the presence of two or more unwanted signals with a specific amplitude and frequency relationship to the wanted signal frequency.

             (2)  The intermodulation response rejection requirement is expressed as a maximum power level of an individual unwanted signal, when in the presence of another signal of equal or greater power level, and with a frequency relationship that may result in a third order or higher intermodulation product on the operating frequency of the radiocommunications receiver.

             (3)  The minimum intermodulation response rejection level, expressed as the minimum tolerable wideband unwanted signal level of the outer interfering signal with offset of 10 MHz or more from the upper or lower frequency limit of the relevant spectrum licence , is -12 dBm/MHz.

             (4)  The assumed unwanted signal is a carrier wave signal of -52 dBm/5MHz at an offset between 5 to 10 MHz from the upper or lower frequency limit of the relevant spectrum licence.

4  Receiver blocking

                   The minimum receiver blocking requirement, expressed as a tolerance to a minimum unwanted signal level, is:

                     (a)  at frequency offsets greater than 10 MHz from the upper or lower frequency limit of the spectrum licence, within the frequency band 2480 MHz to 2590 MHz, for a wideband unwanted signal – a power spectral density of -18 dBm/MHz; and

                     (b)  outside the frequency band 2480 MHz to 2590 MHz, for an unwanted signal – a total mean power of -15 dBm.

5  Receiver antenna gain and feeder losses

                   The antenna gain and feeder loss recorded for the radiocommunications receiver on the Register should be used for coordination. If an antenna gain or feeder loss is not specified in the Register, then use an antenna gain (including losses) of 17 dBi in all directions.

Schedule 2          Compatibility requirement

                         (subsections 5(1) and 13(1))

1  Compatibility requirement

             (1)  The compatibility requirement for a fixed receiver, operated under a spectrum licence (the receiver’s spectrum licence), to be provided by a radiocommunications transmitter operated under an apparatus licence or a spectrum licence, is a minimum wanted signal level, at the antenna connector port of the receiver, of – 102.5 dBm/MHz for 90% of the time in any 1 hour period.

             (2)  Logarithmic scaling should be used to find the appropriate level in alternative bandwidths.