Commonwealth of Australia
Radiocommunications Act 1992
Radiocommunications (Unacceptable Levels of Interference28 GHz and 31 GHz Bands) Determination 1998
THE AUSTRALIAN COMMUNICATIONS AUTHORITY determines the following unacceptable levels of interference under section 145 of the Radiocommunications Act 1992.
Dated 11 November 1998.
A.J SHAW Chairman
R HORTON Deputy Chairman
Australian Communications Authority
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CONTENTS
Clause
1. Title
2. Commencement
3. Purpose
4. Interpretation
5. Group of transmitters
6. Group of receivers
7. Unacceptable level of interference
8. Emission designator
9. Registration
Schedules
Schedule 1 Centre location and effective radius of a transmitter
Schedule 2 Antenna height above ground
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Title
1. This determination is called the Radiocommunications (Unacceptable Levels of Interference - 28 GHz and 31 GHz Bands) Determination of 1998.
Commencement
2. This determination commences on 11 November 1998.
Purpose
3. This determination sets out what is an unacceptable level of interference caused by a transmitter operating under a spectrum licence issued in the 28 GHz and 31 GHz bands, so as to ensure that high levels of emission from transmitters operated under a licence are kept within the geographic area and frequency band of the licence.
[NOTES:
1. The ACA may refuse to register a transmitter if the operation of the transmitter could cause an unacceptable level of interference to the operation of other radiocommunications devices - see s.145 of the Act.
2. The ACA has issued written advisory guidelines under s.262 of the Act about compatibility requirements in relation to the assignment of frequencies for transmitters operated under apparatus licences and the operation of transmitters under spectrum licences. The ACA will take these guidelines into account during the settlement of interference disputes. Each case will be assessed on its merits. The guidelines do not prevent a licensee negotiating other compatibility requirements with another licensee. The guidelines are:
Copies are available from the ACA.]
Interpretation
4. (1) In this determination, unless the contrary intention appears:
Act means the Radiocommunications Act 1992.
Australian National Spheroid means the Australian National Spheroid published in the Gazette on 6 October 1966 and used with the Australian Geodetic Datum 1984.
effective occupied bandwidth, in relation to a transmitter, means the minimum width of a frequency band having fixed upper and lower limits that is necessary to contain 99% of the true mean power of the transmitter’s emission at any time.
emission centre frequency, in relation to a transmitter, means the frequency midway between the lower and upper frequency limits of the transmitter’s effective occupied bandwidth.
emission designator has the meaning given by clause 8.
error means the uncertainty, relating to the estimated value of a specified parameter, that results in a 95% level of confidence that the true value of the parameter is within the range:
(a) estimated value minus the uncertainty; to
(b) estimated value plus the uncertainty
fixed receiver means a radiocommunications receiver located at a fixed point on land or sea and not established for use while in motion.
fixed transmitter means a radiocommunications transmitter located at a fixed point on land or sea and not established for use while in motion.
geographic area, in relation to a spectrum licence, means the area within which operation of a radiocommunications device is authorised under the licence.
group of receivers has the meaning given by clause 6.
group of transmitters has the meaning given by clause 5.
indoor, for a fixed transmitter, means a transmitter having an antenna with its phase centre located within, and at least 5 metres from the external surface of, an enclosed space.
outdoor, for a fixed transmitter, means a transmitter that is not an indoor fixed transmitter.
publish includes publish electronically.
towns mobile list means the list giving the names of towns, latitude and longitude of the centre location and the effective radius for each town, published by the ACA, copies of which are available from the ACA.
28 GHz band means the frequency band 27.5 Ghz - 28.35 Ghz;
31 Ghz band means the frequency band 31 Ghz - 31.3 GHz.
[NOTE: The following terms, used in this determination, are defined in the Radiocommunications Act 1992 and have the meanings given to them by that Act:
frequency band interference
ACA spectrum licence
transmitter.]
(2) In this determination, the range of numbers that identifies a frequency band includes the higher, but not the lower, number.
Group of transmitters
5.(1) For the purpose of this determination, two or more fixed transmitters are a group of transmitters if a height can be calculated for the group and:
(a) they have the same:
(i) emission centre frequency; and
(ii) emission designator; and
(b) each has an antenna of the same type, model and manufacturer; and
(c) they are operated for the purpose of communicating with the same receiver or group of receivers; and
(d) they have the same identification number assigned by the ACA to the antenna used with each transmitter.
(2) A transmitter may belong to more than one group of transmitters.
Group of receivers
6.(1) For the purpose of this determination, two or more fixed receivers are a group of receivers if a height can be calculated for the group and:
(a) each has an antenna of the same type, model and manufacturer; and
(b) they are operated for the purpose of communicating with the same transmitter or group of transmitters; and
(c) they have the same identification number assigned by the ACA to the antenna used with each receiver.
(2) A receiver may belong to more than one group of receivers.
Unacceptable level of interference
7. (1) This clause sets out what are unacceptable levels of interference for the purposes of section 145 of the Act.
[NOTE: Under s.145, the ACA may refuse to register a transmitter if the operation of the transmitter could cause an unacceptable level of interference to the operation of other radiocommunications devices.]
(2) A level of interference caused by a transmitter or group of transmitters operated under a spectrum licence issued for the 28 GHz or the 31 GHz band is unacceptable if the operation results in a breach of a core condition of the licence relating to the maximum permitted level of radio emission from the transmitter or any transmitter within the group:
(a) outside the parts of the spectrum the use of which is authorised by the licence; or
(b) outside the geographic area of the licence.
[Notes:
1. S.66(1) of the Act deals with core conditions relating to maximum permitted levels of radio emissions.
2. The ACA has used the concept of device boundary criteria in developing spectrum licensing at lower frequency bands. The ACA does not intend to use device boundary criteria to create an in-band emission buffer zone along the boundaries of the geographic areas of spectrum licences at 28 GHz or 31 GHz. The device boundary criteria is a mechanism used to keep emissions within the geographic area of a spectrum licence and should be applied when levels of emissions are strongly influenced by the effective antenna heights of the transmitters. At 28 GHz and 31 GHz, the high propagation loss helps to ensure equity in the levels of emission emanating from adjacent spectrum licences without the need for additional constraints on the basis of effective antenna height. Device boundaries should be used at lower frequencies eg 2 GHz, otherwise emissions will not be equitably contained within the spectrum space that a person is licensed to use. The core conditions at 28 GHz and 31 GHz allow maximum radiated power for any transmitter to be constant throughout the entire geographic area (including transmitters located on the boundary) and licensees may need to move their receivers back from the boundary in order to be certain of protection. Therefore, at 28 GHz and 31 GHz, the emission buffer zone that is normally created through application of the device boundary criteria, which places constraints on transmitter emission levels as a function of distance to the geographic boundary of the licence, will instead be created by having the adjacent licensee set receivers back from the boundary.]
(3) A transmitter on an airship or on a balloon is taken to cause unacceptable interference when it is operated at a height greater than 100 metres above the ground.
(4) If the centre location, effective radius or antenna height above ground cannot be calculated for a transmitter or a group of transmitters, the transmitter or group is taken to cause unacceptable interference.
Emission designator
8. (1) In this determination, a reference to an emission designator, in relation to a transmitter, is a reference to the designation of the transmitter’s emission worked out in accordance with Article 4 of the Radio Regulations published by the International Telecommunication Union as in force on the day on which this determination commences.
(2) For the purpose of working out the designation of the transmitter’s emission, the references in Article 4 to necessary bandwidth for a given class of emission are taken to be references to the effective occupied bandwidth of the transmitter.
[Note: Article 6 of the Radio Regulations contains examples of how the emission designator is worked out.]
Registration
9. (1) For the purposes of registration, the centre location and effective radius of a transmitter operating in the 28GHz or 31 GHz band are calculated in according with Schedule 1.
(2) For the purposes of registration, the antenna height above ground of a transmitter operating in the 28GHz or 31 GHz band is calculated in according with Schedule 2.
(3) For the purposes of registration, the maximum error for antenna azimuth and mechanical antenna tilt is:
(a) for a transmitter operating in the 28 GHz or 31 GHz band—2 degrees; and
(b) for a group of transmitter operating in the 28 GHz or 31 GHz band—180 degrees.
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SCHEDULES
SCHEDULE 1
Clause 4(1)
Centre location and effective radius of a transmitter
[NOTE: A model for the locations of a group of transmitters (the effective location) is the circumference of the circle defined by the centre location and the effective radius.]
1. The centre location of a transmitter is the centre of a circle lc with an effective radius re. This Schedule sets out the lc and re of particular transmitters.
For a fixed transmitter, lc is the location (by latitude and longitude with reference to the Australian National Spheroid) of the phase centre of the transmitter’s antenna and re is zero.
In measuring the latitude and longitude, the following errors are acceptable:
(a) in a high radio-dense area—less than 10 metres, measured using a differential GPS unit;
(b) in a medium radio-dense area—less than 100 metres, measured using a standard GPS unit;
(c) in any other area—less than 1 kilometre, measured using a map.
[NOTE: The ACA issues site identifiers for established radiocommunications locations.]
For a group of fixed transmitters operating within the limits of a town specified in the towns mobile list, lc and re are taken to be those specified in the towns mobile list for that town.
4. Centre location and effective radius of a group of fixed transmitters located near a central point
For a group of fixed transmitters:
(a) supported by the same structure; and
(b) having the phase centre of each transmitter’s antenna located within 10 metres of the same central point;
lc is the central point and re is zero.
[NOTE: The centre location, effective radius and antenna height above ground of a receiver are calculated as if the receiver is a transmitter.]
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SCHEDULE 2
Clause 4(1)
Antenna Height Above Ground
1. The antenna height above ground is determined in accordance with its transmitter, as set out in this Schedule.
2. Antenna height above ground of an outdoor fixed transmitter
The antenna height above ground (“hg”) for an outdoor fixed transmitter, is the vertical height in
metres of the phase centre of the fixed transmitter’s antenna measured with an error of less than 5 parts in 100 and relative to the point:
(a) located on the line of intersection between the external surface of the structure supporting the antenna and the surface of the ground or sea; and
(b) having the lowest elevation on that line.
[NOTE: Indoor transmitters are exempt from registration.]
3. Antenna height above ground of a group of fixed transmitters
For a group of fixed transmitters where the antenna height above ground of the highest transmitter (hgmax), calculated in accordance with clause 2, is equal to or less than 20 metres, the antenna height above ground of the group is hgmax.
However, if a fixed transmitter in the group transmits for more than 5% of the time in any 1 hour period, each transmitter in the group is to be treated as if it were a single fixed transmitter and the antenna height above ground of each fixed transmitter is to be worked out as for a single fixed transmitter.
4. Antenna height above ground of a group of fixed transmitters located near a central point
For a group of fixed transmitters:
(a) all supported by the one structure; and
(b) having the phase centre of each transmitter’s antenna located within 10 metres of the same central point;
the antenna height above ground of the group is calculated as if it is a single fixed transmitter located at the central point and with a hg, calculated in accordance with clause 2, equal to that calculated for the antenna with the largest hg.