Radiocommunications Advisory Guidelines (Managing Interference from Apparatus-licensed and Class-licensed Transmitters – 2 GHz Band) 2015
Radiocommunications Act 1992
The AUSTRALIAN COMMUNICATIONS AND MEDIA AUTHORITY makes these Advisory Guidelines under section 262 of the Radiocommunications Act 1992.
Dated 15th May 2015
Chris Chapman
[signed]
Member
 
 
Richard Bean
[signed]
Member /General Manager
 
Australian Communications and Media Authority
 
BACKGROUND
 
A spectrum licence authorises the use of a particular part of the spectrum, in a particular geographic area for a particular period.  Interference occurring between adjacent licences consists of:
·      in-band interference, across the geographic boundaries; and
·      out-of-band interference, across the frequency boundaries.
This interference is managed by creating emission buffer zones along the geographic and frequency boundaries of the licence, using a number of tools provided by the Radiocommunications Act 1992, including:
·      core conditions specified in all spectrum licences (see section 66 of the Act), about:
            - emission limits outside the area; and
            - emission limits outside the band;
·      determinations made under section 145 of the Act about what constitutes unacceptable interference; and
·      advisory guidelines made under section 262 of the Act, about managing interference in specific circumstances.
The following advisory guidelines have been made for the management and settlement of interference to receivers operating under spectrum licences in the 2 GHz band and caused by transmitters operating under apparatus or class licences.  In all cases, for the purposes of these guidelines, the receivers and transmitters referred to are radiocommunications devices located at a fixed point on land or sea and not established for use while in motion.
Part 1                 Introduction
 
Title
1.1       These guidelines are called the Radiocommunications Advisory Guidelines (Managing Interference from Apparatus-licensed and Class-licensed Transmitters – 2 GHz Band) 2015.
 
Commencement
1.2       These guidelines commence on the day after they are registered.
Note   All legislative instruments and compilations are registered on the Federal Register of Legislative Instruments kept under the Legislative Instruments Act 2003. See http://www.comlaw.gov.au.
 
Revocation
1.3       The Radiocommunications Advisory Guidelines (Managing Interference from Apparatus-licensed and Class-licensed Transmitters – 2 GHz Band) 2000 [F2005B00284] are revoked.
 
Purpose of these guidelines
1.4       The purpose of these advisory guidelines is to manage interference, by providing for the protection of registered fixed receivers operating under spectrum licences issued for the 2 GHz band, caused by fixed transmitters operating under apparatus licences or under class licences.
 
Interpretation
1.5(1)   In these guidelines, unless the contrary intention appears:
2 GHz band means the following frequency bands:
(a) 1900 MHz – 1920 MHz (the 2 GHz Lower Band);
(b) 1920 MHz – 1980 MHz (the 2 GHz Upper Band A);
(c) 2110 MHz – 2170 MHz (the 2 GHz Upper Band B).
Act means the Radiocommunications Act 1992.
Register means the Register established under section 143 of the Act.
section 145 determination means the Radiocommunications (Unacceptable Levels of Interference¾2 GHz Band) Determination 2015.
1.5(2)  A term used in these guidelines that is defined in the section 145 determination has the same meaning as in that determination.
 
Note The following terms, used in these guidelines, are defined in the Act and have the meanings given to them by the Act:
ACMA                                                   apparatus licence
class licence                          `               frequency band
interference                                           spectrum licence
transmitter.
Part 2                 Managing Interference from Non-spectrum Licensed Services
In-band interference
2.1(1)   In-band interference caused in a receiver operating under a spectrum licence by a transmitter operating under an adjacent spectrum licence is managed by:
(a) the core conditions of the licence under section 66 of the Act; and
(b) the device boundary criteria under the section 145 determination.
2.1(2)   In-band interference caused in a receiver operating under a spectrum licence by a transmitter operating under an apparatus licence issued on or after 4 December 2000 is managed as if the transmitter is operated under a spectrum licence.  The same device boundary criteria that apply to spectrum licensed transmitters also apply to apparatus licensed transmitters. Therefore, spectrum licences are afforded the same level of in-band protection from apparatus licensed transmitters as they are afforded from transmitters operated under adjacent spectrum licences. 
2.1(3)   The ACMA would not regard in-band interference to a receiver operating under a spectrum licence caused by a transmitter operating under a class licence as unacceptable if the operation of the transmitter complies with all relevant conditions of the class licence. 
Note Spectrum licensees must accept any interference caused by in-band apparatus-licensed transmitters that operate in adjacent geographical areas whose apparatus licences were first issued before 4 December 2000.
Out-of-band interference
2.2(1)  Out-of-band interference is difficult to predict because the levels and frequencies of unwanted emissions depend on both the proximity, and the operating frequencies, of transmitters and receivers.  In addition, out-of-band interference:
(a)    can extend for many MHz either side of the frequency boundary of a spectrum licence;
(b)   is dependent on the quality of the receiver as well as the levels of transmitter emission; and
(c)    is difficult to accurately model.
2.2(2)  If emission limits were used to manage out-of-band interference for devices in close proximity, the interference modelling inaccuracy would require large probability margins to be added to those limits.  These margins would place severe constraints on use of the spectrum because the frequency boundaries of a spectrum licence extend throughout the entire geographic area of the licence.  Therefore, emission limits that manage out-of-band interference for the entire geographic area of a spectrum licence (including communal sites) cannot be used because they would lead to a severe loss of use of the spectrum on both sides of the frequency boundary.
2.2(3)  Instead of making large tracts of spectrum space unusable through the imposition of emission limits, the interference is managed through procedures based on a compatibility requirement for existing receivers.  A minimum level of receiver performance has to be specified in conjunction with the compatibility requirement because the performance level of receivers:
(a) affects the level of interference; and
(b) varies widely for receivers operating under spectrum licences.
 
Part 3      Minimum Level of Receiver Performance
 
Recording receiver details in the Register
3.1       A receiver will not be afforded protection unless details of the receiver are in the Register.
 
Mobile devices
3.2       The compatibility requirement does not apply to mobile devices because the transient nature of mobile devices prevents the use of a practical interference management procedure.
Note The ACMA does not intend to require the registration of mobile transmitters - see subsection 69(2) of the Act and the registration conditions of spectrum licences.
 
Receiver performance level
3.3       The level of interference caused by out-of-band emissions depends on the interference susceptibility of a receiver.  Emission levels from transmitters should not have to be reduced below a point where the performance of the receiver is really the problem.  Therefore, it is necessary to establish a benchmark minimum receiver performance level when setting a compatibility requirement for receivers.  The receiver performance level is set out in Schedule 1.  A receiver must meet this level of performance to gain protection. 
Note Schedule 1 specifies the anticipated receiver performance based on the most current information provided by industry at the time of issue of these guidelines.  These performance requirements are able to be amended in the future, if it can be demonstrated that the parameters of typical equipment intended to be deployed in the band readily meet any proposed changes.  Such changes would be introduced in consultation with 2 GHz band licensees.
 
Part 4                 Compatibility Requirement
 
Apparatus licensed transmitters
4.1       A fixed transmitter operating under an apparatus licence must meet the compatibility requirement in Schedule 2 in relation to a fixed receiver:
(a)        with a minimum level of performance; and
(b) registered before the issue of the apparatus licence under which the transmitter operates.
 
Class licensed transmitters
4.2       A fixed transmitter operating under a class licence must comply with the conditions of the class licence.
Schedule 1     Receiver minimum level of performance
                                    (Section 3.3)
 
The minimum performance level for a receiver relates to:
·         selectivity;
·         intermodulation immunity; and
·         blocking.
 
Frequency offsets are specified with respect to the carrier centre frequency of the transmitter communicating with the receiver.  All levels are referenced to the antenna connector of the equipment.  The notional antenna for a fixed receiver has a total gain of 19 dBi in all directions, including feeder losses.
Note  For testing purposes (if required), a minimum wanted signal of -120 dBm per 1 MHz (or equivalent) should be used where possible, otherwise Receiver Sensitivity Level is set at + 3dB.
Receiver Adjacent Channel Selectivity
Adjacent Channel Selectivity means a measure of the ability of a receiver to receive a wanted signal in the presence of an unwanted adjacent channel signal at a given frequency offset.
The minimum adjacent channel selectivity is 45 dB, measured at an offset of 5 MHz.
Receiver Intermodulation Response Rejection
Intermodulation Response Rejection means a measure of the capability of a receiver to receive a wanted signal in the presence of two or more unwanted interfering signals which have a specific frequency relationship to the wanted signal.
The minimum intermodulation rejection level is -54 dBm per 1 MHz, at an offset of 20 MHz or more.
Receiver Blocking
Receiver Blocking means a measure of the ability of a receiver to receive a wanted signal in the presence of a high level unwanted interferer on frequencies other than those of the adjacent channels.
The minimum unwanted signal level to cause receiver blocking is:
·         a signal level of -46 dBm per 1 MHz with a frequency offset of 10 MHz or more; and
·         a signal level of -21 dBm per 1 MHz for frequencies outside the band 1880 to 2190 MHz.
Note The accuracy of measuring equipment, measurement procedures and any corrections to measurements necessary to take account of practical filter shape factors would normally be in accordance with good engineering practice.
 
 
 
 
Schedule 2        Compatibility requirement
     (Section 4.1)
 
The compatibility requirement is an unwanted signal level that is never more than:
 -126 dBm for more than 1% of the time in any 1 hour period, when measured as mean power within a 30 kHz rectangular bandwidth that is within the frequency band of the spectrum licence.
Note The maximum unwanted signal level is the target interference level at the fixed receiver, and the 30 kHz rectangular bandwidth provides a method of normalising the requirement for different transmitter power spectral densities.