PART 7: INTERFERENCE MANAGEMENT SCHEME FOR DIGITAL TELEVISION
Application of Part 7
109. This part applies to a licensee (a digital licensee) that is licensed to provide a television service, or a datacasting service, in digital mode.
110. In this part:
‘analog licensee’ means a licensee that is licensed to provide a television service in analog mode;
‘ancillary device’ means a device that:
is used in conjunction with a television receiver; and
generates a radiofrequency signal in the broadcasting services bands;
Some examples 1 A games console. 2 A subscription television set-top box. 3 A VCR.
Note on ancillary and other devices:
This part does not apply to several types of devices that currently share the broadcasting spectrum. These devices include medical telemetry devices and wireless microphones.
Ancillary devices do not radiate radiofrequency signals, and are not licensed to use the radiofrequency spectrum in any way. This part does not apply to ancillary devices.
With the introduction of digital television services, ancillary devices and other types of devices may experience interference and require retuning, reconnection or replacement to operate on available spectrum. Except where otherwise specified, the digital licensee should not bear the cost of rectifying the interference or interruption of service if the interference is to these types of devices.
Digital licensees are not responsible for the costs involved with retuning, reconnection and replacement of devices and ancillary devices to which this part does not apply.
‘authorised person’, in relation to a digital licensee, means a person that is authorised by that licensee to operate radiocommunications devices under an apparatus licence that relates to the digital licensee’s licence;
Note A digital licensee is also the licensee of an apparatus licence under the Radiocommunications Act 1992. The authorisation procedure mentioned in the definition is set out in Division 4 of Part 3.3 of that Act.
‘complaint’ means a complaint of unacceptable interference as a result of a transmission in digital mode;
‘digital licensee’ means a licensee that is mentioned in guideline 109 of these guidelines;
‘digital transmission’ means the transmission of a television or a datacasting service in digital mode;
‘ERP’ means effective radiated power;
‘interference hotline’ means the telephone facility that is described in guideline 125 of these guidelines;
‘interference study’ means an investigation of interference that may include (but is not limited to):
Part Part 7 - Technical Planning Guidelines (December 2003) - INTERFERENCE MANAGEMENT SCHEME FOR DIGITAL TELEVISION | Zoe
measuring the field strength of transmissions; and
assessing the interference; and
making observations about the potential causes of the interference;
‘notification area’, for a transmission, means an area that is described in guideline 112, 113, 114 or 115 of these guidelines as applying to the transmission;
‘obligation period’ means the period that is described in guidelines 137 to 140 of these guidelines;
‘postcode population threshold’ has the meaning set out in guideline 111 of these guidelines;
‘predicted interference’ means unacceptable interference that is described in paragraph 150 (a) of these guidelines;
‘unacceptable interference’ means interference:
that is caused to an analog service described in guideline 90 of these guidelines; and
to which guidelines 91, 92, 93, 94 and 95 of these guidelines can be applied;
‘unpredicted interference’ means unacceptable interference that is described in paragraph 150 (b) of these guidelines;
‘VCR’ means an ancillary device that can be used by a person:
to record a television program transmitted by a broadcaster in analog mode; or
to play a program.
Postcode population threshold
111. In this part:
a place is in a ‘metropolitan postcode area’, for a commercial television broadcasting licence, if:
the licence area of the licence includes the GPO of Sydney, Melbourne, Brisbane, Adelaide or Perth; and
either:
the place is in that licence area; or
the postcode of the place is the same as the postcode of any place in that licence area; and
a ‘postcode population threshold’ exists for a place in a metropolitan postcode area if:
there are unresolved complaints regarding unacceptable interference that is caused by digital transmission; and
the number of complaints is equal to at least 1% of households in the area; and
a place is in a ‘non-metropolitan postcode area’, for a commercial television broadcasting licence, if paragraph (a) does not apply; and
a ‘postcode population threshold’ exists for a place in a non-metropolitan postcode area if:
there are unresolved complaints regarding unacceptable interference that is caused by digital transmission; and
the number of complaints is equal to at least 0.1% of households in the area.
Notification areas
112. For a transmission made using broadcasting services bands frequency in the range 520 to 820 MHz, an area that receives the transmitted signal at a field strength of at least 41dBV/m from the transmitter is a notification area.
113. Each of the following areas is a notification area for a digital transmission made using any channel (the proposed channel) and VHF Band III:
is capable of receiving the transmitted signal at a field strength of at least 44dBV/m; and
is also capable of receiving a signal from a television service in analog mode, on a channel adjacent to the proposed channel, at a field strength of at least 50dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is less than 300W, an area in that sector that:
is not more than 100 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as the proposed channel, at a field strength of at least 50dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is at least 300W but less than 3kW, an area in that sector that:
is not more than 170 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as the proposed channel, at a field strength of at least 50dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is at least 3kW but less than 30kW, an area in that sector that:
is not more than 270 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as the proposed channel, at a field strength of at least 50dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is at least 30kW but less than 300kW, an area in that sector that:
is not more than 400 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as the proposed channel, at a field strength of at least 50dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is at least 300kW, an area in that sector that:
is not more than 500 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as the proposed channel, at a field strength of at least 50dBV/m.
114. Each of the following areas is a notification area for a digital transmission made using any channel (the proposed channel) and UHF Band IV:
is capable of receiving the transmitted signal at a field strength of at least 50dBV/m; and
is also capable of receiving a signal from a television service in analog mode, on a channel adjacent to the proposed channel, at a field strength of at least 62dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is less than 300W, an area in that sector that:
is not more than 50 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as the proposed channel, at a field strength of at least 62dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is at least 300W but less than 3kW, an area in that sector that:
is not more than 90 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as the proposed channel, at a field strength of at least 62dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is at least 3kW but less than 30kW, an area in that sector that:
is not more than 140 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as the proposed channel, at a field strength of at least 62dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is at least 30kW but less than 300kW, an area in that sector that:
is not more than 200 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as the proposed channel, at a field strength of at least 62dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is at least 300kW, an area in that sector that:
is not more than 300 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as the proposed channel, at a field strength of at least 62dBV/m.
115. Each of the following areas is a notification area for a digital transmission made using any channel (the proposed channel) and UHF Band V:
is capable of receiving the transmitted signal at a field strength of at least 54dBV/m; and
is also capable of receiving a signal from a television service in analog mode, on a channel adjacent to the proposed channel, at a field strength of at least 67dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is less than 300W, an area in that sector that:
is not more than 50 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as to the proposed channel, at a field strength of at least 67dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is at least 300W but less than 3kW, an area in that sector that:
is not more than 90 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as the proposed channel, at a field strength of at least 67dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is at least 3kW but less than 30kW, an area in that sector that:
is not more than 140 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as the proposed channel, at a field strength of at least 67dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is at least 30kW but less than 300kW, an area in that sector that:
is not more than 200 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as the proposed channel, at a field strength of at least 67dBV/m;
if the maximum ERP of the transmitter specified in the digital channel plan, for any sector, is at least 300kW, an area in that sector that:
is not more than 300 kilometres from the transmitter; and
is capable of receiving a signal from a television service in analog mode, on the same channel as the proposed channel, at a field strength of at least 67dBV/m.
Agreements between licensees
116. This part applies to each digital licensee.
117. However, nothing in this part prevents a digital licensee that is required to take action in accordance with this part from:
making an agreement with an analog licensee that is licensed to transmit services in analog mode that the other licensee will take the necessary action; or
making an agreement with 1 or more licensees or other persons to comply with a requirement under this part on a collective basis; or
relying on an agreement, with the effect described in paragraph (a) or (b), that was made before this guideline commences.
Example for paragraph (b) Providing a single telephone number for an interference hotline.
118. If a digital licensee makes, or relies on, an agreement for guideline 117 of these guidelines:
any obligation of the licensee under this part is taken to be fulfilled by the licensee if the obligation is fulfilled by a person acting in accordance with the agreement; but
the agreement does not relieve the licensee of the obligation if the obligation is not fulfilled by the licensee personally, or a person acting in accordance with the agreement.
Start up procedure
119. If a digital licensee plans to do an act that is mentioned in guideline 12 of these guidelines:
the digital licensee shall comply with the requirements in guidelines 120 to 131 of these guidelines; and
the digital licensee shall not comply with the requirements in guideline 13 of these guidelines.
Note Guideline 12 mentions the following acts:
planning to establish a transmitter to transmit a broadcasting or datacasting service;
planning to change the technical operating specifications of a transmitter which is authorised for transmitting a broadcasting or datacasting service (other than a change of transmission site).
Advertisements
120. At least seven days before the first test transmission, the digital licensee or an authorised person shall place advertisements in each newspaper that has the highest circulation in each urban centre in the notification area of at least 2 500 persons. The advertisement should:
include the address and telephone number of the person responsible for the tests; and
give details of the date of each proposed test transmission and the frequency to be used; and
state that members of the public should contact the licensee or authorised person if a test transmission causes interference to other radiocommunications; and
include the contact details of an appropriate person; and
state that the information mentioned in paragraph 122 (a) of these guidelines is available, free of charge, in the ways that the licensee has chosen for the purposes of guideline 123 of these guidelines.
The digital licensee or authorised person shall give the ABA a copy of the advertisement as soon as practicable after publishing it.
Advance notification
121. At least seven days before the first test transmission, the licensee or an authorised person shall advise the following persons of the date and proposed technical operating specifications of each test transmission:
the Minister;
the ABA;
the ACA office for the notification area;
a person that:
provides services using VHF Band III or UHF; or
is a licensed operator of a retransmission facility that is to provide services using VHF Band III or UHF;
each broadcasting licensee that provides services within the notification area;
each datacasting licensee that provides services within the notification area;
each licensee for a subscription broadcasting service that provides services within the notification area;
each Member of the Commonwealth Parliament who represents an electorate that includes a part of the notification area;
each Member of the Parliament of a State or Territory who represents an electorate that includes a part of the notification area;
each local government body that has responsibility for the notification area;
the chief executive officer, or similar person, of each hospital that is in the notification area;
the Minister of the State or Territory who is responsible for health services.
The digital licensee or authorised person shall also include the address and telephone number of the person responsible for the tests, the contact details of an appropriate person, information about the interference hotline, and the written information mentioned in guideline 122 of these guidelines.
Written information
122. At least seven days before the first test transmission, the digital licensee shall have completed arrangements to provide written information that:
explains interference issues in the form of:
statements or replies to ‘frequently asked questions’; and
statements about why interference might be a problem in the area; and
statements about common solutions for resolving interference; and
gives contact details of the licensee (including a phone number and email address).
123. The arrangements shall include:
the publication of the information:
in a brochure or pamphlet in which all of the pages are bound or joined together (rather than being in a loose-leaf format); or
on a sheet of printed material; and
the publication of the information on a website maintained by or for the digital licensee; and
making the information available for use, on request, as part of the interference hotline; and
making the information available in at least one of the following ways:
as an insert or advertisement in at least 2 publications that display a schedule of television programs to be shown in the notification area;
by delivering the publication mentioned in paragraph (a) to each household in the notification area;
as a ‘crawler’ that:
forms part of a television program transmitted by the broadcaster in analog mode; and
is run as part of a transmission during prime time at intervals not more than 25 minutes apart over a period of 1 month from the commencement of digital transmissions; and
is run at other times that the digital licensee chooses; and
provides the information in summary form (including information about the existence of the interference hotline and the availability of the publication mentioned in paragraph (a) to callers to the hotline); and
as an advertisement that:
forms part of a television program transmitted by the broadcaster in analog mode; and
is run as part of a transmission during prime time at intervals not more than 25 minutes apart over a period of 1 month from the commencement of digital transmissions; and
is run at other times that the digital licensee chooses.
Note The brochure or pamphlet shall be available to the public at all times during the obligation period: see guideline 141 of these guidelines.
124. The digital licensee shall ensure that the information is available from the day of the first transmission.
Interference hotline
125. At least seven days before the first test transmission, the digital licensee or an authorised person shall have established a telephone number that can be used to make complaints about interference from the transmission of digital television or datacasting services. The digital licensee or authorised person shall decide whether to establish the number for use by making freephone calls or local rate calls.
Note The interference hotline shall be available to the public at all times during the obligation period: see guideline 142 of these guidelines.
Media releases
126. At least seven days before the first test transmission, the digital licensee or an authorised person shall have completed the publication and distribution of media releases for media organisations that operate in the notification areas. A media release should include:
a summary of the information that is mentioned in guidelines 120 to 125 of these guidelines; and
the technical operating specifications of the transmitter (as defined in these guidelines).
127. If arrangements have been made in accordance with guidelines 120 to 126 of these guidelines, test transmissions may be made. Test transmissions shall be conducted for at least seven days.
128. The digital licensee shall, for at least seven days, conduct test transmissions in accordance with the technical operating specifications that the licensee intends to apply to the transmissions after the testing procedure is complete.
129. The digital licensee or an authorised person shall undertake any necessary further planning so as to eliminate or minimise unacceptable interference that is identified during a test transmission.
130. All interference caused by a test transmission described in guideline 128 of these guidelines should be eliminated or minimised before the test transmission procedure is completed.
131. Interference assessment reports, and documentation of any relevant calculations, shall be made available on request to the ABA and the ACA.
Log of technical operating specifications
132. A digital licensee shall make and keep a log of technical operating specifications that outlines temporary and long term changes to the operating conditions of transmitters.
133. The digital licensee shall record in the log of technical operating specifications any change to the technical operating specifications of a transmitter, including:
the date on which the change was made; and
the original technical operating specifications; and
the new technical operating specifications; and
the nature of the change; and
the reason for making the change.
134. The ABA may, by written notice given to a digital licensee, require the licensee:
to make the log of technical operating specifications available for inspection by a member of the staff of the ABA; and
to permit that member to make copies of anything in the log.
Note The ABA may give to the ACA the information in a log of technical specifications.
Interference complaints: test transmissions and other transmissions
135. Complaints from viewers about unacceptable interference from a digital transmission may be made using the interference hotline.
136. It is also possible that a person who is mentioned in a paragraph of guideline 121 of these guidelines will receive a complaint about unacceptable interference from a digital transmission.
If the person forwards the complaint to the digital licensee, and includes the matters that are required in the register of complaints, the digital licensee shall treat the complaint as a complaint from the viewer.
If the person forwards the complaint to the digital licensee, but does not include all of the matters that are required in the register of complaints, the digital licensee is not required to treat the complaint as a complaint from the viewer.
Note A person who is mentioned in a paragraph of guideline 121 of these guidelines will be given information about the complaints process, but is under no obligation to forward a complaint or to refer a viewer to the interference hotline.
Obligation period
137. For a period of 12 months after the commencement of digital transmission, the digital licensee that is responsible for the transmission shall:
investigate complaints about unacceptable interference; and
identify and rectify any unacceptable interference that has occurred as a result of the digital transmission.
This period is the obligation period for the digital licensee.
138. The ABA may, in writing, extend an obligation period for a digital licensee. The ABA:
may extend the period more than once; but
may extend the period only if the period has not already expired.
An obligation period for a digital licensee cannot end later than 18 months after the commencement of digital transmission by the digital licensee, unless the obligation period is a new period created in accordance with paragraph 140 (a) or 140 (c) of these guidelines.
139. If the ABA proposes to extend an obligation period for a digital licensee, the ABA shall notify the digital licensee before the end of the current obligation period.
140. An obligation period is affected as follows by changes to the technical operating specifications of a transmitter:
there is a change to the technical operating specifications of a transmitter; and
the change is made to comply with a requirement of these guidelines —
a new obligation period of 12 months starts from the day of the change;
there is a change to the technical operating specifications of a transmitter; but
the specifications are, within a reasonable period, returned to specifications that are the same as all of the previous technical operating specifications —
the obligation period returns to the period that was in force immediately before the change;
there is a change to the technical operating specifications of a transmitter; and
paragraphs (a) and (b) do not apply to the change —
a new obligation period of 12 months starts from the day of the change.
Note Changes to the technical operating specifications of a transmitter regularly occur as a part of standard broadcasting practice and maintenance, and it is not intended that every change to technical operating specifications will incur a new obligation period.
Standard maintenance often includes a temporary deviation from the original technical operating specifications followed by a return to the original specifications.
141. A digital licensee, or an authorised person, that is mentioned in guideline 123 of these guidelines shall ensure that the brochure or pamphlet that is mentioned in the guideline is available to the public at all times during the obligation period.
142. A digital licensee, or an authorised person, that is mentioned in guideline 125 of these guidelines shall ensure that the interference hotline is maintained at all times during the obligation period, either by a human operator or by the availability of a recorded message service. The licensee or person is not required to have personnel in attendance, to answer calls, at all times.
Register of complaints
143. A digital licensee shall make and keep a register, during the obligation period, of interference complaints that the digital licensee has received.
144. The register shall include the following information for each complaint:
the date on which the complaint was received;
the name and address of the complainant;
the postcode of the complainant;
the nature of the complaint;
any action taken, including evidence showing that:
the action was taken; and
the action was an appropriate response;
whether the complaint has been resolved.
145. The digital licensee shall not disclose information in the register to another person, other than the ABA or the ACA, unless the disclosure is required as part of the resolution of the complaint.
146. The ABA may, by written notice given to a digital licensee, require the person:
to make the register available for inspection by a member of the staff of the ABA; and
to permit that member to make copies of anything in the register.
Note The ABA may give to the ACA the information in a register.
Predicted and unpredicted interference to analog transmissions: background
147. The Conversion Schemes require the ABA to identify digital channels to be available in an area. This is achieved through the Digital Channel Plan (DCP) process. In formulating a DCP, the engineering work conducted by the ABA identifies unacceptable interference that is likely to occur to the direct reception of a television program transmitted by a broadcaster in analog mode if a particular channel is used. The DCP then allots the channel with ERP restrictions to overcome this problem until the digital licensee can rectify it.
Note The direct reception of a television program transmitted by a broadcaster in analog mode may be achieved by means of a television set, or a television tuner within a VCR.
148. For guideline 147 of these guidelines, interference caused by or to an ancillary device is not interference to direct reception.
149. However, the DCP may not identify all potential interference issues. Therefore, while some channels are allotted without ERP restrictions, unacceptable interference may still be caused by transmissions using those channels.
Note In developing DCPs the ABA has identified only situations where unacceptable interference is likely to occur. It is possible that while a DCP has predicted situations of unacceptable interference to some analog services, interference that has not been predicted may also occur to other analog services.
If the ABA has predicted interference in the DCP, operation at a reduced power may resolve the predicted interference issues, but there could still be an issue relating to unpredicted interference.
150. The ABA distinguishes between:
predicted interference, which is interference that has been anticipated in a DCP; and
unpredicted interference, which is interference that has not been anticipated in a DCP.
Note A licensee that uses a frequency that is subject to predicted interference has licence conditions placing ERP restrictions on transmissions. Therefore, it is not expected that further unacceptable interference will occur. If further unacceptable interference does occur, this would be treated as unpredicted interference.
The ABA has foreshadowed in its DCPs the possibility that, if predicted interference is eliminated, the ERP restrictions would be removed.
Management of predicted interference
151. A digital licensee that uses a frequency that is subject to predicted interference shall:
conduct an interference study to determine the scope of the interference; and
make arrangements with each analog licensee that is identified as a recipient of the interference to resolve any issues relating to the interference; and
either:
apply to the ABA to have the ERP restriction that relates to the predicted interference removed when the interference issues are resolved; or
if it possible to transmit without the ERP restriction, in accordance with the arrangements under paragraph (b), transmit without the restriction.
Note Under the Act, a digital licensee is also required to comply with the conditions on the licensee’s licence.
152. For the purpose of subparagraph 151 (c) (ii) of these guidelines, the digital licensee shall:
notify the ABA, before transmitting without the ERP restriction, that it is possible for the licensee to transmit without the restriction; and
give the ABA a copy of the arrangements with evidence that the analog licensee has endorsed or agreed to the arrangements.
153. For the purpose of conducting the interference study that is mentioned in paragraph 151 (a) of these guidelines, the digital licensee:
may conduct test transmissions, without ERP restrictions, for not more than two hours in total on a day; but
shall not conduct any test transmissions between 6.30 pm and 9.30 pm, local time.
154. In considering an application to remove an ERP restriction, the ABA intends to consider:
the extent to which the digital licensee has tried to rectify the interference; and
any relevant results from the interference study that is mentioned in paragraph 151 (a) of these guidelines; and
any arrangement between the digital licensee and an analog licensee that is identified as a recipient of the interference for the purposes of paragraph 151 (b) of these guidelines.
Management of unpredicted interference: handling complaint
155. A digital licensee shall investigate:
each unresolved complaint that it receives from its interference hotline; and
each complaint that is referred to it in accordance with paragraph 136 (a) of these guidelines; and
each complaint that the digital licensee chooses to treat as a complaint in accordance with paragraph 136 (b) of these guidelines;
to determine whether there is any unacceptable interference and, if so, the action that is required to resolve the complaint in accordance with guideline 163 of these guidelines.
156. Subject to guideline 157 of these guidelines, if the digital licensee determines that the interference that was experienced by the complainant is not unacceptable interference, the licensee shall:
notify the complainant to that effect; and
provide evidence in support of the licensee’s determination.
157. If the digital licensee determines that the interference that was experienced by the complainant is not caused by a digital transmission, the digital licensee shall:
notify the complainant of the cause of the interference; and
refer the complaint to the ACA; and
refer the complainant to another person if it is identified that the interference is caused by that person’s transmissions.
Note Part 7 of these guidelines is concerned mainly with interference that is caused by digital transmissions, however, interference can be caused by sources other than digital transmissions (for example, analog television transmissions or the use of radiocommunications devices).
158. If the digital licensee determines that the interference that was experienced by the complainant is unacceptable interference that is caused by a source other than the digital licensee’s digital transmissions, the digital licensee shall:
notify the complainant of the cause of the interference and
refer the complaint to the ACA; and
refer the complainant to another person if it is identified that the interference is caused by that person’s transmissions.
159. If a complaint is referred to the ACA under guideline 157 or 158 of these guidelines, the digital licensee shall provide evidence in support of the licensee’s determination.
160. If the ACA determines that the unacceptable interference identified in a complaint referred to the ACA under guideline 157 or 158 of these guidelines is caused by a digital licensee’s digital transmissions, it shall refer the complaint to that licensee. The licensee may be the licensee who referred the complaint to the ACA.
161. If the digital licensee determines that the interference that was experienced by the complainant is unacceptable interference caused by the digital licensee’s digital transmissions, but is being caused to an ancillary device, or to another device or service to which this part does not apply, the digital licensee shall resolve the complaint by giving the complainant advice about:
retuning ancillary devices; and
appropriate cabling methods for connecting televisions and ancillary devices; and
the contact information of persons who may be able to assist with these tasks.
The digital licensee shall also notify licensees for subscription broadcasting services that provide services within the notification area about the advice, and invite them to comment on it.
162. If the digital licensee determines that the interference that was experienced by the complainant:
is unacceptable interference; and
is caused by the digital licensee’s digital transmissions; and
is not being caused to an ancillary device —
the digital licensee shall resolve the complaint as soon as practicable.
Management of unpredicted interference: resolution of complaint (general)
163. A complaint is resolved only in one of the following ways:
the complainant is satisfied;
the digital licensee reduces the unpredicted interference to a level that does not make it unacceptable interference (including a reduction by the use of equipment such as a filter on a transmitter);
the digital licensee:
provides reception equipment to the complainant that reduces the unpredicted interference to a level that does not make it unacceptable interference (for example, a new antenna); or
adjusts or fits a device to the receiver in order to eliminate or minimise the interference;
a transmitter is modified to reduce the unpredicted interference to a level that does not make it unacceptable interference;
for a complaint to which guideline 161 of these guidelines applies, the digital licensee gives the advice that is mentioned in that guideline.
164. The digital licensee shall:
provide reception equipment; or
adjust or fit a device to the receiver in order to eliminate or minimise interference —
at no cost to the complainant.
165. If a digital licensee that is investigating an interference complaint has made a change to the technical operating specifications of a transmitter as part of the investigation (whether or not the transmitter is controlled by the digital licensee), the digital licensee shall notify the complainant of the changes to the technical operating specifications.
Note The change to the specifications is an act to which guideline 119 of these guidelines applies.
Management of unpredicted interference: resolution of complaint (post code population threshold)
166. If the number of unresolved complaints relating to a digital licensee reaches a postcode population threshold, the digital licensee shall:
comply with guidelines 168 to 171 of these guidelines within fourteen days after the day on which the number of unresolved complaints reaches the threshold; and
comply with guidelines 172 to 176 of these guidelines.
The period of fourteen days is the resolution period.
167. If the ABA believes that it is in the public interest for a digital licensee to comply with guidelines 168 to 171 of these guidelines, even though the number of unresolved complaints relating to a digital licensee has not reached the postcode population threshold:
the ABA may notify the digital licensee to that effect; and
if the ABA notifies the digital licensee, the digital licensee shall:
comply with guidelines 168 to 171 of these guidelines within fourteen days after the day on which the notification is received; and
comply with guidelines 172 to 176 of these guidelines.
The period of fourteen days is the resolution period.
168. The digital licensee shall:
conduct an interference study; and
determine the cause of the interference; and
take action to resolve the complaints.
169. The digital licensee shall, if practicable, rectify the interference, without lowering the ERP, before the end of the resolution period.
170. If it is not practicable for the digital licensee to rectify the interference, without lowering the ERP, before the end of the resolution period, the digital licensee shall lower the ERP to the extent that a sufficient number of complaints can be resolved to reduce the number of unresolved complaints to less than the postcode population threshold.
Note A complaint that cannot be resolved after actions taken in accordance with these guidelines is an unresolved complaint: see guideline 163 of these guidelines.
171. The digital licensee shall notify the ABA, and each complainant who has an unresolved complaint, that:
the number of unresolved complaints has reached the threshold; and
the digital licensee is in the process of investigating the cause of the interference in accordance with these guidelines.
172. At the conclusion of the resolution period, the digital licensee shall notify the ABA, and each complainant, in writing, of:
the results of the interference study; and
the action taken by the digital licensee to resolve the complaints, including evidence showing that:
the action was taken; and
the action was an appropriate response.
Note Ways of resolving a complaint are explained in guideline 163 of these guidelines.
173. If the digital licensee has not lowered the ERP as part of the action taken to resolve the complaints, the digital licensee shall also give empirical evidence to the ABA in support of the reasons why it is not necessary.
Example The digital licensee has rectified the problem by installing a filter on the transmitter.
174. If:
the report of the interference study states that the ERP should be lowered to avoid interference; or
the ABA has not received the report by the end of the resolution period;
the ERP of the digital licensee’s transmitter shall be reduced sufficiently to reduce the number of unresolved complaints relating to the digital licensee to less than the postcode population threshold.
175. If the ERP of a digital licensee’s transmitter has been lowered, the ERP shall not be increased unless:
the digital licensee has notified the ABA that the digital licensee intends to transmit at the new ERP; and
the digital licensee has given the ABA the report of a new interference study; and
the measurements of the field strength of transmissions that are included in the new interference study were taken at the same sites that were used in the original interference study; and
the digital licensee has given the ABA a report of the actions taken (including evidence); and
the ABA is satisfied that the digital licensee has taken action to ensure that unacceptable interference will not occur.
176. For the purpose of preparing the report that is mentioned in paragraph 175 (b) of these guidelines, the digital licensee:
may conduct test transmissions, without ERP restrictions, for not more than two hours in total on a day; but
shall not conduct any test transmissions between 6.30 pm and 9.30 pm, local time.
Appendix 1:
Emission Standard for the Australian Amplitude Modulation Sound Broadcasting Service
The purpose of the emission standard for the Australian Amplitude Modulation Sound Broadcasting Service is to define the parameters to be used for sound broadcasting in the frequency band 526.5 to 1606.5 kHz. This emission standard supersedes the Draft Emission Standard for the Australian Amplitude Modulation Sound Broadcasting Service prepared by the Department of Transport and Communications in 1992.
The standard follows international practice and is based on relevant parts of ITU-R Recommendations BS.598 and BS.639. Provision is made for stereophonic as well as monophonic program transmission.
In general, tolerances are not specified as this standard is intended to define the nominal values for the transmitted signal. Where tolerances are specified, they relate to parameters that would influence the potential of the installation to interfere with other services or are needed to meet the technical operating conditions determined for the particular service.
This standard does not encompass technical equipment performance, measurement methods or operational procedures.
(Unless defined below, words shall have the same meanings as in the Broadcasting Services Act 1992, or the Radiocommunications Act 1992, or the ITU Radio Regulations, as appropriate)
1. In this standard the following definitions apply:
‘channel’ means an AM broadcasting channel that is described in guidelines 2 and 3;
‘C-QUAM’ means compatible quadrature amplitude modulation;
‘M signal’ means a signal equal to the sum of the left hand signal (L) and the right hand signal (R). This signal forms the compatible monophonic signal used to amplitude modulate the carrier;
‘necessary bandwidth’ means, for a given class of emission, the width of the frequency band which is just sufficient to ensure the transmission of information at the rate and with the quality required under specified conditions;
‘out-of-band emission’ means an emission on a frequency or frequencies immediately outside the necessary bandwidth which results from the modulation process, but excluding spurious emissions;
‘pilot signal’ means a sinusoidal signal used to phase modulate the carrier of a stereo transmission to indicate to the receiver the presence of a (C-QUAM) stereo transmission;
‘S signal’ means a signal equal to the difference between the left hand signal (L) and the right hand signal (R). This signal forms the stereo difference signal used to phase modulate the carrier; and
‘spurious emission’ means an emission on a frequency or frequencies which are outside the necessary bandwidth and the level of which may be reduced without affecting the corresponding transmission of information. Spurious emissions include harmonic emissions, parasitic emissions, intermodulation products and frequency conversion products, but exclude out-of-band emissions.
2. The width of the radio frequency channel shall be 9 kHz.
3. The channel spacing shall be 9 kHz with the lowest channel centre frequency being 531 kHz and the highest channel centre frequency being 1602 kHz.
4. Unless otherwise specified, the frequency of the carrier shall be maintained within 10 Hz.
Note Reference: ITU Radio Regulations (2001 edition), appendix 2, Table of Transmitter Frequency Tolerances.
Main carrier location and modulation
5. The carrier shall be centrally located in the channel and shall be amplitude modulated to a maximum of 125 per cent positive and 100 per cent negative modulation by the sum signal (L+R). For stereo transmissions, the carrier shall also be phase modulated to a maximum of 1.26 radians by the combination of the difference signal (L‑R) and a 25 Hz pilot signal.
Polarisation of the radiated signal
6. The polarisation of the radiated signal shall be as specified by the ABA.
Out-of-band and spurious emissions
7. The necessary bandwidth of the radio frequency emission is deemed to extend 9 kHz from the carrier frequency.
8. Any emission on a frequency removed from the carrier by more than 9 kHz, and up to and including 18 kHz, shall be attenuated at least 25 dB below the level of the carrier. Any emission on a frequency removed from the carrier by more than 18 kHz, and up to and including 27 kHz, shall be attenuated at least 35 dB below the level of the carrier. For frequencies removed from the carrier by more than 27 kHz, the level of any emission shall be further attenuated at a rate of 1 dB per kHz, or shall not exceed a level of 200 V/m, whichever is less stringent. The emission mask of the radiated signal is shown in figure A1-1.
9. Out-of-band and spurious emissions shall be quoted with respect to the carrier level and shall be measured at a distance of one kilometre from the antenna system.
Figure A1.1: Emission mask for radiated field strength
Program signal characteristics
Monophonic transmission
10. The signal shall be double sideband amplitude modulated. The modulation depth is not to exceed 125 per cent for positive modulation and 100 per cent for negative modulation.
The instantaneous amplitude of the modulated carrier shall satisfy the expression:
11. The compatible quadrature amplitude modulation (C-QUAM) system shall be employed for the transmission of stereophonic signals.
12. The radiated signal shall consist of a carrier, amplitude modulated by the monophonic sum signal (L+R) and phase modulated by the stereophonic difference signal (LR). The pilot signal must be included in stereo transmissions.
13. Amplitude modulation depth shall not exceed 125 per cent for positive modulation and 100 per cent for negative modulation.
14. Phase modulation shall not exceed 1.26 radians including the pilot signal.
15. The instantaneous amplitude of the modulated carrier shall satisfy the expression:
Note In the presence of modulation processing, the gamut of M and S signals must be constrained. The magnitude of the S signal must be limited in the presence of high negative amplitude modulation. See guideline 18 ‘Gamut of Sum and Difference Modulation’. This limiting is normally implemented in the C‑QUAM modulator.
Pilot tone
16. The pilot tone (denoted above by P) must be included with all transmissions in the stereo mode. The frequency of the tone shall be 25 Hz 0.1 Hz and it shall phase modulate the carrier to 0.05 0.01 radians of deviation in the absence of (LR) channel signal.
Audio frequency response
17. The steady state audio frequency response shall be nominally flat over the range of 50 Hz to 7 kHz.
Note 1 Appropriate audio filtering may be required at the input to the transmitter in order to meet the out-of-band and spurious emission requirements of guideline 8.
Note 2 Performance parameters are not specified in this standard. However, to obtain good monophonic reception from stereophonic broadcasts, the relative delay of L and R signals originating from the same source needs to be within acceptable limits on arrival at the modulator input, otherwise cancellation may take place in the M signal matrix. Such delays may occur in any section of the system where L and R signals follow separate routes - such as in tape recorders and relay circuits, or in the acoustic paths to spaced microphones. Consequently, relative signal delay needs careful attention in program production and system engineering.
Gamut of sum and difference modulation
18. As a result of applying modulation processing separately to the sum (M) and difference (S) signals, unnatural combinations of M and S signals become possible. That is, M and S signals may be generated in combinations which are not realisable in natural sound fields.
The maximum permissible phase deviation of the carrier is not more than 1.26 radians and the instantaneous carrier amplitude must not be reduced to zero with phase modulation simultaneously present. Hence the C-QUAM modulator must apply limits to the level of difference signals (i.e. the S signal magnitude) during high instantaneous negative amplitude modulation (i.e. negative values of the M signal) or vice versa.
Figure A1.2 represents the gamut of M and S signals (normalised so that M lies between +1.25 and 1 and S lies between +1 and 1) that result in permissible levels of amplitude and phase modulation of the carrier.
Note It will be observed that the limit on the S signal amplitude while the M signal is close to 1 is not a severe practical constraint. The long term average of normal stereo program material forms an ellipse on the above diagram with the major semi axis coinciding with the M axis. The ratio of major to minor axes of this ellipse is normally greater than 2:1.
Appendix 2:
Emission Standard for the Australian Frequency Modulation Sound Broadcasting Service
The purpose of the emission standard for the Australian Frequency Modulation Sound Broadcasting Service is to define the parameters to be used for sound broadcasting in the frequency band 87.5 to 108 MHz. This standard supersedes the Emission Standard for the Australian Frequency Modulation Sound Broadcasting Service, published by the Department of Transport and Communications in July 1992. Provision is made for stereophonic as well as monophonic program transmission.
The standard for transmission of the main sound program follows international practice and is based on the pilot-tone system specified in ITU-R Recommendation BS.450.
The preferred standard for the transmission of an ancillary communications service (ACS) is that developed by the then Department of Communications and the Arts following field and laboratory tests. It is based on a 67 kHz sub-carrier frequency. The scope of the ACS standard has been expanded to include specifications under which alternative ACS sub-carrier frequencies may be used.
In general, tolerances are not specified as this standard is intended to define the nominal values for the transmitted signal.
(Unless defined below, words shall have the same meanings as in the Broadcasting Services Act 1992, or the Radiocommunications Act 1992, or the ITU Radio Regulations, as appropriate)
1. In this standard, the following definitions apply:
‘ancillary communication service’ means a separate supplementary information service on a modulated sub-carrier;
‘baseband’ means the composite modulating signal applied to produce frequency modulation of the main carrier. In the case of monophonic transmission without an ancillary communications service, this is the audio signal;
‘channel’ means an FM broadcasting channel that is described in guidelines 2 and 3;
‘M signal’ means a signal equal to one half the sum of the left hand signal (L) and the right hand signal (R). This signal forms the compatible monophonic component of the stereophonic baseband signal;
‘main carrier’ means the VHF signal modulated by the baseband signal;
‘maximum deviation’ means the maximum value permitted for deviation of the carrier frequency from its unmodulated frequency;
‘necessary bandwidth’ means, for a given class of emission, the width of the frequency band which is just sufficient to ensure the transmission of information at the rate and with the quality required under specified conditions;
‘out-of-band emission’ means an emission on a frequency or frequencies immediately outside the necessary bandwidth which results from the modulation process, but excluding spurious emissions;
‘pilot signal’ means an unmodulated sine wave signal forming part of the stereophonic baseband signal used to regenerate the suppressed sub-carrier, or to permit detection of suppressed sub-carrier modulation;
‘pre-emphasis’ means a process whereby the level of audio signals is increased with increase in frequency prior to encoding or modulating the main carrier. Complementary de-emphasis at the receiver reduces the level of upper audio frequency noise components in the reproduced signals. Pre-emphasis can be applied to either the L and R signals or to the M and S signals;
‘S signal’ means a signal equal to one half of the difference between the left hand signal (L) and the right hand signal (R). This signal forms the difference signal used to amplitude modulate the 38 kHz (suppressed) sub-carrier;
‘spurious emission’ means an emission on a frequency or frequencies which are outside the necessary bandwidth and the level of which may be reduced without affecting the corresponding transmission of information. Spurious emissions include harmonic emissions, parasitic emissions, intermodulation products and frequency conversion products, but exclude out-of-band emissions;
‘sub-carrier’ means a carrier which is applied as a component of the baseband signal to modulate the main carrier; and
‘stereophonic signal’ means the baseband or modulating signal which comprises: the M signal; sidebands of the S signal amplitude modulated 38 kHz suppressed sub-carrier; and the pilot signal of frequency 19 kHz. This composite signal has a spectrum width of 53 kHz.
2. The width of the radio frequency channel shall be 200 kHz.
3. The channel spacing shall be 200 kHz with the lowest channel centre frequency being 87.7 MHz and the highest channel centre frequency being 107.9 MHz. A carrier frequency offset of 100 kHz may be specified.
4. Unless otherwise specified, the frequency of the unmodulated carrier shall be maintained within 1000 Hz for a transmitter fed with a baseband signal or 2000 Hz for a transmitter fed with a signal derived from another transmitter by frequency conversion (i.e. not demodulation).
5. Channels allocated for the Australian Frequency Modulation Sound Broadcasting Service are shown in table A2.1.
Main carrier location and modulation
6. The main carrier shall be centrally located in the channel and shall be frequency modulated by the baseband signal.
7. The maximum frequency deviation of the main carrier shall not exceed 75 kHz. A positive value of the baseband signal (i.e. when the signal crosses the time axis with a positive slope) shall correspond to a positive frequency deviation of the main carrier.
Polarisation of the radiated signal
8. The polarisation of the radiated signal shall be as specified by the ABA.
Out-of-band and spurious emissions
9. The necessary bandwidth of the radio frequency emission is deemed to extend 120 kHz from the carrier frequency.
10. Any emission on a frequency removed from the carrier by more than 120 kHz, and up to and including 240 kHz, shall be attenuated at least 25 dB below the level of the unmodulated carrier. Any emission on a frequency removed from the carrier by more than 240 kHz, and up to and including 600 kHz, shall be attenuated at least 35 dB below the level of the unmodulated carrier. Any emission on a frequency removed from the carrier by more than 600 kHz shall be attenuated at least 43 + 10log P dB (where P is transmitter power in watts) below the level of the unmodulated carrier, or 80 dB, whichever is the lesser attenuation.
Main program signal characteristics
Monophonic transmission
11. The baseband signal shall comprise audio frequency components of the program signal within the band 30 Hz to 15 kHz. Pre-emphasis of the audio signal shall be in accordance with the admittance/frequency characteristic of a parallel resistance-capacitance circuit having a time constant of 50 microseconds (see figure A2-4).
12. For monophonic transmission, without pilot sub-carrier, the deviation of the main carrier by the M signal shall not exceed 75 kHz.
Stereophonic transmission
13. The pilot-tone system shall be employed for the transmission of stereophonic signals. In this system the baseband signal consists of:
a compatible signal, M, which shall produce a deviation of the main carrier of not more than 67.5 kHz;
a double sideband, amplitude modulated, suppressed sub-carrier signal generated by the modulating signal S. This signal shall produce a frequency deviation of the main carrier not exceeding 67.5 kHz when L and R signals are equal and of opposite phase; and
a pilot signal which shall have a frequency equal to one half of that of the sub-carrier, and shall produce a frequency deviation of the main carrier of not less than 6 kHz and no more than 7.5 kHz.
For stereophonic transmission, under all conditions of modulation by the composite baseband signal, the maximum instantaneous carrier frequency deviation shall not exceed 75 kHz.
Sub-carrier frequency
14. The frequency of the (suppressed) sub-carrier shall be 38,000 4 Hz.
Sub-carrier suppression
15. The residual sub-carrier shall not produce a deviation of the main carrier of more than 750 Hz.
Audio frequency response
16. The M and S channels shall substantially pass audio frequency components in the band 30 Hz to 15 kHz.
Pre-emphasis
17. Pre-emphasis of the signal S shall be identical with that of the compatible signal M and shall be the same as that for monophonic transmission. The pre-emphasis characteristic of the audio signal shall be in accordance with the admittance/frequency characteristic of a parallel resistance-capacitance circuit having a time constant of 50 microseconds (see figure A2.4).
Modulation polarity
18. The relative phase of the pilot signal and the sub-carrier is such that, when the transmitter is modulated by a multiplex signal for which L is positive and R = L, this signal crosses the time axis with a positive slope each time the pilot signal has an instantaneous value of zero. The phase of the pilot signal should not differ by more than 3 degrees from the above state. Moreover, a positive value of the multiplex signal corresponds to a positive frequency deviation of the main carrier.
Note To obtain good monophonic reception from stereophonic broadcasts, the relative delay of L and R signals originating from the same source needs to be within acceptable limits on arrival at the encoder input, otherwise cancellation may take place in the M signal matrix. Such delays may occur in any section of the system where L and R signals follow separate routes - such as in tape recorders and relay circuits, or in the acoustic paths to spaced microphones. Consequently, relative signal delay needs careful attention in program production and system engineering.
Ancillary communications services
Sub-carrier signals
19. Information supplementary to the main sound broadcasting program may be transmitted on sub-carriers located above the M and S signals. In this standard, three classes of sub-carrier are considered:
67 kHz sub-carrier;
57 kHz sub-carrier; and
other sub-carriers below 95 kHz.
20. Ancillary Communications Service (ACS) sub-carriers may be used singly or in combination on condition that:
the use of such sub-carriers shall not cause interference to or degradation of the main channel or other channels;
the deviation of the main carrier due to the entire baseband signal, including all ACS signals, shall not exceed 75 kHz; and
the deviation of the main carrier by any one ACS sub-carrier alone shall not exceed 7.5 kHz.
Sub-carrier frequencies below 57 kHz and above 95 kHz shall not be used.
67 kHz ACS sub-carrier
Sub-carrier frequency
21. The sub-carrier frequency shall be 67 kHz 100 Hz.
Peak deviation (sub-carrier)
22. For audio program and tone signals the peak deviation of the sub-carrier shall be dependent on the highest frequency modulating the sub-carrier in accordance with figure A2.1 (for audio program) and figure A2.2 (for audio frequency shift keyed data).
23. For direct FSK modulation the peak deviation of the sub-carrier shall be dependent on the injection level of the sub-carrier in accordance with figure A2.3 when it is directly modulated with data signals.
Pre-emphasis
24. Pre-emphasis to a time constant of 150 microseconds may be applied to an analog music or speech signal modulating the sub-carrier (see figure A2.4).
25. Sideband products in the baseband resulting from modulation of the sub-carrier shall not degrade the main channel L and R (or M and S) signals. Additionally, such products shall be attenuated to the extent necessary to meet the out-of-band and spurious emission requirements of this standard (see guideline 10). This may require attenuation of such products, when averaged in a 3 kHz bandwidth of baseband frequencies below 53 kHz and above 81 kHz, to at least 60 dB below the level of the unmodulated sub-carrier.
57 kHz ACS sub-carrier
Radio data system (RDS)
26. The 57 kHz sub-carrier is primarily intended for use with systems complying with the specification for the Radio Data System (RDS) as published in CENELEC EN50076:1998.
Use of RDS signals
27. Elements of the RDS data signal intended to carry information about main program content shall be reserved for use by the broadcaster of the main sound broadcasting program service. Non-program related data capacity of the RDS signal may be used for the transmission of supplementary information.
Non-RDS use
28. 57 kHz ACS services, not complying with the EN 50076 specification, may operate provided they do not cause false operation in receivers equipped with decoders for the reception of RDS signals conforming with EN 50076.
Other sub-carriers below 95 kHz
ACS frequency
29. An ACS sub-carrier frequency, other than 57 kHz or 67 kHz, may be used subject to the provisions in guideline 20.
30. Sideband products in the baseband resulting from modulation of the sub-carrier shall not degrade the main channel L and R (or M and S) signals. Additionally, such products shall be attenuated to the extent necessary to meet the out-of-band and spurious emission requirements of this standard (see guideline 10). This may require attenuation of such products, when averaged in a 3 kHz bandwidth of baseband frequencies below 53 kHz and above 99 kHz, to at least 60 dB below the maximum level of the sub-carrier.
Multiple sub-carriers
ACS frequencies
31. Any combination of 57 kHz and frequencies in the range 65 to 95 kHz may be used subject to the provisions in guidelines 19 to 30.
32. Sideband products in the baseband resulting from modulation of the sub-carriers (used singly or in combination) shall not degrade the main channel L and R (or M and S) signals. Additionally, such products shall be attenuated to the extent necessary to meet the out-of-band and spurious emission requirements of this standard (see guideline 10). This may require attenuation of such products, when averaged in a 3 kHz bandwidth of baseband frequencies below 53 kHz and above 99 kHz, to at least 60 dB below the maximum level of one sub-carrier.
Table A2.1: Frequency limits of Australian FM channels
Figure A2.4: Audio frequency pre-emphasis characteristics for 50 and 150 microsecond time constant
Appendix 3:
Emission Standard for the Australian Analog Terrestrial Television Service
The purpose of the emission standard for the Australian Analog Terrestrial Television Service is to define the parameters to be used for terrestrial broadcasting of analog television. This standard supersedes the Emission Standard for the Australian Terrestrial Television Service - sixth edition (Department of Transport and Communications, March 1989).
The standard is a variant of the PAL-B system described in ITU-R Recommendation BT.470 and BS.707.
The standard incorporates changes to channel numbering consequent to the adoption of 7 MHz channel spacing in Bands IV and V; specifications for the dual channel sound system; and line allocations in the vertical blanking interval for Teletext and closed caption data transmission.
The following characteristics are at variance with the PAL-B standard:
depth of vision modulation (see guideline 5);
use of lines in the vertical blanking interval (see guideline 19); and
group delay pre-correction (see figure A3.7).
(Unless defined below, words shall have the same meanings as in the Broadcasting Services Act 1992, or the Radiocommunications Act 1992, or the ITU Radio Regulations, as appropriate)
1. In this standard, the following definitions apply:
‘channel’ means an analog television broadcasting channel that is described in guideline 2;
‘necessary bandwidth’ means, for a given class of emission, the width of the frequency band which is just sufficient to ensure the transmission of information at the rate and with the quality required under specified conditions;
‘out-of-band emission’ means an emission on a frequency or frequencies immediately outside the necessary bandwidth which results from the modulation process, but excluding spurious emissions; and
‘spurious emission’ means an emission on a frequency or frequencies which are outside the necessary bandwidth and the level of which may be reduced without affecting the corresponding transmission of information. Spurious emissions include harmonic emissions, parasitic emissions, intermodulation products and frequency conversion products, but exclude out-of-band emissions.
Television channels
2. The width of the television channel shall be 7 MHz. Channel arrangements for the Australian Analog Terrestrial Television Service are shown in table A5.1 (see appendix 5).
Location of carriers within the channel
3. The nominal vision carrier frequency shall be 1.25 MHz above the lower frequency limit of the channel. The frequency of the unmodulated sound carrier for single sound carrier operation, or the lower frequency sound carrier of a dual sound carrier channel shall be 5.5 MHz above the vision carrier frequency. The frequency of the unmodulated second sound carrier of a dual sound carrier channel shall be 15.5 times the line frequency (242.1875 kHz) above the frequency of the first unmodulated sound carrier. Figure A3.5 details the nominal location of the carriers and sidebands within the channel.
Unless otherwise specified, the frequency tolerance of the vision and sound carriers shall be maintained within ±500 Hz. The ABA may specify frequency offsets from the nominal vision carrier frequency.
Note Reference: ITU Radio Regulations (2001 Edition), appendix 2, Table of Transmitter Frequency Tolerances.
Vision carrier modulation
4. The vision carrier shall be amplitude modulated by the video signal. Negative modulation shall be employed: that is a decrease in brightness shall cause an increase in the vision carrier amplitude.
Modulation levels of the vision carrier
5. Black and blanking levels shall be equal in amplitude and correspond to 76 per cent of the peak vision carrier amplitude. Reference white level shall correspond to 20 per cent of the peak vision carrier amplitude.
Sound carrier modulation
6. The sound carrier or carriers shall be frequency modulated by the audio signal. The peak deviation of the emitted signal shall be 50 kHz.
Polarisation of the radiated signals
7. The polarisation of the radiated sound and vision signals shall be the same and shall be as specified by the ABA.
Vision to sound power ratio
8. The nominal ratio of the vision carrier power at the sync pulse tips to the mean power output of the sound carrier or carriers shall be:
10 dB where the station transmits a single sound channel only; or
13 dB and 20 dB for the first and second sound carriers respectively where the station transmits dual sound signals.
Limits on spurious emissions
9. The level of any spurious emission shall not exceed that specified in the ITU Radio Regulations (appendix 3, 2001 edition).
Video characteristics
Scanning
Aspect ratio
10. The aspect ratio of the television picture shall be four units horizontally to three units vertically.
Scanning sequence
11. During active scanning intervals the scene shall be scanned from left to right horizontally, and from top to bottom vertically, at uniform velocities.
Number of lines and interlace
12. The number of scanning lines per picture shall be 625 interlaced two to one.
Picture and field frequencies
13. The nominal picture and field frequencies shall be 25 Hz and 50 Hz respectively, and equal to the appropriate sub-multiples (625 and 312.5 respectively) of the line frequency.
Colour sub-carrier and line frequencies
14. The colour sub-carrier frequency (sc) shall be 4433618.75 Hz ±5 Hz and the relationship between sc and the line frequency (H) shall be:
15. The video signal comprises the synchronising information occurring alternately on a time division basis with the picture signal as shown in figure A3.1. The picture signal comprises the luminance component together with the chrominance components if present. The nominal synchronising pulse amplitude shall be 3/7 of the blanking to reference white amplitude. Table A3.2 specifies the timing intervals of the video signal and figure A3.2 illustrates this relationship.
Colour picture signal
16. Coding of the colour information shall be in accordance with the Phase Alternation Line (PAL) system. In this system the colour picture signal, EM, contains a luminance component E’Y, and also simultaneous chrominance components E’U sin(2sct) and E’V cos(2sct) with the phase of the latter component being changed by 180° on alternate lines. The equation of the colour picture signal is:
E’R, E’G, E’B are, respectively, the red, green and blue gamma corrected voltages required for tristimulus matching. The value of the exponent for this correction shall be related to a display tube gamma of 2.8, and shall be consistent with optimum colour fidelity.
The sign of the term E’V cos(2sct) is positive during odd lines of the first and second fields and during even lines of the third and fourth fields (see figure A3.4).
As a consequence of the choice of colour difference signals the chrominance components both disappear in the absence of colour.
The resulting video signal for fully saturated primary and complementary colours at full luminance is shown in figure A3.2.
Bandwidth of colour difference signals
17. The colour difference signals shall be limited in bandwidth prior to modulation of the colour sub-carriers by a circuit having an approximate Gaussian response, with an attenuation of not more than 3 dB at 1.3 MHz, but greater than 20 dB at and above 4.0 MHz.
Colour synchronisation
18. A burst of 10 cycles of the colour sub-carrier frequency shall occur during each line blanking period, commencing nominally 5.6 microseconds after the half amplitude point of the leading edge of the line synchronising pulse. At the point of encoding the peak to peak amplitude of the sub-carrier burst shall be 3/7 of the blanking to reference white signal amplitude and thereafter the amplitude and phase of the burst shall be preserved relative to the chrominance signal. The envelope of the sub-carrier burst signal shall have a build-up time consistent with the bandwidth restriction of the colour difference signals.
The sub-carrier burst shall be omitted for nine consecutive lines starting at or before the beginning of each field blanking interval in a four field sequence as illustrated by figure A3.4. The phase sequence of the colour sub-carrier burst is also detailed in figure A3.4.
The phase of the sub-carrier burst relative to the +E’U signal reference phase axis shall be +135° on odd lines of the first and second fields and on even lines of the third and fourth fields and –135° on even lines of the first and second fields and on odd lines of the third and fourth fields (see figure A3.3).
During the transmission of monochrome signals the colour burst may be suppressed.
Special signals in the vertical blanking interval
19. Lines 10 to 22 and lines 323 to 335 may be transmitted for such purposes as control of equipment, source identification, data transmission and circuit performance testing.
Lines 17, 18, 330 and 331 are preferred for circuit performance testing purposes.
Teletext signals on lines 21 and 334 shall be restricted to closed caption services.
Lines 22 and 335 are preferred for the measurement of noise, ie. only blanking level should be transmitted on these lines.
Detailed specifications relevant to Teletext and closed caption data transmissions are given in the Teletext System Standard, issued by the former Department of Transport and Communications.
The line numbering sequence is detailed in figure A3.4.
Primary colour signals
20. Spectral response of the optical section in the colour picture signal source, together with any matrix of the three sensor outputs, shall be such that the E’R, E’G, E’B signals will reproduce an image with optimum colour fidelity on a colour picture tube having phosphors with the following CIE*15 chromaticity coordinates, and balance for a white chromaticity of CIE Illuminant D65, shown in table A3.1.
Table A3.1: CIE*15 Chromaticity coordinates and balance for a white chromaticity of CIE illuminant D65
| | Chromaticity | Coordinates |
| | X | Y |
| Red phosphor | 0.64 | 0.33 |
| Green phosphor | 0.29 | 0.60 |
| Blue phosphor | 0.15 | 0.06 |
| Illuminant D65 | 0.313 | 0.329 |
Colorimetry, International Commission on Illumination (Comité Internationale d’Éclairage)
Vision signal characteristics
Characteristics of the vision transmitter
21. Vestigial sideband transmission shall be used. The response at the television channel limits shall be reduced by at least 20 dB, relative to the response at 1.5 MHz above the vision carrier.
Group delay/frequency response
22. The vision transmitter shall incorporate group delay correction so that the overall group delay/frequency response of the transmitter and standard vestigial sideband demodulator shall be flat to 5 MHz. The group delay characteristic shall be in accordance with figure A3.7.
Sound signal characteristics
Characteristics of the sound transmitter
23. The sound transmitter or transmitters shall be capable of operating with audio modulating frequencies between 40 Hz and 15 kHz. The audio modulating signal shall be pre-emphasised, as shown in figure A3.6, in accordance with the impedance/frequency characteristic of a series resistance-inductance network having a time constant of 50 microseconds.
First or single sound carrier modulation
24. For a single sound carrier system the carrier shall be modulated by the audio signal. The modulation of the first sound carrier of a dual sound system for the various transmission modes shall be in accordance with the following:
monophonic transmission - the carrier shall be modulated by the audio signal;
stereophonic transmission - the carrier shall be modulated by the compatible monophonic, or sum, component of the stereophonic audio signal, (L+R)/2;
separate sound signal transmission - the carrier shall be modulated by the monophonic signal of the first sound channel.
Second sound carrier modulation
25. The modulation of the second sound carrier of a dual sound system for the various transmission modes shall be in accordance with the following:
monophonic transmission - the carrier shall be modulated by the same audio signal as the first sound carrier;
stereophonic transmission - the carrier shall be modulated by the audio signal arriving from the right hand signal source (R);
separate sound signal transmission - the carrier shall be modulated by the monophonic signal of the second sound channel.
Identification of transmission mode
26. To identify the type of signal being transmitted, the second sound carrier shall be frequency modulated to a deviation of ±2.5 kHz ±500 Hz by a sub-carrier of 3.5 times the line frequency (ie. 54.6875 kHz) This sub-carrier shall be:
unmodulated for monophonic transmission;
50 per cent amplitude modulated with 117.5 Hz (line frequency divided by 133) for stereophonic transmission; and
50 per cent amplitude modulated with 274.1 Hz (line frequency divided by 57) for separate sound signal transmission.
Table A3.2: Timing intervals of the video signal
Duration (measured between half amplitude points) Microseconds Nominal Value Tolerance
Field period (V) 20000
Line period (H) 64
Line blanking interval 12 +0.0, –0.3
Front porch interval 1.5 +0.3, –0.0
Line synchronising pulse interval 4.7 ±0.2
Field blanking interval 25 H + 12 +0, –0.3
Duration of field synchronising pulse sequence 2.5 H
Duration of pre-equalising pulse sequence 2.5 H
Duration of post-equalising pulse sequence 2.5 H
Duration of equalising pulse 2.35 ±0.1
Interval between field synchronising pulses 4.7 ±0.2
Colour sub-carrier burst
start, from leading edge of line synchronising pulse 5.6 ±0.1
duration (nominally 10 cycles) 2.25 ±0.25
duration of burst blanking pulse (per field) 9 H
Build-up time (10 to 90 per cent amplitude points)
Edges of
blanking pulses 0.3 ±0.1
synchronising signals 0.3 ±0.1
Table A3.3: Colour sub-carrier amplitudes and phases for fully saturated primary and complementary colours
Colour Luminance Peak to Peak Chrominance Chrominance Angle(2)
Figure A3.7: Nominal group delay precorrection characteristic
Appendix 4:
Transmission Standard for the Australian Digital Terrestrial Television Service
The transmission standard applicable to Australian digital television broadcasting and datacasting services is identified below. The standard has been prepared by Standards Australia and may be adopted by broadcasters and datacasters according to their own requirements.
Transmission standard
1. Aside from clause 4.8.2 (Aus) of section 3 that is mandatory under guideline 107, Australian Standard AS4599-1999 Digital television – Terrestrial broadcasting – Characteristics of digital terrestrial television transmissions (incorporating Amendment No. 1) is recommended by the ABA only and is not mandatory under these guidelines.
2. Channels that may be used for the Australian Digital Terrestrial Television Service are shown in table A5.1 (see appendix 5).
Appendix 5:
Channels for the Australian Terrestrial Television Service
Table A5.1: Channels for the Australian Terrestrial Television Service
Note 1 Television Band I (channels 0, 1 & 2) and Band II (channels 3, 4 & 5) are not being considered for new analog television services or for the introduction or ongoing transmission of digital television services.
Note 2 VHF channel 5A is currently within the Broadcasting Services Bands (BSB) and has been recommended for clearance by the ABA and ACA to allow for the introduction of Low Earth Orbiting (LEO) satellites. Channel 5A is not being considered for new analog television services or for the introduction or ongoing transmission of digital television services.
Note 3 Clearance of radiocommunication services from 202-208 MHz and from 222-230 MHz has allowed a revised channel arrangement to be implemented. The current channel arrangement has two new channels (channels 9A and 12). To accommodate channel 9A, channels 10 and 11 were shifted up in frequency 1 MHz.
Note 4 The majority of existing services on channels 10 and 11 were assigned using the superseded channel arrangement. Services on channels 10 and 11 may be required to shift in frequency to align with the current channel arrangement. Any such requirement will be considered on a case-by-case basis. New services on channels 10 and 11 will be assigned according to the current channel arrangement i.e. channel 10 (209-216 MHz) and channel 11 (216-223 MHz).
Note 5 UHF Television channel 27 has a bandwidth of 6 MHz and therefore is not currently suitable for digital television services. The ABA and ACA are considering ways of making use of channel 27 as a 7 MHz channel.
Note 6: The ABA and ACA are considering spectrum that may be re-allocated for non-broadcasting purposes due to the increased spectral efficiency with Digital Television. In particular the use of part, or the entire frequency band 806-820 MHz is under consideration. Where practicable the ABA will endeavour to avoid the use of channels 68 and 69.
Note 7 Offsets from these nominal channel frequencies may be applied. In the case of digital television offsets of +125 kHz and –125 kHz may be applied.
Explanatory Notes
Introduction
Under section 33 of the Broadcasting Services Act 1992, the ABA is required to prepare technical guidelines for the planning of individual radio and television services that use the broadcasting services bands. Despite their name, the Technical Planning Guidelines (TPGs) contain mandatory technical requirements to be met by commercial, community (including temporary community) broadcasting licensees and datacasting licensees using the broadcasting services bands when planning and operating new transmission facilities or proposing changes to existing facilities.
By reason of sections 108A(1)(d), 109(1)(e) and 109A(1)(f) of the Radiocommunications Act 1992, the licensee of a transmitter licence issued to the holder of a temporary community broadcasting licence issued under Part 6A of the Broadcasting Services Act, or a commercial radio or television broadcasting licence issued under Part 4 of the Broadcasting Services Act, or a community radio or television broadcasting licence issued under Part 6 of the Broadcasting Services Act, or the holder of a datacasting transmitter licence issued under section 100 of the Radiocommunications Act, or any authorised person, must comply with these guidelines.[2]
Note that transmitter licences for National Broadcasting Services issued under sections 100 or 100B, or narrowcasting licences issued under section 100 of the Radiocommunications Act, may also include a licence condition requiring compliance with specified guidelines or parts of these guidelines.
These explanatory notes are designed to assist broadcasters and others involved with the broadcasting industry to understand how the TPGs apply to the planning and operation of transmitters using the broadcasting services bands.
Planning before the Broadcasting Services Act 1992
Planning under the former Broadcasting Act 1942 was carried out by the appropriate Government Department on a site-specific basis with detailed engineering specifications of the transmitting antenna radiation performance.
Guidance to broadcasters was provided through a document known as the draft Planning Guidelines (also known as GS1 through GS4). These guidelines were never given status other than draft because of uncertainty as to what head of power was appropriate for such documents and what force they might have. In 1992, GS1 through GS4 were restructured into a single document and published as the Technical Planning Parameters and Methods for Terrestrial Broadcasting (the TPPs) by the then Department of Transport and Communications.
The TPPs were developed in consultation with the industry and its engineering consultants and included all of the essential planning requirements, plus a great deal of advisory information to assist facilities planners. The TPPs were based on relevant Reports and Recommendations of the International Telecommunications Union (ITU) and on planning methods and practices developed in North America, United Kingdom and Europe, as well as broadcasting planning techniques and planning parameters developed in Australia.
The TPPs did not have the force of law but rather were detailed planning guides based on generally accepted planning methods, which if applied to proposals by licence applicants, were likely to meet the requirements of the regulator.
Transmitter specifications issued as a result of this planning process (a licence warrant under the former Act) had the force of law, and essentially required even slight changes to the antenna system to be approved by the Department (on behalf of the Minister) even though such changes may have no impact on other users of the spectrum or the public at large. The planning process, although spelt out in the Draft Guidelines and later the TPPs, did not provide clear guidance as to how licensees should interpret them, and there was no widely available public database of Australia-wide frequency assignments against which licensees could plan changes. As a result even small changes to specifications required considerable dialogue between the applicant and the regulator, with attendant high resource costs, a risk of somewhat arbitrary decisions, and time delays.
Overview of planning under the Broadcasting Services Act 1992
The Broadcasting Services Act moved the focus on service planning by the regulator to one based on establishment of a strategic framework of frequency assignments and licence and technical specifications for services throughout the country, leaving the detailed implementation of the specifications for transmitting facilities to individual licensees.
Under the Broadcasting Services Act, the ABA was first required to determine through a public consultation process, the Planning Priorities; that is, the priority in which various services and areas of Australia would be planned. The Planning Priorities were determined by the ABA in September 1993. This was followed by determination of the Frequency Allotment Plan (FAP), which identifies the channel capacity that is to be planned for broadcasting services. The FAP, while it outlines the number of services that are to be planned in each area, does not contain specific frequencies. The FAP was first determined in August 1994 and is varied from time to time. The third and final stage of the planning process is the determination of Licence Area Plans. Licence area plans specify the number and characteristics, including technical specifications, of broadcasting services to be made available in each area of Australia.
Technical specifications and licence area plans (LAPs)
In licence area planning, the approach taken by the ABA is to establish technical specifications for transmitters in a way that provides a performance envelope within which the transmitter and its associated transmitting antenna or radiating system must operate.
In determining the technical specifications for each service in the LAP, the frequency planning is highly dependent upon the physical location of the transmitter and the height of its antenna. The location of the transmitter relative to the licence area to be served determines the radiated power required in various directions, commonly referred to as the radiation pattern. However, the requirement to reuse channels in other areas means there is an upper limit on the radiated power that might be permitted in certain directions in order to provide a substantially interference free service for other users of the same or adjacent channels in neighbouring licence areas.
The LAP specifies the nominal location of the transmitting site and provides the performance envelope within which transmitters must operate; licensees, in implementing their transmitting facilities to meet these specifications, are also required to take account of the mandatory requirements of the TPGs.
Compliance with technical specifications of a licence and the TPGs
The licensee, having established the transmission facilities, must be able to provide evidence of appropriate engineering and interference analysis having been conducted and be able to demonstrate that the operating transmitting arrangements comply with the technical specifications in the LAP and with the TPGs. Such evidence, provided it appears prima facie to meet this requirement, will be accepted at face value but will remain a matter of record in the event of the transmitter’s operating specifications subsequently being found non‑compliant.
The ABA and/or the ACA, in discharging their responsibilities, may at any time, and without notice, conduct or commission spot checks of operating services to confirm compliance with licence specifications. In the event that problems are discovered, the ABA will bring the matter to the attention of the licensee and provide the licensee with an opportunity to provide relevant material indicating all reasonable steps have been taken to comply and to ensure continued compliance with the licence specifications. The licensee will be required to take appropriate action to restore the service to compliance. These arrangements assume licensees will take all reasonable steps to comply and that non-compliance is more likely to be the result of technical equipment failure or misalignment, rather than blatant disregard for the specifications.
The ABA and/or the ACA will take appropriate action under the relevant Acts in the event of blatant or reckless disregard for the specifications.
Variations to technical specifications in LAPS or digital channel plans (DCPs)
The ABA cannot make substantive changes to existing specifications in a LAP or Digital Channel Plan (DCP) except by way of production of a new LAP or DCP, or formal variation of the existing LAP or DCP. In the latter case, the change is more likely to be initiated by a licensee seeking a variation to the transmitter licence (such as a frequency change or power increase).
Production of, or variation to, a LAP requires wide public consultation in accordance with section 27 of the Act. This will include consultation with all potentially affected parties.
Production of a DCP requires consultation in accordance with section 10 of the Commercial Television Conversion (CTC) Scheme or section 10 of the National Television Conversion (NTC) Scheme. In varying a DCP under section 14 of the CTC Scheme or section 13 of the NTC Scheme, the ABA must decide whether it is appropriate to invite comments on the variation.
Broadcasting licensees should note that commercial disagreement on the cost of access to a site (especially where there is no alternative) would not, of itself, be regarded as a sound basis for seeking a LAP or DCP variation. The ABA has provided wide opportunity for potential licensees to explore and propose alternative sites during the LAP or DCP public consultation process. Consistent with broadcast planning objectives, and the desire to use established sites for both economic and environmental reasons, the ABA has endeavoured to avoid creating situations that force the use of a particular site and hence may potentially escalate the entry price. However, in some situations there may be no alternative and the cost of use of the site has to be accepted as a price of entry and operation of the service.
Transmitter operation away from the nominal location
The TPGs provide some flexibility for licensees wishing to use an alternative transmitter site to the nominal location specified in the LAP or DCP.
The TPGs contain the criteria the ABA will use when considering whether to approve an alternative site. The criteria are designed to ensure, amongst other things, that use of the alternative site will not cause interference to radiocommunications services, or to existing or planned broadcasting services shown in the LAP or DCP. The licensee must continue to comply with the other technical specifications contained in the LAP or DCP, as well as all applicable requirements of the TPGs.
Notwithstanding this new relative freedom, the ABA and ACA must know precisely where transmitters are located and their characteristics so that they can be taken into account in planning and interference analysis. Hence, before transmissions at any alternative site can commence an appropriate transmitter licence (which will specify the exact site and primary radiation parameters) must be obtained.
The procedure to be followed by a broadcasting licensee seeking to locate a transmitter at an alternative site is further explained below, under Change of Transmitter Site Procedure.
Planning and development approvals from other Authorities
In addition to the requirements of the LAP or DCP technical specifications and the TPGs, licensees are reminded of their responsibility to obtain all necessary approvals for site planning and environmental matters from the relevant Federal, State/Territory and local government authorities. Licensees must also comply with Australian Communications Authority (ACA) regulatory arrangements for human exposure to Electromagnetic Radiation (EMR), which are applicable to broadcasting transmitters. Further information on the ACA’s EMR regulatory arrangements can be obtained from the ACA website (www.aca.gov.au).
Outline of the technical planning guidelines
The TPGs are divided into a number of sections, covering issues which are common to all broadcasting services, and sections covering issues specifically related to AM radio, FM radio, analog television or digital television, including the emission standards for these broadcasting services.
Introduction
The introduction outlines the relevance of the TPGs to the LAP or DCP; it details the broadcasting services bands and gives the definition for terms used in the TPGs. Essentially, the TPGs are to be read in conjunction with the technical specifications of the relevant LAP or DCP.
It should be noted that there is provision for some of the parameters specified in the TPGs to be varied by exception in the LAP or DCP or transmitter licence, as appropriate. For instance, the planned minimum field strength for an FM service in rural areas is normally 54 dBV/m, however a higher median field strength may be specified in the LAP for a suburban or urban only service.
Part 1: Start‑up procedure
With development and expansion of broadcasting services, the density of transmitters leads to circumstances where existing services might be subject to interference as new services commence. Often this is because the radiocommunications environment has changed and better engineering practices are needed at existing sites to allow more services to operate free from interference.
The start‑up procedures require anyone seeking to establish, or to change the technical operating specifications of, a transmitter for a commercial, community (including temporary community) broadcasting service or datacasting service to follow a specified procedure to confirm that the transmitter is operating in compliance with the approved specifications and the TPGs, and that it does not cause interference to other services.
Radio, analog television and datacasting licensees are required to: advertise in the newspapers circulating in the licence area or datacasting service area of the approved service at least seven days before commencing test transmissions; to advise the ABA, the ACA and other broadcasters within, and adjacent to, the licence area or datacasting service area of the date and time of commencement of the test transmissions, the duration of the test transmissions and proposed technical operating specifications of the test transmissions; and, where practicable, to make regular announcements during the test transmissions identifying the licensee and providing sufficient information for members of the public to contact the licensee if the broadcast causes interference.
The start-up procedures for television or datacasting services provided in digital mode differ to those for analog services, although they share many of the above-mentioned requirements. The requirements for digital television are specified in Part 7 (Interference Management Scheme for Digital Television) of the TPGs.
Part 2: Change of transmitter site procedure
The TPGs include some flexibility in the choice of transmitting site. Where a licensee does not propose to site a transmitter at the nominal location specified in the LAP or DCP, the licensee must complete appropriate electromagnetic compatibility calculations for the alternative site to show that no interference will be caused to other services. The licensee must submit the EMC calculations to the ABA, together with an application for a test transmission licence. If the ABA is satisfied that the EMC calculations prove that operation from the alternative site will not cause interference and that relevant guidelines of the TPGs will be complied with, the ABA will allocate a test transmission licence. The licensee must then conduct test transmissions in accordance with the terms of the test transmission licence.
On completion of the test transmission, the licensee must provide to the ABA the results of the test transmissions including any interference assessment reports, and details of any complaints of interference made during the tests, together with a completed application form seeking variation of the relevant transmitter licence. If the ABA is satisfied that operation of the transmitter from the alternative site will not cause interference to other radiocommunication services and that relevant guidelines of the TPGs will be complied with upon commencement of transmissions from the new site, then it will vary the conditions attaching to the transmitter licence issued under the relevant provisions of the Radiocommunications Act.
Part 3: AM radio
This part of the TPGs applies to a licensee (or authorised person) who intends to implement, or change the technical operating specification of, an AM radio broadcasting service.
Under this part the AM licensee is required to site the transmitter within the licence area of the broadcasting service, unless otherwise permitted by the LAP. The radiated power of the transmission (in terms of cymomotive force or CMF), in any given direction, must also not exceed the maximum power specified by the LAP.
Unless otherwise specified in the LAP or transmitter licence, the licensee is required to provide a minimum CMF to urban centres within the licence area. This is to ensure that an adequate level of service is provided to all communities of significance, and not just to the larger population centres in the licence area.
The TPGs specify a maximum field strength that is permitted within population centres. The purpose of this requirement is to avoid excessive signal levels that may interfere with, or degrade the performance of, receivers.
The LAP process will normally ensure the location and corresponding transmission characteristics specified for the service are sufficient to achieve adequate coverage of population centres within the licence area, while ensuring any signal overspill in to adjacent areas is minimised. Where a licensee proposes to site a transmitter away from the nominal location specified in the LAP, the TPGs require that the field strength of the transmission, in any urban centre beyond the licence area boundary, not exceed that which would be received from a transmitter operating at the nominal location, or a specified maximum field strength, whichever is greater. Therefore, licensees seeking to operate away from the nominal location must have particular regard to signal overspill into adjacent areas.
The TPGs also require that operation of the transmitter not cause interference to other AM radio services or radiocommunications services. In the event of interference to an AM service the licensee is required (at the licensees expense) to fit devices to the transmitter or the affected receivers, or undertake other measures necessary to eliminate or minimise the interference. The licensee must ensure the AM broadcasting service transmission complies with the Emission Standard for the Australian Amplitude Modulation Sound Broadcasting Service, which is at appendix l of the TPGs.
Part 4: FM radio
This part applies to a licensee (or authorised person) seeking to implement, or change the technical operating specification of, an FM radio broadcasting service.
The FM licensee must ensure the transmitter is sited within the licence area of the broadcasting service, unless otherwise permitted by the LAP. The radiated power of the transmission (expressed in terms of the effective radiated power or ERP), in any given direction, must also not exceed the maximum power specified in the LAP.
To minimise the possibility of interference to receivers, the TPGs impose constraints on the permitted discrepancy in received field strength between adjacent FM services separated in frequency by 800 kHz. This requirement is only applicable to licensees who propose to site their transmitting facilities away from the nominal location specified in the LAP.
A minimum level of service requirement is also specified for FM services in order to ensure all communities of significance within the licence area are adequately served.
FM licensees are required to ensure the height of the transmitting antenna does not exceed the maximum height specified in the LAP. Where the transmitter is sited at a location other than the nominal location specified in the LAP, the licensee must ensure the antenna height, when specified in terms of the Australian Height Datum (AHD), does not exceed the maximum antenna height above AHD at the nominal location permitted by the LAP.
The TPGs also specify the maximum field strength permitted within the licence area, as well as beyond the licence area boundary. The maximum field strength within a licence area is determined so that receivers do not suffer overload from excessive signal levels, while the maximum field strength beyond the licence area is specified so as to minimise overspill of the signal in to adjacent areas.
The licensee must ensure the FM broadcasting service transmission complies with the Emission Standard for the Australian Frequency Modulation Sound Broadcasting Service, which is at appendix 2 of the TPGs.
Part 5: Analog television
The requirements for analog terrestrial television services using the VHF or UHF television broadcasting services bands are very similar to those for FM radio.
One notable exception relates to transmitter siting. It is desirable that a television transmitter be located so that, for a particular band, ie. VHF or UHF, viewers within population centres of the licence area of the service receive all television services, licensed to serve that area, from a single direction. The need for viewers to install multiple same band antennas reduces the protection from interference assumed in the licence area planning process.
The radiated signal characteristics of analog television services are required to comply with the Emission Standard for the Australian Analog Terrestrial Television Service, which is at appendix 3 of the TPGs.
Part 6: Digital television
The guidelines related to digital television broadcasting and datacasting services follow a generally similar approach to those of analog television. There are, however some additional considerations due to, for example, the possibility of single frequency network operation and its implications for adjacent channel services. Some further explanatory notes on aspects of digital television are provided in Annex B.
The radiated signal characteristics of digital television services are required to comply with clause 4.8.2 (Aus) of section 3 of Australian Standard AS4599-1999 Digital Television – Terrestrial Broadcasting – Characteristics of digital terrestrial television transmissions (see appendix 4).
Part 7: Interference management scheme for digital television
Part 7 contains the Interference Management Scheme for digital television. This scheme applies to digital television broadcasting and datacasting transmitter licensees and is designed to ensure that a viewer’s analog television service is protected from interference from digital transmissions, and where such interference does occur, that resolution is achieved in a timely manner.
Emission standards for broadcasting transmitters
The TPGs also contain the standards applicable to broadcasting transmitters that operate in the terrestrial broadcasting services bands. The emission standards for radio and analog television services are substantially the same as those published by the former Department of Transport and Communications in the period 1989-92.
Reference to the relevant digital television standard is provided in appendix 4. This standard has been prepared by Standards Australia and may be adopted by broadcasters and datacasters according to their own requirements. Aside from the radiated signal spectrum mask of Australian Standard AS4599-1999, that is mandatory under guideline 107, the standard is recommended by the ABA only and is not mandatory under the TPGs.
Emission standard for the Australian Amplitude Modulation Sound Broadcasting Service
The AM emission standard is based on the Draft Emission Standard for the Australian Amplitude Modulation Sound Broadcasting Service published by the former Department of Transport and Communications in 1992.
The standard follows international practice with provision for stereophonic program transmission based on the C-QUAM system.
The emission standard details the channel assignments for the AM radio broadcasting service, program signal characteristics for mono and stereo transmission and the radiated signal characteristics of the AM transmission.
Emission standard for the Australian FM Sound Broadcasting Service
The FM radio emission standard is based on the Emission Standard for the Australian Frequency Modulation Sound Broadcasting Service determined by the Minister for Transport and Communications pursuant to s.125D of the Broadcasting Act 1942, and published by the former Department of Transport and Communications in July 1992.
The emission standard covers the radiated signal characteristics of the transmission, nominal channel assignments for the FM radio broadcasting service, main program signal characteristics for both mono and stereo transmission, and includes requirements for ancillary communications services carried as subcarriers on the main FM carrier.
Emission standard for the Australian Analog Terrestrial Television Service
The analog television emission standard is based on the Emission Standard for the Australian Terrestrial Television Service determined by the Minister of Transport and Communications pursuant to section 125D of the Broadcasting Act 1942, and published by the former Department of Transport and Communications in March 1989.
The emission standard details the channelling arrangements for the analog television service as well as the video, vision and sound signal characteristics of the transmission.
The emission standard does not include the standard for teletext services provided in conjunction with the television transmission.
TPGs and Australian Broadcasting Authority planning handbooks
Because they are legally binding, the TPGs include only the mandatory requirements to be met by broadcasters in planning and operating new transmission facilities, or in seeking changes to existing facilities. Supporting information on suitable analog planning and measurement methods is contained separately in Technical Planning Parameters and Methods for Terrestrial Broadcasting (TPPs), first published by the Department of Transport and Communications in June 1992.
The TPGs and TPPs were included as Parts 1 and 2 respectively of the Interim Australian Broadcasting Planning Handbook until December 2000, when the Handbook was superseded. The TPGs and TPPs are now included in the ABA’s Broadcasting Planning Manual (BPM) – a new publication which brings together all planning related documents, as well as additional reference material, in to a single publication. Copies of the TPGs, TPPs and other documents that form part of the Broadcasting Planning Manual are available from the ABA website (www.aba.gov.au).
The TPPs are based on broadcasting planning parameters and methods of measurement defined in Recommendations and Reports of the International Telecommunications Union (ITU), as well as planning practices developed in Australia, North America, Europe and Britain over many years.
The TPPs are intended for broadcasters, planning consultants and operators of broadcasting facilities involved in detailed design of broadcasting transmitting facilities or in the preparation of planning submissions to the ABA.
The planning values and methods set out in the TPPs are generally consistent with international practice. Alternative method(s) may be used but facilities planners would need to be in a position to demonstrate that the alternative method(s) yield results comparable with those set out in the TPPs.
In respect of such alternative method(s), which may include various computer based prediction models, system designers need to be aware that no model is an exact replication of real propagation phenomena. The type of terrain and other variable factors make some models better in some circumstances than others, and the probabilistic nature of radio frequency propagation requires statistical methods of prediction. The methods set out in the TPPs represent accepted international practice and include statistical allowances based on many years and many different field measurements of propagation in different parts of the world.
For planning of digital television and datacasting services, the information contained in the TPPs is also supplemented by the ABA’s Digital Terrestrial Television Broadcasting Planning Handbook. This Handbook is also available from the ABA website.
Relationship between the TPGs, FAP, LAPs, the Broadcasting Services and Radiocommunications Acts
Technical planning guidelines
The Broadcasting Services Act requires the ABA to develop technical planning guidelines (TPGs) for the technical planning of individual services that use the broadcasting services bands as a means of delivery. The TPGs set out the mandatory requirements that are to be met by licensees when completing the detailed planning of broadcasting transmitting facilities, and are to be read in conjunction with the technical specifications contained in the LAP.
The TPGs include the emission standards for AM, FM and television broadcasting transmitters, and are applied to commercial, community (including temporary community) broadcasting licensees and datacasting licensees through the powers contained in the Broadcasting Services Act. The TPGs may also be applied to national broadcasting transmitters and to narrowcasting services that use the broadcasting services bands, through Licence Conditions Determinations (prepared by the ACA) or special conditions attached to transmitter licences issued under the powers contained in the Radiocommunications Act.
Frequency allotment plan
The Frequency Allotment Plan (FAP) determines the number of channels that are to be available in particular areas of Australia to provide broadcasting services using the broadcasting services bands. The FAP identifies the capacity that is to be available for AM radio, FM radio and VHF/UHF television services.
The FAP apportions broadcasting services bands in particular parts of Australia to accommodate existing and future radio and television services. The FAP was determined by the ABA in August 1994, following wide public consultation, and is varied from time to time.
Licence area plans
A LAP details the number and characteristics of the broadcasting services that are to be made available within particular areas of Australia. The characteristics of each service include the service’s licence area, category, carrier frequency(s), transmitter site(s) and technical conditions, including maximum effective radiated power in each direction from the transmitter site.
If there are changes to the number of available channels arising from the determination of a LAP, the relevant FAP is varied to reflect those changes.
The determination of a LAP follows wide public consultation and is based on the preparation of a draft LAP to allow comment by affected communities, as well as broadcasters and other interested parties, before finalisation.
How to obtain a broadcasting service licence and the relevant transmitter licence
For commercial and community broadcasting services, completion of the LAP process for an area makes capacity available for new broadcasting services. The LAP will describe the type of services to be made available and the technical specifications applicable to those services.
The ABA will advertise the availability of spectrum capacity and invite applications for a broadcasting service licence. For new commercial broadcasting services, the ABA will conduct a price based allocation process to determine which applicant(s) are to be granted the licence(s) on offer. For new community broadcasting services, the ABA will invite applications and will conduct a merit-based allocation process to determine which of the applicants will be granted a licence.
With the issue of a broadcasting service licence comes an entitlement to a radiocommunications apparatus licence (i.e. transmitter licence) to operate the broadcasting transmission facilities to provide the service.
For more information about applying for a transmitter licence for new commercial or community broadcasting services, please refer to the ABA fact sheet Transmitter licences for new commercial and community broadcasters.
Alternative uses of the broadcasting services bands
Where planned spectrum capacity is not used for broadcasting services, that capacity may be made available for alternative uses, such as open narrowcasting. Allocation of rights to use the available spectrum capacity may entail a price based allocation process similar to that used for allocation of commercial broadcasting service licences.
The TPGs may be applied to transmitter licences for these services as a condition of the transmitter licence, in addition to the licensed technical specification for the service.
Annex A:
Policy Assumptions used in Planning
The policy assumptions used in analog and digital broadcasting planning are contained in the following documents:
The ABA’s General Approach to Analog Planning; and
The ABA’s General Approach to Digital Terrestrial Television Broadcasting Planning.
Annex B:
Explanatory Notes related to Digital Television
The DCPs specify the ERP levels expected to meet the ‘same level of coverage’ objectives given in 6(3) (f) of Schedule 4 of the Broadcasting Services Act. However, some DCPs include channel allotments with directional ERP restrictions on some services that apply until certain analog television services cease transmission. Notwithstanding the legislative requirement, these limits may mean, in some instances, that it will not be practicable to achieve the same coverage goal until the concerned analog transmission ceases.
Maximum antenna height requirements
The digital television section does not include guidelines relating to maximum antenna height. The Maximum Field Strength beyond the Licence Area or Datacasting Service Area, Minimum Level of Service Requirements and guidelines relating to not causing interference to other services more directly address the ABA’s concerns than would a restriction on antenna height.
A nominal antenna height specification is included in the technical specifications associated with the DCP for information. This nominal height is used by the ABA in performing interference predictions as part of its channel planning process.
Adjacent channel and SFN operation
Planning for digital television and datacasting services has made use of adjacent channel operation (either between two adjacent digital services, or between a digital service and an adjacent analog service) on the assumptions that: the adjacent channel transmissions are effectively co-sited; and the ratio of adjacent channel ERP levels is constrained to be within an appropriate range.
When applying the guidelines related to adjacent channel interference, account should be taken of variable factors affecting the relative levels of received adjacent channel transmissions, such as differences in transmitter radiation patterns (in both the horizontal and vertical planes), frequency dependency of receiving antenna system performance and differences in the actual transmission sites. Until better information is available, a value of 5 dB has been applied to the basic protection ratio values for sites where the adjacent services are transmitted from common antennas. Other cases will require more detailed case-by-case examination.
Where additional transmission sites are proposed, it may prove difficult to satisfy the necessary adjacent channel protection requirements in cases where transmitters are not effectively co-sited, and/or in cases where widely different ERP levels are used by the adjacent channel services.
Recognising this constraint, guideline 96 has been written to ensure that digital services operating in accordance with the DCP are protected.
In the particular case of potential adjacent channel interference between two digital services where one, or both, of the proposed digital services is not included in a DCP, it may be possible to satisfy the adjacent channel interference conditions through negotiation between the operators of the adjacent channel services. The required end result is that, in each area where adjacent channel interference could arise, the transmitters providing the adjacent channel services should be effectively co-sited and their relative ERP levels should be co-ordinated to ensure that the conditions of Part 6 of the Technical Planning Guidelines covering adjacent channel interference are satisfied.
Levels of allowable interference
Whenever any new service is added into an existing service arrangement there will be some increase, even if it is very small, in the interference received by the existing services. In assessing whether the general objective that “there should be no noticeable increase in interference to other services” is satisfied, in terms of practical engineering, the task is to set guidelines that ensure that any increase in interference is constrained to a level that would not adversely impact on existing services. These guidelines have quantified the amounts of interference that would be allowable for the cases of (i) interference to analog television services, and (ii) interference to digital television services. The signal degradation characteristics of analog and digital television systems have been taken into account in determining these limits.
No attempt has been made to quantify levels of interference that would be allowable for other radiocommunications services (including broadcasting services other than analog and digital television). Unlike television-to-television interference mechanisms where the characteristics of the device potentially suffering interference can be fairly readily defined, potential interference mechanisms between television and services other than television are much less amenable to detailed specification because the range and characteristics of the devices that could potentially suffer interference is large and diverse. This problem is particularly complex when potential interference mechanisms between services operating in different bands of the radiocommunication spectrum are considered. The current interference management process, which is complaints based and prefaced on the incoming service resolving any interference to existing services, appears to have worked adequately without the need for inclusion of such detailed definitions within the TPGs.
For analog television where the ratio of wanted to unwanted (digital) signals is 41 dB or lower, a degradation of no more than 2 dB in the co-channel carrier-to-noise ratio measured at the receiver input terminals has been permitted. This 2 dB degradation value is based on the interfering signal causing no more than 0.5 grades of degradation on a 5-grade impairment scale. The basis for this is that the human perception descriptors applicable to impairments to planned television reception (grade 5 – imperceptible; grade 4 – perceptible, but not annoying; grade 3 – slightly annoying) are fairly closely spaced and it seems reasonable to assume that defining a 0.5 grade change as an allowance for interference will not be perceived as having a noticeable impact on the level of interference to the signal. The relationship between subjective impairment gradings and carrier-to-noise (or unweighted video-signal-to-noise) ratio is given in texts such as ITU-R Recommendation BT.654. or Hutson, G.H. – Colour Television: system principles, engineering practice, and applied technology, 2nd Ed, McGraw Hill 1990.
For digital television where the received co-channel carrier-to-noise-plus-interference ratio is 20 dB or lower, a degradation of no more than 1 dB in the carrier-to-noise ratio measured at the receiver input terminals has been permitted. This 1 dB degradation value was suggested in the report of the sub-group on ‘same level of coverage and potential reception quality’ (appendix B of Digital Terrestrial Television Broadcasting Planning Handbook). The allowable value for digital television was chosen to be more stringent than for the comparable analog case. This was done in recognition of the concern that viewers in a marginal reception situation for a digital service could suffer a complete loss of service with a small increase in interference whereas in a marginal analog reception situation a slight increase in interference would cause a slight increase in visible and/or audible noise.
Measurement and assessment of interference
The interference ratio limits discussed above specify levels that are measured at the input terminals of a reference receiver. While this definition is closely tied to the receiver performance degradation due to interference it does present difficulties in relating these values to field strength measurements.
Field strength measurements can be subject to considerable variability. Even when measured at 10 metres above ground, the field strength may vary considerably with small changes in location or frequency; this is particularly so if the environment is subject to clutter. Field strength measurements can also be subject to short term and seasonal time variations. Variations in the field strengths of wanted and interfering signals will not necessarily be well correlated. Ideally, to obtain reliable and repeatable results it would be necessary to perform a large set of wanted and interfering signal field strength measurements. Notwithstanding time and cost considerations, in many situations terrain or access considerations would make this difficult or impractical. Experienced field strength surveyors may, however, be able to select representative sites where clutter and other confounding effects are minimised and where reproducible results can be obtained from a limited number of field strength measurements.
Calculated field strength predictions do not suffer the variability of measured field strength values. However, as with any mathematical or empirical model, the accuracy of predicted field strength values depends on how well the prediction model represents the real situation. Predicted field strength values can be a convenient method by which to assess claims about potential interference but their use should be tempered by knowledge of how well the prediction model fits the actual situation. Predictions can be used with greatest confidence where they are supported by field strength measurements from nearby areas.
In the final analysis judgements may need to be made based on the combination of data that is available. This could include whatever field strength measurements are available, comparative measurements made when the suspected interfering source is cycled on and off, or reduced in power by a known number of dB, and field strength prediction calculations for wanted and unwanted signals (especially where these predictions have been validated by field measurements in nearby areas). It is noted that while cycling of power of suspected digital interference sources could be a very useful technique for investigation of interference during the start up period, it may be more difficult to apply this technique for high power digital services once they commence normal operation.
[1] The reference to a licence issued under Part 4 or Part 6 of the Broadcasting Services Act includes a licence which continues in force pursuant to the provisions of section 5(1) of the Broadcasting Services (Transitional Provisions and Consequential Amendments) Act 1992 as if the licence had been allocated under Part 4 or Part 6 of the Broadcasting Services Act. i.e. a commercial or community licence under the Broadcasting Act 1942.
[2] The reference to a licence issued under Part 4 or Part 6 of the Broadcasting Services Act includes a licence which continues in force pursuant to the provisions of section 5(1) of the Broadcasting Services (Transitional Provisions and Consequential Amendments) Act 1992 as if the licence had been allocated under Part 4 or Part 6 of the Broadcasting Services Act. i.e. a commercial or community licence under the Broadcasting Act 1942.