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, digital television or digital radio, including the emission standards for these broadcasting services.
Introduction
The introduction outlines the relevance of the TPGs to the LAP, DCP or DRCP. The introduction also details the broadcasting services bands and gives the definition for terms used in the TPGs. The TPGs are to be read in conjunction with the technical specifications of the relevant LAP, DCP or DRCP.
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, DCP, DRCP 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 service that is only planned to serve suburban or urban areas.
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, datacasting service or digital radio multiplex 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.
AM and FM radio, analog television, datacasting transmitter and digital radio multiplex transmitter licensees are required:
(a) to advertise in the newspapers circulating in the licence area, the designated BSA radio area or datacasting service area of the approved service at least 7 days before commencing test transmissions; and
(b) to advise ACMA 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
(c) to advise broadcasters that are within and adjacent:
(i) to the licence area; or
(ii) to the 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
(d) if 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 television 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, DCP or DRCP, 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 ACMA, together with an application for a test transmission licence. If ACMA 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, ACMA 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 ACMA 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 ACMA is satisfied that operation of the transmitter from the alternative site will not cause interference to other services provided by radiocommunications licensees 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 licensed radiocommunication 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 A.
The radiated signal characteristics of digital television services are required to comply with clause 6.2.8 of Australian Standard AS 4599.1‑2007 Digital television – Terrestrial broadcasting – Part 1: 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.
Part 8: Digital radio
The guidelines related to digital radio and restricted datacasting services follow a generally similar approach to those of digital television. However, in some instances, the digital radio provisions reflect provisions contained in Part 4: FM radio.