Australian and New Zealand television frequencies
Television frequency allocation has evolved since the commencement of television in Australia in 1956, and later in New Zealand in 1960. There was no coordination between the national spectrum management authorities in either country to harmonize the channel frequency allocations. Whilst this can be partially explained by geographical and population considerations, the management of the spectrum in both countries is largely the product of the differing economic forces and the respective political responses.
The demand and planning for television in Australia intensified after the second world war, with the Chifley government first favouring the existing British model (state monopoly) in 1948. This was later to be revised by the Menzies Government to include privately owned and operated commercial services that formed a hybrid between the arrangements found in the UK and the United States. Conversely, New Zealand opted for the British model of a state monopoly when it commenced television services four years later, with a single channel being available until 1975, and private commercial services not being introduced until the late 1970s.
- 1 Contributory Historical Development in Australia
- 2 Differences in Terrestrial TV frequencies
- 3 Frequency allocation table
- 4 Current Australian Channel Allocation by State/Territory as at August 2015
- 5 See also
- 6 References
- 7 External links
Contributory Historical Development in Australia
Australian television commenced in 1956 in Melbourne and Sydney to coincide with the 1956 summer Olympics. Three stations commenced operations on a ten channel spectrum arrangement: the ABC operating in the VHF low band (VHF Ch 2), and the commercial stations operating in the VHF high band (VHF Ch 7 & 9). At the outset, commercial stations were independently owned, but due to economic forces network affiliations were soon established. This pattern of television spectrum allocation was replicated in most of the state capital cities over the subsequent decade, with the exception of Hobart (one commercial service on VHF 6) and eventually Darwin (both the ABC and the commercial service were allocated in the VHF high band).
Geographical conditions differed in Melbourne and Sydney. The Melbourne transmission towers were located on the nearby Mount Dandenong, and their elevation and broadcasting power on an otherwise relatively flat terrain meant that the broadcasting signal could be reached for some considerable distance, although there were some areas that experienced reception difficulties due to hills or buildings.
In Sydney the broadcast towers were collocated on the original studio sites, and given the undulating geography of Sydney there were many areas that experienced reception difficulties. In addition, the presence of the Blue Mountains to the west of Sydney meant that capital city broadcasting did not penetrate into the hinterland of NSW, unlike that of Melbourne. It is possible that the penetration of weak signals into the Victorian hinterlands hastened the demand for the establishment of regional television stations, which commenced in 1961. The Australian Government restricted regional television broadcasting to one commercial service and a repeater station of the national broadcaster from the capital city ABC station. Regional television stations tended to be allocated to VHF 6, 8 or in some cases 10.
Differences in Terrestrial TV frequencies
In the analogue television era, Australia used A2 for Television Stereo transmission while NZ used NICAM Digital Stereo. There is a frequency offset for many DTV channels between Australia and NZ. On top of this, NZ DTV audio on SD channels use the newer AAC compression with MPEG-4 LOAS encapsulation due to NZ DTV being put into wide spread use after 2006.
However, audio transmission issues are only a modest aspect of the differences that have evolved over the past 50 years of television transmission in Australasia.
The important differences
Australia and New Zealand evolved different TV frequency allocations for historically different reasons
- Both Australia and New Zealand use 7 MHz channel spacing (PAL B) on VHF, but the frequencies and channel numbers differ even more substantially now because of Australia revising its VHF TV band usage.
- Australia adopted Zweiton stereo, and NZ adopted NICAM stereo.
- For analog PAL service the only difference is the placement of the NICAM carrier vs the Zweiton carrier, for broadcasters using NICAM. NZ, however, uses its own special NICAM offset that is not used in Europe, while Australia's Zweiton(?) service is unchanged.
- Except for a channel offset factor for Australia: Australia, NZ, Fiji and PNG have the same UHF band allocation for TV broadcasting.
What led to the differences
What are the important underlining circumstances that led to the different allocations?
- Universally the VHF low band channels of 0, 1, 2 and 3 were allocated on an ad hoc basis in Australia and NZ without any trans-Tasman coordination.
- Australia decided against adopting the 405 line system, and indirectly forbade its experimental transmission in the VHF band until the 625 line system could be launched.
- Only after AU-VHF-6 was allocated did NZ adopt the same VHF high band allocations as Australia.
- There never have been any ongoing attempts at coordination of TV allocations in Australasia until the 1990s.
- Australia adopted 7 MHz channel spacing (PAL B) on UHF as the 8 MHz allocation associated with later versions of PAL and SECAM had not emerged.
- New Zealand considered using 405 lines for television, but adopted 7 MHz 625 lines on both the VHF low band and high band. New Zealand's initial choice of frequencies in the VHF range (CH: 1, 2, 3) was done on an ad hoc basis. The ad hoc allocations in the VHF low band immediately led to substantial discrepancies with Australia's VHF TV service allocation for channels allocated before AU-VHF-6.
- The NZ 405 line allocation principal only affects NZ VHF CH1, CH2 and CH3.
- Fiji, Papua New Guinea and New Zealand all adopted 8 MHz channel spacing (PAL G) on UHF more or less in unison due to their later adoption of PAL.
Channel obsolescence related to DVB-T transition
With the introduction of Digital Television in Australia VHF channels 6-12 and UHF 28-69 will become primary.
Modified channels (2001–2004)
- With the introduction of digital television into Australia in 2001, VHF (Band III) channels 10 and 11 were moved up by 1 MHz.
- This allocation change allowed a full 7 MHz for a new channel (9A).
- VHF channel 12 was added following the new channel 11 to compensate for the change.
Obsolete channels (2011–2013)
- VHF (Band I & II) channels 0-2 and 5A will cease to be used for television when analogue television broadcasting ceases.
- Channels 0, 1 and 2 will be specifically be phased out as they are not suitable for digital television due to Radio Frequency Interference issues.
- Television broadcasts on channels 3, 4, and 5 were discontinued in most regional areas in 1991 and 1992. Since the frequencies for these channels overlapped the range used for FM radio, any television broadcasts on these channels prevented the allocation of new FM radio licences, predominantly in regional areas.
- VHF Low Band DX using ITU TV Band (I) and part of Band (III) from NZ may disappear with the transition to DVB-T.
Channel obsolescence issued related to DVB-T transition
- Channels 1, 2, and 3 may be made obsolete with the adoption of DVB-T, but this may not occur until 2015.
- VHF Low Band DX to and from Australia may disappear with the transition to DVB-T.
Australasian region VHF low band obsolescence issues
In some parts of the world, like Europe, the VHF TV band is used by other services because UHF has propagation qualities that are better suited for densely populated urban centres and regions.
Why VHF will remain in use in Australasia for TV broadcasting
- NZ will keep using the VHF band, as VHF has propagation characteristics that allow it to serve large regions with modest power requirements.
- However, some of the NZ and Australian VHF low band channels [(0 Australia only)], 1, 2, 3] and [4, 5A Australia only] may be reallocated to bring the region into line with a more common VHF high band allocation scheme.
- Due to similar economics of broadcasting in rural Australia, it is expected that the VHF high band (above 5A) will remain in use with no appreciable changes.
- With the introduction of Digital Television in Australia (using channels VHF 6-12 and UHF 28-69), VHF channels 0-5A will cease to be used for television when analogue television broadcasting ceases.
Channel numbering issues
Frequency allocation table
DVB-T channel allocation note
- The allocation for terrestrial television must be seen in terms of uniform system G 8 MHz blocks (for bands IV and V in NZ) and system B 7 MHz blocks (for bands I to V in Australia) after the cessation of analogue television.
- DVB-T, analogue systems B and G utilize the same 250 kHz guard-band.
- After analogue television transmissions have ceased, only the preferred main carrier wave centre frequency should be listed as QAM modulates all AV channels and other data into a single H.222 data stream.
- Digital services on channels above Ch 51 are going to change channel after the analog services are switched off. The ACMA has published the pre-stack and post-stack channel in a spreadsheet on its website.
- Australian channel 12 was discontinued decades ago but is being reintroduced with digital television, generally for the ABC in the major metropolitan areas.
- A common problem (for metropolitan areas in particular) of difficulty receiving digital 10 (on channel 11) and digital ABC (on channel 12) is because older antennas were not designed to receive channels 11 and 12. Many VHF Band III antennas were only designed to receive channels 6 to 10 for analog television transmissions.
- Australia and New Zealand analog sub-carriers use the standard B/G offsets from the vision carrier.
|FM Mono Audio
|FM Mono Audio
Current Australian Channel Allocation by State/Territory as at August 2015
The following tables demonstrate the number of frequency allocations in each state and territory of mainland Australia and now the Cocos Islands, Christmas Island and from the Bayu-Undan Gas Project in the Timor Sea. Australia has completed the shut down of analogue services, and digital frequencies occurring above UHF channel 51 have been progressively reallocated to lower adjacent channels to free up the higher spectrum for other uses. In October 2014 there were some 3188 digital channels assigned throughout Australia and its external territories; however, the reallocation procedures have seen a decline in the number of assigned channels to 2801 by August 2015.
Digital Channel Allocation
- The external territories include the Cocos Islands, Christmas Island & the Bayu-Undan Gas Project in the Timor Sea.
National Broadcaster Transmission sites
The ABC has the highest number of transmission sites: often, but not always, SBS and ABC signals are transmitted from the same masts.
Commercial Broadcaster Transmission sites
Some commercial broadcasters have a call sign that operates over multiple areas, whereas others may only serve a single area. This is due to historical ownership of regional stations. Nevertheless, most regional stations are now affiliated with the major metropolitan networks.
|Broadcast Call Sign||ACT||NSW||VIC||QLD||SA||TAS||WA||NT||Extra territorial*||Nationwide|
- Television channel frequencies
- Moving image formats
- Broadcast television systems