[LINK] Re: Link Digest, Vol 170, Issue 54
stewart_fist at optusnet.com.au
Thu Jan 25 10:45:26 AEDT 2007
Carl replies to my question as to why we didn't use UHF TV Channels 12 to 27
> Because they are already in use for other purposes.
>There is no "spectrum gap". That is the part of the spectrum where
> the vast majority of two-way radio and similar services sit.
OK, I may have over simplified with "spectrum gap" because I realise that
even in the international TV spectrum allocation there are slots left for
But the fact remains that:
1. every television set sold in Australia in the last 20 years has had
tuners capable of handling 16 of the standard 7MHz channels in this "TV gap"
that we don't have.
2. It's not as if Australia with its 20 million people, spread out over a
landmass the size of Europe or North America, and having no radio
competition (above MW) with any neighbours, is so desperate for spectrum
that it has to steal 16 x 7 MHz of bandwidth from the international
3. It's not as if Australia has a large electronics manufacturing industry
producing unique products to go into this gap. Anything that is using this
spectrum, I would think, would be readily convertible, probably just by
changing a crystal.
> It's not vacant. It's packed with other services like police, fire
> brigade, ambulance, RFS, taxis, courier companies, etc. Where do
> these services go if you reallocate the spectrum to digital
You use the term "packed" as if Australia has some special spectrum load
requirements not yet experienced by other nations, or by Europe as a whole.
I find this claim ridiculous.
Your list of requirements is all for voice or low-speed data. And such
vacant bandwidth can be found almost anywhere in the spectrum, if those
doing the allocation are even half-competent.
The total bandwidth required for all of the list would be less than half the
bandwidth of one television channel, and it would be better in the VHF band
where they have already recovered Channel 0 (45-52MHz). They have also
recovered Channel 5A (137-144MHz) which was an Australia-only allocation,
discovered later to be required for LEO satellites.
Consider the fact that the whole of the population of the USA and Europe
manage to slot their cellphone usage into less than the bandwidth required
for two television channels. This would be a hundred times the combined
requirements of police, ambulance, taxies, fire etc.
I have a multi-channel ham radio receiver which allows me to scan the MW to
SHF frequencies. The power needle twitches solidly whenever it registers
even the faintest signal from outer Mongolia -- even when I can only faintly
hear that a voice station exists.
Yet it can traverse most of the Australian spectrum at almost any time of
the day or night, from a location in the middle of Sydney (supposedly the
most overloaded point in the country), and it shows enormous gaps in the
spectrum at all times - day or night.
Allocation doesn't equal use.
For the first twenty years I've been writing about this stuff, the official
explanation for the 12-27 gap was that it was needed as a 'Defence
allocation", and therefore couldn't be discussed with the media.
Later the Defence people said that they only ever wanted to use spectrum
also used by potential allies - the Europeans and Americans - which tended
to rule this out as a defence imperative.
Now we find that, in the lead up to the introduction of digital television
(which begun officially in 1990 following a Senate Inquiry) that this
spectrum has been allocated to emergency services.
Bureaucracy gone made ... or worse.
Stewart Fist, writer, journalist, film-maker
70 Middle Harbour Road, LINDFIELD, 2070, NSW, Australia
Ph +61 (2) 9416 7458
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