Uses of the Radio spectrum was Re: [LINK] Re: TV Spectrum for Last Mile

Sat Jun 9 03:22:33 AEST 2007

Richard Chirgwin wrote:
> George Bray wrote:
> 
>>> So. Does anyone on Link care enough about the broadband-over-TV-channels
>>> idea to explain how it stacks up into a business case that genuinely
>>> competes with DSL etc?
>>>
>>> RC

Interested enough to work through the issues on Link.

I wasn't advocating broadband (highspeed bi-directional) over the radio
spectrum. Rather use of the Radio spectrum instead of wires/cables for
foxtel and other subscription video and audio services traditionally
known as TV and radio.

This could include free to air and subscriber servcies - ie golf,
football and horseracing.
Picking up on Carl's comments on Canberra/Transact (which I understand
is already digital) experience. The analogue optus/telstra cable/set top
need to also be replaced.

Carl Makin wrote:
>
> On 08/06/2007, at 12:05 PM, Marghanita da Cruz wrote:
>
>> Carl Makin wrote:
>>
>>> amplifier and breaks  out to 4 TVs and the video.  The  distribution
>>> system also feeds the  Transact TV signal (mostly  nailed to Disney
>>> Channel) around the  house.  We use both an XBox  and an iMac as the
>>> frontends.  It has  100GB of disk
>>
>> Sounds like you aren't receiving any "wireless"  broadcast services  -
>> just the
>> transact cable service.
>
>
> No, the transact TV service is there almost solely for Disney Channel
> and Cartoon Network these days.  We think $20/month is good value to
> keep the kids off commercial afternoon tv.  We used to get the
> Discovery channel package as well, but although it only cost $10/ month
> it wasn't worth it.  I can't see how Transact itself can be  viable.
> The TV service is poor and the transweb internet connection  is
> expensive and is now slower than cheaper ADSL2+ offerings.  The  only
> available ISPs are also expensive and very inflexible.  The  telephone
> service is fine, but since there are so few other Transact  customers
> the "free calls" to other transact customers is basically  useless.
>
> Once the kids lose interest in Disney Channel then we'll probably  toss
> Transact altogether.
>
> The recording system uses the free-to-air digital TV signals from
> Tuggeranong Hill (southern Canberra) which is the same tower as
> transmits the analogue signals.  It gets the EPG (electronic program
> guide) from the OzTivo project and has been the best thing to happen  to
> tv in our house since aggregation. :)
>
>
> Carl.

As far as uses of the radio spectrum go, it seems that mobile
communication has a priority over highspeed interactive. Radio and TV 
reception in
moving cars, busses and trains is useful.
<http://www.itu.int/osg/spu/stn/spectrum/material.html>

some references for further reading
1998 prices and purchasers of spectrum:
<http://auction.acma.gov.au/auction_results/2nd_pcs_results_page/index.asp>

and from Wikipedia

> Return channel
>
> DVB has standardised a number of return channels that work together 
with DVB(-S/T/C) to create bi-directional communication. RCS is short
for Return Channel Satellite, and specifies return channels in C, Ku and
Ka frequency bands with return bandwidth of up to 2 Mbit/s. DVB-RCT is
short for Return Channel Terrestrial, specified by ETSI EN 301958
<http://en.wikipedia.org/wiki/DVB#Return_channel>

Ofcourse, Australia has limited demand for the radio spectrum than more
heavily populated areas like the mega cities of the world and I think
this will drive the development of applications. By recognising this
(with an obvious vested interest) it would be great if Sydney became as
aTestbed ;-)

Marghanita

>>
>>
>> I know we've sparred on this before Richard, but here goes. This isn't
>> a business case, just my understanding of the current opportunity to
>> use TV spectra for last mile delivery.
>>
>> 1) The early work on BushLan by ANU said they were achieving
>> 100-200kbps. Many years ago now.
>>
>> <http://wwwrsphysse.anu.edu.au/bushlan/background.html>
> 
> No arguments there. But there's a big gap between the BushLAN work and 
> the utopian ideal - that's where I get toey!
> 
>> 2) When I investigated this issue for the wireless broadband enquiry
>> my discussion with management of Broadcast Australia indicated that
>> yes, using the VHF band was certainly possible and there existed at
>> the time USB modems that worked to 400kbps. That technology might be
>> better now too. The upstream link still uses a copper modem line, at
>> whatever that will do.
> 
> No argument that "the VHF band is possible". Possible does not also 
> equate to practical or economical.
> 
>>
>> 3) We have world's best expertise in RF electronics in the CSIRO, so
>> it's plausible that IP over VHF/UHF could be developed further.
>> Perhaps specifically to make good use of the national BA network for
>> regional users.
>>
>> Using the TV spectrum for a downlink has been diss'd on this list
>> before, based on the experiences of people trying to get DVB-T
>> television channels. Certainly, it's not ideal reception everywhere.
>> But where it does work, it works well. That digital TV channel you're
>> getting is up to 10Mbps coming down that antenna.
>>
>> At this point in the debate, however, I'd say that IP over VHF/UHF is
>> a potential technology for regional networking (100km from town) that
>> needs to be considered as a solution for *some* last miles. Combined
>> with the nationwide resources of the Broadcast Australia transmission
>> network, linked to a national fibre network, using IP on the TV
>> spectrum can be a last mile where other technologies don't reach.
> 
> Hmm. Broadcast Australia is no longer a public sector organisation; 
> those antennaes are privately held, and as has been remarked by regional 
> wireless providers, tower space isn't given away for free!
> 
> If a user is 100km from town, they could use satellite, which is also 
> sub-optimal but workable and available now...
> 
>>
>> This technology only needs to compete with DSL if the organisation
>> funding it is Telstra.  Any other organisation assessing the business
>> value (in terms of the establishment cost, and end-user utility) of TV
>> spectra would be thinking about the broadband black holes it fills.
>>
>> I firmly believe that the VHF/UHF network can contribute to more
>> diversity in the BB last mile solutions. If the regional copper
>> network is not capable of high downstream speeds, why not use existing
>> high-bandwidth, wide area RF?
> 
> ...because a data broadcast is not the same as Internet access. This 
> spectrum is good at broadcasts; but less good at one-to-one. Even the 
> radios used for one-to-one voice comms in VHF are broadcasting: you see 
> the signal whether you're north, south, east or west of the transmitter.
> 
> I agree that the regional / remote user should have Internet access at 
> the best-possible bandwidth. I also subscribe to the socialist notion 
> that it can easily be cross-subsidised from the city. This isn't saying 
> '"no bush broadband" - just that I think VHF isn't the solution. However...
> 
>>
>> I'll try and find Gerard at ANU and see where this scene is at.
> 
> Please do! I am interested in the BushLAN work.
> 
> RC
> 
>>
>> George
>>
>>
>>
>>
>>
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-- 
Marghanita da Cruz
http://www.ramin.com.au/
Telephone: 0414-869202