[LINK] FW: NextG Wireless Stays Up As NBN Fibre Broadband Crashes

[Tom Koltai]

> -----Original Message-----
> From: Tom Koltai [mailto:tomk at unwired.com.au] 
> Sent: Friday, 4 February 2011 12:37 PM
> To: 'Richard Chirgwin'; 'link at mailman.anu.edu.au'
> Subject: RE: [LINK] NextG Wireless Stays Up As NBN Fibre 
> Broadband Crashes
> 
> 
> 
> 
> > -----Original Message-----
> > From: link-bounces at mailman.anu.edu.au
> > [mailto:link-bounces at mailman.anu.edu.au] On Behalf Of 
> Richard Chirgwin
> > Sent: Friday, 4 February 2011 11:30 AM
> > To: link at mailman.anu.edu.au
> > Subject: Re: [LINK] NextG Wireless Stays Up As NBN Fibre 
> > Broadband Crashes
> > 
> > 
> > On 4/02/11 11:16 AM, Marghanita da Cruz wrote:
> > > Richard Chirgwin wrote:
> > >> It seems to me that the purpose of a trial deployment is 
> to obtain 
> > >> information. In that sense, the Townsville experience will be a
> > >> success: NBN Co will learn about the extent of damage a
> > cyclone will
> > >> cause to an overhead fibre.
> > >>
> > >
> > > I agree.
> > >
> > >> The Smarthouse story, in my view, conflates TV broadcasting and 
> > >> NextG. I would imagine that the TV broadcasters were using the 
> > >> satellite dishes that you'll see on any and every outside
> > broadcast
> > >> van - not NextG.
> > >>
> 
> 
> I think Richard hit the nail squarly. Investigation would 
> doubtless show that the ABC uplinks at 14.5 Ghz to D3, 
> downlinks at 12.75 GHz at either Belrose or Oxford Falls in 
> Sydney and then delivers via fibre to an internet exchange 
> point. Optus also offer high speed dedicated ATM/Fibre 
> routes, however IP is much cheaper and the ABC might not be 
> using an Optus billed service. (Depends on who won the tender).
> 
> > > report), in the lead up to the arrival of the cyclone, as "via
> > > broadband". It is worth noting, that there were digital artefacts.
> 
> The artifacts are possibly acoustic waves reaching the 
> ionosphere interfering with the uplink/downlink as can be 
> expected on Ku band when the acoustic field of a cyclone is 
> significant (as it would be in a cat 5 cyclone). It only 
> requires 1 or 2 hz of acoustic waves to knock the electrons 
> miles off their intended course.
> 
> The effect is similar to direct broadcast Satelite Cable TV 
> when heavy rain is experienced in the troposphere. The little 
> electrons just can't get through in a straight line and when 
> not enough of them make it, MPEG-2 spec says "Fudge by 
> selecting some neighbouring pixels and copy paste..."
> 
> If the broadcasters upgraded their antiquated MPEG-2 systems, 
> sent dual streams and cached a 10 seconds spool, we would 
> doubtless see zero pixelation. 
> However, I also believe that pixelation is a "special effect" 
> utilised by some mixers to produce the "affect" of "We are in 
> a Cyclone affected area and here is the pixelation to prove 
> it" mindset.
> 
> Or am I becoming too cynical in my advancing years?
> It could be that the ABC budget is VSAT uplink only... 
> <grin>. Showing pixelated versions of News articles may be 
> the ABC's methodology of increasing fuinding for next year.
> 
> 
> Tom
>