[LINK] What I don't like about Turnbull's NBN

[Richard]

Paul,

Unfortunately, the presentation I have privately from a friend hasn't 
yet been published, which is a pain for citation.

A1 Telekom's field trial in Austria, covering 500 premises, was 
interesting. A1 is a happy customer of VDSL2 plus vectoring - but on 
customer copper, the performance at 800 meters converged to about 25 
Mbps. Which is in line with what you mentioned about "ADSL2++++"

Within the 100m to 800m range, what I found interesting in the raw data 
was that on the same copper plant, VDSL2 + vectoring has a greater 
top-to-bottom variation than ADSL2+ - bottom speeds of the two 
technologies are about the same beyond 300 meters.

I wish A1 Telekom would publish its data so I can do a proper public 
analysis of it!

Cheers,
Richard Chirgwin

On 25/04/13 2:16 PM, Paul Brooks wrote:
> While I'm definitely not a fan of the latest proposal, I think it is important that
> rebuttal should also be based on facts, and that un-challenged assertions are
> unhelpful no matter what side you're on.
>
> Frank - you've done a great job of distilling out many of the issues, and I don't want
> to detract from those, but there is one item that is more urban myth than fact...
>
> To that point....
>
>
> On 23/04/2013 6:49 PM, Frank O'Connor wrote:
>> 6. Probably won't scale as well as Turnbull estimates, and the signal attenuation and drop-off is much higher than he estimates. Only those living right on top of the cabinets (read ... just outside their door) will get 40-50Mbs ... the other 80 to 100 or so clients per cabinet will get from there down to 5 Mbs ... with I estimate a mean value of about 10-15 Mbs.
> Assuming they build the 60,000 cabinets, and shorten all the copper lines to being no
> more than 800 metres long, then real-world measurements show they should achieve
> reasonable speeds over those distances. Signal attenuation and drop-off isn't
> dramatically more than ADSL2+, as VDSL2 is just ADSL2++++, extended to higher frequencies.
> At a minimum, on maximum length 800 metre lines VDSL2 will deliver at least as much as
> ADSL2+ would on 800m lines, and usually considerably more.
>
> While these are AlcatelLucent test results, and so subject to the usual vendor
> caution, they appear to be based on tests on real-world copper networks.
>
> http://www2.alcatel-lucent.com/techzine/vdsl2-vectoring-in-a-multi-operator-environment-separating-fact-from-fiction/
> shows that normal (non-vectored) VDSL2 at 800m should deliver between 28 - 38 Mbps,
> and vectoring should raise this to 50 Mbps, at 800m.
>
> http://www2.alcatel-lucent.com/techzine/vdsl2-vectoring-delivers-on-its-promise/ shows
> vectored VDSL2 delivers at least 40, and for latest tech around 60 - 80 Mbps at 800
> metres. Caution is that we don't know what gauge copper the various telcos had
> installed and were tested over, good results might be due to better tech, or a telco
> infrastructure with thicker wires.
>
> At the very least, everyone should get better than ADSL2+ at 800 metres, which is
> around 18 - 20 Mbps.
>
> P.
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