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

[Paul Brooks]

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.