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<div class="moz-cite-prefix">On 23/09/2013 12:07 PM, George
Michaelson wrote:<br>
</div>
<blockquote
cite="mid:5A43868E-EF6C-4246-9596-C6CCB1594123@apnic.net"
type="cite">
<pre wrap="">interesting my arse! George, they're the vendor who proposed the standard!
you've seen Simon Hacketts piece on whirlpool where he makes it explicit vectoring cannot work in out competitive environment? it demands re-centralization of the copper because it uses the same RF space as ADSL to do slightly different, but incompatible, modelling of noise.
Its one or the other: entire D/SLAM replacement required. the whole bundle does one, or the other.</pre>
</blockquote>
There are two different issues, which need to be addressed
separately, but are often confused - but they lead to the same
result in the end.<br>
<br>
Some existing nodes (e.g. some RIM cabinets) are dual-fed with fibre
and copper from a nearby exchange - some exchange copper passes
through the node.<br>
When you have exchange-connected ADSL2 and node-fed DSL (including
ADSL2+) in the same binder, bad stuff happens because of the
stronger/closer transmissions from the node-fed line-cards drowns
out the exchange-fed signals, so exchange-fed lines (typically
ADSL2) suffers.<br>
This happens regardless of whos equipment it is - this effect
doesn't require centralised control of the copper, but it does
require that people with DSLAMs in exchanges recognise that their
signals might be drowned out to the point of unusability by people
with DSLAMs in nodes - or the people with DSLAMs in nodes need to be
required to reduce their signal strength, which is the current
situation.<br>
This isn't a problem in purely fibre-fed nodes, and isn't a
vectoring problem - ADSL2 can coexist with vectored VDSL2+ in pure
fibre-fed nodes.<br>
<br>
Vectoring however, does require centralised single-DSLAM-operator
control of all lines, as the same DSLAM vector CPU needs to do the
NxN anti-phase interference calculations and coordinate all lines.
This has nothing to do with presence of ADSL, and is true even in
purely fibre-fed nodes which don't have the near/far problem above.
In essence, vectoring requires ULLS access to be repealed for
vectored copper cables.<br>
<br>
<br>
<blockquote
cite="mid:5A43868E-EF6C-4246-9596-C6CCB1594123@apnic.net"
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<pre wrap="">
here be (regulatory) dragons...</pre>
</blockquote>
<br>
Yup - the repeal of ULLS declaration being just one of them.<br>
<br>
<br>
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<pre wrap="">
-G
On 23/09/2013, at 10:42 AM, George Fong <a class="moz-txt-link-rfc2396E" href="mailto:george@lateralplains.com"><george@lateralplains.com></a> wrote:
</pre>
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<pre wrap="">Looks like they have started down the track.
<a class="moz-txt-link-freetext" href="http://www.afr.com/p/australia2-0/telstra_targets_billion_dollar_nbn_X8Wul0CVmC2TossqGfpqMP">http://www.afr.com/p/australia2-0/telstra_targets_billion_dollar_nbn_X8Wul0CVmC2TossqGfpqMP</a>
Interestingly, they are using equipment from Alcatel-Lucent.
Cheers
g.
--
<siggeorge.png>
Just remember, wherever you go .... there you are.
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