The National Broadband Network in Australia was for a short while seen by
some as something for the UK to aspire too, then once a new Government had
counted the dollars needed they decided to downgrade from lots of FTTH/FTTP to
a FTTC/FTTB mixture with the more rural parts getting the wireless or satellite
service they would have previously got.
Now it seems the NBN is very quickly descending into a farce, the need to
co-exist with ADSL2+ in the network and a
frequency plan that limits VDSL2 to using the same spectrum as ADSL2+ means
that until the up to 8 MHz, 17 MHz or 30 MHz bands are opened up to VDSL2 the
FTTC deployments will be limited to 12 Mbps to avoid destroying exchange based
ADSL2+ signals. For FTTB where the DSLAM is in the basement of an apartment
building the speeds allowed are doubled to a massive 25 Mbps.
It is thought that the frequency plans to allow VDSL2 to run properly will
be approved in 2016, but one wonders why deployment went ahead before
approval.
The UK frequency plan for VDSL2 does use three different power masks to
ensure insignificant impact on ADSL/ADSL2+ exchange based services based on
distance of the cabinet from the exchange, but this is normally not noticed by
users since the profile 17a VDSL2 has lots of spectrum available to itself.
Test your broadband speed
Follow us on X for the latest broadband news 
To be honest, as more people further back my long phone line sign up to VDSL2, if anything my ADSL2 is getting slightly better. Nothing to do with VDSL but rather less ADSL2 lines interfering with each other I’m guessing.
Are you sure this is about the frequencies that can be used by VDSL2?
According to a subsequent update, the confusion appears to be about the “PIR” and “CIR” rates – which look to be the guarantees made for peak-hour usage.
Essentially, it is the same confusion we see here about the 15Mbps assured rates.
http://blog.jxeeno.com/incorrect-documentation-fttn-speeds-will-not-be-121-during-transition/
This story doesn’t seem to have set the Whirlpool NBN forum alight.
This all sounds rather bizarre to me. I can only think that NBN are planning to reuse the ADSL2+ frequencies. Perhaps they have very long sub-loops and the higher VDSL frequencies aren’t of much use. Of course this raises a point I’ve made before. It seems to me that in some areas (especially where there’s no LLU), much greater reach could be achieved if all lines going via selected cabinets were serviced by FTTC using a power mask which utilised the ADSL2+ frequencies.
Of course there would have to be a capped product with similar wholesale costs to the exchange-based services.
The frequencies and power used them yes.
“NBN Co will disable Downstream Power Back-off in respect of an NBN Co Node when NBN Co is satisfied that Downstream Power Back-off is no longer required in respect of that part of the NBN Co FTTB Network or NBN Co FTTN Network (as the case may be). The Co-existence Period for Ordered Products supplied by means of that NBN Co Node will cease at such time.”
The PIR and CIR are the result of the power back off.
Incidentally, NBN produce a weekly progress report. Early progress was snail-like, but it does seem to have accelerated with about 560k properties passed in the last 12 months (against 370k and 190k in the prior two years).
Note that this is a hugely expensive project.
http://www.nbnco.com.au/corporate-information/about-nbn-co/corporate-plan/weekly-progress-report.html
@Euler
IIRC, previous calculations show that the bit-loading masked out by the PSD masks accounts for around 10Mbps, for lines running at full speed.
Obviously less of that would be available to longer lines, but it would still prove to be a useful boost.
@Andrew
Here’s another article that talks about the position of the CA (== NICC), and their discussions about the use of spectrum from different nodes:
http://www.businessspectator.com.au/article/2015/6/12/technology/nbns-fttn-confusion-makes-any-guarantees-pointless
The CA stuff on power masks is fine (and to be expected, given their use of FTTB too), but the stuff related to the 12/1 CIR is still pure obfuscation.
The Aussies *will* be retricted, but no more than we are here.
@WWW
Those masked out frequencies are still. the ones that have the longest reach. Longer subloops won’t get the full 10mbps, but it’s still the most useful part of the spectrum. I’m not recommending this as a way of extending the reach of “superfast” speeds (although it will help), but more as a way of providing functionally useful speeds on longer lines. As an example, my brother’s house gets less than 1mbps from the exchange. Their cabinet is being enabled, but it’s 2km distant. If ADSL2+ frequencies were available, it might well get 10mbps using FTTC.