Australian NBN can only use VDSL2 at low speeds

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.

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