I recently found an Australian document from their equivalent of NICC. It describes the (technical & non-technical) things needed in order to roll out FTTN (their name for our FTTC) instead of the current FTTH-based plan for NBN Co: WC58 INDUSTRY PAPER ON FTTN AND VDSL2 REGULATION
(see attachment 1)
What is interesting about their deployment is that they very much have in mind that the NBN rollout is a full replacement for legacy broadband - so they discuss the transition from today (including exchange-based ADSL and SLU) to the future (barring SLU, and allowing for FTTN cabinets mingled with basement FTTN in MDU).
For the transition, they note that VDSL2 will need PSD masks to prevent interference with exchange-based ADSL (and will need to avoid vectoring over those frequencies too). Very much the same as we do here.
The cost of applying those PSD masks, and the alien crosstalk on those frequencies, appears to be an "up to" 15Mbps drop in speeds
Because the problem is at the lowest frequencies, I'd say that is a drop in speed for *every* FTTN line. Today's Ofcom report indicates rural FTTC averages 29Mbps; an extra 15 would be a significant jump.
If we want BDUK to reach a higher percentage of people with superfast speeds, wouldn't an easy answer be to phase out exchange-based ADSL, including LLU?Especially in rural areas?
Shouldn't we at least have the discussion going on somewhere?