One of the most detailed explanations if I ever saw one...

So, to sum up, in general PSD masks are used to reduce interference/crosstalk. For each frequency there is a PSD mask applied (according to the DSL tech used) and is implemented in the "last mile".

Am I correct?

In reply to a post by rockyray85:

One of the most detailed explanations if I ever saw one...

So, to sum up, in general PSD masks are used to reduce interference/crosstalk. For each frequency there is a PSD mask applied (according to the DSL tech used) and is implemented in the "last mile".

Am I correct?

The mask covers all frequencies in the service, but has specific parameters at each point and those are applied.

Imagine having a piece of card with a hole cut in it - the mask. This is placed over the frequency/power plot and checked to ensure everything lies with the area defined by the hole - anything outside then needs to be rectified.