Mask construction, overview

Written on 3:15 AM by ooe

The ANFP masks were constructed by a superficially simple procedure:

1. the network interfaces were grouped into clusters of mutual neighbours;

2. the system types to be admitted a priori were identified;

3. for each given system type the deployment rule was identified;

4. taking the deployment rules together the network interface clusters were categorised into ‘zones’ (the zone indicates which ends of given systems might be installed on at least one line end in the cluster);

5. for each end of each given system type a spectral mask was obtained;

6. for each zone a composite mask was produced (being the envelope of the spectral masks of all system ends which might be found installed at the cluster).

Note this allows each network interface to be assigned a single particular mask.

The simplicity and transparency of this process enabled an informed cross industry debate in the appropriate regulatory committee known as the DSL Task Group, and eventually regulator buy-in to one of the compromises proposed by that group [4,5].