Alcatel Unleashed

And during registration - DECT set registered with PLI=31?
Normaly if declared PLI f.e. 27 - DECT sets without "network" rights registered with PLI=31 (you can use exstended format for "dectinston" command).

No. PLI for Mixed DECT systems will be calculated automatically to fit both PARI values.
It's not good to have the same PARI and it's not allowed to have overlapping of radio coverage.
Minimum distance is -90 dB plus 90 meter.