Siemens HIPATH 8000 - Manual (Page 65)

Basic functions
65
Step by Step
Picking up a group call
The pop-up menu opens:
Confirm the option shown.
or
^
Lift the handset (only if the appropriate function is set
by your administrator).
or
R
Press the sensor key programmed with the "Call pickup"
function (if configured). The speakerphone function is
activated.
Ignoring a group call
Select and confirm the option shown. The phone stops
signaling the group call.
Pickup call
Ignore