Answer a waiting call
You can answer a call when you have another call in progress. Call waiting is a network service.
Select the waiting call and 
. The first call is put on hold.
Activate, deactivate, or check the status of the service
Select 
and Device > Call , and activate or deactivate Call waiting.
Swap between an active call and a call on hold
Select the call.
Connect the call on hold to the active call to start a conference call
Select 
Conference call.
End an active call
Select 
.
End both calls
Select 
> End all calls .