If the phone has no SIM card or card connection is otherwise "inactive", only call that could happen in that situation should be a emergency call. I think it would be very comforting feature for customer to hear tone in the line in that situation.
If the phone has no SIM card or card connection is otherwise "inactive", only call that could happen in that situation should be a emergency call. I think it would be very comforting feature for customer to hear tone in the line in that situation.