Siemens M35 Series Service Manual page 43

Next, the GSM test set will initial a call to the mobile phone through the Antenna Coupler. Press
the Call key when the mobile phone ring, and the GSM test set will start Tx Power
measurements on the GSM and GSM1800 channel specified by the configuration setting.
Next, the GSM test set will end the call to the mobile phone and the screen will prompt for Dialing
from the mobile phone. At this test step, please move the mobile phone to the Antenna Cradle
and switch the RF switch to EXT ANT position. Once the mobile phone log to the GSM test set,
dial 1234 and the Send key.