From the Home screen All tray, select Options. To expand the tray, press the Menu button then select Open Tray.
Select Networks and Connections.
Select Mobile Network.
Select the current setting in the Network Selection Mode field.
Select the appropriate setting. Depending upon the Network Technology selected (e.g. Global, 1XEV, GSM/UMTS), the options may vary.
Manual The preferred international carrier is automatically selected. You can manually tap an alternate carrier but it may require as many as six registration attempts with that carrier prior to successful registration.