Connecting to the Network
After successfully entering your PIN code, your phone searches for an available GSM network. The network search is automatic, but may take a few seconds (see also “Main Menu
You are ready to make and receive calls when the
Network Operator's name appears on the display.
The following indicates the strength of the received network signal. If the signal is very weak, there is a risk of losing service.
Strong signal Weak signal No service
If you cannot obtain service
One reason for failure to obtain network service is that the reception strength may be too weak. Try moving to a higher elevation, to a window or open space. Make sure that there is nothing obstructing the antenna.
Roaming 
If you are out of range of your “Home” Network Operator, especially when you are abroad, another Network Operator may be selected automatically, subject to signal strength and roaming agreements between Network Operators. Contact your Network Operator/Service Provider for details.