Nokia 252C - Manual (Page 11)

4
Signal Strength Indication
A cellular phone sends and receives radio signals. As with
all radio equipment, the quality of radio reception depends
on the strength of the radio signal in the area where you
are operating your phone.
The strength of the cellular signal is shown by
the vertical bar on the left-hand side of the dis-
play. The higher the bar, the stronger the signal
at your present location.
When
NO SERVICE
is displayed, the phone is
either outside of the cellular service area or re-
stricted from entering service, and calls cannot
be made or received.
If the signal is poor and you are using the phone in a
building, you may get better reception near a window.