A communication apparatus capable of wireless communications with one or more base stations is disclosed. The communication apparatus includes a receiving unit configured to receive a signal transmitted from the base station, a judging unit configured to judge whether the communication apparatus is located in an area satisfying a predetermined criterion, in accordance with the signal received at the receiving unit, and an authentication unit configured to perform an authentication process for a user of the communication apparatus if the judging unit judges that the communication apparatus is not located in the area satisfying the criterion.