Patent ID: 7831261

Claim:
A communication terminal capable of packet communication, comprising: a first detection means for detecting termination of packet communication, identifying cell identification information of a serving cell of the terminal based on a broadcast information received from a network when detecting termination of packet communication, and storing the identified cell identification information in a storage means; a second detection means for detecting that the serving cell of the terminal has changed, by extracting the cell identification information included in the broadcast information each time the broadcast information is transmitted from the network to the terminal and judging that the serving cell has changed when the extracted cell identification information differs from the previously extracted cell identification information; a judgment means for judging whether or not the cell identification information, after the change detected by the second detection means, is stored in the storage means, by receiving notification that the serving cell has changed from the second detection means and searching for the cell identification information received along with the notification from among the cell identification information stored in the storage means, and for outputting an area information indicating within a service area zone; and a recognition means for receiving the area information indicating within a service area zone from the judgment means and making a user recognize by a display means that packet communication is possible in said cell.