Network server, mobile communication terminal, and operating method thereof

A network server, comprising:

• a verification unit to determine if a mobile communication terminal entering a coverage area of a small-sized base station is a temporary closed subscriber group (CSG) member, and to verify an expiration time offered to the mobile communication terminal if the mobile communication terminal is the temporary CSG member;
• a determination unit to compare the verified expiration time with a threshold time value;
• and
• a message transmission unit to transmit to the mobile communication terminal a report command message including the expiration time and a report cycle if the expiration time exceeds the threshold time value to drive a terminal timer of the mobile communication terminal to reduce the expiration time, and to receive the reduced expiration time transmitted from the mobile communication terminal.

A mobile communication terminal, comprising:

• a reception unit to receive a message from a network server in accordance with an entrance of the mobile communication terminal into a coverage area of a small-sized base station connected to the network server;
• a message definition unit to define the message as a driving command message if an expiration time is included in the received message;
• and
• a terminal control unit to extract the expiration time from the defined driving command message, and to drive a terminal timer to reduce the extracted expiration time.

A method for operating a network server, the method comprising:

• verifying if a mobile communication terminal entering a coverage area of a small-sized base station is a temporary closed subscriber group (CSG) member, and verifying an expiration time offered to the mobile communication terminal if the mobile communication terminal is the temporary CSG member;
• comparing the expiration time with a first threshold time value;
• and
• transmitting to the mobile communication terminal a driving command message including the expiration time if the expiration time is less than the first threshold time value to drive a terminal timer of the mobile communication terminal to reduce the expiration time.

A method for operating a mobile communication terminal, the method comprising:

• receiving a message from a network server in accordance with an entrance of the mobile communication terminal into a coverage area of a small-sized base station connected to the network server;
• defining the received message as a driving command message if an expiration time is included in the received message;
• extracting the expiration time from the defined driving command message;
• and
• driving a terminal timer of the mobile communication terminal to reduce the extracted expiration time.