Method for transmitting and receiving paging messages

A method of performing idle mode operation carried out by a mobile station, the method comprising,

• receiving a first paging information of a first paging group and a second paging information of a second paging group from at least one base station;
• entering idle mode at a first coverage belonging to the first paging group and starting a first timer for a periodic location update;
• determining a paging group of a currently preferred base station;
• starting a second timer, if the paging group of the currently preferred base station is determined to be the second paging group;
• and
• performing location update when the second timer expires.

A mobile station for performing idle mode operation, the mobile station comprising:

• a processor;
• and
• a radio communication (RF) module configured to transceive a radio signal externally under the control of the processor,
• wherein the processor is configured to:
• receive a first paging information of a first paging group and a second paging information of a second paging group from at least one base station;
• enter idle mode at a first coverage belonging to the first paging group and starting a first timer for a periodic location update;
• determine a paging group of a currently preferred base station;
• start a second timer, if the paging group of the currently preferred base station is determined to be the second paging group;
• and
• perform location update when the second timer expires.