Method for handling an idle handoff between base stations supporting different services

A method for setting a protocol revision value for determining an environment of a service provided by a second base station by a mobile station during a handoff from a first base station to the second base station in an idle state in a mobile communication system including the first base station and the second base station neighboring the first base station, a service supported by the second base station being different from a service supported by the first base station, the method comprising the steps of:

• (a) receiving an extended system parameter message (ESPM) from the second base station;
• (b) comparing a length of the received ESPM with a length of a preset ESPM;
• (c) if the length of the received ESPM is equal to or longer than the length of the preset ESPM, comparing a protocol revision value indicating a service supported by the mobile station with a preset protocol revision value and setting a protocol revision value of the mobile station according to the comparison results;
• (d) comparing the set protocol revision value of the mobile station with the preset protocol revision value;
• and
• (e) if the set protocol revision value of the mobile station is equal to or larger than the preset protocol revision value, comparing the protocol revision value indicating the service supported by the mobile station with a protocol revision value included in the received ESPM and setting the protocol revision value of the mobile station according to the comparison results.