Method of performing status report in a mobile communication system

A user equipment (UE) for transmitting reception status report of data transmitted from a base station in a mobile communication system, the user equipment is set to perform the steps of:

• periodically transmitting reception status report of at least one first data block in the radio link control (RLC) protocol layer every first time period value (T1) of at least one parameter, the at least one first data block being transmitted from the base station;
• changing the first time period value (T1) of the at least one parameter to a second time period value (T2) if a previously set event occurs or if at least one predefined condition is satisfied, wherein the second time period value (T2) is smaller than the first time period value (T1);
• and
• periodically transmitting reception status report of at least one second data block every the second time period value (T2) of the at least one parameter, the at least one second data block being transmitted from the base station,
• wherein the at least one parameter includes a time period value for transmitting the reception status report,
• wherein the at least one predefined condition is satisfied if intensity of a reference signal transmitted from the base station becomes smaller than a predefined first threshold value, if intensity of a reference signal transmitted from a neighboring base station becomes greater than a predefined second threshold value, or when the user equipment transmits a measurement report message to the base station, and
• wherein the second time period value (T2) is smaller than the first time period value (T1).