Apparatus and method for performing scanning of assigned secondary carrier in a wireless access system

PURPOSE: A scanning performing method of an allocation secondary carrier and a method thereof are provided to prevent unnecessary scanning report about an active secondary carrier. CONSTITUTION: A terminal scans an inactive secondary carrier(S420). In case a scanning result about the inactive secondary carrier satisfies trigger conditions of a specific trigger field, the terminal reports the scanning result(S430, S440). The base station determines the carrier activation of the inactive secondary carrier. The base station directs the activation of the inactive secondary carrier(S450, S460).