The present invention relates to methods for performing fast handover by a terminal in an environment in which multiple femto base stations exist. A method for performing handover by a terminal includes transmitting, to a serving femto base station, a message for requesting seamless handover within a group including multiple femto base stations, the serving femto base station belonging to the group; receiving, from the serving femto base station, first command message including power information and allocation information; broadcasting an uplink signal that is applied with transmission power indicated by the power information, through an uplink resource indicated by the allocation information; receiving second command messages including measurements of the uplink signal measured by the multiple femto base stations from the serving femto base stations; and performing network re-entry to a target base station among the femto base stations.