Method for performing handover in wireless communication system and device for same

A method for performing handover by a user equipment (UE) without a wireless local area network (WLAN) termination (WT) change from a source eNodeB (eNB) to a target eNodeB (eNB) in a wireless communication system, the method comprising:

• transmitting an end-marker request for requesting retransmission of an end-marker packet to the target eNB when a loss of the end-marker packet is detected after the handover without the WT change has started;
• and
• retransmitting the end-marker request or performing a recovery procedure for the end-marker packet when the end-marker packet is not received from the target eNB after the transmission of the end-marker request,
• wherein when the handover procedure without the WT change is successfully started, starting a predefined timer, and
• wherein when the end-marker packet is not received prior to expiration of the predefined timer, determining the end-marker packet is lost.