A method of obtaining system frame number for handover is provided. A UE receives a handover command from a serving base station in a serving cell. The UE performs downlink synchronization with a target base station. Upon synchronization, the UE determines a radio frame boundary of a target cell. The UE then obtains a system frame number of the target cell based on the radio frame boundary. The UE performs a handover procedure with the target cell by transmitting a RACH preamble to the target base station. The RACH preamble is transmitted over a PRACH resource determined from the system frame number without reading SFN information from a PBCH/BCH broadcasted from the target base station. Finally, the UE establishes data connection with the target base station. Handover interruption time is reduced by obtaining SFN before PBCH reading and decoding.