Method and apparatus for short handover latency in wireless communication system using beam forming

A method for handover in a serving Base Station (BS) of a wireless communication system which adjusts a beam direction, the method comprising:

• receiving a scan request message for scanning a downlink (DL) beam or a DL beam and uplink (UL) beam for a mobile station (MS), from the MS;
• sending a scan response message comprising information about whether to perform scanning or scanning and association, to the MS;
• receiving from the MS a scan report message comprising information of the DL beam or the DL beam and UL beam for the MS and a result of the scanning or the scanning and association;
• and
• performing a handover from the serving BS to a neighboring BS,
• wherein after the handover, the MS is configured to transmit and receive data to and from the neighboring BS based on the DL beam or the DL beam and UL beam.

A method for handover in a neighboring base station (BS) of a wireless communication system which adjusts a beam direction, the method comprising:

• performing scanning or scanning and association with a mobile station (MS) to scan a downlink (DL) beam or DL beam and uplink (UL) beam for the MS;
• receiving from the serving BS a network handover (NW-HO) request message based on a scan response message comprising a result of the scanning or the scanning and association of the MS and information of the DL beam or the DL beam and UL beam determined by the MS;
• and
• after a handover from the serving BS to the neighboring BS, transmitting and receiving data to and from the MS based on the DL beam or the DL beam and UL beam.

An apparatus of a mobile station (MS) for handover in a wireless communication system which adjusts a beam direction, the apparatus comprising:

• a transmitter configured to send a scan request message for scanning a downlink (DL) beam or a DL beam and uplink (UL) beam with respect to a serving base station (BS) and a neighboring BS, to the serving BS;
• a receiver configured to scan a response message;
• and
• a controller configured to perform scanning or scanning and association with the serving BS and the neighboring BS based on the scan response message, determine the DL beam or the DL beam and UL beam for the MS based on a result of the scanning or the scanning and association, and after a handover from the serving BS to the neighboring BS, transmit and receive data to and from the neighboring BS based on the DL beam or the DL beam and UL beam.

An apparatus of a serving base station (BS) for handover in a wireless communication system which adjusts a beam direction, the apparatus comprising:

• at least one antenna comprising a plurality of antenna elements;
• a receiver configured to scan a request message for scanning a downlink (DL) beam or a DL beam and uplink (UL) beam for a mobile station (MS), and a scan report message comprising information of the DL beam or the DL beam and UL beam for the MS and a result of scanning or scanning and association, from the MS;
• a transmitter configured to send a scan response message comprising information about whether to perform the scanning or the scanning and association, to the MS;
• and
• a controller configured to perform a handover from the serving BS to a neighboring BS,
• wherein after the handover, the MS is configured to transmit and receive data to and from the neighboring BS based on the DL beam or the DL beam and UL beam.

An apparatus of a neighboring base station (BS) for handover in a wireless communication system which adjusts a beam direction, the apparatus comprising:

• at least one antenna comprising a plurality of antenna elements;
• a transmitter;
• a receiver;
• and
• a controller,
• wherein the controller is configured to perform scanning or scanning and association with a mobile station (MS) to scan a downlink (DL) beam or DL beam and uplink (UL) beam for the MS,
• wherein the receiver is configured to receive from the serving BS a network handover (NW-HO) request message based on a scan response message comprising a result of the scanning or the scanning and association of the MS and information of the DL beam or the DL beam and UL beam determined by the MS;
• and
• wherein the transmitter and the receiver, after a handover from the serving BS to the neighboring BS, are configured to transmit and receive data to and from the MS based on the DL beam or the DL beam and UL beam.