Data forwarding apparatus and method for reducing handover interruption time in a wireless communication system

An operation method of a Mobile Station (MS) for data forwarding in a wireless communication system, the method comprising:

• performing a HandOver (HO) procedure from a serving Base Station (BS) to a target BS;
• after completing the HO procedure with the target BS, synchronizing with the serving BS at a previously negotiated serving BS frame start time point;
• receiving data packets existing in a queue through an air link directly from the serving BS;
• switching synchronization at a previously negotiated target BS frame start time point, and synchronizing with the target BS;
• and
• receiving new data packets from the target BS.

An operation method of a Mobile Station (MS) for data forwarding in a wireless communication system, the method comprising:

• performing a HandOver (HO) procedure from a serving Base Station (BS) to a target BS;
• requesting the serving BS to forward data packets existing in a queue, after completing the HO procedure with the target BS;
• receiving the data packets existing in the queue through an air link directly from the serving BS;
• sending the target BS a message requesting the target BS to transmit new data packets, when packets informing of the end of data packets are received from the serving BS;
• and
• receiving new data packets from the target BS.

An operation method of a serving Base Station (BS) for data forwarding in a wireless communication system, the method comprising:

• determining the use or non-use of an air link for forwarding of data packets of a Mobile Station (MS) existing in a queue;
• when determining the use of the air link for the forwarding of the data packets, synchronizing with the MS at a time point at which the MS completes a HandOver (HO) procedure with a target BS;
• and
• forwarding the data packets existing in the queue directly to the MS through the air link.

A wireless communication system for data forwarding, the system comprising:

• a Mobile Station (MS) for performing a HandOver (HO) procedure from a serving Base Station (BS) to a target BS, after completing the HO procedure with the target BS, synchronizing with the serving BS at a previously negotiated serving BS frame start time point, receiving data packets existing in a queue through an air link directly from the serving BS, switching synchronization at a previously negotiated target BS frame start time point, synchronizing with the target BS, and receiving new data packets from the target BS;
• the serving BS for synchronizing with the MS at the previously negotiated serving BS frame start time point, and for forwarding the data packets existing in the queue directly to the MS through the air link;
• and
• the target BS for synchronizing with the MS at the previously negotiated target BS frame start time point, and for transmitting new data packets to the MS.

A wireless communication system for data forwarding, the system comprising:

• a Mobile Station (MS) for performing a HandOver (HO) procedure from a serving Base Station (BS) to a target BS, after completing the HO procedure with the target BS, sending the serving BS a message requesting the serving BS to forward data packets existing in a queue and receiving data packets existing in a queue through an air link directly from the serving BS, and, when packets informing of the end of the data packets are received from the serving BS, sending the target BS a message requesting the target BS to transmit new data packets and receiving new data packets from the target BS;
• the serving BS for, when the message requesting the serving BS to forward the data packets existing in the queue is received from the MS, forwarding the data packets existing in the queue directly to the MS through the air link;
• and
• the target BS for, when the message requesting the target BS to transmit the new data packets is received from the MS, transmitting new data packets to the MS.