Handover control method and device therefor

A method of performing handover by a User Equipment (UE), comprising:

• receiving, from a source evolved NodeB (eNB), a Radio Resource Control (RRC) connection reconfiguration message comprising information indicating an improved handover mode for reducing service interruption;
• maintaining connection to the source eNB and continually performing a data transmission/reception operation with the source eNB when the UE includes configuration for supporting the improved handover mode;
• transmitting a signal for random access to a target eNB;
• and disconnecting the connection to the source eNB and interrupting the data transmission/reception operation with the source eNB based on whether the signal is transmitted, wherein the RRC connection reconfiguration message comprises mobility control information including information indicating the improved handover modewherein the disconnecting and interrupting comprises:
• disconnecting the connection and interrupting the transmission/reception operation performed with the source eNB when random-access preamble information is transmitted to a target cell of the target eNB via a Physical Random Access Channel (PRACH), wherein the disconnecting and interrupting comprises:
• resetting a Medium Access Control (MAC) entity of the UE;
• and
• wherein the information indicating the improved handover mode is generated by the target eNB and is received by the UE.

A source evolved NodeB (eNB) for controlling handover of a User Equipment (UE), the source eNB comprising:

• a transmitter configured to transmit a handover request message comprising information indicating an improved handover mode for reducing service interruption to a target eNB when performing handover of the UE is determined;
• a receiver configured to receive, from the target eNB, a handover request acknowledgement message comprising information indicating the improved handover mode;
• and a controller configured to maintain connection to the UE and continually perform a data transmission/reception operation with the UE until the UE transmits a first signal to a target cell of the target eNB according to the improved handover mode, wherein the transmitter further transmits a Radio Resource Control (RRC) connection reconfiguration message comprising mobility control information to the UE, and wherein the handover request acknowledgement message comprises a Radio Resource Control (RRC) container including the mobility control information, and the mobility control information indicates the improved handover mode wherein the first signal comprises the random-access preamble information and is transmitted by the UE to the target cell of the target eNB via a Physical Random Access Channel (PRACH), wherein the receiver further receives, from the target eNB, information indicating completion of handover of the UE;
• and wherein the controller disconnect the connection and interrupts the data transmission/reception operation with the UE when the information indicating completion of handover of the UE is received.