Handover method and apparatus

A server in charge of a control plane within a mobile communication network, the server comprising:

• a transceiver;
• and
• a controller configured to:
• control the transceiver to receive a message related to a handover, including a first parameter indicating a cause for the handover,
• transmit a handover command message to a first base station for a terminal to perform a handover to a second base station, when the network node determines that handover is needed based on the cause,
• receive a status report message including a second parameter indicating whether or not the cause for handover is solved, and
• transmit a reverse handover request message to the second base station for the terminal to perform reverse handover to a target base station, when the network node determines that a reverse handover is needed,
• wherein the network node determines that the handover is needed, if the first base station is closed subscriber group (CSG) cell and the cause is an expiry of a CSG membership, and
• wherein the network node determines that the reverse handover is needed, if the cause is an expiry of a CSG membership and the second parameter indicates updating of the CSG membership.