Method and apparatus for handover control in a mobile communication system with csg

A communication terminal having a connection to a Home eNodeB (HeNB) in a Closed Subscriber Group (CSG) cell, the communication terminal comprising:

• a radio link monitor unit that detects a radio link problem that the connection to the HeNB is likely to be lost;
• a timer manager that starts a timer when the radio link monitor unit detects the radio link problem;
• a cell detection unit that searches available cells;
• and a cell selection unit that selects a target cell among the available cells;
• and
• wherein the cell selection unit selects the target cell out of only CSG cells before the timer expires, and tries to re-establish a connection to a HeNB in the target CSG cell.

A communication system enabling a communication terminal to handover between a Closed Subscriber Group (CSG) cell and a macro cell, the system comprising:

• a communication terminal having a connection to a Home eNodeB (HeNB) in the CSG cell that comprises,
• a radio link monitor unit that detects a radio link problem that the connection between the HeNB and the communication terminal is likely to be lost;
• a timer manager that starts a timer when the radio link monitor unit detects the radio link problem;
• a cell detection unit that searches available cells;
• and
• a cell selection unit that selects a target cell among the available cells;
• and
• the HeNB in the CSG cell that comprises,
• a timer manager that starts the timer when the radio link problem is detected;
• a connection manager that detects the radio link problem, and manages the connection between the communication terminal and the HeNB;
• and
• a handover manager that performs partial handover preparation to the macro cell after the timer expires;
• and
• wherein the cell selection unit in the communication terminal selects the target cell out of only CSG cells before the timer expires, and tries to re-establish a connection to a HeNB in the target CSG cell.

A method used for a communication terminal having a connection to a Home eNodeB (HeNB) in a Closed Subscriber Group (CSG) cell, the method comprising:

• a radio link monitoring step that detects a radio link problem that the connection to the HeNB is likely to be lost;
• a timer starting step that starts a timer when detecting the radio link problem;
• a cell detecting step that searches available cells;
• and a cell selecting step that selects a target cell among the available cells;
• and
• wherein the cell selecting step selects the target cell out of only CSG cells before the timer expires, and tries to re-establish a connection to a HeNB in the target CSG cell.