COMMUNICATION SYSTEM, BASE STATION, MOBILE STATION, MANAGEMENT APPARATUS, HANDOVER CONTROL METHOD, AND PROGRAM

In an overlay cell configuration in which a second cell, a second cell of a same frequency and a third cell of a different frequency are overlapped at least partially with each other, a concentration of communication traffic on the first cell is prevented. It is obtained of a measurement result (MR) including a measurement result of a reception-quality level measured at the same frequency reported by a mobile station connected to a second base station of the same frequency and a cell identifier of a receiving target cell, it is decided whether to change a value of a parameter for determination used for determining a different-frequency-measurement start that is set in the second base station of the same frequency, based on the measured value of the reception-quality level of the signal from the first cell included in the measurement report (MR), when the measurement report (MR) includes the cell identifier of the first cell, and the value of the parameter for determination is changed based on a result of the deciding.