A radio network controller includes an acquisition unit configured to acquire a radio communication state of a neighboring cell located around a cell formed by a base station which the mobile station camps on among base stations, and a level determination unit configured to determine the in-out reception level based on an acquisition result of the radio communication state by the acquisition unit. The level determination unit calculates an estimated reception level of the radio channel in a reception level tie point P in which the reception level of the radio channel transmitted by a base station 200 and the reception of the radio channel transmitted by a target base station 202 become substantially equal to each other, and determines the in-out reception level based on the calculated estimated reception level α.