A wireless communication system includes a wireless base station FAP2 which communicates with a mobile communication terminal UE1; a core network apparatus CN4 which is a higher-level apparatus of the wireless base station; and a femto wireless base station gateway GW3 which relays between the FAP2 and the core network apparatus CN4. The wireless base station FAP2 includes a determination unit 21a which determines whether to stop voice call reception processing or voice call transmission processing with reference to determination information upon detection of a voice call reception to the mobile communication terminal UE1 within a communication service area or a voice call transmission from the mobile communication terminal UE1 within the communication service area in the FAP2; and a signal processing unit 25a which informs a higher-level apparatus of a message including a determination result when the determination unit determines to stop the processing.