A base station registers a mobile station subjected to the call reception control of the base station. When connection between the mobile station registered by the base station and a higher-level device of the base station is terminated after detecting that the mobile station is located in a communication area of the base station, the base station causes the higher-level device to maintain information indicating that the mobile station is located in the communication area, without notifying the higher-level device of termination of the connection. When a call addressed to the mobile station is detected after termination of the connection between the mobile station and the higher-level device, the base station gives a notification about detection of the call.