Abstract: A feature extracting unit obtains sensor data from a plurality of sensors to calculate each feature. When an event determining unit determines the occurrence of an event based on each feature, a display data constructor generates remote-controller display data for displaying the event, and controls a remote-controller display device to display the remote-controller display data. When a user decision is input from a user input IF based on this display, a control unit controls the sensors to be turned ON or OFF. When an infrared sensor detects an abnormality, a microwave sensor whose power consumption is small after the infrared sensor is turned ON. When the microwave sensor detects an abnormality, a video camera and a microphone are turned ON, and the microwave sensor is turned OFF. A communication unit wirelessly transmits an image signal captured by the video camera and an audio signal processed by the microphone.