The mobile terminal 300 uses the positioning satellites 200 to obtain current-position information on the mobile terminal 300 (711). The IoT devices 100 measure a surrounding environment with measurement units 110, and transmit the sensed data and attribute information, as frames, at predetermined frequencies (712, 713). The mobile terminal 300 obtains the attribute information from the frames. Furthermore, the business-organization server 450 obtains the sensed data from the frames.

The mobile terminal 300 transmits the position information on the mobile terminal 300 and the attribute information on the IoT devices 100 (714). The information server 500 stores the attribute information that has been received in the database (716). At this time, arrangement positions and operation states of the IoT devices 100 may be more accurately grasped using a statistical method, on the basis of attribute information on the IoT devices 100 and position information that are collected from a plurality of mobile terminals 300.

Thereafter, the mobile terminal 300 predicts a movement position of the mobile terminal 300 as necessary (721). Then, the mobile terminal 300 requests supply of attribute information on IoT devices 100 around the predicted position information (722). In response to the request of the mobile terminal 300, the information server 500 reads attribute information on the IoT devices 100 from the database (724), and transmits the attribute information (727).