A mobile terminal comprising: a wireless communication unit configured to transmit or receive signals; a first camera configured to acquire images; a display configured to display the acquired image; an ultrasound transmission unit configured to transmit ultrasound signals; and a controller configured to: cause the wireless communication unit to transmit a first detection prepare request signal to allow a plurality of external devices (221, 222, 223) located within a control area to switch to a prepare state; cause the first camera to acquire an image including at least one of the plurality of external devices (221, 222, 223) that switches to the prepare state; cause the ultrasound transmission unit to selectively transmit an ultrasound signal to the at least one of the plurality of external devices (221, 222, 223) included in the image; cause the wireless communication unit to receive associated control information from each of the at least one of the plurality of external devices (221, 222, 223); and cause the display to display a graphic image related to the associated control information from each of the at least one of the plurality of external devices (221, 222, 223). a wireless communication unit configured to transmit or receive signals; a first camera configured to acquire images; a display configured to display the acquired image; an ultrasound transmission unit configured to transmit ultrasound signals; and a controller configured to: cause the wireless communication unit to transmit a first detection prepare request signal to allow a plurality of external devices (221, 222, 223) located within a control area to switch to a prepare state; cause the first camera to acquire an image including at least one of the plurality of external devices (221, 222, 223) that switches to the prepare state; cause the ultrasound transmission unit to selectively transmit an ultrasound signal to the at least one of the plurality of external devices (221, 222, 223) included in the image; cause the wireless communication unit to receive associated control information from each of the at least one of the plurality of external devices (221, 222, 223); and cause the display to display a graphic image related to the associated control information from each of the at least one of the plurality of external devices (221, 222, 223). cause the wireless communication unit to transmit a first detection prepare request signal to allow a plurality of external devices (221, 222, 223) located within a control area to switch to a prepare state; cause the first camera to acquire an image including at least one of the plurality of external devices (221, 222, 223) that switches to the prepare state; cause the ultrasound transmission unit to selectively transmit an ultrasound signal to the at least one of the plurality of external devices (221, 222, 223) included in the image; cause the wireless communication unit to receive associated control information from each of the at least one of the plurality of external devices (221, 222, 223); and cause the display to display a graphic image related to the associated control information from each of the at least one of the plurality of external devices (221, 222, 223).