A smart speaker for providing a sound service based on an artificial intelligence platform, while being communicatively connected to an external server is disclosed. The smart speaker includes a first transceiver for connection to a wireless local area network (WLAN), a second transceiver for connection to a mobile communication network, and a processor configured to control communication connection to the external server through the first transceiver in indoor mode, and control communication with the external server through the second transceiver in outdoor mode.