Abstract: A Bluetooth system includes a set-top box transmitting/receiving data to/from a communication terminal, and a Bluetooth module installed on the outside of the set-top box and connected to the set-top box through a first cable, and converting the data into a predetermined format. The Bluetooth module is installed at a position to meet an optimal data receiving condition. The set-top box includes a first connection unit to which the first cable is connected. A failure in the data communication of the set-top box caused by the limitation in the installation location and area, such as walls or other blocking structure surrounding the set-top box, can be addressed.