Provided are a wireless power transmitter including a power conversion unit configured to transfer wireless power to a wireless power receiver by forming magnetic coupling with the wireless power receiver; and a communication/control unit configured to communicate with the wireless power receiver to control transmission of the wireless power and to perform application level data communication, wherein the communication/control unit transmits or receives data stream comprising sequence of data packets carrying the application level data based on application level data transport stream, wherein the data stream comprises an auxiliary data control packet at the end of the data stream.