The present invention relates to a wireless communication system, and more specifically, to a method and apparatus for determining an operating mode of a device. A method for switching an operating mode of a device from a white-space bandwidth according to one embodiment of the present invention comprises the steps of: starting a timer related to database access if the device is operating in a first operating mode; determining whether a message is received from the database while the timer is in operation; and switching to a second operating mode if a message is not received from the existing database and the timer has expired.