A method and an apparatus for scanning existing networks in TV White Space are disclosed. For scanning existing networks at a station to operate as an unlicensed device in a regulatory domain where a licensed device and the unlicensed device are permitted to operate, the method comprises: receiving a white space map (WSM) comprising information for available channels to be used for the unlicensed device to operate a wireless local area network (WLAN) operation and maximum transmission powers allowed for each of the available channels from an enabling station, wherein the enabling station is a station determining the available channels at its location using its own geographic location identification and a regulatory database access capability; and scanning the existing networks on the available channels identified within the received WSM.