A method of operating in a wireless local area network system is provided. The method includes receiving a channel usage response from an access point, the channel usage response comprising channel usage information and transmit power regulation information, the channel usage information being for coexistence with an infrastructure network, and operating by using the channel usage information. The channel usage information includes at least one channel entry field indicating at least one recommended channel and a usage mode field indicating usage of the at least one recommended channel listed in the at least one channel entry field. The transmit power regulation information includes a plurality of maximum transmit power fields. Each of maximum transmit power field specifies a maximum transmit power limit for transmission on a corresponding channel bandwidth.