Patent ID: 7729319

Claim:
A base station of a first wireless LAN system initiating communication at fixed intervals, the base station comprising: a no-signal section determiner that determines whether there is a no signal section between a data block in a downlink phase for transmitting downlink data and a data block in an uplink phase allocated first to transmit uplink data, both of which are contained in frame data to be arranged upon scheduling of a communication frame of said first wireless LAN system; and a scheduler that, when said no-signal section determiner determines that there is a no signal section, schedules the transmission of a communication disable signal that prohibits communication in the no signal section by a second wireless LAN system, wherein said second wireless LAN system is arranged to initiate communication after waiting till a channel through which both of said first and second wireless LAN systems are able to perform in communication becomes vacant, wherein: when the no signal section is longer than a gap time from the finish time of the downlink phase to the time of finishing detecting the vacancy of the channel by said second wireless LAN system, said scheduler transmits the communication disable signal at timing earlier than the finish time of the gap time.