Wireless communication system, wireless communication method, wireless LAN access point, and wireless LAN station

A wireless LAN access point in a wireless communication system in which one wireless LAN access point (which is hereinafter referred to as an “AP”) and a plurality of wireless LAN stations (each of which is hereinafter referred to as an “STA”) are connected to each other, and in which an uplink data frame is simultaneously transmitted from each of the plurality of STAs to the AP in a multiple access scheme, the wireless LAN access point comprising:

• a station information collection unit that collects station information from the plurality of STAs, where the station information is used for selection of STAs performing simultaneous transmission and for control of the simultaneous transmission, said station information being traffic information in each STA in the plurality of STAs, or a received power from each STA in the plurality of STAs, or a channel status from each STA in the plurality of STAs;
• a simultaneous-transmission determination unit that selects, from among said plurality of STAs, a combination of STAs performing the simultaneous transmission based on the station information;
• a set of downlink transmission queues, where each downlink transmission queue in the set of downlink transmission queues corresponds to a different access category;
• a downlink access control unit that transmits a downlink data frame via one of the downlink transmission queues;
• a trigger transmission unit that transmits to each of the STAs, which simultaneously transmits the uplink data frame, a trigger frame via a trigger transmission queue, where the trigger frame instructs to perform the simultaneous transmission, and includes information necessary for the control of the simultaneous transmission;
• and
• a set of CSMA/CA control units, where each CSMA/CA control unit corresponds to a downlink transmission queue in the set of downlink transmission queues and acquires a channel access right for transmitting the trigger frame or a downlink data frame from the AP to each of the STAs;
• and
• a set of selection units, where each selection unit corresponds to a downlink transmission queue in the set of downlink transmission queues and selects a downlink frame or a trigger frame to be transmitted by using the channel access right acquired by the corresponding CSMA/CA control unit.