A wireless LAN access point, AP, to which a plurality of wireless LAN stations, STAs, are connected and a wireless frame is simultaneously transmitted from each of the plurality of STAs to the AP in a multiple access scheme, comprising: a station information collection unit configured to collect from the plurality of STAs station information which is used for selection of STAs performing simultaneous transmission and for control of the simultaneous transmission, said station information collection unit being configured to collect propagation characteristic information of the STA as the station information; a simultaneous transmission determination unit configured to select a combination of STAs performing the simultaneous transmission based on the station information, a trigger transmission unit configured to transmit to each of the STAs performing the simultaneous transmission a trigger frame which instructs to perform the simultaneous transmission and which includes information necessary for the control of the simultaneous transmission, a plurality of first CSMA/CA control units (23-1,..., 23-4) configured to acquire a channel access right for transmitting a downlink data frame from the AP to each of the STAs, a plurality of second CSMA/CA control units (33-1,..., 33-4) configured to acquire a channel access right for transmitting the trigger frame, wherein each of the first CSMA/CA control units (23-1,..., 23-4) and the second CSMA/CA control units (33-1,..., 33-4) corresponds to an access category, and an access control unit configured to set a default value of an Enhanced Distributed Channel Access, EDCA, parameter in accordance with the access category, in a common-use manner, for the plurality of first CSMA/CA control units (23-1,..., 23-4) and the plurality of second CSMA/CA control units (33-1,..., 33-4) associated with a same access category and apply a weighting to the default value of the EDCA parameter in such a manner that the access control of the trigger frame takes precedence, and transmit one of the wireless frame and the trigger frame that acquired the channel access right by performing individual CSMA/CA control. a station information collection unit configured to collect from the plurality of STAs station information which is used for selection of STAs performing simultaneous transmission and for control of the simultaneous transmission, said station information collection unit being configured to collect propagation characteristic information of the STA as the station information; a simultaneous transmission determination unit configured to select a combination of STAs performing the simultaneous transmission based on the station information, a trigger transmission unit configured to transmit to each of the STAs performing the simultaneous transmission a trigger frame which instructs to perform the simultaneous transmission and which includes information necessary for the control of the simultaneous transmission, a plurality of first CSMA/CA control units (23-1,..., 23-4) configured to acquire a channel access right for transmitting a downlink data frame from the AP to each of the STAs, a plurality of second CSMA/CA control units (33-1,..., 33-4) configured to acquire a channel access right for transmitting the trigger frame, wherein each of the first CSMA/CA control units (23-1,..., 23-4) and the second CSMA/CA control units (33-1,..., 33-4) corresponds to an access category, and an access control unit configured to set a default value of an Enhanced Distributed Channel Access, EDCA, parameter in accordance with the access category, in a common-use manner, for the plurality of first CSMA/CA control units (23-1,..., 23-4) and the plurality of second CSMA/CA control units (33-1,..., 33-4) associated with a same access category and apply a weighting to the default value of the EDCA parameter in such a manner that the access control of the trigger frame takes precedence, and transmit one of the wireless frame and the trigger frame that acquired the channel access right by performing individual CSMA/CA control.