A wireless Local Area Network, LAN, system comprising: a wireless LAN base station; and a plurality of wireless LAN terminals (STA 1-STA n) configured to perform uplink multi-user communication with the wireless LAN base station, wherein the wireless LAN base station is configured to transmit, to the plurality of wireless LAN terminals (STA 1-STA n), a trigger frame that includes a first value that is specific to a wireless LAN terminal after association with the wireless LAN base station and associated with a first resource unit, RU, and a second value that is common to wireless LAN terminals before association with the wireless LAN base station and associated with a second resource unit, wherein the first value indicates the wireless LAN terminal after the association, to transmit uplink data using the first resource unit and the second value indicates a wireless LAN terminal before association, to transmit uplink data using the second resource unit, wherein the wireless LAN terminal after the association and the wireless LAN terminal before the association are included in the plurality of wireless LAN terminals (STA 1-STA n), wherein the trigger frame is for allocating resource units, and the wireless LAN terminal before the association is configured to: receive the trigger frame from the wireless LAN base station, and transmit, to the wireless LAN base station, the uplink data using the second resource unit, in a case where the second value is included in the trigger frame, and the wireless LAN terminal after the association is configured to: receive the trigger frame from the wireless LAN base station, and transmit, to the wireless LAN base station, the uplink data using the first resource unit, in a case where the first value is included in the trigger frame. a wireless LAN base station; and a plurality of wireless LAN terminals (STA 1-STA n) configured to perform uplink multi-user communication with the wireless LAN base station, wherein the wireless LAN base station is configured to transmit, to the plurality of wireless LAN terminals (STA 1-STA n), a trigger frame that includes a first value that is specific to a wireless LAN terminal after association with the wireless LAN base station and associated with a first resource unit, RU, and a second value that is common to wireless LAN terminals before association with the wireless LAN base station and associated with a second resource unit, wherein the first value indicates the wireless LAN terminal after the association, to transmit uplink data using the first resource unit and the second value indicates a wireless LAN terminal before association, to transmit uplink data using the second resource unit, wherein the wireless LAN terminal after the association and the wireless LAN terminal before the association are included in the plurality of wireless LAN terminals (STA 1-STA n), wherein the trigger frame is for allocating resource units, and the wireless LAN terminal before the association is configured to: receive the trigger frame from the wireless LAN base station, and transmit, to the wireless LAN base station, the uplink data using the second resource unit, in a case where the second value is included in the trigger frame, and receive the trigger frame from the wireless LAN base station, and transmit, to the wireless LAN base station, the uplink data using the second resource unit, in a case where the second value is included in the trigger frame, and the wireless LAN terminal after the association is configured to: receive the trigger frame from the wireless LAN base station, and transmit, to the wireless LAN base station, the uplink data using the first resource unit, in a case where the first value is included in the trigger frame. receive the trigger frame from the wireless LAN base station, and transmit, to the wireless LAN base station, the uplink data using the first resource unit, in a case where the first value is included in the trigger frame.