In a wireless local area network system including a plurality of types of access points (APs), a first type AP receives a trigger frame from a second type AP, wherein the trigger frame may include first information related to resource allocation for a first block acknowledgment (BA) frame transmitted by a station (STA) to the first type AP. The first type AP may transmit, to the STA, a physical protocol data unit (PPDU) including data for the STA and the first information. The first type AP may receive, from the STA, the first BA frame on the basis of the first information.