the processor 1901 is further configured to broadcast a multi-block acknowledgement M-BA frame, where the M-BA frame includes one or more piece of association acknowledgement information, and the association acknowledgement information is acknowledgement information of the association request message, where if the trigger frame includes a temporary identifier that is allocated by the AP to each available subchannel, the association acknowledgement information includes a MAC address of one or more second STA, so that each second STA determines that the association acknowledgement information is acknowledgement information sent by the AP to the second STA and uses a temporary identifier of a corresponding available subchannel as a first AID of the second STA, where the second STA is a first STA corresponding to the association request message successfully received by the AP; otherwise, the association acknowledgement information includes a MAC address of one or more second STA and a first AID that is allocated by the AP to the second STA; and
a transmitter 1903, configured to send an association response message to the corresponding second STA according to the first AID, where the association response message is used to indicate that an association between the second STA and the AP is successfully established, the association response message includes a second AID, the second AID is used to identify the second STA, and the second AID is the same as or different from the first AID.
The association establishment apparatus provided in this embodiment can be configured to perform the method steps in the embodiment shown in