With reference to the sixth aspect or the first possible implementation, in a third possible implementation of the sixth aspect, a special traffic identifier TID in the association acknowledgement information is further used to indicate that the association acknowledgement information is the acknowledgement information of the association request message.
With reference to any one of the sixth aspect to the second possible implementation, in a fourth possible implementation of the sixth aspect, a special traffic identifier TID or all 4 bits of a TID in the association acknowledgement information indicates or indicate a quantity of second STAs to which the AP sends acknowledgement requests by using a same piece of association acknowledgement information.
With reference to any one of the sixth aspect to the third possible implementation, in a fifth possible implementation of the sixth aspect, the association acknowledgement information further includes a statistical identifier, and the statistical identifier indicates a quantity of second STAs to which the AP sends acknowledgement requests by using a same piece of association acknowledgement information.
With reference to the fifth possible implementation of the sixth aspect, in a sixth possible implementation of the sixth aspect, the statistical identifier is located after per traffic identifier information in the association acknowledgement information.
With reference to the fifth possible implementation of the sixth aspect, in a seventh possible implementation of the sixth aspect, the statistical identifier occupies a bit reserved in block acknowledgement starting sequence control in the association acknowledgement information.