A communication apparatus method includes a non-transitory memory configured to store non-transitory instructions, and one or more processors coupled with the non-transitory memory. The one or more processors are configured to execute the non-transitory instructions to thereby cause the communication apparatus to generate a trigger frame, and send the trigger frame to the stations. The trigger frame is useable to trigger each station of a plurality of stations in a plurality of basic service sets to send a corresponding trigger based physical protocol data unit, and the trigger frame comprises identification information of the plurality of basic service sets and identification information of the plurality of stations.