A multi-user uplink transmission is performed by analyzing, by a first wireless station, a spatial reuse field in a first frame, and generating, by the first wireless station, a second frame, wherein the second frame includes a spatial reuse field that is generated based on the spatial reuse field of the first frame. The first frame and the second frame are within the same transmission opportunity (TXOP) and the first frame is transmitted prior to the second frame during the TXOP.