Aspects of the present disclosure generally relate to enhanced multi-user (MU) uplink (UL) protocols in wireless networks that allow non-UL transmissions to be performed simultaneously with triggered MU UL transmissions. A station may send a trigger frame triggering MU transmissions with an appropriate signaling to allow non-UL transmissions, i.e. transmission to another station, in a resource unit of the MU transmission. Examples of non-UL transmissions include Direct Link transmissions as well as downlink (DL) transmissions. The present disclosure regards how acknowledgment of or response to such transmissions can be efficiently performed. A response resource unit to be used within a MU transmission by the DiL/DL destination station to send a response to the (DiL/DL) data transmission may be signaled in the trigger frame triggering the DiL/DL transmissions in appropriate resource units.