This disclosure provides systems, methods, and apparatuses for operating a wireless station in a multiple basic service set identifier (BSSID) set including a transmitted BSSID (Tx BSSID) and a number of non-transmitted BSSIDs (non-Tx BSSIDs). In some implementations, the wireless station may receive a trigger frame containing a number of association identifier (AID) values based on a group AID mapping contained in a partial virtual bitmap of a traffic indication map (TIM) element, and may determine whether the trigger frame allocates one or more random resource units (RUs) for use by the station based on one or more of the AID values contained in the trigger frame.