This disclosure describes methods, devices, and systems related to generate a trigger frame including one or more resource block identifications (RBIDs), each RBID being associated with a respective resource unit of one or more resource units on a communication channel; cause to transmit the first trigger frame to each of one or more devices; process a received a power save poll (PS-poll) bit from a first device of the one or more devices on a spatial stream and a first resource unit of the one or more resource units; cause to transmit an acknowledgment to each of the one or more user devices; cause to transmit data buffered in the at least one processor to the first device; and process a received an acknowledgment from the first device confirming receipt of the data.