Automatic Power Save Delivery (APSD)

A power saving method which uses both scheduled and unscheduled frame delivery methods

APSD is a power saving method which uses both scheduled (S‐APSD) and unscheduled (U‐APSD) frame delivery methods. S‐APSD sends frames to a power save STA from the AP at a planned time. U‐APSD sends frames to a power save STA from the AP when the STA sends a frame to the AP. The frame from the STA is considered a trigger frame.