Product and Software: This article covers all ArubaOS with WMM enabled on the SSID profile.
Every 802.11 frame has a control field. This field indicates the type of 802.11 frame: management, control, or data. If the AP is configured for WMM Power Save, the AP starts to buffer traffic for a client when the client sets the "power management" flag. The AP buffers traffic for the client until it sees a valid trigger frame (802.11 data frame).
When a client is in power-save mode, it wakes up at its listening interval for the beacon frames. If it sees its association-ID in the beacon frame, it should send a valid 802.11 data frame to the AP to trigger the release of the buffer. For the ArubaOS implementation, the trigger frame releases the buffers for all buffer data in all access categories. The client then goes back to sleep, when the more-data flag is set to "0".