Unscheduled Automatic Power Save Delivery

Unscheduled automatic power save delivery overview

Unscheduled automatic power save delivery (U-APSD) is a power-saving mechanism that

  • is defined as a QoS facility in IEEE 802.11e standards

  • delivers multiple downlink packets in response to a single uplink trigger, and

  • reduces wireless latency and extends mobile device battery life

Additional information

  • U-APSD activates automatically when WMM (Wi-Fi Multimedia) is enabled.

  • U-APSD eliminates the need for polling individual packets at the access point.

Possible sequence for U-APSD operation:

A client device sends a single uplink trigger packet. In response, the access point delivers multiple queued downlink packets based on that single trigger.

View unscheduled automatic power save delivery

Show detailed information of a client by MAC address.


        Device# show wireless client mac-address 2B:5B:B3:18:56:E9 detail
        Output Policy State : Unknown
        Output Policy Source : Unknown
        WMM Support : Enabled
        U-APSD Support : Enabled
        U-APSD value : 15
        APSD ACs    : BK(T/D), BE, VI(T/D), VO(T/D)
        Power Save : OFF
        Current Rate : 
        
        --------------------------
        BK : Background
        BE : Best Effort
        VI : Video
        VO : Voice.
        
        T: UAPSD Trigger Enabled
        D: UAPSD Delivery Enabled
        T/D : UAPSD Trigger and Delivery Enabled