Symbol Technologies AP-5131 - Manual (Page 163)

Network Management 5-39
9. Click Apply to save any changes to the New QoS Policy or Edit QoS Policy screen to return
to the Quality of Service Configuration screen. Navigating away from the screen without
clicking Apply results in all changes to the screens being lost.
10. Click Cancel to securely exit the New QoS Policy or Edit QoS Policy screen to return to the
Quality of Service Configuration screen.
11. Click Logout within the Quality of Service Configuration screen to securely exit the AP-5131
Symbol Access Point applet. A prompt displays confirming the logout before the applet is
closed.
U-APSD (WMM Power Save) Support
With this latest release, the AP-5131 now supports Unscheduled Automatic Power Save Delivery
(U-APSD), often referred to as WMM Power Save. U-APSD provides a periodic frame exchange
between a voice capable MU and the AP-5131 during a VoIP call, while legacy power management
is still utilized for typical data frame exchanges. The AP-5131 and its associated MU activate the new
U-APSD power save approach when a VoIP traffic stream is detected. The MU then buffers frames
from the voice traffic stream and sends a VoIP frame with an implicit "poll" request to its associated
AP-5131. The AP-5131 responds to the poll request with buffered VoIP stream frame(s). When a
voice-enabled MU wakes up at a designated VoIP frame interval, it sends a VoIP frame with an
implicit "poll" request to its associated AP-5131. The AP -5131 responds to the poll request with
buffered VoIP stream frame(s).
TXOPs Time ms TXOP times range from 0.2 ms (background priority) to 3 ms (video
priority) in a 802.11a network, and from 1.2 ms to 6 ms in an
802.11b/g network. The TXOP bursting capability greatly enhances
the efficiency for high data rate traffic such as streaming video
NOTE The AP-5131 ships with the U-APSD feature disabled by default. It is
automatically enabled when WMM is enabled for a WLAN. Thus, U-APSD
is only functional when WMM is enabled. If WMM is disabled, then
U-APSD is disabled as well.