ASCOM I62 - Determining if Handset Signals Its Use of U-APSD; Packet Classification of U-APSD in the AP

TD 92685EN
28 June 2012 / Ver. A
Troubleshooting Guide
Ascom i62 VoWiFi Handset
56
7. VoWiFi Handset
in figure 17, the WMM parameter indicates that U-ASPD is supported:
Figure 17. Capture Packets Trace
7.2.2 Determining if Handset Signals its use of U-APSD
The handset advertises its use of U-APSD and negotiates the use of U-APSD during th
e
association process. An association process when U-APSD is enabled is illustrated in figure
18:
Figure 18. U-APSD Category Assignment
7.2.3 Packet Classification of U-APSD in the AP
Section 3.5.2 U-APSD PS Mode Operation on pa
ge 15 describes the procedure where an AP
starts an unscheduled service period and delivers buffered frames when it rec
eives a trigger
frame from the handset. A voice packet acts as the trigger.
This section describes how the an unscheduled servic
e period may be interpreted in an
OmniPeek trace. In figure 19 an uplink trigger frame triggers buffered data and the correct
QoS settings are verified. These settings are UP 6 for both the voice queue and signaling
data.
In figure 19, the numbered points illustrate the following:
1 The five packets that have been buffered by the AP for delivery to the handset.
2 The voice packet that acts as the trigger frame from
the handset.