Unscheduled Automatic Power Save Delivery (U-APSD)
In the previous blog, we have seen the details of legacy power save mode. Now, let us see how to overcome the shortcomings of legacy power save with the adoption of U-APSD. In this post, we discuss
- The reasons why IEEE introduced Unscheduled Automatic Power Save Delivery spec
- Concept of WMM access categories
- How the U-APSD Process works
- How effective is U-APSD compared to legacy power save
U-APSD / WMM Power Save is a power save mechanism that is a part of IEEE 802.11e amendment for QoS. Some applications like VoIP and Live Video generate a predefined number of packets periodically (e.g.: VoIP 20ms). As discussed in the previous post, Legacy power save mode is time driven (and not event driven). Hence, it introduces unwanted latency and inefficiency. UAPSD is designed to address these issues along with WMM Classification.