U-APSD is a relatively new technology, Intel is continuously improving the functionality and compatibility of the devices, however, some environments may present interoperability issues when U-APSD is enabled and disabling it may be required for proper operation.
Here are some actions that you may apply:
- Install Intel® PROSet/Wireless Software for Windows 8.1* version 17.16.0.
- Contact the AP manufacturer and update the Firmware.
- Try setting the Power Plan to Maximum Performance (plugged in and on battery) and check if the issue is solved.
For further assistance, let us know the following:
Computer brand and model, driver version shown in device manager, AP model and firmware version.
Is there a specific reason why you require U-APSD?
I'd like to better understand your comments:
Then I associated my Intel 7260AC to AP, I can see U-APSD in first time Association Request frame with SP=2, all 4 ACs are set.
But after I transmit some UDP downstream traffic from wired network, I found Intel 7260AC stopped to use U-APSD and change back to use legacy power save.
I disconnect it to AP and reconnect again, I found this time U-APSD bit and all 4 ACs are not set in Association Request frames.
Are you using a software application that supports adapter switching? It appears that you are switching between wired and wireless. This should not change settings specific to the wireless adapter. Are any settings changed on the wired side when switching the other direction?
Can you provide the trace file that shows the Association Request frames? You can send these to our Support team by opening a case.
Please provide more details on your configuration so we can assist you.