Android Phones are losing WLAN connectivity after several minutes

[M_Nees]

EWC V9.21.12 - WLAN running now stable for laptops! Except Android SmartPhones have problems anymore!

If the Smartphone is newly connected all working well - also if i ping the system continiously - no problems. If i stop the ping, then after some time the client have no internet connection - wlan seem to be assiciated. If i disassociate (both sides) and re-connect this device new all working well for several time (minutes). If i restart the AP also all working well for some time. So allways if a smartPhone client is online for more than a few minutes the problem begins (looses IP / Internet Connectivity).

only 2,4Ghz is online, no channel bundeling (20Mhz Channels), no special options set.

After some debugging (wireshark capture) i see that if the clients are not working, the smartphones are sending a lot of "Qos Null function (No data)" packets. If i ask Mr. Google he tell me that this packets managing powersafe modus. Thats correct - wireshark tells in one packet (of the problematic clients) "STA will go to sleep" - next packets tells "STA will stay up" ?! And this toggle several times a second!

So how can i avoid this ?

i cannot disable powersafe mode on clients because i have no access to them. Because this is payed WLAN service we have to provide a working service (without have the ability to tough client systems) and without disruption and re-connects.

How can i solve that problem ?

[Ostrovsky__Yury]

Correct , the MFP is only a feature of secured WLAN .
Optimize for PS will not help , this feature affects only multicast traffic .
Btw , what sort of Android phones you are talking about - is there a particular model , or just any Android having this issue?
How about 5Ghz radio - do you see the same issues there? Or only 2.4/open SSID/9.21/

[Sai_Prasad_Rao_]

Hi Ostrovsky

Above option is only available for secured WLAN Service (WPA/WPA2 etc), what about open WLAN Service ?

[Ostrovsky__Yury]

Try to disable Management Frame Protection (on VNS-->WLAN service -->Privacy) , we have seen devices having such issue if its enabled .

[Ronald_Dvorak]

I normally only enable WMM & 802.11e and leave U-APSD off.

[Sai_Prasad_Rao_]

Is there power save option enable/disable on Access Point radio's. I can see some "Optimized for power save" option on radios.