Preyash,
You don't provide much information, such as AP model, firmware version, size of your location and distribution of APs etc. Debugging wifi issues is hard. You will need to look for patterns - it may be a client side issue - which may be why logs on controller show no error.
- Was this working fine for a long time and now having new problems or a new/recent deployment?
- Have your APs been on line for a long time without a reboot?
- One particular AP or location? or most/all of them?
- One kind of client or differnet kinds? ie PCs Mac Android etc.
So I'll tell you to do the standard stuff:
- FIrst make sure your controller firmware is up to date.
- Reboot your controller and power cycle the APs - I've found when the clients have strange issues, sometimes the AP gets stuck or confused with cached information.
- Check for any client updates - either ones that have not been applied or, sometimes a recent one that was installed when the problems started.