Controllerless Networks

I got a problem with iap 305 with both 5ghz and 2.4 ghz radio.Clients with 802.11 ac adapter has no issue but clients with b/g/n adapter occur high latency issue with my wireless. I got the radio setting as below

any configuration requirement for my wireless network?Please suggest.

In the first instance consider reducing your maximum transmit power to either 12 or 15. There is numerous reasons why this can cause issues (near/far, large coverage cells etc, CCI). 

Also, how are you measuring this latency? To an external server or internally?

I am measuring my latency by pinging local gateway bro.We are installing AP like in usual office.

omething to be aware of, when laptops are running on AC, the OS has different power profiles based on whether they are AC or on battery. When on battery, the OS (windows by default here) will put maximum power saving settings on the WLAN nic which puts the radio is maximum PSP. You can change the power profile of the operating system in windows such that when on battery, the radio is not put in maximum power saving mode. This will minimize or stop altogether any PSP activity and latency will very likely return to normal. The AP itself has no control, nor does it have any awareness nor can it differentiate between clients on AC versus battery, it's all in what the client does in terms of turning the radio on and off to save batter that matters, But clients with high power saving profiles neabled with more aggressively sleep the radio, send more PSP messages to the AP to indicate power save mode is on, and the result makes ping responses go WAY WAY up.

This may have nothing to do with the settings of the APs, but Craig's notes are worth following.

We've been seeing the exact same issue with a deployent of 515 IAP units. We see random very high latency (like over 2 secs) to hosts on the LAN on 2.4GHz but as soon as I force the nic to 5GHz it drops down to a steady 2ms. This is occurring on a number of laptops with Intel wireless cards all with latest firmware, all on AC power with the recommended power settings configured on all APs.

You can expect performance on the 2.4ghz band to be worse due to the sheer number of interferers on the band that will cause performance issues beyond your control.  You can reduce co-channel interference by dropping the power on the 2.4ghz band and enable broadcast filtering, but non-wifi interferers on the 2.4ghz band will cause you periodic issues.  The long-term move is to move to 5ghz.