Wifi disturbance following channel disable for Radio 802.11a

[ksoltani]

Hello,

At our site, we use wifi with Frequency 5 GHZ, Radio: 802.11a only

Cisco Wlc AIR-CT5520-K9, Software Version 8.5.151.0
AP Cisco AIR-AP2802E-E-K9, Primary SW version 8.5.151.0
802.11a > RRM > Dynamic Channel Assignment (DCA)
Dynamic Channel Assignment Algorithm
Channel Width 20 MHZ is provide 25 channel
I have ssid with this radio work good, but following the channel statement for needs, I disable channel 36, 40, 44

after that i have profil ssid (X) work this Radio: 802.11a Channel Width 20 MHZ
disappear immediately only to return 3 or 4 minutes later
and when I manage to click on it to be able to connect when I have finished entering all the information it should connect immediately to the network

After the disable the channel I received a wifi connection disturbance for an ssid x profile

can you receive wifi disturbance after deactivating the channels?
Is there a document that can clarify this part, I need your help

[ammahend]

when you deactivate a channel all clients connected to APs working on that channel will disconnect. RRM will reassign new channel to these APs. so it will be a disruptive change.

I don't know if its written exactly like this somewhere, but its understandable that if you took away the RF medium (operating channel) then clients will be momentarily be disrupted.

you can read this document to understand DCA behavior, hopefully it will help.

https://www.cisco.com/c/en/us/td/docs/wireless/controller/technotes/8-3/b_RRM_White_Paper/dca.html#id_15157

[Haydn Andrews]

as Ammahend said, when ever you alter the DCA channels or a RF profile all APs utilising that setting will disconnect and reconnect to the WLC hence dropping client traffic whilst that happens.

RRM will then recalculate the channel plan, this can take a few hours dependant on the environment before it settles down during which could cause some client disruption. 

[ksoltani]

@ammahend @Haydn Andrews  thank you very much for your information

As I said in our company, we use wifi with the radio 802.11a Network Status and the channel with 20 MHz but for my manager to deactivate channels 36, 40, 44 as illustrated in screenshot
This makes a wifi disturbance, when you connected to SSID "X" cannot connect despite before connected stable without worry
My question: is there a solution to disable channels 36, 40, 44 at the wlc level and make wifi stable without disturbance or is it not recommended?

Is not recommanded that