Ah, TIL . Any suggestions for an appropriate value? Or just play with values between 10-25?for RB2011 to change the power you need to use tx-power-mode=all-rates-fixed
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Click on the Advanced Tab in wireless interface and go to the Current-TX-Power tab.
I've set the channel-width to 20mhz with no success. Can you tell me where I can see the output power?could you check what is the output power at the moment when you are using that AP?
Try setting the channel-width to 20mhz and check again.