AC68u: auto channel selection dependency on tx power?

[Maghook]

Currently using three 5dBi Delock RP-SMA (Asus WL-ANT157) antennas on my AC68U(374.43_2). Only need to cover one floor in the house while several other APs are around my apartment.

While playing around with tx power (e.g. lowering from default 80 to 60 or 40 because of switch from default 2dBi Asus stock antennas to 5dBi Delock) I noticed that the implemented auto channel selection algorithm only performs correct if I choose tx power 100. Just noticed that when lowering tx power below 100 the auto channel selection outcome is always non-optimal. This is true for both 2,4 and 5Ghz bands. I have also observed this behaviour with using the stock antennas on my AC68u instead of the Delock ones.

I´m interested if anyone else also noticed this? Seems to me that auto channel selection should not be recommended if not switched tx power to 100.

 

[drabisan]

Yes, for every regulatory domain (UE, EU, Japan etc) there is a connection between maximum power allowed and frequency.
You cannot emit with maximum power on every channel. Even if you set a certain power on a certain channel, your device may not use that exact power, due to regulatory restrictions.

I don't know the details about auto channel selection Asus implemented. I choose to survey the channels every now and then and set the channels my router is using not be interfere with anybody else.

 

[Maghook]

Yes, for every regulatory domain (UE, EU, Japan etc) there is a connection between maximum power allowed and frequency.
You cannot emit with maximum power on every channel. Even if you set a certain power on a certain channel, your device may not use that exact power, due to regulatory restrictions.

I don't know the details about auto channel selection Asus implemented. I choose to survey the channels every now and then and set the channels my router is using not be interfere with anybody else.

Concerning auto channel selection my imagination is that the related algorithm should be more or less independent of the selected tx power with the clear exception of 5Ghz band /w DFS. I would assume auto channel determination sould be primary based on interference with other 802.11 radios, blutooth, microweave, baby phones, weather radar etc. But I could be wrong

I can't imagine why should the regulatory domain would have so much influence that on the 2,4Ghz band the auto channel selection will always choose ch6 in my case where other strong APs are operating while tx power is set below 100 and otherwise when I set tx power to 100 it instantly selects ch1 which is the ch which I would definitely choose myself after conducting a site survey?