How to understand macOS wireless diagnostics? I run wireless diagnostics:



to see which channels are best for my WiFi. In log I see:

# --- Wireless Environment
    2.4 GHz Networks            : 4
    5 GHz Networks              : 3
    Current Channel Networks    : 1
    Recommended 2.4GHz Channels : [ 2 3 5 6 7 8 9 10 ] 11 1 4 
    Recommended 5GHz Channels   : [ 40 44 48 ] 36 


How can I interpret values in brackets and outside brackets? Which channel should I choose from recommended ones?
I advise you to use this diagnostic tool twice:


in the exact position where you intend to place your Wi-Fi router,
in the exact position where you want to get the best access for your Wi-Fi client.


The number inside brackets are channels to avoid, the others the ones to use.

From your diagnostic results it would be a bad idea to use the “automatic” channel selection on your router because this is conceptually a total error as soon as you have neighbours networks. The router cannot diagnose the wireless environment where you will seat with your iPhone.

From the partial results you got, I advise you to configure your router to work on channel 36 (5 GHz) which won’t be subject to interferences (as it will be the case with channels 1, 4 and 11 even if they are actually free.

If you want to further improve your skill in the wireless world, I suggest you to try iStumbler. It is now a commercial product but it worths much more. I use it since many years in private and professionnal environments