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I've been reading a lot about channels lately. I understand everything about congestion and wanting to use the channels that have the least traffic. I get it. One thing I'm trying to grok is this -- assuming there is literally no other Wi-Fi network anywhere near you (which is unrealistic most of the time), what are the pros/cons of channels 1 and 11?

I pick 1 and 11 as they're the lowest and highest frequency. Not because they're non-overlapping like 1, 6, and 11 are (remember, we're in a desert of Wi-Fi signals, we don't care about "overlapping"). I pick them because they're the highest/lowest.

My naive guess is that it is somewhat like switching from 2.4 GHz to 5 GHz network, only much more minute. I would guess that channel 1 has more range indoors than channel 11 in the same way that 2.4 GHz has more range indoors than 5 GHz due to being a lower frequency and being better able to pierce walls. (In the same way lower frequency sounds can better pierce walls.)

My second guess, but I'm more unsure about this, is that channel 11 being at a higher frequency will allow faster speeds in the same way 5 GHz has faster speeds than 2.4 GHz. I'm more unsure about this though as I think the speed increase has more to do with the standard than the frequency.


Some background: I have seen (but not sure where) that channel 1 is "the best" assuming you're able to get it. I realize that's kind of a silly statement because 99% of the time the true answer is "it depends." I was thinking that lower channels were faster but then I realized that lower channels are lower frequencies and 5 GHz is faster and at a higher frequency. So when I began to really question why channel 1 is "the best" I realized that that's not necessarily true.

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If an advantage to one or the other could be reliably empirically measured, I'm sure it would have been reported by now.

One thing I can definitely say is false is the notion that a higher frequency channel allows faster performance. It's the width of the channel that matters, not its center frequency. The 5GHz band is so much wider than the 2.4GHz band, that the 5GHz band allows for channels that are 2x, 4x, and 8x as wide as the 20MHz-wide channels you're stuck with in 2.4GHz.

If I had to speculate on which channel you're most likely to get the best rates at various ranges, I would guess channel 6. Because if you look at the internal power tables in the firmware/ROMs for Wi-Fi chipsets, you'll see that channel 6 is usually allowed to use a little bit more power than the band-edge channels of 1 and {either 11 or 13}. This is because the regulatory certification rules are strict about out-of-band emissions, so the band-edge channels, which are more likely to "leak" a little out of band, often have to have their power trimmed back a little to meet regulatory limits. I'm still not sure you'd be able to measure that difference in your own home.

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  • Good answer. I disagree that you are stuck with 20MHz wid channels on 2.4GHz though - and this is relevant because you can have 40, 80 and even 160mhz channels - The larger the channel the closer to the center of the available spectrum it needs to be. See support.metageek.com/hc/en-us/articles/…
    – davidgo
    Feb 16, 2021 at 0:57
  • @davidgo those wide channels are in the 5GHz range (802.11ac doesn’t support 2.4GHz)
    – Greg W
    Feb 16, 2021 at 1:14
  • @gregw Dog. You are largely right of-course. 2.4 gig does offer 40mhz channels on 802.11n though.
    – davidgo
    Feb 16, 2021 at 2:11
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    @davidgo 2.4GHz only allows 20 and 40, not 80 or 160. Though the standards allow 40, it doesn't work out in reality because it doesn't leave room for the 2-4 channels you need to cover even a 2D (single floor) map well, and it doesn't leave room for Bluetooth, so 2.4GHz Wi-Fi devices that support Bluetooth set the "40MHz intolerant" flag that knocks the network down to 20MHz channels anyway. No Apple products ever use 40MHz in 2.4GHz even when it's available, and pro installers consider 20MHz channels "best practice" in 2.4GHz. So as a practical reality, 2.4GHz means 20MHz channels.
    – Spiff
    Feb 16, 2021 at 19:01
  • @spiff. Ta. TIL....
    – davidgo
    Feb 16, 2021 at 22:45
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My naive guess is that it is somewhat like switching from 2.4 GHz to 5 GHz network, only much more minute. I would guess that channel 1 has more range indoors than channel 11 in the same way .....

Actiontec article

In the U.S., the 2.4 GHz range is divided into 11 channels and you can use any of these channels for your wireless network. Channel 1 uses the lowest frequency band and each subsequent channel uses a slightly higher frequency.

The difference in channel frequency is not all that great so that is not a large determining factor.

Here is a screen shot from Inssider Office showing a wide usage of channel numbers right near me. My routers use Channel 6.

enter image description here

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In some countries, certain channels have higher power limits, so if you're devices are far from your own router, then it makes sense to use higher-power channels if the router and devices are capable of higher power.

As for interference, use an application such as Nirsoft's WiFi Info View to view currently active channels in your area, as shown below.

WiFi Info View

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  • The chart you linked to showed that every country uses a single power limit on all 2.4GHz channels, so that isn't a reason to choose one 2.4GHz channel over another.
    – Spiff
    Feb 15, 2021 at 22:06

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