I understand 100% of that, I merely thought OpenWrt let you set the 40 and 20.
If that's not the case, I agree the list is more confusing than other methods of listing channels used by other developers.
It only allows you to choose channels in the 20mhz range.
To select an 80 mhz channel you select the center frequency of the LOWEST 20 mhz channel and then select the bandwidth
pretty dumb huh..
Fun part is it will only actually work if you make a "valid" selection so the software already knows what is correct. it's just not in the UI.
if the selection is invalid the radio will not associate correctly.
So for mine channel selecting channel 116 and selecting 80Mhz should really just be channel 122
3 Likes
Yes, and then you set...20, 40, 80 or 160 - as I noted before, I thought this would allow the person to determine what [20Mhz] frequency "range(s)" was in use.
Whoa...are you saying that you only get 80 MHz if you select: 36,52,100,116,132 or 149 and then select 80 MHz?
Are you saying it fails otherwise????
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YES ! That is what I am saying.
if i select a different channel like 44 and set the width to 80 it fails.
So something has got to give.
(to be clear it does not fail it when saving the setting it just makes the radio not work)
basically you have to understand the bandpland and OpenWRT's odd implementation of the bandplan to setup your wireless network in the UI. My "Channel = bandwidth" solution would fix this.
I am a computer system engineer for a living. This is what I do and it took ME a wile to figure out what the issue was. Which is why I think we need to make this work more gooder 
4 Likes
As am I; and now I'm curious to duplicate this...but I don't think occurs on 40 MHz devices (my test router).
well can you set it to 40Mhz and channel 40 or 56?
Yes, and it works.
and the radio associates properly?
If you choose channel 40 and 40mhz your center frequency is 5210 and that is not valid. (but it may be ubiquity valid) it is not industry standard
I think the options are emulate Ubiquiti, "store whatever they choose, calculate/use the correct base channel for the specified freq/width, hint at the conclusion (upper extension or lower extension)", or make the ui presentation adapt to width changes by greying out and shifting to a valid frequency.
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Yep...to be clear, I think I have production device set in that manner now - verify...I have 161 set at 40 MHz...which under your same issue should fail unless set to 157:
I was thinking about that. Greying out ones that will not work correctly. This would keep the same methodology but stop users from selecting "bad" frequencies.
A radio button to "Override" could allow for non standard settings for the tweakers.
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161 is in a weird place at the end. try 40 or 56.
Perhaps not even greying out, just lighting a "non-standard base channel for this channel width" mouseover warning bulb that explains the implication.
that would also work.
Maybe just color them green/red as appropriate
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That would be pretty intuitive and still non-restrictive. Sounds like a good path.
well where do we go from here?
Interestingly the same "rules" regarding channel and channel width apply to wifi6 and they were even nice enough to use odd number instead of even.
So... you set the channel, it waits 90 seconds listening for radar interference, in the meantime the 90 second time expires... then it reverts...
I don't think this was thought out very well. That means often you can only change the channel if you connect via the 2.4 Ghz band or ethernet cable. And if you have a mesh... forgetaboutit.
It's recommend to make such edits via Ethernet only. In fact it's best practice not to make config changes on an interface that will loose connection. Lastly, a channel change will always result in loosing connection.
Does the above still hold for 23.05.2?
I see no country code in wirerless/advanced settings
iw reg set gives me this:
root@OpenWrt:~# iw reg get
global
country 00: DFS-UNSET
(755 - 928 @ 2), (N/A, 20), (N/A), PASSIVE-SCAN
(2402 - 2472 @ 40), (N/A, 20), (N/A)
(2457 - 2482 @ 20), (N/A, 20), (N/A), AUTO-BW, PASSIVE-SCAN
(2474 - 2494 @ 20), (N/A, 20), (N/A), NO-OFDM, PASSIVE-SCAN
(5170 - 5250 @ 80), (N/A, 20), (N/A), AUTO-BW
(5250 - 5330 @ 80), (N/A, 20), (0 ms), DFS, AUTO-BW, PASSIVE-SCAN
(5490 - 5730 @ 160), (N/A, 20), (0 ms), DFS, PASSIVE-SCAN
(5735 - 5835 @ 80), (N/A, 20), (N/A), PASSIVE-SCAN
(57240 - 63720 @ 2160), (N/A, 0), (N/A)
And manually I seem to be unable to select any other channel than 36 (I get that one one selecting auto)
Selecting channel 52 (which is 80 MHz away from 36 does not work.
edit: I've been investigating a bit more, and if I do a iw phy the following channels are listed
Frequencies:
* 5180 MHz [36] (20.0 dBm)
* 5200 MHz [40] (20.0 dBm)
* 5220 MHz [44] (20.0 dBm)
* 5240 MHz [48] (20.0 dBm)
* 5260 MHz [52] (20.0 dBm) (no IR, radar detection)
* 5280 MHz [56] (20.0 dBm) (no IR, radar detection)
* 5300 MHz [60] (20.0 dBm) (no IR, radar detection)
* 5320 MHz [64] (20.0 dBm) (no IR, radar detection)
* 5500 MHz [100] (20.0 dBm) (no IR, radar detection)
* 5520 MHz [104] (20.0 dBm) (no IR, radar detection)
* 5540 MHz [108] (20.0 dBm) (no IR, radar detection)
* 5560 MHz [112] (20.0 dBm) (no IR, radar detection)
* 5580 MHz [116] (20.0 dBm) (no IR, radar detection)
* 5600 MHz [120] (20.0 dBm) (no IR, radar detection)
* 5620 MHz [124] (20.0 dBm) (no IR, radar detection)
* 5640 MHz [128] (20.0 dBm) (no IR, radar detection)
* 5660 MHz [132] (20.0 dBm) (no IR, radar detection)
* 5680 MHz [136] (20.0 dBm) (no IR, radar detection)
* 5700 MHz [140] (20.0 dBm) (no IR, radar detection)
* 5720 MHz [144] (20.0 dBm) (no IR, radar detection)
* 5745 MHz [149] (20.0 dBm) (no IR)
* 5765 MHz [153] (20.0 dBm) (no IR)
* 5785 MHz [157] (20.0 dBm) (no IR)
* 5805 MHz [161] (20.0 dBm) (no IR)
* 5825 MHz [165] (20.0 dBm) (no IR)
* 5845 MHz [169] (disabled)
* 5865 MHz [173] (disabled)
* 5885 MHz [177] (disabled)
However in the GUI I can only select up to channel 144.
(btw this is on an asus rt-ax1800u)
edit2: I noticed that I can use iw reg set NL to select my country. Then I do get to see channels > 144.
But unfortunately the setting is lost after reboot.