Using outdoor channels only

Installing and Using OpenWrt Network and Wireless Configuration
1

I have the following configuration:

iw reg get
country CH: DFS-ETSI
    (2402 - 2482 @ 40), (N/A, 20), (N/A)
    (5170 - 5250 @ 80), (N/A, 20), (N/A), AUTO-BW
    (5250 - 5330 @ 80), (N/A, 20), (0 ms), DFS, AUTO-BW
    (5490 - 5710 @ 160), (N/A, 27), (0 ms), DFS
    (57000 - 66000 @ 2160), (N/A, 40), (N/A)

I would like to disable the ranges:
(5170 - 5250 @ 80), (N/A, 20), (N/A), AUTO-BW
(5250 - 5330 @ 80), (N/A, 20), (0 ms), DFS, AUTO-BW

and use only:
(5490 - 5710 @ 160), (N/A, 27), (0 ms), DFS

Because it gives the highest legal power level, which I need due to the long distance of my link.

Is that possible to achieve?

Uwe

2

Yes, set the AP to a channel in the 5490 - 5710 range.

3

Well, I did, but when it detects radar then it switches to a channel outside of this range. Any idea?

4

WHOA!!!

That's a regulatory setting! You can't circumvent the regulatory setting! And any DFS workaround would be configuring an illegal transmitter.

  • You could try a directional antenna - if modified antennas are allowed in your country.
  • Your other option is to use a non-DFS channel
6

He did not say he was trying to disable radar detection, just restrict the available channels to that 220mhz range. Would a radar necessarily kill the the full range at all times?

7

Your router is detecting a radar on the channel you are selecting, and as per legal requirements, it is jumping into another channel. You need to choose a channel free of signals from radars.

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8

Well, at least in Germany the lower frequency range (below 5490 MHz) is marked as "for indoor use only". From my point of view it doesn't make sense to automatically change the frequency of an outdoor device to a frequency with a lower power limit, that is intended for indoor use.

But I don't know the exact wording of the official regulations. There are about 10 channels to choose from in the range of 5490 to 5710 MHz. Normally, this should be sufficient to avoid frequencies, occupied by radar.

9

What the regulation says, in layman terms, is that the device must check for radar signals in the frequency selected by the user, and jump to another channel where no such radar signals are detected.

So, unless there is a bug, if your device jumps from the channel you selected, is because it has detected a nearby radar operating in that frequency, and there is nothing (legal) that you can do to avoid that.

If you are sure that there are free channels in that range, I would just try them all until it stays fixed.

1 Like
10

My impression is that the manufacturer firmwares are basically lazy, and the programmers typically have set it up so that if radar is detected they jump to somewhere that has zero chance of sharing radar, such as "indoor only" band.

I agree with eduperez, if there are channels in your region without radar activity, just keep trying some until it stays put... But at the same time, remember that false-positive detections are a thing and you may never get it to stay put.

1 Like
11

I would check the regulations as I believe that use of the the upper channels require licensing, at least for "outdoor" use, in the EU (in addition being subject to the requirement that DFS be implemented and operational).