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dnordenberg
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hap ac2 selects outdoor 5ghz frequency by default when indoor is selected

Tue Mar 30, 2021 10:54 pm

Hi!
A friend bought a hap ac2 and could not get 5ghz ssid to show up on his devices. I looked at it and didn't se any faults with his very default config. Only country was changed to sweden and installation was changed and indoor.
After a while I see that an outdoor frequency of 5580 was selected when frequency is set to auto. This will of couse not work since all devices was indoor ones. Why is a outdoor frequency selected when installation is obviously set to indoor?
Version 6.48.1 but problem was before upgrade from factory fw, think it was 6.45 something.
 
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mkx
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Re: hap ac2 selects outdoor 5ghz frequency by default when indoor is selected

Tue Mar 30, 2021 11:29 pm

installation=indoor or outdoor is not physical, but rather political setting. In certain countries there are certain frequency channels which are only allowed for indoor use (these usually come with lower Tx power limits as well) and other frequency channels are allowed for outdoor use ... which actually means "any" use. However Mikrotik decided to read it verbatim and when AP is set to indoor, it won't use outdoor frequencies. So in reality one should set installation=any.

In 5GHz band the instalation=indoor is even worse: most of indoor-only channels come with burden of DFS ... which means AP has to take measurements on channel to detect a possible radar and if it does, it needs to switch off transmissions immediately. Before it can select such channel for transmission it has to listen for 1 to 10 minutes (the later on channels used by weather radars). So either set AP to installation=outdoor or let router wait a bit longer before you freak out.

BTW, log does contain DFS-related information if it's kicking in ...
 
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bpwl
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Re: hap ac2 selects outdoor 5ghz frequency by default when indoor is selected

Tue Mar 30, 2021 11:45 pm

There is some special interpretation of indoor/outdoor freq by Mikrotik.. In some of their country tables they tag the outdoor freq as "outdoor". In some other they don't tag the outdoor freq (what is correct in MHO). Then they have installation "indoor/outdoor/any".
Installation outdoor will not allow freq tagged as indoor. (They are illegal if used outdoor, because they can disturb some services)
Installation indoor will not allow freq tagged as outdoor in MT. (There is no reason to do so for legal requirements. If you are indoor, outdoor freq will not harm anyone.)
To avoid this blocking of the outdoor freq, there is installation "any".

So some devices (SXT, Omnitik, ...) can only set installation outdoor, and cannot use indoor (=illegal) freq.
There should not be any device that is limited to indoor freq only.

For Sweden , you have in the list:
[admin@MikroTik] > interface wireless info country-info sweden
  ranges: 2402-2482/b,g,gn20,gn40(20dBm)
          2417-2457/g-turbo(20dBm)
          5170-5250/a,an20,an40,ac20,ac40,ac80,ac160,ac80+80(23dBm)/passive,indoor
          5170-5330/a,an20,an40,ac20,ac40,ac80,ac160,ac80+80(20dBm)/dfs,passive,indoor
          5250-5330/a,an20,an40,ac20,ac40,ac80,ac160,ac80+80(20dBm)/dfs,passive,indoor
          5490-5710/a,an20,an40,ac20,ac40,ac80,ac160,ac80+80(27dBm)/dfs,passive
This is correct for remaining legal.

If you want to limit the freq used , either set it manually (preferred instead of "auto") and set the "scan list" or make a "channel list".

Indeed some devices or sticks (like my Edimax EW-7822UTC) are limited and can only connect to non-DFS freq. This is very limited for Europe (channel 36-48 only)
So even indoor-only would not be good enough as limitation on the AP.

(MKX is faster in typing than me. I will post it anyway .... :-) )
 
dnordenberg
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Re: hap ac2 selects outdoor 5ghz frequency by default when indoor is selected

Wed Mar 31, 2021 8:19 am

In 5GHz band the instalation=indoor is even worse: most of indoor-only channels come with burden of DFS ... which means AP has to take measurements on channel to detect a possible radar and if it does, it needs to switch off transmissions immediately. Before it can select such channel for transmission it has to listen for 1 to 10 minutes (the later on channels used by weather radars). So either set AP to installation=outdoor or let router wait a bit longer before you freak out.

BTW, log does contain DFS-related information if it's kicking in ...
I have certainly waited the DFS time, AP was up but laptops and mobile phones did not seem to monitor this high frequency here in sweden. We do not have DFS requirements on low 5GHz. Not sure if indoor usage is strictly forbidden here on high frequencies but it is certainly not common. My understanding is that indoor clients scan 5170-5330 here.
 
dnordenberg
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Re: hap ac2 selects outdoor 5ghz frequency by default when indoor is selected

Wed Mar 31, 2021 9:16 am

For Sweden , you have in the list:
[admin@MikroTik] > interface wireless info country-info sweden
  ranges: 2402-2482/b,g,gn20,gn40(20dBm)
          2417-2457/g-turbo(20dBm)
          5170-5250/a,an20,an40,ac20,ac40,ac80,ac160,ac80+80(23dBm)/passive,indoor
          5170-5330/a,an20,an40,ac20,ac40,ac80,ac160,ac80+80(20dBm)/dfs,passive,indoor
          5250-5330/a,an20,an40,ac20,ac40,ac80,ac160,ac80+80(20dBm)/dfs,passive,indoor
          5490-5710/a,an20,an40,ac20,ac40,ac80,ac160,ac80+80(27dBm)/dfs,passive
I got a slightly different result
  ranges: 2402-2482/b,g,gn20,gn40(20dBm)
          2417-2457/g-turbo(20dBm)
          5170-5250/a,an20,an40,ac20,ac40,ac80,ac160,ac80+80(23dBm)/passive,indoor
          5170-5330/a,an20,an40,ac20,ac40,ac80,ac160,ac80+80(20dBm)/dfs,passive,indoor
          5250-5330/a,an20,an40,ac20,ac40,ac80,ac160,ac80+80(20dBm)/dfs,passive,indoor
          5490-5710/a,an20,an40,ac20,ac40,ac80,ac160,ac80+80(27dBm)/dfs,passive
          5190-5310/a-turbo(20dBm)/dfs
          5180-5300/a-turbo(20dBm)/dfs
          5520-5680/a-turbo(27dBm)/dfs,passive
          5510-5670/a-turbo(27dBm)/dfs,passive
          902-927/b,g,g-turbo,gn20,gn40(30dBm)
Very strange it mentions 902-927 because that is very off limits here I believe, 800 and 900 is for GSM here and if I look that ISM band up on wiki it says America only...
 
dnordenberg
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Re: hap ac2 selects outdoor 5ghz frequency by default when indoor is selected

Wed Mar 31, 2021 9:23 am

Looks like mid 5GHz is selectable on some other APs too so mikrotiks usage is probably correct.
It may have been that the clients I had available for testing simply did not support mid 5GHz, we only had older devices to test with.
 
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mkx
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Re: hap ac2 selects outdoor 5ghz frequency by default when indoor is selected

Wed Mar 31, 2021 1:59 pm

(MKX is faster in typing than me. I will post it anyway .... :-) )

I'd be disappointed if you didn't. It's always pleasure to read your highly skilled and very informative posts, I always learn something new.
 
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bpwl
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Re: hap ac2 selects outdoor 5ghz frequency by default when indoor is selected

Thu Apr 01, 2021 7:43 pm

I got a slightly different result
Yes I did cut off the output. a-turbo mode ???? Don't know what that is. Actually mode "a" is not used in European continent, AFAIK.

On the more recent RoS versions, you have the ability to select "skip DFS" on a 5 GHz WLAN interface , skip ALL DFS, or skip only the 10 minute weather channel DFS.
From 5250 MHz and up, all is DFS indoor (and outdoor in Europe)! Some older devices , and my USB wifi dongle (I had to look up the specs) I mentioned before, does not support DFS channels, so only 5170-5250 (channel 36,40,44,48). In that case adding "skip dfs" would keep the AP away from those DFS channels. But I do prefer to set the freq myself ("auto" is not a smart "auto" with MT.)
Be aware that with XX and XXXX you don't know in what direction the freq extension is taken.(Ce, eC, Ceee, eCee, eeCe, eeeC are much more specific.)
 
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bpwl
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Re: hap ac2 selects outdoor 5ghz frequency by default when indoor is selected

Thu Apr 01, 2021 7:54 pm

(MKX is faster in typing than me. I will post it anyway .... :-) )

I'd be disappointed if you didn't. It's always pleasure to read your highly skilled and very informative posts, I always learn something new.
Well sometimes it takes a while to formulate the answer. And then somebody was quicker. I even learn that simple "cookbook" answers are sometimes more appreciated. I just share what I learn or experience. The only way to remember it for me is by trying to understand how it works or seems to work. The forum is a great source of information, by what works, but as important by what is not working as expected.

Like this topic ... it probably is not an indoor/outdoor issue, but a DFS / non-DFS issue.

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