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freifunkh / site

Freifunk Hannover specific Gluon site configuration for Firmware building.
https://hannover.freifunk.net
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site.conf: add srd (aditional outdoor) channels #76

Open AiyionPrime opened 2 years ago

AiyionPrime commented 2 years ago

149-161 and 165-173

in germany these channels are capped to 25mW. They are expected to have significantly more airtime available.

@ctandi suggested to add these channels to our site, so he might test that this PR does indeed work for him as expected.

ctandi commented 2 years ago

Me and a curious colleague just conducted some tests on the matter: I can now confirm that setting the auto-channel-list on the AVM Fritz!Box 4040 and the TP-Link EAP225 Outdoor to 100-173 works fine. The automatic channel selection happens just as swiftly as with the previous configuration and was observed making choices above 140 – in our case with 149.

However, our test also suggested that there might be limited client support for this. The regulatory domain in Ubuntu has channels above 165 disabled. In addition, we discovered that some smartphones either lack the support for these frequencies or have them disabled: A Samsung Galaxy A51 and a Sony Xperia X Compact could not see the networks on channels above 165. Only our high-end models (Motorola Edge 20, Google Pixel 5) worked flawlessly above 165.

We should definitely do more testing as to not exclude anybody with our channel configuration – especially not those with lower-end-phones that do depend on our network. If I recall correctly, @bschelm, @s-2 and raute do use older Android phones. @1977er uses an iOS device. I'd appreciate if you could do a quick test on channels 149, 161 and 165, so that we can get an idea of whether or not 100-165 is the way to go. Thanks!

1977er commented 2 years ago

GDPR, GDPR!

s-2 commented 2 years ago

do use older Android phones

You seem to have a curious definition of older Android phones. Mine would not know about the existence of any wifi beyond channel 13. Or maybe 12? I actually haven't checked.

The discussion somehow resembles the issues with channel 13 (e.g. my Chuwi MiniBook has screen issues when the wifi card uses channel 13, they probably did not test that at the Chinese factory due to the different regdomain).

I just hit iw list on my Sailfish OS device (Sony Xperia 10 II), and indeed it shows some of them as disabled:

...
                        * 5700 MHz [140] (24.0 dBm) (radar detection)
                        * 5720 MHz [144] (24.0 dBm) (radar detection)
                        * 5745 MHz [149] (30.0 dBm)
                        * 5765 MHz [153] (30.0 dBm)
                        * 5785 MHz [157] (30.0 dBm)
                        * 5805 MHz [161] (30.0 dBm)
                        * 5825 MHz [165] (30.0 dBm)
                        * 5845 MHz [169] (disabled)
                        * 5865 MHz [173] (disabled)

Not sure if this is a regdomain setting issue with Sailfish OS, or a limitation of the underlying hardware (which should then affect Android running on that phone as well).

I heard rumours about a German SIM Card being required to unlock all channels for the EU regdomain, which would only happen on first boot with some phones, and can't be fixed later; not sure how much of that is true.

I guess the use case for this would be tri-band devices, or dual-band without mesh on 5GHz?

ctandi commented 2 years ago

@s-2 In the EU it's 1 to 13 :)

Judging from the iw list output, I suspect that your devices regdomain is not properly configured, since the EU limit for the channels 149 to 173 is 13/14 dBm. Either way, it would be great if you could test whether this works or not.

I guess the use case for this would be tri-band devices, or dual-band without mesh on 5GHz? Yes, but not only: These channels do actually allow for outdoor-legal channel configurations that include mesh. As you can see from the output, radar detection is not required from 149 to 173.

s-2 commented 2 years ago

So we dug out a few more Android devices:

Samsung Galaxy J3 (2016) (SM-J320FN, Android 5.1.1): ...is a few years newer than S5 mini, but it turns out it actually just supports 2.4G only :joy:

In general, the 25mW limitation reduced the range quite a lot, even within the same apartment, so at first we thought the tested devices would not support the channels tested, but just needed to be closer to the AP...

Judging from the iw list output, I suspect that your devices regdomain is not properly configured, since the EU limit for the channels 149 to 173 is 13/14 dBm.

Regarding the Sailfish OS device, the (Snapdragon 665 built-in?!) Wifi refuses to have its regdomain altered ((self-managed) as listed by iw reg get) and is stuck to US: DFS-FCC; even inserting a German SIM Card and rebooting many times did not help. It's probably set by some dark magic within proprietary Qualcomm firmware / driver stuff, which is maybe why they asked people to run this phone on Android for a while before flashing to Sailfish (which would include inserting a SIM Card on Android, making calls etc... So, no thanks :innocent: I guess this is a brick now in terms of Wifi).

I wonder if we should support these channels, not because of the device support, but the reduced range. For outdoor nodes with clients within line-of-sight this might be a good idea, also as backhaul for mesh connections, but for the normal user running a node, there should at least be some way of disabling these channels in the gluon-web config, if only for the range resulting from 25mW.