Automatic channel selection

Installing and Using OpenWrt Network and Wireless Configuration
1

Hello all,

I am using router https://openwrt.org/toh/linksys/linksys_ea6350_v3.

Currently I have 19.07 RC1 installed.

I live in an apartment building, my WiFi shows at-least 10 APs at a time due to surrounding neighbors.
Currently to improve the speed, I analyze available wi-fi channels and assign it manually.

Is it possible to make this process automatic?

I have gone through below article.

To use this thread, I believe "hostpad" package should be installed on my router.

Is this the only way to achieve auto selection?
Is there any UI package available through which we can set the configs instead of the config files?

2

Navigating to Network > Wireless. It's installed with the LuCI web GUI.

3

I doubt, that AUTO channel does a search for the least crowded channel. Usually it simply uses some standard channel, like 1 or 6. You should write script to list channels in use and select a proper one for your surroundig. Start script after boot, or via cron.

4

Seems like, the automatic channel selection is handled by hostapd.
By default channels 1, 6, 11 are preferred over the other channels.
See:
https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf
Section: ACS tuning - Automatic Channel Selection

This can be used, e.g., to prefer
the commonly used 2.4 GHz band channels 1, 6, and 11 (which is the default
behavior on 2.4 GHz band if no acs_chan_bias parameter is specified

Openwrt does support the following options:
chanlist = channels
acs_chan_bias
acs_exclude_dfs

But is ACS any good? How does hostapd measure the interference for each channel?

5

In some countries, notably Germany, this behaviour is not optional but mandatory by law, if a 5GHz AP in any but few channels is to be operated, in order to avoid interference with prioritised services (in Germany the weather RADAR system). So the functionality is probably there, but possibly not employed in the 2.4GHz band.

6

DFS is implemented on 5 GHz channels as required.

This is different than “auto” which, as far as I know, does not scan the channels.

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7

DFS is only about not interfering with RADAR systems. It doesn't consider neighboring wifi signals. I don't think there is any provision in OpenWrt to choose a channel automatically based on scanning for other WiFi.

1 Like