WiFi Access Point should support the Automatic Channel Selection

[pierantoniomerlino]

Currently Kura allows to set up a WiFi Access Point through the webUI. The wireless channel of the link can be statically configured at the bottom of the "Wireless" tab.

However, in some situations the channel cannot be statically chosen and a dynamic approach is preferable. The underlying Linux drivers typically support the Automatic Channel Selection [1], [2] which selects the communication channel based on various metrics.

It'd be possible to select this feature from the webUI. As reported in [1], the channel parameter in the hostapd.conf file has to be set to acs_survey or 0 to enable the automatic channel selection. However, this is supported only if the Linux driver is compiled with the parameter CONFIG_ACS=y, as presented in [2].

[1] https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf [2] https://wireless.wiki.kernel.org/en/users/documentation/acs

[pierantoniomerlino]

The RPi with Raspbian Buster (10) has the hostapd tool compiled with the CONFIG_ACS=y, so it is possible to enable the ACS.

[pierantoniomerlino]

Some comments regarding channel, frequencies and acs:

• Kura can configure wifi AP only at 2.4GHz even if the underlying hw/sw supports 5GHz. In particular, Kura supports ieee80211 b/g/n
• when acs is enabled, the channel is chosen accordingly the wifi version (1-11 for 2.4GHz and >36 for 5GHz)
• the hostapd service can be configured to use only a specific range of channels with the chanlist option when in acs mode

Is there any specific reason that Kura cannot support 5GHz channels?