Single radio, Multiple channels/bands (Intel AX201)

[barhun]

Hi there,

I have a mini PC with Intel AX201. I'm using it as a travel router/workstation which runs an AP on the 2.4GHz band. I have no problem when its upstream is a wired connection or a wireless one on the 2.4GHz band. However, since Intel AX201 only supports AP mode on the 2.4GHz band, it tries and fails to create the AP on the 5GHz band whenever the upstream is a 5GHz wireless connection. Is there a way to keep the STA from resetting radio configuration, so that the AP remains on the 2.4GHz band even when the STA is on the 5GHz band?

Note: I know the wifi chipset supports dual simultaneous channels, I can manually create an AP on the 2.4GHz band while connected as the STA on the 5GHz; but I want this to be handled by OpenWRT if there is a way to configure properly.

[frollic]

Nm, I think I misunderstood.

Check the tavelmate package though.

[brada4]

Intel network cards support AP mode only in 2.4GHz band, only 20MHz wide IF AT ALL

That is well documented by intel sales materials themselves.

[barhun]

Thanks for the replies! I know that this Intel WiFi chip supports AP mode only on the 2.4GHz band. The problem occurs when the STA is a 5GHz network. After successful connection by the wpa_supplicant process, it resets the radio configuration to the 5GHz band and the respective channel, then hostapd fails to create an AP. There are no issues when the upstream is a 2.4GHz network or a wired connection. Is there a way to keep the STA from resetting the radio config after connecting to a 5GHz network so that the AP remains on the 2.4GHz band? The following is the contents of the file /etc/config/wireless.

config wifi-device 'radio0'
	option type 'mac80211'
	option path 'pci0000:00/0000:00:14.3'
	option channel '9'
	option band '2g'
	option htmode 'HE40'
	option noscan '1'

config wifi-iface 'default_radio0'
	option device 'radio0'
	option network 'lan'
	option mode 'ap'
	option ssid 'OpenWrt'
	option encryption 'psk2'
	option key 'abcdefgh'

config wifi-iface 'wifinet1'
	option device 'radio0'
	option network 'wwan'
	option mode 'sta'
	option ssid 'home-5ghz'
	option encryption 'psk2'
	option key 'stuvwxyz'

[frollic]

Perhaps this is valid, after all ...

This is expected behavior when the same radio is used for client (STA) and AP modes simultaneously.

The reason is that the channel is chosen based on the upstream AP via the STA mode connection. Even if you manually specify the channel, STA mode will actually ignore that as it will simply try to connect (on any channel) to the upstream.

The AP mode operation cannot start until the STA mode is established. If the STA mode cannot connect to the upstream, the resulting situation is that the AP will not start.

There are two solutions to this issue:

1. Put the STA mode on one radio and the AP mode on the other.

2. Use Travelmate to "gracefully" fail when the upstream cannot be reached. This basically will disable the STA mode part of the config if the connection cannot be established after a timeout period. (Travelmate has other cool features, too).

[barhun]

Thanks for the reply, @frollic.

It says the following on the documentation page of Travelmate:

• STA interfaces operate in an “always off” mode, to make sure that the AP is always accessible

I think it solves my issue, I'll try and see. (: