Sorry for the noob question here. Despite of having a fair understanding and being using OpenWRT for quite some time, I now have a noob question...
I have always configured my 5Ghz radio as "AC" only (VHT80), but now I have to support an old MacBook Air that has only 802.11n support.
The first thing I've tried was changing htmode to "VHT40". But per documentation this seems to be 802.11ac only and the old MacBook was not able to connect to the 5Ghz band (2.4Ghz is connecting OK but it has too much interference where I live).
Then I changed htmode to HT40 and the old MacBook connected successfully. But with this all 802.11ac clients now are connecting in 802.11n mode as well (no more 802.11ac).
I searched online and in the documentation and I was not able to find a clear answer about which configuration I should use to support mixed 802.11n and 802.11ac (@40Mhz) in the 5GHz band.
Below is my current "/etc/config/wireless" configured with HT40 which is allowing the 802.11n client to connect to the 5GHz radio but seems to downgrade all 802.11ac clients to 802.11n speeds.
Any advice would be greatly appreciated. Thanks!
root@ap3:~# cat /etc/config/wireless config wifi-device 'radio0' option type 'mac80211' option hwmode '11a' option path 'pci0000:00/0000:00:00.0' option country 'BR' option cell_density '0' option channel '36' option htmode 'HT40' config wifi-iface 'default_radio0' option device 'radio0' option network 'lan' option mode 'ap' option ssid 'dshome5ghz' option encryption 'psk2+ccmp' option key '****' config wifi-device 'radio1' option type 'mac80211' option hwmode '11g' option path 'platform/ahb/18100000.wmac' option htmode 'HT20' option channel '6' option country 'BR' option cell_density '0' config wifi-iface 'default_radio1' option device 'radio1' option network 'lan' option mode 'ap' option ssid 'dshome' option encryption 'psk2+ccmp' option key '****'