5Ghz Congestion

[chadster766]

Recently I've been experimenting with different 5Ghz channel and channel width configurations.

My testing seems to indicate some wireless routers configured for 80Mhz (AC) could failover to channel 36 regardless of the channel you specify. Also many DFS channel ranges don't support or are regulated to not allow 80Mhz. In the upper non-DFS channels 80Mhz may not be allowed as well.

I've used the below Wiki for 5Ghz testing but the driver I'm testing doesn't follow it regardless of the country code I use:
5 GHz (802.11a/h/j/n/ac)

It would be very easy for the average user to not ever notice that their wireless router is not broadcasting on the 5Ghz channel and channel width they specified. In some user testing N performance is close to AC so throughput tests wouldn't alert them to the issue.

Wouldn't the AC protocol 80Mhz easily congest the current 5Ghz channel range including DFS channels with several SSIDs and in the case of non-DFS only two SSIDs? This might not be a big issue since 5Ghz is mostly line of sight with very low building material penetration properties so that could possibly greatly lower congestion between buildings and out in the open.

I'm hoping to can get more clarification on what different makes and models of wireless routers or wireless drivers actually do in the 5Ghz signal range.

 

[chadster766]

For instance a Meraki AP in Canada when set to channel 144 will failover to channel 36. When you look at it's configuration the Meraki will display configured as channel 144 but show it's broadcasting on channel 36:

This seem to indicate that the Cisco Meraki isn't following the Wiki 5Ghz wireless channel chart.

Shoot I circled the wrong channel (140) in the Acrylic Wifi pic instead of (144) but you should get the point

 

[chadster766]

I've got some new information. The opensource router firmware I'm working on is for the Linksys WRT1900\1200 models. It's called McDebian. I'm using a slightly modified wireless driver who's source comes from the below GitHub repo:

https://github.com/kaloz/mwlwifi

With help from forum users I resolved my 5Ghz congestion problem and stayed inside the regulatory domain rules:

I updated the country code regulatory database using files from the kernel dev source:

https://wireless.wiki.kernel.org/en/developers/regulatory/wireless-regdb

This resolved some of the issue but I also needed to change my hostapd 5Ghz wlan config file.

I changed ht_capab to a single 80Mhz option, removed vht_capab entirely and configured vht_oper_centr_freq_seg0_idx to the base channel + 6.

interface=wlan1
bridge=br0
driver=nl80211
ctrl_interface=/var/run/hostapd
ssid=McDebian50
ignore_broadcast_ssid=0
hw_mode=a
channel=100
auth_algs=1
wmm_enabled=1
ieee80211n=1
ht_capab=[HT40+]
ieee80211ac=1
vht_oper_chwidth=1
vht_oper_centr_freq_seg0_idx=106
ieee80211h=1
ieee80211d=1

wpa=2
wpa_passphrase=mcdebian123
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP
rsn_pairwise=CCMP
country_code=US

I now get 80Mhz on the entire 5Ghz channel range including DFS!