Wi-Fi 6 AX201 160mhz adapter can't connect to 5Ghz UNII-2a/c channels

[FlorinStef]

Hello,

please help me with the issue I have when I try to connect to my SOHO router at home in 5GHz band (ac):

Laptop: Dell Latitude 5520, win 10 pro; It is equipped with WIFI card: Intel Wi-Fi 6 AX201 160mhz. Installed driver: Intel 22.50.1.1 (4/28/2021). 

router: ASUS RT-AC53 - last firmware installed 3.0.0.4.380_10760-g21a5898; no MAC filtering, network name is not hidden.

range ~5 meters laptop to router.

Connection to 2.4 GHz band works fine only at the beginning. Average speedtest to my ISP web site shows ~75 Mbs download / ~55 Mbs upload. After a while (30 mins. of working or standby) it drops to ~20 Mbs download / 15 upload. I set up the WIFI card not to be disconnected for power saving. If at this point I disable & re-enable WIFI, it goes back to ~75 dw / ~55 up speeds.

Connection to 5GHz band is not stable. I must press Connect button 3 to 5 times to get my laptop connected and it works only when router is broadcasting on 5G UNII-1 channels (e.g. 40, 44). When connected, speedtest shows ~170 Mbs download / ~150 Mbs upload which is not really great in my opinion. After a while the connection to 5G is lost and my laptop goes on 2.4 band.
I was never been able to connect this laptop to 5G when router is broadcasting in UNII-2a (e.g. 56, 60) or UNII-2c channels. The network is visible but I receive all the time "Can't connect to this network".
All other equipments in my house (smartphones, another laptop Lenovo Ideapad 330-17ich, my old office DELL laptop) do not encounter any issues connecting to my 5G network.

All in all my issues are:
1. Connection speed when using 2.4 GHz band drops unexpectedly;
2. Connection to 5GHz band to UNII-1 channels (e.g. 40, 44) is not stable;
3. Connection to 5GHz band to UNII-2a channels (e.g. 56, 60) or UNII-2c is not possible. I must say this would be the best option for me, since in my flat I'm surrounded by a lot of other neighbor networks and this band is currently free.

please let me know how can i solve the problems listed above.

thank you,
Florin

[Khun_Doug]

FlorinStef,

The U-NII-2A and U-NII-2C channels are referred to as DFS Channels, or Dynamic Frequency Selection. There are places where RADAR signals would conflict with usage of these channels. The routers are smart enough to recognize this and switch off to non-DFS channels. If you are having trouble getting things to work using DFS channels, there is likely some type of contention or interference on those channels. Here is a link to more information about DFS and RADAR: https://netbeez.net/blog/dfs-channels-wifi/#:~:text=Dynamic%20Frequency%20Selection%20%28DFS%29%20is%20a%20WiFi%20function,to%20increase%20the%20number%20of%20available%20WiFi%20channels.

You can download NetSpot on a mobile phone or from the Windows Store to monitor wireless traffic at your location. That would give you an idea of what other wireless signals there are, how strong the signals are, and what channels are involved. There is also a direct download link for Windows that provides a slightly better version of the utility (it can identify AX signals). The link for the tool is here: https://www.netspotapp.com/netspotpro.html   Be sure to get the Free version at the bottom of the page.

Please post back with the results of the NetSpot research. That will likely be helpful in resolving your issue(s).

[FlorinStef]

Dear Khun_Doug,

Thank you for your quick answer! I really appreciate you took your time during weekend to deal with my issue and I’m very sorry for my late answer.

I'm not an expert, but I consider myself familiar with usage and limitations of DFS channels on 5G band. Even so, I read the links from your previous post carefully and follow your instructions.
So, at my location, south to Bucharest downtown, there are no nearby radars, no airports or meteo stations. The only interference in this area is from neighbor WIFIs which influences my connection speed and I'm trying to get the best of it. My modem never dropped its 5G signal as it is supposed to do in case a RADAR signal is detected.
Usually, it is set to auto channel / auto bandwidth and once a 5G channel is selected during start/reboot, it keeps it for a long period of time, in my opinion it is kept until the next reboot, but I’m not sure, actually.

Currently I'm using Wifi Analyzer on my android smartphone to check nearby networks and their signal strength. I also installed NetSpot on my laptop as you recommended. To be honest I consider WIFI Analyzer on android to be more accurate in terms of band spread and covered channels than NetSpot.

This evening I did some tests on my 5G WIFI using several set-ups to verify connection capabilities of my wifi card.
The network card wireless mode is set to "4. 802.11ax"
Please find in attachment "WIFI 5G.docx" the result of those tests. It includes captions which may allow you to check if my set-up was correct.

thank you,

Florin Stefan

PS: I also did some tests with network card wireless mode set to "3. 802.11ac" and Channel with for 5GHz to "Auto". Using these configs I was able to connect to U-NII-2C (e.g. 108) only when my modem is set for a 20 MHz band spread. The connection speed in such case is slower than using 2.4 band.

[Khun_Doug]

FlorinStefan,

I was in Bucharest back in 2011 or 2012, October. I loved being in the Old Town. Definitely had some good Mai Tais

On to your problem ... From the scans you have taken, I see you have quite a lot of signal in your area. But the most troubling part of your report is the TP-Link unit. This is the third thread I am participating in where people are having issues with TP-Link mesh networks. In your case, I believe the TP-Link mesh is clobbering your U-NII-1 channels so badly that your network is failing. And the network monitor reports do show a strong signal from the TP-Link unit. I know that wasn't the information you were expecting, but it is an observation I am seeing repeatedly. In the other two threads, the users are having trouble connecting to TP-Link mesh network.

I would try some tests with the router, choosing 40 MHz signal on the 5 GHz band, and probe around for channels in the U-NII-2 area.

And just so others reading this thread don't think we overlooked the obvious: Please download the latest wireless AND Bluetooth driver for your laptop. Uninstall both, reboot, and then install the drivers from the manufacturer. I know others are going to blame the driver, so please rule that out. I'm sure it is not the driver, but this step takes a driver problem out of the picture.