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RT-AX92U isn't using 80mhz band for 5G-2?

Krom2040
Level 7
I have my RT-AX92U set up to use the 80Mhz band for the 5G-2 network:

93834

and Netspot is showing that it only presents as a 40Mhz band:

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In fact, the 160Mhz option also doesn't seem to work any better. Is there some way to verify that this is either a router problem or maybe just an issue with my desktop NIC or Netspot? When I set the 5G-1 network to 80Mhz, Netspot does correctly detect that channel width as 80.
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jzchen
Level 15
Unfortunately (for me) you've cut off all the labels for the fields and I do not have an AX92 to align what those fields mean. Similar with the NetSpot chart I mostly use the app on my phone.

Unless you're out far away from civilization, there are many possible sources of interference. The higher you go 20 -> 160 the more chance someone/something else is using that frequency range and hence the router chooses a smaller range to use. That may not have interference.

NetSpot is good have a look around with it.

jzchen wrote:
Unfortunately (for me) you've cut off all the labels for the fields and I do not have an AX92 to align what those fields mean. Similar with the NetSpot chart I mostly use the app on my phone.

Unless you're out far away from civilization, there are many possible sources of interference. The higher you go 20 -> 160 the more chance someone/something else is using that frequency range and hence the router chooses a smaller range to use. That may not have interference.

NetSpot is good have a look around with it.


My fault! Here are the configuration screens with the row descriptions included:

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93845

I have tried this on numerous channels and all have exhibited the same limitation of a 40Mhz band. I don't see any conflicts there:

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I'm explicitly telling the router to use 80Mhz rather than to auto-select one, so I would really expect it to do that or produce some kind of error.

I'm assuming you're already aware of the contiguous bands as you've chosen channels 36 and 132. 132 is a DFS channel I know you already noted you've tried others but just in case you weren't aware 149 is not. 36 and 149 are the two 160 MHz bands if I'm not mistaken that fall outside of DFS. (Channel 100 starts the 3rd 160 MHz block but falls within DFS).

I've linked the Wikipedia article on channels for anyone's reference:

https://en.wikipedia.org/wiki/List_of_WLAN_channels#United_States

According to this article I'm trying to list the DFS channels:

http://wifinc.net/dfs-channels-and-why-to-avoid-them-even-though-you-say-you-cannot/#:~:text=There%2....

"52, 56, 60, 64, 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140, and 144"

Fair enough one would hope that the router will produce some sort of error warning given you've forced 80 MHz but it did not follow.

Whether DFS affects availability of 80 MHz I'm not sure, but I also noticed that the 5 GHz-2 is a slightly weaker signal, and signal strength does limit your ability to go higher, to 80 MHz or 160 MHz). Can you possibly relocate to improve the signal strength and try again?

jzchen wrote:
Whether DFS affects availability of 80 MHz I'm not sure, but I also noticed that the 5 GHz-2 is a slightly weaker signal, and signal strength does limit your ability to go higher, to 80 MHz or 160 MHz). Can you possibly relocate to improve the signal strength and try again?


The wifi adapter is about two feet away from the router so it's hard for me to imagine that signal strength is a huge concern. I can move my laptop right on top of it and it still only shows a 40MHz signal, even when I enabled the 160MHz channel. Is this router effectively pointless unless you're miraculously in an area with no DFS interference at all?

Saltgrass
Level 13
I currently have my unit set as a AiMesh node and cannot check it. But the 5-2 radio is a 4x4 version where the 5-1 is a 2x2. Maybe it needs the bandwidth for that capability.
Maximus Z790 Hero,
Intel i9-13900k
Intel BE200

Saltgrass wrote:
I currently have my unit set as a AiMesh node and cannot check it. But the 5-2 radio is a 4x4 version where the 5-1 is a 2x2. Maybe it needs the bandwidth for that capability.


If it's still a node connected directly to your AXE16000, (as opposed to an intermediary), can you see the signal details there?

jzchen wrote:
If it's still a node connected directly to your AXE16000, (as opposed to an intermediary), can you see the signal details there?


I can't see anything that refers to the bandwidth, just the 5Ghz-2 is showing active for the backhaul. It is showing a PHY rate of Transmit 2162 and Receive 1701 Mbps.
Maximus Z790 Hero,
Intel i9-13900k
Intel BE200

Saltgrass wrote:
I currently have my unit set as a AiMesh node and cannot check it. But the 5-2 radio is a 4x4 version where the 5-1 is a 2x2. Maybe it needs the bandwidth for that capability.


I think @Saltgrass is onto something. Per ASUS specs:

AX6100 ultimate AX performance : 400 Mbps+ 867 Mbps+ 4804 Mbps

I'm afraid it's a limitation of this model.

Krom2040
Level 7
I'm still not entirely clear; are you saying that this router just doesn't support high bandwidth in the non-DFS ranges, so the 4804 Mbps transfer rates just won't happen?