Channel limited wireless interfaces lose connection when wireless channels change

Installing and Using OpenWrt
1

My situation
I have a Linksys MR8300 router running OpenWrt 22.03.3. This is a tri-band router with two 5GHz radios and one 2.4GHz radio. I live in a university residence where internet is provided by the university. However, no ethernet connections are available, only wifi access to the Eduroam network. I use one of the 5GHz radios to connect to Eduroam wifi as a client and then I use the other 5GHz radio and the 2.4GHz radio to relay this internet connect and create my own LAN.

The problem
In order to have two 5GHz radios on the same router without interference the two radios are channel limited. One radio is limited to channels 36-64 and the other is 100-165. I'm not sure if this is a hardware limit or a software limit but it causes an issue with my connection. The university's router in my home that hosts the Eduroam network automatically optimizes the wifi connection by changing which channel it transmits on. The problem is, it very often switches to a channel that is in the other range of channels. When this happens I lose my internet connection. This means that I need to swap which one of my two 5GHz radios is acting as a client and which one is acting as a host for my LAN.

Solving the problem
I can think of two solutions. One solution is that the channel limits need to be removed on my 5GHz radios and then they need to change channels automatically so that they don't interfere.
A more practical solution could be to create a script that automatically detects when the Eduroam router changes channels to the other range and then it switches the radios from Client/Host to Host/Client.

However, I am not sure how to do either of these things. Does anyone have any ideas?

2

When the school's wifi channel is in one range, does it show up in a scan performed by the opposite radio?

3

If i knew how, I would script an scan that scans all available channels for a specific SSID and as soon as the SSID is found, switches to the corresponding channel. Is that too naive a thought?

4

That's my thought too. Before I can help, though, I need to know the answer to my question.

I need to know, for example, if you go to LuCI -> Network -> Wireless, if the school's wifi is on channel 60, does its SSID show up when you do a scan on the radio that is 100-165?

5

Does Travelmate help?

2 Likes
6

Both, the hardware is tuned to support one of the two sub-ranges only, the software follows suit.

7

Short answer, yes. However it is more complicated than that. The school's wifi is a mesh network, so many access points hosting the same SSID on different channels and sometimes the access points change channels. However, I want to connect only to the closest access point so that I get the most stable and fastest connection. I know how to force the connection by setting the BSSID but if the access point changes channels then I lose my connection.

8

This seems like it may help. I will have to test it, but I am away for the weekend. I'll try it next week.