AirPort network frequency - how to disable 5 GHz on Express?

To close this out:

Unfortunately there are very few options out here in the Mojave Desert. No cable is pulled to this rural area. (It is a beautiful, quiet, very lightly populated place but there are trade-offs such as this.) Other than satellite based ISPs which I won't consider, there is one other long range wireless ISP which I used and dropped many years ago due to horrible reliability. Frontier communications, the telco out here is newly offering some customers land line based fiber to copper last mile service but it does not yet reach my address for me to consider and in any case I dropped Frontier's copper land line service due to lack of reliability so I'd be very wary of using them for anything else. (I sort of want to see what SpaceX's Starlink will be like and have submitted to be added to their beta list although I do have big reservations as to light pollution that is being caused by light reflection on that systems many hundreds (soon to be thousands) of satellites.)

The ISP has forwarded an excerpt of their current TOS which says "…IT IS MOST IMPORTANT TO KEEP THE 5GHZ BAND ON YOUR DUAL BAND ROUTER DISABLED TO AVOID DIRECT SIGNAL INTERFERENCE (contributes to slowing, buffering, lag, intermittent connection). This interference can also cause problems with our towers and other MojaveWifi customers. Please be advised that our “Terms of Service and Acceptable Use Policy” STRICTLY PROHIBITS purposeful interference with our signal. 

To optimize your router’s signal …". This condition is not contained in the TOS doc they gave me in 2018 nor in the TOS from the initial installation in 2010. Through this saga I've repeatedly asked for the current TOS but as of yet I've not gotten it.

I've now deinstalled the Apple network equipment and replaced it with a TP-Link router and extender which allows me to disable 5GHz and works adequately but required a few support calls to them to get security setting configured correctly. I miss the Apple "it just works" equipment 😂

That is all.

Thanks for your reply.

Can you clarify your statement that "You cannot use the Express in Extend wireless mode"? I have had my network configured this way for years and can observe that without the Express units in operation the range of the network is more limited.

Also, do you have a reason that only one of the Express units, at least according to the ISP, is broadcasting on both frequencies? It could be possible that what the ISP is telling me is not accurate as well.

I agree that the situation is unique. I do not see anything in the ISP TOS document (from 2014) that refers to this a being "non compliant" and have asked them to clarify this for me.

The full set of hardware is externally mounted dish -> ethernet to power-over-ethernet brick -> ethernet into back of my AirPort Extreme -> 2 wireless Airport Express to extend WiFi. The main Extreme router mode us set it Off (Bridge Mode).

This is a screen cap that the ISP sent to me "showing" the 5 GHz signal from one of the Expresses:

At this point I will wait to hear from the ISP to clarify what in the TOS I am non-compliant with. While my networking knowledge is very limited, I'd think that given my location I am also curious as to what sort of negative interference the presence of both frequencies could cause. My closest neighbors are .25 miles, if that, and while they both use the same ISP, I can't even see any other SSIDs this far away.

I agree that poking into my network is problematic. I happen to know the owner of the ISP - I was one of his first customers out here when he started his business 10+ years ago - so if I can't resolve this configuration-wise I would probably contact him to see if this is a real issue for customers or if this is just one of his techs doing "radio interference investigations" as he conveyed to me, and just following procedures, but perhaps not really an issue for their network. OTOH I do want to be a good network citizen 😎

I may try your suggestion of resetting one of the Extremes as well.

Thanks for your taking the time on this.

As initial mentioned this is a wireless based ISP but I don't see any exclusion of 5GHz in the most recent TOS that I have - 2018. I've asked the ISP for clarification but have received no answer as of yet.

I could try to locate and run the Windows based utility and run it in a Parallels VM but even if I did it would not eliminate the "offending" 5GHz.

BTW, I am looking at alternative hardware vendors in case I really need to solve this problem. So far I've looked at eero but their equipment can only temporarily disable 5GHz for 10 minutes for configuration/troubleshooting purposes. Anyone have recommendation for vendor equipment that might "solve" this for me?

Further to this, I received input from the ISP owner as follows:

… the behavior of the extenders in selecting a channel is that they scan the frequency utilization in an area and attempt to find the best possible non interfering channel available. Some devices do this well others do it poorly and continue to interfere. Apple devices unfortunately seem to often be a point of problem due to their basis in BSD / Linux and use similar drivers which occasionally are problematic. If you notice consistently that the signal/ performance of your extenders seems poor, Start a streaming video on your device which is most closely connected to the antenna and not using the extenders. Unplug the extenders for 5 minutes and while the video is running (frequency is being utilized) plug in the extender.This may provoke the main router and the extenders to do a new selection of frequency which may be least interfering. Also, you dont have to turn off the 5 GHz completely. For best usage, set your system to the best of your ability to avoid using any channels which do not overlap within 50 MHz in either direction from 5200 to 5250, and 5800 to 5890. Those channels are being used by the exact Access point that your mojavewifi antenna is connected to. This varies from wherever you are in our network but the principle is the same.

He also said in another email that in the initial message from the support rep, "compliance is definitely the wrong word" to use in this situation. As I read this it seems that the concern is the conflict between 5GHz broadcasts from my WiFi equipment and the frequency ranges that the ISP transceiver uses potentially affecting the performance on my network. In looking into this further I looked at this page - https://en.wikipedia.org/wiki/List_of_WLAN_channels#5_GHz_or_5.9_GHz_(802.11a/h/j/n/ac/ax) - for 5GHz channels and frequencies and then looked at the ranges he specified and if I am reading this right I don't see a channel in the AirPort Utility that I could manually set the Extreme to that wouldn't still conflict with the frequency ranges used by the ISP transceiver. And even if I could find such a setting it would likely be a moot point as the Express extenders would still do their own thing independent of the Extreme.

In any case it appears that I am not out of compliance and can continue to use my existing AirPorts and not be in violation of the ISP TOS.

(One other note, I did investigate one alternative, the eero mesh routing system. In talking to them I found that they don't allow a way to disable 5GHz nor tailor 5GHz uses to channels that wouldn't conflict with the ISP transceiver ranges.)

So, unless I hear more from the ISP to the contrary I will just continue operating as I have been with my existing AirPort hardware. Thanks to you folks for your knowledgeable input on this.