Force 180 AP TDD Mode, DFS issues

Hi all, I have a setup with 3 force 180s with AP in TDD mode using DFS frequency. So I am getting dfs hits and it changes frequency quite often. I have a similar setup in a few locations and they seem fine. Not sure if these are legitimate dfs hits or false ones. I have not tried every dfs yet but will systematically try each one. Sometimes it will last for a few days with out changing frequencies and the next day 3 or 4 times in one day.


Edit Forgot to mention that I have many other force 180 in ptp and eptp mode using DFS channels and they never do this.

This sounds like a spurious rf blast.

Try moving where the AP is, changing its direction will help.

As for the source, good luck but I have had 5ghz wifi APs do this to ours.

Thank you for the reply!

Sorry, I am misunderstanding, could you elaborate? I had this customer installed in May of 2020 and just the last week have been encountering this problem.

Move the AP to one of the other loactions so that it doesnt point the same way.

The radio is looking for a very wide and powerful blast of rf energy to determine if its a radar signal. To help determine where this is coming from you simply reverse the roles of the radios involved as only the AP determines if its a dfs radar event.

Also, make sure you use the latest firmware as there is a fix for a series of false radar detections. 4.6-rc35 is very stable in this regard

Thank you, understood!

So I have not been able to get on site yet but remotely I put the AP into ePTP and had the house as the slave, used the same dfs frequency and it has been solid with zero dfs hits. Thoughts?

If all you did was switch to eptp then IDK. But if you swapped the ends (made the ap an sm and the sm an ap) then that would make a huge difference when considering interference.

Eptp does the same as PTP-TDD but it uses a flexible frame so timing isnt as important. The gain is a few ms in latency but wreaks havoc for more than a few radios and makes sharing a channel almost impossible.

Thank you for your reply. I guess I am just curious to why the dfs hits stopped when in ptp mode and not in tdd mode using dfs channels.

Could be a bug in the firmware that isnt as sensitive in eptp mode.

Al I can tell you for sure is that only the AP is looking for DFS events which are just a large rf blast. Hence why I said to swap the ends.
You could also turn the power way down on the ap so that both ends see each other around -65 then see if it is just the radios being too close. I know the AP will trigger DFS by the SM too.

A good rule of thumb is to only use DFS channels for indoor wifi as they are protected there.

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