Mimosa AP shutting down ePMP APs and backhauls

We are in a ver rural area and since ePMP , and before that Ubiquiti , came out we have never had a single DFS event. Then a couple of weeks ago ePMP radios and backhauls in and around one town started shutting off RF due to DFS detection. Radios are all running 2.6.1 and since we had never experienced a single DFS event since DFS existed we of course didn't have alternate channels configured. So I spent the night trying to channel plan with 3 channels per radio and not understanding why almost anywhere I went the AP's would come up in DFS shut down even with 2 alternate channels configured... wow what a headache.

Anyway the next day I found the the culprit. A local company had decided they are going into the WISP business, and threw up a little (short, the Omni antenna is maybe 8' tall) mimosa AP on a pole on the roof of their building. This thing is eating up almost all of the DFS frequencies and it's a monster. Two ePMP 2000 AP's that are about 1/2 a mile from the thing I can't even get them to turn on RF if they are within 20Mzh of the 80Mhz (I think) channels the mamosa is using.

They hooked up about a dozen local business (no install fee and free for 6 months as it is just a test) and talking to one of their customers they said it has run flawlessly since it was installed. What gives ? This thing just punches my AP's in the face and my AP's don't appear to have any affect on them at all... Also, even with our radios up on towers we have from time to time ran into interference issues with consumer wifi routers in houses right next to/under the tower (no DFS events, just normal rf interference.. I hate AC WiFi routers...). They set this Mimosa on top of building with apartments in it, surrounded by buildings with apartments and retail and it just hums right along with 25 or 30 WiFi routers within a few hundred feet. I don't even know how that is possible.

I guess mostly what I'm confused about is why this mimosa AP forces all of my ePMP radios into DFS shutdown mode or forces them to start playing musical channels all while appearing to be completely unaffected by my radios and the crapload of WiFi routers surrounding it. Luckily it never changes channels, it just sets there playing king of the RF hill.

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Is the mimosa running a DFS channel too, or is it running in the high or low band?  If they are running a DFS channel and are coming in that hot they are likely running way above EIRP.  Perhaps you could have a friendly conversation with them and explain the issue and rules?

The front end on ePMP 1000 I find to be very sensitive to near-channel interference unfortunately.  The 2000 series should be much better in this situation due to it's active filtering.  You could also look for ways to physically shield your gear from their noise by changing sector azimuth if possible.  Using things like RF Armor won't do anything for you if the noise is in front of your gear.

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You could try the newest firmware 3.2.1, which has a number of DFS fixes:


False radar detection on DFS channel FCC1322 Type1 22


False radar detection on DFS channel FCC1322 Type1 24


"You could try the newest firmware 3.2.1, which has a number of DFS fixes:"

Yeah, I may upgrade one of our AP's to that tonight and see how it does.


The 3.2.1 firmware seems to have fixed the false positive DFS events !