How to enable Spectrum Analyzer and use the data for ePMP AC and AX RADIOs

This article explains the details related to enabling the spectrum analyzer and using the analyzer data to choose the best frequency.

Why run the Spectrum Analyser?

The ePMP devices are unlicensed and are usually used in co-existence with other vendors/ devices using the same frequency.

Spectrum analyzer is a handy tool that is inbuilt in an ePMP AC and AX devices that can be used, without disrupting the live traffic (In rare cases, it may cause slowness or link drop).

The step-by-step process to enable the spectrum analyzer and how to use the report to select the best channel is mentioned below.

How to run it

To enable the spectrum analyzer: Configure >> Tools >> Spectrum Analyzer >> enable and save

Run the spectrum analyzer for 15 mins and it should populate the information for user reference

You will get the data scanned by the analyzer, similar to the below image.

Note: You can choose different scanning modes: Light and Detailed:

  • Light Mode - only Management Frames will be captured for Interferer detection. Some Interferers may not be discovered. Scanning results may slightly vary from actual environmental conditions.
  • Detailed Mode - Management, Control, and Data Frames will be captured for Interferer detection. All Interferers will be discovered. Could cause performance degradation or even session drops.

How to use the data to select the best frequency

  • Select extreme low or High frequency.
  • Run the spectrum analyzer for some time.
  • You will get a list of all the available interferers.

The interference levels in the above sample are -82 and -46. Depending on the RSSI level, these (-46 dBm, -50dBm, etc) are sufficient to cause issues on the respective frequencies.

Try to find the clean frequency or least affected one, say we can choose 5055, 5150, etc as per the above scan result. This will ensure that the link is working at its optimum and give the best performance.


Why is the -39 from the Genexis WiFi in no way reflected in the SA graph above it ?

Why does the Cambium AP show up on the detailed interferer list but is nowhere to be found on the interferer graph above.

Why does what appears to be other ePMP AP’s (or some kind of APs) right next to the one detected at 5655 not show up on the interferer graph or list ?

Why is there absolutely no SA data after 5770 or between 5370 and 5450 ?


Hi @brubble1 , Now the content has been updated with clear SA details with interference.

Doesn’t answer what I ask about the previous content.

Maybe put the previous content back up , with the redone stuff, and put a note on there " The ePMP interface is so bad your graphs may display completely bogus and inaccurate/missing information. You may need to work at this for days before getting information that is… probably… mostly… sort of accurate/complete. Then again it may never really show correct / useful information. As you can see, we gave up on the first graph and just went and found a different one that , probably also has missing/wrong information but for our purposes it will work.

Hopefully this “How To” will help to use the SA should it some day become useful.

While we at Cambium think this is a great tool/way to trouble shoot your RF issues maybe you will want to supplement the SA with a divining rod made from yagi antennas with some crayons taped to them. This will be about as accurate as the SA and you get to go outside and get exercise ! So FUN! Not to mention that when other WISP owners see you out and about with your Yagis and Crayons you can be proud knowing they are probably saying “That guy went with the most expensive WISP hardware available ! He spent the big bucks and went with Cambium”.


@brubble1, I always enjoy to read your feedback! Yes, this time we made an error: being in hurry we grab SA screenshot too quickly not giving it enough time to collect and a process detailed information.It needs 10 - 15 min to give more or less full picture.

But you know SA in ePMP is not a real measuring equipment! It is one more radio, the same is used for data transmission. It can not be too precise and accurate. It is just for common situation understanding. Real SA is a different equipment with different price.

And from FW to FW we work on it to make it better! Also 4.7.0 will have improvements. Also related to issues reported by you.

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We didn’t leave it running long enough

When it’s doing what the original screen cap showed you can leave it running for days, weeks or months and it won’t make a difference.

It’s not really a tool

Yet every other (less expensive) solution out there has managed to provide SA and SS tools that consistently provide useful and reasonably accurate information displayed in a useful way. The much more expensive ePMP provides excuses for why it can’t do the same even with a radio dedicated to that 1 job.

4.7 !

I ran the most recent RC on a new micropop in an attempt to figure out what channels would work best. The SA was just as sad and useless on 4.7RC# as it was on 4.6.2.

Not really feeling confident that Cambium has recognized the problem or knows what they need to fix/improve…

Could you give a screenshot and something you compare with?

So do you not understand that the complaint with the ePMP SA isn’t about the way it looks but the fact that it doesn’t work most of the time ? Or are you asking me for a screen cap on a competitor’s SA actually working ? Do you not believe other’s are able to make SA’s that actually… work ?


Ubiquiti AF5xHD . Logged into the radio and BOOM look at all that info right on the main screen. Clicked tools / SA and BOOM look at that. Screen cap taken with in few seconds of opening the tool that I didn’t really have to open because … well I mean, look at that home screen (OMG BOTH ENDS OF THE CONNECTION on top of that !)

Now, an ePMP 3000 AP mounted 2 feet above the above the AF5xHD and pointing very close to the same direction. OH and the SA was already running on it, so probably been running for weeks orr is it, because… really how do you tell if it’s even working or if its setting there locked up. Well, I’ll tell you. Set there and watch it very closely for a few minutes and might see a pixel change here or there.

Oh and notice the wealth of useful information the Ubiquiti is displaying behind the SA tool there on its home screen… and the SA tool is covering the other half where it is displaying the very same info but for the other end of the link ! HoLY WOW ePMP sucks so bad… takes 3 times as long to show 1/8th the information and the information it shows may or may not be made up…

But still, you obviously don’t understand the problem because the problem here isn’t that the ePMP SA/SS tool doesn’t look as good as everyone else’s the ePMP SA/SS would be amazing , awesome, the best of any of them… IF IT WORKED RIGHT. OK I wish when you moved the pointer on one graph in the ePMP there would be a line on both graphs like there is on the Ubiquiti but otherwise it just needs to “work reliably”.

OH OH how about when a customers F300-16 ePMP SA is running , mounted on a trailer house with the customer’s router literally 2 feet away on the other side of the wall and the ePMP SS sees nothing, no interferers no matter how long you run it but I can pull up in the customers driveway 200ft from the trailer house and with my phones WiFiMan app see not only the customer’s WiFi router but the SSID of the Vizio TV and his HP Printer and immediately know why his Amazon fire stick isn’t working. So I get out of my rig , walk over to the corner of the trailer house where the F300-16 is mounted just a foot above my head, unable to ID anything and my phone identifies not only the 3 devices in the trailer house but the neighbors wifi in the same direction the F300-16 is pointing and two others that I’m not sure where they were at. Had the ePMP’s amazing SA/SS been working I could have told the customers , without driving out to their house, that the reason their firestick wasn’t working was because the Vizeo TV it plugged into was using the exact same channel as the WiFi router.


Gosh Andrii… I for one appreciate that you’re asking, and wanting to know… but… gosh… it’s shocking that Cambium doesn’t already know. We’ve been telling you all this since the beginning of ePMP time.

I honestly don’t even know what to type here anymore. It doesn’t show interferers which we know are there. It doesn’t allow us to pick a PTP frequency which will work both on the Master and on the Slave side. It regularly just erases all it’s data, and blanks the screen out… so even leaving it running for 6 hours may (or may not) result in anything at all, because it might decide to simply erase the info and start over with a blank screen. And it’s not getting any better, and now it seems that apparently part of that is that Cambium isn’t even aware that there is a problem?

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Upgrade to v4.7. ePMP Spectrum Analyzer has been running for a week or more… may be even worse now.

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