SYNC'd AP Spectrum analysis - listens only during receive window

When running an AP spectrum analysis, your results will be poor if its co-located with other access points, as the TX energy from these near field devices will show up in large swaths of spectrum.

Make it possible to run an AP based spectrum analysis where the device is only in RX mode during GPS sync'd receive windows. This will show you a clean spectrum analysis result.

If using a beamformer based multiple AP antenna system, this is actually necessary to prevent damage to the AP radio during spectrum analysis.

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Good idea! Would be handy to not have to turn off an entire tower to figure out if given noise is from an AP or some other source.

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That's an excellent idea for all product lines - it's excellent having a Spectrum Analyzer built in, but if you survey from an AP at a tower, it would be great if it can tell what is true noise-noise, and what is synced co-located signal which won't be interference.

This would be outstandingly useful in my environment.  There's noise everywhere here, and being able to tell which noise is sync'd with our equipment and which isn't would be fantastic.

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As an update, the LBT feature actually works this way.  It only triggers on noise during the listening portion of the frame.

If you want to know if you're synchronized with a competitor or different brand of equipment, find an AP that has a very strong signal from them and set your AP to use that frequency.  If it's not synchronized, LBT will trigger.

It's not quite as good as adding it to the spectrum analyzer, but it's useful for identifying whether or not a given noise source is synched.

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The  Spectrum Analyzer on AP is also helpful in diagnostic works, when a problem with antenna or feeder is suspected. When the  AP is colocated on the tower with another APs, all synced or even not, but there are no other interferers around, the spectrum analyzer working all the time  (i.e. not only in Rx timeslots) would help to recognize the failure of antenna  or feeder. In such case, knowing the colocated AP's signals should be quite strong in the spectrum, if we see nothing (only -99 dBm background), we can be sure the antenna or the feeder (or RF input) are seriously damaged (shorted or cut).

From this point of view, having a SA feature  without syncing to colocated APs  is useful. Of course, to evaluate the interferences from other sources around, a SA feature working  only during Rx timeslots is also useful. So, the best would be to give the user a choice: SA not sync'ed and SA sync'ed.

This conclusion arises from my experience with PMP100AP and PMP450AP.

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Bump. I see several ideas related to this request. I’m interested in the PMP450 but I assume this could also apply to other product families.

At the AP tower end it would be useful if the spectrum analyzer was aware of sync so that it would be possible to distinguish self-interference that is controlled by sync versus uncontrolled noise from other sources.

At the SM end it would be useful for the spectrum analysis to ignore the signal (color code) from the AP that is it’s intended target, in order to provide a better indication of local background noise.

As far as I know neither of these capabilities are currently available.


Desperately need this or something like it.

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Not to worry - it’s been “Under Consideration” for 6 years, so probably soon, right? :wink:

If cnMaestro could start a spectrum sweep on a group of APs in region simultaneously then resume transmit simultaneously as well that would be great. It seems like when we do this manually some APs will start transmitting again before the sweep is done on others and skew results.


Excellent idea - except Cambium would then want to sell us that feature with yet another license key scheme.

Just going to bump this again. Another feature really needed is 5mhz resolution on the SA without a reboot. We do this on 5.x ghz with a script and reboot the AP and run SA on all desired APs simultaneously to avoid seeing our own noise. After the SA is complete we restore settings and reboot again with the script. Problem is that 3.x ghz APs on SAS do not like frequency and bandwidth changes especially in night during CPAS. Scanning at say 20 mhz does not give a real fine view of noise on spectrum at all either.

Is this still in the works? I recently started working on some sites that are in need of some TLC. Being able to get a clean analysis would be extremely Helpful.