No RSSI measurements in the range between -40 and -90 are available...

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  • Updated 2 years ago
  • (Edited)
When I attempt to check RSSI in certain areas of my deployment I occasionally  get the following message "No RSSI measurements in the range between -40 and -90 are available..." - My radio power settings are relatively low due to the nature of the environment which may have something to do with it. When I run a 'show ACSP neighbour' command it shows no AP's in range. 

Globally disabling 'calibrate heatmaps' seems counter productive as I would rather use the real-world RSSI figures than predictive. 
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Luke Harris

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Posted 2 years ago

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Steve Kellogg

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I've run into this same issue and will be interested to hear the replies!
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Malcolm Snelgrove

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You on the right track. You get the message when you your APs can't see each other, for various reasons e.g. too far apart, environmental factors or interference or on low power.

If you go to the Map Global Settings screen under Maps -> Operations (under View or Devices tab -> Global Settings) you can try changing the minimum dBm value of the range to get the ACSP Neighbour table populated.

I have also had success using RSSI on the maps by changing the number of measurements (i.e. APs that can see one AP) from 3 to 2 or 1. Of course the accuracy of the RSSI measurements gets progressively worst as well, but some information is better then none, and I found it reasonably accurate as an first order approximation.

If the problem only happens occasionally, you can also play with using the historical data for the RSSI instead of the actual with the "Consider RSSI measurements..." option and change the number of minutes. I have this set on the default of 5 minutes for my low density environment.
(Edited)
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Luke Harris

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Malcolm, I fear my lack of patience lead me to an unsatisfactory conclusion. The area in question had recently been re-configured with some changes made to radio settings and channels etc. I would imagine ACSP was still in a negotiation stage at the time I raised this query. However that doesn't dismiss the statement you made regarding environmental factors, interference and distance between APs. Worth remembering.