Why is the signal strength in the Air Marshal expressed in positive values?

[Brian_Scheele]

When I look at "Other SSIDs" in the Air Marshal, all signal strengths are reported as positive values - probably because the unit of measure is dB, and not dBm.  So, it is a ratio.  A ratio to what?  Why would I see 33 dB when I turn on the hotspot on my cell phone, and see -67dBm when reported by my UniFi dashboard?  

I was asking on another forum about a neighbor who was showing up with 50+ devices at >90dB signal strength, hosing my own WiFi, and they insisted that it should be a non-issue because that is essentially zero.  But, -90dBm would be essentially nothing - not positive 93dB as I see in the dashboard.

[BrandonS]

I am not sure the answer to your specific question, but personally I never noticed or paid attention to the dB listed in Air Marshal under the ‘other’ tab.  I would be much more concerned with channel utilization and the RF spectrum view if I suspect WiFi or non WiFi interference.  The best way in my opinion to increase performance and reliability in radio noisy environments is to have more radios closer to the clients with lower power and preferably 5Ghz.  I guess you could ask your neighbors to adjust their gear, but that seems a long shot at best that they even have a clue or could if they wanted to.

[ww · Accepted solution]

I supose its snr like here https://documentation.meraki.com/MR/WiFi_Basics_and_Best_Practices/Signal-to-Noise_Ratio_(SNR)_and_W...

[Brian_Scheele]

That now makes perfect sense - SNR.  Thanks!