Hi, I can only really speak for airFiber, but, I think this is a general rule.
As an FYI, there is much more information on this topic (including color charts, etc) on the Tx Power Thread under airFiber on the Ubiquiti web site. I am not pushing the site per-se, just that this thread appears to be a spill over from that one. Chuck On Tue, Jan 13, 2015 at 12:49 PM, Ty Featherling <[email protected]> wrote: > Thank you Chuck, this is what was missing. At least, these are the numbers > that were missing to calculate SNR ourselves. I take it this applies to > both the AF5 and the RocketAC radios or are their noise floor estimates be > different since they are different chipsets? > > -Ty > > On Tue, Jan 13, 2015 at 9:06 AM, Chuck Macenski <[email protected]> > wrote: > >> Hi, >> >> I should learn to sleep at night and email during the day. The tl;dr >> should have read: Sensitivity for a Modulation Rate at a given bandwidth >> (from the spec sheet) minus the clean noise floor for that bandwidth (see >> below) equals the signal needed over the actual noise floor for a given >> modulation. >> >> A rough estimate for the clean noise floor would be (50MHz=-97dBm, >> 40=-98dBm, 30=-99dBm, 20=-101dBm, 10=-104dBm). >> >> Chuck >> >> On Tue, Jan 13, 2015 at 8:39 AM, Chuck McCown <[email protected]> wrote: >> >>> Noodling around with Chucks info: >>> >>> Noise floor = –80 >>> Sensitivity = –82 >>> -80 – (-82) = 2 dB >>> RX signal required –80 + 2 = –78 dBm >>> >>> Noise floor = –40 >>> Sensitivity = –82 >>> -40 – (-82) =42 dB >>> -40 + 42 = +2dBm (Not sure I want to stand in front of the transmitter) >>> >>> Some simple algebra: >>> >>> Required RX signal =Noise floor + (Noise Floor – Sensitivity) >>> >>> - simplifying - >>> >>> RX signal = (2 * Noise floor )-Sensitivity >>> >>> So, every dB of noise floor == 2dB of RX signal. >>> >>> Have I got this right Chuck? >>> >>> *From:* Chuck Macenski <[email protected]> >>> *Sent:* Monday, January 12, 2015 11:25 PM >>> *To:* [email protected] >>> *Subject:* Re: [AFMUG] Af5 >>> >>> >>> tl;dr...the natural noise floor for the band minus the sensitivity of >>> that band for a given modulation equals the signal needed over the noise >>> floor for a given modulation. >>> >>> >> >> >
