[Zachariah]

What is good/bad for these:

(ie, do I want a high number or a low one
... and please say whether high means closer to zero
or higher ignoring the negative sign).

Signal
Noise
SNR
Signal Quality

(from http://192.168.1.1/Status_Wireless.asp)


(and, yes I looked in the wiki and did multiple searches, but didn't find the answer)


edit: ... forgot to say thanks, but don't feel like bumping the thread just for that

[CaScAdE]

Signal -> Low is good (well -1 is good, -98 is bad, mathematically -1 is higher than -98 but you know what i mean because you asked for ignoring the minus)
Noise -> High is good (-98 is good, -1 is bad)
SNR -> High is good (should be the same as difference between noice and signal)
Signal Quality -> High is good (somehow like SNR but indexed to 100 with noise as base, percentage of the best theoretical available qualiry regarding to your local-noise, difficult to explain *g*)

Edit:
Regarding to one of my WRT's I will state an example, keep in mind that some numbers are rounded for output by the driver but internally kept with some more decimal places...
Examples would be:

[AndyD]

Good question...well answered.....thnx

[votetrev]

Yeah, Great answer!

[Sacrabolt]

[dicksons]

negative numbers and logarithmic ratios leave a lot of people in the dust...

SNR is all you really care about (unless it's really low like below 10, in which case signal and noise need examined for optimization)

double-digit SNR will get you megabit thruput

I've seen a table somewhere detailing the SNR required to hit specific 802.11G link speeds (btw link speeds <> thruput)

the "percentage" isn't meaningful in practical terms - it only exists cause it's easy to graph. ignore it.

[deneb]

To elaborate a little, any number with dB after it means it is on a logarithmic scale. To get the SNR you would divide signal by noise, right? Well, yes, but remember that when working in a log scale you are basically dealing with an exponent, so where you would divide:

SNR = n^SIGNAL / n^NOISE

in regular, non-log world, you actually end up subtracting the exponents. Try it:

2^8 / 2^6 = 256/64 = 4 = 2^2 = 2^(8-6)

This is what you must do in log world to get your ratio, i.e. to get SNR from numbers in dB simply subract them:

SNR (dB) = SIGNAL (dBW) - NOISE (dBW)

Also, when a dB number is negative, that means it is less than 1:
0dB = 1
-1dB = a little less than 1
-99dB = almost 0

so you want your signal to be close to 0dB and your noise to be close to -99dB or lower

This brings me to my question, what does the noise reference setting do? Is this just used to calculate that useless percentage for signal strength?