OT: Improving laptop wifi reception

[Marko Vojinovic]

On Thursday 25 August 2011 16:06:28 Bob Goodwin wrote:
> On 25/08/11 10:43, Marko Vojinovic wrote:
> > On Thursday 25 August 2011 13:24:00 Bob Goodwin wrote:
> >>>          Clients
> >>>          MAC Address 	Interface 	Uptime 	TX Rate 	RX Rate 	Signal
> >>>          Noise 	SNR 	Signal Quality
> >>>          00:1E:52:86:4B:C3 	eth1 	N/A 	N/A 	N/A 	-42 	-88 	46
> >>>          64%
> >>>          B8:FF:61:35:AC:CC 	eth1 	N/A 	N/A 	N/A 	-52 	-88 	36
> >>>          52%
> >>>          00:1F:1F:A5:D6:84 	eth1 	N/A 	N/A 	N/A 	-62 	-88 	26
> >>>          39%
> >>>          00:AA:BB:CC:DD:10 	eth1 	N/A 	N/A 	N/A 	-67 	-88 	21
> >>>          33%
> >>>          0C:EE:E6:84:F3:A9 	eth1 	N/A 	N/A 	N/A 	-55 	-88 	33
> >>>          48%
> >>>          00:11:85:8C:CC:25 	eth1 	N/A 	N/A 	N/A 	-61 	-88 	27
> >>>          40%
> >>>          00:02:6F:9B:BA:C4 	eth1 	N/A 	N/A 	N/A 	-42 	-88 	46
> >>>          64%
> >>>          00:1D:73:C9:11:94 	eth1 	N/A 	N/A 	N/A 	-57 	-88 	31
> >>>          45%
> > 
> > I'm confused --- there is the "Signal" column, the "Noise" column, and
> > the "SNR" column which apparently has nothing to do with the ratio
> > between signal and noise. In addition, how is the "Signal Quality"
> > estimated?
> 
>         I'm sorry, the lines were "wrapped" messing up the formatting.
> 
>         There are four numbers of interest, Signal, Noise, SNR, and
>         Signal Quality.
> 
>         Signal quality is expressed as a percentage. For instance the
>         first line shows the series
>         -42 -88 46 64%
> 
>         The received signal level -42 dbm
>         The receiver noise level -88 dbm
>         Signal to noise ratio 46
>         Signal quality 64%
> 
>         I did not create the system, I am merely a user but that's is
>         how I interpret it.

I'm not complaining about formatting. What I don't understand is why is SNR 
equal to 46, and not to the ratio of signal to noise, ie. 42/88, which is not 
46, but 0.47? Or take the next row in your table: signal: -52, noise: -88, 
SNR: 36, quality: 52%. However, the ratio of signal to noise is 52/88 = 0.59, 
which has apparently nothing to do with the given SNR value 36, nor with the 
signal quality of 52%.

How am I supposed to understand these numbers if the "Signal to Noise Ratio" 
is not equal to the ratio of signal to noise? :-)

Furthermore, if the ratio between signal and noise does not represent the 
overall quality of the signal, how is the "signal quality" parameter measured?

Is there some explanation about the definitions of the columns in that table? 
And can you tell me what tool did you use to generate these numbers? Maybe 
there's some explanation in its man page, and besides I am sort of interested 
in using some tool to measure the geometry of my own wireless net here...

P.S. Sorry for hijacking the topic from the OP... ;-)

Best, :-)
Marko