[kismac] Re: Interpreting signal strength

  • From: Ben Short <bshort@xxxxxxxxxxxx>
  • To: kismac@xxxxxxxxxxxxx
  • Date: Tue, 06 Jul 2004 18:32:41 +1000

My understanding of the kismac signal strength is that it actually refers to the Signal to Noise (SNR) of the signal.

Work out what the noise floor is around the area (varies between -96dB and -104dB here), add the SNR to it
(eg kismac signal of 20 would give -76 db on a good day with the above noise floor), and you will have your
signal strength.

I do agree its a bit of a messy way of doing it though. Perhaps future releases could change this? (if there are
future releases ;))

uDecker wrote:

On a number of occasions, I use Kismac for work, scanning signal strength and penetration. However, using other programs, I am used to seeing numbers for Signal (numbers like -60dB), Noise (numbers like -95dB), and SNR (usually not a real ratio - just Signal minus Noise, a positive number, such as 25, when signal is -69dB and noise is -94dB, for example.)

In Kismac, we get one number - Signal. Which doesn't correspond to any dB reading I get with any other program, PC or Mac. It doesn't seem to be on a 0-100 scale, and it also doesn't seem to correspond to dB. How should I interpret the Signal reading in Kismac - how is the number generated?

Also - if I were to dig into the code - does Kismac actually get dB readings for signal and noise? I use any variety of cards with the program, from my laptop's built-in broadcom airport extreme card to pcmcia's from YDI, Orinoco, Enterasys and Cisco.


Other related posts: