On May 8, 2009, at 10:30 AM, iodavide@xxxxxxxxx wrote:
Hi
I'm using mac80211 for Intel(R) Pro Wireless 3945 in order to capture
Received Signal Strength from Radiotap headers.
I've created two interface
(wlan0 and mon0) up to the same Intel card and configured mon0 in
monitor-mode.
Radiotap shows SSI Signal (dB) and SSI Noise (dB) but I've some
doubts about
their values.
I read that SSI is related to a not specified dB value of the
card but I can't find more information about it and about relation
between RSSI
and RSS.
Noise is always 0dB and I read that signal-to-noise ratio (SNR)
cannot be computed by ``SSI Signal - SSI Noise'' because the noise
in Radiotap
Header usually is captured as the background noise level when no
packet is
transmitted. Thus, the SSI Noise can be interpreted as link quality
but cannot
be used to properly compute the SNR.
Some of you know if I can trust in
Radiotap SSI Signal dB value?
I need very reliable SSI values!
You might want to check out the radiotap Wiki:
http://www.radiotap.org/
or ask on the radiotap mailing list (see the wiki for information).