noise level measurement with Atheros driver

[Lang, Tanja]

Hi,

 

  I would like to record signal strength and noise level for each client
packet received on a wireless access point. I found the fields
IEEE80211_RADIOTAP_DBM_ANTSIGNAL and     IEEE80211_RADIOTAP_DBM_ANTNOISE
in the radiotap header which should give me this information. 

 

The 'wi' interface sets both of these values in if_wi.c 

if_wi.c:                sc->sc_rx_th.wr_antnoise = frmhdr.wi_rx_silence;

if_wi.c:                sc->sc_rx_th.wr_antsignal = frmhdr.wi_rx_signal;

 

While the 'ath' interface only provides signal strength information.

if_ath.c             sc->sc_rx_th.wr_antsignal = ds->ds_rxstat.rs_rssi;

 

Is the Atheros driver (which my current wireless card in the AP uses)
capable of providing noise information? If yes, which line needs to be
added in if_ath.c?

 

Thanks,

Tanja