RX signal level calculation

Jean Tourrilhes jt at bougret.hpl.hp.com
Tue Feb 18 13:25:42 EST 2003


Ricardo Galli wrote :
> Hi Jouni (and Jean),
> 	I have a question about how to interpret the received signal level.
> 
> In hostap_ap.c (in prism2_ap_get_sta_qual() and 
> prism2_ap_translate_scan()) you pass it to dBm by first doing:
> 
> 	level = (level - 27) * 92/127;
> 	level = HFA384_LEVEL_TO_dBm(level);
> 
> But in hostap_ioctl.c (in prism2_translate_scan() and 
> hostap_get_wireless_stats() ) you don't do the first normalization, but 
> directly:
> 
> 	level = HFA384_LEVEL_TO_dBm(level);
> 
> Why is there such a difference? Is it related to hardware register for 
> different modes?
> 
> Thanks,
> 
> -- 
>   ricardo galli       GPG id C8114D34

	Err... Either it's a bug, or it's another of those firmware
weirdnesses. Jouni is the one who know about the chip details. Anyway,
it seems that in recent firmware Intersil has added new support for
dBm calibration.
	Regards,

	Jean




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