Subject: Re: 802.11 Transmit power control
To: None <>
From: David Young <>
List: tech-net
Date: 10/31/2004 14:28:22
On Sun, Oct 31, 2004 at 08:52:27PM +0100, Pavel Cahyna wrote:
> On Sun, 31 Oct 2004 18:43:03 +0000, David Young wrote:
> > Great!
> > 
> > My API put too much functionality in the kernel.  FreeBSD has a vastly
> > simpler API, IEEE80211_IOC_TXPOWER, which now I prefer, except with
> > these semantics:
> ...
> > 4 settings are *unitless*; if it matters, you may keep calibrate your
> >   card and keep the calibration values in userland; maybe ifconfig
> >   should render some assistance
> I still see an issue with it: if the driver *knows* what are the correct
> units, why shouldn't it provide that information to userland, instead of
> requiring me to calibrate the card?

What with manufacturing variation, aging components, and the variety of
power amps, how does a driver know the correct units?  I feel fairly
certain that there is not a driver in NetBSD that can tell us with
what its transmit power units are with the certainty we need for, say,
complying with wireless regulations.


David Young             OJC Technologies      Urbana, IL * (217) 278-3933