carl9170 driver - reducing the output power

["Michal Kudelski" <michal@idsia.ch>]

Hi all,

I'm engaged in a research project that requires us to 
reduce the range of an ad-hoc wifi network. However, when 
I change the txpower (either using iwconfig, or iw 
command), I can only see the difference when I display the 
current configuration (e.g., with iwconfig). I cannot see 
any difference in the actual tx power observed on a 
spectrum analyzer.

Thus, my question is: is the function of changing the 
txpower really supported? If it is, what steps should I 
take to make it work? I tried with ifconfig up/down when I 
change the txpower, but it does not change anything. Maybe 
I do something wrong? Do I use the correct versions of the 
firmware and the driver?

I've noticed a patch related to this issue, published on 
2012-01-27 by Christian Lamparter. It seems that it is 
included in my driver version, but maybe I'm wrong and I 
should apply some additional patch?

We use NetGear WNDA3100(v1) hardware [Atheros 
AR9001U-(2)NG] and carl9170 driver 
(driverversion=3.0.0-21-generic firmware=1.9.2).

Best regards,
Michal Kudelski