iwlist txpower -> no answer !?

Jouni Malinen jkmaline
Sun Jan 19 19:41:40 PST 2003

On Sun, Jan 19, 2003 at 12:11:59PM -0500, Alexis wrote:

> root at alexis:~# iwlist wlan0 txpower
> wlan0     No transmit-powers ? Please update driver...
> 	^^^^^^ what does this mean ?

Which part of that error message is unclear? The one saying that driver
did not provide any transmit power levels or the one saying that you
would need to update the driver to get this list? ;-)

Host AP driver does not report TX levels in that list since it cannot
give correct list and there would actually be 128 different values in
that list.

> 	I have another question : I read on a list that for iwconfig
> 20dBm was the max tx power regardless of the real card capability.
> But when connected, doing :
> 	iwconfig wlan0 txpower 20dBm will set the power output to 14dBm

This should not really happen.. Host AP driver should use a local value
and not query the card if you have configured txpower. What were the
exact commands you used to get this result?

> 	iwconfig wlan0 txpower 200mW will set the power output to 24dBm

iwconfig converts that 200mW into 24dBm before passing the value to
the driver and the driver return whatever was configured as explained

Jouni Malinen                                            PGP id EFC895FA

More information about the Hostap mailing list