Tx power conttrol issue

Jiri Fojtasek jiri.fojtasek at hlohovec.net
Fri Aug 1 16:49:09 EDT 2003

Jirka Bohac wrote:

>>The txpower code is embraced by a MACRO RAW_TXPOWER_SETTING.
>>However this macro is not defined yet.
>>That's what you mean "I believe txpower control is removed from v0.0.4."
>Yes, up to 0.0.3, txpower can be controlled directly with "iwconfig xxx
>txpower". However, there are a couple of problems. The setting does not
>remain in effect after a "card reset", which is performed from time to
>time by the driver. So after the first reset, the power is back on "auto".
>Furthermore, the driver still thinks its on "fixed" and won't let you
>set it to "fixed" again, until you first turn it to "auto" and then back
>to "fixed" again.....
>I tried to address these issues in my patch, located at
>http://jikos.cz/~jbohac/hostap (tha patch also re-enables txpower
>control for 0.0.4)
>Maybe it's because of these problems that Jouni disabled the txpower
>control support. He also says that the setting is not accurate - indeed,
>the "decibells" you use in iwconfig have NOTHING TO DO with real output
>power expressed in dBm. Jouni probably wants to use a special prism
>power feedback register, CR58, for more accurate setting.
>However, in our network where most people use the same kind of card, we
>have our own calibrations, and we learned to live with the old system.
>The absence of txpower control in 0.0.4 is a big pain for us :( 
>Anything would be better than nothing at all.
>	Jouni: 
>	Is any help needed to get txpower control back in the driver?
>CZFree.Net, Czechia
>HostAP mailing list
>HostAP at shmoo.com

Here is good explain hows ALC works. Maybe a testing of the CR58, an 
making feedback to the CR31 every TX frame will solve that txpower 


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