[Madwifi-devel] Strange behavior of txpower

[David F. <df...@ac...>]

Hi all,
I am doing some experiments with several laptops and PCMCIA cards using 
madwifi as wireless driver and using it in monitor mode (with channel 
40, rate 6Mbps, and txpower 16). What I realized is that, after 
inserting the PCMCIA card and starting the monitor mode, and after 6 
minutes approximately, the wireless card starts to transmit the frames 
with more power!
For example, If I have two laptops, one sending hello messages every 
second and the other one sniffing them and printing the SSI signal of 
the received hellos, I can see how during the first 6 minutes 
approximately, I receive the hello messages at 39dB in mean. But after 6 
minutes (and of course, without moving or plugging/unplugging the 
laptops), I start to receive the hello messages at 58dB in mean (a more 
realistic value if we bear in mind that the two laptops are one in front 
of the other).
And this behavior does not depend on if the laptop which sends the hello 
messages is plugged or not.

Has someone experienced the same behavior?
Could someone explain me why the txpower of the wireless card is 
incremented in 6 minuts after inserting the PCMCIA card?
Is there a power saving strategy or something like that which causes 
this "strange" behavior?

Thanks a lot!
david

-- 
========================================================================
  0 0 0  David Fusté i Vilella       |    Dept. of Comp. Architecture
  0 0 0  Ph.D. Student               |    UPC-Campus Nord, D6-001
  0 0 0  email: df...@ac...    |    C/ Jordi Girona, 1-3
  U P C  phone: 0034 93 401 67 83    |    08034 Barcelona - SPAIN
                www: http://personals.ac.upc.edu/dfuste/
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