txpower settings + ALC option

[Ajeet]

Thanks for the advice and links.

Fortunately my PC-card's(Zyxell B-101) antenna is detachable, so i 
detached it from STA's PC-CARD and now i am able to make a handoff 
between two APs placed at opposite corners in a room of 15 feet. but I 
have not tested it yet when data being transfered between STAs and a 
host on DS.

But my original question about info on ALC option(in iwpriv) and if 
there is any relation between ALC and txpower option(in iwconfig) still 
remains unanswered.

Also when i do "iwpriv wlan0 getalc" it gives error that Operation not 
supported. Does it depend on PC-Cards model/manufacturer or only the 
firmware. I have 1.8.0 firmware.

Any clues?

-ajeet.

Ged Haywood wrote:
> Hello there,
> 
> On Thu, 10 Feb 2005, Ajeet wrote:
> 
> 
>>>>So what do i need to do to reduce trasmitt power of APs.
>>>
>>>I think you might need to do more than reduce the AP transmit power,
>>>since you would not be reducing the AP receiver sensitivity at the
>>>same time.  It might be better to put a simple divider network between
>>>the antenna and the AP.
>>
>>These are not commercial APs but are built using Prism2.5 PC-card in a
>>laptops
> 
> 
> That makes no difference.
> 
> 
>>and i am quite new to this area
> 
> 
> So I gather.  :)
> 
> 
>>so i dont understand what you mean by divider network between
>>antenna and the AP....can you explain a little bit more.
> 
> 
> The idea is to throw away some of the transmitted and/or received RF
> power by using (for example) a resistor network connected between the
> radio device and its antenna.  Another way would be to put the radio
> device and its antenna into a metal box.  You could make a few holes
> in the box to let some of the radio energy leak in and out - I don't
> think the results would be very predictable but I'd be interested to
> hear your experience. :)
> 
> You might find this useful:
> 
> http://www.qsl.net/n9zia/wireless/appendixF.html
> 
> 
>>>You could also try for example simply using a dummy load instead of an
>>>antenna on the APs.
>>
>>Again i dont get your point here about dummy load.
> 
> 
> See for example
> 
> http://www.pcs-electronics.com/en/guide.php?sub=antennas
> 
> and try Googling, there is a lot of information out there on this kind
> of subject.
> 
> Be aware that what works at 10MHz or 100Mz might not work at 2.4GHz.
> You will need to do some reading on the subjects before you can make
> really useful RF measurements. :)
> 
> 73,
> Ged.