Re: Longdistance 5.8GHz p2p links: Low signal with17dbm :-(

Hi

The SR5 have a 7dBm power offset, so if you can get 19dBm with madwifi
then you are really putting out 26dBm which is the max for the SR5. 

If you are only able to get 17dBm, then look at your regdomain and
channel selection. Have a look in ah_regdomain.c in the open hal and you
will see that depending on channel/regdomain, etc, the tx power may be
limited to 17dBm, so you could make some mod's to make sure you get the
max out of the card.

Also keep in mind that these cards only actually output 26dBm for the
lower data rates, after which the output power will be more like 21dBm
for the highest rates (check out the SR5 datasheet for details). So in a
lot of cases 17dBm plus the 7dBm offset = 24dBm which is more than the
card will put out anyway for the higher data rates.

If you are getting signal strength of around -81dBm this should be quite
workable - make sure you have ANI (i.e. interference mitigation) turned
off as this will reduce the Rx sensitivity of the radio to the point
where -81dBm may be too low. There have also been a couple of patches
for ANI so make sure they are applied to whatever version of madwifi you
are using.

Hope this Helps

Brett

> -----Original Message-----
> From: Beat Meier [mailto:[email protected]]
> Sent: Tuesday, 20 April 2010 9:57 PM
> To: [email protected]
> Subject: [Madwifi-users] Longdistance 5.8GHz p2p links: Low signal
> with17dbm :-(
> 
> Hello again
> 
> I'm still stucking with the output power of 5.8GHz links.
> Is there anyone who has modified madwifi hal to use full power of
5.8GHz
> band of ubiquity cards (SR5)?
> I need a 25km link in 5.8GHz and I really want to use my wrap boards
> with madwifi driver.
> I tried to modify the madwifi hal but the output did not change :-(
> Nobody is using longdistance 5.8GHz p2p links which needs more than
> 17dbm???
> I have 81dbm and as we now madwifi won't be able to work with this in
> 5.8GHz :-(
> It needs a level of at least 70-74dbm to work realiable...
> 
> Thanks a lot for any hint!!!!
> 
> Beat
> 
>
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