Date: Thu, 26 May 2011 03:14:19 +0000 From: Shant Kassardjian <shant@skylab.ca> To: <adrian@freebsd.org> Cc: freebsd-wireless@freebsd.org Subject: RE: SR71-A Txpower Question Message-ID: <SNT128-W25A2DB32DB35721CA94E9EDC770@phx.gbl> In-Reply-To: <BANLkTi=V6c5b_9Y4QMvGSRO12WpUt0g70Q@mail.gmail.com> References: <SNT128-W29A6964FF2FE4EF51F555EDC750@phx.gbl>, <BANLkTi=V6c5b_9Y4QMvGSRO12WpUt0g70Q@mail.gmail.com>
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Hello Adrian=2C Glad to see you're always there for us!=20 I spent countless hours looking for ubiquiti documentation that proves sett= ing txpower 0 turns off the device...=20 and found nothing so far. Either way=2C I still see this as a useful featur= e to consider :)=20 Thanks for the detailed explanation regarding the txpower formula=2C it mak= es much more sense now whenever I play with the power transmit settings. Thanks again! Shant K > Date: Wed=2C 25 May 2011 00:43:21 +0800 > Subject: Re: SR71-A Txpower Question > From: adrian@freebsd.org > To: shant@skylab.ca > CC: freebsd-wireless@freebsd.org >=20 > Hi=2C >=20 > ifconfig wlan0 txpower 0 merely sets the txpower to 0dBm=2C which isn't > "off" strictly speaking. It's actually 1mW. >=20 > The SR-71A also has a TX power offset in hardware. If I remember > right=2C the hardware is actually a couple of dBm higher than what you > configure. So when you configure 19 dBm=2C you're programming the > hardware at 19dBm=2C but the hardware responds by allowing a max of > 16dBm per channel=2C which is * 3 (3 TX chains=2C as per the patch I gave > you) to give ~ 21dBm. I'd have to check the math to get the exact tx > power offset but that's roughly what's going on. >=20 > Now=2C if it's documented somewhere that 0 dBm should be "killing" the > interface=2C let me know. :) >=20 >=20 >=20 > Adrian >=20 > On 25 May 2011 00:24=2C Shant Kassardjian <shant@skylab.ca> wrote: > > > > Hello FreeBSD-Wireless=2C > > > > I've been running SR71-A on FreeBSD 8.1 for quite some time now and it'= s been running very well. Many thanks to Adrian Chadd who really helped iro= ning out all my questions! > > > > My only problem so far that I've noticed is that when I do: ifconfig w= lan0 txpower 0=3B this does not turn off power to the wireless as it's supp= ose to and rather I have to bring down the interface manually to shut it do= wn hence whenever I need to start it up again I have to reconfigure the int= erface. > > > > >From my observation it looks like changing the txpower rate using ifco= nfig has little to no effect controlling this adapter. > > > > > > My question is that=2C could it be because I have compiled the kernel w= ith the following modifications as suggested by Adrian Chadd to take advant= age of Max 3x antenna transmit power that I am having this problem? > > > > Edit sys/dev/ath/ath_hal/ar5416/ar5416.h: > > > > #define AR5416_DEFAULT_RXCHAINMASK 7 > > #define AR5416_DEFAULT_TXCHAINMASK 7 > > > > > > Does anyone else have this symptom with their SR71-A (AR5416)? > > > > > > Many thanks in advance=3B > > > > Regards=2C > > Shant K. > > ______________________________= _________________ > > freebsd-wireless@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-wireless > > To unsubscribe=2C send any mail to "freebsd-wireless-unsubscribe@freebs= d.org" > > =
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