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, Glad to see you're always there for us! I spent countless hours looking for ubiquiti documentation that proves setting txpower 0 turns off the device... and found nothing so far. Either way, I still see this as a useful feature to consider :) Thanks for the detailed explanation regarding the txpower formula, it makes much more sense now whenever I play with the power transmit settings. Thanks again! Shant K > Date: Wed, 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 > > Hi, > > ifconfig wlan0 txpower 0 merely sets the txpower to 0dBm, which isn't > "off" strictly speaking. It's actually 1mW. > > The SR-71A also has a TX power offset in hardware. If I remember > right, the hardware is actually a couple of dBm higher than what you > configure. So when you configure 19 dBm, you're programming the > hardware at 19dBm, but the hardware responds by allowing a max of > 16dBm per channel, which is * 3 (3 TX chains, 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. > > Now, if it's documented somewhere that 0 dBm should be "killing" the > interface, let me know. :) > > > > Adrian > > On 25 May 2011 00:24, Shant Kassardjian <shant@skylab.ca> wrote: > > > > Hello FreeBSD-Wireless, > > > > 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 ironing out all my questions! > > > > My only problem so far that I've noticed is that when I do: ifconfig wlan0 txpower 0; this does not turn off power to the wireless as it's suppose to and rather I have to bring down the interface manually to shut it down hence whenever I need to start it up again I have to reconfigure the interface. > > > > >From my observation it looks like changing the txpower rate using ifconfig has little to no effect controlling this adapter. > > > > > > My question is that, could it be because I have compiled the kernel with the following modifications as suggested by Adrian Chadd to take advantage 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; > > > > Regards, > > Shant K. > > _______________________________________________ > > freebsd-wireless@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-wireless > > To unsubscribe, send any mail to "freebsd-wireless-unsubscribe@freebsd.org" > >
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