Date: Fri, 27 May 2011 00:04:34 +0800 From: Adrian Chadd <adrian@freebsd.org> To: Shant Kassardjian <shant@skylab.ca> Cc: freebsd-wireless@freebsd.org Subject: Re: SR71-A Txpower Question Message-ID: <BANLkTinYQM1T-X4rYTWFog7dNLiH6Dc5uw@mail.gmail.com> In-Reply-To: <SNT128-W25A2DB32DB35721CA94E9EDC770@phx.gbl> References: <SNT128-W29A6964FF2FE4EF51F555EDC750@phx.gbl> <BANLkTi=V6c5b_9Y4QMvGSRO12WpUt0g70Q@mail.gmail.com> <SNT128-W25A2DB32DB35721CA94E9EDC770@phx.gbl>
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Hi! No worries. I plan on digging up my previous emails with Ubiquiti and documenting exactly what the SR-71A behaviour should be. Thanks, Adrian On 26 May 2011 11:14, Shant Kassardjian <shant@skylab.ca> wrote: > > 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" >> > > _______________________________________________ > 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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