Hi, I need to check the numbers (I am half asleep), but, yes, that sounds correct.
Chuck On Mon, Jan 12, 2015 at 10:28 PM, Jeremy <jeremysmi...@gmail.com> wrote: > So, am I understanding correctly... If you are on a 50MHz Channel BW with > a signal of -58 you need a noise floor of -97 to maintain 1024QAM. So, if > the noise floor is -75 we are 22db off so you can add that to -58 and > figure -80, or QPSK. Is this the correct math? > > On Mon, Jan 12, 2015 at 8:44 PM, Chuck Macenski <ch...@macenski.com> > wrote: > >> Hi, >> >> I believe the number you are looking for is the sensitivity per >> modulation rate minus the base noise floor for a given bandwidth (see >> Matt's earlier post). This gives you the required signal over the noise >> floor. If the noise floor goes up, the effective sensitivity goes up >> accordingly. >> >> What am I missing? >> >> Chuck >> >> On Mon, Jan 12, 2015 at 5:23 PM, Josh Reynolds <j...@spitwspots.com> >> wrote: >> >>> This. >>> >>> josh reynolds :: chief information officer >>> spitwspots :: www.spitwspots.com >>> >>> On 01/12/2015 11:00 AM, Mike Hammett wrote: >>> >>> Matt, that doesn't really help. >>> >>> In many areas, my noise/interference/whatever is -75. If I knew how much >>> margin was required per modulation, I could figure out how much signal I >>> need for that speed. >>> >>> I can't do that with your published numbers. >>> >>> >>> >>> ----- >>> Mike Hammett >>> Intelligent Computing Solutionshttp://www.ics-il.com >>> >>> ----- Original Message ----- >>> From: Matt Hardy <m...@ubnt.com> <m...@ubnt.com> >>> To: af@afmug.com >>> Sent: Mon, 12 Jan 2015 12:42:52 -0600 (CST) >>> Subject: Re: [AFMUG] Af5 >>> >>> Hi Mike, >>> The numbers in our datasheet do convey the SNR (which assumes AWGN for >>> noise value); this is pretty standard among all our datasheets. >>> The noise floor value varies based on channel BW, so a rough estimate for >>> noise floor would be (50MHz=-97dBm, 40=-98dBm, 30=-99dBm, 20=-101dBm, >>> 10=-104dBm). >>> >>> As far as transmit power / modulation, all modulations up to 64QAM can run >>> at full transmit power. 256QAM is ~2dB lower, and 1024QAM is something like >>> 4dB lower (it depends on other external factors). >>> >>> All of this and more is already provided with the integrated link >>> configuration tool, including channel bandwidth, duplex frequency spacing, >>> TX power and a bunch of other stuff. It's recommended to use this tool to >>> configure links because of all of the additional factors. >>> >>> But if you need to run a simple link calc to estimate a link's performance >>> at certain distance, you should have enough info. >>> >>> Hope that helps... >>> >>> -Matt >>> >>> >>> On Sat, Jan 10, 2015 at 10:06 AM, Mike Hammett <af...@ics-il.net> >>> <af...@ics-il.net> wrote: >>> >>> >>> Not at all, Matt. Those are receive sensitivities. >>> >>> >>> The left side of this picture is needed for the airFibers. You publish the >>> right side only. >>> >>> >>> This information is also not available for the airFibers. >>> >>> >>> >>> ----- >>> Mike Hammett >>> Intelligent Computing Solutionshttp://www.ics-il.com >>> >>> ------------------------------ >>> *From: *"Matt Hardy" <m...@ubnt.com> <m...@ubnt.com> >>> *To: *af@afmug.com >>> *Sent: *Friday, January 9, 2015 5:34:43 PM >>> *Subject: *Re: [AFMUG] Af5 >>> >>> This? >>> [image: Inline image 1] >>> >>> On Thu, Jan 8, 2015 at 5:18 PM, Mike Hammett <af...@ics-il.net> >>> <af...@ics-il.net> wrote: >>> >>> >>> Hard to tell because they won't publish their Tx and SNR requirements. >>> I'd just make educated guesses and plug it into a path calc. >>> >>> BTW: Ben, Matt... where are those numbers? >>> >>> >>> >>> ----- >>> Mike Hammett >>> Intelligent Computing Solutionshttp://www.ics-il.com >>> >>> ------------------------------ >>> *From: *"Craig House" <cr...@totalhighspeed.net> <cr...@totalhighspeed.net> >>> *To: *af@afmug.com >>> *Sent: *Thursday, January 8, 2015 3:24:58 PM >>> *Subject: *[AFMUG] Af5 >>> >>> I have used some AF 24 hours but no AF5 for backhaul yet what is the max >>> distance people are seeing for the AF 5 at full modulation >>> >>> Sent from my iPhone >>> >>> >>> >>> >>> >> >
