Real usable capacity at Layer 2 Ethernet depends on several variables besides the modulation level and the regulatory bandwidth. For 1024 QAM there are 10 bits per symbol so theoretically one would expect to get 400 Mbps in a 40 MHz channel (10 bits x 40 MHz symbol rate).
To actually make a radio that meets FCC spectrum masks, a reduction of the symbol rate down to around 35 MHz is required plus filtering, giving a max of 350 Mbps over the air. After that, Forward Error Correction (FEC) is required which is typically around 85-90 % for most microwave radios using LDPC, giving a net throughput of around 300 to 315 Mbps. Add header compression at layer 2 which in the worst case for large packets adds about 2.5 % improvement and you get to around 325 Mbps, which is what Trango and others get on a single 40 MHz channel with the newest technology. Ubiquiti maybe using a lower FEC rate like 75-80% (or a lower symbol rate if the filtering is not steep enough) and no header compression, which would give them about 250 Mbps for large packets. Hope that helps! Chris Gustaf Trango Systems On Fri, Jan 13, 2017 at 2:39 PM, Mathew Howard <mhoward...@gmail.com> wrote: > What other radios will only do 250Mbps (502.4Mbps capacity according to > the data sheet...) on one 40mhz single polarity channel at 256qam? The > other's I've looked at are typically around 300Mbps... > > Not that I'm saying the AF11 is a bad radio, I plan on putting up at least > a few of them this year... but I find it a little funny that they use > 1024qam as a selling point, when it can't do as much throughput at 1024qam > as other radios do at 256qam. > > On Fri, Jan 13, 2017 at 4:19 PM, Eric Kuhnke <eric.kuh...@gmail.com> > wrote: > >> I think this whole thread can be summed up that there's no magical way to >> get around the shannon limit and bps/Hz coding efficiency for a given >> channel size and modulation... From the technical perspective of people >> who have to really understand the FDX capacity of a new PTP link, the ubnt >> marketing department is divorced from reality, it's not 1200 Mbps no matter >> how many slick PDFs they publish. >> >> One 40 MHz channel single polarity at 1024QAM 5/6 code rate is going to >> be nearly the same efficiency bps/Hz from many different manufacturers. >> Multiply as necessary for dual polarity or for larger channel sizes such as >> 60, 80 or 112 MHz. >> >> >> >> On Fri, Jan 13, 2017 at 9:38 AM, Faisal Imtiaz <fai...@snappytelecom.net> >> wrote: >> >>> FYI... on a "single" 40mhz channel 'dual polarity' (mimo) the expected >>> throughput on Af11x is 500meg duplex. >>> >>> Faisal Imtiaz >>> Snappy Internet & Telecom >>> 7266 SW 48 Street >>> Miami, FL 33155 >>> Tel: 305 663 5518 x 232 <(305)%20663-5518> >>> >>> Help-desk: (305)663-5518 <(305)%20663-5518> Option 2 or Email: >>> supp...@snappytelecom.net >>> >>> ------------------------------ >>> >>> *From: *"Josh Baird" <joshba...@gmail.com> >>> *To: *af@afmug.com >>> *Sent: *Friday, January 13, 2017 10:30:10 AM >>> >>> *Subject: *Re: [AFMUG] Our UBNT AF11x experience >>> >>> But if I can get 80mhz channels in both polarities (running at >>> 56Mhz/1024QAM with this radio), I should be able to at least double he >>> capacity of my PTP-800 link which can do 228Mbps. Right? >>> >>> On Thu, Jan 12, 2017 at 5:55 PM, Mike Hammett <af...@ics-il.net> wrote: >>> >>>> At 40 MHz and a single polarity, you're looking at an almost >>>> insignificant increase in throughput. >>>> >>>> Their claim is 1.2 gb+. >>>> Cut that in half as they're advertising the aggregate, so 600 mb+. >>>> That's using both polarities, so now only 300 mb+. >>>> Only I haven't heard of anyone getting much more than 500 in a single >>>> direction (they may certainly exist, I just haven't seen them), so now that >>>> 300 is really only 250. >>>> >>>> >>>> Not much of an upgrade unless you can also get larger channels in both >>>> polarities. >>>> >>>> >>>> >>>> ----- >>>> Mike Hammett >>>> Intelligent Computing Solutions <http://www.ics-il.com/> >>>> <https://www.facebook.com/ICSIL> >>>> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> >>>> <https://www.linkedin.com/company/intelligent-computing-solutions> >>>> <https://twitter.com/ICSIL> >>>> Midwest Internet Exchange <http://www.midwest-ix.com/> >>>> <https://www.facebook.com/mdwestix> >>>> <https://www.linkedin.com/company/midwest-internet-exchange> >>>> <https://twitter.com/mdwestix> >>>> The Brothers WISP <http://www.thebrotherswisp.com/> >>>> <https://www.facebook.com/thebrotherswisp> >>>> >>>> >>>> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> >>>> ------------------------------ >>>> *From: *"Josh Baird" <joshba...@gmail.com> >>>> *To: *af@afmug.com >>>> *Sent: *Thursday, January 12, 2017 11:47:42 AM >>>> *Subject: *Re: [AFMUG] Our UBNT AF11x experience >>>> >>>> This PTP800 is only capable of running at 40Mhz (ODU-A) so it can only >>>> do 228Mbps full-duplex. The AF11x should be able to do much more than >>>> that, right? >>>> >>>> On Thu, Jan 12, 2017 at 12:05 PM, Gino Villarini <g...@aeronetpr.com> >>>> wrote: >>>> >>>>> IIRC, PTP800 is Remec Style, you'll need Remec to N connector adapters >>>>> (AF11x is N) >>>>> >>>>> What do you expect to achieve with this upgrade? Not much capacity >>>>> difference between PTP800 and AF11x, maybe 50-80- mbps more. Only if you >>>>> have a xpic license you can double your throughput with the af11x >>>>> >>>>> From: Af <af-boun...@afmug.com> on behalf of Josh Baird < >>>>> joshba...@gmail.com> >>>>> Reply-To: "af@afmug.com" <af@afmug.com> >>>>> Date: Thursday, January 12, 2017 at 9:12 AM >>>>> To: "af@afmug.com" <af@afmug.com> >>>>> Subject: Re: [AFMUG] Our UBNT AF11x experience >>>>> >>>>> Good news - thanks for sharing. >>>>> >>>>> Somewhat un-related question: >>>>> >>>>> I have a PTP-800 link using these dishes: >>>>> >>>>> http://www.hol4g.com/AC/product.aspx?number=ANC-VHLP3-11W-RR >>>>> 1&p=237127&sc=0 >>>>> >>>>> Do you know if I can re-use these dishes with the AF11x? Do I need >>>>> adapters? >>>>> >>>>> Josh >>>>> >>>>> >>>>> >>>>> >>>>> *Gino Villarini* >>>>> President >>>>> Metro Office Park #18 Suite 304 Guaynabo, Puerto Rico 00968 >>>>> >>>>> >>>>> On Thu, Jan 12, 2017 at 8:07 AM, Gino Villarini <g...@aeronetpr.com> >>>>> wrote: >>>>> >>>>>> Hey all, just dropping by to share our experience with AF11x, we habe >>>>>> been beta testing the unit since Sept and for the last 3 months, the unit >>>>>> has been rock solid. >>>>>> >>>>>> >>>>>> >>>>>> We are very happy with its performance, just wished it had a SFP >>>>>> port! >>>>>> >>>>>> >>>>>> >>>>>> This unit replaced a Mimosa B11 unit that we were having some >>>>>> intermitent throughtput issues, >>>>>> >>>>>> >>>>>> >>>>>> The swap was easy since we reused the Jirous Dishes and only had to >>>>>> add the af11x adapters to it, >>>>>> >>>>>> >>>>>> >>>>>> The link went live on 9/21/16 and on the first weeks we experienced >>>>>> some lockups, but after a revised beta fw was applied, all issues went >>>>>> away. >>>>>> >>>>>> >>>>>> >>>>>> For UBNT, please add SFP port and continue the good work towards a >>>>>> af6x and af18x >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> *Gino Villarini* >>>>>> President >>>>>> Metro Office Park #18 Suite 304 Guaynabo, Puerto Rico 00968 >>>>>> >>>>>> >>>>>> >>>>> >>>> >>>> >>> >> >
