In a small/medium sized city where it might become difficult to coordinate new 11 GHz PTP someday in the future, but you have a need for 400-600 Mbps to a site now, it's not a bad way to "reserve" a dual polarity 80 MHz channel if you can get it, either...
Some day in the future, remove the AF11FX and replace it with a much more expensive 2048-4096QAM dual polarity radio that can use the full width of the 80 MHz. On Thu, May 25, 2017 at 7:24 PM, Mathew Howard <mhoward...@gmail.com> wrote: > Yeah, I saw somewhat of an explanation from ubnt at one point... I don't > remember the details, but I'm pretty sure FEC was part of the reason. > > For an $800 radio, they're good at what the do and they have their place, > but people shouldn't expect them to perform the same as a $4000 radio. > > On May 25, 2017 9:15 PM, "Eric Kuhnke" <eric.kuh...@gmail.com> wrote: > > I'm going to eat my own words a little bit here. Just compared the AF11FX > datasheet side by side with the SAF Integra for a theoretical 40 MHz single > polarity FDD link. The AF11FX is something like 252Mbps, the SAF is a > claimed 315 Mbps in the same 40 MHz wide. > > My theory is that ubnt has done something that is lower cost with the > radio circuitry that doesn't allow it to very closely approach the edges of > a 40 MHz channel without excessively strong signal leaking over the edge of > a channel mask (as viewed by a spectrum analyzer), and possibly has > additional FEC which is opaque to the end user. > > But that makes total sense when comparing $799/unit to $4000/unit+. > > https://dl.ubnt.com/datasheets/airfiber/airFiber_AF-11FX_DS.pdf > > https://www.saftehnika.com/files/downloads/4e6954be-a416-e61 > 1-a0d1-0050569a8c0f/Integra%20series%20DS%20v1.39.pdf > > > > On Thu, May 25, 2017 at 7:12 PM, Bill Prince <part15...@gmail.com> wrote: > >> I don't know that anyone has really examined the overhead required by >> OFDM (AF11) versus the overhead required by the various other licensed >> vendor proprietary modulation schemes. I think this would be the primary >> issue. I know we get over 500 Mbps through a Dragonwave on a single 50 MHz >> channel. Two channels should theoretically get over 1 Gbps. The AF11 comes >> out of the chute doing dual polarity, so that would be the comparison. >> >> >> bp >> <part15sbs{at}gmail{dot}com> >> >> >> On 5/25/2017 7:06 PM, Eric Kuhnke wrote: >> >> If all you can get on a particular path is a theoretical single 40 MHz >> wide FDD channel pair, one polarity, I don't see how the 1024QAM bps/Hz >> efficiency would be significantly worse than a competing single polarity >> product (SAF Integra, etc) running in the same channel size. Unless you are >> counting more expensive competing products that advertise header >> compression and very different Mbps rates for 64-byte vs much larger packet >> sizes. >> >> It's very cost effective so I will forgive it many things, my main >> problem is that it can't actually *use* near the full width of an 80 MHz >> channel. >> >> On Thu, May 25, 2017 at 6:26 PM, George Skorup <george.sko...@cbcast.com> >> wrote: >> >>> Yeah. Cost is one thing, but if all you can get is a single polarity on >>> a particular path, the AF11 is probably one of the last things I'd look at. >>> Congestion is a problem around here. >>> >>> >>> On 5/25/2017 8:21 PM, Seth Mattinen wrote: >>> >>>> On 5/25/17 18:12, Mathew Howard wrote: >>>> >>>>> >>>>> We're running the full 56mhz/MIMO... I haven't been able to get them >>>>> to run at 1024qam yet (antennas still need to be fine tuned, it wasn't >>>>> ideal weather conditions when we put them up, so I'm hoping we'll be able >>>>> to get a bit more out them), so they're only at around 550Mbps capacity >>>>> (and I've verified the link will do around 500Mbps with real traffic). >>>>> >>>>> >>>> >>>> Only 500 meg with two channels? Crap, I have an old Exalt that can do >>>> that with only one channel at 256QAM. >>>> >>> >>> >> >> > >
