The other nice thing about using 3' and 4' size antennas on short paths
like that, you get a narrower beam width and better f/b ratio, making it
more likely you can coordinate the link successfully.

Avoiding the field strength Rx do not exceed values at other sites which
are off-azimuth and behind your sites by 10 to 15 degrees.

I recently did exactly the same thing with an Exalt ExtremeAir 18 link in
Seattle. It runs at -37 with a 2' on one end and a 3' high performance on
the other.



On Wed, Oct 29, 2014 at 5:49 AM, Caleb Knauer via Af <[email protected]> wrote:

> I don't have the calcs handy atm but it was calculated 5x9 at 2048QAM.
> Short link though, 3.5 miles with 3'/4' dishes, RSL low 30's.  Quite
> aware of how quick 2048 will drop down, and 80mhz channels would have
> given more wiggle room to drop rates and still maintain 1Gbps but
> there was a time crunch for the project and the 60mhz heads were in
> stock.  Even at 256QAM the throughput is adequate *for this particular
> application* if the fade is worse than calcs.
>
> On Tue, Oct 28, 2014 at 6:22 PM, Eric Kuhnke via Af <[email protected]> wrote:
> > yeah, 2048QAM, but what is your fade margin from the threshold required
> to
> > run at 2048QAM vs. when it will step down to 256QAM and no longer be a 1
> > Gbps radio?
> >
> > If I recall right an IP20C requires an RSSI of something like -57.5 to
> > operate at 2048QAM and will become a 256QAM radio at -63 or thereabouts.
> Not
> > much fade margin. Not something you can reliably predict as a five nines
> > true 1Gbps link pretending to be a fiber patch cable between two routers.
> >
> > Unless you're running it at sub-4km distances with 60cm size antennas and
> > the normal RSL is -35.0....
> >
> >
> >
> > On Tue, Oct 28, 2014 at 5:40 AM, Caleb Knauer via Af <[email protected]>
> wrote:
> >>
> >> We just put up a Ceragon IP20c link last week, 3.5 miles, one 60Mhz
> >> frequency pair, 1030Mbps full duplex using 2048QAM, uses two cores
> >> (same frequency) in a single FODU chasis and a combiner on the
> >> antenna.  Looks like any other single FODU install, very clean.  Not
> >> inexpensive however.
> >>
> >> On Tue, Oct 28, 2014 at 7:02 AM, Matt Jenkins via Af <[email protected]>
> wrote:
> >> > Cambium PTP820c
> >> > Exalt ExtremeAir
> >> >
> >> > Both will give you 1gig in a single radio.
> >> >
> >> > Matthew Jenkins
> >> > SmarterBroadband
> >> > [email protected]
> >> > 530.272.4000
> >> >
> >> > On 10/27/2014 03:25 PM, Peter Kranz via Af wrote:
> >> >>
> >> >>
> >> >> Has anyone shopped full Gig licensed links lately, which is the best
> >> >> bargain?
> >> >>
> >> >> *Peter Kranz
> >> >> *Founder/CEO - Unwired Ltd
> >> >> www.UnwiredLtd.com <http://www.unwiredltd.com/>
> >> >> Desk: 510-868-1614 x100
> >> >> Mobile: 510-207-0000
> >> >> [email protected] <mailto:[email protected]>
> >> >>
> >> >
> >
> >
>

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