The "magnitudes of power" part may not be fully understood by people who've never built a large C-band earth station: Imagine something with 75dB of gain:
http://www.satcomresources.com/Xicom-XTRD-2000C-C-Band-TWTA-Rack-Mount-2250W_2 On Thu, Feb 9, 2017 at 12:45 PM, Hardy, Tim <[email protected]> wrote: > Umm, Tim – not the other guy - author or actor! Coordination distance is > actually 125 miles with a 125-mile keyhole +/- 5 degrees around the main > beam. You might think this is overkill, but we have seen catastrophic > interference cases beyond even these distances, so industry settled on > these to make sure that longer main beam cases were examined. A couple of > additional things to consider at 6 GHz: > > > > The FCC minimum path distance at 6 GHz is 17 kilometers - paths less than > this distance can be licensed but there are required EIRP restrictions. > Usually, you would want to reduce power on a shorter path anyway to avoid > saturating your receivers. > > > > Do not forget about c-band satellite ground stations. These transmit in > the lower 6 GHz band (some even in upper 6) in magnitudes of power much > greater than a fixed point-to-point system. Most of these stations in the > States are licensed full-band, full-arc so if a problem is indicated and > there is no clutter or other shielding, it is difficult to clear anything. > We have seen major issues when these cases are overlooked. > > > > *From:* Af [mailto:[email protected]] *On Behalf Of *Chuck McCown > *Sent:* Thursday, February 09, 2017 3:11 PM > *To:* [email protected] > *Subject:* Re: [AFMUG] 11GHz and 18GHz real throughput > > > > You have to look out to 50 miles and check the energy coming off your > antenna in all directions. > > Tom Hardy or Liz Creekmore could tell us much more. > > > > *From:* Brett A Mansfield > > *Sent:* Thursday, February 09, 2017 1:08 PM > > *To:* [email protected] > > *Subject:* Re: [AFMUG] 11GHz and 18GHz real throughput > > > > Okay, so in The valley I'm looking at there is one 6GHz link that is > nowhere I near where I plan to put mine, there are two 11GHz links, neither > of which would cross paths with mine, no 13 GHz at all, and two small links > in 18 and 23 GHz that might conflict. > > > > Now to start looking at a product to use. What do people recommend for 6 > and 11 GHz? Would it be cheaper and easier to just put up a few hops and > use the AF? What do you guys suggest? I got the exact path length. It's > only a mere 8 miles. I really thought it would be 15, but I was pleasantly > mistaken. > > Thank you, > > Brett A Mansfield > > > On Feb 9, 2017, at 12:55 PM, Chuck McCown <[email protected]> wrote: > > My teachers told me about the coming ice age... > > > > *From:* Jaime Solorza > > *Sent:* Thursday, February 09, 2017 12:42 PM > > *To:* Animal Farm > > *Subject:* Re: [AFMUG] 11GHz and 18GHz real throughput > > > > Trust the math... It's science and engineering based.... Like global > warming.... Zaz. Toooooo easy.... Recipes on the way > > > > On Feb 9, 2017 9:27 AM, "Ken Hohhof" <[email protected]> wrote: > > Something else that gets some people into trouble is the difference in how > path loss and rain fade act with increased distance. The post Mike linked > to makes this clear. > > > > We get used to double the distance = 6 dB more path loss, which can be > made up via antenna gain. > > > > But double the distance potentially means double the rain fade in dB. So > 40 dB could become 80 dB. You’re not going to make that up with bigger > dishes. > > > > Of course, your local weather patterns are also a factor. If you > typically get big storms with heavy rain for 20+ miles, this analysis is > correct. But if you typically get little popup storms, or front boundaries > that move across a microwave path without actually raining on the entire > path, this analysis is overly pessimistic. It also matters whether the > path is north-south or east-west, if like us you typically get storms > moving from west to east. > > > > How people use the Internet is also a factor. It used to be, as long as > you could get email and look stuff up on Google, your Internet was > working. But now if an HD video stream stops to rebuffer, you have “no > Internet”. Which may seem silly to us, but if watching movies is the only > thing you use the Internet for, and you can’t watch movies, then your > Internet is broken. And while 10 years ago people were doing totally new > things via the Internet, today they are more likely replacing something > like satellite TV with a streaming service to save money or add > convenience. But they still expect DirecTV Now to be as simple and > reliable as broadcast TV, they don’t expect to pay more for their Internet, > but whenever there’s a problem they are told it must be their crappy > Internet. > > > > > > *From:* Af [mailto:[email protected] <[email protected]>] *On > Behalf Of *Mathew Howard > *Sent:* Thursday, February 9, 2017 9:58 AM > *To:* af <[email protected]> > *Subject:* Re: [AFMUG] 11GHz and 18GHz real throughput > > > > Yeah, I really don't trust them that much either, but they're certainly > useful for getting an idea of how different areas compare. Things will > certainly work differently in Utah than they do for us in southern > Wisconsin/northern Illinois. > > > > On Thu, Feb 9, 2017 at 9:53 AM, Mike Hammett <[email protected]> wrote: > > Assuming you trust the models. > > I for one, don't. > > https://www.facebook.com/thebrotherswisp/posts/ > 956205354504917?match=cmFpbg%3D%3D > > > > ----- > Mike Hammett > Intelligent Computing Solutions <http://www.ics-il.com/> > <image001.jpg> <https://www.facebook.com/ICSIL><image001.jpg> > <https://plus.google.com/+IntelligentComputingSolutionsDeKalb>< > image001.jpg> > <https://www.linkedin.com/company/intelligent-computing-solutions> > <image001.jpg> <https://twitter.com/ICSIL> > Midwest Internet Exchange <http://www.midwest-ix.com/> > <image001.jpg> <https://www.facebook.com/mdwestix><image001.jpg> > <https://www.linkedin.com/company/midwest-internet-exchange><image001.jpg> > <https://twitter.com/mdwestix> > The Brothers WISP <http://www.thebrotherswisp.com/> > <image001.jpg> <https://www.facebook.com/thebrotherswisp><image001.jpg> > > > <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> > ------------------------------ > > *From: *"Mathew Howard" <[email protected]> > *To: *"af" <[email protected]> > *Sent: *Thursday, February 9, 2017 9:29:53 AM > *Subject: *Re: [AFMUG] 11GHz and 18GHz real throughput > > It may not be a rain forest, but it's not a desert either... there's going > to be a big difference between rainzones K and B. According to Mimosa's > design tool, the Rain Fade in Utah would only be around 17db, which should > make 15 miles easily doable at 11ghz. > > > > On Wed, Feb 8, 2017 at 9:54 PM, Ken Hohhof <[email protected]> wrote: > > At 15 miles in 11 GHz I get 40+ dB rain fade. Only acceptable with 5 or 6 > GHz backup. I wouldn't even think about trying 18 GHz at that distance. > And this is northern Illinois, not a rain forest. > > Oh, and you can deny climate change all you want, but in many places the > rain models are optimistic. > > > -----Original Message----- > From: Af [mailto:[email protected] <[email protected]>] On Behalf > Of Trey Scarborough > Sent: Wednesday, February 8, 2017 9:33 PM > To: [email protected] > Subject: Re: [AFMUG] 11GHz and 18GHz real throughput > > I have a 18ghz 15mile link with no issues. and 4' dishes. It was the only > thing I could get 80mhz channels in. > > shouldn't be a problem with 11ghz at all just depends on the equipment > used. It also depends on your definition of huge... For some its 3" for > others it is 8'. completely acceptable for most rain regions with 4' dishes. > > On 2/8/2017 7:54 PM, Mike Hammett wrote: > > http://media.cmgdigital.com/shared/lt/lt_cache/thumbnail/610/img/photo > > s/2017/02/08/94/08/sex-offender-sought.jpg > > > > I've seen this too, doesn't mean I'd recommend anyone do it. > > > > > > > > ----- > > Mike Hammett > > Intelligent Computing Solutions <http://www.ics-il.com/> > > <https://www.facebook.com/ICSIL><https://plus.google.com/+IntelligentC > > omputingSolutionsDeKalb><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/m > > idwest-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: *"Jeremy" <[email protected]> > > *To: *[email protected] > > *Sent: *Wednesday, February 8, 2017 7:51:51 PM > > *Subject: *Re: [AFMUG] 11GHz and 18GHz real throughput > > > > I have seen an 18GHz link that far with 6' dishes. > > > > On Wed, Feb 8, 2017 at 6:42 PM, Mike Hammett <[email protected] > <[email protected]%0b>> <mailto:[email protected] <[email protected]>>> > wrote: > > > > Not a chance at 18. Maybe 11, but that's even far for 11 GHz without > > huge dishes. > > > > Play with Mimosa's designer, Cambium's LinkPlanner, etc. > > > > > > > > ----- > > 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: *"Brett A Mansfield" <[email protected] > <[email protected]%0b>> <mailto:lists@ > silverlakeinternet.com <[email protected]>>> > > *To: *[email protected] <mailto:[email protected] <[email protected]>> > > *Sent: *Wednesday, February 8, 2017 7:38:58 PM > > *Subject: *[AFMUG] 11GHz and 18GHz real throughput > > > > > Hi, > > > > I've never yet done a licensed link and there is plenty of these two > > frequencies available in my area. I need to be able to get 500Mbps > > at about 15 miles. Is that possible with either of these? > > > > What kind of real world speeds can I expect out of these and what > > channel size do I need to license to get those speeds? > > > > Is there something else I should consider? What brand/model radios > > and dishes, what other frequencies for easier licensing, etc? > > > > It would be great to be able to get a gig that distance, but I'm > > trying to be realistic and get just what I really need to start with. > > > > No legal advice please, just your experience with it and any > > knowledge you'd be able/willing to share with the licensing of these > > frequencies. > > > > Thank you, > > Brett A Mansfield > > > > > > > > > > > > > > >
