With tower coverage and radio mobile, path calculations and results are going to vary greatly by the amount of reliability you have set in the configuration. What you use for spot mode for ptmp is a lot different than if you want 99% or more uptime. Each decimal place in radio mobile wants another 10 dB signal to meet the reliability. This is a good tool to determine the path profile but you really want to use some other path calc tool that is designed for PTP links so that you get a reliable uptime calculation result. The Longley Rice propagation model used for Radio Mobile is not that good to reliability calculations in PTP paths. It’s usually conservative unless you have your availability numbers set too low say at 70 or 80%.
Long story short Kurt, find a path calc tool to run the signal numbers now that you have established you have a path. As Adam has said I would not be overly concerned with those trees in the path as much as having the right tool to show your predicted signal. A good path calc tool for PTPT gives you almost the exact numbers for signal you should have for alignment. Radio Mobile and by default tower coverage will not calculate the paths the same way. Thank You, Brian Webster www.wirelessmapping.com www.Broadband-Mapping.com From: AF [mailto:[email protected]] On Behalf Of Kurt Fankhauser Sent: Thursday, December 06, 2018 4:32 PM To: [email protected] Subject: Re: [AFMUG] 25 mile shot AF5XHD NLOS ??? after looking at another tower i think i can go with the 3 foot dishes now. that puts me at -57 and tower coverage is supposed to be factoring in a little bit of tree fade so even if i fade 10db more im still at -67 which should be enough i would think. On Thu, Dec 6, 2018 at 4:12 PM Mathew Howard <[email protected]> wrote: So, to achieve 150Mbps each way, you would need 300Mbps aggregate with an AF5xHD, which means that you're going to need a minimum of a 40mhz channel at 8X (256QAM). to get 8X, you can use a maximum of 22dbm TX power, which by my calculations, would give you a signal of roughly -58 with 2' dishes - an AF5xHD is supposed to be able to do 8x at -65 on a 40mhz channel, so assuming no noise and clear LOS, that'd work just fine and give you a few db to spare. Realistically, you probably aren't going to get 8X on that link, so you'd need to bump it up to a 50mhz channel and hope 6X works. That lets you bump the TX power up a couple more db, and now you only need a -69 to get the desired capacity, which starts to look a lot more promising... but those trees could easily cost you more than 10db, and we don't know what kind of noise you're going to be dealing with. Going to 3' dishes on both ends should gain you 8db, but if you can't use 3' dishes, that doesn't really matter. My guess is that those trees are going to be cutting the signal down more than what 3' dishes would gain, but I don't believe that trees in towercoverage are accurate enough to really try to predict that. Of course if you don't mind burning up the entire 5.8ghz band, you could use an 80mhz (or even 100mhz) channel, and then you'd only need 4X to get that kind of bandwidth, which would let you go up to 29dbm TX power, and you'd only need a signal of -71, which would mean you could afford to lose around 20db to the trees... On Thu, Dec 6, 2018 at 2:40 PM Adam Moffett <[email protected]> wrote: I got over 300mbps at 16.7 miles with 3' dishes on the AF5XHD. The catch is you need a large channel for these high data rates and you have to have a solid SNR across the whole channel. That's no guarantee. I don't think those intermittent trees in the bottom half of the Freznel zone are as big of a problem as people are making out. The bigger problem I see is the 2' dishes. I would not bet the farm on getting 150mbps out of it. -Adam On 12/6/2018 2:48 PM, Kurt Fankhauser wrote: Josh, who did you do that link for? On Thu, Dec 6, 2018 at 2:38 PM Josh Luthman <[email protected]> wrote: Not just no but hell no. 150 megs isn't going to happen. I wouldn't even count on it associating. I did a 15 mile shot and I was a lot higher on both sides maybe half an hour from where you're at. Josh Luthman Office: 937-552-2340 Direct: 937-552-2343 1100 Wayne St Suite 1337 Troy, OH 45373 On Thu, Dec 6, 2018 at 2:20 PM Kurt Fankhauser <[email protected]> wrote: found another site with better looking profile, 100 foot higher elevation on one of the ends. (see attached) On Thu, Dec 6, 2018 at 2:04 PM Mathew Howard <[email protected]> wrote: ubnt doesn't make a product that's going to work good for that situation... The only thing that might work better than AF5XHD for that is going to be AF-2X, or maybe AF-3X, but the chances of getting 150mbps out of either of those is pretty slim. Now, as far as if AF5XHD's with 2' dishes will work... who knows, it depends on how much the trees actually block it, which probably isn't really possible to accurately predict. You're pretty much going to have to try it to know what it will do, but personally, I wouldn't do it unless I really had to. On Thu, Dec 6, 2018 at 12:45 PM Timothy Steele <[email protected]> wrote: everything about that email just wants to make me ask why-why oh why.. I would use https://link.ubnt.com/ to find the product that would work best On Thu, Dec 6, 2018 at 1:31 PM Kurt Fankhauser <[email protected]> wrote: Trying to do a NLOS shot with AF5XHD's thats 25 miles (see attached topo). Only have done 10-12 mile shots before that are NLOS. I have had good success doing the 10 mile shots skimming tree tops but not sure if the added distance is going to drastically change that. According to TowerCoverage this link is showing it will work. Can't use 3 foot dishes due to wind loading only able to use 2 footers. Anyone think this should work? Only need about 150mbps each way. -- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com
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