AnonDOG
@12.160.x.x
| reply to Nathan H
Re: 8 mile NLOS link
NLOS |
This image shows the bad news. I have *assumed* an antenna height at each end of the proposed link of 78 feet.
On the path I have marked a red circle where there is a tall hill in the path.
Even at 78 feet on both ends you only have .2 F1 fresnel clearance over the large hill. That is a pretty bad situation. You probably will have trouble making a legal (FCC legal) link over that hill.
If that hill is also covered with trees, even at 900 MHz, you probably wont be able to make a good link at all.
Sorry. Consider doing that link in two hops.
-m- |
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Nathan H
@choiceone.net | reply to Nathan H
Did I give the right coordinates? |
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Nathan H
@choiceone.net | reply to Nathan H
Ok, thanks. These should be correct: My house: 40 58 01.31 N, 85 35 12.07 W. Grain leg: 40 56 38.39 N, 85 26 22.67 W. |
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robbin
Premium,MVM
join:2000-09-21
Leander, TX | reply to PersComp
Actually it is easier than that. Just enter the address and let it zoom in. Then move the pointer (hand) to the exact location and look at the bottom of the screen and you should see the coordinates in the default view. |
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PersComp
Premium
join:2005-08-17
Cayce, SC | reply to Nathan H
You can turn on lat/long grid with one of the menu items at the top. Then just zoom into your location. |
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Nathan H
@choiceone.net | reply to Nathan H
Sorry about not getting the coordinates correct, how do you get them in google earth? I was having some problems and that was why my numbers where different. |
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AnonDOG
@12.160.x.x
| reply to Semaphore
Moto claims their receive sensitivity is -90 dBm. We have seen them hit that and better; however, Moto wants a 3 dB SNR minimum. That takes us to -87 dBm @ single speed with no fade margin. Moto claims that they can operate reliably with a 6 dB fade margin. We have not seen that but our area is heavy forest, maybe in other areas you can get that kind of performance. We have not been so lucky. We figure in a fade margin of 12 dB and that takes us to -75 dBm minimum receive signal on a link. If the tech gets less than that and does not call into the office and talk with me personally to get my authorization he had better not hang that radio. 
I further reduce that by 3 dB because it only because feels good to have a map that I can be very comfortable with when I claim a site will have coverage. Moto claims that it wants -66 dBm to run reliably at double speed, by the way.
I might have been a bit tough on that map but he is still a very long way outside of the coverage area for a 75' access point.
When we get better coordinates I'll do a more lenient plot.
-m- |
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Semaphore
Premium
join:2003-11-18
Arnprior On. | reply to AnonDOG
Just curious. Why do you set RM Threshold to -72 ? That seems sort of low for Canopy 900Mhz. Moto's Propaganda says -90. We try for -86 or better.
S |
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AnonDOG
@12.160.x.x
| reply to Nathan H
There is a discrepancy between the two sets of coordinates he posted for his WISP. The Northing varies by 20 seconds. At his lattitude this will be around 1200 feet.
Nathan, check your coordinates. Get them correct or nothing else will matter. |
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lutful
Premium
join:2005-06-16
Ottawa, ON | reply to AnonDOG
said by AnonDOG :
The CPE modeled was a Canopy SM with a 14 dBi Yagi.
AnonDOG, what is the probability of making the link with a Hyperlink 18dBi grid at 70ft that Nathan mentioned at his end? |
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robbin
Premium,MVM
join:2000-09-21
Leander, TX | reply to StormeAngel
Radio Mobile |
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StormeAngel
join:2006-05-25
Fort Wayne, IN | reply to AnonDOG
What did you use to make the map with? |
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AnonDOG
@12.160.x.x
| reply to Nathan H
Here is the coverage area of your WISP.
This presumes Motorola Canopy hardware in it's standard configuration at 75 feet on his end and at 45 feet on your end.
The CPE modeled was a Canopy SM with a 14 dBi Yagi.
You will observe that you are well outside of his coverage area. Worse that that there is a tall mound about half way between you and him. You can not even clear that mound with an antenna less than 45' at your end.
To make this link you will need to be at about 90 feet on your end and then it will be marginal.
This is because it is so difficult to get frenel clearance over that hill I mention. |
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LLigetfa
join:2006-05-15
Fort Frances, ON
| reply to uscomputing
Ja, but there were lots of CPE brands tossed about. Funny that it is only at about page 2 that the full details reveal but by then everyone is off on a different tangent. Just trying to get them facing the right direction again.
So Nathan, are you hoping to hit the WISP's tower, or do you plan to setup your own relay from somewhere in between? If you plan to hit their tower, you need to know what frequency they are running. Moto Canopy comes in different flavors.
We have a new WISP setting up here soon and they are talking Canopy with a reach of 14 KM (8.7 miles).
If your WISP will not do a free site survey, you may have to pay them to come out and if they don't have a bucket truck, you may have to pull in a favour and find one for them. |
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uscomputing
join:2005-01-26
Buffalo, NY | reply to Nathan H
That's true, LLigetfa - but you can use other brands of antennas with them. |
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LLigetfa
join:2006-05-15
Fort Frances, ON | reply to Nathan H
said by Nathan H :
The brand they use is "Motorola Canopy".
I thought I read somewhere that they (Moto Canopy) use proprietary chipsets so you cannot use any other brand of CPE. |
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Nathan H
@choiceone.net | reply to Nathan H
You mean a site servey at my house? They won't do that. The whole reason I started this topic is because the wisp says I'm too far and they won't mess with me  |
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lutful
Premium
join:2005-06-16
Ottawa, ON | reply to Nathan H
Please ask your WISP to do a site survey using connectorized SM and a few high gain antenna choices. |
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Nathan H
@choiceone.net | reply to Nathan H
The brand they use is "Motorola Canopy". I can't get the towers height, but it's probably somewhere around 70'. |
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Nathan H
@choiceone.net
| reply to Nathan H
I called them again today but to no avail. I keep getting customer service people who have no idea about anything! The last customer service woman I talked to said that someone who knew what they were talking about (not her exact words) would call me back. So I'm still waiting on that call... |
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