Inssomniak
Premium
join:2005-04-06
Cayuga, ON
| backhauling
Hi all.
I hope this is a reasonable post for this forum.
Im looking to establish a long range backhaul (18 miles/28kms), non/near line of sight over generally flat terrain mostly farmland.
Ive researched 900mhz and 5ghz systems that might do the job, but I am somewhat not sure (actual vs advertised) if its a feasible link. Im looking for owners of WISPs that have established a link like this, 10-20mbps is target speed. I was originally going to backhaul on a T1 but I believe it to be more cost effective to wireless backhaul to the NOC where internet services are MUCH cheaper/readily available. Im open to hardware suggestions, cost, tips, anything..
Thanks! |
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LLigetfa
join:2006-05-15
Fort Frances, ON
| When I speed read this and catch "18 miles", "NLOS", and "10-20 mbps", the first thing that comes to mind is "impossible".
5GHz is predominantly LOS and while 900MHz is more tolerant of NLOS, with the 4 Watt EIRP limit, 18 miles is a dream.
Try not to loose sleep over it.  |
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Keithb
join:2003-09-16
US
| reply to Inssomniak
Search for the user bumkus as I've read some of his stories. A good thread: »Most distant client in a PtMP setting?
Unbelievable shots I must say, but these guys would be the ones to let us know what's possible. |
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LLigetfa
join:2006-05-15
Fort Frances, ON
| With the heigher EIRP allowed for PtP, IMHO the 2.4GHz ISM band would stand a better chance.
900MHz could also stand a chance depending on antenna height. It is best to have at least one end up really high so that much of the fresnel zone is clear. Don't expect to clip treetops the whole length and expect it to work. If you gave us antenna heights and GPS coords, we could look at the path in RM. |
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AMD Phreak
Premium
join:2003-12-14 | Orthagon if you can afford it. |
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Inssomniak
Premium
join:2005-04-06
Cayuga, ON
| OK.. well.. I *Think* I can get a tower midpoint that would give me LOS to both the NOC and the proposed POP. That would divide my distance approximately in half, and give me *very* near LOS, if not LOS. Im not sure of how you experts calculate required tower heights, the geographical differences in terrain, etc..
42.9516 degrees Lat, 79.8578 Deg Long = NOC
42.8962 degrees Lat, 80.1429 Deg Long = POP
42.9021 degrees Lat, 80.0024 Deg Long = Possible repeater tower location. |
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superdog
I Need A Drink
Premium,MVM
join:2001-07-13
Lebanon, PA
| OK, What You want to do "MAY" be possible, but it is going to depend on a LOT of variables. 5Ghz may work, but since You said the word "farmland", I am going to say no way, as the earth itself does not have enough reflective properties to make even an Orthagon radio work, as it relies on scattered signals (OFDM) in a near LOS situation to give You the best thruput.
If we look at 2.4Ghz, Your chances are getting better, but not a whole lot more. While 2.4Ghz does not have as many issues in a near LOS situation that 5Ghz does, there are fresnel zone issues that require a greater height on both ends. I think that the radios may hook up, but the thruput will be so terrible that a T1 will look better every day. 
Forget 900Mhz, as You will not have enough juice to complete the link, and if You could make it work, the thruput is not very good.
Your best bet is to make 2 hops with one in the middle, use 5Ghz and just get the radios high enough that every thing works. 
--
»www.wavecrazy.net Join WISPA today! »www.wispa.org/ |
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Inssomniak
Premium
join:2005-04-06
Cayuga, ON
| Im still considering tower locations for an antenna here, Of course with permission to rent/use space on it, There is a water tower that I could use, and relay to NOC only a few hundred meters away, there is also a decommissioned tower that was used temporarily as a microwave transmission tower between two Bell CO's, I could also relay to NOC only a few hundred meters away. I doubt that Bell Canada would let me use space on that, they would probably laugh at me, but the town might give me a spot on the water tower, Im not sure if they would laugh at that too. |
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LLigetfa
join:2006-05-15
Fort Frances, ON
| I ran a few shots with 100 foot towers. They do not factor for any trees. NOC to POP will not work. POP to T3 would work but then T3 to NOC is still a show stopper. You need a mid-point that is closer to the NOC that is down in a hole. |
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lutful
Premium
join:2005-06-16
Ottawa, ON
 ·TekSavvy Solutions..
| reply to Inssomniak
The water tower may be your best option to get some height at the NOC side.
said by Inssomniak  : town might give me a spot on the water tower, Im not sure if they would laugh at that too. They will not laugh as many water towers in rural Ontario are used for wireless service. However they may ask you to use a professional contractor for installations.
There are a few posts in this forum with equipment mounting ideas for water towers. |
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Inssomniak
Premium
join:2005-04-06
Cayuga, ON
| Thanks up to now for all the information.
I dont have or even know what that program is that you used to do that, nor if I did, would know how to use it, but I was hoping to run some tests again, using virtually the same locations, with different tower heights, Assume the Middle tower and the tower at the NOC were 50 feet higher ( I believe the water tower to be at least that, but couldnt get any information on that yet).. The middle tower is marginally closer to the NOC, but not by much. The center tower is a private tower used now for a wind turbine.
There is no "holes" in the area to stick a tower, its, well, flat, until you fall into the valley of the NOC (large river).
Thanks for any help ! |
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battleop
join:2005-09-28
00000 | reply to lutful
They might also ask for your arm and your leg. Many places like that are spoiled by the money that the Cell companies are willing to pay. On the other hand you might be able to trade service(s) for a spot on the tank. |
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