1.83 mile link through trees

Hello,



I am considering using the Motorola Canopy 900 mhz product. I wish to setup an AP 77 ft up on a tower with the main purpose of serving a specific site (with the benefit of being able to provide to other sites).

The link is approximately 1.83 miles long, and at least from a topographic perspective it has line of site. The problem comes that from the .6 mile mark to the 1.3 mile mark there is a large number of trees. Given the height of the two locations (base station and remote), and the angle of attack, we have an approximate 40 ft minimum clearance between the ground and where an imaginary line would go between the two radios. The issue is that some (a lot) of the trees are likely very close and over the 40 ft limit…

Will the 900 mhz solution work (well?) in a situation where it is going through many trees (albeit the tops of them) or is it really only for going through a few trees? Also, will the link distance (1.83 miles) and this fact affect things? I don’t particularly wish to purchase the system without a good chance of it working…

Thanks!

We have had very good luck with the 900 through trees NON LOS. At that close of a distance I would think it would do just fine. Use Hardware Schedualing.

900 works great through trees here in Texas. 900 seems to be rock solid in rural areas, close to interstates where much “other” noise is present they do not seem to work as well. As of today I would not use hardware scheduling - I was initially but reverted back to software due to huge numbers of re-connects.

After reviewing the issues with HS… I take that back! Some of our clients have over 10,000 reregisters.

natek,

I am in Southeast Texas at the bottom of an area known as the BIG THICKET. I am VERY used to dealing with trees. Maybe my idea of “lots of trees” is exaggerated, b/c I keep reading how these guys can shoot through “lots of trees” w/ no problem. The truth of the matter is that the results vary from site to site.

You might want to consider going higher with either or both of the radios, if possible.

Our situation was a bit different, since the slope of the line between our radios was steeper (and the receiving radio was about 15ft from the ground), but here is an example of our results when going higher at the transmit point:

Our trees range from ~60-90ft (70ft avg). At 110 ft we were lucky to register at 1.5 mi. At 150 ft, I’ve registered up to ~4.2 mi.

But, again, as I’ve said, the results vary from site to site. I’ve been at 1.3 mi and registered with roughly the same jitter and signal strength (yes, I used the same test SM with the same AP).

I don’t mean to put a damper on the other posts. I just mean to be realistic, so that you can make an informed decision.

Good luck!