a week ago
I am in need of connecting two buildings that are just over 4000 ft (1.2 km) from each other. The line of sight is NOT perfectly clear. There do not appear to be any major obstructions, i.e no tall building etc, just mostly some trees and a few roof peaks. The connection is not likely to need heavy bandwidth. Mostly to tie into active directory login and general file sharing. No video or minimal video on occasion.
My thoughts are that I should use one of the units capaple of 900 mhz to cut through the clutter. I'd like to try avoid having to put up raised antenna mast if possible. Both buildings are already 2 1/2 story in height. The RocketM and NanoStationM both appear to be possibilities, but I have never used either up to date. Am I headed in the right direction? Can anyone suggest for or against a specific setup?
I've looked at a few other similar posts in the forum, but most seem to have extremely short distances- so I can't exactly find a comparable situation at the moment.
Thank you in advance!
first ot all, 4000 ft is not exactly a "short distance", I just installed 100ft PtP link
my rule: no clear line of sight, no link
trees are the worst, even if they look like the least problem - they move from the wind and they contain water
finally - lower frequencies penetrate obstacles better, but lower frequencies also have bigger Fresnel zone, actually I don't know which one is more important
Thanks for the thoughts so far. Short distance is obviously relative. I understand your statements, but if I was talking about 100 ft I would just use a regular access point. When I see the specs on some of the units being rated for 15 to 20 km, my 4000 ft is just over 1 km- hence my assessment as short distance.
So far it looks like I may be able to attain a direct line of sight if I elevate one end approximately 15 feet. While I was hoping to avoid raising a pole mount on either end- I think a 15 to 20 ft rise to achieve direct LOS is better value than attempting to power through a few obstructions. I'm hoping to have some exact measurements tomorrow.
Yep, LOS always wins. Free-space path loss attenuation is a fraction of the attenuation of a tree or building. Use a smaller gain (or grid style) antenna at your elevated end to reduce wind load and make up the gain with a larger antenna at the other end.