How well would the Canopy 900 mhz connectorized access point work with a 5 DB antenna do in the following scenario:
6 miles from the base station to the subscriber, passing through some trees (a single line of trees near the base station and then the tops of several lines of trees closer to the subscriber)… A 13db Yagi antenna on the subscriber side
Does anyone have any installs in a (somewhat) urban environment with that kind of distance going through some trees in the 900 mhz band? How reliable are they?
We are having some trouble finding tower/roof space in the area we wish to provide service to, however we have an existing POP 6 miles away…
Thanks.
natek,
You shouldn’t have a problem in my opinion. We have rezi’s 10-15 miles out with NO LOS and some heavy trees. Some we use yagi’s on, and others we don’t. Our 900 AP is sectorized 120.
Z
Same here,
We strive to keep land forms out of the fresnel zone. With that, we have found that 900 eq with high gain yagis have considerable tree peneration power.
YMMV, of course.
natek wrote: How well would the Canopy 900 mhz connectorized access point work with a 5 DB antenna do in the following scenario:
6 miles from the base station to the subscriber, passing through some trees (a single line of trees near the base station and then the tops of several lines of trees closer to the subscriber).. A 13db Yagi antenna on the subscriber side
Does anyone have any installs in a (somewhat) urban environment with that kind of distance going through some trees in the 900 mhz band? How reliable are they?
We are having some trouble finding tower/roof space in the area we wish to provide service to, however we have an existing POP 6 miles away..
Thanks.
It is impossible to give you a definate "Yes" or "No" answer.
Ex: I have a 7.7 mile link. The customer is on a hill overlooking a large open field. The shot then crosses a couple of miles of water. The link is reliable.
Ex: I have a link 1.56 miles. The customer is down in the woods. The link is unreliable and the signal strength is LESS than on the first link.
"Some trees" means one thing in Mich and something very different in Oklahoma or Virginia.
I have observed that in Virginia where the average tree height is about 70' and the tree density is some of the highest on the planet that I can reliably penetrate about 1/2 mile of trees 100% of the time. This squares with the physics of RF absorbtion which suggests that vegetation costs about 10 dB per 100 meters at 900 MHz. That said, even here, a mile long shot probably will not have half a mile of trees in it. Therefore we have found that when we are doing trees and have an NLOS shot in our area we can expect about 1.5 miles of range.
For example. I only *just* got back from a test at 2.14 miles, NLOS (some trees) which showed a received signal of about -80 dBm only if I put the (17 dBi Yagi) antenna at 40'.
-m-
My situation is such that the closest I get is 3 miles extending out to 25 miles. Generally I have LOS however is some instances I need to go through trees. In several cases the customer is beyond 10 miles.
The Connectorized 900 with a 13dBi Yagi works great but is not the end all solution. sometimes ya just gotta install it and see what happens.
Jerry Richardson
airCloud Communications
Don’t want to sound stupid, but what is a Yagi?
Just type in 13 dbi yagi antenna in google, you’ll find pics. We use Yagi’s or “squirrel” antenna’s because some offer higher gain and a more focused beamwidth. This helps cut down jitter, correct?
A Yagi is a highly directional antenna design. Gain can range from 9dB to 18dB.
I will only use a higher gain antenna as a last resort and even then with hesitation. The idea in any RF network is to use the lowest amount of energy to establish a link with adequate margin.
I would discourage anyone using them in an attempt to lower jitter unless all other possibilities have been exhausted such as elevationg the antenna, etc.