Can anyone give me a ballpark loss for a 900 MHz signal, thru mixed hardwoods & pines, suburban area, of a 1/4 mile & a 1/2 mile path? Been getting spanked a bit (but spanking back a good amount) for a point to multipoint link. Link is working now, esp. at the 1/4 mile point, but over the 1/2 mile path, there's about 30 dB more loss.
Thanks!
propagation path
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kb4mdz
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Re: propagation path
Got the Free Space loss; looking for ballpark figures for going thru a suburban area of mixed hardwood & pines. 2 dB? 5?
Re: propagation path
Trees are 10 to 20 dB of loss per tree in the direct path. Loss depends on the size and density of the tree, and whether it's dormant or flushing.
Walls are 10db to infinity depending on materials. Grounded metallic structures don't pass rf, but some make leak in through windows or doorways. Wooden structures offer the least attenuation.
Walls are 10db to infinity depending on materials. Grounded metallic structures don't pass rf, but some make leak in through windows or doorways. Wooden structures offer the least attenuation.
Re: propagation path
When we were doing cellular 800 propagation, the number we used for "ground clutter" was always 20 db. Seemed to make things work so much better when it was plotted. Actually matched what we found when doing drive testing.
But you can use what ever number fits your location. Down here along the Gulf Coast, we had to deal with the long needle pine trees. The needles were almost resonant at the 850 MHz. range frequencies. Played heck with trying to get a signal to go very far.
But you can use what ever number fits your location. Down here along the Gulf Coast, we had to deal with the long needle pine trees. The needles were almost resonant at the 850 MHz. range frequencies. Played heck with trying to get a signal to go very far.