LinkPlanner Clutter

Hi all, I have a 6GHz deployment setup in linkplanner and I just dont know what to do about the clutter… on default the link planner shows my area of deployment as deciduous forest and the links to SM look like its going through a forest but it is not the case for the area in real time. So I put deciduous to 0ft and left light trees, which it is, and now my links show zero obstructions, any insight?

The purposed tower will be 300 meters from first part of the town, 600 meters from middle of town and 800 meters from the edge of town. So I just want to try and create as accurate as possible… how does 6ghz do with near line of sight/trees at those types of distances?

Link Planner treats clutter like it’s a wall. The resolution of the clutter is 30m/pixel, which means that a square approx. 100 ft x 100 ft will be painted with the most significant quality of the area…when its trees LP only knows the height by setting in the project configuration. What you can do to increase accuracy on PTP shots is to edit the clutter along the path, giving the correct classification, and the correct height (if you know that…if I need that kind of accuracy - to determine minimum mounting height, for example). I do 10 or more LP projects per week, and if I edit clutter once every 3 months or so, that is all.

802.11ax has mechanisms to deal with the multipath that going through trees causes. To add a bit more accuracy to a LP propagation simulation, if I know that trees are impacting my path, I normally use 140 dB/km as an attenuation factor for most trees in a boreal forest area. For example, if I measure 50m of tree obstruction on a particular path, the added attenuation is 50/1000 * 140dB, which calculates to 7dB or so added to the propagation loss if I’m shooting through the tops of the trees. If my SM is just above the ground, and my AP is just above the top of the trees, I might use 200 dB/km as the attenuation factor - it depends on the relationship between antenna heights and the actual clutter.

Let’s further the example. Let’s use a 10km path @ 6200 MHz. Free space loss is 128 dB. I’m impacted by my 50m of treetop attenuation, so my real propagation loss is 135 dB. In 6 GHz, my max EIRP is +36 dBm, minus my 135 dB propagation loss means my RSSI before antenna gain is -99 dBm. If my antenna gain is 25 dBi (assuming a Force 4625, for example), then I’d expect a max RSSI of -74 dBm at the SM. Let’s say LP calculates my rain fade at 8 dB for my rain zone. That means my average RSSI might be -82 dBm. Is that enough RSSI, and more importantly SNR above noise floor to pass the volume of traffic planned for this direction on the link?

I hope this helps!

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