Need help estimating NLOS coverage from tower

Hi all!

I’m thinking of starting a “neighborhood” WISP – buying a dedicated connection, installing a tower, reselling to nearby houses.

I’m in an area with a lot of houses surrounded by trees, so LOS will be out of the question for a lot of people. Here is a drone video of the area. The drone is ~200 feet in the air, approximately the height of the tower I would install.

I’m wondering how 450 CBRS will work in my case. Am I likely to reach houses 1 mile, 2 miles, 3 miles out? What kind of speeds would I be able to provide to my subscribers?

I would appreciate any help on this!

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Hello Sir,

here are my recommendations:

  1. Take the GPS coordinates of where you will put your tower.
  2. Take GPS coordinates of the around 20 clients you might install in your area with hard line of sight from your tower.
  3. Put this into LINKPLanner and try to make a coverage study with the PMP 450m/450i AP 3.5 GHz. From LINKPlanner, you will be able to see how much capacity you would have to your clients. Do also share this file with Cambium Networks to assist you with the cnHeat tool in order to see how much foliage is affecting client links.
  4. There is also the LTE cnRanger in 2.5 GHz with better propagation into trees.
  5. PMP 450i 900 MHz can have much better propagation into trees

But, you need spectrum into 3.5 or 2.5 GHz and 900 MHz if you want to use them.

To know the real capacity this shall come from LINKPlanner file study and cnHeat study.
Let me know if you are used with LINKPlanner.

The other thing you can do is to connect with 3.5 GHz PMP 450m/450i the clients with NLOS or LOS and maybe build new small guyed towers that shall connect the others client with Non LOS from the first tower as a future plan.

Sincerely yours,

Niragira Olympe


LINKPlanner can help you get a general feel for the results, and cnHeat is a terrific tool if you do choose to go through with it. With cnHeat, the system will show you heatmaps which you can adjust with sliders to see what height you would need to obtain a target signal level.

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You would need to spend a bunch of time in LinkPlanner building out obstacles etc (for each PTMP link). cnHeat would be a better choice in my opinion (although it’s not free, but reasonably priced for a single tower in your situation)

Just my two cents, but go higher.
I would use 900mhz (pmp450i) and slant-45 (±45) antennas. 2.4, 3.5 and 5ghz will work well during winter but leafy trees tend to kill the short wave lengths. 900mhz is 31.5cm (13 inch) and goes through trees without too much difficulty.

Linkplaner and cnHeat are your best friends, just remember to model as many client links as possible. You should be able to get close to 10 miles (16km) but that depends on the antennas used. KP performance makes some nice performing 900mhz antennas that I can highly recommend.

You can do this with a couple APs but plan for four and use gps timing to allow frequency reuse with a single 20mhz channel. Not an officially approved configuration but as long as the APs are configured the same except for the sector id and ip addres. Make sure you place enough horizontal distance between AP antennas to ensure the back to back antennas are in each others back null. This is usually 2m to 3m but with 900mhz its closer to 4m. Best to put two antennas on the ground and see how far apart you need to be for the AP not to see a sm on the other antenna.

Congratulations on thinking about taking the plunge and becoming busier than you ever have been! Dont forget to get a copy of your local and federal regulations.