/3.1GHz_ground_PATHSS

Example Ground Based System Calculation

Primary LanguageMATLAB

Example code to show the ground-based calculation.

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IMPORTANT: THIS IS NOT THE CODE BEING USED BY DOD IN THE PATHSS STUDY Note: Some things have been simplified for understanding to the reader and to decrease the computational time. The simplifications are noted. The simplifications do not result in a large delta-dB.

Note that ITM is being used, instead of TIREM. To run TIREM, an additional matlab toolbox and TIREM license need to be purchased. To remove the variable of different terrain databases, a 3 arc-second database is available. In most cases, this simplification to a lower resolution terrain database results in a minimum delta-db difference.

Note: Some input parameters are placeholders and do not reflect the input parameters used in the DoD Pathss Study. Placeholder values try to provide a close-enough parameter to illustrate the analysis methodology.

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To initialize a simulation, run the file "initialize_sim_folder_ground_based_rev4_github_check.m"

This will create a simulation folder "Rev104" that has a Fort Sill Example. (This might be hard to run on a desktop computer.)

A more simplified simulation can be done by running the file "initialize_sim_folder_ground_based_rev4_github_check_slim.m"

This will create the simulation folder "Rev105" that has a Fort Sill Example.

Then run the file "init_run_sim_folder_ground_based_rev1_github_check.m"

This will perform the calculation.

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Military Installation Information is Publicly Available:

https://catalog.data.gov/dataset/tiger-line-shapefile-2019-nation-u-s-military-installation-national-shapefile

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The simulation will output Excel files that contain all the Link Budget information, so that the calculations can be checked.

For Example: to check the power received (from each Base Station to the Federal System):

[Column T (FtSill_GB1_Point1_Link_Budget.xlsx)] – [Federal Antenna Loss (FtSill_GB1_Point1_Fed_Azi_Ant_Loss.xlsx)] = [(FtSill_GB1_Point1_Pr_dBm_Azi.xlsx)]

In this example, there are 240 azimuths that the federal system is pointing. (0-360 with a 1.5 degreee step size.)

To calculate the aggregate interferece, for each azimuth, in [FtSill_GB1_Point1_Pr_dBm_Azi.xlsx], the column "IH", a "1" indicates that the Base Station will be be turned-off. A "0" indicates that a Base Station can transmit.

Copy the sheet, cut the rows of Base Stations that need to be turned off, convert from dBm to Watts, sum each column (which is a discrete azimuth), and convert back to dBm.

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There is an option to run the simulation with the parallel toolbox. (If you have it.)

https://www.mathworks.com/products/parallel-computing.html

The "parallel" functions relate to the simulation points for a specific location.

For example, if a server has 24 cores, but there are only 10 protection points for a specific location, only 10 cores will be used.

Parallel functions include: Pathloss, Movelist, Movelist with Mitigation, and Aggregate Check.

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At this time, the Mapping Toolbox is needed to run the matlab code.

https://www.mathworks.com/products/mapping.html

I'm trying to remove this dependency.

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To run ITM (propagation model) you'll need to download some files (6GBs: Too big to upload here.)

https://sfc.doc.gov/w/f-4209b4bd-c19b-41aa-b8ba-a9d10c453fe3

(Contant nlasorte@ntia.gov if you can't access the terrain database files.)

(Keeping the same terrain database removes one factor that causes differences between the results.)

(Place all the files from the Terrain Folder ("USGS") to the following path --> C:\USGS

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Another way to calculate path loss with ITM is through the Matlab Longley-Rice propagation model. (This option will be added soon.)

https://www.mathworks.com/help/antenna/ref/rfprop.longleyrice.html

Note: You will need the Antenna Toolbox.

https://www.mathworks.com/products/antenna.html

(Note that this uses the Matlab Terrain Database --> gmted2010)

https://www.mathworks.com/help/map/access-basemaps-terrain-geographic-globe.html

By default, the geographic globe uses terrain data hosted by MathWorks and derived from the GMTED2010 model by the USGS and NGA. You need an active internet connection to access this terrain data, and you cannot download it.

TIREM can also be calculated through Matlab.

https://www.mathworks.com/help/antenna/ref/rfprop.tirem.html

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If you don't have the Parallel Toolbox, you can still leverage the parallel function on a server with Matlab Runtime.

https://www.mathworks.com/products/compiler/matlab-runtime.html

Download the R2022b (9.13) release and install on your machine.

The app is "ground_3GHz_rev1.exe" (For this version of the App you will still need the Terrain Database downloaded, but no internet connection needed.)

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If you can't download the ITM code and Terrain Database (6GB) and don't have the antenna toolbox, there is a matlab runtime version available that allows you to run the analysis. (This option will be added soon.)

https://www.mathworks.com/products/compiler/matlab-runtime.html

Download the R2022b (9.13) release and install on your machine.

When you run the analysis, you will still need an active internet connection to access the Matlab terrain data.

In this case, a basic version of Matlab is only needed to initalize the simulation parameters.

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Prerequisites for the App

Verify that MATLAB Runtime(R2022b) is installed. If not, you can run the MATLAB Runtime installer. To find its location, enter

>>mcrinstaller

at the MATLAB prompt. NOTE: You will need administrator rights to run the MATLAB Runtime installer.

Alternatively, download and install the Windows version of the MATLAB Runtime for R2022b from the following link on the MathWorks website:

https://www.mathworks.com/products/compiler/mcr/index.html

For more information about the MATLAB Runtime and the MATLAB Runtime installer, see "Distribute Applications" in the MATLAB Compiler documentation
in the MathWorks Documentation Center.

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For the shipborne example, use: https://github.com/nicklasorte/3.1GHz_ground/blob/main/initialize_sim_folder_shipborne_rev2_clean_up.m

This file will initialize set of folders. In this example, it’s just one point (#1750), in the ocean, 10km off shore, near Norfolk. The same code that is used to run the ground based systems is also used for the shipborne systems. Just point the code at the “Rev###” folder. The outputs are the same, with the excel spread sheets and figure.

Any set of points, 10km off shore, can be chosen. (Similar to the CBRS DPAs.) The CBRS ports, like Norfolk, San Diego, etc, are also included and run the same way. To select which points to simulate, change the code on lines 140-142.