PGM-A Technical Notes.pdf

8/21/2019 PGM-A Technical Notes.pdf

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Technical Note

Cover Page

PGM-A Propagation Model

The PGM-A propagation model emulates the Asset

propagation model and is intended to enable users to re-use

propagation models in PlanetEVthat have been tuned usingAsset. This propagation model is not distributed with

PlanetEVand is only available upon request.


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Copyright 20022006

Metapath Software International (US), Inc.

A Marconi Company

Notice

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(US), Inc., a Marconi company (MSI or Marconi) and may not be copied, transmitted, stored in

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consent of Marconi. Information contained in this document supersedes that found in any previous

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MARCONI MAKES NO WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING, WITHOUT

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PURPOSE, WITH RESPECT TO THIS DOCUMENT OR THE INFORMATION CONTAINED

HEREIN.

Trademark Acknowledgement

Marconi, Metapath, Ceer, PlanetNOVA, Ceos, Planet, and deciBel Planner are trademarks or

registered trademarks of the Marconi group of wireless telecommunication companies which include

MSI, Metapath Software International Limited, and Northwood Technologies, Inc. WaveSight is atrademark of Wavecall. This document may contain other trademarks, trade names, or service marks

of other organizations, each of which is the property of its respective owner.


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PGM-A Propagation ModelPGM-A Technical Note

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Introduction

The PGM-A propagation model enables customers migrating from Asset to

re-use their tuned Asset macrocell models within PlanetEV. The algorithms

used in the PGM-A propagation model are modified versions of those used inthe PGM propagation model included with PlanetEV. As you would do in

Asset, you can define model parameters (k-factors) that influence results.

Using the PGM-A propagation model, you will produce results that are

comparable to those achieved using Asset in the most common

implementations of the model. Results will not be precisely the same.

However, performance is very comparable to Asset.

Although it is typically recommended that you use PlanetEVmodels and tune

them using measurements, it can be a more cost effective approach to

replicate Asset models in PlanetEVusing the PGM-A model as there is no

need to retune models.

This document provides the information necessary to successfully use the

PGM-A propagation model, and it is intended for use during evaluation

periods or when Marconi Wireless implementation services are not being

used. This document explains how to add the PGM-A propagation model and

associated user documentation to PlanetEV, details some key differences

between the PGM and the PGM-A propagation models, and explains how to

edit the PGM-A propagation model.

Prerequisites to PGM-A propagation model use

In order to successfully use the PGM-A propagation model to migrate tuned

Asset macrocell models to PlanetEV, the following requirements must be met

before using the PGM-A propagation model:

1 Project data and site configurations must be converted for use in

PlanetEV.

The project must be set up to replicate the Asset project. It is imperative

that the site configuration, antenna data, and all related parameters are

The performance of prediction generation using the PGM-A model hasproven to be very similar to that of the original Asset predictions.

However, the performance is not guaranteed and use of this model is optional.

All efforts will be made to support this propagation model in the event of a

defect; however, it is distributed as an Add-on tool that is not part of the

standard software warranty.


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PGM-A Technical Note

identical to those in Asset. PlanetEVutilities are available to support this

effort. For more information, contact Technical Support.

2 The geodata (height and clutter data) must be the same files as those

available in Asset in order to achieve similar results.3 Clutter classes must have the same names or be mapped using the

PlanetEVClutter Property Assignment dialog box.

Adding the PGM-A propagation model and user documentation

to Planet EV

The PGM-A propagation model is not part of the standard PlanetEV

installation. As the model has a very specific purpose (i.e., supporting

customers migrating from Asset), it is only distributed to specific customers

or for specific projects. It is available upon request from Technical Support or

Product Management.

To add the PGM-A propagation model and userdocumentation to Planet EV

1 Copy the PGM-A.mdl to the PlanetEV/mdl folder.

2 Copy the PGMA.chm file to the PlanetEV/Help folder.

3 Copy the PGM-A Technical Notes.pdf file to the PlanetEV/Help/User

Guides folder.

Currently, there is no automated method of converting Asset model

data into Planet EVmodel (.dpm) files or related Clutter Property

Assignment (.cpa) files. This must be done manually.

In Asset, model parameters are saved in the Model-List001.XML file.This file provides quick access all model parameters (alternatively, you

can view model parameters in the Asset user interface).

Typically, the distribution and installation of this propagation model and

the conversion of Asset models will be part of a Planet EV

Implementation service. It is strongly recommended that customers make use

of these services for migration projects.


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Workflow for using the PGM-A propagation model

Step 1 Open the Model-List001.XML file generated using Asset.

The model name is listed in the ID column and is shown on

multiple lines (one line for each clutter class). K factors for amodel will be listed on several lines but the values will all be the

same.

Step 2 Edit PGM-A propagation model parameters replicating the Assetmodel. See Editing PGM-A propagation model parameters on

page 5.

Ensure that the model name is exactly the same as that used in

Asset.

Step 3 Create a Clutter Property Assignment (.cpa) file to associate withthe new model. See Creating a .cpa file for the PGM-A

propagation model on page 10.

Step 4 For every Asset model, repeat the steps of the workflow to createa model (.dpm) file in Planet EV.

Editing PGM-A propagation model parameters

The first step in the creation of a new propagation model is to edit model

parameters. Then, you need to create a clutter property assignment (.cpa) file

to associate with it.

To edit PGM-A propagation model parameters

1 Open a project in PlanetEV.

2 In the Project Datacategory, right-click Propagation Modelsand

choose New.

3 In the Propagation Model Typedialog box, choose PGM-Aand click

OK.

The Propagation Model Editor opens.


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4 On the Settingstab, in the Frequencybox, define the frequency as shown

in the FREQUENCY column of the Model-List001.XML file.

5 In the Receiver Heightbox, define the receiver height as shown in the

MOBILE-HEIGHT column of the Model-List001.XML file.

6 From the Earth Curvaturelist, choose one of the following options:

4/3 Earth Curvaturewhen the value in the EARTH-RADIUS

column of the Model-List001.XML file is approximately 8500.

Normal Earth Curvaturewhen the value in the

EARTH-RADIUS column of the Model-List001.XML file is

approximately 6400.

7 Click Edit.

The PGM-A Parameters dialog box opens.


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8 On the Generaltab, in the Model Typesection, choose one of the

following options:

1 piecethis type of model uses factors K1 to K7. Factors

K1 (near) and K2 (near) are not used to define a 1-piece model.

2 Piecethis type of model uses factors K1 to K7 as well as

K1 (near) and K2 (near).

9 If you chose the 2-piece model, in the Distancebox, define the distance

(in meters) at which to use the constants K1 (near) and K2 (near).

10 In the K Factorssection, define the K1 to K7 values as the K1 to K7

values in Model-List001.XML file or Asset GUI.

11 If you are using a 2-piece model, in the K1 (near)and the K2 (near)

boxes enter a value between -150 and 250.

12 Click the Path Cluttertab.


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13 If clutter through loss is used in the Asset model, enable the Enable the

Path Cluttercheck box and define the distance as the K12 value

contained in the Model-List001.XML file or Asset GUI.

14 Click the Diffractiontab.


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15 In the Knife-Edge Merging Distancebox, define the distance as K11 in

the Model-List001.XML file or Asset GUI.

16 Click the Effective Antenna Heighttab.

17 Choose one of the following options:

Absolutethis is the same as the Base Height algorithm inAsset.

Relativethis is the same as the Spot Height algorithm in

Asset.

Averagethis is the same as the Average Height algorithm in

Asset. You must define the ground level in the prediction area

when you chose this type.

Slopethis is the same as the Slope algorithm in Asset. You

must define the slope distance, the minimum height, and the

maximum height when you chose this type.

18 When you have finished editing the propagation model parameters, click

OK.

19 Create a .cpa file to associate with the model. See Creating a .cpa file for

the PGM-A propagation model onpage 10.


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Creating a .cpa file for the PGM-A propagation model

In order to create a new model, you must create a .cpa file to associate with it.

1 In the Propagation Model Editor, click the Clutter Propertiestab.

2 Click Edit CPA.

If your project uses clutter, clutter classes are automatically displayed in

the Clutter Property Assignment dialog box.

3 In the Clutter Property Assignmentdialog box, ensure that the clutter

classes contained in the Model-List001.XMLfile are listed in the

Reference Namebox.

4 Define the Clutter Absorption Lossfor each clutter class as contained in

the OFFSET column of the Model-List001.XMLfile.

5 Define the Through Clutter Lossfor each clutter class as contained in

the MOBILE-HEIGHT3 column of the Model-List001.XMLfile.

6 From the Filemenu, choose Save Asto save the .cpa file.

7 In the Save Asdialog box, in the File Namebox, type a name for the file

and click Save.

8 Click Close.

9 In the Propagation Model Editor, choose FileSaveto save the new

propagation model.


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10 In the Save Asdialog box, in the File Namebox, type the same name for

the propagation model as that used in Asset and click Save.

11 Click Close.

The new propagation model is added to the Propagation Models node inthe Project Data category of the Project Explorer.

For additional information on propagation models, or for information on

working with PlanetEV, see the PlanetEV User Guide.

Comparing the PGM and PGM-A propagation models

Both the Asset model and PGM model support two-piece models, where two

sets of slope and intercept and are defined. One set is used for near Tx

predictions (d < distance) and the second set for predictions (d > distance). Inthe PGM model, distance is entered in meters while in the Asset model,

distance is entered in km.

PGM propagation model

The received signal strength at the mobile is given by the following equation

in the PGM propagation model.

Equation 1.1 Received signal strength in the PGM propagation model

Where

is the receive power in dBm.

is the transmit power (ERP) in dBm.

is the constant offset in dB.

is the multiplying factor for log(d).

With the two-piece model, both and can be assigned two sets of values.

One set is used for d< distance and the other for d> distance, where distance is

the distance in meters away from the base site specified in the Model Editor.

is the multiplying factor for log( ). It compensates for gain due to antenna

height.

K1 K2

PRX

PTX

K1

K2

d( )log K3

Hef f

( )log K4

Di ff ract ion K5

Hef f

( ) d( )loglog

K6 Hmeff)( KCLUTTER

+ + + + +

+ +

=

PRX

PTX

K1

K2

K1 K2

K3 Hef f


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is the multiplying factor for diffraction calculation.

is the Okumura-Hata type of multiplying factor for .

is the correction factor for the mobile effective antenna height gain ( ).

d is the distance, in meters, of the receiver from the base site.

is the effective height of base site antenna from ground.

Diffraction is the value calculated for loss due to diffraction over an obstructed path.

The value produced is a negative number, so a positive multiplication factor, is

required.

is the gain in dB for the clutter type at the mobile position in Planet DMS. In

PlanetEV, represents a loss.

is the mobile effective antenna height.

PGM-A propagation model

In order to achieve similar results to those obtained using the Asset model, the

PGM-A propagation model received signal equation (Equation 1.1) was

modified. The following sections detail key mappings between the two

models:

K-factor mapping. See K-Factor mapping onpage 13.

effective transmit antenna height mapping. See Effectivereceive antenna heights mapping onpage 13.

clutter parameters. See Clutter parameters onpage 13.

diffraction loss calculations. See Diffraction loss calculations

onpage 14.

K4

K5 Hef f( ) d( )loglog

K6

K6H

ef f

Hef f

K4

KCLUTTER

KCLUTTER

Hmeff


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K-Factor mapping

K factors in the Asset propagation model can be mapped to those in the PGM

model as follows:

Where

The capital letter K indicates a K-factor in the PGM propagation model and

small letter k indicates a K-factor in the Asset model.

Effective receive antenna heights mapping

In Asset model, the height of Rx antenna is defined as the height of the mobile

above ground. However, in the PGM model, an effective Rx height is used, as

this typically leads to more accurate predictions.

Clutter parameters

The following table contains a comparison between the parameters in the

Asset model versus those in the PGM model.

In the mapping equation for K1, the k4(logHms) term is only valid if the

Rx height is defined globally and not per clutter. If the Rx height is

defined by clutter, then the Rx height must be set to zero.

Asset Model PGM

Offset-loss (dB) Clutter Absorption Loss

Height Clutter Height (m)

Separation (m) Clutter Separation

K1 k1 3k2 k4 Hms( )log+( )=

K2 k2pa=

K3 k5 3k6( )=

K4 k7=

K5 k6=

K6 k3=


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Diffraction loss calculations

In the Asset model, there are four methods for computing diffraction losses

due to radio wave propagation over obstacles. These methods include the

Bullington, Japanese Atlas, Deygout, and Epstein-Peterson methods. PGM

only includes a modified version of the Epstein-Peterson method for

computing losses due to diffraction, which is automatically balanced with a

Bullington algorithm, as a function of the profile characteristics; this method

provides more accuracy as it allows for an automated adaptation of the

algorithm for each predicted point. In this method, if there are more than three

knife edges between the Tx and Rx, the first two knife edges are fixed, but the

remaining knife edges are combined into the third knife edge. Both PGM andAsset models include an option for merging the distance of knife edges where

knife edges with a distance of less than the merging distance are represented

as a single knife edge.

Through-loss (dB) Through Clutter Loss is mapped to the Path

Clutter parameter in PGM via the following:

Through-loss Distance was mapped to PathClutter Distance

Function Coefficient was set to 1

Triangular Function type was selected

The Clutter Properties Assignment dialog box

was modified to include the Through-loss

parameter defined in the Asset model

Through-loss Distance

Asset Model PGM

Documents

PGM-A Technical Notes.pdf