Atoll 3.1.2 Model Calibration Guide E1

8/11/2019 Atoll 3.1.2 Model Calibration Guide E1

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v e r s i o n 3.1.2

AT312_MCG_E1

Model Calibration Guide


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Atoll 3.1.2 Model Calibration Guide

Atoll 3.1.2 Model Calibration Guide Release AT312_MCG_E1

Copyright 1997 - 2012 by Forsk

The software described in this document is provided under a licence agreement. The software may only be used or copiedunder the terms and conditions of the licence agreement. No part of this document may be copied, reproduced or distributedin any form without prior authorisation from Forsk.

The product or brand names mentioned in this document are trademarks or registered trademarks of their respective regis-tering parties.

IntroductionTo find an accurate propagation model for determining path losses is a leading issue when planning a mobile radio network.Two strategies for predicting propagation losses are in use these days. One of these strategies is to derive an empirical prop-agation model from measurement data, and the other is to use a deterministic propagation model. Atolls Standard Propaga-tion Model is a macrocell propagation model based on empirical formulas and a set of parameters.

When Atoll is installed, the SPM and Hata model parameters are set to their default values. However, they can be adjusted totune the propagation model according to actual propagation conditions. This calibration process of the Standard Propagationand Hata Models facilitates improving the reliability of path loss and, hence, coverage predictions.

This guide describes the way to import and manage the necessary measurement data. It also indicates the calibration methodand the steps to calibrating the SPM and Hata models, from planning the CW measurement surveys to obtaining the finalpropagation model. The resulting tuned propagation model is directly usable in Atoll as an additional model.


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Table of Contents

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2 Standard Propagation Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.1 SPM Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.2 The Correspondence Between the SPM and Hata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132.2.1 Hata Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132.2.2 Correspondence Between Hata and SPM Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.2.2.1 Reducing the Hata and SPM Equations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142.2.2.2 Equating the Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.2.3 Typical SPM Parameter Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2.3 Making Calculations in Atoll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152.3.1 Visibility and Distance Between Transmitter and Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152.3.2 Effective Transmitter Antenna Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2.3.2.1 Height Above Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162.3.2.2 Height Above Average Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162.3.2.3 Slope at Receiver Between 0 and Minimum Distance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162.3.2.4 Spot Ht. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162.3.2.5 Absolute Spot Ht. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162.3.2.6 Enhanced Slope at Receiver. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

2.3.3 Effective Receiver Antenna Height. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192.3.4 Correction for Hilly Regions in Case of LOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192.3.5 Diffraction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202.3.6 Losses Due to Clutter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202.3.7 Recommendations for Using Clutter with the SPM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

3 Collecting CW Measurement Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

3.1 Before You Start. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273.1.1 Geographic Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273.1.2 Measurement Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

3.2 Guidelines for CW Measurement Surveys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283.2.1 Selecting Base Stations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283.2.2 Planning the Survey Routes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293.2.3 Radio Guidelines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293.2.4 Additional Deliverable Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

4 The Model Calibration Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

4.1 Setting Up Your Calibration Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334.1.1 Creating an Atoll Calibration Document. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

4.1.1.1 Setting Coordinates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344.1.1.2 Importing Geo Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

4.1.2 Importing CW Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344.1.2.1 Importing a CW Measurement Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354.1.2.2 Importing Several CW Measurement Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364.1.2.3 Creating a CW Measurement Import Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 384.1.2.4 Defining the Display of CW Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

4.1.3 Verifying the Correspondence Between Geo and Measurement Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424.1.4 Filtering Measurement Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

4.1.4.1 Filtering on Clutter Classes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

4.1.4.2 Signal and Distance Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454.1.4.2.1 Typical Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 464.1.4.2.2 Using Manual Filtering on CW Points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 464.1.4.2.3 Creating an Advanced Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 474.1.4.2.4 Using the Filtering Assistant on CW Measurement Points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47


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4.1.4.3 Filtering by Geo Data Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 504.1.4.3.1 About Diffraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 504.1.4.3.2 About Specific Sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 504.1.4.3.3 About Potentially Invalid Measurement Levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514.1.4.3.4 Deleting a Selection of Measurement Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534.1.4.3.5 Using Filtering Zones on CW Measurement Points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544.1.4.3.6 Filtering by Angle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

4.1.5 Selecting Base Stations for Calibration and for Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

4.2 Calibrating the SPM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 564.2.1 Quality Targets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 564.2.2 Setting Initial Parameters in the SPM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

4.2.2.1 Parameters Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 564.2.2.2 Clutter Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

4.2.3 Running the SPM Calibration Process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 594.2.3.1 The Automatic Calibration Wizard. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 614.2.3.2 The Assisted Calibration Wizard. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

4.3 Calibrating Hata Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 634.3.1 Quality Targets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 644.3.2 Setting Initial Parameters in the Hata Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

4.3.2.1 Defining General Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

4.3.2.2 Selecting an Environment Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 654.3.2.3 Creating or Modifying Environment Formulas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 654.3.3 Running the Hata Calibration Process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

4.4 Analysing the Calibrated Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

4.5 Finalising the Settings of the Calibrated SPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

4.6 Deploying the Calibrated Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 754.6.1 Copying a Calibrated Model to Another Document. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 764.6.2 Deploying a Calibrated Model to Transmitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

5 Additional CW Measurement Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81

5.1 Creating a CW Measurement Path. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

5.2 Drawing a CW Measurement Path. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

5.3 Merging Measurement Paths for a Same Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

5.4 Smoothing Measurements to Reduce the Fading Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

5.5 Calculating Best Servers Along a CW Measurement Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 835.5.1 Adding Transmitters to a CW Measurement Path. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 845.5.2 Selecting the Propagation Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 845.5.3 Setting the Display to Best Server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 845.5.4 Calculating Signal Levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 845.5.5 Displaying Statistics Over a Measurement Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 845.5.6 Displaying Statistics Over Several Measurement Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

6 Survey Site Form . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .89


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Chapter 1

IntroductionThis chapter presents the Model Calibration Guide .


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Atoll 3.1.2 Model Calibration GuideChapter 1: Introduction


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Atoll 3.1.2 Model Calibration GuideAT312_MCG_E1

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1 IntroductionThe Model Calibration Guide is intended for project managers or anyone else responsible for calibrating the Standard Propa-gation Model (SPM) or Hata Models (Okumura-Hata and Cost-Hata) using continuous wave (CW) measurements. To that end,the Model Calibration Guide presents you with detailed information on the SPM and guides you through the calibrationprocess of both types of models.

It is not the intention of this guide to explain in detail how to use Atoll , nor to provide detailed technical information aboutAtoll projects. For information on using Atoll , see the User Manual and the Administrator Manual . For detailed technical infor-mation about Atoll projects, see the Technical Reference Guide .

The Model Calibration Guide follows the calibration process from planning the CW survey, to incorporating the CW measure-ments into Atoll , to using the CW measurements to calibrate the SPM.

If this is the first time you are calibrating Atoll s SPM, you might want to read though the entire Model Calibration Guide . Or,you can go directly to the chapter that interests you:

The Standard Propagation Model: This chapter describes the Atoll SPM, including the SPM formula and the Hata for-mula on which the SPM is based. Other aspects described include, typical SPM parameter values, making calculationsusing the SPM, and recommendations for using the SPM.

CW Measurements: This chapter explains the role of CW measurements in calibrating the SPM. It also gives you infor-mation that will help you successfully plan and carry out a CW survey.

The Model Calibration Process: This chapter explains the entire calibration process for any model type:

- Creating an Atoll document that to use to calibrate a propagation model.- Importing the measurements from the CW survey into the new Atoll document.- Filtering the imported CW measurements to ensure that you are using only the most relevant data.- Calibrating the SPM or Hata Models, using either the automatic or the assisted method (SPM only).- Finalising and deploying the calibrated model.

This guide also contains an appendix with additional information on using CW measurements in Atoll .


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Chapter 2

Standard PropagationModel

This chapter provides information on theStandard Propagation Model.

In this chapter, the following are explained:

"SPM Formula" on page 13

"The Correspondence Between the SPM and Hata" onpage 13

"Making Calculations in Atoll" on page 15


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Atoll 3.1.2 Model Calibration GuideChapter 2: Standard Propagation Model


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2 Standard Propagation ModelThe Standard Propagation Model is a propagation model based on the Hata formulas and is suited for predictions in the 150to 3500 MHz band over long distances (from one to 20 km). It is best suited to GSM 900/1800, UMTS, CDMA2000, WiMAX,Wi-Fi, and LTE radio technologies.

2.1 SPM FormulaThe Standard Propagation Model is based on the following formula:

where:

received power (dBm)

transmitted power (EIRP) (dBm)

constant offset (dB)

multiplying factor for

distance between the receiver and the transmitter (m)


effective height of the transmitter antenna (m)

multiplying factor for diffraction calculation. must be a positive number.

losses due to diffraction over an obstructed path (dB)




effective height of the receiver antenna (i.e., mobile antenna height) (m)


average of weighted losses due to clutter corrective factor for hilly regions (=0 in case of NLOS)

2.2 The Correspondence Between the SPM and HataIn this section, the Hata formula on which the SPM is based is described. The correspondence between the SPM and the Hataformula is also described.

2.2.1 Hata FormulaThe SPM formula is derived from the basic Hata formula, which is:

where,

, , , , , Hata parameters

Frequency in MHz Effective BS antenna height in metres

Distance in kilometres Mobile antenna height correction function

Clutter correction function

P R P Tx K 1 K 2 Log d ( ) K 3 Log H Tx eff ( ) K 4 DiffractionLoss K 5 Log d ( ) Log H Tx eff ( )

+ + + + +

K 6 H Rx eff K 7 Log H Rx eff ( ) K clutter f clutter ( ) K hil l LOS,+ + +

=

P R

P Tx

K 1

K 2 Log d ( )d

K 3 Log H Tx eff ( )

H Tx eff

K 4 K 4

DiffractionLoss

K 5 Log d ( ) Log H Tx eff ( )

K 6 H Rx eff

K 7 Log H Rx eff ( )

H Rx eff

K clutter f clutter ( )

f clutter ( )K hil l LOS,

L A1 A2 f log A 3 h BSlog B 1 B 2 h BSlog B 3 h BS+ +( ) d log a h m( ) C clutter + + +=

A 1 A2 A3 B 1 B 2 B 3

f

h BS

d

a h m( )

C clutter


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Typical values for Hata model parameters are:

A1 = 69.55 for 900 MHz, A 1 = 46.30 for 1800 MHz A2 = 26.16 for 900 MHz, A 2 = 33.90 for 1800 MHz A3 = 13.82 B 1 = 44.90 B 2 = 6.55 B 3 = 0

2.2.2 Correspondence Between Hata and SPM ParametersIn this section, the Hata and SPM parameters are compared.

2.2.2.1 Reducing the Hata and SPM EquationsBecause you are only dealing with standard formulas, you can ignore the influence of diffraction and clutter correction. It is

understood that, with appropriate settings of A 1 and K 1, and taking only one clutter class into consideration, you can set theclutter correction factor to zero without reducing the validity of the following equations.

The correction function for mobile antenna height can also be ignored. The mobile antenna height correction factor is zerowhen h m=1.5 m, and has negligible values for realistic mobile antenna heights. The B 3 parameter is usually not used and canbe considered to be 0.

The Hata formula can now be simplified to:

where:

, , , , , Hata parameters

Frequency in MHz Effective BS antenna height in metres

Distance in kilometres

The SPM formula can be simplified to:

If you rewrite the Hata equation using with the distance in metres as in the SPM formula, you get:

This leads to the following equation:

2.2.2.2 Equating the CoefficientsIf you compare the simplified Hata and SPM equations, you see the following correspondence between the coefficients:

The distance in this equation is given in kilometres as opposed to the SPM, where thedistance is given in metres.

L A1 A2 f log A 3 h BSlog B 1 B 2 h BSlog +( ) d log + + +=

A 1 A2 A3 B 1 B 2

f

h BS

d

L K 1 K 2 d log K 3 h BSlog K 5 d log h BSlog K 6 h meff K 7 Log h meff ( )+ + + + +=

L A1 A2 f log A 3 h BSlog B 1 B 2 h BSlog +( ) d

1000 -------------log + + +=

L A1 A2 f log 3 B 1 A3 3 B 2 ( ) h BSlog B 1 d log B 2 h BSlog d log ++ + +=

K 1 A1 A2 f log 3 B 1 +=

K 2 B 1=

K 3 A3 3 B 2 =

K 5 B 2 =

K 6 0 =

K 7 0 =


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2.2.3 Typical SPM Parameter ValuesBy referring to typical Hata parameters, typical SPM parameters can be determined as the following:

K1 depends on the frequency, some examples are:

2.3 Making Calculations in AtollIn this section, the different aspects of making calculations using the SPM are explained in detail:

"Visibility and Distance Between Transmitter and Receiver" on page 15

"Effective Transmitter Antenna Height" on page 15 "Effective Receiver Antenna Height" on page 19 "Correction for Hilly Regions in Case of LOS" on page 19 "Diffraction" on page 20 "Losses Due to Clutter" on page 20 "Recommendations for Using Clutter with the SPM" on page 21 .

2.3.1 Visibility and Distance Between Transmitter and ReceiverFor each calculation pixel, Atoll determines:

The distance between the transmitter and the receiver.

- If the transmitter-receiver distance is less than the maximum user-defined distance (the break distance), the

receiver is considered to be near the transmitter. Atoll will use the set of values called Near transmitter.- If the transmitter-receiver distance is greater than the maximum distance, the receiver is considered far from the

transmitter. Atoll will use the set of values called Far from transmitter.

Whether the receiver is in the transmitter line of sight or not.

- If the receiver is in the transmitter line of sight, Atoll will take into account the set of values (K 1, K2)LOS. The LOSis defined by no obstruction along the direct ray between the transmitter and the receiver.

- If the receiver is not in the transmitter line of sight, Atoll will use the set of values (K 1, K2)NLOS.

2.3.2 Effective Transmitter Antenna HeightThe effective transmitter antenna height ( HTxeff ) can be calculated using one of six different methods:

"Height Above Ground" on page 16 "Height Above Average Profile" on page 16 "Slope at Receiver Between 0 and Minimum Distance" on page 16 "Spot Ht" on page 16 "Absolute Spot Ht" on page 16

Project type Frequency (MHz) K 1

GSM 900 935 12.5

GSM 1800 1805 22

GSM 1900 1930 23

UMTS 2045 a

a. 2045 MHz = (2140 + 1950)/2. It is the average of the downlink and uplink centre frequencies of the band.

23.8

1xRTT 1900 23

WiMAX and Wi-Fi

2300 25.6

2500 26.8

2700 27.9

3300 30.9

3500 31.7

K 2 44.90 =

K 3 5.83=

K 5 6.55 =


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"Enhanced Slope at Receiver" on page 17 .

2.3.2.1 Height Above GroundThe transmitter antenna height is its height above the ground ( HTx in metres).

2.3.2.2 Height Above Average ProfileThe transmitter antenna height is determined relative to an average ground height calculated along the profile between atransmitter and a receiver. The profile length depends on the minimum distance and maximum distance values and is limitedby the transmitter and receiver locations. Distance min. and Distance max are minimum and maximum distances from thetransmitter respectively.

where,

is the ground height (ground elevation) above sea level at transmitter (m).

is the average ground height above sea level along the profile (m).

2.3.2.3 Slope at Receiver Between 0 and Minimum DistanceThe transmitter antenna height is calculated using the ground slope at the receiver.

where,

is the ground height (ground elevation) above sea level at the receiver (m).

is the ground slope calculated over a user-defined distance (Distance min.). In this case, Distance min. is the dis-tance from the receiver.

2.3.2.4 Spot H t If then,

If then,

2.3.2.5 Absolute Spot H t

These values are only used in the last two methods and have different meanings for each method.

H Txeff H Tx =

If the profile is not located between the transmitter and the receiver, HTxeff equals HTx only.

H Txeff H Tx H 0T x H 0 ( )+=

H 0T x

H 0

If , Atoll uses 20 m in calculations.

If , Atoll takes 200 m.

H Txeff H Tx H 0T x +( ) H 0R x K d +=

H 0R x

K

H Txeff 20m

H 0T x H 0R x > H Txeff H Tx H 0T x H 0R x ( )+=

H 0T x H 0R x H Txeff H Tx =

Distance min. and distance max are set to 3000 and 15000 m following ITU recommenda-tions (low frequency broadcast f < 500 Mhz) and to 0 and 15000 m following Okumurarecommendations (high frequency mobile telephony).

H Txeff H Tx H 0T x H 0R x +=


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2.3.2.6 Enhanced Slope at ReceiverAtoll offers a new method called Enhanced slope at receiver to evaluate the effective transmitter antenna height.

The X-axis and Y-axis represent positions and heights respectively. It is assumed that the X-axis is oriented from the transmit-ter (origin) towards the receiver.

This calculation is made in several steps:

1. Atoll determines line of sight between the transmitter and the receiver.

The LOS line equation is:

where,

- is the receiver antenna height above the ground (m).

- i is the point index.- Res is the profile resolution (distance between two points).

2. Atoll extracts the transmitter-receiver terrain profile.

3. Hills and mountains are already taken into account in diffraction calculations. Therefore, in order for them not to neg-atively influence the regression line calculation, Atoll filters the terrain profile.

Atoll calculates two filtered terrain profiles; one established from the transmitter and another from the receiver. Itdetermines the filtered height of every profile point. Profile points are evenly spaced on the basis of the profile reso-lution. To determine the filtered terrain height at a point, Atoll evaluates the ground slope between two points andcompares it with a threshold set to 0.05; where three cases are possible.

Some notations defined hereafter are used in next part.

- is the filtered height.

- is the original height. The original terrain height is determined from extracted ground profile.

When filtering starts from the transmitter:

Let us assume that

For each point, there are three different possibilities:

a. If and ,

Then,

b. If and

Then,

c. If

Figure 2.1: Enhanced Slope at Receiver

Los i ( ) H 0T x H Tx +( ) H 0T x H Tx +( ) H 0R x H Rx +( ) ( )

d ------------------------------------------------------------------------------- Res i ( ) =

H Rx

H filt

H orig

H f i lt T x Tx ( ) H orig Tx ( )=

H orig i ( ) H orig i 1 ( )> H orig i ( ) H orig i 1 ( )

Re s------------------------------------------------------ 0.05

H f il t T x i ( ) H f i lt T x i 1 ( ) H orig i ( ) H orig i 1 ( ) ( )+=

H orig i ( ) H orig i 1 ( )> H orig i ( ) H orig i 1 ( )

Re s

------------------------------------------------------ 0.05 >

H f il t T x i ( ) H f i lt T x i 1 ( )=

H orig i ( ) H orig i 1 ( )


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Then,

If, as well,

Then,

When filtering starts from the receiver:

Let us assume that

For each point, there are three different possibilities:

a. If and ,

Then,

b. If and

Then,

c. If

Then,

If, as well,

Then,

Then, for every point of profile, Atoll compares the two filtered heights and chooses the higher one.

4. Atoll determines the influence area, R. It corresponds to the distance from receiver at which the original terrain profileplus 30 metres intersects the LOS for the first time (when beginning from transmitter).

The influence area must satisfy additional conditions:

- ,- ,- R must contain at least three pixels.

5. Atoll performs a linear regression on the filtered profile within R in order to determine a regression line.

The regression line equation is:

and

where,

i is the point index. Only points within R are taken into account.

d(i) is the distance between i and the transmitter (m).

Then, Atoll extends the regression line to the transmitter location. Its equation is:

When several influence areas are possible, Atoll chooses the highest one. If d < 3000m, R = d .

H f i lt T x i ( ) H f il t T x i 1 ( )=

H f i l t i ( ) H orig i ( )>

H f i lt T x i ( ) H orig i ( )=

H filt Rx ( ) H orig Rx ( )=

H orig i ( ) H orig i 1+( )> H orig i ( ) H orig i 1+( )

Re s------------------------------------------------------- 0.05

H f i lt R x i ( ) H f il t R x i 1+( ) H orig i ( ) H orig i 1+( ) ( )+=

H orig i ( ) H orig i 1+( )> H orig i ( ) H orig i 1+( )

Re s------------------------------------------------------- 0.05 >

H f i lt R x i ( ) H f il t R x i 1+( )=

H orig i ( ) H orig i 1+( )

H f i lt R x i ( ) H f il t R x i 1+( )=

H f i l t i ( ) H orig i ( )>

H f i lt R x i ( ) H orig i ( )=

H filt i ( ) max H f i lt T x i ( ) H f i lt R x i ( ),( )=

R 3000mR 0.01 d

y ax b+=

a

d i ( ) d m ( ) H f i l t i ( ) H m ( )i

d i ( ) d m ( )2

------------------------------------------------------------------------=

b H m ad m =

H m1n--- H filt i ( )

i

=

d m d R

2 ---- =


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6. Then, Atoll calculates the effective transmitter antenna height, (m).

If HTxeff is less than 20 m, Atoll recalculates it with a new influence area, which begins at the transmitter.

7. If is less than 20 m (or negative), Atoll evaluates the path loss using and applies a correction

factor.

Therefore, if ,

where,

2.3.3 Effective Receiver Antenna Height

where,

is the height of the receiver antenna above the ground (m).

is the ground height (ground elevation) above sea level at the receiver (m).

is the ground height (ground elevation) above sea level at the transmitter (m).

2.3.4 Correction for Hilly Regions in Case of LOSAn optional corrective term enables Atoll to correct path loss for hilly regions when the transmitter and the receiver are inline of sight.

Therefore, if the receiver is in the transmitter line of sight and the hilly terrain correction option has been selected:

When the transmitter and the receiver are not in line of sight, the path loss formula is:

is determined in three steps. Influence area, R, and regression line are assumed to be available.

1. For every profile point within the influence area, Atoll calculates height deviation between the original terrain profileand regression line. Then, it sorts points according to the deviation and draws two lines (parallel to the regression line),one which is exceeded by 10% of the profile points and the other one by 90%.

2. Atoll evaluates the terrain roughness, h; it is the distance between the two lines.

3. Atoll calculates .

If ,

If , 1000m will be used in calculations.

If is less than 20 m, an additional correction is taken into account (step 7).

regr i ( ) a i Res( ) b+=

H Txeff

H Txeff H 0T x H Tx b +

1 a 2 +--------------------------------------=

H Txeff 1000m>

H Txeff

H Txeff H Txeff 20m=

H Txeff 20m

Documents

Atoll 3.1.2 Model Calibration Guide E1