atoll 2.8.1 model calibration guide

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AtollRF Planning & Optimisation Software

Measurements and Model

Calibration Guide

v e r s i o n 2.8.1

AT281_MCG_E0


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Measurements and Model Calibration Guide

© Forsk 2009 AT281_MCG_E0 3

Contact Information

Atoll 2.8.1 Measurements and Model Calibration Guide Release AT281_MCG_E0

© Copyright 1997 - 2009 by Forsk

The software described in this document is provided under a licence agreement. The software may only be used/copied

under the terms and conditions of the licence agreement. No part of this document may be copied, reproduced or

distributed in any form without prior authorisation from Forsk.

The product or brand names mentioned in this document are trademarks or registered trademarks of their respective

registering parties.

Introduction

To 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 propagation model from measurement data, and the other is to use a deterministic propagation model. Atoll’s

Standard Propagation 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

to tune the propagation model according to actual propagation conditions. This calibration process of the Standard

Propagation and 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

method and the steps to calibrating the SPM and Hata models, from planning the CW measurement surveys to obtaining

the final propagation model. The resulting tuned propagation model is directly usable in Atoll as an additional model.

Forsk (Head Office) 7 rue des Briquetiers

31700 Blagnac

France

www.forsk.com

[email protected]

[email protected]

+33 (0) 562 74 72 10

+33 (0) 562 74 72 25

+33 (0) 562 74 72 11

Web

Sales and pricing information

Technical support

General

Technical support

Fax

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Suite 3100

Chicago, IL 60606

USA

[email protected]

[email protected]

+1 312 674 4846

+1 888 GoAtoll (+1 888 462 8655)

+1 312 674 4847

Sales and pricing information

Technical support

General

Technical support

Fax

Forsk (China Office) Suite 302, 3/F, West Tower,

Jiadu Commercial Building,

No.66 Jianzhong Road,

Tianhe Hi-Tech Industrial Zone,

Guangzhou, 510665,

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+86 20 8553 8938

+86 20 8553 8285

+86 10 6513 4559

Web

Information and enquiries

Telephone

Fax (Guangzhou)

Fax (Beijing)


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Table of Contents

Table of Contents

1 Introduction ..................................................................................... 11

2 Standard Propagation Model .......................................................... 152.1 SPM Formula ......................................................................................................................................... 15

2.2 The Correspondence Between the SPM and Hata ................................................................................ 15

2.2.1 Hata Formula.................................................................................................................................... 15

2.2.2 Correspondence Between Hata and SPM Parameters .................................................................... 16

2.2.2.1 Reducing the Hata and SPM Equations ..................................................................................... 16

2.2.2.2 Equating the Coefficients............................................................................................................ 16

2.2.3 Typical SPM Parameter Values ....................................................................................................... 16

2.3 Making Calculations in Atoll ................................................................................................................... 17

2.3.1 Visibility and Distance Between Transmitter and Receiver .............................................................. 17

2.3.2 Effective Transmitter Antenna Height............................................................................................... 17

2.3.2.1 Height Above Ground ................................................................................................................. 17

2.3.2.2 Height Above Average Profile..................................................................................................... 172.3.2.3 Slope at Receiver Between 0 and Minimum Distance ................................................................ 17

2.3.2.4 Spot Ht........................................................................................................................................ 18

2.3.2.5 Absolute Spot Ht......................................................................................................................... 18

2.3.2.6 Enhanced Slope at Receiver ...................................................................................................... 18

2.3.3 Effective Receiver Antenna Height................................................................................................... 20

2.3.4 Correction for Hilly Regions in Case of LOS .................................................................................... 20

2.3.5 Diffraction ......................................................................................................................................... 21

2.3.6 Losses Due to Clutter ....................................................................................................................... 21

2.3.7 Recommendations for Using Clutter with the SPM .......................................................................... 22

3 Collecting CW Measurement Data.................................................. 293.1 Before You Start..................................................................................................................................... 29

3.1.1 Geographic Data .............................................................................................................................. 293.1.2 Measurement Data........................................................................................................................... 29

3.2 Guidelines for CW Measurement Surveys ............................................................................................. 30

3.2.1 Selecting Base Stations ................................................................................................................... 30

3.2.2 Planning the Survey Routes ............................................................................................................. 30

3.2.3 Radio Criteria ................................................................................................................................... 31

3.2.4 Additional Deliverable Data .............................................................................................................. 31

4 The Model Calibration Process....................................................... 354.1 Setting Up Your Calibration Project ....................................................................................................... 35

4.1.1 Creating an Atoll Calibration Document ........................................................................................... 35

4.1.1.1 Setting Coordinates .................................................................................................................... 36

4.1.1.2 Importing Geo Data . ................................................................................................................... 36

4.1.2 Importing CW Measurements........................................................................................................... 364.1.2.1 Importing a CW Measurement Path ........................................................................................... 37

4.1.2.2 Importing Several CW Measurement Paths ............................................................................... 38

4.1.2.3 Creating a CW Measurement Import Configuration.................................................................... 40

4.1.2.4 Defining the Display of CW Measurements ................................................................................ 40

4.1.3 Checking and Correcting the Correspondence Between Geo and Measurement Data ................... 43

4.1.4 Filtering Measurement Data ............................................................................................................. 44

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

4.1.4.2 Signal and Distance Filtering ...................................................................................................... 46

4.1.4.2.1 Typical Values....................................................................................................................... 46

4.1.4.2.2 Using Manual Filtering on CW Points ................................................................................... 46

4.1.4.2.3 Creating an Advanced Filter ................................................................................................. 47

4.1.4.2.4 Using the Filtering Assistant on CW Measurement Points.................................................... 47

4.1.4.3 Filtering by Geo Data Conditions................................................................................................ 49

4.1.4.3.1 About Diffraction ................................................................................................................... 49

4.1.4.3.2 About Specific Sections ........................................................................................................ 50

4.1.4.3.3 About Potentially Invalid Measurement Levels ..................................................................... 50

4.1.4.3.4 Deleting a Selection of Measurement Points ........................................................................ 52


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4.1.4.3.5 Using Filtering Zones on CW Measurement Points...............................................................53

4.1.4.3.6 Filtering by Angle ...................................................................................................................54

4.1.5 Selecting Base Stations for Calibration and for Verification..............................................................54

4.2 Calibrating the SPM................................................................................................................................55

4.2.1 Quality Targets..................................................................................................................................55

4.2.2 Setting Initial Parameters in the SPM ...............................................................................................55

4.2.2.1 Parameters Tab...........................................................................................................................55

4.2.2.2 Clutter Tab...................................................................................................................................57

4.2.3 Running the SPM Calibration Process..............................................................................................58

4.2.3.1 The Automatic Calibration Wizard...............................................................................................59

4.2.3.2 The Assisted Calibration Wizard .................................................................................................61

4.3 Calibrating Hata Models .........................................................................................................................62

4.3.1 Quality Targets..................................................................................................................................62

4.3.2 Setting Initial Parameters in the Hata Models ...................................................................................62

4.3.2.1 Defining General Settings ...........................................................................................................62

4.3.2.2 Selecting an Environment Formula .............................................................................................63

4.3.2.3 Creating or Modifying Environment Formulas .............................................................................63

4.3.3 Running the Hata Calibration Process ..............................................................................................63

4.4 Analysing the Calibrated Model ..............................................................................................................65

4.5 Finalising the Settings of the Calibrated SPM ........................................................................................70

4.6 Deploying the Calibrated Model..............................................................................................................72

4.6.1 Copying a Calibrated Model to Another Document...........................................................................72

4.6.2 Deploying a Calibrated Model to Transmitters ..................................................................................73

5 Additional CW Measurement Functions ..........................................775.1 Creating a CW Measurement Path.........................................................................................................77

5.2 Drawing a CW Measurement Path .........................................................................................................78

5.3 Merging measurement paths for a same transmitter ..............................................................................78

5.4 Smoothing Measurements to Reduce the Fading Effect ........................................................................78

5.5 Calculating Best Servers Along a CW Measurement Path.....................................................................79

5.5.1 Adding Transmitters to a CW Measurement Path.............................................................................79

5.5.2 Selecting the Propagation Model ......................................................................................................79

5.5.3 Setting the Display to Best Server ....................................................................................................80

5.5.4 Calculating Signal Levels ..................................................................................................................80

5.5.5 Displaying Statistics over a measurement path ................................................................................80

5.5.6 Displaying Statistics over several measurement paths.....................................................................80

6 Survey Site Form.............................................................................85


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List of Figures

List of Figures

Figure 2.1 : Enhanced Slope at Receiver ................................................................................................................... 18

Figure 2.2 : Losses due to Clutter............................................................................................................................... 22Figure 2.3 : Setting losses per clutter class ................................................................................................................ 23

Figure 2.4 : Tx-Rx profile ............................................................................................................................................ 23

Figure 2.5 : Settings when using clutter heights set per class.................................................................................... 24

Figure 2.6 : Diffraction caused by surrounding buildings when the receiver is indoors.............................................. 24

Figure 2.7 : Clutter class settings when using a clutter height file .............................................................................. 25

Figure 4.1 : The Setup tab of the Import of Measurement Files dialogue................................................................... 37

Figure 4.2 : Defined thresholds as they will appear in the Legend............................................................................. 43

Figure 4.3 : Distribution of the Measured Signal Strength around a station ............................................................... 43

Figure 4.4 : Point distribution in the different clutter classes....................................................................................... 45

Figure 4.5 : Filtering Assistant Launching................................................................................................................... 48

Figure 4.6 : Point Selection Tool in the Filtering Assistant.......................................................................................... 48

Figure 4.7 : Point Exclusion Tool in the Filtering Assistant ......................................................................................... 49

Figure 4.8 : Point Analysis Tool window showing diffraction peaks............................................................................ 50

Figure 4.9 : Distribution of the point positions around a station .................................................................................. 51

Figure 4.10 : The CW Measurement Analysis Tool window ......................................................................................... 52

Figure 4.11 : Simultaneous display of measurement path and table ............................................................................ 53

Figure 4.12 : Angular Filter around a station................................................................................................................. 54

Figure 4.13 : SPM Transmitter effective height method selection ................................................................................ 56

Figure 4.14 : Calculating the total clutter loss between the transmitter and the receiver.............................................. 57

Figure 4.15 : Comparative behaviour of the clutter weighting functions in the SPM..................................................... 58

Figure 4.16 : Calibration launching on SPM model....................................................................................................... 59

Figure 4.17 : Path and Calibration method selection for SPM Calibration.................................................................... 59

Figure 4.18 : Range definition for SPM parameters during calibration ......................................................................... 60

Figure 4.19 : SPM Comparative Calibration Results .................................................................................................... 60

Figure 4.20 : Table listing the correlation of the SPM variables to the global error ...................................................... 61Figure 4.21 : Calibration launching on Hata models ..................................................................................................... 64

Figure 4.22 : Path and Calibration method selection for SPM Calibration.................................................................... 64

Figure 4.23 : Range definition for SPM parameters during calibration ......................................................................... 65

Figure 4.24 : Hata Models Comparative Calibration Results........................................................................................ 65

Figure 4.25 : Selecting the calibrated model for all CW measurement paths ............................................................... 66

Figure 4.26 : Calculating the signal levels on all CW measurement paths................................................................... 66

Figure 4.27 : Selecting on of the verification stations for the statistics ......................................................................... 67

Figure 4.28 : Comparative statistics of the verification stations.................................................................................... 67

Figure 4.29 : Distribution of error around a verification station ..................................................................................... 68

Figure 4.30 : Opening the CW Measurement Analysis tool.......................................................................................... 69

Figure 4.31 : CW Measurement Analysis ..................................................................................................................... 70

Figure 4.32 : Description of the available clutter classes.............................................................................................. 72

Figure 5.1 : The New CW Measurement Path dialogue ............................................................................................. 77

Figure 5.2 : Sliding Window Property Dialogue .......................................................................................................... 79


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Introduction

Chapter 1

Atoll RF Planning & Optimisation Software


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Chapter 1: Introduction

© Forsk 2009 AT281_MCG_E0 11

1 Introduction

The Model Calibration Guide is intended for project managers or anyone else responsible for calibrating the Standard

Propagation 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

calibration process 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 about

Atoll projects. For information on using Atoll, see the User Manual and the Administrator Manual . For detailed technical

information 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 meas-

urements 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 formula on which the SPM is based. Other aspects described include, typical SPM parameter values, making

calculations using 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

information 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 2Standard Propagation Model



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Chapter 2: Standard Propagation Model

© Forsk 2009 AT281_MCG_E0 15

2 Standard Propagation Model

The Standard Propagation Model is a propagation model based on the Hata formulas and is suited for predictions in the

150 to 3500 MHz band over long distances (from one to 20 km). It is best suited to GSM 900/1800, UMTS, CDMA2000,

WiMAX, and LTE radio technologies.

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

where:

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

Hata formula is also described.

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

where,

Typical values for Hata model parameters are:

• A1 = 69.55 for 900 MHz, A1 = 46.30 for 1800 MHz

• A2 = 26.16 for 900 MHz, A2 = 33.90 for 1800 MHz

• A3 = 13.82• B1 = 44.90

• B2 = 6.55

• P R received power (dBm)• P Tx transmitted power (EIRP) (dBm)• K 1 constant offset (dB)• K 2 multiplying factor for Log(d)• d distance between the receiver and the transmitter (m)• K 3 multiplying factor for Log(HTxeff )

• effective height of the transmitter antenna (m)

• K 4 multiplying factor for diffraction calculation. K4 must be a positive number • DiffractionLoss losses due to diffraction over an obstructed path (dB)• K 5 multiplying factor for Log(HTxeff) x Log(d)• K 6 multiplying factor for HRxeff • K 7 multiplying factor for Log(HRxeff)

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

• K clutter multiplying factor for f(clutter)• f(clutter) average of weighted losses due to clutter • K hill, LOS corrective factor for hilly regions (=0 in case of NLOS)

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 ef f K 7 Log H Rx eff

K clutter f c lu tt er K h il l L OS+ + +

–=

H Tx eff

H Rx eff

• A1, A2, A3, B1,

B2Hata parameters

• f Frequency in MHz• hBS Effective BS antenna height in metres

• d Distance in kilometres• a(hm ) Mobile antenna height correction function• Cclutter Clutter correction function

Note: The distance in this equation is given in kilometres as opposed to the SPM, where the

distance is given in metres.

L A1 A2 f log A3 hBSlog B1 B2 hBSlog + d log a hm C clutter – –+ + +=


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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 Equations

Because 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 A1 and K1, and taking only one clutter class into consideration, you can set

the clutter 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 hm=1.5 m, and has negligible values for realistic mobile antenna heights.

The Hata formula can now be simplified to:

where:

• A1, A2 , A3, B1, B2 Hata parameters

• f Frequency in MHz

• hBS Effective BS antenna height in metres

• d 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 Coefficients

If you compare the simplified Hata and SPM equations, you see the following correspondence between the coefficients:

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:

L A1 A2 f log A3 hBSlog B1 B2 hBSlog + d log + + +=

L K 1 K 2 d log K 3 hBSlog K 5 d log hBSlog K 6 hmeff K 7 Log hmeff + + + + +=

L A1 A2 f log A3 hBSlog B1 B2 hBSlog + d

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

L A1 A2 f log 3 B1 – A3 3 B2 – hBSlog B1 d log B2 hBSlog d log ++ + +=

K 1 A1 A2 f log 3 B1 –+=

K 2 B1=

K 3 A3 3 B2 –=K 5 B2 =

K 6 0 =

K 7 0 =

Project type Frequency (MHz) K 1

GSM 900 935 12.5

GSM 1800 1805 22

GSM 1900 1930 23

UMTS 2110 23.8

1xRTT 1900 23

WiMAX

2300 24.7

2500 25.4

2700 26.1

3300 27.8

3500 28.3

K 2 44.90 =

K 3 5.83=

K 5 6.55 –=


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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 17

• "Effective Transmitter Antenna Height" on page 17

• "Effective Receiver Antenna Height" on page 20

• "Correction for Hilly Regions in Case of LOS" on page 20

• "Diffraction" on page 21

• "Losses Due to Clutter" on page 21

• "Recommendations for Using Clutter with the SPM" on page 22.

2.3.1 Visibility and Distance Between Transmitter and Receiver For 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 (K1, K2)LOS. The

LOS is 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 (K1, K2)NLOS.

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

• "Height Above Ground" on page 17

• "Height Above Average Profile" on page 17

• "Slope at Receiver Between 0 and Minimum Distance" on page 17

• "Spot Ht" on page 18

• "Absolute Spot Ht" on page 18

• "Enhanced Slope at Receiver" on page 18.

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

H Txeff = H Tx

2.3.2.2 Height Above Average Profile

The transmitter antenna height is determined relative to an average ground height calculated along the profile between a

transmitter and a receiver. The profile length depends on the minimum distance and maximum distance values and is

limited by the transmitter and receiver locations. Distance min. and Distance max are minimum and maximum distances

from the transmitter 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 Distance

The 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

distance from the receiver.

Note: If the profile is not located between the transmitter and the receiver, H Txeff equals H Tx only.

H Txeff H Tx H 0T x H 0 – +=

H 0T x

H 0

H Txeff H Tx H 0T x + H 0R x – K d +=

H 0R x

K


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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.

2.3.2.6 Enhanced Slope at Receiver Atoll 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 trans-

mitter (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

negatively 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. It

determines 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 and

compares it with a threshold set to 0.05; where three cases are possible.

Some notations defined hereafter are used in next part.

Notes:

• If , Atoll uses 20 m in calculations.

• If , Atol l takes 200 m.

H Txeff 20m

H Txeff 200m

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 =

Note: 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 Okumura rec-

ommendations (high frequency mobile telephony).

H Txeff H Tx H 0T x H 0R x –+=

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


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- 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

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

profile plus 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:

Notes:

• When several influence areas are possible, Atoll chooses the highest one.

• If d < 3000m, R = d .

H f i l t

H orig

H fi lt Tx – Tx H orig Tx =

H orig i H orig i 1 – H orig i H orig i 1 – –

Res

------------------------------------------------------- 0.05

H fi lt Tx – i H fi lt Tx – i 1 – H orig i H orig i 1 – – +=

H orig i H orig i 1 – H orig i H orig i 1 – –

Res------------------------------------------------------- 0.05

H f ilt Tx – i H f il t Tx – i 1 – =

H orig i H orig i 1 –

H f ilt Tx – i H f il t Tx – i 1 – =

H filt i H orig i

H fi l t Tx – i H orig i =

H filt Rx H orig Rx =

H orig i H orig i 1+ H orig i H orig i 1+ –

Res------------------------------------------------------- 0.05

H f il t Rx – i H fi lt Rx – i 1+ H orig i H orig i 1+ – +=

H orig i H orig i 1+ H orig i H orig i 1+ –

Res------------------------------------------------------- 0.05

H fi lt Rx – i H fil t Rx – i 1+ =

H orig i H orig i 1+

H fi lt Rx – i H fil t Rx – i 1+ =

H filt i H orig i

H fi l t Rx – i H orig i =

H filt i max H fi lt Tx – i H fil t Rx – i =

R 3000m

R 0.01 d

y ax b+=


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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

profile and 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 ,

Else

If ,

Else

i Rx is the point index at receiver.

2.3.5 Diffraction

Four methods are available to calculate diffraction loss over the transmitter-receiver profile. These methods are explained

in the Technical Reference Guide.

• Deygout

• Epstein-Peterson

• Deygout with correction

• Millington

Along the transmitter-receiver profile, you can take one of the following into consideration:

• Ground altitude and clutter height (Consider heights in diffraction option). In this case, Atoll uses clutter height

information from the clutter heights file if it is available in the ATL document. Otherwise, Atoll considers averageclutter height specified for each clutter class in the clutter classes file description.

• Only ground altitude.

2.3.6 Losses Due to Clutter Atoll calculates f(clutter) over a maximum distance from the receiver.

where,

• L: loss due to clutter defined in the Clutter tab by the user (in dB).

• w : weight determined through the weighting function.

• n: number of points taken into account over the profile. Points are evenly spaced depending on the profile resolu-

tion.

Four weighting functions are available:

• uniform weighting function:

• triangular weighting function:

• , where d’ i is the distance between the receiver and the ith point and D is the maximum distance

defined.

• logarithmic weighting function:

Lmodel K 1 LOS K 2 LOS d log K 3 H Txeff log K 5 H Txeff d log log K 6 H Rx K clutter f c lu tt er K h il l L OS+ + + + + +=

Lmodel K 1 N LO S K 2 N LO S d log K 3 H Txeff log K 4 Diffraction K 5 H Txeff d log log K 6 H Rx K clutter f c lut te r + + + + + +=

K h il l L OS

K h il l L OS

K h il l L OS K h K hf +=

0 h 20m K h 0 =

K h 7.73 h log 2

15.29 h log – 6.746 +=

0 h 10m K hf 2 – 0.1924 H 0R x H Rx regr i Rx –+ =

K hf 2 – 1.616 h log 2

– 14.75 h log 11.21 –+ H 0R x H Rx r egr i Rx –+

h------------------------------------------------------------- =

f c lu tt er Li w i i 1=

=

w i 1

n---=

w i d i

d j

n

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

d i D d 'i –=

w i

d i

D---- 1+

log

d j D---- 1+

log

n

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


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• exponential weighting function:

The following chart shows the weight variation with the distance for each weighting function.

2.3.7 Recommendations for Using Clutter with the SPM

The decision of what clutter information you should use with the SPM depends on the type and quality of the available

information. Normally you want to use the most detailed and most accurate information. This section gives a few recom-

mendations on using the information available to you efficiently with the SPM. The following scenarios are possible:

• No clutter height information is available: You do not have a clutter height file and the height per clutter classis either not defined, or is too roughly defined. In this case, you should define a loss per clutter class and not use

the height per clutter class. For more information, see "Losses per Clutter Class" on page 22.

• No clutter height file is available: You do not have a clutter height file. However, the clutter classes file has rel-

atively good data defining the height per clutter class and has a high enough resolution. In this case, you can use

the height per clutter class, but, if you use the height per clutter class, you must not define a loss per clutter class.

For more information, see "Clutter Height per Class" on page 23.

• Clutter height file is available: You have a clutter height file available that has accurate data over a resolution

that is fine enough for your network. In this case, you should use the clutter height file. But, if you use the clutter

height file, you must not use a loss per clutter class. For more information, see "Clutter Height File" on page 24.

More information is given on each option in the following sections.

Losses per Clutter Class

If you specify losses per clutter class, as illustrated in Figure 2.3, you must not consider clutter altitudes in diffraction lossover the transmitter-receiver profile. This approach is recommended if the clutter height information is statistical (i.e.,

where the clutter is roughly defined and without a defined altitude).

Figure 2.2: Losses due to Clutter

w i e

d i D----

1 –

e

d j

D----

1 –

j 1=

n

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

Note: Because the Standard Propagation Model is a statistical propagation model, using this

approach is recommended.


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© Forsk 2009 AT281_MCG_E0 23

Clutter Height per Class

If you consider clutter height per class, as illustrated in Figure 2.5, you must not define any loss per clutter class. In this

case, f(clutter) will be "0;" losses due to clutter will only be taken into account in calculated diffraction. This approach is

recommended if the clutter height information is semi-deterministic (i.e., where the clutter is roughly defined with an aver-

age altitude per clutter class).

When the clutter height information is an average height defined for each clutter class, you must specify a receiver clear-

ance per clutter class. Both ground and clutter height are considered along the entire transmitter-receiver profile except

over a specific distance around the receiver (clearance), in which Atoll bases its calculations only on the DTM. The clear-

ance information is used to model streets because it is assumed that the receiver is in the street.

In Figure 2.4, the ground altitude and clutter height (in this case, average height specified for each clutter class in the clut-

ter classes map description) are taken into account along the profile.

Figure 2.3: Setting losses per clutter class

Figure 2.4: Tx-Rx profile


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Clutter Height File

If you use a clutter height file, do not define any loss per clutter class, as illustrated in Figure 2.7. In this case, f(clutter) will

be "0;" losses due to clutter will only be taken into account in calculated diffraction. This approach is recommended if the

clutter height information is deterministic (in this case, where there is a clutter height file).

It is not necessary to define receiver clearance if the height information is from a clutter height file; the clutter height infor-

mation is accurate enough to be used without additional information such as clearance. Atoll calculates the path loss if

the receiver is in the street (i.e., if the receiver height is higher than the clutter height). If the receiver height is lower than

the clutter height, the receiver is assumed to be inside a building. In this case, Atoll does not consider any diffraction for

the building (or any clearance) but takes into account the clutter class indoor loss as an additional penetration loss. Never-

theless, Atoll does consider diffraction caused by surrounding buildings. In Figure 2.6 on page 24 this diffraction is

displayed with a green line.

Figure 2.5: Settings when using clutter heights set per class

Important: In order to consider indoor losses inside a building when only using a deterministic clutter

map (i.e., a clutter height map), you must clear the Indoor Coverage check box when cre-

ating a prediction or indoor losses will be added twice (once for the entire reception clutter

class and once as indoor losses).

Figure 2.6: Diffraction caused by surrounding buildings when the receiver is indoors


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© Forsk 2009 AT281_MCG_E0 25

Figure 2.7: Clutter class settings when using a clutter height file


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Collecting CW Measurement Data

Chapter 3



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Chapter 3: Collecting CW Measurement Data

© Forsk 2009 AT281_MCG_E0 29

3 Collecting CW Measurement Data

CW measurements, i.e., measurements made in the field for a single transmitter at a given frequency (continuous wave),

are used to calibrate propagation models. Creating CW measurements in Atoll can be made either by importing meas-

urements or general data samples (including Planet® data) or by pasting measurement results directly in the document.

When you import measurements, you can save the settings used during the import procedure in a configuration which you

can used the next time you import similar measurements.

Atoll enables very complete management of CW measurements and provides several features allowing you to update

geographical data, define additional fields, or define how the path will be displayed.

This chapter presents the points to be considered when planning a CW survey in order to get the most accurate and useful

measurements. Once you have made a CW survey and have collected the CW measurements, importing them into Atoll

and using them to calibrate a propagation model (SPM or Hata models) is explained in "Setting Up Your Calibration

Project" on page 35.

Atoll offers other possibilities for working with CW measurements. For more information, see "Additional CW Measurement

Functions" on page 77.

3.1 Before You StartBefore you make a CW survey, it is essential to properly prepare for it. This section describes the data you must have

before you start your CW survey:

• "Geographic Data" on page 29

• "Measurement Data" on page 29.

3.1.1 Geographic DataYou must have up-to-date geographic data when you are planning your CW survey. If you perform a CW survey on an

area for which you do not have up-to-date geographic data of sufficient quality, you will not be able to use the CW meas-

urements you have collected to calibrate the propagation model. In any case, up-to-date geographic data will be later

required to produce realistic results in coverage predictions.

The types of geographic data you will need are the following:

• Raster geographic data: The SPM or Hata Models can use raster geographic data as input. It can obtain the

ground elevation information from the DTM (Digital Terrain Model) files and clutter information from either clutter

classes files or clutter heights files.

Clutter classes files describe the land cover (dense urban areas, buildings, residential areas, forests, open areas,

villages etc.). In these files, the ground is represented by a grid where each pixel corresponds to a code allocated

to a main type of cover, in other words, to a clutter class. Clutter height maps describe the altitude of clutter over

the DTM with one altitude defined for each pixel. Clutter height maps can offer more precise information than defin-

ing an altitude per clutter class because, in a clutter height file, it is possible to have different heights within a single

clutter class.

DTM and clutter class files must be of a sufficiently high resolution to obtain a high-quality and accurate results in

a calibration project. The resolution of geographic data should typically be:

- 25 m or less for urban areas

- 50 m or less for rural areas.

• Vector data: Vector maps, representing at least major roads, are useful for planning and verifying measurement

survey routes.

• Scanned maps: Scanned maps are useful for planning and verifying measurement survey routes in urban areas.

3.1.2 Measurement DataIt is strongly recommended to use CW (continuous wave) measurements to calibrate the SPM or Hata models. Although

it is possible to calibrate the SPM or Hata models using drive test data, it is not the recommended approach:

• Since drive test data are made on a real network, part of the measured signal is actually due to interference.

• Using directional antennas implies that the propagation calculation strongly depends on the accuracy of antenna

patterns, and only the measurement points in the direction of the main beam are relevant.

• Several frequencies are measured for drive test data, although the SPM or hata models are calibrated only for a

base frequency.

• The sampling rate of each measured station is low because a lot of stations are scanned at the same time. There-

fore, the Lee criterion cannot be fulfilled (see "Guidelines for CW Measurement Surveys" on page 30).

• Only the signal from the best server is scanned and, therefore, the signal level is measured over only a short dis-

tance from each transmitter. Therefore, the model will only be calibrated for coverage predictions and not for the

evaluation of interference.


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Therefore, you should plan CW measurement surveys if you need measurements to calibrate the SPM or Hata models.

However, before planning and performing CW a measurement survey:

• Determine the number of required propagation models depending on representative area types (urban, suburban,

flat_rural, hilly_rural, etc.), and on the number of frequency bands (GSM 900, GSM 1800, UMTS, etc.). One prop-

agation model for each "area type–frequency band" pair must be calibrated.

• Select a representative area of each area type, where the measurement survey campaigns will be performed.

• For each area type, select at least 8 sites (6 for calibration and 2 for verification), which respect the conditions

described in "Guidelines for CW Measurement Surveys" on page 30.

• For each selected site, define a survey route, which respects the conditions described in "Guidelines for CW Meas-

urement Surveys" on page 30.

• Ensure that it will be possible to respect all other criteria described in "Guidelines for CW Measurement Surveys"on page 30 when performing the measurement survey.

3.2 Guidelines for CW Measurement SurveysThe quality of the calibrated propagation model depends strongly on the quality of the CW measurements. Therefore, you

can only meet the quality targets if the CW measurements, on which the calibration will be based, are of good quality, the

provided radio data are correct, and the calibration procedure described in "The Model Calibration Process" on page 35

is followed.

This section gives some information for planning a CW measurement survey. Keeping this information in mind when you

are planning the survey route will help guarantee high-quality measurements that can serve as input for the SPM (or Hata

models) calibration project.

In this section, the following are described:• "Selecting Base Stations" on page 30

• "Planning the Survey Routes" on page 30

• "Radio Criteria" on page 31

• "Additional Deliverable Data" on page 31.

3.2.1 Selecting Base StationsWhen selecting stations to be used in the CW measurement survey, the following guidelines should be respected:

• A minimum of about eight stations should be measured for each propagation model to be calibrated. The exact

number of stations depends on the terrain.

• Selected stations should fulfil the following conditions:

- The stations should have good RF clearance, in other words, the stations selected should not be obstructed

in any direction.

- An omnidirectional antenna should be used.

- The antennas on the measured stations should represent the full variation of antenna heights (typically from

20 m. to 50 m.) in the area covered by the survey. A histogram displaying the antenna heights can be a useful

tool in determining what antenna heights should be represented.

- The terrain within a relevant radius around each selected station should be representative of the entire area

covered by the survey. For example, in a relatively flat region, all rural stations selected should be surrounded

by relatively flat terrain within a radius of 10 km; a station surrounded with hilly terrain would not give meas-

urements representative of the entire area.

- If there is a variety of different types of clutter in the survey area (open, urban, suburban, dense urban, etc.),

there should be as equal a distribution as possible of the major clutter categories within a relevant radius of each station.

- There should be sufficient roads available to enable easy access with transmission equipment on all sides of

each station.

3.2.2 Planning the Survey RoutesWhen selecting survey routes to be used in the CW measurement survey, the following guidelines should be respected:

• Measurement surveys should be performed over a long enough distance to allow the noise floor of the receiver to

be reached. Typical distances are:

- Rural areas: approximately 10 km

- Suburban areas: approximately 2 km

- Urban areas: approximately 1 km

• The measurement routes must be laid out so that they have equal numbers of samples near as well as far from

the station in all directions.

• The survey routes should not cross forests or rivers; such clutter types should be avoided. Even profiles between

the transmitter and the receiver should not cross such kinds of clutter, if these types of clutter are not especially

representative of the area. These points will have to be filtered out during the calibration process.

Note: To avoid problems if the measurements of one or more stations must be rejected, a mini-

mum of 10 stations for each propagation model to be calibrated is recommended.


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Chapter 3: Collecting CW Measurement Data

© Forsk 2009 AT281_MCG_E0 31

• When planning the survey routes, any proposed routes should be presented for approval to the project manager

in the form of vector maps in a format that can be imported in Atoll.

• The maps used to plan the survey routes should use the same projection system as the scanned maps in the Atoll

calibration project. This will allow you to validate the survey routes beforehand.

• The GPS of the CW measurement equipment should be configured to match that of the mapping data.

• If possible, before actually making the survey, you should try to ensure consistency between the coordinates given

by the GPS on the survey route with those used in Atoll by making a test drive without taking measurements.

3.2.3 Radio CriteriaWhen planning a CW measurement survey, the following radio guidelines should be followed:

• The area to be covered by the CW measurement survey must be scanned before performing the drive test to

ensure that there is no interference.

• Only one frequency must be measured during a single survey.

• The frequency measured must be clean:

- For GSM, there must be 3 contiguous unused channels (i.e., a clearance of 200 kHz on either side of the

measured signal).

- For UMTS and CDMA2000, there must be one unused carrier. This can be verified by checking whether the

reception level is at zero when the transmitter is off.

• The Lee criterion must be satisfied in terms of sampling rate to overcome the effects of fast fading.

At least 36 samples must be collected over a distance of 40. But, because the required rate depends on the high-est speed the vehicle would travel during the survey, the vehicle speed must be adapted accordingly. The following

table provides a list of required rates corresponding to different vehicle speeds in order to respect the Lee criterionfor a frequency 900 MHz.

• The measured signals over the distance of 40 should be averaged, with the mean signal level (50th percentile)being the one stored.

• The maximum distance between 2 stored measurement points should be equal to one half the resolution of the

clutter file used. This is necessary to obtain a good representative sample of each clutter class.

• At least 5,000 points per station must remain after averaging. A typical number of points per measured station isbetween 10,000 and 20,000 points.

3.2.4 Additional Deliverable Data

During the survey, certain types of information should be collected in addition to measurements. This additional informa-

tion will aid in interpreting the collected CW measurement data and will increase the overall quality of not only the CW

survey but of the subsequent calibration.

The following data should be collected during the survey:

• Measurement data: The radio data collected should meet the following criteria:

- The measurements to be imported should correspond to the average of the measured signals over the dis-

tance of 40.- The maximum distance between 2 stored measurement points should be equal to one half the resolution of

the clutter class file used. This is necessary to obtain a good representative sample of each clutter class.

- The survey should have at least 5,000 points per station. A typical number of points per measured station is

between 10,000 and 20,000 points.

• A rooftop sketch: A rooftop sketch must be provided indicating the locations of:

- The transmitting antenna

- Any rooftop obstacles (including their relative location, distance from transmitter, and height)

- Any nearby obstacles (for example, other buildings) within 400 m. of the transmitter (including their relative

location, distance from transmitter, height, and width)

• Panoramic photographs: Panoramic photographs should be taken from each rooftop of each station starting

from north and turning clockwise. These photographs should show the surroundings in all directions. The azimuth

and station number should be recorded for each photograph.

• Transmission data: The following data should be recorded for all stations:

- Precise coordinates of each station measured during the CW survey- Antenna patterns, downtilt, azimuth (if the antenna is not perfectly omnidirectional), and antenna height

- Transmission power, and transmission gain and losses

Highest Speed (Km/h) Sampling Rate (samples per sec)

60 45

90 68

120 90

150 113


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Chapter 4The Model Calibration Process

Chapter 4



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Chapter 4: The Model Calibration Process

© Forsk 2009 AT281_MCG_E0 35

4 The Model Calibration Process

This chapter explains the propagation model calibration process, from creating or selecting the project you will use to cali-

brate the model, to calibrating the model, to deploying the calibrated propagation model. Two types of models can be cali-

brated : SPM and Hata Models (Hokumura and Cost-Hata).

Before you can begin the calibration process, you must ensure that you have properly prepared for the process. First, the

necessary CW measurements must be available. For information on planning the CW measurement survey, see "Collect-

ing CW Measurement Data" on page 29.

When the CW measurement data is available, you can begin the SPM calibration process:

1. Setting up the calibration project: The first step consists of creating an Atoll document with all of the network

and geographical data necessary to recreate the CW measurement survey area. When the Atoll document has

been created with all the necessary data, you can import the CW measurement data and filter them in order to

ensure that only meaningful data is used for calibration.

- "Setting Up Your Calibration Project" on page 35.

2. Calibrate the SPM: When the CW measurement data has been selected and filtered, you can begin calibrating

the model. You must first set a few initial parameters in the propagation model and then you can begin the cali-

bration process, using either the automated or the assisted method. After calibration, Atoll offers several different

ways for you to analyse the calibrated propagation model.

- "Calibrating the SPM" on page 55.

3. Finalising the calibrated propagation model: When you have calibrated the propagation model and are satis-

fied with the results, you must make a few final adjustments to compensate for values that could not be calibrateddue to missing or incomplete data. The missing values can be extrapolated from existing data or from standard

values.

- "Finalising the Settings of the Calibrated SPM" on page 70.

4. Deploying the calibrated propagation model: The final propagation model can now be deployed to the trans-

mitters for which it was calibrated.

- "Deploying the Calibrated Model" on page 72.

4.1 Setting Up Your Calibration ProjectWhen you set up the calibration project, you must first create or select an Atoll document with the network and geograph-

ical data necessary to recreate the CW measurement data survey area. Creating the Atoll document is explained in "Creat-

ing an Atoll Calibration Document" on page 35. If you already have an Atoll document that you will use to calibrate thepropagation model, you can continue directly with "Importing CW Measurements" on page 36.

When you have imported the CW measurements, your next step is to verify that the CW measurement data you have just

imported correspond to the geographical data of the Atoll document you will be using for calibration. This step is very

important because Atoll will use the geographical data of the document to evaluate the CW measurement points. If the

points are not properly situated on the map, Atoll will not be able to apply the correct geographical data, especially clutter

to each point. This is explained in "Checking and Correcting the Correspondence Between Geo and Measurement Data"

on page 43.

In theory, the imported measurement values are supposed to be smoothed by the measurement equipment so that they

are not subject to any fading effect. In the case the fading effects occur on the measured samples, and in order to improve

the input data for calibration, you can average them by defining a smoothing sliding window as explained in "Smoothing

Measurements to Reduce the Fading Effect" on page 78.

Once you are satisfied that the positions of the CW measurement points correspond properly to the geographical data in

the Atoll document, you can filter out the CW measurement data that, for various reasons, can not be used in the calibra-

tion process. This is explained in "Filtering Measurement Data" on page 44.

After preparing the CW measurement data, the final step before proceeding to the calibration step is selecting the base

stations that will be used for calibration and those that will be used to verify the calibration process, as explained in "Select-

ing Base Stations for Calibration and for Verification" on page 54.

4.1.1 Creating an Atoll Calibration DocumentYou can create the Atoll calibration document in one of two ways:

• From a template: You can create a new Atoll document from a template. Atoll is delivered with a template for

each technology you will be planning for. For information on creating a document from a template, see the User

Manual .

• From an existing document: If you already have an existing document covering the CW measurement survey

area, you can make a copy of it to use in the calibration process so that you can calibrate the propagation model-without making changes to the original document. For information on making a copy of an existing document, see

the User Manual .


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Once you have created the calibration document, you must set a few necessary parameters and import or create the

preliminary data. These steps are explained in the following sections:

• "Setting Coordinates" on page 36

• "Importing Geo Data" on page 36.

4.1.1.1 Setting Coordinates

In Atoll, you define the two coordinate systems for each Atoll document: the projection coordinate system and the display

coordinate system. By default, the same coordinate system is used for both.

The maps displayed in the workspace are referenced with the same projection system as the imported geographic datafiles; thus, the projection system depends on the imported geographic file.

For more information on the projection and display coordinate systems in Atoll, see the User Manual .

4.1.1.2 Importing Geo Data

The geographic data is an important part of an Atoll document when the document is going to be used for a calibration

project. Several different geographic data types are used in a calibration project:

• Digital Terrain Model: The DTM describes the elevation of the ground over sea level and is indispensable in a

calibration project.

• Clutter Classes: The clutter class geo data file describes land cover or land use. Either clutter classes or clutter

heights must be present in a calibration project.

• Clutter Heights: Clutter height maps describe the altitude of clutter over the DTM with one altitude defined per

pixel. Clutter height maps can offer more precise information than defining an altitude per clutter class because,

in a clutter height file, it is possible to have different heights within a single clutter class.

• Vector Maps: Maps with possible survey routes defined as vectors can be imported to verify the planned survey

routes against other maps.

• Scanned Images: Scanned images are geographic data files which represent the actual physical surroundings,

for example, road maps or satellite images. They are used to provide a precise background for other objects. Although they are not used in calculations, they can be used to verify the accuracy of proposed survey routes.

• WMS Raster-format Geo Data Files: Raster images from a Web Map Service (WMS) server. The image must

be in TIF format and be referenced in the document; it can not be embedded. You can use a WMS image to add

a precise background for other objects, or to add place names, or a map of roadways. WMS images are not used

in calculations.

For more information on any of the geographic data formats that can be used in Atoll, see the User Manual , and the Tech-

nical Reference Guide. For information on importing geographic data, see the User Manual .

4.1.2 Importing CW MeasurementsIn Atoll, you can import CW measurement files in the form of ASCII text files (with tabs, semi-colons, or spaces as sepa-

rator), with DAT, TXT, and CSV extensions. For Atoll to be able to use the data in imported files, the imported files must

contain the following information:• The position of the CW measurement points. When you import the data, you must indicate which columns give the

abscissa and ordinate (XY coordinates) of each point.

• The measured signal level at each point.

The imported files can also contain other information, such as point names and field characteristics, that can be used to

define the display of measurement points, for example, to filter points.

You can import a single CW measurement file or several CW measurement files at the same time. If you regularly import

CW measurement files of the same format, you can create an import configuration. The import configuration contains infor-

mation that defines the structure of the data in the CW measurement file. By using the import configuration, you will not

need to define the data structure each time you import a new CW measurement file.

In this section, the following are described:

• "Importing a CW Measurement Path" on page 37

• "Importing Several CW Measurement Paths" on page 38

• "Creating a CW Measurement Import Configuration" on page 40• "Defining the Display of CW Measurements" on page 40.

Note: All imported raster geographic files must be use the same cartographic system. If not, you

must convert them to a single cartographic system.

Note: The only propagation models that can take clutter heights into account in calculations are

the Standard Propagation Model and WLL model.


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© Forsk 2009 AT281_MCG_E0 37

4.1.2.1 Importing a CW Measurement Path

To import a CW measurement file:

1. Click the Data tab in the Explorer window.

2. Right-click the CW Measurements folder. The context menu appears.

3. Select Import from the context menu. The Open dialogue appears.

4. Select the file or files you want to open.

5. Click Open. The Import of Measurement Files dialogue appears.

6. On the General tab:

a. Enter a Name for the CW measurement. By default, the CW measurement is given the name of the file being

imported.

b. Under Reference Transmitter , select the Transmitter with which the CW measurements were made and se-

lect the Frequency.

c. Under Receiver , enter the Height of the receiver, the Gain, and the Losses.

d. Under Measurements, define the Unit used for the CW measurements.

e. If the Coordinates used for the CW measurement data are different than the one displayed, click the Browse

button ( ) and select the coordinate system used.

7. Click the Setup tab (see Figure 4.1). If you already have an import configuration defining the data structure of the

imported file or files, you can select it from the Configuration list on the Setup tab of the Import of Measurement

Files dialogue. If you do not have an import configuration, continue with step 8.

a. Under Configuration, select an import configuration from the Configuration list.

b. Continue with step 9.

Important: CW measurements are usually made using WGS84. By default the coordinate system dis-

played in the coordinates field is the display system used in the document. If the CW meas-urements were made using WGS84, be sure to select WGS84, a geographic system as

indicated by the globe symbol ( ).

Figure 4.1: The Setup tab of the Import of Measurement Files dialogue

http://-/?-http://-/?-http://-/?-http://-/?-


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8. Under File, on the Setup tab:

a. Enter the number of the 1st Measurement Row, select the data Separator , and select the Decimal Symbol

used in the file.

b. Click Setup to link file columns and internal Atoll fields. The CW Measurement Setup dialogue appears.

c. Select the columns in the imported file that give the X-Coordinates and the Y-Coordinates of each point in

the CW measurement path file.

d. In the Measurements box, select the field that contains the value of the measured signal for each defined

point.

e. Click OK to close the CW Measurement Setup dialogue.

f. If there is other data available in the file, in the table under File, define the Type for each additional column of

data.

9. Once you have defined the import parameters, click Import. The CW measurement data are imported into the cur-

rent Atoll document.

4.1.2.2 Importing Several CW Measurement Paths

To import several CW measurement files:


2. Right-click the CW Measurements folder. The context menu appears.

3. Select Import from the context menu. The Open dialogue appears.

4. Select the file or files you want to open.

5. Click Open. The Import of Measurement Files dialogue appears.

6. On the General tab:

a. Enter a Name for the CW measurement. By default, the CW measurement is given the name of the file being

imported.

b. Under Reference Transmitter , select the Transmitter with which the CW measurements were made and se-

lect the Frequency.

c. Under Receiver , enter the Height of the receiver, the Gain, and the Losses.

d. Under Measurements, define the Unit used for the CW measurements.

e. If the Coordinates used for the CW measurement data are different than the one displayed, click the Browse

button ( ) and select the coordinate system used.

7. Click the Setup tab (see Figure 4.1). If you already have an import configuration defining the data structure of the

imported file or files, you can select it from the Configuration list on the Setup tab of the Import of Measurement

Files dialogue. If you do not have an import configuration, continue with step 8.a. Under Configuration, select an import configuration from the Configuration list.

b. Continue with step 9.

Notes:

• When importing a CW measurement path file, existing configurations are available in the Files

of type list of the Open dialogue, sorted according to their date of creation. After you have

selected a file and clicked Open, Atoll automatically proposes a configuration, if it recognises

the extension. In case several configurations are associated with an extension, Atoll chooses

the first configuration in the list.

• The defined configurations are stored, by default, in the file "MeasImport.ini", located in the direc-

tory where Atoll is installed. For more information on the MeasImport.ini file, see the Adminis-

trator Manual .

Note: You can also identify the columns containing the XY coordinates of each point in the CW

measurement path by selecting them from the Field row of the table on the Setup tab.

Note: You can select contiguous files by clicking the first file you want to import, pressing SHIFT

and clicking the last file you want to import. You can select non-contiguous files by press-

ing CTRL and clicking each file you want to import.

Important: CW measurements are usually made using WGS84. By default the coordinate system dis-

played in the coordinates field is the display system used in the document. If the CW meas-

urements were made using WGS84, be sure to select WGS84, a geographic system as

indicated by the globe symbol ( ).

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8. Under File, on the Setup tab:

a. Enter the number of the 1st Measurement Row, select the data Separator , and select the Decimal Symbol

used in the file.

b. Click Setup to link file columns and internal Atoll fields. The CW Measurement Setup dialogue appears.

c. Select the columns in the imported file that give the X-Coordinates and the Y-Coordinates of each point in

the CW measurement path file.

d. In the Measurements box, select the field that contains the value of the measured signal for each defined

point.

e. Click OK to close the CW Measurement Setup dialogue.

f. If there is other data available in the file, in the table under File, define the Type for each additional column of

data.

9. If you wish to save the definition of the data structure so that you can use it again, you can save it as an import

configuration:

a. On the Setup tab, under Configuration, click Save. The Configuration dialogue appears.

b. By default, Atoll saves the configuration in a special file called "MeasImport.ini" found in Atoll’s installation

folder. In case you cannot write into that folder, you can click Browse to choose a different location.

c. Enter a Configuration Name and an Extension of the files that this import configuration will describe (for ex-

ample, "*.csv").

d. Click OK.

Atoll will now select this import configuration automatically every time you import a drive test data path filewith the selected extension. If you import a file with the same structure but a different extension, you will be

able to select this import configuration from the Configuration list.

10. Once you have defined the import parameters, you can import the selected files:

- When importing several files for the same transmitter: Click Import All. The CW measurement data are

imported into the current Atoll document.

- When importing several files for different transmitters:

i. Click Import. The CW measurement data are imported into the current Atoll document.

ii. Click the General tab to ensure that the information on the General tab, especially the Reference Trans-

mitter selected, reflect the current file being imported.

iii. If necessary, click the Setup tab and redefine the import configuration for the current f ile being imported.

iv. Click Import to import the current file.

v. Repeat these steps for each file being imported.

Notes:

• When importing a CW measurement path file, existing configurations are available in the Files

of type list of the Open dialogue, sorted according to their date of creation. After you have

selected a file and clicked Open, Atoll automatically proposes a configuration, if it recognises

the extension. In case several configurations are associated with an extension, Atoll chooses

the first configuration in the list.

• The defined configurations are stored, by default, in the file "MeasImport.ini", located in the direc-

tory where Atoll is installed. For more information on the MeasImport.ini file, see the Adminis-

trator Manual .

Note: You can also identify the columns containing the XY coordinates of each point in the CW

measurement path by selecting them from the Field row of the table on the Setup tab.

Notes:

• You do not have to complete the import procedure to save the import configuration and have it

available for future use.

• When importing a CW measurement file, you can expand the MeasImport.ini file by clicking the

button ( ) in front of the file in the Setup part to display all the available import configurations.

When selecting the appropriate configuration, the associations are automatically made in the

table at the bottom of the dialogue.

• You can delete an existing import configuration by selecting the import configuration under

Setup and clicking the Delete button.

Note: When you click the Import All button, Atoll does not import files that do match the cur-

rently selected import configuration. It displays an error message and continues with the

next file.


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4.1.2.3 Creating a CW Measurement Import Configuration

If you regularly import CW measurement files of the same format, you can create an import configuration the first time you

import the CW measurement files. The import configuration contains information that defines the structure of the data in

the CW measurement file. By using the import configuration, you will not need to define the data structure each time you

import a new CW measurement file.

To create a CW measurement import configuration:


atoll 2.8.1 model calibration guide

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