Atoll
RF Planning & Optimisation Software
Technical Reference Guide
v e r s i o n 2.8.1
AT281_TRG_E1
Technical Reference Guide
Contact Information
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Sales and pricing information
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Atoll 2.8.1 Technical Reference Guide Release AT281_TRG_E1
© 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.
About Technical Reference Guide
This document is targeted at readers with a prior knowledge of Atoll, its operation and basic functioning. It is not the User
Manual for Atoll, and does not teach how to operate and use Atoll. It is a supplementary document containing detailed
descriptions of models, algorithms and concepts adopted in Atoll. Therefore, it concerns only the appropriate personnel.
Atoll Technical Reference Guide is divided into three parts with each part comprising similar topics. The first part contains
descriptions of general terms, entities, ideas and concepts in Atoll that are encountered throughout its use. It is followed
by the second part that consists of descriptions of entities common to all types of networks and the algorithms that are
technology independent and are available in any network type. Lastly, the guide provides detailed descriptions of each
basic type of network that can be modelled and studied in Atoll.
© Forsk 2009
AT281_TRG_E1
3
Technical Reference Guide
4
AT281_TRG_E1
© Forsk 2009
Table of Contents
Table of Contents
1
1.1
1.1.1
1.1.1.1
1.1.1.2
1.1.1.3
1.1.1.4
1.1.1.5
1.1.1.6
1.1.2
1.1.2.1
1.1.2.2
1.1.2.3
1.1.3
1.1.3.1
1.1.3.2
1.1.3.3
1.1.3.4
1.1.3.5
1.1.4
1.2
1.2.1
1.2.2
1.3
2
2.1
2.1.1
2.1.1.1
2.1.1.2
2.1.1.2.1
2.1.1.2.2
2.1.1.3
2.1.1.3.1
2.1.1.3.2
2.1.1.3.3
2.1.1.3.4
2.1.1.4
2.1.1.5
2.1.1.6
2.1.1.7
2.1.2
2.2
2.2.1
2.2.2
2.2.3
2.2.4
2.2.5
2.2.6
2.2.7
2.2.8
2.2.8.1
2.2.8.2
2.2.8.3
2.2.9
2.2.9.1
3
3.1
© Forsk 2009
Coordinate Systems and Units ....................................................... 27
Coordinate Systems............................................................................................................................... 27
Description of Coordinate Systems .................................................................................................. 27
Geographic Coordinate System.................................................................................................. 27
Datum ......................................................................................................................................... 27
Meridian ...................................................................................................................................... 27
Ellipsoid ...................................................................................................................................... 27
Projection.................................................................................................................................... 28
Projection Coordinate System .................................................................................................... 28
Coordinate Systems in Atoll ............................................................................................................. 28
Projection Coordinate System .................................................................................................... 28
Display Coordinate System ........................................................................................................ 28
Internal Coordinate Systems ...................................................................................................... 28
File Formats ..................................................................................................................................... 29
Unit Codes .................................................................................................................................. 29
Datum Codes.............................................................................................................................. 30
Projection Method Codes ........................................................................................................... 31
Ellipsoid Codes ........................................................................................................................... 31
Projection Parameter Indices...................................................................................................... 32
Creating a Coordinate System ......................................................................................................... 32
Units ....................................................................................................................................................... 32
Power Units ...................................................................................................................................... 32
Length Units ..................................................................................................................................... 33
BSIC Format .......................................................................................................................................... 33
Geographic and Radio Data ........................................................... 37
Geographic Data .................................................................................................................................... 37
Data Type......................................................................................................................................... 37
Digital Terrain Model (DTM) ....................................................................................................... 37
Clutter (Land Use) ...................................................................................................................... 38
Clutter Classes...................................................................................................................... 38
Clutter Heights ...................................................................................................................... 38
Traffic Data ................................................................................................................................. 38
User Profile Environment Based Traffic Maps ...................................................................... 38
User Profile Traffic Maps....................................................................................................... 38
Sector Traffic Maps ............................................................................................................... 38
User Density Traffic Maps..................................................................................................... 39
Vector Data................................................................................................................................. 39
Scanned Images......................................................................................................................... 39
Population................................................................................................................................... 39
Other Geographic Data............................................................................................................... 39
Supported Geographic Data Formats .............................................................................................. 39
Radio Data ............................................................................................................................................. 40
Site ................................................................................................................................................... 40
Antenna ............................................................................................................................................ 40
Transmitter ....................................................................................................................................... 40
Repeater........................................................................................................................................... 40
Remote Antenna .............................................................................................................................. 41
Station .............................................................................................................................................. 41
Hexagonal Design ............................................................................................................................ 41
GSM GPRS EGPRS Documents ..................................................................................................... 41
TRX............................................................................................................................................. 41
Subcell ........................................................................................................................................ 41
Cell Type..................................................................................................................................... 41
All CDMA, WiMAX, and LTE Documents ......................................................................................... 41
Cell.............................................................................................................................................. 41
File Formats .................................................................................... 45
BIL Format ............................................................................................................................................. 45
AT281_TRG_E1
5
Technical Reference Guide
3.1.1
3.1.1.1
3.1.1.2
3.1.1.2.1
3.1.1.2.2
3.1.1.2.3
3.2
3.2.1
3.2.2
3.2.2.1
3.3
3.3.1
3.3.1.1
3.3.1.2
3.3.1.2.1
3.3.2
3.3.3
3.3.3.1
3.4
3.4.1
3.4.2
3.4.2.1
3.5
3.6
3.7
3.8
3.9
3.10
3.11
3.12
3.12.1
3.12.2
3.13
3.14
3.14.1
3.14.1.1
3.14.1.2
3.14.2
3.14.2.1
3.14.2.2
3.14.3
3.14.3.1
3.14.3.2
3.14.4
3.14.5
3.15
3.15.1
3.15.2
3.16
3.16.1
3.16.2
3.17
3.17.1
3.17.1.1
3.17.1.1.1
3.17.1.1.2
3.17.1.1.3
3.17.1.2
3.17.2
3.18
3.18.1
3.18.1.1
3.18.1.1.1
3.18.1.1.2
3.18.1.1.3
3.18.1.2
3.18.2
3.19
6
HDR Header File...............................................................................................................................45
Description ..................................................................................................................................45
Samples ......................................................................................................................................46
Digital Terrain Model..............................................................................................................46
Clutter Classes File................................................................................................................46
BIL File...................................................................................................................................46
TIF Format ..............................................................................................................................................47
TFW Header File...............................................................................................................................47
Sample ..............................................................................................................................................48
Clutter Classes File .....................................................................................................................48
BMP Format............................................................................................................................................48
BMP File Description.........................................................................................................................48
BMP File Structure ......................................................................................................................48
BMP Raster Data Encoding ........................................................................................................50
Raster Data Compression Descriptions.................................................................................50
BPW/BMW Header File Description..................................................................................................51
Sample ..............................................................................................................................................51
Clutter Classes File .....................................................................................................................51
Generic Raster Header File (.wld) ..........................................................................................................51
WLD File Description ........................................................................................................................51
Sample ..............................................................................................................................................51
Clutter Classes File .....................................................................................................................51
DXF Format ............................................................................................................................................52
SHP Format ............................................................................................................................................52
MIF Format .............................................................................................................................................52
TAB Format ............................................................................................................................................52
ECW Format ...........................................................................................................................................53
Erdas Imagine Format ............................................................................................................................53
Planet EV/Vertical Mapper Geographic Data Format .............................................................................54
ArcView Grid Format ..............................................................................................................................54
ArcView Grid File Description ...........................................................................................................54
Sample ..............................................................................................................................................55
Other Supported Geographic Data File Formats ....................................................................................55
Planet Format .........................................................................................................................................55
DTM File............................................................................................................................................55
Description ..................................................................................................................................55
Sample ........................................................................................................................................56
Clutter Class Files .............................................................................................................................56
Description ..................................................................................................................................56
Sample ........................................................................................................................................56
Vector Files .......................................................................................................................................57
Description ..................................................................................................................................57
Sample ........................................................................................................................................57
Image Files........................................................................................................................................57
Text Data Files ..................................................................................................................................57
MNU Format ...........................................................................................................................................58
Description ........................................................................................................................................58
Sample ..............................................................................................................................................58
XML Table Export/Import Format ...........................................................................................................58
Index.xml File ....................................................................................................................................59
XML File ............................................................................................................................................59
Externalised Propagation Results Format ..............................................................................................60
DBF File ............................................................................................................................................61
DBF File Format ..........................................................................................................................61
DBF Structure ........................................................................................................................61
DBF Header (Variable Size - Depends on Field Count) ........................................................61
Each DBF Record (Fixed Length)..........................................................................................63
DBF File Content.........................................................................................................................63
LOS File ............................................................................................................................................64
Externalised Tuning Files .......................................................................................................................64
DBF File ............................................................................................................................................64
DBF File Format ..........................................................................................................................64
DBF Structure ........................................................................................................................64
DBF Header (Variable Size - Depends on Field Count) ........................................................64
Each DBF Record (Fixed Length)..........................................................................................66
DBF File Content.........................................................................................................................66
PTS File ............................................................................................................................................66
Interference Histograms File Formats ....................................................................................................66
AT281_TRG_E1
© Forsk 2009
Table of Contents
3.19.1
3.19.1.1
3.19.2
3.19.2.1
3.19.2.1.1
3.19.2.1.2
3.19.2.2
3.19.2.2.1
3.19.2.2.2
3.19.3
3.19.3.1
3.19.4
3.19.4.1
4
4.1
4.2
4.2.1
4.2.1.1
4.2.1.2
4.2.2
4.2.2.1
4.2.2.2
4.2.3
4.3
4.3.1
4.3.2
4.3.2.1
4.3.2.2
4.3.3
4.3.3.1
4.3.3.1.1
4.3.3.1.2
4.3.3.2
4.4
4.4.1
4.4.1.1
4.4.1.2
4.4.1.3
4.4.2
4.4.2.1
4.4.2.2
4.4.2.2.1
4.4.2.2.2
4.4.2.2.3
4.4.2.3
4.4.3
4.4.3.1
4.4.3.2
4.4.3.2.1
4.4.3.2.2
4.4.3.2.3
4.4.3.2.4
4.4.3.2.5
4.4.3.2.6
4.4.3.2.7
4.4.3.3
4.4.3.3.1
4.4.3.3.2
4.4.3.4
4.4.4
4.4.4.1
4.4.4.2
4.4.4.2.1
4.4.4.2.2
4.4.5
4.4.5.1
4.4.5.2
© Forsk 2009
One Histogram per Line (.im0) Format............................................................................................. 67
Sample........................................................................................................................................ 67
One Value per Line with Dictionary File (.clc) Format ...................................................................... 68
CLC File...................................................................................................................................... 68
Description ............................................................................................................................ 68
Sample .................................................................................................................................. 69
DCT File...................................................................................................................................... 69
Description ............................................................................................................................ 69
Sample .................................................................................................................................. 70
One Value per Line (Transmitter Name Repeated) (.im1) Format ................................................... 70
Sample........................................................................................................................................ 71
Only Co-Channel and Adjacent Values (.im2) Format ..................................................................... 72
Sample........................................................................................................................................ 72
Calculations .................................................................................... 75
Overview ................................................................................................................................................ 75
Path Loss Matrices................................................................................................................................. 76
Calculation Area Determination........................................................................................................ 77
Computation Zone ...................................................................................................................... 77
Use of Polygonal Zones in Coverage Prediction Reports........................................................... 77
Calculate / Force Calculation Comparison ....................................................................................... 78
Calculate..................................................................................................................................... 78
Force Calculation........................................................................................................................ 78
Matrix Validity ................................................................................................................................... 78
Path Loss Calculations........................................................................................................................... 79
Ground Altitude Determination ......................................................................................................... 79
Clutter Determination ....................................................................................................................... 80
Clutter Class ............................................................................................................................... 80
Clutter Height.............................................................................................................................. 80
Geographic Profile Extraction........................................................................................................... 80
Extraction Methods ..................................................................................................................... 80
Radial Extraction ................................................................................................................... 80
Systematic Extraction ........................................................................................................... 81
Profile Resolution: Multi-Resolution Management...................................................................... 82
Propagation Models ............................................................................................................................... 84
Okumura-Hata and Cost-Hata Propagation Models......................................................................... 85
Hata Path Loss Formula ............................................................................................................. 85
Corrections to the Hata Path Loss Formula................................................................................ 85
Calculations in Atoll .................................................................................................................... 85
ITU 529-3 Propagation Model .......................................................................................................... 86
ITU 529-3 Path Loss Formula..................................................................................................... 86
Corrections to the ITU 529-3 Path Loss Formula ....................................................................... 86
Environment Correction ........................................................................................................ 86
Area Size Correction ............................................................................................................. 86
Distance Correction .............................................................................................................. 87
Calculations in Atoll .................................................................................................................... 87
Standard Propagation Model (SPM) ................................................................................................ 87
SPM Path Loss Formula............................................................................................................. 87
Calculations in Atoll .................................................................................................................... 88
Visibility and Distance Between Transmitter and Receiver................................................... 88
Effective Transmitter Antenna Height ................................................................................... 88
Effective Receiver Antenna Height ....................................................................................... 91
Correction for Hilly Regions in Case of LOS ......................................................................... 91
Diffraction .............................................................................................................................. 92
Losses due to Clutter ............................................................................................................ 92
Recommendations ................................................................................................................ 93
Automatic SPM Calibration......................................................................................................... 93
General Algorithm ................................................................................................................. 94
Sample Values for SPM Path Loss Formula Parameters ..................................................... 94
Unmasked Path Loss Calculation............................................................................................... 95
WLL Propagation Model ................................................................................................................... 96
WLL Path Loss Formula ............................................................................................................. 96
Calculations in Atoll .................................................................................................................... 96
Free Space Loss ................................................................................................................... 96
Diffraction .............................................................................................................................. 96
ITU-R P.526-5 Propagation Model ................................................................................................... 96
ITU 526-5 Path Loss Formula..................................................................................................... 96
Calculations in Atoll .................................................................................................................... 97
AT281_TRG_E1
7
Technical Reference Guide
4.4.5.2.1
4.4.5.2.2
4.4.6
4.4.6.1
4.4.6.2
4.4.6.2.1
4.4.6.2.2
4.4.7
4.4.7.1
4.4.7.2
4.4.7.3
4.4.8
4.4.8.1
4.4.8.1.1
4.4.8.1.2
4.4.8.1.3
4.4.8.1.4
4.4.8.1.5
4.4.8.1.6
4.4.9
4.4.10
4.4.10.1
4.4.10.2
4.4.10.2.1
4.4.10.2.2
4.4.10.2.3
4.4.10.2.4
4.4.10.2.5
4.5
4.5.1
4.5.2
4.6
4.6.1
4.6.2
4.6.3
4.6.4
4.6.4.1
4.7
4.7.1
4.7.1.1
4.7.1.2
4.7.2
4.7.2.1
4.7.2.1.1
4.7.2.1.2
4.7.2.2
4.7.2.2.1
4.7.2.2.2
4.8
4.8.1
4.8.1.1
4.8.1.2
4.8.1.3
4.8.1.4
4.8.2
5
5.1
5.1.1
5.1.2
5.1.2.1
5.1.2.2
5.1.3
5.1.3.1
5.1.3.1.1
5.1.3.1.2
5.1.3.1.3
5.1.3.1.4
8
Free Space Loss....................................................................................................................97
Diffraction...............................................................................................................................97
ITU-R P.370-7 Propagation Model....................................................................................................97
ITU 370-7 Path Loss Formula .....................................................................................................97
Calculations in Atoll .....................................................................................................................97
Free Space Loss....................................................................................................................97
Corrected Standard Loss.......................................................................................................97
Erceg-Greenstein (SUI) Propagation Model .....................................................................................98
SUI Terrain Types .......................................................................................................................99
Erceg-Greenstein (SUI) Path Loss Formula................................................................................99
Calculations in Atoll ...................................................................................................................100
ITU-R P.1546-2 Propagation Model................................................................................................100
Calculations in Atoll ...................................................................................................................101
Step 1: Determination of Graphs to be Used.......................................................................101
Step 2: Calculation of Maximum Field Strength...................................................................101
Step 3: Determination of Transmitter Antenna Height .........................................................101
Step 4: Interpolation/Extrapolation of Field Strength ...........................................................101
Step 5: Calculation of Correction Factors ............................................................................103
Step 6: Calculation of Path Loss..........................................................................................104
Sakagami Extended Propagation Model.........................................................................................104
Appendices .....................................................................................................................................106
Free Space Loss .......................................................................................................................106
Diffraction Loss..........................................................................................................................106
Knife-Edge Diffraction..........................................................................................................106
3 Knife-Edge Deygout Method.............................................................................................107
Epstein-Peterson Method ....................................................................................................108
Deygout Method with Correction .........................................................................................108
Millington Method.................................................................................................................109
Path Loss Tuning..................................................................................................................................109
Standard Tuning on Transmitters....................................................................................................109
Path Loss Tuning of Repeaters.......................................................................................................110
Antenna Attenuation Calculation ..........................................................................................................111
Calculation of Azimuth and Tilt Angles............................................................................................111
Antenna Pattern 3-D Interpolation...................................................................................................112
Additional Electrical Downtilt Modelling...........................................................................................113
Antenna Pattern Smoothing ............................................................................................................113
Smoothing Algorithm .................................................................................................................115
Shadowing Model .................................................................................................................................115
Shadowing Margin Calculation........................................................................................................119
Shadowing Margin Calculation in Predictions ...........................................................................120
Shadowing Margin Calculation in Monte-Carlo Simulations......................................................121
Macro-Diversity Gains Calculation ..................................................................................................122
Uplink Macro-Diversity Gain Evaluation ....................................................................................122
Shadowing Error PDF (n Signals)........................................................................................122
Uplink Macro-Diversity Gain ................................................................................................124
Downlink Macro-Diversity Gain Evaluation ...............................................................................124
Shadowing Error PDF (n Signals)........................................................................................125
Downlink Macro-Diversity Gain............................................................................................127
Appendices ...........................................................................................................................................127
Transmitter Radio Equipment .........................................................................................................127
UMTS HSPA, CDMA2000 1xRTT 1xEV-DO, and TD-SCDMA Documents..............................128
GSM GPRS EGPRS Documents ..............................................................................................129
WiMAX 802.16d and WiMAX 802.16e Documents ...................................................................130
LTE Documents.........................................................................................................................131
Secondary Antennas.......................................................................................................................132
GSM GPRS EDGE Networks ........................................................135
General Prediction Studies ...................................................................................................................135
Calculation Criteria..........................................................................................................................135
Point Analysis..................................................................................................................................135
Profile Tab .................................................................................................................................135
Reception Tab ...........................................................................................................................135
Coverage Studies............................................................................................................................136
Service Area Determination ......................................................................................................136
All Servers ...........................................................................................................................136
Best Signal Level and a Margin ...........................................................................................136
Second Best Signal Level and a Margin..............................................................................136
Best Signal Level per HCS Layer and a Margin ..................................................................137
AT281_TRG_E1
© Forsk 2009
Table of Contents
5.1.3.1.5
5.1.3.1.6
5.1.3.1.7
5.1.3.1.8
5.1.3.2
5.1.3.2.1
5.1.3.2.2
5.2
5.2.1
5.2.1.1
5.2.1.1.1
5.2.1.1.2
5.2.1.2
5.2.1.2.1
5.2.1.2.2
5.2.1.3
5.2.1.3.1
5.2.1.3.2
5.2.2
5.2.2.1
5.2.2.1.1
5.2.2.1.2
5.2.2.1.3
5.2.2.2
5.2.2.2.1
5.2.2.2.2
5.2.2.2.3
5.3
5.3.1
5.3.1.1
5.3.1.2
5.3.1.2.1
5.3.1.2.2
5.3.1.2.3
5.3.2
5.3.2.1
5.3.2.1.1
5.3.2.1.2
5.3.2.2
5.3.2.2.1
5.3.2.2.2
5.3.2.2.3
5.3.2.2.4
5.3.2.2.5
5.3.2.2.6
5.4
5.4.1
5.4.1.1
5.4.1.2
5.4.1.3
5.4.2
5.4.2.1
5.4.2.1.1
5.4.2.1.2
5.4.2.1.3
5.4.2.1.4
5.4.2.1.5
5.4.2.1.6
5.4.2.2
5.4.2.2.1
5.4.2.2.2
5.4.2.2.3
5.4.2.2.4
5.4.2.2.5
5.4.2.2.6
5.5
5.5.1
5.5.2
© Forsk 2009
HCS Servers and a Margin ................................................................................................. 137
Highest Priority HCS Server and a Margin.......................................................................... 137
Second Best Signal Level per HCS Layer and a Margin .................................................... 138
Best Idle Mode Reselection Criterion (C2).......................................................................... 138
Coverage Display ..................................................................................................................... 139
Plot Resolution .................................................................................................................... 139
Display Types ..................................................................................................................... 139
Traffic Analysis..................................................................................................................................... 140
Traffic Distribution .......................................................................................................................... 140
Normal Cells (Nonconcentric, No HCS Layer).......................................................................... 140
Circuit Switched Services.................................................................................................... 140
Packet Switched Services................................................................................................... 140
Concentric Cells........................................................................................................................ 140
Circuit Switched Services.................................................................................................... 140
Packet Switched Services................................................................................................... 140
HCS Layers .............................................................................................................................. 140
Circuit Switched Services.................................................................................................... 141
Packet Switched Services................................................................................................... 141
Calculation of the Traffic Demand per Subcell ............................................................................... 141
User Profile Traffic Maps .......................................................................................................... 141
Normal Cells (Nonconcentric, No HCS Layer) .................................................................... 141
Concentric Cells .................................................................................................................. 141
HCS Layers......................................................................................................................... 142
Sector Traffic Maps................................................................................................................... 146
Normal Cells (Nonconcentric, No HCS Layer) .................................................................... 146
Concentric Cells .................................................................................................................. 146
HCS Layers......................................................................................................................... 146
Network Dimensioning ......................................................................................................................... 150
Dimensioning Models and Quality Graphs ..................................................................................... 150
Circuit Switched Traffic ............................................................................................................. 150
Packet Switched Traffic ............................................................................................................ 150
Throughput.......................................................................................................................... 150
Delay ................................................................................................................................... 153
Blocking Probability............................................................................................................. 153
Network Dimensioning Process ..................................................................................................... 154
Network Dimensioning Engine.................................................................................................. 154
Inputs .................................................................................................................................. 154
Outputs ............................................................................................................................... 155
Network Dimensioning Steps.................................................................................................... 155
Step 1: Timeslots Required for CS Traffic........................................................................... 155
Step 2: TRXs Required for CS Traffic and Dedicated PS Timeslots................................... 155
Step 3: Effective CS Blocking, Effective CS Traffic Overflow and Served CS Traffic ......... 156
Step 4: TRXs to Add for PS Traffic ..................................................................................... 156
Step 5: Served PS Traffic ................................................................................................... 158
Step 6: Total Traffic Load.................................................................................................... 158
Key Performance Indicators Calculation .............................................................................................. 158
Circuit Switched Traffic................................................................................................................... 159
Erlang B .................................................................................................................................... 159
Erlang C.................................................................................................................................... 159
Served Circuit Switched Traffic................................................................................................. 159
Packet Switched Traffic .................................................................................................................. 159
Case 1: Total Traffic Demand > Dedicated + Shared Timeslots .............................................. 160
Traffic Load ......................................................................................................................... 160
Packet Switched Traffic Overflow ....................................................................................... 160
Throughput Reduction Factor ............................................................................................. 160
Delay ................................................................................................................................... 160
Blocking Probability............................................................................................................. 160
Served Packet Switched Traffic .......................................................................................... 160
Case 2: Total Traffic Demand < Dedicated + Shared Timeslots .............................................. 160
Traffic Load ......................................................................................................................... 160
Packet Switched Traffic Overflow ....................................................................................... 160
Throughput Reduction Factor ............................................................................................. 161
Delay ................................................................................................................................... 161
Blocking Probability............................................................................................................. 161
Served Packet Switched Traffic .......................................................................................... 161
Neighbour Allocation ............................................................................................................................ 161
Global Allocation for All Transmitters ............................................................................................. 161
Allocation for a Group of Transmitters or One Transmitter ............................................................ 164
AT281_TRG_E1
9
Technical Reference Guide
5.6
5.6.1
5.6.1.1
5.6.1.1.1
5.6.1.1.2
5.6.1.1.3
5.6.1.1.4
5.6.1.1.5
5.6.1.2
5.6.1.2.1
5.6.1.2.2
5.6.1.2.3
5.6.1.2.4
5.6.1.3
5.6.1.3.1
5.6.1.3.2
5.6.1.4
5.6.1.4.1
5.6.1.4.2
5.6.1.4.3
5.6.1.4.4
5.6.2
5.7
5.7.1
5.7.1.1
5.7.1.2
5.7.1.3
5.7.1.4
5.7.1.5
5.7.1.6
5.7.2
5.7.2.1
5.7.2.2
5.7.2.3
5.7.2.4
5.7.3
5.7.3.1
5.7.3.1.1
5.7.3.1.2
5.7.3.2
5.7.3.2.1
5.7.3.2.2
5.7.3.3
5.7.3.3.1
5.7.3.3.2
5.7.3.4
5.7.3.4.1
5.7.3.4.2
5.7.3.5
5.7.3.5.1
5.7.3.5.2
5.7.3.6
5.7.3.6.1
5.7.3.6.2
5.7.4
5.7.4.1
5.7.4.1.1
5.7.4.1.2
5.7.4.2
5.7.4.2.1
5.7.4.2.2
5.7.4.2.3
5.7.4.2.4
5.7.4.2.5
5.7.4.2.6
5.7.4.2.7
5.8
5.8.1
10
Interference Prediction Studies.............................................................................................................165
Coverage Studies............................................................................................................................165
Service Area Determination ......................................................................................................165
All Servers ...........................................................................................................................165
Best Signal Level per HCS Layer and a Margin ..................................................................165
Best Signal Level of the Highest Priority HCS Layer and a Margin .....................................165
Second Best Signal Level per HCS Layer and a Margin .....................................................166
Best Idle Mode Reselection Criterion (C2) ..........................................................................166
Carrier to Interference Ratio Calculation ...................................................................................166
Carrier Power Level .............................................................................................................167
Interference Calculation.......................................................................................................167
Collision Probability for Non Hopping Mode ........................................................................169
Collision Probability for BBH and SFH Modes.....................................................................169
Coverage Area Determination...................................................................................................170
Interference Condition Satisfied by At Least One TRX........................................................170
Interference Condition Satisfied by The Worst TRX ............................................................170
Coverage Area Display .............................................................................................................170
C/I Level...............................................................................................................................170
Max C/I Level.......................................................................................................................171
Min C/I Level........................................................................................................................171
Transmitter...........................................................................................................................171
Point Analysis..................................................................................................................................171
GPRS EDGE Coverage Studies...........................................................................................................171
Coverage Area Determination.........................................................................................................171
All Servers .................................................................................................................................172
Best Signal Level per HCS Layer and a Margin ........................................................................172
Second Best Signal Level per HCS Layer and a Margin...........................................................172
HCS Servers and a Margin .......................................................................................................172
Highest Priority HCS Server and a Margin ................................................................................172
Best C2......................................................................................................................................172
Calculation Options .........................................................................................................................172
Calculations Based on C ...........................................................................................................173
Calculations Based on C/I Without Considering Thermal Noise ...............................................173
Calculations Based on C/I Considering Thermal Noise ............................................................173
Ideal Link Adaptation (ILA) ........................................................................................................173
Coverage Study Scenarios .............................................................................................................173
GPRS/EDGE Studies Based on C Without ILA.........................................................................173
Coding Scheme Based on C Without ILA............................................................................173
Throughput Based on C Without ILA ...................................................................................174
GPRS/EDGE Studies Based on C With ILA..............................................................................174
Coding Scheme Based on C With ILA.................................................................................174
Throughput Based on C With ILA ........................................................................................174
GPRS/EDGE Studies Based on C/I Without ILA and Thermal Noise .......................................174
Coding Scheme Based on C/I Without ILA and Thermal Noise ..........................................174
Throughput Based on Worst Case Between C and C/I Without ILA....................................175
GPRS/EDGE Studies Based on C/I With ILA and Without Thermal Noise ...............................175
Coding Scheme Based on C/I With ILA and Without Thermal Noise ..................................175
Throughput Based on Worst Case Between C and C/I With ILA.........................................176
GPRS/EDGE Studies Based on C/I Without ILA and With Thermal Noise ...............................176
Coding Scheme Based on C/I Without ILA and With Thermal Noise ..................................176
Throughput Based on Interpolation Between C/N and C/(I+N) Without ILA ........................176
GPRS/EDGE Studies Based on C/I With ILA and Thermal Noise ............................................177
Coding Scheme Based on C/I With ILA and Thermal Noise ...............................................177
Throughput Based on Interpolation Between C/N and C/(I+N) With ILA .............................177
Coverage Display............................................................................................................................178
GPRS/EDGE Coding Schemes Study Display Types ...............................................................178
Coding Schemes .................................................................................................................178
Best Coding Schemes .........................................................................................................178
RLC/MAC and Application Throughput/Timeslot Studies Display Types ..................................178
Relation Between RLC/MAC and Application Throughputs.................................................178
Throughput/Timeslot............................................................................................................178
Best Throughput/Timeslot....................................................................................................178
Average Throughput/Timeslot .............................................................................................178
Block Error Rate Computation .............................................................................................178
BLER Percentage ................................................................................................................179
Maximum BLER Percentage ...............................................................................................179
Circuit Quality Indicators Studies..........................................................................................................179
Circuit Quality Indicators .................................................................................................................179
AT281_TRG_E1
© Forsk 2009
Table of Contents
5.8.2
5.8.2.1
5.8.2.2
5.8.2.3
5.8.2.4
5.8.2.5
5.8.3
5.8.3.1
5.8.3.2
5.8.3.3
5.8.4
5.8.4.1
5.8.4.2
5.8.4.3
5.8.4.4
5.8.5
5.8.5.1
5.8.5.1.1
5.8.5.1.2
6
6.1
6.1.1
6.1.2
6.1.2.1
6.1.2.2
6.1.3
6.1.3.1
6.1.3.1.1
6.1.3.1.2
6.1.3.1.3
6.1.3.2
6.1.3.2.1
6.1.3.2.2
6.2
6.2.1
6.2.2
6.2.3
6.2.4
6.3
6.4
6.4.1
6.4.1.1
6.4.1.1.1
6.4.1.1.2
6.4.1.2
6.4.1.2.1
6.4.1.2.2
6.4.1.2.3
6.4.2
6.4.2.1
6.4.2.2
6.4.2.3
6.4.2.3.1
6.4.2.3.2
6.4.2.3.3
6.4.2.3.4
6.4.2.3.5
6.4.2.3.6
6.4.2.4
6.4.2.4.1
6.4.2.4.2
6.4.2.4.3
6.4.2.4.4
6.4.2.5
6.4.3
6.4.3.1
6.4.3.2
© Forsk 2009
Coverage Area Determination........................................................................................................ 181
All Servers ................................................................................................................................ 181
Best Signal Level per HCS Layer and a Margin ....................................................................... 181
Second Best Signal Level per HCS Layer and a Margin .......................................................... 181
HCS Servers and a Margin....................................................................................................... 181
Highest Priority HCS Server and a Margin ............................................................................... 182
Calculation Options ........................................................................................................................ 182
Calculations Based on C/N....................................................................................................... 182
Calculations Based on C/(I+N) ................................................................................................. 183
Ideal Link Adaptation (ILA) ....................................................................................................... 183
Calculation Scenarios..................................................................................................................... 183
CQI Study Based on C/N Without ILA ...................................................................................... 183
CQI Study Based on C/N With ILA ........................................................................................... 183
CQI Study Based on C/(I+N) Without ILA................................................................................. 184
CQI Study Based on C/(I+N) With ILA...................................................................................... 184
Coverage Display ........................................................................................................................... 185
Circuit Quality Indicators Study Display Types ......................................................................... 185
FER/BER/MOS ................................................................................................................... 185
Max FER/Max BER/Max MOS ............................................................................................ 185
UMTS HSPA Networks ................................................................. 189
General Prediction Studies .................................................................................................................. 189
Calculation Criteria ......................................................................................................................... 189
Point Analysis ................................................................................................................................. 189
Profile Tab ................................................................................................................................ 189
Reception Tab .......................................................................................................................... 189
Coverage Studies ........................................................................................................................... 190
Service Area Determination...................................................................................................... 190
All Servers........................................................................................................................... 190
Best Signal Level and a Margin .......................................................................................... 190
Second Best Signal Level and a Margin ............................................................................. 190
Coverage Display ..................................................................................................................... 191
Plot Resolution .................................................................................................................... 191
Display Types ..................................................................................................................... 191
Definitions and Formulas ..................................................................................................................... 192
Inputs.............................................................................................................................................. 192
Ec/I0 Calculation ............................................................................................................................ 197
DL Eb/Nt Calculation ...................................................................................................................... 198
UL Eb/Nt Calculation ...................................................................................................................... 199
Active Set Management ....................................................................................................................... 200
Simulations........................................................................................................................................... 200
Generating a Realistic User Distribution ........................................................................................ 200
Simulations Based on User Profile Traffic Maps ...................................................................... 201
Circuit Switched Service (i) ................................................................................................. 201
Packet Switched Service (j) ................................................................................................ 201
Simulations Based on Sector Traffic Maps............................................................................... 204
Throughputs in Uplink and Downlink................................................................................... 204
Total Number of Users (All Activity Statuses) ..................................................................... 205
Number of Users per Activity Status ................................................................................... 205
Power Control Simulation............................................................................................................... 206
Algorithm Initialization............................................................................................................... 207
R99 Part of the Algorithm ......................................................................................................... 207
HSDPA Part of the Algorithm.................................................................................................... 211
HSDPA Power Allocation .................................................................................................... 211
Number of HS-SCCH Channels and Maximum Number of HSDPA Bearer Users............. 212
HSDPA Bearer Allocation Process ..................................................................................... 212
Fast Link Adaptation Modelling ........................................................................................... 214
MIMO Modelling .................................................................................................................. 224
Scheduling Algorithms ........................................................................................................ 224
HSUPA Part of the Algorithm.................................................................................................... 226
Admission Control ............................................................................................................... 226
HSUPA Bearer Allocation Process ..................................................................................... 228
Noise Rise Scheduling ........................................................................................................ 229
Radio Resource Control...................................................................................................... 233
Convergence Criteria................................................................................................................ 233
Results ........................................................................................................................................... 233
R99 Related Results................................................................................................................. 233
HSPA Related Results.............................................................................................................. 235
AT281_TRG_E1
11
Technical Reference Guide
6.4.3.2.1
6.4.3.2.2
6.4.3.2.3
6.4.3.2.4
6.4.4
6.4.4.1
6.4.4.2
6.4.4.2.1
6.4.4.2.2
6.4.4.2.3
6.4.4.3
6.4.4.3.1
6.4.4.3.2
6.4.4.4
6.4.4.5
6.4.4.6
6.5
6.5.1
6.5.1.1
6.5.1.1.1
6.5.1.1.2
6.5.1.1.3
6.5.2
6.5.2.1
6.5.2.1.1
6.5.2.1.2
6.5.2.2
6.5.2.2.1
6.5.2.2.2
6.5.2.3
6.5.2.3.1
6.5.2.3.2
6.5.2.4
6.5.2.4.1
6.5.2.4.2
6.5.2.4.3
6.5.2.5
6.5.2.5.1
6.5.2.5.2
6.5.2.6
6.5.2.6.1
6.5.2.6.2
6.5.2.6.3
6.6
6.6.1
6.6.2
6.6.3
6.6.3.1
6.6.3.2
6.7
6.7.1
6.7.1.1
6.7.1.2
6.7.1.2.1
6.7.1.2.2
6.7.1.3
6.7.1.3.1
6.7.1.3.2
6.7.1.3.3
6.7.2
6.7.2.1
6.7.2.1.1
6.7.2.1.2
6.7.2.1.3
6.7.2.1.4
6.7.2.2
6.8
6.8.1
12
Statistics Tab .......................................................................................................................235
Mobiles Tab .........................................................................................................................236
Cells Tab..............................................................................................................................238
Sites Tab..............................................................................................................................239
Appendices .....................................................................................................................................240
Admission Control in the R99 Part ............................................................................................240
Resources Management ...........................................................................................................240
OVSF Codes Management..................................................................................................240
Channel Elements Management .........................................................................................241
Iub Backhaul Throughput.....................................................................................................242
Downlink Load Factor Calculation .............................................................................................243
Downlink Load Factor per Cell.............................................................................................243
Downlink Load Factor per Mobile ........................................................................................244
Uplink Load Factor Due to One User ........................................................................................244
Inter-carrier Power Sharing Modelling .......................................................................................246
Best Server Determination in Monte Carlo Simulations - Old Method ......................................247
UMTS HSPA Prediction Studies...........................................................................................................249
Point Analysis..................................................................................................................................249
AS Analysis Tab ........................................................................................................................249
Bar Graph and Pilot Sub-Menu............................................................................................249
Downlink Sub-Menu.............................................................................................................251
Uplink Sub-Menu .................................................................................................................256
Coverage Studies............................................................................................................................259
Pilot Reception Analysis ............................................................................................................259
Prediction Study Inputs........................................................................................................260
Study Display Options .........................................................................................................260
Downlink Service Area Analysis ................................................................................................261
Prediction Study Inputs........................................................................................................261
Study Display Options .........................................................................................................261
Uplink Service Area Analysis ....................................................................................................262
Prediction Study Inputs........................................................................................................263
Study Display Options .........................................................................................................263
Downlink Total Noise Analysis ..................................................................................................264
Study Inputs.........................................................................................................................264
Analysis on All Carriers........................................................................................................264
Analysis on a Specific Carrier..............................................................................................265
HSDPA Prediction Study ...........................................................................................................265
Prediction Study Inputs........................................................................................................265
Study Display Options .........................................................................................................266
HSUPA Prediction Study ...........................................................................................................269
Prediction Study Inputs........................................................................................................270
Calculation Options..............................................................................................................270
Display Options....................................................................................................................270
Automatic Neighbour Allocation............................................................................................................272
Neighbour Allocation for All Transmitters........................................................................................272
Neighbour Allocation for a Group of Transmitters or One Transmitter............................................276
Importance Calculation ...................................................................................................................276
Importance of Intra-carrier Neighbours .....................................................................................276
Importance of Inter-carrier Neighbours .....................................................................................277
Primary Scrambling Code Allocation ....................................................................................................278
Automatic Allocation Description.....................................................................................................278
Options and Constraints ............................................................................................................278
Allocation Process.....................................................................................................................279
Single Carrier Network.........................................................................................................280
Multi-Carrier Network...........................................................................................................280
Priority Determination ................................................................................................................281
Cell Priority ..........................................................................................................................281
Transmitter Priority ..............................................................................................................283
Site Priority ..........................................................................................................................283
Allocation Examples........................................................................................................................283
Allocation Strategies and Use a Maximum of Codes ................................................................283
Strategy: Clustered ..............................................................................................................284
Strategy: Distributed ............................................................................................................285
Strategy: ‘One Cluster per Site ............................................................................................285
Strategy: ‘Distributed per Site ..............................................................................................286
Allocate Carriers Identically .......................................................................................................286
Automatic GSM-UMTS Neighbour Allocation .......................................................................................287
Overview .........................................................................................................................................287
AT281_TRG_E1
© Forsk 2009
Table of Contents
6.8.2
6.8.2.1
6.8.2.2
6.8.2.3
6.8.2.3.1
6.8.2.3.2
7
7.1
7.1.1
7.1.2
7.1.2.1
7.1.2.2
7.1.3
7.1.3.1
7.1.3.1.1
7.1.3.1.2
7.1.3.1.3
7.1.3.2
7.1.3.2.1
7.1.3.2.2
7.2
7.2.1
7.2.1.1
7.2.1.2
7.2.1.3
7.2.1.4
7.2.1.5
7.2.2
7.2.2.1
7.2.2.2
7.2.2.3
7.2.2.4
7.3
7.4
7.4.1
7.4.1.1
7.4.1.1.1
7.4.1.1.2
7.4.1.2
7.4.1.3
7.4.2
7.4.2.1
7.4.2.1.1
7.4.2.1.2
7.4.2.1.3
7.4.2.2
7.4.2.2.1
7.4.2.2.2
7.4.2.2.3
7.4.3
7.4.3.1
7.4.3.2
7.4.3.2.1
7.4.3.2.2
7.4.3.3
7.4.3.3.1
7.4.3.3.2
7.4.3.4
7.5
7.5.1
7.5.1.1
7.5.1.2
7.5.1.2.1
7.5.1.2.2
7.5.1.3
7.5.1.3.1
7.5.1.3.2
© Forsk 2009
Automatic Allocation Description .................................................................................................... 287
Algorithm Based on Distance ................................................................................................... 287
Algorithm Based on Coverage Overlapping ............................................................................. 288
Appendices ............................................................................................................................... 290
Delete Existing Neighbours Option ..................................................................................... 290
Calculation of Inter-Transmitter Distance............................................................................ 290
CDMA2000 Networks ................................................................... 293
General Prediction Studies .................................................................................................................. 293
Calculation Criteria ......................................................................................................................... 293
Point Analysis ................................................................................................................................. 293
Profile Tab ................................................................................................................................ 293
Reception Tab .......................................................................................................................... 294
Coverage Studies ........................................................................................................................... 294
Service Area Determination...................................................................................................... 294
All Servers........................................................................................................................... 294
Best Signal Level and a Margin .......................................................................................... 294
Second Best Signal Level and a Margin ............................................................................. 294
Coverage Display ..................................................................................................................... 295
Plot Resolution .................................................................................................................... 295
Display Types ..................................................................................................................... 295
Definitions and Formulas ..................................................................................................................... 296
Parameters Used for CDMA2000 1xRTT Modelling ...................................................................... 296
Inputs ........................................................................................................................................ 296
Ec/I0 Calculation....................................................................................................................... 300
DL Eb/Nt Calculation ................................................................................................................ 300
UL Eb/Nt Calculation ................................................................................................................ 301
Simulation Results .................................................................................................................... 303
Parameters Used for CDMA2000 1xEV-DO Modelling .................................................................. 304
Inputs ........................................................................................................................................ 304
Ec/I0 and Ec/Nt Calculations .................................................................................................... 307
UL Eb/Nt Calculation ................................................................................................................ 308
Simulation Results .................................................................................................................... 309
Active Set Management ....................................................................................................................... 310
Simulations........................................................................................................................................... 311
Generating a Realistic User Distribution ........................................................................................ 311
Number of Users, User Activity Status and User Data Rate..................................................... 311
Simulations Based on User Profile Traffic Maps................................................................. 311
Simulations Based on Sector Traffic Maps ......................................................................... 314
Transition Flags for 1xEV-DO Rev.0 User Data Rates............................................................. 319
User Geographical Position ...................................................................................................... 319
Network Regulation Mechanism..................................................................................................... 319
CDMA2000 1xRTT Power Control Simulation Algorithm.......................................................... 319
Algorithm Initialization ......................................................................................................... 320
Presentation of the Algorithm.............................................................................................. 320
Convergence Criterion ........................................................................................................ 326
CDMA2000 1xEV-DO Power/Data Rate Control Simulation Algorithm .................................... 327
Algorithm Initialization ......................................................................................................... 328
Presentation of the Algorithm.............................................................................................. 328
Convergence Criterion ........................................................................................................ 333
Appendices..................................................................................................................................... 334
Admission Control..................................................................................................................... 334
Resources Management........................................................................................................... 334
Walsh Code Management .................................................................................................. 334
Channel Element Management .......................................................................................... 335
Downlink Load Factor Calculation ............................................................................................ 335
Downlink Load Factor per Cell ............................................................................................ 335
Downlink Load Factor per Mobile........................................................................................ 337
Best Server Determination in Monte Carlo Simulations - Old Method...................................... 337
CDMA2000 Prediction Studies............................................................................................................. 339
Point Analysis: The AS Analysis Tab ............................................................................................. 339
Bar Graph and Pilot Sub-Menu................................................................................................. 339
Downlink Sub-Menu.................................................................................................................. 341
CDMA2000 1xRTT.............................................................................................................. 341
CDMA2000 1xEV-DO ......................................................................................................... 345
Uplink Sub-Menu ...................................................................................................................... 346
CDMA2000 1xRTT.............................................................................................................. 346
CDMA2000 1xEV-DO ......................................................................................................... 350
AT281_TRG_E1
13
Technical Reference Guide
7.5.2
7.5.2.1
7.5.2.2
7.5.2.2.1
7.5.2.2.2
7.5.2.3
7.5.2.3.1
7.5.2.3.2
7.5.2.4
7.5.2.4.1
7.5.2.4.2
7.6
7.6.1
7.6.2
7.6.3
7.6.3.1
7.6.3.2
7.7
7.7.1
7.7.1.1
7.7.1.2
7.7.1.2.1
7.7.1.2.2
7.7.1.2.3
7.7.1.3
7.7.1.3.1
7.7.1.3.2
7.7.1.3.3
7.7.2
7.7.2.1
7.7.2.2
7.7.2.3
7.8
7.8.1
7.8.2
7.8.2.1
7.8.2.2
7.8.2.3
8
8.1
8.1.1
8.1.2
8.1.3
8.1.4
8.1.5
8.1.6
8.1.7
8.1.8
8.1.8.1
8.1.8.2
8.1.8.3
8.2
8.2.1
8.2.1.1
8.2.1.2
8.2.2
8.2.2.1
8.2.2.2
8.2.2.2.1
8.2.2.2.2
8.2.2.3
8.2.2.4
8.2.2.5
8.2.2.5.1
8.2.2.5.2
8.2.2.6
8.2.2.6.1
14
Coverage Studies............................................................................................................................353
Pilot Reception Analysis ............................................................................................................353
Downlink Service Area Analysis ................................................................................................354
CDMA2000 1xRTT ..............................................................................................................354
CDMA2000 1xEV-DO ..........................................................................................................356
Uplink Service Area Analysis ....................................................................................................357
CDMA2000 1xRTT ..............................................................................................................357
CDMA2000 1xEV-DO ..........................................................................................................358
Downlink Total Noise Analysis ..................................................................................................361
Analysis on all Carriers ........................................................................................................361
Analysis on a Specific Carrier..............................................................................................362
Automatic Neighbour Allocation............................................................................................................362
Neighbour Allocation for all Transmitters ........................................................................................362
Neighbour Allocation for a Group of Transmitters or One Transmitter............................................365
Importance Calculation ...................................................................................................................365
Importance of Intra-carrier Neighbours .....................................................................................365
Importance of Inter-carrier Neighbours .....................................................................................366
PN Offset Allocation..............................................................................................................................367
Automatic Allocation Description.....................................................................................................367
Options and Constraints ............................................................................................................367
Allocation Process.....................................................................................................................368
Single Carrier Network.........................................................................................................368
Multi-Carrier Network...........................................................................................................369
Difference between Adjacent and Distributed PN-Clusters .................................................369
Priority Determination ................................................................................................................370
Cell Priority ..........................................................................................................................370
Transmitter Priority ..............................................................................................................371
Site Priority ..........................................................................................................................372
Allocation Examples........................................................................................................................372
Strategy: PN Offset per Cell ......................................................................................................373
Strategy: Adjacent PN-Clusters Per Site...................................................................................373
Strategy: ‘Distributed PN-Clusters Per Site ...............................................................................374
Automatic GSM-CDMA Neighbour Allocation.......................................................................................374
Overview .........................................................................................................................................374
Automatic Allocation Description.....................................................................................................374
Algorithm Based on Distance ....................................................................................................375
Algorithm Based on Coverage Overlapping ..............................................................................375
Delete Existing Neighbours Option ...........................................................................................377
TD-SCDMA Networks....................................................................381
Definitions and Formulas ......................................................................................................................381
Inputs ..............................................................................................................................................381
P-CCPCH Eb/Nt and C/I Calculation ..............................................................................................385
DwPCH C/I Calculation ...................................................................................................................386
DL TCH Eb/Nt and C/I Calculation..................................................................................................386
UL TCH Eb/Nt and C/I Calculation..................................................................................................386
Interference Calculation ..................................................................................................................387
HSDPA Dynamic Power Calculations .............................................................................................387
Smart Antenna Models....................................................................................................................387
Downlink Beamforming .............................................................................................................387
Uplink Beamforming ..................................................................................................................388
Uplink Beamforming and Interference Cancellation (MMSE) ....................................................388
Signal Level Based Calculations ..........................................................................................................389
Point Analysis..................................................................................................................................389
Profile Tab .................................................................................................................................389
Reception Tab ...........................................................................................................................389
RSCP Based Coverage Predictions................................................................................................390
Calculation Criteria ....................................................................................................................390
P-CCPCH RSCP Coverage Prediction .....................................................................................390
Coverage Condition .............................................................................................................390
Coverage Display ................................................................................................................391
Best Server P-CCPCH Coverage Prediction.............................................................................391
P-CCPCH Pollution Coverage Prediction..................................................................................391
DwPCH RSCP Coverage Prediction .........................................................................................392
Coverage Condition .............................................................................................................392
Coverage Display ................................................................................................................392
UpPCH RSCP Coverage Prediction..........................................................................................392
Coverage Condition .............................................................................................................392
AT281_TRG_E1
© Forsk 2009
Table of Contents
8.2.2.6.2
8.2.2.7
8.2.2.7.1
8.2.2.7.2
8.2.2.8
8.3
8.3.1
8.3.1.1
8.3.1.1.1
8.3.1.1.2
8.3.1.2
8.3.1.2.1
8.3.1.2.2
8.3.1.2.3
8.3.2
8.3.2.1
8.3.2.2
8.3.2.2.1
8.3.2.2.2
8.3.2.2.3
8.3.2.2.4
8.3.2.2.5
8.3.2.2.6
8.3.2.2.7
8.3.2.3
8.3.2.3.1
8.3.2.3.2
8.3.2.3.3
8.3.2.3.4
8.3.2.3.5
8.3.2.4
8.4
8.4.1
8.4.2
8.4.3
8.4.4
8.4.5
8.4.6
8.4.7
8.4.8
8.4.9
8.4.10
8.4.11
8.5
8.5.1
8.5.1.1
8.5.1.2
8.5.1.3
8.5.1.4
8.5.1.4.1
8.5.1.4.2
8.5.1.4.3
8.5.1.5
8.5.2
8.5.3
8.5.4
8.5.4.1
8.5.4.1.1
8.5.4.1.2
8.5.4.2
8.5.4.2.1
8.5.4.2.2
8.5.4.2.3
8.6
8.6.1
8.7
8.7.1
8.7.2
© Forsk 2009
Coverage Display................................................................................................................ 392
Baton Handover Coverage Prediction ...................................................................................... 393
Coverage Condition ............................................................................................................ 393
Coverage Display................................................................................................................ 393
Scrambling Code Interference Analysis.................................................................................... 393
Monte Carlo Simulations ...................................................................................................................... 394
Generating a Realistic User Distribution ........................................................................................ 394
Simulations Based on User Profile Traffic Maps ...................................................................... 394
Circuit Switched Service (i) ................................................................................................. 395
Packet Switched Service (j) ................................................................................................ 395
Simulations Based on Sector Traffic Maps............................................................................... 398
Throughputs in Uplink and Downlink................................................................................... 398
Total Number of Users (All Activity Statuses) ..................................................................... 398
Number of Users per Activity Status ................................................................................... 399
Power Control Simulation............................................................................................................... 399
Algorithm Initialisation............................................................................................................... 400
R99 Part of the Algorithm ......................................................................................................... 400
Determination of Mi’s Best Server (SBS(Mi))...................................................................... 400
Dynamic Channel Allocation ............................................................................................... 401
Uplink Power Control .......................................................................................................... 402
Downlink Power Control...................................................................................................... 404
Uplink Signals Update......................................................................................................... 406
Downlink Signals Update .................................................................................................... 406
Control of Radio Resource Limits (Downlink Traffic Power and Uplink Load) .................... 406
HSDPA Part of the Algorithm.................................................................................................... 407
HSDPA Power Allocation .................................................................................................... 407
Connection Status and Number of HSDPA Users .............................................................. 409
HSDPA Admission Control.................................................................................................. 409
HSDPA Dynamic Channel Allocation.................................................................................. 410
Ressource Unit Saturation .................................................................................................. 410
Convergence Criteria................................................................................................................ 410
TD-SCDMA Prediction Studies ............................................................................................................ 411
P-CCPCH Reception Analysis (Eb/Nt) or (C/I) ............................................................................... 411
DwPCH Reception Analysis (C/I) ................................................................................................... 412
Downlink TCH RSCP Coverage ..................................................................................................... 414
Uplink TCH RSCP Coverage ......................................................................................................... 414
Downlink Total Noise...................................................................................................................... 415
Downlink Service Area (Eb/Nt) or (C/I)........................................................................................... 416
Uplink Service Area (Eb/Nt) or (C/I) ............................................................................................... 418
Effective Service Area (Eb/Nt) or (C/I) ........................................................................................... 419
Cell to Cell Interference .................................................................................................................. 420
UpPCH Interference ....................................................................................................................... 421
HSDPA Coverage .......................................................................................................................... 421
Smart Antenna Modelling..................................................................................................................... 422
Modelling in Simulations................................................................................................................. 423
Grid of Beams Modelling .......................................................................................................... 423
Adaptive Beam Modelling ......................................................................................................... 424
Statistical Modelling .................................................................................................................. 425
Beamforming Smart Antenna Models....................................................................................... 425
Downlink Beamforming ....................................................................................................... 426
Uplink Beamforming............................................................................................................ 427
Uplink Beamforming and Interference Cancellation (MMSE).............................................. 428
3rd Party Smart Antenna Modelling.......................................................................................... 429
Construction of the Geographic Distributions ................................................................................. 429
Modelling in Coverage Predictions ................................................................................................. 431
HSDPA Coverage Prediction ......................................................................................................... 431
Fast Link Adaptation Modelling................................................................................................. 431
CQI Based on P-CCPCH Quality ........................................................................................ 432
CQI Based on HS-PDSCH Quality...................................................................................... 435
Coverage Prediction Display Options ....................................................................................... 437
Colour per CQI .................................................................................................................... 437
Colour per Peak Throughput............................................................................................... 437
Colour per HS-PDSCH Ec/Nt.............................................................................................. 437
N-Frequency Mode and Carrier Allocation........................................................................................... 437
Automatic Carrier Allocation........................................................................................................... 437
Neighbour Allocation ............................................................................................................................ 438
Neighbour Allocation for All Transmitters ....................................................................................... 439
Neighbour Allocation for a Group of Transmitters or One Transmitter ........................................... 441
AT281_TRG_E1
15
Technical Reference Guide
8.7.3
8.8
8.8.1
8.8.1.1
8.8.1.2
8.8.1.3
8.8.1.3.1
8.8.1.3.2
8.8.1.4
8.8.1.4.1
8.8.1.4.2
8.8.1.4.3
8.8.2
8.8.2.1
8.8.2.1.1
8.8.2.1.2
8.8.2.1.3
8.8.2.1.4
8.8.2.2
8.9
8.9.1
8.9.1.1
8.9.1.2
8.9.1.3
8.9.1.3.1
8.9.1.3.2
9
9.1
9.1.1
9.1.2
9.1.3
9.1.3.1
9.1.3.2
9.1.3.3
9.1.3.4
9.1.3.5
9.1.4
9.1.4.1
9.1.4.2
9.1.4.3
9.1.4.4
9.1.4.5
9.1.4.6
9.1.4.7
9.1.4.8
9.1.4.9
9.1.4.10
9.1.5
9.1.5.1
9.1.5.2
9.1.6
9.1.6.1
9.1.7
9.1.7.1
9.1.7.2
9.1.7.3
9.2
9.2.1
9.2.1.1
9.2.1.2
9.2.1.3
9.2.2
9.2.2.1
9.2.2.1.1
9.2.2.1.2
9.2.2.1.3
9.2.2.2
16
Importance Calculation ...................................................................................................................441
Scrambling Code Allocation..................................................................................................................442
Automatic Allocation Description.....................................................................................................443
Allocation Constraints and Options ...........................................................................................443
Allocation Strategies..................................................................................................................443
Allocation Process.....................................................................................................................444
Single Carrier Network.........................................................................................................444
Multi-Carrier Network...........................................................................................................445
Priority Determination ................................................................................................................445
Cell Priority ..........................................................................................................................445
Transmitter Priority ..............................................................................................................448
Site Priority ..........................................................................................................................448
IScrambling Code Allocation Example ............................................................................................448
Single Carrier Network ..............................................................................................................448
Strategy: Clustered ..............................................................................................................449
Strategy: Distributed per Cell...............................................................................................449
Strategy: One SYNC_DL Code per Site ..............................................................................450
Strategy: Distributed per Site...............................................................................................450
Multi Carrier Network.................................................................................................................450
Automatic GSM/TD-SCDMA Neighbour Allocation ..............................................................................451
Automatic Allocation Description.....................................................................................................451
Algorithm Based on Distance ....................................................................................................452
Algorithm Based on Coverage Overlapping ..............................................................................452
Appendices................................................................................................................................454
Delete Existing Neighbours Option......................................................................................454
Calculation of Inter-Transmitter Distance ............................................................................454
WiMAX BWA Networks..................................................................457
Definitions and Formulas ......................................................................................................................457
Input ................................................................................................................................................457
Co- and Adjacent Channel Overlaps Calculation............................................................................461
Preamble Signal Quality Calculations .............................................................................................461
Preamble Signal Level Calculation............................................................................................461
Preamble Noise Calculation ......................................................................................................462
Preamble Interference Calculation ............................................................................................462
Preamble C/N Calculation .........................................................................................................462
Preamble C/(I+N) Calculation....................................................................................................462
Traffic and Pilot Signal Quality Calculations ...................................................................................463
Traffic and Pilot Signal Level Calculation (DL) ..........................................................................463
Traffic and Pilot Noise Calculation (DL) ....................................................................................463
Traffic and Pilot Interference Calculation (DL) ..........................................................................463
Traffic and Pilot C/N Calculation (DL) .......................................................................................464
Traffic and Pilot C/(I+N) Calculation (DL) ..................................................................................465
Traffic Signal Level Calculation (UL) .........................................................................................465
Traffic Noise Calculation (UL) ...................................................................................................465
Traffic Interference Calculation (UL) .........................................................................................466
Traffic C/N Calculation (UL) ......................................................................................................466
Traffic C/(I+N) Calculation (UL) .................................................................................................466
Channel Throughput Calculation.....................................................................................................467
Calculation of Total Cell Resources ..........................................................................................467
Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation...........468
Scheduling and Radio Resource Management...............................................................................469
User Throughput Calculation.....................................................................................................470
Smart Antenna Models....................................................................................................................471
Downlink Beamforming .............................................................................................................471
Uplink Beamforming ..................................................................................................................471
Uplink Beamforming and Interference Cancellation (MMSE) ....................................................472
Calculation Processes ..........................................................................................................................472
Point Analysis..................................................................................................................................472
Profile Tab .................................................................................................................................473
Reception Tab ...........................................................................................................................473
Signal Analysis Tab ...................................................................................................................473
Preamble Signal Level Coverage Predictions.................................................................................473
Coverage Area Determination...................................................................................................474
All Servers ...........................................................................................................................474
Best Signal Level and a Margin ...........................................................................................474
Second Best Signal Level and a Margin..............................................................................474
Coverage Display ......................................................................................................................474
AT281_TRG_E1
© Forsk 2009
Table of Contents
9.2.2.2.1
9.2.2.2.2
9.2.3
9.2.3.1
9.2.3.2
9.2.3.3
9.2.3.3.1
9.2.3.3.2
9.2.3.3.3
9.2.4
9.2.5
9.2.5.1
9.2.5.1.1
9.2.5.1.2
9.2.5.2
9.2.6
9.2.6.1
9.2.6.2
9.2.6.3
9.2.6.3.1
9.2.6.3.2
9.2.6.3.3
9.2.6.3.4
9.2.6.3.5
9.2.6.3.6
9.2.6.3.7
9.2.6.3.8
9.2.6.3.9
9.3
9.3.1
9.3.1.1
9.3.1.2
9.3.1.3
9.3.1.4
9.3.1.5
9.3.2
9.3.2.1
9.3.2.2
9.3.2.3
9.3.2.4
9.3.2.5
9.3.3
9.3.4
9.3.5
9.3.6
9.3.6.1
9.3.6.2
9.3.6.3
9.3.6.3.1
9.3.6.3.2
9.3.6.4
9.3.6.5
9.3.6.6
9.3.6.7
9.3.6.8
9.3.6.8.1
9.3.6.8.2
9.3.6.9
9.3.6.10
9.3.7
9.3.7.1
9.3.7.1.1
9.3.7.1.2
9.3.7.1.3
9.3.7.1.4
9.3.7.2
9.3.8
9.3.8.1
© Forsk 2009
Coverage Resolution .......................................................................................................... 474
Display Types ..................................................................................................................... 474
Effective Signal Analysis Coverage Predictions ............................................................................. 475
Coverage Area Determination .................................................................................................. 476
Coverage Parameter Calculation.............................................................................................. 476
Coverage Display ..................................................................................................................... 476
Coverage Resolution .......................................................................................................... 476
Effective Signal Analysis (DL) Display Types ..................................................................... 476
Effective Signal Analysis (UL) Display Types ..................................................................... 477
Calculations on Subscriber Lists .................................................................................................... 477
Monte Carlo Simulations ................................................................................................................ 478
Generating a Realistic User Distribution................................................................................... 478
Simulations Based on User Profile Traffic Maps and Subscriber Lists ............................... 478
Simulations Based on Sector Traffic Maps ......................................................................... 480
Simulation Process ................................................................................................................... 482
C/(I+N)-Based Coverage Predictions ............................................................................................. 486
Coverage Area Determination .................................................................................................. 486
Coverage Parameter Calculation.............................................................................................. 486
Coverage Display ..................................................................................................................... 487
Coverage Resolution .......................................................................................................... 487
Coverage by C/(I+N) Level (DL) Display Types.................................................................. 487
Coverage by Best Bearer (DL) Display Types .................................................................... 488
Coverage by Throughput (DL) Display Types..................................................................... 488
Coverage by Quality Indicator (DL) Display Types ............................................................. 489
Coverage by C/(I+N) Level (UL) Display Types.................................................................. 489
Coverage by Best Bearer (UL) Display Types .................................................................... 490
Coverage by Throughput (UL) Display Types..................................................................... 490
Coverage by Quality Indicator (UL) Display Types ............................................................. 491
Calculation Algorithms ......................................................................................................................... 491
Co- and Adjacent Channel Overlaps Calculation ........................................................................... 491
Conversion From Channel Numbers to Start and End Frequencies ........................................ 492
Co-Channel Overlap Calculation .............................................................................................. 493
Adjacent Channel Overlap Calculation ..................................................................................... 493
FDD – TDD Overlap Ratio Calculation ..................................................................................... 494
Total Overlap Ratio Calculation ................................................................................................ 495
Preamble Signal Level and Quality Calculations............................................................................ 495
Preamble Signal Level Calculation ........................................................................................... 495
Preamble Noise Calculation ..................................................................................................... 496
Preamble Interference Calculation ........................................................................................... 498
Preamble C/N Calculation ........................................................................................................ 499
Preamble C/(I+N) Calculation ................................................................................................... 499
Best Server Determination ............................................................................................................. 500
Service Area Calculation ................................................................................................................ 501
Permutation Zone Selection (WiMAX 802.16e).............................................................................. 501
Traffic and Pilot Signal Level and Quality Calculations .................................................................. 502
Traffic and Pilot Signal Level Calculation (DL) ......................................................................... 502
Traffic and Pilot Noise Calculation (DL).................................................................................... 503
Traffic and Pilot Interference Calculation (DL).......................................................................... 505
Traffic and Pilot Interference Signal Levels Calculation (DL).............................................. 505
Effective Traffic and Pilot Interference Calculation (DL) ..................................................... 508
Traffic and Pilot C/N Calculation (DL)....................................................................................... 512
Traffic and Pilot C/(I+N) and Bearer Calculation (DL) .............................................................. 514
Traffic Signal Level Calculation (UL) ........................................................................................ 516
Traffic Noise Calculation (UL)................................................................................................... 517
Traffic Interference Calculation (UL)......................................................................................... 517
Traffic Interference Signal Levels Calculation (UL)............................................................. 518
Noise Rise Calculation (UL) ................................................................................................ 518
Traffic C/N Calculation (UL)...................................................................................................... 519
Traffic C/(I+N) and Bearer Calculation (UL) ............................................................................. 522
Channel Throughput Calculation.................................................................................................... 526
Calculation of Total Cell Resources.......................................................................................... 526
Calculation of Sampling Frequency .................................................................................... 526
Calculation of Symbol Duration........................................................................................... 526
Calculation of Total Cell Resources - TDD Networks ......................................................... 527
Calculation of Total Cell Resources - FDD Networks ......................................................... 528
Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation .......... 529
Scheduling and Radio Resource Management .............................................................................. 532
Scheduling and Radio Resource Allocation.............................................................................. 532
AT281_TRG_E1
17
Technical Reference Guide
9.3.8.2
9.3.9
9.3.9.1
9.3.9.2
9.3.9.3
9.4
9.4.1
9.4.2
9.4.3
9.4.3.1
9.4.3.2
9.4.3.3
9.4.4
9.4.4.1
9.4.4.2
9.4.4.3
10
10.1
10.1.1
10.1.2
10.1.3
10.1.4
10.1.4.1
10.1.4.2
10.1.4.3
10.1.4.4
10.1.4.5
10.1.4.6
10.1.4.7
10.1.4.8
10.1.4.9
10.1.4.10
10.1.4.11
10.1.5
10.1.5.1
10.1.5.2
10.1.5.3
10.1.6
10.1.6.1
10.2
10.2.1
10.2.1.1
10.2.1.2
10.2.1.3
10.2.2
10.2.2.1
10.2.2.1.1
10.2.2.1.2
10.2.2.1.3
10.2.2.2
10.2.2.2.1
10.2.2.2.2
10.2.3
10.2.3.1
10.2.3.2
10.2.3.3
10.2.3.3.1
10.2.3.3.2
10.2.3.3.3
10.2.4
10.2.5
10.2.5.1
10.2.5.1.1
10.2.5.1.2
10.2.5.2
10.2.6
10.2.6.1
18
User Throughput Calculation.....................................................................................................539
Smart Antenna Models....................................................................................................................540
Downlink Beamforming .............................................................................................................541
Uplink Beamforming ..................................................................................................................542
Uplink Beamforming and Interference Cancellation (MMSE) ....................................................543
Automatic Allocation Algorithms ...........................................................................................................545
Automatic Neighbour Allocation ......................................................................................................545
Automatic Inter-Technology Neighbour Allocation ..........................................................................547
Automatic Frequency Planning .......................................................................................................550
Separation Constraint and Relationship Weights ......................................................................550
Calculation of Cost Between TBA and Related Cells ................................................................550
AFP Algorithm ...........................................................................................................................553
Automatic Preamble Index Allocation .............................................................................................553
Constraint and Relationship Weights ........................................................................................554
Calculation of Cost Between TBA and Related Cells ................................................................554
Automatic Allocation Algorithm..................................................................................................557
LTE Networks ................................................................................561
Definitions and Formulas ......................................................................................................................561
Input ................................................................................................................................................561
Downlink Transmission Powers Calculation ...................................................................................564
Co- and Adjacent Channel Overlaps Calculation............................................................................565
Signal Level and Signal Quality Calculations..................................................................................566
Signal Level Calculation (DL) ....................................................................................................566
Noise Calculation (DL) ..............................................................................................................567
Interference Calculation (DL) ....................................................................................................567
C/N Calculation (DL) .................................................................................................................568
C/(I+N) Calculation (DL) ............................................................................................................568
Signal Level Calculation (UL) ....................................................................................................569
Noise Calculation (UL) ..............................................................................................................570
Interference Calculation (UL) ....................................................................................................570
Noise Rise Calculation (UL) ......................................................................................................570
C/N Calculation (UL) .................................................................................................................570
C/(I+N) Calculation (UL) ............................................................................................................571
Channel Throughput Calculation.....................................................................................................571
Calculation of Downlink Cell Resources....................................................................................571
Calculation of Uplink Cell Resources ........................................................................................572
Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation...........572
Scheduling and Radio Resource Management...............................................................................573
User Throughput Calculation.....................................................................................................574
Calculation Processes ..........................................................................................................................575
Point Analysis..................................................................................................................................575
Profile Tab .................................................................................................................................575
Reception Tab ...........................................................................................................................575
Signal Analysis Tab ...................................................................................................................575
Downlink Reference Signal Level Coverage Predictions ................................................................576
Coverage Area Determination ...................................................................................................576
All Servers ...........................................................................................................................576
Best Signal Level and a Margin ...........................................................................................576
Second Best Signal Level and a Margin..............................................................................576
Coverage Display ......................................................................................................................577
Coverage Resolution ...........................................................................................................577
Display Types ......................................................................................................................577
Effective Signal Analysis Coverage Predictions..............................................................................578
Coverage Area Determination ...................................................................................................578
Coverage Parameter Calculation ..............................................................................................578
Coverage Display ......................................................................................................................578
Coverage Resolution ...........................................................................................................578
Effective Signal Analysis (DL) Display Types ......................................................................578
Effective Signal Analysis (UL) Display Types ......................................................................579
Calculations on Subscriber Lists .....................................................................................................580
Monte Carlo Simulations .................................................................................................................580
Generating a Realistic User Distribution ...................................................................................580
Simulations Based on User Profile Traffic Maps and Subscriber Lists................................581
Simulations Based on Sector Traffic Maps..........................................................................582
Simulation Process....................................................................................................................584
C/(I+N)-Based Coverage Predictions..............................................................................................587
Coverage Area Determination ...................................................................................................587
AT281_TRG_E1
© Forsk 2009
Table of Contents
10.2.6.2
10.2.6.3
10.2.6.3.1
10.2.6.3.2
10.2.6.3.3
10.2.6.3.4
10.2.6.3.5
10.2.6.3.6
10.2.6.3.7
10.2.6.3.8
10.2.6.3.9
10.3
10.3.1
10.3.2
10.3.2.1
10.3.2.2
10.3.2.3
10.3.2.4
10.3.3
10.3.3.1
10.3.3.2
10.3.3.3
10.3.3.4
10.3.3.5
10.3.3.6
10.3.3.7
10.3.3.8
10.3.3.8.1
10.3.3.8.2
10.3.3.9
10.3.3.10
10.3.4
10.3.5
10.3.6
10.3.6.1
10.3.6.1.1
10.3.6.1.2
10.3.6.2
10.3.7
10.3.7.1
10.3.7.2
10.4
10.4.1
10.4.2
10.4.3
10.4.3.1
10.4.3.2
10.4.3.3
10.4.4
10.4.4.1
10.4.4.2
10.4.4.3
11
11.1
11.1.1
11.1.1.1
11.1.1.1.1
11.1.1.1.2
11.1.1.1.3
11.1.1.2
11.1.1.2.1
11.1.1.2.2
11.1.1.3
11.1.1.3.1
11.1.1.3.2
11.1.1.4
11.1.1.4.1
© Forsk 2009
Coverage Parameter Calculation.............................................................................................. 587
Coverage Display ..................................................................................................................... 588
Coverage Resolution .......................................................................................................... 588
Coverage by C/(I+N) Level (DL) Display Types.................................................................. 588
Coverage by Best Bearer (DL) Display Types .................................................................... 589
Coverage by Throughput (DL) Display Types..................................................................... 589
Coverage by Quality Indicator (DL) Display Types ............................................................. 590
Coverage by C/(I+N) Level (UL) Display Types.................................................................. 590
Coverage by Best Bearer (UL) Display Types .................................................................... 591
Coverage by Throughput (UL) Display Types..................................................................... 591
Coverage by Quality Indicator (UL) Display Types ............................................................. 592
Calculation Algorithms ......................................................................................................................... 593
Downlink Transmission Powers Calculation................................................................................... 593
Co- and Adjacent Channel Overlaps Calculation ........................................................................... 596
Conversion From Channel Numbers to Start and End Frequencies ........................................ 596
Co-Channel Overlap Calculation .............................................................................................. 597
Adjacent Channel Overlap Calculation ..................................................................................... 597
Total Overlap Ratio Calculation ................................................................................................ 598
Signal Level and Signal Quality Calculations ................................................................................. 599
Signal Level Calculation (DL) ................................................................................................... 599
Noise Calculation (DL).............................................................................................................. 601
Interference Calculation (DL).................................................................................................... 602
C/N Calculation (DL)................................................................................................................. 605
C/(I+N) and Bearer Calculation (DL) ........................................................................................ 607
Signal Level Calculation (UL) ................................................................................................... 610
Noise Calculation (UL).............................................................................................................. 612
Interference Calculation (UL).................................................................................................... 612
Interfering Signal Level Calculation (UL)............................................................................. 612
Noise Rise Calculation (UL) ................................................................................................ 613
C/N Calculation (UL)................................................................................................................. 614
C/(I+N) and Bearer Calculation (UL) ........................................................................................ 616
Best Server Determination ............................................................................................................. 619
Service Area Calculation ................................................................................................................ 620
Channel Throughput Calculation.................................................................................................... 620
Calculation of Total Cell Resources.......................................................................................... 620
Calculation of Downlink Cell Resources ............................................................................. 620
Calculation of Uplink Cell Resources .................................................................................. 622
Channel Throughput, Cell Capacity, and Allocated Bandwidth Throughput Calculation .......... 623
Scheduling and Radio Resource Management .............................................................................. 626
Scheduling and Radio Resource Allocation.............................................................................. 626
User Throughput Calculation .................................................................................................... 631
Automatic Allocation Algorithms........................................................................................................... 632
Automatic Neighbour Allocation ..................................................................................................... 632
Automatic Inter-Technology Neighbour Allocation ......................................................................... 635
Automatic Frequency Planning ...................................................................................................... 637
Separation Constraint and Relationship Weights ..................................................................... 637
Calculation of Cost Between TBA and Related Cells ............................................................... 638
AFP Algorithm........................................................................................................................... 640
Automatic Physical Cell ID Allocation............................................................................................. 640
Constraint and Relationship Weights........................................................................................ 641
Calculation of Cost Between TBA and Related Cells ............................................................... 641
Automatic Allocation Algorithm ................................................................................................. 644
Repeaters and Remote Antennas................................................. 647
Modelling Repeaters ............................................................................................................................ 647
CDMA Documents.......................................................................................................................... 647
Over the Air............................................................................................................................... 647
Signal Level Received From Repeaters.............................................................................. 647
Gain Automatic Calculation................................................................................................. 648
Donor Side Parameter Automatic Calculation..................................................................... 649
Microwave Link ......................................................................................................................... 650
Signal Level Received From Repeaters.............................................................................. 650
Gain Automatic Calculation................................................................................................. 651
Fibre Link .................................................................................................................................. 652
Signal Level Received From Repeaters.............................................................................. 652
Gain Automatic Calculation................................................................................................. 652
Appendices ............................................................................................................................... 653
Automatic Controls.............................................................................................................. 653
AT281_TRG_E1
19
Technical Reference Guide
11.1.1.4.2
11.1.1.4.3
11.1.2
11.1.2.1
11.1.2.1.1
11.1.2.1.2
11.1.2.1.3
11.1.2.2
11.1.2.2.1
11.1.2.2.2
11.1.2.3
11.1.2.3.1
11.1.2.3.2
11.1.2.4
11.1.2.4.1
11.2
11.2.1
11.2.1.1
11.2.1.2
11.2.2
11.2.2.1
11.2.2.2
20
Carrier Power and Interference Calculation.........................................................................654
Consideration of Repeater Noise Figure .............................................................................656
GSM Documents.............................................................................................................................656
Over the Air ...............................................................................................................................656
Signal Level Received From Repeaters ..............................................................................656
EIRP Automatic Calculation.................................................................................................657
Donor Side Parameter Automatic Calculation .....................................................................658
Microwave Link..........................................................................................................................659
Signal Level Received From Repeaters ..............................................................................659
EIRP Automatic Calculation.................................................................................................659
Fibre Link...................................................................................................................................660
Signal Level Received From Repeaters ..............................................................................660
EIRP Automatic Calculation.................................................................................................661
Appendices................................................................................................................................661
Automatic Controls ..............................................................................................................661
Modelling Remote Antennas.................................................................................................................662
CDMA Documents ..........................................................................................................................662
Signal Level Received From Repeaters ....................................................................................662
Gain Automatic Calculation .......................................................................................................662
GSM Documents.............................................................................................................................663
Signal Level Received From Repeaters ....................................................................................663
EIRP Automatic Calculation ......................................................................................................664
AT281_TRG_E1
© Forsk 2009
List of Figures
List of Figures
Figure 2.1:
Figure 2.2:
Figure 2.3:
Figure 4.1:
Figure 4.2:
Figure 4.3:
Figure 4.4:
Figure 4.5:
Figure 4.6:
Figure 4.7:
Figure 4.8:
Figure 4.9:
Figure 4.10:
Figure 4.11:
Figure 4.12:
Figure 4.13:
Figure 4.14:
Figure 4.15:
Figure 4.16:
Figure 4.17:
Figure 4.18:
Figure 4.19:
Figure 4.20:
Figure 4.21:
Figure 4.22:
Figure 4.23:
Figure 4.24:
Figure 4.25:
Figure 4.26:
Figure 4.27:
Figure 4.28:
Figure 5.1:
Figure 5.2:
Figure 5.3:
Figure 5.4:
Figure 5.5:
Figure 5.6:
Figure 5.7:
Figure 5.8:
Figure 5.9:
Figure 5.10:
Figure 5.11:
Figure 5.12:
Figure 5.13:
Figure 6.1:
Figure 6.2:
Figure 6.3:
Figure 6.4:
Figure 6.5:
Figure 6.6:
Figure 6.7:
Figure 6.8:
Figure 6.9:
Figure 6.10:
Figure 6.11:
© Forsk 2009
Digital Terrain Model.................................................................................................................................. 37
Schematic view of a DTM file .................................................................................................................... 37
Clutter Classes .......................................................................................................................................... 38
Example 1: Single Calculation Area .......................................................................................................... 77
Example 2: Multiple Calculation Areas ...................................................................................................... 77
Ground Altitude Determination - 1 ............................................................................................................. 79
Ground Altitude Determination - 2 ............................................................................................................. 79
Ground Altitude Determination - 3 ............................................................................................................. 80
Ground Altitude Determination - 4 ............................................................................................................. 80
Clutter Height............................................................................................................................................. 80
Radial calculation method.......................................................................................................................... 81
Site-bin centre profile................................................................................................................................. 81
Radial calculation method.......................................................................................................................... 82
Enhanced Slope at Receiver ..................................................................................................................... 89
Losses due to Clutter................................................................................................................................. 92
Tx-Rx profile .............................................................................................................................................. 93
Knife-Edge Diffraction.............................................................................................................................. 106
Deygout Construction – 1 Obstacle ......................................................................................................... 107
Deygout Construction – 3 Obstacles ....................................................................................................... 108
Epstein-Peterson Construction ................................................................................................................ 108
Millington Construction ............................................................................................................................ 109
Azimuth and Tilt Computation.................................................................................................................. 111
Vertical Pattern Transformation due to Electrical Downtilt....................................................................... 113
Vertical Antenna Pattern.......................................................................................................................... 114
Peaks and Nulls in the Antenna Pattern .................................................................................................. 114
Log-normal Probability Density Function ................................................................................................. 115
Normalised Margin .................................................................................................................................. 121
Margin - Probability (Case of 2 Signals) .................................................................................................. 126
Margin - Probability (Case of 3 Signals with sigma = 8dB, delta1 = 1dB) ............................................... 127
Margin - Probability (Case of 3 Signals with sigma = 8dB, delta1 = 2dB) ............................................... 127
Reference Point - Location of the Transmission/Reception parameters ................................................. 128
Representation of a Concentric Cell TXi.................................................................................................. 142
Representation of Micro and Macro Layers............................................................................................. 143
Concentric Cells....................................................................................................................................... 144
Concentric Cells....................................................................................................................................... 148
Reduction of Throughput per Timeslot .................................................................................................... 151
Reduction Factor for Different Packet Switched Traffic Loads (Lp, X-axis)............................................. 152
Blocking Probability for Different Packet Switched Traffic Loads (Lp, X-axis)......................................... 154
Network Dimensioning Process............................................................................................................... 154
Minimum Throughput Reduction Factor .................................................................................................. 158
Overlapping Zones .................................................................................................................................. 163
FER vs. C/I Graphs.................................................................................................................................. 180
BER vs. C/I Graphs ................................................................................................................................. 180
MOS vs. C/I Graphs................................................................................................................................. 181
Description of a Packet Session .............................................................................................................. 202
UMTS HSPA Power Control Algorithm.................................................................................................... 206
Connection status of HSDPA bearer users ............................................................................................. 212
HSDPA Bearer Allocation Process for Packet (HSPA - Constant Bit Rate) Service Users..................... 213
HSDPA Bearer Allocation Process for Packet (HSDPA) and Packet (HSPA) Service Users ................. 214
HSDPA UE Categories Table .................................................................................................................. 219
HSDPA Radio Bearers Table .................................................................................................................. 220
HSUPA UE Categories Table .................................................................................................................. 227
HSUPA Radio Bearers Table .................................................................................................................. 227
HSUPA Bearer SelectionTable................................................................................................................ 228
HSUPA Bearer Allocation Process for Packet (HSPA - Constant Bit Rate) Service Users..................... 229
AT281_TRG_E1
21
Technical Reference Guide
Figure 6.12:
Figure 6.13:
Figure 6.14:
Figure 6.15:
Figure 6.16:
Figure 6.17:
Figure 6.18:
Figure 6.19:
Figure 7.1:
Figure 7.2:
Figure 7.3:
Figure 7.4:
Figure 7.5:
Figure 7.6:
Figure 7.7:
Figure 8.1:
Figure 8.2:
Figure 8.3:
Figure 8.4:
Figure 8.5:
Figure 8.6:
Figure 8.7:
Figure 8.8:
Figure 8.9:
Figure 8.10:
Figure 8.11:
Figure 8.12:
Figure 8.13:
Figure 8.14:
Figure 8.15:
Figure 8.16:
Figure 8.17:
Figure 8.18:
Figure 8.19:
Figure 8.20:
Figure 8.21:
Figure 9.1:
Figure 9.2:
Figure 9.3:
Figure 9.4:
Figure 9.5:
Figure 9.6:
Figure 9.7:
Figure 9.8:
Figure 9.9:
Figure 9.10:
Figure 9.11:
Figure 9.12:
Figure 9.13:
Figure 9.14:
Figure 9.15:
Figure 9.16:
Figure 9.17:
Figure 9.18:
Figure 9.19:
Figure 10.1:
Figure 10.2:
Figure 10.3:
Figure 10.4:
Figure 10.5:
Figure 10.6:
Figure 10.7:
22
HSUPA Bearer Allocation Process for Packet (HSPA) Service Users .....................................................
OVSF Code Tree Indices (Not OVSF Code Numbers) ............................................................................
Overlapping Zone for Intra-carrier Neighbours.........................................................................................
Overlapping Zone for Inter-carrier Neighbours - 1st Case .......................................................................
Overlapping Zone for Inter-carrier Neighbours - 2nd Case ......................................................................
Neighbourhood Constraints......................................................................................................................
Primary Scrambling Codes Allocation ......................................................................................................
Inter-Transmitter Distance Computation ..................................................................................................
CDMA2000 1xRTT Power Control Algorithm ...........................................................................................
CDMA2000 1xEVDO Power Control Algorithm ........................................................................................
Walsh Code Tree Indices (Not Walsh Code Numbers) ............................................................................
Overlapping Zones - 1st Case..................................................................................................................
Overlapping Zones - 2nd Case ................................................................................................................
Neighbourhood Constraints......................................................................................................................
PN Offset Allocation .................................................................................................................................
Description of a Packet Session...............................................................................................................
TD-SCDMA Power Control Algorithm ......................................................................................................
Grid Of Beams Modelling .........................................................................................................................
GOB Modelling - Determination of the Best Beam...................................................................................
Adaptive Beam Modelling - Determination of the Best Beam ..................................................................
Linear Adaptive Antenna Array ................................................................................................................
Downlink Beamforming ............................................................................................................................
Uplink Beamforming .................................................................................................................................
Uplink Adaptive Algorithm ........................................................................................................................
Construction of the Geographic Distribution of Downlink Traffic Power ...................................................
Geographic Distribution of Downlink Traffic Power ..................................................................................
Geographic Distribution of downlink traffic power and uplink load ...........................................................
Radio Bearers Table ................................................................................................................................
UE Categories Table ................................................................................................................................
Weighted Distance Between Transmitters ...............................................................................................
N-frequency Neighbour Allocation............................................................................................................
Overlapping Coverages............................................................................................................................
Neighbourhood Constraints......................................................................................................................
Scrambling Code Allocation Example ......................................................................................................
Scrambling Code Allocation to All Carriers ..............................................................................................
Inter-Transmitter Distance Computation ..................................................................................................
WiMAX Simulation Algorithm ...................................................................................................................
Victim and Interfering Mobiles ..................................................................................................................
Simulation Convergence Stability Factor .................................................................................................
Co-Channel and Adjacent Channel Overlaps ..........................................................................................
Downlink C/(I+N) calculation in Simulations.............................................................................................
Downlink C/(I+N) calculation in Coverage Predictions .............................................................................
Segmentation ...........................................................................................................................................
Segmentation Interference Scenarios ......................................................................................................
Linear Adaptive Antenna Array ................................................................................................................
Downlink Beamforming ............................................................................................................................
Uplink Beamforming .................................................................................................................................
Uplink Adaptive Algorithm ........................................................................................................................
Determination of Adjacent Cells ...............................................................................................................
Overlapping Zones ...................................................................................................................................
Inter-Transmitter Distance Calculation .....................................................................................................
Weighted Distance Between Cells ...........................................................................................................
Importance Based on Distance Relation ..................................................................................................
Weighted Distance Between Cells ...........................................................................................................
Importance Based on Distance Relation ..................................................................................................
LTE Simulation Algorithm .........................................................................................................................
Co-Channel and Adjacent Channel Overlaps ..........................................................................................
Determination of Adjacent Cells ...............................................................................................................
Overlapping Zones ...................................................................................................................................
Inter-Transmitter Distance Calculation .....................................................................................................
Weighted Distance Between Cells ...........................................................................................................
Importance Based on Distance Relation ..................................................................................................
AT281_TRG_E1
229
241
273
274
275
282
284
290
320
327
334
363
364
370
372
396
400
423
424
424
425
426
427
428
430
430
431
434
435
438
440
440
446
448
451
454
482
483
484
492
507
507
509
510
540
541
542
543
545
546
548
552
552
556
557
585
596
633
634
635
639
640
© Forsk 2009
List of Figures
Figure 10.8:
Figure 10.9:
Figure 11.1:
Figure 11.2:
Figure 11.3:
Figure 11.4:
Figure 11.5:
Figure 11.6:
Figure 11.7:
Figure 11.8:
Figure 11.9:
Figure 11.10:
Figure 11.11:
Figure 11.12:
Figure 11.13:
Figure 11.14:
Figure 11.15:
Figure 11.16:
Figure 11.17:
Figure 11.18:
Figure 11.19:
Figure 11.20:
Figure 11.21:
Figure 11.22:
Figure 11.23:
Figure 11.24:
Figure 11.25:
Figure 11.26:
© Forsk 2009
Weighted Distance Between Cells...........................................................................................................
Importance Based on Distance Relation .................................................................................................
CDMA Documents - Over the Air Repeater.............................................................................................
Over the Air Repeater - Downlink Total Gain ..........................................................................................
Over the Air Repeater - Uplink Total Gain ...............................................................................................
Angle from North (Azimuth) .....................................................................................................................
Positive/Negative Mechanical Downtilt ....................................................................................................
Tilt Angle Computation ............................................................................................................................
CDMA Documents - Microwave Link Repeater .......................................................................................
Microwave Link Repeater - Downlink Total Gain.....................................................................................
Microwave Link Repeater - Uplink Total Gain .........................................................................................
CDMA Documents - Fibre Link Repeater ................................................................................................
Fibre Link Repeater - Downlink Total Gain..............................................................................................
Fibre Link Repeater - Uplink Total Gain ..................................................................................................
GSM Documents - Over the Air Repeater ...............................................................................................
Over the Air Repeater - EIRP ..................................................................................................................
Angle from North (Azimuth) .....................................................................................................................
Positive/Negative Mechanical Downtilt ....................................................................................................
Tilt Angle Computation ............................................................................................................................
GSM Documents - Microwave Link Repeater..........................................................................................
Microwave Link Repeater - EIRP.............................................................................................................
GSM Documents - Fibre Link Repeater...................................................................................................
Fibre Link Repeater - EIRP......................................................................................................................
CDMA Documents - Remote Antenna Signal Level ................................................................................
Remote Antennas - Downlink Total Gain.................................................................................................
Remote Antennas - Uplink Total Gain .....................................................................................................
GSM Documents - Remote Antenna Signal Level...................................................................................
Remote Antennas - EIRP ........................................................................................................................
AT281_TRG_E1
643
644
647
648
649
649
650
650
650
651
651
652
653
653
657
657
658
658
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659
660
660
661
662
663
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663
664
23
Technical Reference Guide
24
AT281_TRG_E1
© Forsk 2009
Chapter 1
Coordinate Systems and Units
This chapter presents the different coordinate systems available in Atoll by default. It describes the projection,
display, and internal coordinate systems, and describes the format of the coordinate systems files. This chapter
also provides details of the different power and length units available in Atoll.
AtollMicrowave
Atoll
Microwave
Planning Software
RF PlanningLink
& Optimisation
Software
Technical Reference Guide
26
AT281_TRG_E1
© Forsk 2009
Chapter 1: Coordinate Systems and Units
1
Coordinate Systems and Units
1.1
Coordinate Systems
A map or a geo-spatial database is a flat representation of data collected from a curved surface. A projection is a means
for producing all or part of a spheroid on a flat sheet. This projection cannot be done without distortion. Therefore, the
cartographer must choose the characteristic (distance, direction, scale, area, or shape) that he wants to be shown accurately at the expense of the other characteristics, or compromise on several characteristics [1-3]. The projected zones are
referenced using cartographic coordinates (meter, yard, etc.). Two projection methods are widely used:
•
•
The Lambert Conformal-Conic Method: A portion of the earth is mathematically projected on a cone conceptually secant at one or two standard parallels. This projection method is useful for representing countries or regions
that have a predominant east-west expanse.
The Universal Transverse Mercator (UTM) Method: A portion of the earth is mathematically projected on a cylinder tangent to a meridian (which is transverse or crosswise to the equator). This projection method is useful for
mapping large areas that are oriented north-south.
The geographic system is not a projection. It is only a representation of a location on the surface of the earth in geographic
coordinates (degree-minute-second, grade) giving the latitude and longitude in relation to the meridian origin (e.g., Paris
for NTF system and Greenwich for ED50 system). The locations in the geographic system can be converted into other
projections.
References:
[1] Snyder, John. P., Map Projections Used by the US Geological Survey, 2nd Edition, United States Government
Printing Office, Washington, D.C., 313 pages, 1982.
[2] http://www.colorado.edu/geography/gcraft/notes/gps/gps_f.html
[3] http://www.posc.org/Epicentre.2_2/DataModel/ExamplesofUsage/eu_cs34.html
[4] http://www.ign.fr/telechargement/Pi/SERVICES/transfo.pdf (Document in French)
1.1.1
Description of Coordinate Systems
A Geographic coordinate system is a latitude and longitude coordinate system. The latitude and longitude are related to
an ellipsoid, a geodetic datum, and a prime meridian. The geodetic datum provides the position and orientation of the ellipsoid relative to the earth.
Cartographic coordinate systems are obtained by transforming each (latitude, longitude) value into an (easting, northing)
value. A projection coordinate system is obtained by transforming each (latitude, longitude) value into an (easting, northing) value. Projection coordinate systems are geographic coordinate systems that provide longitude and latitude, and the
transformation method characterised by a set of parameters. Different methods may require different sets of parameters.
For example, the parameters required for Transverse Mercator coordinate systems are:
•
•
•
•
•
The longitude of the natural origin (central meridian)
The latitude of the natural origin
The False Easting value
The False Northing value
A scaling factor at the natural origin (central meridian)
Basic definitions are presented below.
1.1.1.1
Geographic Coordinate System
The geographic coordinate system is a datum and a meridian. Atoll enables you to choose the most suitable geographic
coordinate system for your geographic data.
1.1.1.2
Datum
The datum consists of the ellipsoid and its position relative to the WGS84 ellipsoid. In addition to the ellipsoid, translation,
rotation, and distortion parameters define the datum.
1.1.1.3
Meridian
The standard meridian is Greenwich, but some geographic coordinate systems are based on other meridians. These
meridians are defined by the longitude with respect to Greenwich.
1.1.1.4
Ellipsoid
The ellipsoid is the pattern used to model the earth. It is defined by its geometric parameters.
© Forsk 2009
AT281_TRG_E1
27
Technical Reference Guide
1.1.1.5
Projection
The projection is the transformation applied to project the ellipsoid of the earth on to a plane. There are different projection
methods that use specific sets of parameters.
1.1.1.6
Projection Coordinate System
The projection coordinate system is the result of the application of a projection to a geographic coordinate system. It associates a geographic coordinate system and a projection. Atoll enables you to choose the projection coordinate system
matching your geographic data.
1.1.2
Coordinate Systems in Atoll
Depending on the working environment, there can be either two or four coordinate systems used in Atoll. If you are working
with stand-alone documents, i.e., documents not connected to databases, there are two coordinate systems used in Atoll:
•
•
Projection coordinate system
Display coordinate system
If you are working in a multi-user environment, Atoll uses four coordinate systems:
•
•
•
•
1.1.2.1
Projection coordinate system for the Atoll document
Display coordinate system for the Atoll document
Internal projection coordinate system for the database
Internal display coordinate system for the database
Projection Coordinate System
The projection coordinate system is the coordinate system of the available raster geographic data files. You should set the
projection coordinate system of your Atoll document so that it corresponds to the coordinate system of the available raster
geographic data. You can set the projection coordinate system of your document in the Options dialog.
All the raster geographic data files that you want to import and use in an Atoll document must have the same coordinate
system. You cannot work with raster geographic data files with different coordinate systems in the same document.
Note:
•
If you import vector geographic data (e.g., traffic, measurements, etc.) with different
coordinate systems, it is possible to convert the coordinate systems of these data into the
projection coordinate system of your Atoll document.
The projection coordinate system is used to keep the coordinates of sites (radio network data) consistent with the
geographic data.
When you import a raster geographic data file, Atoll reads the geo-referencing information from the file (or from its header
file, depending on the geographic data file format), i.e., its Northwest pixel, to determine the coordinates of each pixel. Atoll
does not use any coordinate system during the import process. However, the geo-referencing information of geographic
data files are considered to be provided in the projection coordinate system of the document.
1.1.2.2
Display Coordinate System
The display coordinate system is the coordinate system used for the display, e.g., in dialogs, in the Map window rulers, in
the status bar, etc. The coordinates of each pixel of geographic data are converted to the display coordinate system from
the projection coordinate system for display. The display coordinate system is also used for sites (radio network data). You
can set the display coordinate system of your document in the Options dialog.
If you import sites data, the coordinate system of the sites must correspond to the display coordinate system of your Atoll
document.
If you change the display coordinate system in a document which is not connected to a database, the coordinates of all
the sites are converted to the new display system.
Note:
•
1.1.2.3
If the coordinate systems of all your geographic data files and sites (radio network data) are
the same, you do not have to define the projection and display coordinate systems
separately. By default, the two coordinate systems are the same.
Internal Coordinate Systems
The internal coordinate systems are the projection and the display coordinate systems stored in a database. The projection
and display coordinate systems set by the administrator in the central Atoll project are stored in the database when the
database is created, and cannot be modified by users. Only the administrator can modify the internal coordinate systems
manually by editing the entries in the CoordSys and the Units tables. All Atoll documents opened from a database will have
the internal coordinate systems of the database as their default projection and display coordinate systems.
When exporting an Atoll project to a database, the currently chosen display coordinate system becomes the internal
display coordinate system for the database, and the currently chosen projection coordinate system becomes the internal
projection coordinate system for the database.
28
AT281_TRG_E1
© Forsk 2009
Chapter 1: Coordinate Systems and Units
Although Atoll stores both the coordinate systems in the database, i.e., the projection and the display coordinate systems,
the only relevant coordinate system for the database is the internal display coordinate system because this coordinate
system is the one used for the coordinates of sites (radio network data).
Users working on documents connected to a database can modify the coordinate systems in their documents locally, and
save these changes in their documents, but they cannot modify the coordinate systems stored in the database.
If you change the display coordinate system in a document which is not connected to a database, the coordinates of all
the sites are converted to the new display system.
If you change the display coordinate system in a document which is connected to a database, the coordinates of all the
sites are converted to the new coordinate system in the Atoll document locally but not in the database because the internal
coordinate systems cannot be changed.
Atoll uses the internal coordinates systems in order to keep the site coordinates consistent in the database which is usually
accessed by a large number of users in a multi-user environment.
1.1.3
File Formats
The Coordsystems folder located in the Atoll installation directory contains all the coordinate systems, both geographic
and cartographic, offered in the tool. Coordinate systems are grouped by regions. A catalogue per region and a "Favourites" catalogue are available in Atoll. The Favourites catalogue is initially empty and can be filled by the user by adding
coordinate systems to it. Each catalogue is described by an ASCII text file with .cs extension. In a .cs file, each coordinate
system is described in one line. The line syntax for describing a coordinate system is:
Code = "Name of the system"; Unit Code; Datum Code; Projection Method Code,
Projection Parameters; "Comments"
Examples:
4230 = "ED50"; 101; 230; 1; "Europe - west"
32045 = "NAD27 / Vermont"; 2; 267; 6, -72.5, 42.5, 500000, 0, 0.9999643; "United
States - Vermont"
You should keep the following points in mind when editing or creating .cs files:
•
The identification code enables Atoll to differentiate coordinates systems. In case you create a new coordinate
system, its code must be an integer value higher than 32767.
When describing a new datum, you must enter the ellipsoid code and parameters instead of the datum code in
brackets. There can be 3 to 7 parameters defined in the following order: Dx, Dy, Dz, Rx, Ry, Rz, S. The syntax of
the line in the .cs file will be:
•
Code = "Name of the system"; Unit Code; {Ellipsoid Code, Dx, Dy, Dz, Rx, Ry,
Rz, S}; Projection Method Code, Projection Parameters; "Comments"
•
There can be up to seven projection parameters. These parameters must be ordered according to the parameter
index (see "Projection Parameter Indices" on page 32). Parameter with index 0 is the first one. Projection parameters are delimited by commas.
For UTM projections, you must provide positive UTM zone numbers for north UTM zones and negative numbers
for south UTM zones.
You can add all other information as comments (such as usage or region).
•
•
Codes of units, data, projection methods, and ellipsoids, and projection parameter indices are listed in the tables below.
1.1.3.1
Unit Codes
Code
© Forsk 2009
Cartographic Units
Code
Geographic Units
0
Metre
100
Radian
1
Kilometre
101
Degree
2
Foot
102
Grad
3
Link
103
ArcMinute
4
Chain
104
ArcSecond
5
Yard
6
Nautical mile
7
Mile
-1
Unspecified
-1
Unspecified
AT281_TRG_E1
29
Technical Reference Guide
1.1.3.2
30
Datum Codes
Code
Datum
Code
Datum
121
Greek Geodetic Reference System 1987
260
Manoca
125
Samboja
261
Merchich
126
Lithuania 1994
262
Massawa
130
Moznet (ITRF94)
263
Minna
131
Indian 1960
265
Monte Mario
201
Adindan
266
M'poraloko
202
Australian Geodetic Datum 1966
267
North American Datum 1927
203
Australian Geodetic Datum 1984
268
NAD Michigan
204
Ain el Abd 1970
269
North American Datum 1983
205
Afgooye
270
Nahrwan 1967
206
Agadez
271
Naparima 1972
207
Lisbon
272
New Zealand Geodetic Datum 1949
208
Aratu
273
NGO 1948
209
Arc 1950
274
Datum 73
210
Arc 1960
275
Nouvelle Triangulation Française
211
Batavia
276
NSWC 9Z-2
212
Barbados
277
OSGB 1936
213
Beduaram
278
OSGB 1970 (SN)
214
Beijing 1954
279
OS (SN) 1980
215
Reseau National Belge 1950
280
Padang 1884
216
Bermuda 1957
281
Palestine 1923
217
Bern 1898
282
Pointe Noire
218
Bogota
283
Geocentric Datum of Australia 1994
219
Bukit Rimpah
284
Pulkovo 1942
221
Campo Inchauspe
285
Qatar
222
Cape
286
Qatar 1948
223
Carthage
287
Qornoq
224
Chua
288
Loma Quintana
225
Corrego Alegre
289
Amersfoort
226
Cote d'Ivoire
290
RT38
227
Deir ez Zor
291
South American Datum 1969
228
Douala
292
Sapper Hill 1943
229
Egypt 1907
293
Schwarzeck
230
European Datum 1950
294
Segora
231
European Datum 1987
295
Serindung
232
Fahud
296
Sudan
233
Gandajika 1970
297
Tananarive 1925
234
Garoua
298
Timbalai 1948
235
Guyane Francaise
299
TM65
236
Hu Tzu Shan
300
TM75
237
Hungarian Datum 1972
301
Tokyo
238
Indonesian Datum 1974
302
Trinidad 1903
239
Indian 1954
303
Trucial Coast 1948
240
Indian 1975
304
Voirol 1875
241
Jamaica 1875
305
Voirol Unifie 1960
242
Jamaica 1969
306
Bern 1938
243
Kalianpur
307
Nord Sahara 1959
244
Kandawala
308
Stockholm 1938
245
Kertau
309
Yacare
247
La Canoa
310
Yoff
248
Provisional South American Datum 1956
311
Zanderij
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© Forsk 2009
Chapter 1: Coordinate Systems and Units
249
1.1.3.3
1.1.3.4
© Forsk 2009
Lake
312
Militar-Geographische Institut
250
Leigon
313
Reseau National Belge 1972
251
Liberia 1964
314
Deutsche Hauptdreiecksnetz
252
Lome
315
Conakry 1905
253
Luzon 1911
322
WGS 72
254
Hito XVIII 1963
326
WGS 84
255
Herat North
901
Ancienne Triangulation Française
256
Mahe 1971
902
Nord de Guerre
903
NAD 1927 Guatemala/Honduras/Salvador
(Panama Zone)
257
Makassar
258
European Reference System 1989
Projection Method Codes
Code
Projection Method
Code
Projection Method
0
Undefined
8
Oblique Stereographic
1
No projection > Longitude / Latitude
9
New Zealand Map Grid
2
Lambert Conformal Conical 1SP
10
Hotine Oblique Mercator
3
Lambert Conformal Conical 2SP
11
Laborde Oblique Mercator
4
Mercator
12
Swiss Oblique Cylindrical
5
Cassini-Soldner
13
Oblique Mercator
6
Transverse Mercator
14
UTM Projection
7
Transverse Mercator South Oriented
Ellipsoid Codes
Code
Name
Major Axis
Minor Axis
1
Airy 1830
6377563.396
6356256.90890985
2
Airy Modified 1849
6377340.189
6356034.44761111
3
Australian National Spheroid
6378160
6356774.71919531
4
Bessel 1841
6377397.155
6356078.96261866
5
Bessel Modified
6377492.018
6356173.50851316
6
Bessel Namibia
6377483.865
6356165.38276679
7
Clarke 1858
6378293.63924683
6356617.98173817
8
Clarke 1866
6378206.4
6356583.8
9
Clarke 1866 Michigan
6378693.7040359
6357069.45104614
10
Clarke 1880 (Benoit)
6378300.79
6356566.43
11
Clarke 1880 (IGN)
6378249.2
6356515
12
Clarke 1880 (RGS)
6378249.145
6356514.86954978
13
Clarke 1880 (Arc)
6378249.145
6356514.96656909
14
Clarke 1880 (SGA 1922)
6378249.2
6356514.99694178
15
Everest 1830 (1937 Adjustment)
6377276.345
6356075.41314024
16
Everest 1830 (1967 Definition)
6377298.556
6356097.5503009
17
Everest 1830 (1975 Definition)
6377301.243
6356100.231
18
Everest 1830 Modified
6377304.063
6356103.03899315
19
GRS 1980
6378137
6356752.31398972
20
Helmert 1906
6378200
6356818.16962789
21
Indonesian National Spheroid
6378160
6356774.50408554
22
International 1924
6378388
6356911.94612795
23
International 1967
6378160
6356774.71919530
24
Krassowsky 1940
6378245
6356863.01877305
25
NWL 9D
6378145
6356759.76948868
26
NWL 10D
6378135
6356750.52001609
27
Plessis 1817
6376523
6355862.93325557
28
Struve 1860
6378297
6356655.84708038
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Technical Reference Guide
29
1.1.3.5
1.1.4
War Office
6378300.583
6356752.27021959
30
WGS 84
6378137
6356752.31398972
31
GEM 10C
6378137
6356752.31398972
32
OSU86F
6378136.2
6356751.51667196
33
OSU91A
6378136.3
6356751.61633668
34
Clarke 1880
6378249.13884613
6356514.96026256
35
Sphere
6371000
6371000
Projection Parameter Indices
Index
Projection Parameter
Index
Projection Parameter
0
UTM zone number
4
Scale factor at origin
0
Longitude of origin
4
Latitude of 1st parallel
1
Latitude of origin
5
Azimuth of central line
2
False Easting
5
Latitude of 2nd parallel
3
False Northing
6
Angle from rectified to skewed grid
Creating a Coordinate System
Atoll provides a large catalogue of default coordinate systems. Nevertheless, it is possible to add the description of
geographic and cartographic coordinate systems. New coordinate systems can be created from scratch or initialised on
the basis of an existing one.
To create a new coordinate system from scratch:
1. Select Tools > Options. The Options dialog opens.
2. Select the Coordinates tab.
3. Click the browse button (...) on the right of the Projection field.
4. Click the New button. The Coordinate System dialog opens.
5. In the Coordinate System dialog,
a. Select the coordinate systems catalogue to which you want to add the new coordinate system.
b. In the General properties section: Enter a name for the new coordinate system, select a unit. You can also
enter any comments about its usage. Atoll assigns the code automatically.
c. In the Category section: Select the type of coordinate system. Enter the longitude and latitude for a geographic coordinate system, or the type of projection and its set of associated parameters for a cartographic coordinate system (false easting and northing, and the first and second parallels).
d. In the Geo section: Specify the meridian and choose a datum for the coordinate system. The associated ellipsoid is automatically selected. You can also describe a geodetic datum by selecting "..." in the Datum list.
In this case, you must provide parameters (Dx, Dy, Dz, Rx, Ry, Rz, and S) needed for the transformation of
the datum into WGS84, and an ellipsoid.
6. Click OK. The new coordinate system is added to the selected coordinate system catalogue.
To create a new coordinate system based on an existing system, select a coordinate system in the Coordinate Systems
dialog before clicking New in step 4. The new coordinate system is initialised with the values of the selected coordinate
system.
1.2
Units
1.2.1
Power Units
Depending on the working environment, there can be either one or two types of units for transmission and reception
powers. If you are working with stand-alone documents, i.e., documents not connected to databases, there is only one unit
used in Atoll:
•
Display power units
If you are working in a multi-user environment, Atoll uses two type of units:
•
•
Display power units for the Atoll document
Internal power units for the database
The display units are used for the display in dialogs and tables, e.g., reception thresholds (coverage prediction properties,
etc.), and received signal levels (measurements, point analysis, coverage predictions etc.). You can set the display units
for your document in the Options dialog.
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© Forsk 2009
Chapter 1: Coordinate Systems and Units
The internal units are the power units stored in a database. The power units set by the administrator in the central Atoll
project are stored in the database when the database is created, and cannot be modified by users. Only the administrator
can modify the internal units manually by editing the entries in the Units tables. All Atoll documents opened from a database will have the internal units of the database as their default power units.
Users working on documents connected to a database can modify the units in their documents locally, and save these
changes in their documents, but they cannot modify the units stored in the database.
1.2.2
Length Units
There are two types of units for distances, heights, and offsets:
•
•
Display length units
Internal length units
The display length units are used to display distances, heights, and offsets in dialogs, tables, and the status bar. You can
set the display units for your document in the Options dialog.
The internal unit for lengths is metre for all Atoll documents whether they are connected to databases or not. The internal
unit is not stored in the databases. The internal unit cannot be changed.
1.3
BSIC Format
Depending on the working environment, there can be either one or two types of BSIC formats. If you are working with
stand-alone documents, i.e., documents not connected to databases, there is only one BSIC format:
•
Display BSIC format
If you are working in a multi-user environment, Atoll uses two type of formats:
•
•
Display BSIC format for the Atoll document
Internal BSIC format for the database
The display format is used for the display in dialogs and tables. You can set the display format for your document from the
Transmitters folder’s context menu.
The internal format is the BSIC format stored in a database. The BSIC format set by the administrator in the central Atoll
project is stored in the database when the database is created, and cannot be modified by users. Only the administrator
can modify the internal format manually by editing the corresponding entry in the Units tables. All Atoll documents opened
from a database will have the internal format of the database as their default BSIC format.
Users working on documents connected to a database can modify the format in their documents locally, and save this
change in their documents, but they cannot modify the format stored in the database.
© Forsk 2009
AT281_TRG_E1
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Technical Reference Guide
34
AT281_TRG_E1
© Forsk 2009
Chapter 2
Geographic and Radio Data
This chapter defines the different types of data with which you can work in Atoll. These data can be
geographic data, such as maps, and radio network data, such as sites, antennas, other equipment and
parameters.
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Chapter 2: Geographic and Radio Data
2
Geographic and Radio Data
2.1
Geographic Data
2.1.1
Data Type
Atoll manages several geographic data types; DTM (Digital Terrain Model), clutter (Land-Use), scanned images, vector
data, traffic data, population, and any other generic data.
2.1.1.1
Digital Terrain Model (DTM)
The DTM (Digital Terrain Model or height) files describe the ground elevation above the sea level. DTM files supported by
Atoll are 16 bits/pixel relief maps in .tif, .bil, Planet© and Erdas Imagine formats and 8 bits/pixel relief maps in .tif, .bil, Erdas
Imagine and .bmp formats. DTM maps are taken into account in path loss calculations by Atoll propagation models.
DTM file provides altitude value (z stated in metre) on evenly spaced points. Abscissa and ordinate axes are respectively
oriented in right and downwards directions. Space between points is defined by pixel size (P stated in metre). Pixel size
must be the same in both directions. First point given in the file corresponds to the centre of the upper-left pixel of the map.
This point refers to the northwest point geo-referenced by Atoll. Four points (hence, four altitude values) are necessary to
describe a “bin”; these points are bin vertices.
Figure 2.1: Digital Terrain Model
Therefore, a n*n bin DTM file requires (n)2 points (altitude values).
Figure 2.2: Schematic view of a DTM file
Notes:
© Forsk 2009
•
Altitude values differ within a bin. Method used to calculate altitudes is described in the
Path loss calculations: Altitude determination part. Concerning DTM map display, Atoll
takes altitude of the southwest point of each bin to determine its colour.
•
In most documents, Digital Elevation Model (DEM) and Digital Terrain Model (DTM) are
differentiated and do not have the same meaning. By definition, DEM refers to altitude
above sea level including, both, ground and clutter while DTM just corresponds to the
ground height above sea level. In Atoll, the DEM term may be used instead of DTM term.
AT281_TRG_E1
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Technical Reference Guide
2.1.1.2
Clutter (Land Use)
You may import two types of clutter files in ATL documents. These files indicate either the clutter class or the clutter height
on each bin of the map.
2.1.1.2.1
Clutter Classes
Atoll supports 8 bits/pixel (255 classes) raster maps in .tif, .bil, .bmp, Erdas Imagine formats or 16 bits/pixel raster maps
in Planet© format. This kind of clutter file describes the land cover (dense urban, buildings, residential, forest, open,
villages, …). A grid map represents ground and each bin of the map is characterised by a code corresponding to a main
type of cover (a clutter class). Atoll automatically lists all the clutter classes of the map. It is possible to specify an average
clutter height for each clutter class manually during the map description step. Clutter maps are taken into account in path
loss calculations by Atoll propagation models.
Clutter file provides a clutter code per bin. Bin size is defined by pixel size (P stated in metre). Pixel size must be the same
in both directions. Abscissa and ordinate axes are respectively oriented in right and downwards directions. First point given
in the file corresponds to the centre of the upper-left pixel of the image. This point refers to the northwest point geo-referenced by Atoll.
Figure 2.3: Clutter Classes
Therefore, a n*n bin Clutter file requires (n)2 code values.
Note:
•
2.1.1.2.2
The clutter code is the same inside a bin.
Clutter Heights
Files supported by Atoll for clutter heights are 8 or 16 bits/pixel raster maps in .tif, .bil and Erdas Imagine formats. The file
provides clutter height value on evenly spaced points. Abscissa and ordinate axes are respectively oriented in right and
downwards directions. Space between points is defined by pixel size (P in metre). Pixel size must be the same in both
directions. First point given in the file corresponds to the centre of the upper-left pixel of the map. This point refers to the
northwest point geo-referenced by Atoll.
These maps are taken into account in path loss calculations by Atoll propagation models.
Note:
•
2.1.1.3
Atoll considers the clutter height of the nearest point in calculations (see Path loss
calculations: Clutter determination part). For map display, Atoll takes clutter height of the
southwest point of each bin to determine its colour.
Traffic Data
Atoll offers different kinds of traffic data:
2.1.1.3.1
User Profile Environment Based Traffic Maps
Atoll supports 8 bits/pixel (256 class) traffic raster maps in .tif, .bil, .bmp, Erdas Imagine formats. These maps provide
macroscopic traffic estimation. Each pixel is assigned an environment class, which is a list of user profiles with a defined
mobility type and a density.
2.1.1.3.2
User Profile Traffic Maps
Atoll supports vector traffic maps with .dxf®, Planet©, .shp, .mif and .agd formats. These maps are detailed traffic estimations (lines, polygons or points carrying a specific traffic). Each polygon, line or point is assigned a specific user profile with
associated mobility type and density. They can be built from population density vector maps.
2.1.1.3.3
Sector Traffic Maps
Atoll supports maps with .agd format. This kind of map is based on the network feedback. It provides actual information
on connections (and not just subscriber estimation) from the network. It is built from a coverage by transmitter prediction
38
AT281_TRG_E1
© Forsk 2009
Chapter 2: Geographic and Radio Data
study that defines sector boundaries for the traffic distribution in each sector. In UMTS and CDMA, either data rates or the
number of users per service are indicated for each transmitter service area. In GSM/TDMA, Atoll expects a number of
Erlangs in case of voice service and data rate values for packet-switched services for each transmitter service area.
2.1.1.3.4
User Density Traffic Maps
This kind of map is only available in GSM/TDMA documents. Atoll supports 16 and 32 bits/pixel traffic raster maps in .tif,
.bil, .bmp, Planet© and Erdas Imagine formats. This map is also based on the network feedback as it deals with network
users information as well. Each pixel is assigned a number of users with a given service, terminal and mobility type.
In GSM documents, traffic maps are taken into account for traffic analysis and network dimensioning. In UMTS and CDMA
documents, they are used by the Monte-Carlo simulator to model user distributions and evaluate related network parameters (cell power, mobile terminal power, …).
2.1.1.4
Vector Data
These data represent either polygons (regions, etc.), lines (roads, coastlines, etc.) or points (towns, etc.). Atoll supports
vector data files in .dxf®, Planet©, .shp, .mif and .agd formats. These maps are only used for display and provide information about the geographic environment.
2.1.1.5
Scanned Images
These geographic data include the road maps and the satellite images. They are only used for display and provide information about the geographic environment. Atoll supports scanned image files in .tif (1, 4, 8, 24-bits/pixel), .bil (1, 4, 8, 24bits/pixel), Planet© (1, 4, 8, 24-bits/pixel), .bmp (1-24-bits/pixel), Erdas Imagine (1, 4, 8, 24-bits/pixel) and .ecw (24-bits/
pixel) formats.
2.1.1.6
Population
Atoll deals with vector population files (polygons, lines or points) in .mif, .shp and .agd formats or 8, 16, 32 bits/pixel raster
population files in .tif, .bil, .bmp and Erdas Imagine formats. Population map describes the population distribution. They
are considered in clutter statistics and in coverage prediction reports.
2.1.1.7
Other Geographic Data
It is possible to import generic geographic data types, other than those listed above, (Customer density, revenue density,
…) in Atoll. These data can be either vector files in .mif, .shp and .agd formats or 8, 16, 32 bits/pixel raster files in .tif, .bil,
.bmp and Erdas Imagine formats. These maps are taken into account in clutter statistics and in coverage prediction
reports.
The ArcView Grid format (.txt) is an ASCII format dedicated to define raster maps. It may be used to export any raster map
such as DTM, images, Clutter Classes and/or Heights, Population, Generic data maps and even coverage predictions.
The contents of an ArcView Grid file are in ASCII and consist of a header, describing the content, followed by the content
in the form of cell values.
Notes:
2.1.2
•
The minimum resolution supported by Atoll is 1m for any raster maps, excepted for
scanned images, for which it is unlimited.
•
DTM and clutter map resolution must be an integer.
•
All the raster maps you want to import in an ATL document must be represented in the
same projection system.
Supported Geographic Data Formats
Atoll offers Import/Export filters for the most commonly used geographic data formats. The different filters are:
© Forsk 2009
File format
Import/
Export
Can contain
Georeferenced
.bil
Both
DTM, Clutter classes and heights, Traffic,
Image, Population, Other data
Yes via .hdr files
.tif
Both
DTM, Clutter classes and heights, Traffic,
Image, Population, Other data
Yes via associated .tfw files if
they exist
Planet©
Both
DTM, Clutter classes, Image, Vector data
Yes via index files
.bmp
Both
DTM, Clutter heights, Clutter classes, Traffic,
Image, Population, Other data
Yes via .bpw (or .bmw) files
.dxf®
Import Only
Vector data, Vector traffic
Yes
.shp
Both
Vector data, Vector traffic, Population, Other
data
Yes
.mif/.mid
Both
Vector data, Vector traffic, Population, Other
data
Yes
AT281_TRG_E1
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Technical Reference Guide
Erdas Imagine
Import Only
DTM, Clutter classes and heights, Traffic,
Image, Population, Other data
Yes
ArcView Grid
Export Only
DTM, Clutter classes and heights, Traffic,
Image, Population, Other data
Yes automatically embedded in
the data file
.agd
Both
Vector data, Vector traffic, Population, Other
data
Yes automatically embedded in
the data file
Vertical Mapper
(.grd, .grc)
Both
DTM, Clutter classes and heights, Traffic,
Image, Population, Other data
Yes automatically embedded in
the data file
.ecw
Import Only
Images
Yes via ers file (not mandatory)
Note:
•
The .wld files may be used as georeferencement file for any type of binary raster file.
•
Tiled .tif format is not supported.
Thus, to sum up, you can import:
•
•
•
•
•
•
•
•
DTM files in .tif (16-bits, 8-bits), .bil (16-bits, 8-bits), Planet© (16-bits), Erdas Imagine (16-bits, 8-bits), Vertical
Mapper (.grd, .grc) and .bmp (8-bits) formats.
Clutter heights files in .tif (16-bits, 8-bits), .bil (16-bits, 8-bits), Planet© (16-bits), Erdas Imagine (16-bits, 8-bits),
Vertical Mapper (.grd, .grc) and .bmp (8-bits) formats.
Clutter classes and traffic raster files in .tif (8-bits), .bil (8-bits), .bmp (8-bit), Erdas Imagine (8-bits) and Vertical
Mapper (.grd, .grc) and Planet© format (16-bits) are also supported.
Vector data files in .dxf®, Planet©, .shp, .mif and .agd formats.
Vector traffic files in .dxf®, Planet©, .shp, .mif and .agd formats.
Scanned image files in .tif (1, 4, 8, 24-bits), .bil (1, 4, 8, 24-bits), Planet© (1, 4, 8, 24-bits), .bmp (1-24-bits), Erdas
Imagine (1, 4, 8, 24-bits), Vertical Mapper (.grd, .grc) and .ecw (Enhanced Compressed Wavelet) (24 bits) formats.
Population files in .mif, .shp, .agd, .tif (8, 16, 32-bits), .bil (8, 16, 32-bits), .bmp (8, 32-bits), Vertical Mapper (.grd,
.grc) and Erdas Imagine (8, 16, 32-bits) formats.
Other generic data types in .mif, .shp, .agd, .tif (8, 16, 32-bits), .bil (8, 16, 32-bits), .bmp (8, 32-bits), Vertical
Mapper (.grd, .grc) and Erdas Imagine (8, 16, 32-bits) formats.
Note:
•
2.2
It is possible to import Packbit, FAX-CCITT3 and LZW compressed .tif files. However, in
case of DTM and clutter, we recommend not to use compressed files in order to avoid poor
performances. If uncompressed files are too big, it is better to split them.
Radio Data
Atoll manages several radio data types; sites, transmitters, antennas, stations and hexagonal designs. Data definition in
Atoll is detailed hereafter.
2.2.1
Site
A site is a geographical point where one or several transmitters (multi-sectored site or station) equipped with antennas are
located.
2.2.2
Antenna
An antenna is a device used for transmitting or receiving electromagnetic waves.
2.2.3
Transmitter
A transmitter is a group of radio devices located at a site. Transmitters are equipped with antenna(s) and other equipment
such as feeder, tower mounted amplifiers (TMA) and BTS.
2.2.4
Repeater
A repeater is a device that receives, amplifies and transmits the radiated or conducted RF carrier both in downlink and
uplink. It comprises a donor side and a server side. The donor side receives the signal from a donor transmitter. This signal
may be carried by different types of links such as radio link, microwave link, or optic fibre. The server side transmits the
repeated signal.
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© Forsk 2009
Chapter 2: Geographic and Radio Data
2.2.5
Remote Antenna
The use of remote antennas allows antenna positioning at locations that would normally require prohibitively long runs of
feeder cable. A remote antenna is connected to the base station via an optic fibre. The main difference from a repeater is
that a remote antenna generates its own cell whereas a repeater extends the coverage of an existing cell.
2.2.6
Station
A station can represent one transmitter on a site or a group of transmitters on a same site sharing the same properties.
You can define station templates and build your network from stations instead of single transmitters.
2.2.7
Hexagonal Design
A hexagonal design is a group of stations created from the same station template.
2.2.8
GSM GPRS EGPRS Documents
2.2.8.1
TRX
A base station (transmitter) consists of several transceivers or TRXs. One TRX supports as many timeslots as the multiplexing factor defined in properties of your frequency band (8 timeslots in GSM networks). Three types of TRXs are
modelled in Atoll:
•
•
•
2.2.8.2
The BCCH TRX type: carries the BCCH,
The TCH TRX type: which is the default traffic carrier,
The TCH_INNER TRX type: this TRX type is an inner traffic carrier.
Subcell
A subcell corresponds to a group of TRXs having the same radio characteristics, the same quality (C/I) requirements, and
common settings. A subcell is characterised by the ‘transmitter-TRX type’ pair. Each transmitter may have one or more
subcells. The most common configurations are the {BCCH, TCH} configuration or the {BCCH, TCH, TCH_INNER} one.
2.2.8.3
Cell Type
A cell type describes the subcells (types of TRXs) that a cell can use and their parameters, which can be different. In the
current Atoll version, the cell type definition must include a TRX type as the BCCH carrier (BCCH TRX type) and another
TRX type as the default traffic carrier (TCH TRX type). Only one TRX type carrying the broadcast and only one TRX type
carrying the default TCH are supported.
2.2.9
All CDMA, WiMAX, and LTE Documents
2.2.9.1
Cell
Cell comprises the carrier characteristics of a transmitter. Cell is characterised by the ‘transmitter-carrier’ pair. The transmitter-carrier pair must be unique.
© Forsk 2009
AT281_TRG_E1
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42
AT281_TRG_E1
© Forsk 2009
Chapter 3
File Formats
Atoll supports a set of file formats for each type of data, may it be geographic data or calculation results.
This chapter contains details of these file formats, their usage, availability, and limitations.
AtollMicrowave
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© Forsk 2009
Chapter 3: File Formats
3
File Formats
3.1
BIL Format
Band Interleaved by Line is a method of organizing image data for multi-band images. It is a schema for storing the actual
pixel values of an image in a file. The pixel data is typically preceded by a file header that contains auxiliary data about the
image, such as the number of rows and columns in the image, a colour map, etc. .bil data stores pixel information band
by band for each line, or row, of the image. Although .bil is a data organization schema, it is treated as an image format.
An image description (number of rows and columns, number of bands, number of bits per pixel, byte order, etc.) has to be
provided to be able to display the .bil file. This information is included in the header .hdr file associated with the .bil file. A
.hdr file has the same name as the .bil file it refers to, and should be located in the same directory as the source file. The
.hdr structure is simple; it is an ASCII text file containing eleven lines. You can open a .hdr file using any ASCII text editor.
Atoll supports the following objects in .bil format:
•
•
•
•
•
•
•
•
Digital Terrain Model (8 or 16 bits)
Clutter heights (8 or 16 bits)
Clutter classes and User profile environment based traffic maps (8 bits)
User density traffic maps (16 or 32 bits)
Raster images (1, 4, 8, 24 bits)
Population maps (8, 16, 32 bits)
Other generic geographic data (8, 16, 32 bits)
Path loss or received signal level value matrices (16 bits)
3.1.1
HDR Header File
3.1.1.1
Description
The header file is a text file that describes how data are organised in the .bil file. The header file is made of rows, each
row having the following format:
keyword
value
where ‘keyword’ corresponds to an attribute type, and ‘value’ defines the attribute value.
Keywords required by Atoll are described below. Other keywords are ignored.
nrows
Number of rows in the image.
ncols
Number of columns in the image.
nbands
Number of spectral bands in the image, (1 for DTM data and
8 bit pictures).
nbits
Number of bits per pixel per band; 8 or 16 for DTMs or
Clutter heights (altitude in metres), 8 for clutter classes file (clutter code), 16 for path loss matrices (path
loss in dB, field value in dBm, dBµV and DBµV/m).
byteorder
Byte order in which image pixel values are stored. Accepted values are M (Motorola byte order) or I (Intel byte order).
layout
Must be ‘bil’.
skipbytes
Byte to be skipped in the image file in order to reach the
beginning of the image data. Default value is 0.
ulxmap
x coordinate of the centre of the upper-left pixel.
ulymap
y coordinate of the centre of the upper-left pixel.
xdim
x size in metre of a pixel.
ydim
y size in metre of a pixel.
Four additional keywords may be optionally managed.
pixeltype
Type of data read (in addition to the length)
which can be :
© Forsk 2009
UNSIGNDINT
Undefined
8, 16, 24 or 32 bits
SIGNEDINT
Integer
16 or 32 bits
FLOAT
Real
32 or 64 bits
AT281_TRG_E1
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Technical Reference Guide
in some cases, this keyword can be replace by datatype defined as follows:
datatype
Type of data read (in addition to the length)
It can be:
Un
Undefined
n bits (8, 16, 24 or 32 bits)
In
Integer
n bits (16 or 32 bits)
Rn
Real
n bits (32 or 64 bits)
RGB24
Integer
3 colour components on 24 bits
The other optional keywords are :valueoffset, valuescale and nodatavalue.
By default, integer data types are chosen with respect to the pixel length (nbits).
valueoffset
Real value to be added to the read value (Vread)
valuescale
Scaling factor to be applied to the read value
So, we have V = V read  valuescale + valueoffset
nodatavalue
3.1.1.2
Value corresponding to “NO DATA”
Samples
Here, the data is 20m.
3.1.1.2.1
3.1.1.2.2
3.1.1.2.3
Digital Terrain Model
nrows
1500
ncols
1500
nbands
1
nbits
8 or 16
byteorder
M
layout
bil
skipbytes
0
ulxmap
975000
ulymap
1891000
xdim
20.00
ydim
20.00
Clutter Classes File
nrows
1500
ncols
1500
nbands
1
nbits
8
byteorder
M
layout
bil
skipbytes
0
ulxmap
975000
ulymap
1891000
xdim
20.00
ydim
20.00
BIL File
.bil files are usually binary files without header. Data are stored starting from the Northwest corner of the area. The skipbytes value defined in the header file allows to skip records if the data do not start at the beginning of the file.
46
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Chapter 3: File Formats
3.2
TIF Format
Tagged Image File Format graphics filter supports all image types (monochrome, greyscale, palette colour, and RGB full
colour images) and Packbit, LZW or fax group 3-4 compressions. .tif files are not systematically geo-referenced. You have
to enter spatial references of the image manually during the import procedure (x and y-axis map coordinates of the centre
of the upper-left pixel, pixel size); an associated file with .tfw extension will be simultaneously created with the same name
and in the same directory as the .tif file it refers to. Atoll will then use the .tfw file during the import procedure for an automatic geo-referencing.
Note:
•
Atoll also supports .tif files using the Packbit, FAX-CCITT3 and LZW compression modes.
You can modify the colour palette convention used by Atoll when exporting .tif files. This can be helpful when working on
.tif files exported by Atoll in other tools. In the default palette, the first colour indexes represent the useful information and
the remaining colour indexes represent the background. It is possible to export .tif files with a palette which defines the
background colour at the colour index 0, and then the colour indexes necessary to represent useful information. Add the
following lines in the Atoll.ini file to set up the new palette convention:
[TiffExport]
PaletteConvention=Gis
Please refer to the Administrator Manual for more details about the Atoll.ini file.
Notes:
•
Using compressed geo data formats (compressed .tif, Erdas Imagine, or .ecw) can cause
performance loss due to real-time decompression. However, you can recover this loss in
performance by:
- Either, hiding the status bar, which provides geographic data information in real time, by
unchecking the Status Bar item in the View menu.
- Or, not displaying some of the information, such as altitude, clutter class and clutter
height, in the status bar. This can be done through the Atoll.ini file, by adding the following
lines:
[StatusBar]
DisplayZ=0
DisplayClutterClass=0
DisplayClutterHeight=0
•
You can also save the produced map in an uncompressed format.
•
Please refer to the Administrator Manual for more details about the Atoll.ini file.
Atoll supports the following objects in .tif format:
•
•
•
•
•
•
•
Digital Terrain Model (8 or 16 bits)
Clutter heights (8 or 16 bits)
Clutter classes and User profile environment based traffic maps (8 bits)
User density traffic maps (16 or 32 bits)
Raster images (1, 4, 8, 24 bits)
Population maps (8, 16, 32 bits)
Other generic geographic data (8, 16, 32 bits)
.tfw file contains the spatial reference data of an associated .tif file. The .tfw file structure is simple; it is an ASCII text file
that contains six lines. You can open a .tfw file using any ASCII text editor.
3.2.1
TFW Header File
The .tfw files contain spatial reference data for the associated .tif file. The header file is a text file that describes how data
are organised in the .tif file. You can open a .tfw file using any ASCII text editor. The header file consists of six lines, with
each line having the following description:
Line
© Forsk 2009
Description
1
x dimension of a pixel in map units
2
amount of translation
3
amount of rotation
4
negative of the y dimension of a pixel in map units
5
x-axis map coordinate of the centre of the upper-left pixel
6
y-axis map coordinate of the centre of the upper-left pixel
AT281_TRG_E1
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Technical Reference Guide
Note:
•
Atoll does not use the lines 2 and 3 when importing a .tif format geographic file.
3.2.2
Sample
3.2.2.1
Clutter Classes File
100.00
0.00
0.00
-100.00
60000.00
2679900.00
3.3
BMP Format
This is the MS-Windows standard format. It holds black & white, 16-, 256- and True-colour images. The palletized 16colour and 256-colour images may be compressed via run length encoding (though compressed .bmp files are quite rare).
The image data itself can either contain pointers to entries in a colour table or literal RGB values. .bmp files are not systematically geo-referenced. You have to enter spatial references of the image manually during the import procedure (x and yaxis map coordinates of the centre of the upper-left pixel, pixel size). When exporting (saving) a .bmp file, an associated
file with .bpw extension is created with the same name and in the same directory as the .bmp file it refers to. Atoll stores
the georeferencing information in this file for future imports of the .bmp so that the .bpw file can be used during the import
procedure for automatic geo-referencing. Atoll also supports .bmw extension for the .bmp related world files.
Atoll supports the following objects in .tif format:
•
•
•
•
•
•
3.3.1
Digital Terrain Model (8 bits)
Clutter Heights (8 bits)
Clutter classes and User density traffic maps (8 bits)
Raster images (1, 4, 8, 24 bits)
Population maps (8, 32 bits)
Other generic geographic data (8, 32 bits)
BMP File Description
A .bmp file contains of the following data structures:
3.3.1.1
•
BITMAPFILEHEADER
bmfh
•
•
•
BITMAPINFOHEADER
RGBQUAD
BYTE
bmih
aColors[]
aBitmapBits[]
Contains some information about the bitmap file (about the file, not
about the bitmap itself).
Contains information about the bitmap (such as size, colours, etc.).
Contains a colour table.
Image data (whose format is specified by the bmih structure).
BMP File Structure
The following tables give exact information about the data structures. The Start-value is the position of the byte in the file
at which the explained data element of the structure starts, the Size-value contains the number of bytes used by this data
element, the Name column contains both generic name and the name assigned to this data element by the Microsoft API
documentation, and the Description column gives a short explanation of the purpose of this data element.
•
Start
Size
1
3
Name
Description
Generic
MS API
2
Signature
bfType
Must always be set to 'BM' to declare that this is a .bmp-file.
4
FileSize
bfSize
Specifies the size of the file in bytes.
7
2
Reserved1
bfReserved1
Unused. Must be set to zero.
9
2
Reserved2
bfReserved2
Unused. Must be set to zero.
11
4
DataOffset
bfOffBits
Specifies the offset from the beginning of the file to the bitmap (raster)
data.
•
48
BITMAPFILEHEADER (Header - 14 bytes):
BITMAPINFOHEADER (InfoHeader - 40 bytes):
AT281_TRG_E1
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Chapter 3: File Formats
Start
Size
15
Name
Description
Generic
MS API
4
Size
biSize
Specifies the size of the BITMAPINFOHEADER structure, in
bytes (= 40 bytes).
19
4
Width
biWidth
Specifies the width of the image, in pixels.
23
4
Height
biHeight
Specifies the height of the image, in pixels.
biPlanes
Specifies the number of planes of the target device, must be
set to zero or 1.
biBitCount
Specifies the number of bits per pixel.
1 = monochrome pallete. # of colours = 1
4 = 4-bit palletized. # of colours = 16
8 = 8-bit palletized. # of colours = 256
16 = 16-bit palletized. # of colours = 65536
24 = 24-bit palletized. # of colours = 16M
27
29
2
Planes
2
BitCount
31
4
Compression
biCompression
Specifies the type of compression, usually set to zero.
0 = BI_RGB no compression
1 = BI_RLE8 8-bit RLE encoding
2 = BI_RLE4 4-bit RLE encoding
35
4
ImageSize
biSizeImage
Specifies the size of the image data, in bytes. If there is no
compression, it is valid to set this element to zero.
39
4
XpixelsPerM
biXPelsPerMeter
Specifies the the horizontal pixels per meter.
43
4
YpixelsPerM
biYPelsPerMeter
Specifies the the vertical pixels per meter.
47
4
ColoursUsed
biClrUsed
Specifies the number of colours actually used in the bitmap. If
set to zero the number of colours is calculated using the
biBitCount element.
51
4
ColoursImportant
biClrImportant
Specifies the number of colour that are 'important' for the
bitmap. If set to zero, all colours are considered important.
Note:
•
•
biBitCount actually specifies the colour resolution of the bitmap. It also decides if there is a
colour table in the file and how it looks like.
- In 1-bit mode the colour table has to contain 2 entries (usually white and black). If a bit in
the image data is clear, it points to the first palette entry. If the bit is set, it points to the
second.
- In 4-bit mode the colour table must contain 16 colours. Every byte in the image data
represents two pixels. The byte is split into the higher 4 bits and the lower 4 bits and each
value of them points to a palette entry.
- In 8-bit mode every byte represents a pixel. The value points to an entry in the colour
table which contains 256 entries.
- In 24-bit mode three bytes represent one pixel. The first byte represents the red part, the
second the green and the third the blue part. There is no need for a palette because every
pixel contains a literal RGB-value, so the palette is omitted.
RGBQUAD array (ColorTable):
Start
Size
1
Name
Description
Generic
MS API
1
Blue
rgbBlue
Specifies the blue part of the colour.
2
1
Green
rgbGreen
Specifies the green part of the colour.
3
1
Red
rgbRed
Specifies the red part of the colour.
4
1
Reserved
rgbReserved
Must always be set to zero.
Note:
•
•
In a colour table (RGBQUAD), the specification for a colour starts with the blue byte, while
in a palette a colour always starts with the red byte.
Pixel data:
The interpretation of the pixel data depends on the BITMAPINFOHEADER structure. It is important to know that the rows
of a .bmp are stored upside down meaning that the uppermost row which appears on the screen is actually the lowermost
row stored in the bitmap. Another important thing is that the number of bytes in one row must always be adjusted by
appending zero bytes to fit into the border of a multiple of four (16-bit or 32-bit rows).
© Forsk 2009
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Technical Reference Guide
3.3.1.2
BMP Raster Data Encoding
Depending on the image BitCount and on the Compression flag there are 6 different encoding schemes. In all of them,
•
•
•
•
Pixels are stored bottom-up, left-to-right.
Pixel lines are padded with zeros to end on a 32-bit boundary.
For uncompressed formats every line will have the same number of bytes.
Colour indices are zero based, meaning a pixel colour of 0 represents the first colour table entry, a pixel colour of
255 (if there are that many) represents the 256th entry. For images with more than 256 colours there is no colour
table.
Encoding type
BitCoun Compressio
t
n
1-bit
B&W images
1
4-bit
16 colour images
4
0
8-bit
256 colour images
8
0
Every byte holds 1 pixel. There are 256 colour table entries.
Padding each line with zeros up to a 32-bit boundary will result in up
to 3 bytes of zeros = 3 'wasted pixels'.
16-bit
High colour images
16
0
Every 2 bytes hold 1 pixel. There are no colour table entries.
Padding each line with zeros up to a 16-bit boundary will result in up
to 2 zero bytes.
0
Every 4 bytes hold 1 pixel. The first holds its red, the second its
green, and the third its blue intensity. The fourth byte is reserved
and should be zero. There are no colour table entries. No zero
padding necessary.
2
Pixel data is stored in 2-byte chunks. The first byte specifies the
number of consecutive pixels with the same pair of colour. The
second byte defines two colour indices. The resulting pixel pattern
will have interleaved high-order 4-bits and low order 4 bits
(ABABA...). If the first byte is zero, the second defines an escape
code. The End-of-Bitmap is zero padded to end on a 32-bit
boundary. Due to the 16bit-ness of this structure this will always be
either two zero bytes or none.
1
The pixel data is stored in 2-byte chunks. The first byte specifies the
number of consecutive pixels with the same colour. The second byte
defines their colour indices. If the first byte is zero, the second
defines an escape code. The End-of-Bitmap is zero padded to end
on a 32-bit boundary. Due to the 16bit-ness of this structure this will
always be either two zero bytes or none.
24
4-bit
16 colour images
4
8-bit
256 colour images
8
Raster Data Compression Descriptions
•
4-bit / 16 colour images
n (Byte 1)
•
50
0
Every byte holds 8 pixels, its highest order bit representing the
leftmost pixel of these 8. There are 2 colour table entries. Some
readers assume that 0 is black and 1 is white. If you are storing
black and white pictures you should stick to this, with any other 2
colours this is not an issue. Remember padding with zeros up to a
32-bit boundary.
Every byte holds 2 pixels, its high order 4 bits representing the left of
those. There are 16 colour table entries. These colours do not have
to be the 16 MS-Windows standard colours. Padding each line with
zeros up to a 32-bit boundary will result in up to 28 zeros = 7 'wasted
pixels'.
24-bit
True colour images
3.3.1.2.1
Remarks
c (Byte 2)
Description
>0
any
n pixels to be drawn. The 1st, 3rd, 5th, ... pixels' colour is in c's high-order 4 bits, the
even pixels' colour is in c's low-order 4 bits. If both colour indices are the same, it
results in just n pixels of colour c.
0
0
End-of-line
0
1
End-of-Bitmap
0
2
Delta. The following 2 bytes define an unsigned offset in x and y direction (y being up).
The skipped pixels should get a colour zero.
0
>=3
The following c bytes will be read as single pixel colours just as in uncompressed files.
Up to 12 bits of zeros follow, to put the file/memory pointer on a 16-bit boundary again.
8-bit / 256 colour images
n (Byte 1)
c (Byte 2)
Description
>0
any
n pixels of colour number c
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Chapter 3: File Formats
3.3.2
0
0
End-of-line
0
1
End-of-Bitmap
0
2
Delta. The following 2 bytes define an unsigned offset in x and y direction (y being up).
The skipped pixels should get a colour zero.
0
>=3
The following c bytes will be read as single pixel colours just as in uncompressed files.
A zero follows, if c is odd, putting the file/memory pointer on a 16-bit boundary again.
BPW/BMW Header File Description
The header file is a text file that describes how data are organised in the .bmp file. The header file is made of rows, each
row having the following description:
Line
Description
1
x dimension of a pixel in map units
2
amount of translation
3
amount of rotation
4
negative of the y dimension of a pixel in map units
5
x-axis map coordinate of the centre of the upper-left pixel
6
y-axis map coordinate of the centre of the upper-left pixel
Atoll supports .bpw and .bmw header file extensions for Import, but exports headers with .bpw file extensions.
3.3.3
Sample
3.3.3.1
Clutter Classes File
100.00
0.00
0.00
-100.00
60000.00
2679900.00
3.4
Generic Raster Header File (.wld)
.wld is a new Atoll specific header format that can be used for any raster data file for georeferencing. At the time of import
of any raster data file, Atoll can use the corresponding .wld file to read the georeferencing information related to the raster
data file. The .wld file contains the spatial reference data of any associated raster data file. The .wld file structure is simple;
it is an ASCII text file containing six lines. You can open a .wld file using any ASCII text editor.
3.4.1
WLD File Description
The .wld file is a text file that describes how data are organised in the associated raster data file. The header file is made
of rows, each row having the following description:
Line
Description
1
x dimension of a pixel in map units
2
amount of translation
3
amount of rotation
4
negative of the y dimension of a pixel in map units
5
x-axis map coordinate of the centre of the upper-left pixel
6
y-axis map coordinate of the centre of the upper-left pixel
3.4.2
Sample
3.4.2.1
Clutter Classes File
100.00
© Forsk 2009
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Technical Reference Guide
0.00
0.00
-100.00
60000.00
2679900.00
3.5
DXF Format
Atoll is capable of importing and working with AutoCAD® drawings in the Drawing Interchange Format (DXF). .dxf files
can have ASCII or binary formats. But only the ASCII .dxf files can be used in Atoll.
.dxf files are composed of pairs of codes and associated values. The codes, known as group codes, indicate the type of
value that follows. .dxf files are organized into sections of records containing the group codes and their values. Each group
code and value is a separate line.
Each section starts with a group code 0 followed by the string, SECTION. This is followed by a group code 2 and a string
indicating the name of the section (for example, HEADER). Each section ends with a 0 followed by the string ENDSEC.
3.6
SHP Format
ESRI (Environmental Systems Research Institute, Inc.) ArcView® GIS Shapefiles have a simple, non-topological format
for storing geometric locations and attribute information of geographic features. A shapefile is one of the spatial data
formats that you can work with in ArcExplorer. .shp data files usually have associated .shx and .dbf files.
Among these three files:
•
•
•
The .shp file stores the feature geometry
The .shx file stores the index of the feature geometry.
The .dbf (dBASE) file stores the attribute information of features. When a shapefile is added as a theme to a view,
this file is displayed as a feature table.
You can define mappings between the coordinate system used for the ESRI vector files, defined in the corresponding .prj
files, and Atoll. In this way, when you import a vector file, Atoll can detect the correct coordinate system automatically. For
more information about defining the mapping between coordinate systems, please refer to the Administrator Manual.
3.7
MIF Format
MapInfo Interchange Format (.mif) allows various types of data to be attached to a variety of graphical items. These ASCII
files are editable, easy to generate, and work on all platforms supported by MapInfo. Vector objects with a .mif extension
may be imported in Atoll.
Two files, a .mif and a .mid, contain MapInfo data. Graphics reside in the .mif file while the text contents are stored in the
.mid file. The text data is delimited with one row per record, and Carriage Return, Carriage Return plus Line Feed, or Line
Feed between lines. The .mif file has two sections, the file header and the data section. The .mid file is optional. When
there is no .mid file, all fields are blank.
You can find more information at http://www.mapinfo.com.
You can define mappings between the coordinate system used for the MapInfo vector files, defined in the corresponding
.mif files, and Atoll. In this way, when you import a vector file, Atoll can detect the correct coordinate system automatically.
For more information about defining the mapping between coordinate systems, please refer to the Administrator Manual.
3.8
TAB Format
TAB files (MapInfo Tables) are the native format of MapInfo. They actually consist of a number of files with extensions
such as .TAB, .DAT and .MAP. All of these files need to be present and kept together for the table to work. These are
defined as follows:
•
•
•
•
•
.TAB: table structure in ASCII format
.DAT: table data storage in binary format
.MAP: storage of map objects in binary format
.ID: index to the MapInfo graphical objects (.MAP) file
.IND: index to the MapInfo tabular (DAT) file
You can find more information at http://www.mapinfo.com.
You can define mappings between the coordinate system used for the MapInfo vector files, defined in the corresponding
.mif files, and Atoll. In this way, when you import a vector file, Atoll can detect the correct coordinate system automatically.
For more information about defining the mapping between coordinate systems, please refer to the Administrator Manual.
TAB files are also supported as georeference information files for raster files (.bmp and .tif). The .TAB file must have the
following format:
52
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Chapter 3: File Formats
!table
!version 300
!charset WindowsLatin1
Definition Table
File "raster.bmp"
Type "RASTER"
(ulxmap,ulymap) (0,0) Label "Pt 1",
(llxmap,llymap) (0,nrows) Label "Pt 2",
(lrxmap,lrymap) (ncols,nrows) Label "Pt 3",
(urxmap,urymap) (ncols,0) Label "Pt 4"
The fields in bold are described below:
3.9
Field
Description
File "raster.bmp"
Name of the raster file (e.g., raster.bmp)
ulxmap
x coordinate of the centre of the upper-left pixel in metres
ulymap
y coordinate of the centre of the upper-left pixel in metres
llxmap
x coordinate of the centre of the lower-left pixel in metres
llymap
y coordinate of the centre of the lower-left pixel in metres
lrxmap
x coordinate of the centre of the lower-right pixel in metres
lrymap
y coordinate of the centre of the lower-right pixel in metres
urxmap
x coordinate of the centre of the upper-right pixel in metres
urymap
y coordinate of the centre of the upper-right pixel in metres
nrows
Number of rows in the image
ncols
Number of columns in the image
ECW Format
The Enhanced Compressed Wavelet file format is supported in Atoll. .ecw files are geo-referenced image files, which can
be imported in Atoll. This is an Open Standard wavelet compression technology, developed by Earth Resource Mapping,
which can compress images with up to a 100-to-1 compression ratio. Each compressed image file contains a header carrying the following information about the image:
•
•
•
•
•
•
3.10
The image size expressed as the number of cells across and down
The number of bands (RGB images have three bands)
The image compression rate
The cell measurement units (meters, degrees or feet)
The size of each cell in measurement units
Coordinate space information (Projection, Datum etc.)
Erdas Imagine Format
Atoll supports Erdas Imagine data files in order to import DTM (8 or 16 bit/pixel), clutter (8 bit/pixel), traffic (8 bit/pixel), and
image (1-24 bit/pixel) files with the .img format. These files use the Erdas Imagine Hierarchical File Format (HFA) structure.
For any type of file, if there are pyramids (storage of different resolution layers), they are used to enhance performance
when decreasing the resolution of the display. Some aspects of working with Erdas Imagine format in Atoll are:
•
•
•
•
Atoll supports uncompressed as well as compressed (or partially compressed) DTM .img files.
You can create a .mnu file to improve the clutter class map loading.
The colour-to-code association (raster maps) may be automatically imported from the .img file.
These files are automatically geo-referenced, i.e., they do not require any additional file for geo-reference.
For image files, the number of supported bands is either 1 (colour palette is defined separately) or 3 (no colour palette but
direct RGB information for each pixel). In case of 3 bands, only 8 bit per pixel format is supported. Therefore, 8-bit images,
containing RGB information (three bands are provided: the first band is for Blue, the second one is for Green and the third
for Red), can be considered as 24 bit per pixel files. 32 bit per pixel files are not supported.
© Forsk 2009
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Notes:
•
Using compressed geo data formats (compressed .tif, Erdas Imagine, or .ecw) can cause
performance loss due to real-time decompression. However, you can recover this loss in
performance by:
- Either, hiding the status bar, which provides geographic data information in real time, by
unchecking the Status Bar item in the View menu.
- Or, not displaying some of the information, such as altitude, clutter class and clutter
height, in the status bar. This can be done through the Atoll.ini file, by adding the following
lines:
[StatusBar]
DisplayZ=0
DisplayClutterClass=0
DisplayClutterHeight=0
3.11
•
You can also save the produced map in an uncompressed format.
•
Please refer to the Administrator Manual for more details about the Atoll.ini file.
Planet EV/Vertical Mapper Geographic Data Format
Vertical Mapper offers two types of grids:
•
•
Numerical continuous grids, which contain numerical information (such as DTM), and are stored in files with the
.grd extension.
Classified grids, which contain alphanumeric (characters) information, and are stored in files with the .grc extension.
Atoll is capable of supporting the Vertical Mapper Classified Grid (GRC) and Vertical Mapper Continuous Grid (GRD) file
formats in order to import and export:
•
•
GRD: DTM, image, population, traffic density, and other data types.
GRC: DTM, clutter classes, clutter heights, environment traffic, image, population, and other data types.
It is also possible to export coverage prediction studies in GRD and GRC formats.
This is the geographic data format used by Planet EV. So, it is possible to directly import geographic data from Planet EV
to Atoll using this format.
3.12
ArcView Grid Format
The ArcView Grid format (.txt) is an ASCII format dedicated to defining raster maps. It may be used to export any raster
map such as DTM, images, clutter classes and/or heights, population, other data maps, and even coverage predictions.
The contents of an ArcView Grid file are in ASCII and consist of a header, describing the content, followed by the content
in the form of cell values.
3.12.1
ArcView Grid File Description
The format of this file is as follows:
ncols XXX
Number of columns of the grid (XXX columns).
nrows XXX
Number of rows of the grid (XXX rows).
xllcenter XXX OR
xllcorner XXX
Significant value relative to the bin centre or corner.
yllcenter OR
yllcorner XXX
Significant value relative to the bin centre or corner.
cellsize XXX
Grid resolution.
nodata_value XXX
Optional value corresponding to no data (no information).
//Row 1
Top of the raster. Description of the first row. Syntax:
ncols number of values separated by spaces.
:
:
//Row N
54
Bottom of the raster.
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Chapter 3: File Formats
3.12.2
Sample
ncols 303
nrows 321
xllcorner 585300.000000
yllcorner 5615700.000000
cellsize 100.000000
nodata_value 0
...
3.13
Other Supported Geographic Data File Formats
Other than the .bil, .tif, Planet, .dxf, .shp, .mif, .img, and .ecw formats, Atoll supports 3 other formats.
The .ist and .dis formats are ASCII files used for Digital Terrain Model only. .ist images come from Istar, whereas .dis
images come from IGN (Institut Géographique National). The .ist format works in exactly the same way as the .bil format,
except for DTM images. For DTM images, the .ist format uses a decimetric coding for altitudes, whereas .bil images use
only a metric coding.
3.14
Planet Format
The Planet geographic data are described by a set of files grouped in a Planet directory. The directory structure depends
on the geographic data type.
Atoll supports the following objects in Planet format:
•
•
•
•
•
Digital Terrain Model (8 and 16 bits)
Clutter class maps (16 bits)
Raster images (1, 4, 8 and 24 bits)
Vector data
Text data
3.14.1
DTM File
3.14.1.1
Description
The DTM directory consists of three files; the height file and two other files detailed below:
•
The index file structure is simple; it is an ASCII text file that holds position information about the file. It contains
five columns. You can open an index file using any ASCII text editor. The format of the index file is as follows:
Field
Acceptable values
Description
File name
Text
Name of file referenced by the index file
East min
Float
x-axis map coordinate of the centre of the upper-left pixel in meters
East max
Float
x-axis map coordinate of the centre of the upper-right pixel in meters
North min
Float
y-axis map coordinate of the centre of the lower-left pixel in meters
North max
Float
y-axis map coordinate of the centre of the upper-left pixel in meters
Square size
Float
Dimension of a pixel in meters
•
The projection file provides information about the projection system used. This file is optional. It is an ASCII text
file with four lines maximum.
Line
Description
Spheroid
Zone
Projection
Central meridian
Latitude and longitude of projection central meridian and equivalent x and y coordinates in meters
(optional)
Note:
•
© Forsk 2009
In the associated binary file, the value -9999 corresponds to ‘No data’ which is supported
by Atoll.
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Technical Reference Guide
3.14.1.2
Sample
Index file associated with height file (DTM data):
sydney1
303900 343900 6227900 6267900 50
Projection file associated with height file (DTM data):
Australian-1965
56
UTM
0 153 500000 10000000
3.14.2
Clutter Class Files
3.14.2.1
Description
The Clutter directory consists of three files; the clutter file and two other files detailed below:
•
The menu file, an ASCII text file, defines the feature codes for each type of clutter. It consists of as many lines
(with the following format) as there are clutter codes in the clutter data files. This file is optional.
Field
Type
Description
Clutter-code
Integer (>1)
Identification code for clutter class
Feature-name
Text (up to 32 characters in length)
Name associated with the clutter-code. (It may contain
spaces)
•
The index file gives clutter spatial references. The structure of clutter index file is the same as the structure of DTM
index file.
Note:
•
3.14.2.2
In the associated binary file, the value -9999 corresponds to ‘No data’ which is supported
by Atoll.
Sample
Menu file associated with the clutter file:
56
1
open
2
sea
3
inlandwater
4
residential
5
meanurban
6
denseurban
7
buildings
8
village
9
industrial
10
openinurban
11
forest
12
parks
13
denseurbanhigh
14
blockbuildings
15
denseblockbuild
16
rural
17
mixedsuburban
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Chapter 3: File Formats
3.14.3
Vector Files
3.14.3.1
Description
Vector data comprises terrain features such as coastlines, roads, etc. Each of these features is stored in a separate vector
file. Four types of files are used, the vector file, where x and y coordinates of vector paths are stored, and three other files
detailed below:
•
The menu file, an ASCII text file, lists the vector types stored in the database. The menu file is composed of one
or more records with the following structure:
Field
Type
Description
Vector type code
Integer > 0
Identification code for the vector type
Vector type name
Text (up to 32 characters in length)
Name of the vector type
The fields are separated by space character.
•
The index file, an ASCII text file, lists the vector files and associates each vector file with one vector type, and
optionally with one attribute file. The index file consists of one or more records with the following structure:
Field
Type
Description
Vector file name
Text (up to 32 characters in length)
Name of the vector file
Attribute file name
Text (up to 32 characters in length)
Name of attribute file associated with the vector file
(optional)
Dimensions
Real
vector file eastmin: minimum x-axis coordinate of all
vector path points in the vector file
vector file eastmax: maximum x-axis coordinate of all
vector path points in the vector file
vector file northmin: minimum y-axis coordinate of all
vector path points in the vector file
vector file northmax: maximum y-axis coordinate of all
vector path points
Vector type name
Text (up to 32 characters in length)
Name of the vector type with which the vector file is
associated. This one must match exactly a vector type
name field in the menu file.
The fields are separated by spaces.
•
3.14.3.2
The attribute file stores the height and description properties of vector paths. This file is optional.
Sample
Index file associated with the vector files
3.14.4
sydney1.airport
313440 333021 6239426 6244784 airport
sydney1.riverlake
303900 342704 6227900 6267900 riverlake
sydney1.coastline
322837 343900 6227900 6267900 coastline
sydney1.railways
303900 336113 6227900 6267900 railways
sydney1.highways
303900 325155 6240936 6267900 highways
sydney1.majstreets
303900 342770 6227900 6267900 majstreets
sydney1.majorroads
303900 342615 6227900 6267900 majorroads
Image Files
The image directory consists of two files, the image file with .tif extension and an index file with the same structure as the
DTM index file structure.
3.14.5
Text Data Files
The text data directory consists of:
•
The text data files are ASCII text files with the following format:
Airport
637111.188 3094774.00
Airport
© Forsk 2009
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Technical Reference Guide
628642.688 3081806.25
Each file contains a line of text followed by easting and northing of that text, etc.
•
The index file, an ASCII text file, stores the position of each text file. It consists of one or more records with the
following structure:
Field
Type
Description
File name
Text (up to 32 characters in length)
File name of the text data file
East Min
Real
Minimum x-axis coordinate of all points listed in the text
data file
East Max
Real
Maximum x-axis coordinate of all points listed in the text
data file
North Min
Real
Minimum y-axis coordinate of all points listed in the text
data file
North Max
Real
Maximum y-axis coordinate of all points listed in the text
data file
Text feature
Text (up to 32 characters in length)
This field is omitted in case no menu file is available.
The fields are separated by spaces.
railwayp.txt -260079 693937 2709348 3528665 Railway_Station
airport.txt -307727 771663 2547275 3554675 Airport
ferryport.txt 303922 493521 2667405 3241297 Ferryport
•
The menu file, an ASCII text file, contains the text features. This file is optional.
1
Airport
2
Ferryport
3
Railway_Station
3.15
MNU Format
3.15.1
Description
A .mnu file is useful when importing clutter classes or raster traffic files in .tif, .bil and .img formats. It gives the correspondence between the clutter (or traffic) code and the class name. It is a text file with the same name as the clutter (or traffic)
file with .mnu extension. It must be stored at the same location as the clutter (or traffic) file. It has the same structure as
the menu file used in the Planet format.
Field
Type
Description
Class code
Integer > 0
Identification code for the clutter (or traffic) class
Class name
Text (up to 50 characters in length)
Name of the clutter (or traffic) class. It may contain spaces.
Separator used can either be a space character or a tab.
3.15.2
Sample
A .mnu file associated to a clutter classes file:
3.16
0
none
1
open
2
sea
3
inland_water
4
residential
5
meanurban
XML Table Export/Import Format
All the data tables in an Atoll document can be exported to XML files.
58
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Chapter 3: File Formats
Atoll creates the following files when exporting data tables to XML files:
•
One index.xml file which contains the mapping between the data tables in Atoll and the corresponding XML file
created by the export.
One XML file per data table which contains the data table format (schema) and the data.
•
The XML import does not modify the active document table and field definitions. Therefore, the Networks and CustomFields tables, although exported, are not imported.
The following sections describe the structures of these two types of XML files created at export.
3.16.1
Index.xml File
The index.xml file stores the system (GSM, UMTS, etc.) and the technology (TDMA, CDMA, etc.) of the document, and
the version of Atoll used for exporting the data tables to XML files. It also contains the mapping between the data tables
in the Atoll document and the XML file corresponding to each data table.
The root tag <Atoll_XML_Config...> of the index.xml file contains the following attributes:
Attribute
Description
Atoll_File_System
Corresponds to the SYSTEM_ field of the Networks table of the exported document
Atoll_File_Technology
Corresponds to the TECHNOLOGY field of the Networks table of the exported
document
Atoll_File_Version
Corresponds to the Atoll version
The index file also contains a list of mapping between the tables exported from Atoll and the XML files corresponding to
each table. This list is sorted in the order the Atoll tables are to be imported.
The list is composed of <XML_Table.../> tags with the following attributes:
Attribute
Description
XML_File
Corresponds to the exported XML file name (e.g., "Sites.xml")
Atoll_Table
Corresponds to the exported Atoll table name (e.g., "Sites")
A sample extract of the index.xml is given below:
<Atoll_XML_Config Atoll_File_System="UMTS" Atoll_File_Technology="CDMA"
Atoll_File_Version="2.x.x build xxxx">
<XML_Table XML_File="CustomFields.xml" Atoll_Table="CustomFields" />
<XML_Table XML_File="CoordSys.xml" Atoll_Table="CoordSys" />
...
</Atoll_XML_Config>
Note that no closing tag </XML_Table> is required.
3.16.2
XML File
Atoll creates an XML file per exported data table. This XML file has two sections, one for storing the description of the table
structure, and the second for the data itself. The XML file uses the standard XML rowset schema (schema included in the
XML file between <s:Schema id=’RowsetSchema’> and </s:Schema> tags).
Rowset Schema
The XML root tag for XML files using the rowset schema is the following:
<xml xmlns:s='uuid:BDC6E3F0-6DA3-11d1-A2A3-00AA00C14882'
xmlns:dt='uuid:C2F41010-65B3-11d1-A29F-00AA00C14882'
xmlns:rs='urn:schemas-microsoft-com:rowset'
xmlns:z='#RowsetSchema'>
The schema definition follows the root tag and is enclosed between the following tags:
<s:Schema id=’RowsetSchema’>
<!-Schema is defined here, using <s:ElementType> and <s:AttributeType> tags ->
</s:Schema>
In the rowset schema, after the schema description, the data are enclosed between <rs:data> and </rs:data>.
Between these tags, each record is handled by a <z:row … /> tag having its attributes set to the record field values since
in the rowset schema, values are handled by attributes. Note that no closing tag </z:row> is required.
© Forsk 2009
AT281_TRG_E1
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Technical Reference Guide
A sample extract of a Sites.xml file containing the Sites table with only one site is given below:
<xml xmlns:s='uuid:BDC6E3F0-6DA3-11d1-A2A3-00AA00C14882'
xmlns:dt='uuid:C2F41010-65B3-11d1-A29F-00AA00C14882'
xmlns:rs='urn:schemas-microsoft-com:rowset'
xmlns:z='#RowsetSchema'>
<s:Schema id='RowsetSchema'>
<s:ElementType name='row' content='eltOnly' rs:updatable='true'>
<s:AttributeType name='NAME' rs:number='1' rs:maydefer='true' rs:writeunknown='true' rs:basetable='Sites' rs:basecolumn='NAME' rs:keycolumn='true'>
<s:datatype dt:type='string' dt:maxLength='50'/>
</s:AttributeType>
<s:AttributeType name='LONGITUDE' rs:number='2' rs:maydefer='true' rs:writeunknown='true' rs:basetable='Sites' rs:basecolumn='LONGITUDE'>
<s:datatype dt:type='float' dt:maxLength='8' rs:precision='15' rs:fixedlength='true'/>
</s:AttributeType>
<s:AttributeType name='LATITUDE' rs:number='3' rs:maydefer='true' rs:writeunknown='true' rs:basetable='Sites' rs:basecolumn='LATITUDE'>
<s:datatype dt:type='float' dt:maxLength='8' rs:precision='15' rs:fixedlength='true'/>
</s:AttributeType>
<s:AttributeType name='ALTITUDE' rs:number='4' rs:nullable='true' rs:maydefer='true' rs:writeunknown='true' rs:basetable='Sites' rs:basecolumn='ALTITUDE'>
<s:datatype
edlength='true'/>
dt:type='r4'
dt:maxLength='4'
rs:precision='7'
rs:fix-
</s:AttributeType>
<s:AttributeType name='COMMENT_' rs:number='5' rs:nullable='true' rs:maydefer='true'
rs:writeunknown='true'
rs:basetable='Sites'
rs:basecolumn='COMMENT_'>
<s:datatype dt:type='string' dt:maxLength='255'/>
</s:AttributeType>
<s:extends type='rs:rowbase'/>
</s:ElementType>
</s:Schema>
<rs:data>
<rs:insert>
<z:row NAME='Site0' LONGITUDE='8301' LATITUDE='-9756'/>
</rs:insert>
</rs:data>
</xml>
3.17
Externalised Propagation Results Format
Propagation results, i.e. the path loss matrices, may be stored in an external folder. This folder consists of a dBASE III
based file named ‘pathloss.dbf’ that contains calculation parameters of all the transmitters considered and one file (or two
when calculating main and extended path loss matrices) per transmitter taken into account. This is a binary file with .los
extension and contains the path loss values for a transmitter.
Note:
•
60
Each transmitter path loss matrix is calculated on the area where calculation radius
intersects the computation zone (see: Computation zone).
AT281_TRG_E1
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Chapter 3: File Formats
3.17.1
DBF File
dBASE III file (pathloss.dbf) has a standard .dbf format described below. Its content can be checked by opening it in MSAccess. The format is detailed hereafter.
3.17.1.1
DBF File Format
For general information, the format of .dbf files in any Xbase language is described.
Following notations are used in tables:
FS = FlagShip
D3 = dBaseIII+
Fb = FoxBase
D4 = dBaseIV
Fp = FoxPro
D5 = dBaseV
CL = Clipper
3.17.1.1.1
3.17.1.1.2
DBF Structure
Byte
Description
0...n
.dbf header (see next part for size, byte 8)
n+1
1st record of fixed length (see next parts)
2nd record (see next part for size, byte10) …
last record
last
optional: 0x1a (eof byte)
DBF Header (Variable Size - Depends on Field Count)
Byte
Size
Contents
Description
Applies for (supported by)
00
1
0x03
plain .dbf
FS, D3, D4, D5, Fb, Fp, CL
0x04
plain .dbf
D4, D5 (FS)
0x05
plain .dbf
D5, Fp (FS)
0x43
with .dbv memo var size
FS
0xB3
with .dbv and .dbt memo
FS
0x83
with .dbt memo
FS, D3, D4, D5, Fb, Fp, CL
0x8B
with .dbt memo in D4 format
D4, D5
0x8E
with SQL table
D4, D5
0xF5
with .fmp memo
Fp
01
3
YYMMDD
Last update digits
All
04
4
ulong
Number of records in file
All
08
2
ushort
Header size in bytes
All
10
2
ushort
Record size in bytes
All
12
2
0,0
Reserved
All
14
1
0x01
Begin transaction
D4, D5
0x00
End Transaction
D4, D5
0x00
ignored
FS, D3, Fb, Fp, CL
0x01
Encrypted
D4, D5
0x00
normal visible
All
15
© Forsk 2009
If .dbf is not empty
1
16
12
0 (1)
multi-user environment use
D4,D5
28
1
0x01
production index exists
Fp, D4, D5
0x00
index upon demand
All
29
1
n
language driver ID
D4, D5
0x01
codepage437 DOS USA
Fp
0x02
codepage850 DOS Multi ling
Fp
0x03
codepage1251 Windows ANSI
Fp
0xC8
codepage1250 Windows EE
Fp
0x00
ignored
FS, D3, Fb, Fp, CL
0,0
reserved
All
Field Descriptor, (see next paragraph)
all
Header Record Terminator
all
30
2
32
n*32
+1
1
0x0D
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Technical Reference Guide
•
Byte
Size
Contents
Description
Applies for (supported by)
0
11
ASCI
field name, 0x00 termin
all
11
1
ASCI
field type (see next paragraph)
all
12
4
n,n,n,n
Fld address in memory
D3
n,n,0,0
offset from record begin
Fp
0,0,0,0
ignored
FS, D4, D5, Fb, CL
16
1
byte
Field length, bin (see next paragraph)
all \ FS,CL: for C field type
17
1
byte
decimal count, bin
all / both used for fld lng
18
2
0,0
reserved
all
20
1
byte
Work area ID
D4, D5
0x00
unused
FS, D3, Fb, Fp, CL
21
2
n,n
multi-user dBase
D3, D4, D5
0,0
ignored
FS, Fb, Fp, CL
23
1
0x01
Set Fields
D3, D4, D5
0x00
ignored
FS, Fb, Fp, CL
24
7
0...0
reserved
all
31
1
0x01
Field is in .mdx index
D4, D5
0x00
ignored
FS, D3, Fb, Fp, CL
•
Size
Field type and size in the .dbf header, field descriptor (1 byte)
Type
Description/Storage
Applies for (supported by)
Char
ASCII (OEM code page chars)
rest= space, not \0 term.
all
n = 1...64kb (using deci count)
FS
n = 1...32kb (using deci count)
Fp, CL
n = 1...254
all
Date
8 ASCII digits (0...9) in the YYYYMMDD format
all
Numeric
ASCII digits (-.0123456789)
variable pos. of float.point
n = 1...20
FS, D4, D5, Fp
N 1...n Numeric
ASCII digits (-.0123456789)
fix posit/no float.point
all
C 1...n
D8
F 1...n
n = 1...20
FS, Fp, CL
n = 1...18
D3, D4, D5, Fb
ASCII chars (YyNnTtFf space)
FS, D3, Fb, Fp, CL
ASCII chars (YyNnTtFf?)
D4, D5 (FS)
Memo
10 digits repres. the start block posit. in .dbt file, or 10 spaces if
no entry in memo
all
V 10
Variable
Variable, bin/asc data in .dbv
4bytes bin= start pos in memo
4bytes bin= block size
1byte = subtype
1byte = reserved (0x1a)
10 spaces if no entry in .dbv
FS
P 10
Picture
binary data in .ftp
structure like M
Fp
B 10
Binary
binary data in .dbt
structure like M
D5
G 10
General
OLE objects
structure like M
D5, Fp
22
short int
binary int max +/- 32767
FS
44
long int
binary int max +/- 2147483647
FS
88
double
binary signed double IEEE
FS
L1
M 10
62
Field descriptor array in the .dbf header (32 bytes for each field)
Logical
AT281_TRG_E1
© Forsk 2009
Chapter 3: File Formats
3.17.1.1.3
Each DBF Record (Fixed Length)
Byte
Size
0
1…n
3.17.1.2
Description
Applies for (supported by)
1
deleted flag "*" or not deleted " "
all
1…
x-times contents of fields, fixed length, unterminated.
For n, see (2) byte 10…11
All
DBF File Content
The .dbf file provides information that is needed to check validity of each path loss matrix.
Field
Type
Description
TX_NAME
Text
Name of the transmitter
FILE_NAME
Text
Name (and optionally, path) of .los file
MODEL_NAME
Text
MODEL_SIG
Text
Name of propagation model used to calculate path loss
Signature (identity number) of model used in calculations. You may check it in the
propagation model properties (General tab).
The Model_SIG is used for the purpose of validity. A unique Model_SIG is
assigned to each propagation model. When model parameters are modified, the
associated model ID changes. This enables Atoll to detect path loss matrix
invalidity. In the same way, two identical propagation models in different projects
do not have the same model IDa.
ULXMAP
Float
X-coordinate of the top-left corner of the path loss matrix upper-left pixel
ULYMAP
Float
Y-coordinate of the top-left corner of the path loss matrix upper-left pixel
RESOLUTION
Float
Resolution of path loss matrix in metre
NROWS
Float
Number of rows in path loss matrix
NCOLS
Float
Number of columns in path loss matrix
FREQUENCY
Float
Frequency band
TILT
Float
Transmitter antenna mechanical tilt
AZIMUTH
Float
Transmitter antenna azimuth
TX_HEIGHT
Float
Transmitter height in metre
TX_POSX
Float
X-coordinate of the transmitter
TX_POSY
Float
Y-coordinate of the transmitter
ALTITUDE
Float
Ground height above sea level at the transmitter in metre
RX_HEIGHT
Float
Receiver height in metre
ANTENNA_SI
Float
Logical number referring to antenna pattern. Antennas with the same pattern will
have the same number.
MAX_LOS
Float
Maximum path loss stated in 1/16 dB. This information is used, when no
calculation radius is set, to check the matrix validity.
CAREA_XMIN
Float
Lowest x-coordinate of centre pixel located on the calculation radiusb
CAREA_XMAX
Float
Highest x-coordinate of centre pixel located on the calculation radius
CAREA_YMIN
Float
Lowest y-coordinate of centre pixel located on the calculation radius
CAREA_YMAX
Float
Highest y-coordinate of centre pixel located on the calculation radius
WAREA_XMIN
Float
Lowest x-coordinate of centre pixel located in the computation zonec
WAREA_XMAX
Float
Highest x-coordinate of centre pixel located in the computation zone
WAREA_YMIN
Float
Lowest y-coordinate of centre pixel located in the computation zone
WAREA_YMAX
Float
Highest y-coordinate of centre pixel located in the computation zone
LOCKED
Boolean
Locking status
0: path loss matrix is not locked
1: path loss matrix is locked.
Boolean
Atoll indicates if losses due to the antenna pattern are taken into account in the
path loss matrix.
0: antenna losses not taken into account
1: antenna losses included
INC_ANT
a.
b.
c.
© Forsk 2009
In order to benefit from the calculation sharing feature, users must retrieve the propagation models from the same
central database. This can be done using the Open from database command for a new document or the Refresh
command for an existing one. Otherwise, Atoll generates different model_ID (even if same parameters are applied
on the same kind of model) and calculation sharing become unavailable due to inconsistency.
These coordinates enable Atoll to determine the area of calculation for each transmitter.
These coordinates enable Atoll to determine the rectangle including the computation zone.
AT281_TRG_E1
63
Technical Reference Guide
3.17.2
LOS File
The data file is a 16 bits binary row file organized in a standard row-column structure. It contains an integer path loss value,
with a 1/16 dB unit. Data are stored starting from the southwest to the northeast corner of the area.
3.18
Externalised Tuning Files
Atoll can tune path loss matrices obtained from propagation results by the use of real measurements (CW Measurements
or Test Mobile Data). For each measured transmitter, Atoll tries to merge measurements and predictions on the same
points and to smooth the surrounding points of the path loss matrices for homogeneity reasons. A transmitter path loss
matrix can be tuned several times by the use of several measurement paths. All these tuning paths are stored in a catalogue. This catalogue is stored under a .tuning folder containing a .dbf file and one .pts file per corrected transmitter. Since
a tuning file can contain several measurement paths, all these measurements are added to the tuning file.
For more information on the path loss tuning algorithm, See "Path Loss Tuning" on page 109.
3.18.1
DBF File
dBASE III file (pathloss.dbf) has a standard .dbf format described below. Its content can be checked by opening it in MSAccess. The format is detailed hereafter.
3.18.1.1
DBF File Format
For general information, the format of .dbf files in any Xbase language is described.
Following notations are used in tables:
FS = FlagShip
D3 = dBaseIII+
Fb = FoxBase
D4 = dBaseIV
Fp = FoxPro
D5 = dBaseV
CL = Clipper
3.18.1.1.1
3.18.1.1.2
DBF Structure
Byte
Description
0...n
.dbf header (see next part for size, byte 8)
n+1
1st record of fixed length (see next parts)
2nd record (see next part for size, byte10) …
last record
last
optional: 0x1a (eof byte)
DBF Header (Variable Size - Depends on Field Count)
Byte
Size
Contents
Description
Applies for (supported by)
00
1
0x03
plain .dbf
FS, D3, D4, D5, Fb, Fp, CL
0x04
plain .dbf
D4, D5 (FS)
0x05
plain .dbf
D5, Fp (FS)
0x43
with .dbv memo var size
FS
0xB3
with .dbv and .dbt memo
FS
0x83
with .dbt memo
FS, D3, D4, D5, Fb, Fp, CL
0x8B
with .dbt memo in D4 format
D4, D5
0x8E
with SQL table
D4, D5
0xF5
with .fmp memo
Fp
01
3
YYMMDD
Last update digits
All
04
4
ulong
Number of records in file
All
08
2
ushort
Header size in bytes
All
10
2
ushort
Record size in bytes
All
12
2
0,0
Reserved
All
14
1
0x01
Begin transaction
D4, D5
0x00
End Transaction
D4, D5
0x00
ignored
FS, D3, Fb, Fp, CL
0x01
Encrypted
D4, D5
15
64
If .dbf is not empty
1
AT281_TRG_E1
© Forsk 2009
Chapter 3: File Formats
normal visible
All
16
12
0 (1)
multi-user environment use
D4,D5
28
1
0x01
production index exists
Fp, D4, D5
0x00
index upon demand
All
29
1
n
language driver ID
D4, D5
0x01
codepage437 DOS USA
Fp
0x02
codepage850 DOS Multi ling
Fp
0x03
codepage1251 Windows ANSI
Fp
0xC8
codepage1250 Windows EE
Fp
0x00
ignored
FS, D3, Fb, Fp, CL
0,0
reserved
All
Field Descriptor, (see next paragraph)
all
Header Record Terminator
all
30
2
32
n*32
+1
1
•
0x0D
Field descriptor array in the .dbf header (32 bytes for each field)
Byte
Size
Contents
Description
Applies for (supported by)
0
11
ASCI
field name, 0x00 termin
all
11
1
ASCI
field type (see next paragraph)
all
12
4
n,n,n,n
Fld address in memory
D3
n,n,0,0
offset from record begin
Fp
0,0,0,0
ignored
FS, D4, D5, Fb, CL
16
1
byte
Field length, bin (see next paragraph)
all \ FS,CL: for C field type
17
1
byte
decimal count, bin
all / both used for fld lng
18
2
0,0
reserved
all
20
1
byte
Work area ID
D4, D5
0x00
unused
FS, D3, Fb, Fp, CL
21
2
n,n
multi-user dBase
D3, D4, D5
0,0
ignored
FS, Fb, Fp, CL
23
1
0x01
Set Fields
D3, D4, D5
0x00
ignored
FS, Fb, Fp, CL
24
7
0...0
reserved
all
31
1
0x01
Field is in .mdx index
D4, D5
0x00
ignored
FS, D3, Fb, Fp, CL
•
Size
Field type and size in the .dbf header, field descriptor (1 byte)
Type
Description/Storage
Applies for (supported by)
Char
ASCII (OEM code page chars)
rest= space, not \0 term.
all
n = 1...64kb (using deci count)
FS
n = 1...32kb (using deci count)
Fp, CL
n = 1...254
all
Date
8 ASCII digits (0...9) in the YYYYMMDD format
all
Numeric
ASCII digits (-.0123456789)
variable pos. of float.point
n = 1...20
FS, D4, D5, Fp
N 1...n Numeric
ASCII digits (-.0123456789)
fix posit/no float.point
all
C 1...n
D8
F 1...n
L1
M 10
© Forsk 2009
0x00
Logical
Memo
n = 1...20
FS, Fp, CL
n = 1...18
D3, D4, D5, Fb
ASCII chars (YyNnTtFf space)
FS, D3, Fb, Fp, CL
ASCII chars (YyNnTtFf?)
D4, D5 (FS)
10 digits repres. the start block posit. in .dbt file, or 10 spaces if
no entry in memo
all
AT281_TRG_E1
65
Technical Reference Guide
3.18.1.1.3
V 10
Variable
Variable, bin/asc data in .dbv
4bytes bin= start pos in memo
4bytes bin= block size
1byte = subtype
1byte = reserved (0x1a)
10 spaces if no entry in .dbv
P 10
Picture
binary data in .ftp
structure like M
Fp
B 10
Binary
binary data in .dbt
structure like M
D5
G 10
General
OLE objects
structure like M
D5, Fp
22
short int
binary int max +/- 32767
FS
44
long int
binary int max +/- 2147483647
FS
88
double
binary signed double IEEE
FS
Each DBF Record (Fixed Length)
Byte
Size
0
1…n
3.18.1.2
FS
Description
Applies for (supported by)
1
deleted flag "*" or not deleted " "
all
1…
x-times contents of fields, fixed length, unterminated.
For n, see (2) byte 10…11
All
DBF File Content
The .dbf file provides information about the measured transmitters participating in the tuning.
3.18.2
Field
Type
Description
TX_NAME
Text
Name of the transmitter
FILE_NAME
Text
Name (and optionally, path) of .pts file
AREA_XMIN
Float
Not used
AREA_XMAX
Float
Not used
AREA_YMIN
Float
Not used
AREA_YMAX
Float
Not used
PTS File
The tuning file contains a header and the list of points.
The contents of the header is:
•
•
•
•
•
•
•
•
•
•
•
•
•
4 bytes : version
4 bytes : flag (can be used to manage flags like active flag)
50 bytes : GUID
4 bytes : Number of points
255 bytes : original measurements name (with prefix Num : for test mobile data and CW: for CW measurements)
256 bytes : comment
4 bytes : X_RADIUS
4 bytes : Y_RADIUS
4 bytes : Gain : measurement gain - losses
4 bytes : Global error
4 bytes : Rx height
4 bytes : Frequency
8 bytes : Tx Position
The list of points contains following 4-uplet for all points
•
•
•
•
3.19
4 bytes : X
4 bytes : Y
4 bytes : Measurement value
4 bytes : Incidence angle.
Interference Histograms File Formats
Interference histograms required by automatic frequency planning tools can be imported and exported.
Notes:
•
66
No validity check is carried out when importing an interference histogram file.
AT281_TRG_E1
© Forsk 2009
Chapter 3: File Formats
3.19.1
•
Atoll only imports interference histograms related to loaded transmitters.
•
The lines starting with the symbol "#" are considered as comments.
•
The interferer TRX type is not specified. In fact, the subcells of the interferer transmitter
differ by their power offsets. If the power offset of a subcell is X with respect to the BCCH,
then its interference C/I histogram will be shifted by X with respect to the BCCH
interference histogram. It contains no further information; therefore, the interferer TRX type
is always BCCH.
•
For each interfered subcell-interferer subcell pair, Atoll saves probabilities for several C/I
values (between 6 to 24 values). Five of these values are fixed; probabilities are calculated
for C/I values equal to –9, 1, 8, 14, and 22 dB. Then, between each fixed C/I value, there
can be up to three additional values (this number depends on the probability variation
between the fixed values). The C/I values have 0.5 dB accuracy and probability values are
calculated and stored with an accuracy of 0.002 for probabilities between 1 and 0.05, and
with an accuracy of 0.0001 for probabilities lower than 0.05.
•
If no power offset is defined on the Interfered TRX type, it is possible to use the "All" value.
•
The values of probability should be absolute (between 0 and 1), and not in precentage
(between 0 and 100%).
One Histogram per Line (.im0) Format
This file contains one histogram per line for each interfered/interfering subcell pair. The histogram is a list of C/I values
with associated probabilities.
The .im0 file consists of two parts:
•
The first part is a header used for format identification. It must start with and contain the following lines:
# Calculation Results Data File.
# Version 1.1, Tab separated format. Commented lines start with #.
•
The second part details interference histogram of each interfered subcell-interferer subcell pair.
The lines after the header are considered as comments if they start with the symbol "#". If not, they must have the following
format:
<Column1><tab><Column2><tab><Column3><tab><Column4><newline>
The 4 tab-separated columns are defined in the table below:
3.19.1.1
Column name
Description
Column1
Interfered transmitter
Name of the interfered transmitter.
Column2
Interfering transmitter
Name of the interferer transmitter.
Column3
Interfered TRX type
Interfered subcell. In order to save storage, all subcells with no power
offset are not duplicated (e.g. BCCH, TCH).
Column4
C/I Probability
C/I value and the probability associated to this value separated by a space
character. This entry cannot be null.
Sample
# Calculation Results Data File.
# Version 1.1, Tab separated format. Commented lines start with #.
# Remark:
C/I results do not incorporate power offset values.
# Fields are:
#-----------------------------------------------------------------------#Transmitter
Interferer
TRX type
{C/I Probability} values
#-----------------------------------------------------------------------#
# Warning, The parameter settings of this header can be wrong if
# the "export" is performed following an "import". They
# are correct when the "export" follows a "calculate".
#
# Service Zone Type is "Best signal level of the highest priority HCS layer".
# Margin is 5.
© Forsk 2009
AT281_TRG_E1
67
Technical Reference Guide
# Cell edge coverage probability 75%.
# Traffic spreading was Uniform
##---------------------------------------------------------------------#
#
Site0_2
Site0_1
BCCH,TCH -10 1 -9 0.996 -6 0.976 -4 0.964 -1 0.936
0 0.932 1 0.924 4 0.896 7 0.864 8 0.848
9 0.832 10 0.824 11 0.804 14 0.712 17 0.66
Site0_2
Site0_3
BCCH,TCH -10 1 -9 0.996 -6 0.976 -4 0.972 -1 0.948
0 0.94 1 0.928 4 0.896 7 0.856 8 0.84
11 0.772 13 0.688 14 0.636 15 0.608 18 0.556
Site0_3
Site0_1
BCCH,TCH -10 1 -9 0.996 -6 0.98 -3 0.948 0 0.932
1 0.924 4 0.892 7 0.852 8 0.832 9 0.816
10 0.784 11 0.764 14 0.644 15 0.616 18 0.564
Site0_3
Site0_2
BCCH,TCH -9 1 -6 0.972 -3 0.964 -2 0.96 0 0.94
1 0.932 4 0.904 7 0.876 8 0.86 9 0.844
11 0.804 13 0.744 14 0.716 15 0.692 18 0.644
3.19.2
One Value per Line with Dictionary File (.clc) Format
Atoll creates two ASCII text files in a specified directory: xxx.dct and xxx.clc (xxx is the user-specified name).
Note:
•
3.19.2.1
CLC File
3.19.2.1.1
Description
When importing interference histograms with standard format, you must specify the .clc file
to be imported. Atoll looks for the associated .dct file in the same directory and uses it to
decode transmitter identifiers. If this file is unavailable, Atoll assumes that the transmitter
identifiers are the transmitter names. In this case, the columns 1 and 2 of the .clc file must
contain the names of the interfered and interferer transmitters instead of their identification
numbers.
The .clc file consists of two parts:
•
The first part is a header used for format identification. It must start with and contain the following lines:
# Calculation Results Data File.
# Version 1.1, Tab separated format. Commented lines start with #.
•
The second part details interference histogram of each interfered subcell-interferer subcell pair.
The lines after the header are considered as comments if they start with the symbol "#". If not, they must have the following
format:
<Column1><tab><Column2><tab><Column3><tab><Column4><tab><Column5><newline>
The 5 tab-separated columns are defined in the table below:
Column name
Description
Column1
Interfered transmitter
Identification number of the interfered transmitter. If the column is empty,
its value is identical to the one of the line above.
Column2
Interfering transmitter
Identification number of the interferer transmitter. If the column is null, its
value is identical to the one of the line above.
Column3
Interfered TRX type
Interfered subcell. If the column is null, its value is identical to the one of
the line above. In order to save storage, all subcells with no power offset
are not duplicated (e.g. BCCH, TCH).
Column4
C/I threshold
C/I value. This column cannot be null.
Probability C/I > Threshold
Probability to have C/I the value specified in column 4 (C/I threshold). This
field must not be empty.
Column5
68
AT281_TRG_E1
© Forsk 2009
Chapter 3: File Formats
Note:
•
3.19.2.1.2
The columns 1, 2, and 3 must be defined only in the first line of each histogram.
Sample
# Calculation Results Data File.
# Version 1.1,
# Remark:
Tab separated format. Commented lines start with #.
C/I results do not incorporate power offset values.
# Fields are:
##------------#------------#------------#-----------#------------------#
#| Interfered | Interfering| Interfered | C/I
#| Transmitter| Transmitter| Trx type
| Probability
|
| Threshold | C/I >= Threshold |
##------------#------------#------------#-----------#------------------#
#
# Warning, The parameter settings of this header can be wrong if
# the "export" is performed following an "import". They
# are correct when the "export" follows a "calculate".
#
# Service Zone Type is "Best signal level of the highest priority HCS layer".
# Margin is 5.
# Cell edge coverage probability 75%.
# Traffic spreading was Uniform
##---------------------------------------------------------------------#
1
2
TCH_INNER
8
1
9
1
2
BCCH,TCH
0.944
10
0.904
11
0.892
14
0.844
15
0.832
16
0.812
17
0.752
22
0.316
25
0.292
8
1
9
0.944
10
.904
13
0.872
14
0.84
17
0.772
Note:
•
If the TCH and BCCH histograms are the same, they are not duplicated. A single record
indicates that the histograms belong to TCH and BCCH both. For example, instead of:
1 2 TCH
1 2 BCCH
-9.5
1
-9.5
- 9
1
- 6
1
- 9
1
- 6
-9.5
1
- 9
1
1
1
We have:
1 2 TCH,BCCH
3.19.2.2
DCT File
3.19.2.2.1
Description
- 6
1
The .dct file is divided into two parts:
•
© Forsk 2009
The first part is a header used for format identification. It must start with and contain the following lines:
AT281_TRG_E1
69
Technical Reference Guide
# Calculation Results Dictionary File.
# Version 1.1, Tab separated format. Commented lines start with #.
•
The second part provides information about transmitters taken into account in AFP.
The lines after the header are considered as comments if they start with the symbol "#". If not, they must have the following
format:
<Column1><tab><Column2><newline>
Column name
Type
Description
Column1
Transmitter name
Text
Name of the transmitter
Column2
Transmitter Identifier
Integer
Identification number of the transmitter
Column3
BCCH during calculation
Integer
BCCH used in calculations
Column4
BSIC during calculation
Integer
BSIC used in calculations
Column5
% of vic’ coverage
Float
Percentage of overlap of the victim service area
Column6
% of int’ coverage
Float
Percentage of overlap of the interferer service area
The last four columns describe the interference matrix scope. One transmitter per line is described separated with a tab
character.
3.19.2.2.2
Sample
# Calculation Results Dictionary File.
# Version 2.1,
Tab separated format. Commented lines start with #.
# Fields are:
##-----------#-----------#-----------#-----------#---------#---------#
#|Transmitter|Transmitter|BCCH during|BSIC during|% of vic'|% of int'|
#|Name
|Identifier |calculation|calculation|coverage |coverage |
##-----------#-----------#-----------#-----------#---------#---------#
#
# Warning, The parameter settings of this header can be wrong if
# the "export" is performed following an "import". They
# are correct when the "export" follows a "calculate".
#
# Service Zone Type is "Best signal level per HCS layer".
# Margin is 5.
# Cell edge coverage probability is 75%.
# Traffic spreading was Uniform (percentage of interfered area)
##---------------------------#
3.19.3
Site0_0
1
-1
-1
100
100
Site0_1
2
-1
-1
100
100
Site0_2
3
-1
-1
100
100
Site1_0
4
-1
-1
100
100
Site1_1
5
-1
-1
100
100
Site1_2
6
-1
-1
100
100
Site2_0
7
-1
-1
100
100
Site2_1
8
-1
-1
100
100
One Value per Line (Transmitter Name Repeated) (.im1)
Format
This file contains one C/I threshold and probability pair value per line for each interfered/interfering subcell pair. The histogram is a list of C/I values with associated probabilities.
The .im1 file consists of two parts:
70
AT281_TRG_E1
© Forsk 2009
Chapter 3: File Formats
•
The first part is a header used for format identification. It must start with and contain the following lines:
# Calculation Results Data File.
# Version 1.1, Tab separated format. Commented lines start with #.
•
The second part details interference histogram of each interfered subcell-interferer subcell pair.
The lines after the header are considered as comments if they start with the symbol "#". If not, they must have the following
format:
<Column1><tab><Column2><tab><Column3><tab><Column4><tab><Column5><newline>
The 5 tab-separated columns are defined in the table below:
Column name
Description
Column1
Interfered transmitter
Name of the interfered transmitter.
Column2
Interfering transmitter
Name of the interferer transmitter.
Column3
Interfered TRX type
Interfered subcell. In order to save storage, all subcells with no power
offset are not duplicated (e.g. BCCH, TCH).
Column4
C/I threshold
C/I value. This column cannot be null.
Probability C/I > Threshold
Probability to have C/I the value specified in column 4 (C/I threshold). This
field must not be empty.
Column5
3.19.3.1
Sample
# Calculation Results Data File.
# Version 1.1, Tab separated format. Commented lines start with #.
# Remark:
C/I results do not incorporate power offset values.
# Fields are:
#-----------------------------------------------------------------------#Transmitter
Interferer
TRX type
C/I
Probability
#-----------------------------------------------------------------------#
# Warning, The parameter settings of this header can be wrong if
# the "export" is performed following an "import". They
# are correct when the "export" follows a "calculate".
#
# Service Zone Type is "Best signal level of the highest priority HCS layer".
# Margin is 5.
# Cell edge coverage probability 75%.
# Traffic spreading was Uniform
##---------------------------------------------------------------------#
Site0_2
Site0_1
BCCH,TCH
-10
1
Site0_2
Site0_1
BCCH,TCH
-9
0.996
Site0_2
Site0_1
BCCH,TCH
-6
0.976
Site0_2
Site0_1
BCCH,TCH
-4
0.964
Site0_2
Site0_1
BCCH,TCH
-1
0.936
Site0_2
Site0_1
BCCH,TCH
0
0.932
Site0_2
Site0_1
BCCH,TCH
1
0.924
Site0_2
Site0_1
BCCH,TCH
4
0.896
Site0_2
Site0_1
BCCH,TCH
7
0.864
Site0_2
Site0_1
BCCH,TCH
8
0.848
Site0_2
Site0_1
BCCH,TCH
9
0.832
Site0_2
Site0_1
BCCH,TCH
10
0.824
...
© Forsk 2009
AT281_TRG_E1
71
Technical Reference Guide
3.19.4
Only Co-Channel and Adjacent Values (.im2) Format
In this case, there is only one .im2 file containing co-channel and adjacent channel interference probabilities specified for
each interfered transmitter – interferer transmitter pair. There is only one set of values for all the subcells of the interfered
transmitter.
Each line must have the following format:
<Column1><SEP><Column2><SEP><Column3><SEP><Column4><newline>
Where the separator (<SEP>) can either be a tab or a semicolon.
The four columns are defined in the table below:
Column name
Description
Column1
Interfered transmitter
Name of the interfered transmitter.
Column2
Interfering transmitter
Name of the interferer transmitter.
Column3
Co-channel interference
probability
Column4
Adjacent channel
interference probability
Probability of having C  I 
Probability of having C  I 
Max
BCCH ,TCH
Max
BCCH ,TCH
 C  I req 
 C  I req  – F
C  I req corresponds to the required C/I threshold. This parameter is defined for each subcell.
F is the adjacent channel protection level.
3.19.4.1
Sample
# Calculation Results Data File.
# Version 1.1, Tab separated format. Commented lines start with #.
# Remark:
C/I results do not incorporate power offset values.
# Fields are:
#-----------------------------------------------------------------------#Transmitter
Interferer
Co-channel
Adjacent channel
#-----------------------------------------------------------------------#
# Warning, The parameter settings of this header can be wrong if
# the "export" is performed following an "import". They
# are correct when the "export" follows a "calculate".
#
# Service Zone Type is "Best signal level of the highest priority HCS layer".
# Margin is 5.
# Cell edge coverage probability 75%.
# Traffic spreading was Uniform
##---------------------------------------------------------------------#
Site0_2
Site0_1
0.226667
0.024
Site0_2
Site0_3
0.27
0.024
Site0_3
Site0_1
0.276
0.02
Site0_3
Site0_2
0.226
0.028
The columns in the sample above are separated with a tab. These columns can also be separated with a semilcolon:
Site0_2;Site0_1;0.226667;0.024
Site0_2;Site0_3;0.27;0.024
Site0_3;Site0_1;0.276;0.02
Site0_3;Site0_2;0.226;0.028
72
AT281_TRG_E1
© Forsk 2009
Chapter 4
Calculations
This chapter describes in detail the calculation of path losses, the propagation models implemented in Atoll
by default, the calculation of antenna attenuation according to antenna patterns, and other calculation
algorithms in Atoll.
AtollMicrowave
Atoll
Microwave
Planning Software
RF PlanningLink
& Optimisation
Software
Technical Reference Guide
74
AT281_TRG_E1
© Forsk 2009
Chapter 4: Calculations
4
Calculations
4.1
Overview
Three kinds of predictions are available in Atoll:
•
Point analysis enables you to visualise transmitter-receiver profile and to get predictions for a user-defined
receiver in real time anywhere on a geographic map (Point analysis window: Profile tab).
Coverage studies consider each bin of calculation areas as a potential receiver you can define. Therefore, covered
bins correspond to areas where a criterion on the predicted received signal is fulfilled.
Point analysis based on path loss matrices enables you to get parameters derived from predicted values in coverage studies (field received, path loss, C/I, UMTS parameters) for a receiver anywhere inside a calculation area
(Point analysis window: Reception, Interference, AS analysis tabs).
•
•
An overview of different analysis methods is presented in the table below:
Coverage studies
Point analysis
Point analysis based on path loss
matrices
Any study
Profile
Reception, Results,
Interference, AS analysis
Receiver
position
At the centre of each
calculation bin within
calculation areas
Anywhere. Even beyond
computation zone
Anywhere inside the calculation areas
Calculation
Path loss matrix
calculation
Real time
No calculation: result coming from path
loss matrices
Profile
extractiona
Radial except when
using SPM
Systematic
Method used for coverage studies: radial
except when using SPM
Result
One value inside a
calculation bin
Different values inside a
calculation bin
One value inside a calculation bin
a.
When using SPM, you can choose either radial or systematic calculation option.
Notes:
•
In coverage studies, Atoll calculates path loss for every bin within calculation areas.
However, only results on calculation bins inside the computation zone are displayed.
•
Profile point analysis is calculated in real time. Therefore, prediction is always consistent
with the network. On the other hand, if you modify any parameter (radio or geo), which may
make matrices invalid, consider updating the matrices before using point analysis based on
path loss matrices.
•
Due to different calculation methods, you can get different results at a same point when
performing a point analysis in profile or reception mode.
In any case, prediction is performed in three steps:
1st step: First of all, Atoll calculates the path loss ( L path ), using the selected propagation model.
L path = L model + L ant
Tx
+ L ant
Rx
L model is the loss on the transmitter-receiver path calculated through the propagation model. L model value depends on
the selected propagation model.
L ant
Tx
L ant
Rx
is the transmitter antenna attenuation (from antenna patterns).
is the receiver antenna attenuation ( L ant
Rx
= 0 ) (from antenna patterns).
Notes:
•
In any project, Atoll considers that the receiver antenna is in the transmitter antenna axis.
Therefore, the receiver antenna attenuation is supposed to be zero.
•
Transmitter antenna attenuation may not be considered in this step. It depends on
propagation model provider, who may choose to include this parameter in L path
calculation. However, all the propagation models available in Atoll calculate L path by
considering transmitter antenna attenuation.
2nd step: When the option “Shadowing taken into account” is selected, Atoll evaluates a shadowing margin,
M Shadowing – model , from the user-defined model standard deviation at the receiver and the cell edge coverage probability.
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Note:
•
For a cell edge coverage probability of 50%, the shadowing margin is always zero. In this
case, Atoll still works as above.
3rd step: Then, Atoll determines the prediction criterion and displays coverage.
For a signal level study,
The signal level at the receiver ( P Rec ) is calculated. We have (in dBm):
P Rec = EIRP – L path – M Shadowing – model – L Indoor +  G ant
Where EIRP = P Tx + G ant
Tx
Rx
– L Rx 
– L Tx
EIRP is the effective isotropic radiated power of the transmitter.
P Tx is the transmitter power.
G ant
Tx
is the transmitter antenna gain.
L Tx are transmitter losses.
M Shadowing – model is the shadowing margin.
L Indoor are the indoor losses, taken into account when the option “Indoor coverage” is selected,
L Rx are receiver losses.
G ant
Rx
is the receiver antenna gain.
Notes:
•
In UMTS and CDMA documents, P Tx = P Pilot and L Tx = L total – DL .
•
In UMTS and CDMA documents, Atoll considers that G ant
Rx
and L Rx equal zero when
calculating the received signal level (in point analysis, Profile and Reception tabs, and in
common coverage studies such as Coverage per transmitter, Coverage by field level,
Overlapping).
•
In GSM_EGPRS documents, L Tx = L total – DL .
•
In GSM_EGPRS documents, receiver is equipped with an antenna with zero gain.
The prediction is performed for a user-defined cell edge coverage probability (x%). This means that the measured criterion
exceeds the predicted criterion for x% of time. The prediction is reliable during x% of time.
Note:
•
4.2
In case of interference studies, only signal from interfered transmitter (C) is downgraded by
the shadowing margin. We consider that interference value (I) is not altered by the
shadowing margin.
Path Loss Matrices
Atoll is able to calculate two path loss matrices per transmitter, a first matrix over a smaller radius computed with a high
resolution and a propagation model (main matrix), and a second matrix over a larger radius computed with a low resolution
and another propagation model (extended matrix).
To be considered for calculations, a transmitter must fulfil the following conditions:
•
•
•
It must be active,
It must satisfy filter criteria defined in the Transmitters folder, and
It must have a calculation area.
In the rest of the document, a transmitter fulfilling the conditions detailed above will be called TBC transmitter.
The path loss matrix size of a TBC transmitter depends on its calculation area. Atoll determines a path loss value ( L path )
on each calculation bin (calculation bin is defined by the resolution) of the calculation area of the TBC transmitter. You may
have one or two path loss matrices per TBC transmitter.
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4.2.1
Calculation Area Determination
4.2.1.1
Computation Zone
Transmitter calculation area is made of a rectangle or a square depending on transmitter calculation radius and the computation zone.
Calculation radius enables Atoll to define a square around the transmitter. One side of the square equals twice the entered
calculation radius.
Since the computation zone can be made of one or several polygons, transmitter calculation area corresponds to the intersection area between its calculation square and the rectangle containing the computation zone area(s).
Figure 4.1: Example 1: Single Calculation Area
Figure 4.2: Example 2: Multiple Calculation Areas
Computation zone(s)
Rectangle containing the computation zone(s)
Calculation area defined (square)
Transmitter
Calculation area: real area for which Atoll calculates path losses
4.2.1.2
Use of Polygonal Zones in Coverage Prediction Reports
Prediction statistics are evaluated over the focus zone, if existing, then over the computation zone, if existing, or over the
whole covered area. The area of the focus and computation zones are calculated by decomposition in triangles.
The area of each prediction is calculated by counting its pixels inside the focus (resp. computation) zone. This number of
pixels multiplied by the area of one of its pixels gives the total area.
This area depends on the study resolution. At the border of the focus (resp. computation) zone, pixels are considered
either IN or OUT of the zone. A pixel is IN if its centre is inside the focus zone.
If a prediction covers the entire focus (resp. computation) zone, its area should be equal to the focus (resp. computation)
zone area, but as these 2 different methods differ, the results may be slightly different. If it happens that the value of the
prediction area is higher than the focus zone area, then the calculated percentage value is higher than 100%. In that case,
Atoll automatically replaces it by 100%.
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4.2.2
Calculate / Force Calculation Comparison
4.2.2.1
Calculate
The Calculate feature (F7) enables you:
1. To calculate prediction studies
The first time you click Calculate (no path loss matrices exist), Atoll computes path loss matrices for each TBC
transmitter. Then, it calculates created and unlocked coverage prediction studies inside the computation zone.
2. To check result validity and update calculations
If calculations have been performed once and you have changed some parameters such as radio data or calculation area, Atoll automatically detects path loss matrices to be recalculated. These are either one or several path
loss matrices that become invalid due to certain modifications. Then Atoll calculates the prediction study, or just
the prediction study if matrices were all still valid.
4.2.2.2
Force Calculation
With the Force calculation feature (Ctrl+F7), Atoll deletes all the path loss matrices even if they are valid, recalculates them
and then updates the results of prediction studies.
Note:
•
4.2.3
Geographic data (DTM, clutter) modification makes path loss matrices invalid. However,
Atoll does not detect this invalidity just by using Calculate. Therefore, to update
calculations, you must click the Force calculation command.
Matrix Validity
Atoll manages path loss matrix validity transmitter by transmitter, even in case of transmitters with two path loss matrices
(main and extended matrices). Therefore, even if only one path loss matrix of the transmitter is invalid, Atoll will recalculate
both of them. All the geographic data modifications and some radio data changes can make matrices invalid. This table
lists these modifications and also changes that have an impact only on prediction studies.
Modification
Matrix validity
Impact on
Calculate
Force
calculation
Frequency
Invalid
Path loss matrices
Sufficient
Not necessary
Antenna* coordinates (site coordinate:
X and Y, Dx and Dy)
Invalid
Path loss matrices
Sufficient
Not necessary
Antennaa height
Invalid
Path loss matrices
Sufficient
Not necessary
a
Invalid
Path loss matrices
Sufficient
Not necessary
a
Invalid
Path loss matrices
Sufficient
Not necessary
a
Antenna pattern
Downtilt
Invalid
Path loss matrices
Sufficient
Not necessary
% Power (when there is other
antennas)
Invalid
Path loss matrices
Sufficient
Not necessary
Site position/altitude
Invalid
Path loss matrices
Sufficient
Not necessary
Grid resolution (main or/and
extended)
Invalid
Path loss matrices
Sufficient
Not necessary
Propagation model (main or/and
extended)
Invalid
Path loss matrices
Sufficient
Not necessary
Propagation model parameters
Invalid
Path loss matrices
Sufficient
Not necessary
Calculation areas
1. Calculation areas gets smaller
Valid
Prediction study
Sufficient
Not necessary
Calculation areas
2. Calculation areas gets larger
Invalid
Path loss matrices
Sufficient
Not necessary
Receiver height
Invalid
Path loss matrices
Sufficient
Not necessary
Receiver losses
Valid
Prediction study
Sufficient
Not necessary
Receiver gain
Valid
Prediction study
Sufficient
Not necessary
Prediction study
Sufficient
Not necessary
Azimuth
Receiver antenna
Rx
= 0
Geographic layer order
Invalid
Path loss matrices Insufficientb
Necessary
Geographic file resolution
Invalid
Path loss matrices Insufficientb
Necessary
Invalid
Insufficientb
Necessary
New DTM map
78
Valid because L ant
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© Forsk 2009
Chapter 4: Calculations
Path loss matrices Insufficientb
New clutter class edition
Invalid
Coverage study resolution
Valid
Prediction study
Sufficient
Not necessary
Cell edge coverage probability
Valid
Prediction study
Sufficient
Not necessary
Coverage study conditions
Valid
Prediction study
Sufficient
Not necessary
Coverage study display options
Valid
Prediction study
Sufficient
Not necessary
Necessary
a.Modification of any parameter related to main or other antennas makes matrix invalid.
b.Except if this action has an impact on the site positions/altitudes.
Tip 1
Calculate or Force Calculation?
If you modify radio data or calculation areas, use the Calculate button. On the other hand, if you change geographic
data, it is necessary to use Force calculation.
Tip 2
Calculation area management
When performing prediction studies, it is recommended to follow this methodology to minimise recalculations:
1st step: Calculate without computation zone.
2nd step: Draw a computation zone and calculate.
3rd step: Decrease the calculation radius and calculate.
4.3
Path Loss Calculations
4.3.1
Ground Altitude Determination
Atoll determines reception and transmission site altitude from Digital Terrain Model map. The method used to evaluate site
altitude is based on a bilinear interpolation. It is described below.
Let us suppose a site S located inside a bin. Atoll knows the altitudes of four bin vertices, S’1, S’’1, S’2 and S’’2, from the
DTM file (Centre of each DTM pixel).
Figure 4.3: Ground Altitude Determination - 1
1st step: Atoll draws a vertical line through S. This line respectively intersects (S’1,S’’1) and (S’2, S’’2) lines at S1 and S2.
Figure 4.4: Ground Altitude Determination - 2
2nd step: Atoll determines the S1 and S2 altitudes using a linear interpolation method.
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Figure 4.5: Ground Altitude Determination - 3
3rd step: Atoll performs a second linear interpolation to evaluate the S altitude.
Figure 4.6: Ground Altitude Determination - 4
4.3.2
Clutter Determination
Some propagation models need clutter class and clutter height as information at receiver or along a transmitter-receiver
profile.
4.3.2.1
Clutter Class
Atoll uses clutter classes file to determine the clutter class.
4.3.2.2
Clutter Height
To evaluate the clutter height, Atoll uses clutter heights file if available in the .atl document; clutter height of a site is the
height of the nearest point in the file.
Example: Let us suppose a site S. In the clutter heights file, Atoll reads clutter heights of four points around the site, S’1,
S’’1, S’2 and S’’2. Here, the nearest point to S is S”2; therefore Atoll takes the S”2 clutter height as clutter height of S.
Figure 4.7: Clutter Height
If you do not have any clutter height file, Atoll takes clutter height information in clutter classes file. In this case, clutter
height is an average height related to a clutter class.
4.3.3
Geographic Profile Extraction
Geographic profile extraction is needed in order to calculate diffraction losses. Profiles can be based on DTM only or on
DTM and clutter both. In fact, it depends on the selected propagation model.
4.3.3.1
Extraction Methods
4.3.3.1.1
Radial Extraction
Atoll draws radials from the site (where transmitter is located) to each calculation bin located along the transmitter calculation area border. In other words, Atoll determines a geographic profile between site and each bin centre.
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Chapter 4: Calculations
Figure 4.8: Radial calculation method
Transmitter
Radial: Atoll will extract a geographic profile for each radial
Centre of a bin located on the calculation border
Receiver: it may be anywhere in point analysis or at the centre of each calculation bin in coverage studies
Figure 4.9: Site-bin centre profile
The receiver may be located either anywhere within a calculation bin (Point prediction) or at the centre of a calculation bin
(Coverage study). Therefore, according to the receiver position, Atoll chooses the nearest profile and uses it (receiver is
considered as located on the profile) to perform prediction study at the receiver.
4.3.3.1.2
Systematic Extraction
In this case, Atoll systematically extracts a geographic profile between the site (where transmitter resides) and the receiver.
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Figure 4.10: Radial calculation method
Transmitter
Geographic profiles
Receiver: it may be anywhere in point analysis or at the centre of each calculation bin in coverage studies
4.3.3.2
Profile Resolution: Multi-Resolution Management
Geographic profile resolution depends on resolution of geographic data used by the propagation model (DTM and/or clutter).
1. 1st case: If the chosen propagation model considers both DTM and clutter heights along the profile, the profile
resolution will be the highest of the two.
Example 1: Standard Propagation Model is used to perform predictions. A DTM map with a 40 m resolution and
a clutter heights map with a 20 m resolution are available.
Both DTM and clutter maps are considered when using the Standard propagation model. Therefore, here, the
profile resolution will be 20 m. It means that Atoll will extract geographic information, ground altitude and clutter
height, every 20 m. To get ground altitude every 20m, Atoll uses the bilinear interpolation method described in
"Ground Altitude Determination" on page 79. Clutter heights are read from the clutter heights map. Atoll takes the
clutter height of the nearest point every 20m (see Path loss calculations: Clutter determination).
Example 2: Standard Propagation Model is used to perform predictions. A DTM map with a 40 m resolution and
a clutter classes map with a 20 m resolution are available. No clutter height file has been imported in .atl document.
Both DTM and clutter maps are considered when using the Standard propagation model. Therefore, here, the
profile resolution will be 20 m. It means that Atoll will extract geographic information, ground altitude and clutter
height, every 20 m. To get ground altitude every 20 m, Atoll uses the bilinear interpolation method described in
"Ground Altitude Determination" on page 79. Atoll uses the clutter classes map to determine clutter height. Every
20 m, it determines clutter class and takes associated average height.
2. 2nd case: If the chosen propagation model takes into account only DTM map along the profile, profile resolution
will be the highest resolution among the DTM files.
Example: Cost-Hata is used to perform predictions. Both DTM maps with 40 m and 25 m resolutions and a clutter
map with a 20 m resolution are available.
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Chapter 4: Calculations
Explorer window
DTM
•
•
DTM 1 (25m)
DTM 2 (40m)
Clutter
•
Clutter (20m)
Work space
Only DTM maps are considered along the whole profile when using Cost-Hata model. Therefore, here, the profile
resolution will be 25 m. It means that Atoll will extract geographic information, only the ground altitude, every 25 m.
DTM 1 is on the top of DTM 2. Thus, Atoll will consider ground elevation read from DTM 1 in the definition area of
DTM 1 and DTM 2 elsewhere. To get ground altitude every 25 m, Atoll uses the bilinear interpolation method
described in "Ground Altitude Determination" on page 79.
Notes:
© Forsk 2009
•
The selected profile resolution does not depend on the geographic layer order. In the last
example, whatever the DTM file order you choose, profile resolution will always be 25m.
On the other hand, the geographic layer order will influence the usage of data to establish
the profile.
•
The calculation bin of path loss matrices defined by the grid resolution is independent of
geographic file resolution.
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Macro cell
Rooftop
Fixed
Cell size
Receiver
location
Receiver
Use
-
Profile
extraction
mode
Mobile
Rooftop
Macro cell
-
-
d > 10 km
1 < d < 1000 km
Low frequencies Land and maritime
Broadcast
mobile, broadcast
-
-
Diffraction
calculation
method
Profile
based on
Free space loss +
Corrections
Free space loss
Corrected
standard
loss
Physical
phenomena
-
30-3000 MHz
100-400 MHz
Frequency
band
ITU 1546
ITU 370-7
(Vienna 93)
Fixed receivers
WLL
Fixed
Street
Macro cell
Radial
DTM
Deygout
(3 obstacles)
Deygout corrected
(3 obstacles)
Free space loss
Diffraction loss
30-10000 MHz
ITU 526-5
150-3500 MHz
Standard Propagation Model
Mobile and Fixed
1 < d < 20 km
GSM, UMTS,
CDMA2000, WiMAX, LTE
Fixed receivers
WLL, Microwave
links, WiMAX
1 < d < 100 km
GSM, CDMA2000,
LTE
Mobile
Street
Mobile
Street
Macro cell
Mini cell
Radial
DTM
Deygout
(1 obstacle)
L(d, f, HRx)
(per environment)
Diffraction loss
150-2000 MHz
COST-Hata
Okumura-Hata
Urban and suburban
GSM 900, GSM 1800,
areas
UMTS, CDMA2000,
100 m < d < 8 km
LTE
Fixed WiMAX
Fixed
Street
Macro cell
Mini cell
Macro cell
Mini cell
Macro cell
Mini cell
Street
Rooftop
Radial
DTM
Deygout
(1 obstacle)
L(d, f, HTx, HRx)
(per environment)
Diffraction loss
1900-6000 MHz
Erceg-Greenstein
(SUI)
Radial
DTM
Deygout
(1 obstacle)
L(d, f, HRx)
(per environment)
Diffraction loss
300-1500 MHz
ITU 529-3
Radial
Systematic
DTM
Clutter
Deygout (3 obstacles)
Epstein-Peterson (3 obstacles)
Deygout corrected (3 obstacles)
Millington (1 obstacle)
Fixed
Street
Rooftop
-
Radial
DTM
Clutter
Deygout
(3 obstacles)
Free space loss
L(d, HTxeff, HRxeff, Diff loss, clutter)
Diffraction loss
30-10000 MHz
WLL
4.4
Propagation
model
Technical Reference Guide
Propagation Models
Propagation models available in Atoll are listed in the table below along with their main characteristics.
© Forsk 2009
Chapter 4: Calculations
Notes:
•
In formulas described above, L model is stated in dB.
•
Under Physical phenomena, L(...) expressions refer to formulas customisable in Atoll.
•
SUI stands for Stanford University Interim models.
4.4.1
Okumura-Hata and Cost-Hata Propagation Models
4.4.1.1
Hata Path Loss Formula
Hata formula empirically describes the path loss as a function of frequency, receiver-transmitter distance and antenna
heights for an urban environment. This formula is valid for flat, urban environments and 1.5 metre mobile antenna height.
Path loss (Lu) is calculated (in dB) as follows:
Lu = A 1 + A 2 log  f  + A 3 log  h Tx  +  B 1 + B 2 log  h Tx  + B 3 h Tx  log d
f is the frequency (MHz).
hTx is the transmitter antenna height above ground (m) (Hb notation is also used in Atoll).
d is the distance between the transmitter and the receiver (km).
The parameters A1, A2, A3, B1, B2, and B3 can be user-defined. Default values are proposed in the table below:
4.4.1.2
Parameters
Okumura-Hata
f 1500 MHz
Cost-Hata
f > 1500 MHz
A1
69.55
49.30
A2
26.16
33.90
A3
-13.82
-13.82
B1
44.90
44.90
B2
-6.55
-6.55
B3
0
0
Corrections to the Hata Path Loss Formula
As described above, the Hata formula is valid for urban environment and a receiver antenna height of 1.5m. For other environments and mobile antenna heights, corrective formulas must be applied.
•
For urban areas: L model1 = Lu – a  h Rx 
•
f 2
For suburban areas: L model1 = Lu – a  h Rx  – 2  log  ------  – 5.4
 28 

•
For quasi-open rural areas: L model1 = Lu – a  h Rx  – 4.78  log  f   + 18.33 log  f  – 35.94
•
For open rural areas: L model1 = Lu – a  h Rx  – 4.78  log  f   + 18.33 log  f  – 40.94
2
2
a(hRx) is a correction for a receiver antenna height different from 1.5m.
Environment
a(hRx)
Rural/Small city
 1.1 log  f  – 0.7 h Rx –  1.56 log  f  – 0.8 
Large city
3.2  log  11.75h Rx   – 4.97
2
Note:
•
4.4.1.3
When receiver antenna height equals 1.5m, a(hRx) is close to 0 dB regardless of
frequency.
Calculations in Atoll
Hata models take into account topo map (DTM) between transmitter and receiver and morpho map (clutter) at the receiver.
1st step: For each calculation bin, Atoll determines the clutter bin on which the receiver is located. This clutter bin corresponds to a clutter class. Then, it uses the Hata formula assigned to this clutter class to evaluate L model1 .
2nd step: This step depends on whether the ‘Add diffraction loss’ option is checked.
•
If the ‘Add diffraction loss’ option is unchecked, Atoll stops calculations.
L model = L model1
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•
If the ‘Add diffraction loss’ option is selected, Atoll proceeds as follows:
a. It extracts a geographic profile between the transmitter and the receiver based on the radial calculation mode.
b. It determines the largest obstacle along the profile in accordance with the Deygout method and evaluates losses due to diffraction L model2 .
L model = L model1 + L model2
Note:
•
Like for any Hata-based model, L model is, by default, limited to the computed free space
loss value. It is also possible to avoid this option (option in the related scrolling menu of
Configuration tab).
4.4.2
ITU 529-3 Propagation Model
4.4.2.1
ITU 529-3 Path Loss Formula
The ITU 529.3 model is a Hata-based model. For this reason, its formula empirically describes the path loss as a function
of frequency, receiver-transmitter distance and antenna heights for a urban environment. This formula is valid for flat,
urban environments and 1.5 metre mobile antenna height.
The standard ITU 529-3 formula, for a receiver located on a urban environment, is given by:
E = 69.82 – 6.16 log f + 13.82 log h Tx –  44.9 – 6.55 log h Tx   log d 
b
where:
E is the field strength for 1 kW ERP
f is the frequency (MHz).
h Tx is the transmitter antenna height above ground (m) (Hb notation is also used in Atoll)
h Rx is the receiver antenna height above ground (m)
d is the distance between the transmitter and the receiver (km)
b is the distance correction
The domain of validity of such is formula is:
•
•
•
•
Frequency range: 300-1500 MHz
Base Station height: 30-200 m
Mobile height: 1-10 m
Distance range: 1-100 km
Since Atoll needs the path loss (Lu) formula, a conversion has to be made. One can find the following conversion formula:
Lu = 139.37 + 20 log f – E
which gives the following path loss formula for the ITU 529-3 model:
Lu = 69.55 + 26.16 log f – 13.82 log h Tx +  44.9 – 6.55 log h Tx   log d 
b
4.4.2.2
Corrections to the ITU 529-3 Path Loss Formula
4.4.2.2.1
Environment Correction
As described above, the Hata formula is valid for urban environment. For other environments and mobile antenna heights,
corrective formulas must be applied.
L model1 = Lu – a  h Rx  for large city and urban environments
f 2
L model1 = Lu – a  h Rx  – 2  log  ------  – 5.4 for suburban area

 28 
2
L model1 = Lu – a  h Rx  – 4.78  log f  + 18.33 log f – 40.94 for rural area
4.4.2.2.2
Area Size Correction
In the formulas above, a  h Rx  is the environment correction and is defined according to the area size
86
Environment
a(Hr)
Rural/Small city
 1.1 log f – 0.7 h Rx –  1.56 log f – 0.8 
Large city
3.2  log  11.75h Rx   – 4.97
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Chapter 4: Calculations
4.4.2.2.3
Distance Correction
The distance correction refers to the term b above.
Distance
b
d<20 km
1
–4
–3
d
b = 1 +  0.14 + 1.87  10 f + 1.07  10 h' Tx    log ------

20
d>20 km
4.4.2.3
0.8
h Tx
where h' Tx = -------------------------------------------–6 2
1 + 7  10 h Tx
Calculations in Atoll
Hata-based models take into account topo map (DTM) between transmitter and receiver and morpho map (clutter) at the
receiver.
1st step: For each calculation bin, Atoll determines the clutter bin on which the receiver is located. This clutter bin corresponds to a clutter class. Then, it uses the ITU 529-3 formula assigned to this clutter class to evaluate L model1 .
2nd step: This step depends on whether the ‘Add diffraction loss’ option is checked.
•
If the ‘Add diffraction loss’ option is unchecked, Atoll stops calculations.
L model = L model1
•
If the ‘Add diffraction loss’ option is selected, Atoll proceeds as follows:
a. It extracts a geographic profile between the transmitter and the receiver based on the radial calculation mode.
b. It determines the largest obstacle along the profile in accordance with the Deygout method and evaluates losses due to diffraction  L model2  .
L model = L model1 + L model2
Note:
•
Like for any Hata-based model, L model is, by default, limited to the computed free space
loss value. It is also possible to avoid this option (option in the related scrolling menu of
Configuration tab)
4.4.3
Standard Propagation Model (SPM)
4.4.3.1
SPM Path Loss Formula
SPM is based on the following formula:
L model = K 1 + K 2 log  d  + K 3 log  H Txeff  + K 4  DiffractionLoss + K 5 log  d   log  H Txeff  +
K 6  H Rxeff  + K 7 log  H Rxeff  + K clutter f  clutter 
with,
K1: constant offset (dB).
K2: multiplying factor for log(d).
d: distance between the receiver and the transmitter (m).
K3: multiplying factor for log(HTxeff).
HTxeff: effective height of the transmitter antenna (m).
K4: multiplying factor for diffraction calculation. K4 has to be a positive number.
Diffraction loss: loss due to diffraction over an obstructed path (dB).
K5: multiplying factor for log  d   log  H Txeff 
K6: multiplying factor for H Rxeff .
K7: multiplying factor for log  H Rxeff  .
H Rxeff : effective mobile antenna height (m).
Kclutter: multiplying factor for f(clutter).
f(clutter): average of weighted losses due to clutter.
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4.4.3.2
Calculations in Atoll
4.4.3.2.1
Visibility and Distance Between Transmitter and Receiver
For each calculation bin, Atoll determines:
•
The distance between the transmitter and the receiver.
If the distance Tx-Rx is less than the maximum user-defined distance (break distance), the receiver is considered to be
near the transmitter. Atoll will use the set of values marked “Near transmitter”.
If the distance Tx-Rx is greater than the maximum distance, receiver is considered far from transmitter. Atoll will use the
set of values “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.
4.4.3.2.2
Effective Transmitter Antenna Height
Effective transmitter antenna height (HTxeff) may be calculated with six different methods.
Height Above Ground
The transmitter antenna height is above the ground (HTx in m).
HTxeff = HTx
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 distance min and distance max values and is limited by the transmitter and receiver locations. Distance min and Distance max are minimum and maximum distances from the transmitter
respectively.
H Txeff = H Tx +  H 0Tx – H 0 
where,
H 0Tx is the ground height (ground elevation) above sea level at transmitter (m).
H 0 is the average ground height above sea level along the profile (m).
Note:
•
If the profile is not located between the transmitter and the receiver, HTxeff equals HTx only.
Slope at Receiver Between 0 and Minimum Distance
The transmitter antenna height is calculated using the ground slope at receiver.
H Txeff =  H Tx + H 0Tx  – H 0Rx + K  d
where,
H 0Rx is the ground height (ground elevation) above sea level at receiver (m).
K is the ground slope calculated over a user-defined distance (Distance min). In this case, Distance min is a distance from
receiver.
Notes:
•
If H Txeff  20m then, Atoll uses 20m in calculations.
•
If H Txeff  200m then, Atoll takes 200m.
Spot Ht
If H 0Tx  H 0Rx then, H Txeff = H Tx +  H 0Tx – H 0Rx 
If H 0Tx  H 0Rx then, H Txeff = H Tx
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Absolute Spot Ht
H Txeff = H Tx + H 0Tx – H 0Rx
Note:
•
Distance min and distance max are set to 3000 and 15000 m according to ITU
recommendations (low frequency broadcast f < 500 Mhz) and to 0 and 15000 m according
Okumura recommendations (high frequency mobile telephony).
These values are only used in the two last methods and have different meanings according to the method.
Enhanced Slope at Receiver
Atoll offers a new method called “Enhanced slope at receiver” to evaluate the effective transmitter antenna height.
Figure 4.11: Enhanced Slope at Receiver
Let x-axis and y-axis respectively represent positions and heights. We assume that x-axis is oriented from the transmitter
(origin) towards the receiver.
This calculation is achieved in several steps:
1st step: Atoll determines line of sight between transmitter and receiver.
The LOS line equation is:
  H 0Tx + H Tx  –  H 0Rx + H Rx  
Los  i  =  H 0Tx + H Tx  – -------------------------------------------------------------------------------- Res  i 
d
where,
H Rx is the receiver antenna height above the ground (m).
i is the point index.
Res is the profile resolution (distance between two points).
2nd step: Atoll extracts the transmitter-receiver terrain profile.
3rd step: Hills and mountains are already taken into account in diffraction calculations. Therefore, in order for them not to
unfavourably 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 filtered height of every profile point. Profile points are evenly spaced on the basis of profile resolution. To determine
filtered terrain height at a point, Atoll evaluates 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.
H filt is the filtered height.
H orig is the original height. Original terrain height is determined from extracted ground profile.
- Filter starting from transmitter
Let us assume that H filt – Tx  Tx  = H orig  Tx 
For each point, we have three different cases:
H orig  i  – H orig  i – 1 
1st case: If H orig  i   H orig  i – 1  and -------------------------------------------------------  0.05 ,
Res
Then, H filt – Tx  i  = H filt – Tx  i – 1  +  H orig  i  – H orig  i – 1  
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H orig  i  – H orig  i – 1 
2nd case: If H orig  i   H orig  i – 1  and -------------------------------------------------------  0.05
Res
Then, H filt – Tx  i  = H filt – Tx  i – 1 
3rd case: If H orig  i   H orig  i – 1 
Then, H filt – Tx  i  = H filt – Tx  i – 1 
If H filt  i   H orig  i  additionally
Then, H filt – Tx  i  = H orig  i 
- Filter starting from receiver
Let us assume that H filt  Rx  = H orig  Rx 
For each point, we have three different cases:
H orig  i  – H orig  i + 1 
1st case: If H orig  i   H orig  i + 1  and -------------------------------------------------------  0.05 ,
Res
Then, H filt – Rx  i  = H filt – Rx  i + 1  +  H orig  i  – H orig  i + 1  
H orig  i  – H orig  i + 1 
2nd case: If H orig  i   H orig  i + 1  and -------------------------------------------------------  0.05
Res
Then, H filt – Rx  i  = H filt – Rx  i + 1 
3rd case: If H orig  i   H orig  i + 1 
Then, H filt – Rx  i  = H filt – Rx  i + 1 
If H filt  i   H orig  i  additionally
Then, H filt – Rx  i  = H orig  i 
Then, for every point of profile, Atoll compares the two filtered heights and chooses the higher one.
H filt  i  = max  H filt – Tx  i  H filt – Rx  i  
4th step: 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 line for the first time (when beginning from transmitter).
The influence area must satisfy additional conditions:
•
R  3000m ,
•
•
R  0.01  d ,
R must contain at least three bins.
Notes:
•
When several influence areas are possible, Atoll chooses the highest one.
•
If d < 3000m, R = d.
5th step: Atoll performs a linear regression on the filtered profile within R in order to determine a regression line.
The regression line equation is:
y = ax + b
  d  i  – dm   Hfilt  i  – Hm 
i
- and b = H m – ad m
a = -----------------------------------------------------------------------2
 d  i  – dm 

i
where,
1
H m = --n
 Hfilt  i 
i
i is the point index. Only points within R are taken into account.
R
d m = d – ---2
d(i) is the distance between i and the transmitter (m).
Then, Atoll extends the regression line to the transmitter location. Therefore, its equation is:
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regr  i  = a   i  Res  + b
6th step: Then, Atoll calculates effective transmitter antenna height, H Txeff (m).
H 0Tx + H Tx – b
H Txeff = -------------------------------------2
1+a
If HTxeff is less than 20m, Atoll recalculates it with a new influence area, which begins at transmitter.
Notes:
•
In case H Txeff  1000m , 1000m will be used in calculations.
•
If H Txeff is still less than 20m, an additional correction is taken into account (7th step).
7th step: If H Txeff is still less than 20m (even negative), Atoll evaluates path loss using H Txeff = 20m and applies a
correction factor.
Therefore, if H Txeff  20m ,
L model = L model   H Txeff = 20m  d f  + K lowant
20   1 –  H Txeff – 20  
d
where, K lowant = --------- –  0.3   H Txeff – 20   – -----------------------------------------------------------------------------5
d  
d
 9.63 + -----------10
-  6.93 + -------------

1000 
1000
4.4.3.2.3
Effective Receiver Antenna Height
H Rxeff =  H Rx + H 0Rx  – H 0Tx
where,
H Rx is the receiver antenna height above the ground (m).
H 0Rx is the ground height (ground elevation) above sea level at the receiver (m).
H 0Tx is the ground height (ground elevation) above sea level at the transmitter (m).
Note:
•
The calculation of effective antenna heights ( H Rxeff and H Txeff ) is based on extracted
DTM profiles. They are not properly performed if you have not imported heights (DTM file)
beforehand.
4.4.3.2.4
Correction for Hilly Regions in Case of LOS
An optional corrective term enables Atoll to correct path loss for hilly regions when the transmitter and the receiver are in
Line-of-sight.
Therefore, if the receiver is in the transmitter line of sight and the Hilly terrain correction option is active, we have:
L model = K 1 LOS + K 2 LOS log  d  + K 3 log  H Txeff  + K 5 log  H Txeff  log  d  + K 6  H Rx + K clutter f  clutter  + K hill LOS
When the transmitter and the receiver are not in line of sight, the path loss formula is:
L model =K 1 NLOS + K 2 NLOS log  d  + K 3 log  H Txeff  + K 4  Diffraction + K 5 log  H Txeff  log  d  + K 6  H Rx + K clutter f  clutter 
K hill LOS is determined in three steps. Influence area, R, and regression line are supposed available.
1st step: For every profile point within 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%.
2nd step: Atoll evaluates the terrain roughness, h; it is the distance between the two lines.
3rd step: Atoll calculates K hill LOS .
We have K hill LOS = K h + K hf
If 0  h  20m , K h = 0
2
Else K h = 7.73  log  h   – 15.29 log  h  + 6.746
If 0  h  10m , K hf = – 2  0.1924   H 0Rx + H Rx – regr  i Rx  
H 0Rx + H Rx – regr  i Rx 
2
Else K hf = – 2   – 1.616  log  h   + 14.75 log  h  – 11.21   ------------------------------------------------------------h
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iRx is the point index at receiver.
4.4.3.2.5
Diffraction
Four methods are available to calculate diffraction loss over the transmitter-receiver profile. They are detailed in the
Appendices.
Along the transmitter-receiver profile, you may consider:
•
•
4.4.3.2.6
Either ground altitude and clutter height (Consider heights in diffraction option),
In this case, Atoll uses clutter height information from clutter heights file if available in the .atl document. Otherwise,
it considers average clutter height specified for each clutter class in the clutter classes file description.
Or only ground altitude.
Losses due to Clutter
n
Atoll calculates f(clutter) over a maximum distance from receiver: f  clutter  =
 Li wi
i=1
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 resolution.
Four weighting functions are available:
•
1
Uniform weighting function: w i = --n
•
di
Triangular weighting function: w i = ------------n
 dj
j=1
•
d i = D – d' i , where d’i is the distance between the receiver and the ith point and D is the maximum distance
defined.
•
d
log  ----i + 1
D

Logarithmic weighting function: w i = ------------------------------------n
d
log  ----j + 1
D


j=1
d
----i
D
•
e –1
Exponential weighting function: w i = -------------------------n
e
dj
---D
–1
j=1
The chart below shows the weight variation with the distance for each weighting function.
Figure 4.12: Losses due to Clutter
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4.4.3.2.7
Recommendations
Beware that the clutter influence may be taken into account in two terms, Diffraction loss and f(clutter) at the same time.
To avoid this, we advise:
1. Not to consider clutter heights to evaluate diffraction loss over the transmitter-receiver profile if you specify losses
per clutter class.
This approach is recommended if the clutter height information is statistical (clutter roughly defined, no altitude).
Or
2. Not to define any loss per clutter class if you take clutter heights into account in the diffraction loss.
In this case, f(clutter)=0. Losses due to clutter are only taken into account in the computed Diffraction loss term.
This approach is recommended if the clutter height information is either semi-deterministic (clutter roughly
defined, altitude defined with an average height per clutter class) or deterministic (clutter sharply defined, altitude
defined with an average height per clutter class or - even better - via a clutter height file).
In case of semi-deterministic clutter information, specify receiver clearance (m) per clutter class. Both ground altitude and
clutter height are considered along the whole transmitter-receiver profile except over a specific distance around the
receiver (clearance), where Atoll proceeds as if there was only the DTM map. The clearance information is used to model
streets.
Figure 4.13: Tx-Rx profile
In the above figure, the ground altitude and clutter height (in this case, average height specified for each clutter class in
the clutter classes map description) are taken into account along the profile.
Clearance definition is not necessary in case of deterministic clutter height information. Clutter height information is accurate enough to be used directly without additional information such as clearance. Two cases can be considered:
1. If the receiver is in the street (clutter height lower than receiver height), Atoll calculates the path loss by considering
potentially some diffraction loss at reception.
2. If the receiver is supposed to be inside a building (clutter height higher than receiver height), Atoll does not consider any difraction (and clearance) from the building but takes into account the indoor loss as an additional penetration loss.
Notes:
•
To consider indoor losses in building only when using a deterministic clutter map (clutter
height map), the 'Indoor Coverage' box must not be checked in predictions unless this loss
will be counted twice inside buildings (on the entire reception clutter class and not only
inside the building).
•
Like for any Hata-based model, L model is, by default, limited to the computed free space
loss value. It is also possible to avoid this option (option in the related scrolling menu of
Configuration tab)
•
4.4.3.3
Even with no clearance, the clutter height (extracted either from clutter class or clutter
height folders) is never considered at the last profile point.
Automatic SPM Calibration
The goal of this tool is to calibrate parameters and methods of the SPM formula in a simple and reproducible way. Calibration is based on imported CW measurement data. It is the process of limiting the difference between predicted and
measured values. For a complete description of the calibration procedure (including the very important prerequisite filtering
work on the CW measurement points), please refer to the User Manual and the SPM Calibration Guide.
The following SPM formula parameters can be estimated:
•
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K1, K2, K3, K4, K5, K6 and K7
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•
•
•
Losses per clutter class (Kclutter must be user-defined)
Effective antenna height method
Diffraction method
Automatic model calibration provides a mathematical solution. The relevance of this mathematical solution with a physical
and realistic solution must be determined before committing these results.
You must keep in mind that the model calibration and its result (standard deviation and root mean square) strongly depend
on the CW measurement samples you use. A calibrated model must restore the behaviour of CW measurements depending on their configuration on a large scale, and not just totally coincide with a few number of CW measurements. The calibrated model has to give correct results for every new CW measurement point in the same geographical zone, without
having been calibrated on these new CW measurements.
4.4.3.3.1
General Algorithm
Propagation model calibration is a special case of the more general Least-Square problems, i.e. given a real m x n matrix
A, and a real m-vector b, find a real n-vector x0 that minimises the Euclidean length of Ax - b.
Here,
m is the number of measurement points,
n is the number of parameters to calibrate,
A is the values of parameter associated variables (log(d), log(heff), etc.) at each measurement point, and
b is the vector of measurement values.
The vector x0 is the set of parameters found at the end of the calibration.
The theoretical mathematical solution of this problem was found by Gauss (around 1830). Further enhancements to the
original method were proposed in the 60's in order to solve the numerical instability problem.
In 1974, Lawson & Hanson [2] proposed a theoretical solution of the least-square problem with general linear inequality
constraints on the vector x0. Atoll implementation is based on this method, which is explained in detail in [1].
References:
[1] Björck A. “Numerical Methods for Least Square Problems”, SIAM, 1996.
[2] Lawson C.L., Hanson R.J. “Solving Least Squares Problems”, SIAM, 1974.
4.4.3.3.2
Sample Values for SPM Path Loss Formula Parameters
The following tables list some sample orders of magnitudes for the different parameters composing the Standard Propagation Model formula.
Minimum
Typical
Maximum
K1
Variable
Variable
Variable
K2
20
44.9
70
K3
-20
5.83
20
K4
0
0.5
0.8
K5
-10
-6.55
0
K6
-1
0
0
K7
-10
0
0
K1 depends on the frequency and the technology. Here are some sample values:
Project type
Frequency (MHz)
K1
GSM 900
935
12.5
GSM 1800
1805
22
GSM 1900
1930
23
UMTS
2110
23.8
1xRTT
1900
23
2300
24.7
2500
25.4
2700
26.1
3300
27.8
3500
28.3
WiMAX
The above K1 values for WiMAX are extrapolated estimates for different frequency ranges. It is highly recommended to
calibrate the SPM using measurement data collected on the field for WiMAX networks before using the SPM for predic-
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tions.
All K paramaters can be defined by the automatic calibration wizard. Since Kclutter is a constant, its value is strongly
dependant on the values given to the losses per clutter classes. From experienced users, the typical losses (in dB) per
clutter class are:
Dense urban
From 4 to 5
Woodland
From 2 to 3
Urban
0
Suburban
From -5 to -3
Industrial
From -5 to -3
Open in urban
From -6 to -4
Open
From -12 to -10
Water
From -14 to -12
These values have to be entered only when considering statistical clutter class maps only.
Note:
•
4.4.3.4
The Standard Propagation Model is deduced from the Hata formulae, valid in the case of
an urban environment. The above values are consistent since they are normalized with
respect to the urban clutter class (0 dB for urban clutter class). Positive values correspond
to denser clutter classes and negative values to less dense clutter classes.
Unmasked Path Loss Calculation
You can use the SPM to calculate unmasked path losses. Unmasked path losses are calculated by not taking into account
the transmitter antenna patterns, i.e., the attenuation due to the transmitter antenna pattern is not included. Such path
losses are useful when using path loss matrices calculated by Atoll with automatic optimisation tools.
The instance of the SPM available by default, under the Propagation Models folder in the Modules tab, has the following
characteristics:
•
•
Signature:
Type:
{D5701837-B081-11D4-931D-00C04FA05664}
Atoll.StdPropagModel.1
You can access these parameters in the Propagation Models table by double-clicking the Propagation Models folder in
the Modules tab.
To make the SPM calculate path losses excluding the antenna pattern attenuation, you have to change the type of the
SPM to:
•
Type:
Atoll.StdPropagModelUnmasked.1
However, changing the type only does not invalidate the already calculated path loss matrices, because the signature of
the propagation model is still the same. If you want Atoll to recognize that the SPM has changed, and to invalidate the path
loss matrices calculated with this model, you have to change the signature of the model as well. The default signature for
the SPM that calculates unmasked path loss matrices is:
•
Signature:
{EEE060E5-255C-4C1F-B36C-A80D3D972583}
The above signature is a default signature. Atoll automatically creates different signatures for different instances of the
same propagation model. Therefore, it is possible to create different instances of the SPM, with different parameter
settings, and create unmasked versions of these instances.
You can change the signature and type of the original instance of the SPM, but it is recommended to make a copy of the
SPM in order not to lose the original SPM parameters. So, you will be able to keep different versions of the SPM, those
that calculate path losses with antenna pattern attenuation, and others that calculate path losses without it.
The usual process flow of an ACP working on an Atoll document through the API would be to:
1. Backup the storage directory of path loss matrices.
2. Set a different storage directory for calculating and storing unmasked path loss matrices.
3. Select the SPM used, backup it’s signature, and change its signature and type as shown above.
4. Perform optimisation using the path loss matrices calculated by the unmasked version of the SPM.
5. Restore the type and the signature of the SPM.
6. Reset the path loss storage directory to the original one.
Notes:
© Forsk 2009
•
It is not possible to calibrate the unmasked version of the SPM using measurement data.
•
You can also use Atoll.ini options, AngleCalculation = 2000 and AngleCalculation = 3000,
for calculating unmasked path losses and angles of incidence, respectively. These options
are only available for the propagation models available with Atoll by default. Please refer to
the Administrator Manual for details.
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•
Using the SPM, you can also calculate the angles of incidence by creating a new instance
of the SPM with the following characteristics:
Type: Atoll.StdPropagModelIncidence.1
Signature: {659F0B9E-2810-4e59-9F0D-DA9E78E1E64B}
Important:
•
The "masked" version of the algorithm has not been changed. It still takes into account
Atoll.ini options. However, the "unmasked" version does not take Atoll.ini options into
account.
•
It’s highly recommended to use one method (Atoll.ini options) or the other one (new
identifier & signature) but not to combine both.
4.4.4
WLL Propagation Model
4.4.4.1
WLL Path Loss Formula
L model = L FS + F Diff  L Diff
Where L FS is the free space loss calculated using the formula entered in the model properties, L Diff is the diffraction loss
calculated using the 3-obstacle Deygout method, and F Diff is the diffraction multiplying factor defined in the model properties.
4.4.4.2
Calculations in Atoll
4.4.4.2.1
Free Space Loss
Please refer to the Appendices for further details about free space loss calculation.
4.4.4.2.2
Diffraction
Atoll calculates diffraction loss along the transmitter-receiver profile built from DTM and clutter maps. Therefore, losses
due to clutter are taken into account in diffraction losses. Atoll takes clutter height information from the clutter heights file
if available in the .atl document. Otherwise, it considers average clutter height specified for each clutter class in the clutter
classes file description.
The Deygout construction (considering 3 obstacles) is used. This method is detailed in the Appendices. The final diffraction losses are determined by multiplying the diffraction losses calculated using the Deygout method by the Diffraction
multiplying factor defined in the model properties.
Receiver Clearance
Define receiver clearance (m) per clutter class when clutter height information is either statistical or semi-deterministic. Both ground altitude and clutter height are considered along the whole profile except over a specific distance
around the receiver (clearance), where Atoll proceeds as if there was only the DTM map (see SPM part). Atoll uses the
clearance information to model streets.
If the clutter is deterministic, do not define any receiver clearance (m) per clutter class. In this case, clutter height
information is accurate enough to be used directly without additional information such as clearance (Atoll can locate
streets).
Receiver Height
Entering receiver height per clutter class enables Atoll to consider the fact that receivers are fixed and located on the roofs.
Visibility
If the option ‘Line of sight only’ is not selected, Atoll computes Lmodel on each calculation bin using the formula defined
above. When selecting the option ‘Line of sight only’, Atoll checks for each calculation bin if the Diffraction loss (as defined
in the Diffraction loss: Deygout part) calculated along profile equals 0.
•
•
In this case, receiver is considered in ‘line of sight’ and Atoll computes Lmodel on each calculation bin using the
formula defined above.
Otherwise, Atoll considers that Lmodel tends to infinity.
4.4.5
ITU-R P.526-5 Propagation Model
4.4.5.1
ITU 526-5 Path Loss Formula
L model = L FS + L Diff
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Where L FS is the free space loss calculated using the formula entered in the model properties and L Diff is the diffraction
loss calculated using the 3-obstacle Deygout method.
4.4.5.2
Calculations in Atoll
4.4.5.2.1
Free Space Loss
Please refer to the Appendices for further details about free space loss calculation.
4.4.5.2.2
Diffraction
Atoll calculates diffraction loss along the transmitter-receiver profile is built from the DTM map. The Deygout construction
(considering 3 obstacles), with or without correction, is used. These methods are detailed in the Appendices.
4.4.6
ITU-R P.370-7 Propagation Model
4.4.6.1
ITU 370-7 Path Loss Formula
If d<1 km, L model = L FS
If d>1000 km, L model = 1000
If 1<d<1000 km, L model = max  L FS CorrectedS tan dardLoss 
d is the distance between the transmitter and the receiver (km).
4.4.6.2
Calculations in Atoll
4.4.6.2.1
Free Space Loss
Please refer to the Appendices for further details about free space loss calculation.
4.4.6.2.2
Corrected Standard Loss
This formula is given for a 60 dBm (1kW) transmitter power.
CorrectedS tan dardLoss = 60 – C n – A H
Rxeff
– A cl – 108.75 + 31.54 – 20 log f
where,
Cn is the field strength received in dBV/m,
AH
Rxeff
is a correction factor for effective receiver antenna height (dB),
Acl is the correction for terrain clearance angle (dB),
f is the frequency in MHz.
Cn Calculation
The Cn value is determined from charts Cn=f(d, HTxeff).
In the following part, let us assume that Cn=En(d,HTxeff) (where En(d,HTxeff) is the field received in dBV/m) is read from
charts for a distance, d (in km), and an effective transmitter antenna height, HTxeff (in m).
First of all, Atoll evaluates the effective transmitter antenna height, H Txeff , as follows:
If 0  d  3km , H Txeff = H 0Tx + H Tx – H 0Rx
If 3  d  15km , H Txeff = H 0Tx + H Tx – H 0  3 ;d 
If 15  d , H Txeff = H 0Tx + H Tx – H 0  3 ;15 
where,
H Tx is the transmitter antenna height above the ground (m).
H 0Tx is the ground height (ground elevation) above sea level at the transmitter (m).
H 0  3 ;d  is the average ground height (m) above sea level for the profile between a point 3 km from transmitter and the
receiver (located at d km from transmitter).
H 0  3 ;15  is the average ground height (m) above sea level for the profile between a point 3 km and another 15 km from
transmitter.
Then, depending on d and HTxeff, Atoll determines Cn using bilinear interpolation as follows.
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If 37.5 HTxeff 1200, Cn= En(d,HTxeff)
Otherwise, Atoll considers d horizon = 4.1  H Txeff (d is stated in km)
Therefore,
If HTxeff < 37.5
If d  d horizon , we have C n = E n  d + 25 – d horizon 37.5 
Else Cn=En(d, 37.5) – En(dhorizon, 37.5) + En(25, 37.5)
If HTxeff > 1200
If d  d horizon , we have C n = E n  d + 142 – d horizon 1200 
Else Cn=En(d, 1200) – En(dhorizon, 1200) + En(142, 1200)
AHRxeff Calculation
AH
Rxeff
H Rx
c
= ---  20  log  ----------
 10 
6
where,
HRx is the user-defined receiver height,
c is the height gain factor.
Note:
•
c values are provided in the recommendation 370-7; for example, c=4 in a rural case.
Acl Calculation
2
If f  300 MHz, A cl = 8.1 –  6.9 + 20 log     – 0.1  + 1  +   – 0.1   
2
Otherwise, A cl = 14.9 –  6.9 + 20 log     – 0.1  + 1  +   – 0.1   
f
With  = –   4000  ---------300
where,
 is the clearance angle (in radians) determined according to the recommendation 370-7 (figure 19),
f is the frequency stated in MHz.
4.4.7
Erceg-Greenstein (SUI) Propagation Model
Erceg-Greenstein propagation model is a statistical path loss model derived from experimental data collected at 1.9 GHz
in 95 macrocells. The model is for suburban areas, and it distinguishes between different terrain categories called the Stanford University Interim Terrain Models. This propagation model is well suited for distances and base station antenna
heights that are not well-covered by other models. The path loss model applies to base antenna heights from 10 to 80 m,
base-to-terminal distances from 0.1 to 8 km, and three distinct terrain categories.
The basic path loss equation of the Erceg-Greenstein propagation model is:
d
PL = A + 10  a  H BS   Log 10  ------
 d 0
4d 0
Where A = 20  Log 10  ------------- . This is a fixed quantity which depends upon the frequency of operation. d is the distance
  
between the base station antenna and the receiver terminal and d0 is a fixed reference distance (100 m). a(HBS) is the
correction factor for base station antenna heights, HBS:
c
a  H BS  = a – b  H BS + ---------H BS
Where 10 m  H BS  80 m , and a, b, and c are correction coefficients which depend on the SUI terrain type.
The Erceg-Greenstein propagation model is further developed through the correction factors introduced by the Stanford
University Interim model. The standards proposed by the IEEE working group 802.16 include channel models developed
by Stanford University. The basic path loss equation with correction factors is presented below:
d
PL = A + 10  a  H BS   Log 10  ------ + a  f  – a  H R 
 d 0
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f
Where a(f) is the correction factor for the operating frequency, a  f  = 6  Log 10  ------------- , with f being the operating
 2000
HR
frequency in MHz. a(HR) is the correction factor for the receiver antenna height, a  H R  = X  Log 10  ------- , where d
 2
depends on the terrain type.
Note:
a(HR) = 0 for HR = 2 m.
•
References:
[1] V. Erceg et. al, “An empirically based path loss model for wireless channels in suburban environments,” IEEE J.
Select Areas Commun., vol. 17, no. 7, July 1999, pp. 1205-1211.
[2] Abhayawardhana, V.S.; Wassell, I.J.; Crosby, D.; Sellars, M.P.; Brown, M.G.; "Comparison of empirical propagation
path loss models for fixed wireless access systems," Vehicular Technology Conference, 2005. IEEE 61st Volume 1, 30
May-1 June 2005 Page(s):73 - 77 Vol. 1
4.4.7.1
SUI Terrain Types
The SUI models are divided into three types of terrains1, namely A, B and C.
•
•
•
Type A is associated with maximum path loss and is appropriate for hilly terrain with moderate to heavy tree
densities.
Type B is characterised with either mostly flat terrains with moderate to heavy tree densities or hilly terrains
with light tree densities.
Type C is associated with minimum path loss and applies to flat terrain with light tree densities.
The constants used for a, b, and c are given in the table below.
Model Parameter
Terrain A
Terrain B
Terrain C
a
4.6
4.0
3.6
0.0075
0.0065
0.005
c (m)
12.6
17.1
20
X
10.8
10.8
20
b
4.4.7.2
(m-1)
Erceg-Greenstein (SUI) Path Loss Formula
The Erceg-Greenstein (SUI) propagation model formula can be simplified from the following equation:
4d 0
d
PL = 20  Log 10  ------------- + 10  a  H BS   Log 10  ------ + a  f  – a  H R 
 d 0
  
(1)
to the equation below:
PL = – 7.366 + 26  Log 10  f  + 10  a  H BS    1 + Log 10  d   – a  H R 
(2)
Where,
•
•
•
•
f is the operating frequency in MHz
d is the distance from the transmitter to the received in m in equation (1) and in km in equation (2)
HBS is the transmitter height in m
HR is the receiver height in m
The above equation is divided into two parts in Atoll:
PL = Lu – a  H R 
Where,
Lu = – 7.366 + 26  Log 10  f  + 10  a  H BS    1 + Log 10  d  
The above path loss formulas are valid for d > d0, i.e. d > 100 m. For d < 100 m, the path loss has been restricted to the
free space path loss with correction factors for operating frequency and receiver height:
4d
4d
PL = 20  Log 10  ------------------ + a  f  – a  H R  instead of PL = 20  Log 10  ------------------
  
  
Where a(f) and a(Hr) have the same definition as given above. Simplifying the above equation, we get,
PL = 12.634 + 26  Log 10  f  + 20  Log 10  d  – a  H R  , or Lu = 12.634 + 26  Log 10  f  + 20  Log 10  d 
1.
The word ‘terrain’ is used in the original definition of the model rather than ‘environment’. Hence it is used
interchangeably with ‘environment’ in this description.
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The above equation is not user-modifiable in Atoll except for the coefficient of Log 10  f  , i.e. 26. Atoll uses the same coefficient as the one you enter for Log 10  f  in Atoll for the case d > d0.
Note:
•
4.4.7.3
You can get the same resulting equation by setting a(hBS) = 2.
Calculations in Atoll
The Erceg-Greenstein (SUI) propagation model takes DTM into account between the transmitter and the receiver, and it
can also take clutter into account at the receiver location.
1st step: For each pixel in the calculation radius, Atoll determines the clutter bin on which the receiver is located. This clutter
bin corresponds to a clutter class. Atoll uses the Erceg-Greenstein (SUI) path loss formula assigned to this clutter class to
evaluate path loss.
2nd step: This step depends on whether the ‘Add diffraction loss’ option is selected or not.
•
•
If the ‘Add diffraction loss’ option is not selected, 1st step gives the final path loss result.
If the ‘Add diffraction loss’ option is selected, Atoll proceeds as follows:
a. It extracts a geographic profile between the transmitter and the receiver using the radial calculation method.
b. It determines the largest obstacle along the profile in accordance with the Deygout method and evaluates losses due to diffraction L Diffraction . For more information on the Deygout method, see "3 Knife-Edge Deygout
Method" on page 107.
The final path loss is the sum of the path loss determined in 1st step and L Diffraction .
Shadow fading is computed in Atoll independent of the propagation model. For more information on the shadow fading
calculation, see "Shadowing Model" on page 115.
4.4.8
ITU-R P.1546-2 Propagation Model
This propagation model is based on the P.1546-2 recommendations of the ITU-R. These recommendations extend the
P.370-7 recommendations, and are suited for operating frequencies from 30 to 3000 MHz. The path loss is calculated by
this propagation model with the help of graphs available in the recommendations. The graphs provided in the recommendations represent field (or signal) strength, given in db  V  m  , as a function of distance for:
•
Nominal frequencies, f n : 100, 600, and 1000 MHz
The graphs provided for 100 MHz are applicable to frequencies from 30 to 300 MHz, those for 600 MHz are applicable to frequencies from 300 to 1000 MHz, and the graphs for 1000 MHz are applicable to frequencies from 1000
to 3000 MHz. The method for interpolation is described in the recommendations (Annex 5, § 6).
•
Transmitter antenna heights, h 1 : 10, 20, 37.5, 75, 150, 300, 600, and 1200 m
For any values of h 1 from 10 to 3000 m, an interpolation or extrapolation from the appropriate two curves is used,
as described in the recommendations (Annex 5, § 4.1). For h 1 below 10 m, the extrapolation to be applied is given
in Annex 5, § 4.2. It is possible for the value of h 1 to be negative, in which case the method is given in Annex 5,
§ 4.3.
•
Time variability, t : 1, 10, and 50 %
The propagation curves represent the field strength values exceeded for 1, 10 and 50 % of time.
•
Receiver antenna height, h 2 : 10 m
For land paths, the graphs represent field strength values for a receiver antenna height above ground, equal to
the representative height of the clutter around the receiver. The minimum value of the representative height of clutter is 10 m. For sea paths, the graphs represent field strength values for a receiver antenna height of 10 m.
For other values of receiver antenna height, a correction is applied according to the environment of the receiver.
The method for calculating this correction is given in Annex 5, § 9.
These recommendations are not valid for transmitter-receiver distances less than 1 km or greater than 1000 km. Therefore
in Atoll, the path loss between a transmitter and a receiver over less than 1 km is the same as the path loss over 1 km.
Similarly, the path loss between a transmitter and a receiver over more than 1000 km is the same as the path loss over
1000 km.
Moreover, these recommendations are not valid for transmitter antenna heights less than the average clutter height
surrounding the transmitter.
Notes:
100
•
The cold sea graphs are used for calculations over warm and cold sea both.
•
The mixture of land and sea paths is not supported by Atoll.
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4.4.8.1
Calculations in Atoll
The input to the propagation model are the transmission frequency, transmitter and receiver heights, the distance between
the transmitter and the receiver, the precentage of time the field strength values are exceeded, the type of environment
(i.e., land or sea), and the clutter at the receiver location.
In the following calculations, f is the transmission frequency, d is the transmitter-receiver distance, and t is the percentage of time for which the path loss has to be calculated.
The following calculations are performed in Atoll to calculate the path loss using this propagation model.
4.4.8.1.1
Step 1: Determination of Graphs to be Used
First of all, the upper and lower nominal frequencies are determined for any given transmission frequency. The upper and
lower nominal frequencies are the nominal frequencies (100, 600, and 2000 MHz) between which the transmission
frequency is located, i.e., f n1  f  f n2 .
Once f n1 and f n1 are known, along with the information about the percentage of time t and the type of path (land or sea),
the sets of graphs which will be used for the calculation are also known.
4.4.8.1.2
Step 2: Calculation of Maximum Field Strength
A field strength must not exceed a maximum value, E Max , which is given by:
E Max = E FS = 106.9 – 20  Log  d  for land paths, and
E Max = E FS + E SE = 106.9 – 20  Log  d  + 2.38  1 – exp  – d  8.94    Log  50  t  for sea paths.
Where E FS is the free space field strength for 1 kW ERP, E SE is an enhancement for sea graphs.
4.4.8.1.3
Step 3: Determination of Transmitter Antenna Height
The transmitter antenna height to be used in the calculation depends on the type and length of the path.
•
Land paths
h 1 = h eff
•
Sea paths
h 1 = Max  1 h a 
Here, all antenna heights (i.e., h 1 , h eff , and h a ) are in expressed in m. h a is the antenna height above ground and h eff
is the effective height of the transmitter antenna, which is its height over the average level of the ground between distances
of 0.2  d and d km from the transmitter in the direction of the receiver.
4.4.8.1.4
Step 4: Interpolation/Extrapolation of Field Strength
The interpolations are performed in series in the same order as described below. The first interpolation/extrapolation is
performed over the field strength values, E , from the graphs for transmitter antenna height to determine E h1 . The second
interpolation/extrapolation is performed over the interpolated/extrapolated values of E h1 to determine E d . And, the thrid
and final interpolation/extrapolation is performed over the interpolated/extrapolated values of E d to determine E f .
Step 4.1: Interpolation/Extrapolation of Field Strength for Transmitter Antenna Height
If the value of h 1 coincides with one of the eight heights for which the field strength graphs are provided, namely 10, 20,
37.5, 75, 150, 300, 600, and 1200 m, the required field strength is obtained directly from the corresponding graph. Otherwise:
•
If 10 m  h 1  3000 m
The field strength is interpolated or extrapolated from field strengths obtained from two curves using the following
equation:
Log  h 1  h Low 
E h1 = E Low +  E Up – E Low   -----------------------------------------Log  h Up  h Low 
Where h Low = 600 m if h 1  1200 m , otherwise h Low is the nearest nominal effective height below h 1 ,
h Up = 1200 m if h 1  1200 m , otherwise h Up is the nearest nominal effective height above h 1 , E Low is the field
strength value for h Low at the required distance, and E Up is the field strength value for h Up at the required
distance.
•
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-
For land path if the transmitter-receiver distance is less than the smooth-Earth horizon distance
d H  h 1  = 4.1  h 1 , i.e., if d  4.1  h 1 ,
E h1 = E 10  d H  10   + E 10  d  – E 10  d H  h 1   , or
E h1 = E 10  12.9 km  + E 10  d  – E 10  d H  h 1   because d H  10  = 12.9 km
-
For land path if the transmitter-receiver distance is greater than or equal to the smooth-Earth horizon distance
d H  h 1  = 4.1  h 1 , i.e., if d  4.1  h 1 ,
E h1 = E 10  d H  10  + d – d H  h 1   , or E h1 = E 10  12.9 km + d – d H  h 1   because d H  10  = 12.9 km
Where E x  y  is the field strength value read for the transmitter-receiver distance of y from the graph available
for the transmitter antenna height of x.
If in the above equation, d H  10  + d – d H  h 1   1000 km even though d  1000 km , the field strength is determined from linear extrapolation for Log (distance) of the graph given by:
Log  d  D Low 
E h1 = E Low +  E Up – E Low   -------------------------------------------Log  D Up  D Low 
Where D Low is penultimate tabulation distance (km), D Up is the final tabulation distance (km), E Low is the
field strength value for D Low , and E Up is the field strength value for D Up .
-
For sea path, h 1 should not be less than 1 m. This calculation requires the distance at which the path has 0.6
of the first Fresnel zone just unobstructed by the sea surface. This distance is given by:
D h1 = D 0.6  f h 1  h 2 = 10 m   (km)
Df  Dh
Where D 0.6 = Max  0.001 ------------------- (km) with D f = 0.0000389  f  h 1  h 2 (frequency-dependent term),

D f + D h
and D h = 4.1   h 1 + h 2  (asymptotic term defined by the horizon distance).
If d  D h1 the 0.6 Fresnel clearance distance for the sea path where the transmitter antenna height is 20 m is
also calculated as:
D 20 = D 0.6  f  h 1 = 20 m   h 2 = 10 m   (km)
Once D h1 and D 20 are known, the field strength for the required distance is given by:
E h1
 E Max


Log  d  D h1 
=  E D +  E D – E D   -------------------------------------h1
20
h1
Log  D 20  D h1 


 E'   1 – F S  + E''  F S
for d  D h1
for D h1  d  D 20
for d  D 20
Where E Max is the maximum field strength at the required distance as calculated in "Step 2: Calculation of
Maximum Field Strength" on page 101, E D
ED
20
h1
is E Max for d = D h1 ,
Log  h1  10 
Log  h1  10 
= E 10  D 20  +  E 20  D 20  – E 10  D 20    ---------------------------------- , E' = E 10  d  +  E 20  d  – E 10  d    ---------------------------------- ,
Log  20  10 
Log  20  10 
and E'' is the field strength calculated as described for land paths. E 10  y  and E 20  y  are field strengths
interpolated for distance y and h 1 = 10 m and 20 m , respectively, and F S =  d – D 20   d .
•
If h 1  0 m
A correction is applied to the field strength, E h1 , calculated in the above description in order to take into account
the diffraction and tropospheric scattering. This correction is the maximum of the diffraction correction,, and tropospheric scattering correction, .
C h1 = Max  C h1d C h1t 
Where
C h1d = 6.03 – J   
with
2
J    =  6.9 + 20  Log    – 0.1  + 1 +  – 0.1  
and
 = K    eff2 ,
–h1
 eff2 = arc tan  ------------- , and K  is 1.35 for 100 MHz, 3.31 for 600 MHz, 6.00 for 2000 MHz.
 9000
e
180  d
C h1t = 30  Log  ------------------------ with  e = ---------------------- , a = 6370 km (radius of the Earth), and k = 4  3 is the effec  e +  eff2
ak
tive Earth radius factor for mean refractivity conditions.
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Step 4.2: Interpolation/Extrapolation of Field Strength for Transmitter-Receiver Distance
In the field strength graphs in the recommendations, the field strength is plotted against distance from 1 km to 1000 km.
The distance values for which field strengths are tabulated are 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200,
225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, 700, 725, 750, 775, 800,
825, 850, 875, 900, 925, 950, 975, 1000. If the transmitter-receiver distance is a value from this list, then interpolation of
field strength is not required and the field strength can be directly read from the graphs.
If the transmitter-receiver distance does not coincide with the list of distances for which the field strengths are accurately
available from the graphs, the field strength are linearly interpolated or extrapolated for the logarithm of the distance using
the following equation:
Log  d  d Low 
E d = E Low +  E Up – E Low   -----------------------------------------Log  d Up  d Low 
Where d Low is the lower value of the nearest tabulated distance to d , d Up is the higher value of the nearest tabulated
distance to d , E Low is the field strength value for d Low , and E Up is the field strength value for d Up .
Step 4.3: Interpolation/Extrapolation of Field Strength for Transmission Frequency
The field strength at the transmission frequency is interpolated from the graphs available for the upper and lower nominal
frequencies as follows:
Log  f  f Low 
E f = E Low +  E Up – E Low   --------------------------------------Log  f Up  f Low 
Where f Low is the lower nominal frequency (100 MHz if f < 600 MHz, 600 MHz otherwise), f Up is the higher nominal
frequency (600 MHz if f < 600 MHz, 2000 MHz otherwise), E Low is the field strength value for f Low , and E Up is the field
strength value for f Up .
In the case of transmission frequencies below 100 MHz or above 2000 MHz, the field strength values are extrapolated
from the two nearer nominal frequency values. The above equation is used for all land paths and sea paths.
4.4.8.1.5
Step 5: Calculation of Correction Factors
Step 5.1: Correction for Receiver Antenna Height
The receiver antenna height correction depends on the type of path and clutter in which the receiver is located. The field
strength values given by the graphs for land paths are for a reference receiver antenna at a height, R (m), representative
of the height of the clutter surrounding the receiver, subject to a minimum height value of 10 m. Examples of reference
heights are 20 m for an urban area, 30 m for a dense urban area, and 10 m for a suburban area. For sea paths the notional
value of R is 10 m.
For land paths, the elevation angle of the arriving ray is taken into account by calculating a modified representative clutter
 1000  d  R – 15  h 1 
height R' , given by R' = Max  1 --------------------------------------------------------------- .


1000  d – 15
Note that for h 1  6.5  d + R , R'  R .
The different correction factors are calculated as follows:
•
For land path in urban and suburban zones
 6.03 – J   
for h 2  R'

C Receiver = 
h
  3.2 + 6.2  Log  f    Log  -----2- for h 2  R'
 R' 

R' – h 2
2
With J    =  6.9 + 20  Log    – 0.1  + 1 +  – 0.1   and  = 0.0108  f   R' – h 2   arc tan  ----------------- .
 27 
10
If R'  10 m , C Receiver is reduced by  3.2 + 6.2  Log  f    Log  ------ .
 R' 
•
For land path other zones
h2
C Receiver =  3.2 + 6.2  Log  f    Log  ------
 10
•
For sea path
d 10 and d h2 are determined as distances at which at which the path has 0.6 of the first Fresnel zone just unobstructed by the sea surface with h 2 = 10 m and variable h 2 , respectively. These distances are given by
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Df  Dh
d 10 = D 0.6  f h 1  h 2 = 10 m   and d h2 = D 0.6  f h 1 h 2  (km), respectively. Here D 0.6 = Max  0.001 -------------------

D f + D h
as explained earlier.
-
h2
If h 2  10 m , C Receiver =  3.2 + 6.2  Log  f    Log  ------
 10
-
h2
If h 2  10 m and d  d 10 , C Receiver =  3.2 + 6.2  Log  f    Log  ------
 10
-
If h 2  10 m and d  d 10 and d  d h2 , C Receiver = 0
-
Log  d  d h2 
h2
If h 2  10 m and d  d 10 and d  d h2 , C Receiver =  3.2 + 6.2  Log  f    Log  ------   -------------------------------------
 10  Log  d 10  d h2 
Step 5.2: Correction for Short Urban/Suburban Paths
This correction is only applied when the path loss is to be calculated over land paths, over a transmitter-receiver distance
less than 15 km, in urban and suburban zones. This correction takes into account the presence of buildings in these zones.
The buildings are assumed to be of uniform height.
The correction represents a reduction in the field strength due to building clutter. It is added to the field strength and is
given by:
C Building = – 3.3  Log  f    1 – 0.85  Log  d    1 – 0.46  Log  1 + h a – R  
Where h a is the antenna height above the ground, and R is the clutter height of the clutter class where the receiver is
located. This correction is only applied when d  15 km and h 1 – R  150 m .
Step 5.3: Correction for Receiver Clearance Angle
This correction is only applied when the path loss is to be calculated over land paths, and over a transmitter-receiver
distance less than 16 km. This correction gives more precise field strength prediction over small reception areas. The
correction is added to the field strength and is given by:
C Clearance = J  '  – J   
2
Where J    =  6.9 + 20  Log    – 0.1  + 1 +  – 0.1   , ' = 0.036  f , and  = 0.065   Clearance  f
 Clearance is the clearance angle in degrees determined from:
•
•
 : The elevation angle of the line from the receiver which just clears all terrain obstructions in the direction of the
transmitter over a distance of up to 16 km but not going beyond the transmitter.
h 1S – h 2S
 Ref : The reference angle,  Ref = arc tan  ------------------------- .
 1000  d 
Where h 1S and h 2S are the heights of the transmitter and the receiver above sea level, respectively.
4.4.8.1.6
Step 6: Calculation of Path Loss
First, the final field strength is calculated from the interpolated/extrapolated field strength, E f , by applying the corrections
calculated earlier. The calculated field strength is given by:
E Calc = E f + C Receiver + C Building + C Clearance
The resulting field strength is given by E = Min  E Calc E Max  , from which the path loss (basic transmission loss, L B ) is
calculated as follows:
L B = 139 – E + 20  Log  f 
4.4.9
Sakagami Extended Propagation Model
The Sakagami extended propagation model is based on the simplification of the extended Sakagami-Kuboi propagation
model. The Sakagami extended propagation model is valid for frequencies above 3 GHz. Therefore, it is only available in
WiMAX 802.16d and WiMAX 802.16e documents by default.
The Sakagami-Kuboi propagation model requires detailed information about the environment, such as widths of the streets
where the receiver is located, the angles formed by the street axes and the directions of the incident waves, heights of the
buildings close to the receiver, etc. The path loss formula for the Sakagami-Kuboi propagation model is [1]:
H 2
L Model = 100 – 7.1  Log  W  + 0.023   + 1.4  Log  h s  + 6.1  Log  H 1  – 24.37 – 3.7   --------  Log  h b  +
 h b0
 43.2 – 3.1  Log  h b    Log  d  + 20  Log  f  + e
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Chapter 4: Calculations
Where,
•
•
•
•
•
•
•
•
•
W is the width (in meters) of the streets where the receiver is located
 is the angle (in degrees) formed by the street axes and the direction of the incident wave
hs is the height (in meters) of the buildings close to the receiver
H1 is the average height (in meters) of the buildings close to the receiver
hb is the height (in meters) of the transmitter antenna with respect to the observer
hb0 is the height (in meters) of the transmitter antenna with respect to the ground level
H is the average height (in meters) of the buildings close to the base station
d is the separation (in kilometres) between the transmitter and the receiver
f is the frequency (in MHz)
The Sakagami-Kuboi propagation model is valid for:
5m
<W<
50 m
0°
<  <
90°
5m
< hs <
80 m
5m
< H1 <
50 m
20 m
< hb <
100 m
0.5 km
<d<
10 km
450 MHz
<f<
2200 MHz
h b0  H
Studies [2] have shown that the Sakagami-Kuboi propagation model can be extended to frequencies higher than 3 GHz,
which also allows a simplification in terms of the input required by the model.
The path loss formula for the extended Sakagami-Kuboi propagation model is:
L Model = 54 + 40  Log  d  – 30  Log  h b  + 21  Log  f  + a
Where a is a corrective factor with three components:
H0
hm
W
a = a  H 0  + a  W  + a  h m  = 11  Log  ------- – 7.1  Log  ------ – 5  Log  --------
 20
 1.5
 20
•
•
•
•
•
•
•
W is the width (in meters) of the streets where the receiver is located
H0 (= hs = H1) is the height (in meters) of the buildings close to the receiver
hb (= hb0) is the height (in meters) of the transmitter antenna with respect to the ground
hm is the height (in meters) of the receiver antenna
H is the average height (in meters) of the buildings close to the base station
d is the separation (in metres) between the transmitter and the receiver
f is the frequency (in GHz)
The extended Sakagami-Kuboi propagation model is valid for:
5m
<W<
50 m
10 m
< H0 <
30 m
10 m
< hb <
100 m
0.1 km
<d<
3 km
0.8 GHz
<f<
8 GHz
1.5 m
< hm <
5m
Studies also show that above 3 GHz, the path loss predicted by the extended model is almost independant of the input
parameters such as street widths and angles. Therefore, the extended Sakagami-Kuboi propagation model can be simplified to the extended Sakagami propagation model:
L Model = 54 + 40  Log  d  – 30  Log  h b  + 21  Log  f  – 5  Log  h m 
The extended Sakagami propagation model is valid for:
10 m
< hb <
100 m
0.1 km
<d<
3 km
3 GHz
<f<
8 GHz
1.5 m
< hm <
5m
The path loss calculation formula of the Sakagami extended propagation model resembles the formula of the Standard
Propagation Model. In Atoll, this model is in fact a copy of the Standard Propagation Model with the following values
assigned to the K coefficients:
K1
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K2
40
K3
-30
K4
0
K5
0
K6
0
K7
-5
For more information on the Standard Propagation Model, see "Standard Propagation Model (SPM)" on page 87.
References:
[1] Manuel F. Catedra, Jesus Perez-Arriaga, "Cell Planning for Wireless Communications," Artech House Publishers,
1999.
[2] Koshiro Kitao, Shinichi Ichitsubo, "Path Loss Prediction Formula for Urban and Suburban Areas for 4G Systems,"
IEEE, 2006.
4.4.10
Appendices
4.4.10.1
Free Space Loss
The calculation of free space loss is based on ITU 525 recommendations.
L FS = 32.4 + 20 log  f  + 20 log  d 
where,
f is the frequency in MHz,
d is the Tx-Rx distance in km,
Free space loss is stated in dB.
4.4.10.2
Diffraction Loss
The calculation of diffraction is based on ITU 526-5 recommendations. General method for one or more obstacles (knifeedge diffraction) is used to evaluate diffraction losses (Diffraction loss in dB). Four construction modes are implemented
in Atoll. All of them are based on this same physical principle presented hereafter, but differ in the way they consider one
or several obstacles. Calculations take the earth curvature into account through the effective Earth radius concept (K
factor=1.333).
4.4.10.2.1
Knife-Edge Diffraction
The procedure checks whether a knife-edge obstructs the first Fresnel zone constructed between the transmitter and the
receiver. The diffraction loss, J(), depends on the obstruction parameter (), which corresponds to the ratio of the obstruction height (h) and the radius of the Fresnel zone (R).
Figure 4.14: Knife-Edge Diffraction
R =
c0  n  d1  d2
--------------------------------f   d1 + d2 
where,
n is the Fresnel zone index,
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Chapter 4: Calculations
c0 is the speed of light (2.99792 x108 ms-1),
f is the frequency in Hz
d1 is the distance from the transmitter to obstacle in m,
d2 is the distance from obstacle to receiver in m.
h
We have:  = --r
where,
R
r = ------2
h is the obstruction height (height from the obstacle top to the Tx-Rx axis).
Hence,
2
For 1 knife-edge method, if   – 0.7 , J    = 6.9 + 20  log    – 0.1  + 1 +   – 0.1  
Else, J    = 0
Note:
•
4.4.10.2.2
In case of multiple-knife edge method, the minimum  required to estimate diffraction loss
is -0.78.
3 Knife-Edge Deygout Method
The Deygout construction, limited to a maximum of three edges, is applied to the entire profile from transmitter to receiver.
This method is used to evaluate path loss incurred by multiple knife-edges. Deygout method is based on a hierarchical
knife-edge sorting used to distinguish the main edges, which induce the largest losses, and secondary edges, which have
a lesser effect. The edge hierarchy depends on the obstruction parameter () value.
1 Obstacle
Figure 4.15: Deygout Construction – 1 Obstacle
A straight line between transmitter and receiver is drawn and the height of the obstacle above the Tx-Rx axis, hi, is calculated. The obstruction position, di, is also recorded. i are evaluated from these data. The point with the highest  value is
termed the principal edge, p, and the corresponding loss is J(p).
Therefore, we have
DiffractionLoss = J   P 
3 Obstacles
Then, the main edge (point p) is considered as a secondary transmitter or receiver. Therefore, the profile is divided in two
parts: one half profile, between the transmitter and the knife-edge section, another half, constituted by the knife-edgereceiver section.
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Figure 4.16: Deygout Construction – 3 Obstacles
The same procedure is repeated on each half profile to determine the edge with the higher . The two obstacles found,
(points t and r), are called ‘secondary edges’. Losses induced by the secondary edges, J(t) and J(r), are then calculated.
Once the edge hierarchy is determined, the total loss is evaluated by adding all the intermediary losses obtained.
Therefore, if  P  0
we have DiffractionLoss = J   P  + J   t  + J   r 
Otherwise, If  P  – 0.7 , DiffractionLoss = J   P 
Note:
•
In case of ITU 526-5 and WLL propagation models, Diffraction loss term is determined as
follows:
- If  P  – 0.78 , we have
DiffractionLoss = J   P  +  J   t  + J   r    t
J  P 
Where, t = min  -------------- 1
 6

- Otherwise DiffractionLoss = 0
4.4.10.2.3
Epstein-Peterson Method
The Epstein-Peterson construction is limited to a maximum of three edges. First, Deygout construction is applied to determine the three main edges over the whole profile as described above. Then, the main edge height, hp, is recalculated
according to the Epstein-Peterson construction. hp is the height above a straight line connecting t and r points. The main
edge position dp is recorded and p and J(p) are evaluated from these data.
Figure 4.17: Epstein-Peterson Construction
Therefore, we have
DiffractionLoss = J   P  + J   t  + J   r 
4.4.10.2.4
Deygout Method with Correction
The Deygout method with correction (ITU 526-5) is based on the Deygout construction (3 obstacles) plus an empirical
correction, C.
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Chapter 4: Calculations
Therefore, If  P  0 ,
we have DiffractionLoss = J   P  + J   t  + J   r  + C
Otherwise DiffractionLoss = J   P  + C
Note:
•
In case of ITU 526-5 propagation model, Diffraction loss term is determined as follows:
- If  P  – 0.78 , we have DiffractionLoss = J   P  + t   J   t  + J   r  + C 
J  P 
Where, t = min  -------------- 1
 6

C = 8.0 + 0.04d (d: distance stated in km between the transmitter and the receiver).
- Otherwise DiffractionLoss = 0
4.4.10.2.5
Millington Method
The Millington construction, limited to a single edge, is applied over the entire profile. Two horizon lines are drawn at the
transmitter and at the receiver. A straight line between the transmitter and the receiver is defined and the height of the
intersection point between the two horizon lines above the Tx-Rx axis, hh, is calculated. The position dh is recorded and
then, from these values, h and J(h) are evaluated using the same previous formulas.
Therefore, we have
DiffractionLoss = J   h 
Figure 4.18: Millington Construction
4.5
Path Loss Tuning
Atoll can tune path loss matrices obtained from propagation results by the use of real measurements (CW Measurements
or Test Mobile Data). For each measured transmitter, Atoll tries to merge measurements and predictions on the same
points and to smooth the surrounding points of the path loss matrices for homogeneity reasons. A transmitter path loss
matrix can be tuned several times by the use of several measurement paths. All these tuning paths are stored in a catalogue. This catalogue is stored under a .tuning folder containing a .dbf file and one .pts file per tuned transmitter. Since a
tuning file can contain several measurement paths, all these measurements are added to the tuning file.
For more information on the tuning files, See "Externalised Tuning Files" on page 64.
4.5.1
Standard Tuning on Transmitters
The same algorithm is used for CW Measurement and Test Mobile Data. It is also the same for main and extended matrices.
Path Losses tuning will be done using two steps.
1.
Total matrix correction
A mean error is calculated between each measured value and the corresponding bin in the pathloss matrix. Mean error is
calculated for each pathloss matrix (main and extended) of each transmitter. This mean error is then applied to all the
matrix bins. This tuning is done to smooth the local corrections (step 2) of measured values and not the tuned bins.
2.
Local correction for each measured value
For each measured value, an ellipse is used to define the pathloss area which has to be tuned. The main axis of the ellipse
is oriented to the transmitter.The ellipse is user-defined by two parameters :
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•
•
The radius of the axis parallel to the Profile (A)
The radius of the axis perpendicular to the Profile (B)
Let’s take M a measurement value and P i the path loss value at point i, before any tuning.
Note:
•
M is limited by the minimum measurement threshold defined in the interface.
The squared elliptic distance between i and M is given by:
2
2
 Xi – XM 
 Yi – YM 
- + -------------------------D i = -------------------------2
2
A
B
Where:
X i and X M are the X-coordinates of i and M respectively
Y i and Y M are the Y-coordinates of i and M respectively
The mean error for the first tuning is given by:
1
E =  --- 
 n
 ei
i
Where e i is the error between measurement and prediction at point i
Note:
•
E is limited by the maximum total correction defined in the interface.
Then, the path loss value is tuned using E:
Pi
new
= Pi
old
+E
Finally, a second tuning ( R i ) is applied where:
R i =  1 – Di    M – g – Pi
new
 so R i =  1 – D i    M – g –  P i
old
+ E
Where g is (measurement gain - losses).
Note:
•
R i is limited by the maximum local correction defined in the interface.
So, the final tuned path loss is:
Pi
tuned
= Pi
new
+ R i so P i
tuned
= Pi
old
+ E + Ri
When several ellipses overlap a pathloss bin, the final tuned path loss is given by:


  1 – d j P j

tuned


j
= ----------------------------------------------------Pi
tuned


d j
n –




j
Where n is the number of overlapping ellipses
4.5.2
Path Loss Tuning of Repeaters
In the case of repeaters, Atoll provides only a composite measured value per pixel which is a combination of the contribution of both a transmitter and one or several repeaters. In order to tune the path loss matrices of donor transmitters and
repaters, its is mandatory to split the contribution of each element in the measured value as starting point.
Let’s take M the measured value.
M = Md + Mr
where :
M d represents the contribution of the donor transmitter in the measured value.
M r represents the contribution of the repeater in the measured value.
Note:
•
110
All the values are used in Watts
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Chapter 4: Calculations
If C d and C r represent respectively the filtered signal level from the donor transmitter and the repeater on a pixel, one
can define the contribution of each element as follows:
Cd
Cr
M d = M  ------------------- and M r = M  ------------------- .
Cd + Cr
Cd + Cr
Following the path loss tuning process described in "Standard Tuning on Transmitters" on page 109, the donor transmitter
(resp. the repeater) is then tuned using M d (resp. M r ) values.
4.6
Antenna Attenuation Calculation
The modelling method used to evaluate transmitter antenna attenuation, L antTx , is described below. Atoll calculates the
accurate azimuth and tilt angles and then, performs a 3-D interpolation of horizontal and vertical patterns to determine the
attenuation of antenna.
Furthermore, you will find explanations about the remote electrical downtilt modelling.
4.6.1
Calculation of Azimuth and Tilt Angles
From the direction of the transmitter antenna and the receiver position relative to the transmitter, Atoll determines the
receiver position relative to the direction of the transmitter antenna (i.e. the direction of the transmitter-receiver path in the
transmitter antenna coordinate system).
aTx and eTx are respectively the transmitter (Tx) antenna azimuth and tilt in the coordinate system S 0  x y z  .
aRx and eRx are respectively the azimuth and tilt of the receiver (Rx) in the coordinate system S 0  x y z  .
d is the distance between the transmitter (Tx) and the receiver (Rx).
Figure 4.19: Azimuth and Tilt Computation
In the coordinate system S 0  x y z  , the receiver coordinates are:
x Rx
cos  e Rx   sin  a Rx   d
y Rx =
cos  e Rx   cos  a Rx   d
z Rx
(1)
– sin  e Rx   d
Let az and el respectively be the azimuth and tilt of the receiver in the transmitter antenna coordinate system
S Tx  x'' y'' z''  . These angles describe the direction of the transmitter-receiver path in the transmitter antenna coordinate
system. Therefore, the receiver coordinates in S Tx  x'' y'' z''  are:
x'' Rx
y'' Rx =
z'' Rx
© Forsk 2009
cos  el   sin  az   d
cos  el   cos  az   d
– sin  el   d
(2)
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According to the figure above, we have the following relations:
x'
y' =
z'
cos  a Tx  – sin  a Tx  0
x
sin  a Tx  cos  a Tx  0  y
z
0
0
1
(3)
and
1
0
0
x''
x'
y'' = 0 cos  e Tx  – sin  e Tx   y'
z''
z'
0 sin  e Tx  cos  e Tx 
(4)
Therefore, the relation between the system S 0  x y z  and the transmitter antenna system S Tx  x'' y'' z''  is:
1
0
0
cos  a Tx  – sin  a Tx  0
x''
x
0
e
cos


–
sin

e

=

y''
sin  a Tx  cos  a Tx  0  y
Tx
Tx
z''
0 sin  e Tx  cos  e Tx 
z
0
0
1
(5)
We get,
x''
y'' =
z''
cos  a Tx 
– sin  a Tx 
0
x
cos  e Tx   sin  a Tx  cos  e Tx   cos  a Tx  – sin  e Tx   y
z
sin  e Tx   sin  a Tx  sin  e Tx   cos  a Tx  cos  e Tx 
(6)
Then, substituting the receiver coordinates in the system S0 from Eq. (1) and the receiver coordinates in the system STx
from Eq. (2) in Eq. (6) leads to a system where two solutions are possible:
1st solution: If a Rx = a Tx , then az = 0 and el = e Rx – e Tx
2nd solution: If a Rx  a Tx , then
1
az = atan -----------------------------------------------------------------------------------------------cos  e Tx 
sin  e Tx   tan  e Rx 
-------------------------------------- + -------------------------------------------------tan  a Rx – a Tx 
sin  a Rx – a Tx 
and
cos  e Tx   tan  e Rx  
 – sin  e Tx 
-
el = atan sin  az    -------------------------------------+ --------------------------------------------------sin  a Rx – a Tx  
 tan  a Rx – a Tx 
If sin  az   sin  a Rx – a Tx   0 , then az = az + 180
4.6.2
Antenna Pattern 3-D Interpolation
The direction of the transmitter-receiver path in the transmitter antenna coordinate system is given by angle values, az and
el. Atoll considers these values in order to determine transmitter antenna attenuations in the horizontal and vertical
patterns. It reads the attenuation H(az) in the horizontal pattern for the calculated azimuth angle az and the attenuation
V(el) in the vertical pattern for the calculated tilt angle el. Then, it calculates the antenna total attenuation, L antTx  az el  .
180 – az
az
L antTx  az el  = H  az  – --------------------------   H  0  – V  el   + ----------   H  180  – V  180 – el  
180
180
Notes:
•
Atoll assumes that the horizontal and vertical patterns are two cross-sections of the 3-D
pattern. In other words, the description of the antenna pattern must satisfy the following:
H(0)=V(0) and H()=V()
In case of an electrical tilt, , the horizontal pattern is a conical section with a  degrees
elevation off the horizontal plane. Here, horizontal and vertical patterns must satisfy the
following:
H(0)=V() and H()=V(-)
If the constraints listed above are satisfied, this implies that:
1. Interpolated horizontal and vertical patterns respectively fit in with the entered horizontal
and vertical patterns, even in case of electrical tilt,
2. The contribution of both the vertical pattern back and front parts are taken into account.
Otherwise, only the second point is guaranteed.
•
112
The above interpolation is performed in dBs.
AT281_TRG_E1
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Chapter 4: Calculations
4.6.3
•
Angle values in formulas are stated in degrees.
•
The above interpolation is not used in case the transmitter antenna is described by a 3-D
antenna pattern.
Additional Electrical Downtilt Modelling
The additional electrical downtilt, AEDT, also referred to as remote electrical downtilt or REDT, introduces a conical transformation of the 3-D antenna pattern in the vertical axis. In order to take it into account, the vertical pattern is transformed
as follows:
V  x  = V  x – AEDT  when x  [– 90,90]
V  x  = V  x + AEDT  when x  [90,270]
Where, the angle values are in degrees.
The vertical pattern transformation is represented below. The left picture shows the initial vertical pattern when there is no
electrical downtilt and the right one shows the vertical pattern transformation due to an electrical downtilt of 10°.
Then, Atoll proceeds as explained in the previous section. It determines the antenna attenuation in the transformed vertical
pattern for the calculated tilt angle (V(el)) and applies the 3-D interpolation formula in order to calculate the antenna total
attenuation, L antTx  az el  .
Figure 4.20: Vertical Pattern Transformation due to Electrical Downtilt
4.6.4
Antenna Pattern Smoothing
Empirical propagation models, like the Standard Propagation Model (SPM), require antenna pattern smoothing in the vertical plane to simulate the effects of reflections and diffractions. Signal level predictions can be improved by smoothing the
high-attenuation points of the vertical pattern. You can smooth vertical as well as horizontal antenna patterns in Atoll.
The antenna pattern smoothing algorithm in Atoll first determines the peaks and nulls in the pattern within the smoothing
angle (ASmoothing) defined by the user. Peaks (P) are the lowest attenuation angles and nulls (N) are the highest attenuation angles in the pattern. Then, it determines the nulls to be smoothed (NSmoothing) and their corresponding angles according to the defined Peak-to-Null Deviation (DPeak-to-Null). DPeak-to-Null is the minimum difference of attenuation in dBs
between two peaks and a null between them. Finally, Atoll smooths the pattern between 0 and the smoothing angle
(ASmoothing) by applying the smoothing to a certain smoothing factor (FSmoothing) defined by the user.
Let’s take an example of an antenna pattern to be smoothed, as shown in Figure 4.21: on page 114. Let DPeak-to-Null be
10 dB, ASmoothing = 90 degrees, and FSmoothing = 0.5.
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Figure 4.21: Vertical Antenna Pattern
Atoll first determines the peaks and nulls in the part of the pattern to be smoothed by verifying the slopes of the pattern
curve at each angle.
Figure 4.22: Peaks and Nulls in the Antenna Pattern
Peaks (P) and Nulls (N):
Angle (°)
Attenuation (dB)
1
0.1
15
33.5
21
13.2
30
37.6
38
16.9
49
32.2
67
15.6
Then, Atoll verifies whether the difference of attenuation at a given angle is DPeak-to-Null less than the before and after it.
This comparison determines the nulls to be smoothed (NSmoothing).
Nulls to be smoothed (NSmoothing):
Angle (°)
Attenuation (dB)
15
33.5
30
37.6
49
32.2
Once the nulls are known, Atoll applies the smoothing algorithm to all the attenuation values at all the angles between the
first peak, the null, and the last peak.
114
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Chapter 4: Calculations
4.6.4.1
Smoothing Algorithm
For all nulls n  N Smoothing surrounded by two peaks P1 and P2 at angles  1 and  2 ,
 A 2 – A 1


-   i –  1  
A i Smoothed = A i – F Smoothing A i –  A  +  -----------------------1
–


 2
1 


Where,
i is the angle in degrees from  1 to  2 incremented by 1 degree,
AAngle is the attenuation at any given angle which can be i,  1 or  2 , and
FSmoothing is the smoothing factor defined by the user.
4.7
Shadowing Model
Propagation models predict the mean path loss as a function of transmission and reception parameters such as frequency,
antenna heights, and distance, etc. Therefore, the predicted path loss between a transmitter and a receiver is constant, in
a given environment and for a given distance. However, in reality different types of clutter may exist in the transmitterreceiver path. Therefore, the path losses for the same distance could be different along paths that pass throught different
types of environments. The location of the receiver in different types of clutter causes variations with respect to the mean
path loss values given by the path loss models. Some paths undergo more loss while others are less obstructed and may
have higher received signal strength. The variation of path loss with respect to the mean path loss values predicted by the
propagation models, depending on the type of environment is called shadow fading (shadowing) or slow fading. "Slow"
fading implies that the variations in the path loss due to shadow fading occur comparatively slower than the fast fading
effect (Rayleigh fading), which is due to the mobile receiving multipath copies of a signal.
Different types of clutter (buildings, hills, etc.) make large shadows that cause variations in the path loss over long
distances. As a mobile passes under a shadow, the path loss to the mobile keeps varying from point to point. Shadow
fading varies as the mobile moves, while fast fading can vary even if the mobile remains at the same location or moves
over very small distances. It is crucial to account for the shadow fading in order to predict the reliability of coverage
provided by any mobile cellular system.
The shadowing effect is modelled by a log-normal (Gaussian) distribution, as shown in Figure 4.23: on page 115, whose
standard deviation  depends on the type of clutter.
Figure 4.23: Log-normal Probability Density Function
Different clutter types have different shadowing effects. Therefore, each clutter type in Atoll can have a different standard
deviation representing its shadowing characteristics. For different standard deviations, the shape of the Gaussian distribution curve remains similar, as shown in Figure 4.23: on page 115.
The accuracy of this model depends upon:
•
•
•
•
•
The suitability of the range of standard deviation used for each clutter class,
The definition (bin size) of the digital map,
How up-to-date the digital map is,
The number of clutter classes,
The accuracy of assignment of clutter classes.
Shadowing is applied to the predicted path loss differently depending on the technology, and whether it is applied to predictions or simulations. The following sections explain how shadowing margins are calculated and applied to different technology documents.
© Forsk 2009
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Technical Reference Guide
Shadowing margins are calculated for a given cell edge coverage probability. The cell edge coverage probability is the
probability of coverage at a pixel located at the cell edge, and corresponds to the reliability of coverage that you are planning to achieve at the cell edge. For example, a cell edge coverage probability of 75 % means that the users located at
the cell edge will receive adequate signal level during 75 % of the time. Therefore, a coverage prediction with a cell edge
coverage probability of x % means that the signal level predicted on each pixel is reliable x % of the time, and the overall
predicted coverage area is reliable at least x % of the time.
References:
[1] Saunders S. “Antennas and propagation for Wireless Communication Systems” pp. 180-198
[2] Holma H., Toskala A. “WCDMA for UMTS”
[3] Jhong S., Leonard M. “CDMA systems engineering handbook” pp. 309-315, 1051-1053”
[4] Remy J.G., Cueugnet J., Siben C. “Systèmes de radiocommunications avec les mobiles” pp. 309-310
[5] Laiho J., Wacker A., Novosad T. “Radio network planning and optimisation for UMTS” pp. 80-81
GSM GPRS EGPRS Documents
The shadowing margins are calculated as explained in "Shadowing Margin Calculation in Predictions" on page 120, and
applied to signal level or C/I as explained below.
•
Signal Level-Based Predictions
Signal level-based predictions include coverage predictions (Coverage by Transmitter, Coverage by Signal Level,
and Overlapping Zones) and calculations in point analysis tabs (Profile and Reception) that require calculation of
the received signal level only, and do not depend on interference.
In these calculations (signal level calculations), a shadowing margin ( M Shadowing – model ) is added to the path loss
( L path ) calculated for each pixel. The shadowing margin is calculated for a given cell edge coverage probability,
and depends on the model standard deviation (  model in dB) associated to the clutter class where the receiver is
located.
•
Interference-Based Predictions
Interference-based predictions include coverage predictions (Coverage by C/I Level, Interfered Zones, GPRS/
EGPRS Coding Schemes, RLC/MAC Throughout/Timeslot, Application Throughput/Timeslot, Circuit Quality Indicators) and calculations in point analysis window’s Interference tab that require calculation of the received signal
level and interference received from other base stations.
In these calculations, ( C  I calculations), the shadowing margin ( M Shadowing – C  I ) is added to the ratio of the
carrier power (C) and the interfering signal levels (I) received from the interfering base stations. This shadowing
margin is calculated for a given cell edge coverage probability and depends on the C/I standard deviation (  C  I
in dB) associated to the clutter class where the receiver is located.
UMTS HSPA and CDMA2000 1xRTT 1xEV-DO Documents
The shadowing margins are calculated as explained in "Shadowing Margin Calculation in Predictions" on page 120 and
"Shadowing Margin Calculation in Monte-Carlo Simulations" on page 121, and applied to signal level, Ec/I0, or Eb/Nt as
explained below.
•
Signal Level-Based Predictions
Signal level-based predictions include coverage predictions (Coverage by Transmitter, Coverage by Signal Level,
and Overlapping Zones) and calculations in point analysis tabs (Profile and Reception) that require calculation of
the received signal level only, and do not depend on interference.
In these calculations (signal level calculations), a shadowing margin ( M Shadowing – model ) is added to the path loss
( L path ) calculated for each pixel. The shadowing margin is calculated for a given cell edge coverage probability,
and depends on the model standard deviation (  model in dB) associated to the clutter class where the receiver is
located.
•
Interference+noise-Based Predictions
Interference+noise-based predictions include coverage predictions (Pilot Reception Analysis, Downlink Total
Noise, Service Area Analyses, Handoff Status, etc.) and point analysis (AS Analysis tab) that require calculation
of the received signal level and intra-cellular interference and noise received from other base stations.
In these calculations, the shadowing margins ( M Shadowing – Ec  Io
M Shadowing –  Eb  Nt 
UL
and
M Shadowing –  Eb  Nt 
DL
) , or
) are added to Ec/I0 or Eb/Nt. This shadowing margin is calculated for a given cell edge
coverage probability and depends on the Ec/I0 or Eb/Nt standard deviations (  Ec  Io ,   Eb  Nt 
DL
, or   Eb  Nt 
UL
,
in dB) associated to the clutter class where the receiver is located.
•
116
Macro-Diversity Gains
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Chapter 4: Calculations
UL
DL
Atoll calculates the uplink and downlink macro-diversity gains ( G macro – diversity and G macro – diversity ) depending
on the receiver handover status. These gains are respectively taken into account to evaluate the uplink Eb/Nt in
case of soft handover and the downlink Ec/Io from best server. For detailed description of the calculation of macrodiversity gains, please refer to "Macro-Diversity Gains Calculation" on page 122.
•
Monte-Carlo Simulations
Random values for shadowing margins are calculated for each transmitter-receiver link and added to the predicted
path loss. A shadowing margin for each transmitter-receiver link in each simulation is obtained by taking a random
value from the probability density distribution for the appropriate clutter class. The probability distribution is a lognormal distribution as explained above.
TD-SCDMA Documents
The shadowing margins are calculated as explained in "Shadowing Margin Calculation in Predictions" on page 120 and
"Shadowing Margin Calculation in Monte-Carlo Simulations" on page 121, and applied to signal level or interference+noise
predictions as explained below.
•
Signal Level-Based Predictions
Signal level-based predictions include coverage predictions (Best Server and RSCP P-CCPCH Coverages, PCCPCG Pollution, Baton Handover Coverage, DwPCH and UpPCH Coverages, Cell to Cell Interference, and
Scrambling Code Interference) and calculations in point analysis tabs (Profile and Reception) that require calculation of the received signal level only, and do not depend on interference.
In these calculations (signal level calculations), a shadowing margin ( M Shadowing – model ) is added to the path loss
( L path ) calculated for each pixel. The shadowing margin is calculated for a given cell edge coverage probability,
and depends on the model standard deviation (  model in dB) associated to the clutter class where the receiver is
located.
•
Interference+noise-Based Predictions
Interference+noise-based predictions include coverage predictions (P-CCPCH Eb/Nt and C/I Coverages, Service
Area Analsyses for downlink and uplink Eb/Nt and C/I, etc.) that require calculation of the received signal level and
interference received from other base stations.
In these calculations, the shadowing margins ( M Shadowing –  Eb  Nt 
M Shadowing –  Eb  Nt 
UL
P – CCPCH
, M Shadowing –  Eb  Nt 
DL
, or
) are added to Eb/Nt. This shadowing margin is calculated for a given cell edge coverage
probability and depends on the Eb/Nt standard deviations (   Eb  Nt 
P – CCPCH
,   Eb  Nt 
DL
, or   Eb  Nt 
UL
, in dB)
associated to the clutter class where the receiver is located.
•
Monte-Carlo Simulations
Random values for shadowing margins are calculated for each transmitter-receiver link and added to the predicted
path loss. A shadowing margin for each transmitter-receiver link in each simulation is obtained by taking a random
value from the probability density distribution for the appropriate clutter class. The probability distribution is a lognormal distribution as explained above.
WiMAX 802.16d and WiMAX 802.16e Documents
The shadowing margins are calculated as explained in "Shadowing Margin Calculation in Predictions" on page 120 and
"Shadowing Margin Calculation in Monte-Carlo Simulations" on page 121 , and applied to signal level or C/(I+N) as
explained below.
•
Signal Level-Based Predictions
Signal level-based predictions include coverage predictions (Coverage by Transmitter, Coverage by Signal Level,
and Overlapping Zones) and calculations in point analysis tabs (Profile and Reception) that require calculation of
the received signal level only, and do not depend on interference.
In these calculations (signal level calculations), a shadowing margin ( M Shadowing – model ) is added to the path loss
( L path ) calculated for each pixel. The shadowing margin is calculated for a given cell edge coverage probability,
and depends on the model standard deviation (  model in dB) associated to the clutter class where the receiver is
located.
•
Interference+noise-Based Predictions
Interference-based predictions include coverage predictions (Coverage by C/(I+N) Level, Coverage by Best
Bearer, Coverage by Throughput, etc.) that require calculation of the received signal level and received interference.
In these calculations, (C/(I+N) calculations), in addition to the shadowing margin ( M Shadowing – model ) added to
the path loss ( L path ) calculated for each pixel, the ratio M Shadowing – model – M Shadowing – C  I is added to the inter-
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fering signal levels (I). M Shadowing – C  I is calculated for a given cell edge coverage probability and depends on
the C/I standard deviation (  C  I in dB) associated to the clutter class where the receiver is located.
•
Monte-Carlo Simulations
Two random values of shadowing margins, for M Shadowing – model based on the model standard deviation (  model
in dB) and M Shadowing – C  I based on the C/I standard deviation (  C  I in dB), are calculated for each mobile.
For signal level calculation, M Shadowing – model is added to the path loss ( L path ) calculated for each mobile. For
C/(I+N) calculations, in addition to the M Shadowing – model added to the path loss ( L path ), the ratio
M Shadowing – model – M Shadowing – C  I is also added to the interfering signal levels (I).
Random values are drawn from the probability density distribution for the appropriate clutter class. The probability
distribution is a log-normal distribution as explained above.
The reason why the ratio M Shadowing – model – M Shadowing – C  I is used can be understood from the following derivation
(linear, not it dB):
Inputs
-
C P : The predicted received carrier power without any shadowing margin.
-
I P : The predicted received interference power without any shadowing margin.
-
m C : Shadowing margin based on the model standard deviation ( 10
-
m C  I : Shadowing margin based on the C/I standard deviation ( 10
-
N : Thermal noise
M Shadowing – model
----------------------------------------------------10
M Shadowing – C  I
---------------------------------------------10
)
)
Calculations
The effective received carrier power is given by:
C = mC  CP
The effective C/I is given by:
C
C
---- = m C  I  ------PIP
I
The above equations lead to:
mC
mC  CP
C
I = -------------------------- = -------------------------= ------------  I P
m
CP
CP
CI
m C  I  ------m C  I  ------IP
IP
mC
Where ------------ corresponds to M Shadowing – model – M Shadowing – C  I in dB.
mC  I
Therefore, the effective C/(I+N) is given by:
mC  CP
C
----------------- = --------------------------------------I + N
m
C
 -----------  I P + N
 mC  I

LTE Documents
The shadowing margins are calculated as explained in "Shadowing Margin Calculation in Predictions" on page 120 and
"Shadowing Margin Calculation in Monte-Carlo Simulations" on page 121 , and applied to signal level or C/(I+N) as
explained below.
•
Signal Level-Based Predictions
Signal level-based predictions include coverage predictions (Coverage by Transmitter, Coverage by Signal Level,
and Overlapping Zones) and calculations in point analysis tabs (Profile and Reception) that require calculation of
the received signal level only, and do not depend on interference.
In these calculations (signal level calculations), a shadowing margin ( M Shadowing – model ) is subtracted from the
signal level calculated for each pixel. The shadowing margin is calculated for a given cell edge coverage probability, and depends on the model standard deviation (  model in dB) associated to the clutter class where the
receiver is located.
•
118
Interference+noise-Based Predictions
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Chapter 4: Calculations
Interference-based predictions include coverage predictions (Coverage by C/(I+N) Level, Coverage by Best
Bearer, Coverage by Throughput, etc.) that require calculation of the received signal level and received interference.
In these calculations, (C/(I+N) calculations), in addition to the shadowing margin ( M Shadowing – model ) subtracted
from the signal level calculated for each pixel, the ratio M Shadowing – model – M Shadowing – C  I is added to the interfering signal levels (I). M Shadowing – C  I is calculated for a given cell edge coverage probability and depends on
the C/I standard deviation (  C  I in dB) associated to the clutter class where the receiver is located.
•
Monte-Carlo Simulations
Two random values of shadowing margins, for M Shadowing – model based on the model standard deviation (  model
in dB) and M Shadowing – C  I based on the C/I standard deviation (  C  I in dB), are calculated for each mobile.
For signal level calculation, M Shadowing – model is subtracted from the signal level calculated for each mobile. For
C/(I+N) calculations, in addition to the M Shadowing – model subtracted from the signal level, the ratio
M Shadowing – model – M Shadowing – C  I is also added to the interfering signal levels (I).
Random values are drawn from the probability density distribution for the appropriate clutter class. The probability
distribution is a log-normal distribution as explained above.
The reason why the ratio M Shadowing – model – M Shadowing – C  I is used can be understood from the following derivation
(linear, not it dB):
Inputs
-
C P : The predicted received carrier power without any shadowing margin.
-
I P : The predicted received interference power without any shadowing margin.
-
m C : Shadowing margin based on the model standard deviation ( 10
-
m C  I : Shadowing margin based on the C/I standard deviation ( 10
-
N : Thermal noise
M Shadowing – model
----------------------------------------------------10
M Shadowing – C  I
---------------------------------------------10
)
)
Calculations
The effective received carrier power is given by:
C = mC  CP
The effective C/I is given by:
C
C
---- = m C  I  ------PIP
I
The above equations lead to:
mC
mC  CP
C
I = -------------------------- = -------------------------= ------------  I P
mC  I
CP
CP
m C  I  ------m C  I  ------IP
IP
mC
Where ------------ corresponds to M Shadowing – model – M Shadowing – C  I in dB.
mC  I
Therefore, the effective C/(I+N) is given by:
mC  CP
C
----------------- = --------------------------------------m
I + N
C
 -----------  I P + N
 mC  I

4.7.1
Shadowing Margin Calculation
The following sections describe the calculation method used for determining different shadowin margins.
The following shadowing margins are calculated using the method described below:
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Network Type
Standard
Deviation
MShadowing
Applied to
 model
M Shadowing – model
C
C  I
M Shadowing – C  I
C/I
 model
M Shadowing – model
C
 Ec  Io
M Shadowing – Ec  Io
Ec/I0
  Eb  Nt 
DL
M Shadowing –  Eb  Nt 
DL
Eb/Nt (DL)
  Eb  Nt 
UL
M Shadowing –  Eb  Nt 
UL
Eb/Nt (UL)
GSM GPRS EGPRS
UMTS HSPA
CDMA2000 1xRTT 1xEV-DO
 model
M Shadowing – model
C
 Ec  Io
M Shadowing – Ec  Io
Ec/I0
  Eb  Nt 
DL
M Shadowing –  Eb  Nt 
DL
Eb/Nt (DL)
  Eb  Nt 
UL
M Shadowing –  Eb  Nt 
UL
Eb/Nt (UL)
 model
  Eb  Nt 
TD-SCDMA
WiMAX 802.16d
WiMAX 802.16e
LTE
4.7.1.1
P – CCPCH
M Shadowing – model
M Shadowing –  Eb  Nt 
P – CCPCH
C
Eb/Nt P-CCPCH
  Eb  Nt 
DL
M Shadowing –  Eb  Nt 
DL
Eb/Nt (DL)
  Eb  Nt 
UL
M Shadowing –  Eb  Nt 
UL
Eb/Nt (UL)
 model
M Shadowing – model
C
C  I
M Shadowing – C  I
C/(I+N)
 model
M Shadowing – model
C
C  I
M Shadowing – C  I
C/(I+N)
Shadowing Margin Calculation in Predictions
Shadowing margins, MShadowing, are calculated from standard deviation values defined for the clutter class where the pixel
(probe mobile) is located, and required cell edge coverage probability, and added to the path loss, Lpath.
Shadowing Error PDF (1 Signal)
The measured path loss in dB can be expressed as a Gaussian random variable:
L = L path +  dB  G  0 1 
where,
•
•
•
Lpath is the predicted path loss,
dB is the user-defined standard deviation of the error,
G(0,1) is a zero-mean unit-variance Gaussian random variable.
Therefore, the probability density function (pdf) for the random (shadowing) part of path loss is:
2
1
p L  x  = ---------------------  e
 dB 2
x
– -------------2
2 dB
The probability that the shadowing error exceeds z dB is
2
x  – ------------2
2 dB

PL  x  z  =

z
1
p L  x  dx = ---------------------  e
 dB 2

dx
z
Normalising x by dividing it bydB:

1
P L  x  z  = ----------- 
2
e
z-------- dB
2
x
– -----2
z
dx = Q  ---------
  dB
where Q is the complementary cumulative function.
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To ensure a given cell edge coverage probability, R L , for the predicted value, a shadowing margin, M Shadowing , is added
to the link budget.
Confidence in the prediction can be expressed as:
C d = P' Tx – L  P rec  L  P' Tx – P rec  G  0 1    dB  M Shadowing
where,
•
P rec is the signal level predicted at the receiver. P rec = P' Tx – L path – M Shadowing
•
P' Tx = EIRP + G antRx – L Rx
•
•
EIRP is the effective isotropic radiated power of the transmitter.
L Rx are receiver losses.
•
G antRx is the receiver antenna gain.
The shadowing margin is calculated such that:
M Shadowing
P  C d  P rec  = R L  M Shadowing  = 1 – P L  x – M Shadowing  0  = 1 – Q  ------------------------------


 dB
A lookup table is used for mapping the values of Q vs. a set of cell edge coverage probabilities.
M Shadowing
Figure 4.24: Normalised Margin M arg in = ---------------------------- dB
In interference-based predictions, where signal to noise ratio is calculated, the shadowing margin is only applied to the
signal from the interfered transmitter (C). We consider that the interference value is not altered by the shadowing margin.
Random variations also exist in the interfering signals, but taking only the average interference gives accurate results. [3]
explains how a certain level of interference is maintained by congestion control in CDMA-based networks.
4.7.1.2
Shadowing Margin Calculation in Monte-Carlo Simulations
Shadowing margins, MShadowing, are calculated from standard deviation values defined for the clutter class where the pixel
(probe mobile) is located, and required cell edge coverage probability, and added to the path loss, Lpath.
Random values are generated during Monte-Carlo simulation. Each user is assigned a service, a mobility type, an activity
status, a geographic position and a random shadowing value.
For each link, path loss (L) can be broken down to L = L path +  .
Here,  is a zero mean gaussian random variable G  0  dB  representing variation due to shadowing. It can be
expressed as the sum of two uncorrelated zero mean gaussian random variables,  L and  P .  L models the error related
to the receiver’s location (surrounding environment), and remains the same for all links between the receiver and the base
stations from which it is receiving signals.  P models the error related to the path between the transmitter and the receiver.
Therefore, in case of two links, we have:
1
 1 =  L +  P for link 1
2
 2 =  L +  P for link 2
i
Standard deviations of  L   L  and  P   P  can be calculated from  i , the model standard deviation   model  , and the
correlation coefficient    between  1 and  2 .
Assuming all  P have the same standard deviations, we have:
2
2
2
 model =  L +  P
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2
L
 = ---------------2
 model
Therefore,
2
2
2
2
 P =  model   1 –  
 L =  model  
 is set to 0.5 in Atoll, which gives:
 model
 model
- and  P = --------------- L = ---------------2
2
Receiver
Therefore, to model shadowing error common to all the signals received at a receiver ( E Shadowing – model ), values are
randomly generated for each receiver. These values have a zero-mean gaussian distribution with a standard deviation of
model

---------------- , where   model  is the model standard deviation associated with the receiver’s clutter class.

2 
Next, Atoll generates another random value for each transmitter-receiver pair. This values represents the shadowing error
Path
not related to the location of the receiver ( E Shadowing – model ). These values also have a zero-mean gaussian distribution
 model
with a standard deviation  ----------------- .

2 
So, we have:
Receiver
Path
E Shadowing – model = E Shadowing – model + E Shadowing – model
Random shadowing error has its mean value at zero. Hence, this shadowing modelling method has no impact on the simulated network load. On the other hand, as shadowing errors on the transmitter-receiver links are uncorrelated, the method
influences the calculated macro-diversity gain in case the mobile is in soft handover.
4.7.2
Macro-Diversity Gains Calculation
The following sections explain how uplink and downlink macro-diversity gains are calculated in UMTS HSPA and
CDMA2000 1xRTT 1xEV-DO documents for predictions and AS Analysis tab of the point analysis tool.
4.7.2.1
Uplink Macro-Diversity Gain Evaluation
In UMTS HSPA and CDMA2000 1xRTT 1xEV-DO, mobiles may be in soft handoff (mobile connected to cells located on
different sites). In this case, we can consider the shadowing error pdf described below.
4.7.2.1.1
Shadowing Error PDF (n Signals)
For each link, path loss (L) can be broken down as:
L = L path + 
 is a zero mean gaussian random variable G  0  dB  representing variation due to shadowing. It can be expressed as
the sum of two uncorrelated zero mean gaussian random variables,  L and  P .  L models error related to the receiver
local environment; it is the same whichever the link.  P models error related to the path between transmitter and receiver.
Therefore, in case of two links, we have:
1
 1 =  L +  P for the link 1
2
 2 =  L +  P for the link 2
Knowing  i , the uplink Eb/Nt standard deviation    Eb  Nt   and the correlation coefficient  between  1 and  2 , we
UL
can calculate standard deviations of  L   L  and  P   P  (assuming all  P have the same standard deviations).
We have:
2
  Eb  Nt 
2
2
= L + P
UL
2
L
 = ------------------------2
  Eb  Nt 
UL
Therefore,
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2
2
 P =   Eb  Nt 
2
UL
2
 L =   Eb  Nt 
UL
 1 – 

2 Signals Without Recombination
In technologies supporting soft handoff (UMTS and CDMA2000), cell is interference limited. As for one link, to ensure a
required cell edge coverage probability R L for the prediction, we add to each link budget a shadowing margin,
2signals
M Shadowing –  Eb  Nt 
UL
.
Prediction reliability in order to have Eb/Nt higher or equal to Eb/Nt from the best server can be expressed as:
Cd
1
1
--------1- = P' Tx1 – L 1 – N 1  CI pred   1  P' Tx1 – L path – N 1 – CI pred
1
N1
or
Cd
1
1
--------2- = P' Tx2 – L 2 – N 2  CI pred   2  P' Tx2 – L path – N 2 – CI pred
2
N2
where
i
CI pred is the quality level (signal to noise ratio) predicted at the receiver for link i.
Ni is the noise level for link i.
We note:
2signals
M Shadowing –  Eb  Nt 
i
UL
= P' Txi – L path – N i – CI pred
i
and
2
1
2
 1 = CI pred – CI pred
2
 1 is the minimum needed margin on each link.
Therefore, the probability of having a quality at least equal to the best predicted one is:
noMRC
RL
noMRC
RL
Cd
 Cd

2signals
1
1
 M Shadowing –  Eb  Nt   = 1 – P L1 L2  --------1-  CI pred --------2-  CI pred
UL
N2
 N1

2signals
 M Shadowing –  Eb  Nt   = 1 – P 
UL
1
1  2
2signals
2signals
  1  M Shadowing –  Eb  Nt    2  M Shadowing –  Eb  Nt 
UL
2
UL
– 1 
2
We can express it using  L ,  P and  P
P
1 2
2signals
UL
= P  L   P
L
P
1 2
2signals
  1 M Shadowing –  Eb  Nt    2  M Shadowing –  Eb  Nt 
1
1
2
 P  P
2signals
  P  M Shadowing –  Eb  Nt 
2signals
2
UL
2signals
2signals
UL
1
2signals
= P    L   P    P  M Shadowing –  Eb  Nt 
P
noMRC
RL
2
UL
–  1  L =  L
–  L  P  M Shadowing –  Eb  Nt 
  1 M Shadowing –  Eb  Nt    2  M Shadowing –  Eb  Nt 
L
2
UL
2
UL
– 1 – L 
2
UL
–  1  L =  L
2signals
–  L  P    P  M Shadowing –  Eb  Nt 
P
2
UL
– 1 –  L 
2signals
 M Shadowing –  Eb  Nt  
UL



1
2signals
2
2signals
2
=  1 – P    L   P    P  M Shadowing –  Eb  Nt  –  L   P    P  M Shadowing –  Eb  Nt  –  1 –  L  d L


L
P
UL
P
UL


–

i
2signals
P    P  M Shadowing –  Eb  Nt 
P



1
=  -----------------  2
 P
 M 2signals

 Shadowing –  Eb  Nt 
UL
– L 
2

e
UL
–  L

–x
---------2
2 P

2signals
 M Shadowing –  Eb  Nt  UL –  L 
dx = Q  ----------------------------------------------------------------------
P

 

Then, we have:
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noMRC
RL
2signals
 M Shadowing –  Eb  Nt  
UL

2signals
2signals
2


 M Shadowing –  Eb  Nt  UL –  L
 M Shadowing –  Eb  Nt UL –  1 –  L

= 1 – P    L   Q  ----------------------------------------------------------------------  Q  ----------------------------------------------------------------------------------- d L


L
P
P






–

If we introduce user defined standard deviation    Eb  Nt   and correlation coefficient    , and consider that P  is a
UL
L
Gaussian pdf:
noMRC
RL
2signals
 M Shadowing –  Eb  Nt  
UL


1
=  1 – ----------- e

2

–

2
– xL
--------2
 M 2signals
Shadowing –  Eb  Nt  UL
2

 M 2signals

– x L   Eb  Nt 

Shadowing –  Eb  Nt UL – x L   Eb  Nt  UL  –  1
UL
-  Q  -------------------------------------------------------------------------------------------------------------------- dx L
 Q  ------------------------------------------------------------------------------------------------------




1–
1–
  Eb  Nt 
  Eb  Nt 





UL
UL
n Signals Without Recombination
We can generalize the previous expression to n signals (n is the number of available signals - Atoll may consider up to 3
signals):
noMRC
RL
nsignals
 M Shadowing –  Eb  Nt  
UL


1
=  1 – ----------- e

2

–

2
– xL
--------2
 M nsignals
Shadowing –  Eb  Nt  UL
2

 M nsignals

– x L   Eb  Nt 

Shadowing –  Eb  Nt UL – x L   Eb  Nt  UL  –  1
UL
-  Q  -------------------------------------------------------------------------------------------------------------------- dx L
 Q  ------------------------------------------------------------------------------------------------------




1–
1–
  Eb  Nt 
  Eb  Nt 





UL
UL
The case where softer handoff occurs (two signals from co-site cells) is equivalent to the one signal case. The Softer/soft
case is equivalent to the two signals case. For the path associated with the softer recombination, we will use combined
SNR to calculate the availability of the link.
Correlation Coefficient Determination
There is currently no agreed model for predicting correlation coefficient    between  1 and  2 . Two key variables influence correlation:
•
•
The angle between the two signals. If this angle is small, correlation is high.
The relative values of the two signal lengths. If angle is 0 and lengths are the same, correlation is zero. Correlation
is different from zero when path lengths differ.
A simple model has been found [1]:
T
 =  ------
 

D1
-------- when  T    
D2
 T is a function of the mean size of obstacles near the receiver and  is also linked to the receiver environment.
In a normal handover status, assuming a hexagonal design for sites,  is close to  (+/- /3) and D1/D2 is close to 1.

In [1,5],  = 0.5 when  = 0.3 and  T = ------ .
10
In Atoll,  is set to 0.5.
4.7.2.1.2
Uplink Macro-Diversity Gain
UL
Atoll determines the uplink macro-diversity gain ( G macro – diversity ) from the shadowing margins calculated in case of one
signal and n signals.
Therefore, we have:
UL
nsignals
G macro – diversity = M Shadowing –  Eb  Nt 
UL
– M Shadowing –  Eb  Nt 
UL
Where n is the number of cell-mobile signals.
4.7.2.2
Downlink Macro-Diversity Gain Evaluation
In UMTS HSPA and CDMA2000 1xRTT 1xEV-DO, in case of soft handoff, mobiles are able to switch from one cell to
another if the best pilot drastically fades. To model this function, we have to consider the probability of fading over the
shadowing margin, both for the best signal and for all the other available signals, in the shadowing margin calculation.
Let us consider the shadowing error pdf described below.
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4.7.2.2.1
Shadowing Error PDF (n Signals)
For each link, path loss (L) can be broken down as:
L = L path + 
 is a zero mean gaussian random variable G  0  dB  representing variation due to shadowing. It can be expressed as
the sum of two uncorrelated zero mean gaussian random variables,  L and  P .  L models the error related to the receiver
local environment, which is the same for all links.  P models the error related to the path between the transmitter and the
receiver.
Therefore, in case of two links, we have:
1
 1 =  L +  P for the link 1
2
 2 =  L +  P for the link 2
Knowing  i , the Ec/Io standard deviation   Ec  I o  and the correlation coefficient  between  1 and  2 , we can calculate
standard deviations of  L   L  and  P   P  (assuming all  P have the same standard deviations).
We have:
2
2
2
 Ec  I o =  L +  P
2
L
 = --------------2
 Ec  I o
Therefore,
2
2
2
2
 P =  Ec  I o   1 –  
 L =  Ec  I o  
2 Available Signals
In technologies supporting soft handoff (UMTS and CDMA2000) cells are interference limited. As for one link, to ensure a
2signals
required cell edge coverage probability R L for the prediction, we add a shadowing margin, M Shadowing – Ec  Io , to each
link budget.
Ec
Ec
Prediction reliability to have -------   -------
for the best server can be expressed as:
Io  Io  pred
Ec
Ec 1
Ec 1
---------1- = P pilot – L 1 – Io   -------
  1  P pilot – L m – Io –  -------
 Io  pred
 Io  pred
1
1
1
Io
Or
Ec
Ec 1
Ec 1
---------2- = P pilot – L 2 – Io   -------
  2  P pilot – L m – Io –  -------
 Io  pred
 Io  pred
2
2
2
Io
We note:
1
Ec
2signals
M Shadowing – Ec  Io = P pilot – L m – Io –  -------
 Io  pred
i
i
Ec 1
Ec 2
2
 1 =  -------
–  -------
 Io  pred  Io  pred
2
 1 is the minimum needed margin on each link.
Therefore, probability of having a quality at least equal to the best predicted one is:
noMRC
RL
noMRC
RL
Ec 1
Ec 2
Ec 1
Ec 1 
2signals
 M Shadowing – Ec  Io  = 1 – P L1 L2  ----------   -------
 ----------   -------
 Io  Io  pred Io  Io  pred
2signals
2signals
2signals
2
 M Shadowing – Ec  Io  = 1 – P 1 2   1  M Shadowing – Ec  Io  2  M Shadowing – Ec  Io –  1 
1
2
We can express it by using  L ,  P and  P
2signals
2signals
2
P 1 2   1  M Shadowing – Ec  Io  2  M Shadowing – Ec  Io –  1  L =  L 
= P  L   P
L
© Forsk 2009
1
1
2
 P  P
2signals
2
2signals
2
  P  M Shadowing – Ec  Io –  L  P  M Shadowing – Ec  Io –  1–  L 
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2signals
2signals
2
P 1 2   1  M Shadowing – Ec  Io  2  M Shadowing – Ec  Io –  1  L =  L
1
2signals
2
2signals
2
= P    L  P    P  M Shadowing – Ec  Io – L  P    P  M Shadowing – Ec  Io – 1 –  L 
L
P
noMRC
RL
P
2signals
 M Shadowing – Ec  Io 

= 1–
 P  L   P  P  MShadowing – Ec  Io – L   P  P  MShadowing – Ec  Io – 1 – L  dL
1
L
2signals
2
P
2signals
2
P
–
2

1
i
2signals
P    P  M Shadowing – Ec  Io –  L  = -----------------P
 P 2

e
 SHO –  L
–x
---------2
2 P
2signals
 M Shadowing – Ec  Io –  L
dx = Q  ------------------------------------------------------------
P


Then, we have:

noMRC
2signals
RL
 M Shadowing – Ec  Io 
= 1–

–
2signals
2signals
2
 M Shadowing – Ec  Io –  L
 M Shadowing – Ec  Io –  1 –  L
P    L   Q  ------------------------------------------------------------  Q  ------------------------------------------------------------------------- d L
L

P




P
If we introduce a user defined Ec/Io standard deviation    and a correlation coefficient    and consider that P  is a
L
Gaussian pdf:
noMRC
RL
2signals
 M Shadowing – Ec  Io 
2

1
= 1 – ----------2

e
–xL
--------2
–
2signals
2signals
2
 M Shadowing – Ec  Io – x L  Ec  I o 
 M Shadowing – Ec  Io –  1 – x L  Ec  I o 
 Q  ------------------------------------------------------------------------------------  Q  ------------------------------------------------------------------------------------------------- dx L
 Ec  I o 1 – 
 Ec  I o 1 – 




n Available Signals
We can generalize the previous expression for n signals (n is the number of available signals - Atoll may consider up to 3
signals):
noMRC
RL
nsignals
 M Shadowing – Ec  Io 
2

1
= 1 – ----------2

–
e
–xL
--------2
nsignals
 M Shadowing – Ec  Io – x L  Ec  I o 
 Q  ------------------------------------------------------------------------------------ x
 Ec  I o 1 – 


n

i=2
nsignals
i
 M Shadowing – Ec  Io –  1 – x L  Ec  I o 
Q  ------------------------------------------------------------------------------------------------- dx L
 Ec  I o 1 – 


2
 1 =1 dB
2
 1 =5 dB
2
 1 =10 dB
Figure 4.25: Margin - Probability (Case of 2 Signals)
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2 signals
3
 1 =5 dB
3
 1 =10 dB
Figure 4.26: Margin - Probability (Case of 3 Signals with sigma = 8dB, delta1 = 1dB)
2 signals
3
 1 =5 dB
3
 1 =10 dB
Figure 4.27: Margin - Probability (Case of 3 Signals with sigma = 8dB, delta1 = 2dB)
Correlation Coefficient Determination
For further information about determination of the correlation coefficient, please see "Correlation Coefficient Determination" on page 127.
4.7.2.2.2
Downlink Macro-Diversity Gain
DL
Atoll determines the downlink macro-diversity gain ( G macro – diversity ) from the shadowing margins calculated in case of
one signal and n signals.
Therefore, we have:
DL
nsignals
G macro – diversity = M Shadowing – Ec  Io – M Shadowing – Ec  Io
Where n is the number of available signals.
Note:
•
Atoll uses the DL macro-diversity gain to calculate Ec/Io. You can force Atoll not to take it
into account through the Atoll.ini file (see Atoll administration files). You must create this file
and place it in the Atoll installation directory.
4.8
Appendices
4.8.1
Transmitter Radio Equipment
Radio equipment such as TMA, feeder and BTS, are taken into account to evaluate:
•
Total UL and DL losses of transmitter ( L total – UL L total – DL ) and transmitter noise figure  NF Tx  in UMTS HSPA,
•
CDMA2000 1xRTT 1xEV-DO, TD-SCDMA, WiMAX 802.16d, WiMAX 802.16e, and LTE documents,
Transmitter total losses  L Total  in GSM GPRS EGPRS documents.
In Atoll, the transmitter-equipment pair is modelled a single entity. The entry to the BTS is considered the reference point
which is the location of the transmission/reception parameters.
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Figure 4.28: Reference Point - Location of the Transmission/Reception parameters
Notes:
•
According to the book “Radio network planning and optimisation for UMTS” by Laiho J.,
Wacker A., Novosad T., the noise figure corresponds to the loss in case of passive
components. Therefore, feeder noise figure is equal to the cable uplink losses.
UL
NF Feeder = L Feeder
•
4.8.1.1
Loss and gain inputs specified in .atl documents must be positive values.
UMTS HSPA, CDMA2000 1xRTT 1xEV-DO, and TD-SCDMA Documents
As the reference point is the BTS entry, the transmitter noise figure corresponds to the BTS noise figure. Therefore, we
have:
NF TX = NF BTS
where NF BTS is the BTS noise figure.
Atoll calculates total UL losses as follows:
UL
UL
UL
UL
L Total – UL = L Misc + L Feeder + L BTS – Conf + NR Repeaters – G Ant – div – G TMA
where,
UL
L Misc are the miscellaneous reception losses (Transmitter property),
UL
UL
UL
UL
UL
L Feeder are the feeder reception losses ( L Feeder = L Feeder  I Feeder + L Connector , where L Feeder , I Feeder and
UL
L Connector are respectively the feeder loss per metre (Feeder property), the reception feeder length in metre (Transmitter
property) and the connector reception losses,
UL
L BTS – Conf are the losses due to BTS configuration (BTS property),
UL
G Ant – div is the antenna diversity gain (Transmitter property),
NR Repeaters is the noise rise at transmitter due to repeaters. This parameter is taken into account only if the transmitter
has active repeater(s),
G TMA is the gain due to TMA.
The noise rise at transmitter due to repeaters is calculated as follows:
For each active repeater ( k ), Atoll calculates a noise injection margin ( NIM Rp ). This is the difference between the donor
k
transmitter noise figure ( NF TX ) and the repeater noise figure received at the donor.
Rp k
NIM Rp = NF TX –  NF Rp + G amp – L

r
k
TX – Rp k


where,
NF Rp is the repeater noise figure,
k
Rp k
G amp is the repeater amplification gain (repeater property),
L
TX – R p k
are the losses between the donor transmitter and the repeater (repeater property).
For each active repeater ( k ), Atoll converts the noise injection margin ( NIM Rp ) to Watt. Then, it uses the values to calcuk
late the noise rise at the donor transmitter due to active repeaters ( NR Repeaters ).
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
NR Repeaters = 10  Log  1 +

1

-
 -----------------NIM Rp 
r
r
The gain due to TMA is calculated as follows:
WithoutTMA
WithTMA
G TMA = NF Composite – NF Composite
where,
WithTMA
WithoutTMA
NF Composite and NF Composite
are the composite noise figures with and without TMA respectively.
Friis' equation is used to calculate the composite noise figure when there is a TMA.
WithTMA
NF Composite
NF Feeder
NF BTS
 NF

-------------------------------------------TMA
 ------------------
10
10
10
10
10
–1
–1


-----------------------------------------------+ ----------------------------------+
= 10  Log 10
UL
UL
UL

G TMA
G TMA
G Feeder

----------------------------------------------------
10
10
10 

10
10
 10
WithoutTMA
And, NF Composite
= NF BTS + NF Feeder
where,
NF Feeder is the feeder noise figure,
NF TMA is the TMA noise figure,
NF BTS is the BTS noise figure,
UL
G TMA is the TMA reception gain,
UL
UL
UL
G Feeder is the feeder UL gain; G Feeder = – L Feeder .
UL
UL
UL
UL
UL
UL
L Feeder is the feeder reception loss ( L Feeder = L Feeder  I Feeder + L Connector , where L Feeder , I Feeder and L Connector
are respectively the feeder loss per metre, the reception feeder length in metre and the connector reception loss),
Atoll calculates total DL losses as follows.
DL
DL
DL
DL
L Total – DL = L TMA + L Feeder + L Misc + L BTS – Conf
where,
DL
L TMA is the TMA transmission loss,
DL
DL
DL
DL
DL
L Feeder is the feeder transmission loss ( L Feeder = L Feeder  I Feeder + L Connector , where L Feeder , I Feeder and
DL
L Connector are respectively the feeder loss per metre, the transmission feeder length in metre and the connector transmission losses),
DL
L Misc are the miscellaneous transmission losses,
DL
L BTS – Conf are the losses due to BTS configuration (BTS property).
4.8.1.2
GSM GPRS EGPRS Documents
Atoll calculates DL total losses as follows:
DL
DL
DL
DL
L Total – DL = L TMA + L Feeder + L Misc + L BTS – Conf
where,
DL
L TMA is the TMA transmission loss,
DL
DL
DL
DL
DL
L Feeder is the feeder transmission loss ( L Feeder = L Feeder  I Feeder + L Connector , where L Feeder , I Feeder and
DL
L Connector are respectively the feeder loss per metre, the transmission feeder length in metre and the connector transmission loss),
DL
L Misc are the miscellaneous transmission losses,
DL
L BTS – Conf are the losses due to BTS configuration (BTS property).
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4.8.1.3
WiMAX 802.16d and WiMAX 802.16e Documents
As the reference point is the BTS entry, the transmitter noise figure corresponds to the BTS noise figure. Therefore, we
have:
NF TX = NF BTS
where NF BTS is the BTS noise figure.
Atoll calculates total UL losses as follows:
UL
UL
UL
L Total – UL = L Misc + L Feeder + L BTS – Conf – G TMA
where,
UL
L Misc are the miscellaneous reception losses (Transmitter property),
UL
UL
UL
UL
UL
L Feeder are the feeder reception losses ( L Feeder = L Feeder  I Feeder + L Connector , where L Feeder , I Feeder and
UL
L Connector are respectively the feeder loss per metre (Feeder property), the reception feeder length in metre (Transmitter
property) and the connector reception losses,
UL
L BTS – Conf are the losses due to BTS configuration (BTS property),
G TMA is the gain due to TMA, which is calculated as follows:
WithoutTMA
WithTMA
G TMA = NF Composite – NF Composite
where,
WithTMA
WithoutTMA
NF Composite and NF Composite
are the composite noise figures with and without TMA respectively.
Friis' equation is used to calculate the composite noise figure when there is a TMA.
WithTMA
NF Composite
NF Feeder
NF BTS
 NF

------------------------------------------TMA
 ------------------
10
10
10
10
10
–1
–1


-----------------------------------------------+ ----------------------------------+
= 10  Log 10
UL
UL
UL

G TMA
G TMA
G Feeder

----------------------------------------------------
10
10
10 

10
10
 10
WithoutTMA
And, NF Composite
= NF BTS + NF Feeder
where,
NF Feeder is the feeder noise figure,
NF TMA is the TMA noise figure,
NF BTS is the BTS noise figure,
UL
G TMA is the TMA reception gain,
UL
UL
UL
G Feeder is the feeder UL gain; G Feeder = – L Feeder .
UL
UL
UL
UL
UL
UL
L Feeder is the feeder reception loss ( L Feeder = L Feeder  I Feeder + L Connector , where L Feeder , I Feeder and L Connector
are respectively the feeder loss per metre, the reception feeder length in metre and the connector reception loss),
Atoll calculates total DL losses as follows.
DL
DL
DL
DL
L total – DL = L TMA + L Feeder + L Misc + L BTS – Conf
where,
DL
L TMA is the TMA transmission loss,
DL
DL
DL
DL
DL
L Feeder is the feeder transmission loss ( L Feeder = L Feeder  I Feeder + L Connector , where L Feeder , I Feeder and
DL
L Connector are respectively the feeder loss per metre, the transmission feeder length in metre and the connector transmission losses),
DL
L Misc are the miscellaneous transmission losses,
DL
L BTS – Conf are the losses due to BTS configuration (BTS property).
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4.8.1.4
LTE Documents
As the reference point is the BTS entry, the transmitter noise figure corresponds to the BTS noise figure. Therefore, we
have:
NF TX = NF BTS
where NF BTS is the BTS noise figure.
Atoll calculates total UL losses as follows:
UL
UL
UL
L Total – UL = L Misc + L Feeder + L BTS – Conf – G TMA
where,
UL
L Misc are the miscellaneous reception losses (Transmitter property),
UL
UL
UL
UL
UL
L Feeder are the feeder reception losses ( L Feeder = L Feeder  I Feeder + L Connector , where L Feeder , I Feeder and
UL
L Connector are respectively the feeder loss per metre (Feeder property), the reception feeder length in metre (Transmitter
property) and the connector reception losses,
UL
L BTS – Conf are the losses due to BTS configuration (BTS property),
G TMA is the gain due to TMA, which is calculated as follows:
WithoutTMA
WithTMA
G TMA = NF Composite – NF Composite
where,
WithTMA
WithoutTMA
NF Composite and NF Composite
are the composite noise figures with and without TMA respectively.
Friis' equation is used to calculate the composite noise figure when there is a TMA.
WithTMA
NF Composite
NF Feeder
NF BTS
 NF

-------------------------------------------TMA
 ------------------
10
10
10
10
10
–1
–1


-----------------------------------------------+ ----------------------------------+
= 10  Log 10
UL
UL
UL

G TMA
G TMA
G Feeder

----------------------------------------------------
10
10
10 

10
10
 10
WithoutTMA
And, NF Composite
= NF BTS + NF Feeder
where,
NF Feeder is the feeder noise figure,
NF TMA is the TMA noise figure,
NF BTS is the BTS noise figure,
UL
G TMA is the TMA reception gain,
UL
UL
UL
G Feeder is the feeder UL gain; G Feeder = – L Feeder .
UL
UL
UL
UL
UL
UL
L Feeder is the feeder reception loss ( L Feeder = L Feeder  I Feeder + L Connector , where L Feeder , I Feeder and L Connector
are respectively the feeder loss per metre, the reception feeder length in metre and the connector reception loss),
Atoll calculates total DL losses as follows.
DL
DL
DL
DL
L total – DL = L TMA + L Feeder + L Misc + L BTS – Conf
where,
DL
L TMA is the TMA transmission loss,
DL
DL
DL
DL
DL
L Feeder is the feeder transmission loss ( L Feeder = L Feeder  I Feeder + L Connector , where L Feeder , I Feeder and
DL
L Connector are respectively the feeder loss per metre, the transmission feeder length in metre and the connector transmission losses),
DL
L Misc are the miscellaneous transmission losses,
DL
L BTS – Conf are the losses due to BTS configuration (BTS property).
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4.8.2
Secondary Antennas
When secondary antennas are installed on a transmitter, the signal level received from it is calculated as follows:



 G ant – m Tx

G ant – i 
X i  -----------------------Tx 
 P Tx   1 –
P Tx  X i  ----------------------
L Tx



L Tx
i
 -----------------------------------------------------------------------+
---------------------------------------------
L ant – m  az m el m 

L ant – i  az i el i  
Tx
Tx
i


= ------------------------------------------------------------------------------------------------------------------------------------------- (not in dB2)
L model

P rec

Where,
PTx is the transmitter power (Ppilot in UMTS HSPA and CDMA2000 1xRTT 1xEV-DO, PP-CCPCH in TD-SCDMA, PPreamble
in WiMAX 802.16d and WiMAX 802.16e, and PDLRS in LTE),
i is the secondary antenna index,
xi is the percentage of power dedicated to the secondary antenna, i,
G ant – m
Tx
is the gain of the main antenna installed on the transmitter,
LTx are transmitter losses (LTx=Ltotal-DL),
G ant – i
Tx
is the gain of the secondary antenna, i, installed on the transmitter,
Lmodel is the path loss calculated by the propagation model,
L ant – m  az m el m  is the attenuation due to main antenna pattern,
Tx
L ant – i  az i el i  is the attenuation due to pattern of the secondary antenna, i.
Tx
The definition of angles, az and el, depends on the used calculation method.
•
•
2.
132
Method 1 (must be indicated in an Atoll.ini file):
- azm: the difference between the receiver antenna azimuth and azimuth of the transmitter main antenna,
- elm: the difference between the receiver antenna tilt and tilt of the transmitter main antenna,
- azi : the difference between the receiver antenna azimuth and azimuth of the transmitter secondary antenna, i,
- eli : the difference between the receiver antenna tilt and tilt of the transmitter secondary antenna, i,
Method 2 (default):
- azm : the receiver azimuth in the coordinate system of the transmitter main antenna,
- elm : the receiver tilt in the coordinate system of the transmitter main antenna,
- azi : the receiver azimuth in the coordinate system of the transmitter secondary antenna, i,
- eli : the receiver tilt in the coordinate system of the transmitter secondary antenna, i.
Formula cannot be directly calculated from components stated in dB and must be converted in linear values.
AT281_TRG_E1
© Forsk 2009
Chapter 5
GSM/GPRS/EDGE Networks
This chapter provides descriptions of all the algorithms for calculations, analyses, automatic allocations and
prediction studies available in GSM GPRS EDGE projects.
Atoll
RF Planning & Optimisation Software
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5
GSM GPRS EDGE Networks
5.1
General Prediction Studies
5.1.1
Calculation Criteria
Three criteria can be studied in point analysis (Profile tab) and in general coverage studies. Study criteria are detailed in
the table below.
Study criteria
Formulas
Signal level received from a transmitter on a TRX type
Txi
Signal level ( P rec )
Txi
Txi
P rec  tt  = EIRP  tt  – P  tt  – L path – M Shadowing – model – L Indoor +  G ant
Rx
– L Rx 
Txi
Txi
L path = L model + L ant
Path loss ( L path )
Txi
Txi
Tx
Txi
L total =  L path + M Shadowing – model + L Indoor + L Tx + L Rx  –  G ant
Total losses ( L total )
Tx
+ G ant 
Rx
where,
EIRP is the effective isotropic radiated power of the transmitter,
L model is the loss on the transmitter-receiver path (path loss) calculated by the propagation model,
L ant
Tx
is the transmitter antenna attenuation (from antenna patterns),
M Shadowing – model is the shadowing margin. This parameter is taken into account when the option “Shadowing taken into
account” is selected,
L Indoor are the indoor losses, taken into account when the option “Indoor coverage” is selected,
L Rx are the receiver losses,
G ant
Rx
is the receiver antenna gain,
P is the power offset defined for the selected TRX type in the transmitter property dialog,
tt is the TRX type (in the GSM GPRS EGPRS.mdb document template, there are three possible TRX types, BCCH, TCH
and inner TCH).
5.1.2
Point Analysis
5.1.2.1
Profile Tab
Txi
Atoll displays the signal level received from the selected transmitter on a TRX type ( P rec  tt  ).
Notes:
•
If power offsets of subcells are identical, field level received from a selected transmitter will
be the same for all the studied TRX types.
•
For a selected transmitter, it is also possible to study the path loss, L path , or the total
Txi
Txi
losses, L total . Path loss and total losses are the same on any TRX type.
5.1.2.2
Reception Tab
Analysis provided in the Reception tab is based on path loss matrices. So, you can study reception from TBC transmitters
for which path loss matrices have been computed on their calculation areas.
Txi
For each transmitter, Atoll displays the signal level received on a TRX type, ( P rec  tt  ).
Reception bars are displayed in a decreasing signal level order. The maximum number of reception bars depends on the
signal level received from the best server. Only reception bars of transmitters whose signal level is within a 30 dB margin
from the best server can be displayed.
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Notes:
•
If power offsets of subcells are identical, field level received from a given transmitter will be
the same whichever the studied TRX type.
•
It is also possible to study the path loss, L path , or the total losses, L total of each
•
You can use a value other than 30 dB for the margin from the best server signal level, for
example a smaller value for improving the calculation speed. For more information on
defining a different value for this margin, see the Administrator Manual.
Txi
Txi
transmitter. Path loss and total losses are the same on any TRX type.
5.1.3
Coverage Studies
For each TBC transmitter, Txi, Atoll determines the selected criterion on each bin inside the Txi calculation area. In fact,
each bin within the Txi calculation area is considered as a potential (fixed or mobile) receiver.
Coverage study parameters to be set are:
•
•
5.1.3.1
The study conditions in order to determine the service area of each TBC transmitter,
The display settings to select how to colour service areas.
Service Area Determination
Atoll uses parameters entered in the Condition tab of the coverage study property dialog to predetermine areas where it
will display coverage.
We can distinguish seven cases as below. Let us assume that:
•
•
5.1.3.1.1
Each transmitter, Txi, belongs to a Hierarchical Cell Structure (HCS) layer, k, with a defined priority and a defined
reception threshold.
The maximum range option (available in the System tab of the Predictions property dialog) is inactive.
All Servers
For each HCS layer, k, the service area of Txi corresponds to the bins where:
Txi
Txi
MinimumThreshold  P rec  tt   or L tot orTotal – Losses
Txi
  MaximumThreshold
Note:
•
5.1.3.1.2
The minimum threshold is either globally defined or specifically for each subcell (subcell
reception threshold)
Best Signal Level and a Margin
The service area of Txi corresponds to the bins where:
Txi
Txi
Txi
MinimumThreshold  P rec  ic   or L total or L path   MaximumThreshold
And
Txi
Txj
P rec  ic   Best  P rec  ic   – M
ji
M is the specified margin (dB).
Best function: considers the highest value.
Notes:
•
If the margin equals 0 dB, Atoll will consider bins where the signal level received from Txi is
the highest.
•
If the margin is set to 2 dB, Atoll will consider bins where the signal level received from Txi
is either the highest or 2dB lower than the highest.
•
If the margin is set to -2 dB, Atoll will consider bins where the signal level received from Txi
is 2dB higher than the signal levels from transmitters, which are 2nd best servers.
5.1.3.1.3
Second Best Signal Level and a Margin
The service area of Txi corresponds to the bins where:
Txi
Txi
Txi
MinimumThreshold  P rec  ic   or L total or L path   MaximumThreshold
And
Txi
P rec  ic   2
136
nd
Best  P Txj  ic   – M
rec
ji
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Chapter 5: GSM GPRS EDGE Networks
M is the specified margin (dB).
2nd Best function: considers the second highest value.
Notes:
•
If the margin equals 0 dB, Atoll will consider bins where the signal level received from Txi is
the second highest.
•
If the margin is set to 2 dB, Atoll will consider bins where the signal level received from Txi
is either the second highest or 2dB lower than the second highest.
•
If the margin is set to -2 dB, Atoll will consider bins where the signal level received from Txi
is 2dB higher than the signal levels from transmitters, which are 3rd best servers.
5.1.3.1.4
Best Signal Level per HCS Layer and a Margin
For each HCS layer, k, the service area of Txi corresponds to the bins where:
Txi
Txi
MinimumThreshold  P rec  tt   or L tot orTotal – Losses
Txi
  MaximumThreshold
And
Txi
Txj
P rec  BCCH   Best  P rec  BCCH   – M
ji
M is the specified margin (dB).
Best function: considers the highest value.
Notes:
•
If the margin equals 0 dB, Atoll will consider bins where the signal level received from Txi is
the highest.
•
If the margin is set to 2 dB, Atoll will consider bins where the signal level received from Txi
is either the highest or 2dB lower than the highest.
•
If the margin is set to -2 dB, Atoll will consider bins where the signal level received from Txi
is 2dB higher than the signal levels from transmitters that are the 2nd best servers.
5.1.3.1.5
HCS Servers and a Margin
For each HCS layer, k, the service area of Txi corresponds to the bins where:
Txi
Txi
MinimumThreshold  P rec  tt   or L tot orTotal – Losses
Txi
  MaximumThreshold
And
Txi
Txj
P rec  BCCH   Best  P rec  BCCH   – M
ji
Txi
The received P rec  tt  exceeds the reception threshold defined per HCS layer
M is the specified margin (dB).
Best function: considers the highest value.
Notes:
•
If the margin equals 0 dB, Atoll will consider bins where the signal level received from Txi is
the highest.
•
If the margin is set to 2 dB, Atoll will consider bins where the signal level received from Txi
is either the highest or 2dB lower than the highest.
•
If the margin is set to -2 dB, Atoll will consider bins where the signal level received from Txi
is 2dB higher than the signal levels from transmitters that are the 2nd best servers.
5.1.3.1.6
Highest Priority HCS Server and a Margin
In this case, the service area of Txi corresponds to the bins where:
Txi
Txi
MinimumThreshold  P rec  tt   or L tot orTotal – Losses
Txi
  MaximumThreshold
And
Txi
Txj
P rec  BCCH   Best  P rec  BCCH   – M
ji
And
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Txi belongs to the HCS layer with the highest priority. The highest priority is defined by the priority field (0: lowest) assumTxi
ing the received P rec  tt  exceeds the reception threshold defined per HCS layer.
M is the specified margin (dB).
Best function: considers the highest value.
Notes:
•
If the margin equals 0 dB, Atoll will consider bins where the signal level received from Txi is
the highest.
•
If the margin is set to 2 dB, Atoll will consider bins where the signal level received from Txi
is either the highest or 2dB lower than the highest.
•
If the margin is set to -2 dB, Atoll will consider bins where the signal level received from Txi
is 2dB higher than the signal levels from transmitters that are the 2nd best servers.
•
5.1.3.1.7
In the case two layers have the same priority, the traffic is served by the transmitter for
which the difference between the received signal strength and the HCS threshold is the
highest. The way the competition is managed between layers with the same priority can be
modified. For more information, see the Administrator Manual.
Second Best Signal Level per HCS Layer and a Margin
For each HCS layer, k, the service area of Txi corresponds to the bins where:
Txi
Txi
MinimumThreshold  P rec  tt   or L tot orTotal – Losses
Txi
  MaximumThreshold
And
Txi
P rec  BCCH   2
nd
Best  P Txj  BCCH   – M
rec
ji
M is the specified margin (dB).
2nd Best function: considers the second highest value.
Notes:
•
If the margin equals 0 dB, Atoll will consider bins where the signal level received from Txi is
the second highest.
•
If the margin is set to 2 dB, Atoll will consider bins where the signal level received from Txi
is either the second highest or 2dB lower than the second highest.
•
If the margin is set to -2 dB, Atoll will consider bins where the signal level received from Txi
is 2dB higher than the signal levels from transmitters that are the 3rd best servers.
5.1.3.1.8
Best Idle Mode Reselection Criterion (C2)
Such type of coverage would is useful :
•
•
To compare Idle and Dedicated mode best servers for Voice traffic
Display the GPRS/EDGE best server map (based on GSM idle mode)
The path loss criterion parameter C1 used for cell selection and reselection is defined by :
Txi
C1 = P rec  BCCH  – MinimumThreshold  BCCH 
The path loss criterion (GSM03.22) is satisfied if C1  0 .
The reselection criterion C2 is used for cell reselection only and is defined by :
C2 = C1 + CELL_RESELECT_OFFSET
where CELL_RESELECT_OFFSET is the Cell Reselect Offset (in dB) defined for at the transmitter level.
The service area of Txi corresponds to the bins where:
Txi
Txi
Txi
MinimumThreshold  P rec  BCCH   or L total or L path   MaximumThreshold
And
C2
Txi
Txj
 BCCH  = Best  C2  BCCH  
j
Best function: considers the highest value.
On each bin, the best C2 value is kept. It corresponds to the best server in Idle Mode. Since the C2 value is an integer
value, so must be rounded.
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5.1.3.2
Coverage Display
5.1.3.2.1
Plot Resolution
Prediction plot resolution is independent of the matrix resolutions and can be defined on a per study basis. Prediction plots
are generated from multi-resolution path loss matrices using bilinear interpolation method (similar to the one used to evaluate site altitude).
5.1.3.2.2
Display Types
It is possible to display the transmitter service area with colours depending on any transmitter attribute or other criteria
such as:
Signal Level (in dBm, dBµV, dBµV/m)
Atoll calculates signal level received from the transmitter on each bin of each transmitter service area. A bin of a service
area is coloured if the signal level exceeds (  ) the defined minimum thresholds (bin colour depends on signal level).
Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many
layers as transmitter service areas. Each layer shows the different signal levels available in the transmitter service area.
Best Signal Level (in dBm, dBµV, dBµV/m)
Atoll calculates signal levels received from transmitters on each bin of each transmitter service area. When other serviceWhen other service areas overlap the studied one, Atoll chooses the highest value. A bin of a service area is coloured if
the signal level exceeds (  ) the defined thresholds (the bin colour depends on the signal level). Coverage consists of
several independent layers whose visibility in the workspace can be managed. There are as many layers as defined
thresholds. Each layer corresponds to an area where the signal level from the best server exceeds a defined minimum
threshold.
Path Loss (dB)
Atoll calculates path loss from the transmitter on each bin of each transmitter service area. A bin of a service area is
coloured if path loss exceeds (  ) the defined minimum thresholds (bin colour depends on path loss). Coverage consists
of several independent layers whose visibility in the workspace can be managed. There are as many layers as service
areas. Each layer shows the different path loss levels in the transmitter service area.
Total Losses (dB)
Atoll calculates total losses from the transmitter on each bin of each transmitter service area. A bin of a service area is
coloured if total losses exceed (  ) the defined minimum thresholds (bin colour depends on total losses). Coverage
consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as
service areas. Each layer shows the different total losses levels in the transmitter service area.
Best Server Path Loss (dB)
Atoll calculates signal levels received from transmitters on each bin of each transmitter service area. When other service
areas overlap the studied one, Atoll determines the best transmitter and evaluates path loss from the best transmitter. A
bin of a service area is coloured if the path loss exceeds (  ) the defined thresholds (bin colour depends on path loss).
Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many
layers as defined thresholds. Each layer corresponds to an area where the path loss from the best server exceeds a
defined minimum threshold.
Best Server Total Losses (dB)
Atoll calculates signal levels received from transmitters on each bin of each transmitter service area. Where service areas
overlap the studied one, Atoll determines the best transmitter and evaluates total losses from the best transmitter. A bin
of a service area is coloured if the total losses exceed (  ) the defined thresholds (bin colour depends on total losses).
Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many
layers as defined thresholds. Each layer corresponds to an area where the total losses from the best server exceed a
defined minimum threshold.
Number of Servers
Atoll evaluates how many service areas cover a bin in order to determine the number of servers. The bin colour depends
on the number of servers. Coverage consists of several independent layers whose visibility in the workspace can be
managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the number of servers exceeds (  ) a defined minimum threshold.
Cell Edge Coverage Probability (%)
On each bin of each transmitter service area, the coverage corresponds to the pixels where the signal level from this transmitter fulfils signal conditions defined in Conditions tab with different cell edge coverage probabilities. There is one coverage area per transmitter in the explorer.
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Best Cell Edge Coverage Probability (%)
On each bin of each transmitter service area, the coverage corresponds to the pixels where the best signal level received
fulfils signal conditions defined in Conditions tab. There is one coverage area per cell edge coverage probability in the
explorer.
Best C2 (dBm)
Atoll calculates C2 values received from transmitters on each bin of each transmitter service area. When other service
areas overlap the studied one, Atoll chooses the highest value. A bin of a service area is coloured if the C2 value exceeds
(  ) the defined thresholds (the bin colour depends on the C2 value). Coverage consists of several independent layers
whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the best C2 value exceeds a defined minimum threshold.
5.2
Traffic Analysis
When starting a traffic analysis, Atoll distributes the traffic from maps to transmitters of each layer according to the compatibility criteria defined in the transmitter, services, mobility type, terminal type properties. Transmitters considered in traffic
analysis are the active and filtered transmitters that belong to the focus zone.
Notes:
•
If no focus zone exists in the .atl document, Atoll takes into account the computation zone.
•
For details of the average timeslot capacity calculation, see the Network Dimensioning
section (calculation of minimum reduction factor).
5.2.1
Traffic Distribution
5.2.1.1
Normal Cells (Nonconcentric, No HCS Layer)
5.2.1.1.1
Circuit Switched Services
A user with a given circuit switched service, c, a terminal, t, and a mobility type, m, will be distributed to the BCCH and
TCH subcells of a transmitter if:
•
•
5.2.1.1.2
The terminal, t, works on the frequency band used by the BCCH subcell,
The terminal, t, works on the frequency band used by the TCH subcell.
Packet Switched Services
A user with a given packet switched service, p, a terminal, t, and a mobility type, m, will be distributed to the BCCH and
TCH subcells of a transmitter if:
•
•
•
•
5.2.1.2
The transmitter is an GPRS/EDGE station (option specified in the transmitter property dialog),
The terminal, t, is technologically compatible with the transmitter,
The terminal, t, works on the frequency band used by the BCCH subcell,
The terminal, t, works on the frequency band used by the TCH subcell.
Concentric Cells
In case of concentric cells, TCH_INNER TRX type has the highest priority to carry traffic.
5.2.1.2.1
Circuit Switched Services
A user with a given circuit switched service, c, a terminal, t, and a mobility type, m, will be distributed to the TCH_INNER,
BCCH and TCH subcells of a transmitter if:
•
•
5.2.1.2.2
The terminal, t, works on the frequency band used by the BCCH subcell,
The terminal, t, works on the frequency band(s) used by the TCH_INNER and TCH subcells.
Packet Switched Services
A user with a given packet switched service, p, a terminal, t, and a mobility type, m, will be distributed to the TCH_INNER,
BCCH and TCH subcells of a transmitter if:
•
•
•
•
5.2.1.3
The transmitter is an GPRS/EDGE station (option specified in the transmitter property dialog),
The terminal, t, is technologically compatible with the transmitter,
The terminal, t, works on the frequency band used by the BCCH subcell,
The terminal, t, works on the frequency band(s) used by the TCH_INNER and TCH subcells.
HCS Layers
For each HCS layer, k, you may specify the maximum mobile speed supported by the transmitters of the layer.
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5.2.1.3.1
Circuit Switched Services
A user with a given circuit switched service, c, a terminal, t, and a mobility type, m, will be distributed to the BCCH and
TCH subcells (and TCH_INNER in case of concentric cells) of a transmitter if:
•
•
•
5.2.1.3.2
The terminal, t, works on the frequency band used by the BCCH subcell,
The terminal, t, works on the frequency band(s) used by the TCH_INNER and TCH subcells,
The user’s mobility, m, is less than the maximum speed supported by the layer, k.
Packet Switched Services
A user with a given packet switched service, p, a terminal, t, and a mobility type, m, will be distributed to the BCCH and
TCH subcells (and TCH_INNER in case of concentric cells) of a transmitter if:
•
•
•
•
•
5.2.2
The transmitter is an GPRS/EDGE station (option specified in the transmitter property dialog),
The terminal, t, is technologically compatible with the transmitter,
The terminal, t, works on the frequency band used by the BCCH subcell,
The terminal, t, works on the frequency band(s) used by the TCH_INNER and TCH subcells,
The user mobility, m, is less than the maximum speed supported by the layer, k.
Calculation of the Traffic Demand per Subcell
Here we assume that:
•
•
•
Users considered for evaluating the traffic demand fulfil the compatibility criteria defined in the transmitter, services, mobility, terminal properties as explained above.
Atoll distributes traffic on subcell service areas, which are determined using the option “Best signal level per HCS
layer” with a 0dB margin and the subcell reception threshold as lower threshold.
Same traffic is distributed to the BCCH and TCH subcells.
5.2.2.1
User Profile Traffic Maps
5.2.2.1.1
Normal Cells (Nonconcentric, No HCS Layer)
Number of subscribers ( X up m ) for each TCH subcell (Txi, TCH), per user profile up with a given mobility m, is inferred as:
X up m  Txi TCH  = S up m  Txi TCH   D
Where Sup,m is the TCH service area containing the user profile up with the mobility m and D is the user profile density.
For each behaviour described in the user profile up, Atoll calculates the probability for the user to be connected with a
given service using a terminal t.
Circuit Switched Services
For a circuit switched service c, we have:
N call  d
p up  c t  = --------------------3600
Where Ncall is the number of calls per hour and d is the average call duration (in seconds).
Then, Atoll evaluates the traffic demand, D up  c t  m , in Erlangs for the subcell (Txi, TCH) service area.
D up  c t  m  Txi TCH  = X up m  Txi TCH   p up  c t 
Packet Switched Services
For a packet switched service p, we have:
N call  V  8
p up  p t  = ------------------------------3600
Where Ncall is the number of calls per hour and V is the transmitted data volume per call (in Kbytes).
Then, Atoll evaluates the traffic demand, D up  p t  m , in kbits/s for the subcell (Txi, TCH) service area.
D up  p t  m  Txi TCH  = X up m  Txi TCH   p up  p t 
5.2.2.1.2
Concentric Cells
In case of concentric cells, Atoll distributes a part of traffic on the TCH_INNER service area (TCH_INNER is the highest
priority traffic carrier) and the remaining traffic on the outer ring served by the TCH subcell. The traffic spread over the
TCH_INNER subcell may overflow to the TCH subcell. In this case, the traffic demand is the same on the TCH_INNER
subcell but increases on the TCH subcell.
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Note:
•
Traffic overflowing from the TCH_INNER to the TCH is not uniformly spread over the TCH
service area. It is still located on the TCH_INNER service area.
Number of subscribers ( X up m ) for each TCH_INNER (Txi, TCH_INNER) and TCH (Txi, TCH) subcell, per user profile up
with a given mobility m, is inferred as:
X up m  Txi,TCH_INNER  = S up m  Txi,TCH_INNER   D
X up m  Txi,TCH  =  S up m  Txi,TCH  – S up m  Txi,TCH_INNER    D
S up m  Txi,TCH_INNER  and S up m  Txi,TCH  respectively refer to the TCH_INNER and TCH subcell service areas
containing the user profile up with the mobility m. D is the user profile density.
Figure 5.1: Representation of a Concentric Cell TXi
Circuit Switched Services
For each user of the user profile up using a circuit switched service c with a terminal t, Atoll calculates the probability
( p up  c t  ) of the user being connected. Calculations are detailed in "Circuit Switched Services" on page 140.
Then, Atoll evaluates the traffic demand, D up  c t  m , in Erlangs in the (Txi, TCH_INNER) and (Txi, TCH) subcell service
areas.
D up  c t  m  Txi,TCH_INNER  = X up m  Txi,TCH_INNER   p up  c t 
D up  c t  m  Txi,TCH  = X up m  Txi,TCH   p up  c t  + D up  c t  m  Txi,TCH_INNER   O max  Txi,TCH_INNER 
Where O max  Txi,TCH_INNER  is the maximum rate of traffic overflow (in %) specified for the TCH_INNER subcell.
Packet Switched Services
For each user of the user profile up using a packet switched service p with a terminal t, probability of the user being
connected ( p up  p t  ) is calculated as explained in "Packet Switched Services" on page 140.
Atoll evaluates the traffic demand, D up  p t  m , in kbits/s in the (Txi, TCH_INNER) and (Txi, TCH) subcell service areas.
D up  p t  m  Txi,TCH_INNER  = X up m  Txi,TCH_INNER   p up  p t 
D up  p t  m  Txi,TCH  = X up m  Txi,TCH   p up  p t  + D up  p t  m  Txi,TCH_INNER   O max  Txi,TCH_INNER 
Where O max  Txi,TCH_INNER  is the maximum rate of traffic overflow (in %) specified for the TCH_INNER subcell.
5.2.2.1.3
HCS Layers
We assume two HCS layers: the micro layer has a higher priority than the macro layer. Txi belongs to the micro layer and
Txj to the macro. The traffic contained in the input traffic map can be assigned to all the HCS layers.
Normal Cells
Atoll distributes traffic on the TCH service areas. The traffic capture is calculated with the option “Best signal level per HCS
macro
layer” meaning that there is an overlap between HCS layers service areas. Let S overlapping  Txj TCH  denote this area
(TCH service area of the macro layer overlapped by the TCH service area of the micro layer). Traffic on the overlapping
area is distributed to the TCH subcell of the micro layer because it has a higher priority. On this area, traffic of the micro
layer may overflow to the macro layer. In this case, the traffic demand is the same on the TCH subcell of the micro layer
but increases on the TCH subcell of the macro layer.
Note:
•
142
Traffic overflowing to the macro layer is not uniformly spread over the TCH service area of
Txj. It is only located on the overlapping area.
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Figure 5.2: Representation of Micro and Macro Layers
Atoll evaluates the traffic demand on the micro layer (higher priority) as explained above. For further details, please refer
to formulas for normal cells. Then, it proceeds with the macro layer (lower priority).
macro
Number of subscribers ( X up m ) for each TCH subcell (Txj, TCH) of the macro layer, per user profile up with the mobility
m, is inferred as:
macro
macro
macro
X up m  Txj TCH  =  S up m  Txj TCH  – S up m – overlapping  Txj TCH    D
macro
Where S up m  Txj TCH  is the TCH service area of Txj containing the user profile up with the mobility m and D is the
profile density.
For each user described in the user profile up with the circuit switched service c and the terminal t, the probability for the
user being connected ( p up  c t  ) is calculated as explained in "Circuit Switched Services" on page 140.
macro
Then, Atoll evaluates the traffic demand, D up  c t  m , in Erlangs in the subcell (Txj, TCH) service area.
macro
S upm – overlapping  Txj TCH 
macro
macro
micro
-  Omax Txi TCH 
D up  c t m  Txj TCH  = X up m Txj TCH   p up  c t  + D up  c t m Txi TCH   --------------------------------------------------------------------------micro
S up m  Txi TCH 
For each user described in the user profile up with the packet switched service p and the terminal t, probability for the user
to be connected ( p up  p t  ) is calculated as explained in "Packet Switched Services" on page 140.
macro
Then, Atoll evaluates the traffic demand, D up  p t  m , in kbits/s in the subcell (Txj, TCH) service area.
macro
S upm – overlapping  Txj TCH 
macro
macro
micro
-  Omax Txi TCH 
D up  p t m  Txj TCH  = X up m Txj TCH   p up  p t  + D up  p t m Txi TCH   --------------------------------------------------------------------------micro
S up m  Txi TCH 
Where O max  Txi TCH  is the maximum rate of traffic overflow (stated in %) specified for the TCH subcell of Txi (micro
micro
layer) and S up m  Txi TCH  is the TCH service area of Txi containing the user profile up with the mobility m.
Concentric Cells
Atoll evaluates the traffic demand on the micro layer (higher priority HCS layer) as explained above. For further details,
please refer to formulas given in case of concentric cells. Then, it proceeds with the macro layer (lower priority HCS layer).
The traffic capture is calculated with the option “Best signal level per HCS layer”. It means that there are overlapping areas
between HCS layers where traffic is spread according to the layer priority. On these areas, traffic of the higher priority layer
may overflow.
The TCH_INNER service area of the macro layer is overlapped by the micro layer. This area consists of two parts: an area
macro
overlapped by the TCH service area of the micro layer S overlapping –  Txi TCH   Txj,TCH_INNER  and another overlapped
macro
by the TCH_INNER service area of the micro layer S overlapping –  Txi,TCH_INNER   Txj,TCH_INNER  .
Let us consider three areas, S1, S2 and S3.
macro
macro
S 1 = S up m  Txj,TCH_INNER  – S up m – overlapping –  Txi TCH   Txj,TCH_INNER 
macro
S 2 = S up m – overlapping –  Txi,TCH_INNER   Txj,TCH_INNER 
macro
S 3 = S up m – overlapping –  Txi TCH   Txj,TCH_INNER  – S 2
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Figure 5.3: Concentric Cells
macro
Where S up m  Txj,TCH_INNER  is the TCH_INNER subcell service area of Txj containing the user profile up with the
mobility m. We only consider the overlapping areas containing the user profile up with the mobility m.
macro
On S1, the number of subscribers per user profile up with a given mobility m ( X up m ) is inferred:
macro
X up m  Txj,TCH_INNER  = S 1  D
Where D is the user profile density.
The traffic spread over the TCH_INNER service area of the micro layer may overflow on the TCH subcell. The traffic overflowing to the TCH subcell is located on the TCH_INNER service area. On S2, the TCH subcell traffic coming from the
TCH_INNER subcell traffic overflow may overflow proportional to R2.
S2
R 2 = ----------------------------------------------------------------micro
S up m  Txi,TCH_INNER 
The traffic spread over the ring served by the TCH subcell of the micro layer only may overflow on S3 proportional to R3.
S3
R 3 = ------------------------------------------------------------------------------------------------------------------micro
micro
S up m  Txi,TCH  – S up m  Txi,TCH_INNER 
micro
micro
Where S up m  Txi,TCH  and S up m  Txi,TCH_INNER  are the TCH and TCH_INNER service areas of Txi respectively
containing the user profile up with the mobility m.
For each user described in the user profile up with a circuit switched service c and a terminal t, the probability for the user
being connected ( p up  c t  ) is calculated as explained in "Circuit Switched Services" on page 140. Then, Atoll evaluates
macro
the traffic demand, D up  c t  m , in Erlangs in the subcell (Txj, TCH_INNER) service area.
macro
macro
D up  c t  m  Txj,TCH_INNER 
X up m  Txj,TCH_INNER   p up  c t  +
= R  D micro
2
up  c t  m  Txi,TCH_INNER   O max  Txi,TCH_INNER   O max  Txi,TCH  +
micro
R 3  X up m  Txi TCH   p up  c t   O max  Txi TCH 
For each user described in the user profile up with a packet switched service p and a terminal t, probability for the user to
be connected ( p up  p t  ) is calculated as explained in "Packet Switched Services" on page 140.
macro
Then, Atoll evaluates the traffic demand, D up  p t  m , stated in kbits/s in the subcell (Txj, TCH_INNER) service area.
macro
macro
X up m  Txj,TCH_INNER   p up  p t  +
D up  p t  m  Txj,TCH_INNER  = R  D micro
2
up  p t  m  Txi,TCH_INNER   O max  Txi,TCH_INNER   O max  Txi,TCH  +
micro
R 3  X up m  Txi TCH   p up  p t   O max  Txi TCH 
Where O max  Txi TCH  and O max  Txi,TCH_INNER  are the maximum rates of traffic overflow (stated in %) specified
for the TCH and TCH_INNER subcells of Txi respectively.
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The area of the TCH ring of the macro layer is overlapped by the micro layer. There are two parts: an area overlapped by
macro
the TCH service area of the micro layer S overlapping –  Txi TCH   Txj,TCH -- TCH_INNER  and another one by the
macro
TCH_INNER service area of the micro layer S overlapping –  Txi,TCH_INNER   Txj,TCH -- TCH_INNER  .
Let us consider three areas, S’1, S’2 and S’3.
macro
macro
macro
S' 1 = S up m  Txj,TCH  – S up m  Txj,TCH_INNER  – S up m – overlapping –  Txi TCH   Txj,TCH -- TCH_INNER 
macro
S' 2 = S up m – overlapping –  Txi,TCH_INNER   Txj,TCH -- TCH_INNER 
macro
S' 3 = S up m – overlapping –  Txi TCH   Txj,TCH -- TCH_INNER  – S' 2
macro
macro
Where S up m  Txj,TCH  and S up m  Txj,TCH_INNER  are the TCH and TCH_INNER subcell service areas of Txj
respectively. We only consider the overlapping areas containing the user profile up with the mobility m.
macro
On S’1, the number of subscribers per user profile up with a given mobility m ( X up m ) is inferred:
macro
X up m  Txj,TCH  = S' 1  D
Where D is the user profile density.
The traffic spread over the TCH_INNER service area of the micro layer may overflow on the TCH subcell. The traffic overflowing on the TCH subcell is located on the TCH_INNER service area. On S’2, the TCH subcell traffic coming from the
TCH_INNER subcell traffic overflow may overflow proportionally to R’2.
S' 2
R' 2 = ----------------------------------------------------------------micro
S up m  Txi,TCH_INNER 
The traffic spread over the ring served by the TCH subcell of the micro layer only may overflow on S’3 proportional to R’3.
S' 3
R' 3 = ------------------------------------------------------------------------------------------------------------------micro
micro
S up m  Txi,TCH  – S up m  Txi,TCH_INNER 
micro
micro
Where S up m  Txi,TCH  and S up m  Txi,TCH_INNER  are the TCH and TCH_INNER service areas of Txi respectively
containing the user profile up with the mobility m.
For each user described in the user profile up with a circuit switched service c and a terminal t, the probability for the user
being connected ( p up  c t  ) is calculated as explained in "Circuit Switched Services" on page 140.
macro
Then, Atoll evaluates the traffic demand, D up  c t  m , in Erlangs in the subcell (Txj, TCH) service area.
macro
X up m  Txj TCH   p up  c t  +
macro
D up  c t  m  Txj TCH  =
macro
D up  c t  m  Txj,TCH_INNER   O max  Txj,TCH_INNER  +
micro
R' 2  D up  c t  m  Txi,TCH_INNER   O max  Txi,TCH_INNER   O max  Txi,TCH  +
micro
R' 3  X up m  Txi TCH   p up  c t  m  O max  Txi TCH 
For each user described in the user profile up with a packet switched service p and a terminal t, the probability for the user
being connected ( p up  p t  ) is calculated as explained in "Packet Switched Services" on page 140.
macro
Then, Atoll evaluates the traffic demand, D up  p t  m , in kbits/s in the subcell (Txj, TCH) service area.
macro
X up m  Txj TCH   p up  p t  +
macro
D up  p t  m  Txj TCH  =
macro
D up  p t  m  Txj,TCH_INNER   O max  Txj,TCH_INNER  +
micro
R' 2  D up  p t  m  Txi,TCH_INNER   O max  Txi,TCH_INNER   O max  Txi,TCH  +
micro
R' 3  X up m  Txi TCH   p up  p t  m  O max  Txi TCH 
Where O max  Txi,TCH  is the maximum rate of traffic overflow (stated in %) specified for the TCH subcell of Txi (micro
layer), O max  Txi,TCH_INNER  the maximum rate of traffic overflow indicated for the TCH_INNER subcell of Txi (macro
layer), O max  Txj,TCH_INNER  the maximum rate of traffic overflow indicated for the TCH_INNER subcell of Txj (macro
micro
layer) and X up m  Txi TCH  the number of subscribers with the user profile up and mobility m on the TCH service area
of Txi (as explained in "Concentric Cells" on page 140).
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5.2.2.2
Sector Traffic Maps
We assume that the traffic map is built from a coverage by transmitter prediction study calculated for the TCH subcells
with options:
•
•
“HCS Servers” and no margin if the network only consists of normal cells and concentric cells,
“Highest Priority HCS Server” and no margin in case of HCS layers.
When creating the traffic map, you have to specify the traffic demand per transmitter and per service (throughput for a
packet switched service and Erlangs for a circuit switched service) and the global distribution of terminals and mobility
types.
Let E c  Txi TCH  denote the Erlangs for the circuit switched service, c, on the TCH subcell of Txi.
Let T p  Txi TCH  denote the throughput of the packet switched service, p, on the TCH subcell of Txi.
We assume that 100% of users have the terminal, t, and the mobility type, m.
5.2.2.2.1
Normal Cells (Nonconcentric, No HCS Layer)
For each circuit switched service, c, Atoll evaluates the traffic demand, Dc,t,m, in Erlangs in the subcell (Txi, TCH) service
area.
D c t m  Txi TCH  = E c  Txi TCH 
For each packet switched service, p, Atoll evaluates the traffic demand, Dp,t,m, in kbits/s in the subcell (Txi, TCH) service
area.
D p t m  Txi TCH  = T p  Txi TCH 
5.2.2.2.2
Concentric Cells
In case of concentric cells, Atoll distributes a part of traffic on the TCH_INNER service area (TCH_INNER is the highest
priority traffic carrier) and the remaining traffic, on the ring served by the TCH subcell only. The traffic spread over the
TCH_INNER subcell may overflow to the TCH subcell. In this case, the traffic demand is the same on the TCH_INNER
subcell and rises on the TCH subcell.
Note:
•
Traffic overflowing from the TCH_INNER to the TCH is not uniformly spread over the TCH
service area. It is only located on the TCH_INNER service area.
For each circuit switched service, c, Atoll evaluates the traffic demand, Dc,t,m, in Erlangs in the subcell, (Txi, TCH_INNER)
and (Txi, TCH), service areas.
S  Txi,TCH_INNER 
D c t m  Txi,TCH_INNER  = -----------------------------------------------------  E c  Txi TCH 
S  Txi TCH 
and
D c t m  Txi,TCH  =
 S  Txi,TCH  – S  Txi,TCH_INNER  
-----------------------------------------------------------------------------------------------  E c  Txi TCH  +
S  Txi TCH 
D c t m  Txi,TCH_INNER   O max  Txi,TCH_INNER 
For each packet switched service, p, Atoll evaluates the traffic demand, Dp,t,m, in kbits/s in the subcell, (Txi, TCH_INNER)
and (Txi, TCH), service areas.
S  Txi,TCH_INNER 
D p t m  Txi,TCH_INNER  = -----------------------------------------------------  T p  Txi TCH 
S  Txi TCH 
and
D p t m  Txi,TCH  =
 S  Txi,TCH  – S  Txi,TCH_INNER  
-----------------------------------------------------------------------------------------------  T p  Txi TCH  +
S  Txi TCH 
D p t m  Txi,TCH_INNER   O max  Txi,TCH_INNER 
Where O max  Txi,TCH_INNER  is the maximum rate of traffic overflow (stated in %) specified for the TCH_INNER subcell,
S  Txi,TCH  and S  Txi,TCH_INNER  are the TCH and TCH_INNER service areas of Txi respectively.
5.2.2.2.3
HCS Layers
We assume we have two HCS layers: the micro layer has a higher priority and the macro layer has a lower one. Txi belongs
to the micro layer and Txj to the macro one. The traffic contained in the input traffic map can be assigned to all the HCS
layers.
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Normal Cells
Atoll distributes traffic on the TCH service areas. The traffic capture is calculated with the option “HCS Servers”. It means
macro
that there is an overlapping area between HCS layers. Let S overlapping  Txj TCH  denote the TCH service area of the
macro layer overlapped by the TCH service area of the micro layer. Traffic on the overlapping area is distributed to the
TCH subcell of the micro layer (higher priority layer). On this area, traffic of the micro layer may overflow to the macro layer.
In this case, the traffic demand is the same on the TCH subcell of the micro layer but rises on the TCH subcell of the macro
layer.
Note:
•
Traffic overflowing on the macro layer is not uniformly spread over the TCH service area of
Txj. It is only located on the overlapping area.
Atoll starts evaluating the traffic demand on the micro layer (highest priority HCS layer).
micro
For each circuit switched service, c, Atoll calculates the traffic demand, D c t m , in Erlangs in the subcell (Txi, TCH) service
area.
micro
D c t m  Txi TCH  = E c  Txi TCH 
micro
For each packet switched service, p, Atoll calculates the traffic demand, D p t m , in kbits/s in the subcell (Txi, TCH) service
area.
micro
D p t m  Txi TCH  = T p  Txi TCH 
Then, Atoll proceeds with the macro layer (lower priority HCS layer). For each circuit switched service, c, Atoll calculates
macro
the traffic demand, D c t m , in Erlangs in the subcell (Txj, TCH) service area.
macro
S overlapping  Txj TCH 
macro
micro
-  O max  Txi TCH 
D c t m  Txj TCH  = E c  Txj TCH  + D c t m  Txi TCH   -----------------------------------------------------------micro
S
 Txi TCH 
macro
For each packet switched service, p, Atoll calculates the traffic demand, D p t m , in kbits/s in the subcell (Txj, TCH) service
area.
macro
S overlapping  Txj TCH 
macro
micro
-  O max  Txi TCH 
D p t m  Txj TCH  = T p  Txj TCH  + D p t m  Txi TCH   -----------------------------------------------------------micro
S
 Txi TCH 
Where O max  Txi TCH  is the maximum rate of traffic overflow (in %) specified for the TCH subcell of Txi (micro cell) and
S
micro
 Txi TCH  the TCH service area of Txi.
Note:
•
You can restrict the traffic assignement of each traffic map to a specific HCS layer in the
running options of the traffic capture. If you do so, no overflow occurs between HCS layers
and the only overflow which is considered occurs within concentric cells (See "Concentric
Cells" on page 140).
Concentric Cells
Atoll evaluates the traffic demand on the micro layer as explained above in case of concentric cells and then proceeds with
the macro layer (lower priority layer).
The traffic capture is calculated with the option “HCS Servers”. It means that there is overlapping areas between HCS
layers where traffic is spread over according to the layer priority. On these areas, traffic of the higher priority layer may
overflow.
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Figure 5.4: Concentric Cells
The TCH_INNER service area of the macro layer is overlapped by the micro layer. This area consists of two parts: an area
macro
overlapped by the TCH service area of the micro layer S overlapping –  Txi TCH   Txj,TCH_INNER  and another overlapped
macro
by the TCH_INNER service area of the micro layer S overlapping –  Txi,TCH_INNER   Txj,TCH_INNER  .
Let us consider three areas, S1, S2 and S3.
S1 = S
macro
macro
 Txj,TCH_INNER  – S overlapping –  Txi TCH   Txj,TCH_INNER 
macro
S 2 = S overlapping –  Txi,TCH_INNER   Txj,TCH_INNER 
macro
S 3 = S overlapping –  Txi TCH   Txj,TCH_INNER  – S 2
Where S
macro
 Txj,TCH_INNER  is the TCH_INNER subcell service area of Txj.
The traffic specified for Txj in the map description ( E c  Txj TCH  ) is spread over S1 proportionally to R1.
S1
R 1 = ------------------------------------------map
S
 Txj TCH 
map
S
 Txj TCH  is the TCH service area of Txj in the traffic map with the option “Best signal level of the highest priority
layer”.
The traffic spread over the TCH_INNER service area of the micro layer may overflow to the TCH subcell. The traffic overflowing to the TCH subcell is located on the TCH_INNER service area. On S2, the TCH subcell traffic coming from the
TCH_INNER subcell traffic overflow may overflow proportional to R2.
S2
R 2 = ----------------------------------------------------------------micro
S
 Txi,TCH_INNER 
The traffic spread over the ring only served by the TCH subcell of the micro layer may overflow on S3 proportional to R3.
S3
R 3 = ------------------------------------------------------------------------------------------------------------------micro
micro
S
 Txi,TCH  – S
 Txi,TCH_INNER 
macro
For each circuit switched service, c, Atoll calculates the traffic demand, D c t m , in Erlangs in the subcell (Txj,
TCH_INNER) service area.
R 1  E c  Txj TCH  +
macro
D c t m  Txj,TCH_INNER  =
micro
R 2  D c t m  Txi,TCH_INNER   O max  Txi,TCH_INNER   O max  Txi TCH  +
micro
micro
S
 Txi TCH  – S
 Txi,TCH_INNER  
-  E c  Txi TCH   O max  Txi TCH 
R 3  --------------------------------------------------------------------------------------------------------------------------micro
S
 Txi TCH 
macro
For each packet switched service, p, Atoll calculates the traffic demand, D p t m , in kbits/s in the subcell (Txj,
TCH_INNER) service area.
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R 1  T p  Txj TCH  +
macro
D p t m  Txj,TCH_INNER  =
micro
R 2  D p t m  Txi,TCH_INNER   O max  Txi,TCH_INNER   O max  Txi TCH  +
micro
micro
S
 Txi TCH  – S
 Txi,TCH_INNER  
-  T p  Txi TCH   O max  Txi TCH 
R 3  --------------------------------------------------------------------------------------------------------------------------micro
S
 Txi TCH 
Where O max  Txi TCH  is the maximum rate of traffic overflow (stated in %) specified for the TCH subcell of Txi,
O max  Txi,TCH_INNER  is the maximum rate of traffic overflow (stated in %) specified for the TCH_INNER subcell of Txi
and S
micro
 Txi TCH  is the TCH subcell service area of Txi.
The area of the TCH ring of the macro layer is overlapped by the micro layer. There are two parts: an area overlapped by
macro
the TCH service area of the micro layer S overlapping –  Txi TCH   Txj,TCH -- TCH_INNER  and another overlapped by the
macro
TCH_INNER service area of the micro layer S overlapping –  Txi,TCH_INNER   Txj,TCH -- TCH_INNER  .
Let us consider three areas, S’1, S’2 and S’3.
S' 1 = S
macro
 Txj TCH  – S
macro
macro
 Txj,TCH_INNER  – S overlapping –  Txi TCH   Txj,TCH -- TCH_INNER 
macro
S' 2 = S overlapping –  Txi,TCH_INNER   Txj,TCH -- TCH_INNER 
macro
S' 3 = S overlapping –  Txi TCH   Txj,TCH -- TCH_INNER  – S' 2
macro
Where S
respectively.
 Txj TCH  and S
macro
 Txj,TCH_INNER  are the TCH and TCH_INNER subcell service areas of Txj
The traffic specified for Txj in the map description ( E c  Txj TCH  ) is spread over S’1 proportional to R’1.
S' 1
R' 1 = ------------------------------------------map
S
 Txj TCH 
map
S
 Txj TCH  is the TCH service area of Txj in the traffic map with the option “Best signal level of the highest priority
layer”.
The traffic spread over the TCH_INNER service area of the micro layer may overflow to the TCH subcell. The traffic overflowing to the TCH subcell is located on the TCH_INNER service area. On S’2, the TCH subcell traffic coming from the
TCH_INNER subcell traffic overflow may overflow proportional to R’2.
S' 2
R' 2 = ----------------------------------------------------------------micro
S
 Txi,TCH_INNER 
The traffic spread over the ring only served by the TCH subcell of the micro layer may overflow on S’3 proportional to R’3.
S' 3
R' 3 = ------------------------------------------------------------------------------------------------------------------micro
micro
S
 Txi,TCH  – S
 Txi,TCH_INNER 
macro
For each circuit switched service, c, Atoll calculates the traffic demand, D c t m , in Erlangs in the subcell (Txj, TCH) service
area.
R' 1  E c  Txj TCH  +
macro
macro
D c t m  Txj
TCH  =
D c t m  Txj,TCH_INNER   O max  Txj,TCH_INNER  +
micro
R' 2  D c t m  Txi,TCH_INNER   O max  Txi,TCH_INNER   O max  Txi TCH  +
micro
micro
S
 Txi,TCH  – S
 Txi,TCH_INNER  
-  E c  Txi TCH   O max  Txi TCH 
R' 3  -----------------------------------------------------------------------------------------------------------------------micro
S
 Txi,TCH 
macro
For each packet switched service, p, Atoll calculates the traffic demand, D p t m , in kbits/s in the subcell (Txj, TCH) service
area.
R' 1  T p  Txj TCH  +
macro
macro
D p t m  Txj TCH  =
D c t m  Txj,TCH_INNER   O max  Txj,TCH_INNER  +
micro
R' 2  D p t m  Txi,TCH_INNER   O max  Txi,TCH_INNER   O max  Txi TCH  +
micro
micro
S
 Txi,TCH  – S
 Txi,TCH_INNER  
-  T p  Txi TCH   O max  Txi TCH 
R' 3  -----------------------------------------------------------------------------------------------------------------------micro
S
 Txi,TCH 
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Where O max  Txj,TCH_INNER  is the maximum rate of traffic overflow (stated in %) specified for the TCH_INNER subcell
of Txj, O max  Txi TCH  is the maximum rate of traffic overflow (stated in %) specified for the TCH subcell of Txi,
O max  Txi,TCH_INNER  is the maximum rate of traffic overflow (stated in %) specified for the TCH_INNER subcell of Txi,
micro
S
 Txi,TCH  is the TCH subcell service area of Txi and S
area of Txi.
5.3
micro
 Txi,TCH_INNER  is the TCH_INNER subcell service
Network Dimensioning
Atoll is capable of dimensioning a GSM GPRS EDGE network with a mixture of circuit and package switched services.
This section describes the technical details of Atoll’s dimensioning engine.
5.3.1
Dimensioning Models and Quality Graphs
In Atoll, a dimensioning model is an entity utilized by the dimensioning engine along with other inputs (traffic, limitations,
criteria, etc.) in the process of dimensioning. A dimensioning model defines the QoS KPIs to be taken into account when
dimensioning a network for both circuit and packet switched traffic. The user can define either to use Erlang B or Erlang
C queuing model for circuit switched traffic and can define which KPIs to consider when dimensioning the network for
packet switched traffic. The dimensioning engine will only utilize the quality curves of the KPI selected. The KPIs not
selected are supposed to be either already satisfactory or not relatively important.
5.3.1.1
Circuit Switched Traffic
The network dimensioning for circuit switched traffic is performed using the universally accepted and adopted Erlang B
and Erlang C formulas. The dimensioning criterion in these formulas is the Grade of Service or the allowed blocking probability of the circuit switched traffic.
In the Erlang B approach, this Grade of Service is defined as the percentage of incoming circuit switched calls that are
blocked due to lack of resources or timeslots. This formula implies a loss system. The blocked calls are supposed to be
lost and the caller has to reinitiate it.
In the Erlang C approach, the Grade of Service is the percentage of incoming calls that are placed in a waiting queue when
there are no resources available, until some resources or timeslots are liberated. This queuing system has no lost calls.
As the load on the system increases, the average waiting time in the queue also increases.
These formulas and their details are available in many books. For example, Wireless Communications Principles and
Practice by Theodore S. Rappaport, Prentice Hall.
Following the common practice, network dimensioning in Atoll is based on the principle that a voice or GSM call has priority
over data transmission. Therefore, as explained later in the network dimensioning steps, Atoll first performs network
dimensioning according to the circuit switched traffic present in the subcell in order to ensure the higher priority service
availability before performing the same for the packet switched traffic.
5.3.1.2
Packet Switched Traffic
Since packet switched traffic does not occupy an entire timeslot the whole time, it is much more complicated to study than
circuit switched traffic. Packet traffic is intermittent and bursty. Whenever there is packet data to be transferred, a Temporary Block Flow (TBF) is initiated for transferring these packets. Multiple TBFs can be multiplexed on the same timeslot.
This implies that there can be many packet switched service users that have the same timeslots assigned for packet data
transfer but at different intervals of time.
This multiplexing of a number of packet switched service users over the same timeslots incurs a certain reduction in the
throughput (data transfer rate) for each multiplexed user. This reduction in the throughput is more perceivable when the
system traffic load is high. The following parts describe the three most important Key Performance Indicators in GPRS/
EDGE networks and how they are modelled in Atoll.
5.3.1.2.1
Throughput
Throughput is defined as the amount of data delivered to the Logical Link Control Layer in a given unit of time. Each temporary block flow (TBF), and hence each user, has an associated measured throughput sample in a given network. Each
network will have a different throughput probability distribution depending on the load and network configuration. Instead
of using the precise probability distributions, it is more practical to compute the average and percentile throughput values.
In GPRS, the resources are shared between the users being served, and consequently, the throughput is reduced as the
number of active users increases. This reduction in user perceived throughput is modelled through a reduction factor. The
throughput experienced by a user accessing a particular service can be calculated as:
User throughput = Number of allocated timeslots x Timeslot capacity x Reduction Factor
Or
User throughput per allocated timeslot = Timeslot capacity x Reduction Factor
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Timeslot Capacity
The timeslot capacity is the average throughput per fully utilized timeslot. It represents the average throughput from the
network point of view. It mainly depends on the network’s propagation conditions and criteria in the coverage area of a
transmitter (carrier power, carrier-to-interference distribution, etc.). It is a measure of how much data the network is able
to transfer with 1 data Erlang, or in other words, how efficiently the hardware resources are being utilized by the network.
It may also depend on the RLC protocol efficiency.
Atoll computes the average timeslot capacity during the traffic analysis and is used to determine the minimum throughput
reduction factor. But since this information is displayed in the network dimensioning results (only due to relevance), this
information has been considered as a part of the network dimensioning process in this document.
Timeslot Utilisation
Timeslot utilization takes into account the average number of timeslots that are available for packet switched traffic. It is a
measure of how much the network is loaded with data services. Networks with timeslot utilisation close to 100% are close
to saturation and the end-user performance is likely to be very poor.
In Atoll this parameter is termed as the Load (Traffic load for circuit switched traffic and packet switched traffic load for
packet switched traffic). It is described in more detail in the Network dimensioning steps section.
Reduction Factor
Reduction factor takes into account the user throughput reduction due to timeslot sharing among many users. The figure
below shows how the peak throughput available per timeslot is reduced by interference and sharing.Reduction factor is a
function of the number of timeslots assigned to a user (Nu), number of timeslots available in the system (Ns) and the average system packet switched traffic load (Lp) (utilization of resources in the system). Data Erlangs or data traffic is given by:
Data Erlangs = L P  N S
Figure 5.5: Reduction of Throughput per Timeslot
More precisely, the reduction factor is a function of the ratio Ns/Nu (Np). Np models the equivalent timeslots that are available for the packet switched traffic in the system. For example, a 24-timeslot system with each user assigned 3 timeslots
per connection can be modelled by a single timeslot connection system with 8 timeslots in total.
The formula for reduction factor can be derived following the same hypotheses followed by Erlang in the derivation of the
blocking probability formulas (Erlang B and Erlang C).
Let X be a random variable that measures the reduction factor in a certain system state:
0
1
X
if n = 0
if 0 < n  N P
N
------P- if n > N P
n
Where n is the instantaneous number of connections in the system. The throughput reduction factor is defined as:

PX= n
 X  ---------------------PX= 0
RF 
n=0
Or,

RF =
PX= n

 X  -----------------------------n=0
 PX= i
i=0
Here, P(X=n) is the probability function of having n connections in the system. Under the same assumptions as those of
the Erlang formulas, the probability function can be written as:
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n
PX= n =
 LP  NP 
-------------------------n!
---------------------------------------------------------------------------------------------NP

i
 LP  NP 
-----------------------+
i!

i=0

i = NP
if 0  n  NP
i
 LP  NP 
------------------------------- i – NP 
N !  NP
+1 P
n
 LP  NP 
------------------------------- i – NP 
N P!  N P
P  X = n  = ---------------------------------------------------------------------------------------------N
P

i
 LP  NP 
-----------------------+
i!

i=0

i = NP
if n > N P
i
 LP  NP 
------------------------------- i – NP 
N !  NP
+1 P
Hence the reduction factor can finally be written as:
NP

i
i
NP
 LP  NP 
--------------------------------   -------
 i – NP   i 
N !  NP
i=1
i = NP + 1 P
RF = ---------------------------------------------------------------------------------------------------------------N

 LP  NP 
------------------------ +
i!
P


i
 LP  NP 
-----------------------+
i!
i=1

i
 LP  NP 
------------------------------- i – NP 
N
!

N
P
+1 P

i = NP
This formula is not directly applicable in any software application due to the summations up to infinity. Atoll uses the following version of this formula that is exactly the same formula without the summation overflow problem.
NP
NP
 NP + 1 

NP
 LP  NP 
L 
-------------------------- – ---------------------   ln  1 – L P  +
-----P-

N
!
n!
n
P


n=1
n=1
RF = ----------------------------------------------------------------------------------------------------------------------------------N
n

P

n=1

n
NP
n
LP
 LP  NP 
 LP  NP 
-------------------------- + -----------------------------  ---------------N P!
1 – LP
n!
The default quality curves for the Reduction Factor have been derived using the above formula. Each curve is for a fixed
number of timeslots available for packet switched traffic (Np) describing the reduction factor at different values of packet
switched traffic load (Lp). The figure below contains all the reduction factor quality curves in Atoll. The Maximum reduction
factor can be 1, implying a maximum throughput, and the minimum can be 0, implying a saturated system with no data
throughput.
Figure 5.6: Reduction Factor for Different Packet Switched Traffic Loads (Lp, X-axis)
Each curve in the above figure represents an equivalent number of packet switched timeslots, NP.
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5.3.1.2.2
Delay
Delay is the time required for an LLC PDU to be completely transferred from the SGSN to the MS, or vice versa. As the
delay is a function of the delays and the losses incurred at the packet level, the network parameters, such as the packet
queue length, and different protocol properties, such as the size of the LLC PDU, become important. It is also quite
dependent upon the radio access round trip time (RA RTT) and has a considerable impact on the application level performance viewed by the user.
The delay parameter is a user level parameter rather than being a network level quantity, like throughput per cell, timeslot
capacity, TBF blocking and reduction factor, hence it is difficult to model and is currently under study. Hence, no default
curve is presently available for delay in Atoll.
5.3.1.2.3
Blocking Probability
In GPRS, there is no blocking as in circuit switched connections. If a new temporary block flow (TBF) establishment is
requested and there are already M users per timeslot, M being the maximum limit of multiplexing per timeslot (Multiplexing
factor), the request is queued in the system to be established later when resources become available.
Supposing that M number of users can be multiplexed over a single timeslot (PDCH), we can have a maximum of M * Np
users in the system. This implies that if a new TBF is requested when there are already M * Np users active, it will be
blocked and placed in a queue. So the blocking probability is the probability of having M * Np + 1 users in the system or
more, meaning,
PX= n
for n =  M  N P  + 1
as in this case n is always greater than Np, we have,
n
 LP  NP 
------------------------------- i – NP 
N P!  N P
P  X = n  = ---------------------------------------------------------------------------------------------N
P

i
 LP  NP 
------------------------ +
i!
i=0

i
 LP  NP 
------------------------------- i – NP 
N
!

N
P
P
+1

i = NP
So, the Blocking Probability can be given as:



BP =
n
 LP  NP 
--------------------------------- 1 – NP 
N !  NP
n = M  NP + 1 P
P  X = n  = -----------------------------------------------------------------------------------------------N

P
n = MN+1

i
 LP  NP 
------------------------ +
i!
i=0

i = NP
i
 LP  NP 
--------------------------------- 1 – NP 
N
!

N
P
+1 P

Eliminating the summations to infinity, the blocking probability can be stated in a simpler form:
M  NP
 LP  NP 
LP
--------------------------------------------  -------------- M  NP – N P  1 – L
P
N P!  N P
BP = ------------------------------------------------------------------------------------------N
P

i=0
NP
i
LP
 LP  NP   LP  NP 
------------------------ + -----------------------------  ---------------N P!
1 – LP
i!
The above formula has been used to generate the default quality curves for blocking probability in Atoll.
These graphs are generated for a user multiplexing factor of 8 users per timeslot. Each curve represents an equivalent
number of packet switched timeslots, NP.
The curves depict the blocking probabilities for different number of available connections (Np) at different packet switched
traffic loads (Lp) for a fixed user multiplexing factor of 8. The figure below contains all the blocking probability curves for
packet switched traffic dimensioning in Atoll. The blocking probability increases with the packet switched traffic load, which
implies that as the packet switched traffic increases for a given number of timeslots, the system starts to get more and
more loaded, hence there is higher probability of having a temporary block flow placed in a waiting queue.
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Figure 5.7: Blocking Probability for Different Packet Switched Traffic Loads (Lp, X-axis)
Reference:
T. Halonen, J. Romero, J. Melero; GSM, GPRS and EDGE performance – Evolution towards 3G/UMTS, John Wiley
and Sons Ltd.
5.3.2
Network Dimensioning Process
The network dimensioning process is described below in detail. As the whole dimensioning process is in fact a chain of
small processes that have there respective inputs and outputs, with outputs of a preceding one being the inputs to the
next, the best method is to detail each process individually in form of steps of the global dimensioning process.
5.3.2.1
Network Dimensioning Engine
During the dimensioning process, Atoll first computes the number of timeslots required to accommodate the circuit
switched traffic. Then it calculates the number of timeslots to add in order to satisfy the demand of packet switched traffic.
This is performed using the quality curves entered in the dimensioning model used. If the dimensioning model has been
indicated to take all three KPIs in to account (throughput reduction factor, delay and blocking probability), the number of
timeslots to be added is calculated such that:
1.
2.
3.
The throughput reduction factor is greater than the minimum throughput reduction factor,
Delay is less than the maximum permissible delay defined in the service properties, and
The blocking probability is less than the maximum allowable blocking probability defined in the service properties.
The figure below depicts a simplified flowchart of the dimensioning engine in Atoll.
Figure 5.8: Network Dimensioning Process
On the whole, following are the inputs and outputs of the network dimensioning process:
5.3.2.1.1
Inputs
•
•
154
Circuit switched traffic demand
Packet switched traffic demand
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•
•
•
•
5.3.2.1.2
Outputs
•
•
•
•
•
•
•
5.3.2.2
Timeslot configurations defined for each subcell
Target traffic overflow rate and Half-rate traffic ratio for each subcell
Service availability criteria: minimum required throughput per user, maximum permissible delay, maximum allowable blocking probability etc.
Dimensioning model parameters: Maximum number of TRXs per transmitter, dimensioning model for circuit
switched traffic, number of minimum dedicated packet switched timeslots per transmitter, maximum number of
TRXs added for packet switched services, KPIs to consider, and their quality curves.
Number of required TRXs per transmitter
Number of required shared, circuit switched and packet switched timeslots
Traffic load
Served circuit switched traffic
Served packet switched traffic
Effective rate of traffic overflow
Actual KPI values: throughput reduction factor, delay and blocking probability
Network Dimensioning Steps
This section describes the entire process step by step as it is actually performed in Atoll. Details of the calculations of the
parameters that are calculated during each step are described as well.
5.3.2.2.1
Step 1: Timeslots Required for CS Traffic
Atoll computes the number of timeslots required to accommodate the circuit switched traffic assigned to each subcell. Atoll
takes the circuit switched traffic demand (Erlangs), calculated in the traffic analysis and assigned to the current subcell,
and the maximum blocking probability defined for the circuit switched service, and computes the required number of timeslots to satisfy this demand using the Erlang B or Erlang C formula (as defined by the user).
If the user-defined target rate of traffic overflow per subcell, OTarget, is greater than the maximum blocking rate defined in
the services properties, it is going to be taken as the Grade of Service required for that subcell instead of the maximum
blocking rate of the service.
For the blocking probability GoS and circuit switched traffic demand TDC, Atoll determines the required number of timeslots TSreq. C for each subcell using formulas described below. In fact, Atoll searches for TSreq. C value until the defined
grade of service is reached.
For Erlang B, we have:
TS reqC
 TD C 
------------------------------ TS reqC !
GoS = ---------------------------------TS
reqC

k
 TD C 
------------------k!
k=0
For Erlang C, we have:
TS reqC
 TD C 
GoS = ----------------------------------------------------------------------------------------------------------------------------------------------------TS
–1
 TD C 
TS reqC
TD C 
- 
+  TS reqC !   1 – -----------------

TS
reqC
reqC

k
 TD C 
------------------k!
k=0
Atoll considers the effect of half-rate circuit switched traffic by taking into account a user-defined percentage of half-rate
traffic. Atoll computes the effective equivalent number of full-rate timeslots that will be required to carry the total traffic with
the defined percentage of half-rate traffic.
If the number of timeslots required to accommodate the full-rate circuit switched traffic is TSreq. FR, and the percentage of
half-rate traffic within the subcell is defined by HR, then the effective number of equivalent full-rate circuit switched timeslots TSeff. that can carry this traffic mix is calculated by:
HR
TS eff = TS reqFR   1 – ---------

2 
Atoll employs this simplified approach to integrating half-rate circuit switched traffic, which provides approximately the
same results as obtained by using the half-rate traffic charts.
5.3.2.2.2
Step 2: TRXs Required for CS Traffic and Dedicated PS Timeslots
This stage of the network dimensioning process computes the number of TRXs required to carry the circuit switched traffic
demand through the number of required timeslots calculated above and the timeslot configuration defined by the user in
the network settings. Atoll distributes the number of required circuit switched timeslots calculated in Step 1 taking into
account the presence of dedicated packet switched timeslots in each TRX according to the timeslot configurations.
If a timeslot configuration defines a certain number of dedicated packet switched timeslots pre-allocated in certain TRXs,
those timeslots will not be considered capable of carrying circuit switched traffic and hence will not be allocated. For example, if 4 timeslots have been marked as packet switched timeslots in the first TRX and Atoll computes 8 timeslots for carry-
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ing a certain circuit switched traffic demand, then the number of TRXs to be allocated cannot be 1 even if there is no packet
switched traffic considered yet.
The total numbers of timeslots that carry circuit switched and packet switched traffic respectively are the sums of respective dedicated and shared timeslots:
TS P = TS S + TS P dedicated and TS C = TS S + TS C dedicated
5.3.2.2.3
Step 3: Effective CS Blocking, Effective CS Traffic Overflow and Served CS Traffic
In this step, the previously calculated number of required TRXs is used to compute the effective blocking rate for the circuit
switched traffic. This is performed by using the Erlang B or Erlang C formula with the circuit switched traffic demand and
the number of required TRXs as inputs and computing the Grade of Service (or blocking probability). It then calculates the
effective traffic overflow rate, Oeff..
In case of Erlang B formula, the effective rate of traffic overflow for the circuit switched traffic is the same as the circuit
switched blocking rate. While in case of the Erlang C model, the circuit switched traffic is supposed to be placed in an
infinite-length waiting queue. This implies that there is no overflow in this case.
From this data, it also computes the served circuit switched traffic. This is the difference of the circuit switched traffic
demand and the percentage of traffic that overflows from the subcell to other subcells calculated above. Hence, for an
effective traffic overflow rate of Oeff. and the circuit switched traffic demand of TDC, the served circuit switched traffic STC
is computed as:
STC = TD C   1 – O eff 
5.3.2.2.4
Step 4: TRXs to Add for PS Traffic
This step is the core of the dimensioning process for packet switched services. First of all, Atoll computes the number of
TRXs to be added to carry the packet switched traffic demand. This is the number of TRXs that contain dedicated packet
switched and shared timeslots.
To determine this number of TRXs, Atoll calculates the equivalent average packet switched traffic demand in timeslots by
studying each pixel covered by the transmitter. This calculation is in fact performed in the traffic analysis process. Knowing
the traffic demand per pixel of the covered area in terms of kbps and the maximum attainable throughput per pixel (according to the C and/or C/I conditions and the coding scheme curves in the GPRS/EDGE configuration), Atoll calculates the
average traffic demand in packet switched timeslots by:
TD P
Timeslots
=

pixel
Traffic demand per pixel (kbps)
---------------------------------------------------------------------------------Throughput per pixel (kbps)
The average timeslot capacity of a transmitter is calculated by dividing the packet switched traffic demand over the entire
coverage area (in kbps) by the packet switched traffic demand in timeslots calculated above.
With the number of timeslots required to serve the circuit switched traffic, the timeslots required for packet switched traffic
and their respective distributions according to the timeslot configurations being known, Atoll calculates the number of
timeslots available for carrying the packet switched traffic demand. These timeslots can be dedicated packet switched
timeslots and the shared ones. So, following the principle that shared timeslots are potential carriers of both traffic types,
TS P = TS S + TS P dedicated
TS C = TS S + TS C dedicated
The packet switched traffic load is calculated by the formula:
 ST C – TS C dedicated + TD P

Timeslots
L P = ---------------------------------------------------------------------------------------------TS P
The second important parameter for the calculation of Reduction Factor, Delay and Blocking Probability is the equivalent
number of available timeslots for packet switched traffic, i.e. NP. This is computed by dividing the total number of timeslots
available for carrying packet switched traffic by the number of downlink timeslots defined in the mobile terminal properties.
So, NP is calculated at this stage as:
TS P
N P = --------------------------TS Terminal
Where, TSTerminal is the number of timeslots that a terminal will use in packet switched calls.
The number timeslots that a terminal can use in packet switched calls is the product of the number of available DL timeslots
for packet-switched services (on a frame) and the number of simultaneous carriers (in case of EDGE evolution).
The number of timeslots that a terminal will use in packet switched calls is determined by taking the lower of the maximum
number of timeslots for packet switched service defined in the service properties and the maximum number of timeslots
that a mobile terminal can use for packet switched services (see above).
TS Terminal = min  TS Max Service TS Max TerminalType 
and TS Max TerminalType = TS DL TerminalType  Carriers DL TerminalType
Here, the min(X,Y) function yields the lower value among X and Y as result.
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Now, knowing the packet switched traffic load, LP, and the equivalent number of available timeslots, NP, Atoll finds out the
KPIs that have been selected before launching the dimensioning process using the quality curves stored in the dimensioning model.
This particular part of this step can be iterative if the KPIs to consider in dimensioning are not satisfied in the first try. If the
KPIs calculated above are within acceptable limits as defined by the user, it means that the dimensioning process has
acceptable results. If these KPIs are not satisfied, then Atoll increases the number of TRXs calculated for carrying packet
switched traffic by 1 (each increment adding 8 more timeslots for carrying packet switched traffic as the least unit that can
be physically added or removed is a TRX) and resumes the computations from Step 3. It then recalculates the packet
switched traffic load, LP, and the equivalent number of available timeslots, NP. Then it recomputes the KPIs with these
new values of LP and NP. If the KPIs are within satisfactory limits the results are considered to be acceptable. Otherwise,
Atoll performs another iteration to find the best possible results.
The calculated values of all the KPIs are compared with the ones defined in the service properties. The values for maximum Delay and Blocking probability are defined directly in the properties but the minimum throughput reduction factor is
calculated by Atoll using the user’s inputs: minimum throughput per user and required availability. This calculation is in fact
performed during the traffic analysis process, but since it is relevant to the dimensioning procedure, it is displayed in a
column in the dimensioning results so that the user can easily compare the minimum requirement on the reduction factor
KPI with the resulting one.
Minimum Throughput Reduction Factor Calculation
The minimum throughput reduction factor is computed using the input data: minimum required throughput per user defined
in the service properties, the average throughput per timeslot deduced from the throughput curves stored in the GPRS/
EDGE configuration properties for each coding scheme, the total number of downlink timeslots defined in the properties
of the mobile terminal (See TS Max TerminalType defintion above) and the required availability defined in the service properties.
It is at the stage of calculating the average timeslot capacity per transmitter that Atoll studies each covered pixel for carrier
power or carrier-to-interference ratio. According to the measured carrier power or carrier-to-interference ratio, Atoll
deduces the maximum throughput available on that pixel through the throughput vs. C or throughput vs. C/I curves of the
GPRS/EDGE configuration.
The throughput per timeslot per pixel TPTS, Pixel can be either a function of carrier power C, or carrier power C and the
carrier-to-interference ratio C/I, depending on the user-defined traffic analysis RF conditions criteria. Therefore,
TP TS Pixel = f  C 
Or
C
TP TS Pixel = f  C  and TP TS Pixel = f  ----
 i
The required availability parameter defines the percentage of pixels within the coverage area of the transmitter that must
satisfy the minimum throughput condition. This parameter renders user-manageable flexibility to the throughput requirement constraint.
To calculate the minimum throughput reduction factor for the transmitter, Atoll computes the minimum throughput reduction factor for each pixel using the formula:
TP user min
RF min Pixel = ------------------------------------------------------------TP TS Pixel  TS Terminal
Once the minimum reduction factor for each pixel is known, Atoll calculates the global minimum reduction factor that is
satisfied by the percentage of covered pixels defined in the required availability. The following example may help in understanding the concept and calculation method.
Example: Let the total number of pixels, covered by a subcell S, be 1050. The reliability level set to 90%. This implies that
the required minimum throughput for the given service will be available at 90% of the pixels covered. This, in turn, implies
that there will be a certain limit on the reduction factor, i.e. if the actual reduction factor in that subcell becomes less than
a minimum required, the service will not be satisfactory.
Atoll computes the minimum reduction factor at each pixel using the formula mentioned above, and outputs the following
results:
RFmin
Number of pixels
0.3
189
0.36
57
0.5
20
0.6
200
0.72
473
0.9
23
0.98
87
So for a reliability level of 90%, the corresponding RFmin will be the one provided at least 90% of the pixels covered, i.e.
945 pixels. The corresponding value of the resulting RFmin in this example hence turns out to be 0.9, since this value
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covers 962 pixels in total. Only 87 of the covered pixels imply an RFmin of 0.98. These will be the pixels that do not provide
satisfactory service.
This calculation is performed for each service type available in the subcell coverage area. The final minimum throughput
reduction factor is the highest one amongst all calculated for each service separately.
The minimum throughput reduction factor RFmin value is a minimum requirement that must be fulfilled by the network
dimensioning process when the Reduction Factor KPI is selected in the dimensioning model.
Figure 5.9: Minimum Throughput Reduction Factor
5.3.2.2.5
Step 5: Served PS Traffic
Atoll calculates the served packet switched traffic using the number of timeslots available to carry the packet switched traffic demand. As the result of the above iterative step, Atoll always finds the best possible answer in terms of number of
timeslots required to carry the packet switched traffic demand unless the requirement exceeds the maximum limit on the
number of the packet switched traffic timeslots defined in the dimensioning model properties. Hence, there is no packet
traffic overflow unless the packet switched traffic demand requires more TRXs than the maximum allowed
5.3.2.2.6
Step 6: Total Traffic Load
This step calculates the final result of the dimensioning process, i.e. the total traffic load. The total traffic load L is calculated
as:
ST C + ST P
L = ----------------------------------------------------------------------------------------------TS C dedicated + TS P dedicated + TS S
Where,
•
•
•
•
•
5.4
STC is the served circuit switched traffic
STP is the served packet switched traffic
TSC, dedicated is the number of dedicated circuit switched timeslots
TSP, dedicated is the number of dedicated packet switched timeslots
TSS is the number of shared timeslots
Key Performance Indicators Calculation
This feature calculates the current values for all circuit switched and packet switched Key Performance Indicators as a
measure of the current performance of the network. It can be used to evaluate an already dimensioned network in which
recent traffic changes have been made in limited regions to infer the possible problematic areas and then to improve the
network dimensioning with respect to these changes.
The concept of this computation is the inverse of that of the dimensioning process. In this case, Atoll has the results of the
dimensioning process already committed and known. Atoll then computes the current values for all the KPIs knowing the
number of required TRXs, the respective numbers of shared and dedicated timeslots and the circuit switched and packet
switched traffic demands.
The computation algorithm utilizes the parameters set in the dimensioning model properties and the quality curves for the
throughput reduction factor, delay and the blocking probability.
The following conventional relations apply:
If,
•
•
•
158
TSC, dedicated is the number of timeslots dedicated to the circuit switched traffic,
TSP, dedicated is the number of timeslots dedicated to the packet switched traffic,
TSS is the number of shared timeslots for a transmitter,
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Then, the number of timeslots available for the circuit switched traffic, TSC, is defined as:
TS C = TS S + TS C dedicated
And the number of timeslots available for the packet switched traffic, TSP, is given by:
TS P = TS S + TS P dedicated
5.4.1
Circuit Switched Traffic
For each subcell, Atoll has already calculated the effective traffic overflow rate and the blocking rate during the dimensioning process. Also knowing the circuit switched traffic demand, TDC, and the number of timeslots available for circuit
switched traffic, TSC, the blocking probability can be easily computed using the Erlang formulas or tables.
5.4.1.1
Erlang B
Under the current conditions of circuit switched traffic demand, TDC, and the number of timeslots available for the circuit
switched traffic, TSC, the percentage of blocked circuit switched traffic can be computed through:
TS C
 TD C 
------------------------- TS C !
% of blocked traffic = ----------------------------TS
C

k
 TD C 
------------------k!
k=0
In a network dimensioning based on Erlang B model, the circuit switched traffic overflow rate, OC, is the same as the
percentage of traffic blocked by the subcell calculated above.
5.4.1.2
Erlang C
Similarly, under the current conditions of circuit switched traffic demand, TDC, and the number of timeslots available for
the circuit switched traffic, TSC, the percentage of delayed circuit switched traffic can be computed through:
TS C
 TD C 
% of traffic delayed = -------------------------------------------------------------------------------------------------------------------------TS – 1
 TD C 
TS C
TD C
+  TS C !   1 – ----------

TS 
C
C

k
 TD C 
-----------------k!
k=0
If the circuit switched traffic demand, TDC, is higher than the number of timeslots available to accommodate circuit
switched traffic, the column for this result will be empty signifying that there is a percentage of circuit switched traffic actually being rejected rather than just being delayed under the principle of Erlang C model.
The circuit switched traffic overflow rate, OC, will be 0 if the circuit switched traffic demand, TDC, is less than the number
of timeslots available for the circuit switched traffic, TSC.
If, on the other hand, the circuit switched traffic demand, TDC, is higher than the number of timeslots available to carry the
circuit switched traffic, TSC, then there will be a certain percentage of circuit switched traffic that will overflow from the
subcell. This circuit switched traffic overflow rate, OC, is calculated as:
TD C – TS C
O C = ----------------------------TD C
5.4.1.3
Served Circuit Switched Traffic
The result of the above two processes will be a traffic overflow rate for the circuit switched traffic for each subcell, OC. The
served circuit switched traffic, STC, is calculated as:
ST C = TD C   1 – O C 
5.4.2
Packet Switched Traffic
Identifying the total traffic demand, TDT, (circuit switched traffic demand + packet switched traffic demand) as:
TD T = TD C + TD P
The following two cases can be considered.
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5.4.2.1
Case 1: Total Traffic Demand > Dedicated + Shared Timeslots
In the case where the total number of timeslots available is less than the total traffic demand, there will be packet switched
data traffic that will be rejected by the subcell as it will not be able to accommodate it. The following results are expected
in this case:
5.4.2.1.1
Traffic Load
The traffic load will be 100%, as the subcell will have more traffic to carry than it can. This implies that the system will be
loaded to the maximum and even saturated. Hence the user level quality of service is bound to be very unsatisfactory.
5.4.2.1.2
Packet Switched Traffic Overflow
In a 100% loaded, or even saturated subcell, the packet switched data calls will start being rejected because of shortage
of available resources. Hence there will be a perceptible packet switched traffic overflow in this subcell, OP. This overflow
rate is calculated as show below:
  TS C dedicated + TS P dedicated + TS S  – ST C 
 100
O P = 1 – ----------------------------------------------------------------------------------------------------------------------------TD P
5.4.2.1.3
Throughput Reduction Factor
The resulting throughput reduction factor for a 100% loaded or saturated subcell will be 0. Hence, the throughput perceived
by the packet switched service user will be 0, implying a very bad quality of service.
5.4.2.1.4
Delay
Again for a 100% loaded or saturated subcell, the delay at the packet switched service user end will be infinite as there is
no data transfer (throughput = 0).
5.4.2.1.5
Blocking Probability
All the data packets will be rejected by the system since it is saturated and has no free resources to allocate to incoming
data packets. Hence, the blocking probability will be 100%.
5.4.2.1.6
Served Packet Switched Traffic
With the packet switched data traffic overflowing from the subcell, there will be a part of that traffic that is not served. The
served packet switched data traffic, STP, is calculated on the same principle as the served circuit switched traffic:
STP = TD P   1 – O P 
5.4.2.2
Case 2: Total Traffic Demand < Dedicated + Shared Timeslots
In the case where the total traffic demand is less than the number of timeslots available to carry the traffic, the subcell will
not be saturated and there will be some deducible values for all the data KPIs. In a normally loaded subcell, the packet
switched data traffic will have no overflow percentage. This is due to the fact that the packet switched data traffic is rather
placed in a waiting queue than be rejected.
Therefore, there will be a within limits packet switched traffic load, LP, calculated as under:
 ST C – TS C dedicated + TD P

Timeslots
L P = ---------------------------------------------------------------------------------------------TS P
The second parameter for computing the KPIs from the quality curves of the dimensioning model is the number of equivalent timeslots available for the packet switched data traffic, NP, which is calculated in the same manner as in the dimensioning process as well:
TS P
N P = --------------------------TS Terminal
These parameters calculated, now Atoll can compute the required KPIs through their respective quality curves.
5.4.2.2.1
Traffic Load
The traffic load is computed knowing the total traffic demand and the total number of timeslots available to carry the entire
traffic demand:
TD T
Traffic Load = ----------------------------------------------------------------------------------------------TS C dedicated + TS P dedicated + TS S
5.4.2.2.2
Packet Switched Traffic Overflow
In a normally loaded subcell, no packet switched data calls will be rejected. The packet switched traffic overflow will, therefore, be 0.
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5.4.2.2.3
Throughput Reduction Factor
The resulting throughput reduction factor for a normally loaded subcell is calculated through the throughput reduction
factor quality curve for given packet switched traffic load, LP, and number of equivalent timeslots, NP.
5.4.2.2.4
Delay
The resulting delay the subcell is calculated through the delay quality curve for given packet switched traffic load, LP, and
number of equivalent timeslots, NP.
5.4.2.2.5
Blocking Probability
The resulting blocking probability for a normally loaded subcell is calculated through the blocking probability quality curve
for given packet switched traffic load, LP, and number of equivalent timeslots, NP.
5.4.2.2.6
Served Packet Switched Traffic
As there is no overflow of the packet switched traffic demand from the subcell under consideration, the served packet
switched traffic will be the same as the packet switched traffic demand:
ST P = TD P
5.5
Neighbour Allocation
The intra-technology neighbour allocation algorithm takes into account all the TBC transmitters. It means that all the TBC
transmitters of the .atl document are potential neighbours.
The transmitters to be allocated will be called TBA transmitters. They must fulfil the following conditions:
•
•
•
•
They are active,
They satisfy the filter criteria applied to the Transmitters folder,
They are located inside the focus zone,
They belong to the folder on which allocation has been executed. This folder can be either the Transmitters folder
or a group of transmitters or a single transmitter.
Only TBA transmitters may be assigned neighbours.
Note:
•
5.5.1
If no focus zone exists in the .atl document, Atoll takes into account the computation zone.
Global Allocation for All Transmitters
We assume a reference transmitter A and a candidate neighbour, transmitter B.
When automatic allocation starts, Atoll checks following conditions:
1.
2.
The distance between both transmitters must be less than the user-definable maximum inter-site distance. If the
distance between the reference transmitter and the candidate neighbour is greater than this value, then the
candidate neighbour is discarded.
The calculation options,
Force co-site transmitters as neighbours: This option enables you to force transmitters located on the reference transmitter
site in the candidate neighbour list. This constraints can be weighted among the others and ranks the neighbours through
the importance field (see after).
Force adjacent transmitters as neighbours: This option enables you to force transmitters geographically adjacent to the
reference transmitter in the candidate neighbour list. This constraints can be weighted among the others and ranks the
neighbours through the importance field (see after).
Notes:
•
© Forsk 2009
Adjacence criterion: Geographically adjacent transmitters are determined on the basis of
their Best Server coverages in 2G (GSM GPRS EDGE) projects. More precisely, a
transmitter TXi is considered adjacent to another transmitter TXj if there exists at least one
pixel of TXi Best Server coverage area where TXj is the 2nd Best Server. The ranking of
the adjacent neighbour transmitter increases with the number of these pixels. The figure
below shows the above concept.
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•
When this option is checked, adjacent cells are sorted and listed from the most adjacent to
the least, depending on the above criterion. Adjacence is relative to the number of pixels
satisfying the criterion.
•
This criteria is only applicable to transmitters belonging to the same HCS layer. The
geographic adjacency criteria is not the same in 3G (UMTS HSPA, CDMA2000) projects.
Force neighbour symmetry: This option enables user to force the reciprocity of a neighbourhood link. Therefore, if the reference transmitter is a candidate neighbour of another transmitter, the later will be considered as candidate neighbour of the
reference transmitter.
Force exceptional pairs: This option enables you to force/forbid some neighbourhood relationships. Therefore, you may
force/forbid a transmitter to be candidate neighbour of the reference transmitter.
Delete existing neighbours: When selecting the Delete existing neighbours option, Atoll deletes all the current neighbours
and carries out a new neighbour allocation. If not selected, the existing neighbours are kept.
There must be an overlapping zone ( S A  S B ) with a given cell edge coverage probability where:
3.
•
•
SA is the area where the received signal level from the transmitter A is greater than a minimum signal level. SA is
the coverage area of reference transmitter A restricted between two boundaries; the first boundary represents the
start of the handover area (best server area of A plus the handover margin named “handover start”) and the
second boundary shows the end of the handover area (best server area of A plus the margin called “handover
end”)
SB is the coverage area where the candidate transmitter B is the best server.
SA  SB
Atoll calculates either the percentage of covered area ( ----------------------  100 ) if the option “Take into account Covered Area” is
SA
selected, or the percentage of traffic covered on the overlapping area S A  S B for the option “Take into account Covered
Traffic”. Then, it compares this value to the % minimum covered area (minimum percentage of covered area for the option
“Take into account Covered Area” or minimum percentage of covered traffic for the option “Take into account Covered
Traffic”). If this percentage is not exceeded, the candidate neighbour B is discarded.
The coverage condition can be weighted among the others and ranks the neighbours through the importance field (see
number 4 below).
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Figure 5.10: Overlapping Zones
4.
The importance values are used by the allocation algorithm to rank the neighbours according to the allocation
reason, and to quantify the neighbour importance.
Atoll lists all neighbours and sorts them by importance value so as to eliminate some of them from the neighbour list if the
maximum number of neighbours to be allocated to each transmitter is exceeded. If we consider the case for which there
are 15 candidate neighbours and the maximum number of neighbours to be allocated to the reference transmitter is 8.
Among these 15 candidate neighbours, only 8 (having the highest importances) will be allocated to the reference transmitter.
As indicated in the table below, the neighbour importance depends on the neighbourhood cause; this value goes from 0
to 100%.
Neighbourhood cause
When
Importance
value
Existing neighbour
Only if the Delete existing neighbours option is not selected
and in case of a new allocation
Existing
importance
Exceptional pair
Only if the Force exceptional pairs option is selected
100 %
Co-site transmitter
Only if the Force co-site transmitters as neighbours option is
selected
(IF) function
Adjacent transmitter
Only if the Force adjacent transmitters as neighbours option is
selected
(IF) function
Neighbourhood relationship that fulfils
coverage conditions
Only if the % minimum covered area is exceeded
(IF) function
Symmetric neighbourhood
relationship
Only if the Force neighbour symmetry option is selected
(IF) function
Except forced neighbour case (importance = 100%), priority assigned to each neighbourhood cause is now linked to the
(IF) Importance Function evaluation. The importance is evaluated through a function (IF), taking into account the following
3 factors:
•
•
•
Co-site factor (C) which is a Boolean factor,
Adjacency factor (A) which deals with the percentage of adjacency,
Overlapping factor (O) meaning the percentage of overlapping
The (IF) function is user-definable using the Min importance and Max importance fields.
Factor
Min
importance
Default value
Max
importance
Default value
Overlapping factor (O)
Min(O)
1%
Max(O)
30%
Adjacency factor (A)
Min(A)
30%
Max(A)
60%
Co-site factor (C)
Min(C)
60%
Max(C)
100%
The (IF) function is evaluated as follows:
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Neighbourhood cause
(IF) function
(IF) function with default Min
and Max default values
Co-site
Adjacent
no
no
Min(O) + Delta(O)(O)
1% + 29%(O)
no
yes
Min(A)+Delta(A){Max(O)(O)+(100%Max(O))(A)}
30% + 30%{30%(O) + 70%(A)}
yes
yes
Min(C)+Delta(C){Max(O)(O)+(100%Max(O))(A)}
60% + 40%{30%(O )+ 70%(A)}
Where Delta(x) = Max(x) - Min(x)
Notes:
•
If there is no overlapping between the range of each factor, the neighbours will be ranked
by neighbourhood cause. Using the default values for minimum and maximum importance
fields, neighbours will be ranked in this order: first co-site neighbours, then adjacent
neighbours, and finally neighbours found on overlapping criterion.
•
If ranges of (IF) factors overlap each other, the neighbours may not be ranked by
neighbourhood cause.
•
The ranking between neighbours from the same category will depend on (A) and (O)
factors.
•
The default value of Min(O)= 1%, ensures that neighbours selected for symmetry will have
an importance greater than 0%. With a value of Min(O)= 0%, neighbours selected for
symmetry, will have an importance field greater than 0% only if there is some overlapping.
In the Results part, Atoll provides the list of neighbours, the number of neighbours and the maximum number of neighbours allowed for each cell. In addition, it indicates the importance (in %) of each neighbour and the allocation reason.
Therefore, a neighbour may be marked as exceptional pair, co-site, adjacent, coverage or symmetric. For neighbours
accepted for co-site, adjacency and coverage reasons, Atoll displays the percentage of area meeting the coverage conditions (or the percentage of covered traffic on this area) and the corresponding surface area (km2) (or the traffic covered
on the area in Erlangs), the percentage of area meeting the adjacency conditions and the corresponding surface area
(km2). Finally, if cells have previous allocations in the list, neighbours are marked as existing.
Notes:
•
No prediction study is needed to perform an automatic neighbour allocation. When starting
an automatic neighbour allocation, Atoll automatically calculates the path loss matrices if
not found.
•
Atoll uses traffic map(s) selected in the default traffic analysis in order to determine the
percentage of traffic covered in the overlapping area.
•
When the option “Force adjacent transmitters as neighbours” is used, the margin
“handover start” is not taken into account. Atoll considers a fixed value of 0 dB.
•
A forbidden neighbour must not be listed as neighbour except if the neighbourhood
relationship already exists and the Delete existing neighbours option is unchecked when
you start the new allocation. In this case, Atoll displays a warning in the Event viewer
indicating that the constraint on the forbidden neighbour will be ignored by algorithm
because the neighbour already exists.
•
The force neighbour symmetry option enables the users to consider the reciprocity of a
neighbourhood link. This reciprocity is allowed only if the neighbour list is not already full.
Thus, if transmitter B is a neighbour of the transmitter A while transmitter A is not a
neighbour of the transmitter B, two cases are possible:
1st case: There is space in the transmitter B neighbour list: the transmitter A will be added
to the list. It will be the last one.
2nd case: The transmitter B neighbour list is full: Atoll will not include transmitter A in the list
and will cancel the link by deleting transmitter B from the transmitter A neighbour list.
5.5.2
•
When the options “Force exceptional pairs” and “Force symmetry” are selected, Atoll
considers the constraints between exceptional pairs in both directions so as to respect
symmetry condition. On the other hand, if neighbourhood relationship is forced in one
direction and forbidden in the other one, symmetry cannot be respected. In this case, Atoll
displays a warning in the Event viewer.
•
In the Results, Atoll displays only the transmitters for which it finds new neighbours.
Therefore, if a transmitter has already reached its maximum number of neighbours before
starting the new allocation, it will not appear in the Results table.
Allocation for a Group of Transmitters or One Transmitter
In this case, Atoll allocates neighbours to:
•
164
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•
•
Neighbours of TBA transmitters marked as exceptional pair, adjacent and symmetric,
Neighbours of TBA transmitters that satisfy coverage conditions.
Automatic neighbour allocation parameters are described in "Global Allocation for All Transmitters" on page 161.
5.6
Interference Prediction Studies
5.6.1
Coverage Studies
Two interference studies with predefined settings are available:
•
•
The coverage by C/I level study: This study provides you a global analysis of the network quality.
The interfered areas study: This study shows the areas where a transmitter is interfered by other ones.
In both cases, Atoll calculates C/I ratio on each calculation bin where conditions on signal level reception are satisfied.
Then, it either considers the bins where the calculated C/I exceeds a lower threshold in the coverage and colours these
bins depending on C/I value (coverage by C/I level study), or it considers the bins where the calculated C/I is lower than
a upper threshold in the coverage and colours them depending on colour of the interfered transmitter (interfered areas
study).
The user-defined thermal noise (N) value is used in the calculations if the corresponding calculation conditions are
selected in the conditions tab of an interference study. The thermal noise is considered to be a white guassian background
noise fixed at the user-defined value for the entire network or part of the network under consideration. This value is defined
in the document database at -121 dBm by default.
All the TBC transmitters are taken into account in these studies. Let us assume that each bin within each TBC transmitter
calculation area corresponds to a probe mobile receiver.
Coverage study parameters to be set are:
•
•
The study conditions in order to determine the coverage area of each TBC transmitter
The display settings to select how to colour coverage areas.
Note:
•
5.6.1.1
For information on the common prediction studies (like coverage by transmitter, profile
study, …), please, refer to Common prediction studies part.
Service Area Determination
The areas, where Atoll will calculate C/I, depend on signal level reception conditions. Atoll uses the parameters entered
in the Conditions tab in order to determine service area of each TBC transmitter. We can distinguish four cases:
Here we presume that:
•
•
5.6.1.1.1
Each transmitter, Txi, belongs to a hierarchical cell structure (HCS) layer, k, with a defined priority.
The maximum range option (available in the System tab of the Predictions property dialog) is inactive.
All Servers
For each HCS layer, k, the service area of Txi corresponds to the bins where:
Txi
Minimum threshold  P rec  tt   Maximum threshold
5.6.1.1.2
Best Signal Level per HCS Layer and a Margin
For each HCS layer, k, the service area of Txi corresponds to the bins where:
Txi
Minimum threshold  P rec  tt   Maximum threshold
and
Txi
Txj
P rec  BCCH   Best  P rec  BCCH   – M
ji
where,
M is the specified margin (dB).
Best function: considers the highest value.
5.6.1.1.3
Best Signal Level of the Highest Priority HCS Layer and a Margin
In this case, the service area of Txi corresponds to the bins where:
Txi
Minimum threshold  P rec  tt   Maximum threshold
and
Txi
Txj
P rec  BCCH   Best  P rec  BCCH   – M
ji
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and
Txi belongs to the HCS layer with the highest priority
where,
M is the specified margin (dB).
Best function: considers the highest value.
5.6.1.1.4
Second Best Signal Level per HCS Layer and a Margin
For each HCS layer, k, the service area of Txi corresponds to the bins where:
Txi
Minimum threshold  P rec  tt   Maximum threshold
and
Txi
P rec  BCCH   2
nd
Txj
Best  P rec  BCCH   – M
ji
where,
M is the specified margin (dB).
2nd Best function: considers the second highest value.
Note:
•
When the maximum range option is selected, Atoll searches for interference on the bins:
- Where the respective criteria described above are checked, and
- Located within a specified distance from the transmitter (maximum range).
5.6.1.1.5
Best Idle Mode Reselection Criterion (C2)
Such type of coverage would is useful :
•
•
To compare Idle and Dedicated mode best servers for Voice traffic
Display the GPRS/EDGE best server map (based on GSM idle mode)
The path loss criterion parameter C1 used for cell selection and reselection is defined by :
Txi
C1 = P rec  BCCH  – MinimumThreshold  BCCH 
The path loss criterion (GSM03.22) is satisfied if C1  0 .
The reselection criterion C2 is used for cell reselection only and is defined by :
C2 = C1 + CELL_RESELECT_OFFSET
where CELL_RESELECT_OFFSET is the Cell Reselect Offset (in dB) defined for at the transmitter level.
The service area of Txi corresponds to the bins where:
Txi
Txi
Txi
MinimumThreshold  P rec  BCCH   or L total or L path   MaximumThreshold
And
C2
Txi
Txj
 BCCH  = Best  C2  BCCH  
j
Best function: considers the highest value.
On each bin, the best C2 value is kept. It corresponds to the best server in Idle Mode. Since the C2 value is an integer
value, so must be rounded.
5.6.1.2
Carrier to Interference Ratio Calculation
Atoll works out carrier to interference ratio on each bin of transmitter service areas.
In order to understand the difference between each frequency hopping mode from the mobile point of view, it is interesting
to consider the Mobile Station Allocation (MSA). MSA is characterised by the pair (Channel list, MAIO). When a non
hopping (NH) mode is used, channel list is a channel while it corresponds to the mobile allocation list (MAL) in case of
base band hopping (BBH) or synthesised frequency hopping (SFH). For BBH, channels of MAL belong to a unique TRX
type.
Examples:
For each example given below, we assume that.
In case of NH, we have:
166
TRX index
Channel list
MAIO
MSA
1
53
*
(53,*)
2
54
*
(54,*)
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In case of BBH, assuming TRXs belong to the same TRX type, we have:
TRX index
Channel list
MAIO
MSA
1
53
*
([53,54,55],0)
2
54
*
([53,54,55],1)
3
55
*
([53,54,55],2)
TRX index
Channel list
MAIO
MSA
1
53 54 55 56
2
([53,54,55,56],2)
2
53 54 55 56
3
([53,54,55,56],3)
In case of SFH, we have:
Therefore, for a mobile station, BBH and SFH work in the same way.
Consider the following notations:
v is a victim transmitter (TBC transmitter with a service area),
MSAS(v) is the set of MSAs associated to v. The number of MSAS(v) depends on TRX type(s) to be analysed (option
available in study properties): you may study a given TRX type tt (There are as many MSA(v) as TRXs allocated to the
subcell (v,tt)) or all the TRX types (The number of MSA(v) corresponds to the number of TRXs allocated to v),
i is a potential interfering transmitter (TBC transmitters which calculation area intersects service area of v),
MSAS(i) is the set of MSAs related to potential interferers i,
INT(v) is the set of transmitters that interfere v.
Several MSAs, m, are related to a transmitter. Therefore, for each victim transmitter v with MSA m (m  MSAS(v)), Atoll
 C v  m 
- , received at the mobile; mobile is connected to a victim transmitter, v with
calculates carrier to interference ratio  --------------- Iv  m  
v
v
a given m. C  m  is the carrier power level received from v on m and I  m  corresponds to the interference received from
interfering transmitters i on m.
Atoll studies the most interfered MSA. So, it considers:
 C v  m 
C
---- = Min  ----------------- except if analysis is detailed (Detailed result option).
 I v
k  Iv  m  
If the interference conditions for the prediction study are defined using the option C/(I+N), Atoll takes the total noise N tot
into account as well.
The total noise is computed by adding the thermal noise N thermal (defined in the document database at -121 dBm by
default) to the noise figure NF (either defined at the terminal type properties level, if a terminal type is defined for the study,
or defined directly in the prediction study conditions) and the inter-technology downlink noise rise, if any,
v DL
NR inter – techno log y (defined at the TRX level). The inter-technology downlink noise rise models the interference level on
m due to the mobiles in external linked projects. So,
v DL
N tot = N thermal + NF + NR inter – techno log y
C
Thus, for computations based on C/(I+N),  ------------------
 I + N tot
v
 Cv  m  
-
= Min  -----------------------------k  Iv  m  + N 
tot
Note:
•
The M Shadowing used in the computations of C/I is a function of C/I standard deviation and
not the Model standard deviation.
5.6.1.2.1
Carrier Power Level
v
v
C  m  = P rec  m 
5.6.1.2.2
Interference Calculation
Potential interferers can be transmitters i (iv), using co-channels and/or adjacent channels. Therefore, we can write:
v
v
v
DL
i
I  m  = I co  m  + I adj  m  + I inter – techno log y  m  + I IMPx3 – G PC
Where
© Forsk 2009
v
•
I co  m  is the interference received at v on m due to co-channels,
•
I adj  m  is the interference received at v on m due to adjacent channels,
v
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DL
•
I inter – techno log y  m  is the total inter-technology interference level on m due to one or several external linked
•
projects,
I IMPx3 is the third order intermodulation interference,
•
G PC is the average power control gain defined for the interfering transmitter i.
i
v
I co  m  is the interference received at v on m due to co-channels, given by:

v
I co  m  =




i  INT  v  n  MSAS  i 

v i
i
p m n  P rec  n   T i  n 

co
v
And, I adj  m  is the interference received at v on m due to adjacent channels, given by:




v
I adj  m  =

i  INT  v  n  MSAS  i 
i
P rec  n 

v i
p m n  -------------------  T i  n 
F
 adj
v i
p m n is the probability of having a co- or adjacent channel collision between MSAs n and m (when n and m contain coand adjacent channels). It depends on the used frequency hopping mode.
i
P rec  n  is the carrier power level received from i on n,
Ti(n) is occupancy of the MSA n.
i
i
T i  n  = L traffic  n   f act  n 
i
If “Average” is selected in the study properties, L traffic  n  is the traffic load defined for the MSA n of i. If “Maximum” option
i
is selected, L traffic  n  = 1 .
i
f act  n  is the activity factor defined for the MSA n of i. If the subcell (i,tt) supports DTX mode, it is a global value specified
in the study properties. Otherwise, the activity factor is 1.
Note:
•
Since BCCH carrier is always On Air, DTX and traffic load gains do not reduce BCCH
i
i
interfering energy. In other words, f act  n  = 1 and L traffic  n  = 1 on the BCCH for the
interference estimation.
DL
Downlink external sources of interferences I inter – network are various and due to complex phenomena (Adjacent Channel
interferences, Wideband Noise, Intermodulation between technologies). The way to easily integrate all these aspects in a
unique parameter is to define Reduction Factors (or Inter-technology Channel Protections - ICP) between technologies.
The value of ICP, in dB in a function of the following parameters:
•
•
•
•
The interfering technology (CDMA, TDMA, OFDM)
The interfering carrier bandwidth in kHz (e.g. 3840 khZ in UMTS)
The victim carrier bandwidth in khZ (here 200 kHz in GSM)
The frequency gap between the carriers of the different technologies (MHz)
The contribution of an external transmitter Tx in the total downlink interferences, on a receiver m is defined by:
Tx
DL
I inter – network  m  =
P Transmitted  ic i 
 -----------------------------------------Tx
Tx m
L
 ICP
ni
total
ic i f m
Where:
th
•
ic i is the i
frequency used by the external transmitter Tx within its list of frequencies
•
P Transmitted  ic i  is the total transmitted Tx power on ic i (dBm)
•
L total are the total losses between the external transmitter and the receiver (dB)
•
ICP ic  f
Tx
Tx
Tx m
i m
is the Inter-technology Channel Protection between the signal transmitted by Tx (on carrier ic) and
received by m (on frequency f m ) with a certain frequency gap
Note:
•
•
168
In case of frequency hopping, the ICP value is weighted according to the fractional load.
In the ICP, the frequency gap is based on the defined base frequency for each technology
(e.g. 935 MHz in GSM 900)
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I IMPx3 has three components, i.e., intermodulation interference from frequencies used by the interfering transmitter, interference due to spurious emissions from the interfering transmitter, and the intermodulation interference received at the
mobile terminal:
TX
SE
Term
I IMPx3 = I IMPx3 + I IMPx3 + I IMPx3
The above components are calculated as follows:
i
P rec
TX
I IMPx3 = ---------------v
L IMPx3
SE i
SE
I IMPx3 = P rec
i
3  P rec
Term
I IMPx3 = -------------------------Prot
2  F IMPx3
i
Where P rec is the carrier power level received from the interferer i, L IMPx3 is the third order intermodulation loss at the
SE i
Prot
victim transmitter v, P rec is the spurious emission power level received from the interferer i, and F IMPx3 is the third order
intermodulation protection factor for the terminal.
For a pair of frequencies, f 1 and f 2 , two third order intermodulation products are generated at frequencies f 3 = 2  f 1 – f 2
and f 4 = 2  f 2 – f 1 . If a transmitter uses f 3 or f 4 , it is interfered by transmitters using f 1 and f 2 . All interferer frequencies
are used to calculate intermodulation products. When several frequency pairs generate intermodulation products, the
IMPs are independenly calculated and added to the interference. If power received over different frequencies is not the
same for two frequencies (not the same power offset for example), the corresponding intermodulation frequencies are
ignored. Frequency hopping is not considered to have any impact on the intermodulation products. IMPs for hopping and
non-hopping cases are considered to be the same.
Intermodulation products generated by the adjacent frequencies of the frequencies actually being used by an interferer
are not taken into account. Similarly, intermodulation interference received on the adjacent frequencies of the frequencies
used by the victim are also ignored.
5.6.1.2.3
Collision Probability for Non Hopping Mode
v i
We have: p m n = 1
5.6.1.2.4
Collision Probability for BBH and SFH Modes
MSA m of v can be defined as the pair ([f1,f2,….fn], MAIO) and MSA n of i as the pair ([f’1,f’2,….f’n], MAIO’) (where f and f’
are channels).
v
i
Now, let us consider the occurrence, OCCUR  f m f' n  , such that a channel f of m can meet a channel f’ of n during hopping
sequence.
There is a collision if f and f’ are co- or adjacent channels. Then, we can define a collision as follows:
v
i
v
i
Collision = OCCUR  f m f' n  such that f m – f' n = 
v
i
(  equals 0 if f m and f' n are co-channels or 1 if adjacent channels)
Therefore, we have:
n collision
v i
p m n = -------------------------n occurence
ncollision and noccurence respectively correspond to the number of collisions and the number of occurrences. They are
closely linked to the correlation between m and n. We can have two cases:
1st Case: MSAs m and n are Correlated
m and n must have identical HSN and synchronisation. The number of occurrences depends on the MAL size, MAIO And
MAIO’.
Example:
Schematic view of hopping sequences
© Forsk 2009
MSA m of v
([34 37 39], MAIO=0)
34 37 39
MSA n of i
([38 36 34], MAIO’=2)
38 36 34
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Here, the number of occurrences is 3; the number of co-channel collisions is 1 and the number of adjacent channel collisions is 1. So, we have:
v i
v i
1
1
 p m n  co = --- and  p m n  adj = --3
3
2nd Case: MSAs m and n are Not Correlated
Condition specified above is not fulfilled.
Probability to have each pair is the same. All the occurrences are possible.
Example:
Schematic view of hopping sequences
MSA m of v
([34 37 39], MAIO=0)
34 37 39
MSA n of i
([38 36 34], MAIO’=2)
38 36 34
Here, the number of occurrences is 9; the number of co-channel collisions is 1 and the number of adjacent channel collisions is 3.
So, we have:
v i
v i
1
1
 p m n  co = --- and  p m n  adj = --9
3
Note:
•
5.6.1.3
Only the carrier power level is downgraded by the shadowing margin. The interference
level is not altered.
Coverage Area Determination
C
C
For each victim transmitter v, coverage area corresponds to bins where  ---- or  ------------ is between lower and upper
 I v
 I + N v
thresholds specified in study properties. There are two possibilities:
5.6.1.3.1
Interference Condition Satisfied by At Least One TRX
This criterion implies that the interference condition defined in the interference study properties dialog must be satisfied
by at least on TRX of the transmitter in order for the pixel under study to be included in the coverage area.
In this case, the coverage area of a transmitter Txi corresponds to the bins where:
C
Minimum threshold   ----
 I v
TRX j
where,
C
 Maximum threshold or Minimum threshold   ------------
 I + N v
 Maximum threshold
TRX j
TRXj is any TRX belonging to Txi.
This coverage area will include all the bins satisfying the above criteria even if they are only covered by the TRX with the
best C/I or C/(I+N) conditions.
5.6.1.3.2
Interference Condition Satisfied by The Worst TRX
This criterion implies that the interference condition defined in the interference study properties dialog must be satisfied
by the worst TRX of the transmitter in order for the pixel under study to be included in the coverage area.
In this case, the coverage area of a transmitter Txi corresponds to the bins where:
C
Minimum threshold   ----
 I v
TRX j
C
 Maximum threshold or Minimum threshold   ------------
 I + N v
 Maximum threshold
TRX j
where, TRXj is the TRX (belonging to Txi) with the worst C/I or C/(I+N) conditions at the bin.
This coverage area will include only the bins satisfying the above criteria, i.e. covered by the TRX with the worst C/I or C/
(I+N) conditions.
5.6.1.4
Coverage Area Display
You can display the transmitter coverage area depending on the C/I (or C/(I+N)) level, prefer a display depending on transmitter colour or on any other transmitter attribute.
5.6.1.4.1
C/I Level
Each bin of the transmitter coverage area is coloured if the calculated C/I (or C/(I+N)) level exceeds (  ) the specified minimum thresholds (bin colour depends on C/I (or C/(I+N)) level). Coverage consists of several independent layers whose
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visibility in the workspace can be managed. There are as many layers as transmitter coverage areas. Each layer shows
the different C/I levels available in the transmitter coverage area.
5.6.1.4.2
Max C/I Level
Atoll compares calculated C/I (or C/(I+N)) levels received from transmitters on each bin of each transmitter coverage area
where coverage areas overlap the studied one and chooses the highest value. A bin of a coverage area is coloured if the
C/I (or C/(I+N)) level exceeds (  ) the specified thresholds (the bin colour depends on the C/I (or C/(I+N)) level). Coverage
consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as
defined thresholds. Each layer corresponds to an area where the highest received C/I level exceeds a defined minimum
threshold.
5.6.1.4.3
Min C/I Level
Atoll compares C/I (or C/(I+N)) levels received from transmitters on each bin of each transmitter coverage area where the
coverage areas overlap the studied one and chooses the lowest value. A bin of a coverage area is coloured if the C/I (or
C/(I+N)) level exceeds (  ) the specified thresholds (the bin colour depends on the C/I (or C/(I+N)) level). Coverage
consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as
defined thresholds. Each layer corresponds to an area where the lowest received C/I level exceeds a defined minimum
threshold.
5.6.1.4.4
Transmitter
Atoll colours each bin of each transmitter coverage area. The bin colour corresponds to the transmitter colour. Coverage
consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as
interfered transmitters.
5.6.2
Point Analysis
Analysis provided in the Interference tab is based on path loss matrices. You can study interference on:
•
•
TBC transmitters for which path loss matrices have been computed,
calculation areas.
Atoll indicates the following at the receiver:
•
•
•
The carrier power level received from the victim transmitter v on the most interfered MAS m,
Either the overall interference received from interfering transmitters i on MAS m (both co-channel and adjacent
channel interferers are considered), or the co-channel interference received from co-channel interfering transmitters i on MAS m, or the adjacent channel interference received from adjacent channel interfering transmitters i on
MAS m (for further information about noise calculation, please refer to Signal to noise calculation: noise calculation
part)
The interference level received from each interfering transmitter i on m. Interferers are sorted in a descending
order w.r.t. carrier power level.
Notes:
•
Neither DTX nor traffic load of TRXs are taken into account to evaluate interference levels.
i
i
Therefore, we have T i  n  = L traffic  n   f act  n  = 1 .
•
5.7
Only carrier power level is downgraded by the shadowing margin. The interference level is
not altered.
GPRS EDGE Coverage Studies
Atoll calculates a coverage area for all the TBC transmitters, assuming that each bin within a TBC GPRS/EDGE transmitter
calculation area corresponds to a probe mobile receiver.
Coverage study parameters to be set are:
•
•
5.7.1
The study conditions in order to determine the coverage area of each TBC transmitter,
The display settings to select how to colour coverage areas.
Coverage Area Determination
Let us assume that:
•
•
•
•
Each transmitter, Txi, belongs to a HCS layer, k, with a defined priority and a reception threshold.
Each transmitter, Txi, is a GPRS/EDGE station.
GPRS/EDGE configuration installed on each transmitter, Txi, does not support 8PSK modulation.
The maximum range option (available in the System tab of the Predictions property dialog) is inactive.
We can have the following four cases.
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5.7.1.1
All Servers
For each HCS layer, k, the coverage area of Txi corresponds to Txi calculation area.
5.7.1.2
Best Signal Level per HCS Layer and a Margin
For each HCS layer, k, the coverage area of Txi corresponds to the bins where the signal level received from Txi,
Txi – EGPRS
P rec
 BCCH  , is the highest one (Txi is the best server) or within a defined margin of the highest signal level
(within a margin of the best server).
Note:
•
If the margin equals 0, the coverage area of Txi corresponds to the bins where
Txi – EGPRS
P rec
5.7.1.3
 BCCH  is the highest.
Second Best Signal Level per HCS Layer and a Margin
For each HCS layer, k, the coverage area of Txi corresponds to the bins where the signal level received from Txi,
Txi – EGPRS
P rec
 BCCH  , is the second highest one (Txi is the second best server) or within a defined margin of the second
highest signal level (within a margin of the second best server).
Note:
•
If the margin equals 0, the coverage area of Txi corresponds to the bins where
Txi – EGPRS
P rec
5.7.1.4
 BCCH  is the second highest.
HCS Servers and a Margin
For each HCS layer, k, the coverage area of Txi corresponds to the bins where the signal level received from Txi,
Txi – EGPRS
P rec
 BCCH  , is the highest one (Txi is the best server) or within a defined margin of the highest signal level
Txi – EGPRS
(within a margin of the best server). In addition P rec
 BCCH  must exceed the reception threshold defined per
HCS layer.
Notes:
•
If the margin equals 0, the coverage area of Txi corresponds to the bins where
Txi – EGPRS
P rec
5.7.1.5
 BCCH  is the highest.
Highest Priority HCS Server and a Margin
In this case, the coverage area of Txi corresponds to the bins where the signal level received from Txi,
Txi – EGPRS
P rec
 BCCH  , is the highest one (Txi is the best server) or within a defined margin of the highest signal level
(within a margin of the best server). And, Txi belongs to the HCS layer with the highest priority. The highest priority is
Txi – EGPRS
defined by the priority field (0: lowest) assuming the received P rec
 BCCH  exceeds the reception threshold
defined per HCS layer.
Note:
•
5.7.1.6
In the case two layers have the same priority, the traffic is served by the transmitter for
which the difference between the received signal strength and the HCS threshold is the
highest. The way the competition is managed between layers with the same priority can be
modified. For more information, see the Administrator Manual.
Best C2
In this case, the coverage area of Txi corresponds to the bins where the best C2 value received from Txi, is the highest
one. It corresponds to the best server in Idle Mode. Since the C2 value is an integer value, so must be rounded.
5.7.2
Calculation Options
GPRS/EDGE studies can be based either on signal level (C), or on the signal level and carrier-to-interference ratio (C/I)
with or without considering the receiver noise (N).
If a reference terminal type is defined when launching a CQI study, Atoll will consider the noise figure defined for that terminal type when computing the total noise ( N tot ). If no terminal type is defined, the value defined in the coverage prediction
properties (8 dB, by default) is used.
Different GPRS/EDGE configuration can be defined for a transmitter and for the reference terminal type. In this case, Atoll
performs an intersection for the coding schemes defined in the transmitter and the reference terminal type GPRS/EDGE
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configuration to determine the coding schemes that are common in the two. Hence, Atoll creates a temporary GPRS/
EDGE configuration comprising only these common coding schemes and uses this configuration to eventually compute
the coding scheme, throughput and other values.
If no reference terminal type is defined or if the defined reference terminal type has no GPRS/EDGE configuration
assigned to it, Atoll will perform the computations based on the GPRS/EDGE configuration of the transmitter. Similarly, if
a transmitter has no GPRS/EDGE configuration defined, Atoll will compute the coverage study considering only the GPRS/
EDGE configuration defined for the reference terminal type. If there is no GPRS/EDGE configuration defined for the transmitter and for the reference terminal type, there will be no coverage for the transmitter.
5.7.2.1
Calculations Based on C
In this case, only the received signal level is taken into account. Atoll evaluates the signal level received from GPRS/EDGE
Txi – EGPRS
transmitters on TRXs (TRX) belonging to a selected TRX type (tt) or on all the TRXs, P rec
5.7.2.2
 TRX  .
Calculations Based on C/I Without Considering Thermal Noise
For GPRS/EDGE studies based on the received signal level and C/I ratio, Atoll evaluates:
•
The signal level received from GPRS/EDGE transmitters on TRXs (TRX) belonging to the selected TRX type (tt)
Txi – EGPRS
or on all the TRXs, P rec
•
 TRX  , and
The carrier-to-interference ratio received on TRXs (TRX) belonging to the selected TRX type (tt) or on all the
Txi – EGPRS
P rec
 TRX 
TRXs, --------------------------------------------------- .
I
Notes:
5.7.2.3
•
When GPRS/EDGE prediction studies calculations are based on C/I, Atoll calculates the
carrier-to-interference ratio for all the GPRS/EDGE TBC transmitters but takes into account
all the TBC transmitters (GSM and GPRS/EDGE) to evaluate the interference.
•
For further information on interference (I) calculation, please refer to Interference prediction
studies: Interference calculation part.
Calculations Based on C/I Considering Thermal Noise
For GPRS/EDGE studies based on the received signal level and C/I ratio considering the effect of thermal noise, Atoll evaluates:
•
The received signal-level-to-thermal-noise ratio from GPRS/EDGE transmitters on TRXs (TRX) belonging to the
Txi – EGPRS
P rec
 TRX 
selected TRX type (tt) or on all the TRXs, --------------------------------------------------- .
N
And
•
The carrier-to-interference-and-noise ratio received on TRXs (TRX) belonging to the selected TRX type (tt) or on
Txi – EGPRS
P rec
 TRX 
all the TRXs, --------------------------------------------------- .
I+N
Where, N is the thermal noise whose value is defined in the document database at -121 dBm by default.
Notes:
5.7.2.4
•
When GPRS/EDGE prediction studies calculations are based on C/I, Atoll calculates the
carrier-to-interference ratio for all the GPRS/EDGE TBC transmitters but takes into account
all the TBC transmitters (GSM and GPRS/EDGE) to evaluate the interference.
•
For further information on interference (I) calculation, please refer to Interference prediction
studies: Interference calculation part.
Ideal Link Adaptation (ILA)
Ideal link adaptation implies that the coding scheme selected will be the one that provides the maximum throughput.
5.7.3
Coverage Study Scenarios
With the above options, there are many different possible scenarios of calculations. These scenarios are described below.
5.7.3.1
GPRS/EDGE Studies Based on C Without ILA
5.7.3.1.1
Coding Scheme Based on C Without ILA
Atoll calculates the signal level received from Txi on each bin of the Txi coverage area. Then, selects a coding scheme,
cs, from among the coding schemes available in the GPRS/EDGE configuration, such that:
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For each TRX type, tt, cs = Lowest  CS

Txi – EGPRS
P rec

 TRX    Reception Threshold  CS
Where, cs is the resulting coding scheme, CS is the set of all available coding schemes, and  Reception Threshold CS
are the values of reception thresholds for the coding schemes available in the GPRS/EDGE configuration, defined in the
Reception Thresholds column of the properties dialog.
There can be more than one coding schemes whose reception thresholds are less than the received signal level. cs is the
coding scheme with the lowest coding scheme number from the lowest priority coding scheme list. Coding scheme lists
are organised as follows from the highest to the lowest priority one : DBS, DAS, MCS and CS.
A Power Backoff, in dBs, can be defined for each subcell using 8PSK, 16QAM or 32QAM modulations (EDGE) based
coding scheme configuration. This power backoff is taken in to account when selecting the codec mode available in the
coverage area of the subcell, such that:
Txi – EGPRS
For each TRX type, tt, P rec
5.7.3.1.2
Txi – EGPRS
 TRX  – P Backoff
 TRX    Reception Threshold  CS
Throughput Based on C Without ILA
Txi – EGPRS
Atoll reads the throughput value for the received signal level, P rec
 TRX  , from the Throughput=f(C) graph asso-
ciated to the coding scheme, cs, determined above.
5.7.3.2
GPRS/EDGE Studies Based on C With ILA
5.7.3.2.1
Coding Scheme Based on C With ILA
With Ideal Link Adaptation active, Atoll selects the coding scheme that provides the highest throughput at the received
signal level value for a bin.
Atoll calculates the signal level received from Txi on each bin of the Txi coverage area. Then, selects a coding scheme,
cs, from among the coding schemes available in the GPRS/EDGE configuration, such that:
For each TRX type, tt, cs = Lowest  CS

Where,
cs
is
the
resulting
Txi – EGPRS
Highest  TP=f  C=P rec
Txi – EGPRS
TP = Highest  TP=f  C=P rec
coding
scheme,
CS
is
the

 TRX   
set
of
all
available
coding
schemes,
and
 TRX    is the highest throughput provided by any coding scheme at the received signal
level, from the Throughput = f(C) graphs defined in the properties dialog.
If there are more than one coding schemes providing the highest throughput at the bin, cs will be the one with the lowest
coding scheme number from the lowest priority coding scheme list. Coding scheme lists are organised as follows from the
highest to the lowest priority one : DBS, DAS, MCS and CS.
A Power Backoff, in dBs, can be defined for each subcell using 8PSK, 16QAM or 32QAM modulations (EDGE) based
coding scheme configuration. This power backoff is taken in to account when selecting the codec mode available in the
coverage area of the subcell, such that:
Txi – EGPRS
For each TRX type, tt, TP = Highest  TP=f  C=P rec
5.7.3.2.2
Txi – EGPRS
 TRX -  P Backoff
 TRX    
Throughput Based on C With ILA
The throughput at the given bin and for each TRX type, tt, is simply the throughput computed earlier for the coding scheme,
cs, determined above. This throughput is computed from the Throughput = f(C) graphs for the value of the received signal
Txi – EGPRS
level at the bin, P rec
 TRX  .
5.7.3.3
GPRS/EDGE Studies Based on C/I Without ILA and Thermal Noise
5.7.3.3.1
Coding Scheme Based on C/I Without ILA and Thermal Noise
Atoll calculates signal level and C/I level received from Txi on each bin of the Txi coverage area. Then, selects two coding
schemes from among the coding schemes available in the GPRS/EDGE configuration, such that:
For each TRX type, tt, cs C = Lowest  CS


And, cs C  I = Lowest  CS


Txi – EGPRS
P rec
Txi – EGPRS
P rec
 TRX 

 TRX    Reception Threshold  CS




------------------------------------------------------   C
---- Threshold
I
 CS
I
Where, csC is the coding scheme determined from the signal level, csC/I is the coding scheme determined from the C/I
level, and CS is the set of all available coding schemes.
 Reception Threshold  CS are the values of reception thresholds for the coding schemes available in the GPRS/EDGE
C
configuration, defined in the Reception Thresholds column of the properties dialog. And,  ---- Threshold
are the values
I
CS
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of C/I thresholds for the coding schemes available in the GPRS/EDGE configuration, defined in the C/I Thresholds column
of the properties dialog.
There can be more than one coding schemes whose reception thresholds are less than the received signal level, and
whose C/I thresholds are less than the received C/I level. cs is the coding scheme with the lowest coding scheme number
from the lowest priority coding scheme list. Coding scheme lists are organised as follows from the highest to the lowest
priority one : DBS, DAS, MCS and CS.
The resulting coding scheme, cs, is the coding scheme with the lowest coding scheme number from the lowest priority
coding scheme list among csC and csC/I. Coding scheme lists are organised as follows from the highest to the lowest priority one : DBS, DAS, MCS and CS.
A Power Backoff, in dBs, can be defined for each subcell using 8PSK, 16QAM or 32QAM modulations (EDGE) based
coding scheme configuration. This power backoff is taken in to account when selecting the codec mode available in the
coverage area of the subcell, such that:
Txi – EGPRS
For each TRX type, tt, P rec
Txi – EGPRS
 TRX  – P Backoff
 TRX    Reception Threshold  CS
And
Txi – EGPRS
Txi – EGPRS
P rec
 TRX  – P Backoff
 TRX   C
-----------------------------------------------------------------------------------------------------------  ---- Threshold
I
 CS
I
5.7.3.3.2
Throughput Based on Worst Case Between C and C/I Without ILA
Atoll determines two throughput values, TPC from the Throughput = f(C) graph corresponding to the coding scheme csC
determined above, and TPC/I from Throughput = f(C/I) graph corresponding to the coding scheme csC/I determined above.
The resulting throughput TP is the lower of the two values, TPC and TPC/I.
TP = Lowest  TP C TP C  I 
5.7.3.4
GPRS/EDGE Studies Based on C/I With ILA and Without Thermal Noise
5.7.3.4.1
Coding Scheme Based on C/I With ILA and Without Thermal Noise
With Ideal Link Adaptation active, Atoll selects the coding scheme that provides the highest throughput at the received
signal level and C/I value for a bin.
Atoll calculates signal level and C/I level received from Txi on each bin of the Txi coverage area. Then, selects two coding
schemes from among the coding schemes available in the GPRS/EDGE configuration, such that:
For each TRX type, tt, cs C = Lowest  CS

And, cs C  I


= Lowest  CS


Txi – EGPRS
TP = Highest  TP=f  C=P rec

 TRX   



Txi – EGPRS

 C P rec

TP = Highest  TP=f  ---- = -----------------------------------  TRX   
I

I

Where, csC is the coding scheme determined from the signal level, csC/I is the coding scheme determined from the C/I
level, and CS is the set of all available coding schemes.
Txi – EGPRS
Highest  TP=f  C=P rec
 TRX    is the highest throughput provided by any coding scheme at the received signal
Txi – EGPRS

 C P rec

level, from the Throughput = f(C) graphs defined in the properties dialog. And, Highest  TP=f  ---- = --------------------------------  TRX  
I

I

is the highest throughput provided by any coding scheme at the received C/I level, from the Throughput = f(C/I) graphs
defined in the properties dialog.
If there are more than one coding schemes providing the highest throughput at the bin, csC and csC/I will be the ones with
the lowest coding scheme number from the lowest priority coding scheme list. Coding scheme lists are organised as
follows from the highest to the lowest priority one : DBS, DAS, MCS and CS.
The resulting coding scheme, cs, is the coding scheme with the lowest coding scheme number from the lowest priority
coding scheme list among csC and csC/I. Coding scheme lists are organised as follows from the highest to the lowest priority one : DBS, DAS, MCS and CS.
A Power Backoff, in dBs, can be defined for each subcell using 8PSK, 16QAM or 32QAM modulations (EDGE) based
coding scheme configuration. This power backoff is taken in to account when selecting the codec mode available in the
coverage area of the subcell, such that:
Txi – EGPRS
For each TRX type, tt, TP = Highest  TP=f  C=P rec
Txi – EGPRS
 TRX -  P Backoff
 TRX    
And
Txi – EGPRS
Txi – EGPRS
 TRX -  P Backoff
 TRX   

 C P rec
TP = Highest  TP=f  ---- = ------------------------------------------------------------------------------------------------------------- 
I

I

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5.7.3.4.2
Throughput Based on Worst Case Between C and C/I With ILA
Atoll determines two throughput values, TPC from the Throughput = f(C) graph corresponding to the coding scheme csC
determined above, and TPC/I from Throughput = f(C/I) graph corresponding to the coding scheme csC/I determined above.
The resulting throughput TP is the lower of the two values, TPC and TPC/I.
TP = Lowest  TP C TP C  I 
5.7.3.5
GPRS/EDGE Studies Based on C/I Without ILA and With Thermal Noise
5.7.3.5.1
Coding Scheme Based on C/I Without ILA and With Thermal Noise
The reception thresholds given for signal level C are internally converted to C/N thresholds (where N is the thermal noise
defined in the document database at -121 dBm by default) in order to be indexed by C/(I+N) values. C/I thresholds are
also indexed by the C/(I+N) value.
Atoll calculates the C/N and C/(I+N) level received from Txi on each bin of the Txi coverage area. Then, selects two coding
schemes from among the coding schemes available in the GPRS/EDGE configuration, such that:

For each TRX type, tt, cs C  N = Lowest  CS



And, cs C   I + N  = Lowest  CS






Txi – EGPRS
P rec
 TRX 
C
------------------------------------------------------   ---------- I + N Threshold CS
N
Txi – EGPRS
P rec
 TRX 




C
------------------------------------------------------   ---------- I + N Threshold CS
I+N
Where, csC/N is the coding scheme determined from the C/N level, csC/(I+N) is the coding scheme determined from the C/
(I+N) level, and CS is the set of all available coding schemes.
C
 ----------- Threshold
I + N
 CS are the values of C/(I+N) thresholds for the coding schemes available in the GPRS/EDGE configuration, determined from the C/I threshold values defined in the C/I Thresholds column of the properties dialog.
There can be more than one coding schemes whose C/(I+N) thresholds are less than the received C/N level, whose C/
(I+N) thresholds are less than the received C/(I+N) level. cs is the coding scheme with the lowest coding scheme number
from the lowest priority coding scheme list. Coding scheme lists are organised as follows from the highest to the lowest
priority one : DBS, DAS, MCS and CS.
The resulting coding scheme, cs, is the coding scheme with the highest coding scheme number from the highest priority
coding scheme list csC/N and csC/(I+N). Coding scheme lists are organised as follows from the highest to the lowest priority
one : DBS, DAS, MCS and CS.
A Power Backoff, in dBs, can be defined for each subcell using 8PSK, 16QAM or 32QAM modulations (EDGE) based
coding scheme configuration. This power backoff is taken in to account when selecting the codec mode available in the
coverage area of the subcell, such that:
Txi – EGPRS
Txi – EGPRS
P rec
 TRX  – P Backoff
 TRX 
C
For each TRX type, tt, ------------------------------------------------------------------------------------------------------------   ------------ Threshold
I + N
 CS
N
And
Txi – EGPRS
Txi – EGPRS
P rec
 TRX  – P Backoff
 TRX   C
-----------------------------------------------------------------------------------------------------------  ------------ Threshold
I + N
 CS
I+N
5.7.3.5.2
Throughput Based on Interpolation Between C/N and C/(I+N) Without ILA
Atoll determines two throughput values, TPC/N from the Throughput = f(C) graph corresponding to the coding scheme csC/
determined above, and TPC/(I+N) from Throughput = f(C/I) graph corresponding to the coding scheme csC/(I+N) determined above.
N
The Throughput = f(C) graph is internally converted to Throughput = f(C/N) graph, in order to be indexed with the C/(I+N)
value. The Throughput = f(C/I) graph is also indexed with the C/(I+N) value. The final throughput is computed by interpolating between the throughput values obtained from these two graphs. The throughput interpolation method consists in
interpolating TPC/N and TPC/(I+N) according to the respective weights of I and N values.
The resulting throughput TP is given by:
TP =   TP C  N +  1 –    TP C   I + N 
Where,
pN
 = --------------------pI + N
pN is the thermal noise power (value in Watts)
p(I+N) is the interferences + thermal noise power (value in Watts)
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TPC/N is the throughput obtained from the C/N graph
TPC/(I+N) is the throughput obtained from the C/I+N graph
5.7.3.6
GPRS/EDGE Studies Based on C/I With ILA and Thermal Noise
5.7.3.6.1
Coding Scheme Based on C/I With ILA and Thermal Noise
The reception thresholds given for signal level C are internally converted to C/N thresholds (where N is the thermal noise
defined in the document database at -121 dBm by default) in order to be indexed by C/(I+N) values. C/I thresholds are
also indexed by the C/(I+N) value.
With Ideal Link Adaptation active, Atoll selects the coding scheme that provides the highest throughput at the received C/
N and C/(I+N) values for a bin.
Atoll calculates the C/N and C/(I+N) level received from Txi on each bin of the Txi coverage area. Then, selects two coding
schemes from among the coding schemes available in the GPRS/EDGE configuration, such that:


For each TRX type, tt, cs C  N = Highest  CS




And, cs C   I + N  = Highest  CS





Txi – EGPRS

 C P rec

TP = Highest  TP=f  ------------ = -----------------------------------  TRX   
N

I + N




Txi – EGPRS

 C P rec
 
TP = Highest  TP=f  ------------ = -----------------------------------  TRX   
I+N

I + N

Where, csC/N is the coding scheme determined from the C/N level, csC/(I+N) is the coding scheme determined from the C/
(I+N) level, and CS is the set of all available coding schemes.
Txi – EGPRS

 C P rec

Highest  TP=f  ------------ = --------------------------------  TRX   is the highest throughput provided by any coding scheme at the received C/
N

I + N

N level, from the Throughput = f(C/(I+N)) graphs converted from the f(C/I) graphs defined in the properties dialog. And,
Txi – EGPRS

 C P rec

Highest  TP=f  ------------ = --------------------------------  TRX   is the highest throughput provided by any coding scheme at the received C/
I
+
N
I
+
N



(I+N) level, from the Throughput = f(C/(I+N)) graphs converted from the f(C/I) graphs defined in the properties dialog.
If there are more than one coding schemes providing the highest throughput at the bin, csC/N and csC/(I+N) will be the ones
with the highest coding scheme number from the highest priority coding scheme list. Coding scheme lists are organised
as follows from the highest to the lowest priority one : DBS, DAS, MCS and CS.
The resulting coding scheme, cs, is the coding scheme with the highest coding scheme number from the highest priority
coding scheme list among csC/N and csC/(I+N). Coding scheme lists are organised as follows from the highest to the lowest
priority one : DBS, DAS, MCS and CS.
A Power Backoff, in dBs, can be defined for each subcell using 8PSK, 16QAM or 32QAM modulations (EDGE) based
coding scheme configuration. This power backoff is taken in to account when selecting the codec mode available in the
coverage area of the subcell, such that:
Txi – EGPRS
Txi – EGPRS
P rec
 TRX  – P Backoff
 TRX 
C
For each TRX type, tt, ------------------------------------------------------------------------------------------------------------   ------------ Threshold
I + N
 CS
N
Txi – EGPRS
Txi – EGPRS
P rec
 TRX  – P Backoff
 TRX 
C
And ------------------------------------------------------------------------------------------------------------   ------------ Threshold
I + N
 CS
I+N
5.7.3.6.2
Throughput Based on Interpolation Between C/N and C/(I+N) With ILA
Atoll determines two throughput values, TPC/N from the Throughput = f(C) graph corresponding to the coding scheme csC/
determined above, and TPC/(I+N) from Throughput = f(C/I) graph corresponding to the coding scheme csC/(I+N) determined above.
N
The Throughput = f(C) graph is internally converted to Throughput = f(C/N) graph, in order to be indexed with the C/(I+N)
value. The Throughput = f(C/I) graph is also indexed with the C/(I+N) value. The final throughput is computed by interpolating between the throughput values obtained from these two graphs. The throughput interpolation method consists in
interpolating TPC/N and TPC/(I+N) according to the respective weights of I and N values.
The resulting throughput TP is given by:
TP =   TP C  N +  1 –    TP C   I + N 
Where,
pN
 = --------------------pI + N
pN is the thermal noise power (value in Watts)
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p(I+N) is the interferences + thermal noise power (value in Watts)
TPC/N is the throughput obtained from the C/N graph
TPC/(I+N) is the throughput obtained from the C/I+N graph
5.7.4
Coverage Display
Coverage area can be displayed with colours depending on:
5.7.4.1
GPRS/EDGE Coding Schemes Study Display Types
5.7.4.1.1
Coding Schemes
Only the bins with a coding scheme assigned are coloured. The bin colour depends on the assigned coding scheme.
Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many
layers as transmitter coverage areas. Each layer shows the coding schemes available in the transmitter coverage area.
5.7.4.1.2
Best Coding Schemes
On each bin, Atoll chooses the highest coding scheme available from the TRXs of different transmitters covering that bin.
Only the bins with a coding scheme assigned are coloured. The bin colour depends on the assigned coding scheme.
Coverage consists of several independent layers whose visibility in the map window can be managed. There are as many
layers as possible coding schemes. Each layer shows the areas where a given coding scheme can be used.
5.7.4.2
RLC/MAC and Application Throughput/Timeslot Studies Display Types
5.7.4.2.1
Relation Between RLC/MAC and Application Throughputs
Application throughput per timeslot is deduced from the RLC/MAC (or gross) throughput per timeslot by the equation:
SF
TP Application = TP RLC  MAC  ---------- – TP Offset
100
Where, TP Application = Application throughput,
TP RLC  MAC = RLC/MAC level throughput,
TP Offset = Throughput offset (kbps) accounting for headers, guard-bits etc.,
SF = Throughput scaling factor (%) accounting for coding, redundance etc.
5.7.4.2.2
Throughput/Timeslot
A bin of a coverage area is coloured if the calculated throughput exceeds the defined minimum threshold. The bin colour
depends on throughput. Coverage consists of several independent layers whose visibility in the map window can be
managed. There are as many layers as transmitter coverage areas. Each layer shows the throughputs that a transmitter
can provide on one timeslot.
5.7.4.2.3
Best Throughput/Timeslot
On each bin, Atoll chooses the highest throughput available from the TRXs of different transmitters covering that bin. A
bin of a coverage area is coloured if the best throughput exceeds the defined minimum threshold. The bin colour depends
on throughput. Coverage consists of several independent layers whose visibility in the map window can be managed.
There are as many layers as defined thresholds. Each layer shows the areas where a throughput can be provided on one
timeslot.
5.7.4.2.4
Average Throughput/Timeslot
On each bin, Atoll calculates the average throughput available from the TRXs of different transmitters covering that bin. A
bin of a coverage area is coloured if the average throughput exceeds the defined minimum threshold. The bin colour
depends on throughput. Coverage consists of several independent layers whose visibility in the map window can be
managed. There are as many layers as defined thresholds. Each layer shows the areas where a throughput can be
provided on one timeslot.
5.7.4.2.5
Block Error Rate Computation
TP
Block error rate is computed according to the formula BLER = -----------------TP MAX
Where, TP = Throughput per timeslot calculated for a bin, and TPMAX = Maximum throughput per timeslot deduced from
the GPRS/EDGE configuration assigned to the terminal type (or transmitter, if no terminal type has been selected for the
study) for the coding scheme calculated for a bin.
Note:
•
178
If TP > TPMAX, then BLER = 0.
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5.7.4.2.6
BLER Percentage
Atoll calculates BLER percentage by considering throughput/timeslot per bin (computed as described earlier) and the
maximum throughput/timeslot possible (deduced from the GPRS/EDGE configuration graphs). A bin of a coverage area
is coloured if the calculated BLER percentage exceeds the defined minimum threshold. The bin colour depends on the
BLER. Coverage consists of several independent layers whose visibility in the map window can be managed. There are
as many layers as transmitter coverage areas. Each layer shows the BLERs that a transmitter experiences on one timeslot.
5.7.4.2.7
Maximum BLER Percentage
On each bin, Atoll chooses the maximum BLER percentage from the BLER values corresponding to TRXs of different
transmitters covering that bin. A bin of a coverage area is coloured if the maximum BLER exceeds the defined minimum
threshold. The bin colour depends on the BLER. Coverage consists of several independent layers whose visibility in the
map window can be managed. There are as many layers as defined thresholds. Each layer shows the areas where a BLER
is observed on one timeslot.
5.8
Circuit Quality Indicators Studies
Atoll calculates a coverage area for all the TBC transmitters. Let us assume that each bin within a TBC transmitter calculation area corresponds to a probe mobile receiver. Coverage study parameters to be set are:
•
•
5.8.1
The study conditions in order to determine the coverage area of each TBC transmitter,
The display settings to select how to colour coverage areas.
Circuit Quality Indicators
Atoll has the following circuit quality indicators included by default:
•
•
•
FER or Frame Erasure Rate
- The number of frames in error divided by the total number of frames. These frames are usually discarded, in
which case this can be called the Frame Erasure Rate.
BER or Bit Error Rate
- BER is a measurement of the raw bit error rate in reception before the decoding process begins. Any factor
that impacts the decoding performance, such as frequency hopping, will impact the correlation between BER
and FER, or the perceived end-user voice quality.
MOS or Mean Opinion Score
- Voice quality can be quantified using mean opinion score (MOS). MOS values can only be measured in a test
laboratory environment. MOS values range from 1 (bad) to 5 (excellent). Different voice codecs have slightly
different FER to MOS correlation since the smaller the voice codec bit rate is, the more sensitive it becomes
to frame erasures.
There are various codec modes defined for AMR depending on the FR and HR channel modes that it supports. Codec
modes defined in Atoll include the basic EFR, FR and HR codec modes along with the AMR codec modes:
•
•
•
•
•
AMR FR
- AMR TCH/AFS12.2
- AMR TCH/AFS10.2
- AMR TCH/AFS7.95
- AMR TCH/AFS7.4
- AMR TCH/AFS6.7
- AMR TCH/AFS5.9
- AMR TCH/AFS5.15
- AMR TCH/AFS4.75
AMR HR
- AMR TCH/AHS7.95
- AMR TCH/AHS7.4
- AMR TCH/AHS6.7
- AMR TCH/AHS5.9
- AMR TCH/AHS5.15
- AMR TCH/AHS4.75
EFR
FR
HR
A codec configuration should contain codec mode adaptation thresholds and quality graphs for the relevant circuit quality
indicators in order to be considered in circuit quality indicators coverage studies. The default codec configuration in Atoll
include default FER, BER and MOS quality graphs with respect to the carrier to interference ratio, and codec mode adaptation thresholds (computed from the FER vs. C/I graphs for all codec modes at 5% FER.).
Note:
•
© Forsk 2009
Depending on the reference CQI, codec mode that provides the lowest BER or FER, or the
highest MOS are selected during computations.
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References:
The above graphs are based on:
[1] T. Halonen, J. Romero, J. Melero; GSM, GPRS and EDGE performance – Evolution towards 3G/UMTS, John Wiley
and Sons Ltd.
[2] J. Wigard, P. Mogensen; A simple mapping from C/I to FER and BER for a GSM type of air interface.
[3] 3GPP Specifications TR 26.975 V6.0.0; Performance characterization of the Adaptive Multi-Rate (AMR) speech
codec (Release 6)
Figure 5.11: FER vs. C/I Graphs
Figure 5.12: BER vs. C/I Graphs
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Figure 5.13: MOS vs. C/I Graphs
5.8.2
Coverage Area Determination
We can have four different cases for coverage area determination. Let us assume that:
•
•
•
5.8.2.1
Each transmitter, Txi, belongs to a HCS layer, k, with a defined priority.
Each transmitter, Txi, is has a codec configuration assigned (Txi as notation).
The maximum range option (available in the System tab of the Predictions property dialog) is inactive.
All Servers
For each HCS layer, k, the coverage area of Txi corresponds to Txi calculation area.
5.8.2.2
Best Signal Level per HCS Layer and a Margin
For each HCS layer, k, the coverage area of Txi corresponds to the bins where the signal level received from Txi,
Txi
P rec  BCCH  , is the highest one (Txi is the best server) or within a defined margin of the highest signal level (within a
margin of the best server).
Note:
•
If the margin equals 0, the coverage area of Txi corresponds to the bins where
Txi
P rec  BCCH  is the highest.
5.8.2.3
Second Best Signal Level per HCS Layer and a Margin
For each HCS layer, k, the coverage area of Txi corresponds to the bins where the signal level received from Txi,
Txi
P rec  BCCH  , is the second highest one (Txi is the second best server) or within a defined margin of the second highest
signal level (within a margin of the second best server).
Note:
•
If the margin equals 0, the coverage area of Txi corresponds to the bins where
Txi
P rec  BCCH  is the second highest.
5.8.2.4
HCS Servers and a Margin
For each HCS layer, k, the coverage area of Txi corresponds to the bins where the signal level received from Txi,
Txi
P rec  BCCH  , is the highest one (Txi is the best server) or within a defined margin of the highest signal level (within a
Txi
margin of the best server). In addition P rec  BCCH  must exceed the reception threshold defined per HCS layer.
Notes:
•
If the margin equals 0, the coverage area of Txi corresponds to the bins where
Txi
P rec  BCCH  is the highest.
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5.8.2.5
Highest Priority HCS Server and a Margin
Txi
In this case, the coverage area of Txi corresponds to the bins where P rec  BCCH  is the highest one (Txi is the best
server) or within a defined margin of the highest signal level (within a margin of the best server). And, Txi belongs to the
HCS layer with the highest priority. The highest priority is defined by the priority field (0: lowest) assuming the received
Txi
P rec  BCCH  exceeds the reception threshold defined per HCS layer.
Note:
•
5.8.3
In the case two layers have the same priority, the traffic is served by the transmitter for
which the difference between the received signal strength and the HCS threshold is the
highest. The way the competition is managed between layers with the same priority can be
modified. For more information, see the Administrator Manual.
Calculation Options
CQI studies can be based either on the signal-to-noise level (C/N) or on the signal-to-noise-plus-interference ratio (C/
(I+N)).
If a reference terminal type is defined when launching a CQI study, Atoll will consider the noise figure defined for that terminal type when computing the total noise (N). If no terminal type is defined, the value defined in the coverage prediction
properties (8 dB, by default) is used.
Different codec configuration can be defined for a transmitter and for the reference terminal type. In this case, Atoll
performs an intersection for the codec modes defined in the transmitter and the reference terminal type codec configuration to determine the codec modes that are common in the two. Hence, Atoll creates a temporary codec configuration
comprising only these common codec modes and uses this codec configuration to eventually compute the CQI values.
If no reference terminal type is defined or if the defined reference terminal type has no codec configuration assigned to it,
Atoll will perform the computations based on the codec configuration of the transmitter. Similarly, if a transmitter has no
codec configuration defined, Atoll will compute the coverage study considering only the codec configuration defined for
the reference terminal type. If there is no codec configuration defined for the transmitter and for the reference terminal
type, there will be no coverage for the transmitter.
For the case where more than one codec modes, compatible with the transmitter - reference terminal type pair, satisfy the
C or C/I conditions at a bin under study, Atoll chooses the codec mode for CQI determination according to their selection
priorities. The table below depicts the selection priorities for all codec modes modeled in Atoll. These selection priorities
are based on the chronological order of their development and on their C/I - MOS performance.
5.8.3.1
Codec Mode
Selection priority
FR
1
HR
2
EFR
3
AMR TCH/AFS4.75
4
AMR TCH/AFS5.15
5
AMR TCH/AFS5.9
6
AMR TCH/AFS6.7
7
AMR TCH/AFS7.4
8
AMR TCH/AFS7.95
9
AMR TCH/AFS10.2
10
AMR TCH/AFS12.2
11
AMR TCH/AHS4.75
12
AMR TCH/AHS5.15
13
AMR TCH/AHS5.9
14
AMR TCH/AHS6.7
15
AMR TCH/AHS7.4
16
AMR TCH/AHS7.95
17
Calculations Based on C/N
Txi
In this case, only signal level received and the total noise are taken into account. Atoll evaluates P rec  TRX  , the signal
level received from transmitter Txi on TRXs (TRX) belonging to the selected TRX type (tt), or on all the TRXs, on each bin
of Txi coverage area and converts it into C/N values using the value of total noise computed as follows:
N tot = N + NF
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Where, N is the thermal noise (defined in the document database at -121 dBm by default), and NF is the receiver noise
figure (either defined at the terminal type properties level, if a reference terminal type is defined for the study, or defined
in the coverage study properties).
The computed total noise N tot is then compared to the codec configuration reference noise N Ref . If the values are the
same, the defined graphs are used as is, unless the entry is downshifted by the difference N tot – N Ref .
5.8.3.2
Calculations Based on C/(I+N)
For circuit quality indicator studies based on the signal-to-noise-and-interference ratio (C/(I+N)), Atoll evaluates:
Txi
•
P rec  TRX 
----------------------------- : The signal-level-to-noise ratio received from transmitter Txi on TRXs (TRX) belonging to the selected
N tot
TRX type (tt) or on all the TRXs.
And
Txi
•
P rec  TRX 
----------------------------- : The carrier-to-interference-and-noise ratio received from transmitter Txi on TRXs (TRX) belonging
I + N tot
to the selected TRX type (tt) or on all the TRXs.
The value of total noise computed as follows:
N tot = N + NF
Where, N is the thermal noise (defined in the document database at -121 dBm by default), and NF is the receiver noise
figure (either defined at the terminal type properties level, if a terminal type is defined for the study, or defined in the coverage study properties).
The computed total noise N tot is then compared to the codec configuration reference noise N Ref . If the values are the
same, the defined graphs are used as is, unless the entry is downshifted by the difference N tot – N Ref .
Note:
•
5.8.3.3
Atoll calculates the carrier-to-interference ratio for all the TBC transmitters but takes into
account all the transmitters (even the ones with no codec configuration assigned) to
evaluate the interference.
Ideal Link Adaptation (ILA)
Ideal link adaptation for circuit quality indicator studies is defined at the codec configuration level. If the ideal link adaptation
option is checked, Atoll will select the codec mode, for the transmitter under study, according to the codec quality graphs
(CQI = f(C/N) and CQI = f(C/I)) related to the defined reference CQI, which may be different from the CQI being calculated.
Otherwise, Atoll will use the adaptation thresholds defined in the Adaptation Thresholds tab to determine the codec mode
to be used in the studies.
5.8.4
Calculation Scenarios
With the above options, there are many different possible scenarios of calculations. These scenarios are described below.
5.8.4.1
CQI Study Based on C/N Without ILA
Atoll calculates signal level received from Txi on each bin of Txi coverage area and converts it into C/N values as described
earlier. Then, Atoll filters all the codec modes that satisfy the C/N values and are common between the transmitter and the
terminal type codec configuration. It then determines the codec mode for the bin, such that:


For each TRX type, tt, cm = Highest Priority  CM





Txi
P rec  TRX 

------------------------------   Adaptation Threshold CM

N tot
Where, cm is the codec mode with the highest priority among the set of codec modes CM having their adaptation threshTxi
P rec  TRX 
olds less than the received C/N level, ----------------------------- .
N tot
From the CQI=f(C/N) graph associated to the selected codec mode cm, Atoll evaluates the CQI for which the study was
Txi
P rec  TRX 
performed corresponding to ----------------------------- for the selected codec mode.
N tot
5.8.4.2
CQI Study Based on C/N With ILA
Ideal link adaptation is used by a codec configuration according to a defined reference CQI (MOS by default).
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Atoll calculates signal level received from Txi on each bin of Txi coverage area and converts it into C/N values as described
earlier. Then, Atoll filters all the codec modes that satisfy the C/N criterion (defined by the CQI = f(C/N) graphs for the reference CQI) and are common between the transmitter and the terminal type codec configuration.
The selected codec mode among these filtered codec modes will be,


For each TRX type, tt, cm = Highest Priority  CM




Or, cm = Highest Priority  CM




 , for MOS
Txi

 C P rec  TRX   
CQI Ref = Highest  CQI=f  ---- = ------------------------------  
N tot

N



 , for BER and FER
Txi

 C P rec  TRX   
CQI Ref = Lowest  CQI=f  ---- = ------------------------------  
N tot

N

Where, cm is the codec mode with the highest priority among the set of codec modes CM for which the reference CQI
Txi
P rec  TRX 
gives the highest or the lowest value at the received C/N level, ----------------------------- .
N tot
If more than one codec mode graphs give the same value for reference CQI, then Atoll selects the codec mode with the
highest priority.
From the CQI = f(C/N) graph associated to the selected codec mode cm, Atoll evaluates the CQI for which the study was
Txi
P rec  TRX 
performed corresponding to ----------------------------- for the selected codec mode.
N tot
5.8.4.3
CQI Study Based on C/(I+N) Without ILA
Atoll calculates the C/I level received from the transmitter on each bin of Txi coverage area, for each TRX and converts it
into C/(I+N). Then, Atoll filters all the codec modes that satisfy the C/(I+N) values and are common between the transmitter
and the terminal type codec configuration.
It then determines the codec mode for the bin, such that:


For each TRX type, tt, cm = Highest Priority  CM





Txi
P rec  TRX 

------------------------------   Adaptation Threshold  CM

I + Ntot
Where, cm is the codec mode with the highest priority among the set of codec modes CM having their adaptation threshTxi
P rec  TRX 
olds less than the received C/(I+N) level, ----------------------------- .
I + Ntot
From the CQI = f(C/I) graph associated to the selected codec mode cm (indexed with the C/(I+N) values), Atoll evaluates
Txi
P rec  TRX 
the CQI for which the study was performed corresponding to ----------------------------- for the selected codec mode.
I + N tot
5.8.4.4
CQI Study Based on C/(I+N) With ILA
Ideal link adaptation is used by a codec configuration according to a defined reference CQI (MOS by default).
Atoll calculates the C/I level received from the transmitter on each bin of Txi coverage area, for each TRX and converts it
into C/(I+N). Then, Atoll filters all the codec modes that satisfy the C/(I+N) criteria (defined by the CQI = f(C/I) graphs for
the reference CQI) and are common between the transmitter and the terminal type codec configuration.
The selected codec mode among these filtered codec modes will be,


For each TRX type, tt, cm = Highest Priority  CM




Or, cm = Highest Priority  CM




 , for MOS
Txi

 C P rec  TRX   
CQI Ref = Highest  CQI=f  ---- = ------------------------------  
I
I
+
N


tot  


 , for BER and FER
Txi

 C P rec  TRX   
CQI Ref = Lowest  CQI=f  ---- = ------------------------------  
I + N tot  

I
Where, cm is the codec mode with the highest priority among the set of codec modes CM for which the reference CQI
Txi
P rec  TRX 
gives the highest or the lowest value at the received C/(I+N) level, ----------------------------- .
I + N tot
If more than one codec mode graphs give the same value for reference CQI, then Atoll selects the codec mode with the
highest priority.
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From the CQI = f(C/I) graph associated to the selected codec mode cm (indexed with the C/(I+N) values), Atoll evaluates
Txi
P rec  TRX 
the CQI for which the study was performed corresponding to ----------------------------- for the selected codec mode.
I + N tot
5.8.5
Coverage Display
Coverage area can be displayed with colours depending on:
5.8.5.1
Circuit Quality Indicators Study Display Types
5.8.5.1.1
FER/BER/MOS
Only the bins with a CQI assigned are coloured. The bin colour depends on the assigned CQI value. Coverage consists
of several independent layers whose visibility in the map window can be managed. There are as many layers as transmitter
coverage areas. Each layer shows the CQI values available in the transmitter coverage area.
5.8.5.1.2
Max FER/Max BER/Max MOS
On each bin, Atoll chooses the maximum CQI value available from the TRXs of different transmitters covering that bin.
Only the bins where the CQI values exceeds a defined threshold are coloured. The bin colour depends on the assigned
CQI value. Coverage consists of several independent layers whose visibility in the map window can be managed. There
are as many layers as the number of thresholds defined. Each layer shows the areas where a given CQI value is available.
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This chapter provides descriptions of all the algorithms for calculations, analyses, automatic allocations,
simulations and prediction studies available in UMTS HSPA projects.
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UMTS HSPA Networks
6.1
General Prediction Studies
6.1.1
Calculation Criteria
Three criteria can be studied in point analysis (Profile tab) and in common coverage studies. Study criteria are detailed in
the table below:
Study criteria
Formulas
Signal level ( P rec ) in dBm
Signal level received from a transmitter on a carrier (cell)
P rec  ic  = EIRP  ic  – L path – M Shadowing – model – L Indoor + G term – L term
L path = L model + L ant
Path loss ( L path ) in dBm
Total losses ( L total ) in dBm
Tx
L total =  L path + L Tx + L term + L indoor + M Shadowing – model  –  G Tx + G term 
where,
EIRP is the effective isotropic radiated power of the transmitter,
ic is a carrier number,
L model is the loss on the transmitter-receiver path (path loss) calculated by the propagation model,
L ant
Tx
is the transmitter antenna attenuation (from antenna patterns),
M Shadowing – model is the shadowing margin. This parameter is taken into account when the option “Shadowing taken into
account” is selected,
L Indoor are the indoor losses, taken into account when the option “Indoor coverage” is selected,
L term are the receiver losses,
G term is the receiver antenna gain,
G Tx is the transmitter antenna gain,
L Tx is the transmitter loss ( L Tx = L total – DL ). For information on calculating transmitter loss, see "UMTS HSPA,
CDMA2000 1xRTT 1xEV-DO, and TD-SCDMA Documents" on page 128.
Notes:
•
EIRP  ic  = P pilot  ic  + G Tx – L Tx ( P pilot  ic  is the cell pilot power).
•
It is possible to analyse all the carriers. In this case, Atoll takes the highest pilot power of
cells to calculate the signal level received from a transmitter.
•
Atoll considers that G term and L term equal zero.
6.1.2
Point Analysis
6.1.2.1
Profile Tab
Atoll displays either the signal level received from the selected transmitter on a carrier ( P rec  ic  ), or the highest signal
level received from the selected transmitter on all the carriers.
Note:
•
For a selected transmitter, it is also possible to study the path loss, L path , or the total
losses, L total . Path loss and total losses are the same on any carrier.
6.1.2.2
Reception Tab
Analysis provided in the Reception tab is based on path loss matrices. So, you can study reception from TBC transmitters
for which path loss matrices have been computed on their calculation areas.
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For each transmitter, Atoll displays either the signal level received on a carrier, ( P rec  ic  ), or the highest signal level
received on all the carriers.
Reception bars are displayed in a decreasing signal level order. The maximum number of reception bars depends on the
signal level received from the best server. Only reception bars of transmitters whose signal level is within a 30 dB margin
from the best server can be displayed.
Note:
•
For a selected transmitter, it is also possible to study the path loss, L path , or the total
losses, L total . Path loss and total losses are the same on any carrier.
•
6.1.3
You can use a value other than 30 dB for the margin from the best server signal level, for
example a smaller value for improving the calculation speed. For more information on
defining a different value for this margin, see the Administrator Manual.
Coverage Studies
For each TBC transmitter, Txi, Atoll determines the selected criterion on each pixel inside the Txi calculation area. In fact,
each pixel within the Txi calculation area is considered as a potential (fixed or mobile) receiver.
Coverage study parameters to be set are:
•
•
6.1.3.1
The study conditions in order to determine the service area of each TBC transmitter,
The display settings to select how to colour service areas.
Service Area Determination
Atoll uses parameters entered in the Condition tab of the coverage study property dialogue to predetermine areas where
it will display coverage.
We can distinguish three cases:
6.1.3.1.1
All Servers
The service area of Txi corresponds to the bins where:
Txi
Txi
Txi
MinimumThreshold  P rec  ic   or L total or L path   MaximumThreshold
6.1.3.1.2
Best Signal Level and a Margin
The service area of Txi corresponds to the bins where:
Txi
Txi
Txi
MinimumThreshold  P rec  ic   or L total or L path   MaximumThreshold
And
Txi
Txj
P rec  ic   Best  P rec  ic   – M
ji
M is the specified margin (dB).
Best function: considers the highest value.
Notes:
•
If the margin equals 0 dB, Atoll will consider bins where the signal level received from Txi is
the highest.
•
If the margin is set to 2 dB, Atoll will consider bins where the signal level received from Txi
is either the highest or 2dB lower than the highest.
•
If the margin is set to -2 dB, Atoll will consider bins where the signal level received from Txi
is 2dB higher than the signal levels from transmitters, which are 2nd best servers.
6.1.3.1.3
Second Best Signal Level and a Margin
The service area of Txi corresponds to the bins where:
Txi
Txi
Txi
MinimumThreshold  P rec  ic   or L total or L path   MaximumThreshold
And
Txi
P rec  ic   2
nd
Best  P Txj  ic   – M
rec
ji
M is the specified margin (dB).
2nd Best function: considers the second highest value.
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Notes:
•
If the margin equals 0 dB, Atoll will consider bins where the signal level received from Txi is
the second highest.
•
If the margin is set to 2 dB, Atoll will consider bins where the signal level received from Txi
is either the second highest or 2dB lower than the second highest.
•
If the margin is set to -2 dB, Atoll will consider bins where the signal level received from Txi
is 2dB higher than the signal levels from transmitters, which are 3rd best servers.
6.1.3.2
Coverage Display
6.1.3.2.1
Plot Resolution
Prediction plot resolution is independent of the matrix resolutions and can be defined on a per study basis. Prediction plots
are generated from multi-resolution path loss matrices using bilinear interpolation method (similar to the one used to evaluate site altitude).
6.1.3.2.2
Display Types
It is possible to display the transmitter service area with colours depending on any transmitter attribute or other criteria
such as:
Signal Level (in dBm, dBµV, dBµV/m)
Atoll calculates signal level received from the transmitter on each pixel of each transmitter service area. A pixel of a service
area is coloured if the signal level exceeds (  ) the defined minimum thresholds (pixel colour depends on signal level).
Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many
layers as transmitter service areas. Each layer shows the different signal levels available in the transmitter service area.
Best Signal Level (in dBm, dBµV, dBµV/m)
Atoll calculates signal levels received from transmitters on each pixel of each transmitter service area. Where other service
areas overlap the studied one, Atoll chooses the highest value. A pixel of a service area is coloured if the signal level
exceeds (  ) the defined thresholds (the pixel colour depends on the signal level). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer
corresponds to an area where the signal level from the best server exceeds a defined minimum threshold.
Path Loss (dB)
Atoll calculates path loss from the transmitter on each pixel of each transmitter service area. A pixel of a service area is
coloured if path loss exceeds (  ) the defined minimum thresholds (pixel colour depends on path loss). Coverage consists
of several independent layers whose visibility in the workspace can be managed. There are as many layers as service
areas. Each layer shows the different path loss levels in the transmitter service area.
Total Losses (dB)
Atoll calculates total losses from the transmitter on each pixel of each transmitter service area. A pixel of a service area is
coloured if total losses exceed (  ) the defined minimum thresholds (pixel colour depends on total losses). Coverage
consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as
service areas. Each layer shows the different total losses levels in the transmitter service area.
Best Server Path Loss (dB)
Atoll calculates signal levels received from transmitters on each pixel of each transmitter service area. Where other service
areas overlap the studied one, Atoll determines the best transmitter and evaluates path loss from the best transmitter. A
pixel of a service area is coloured if the path loss exceeds (  ) the defined thresholds (pixel colour depends on path loss).
Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many
layers as defined thresholds. Each layer corresponds to an area where the path loss from the best server exceeds a
defined minimum threshold.
Best Server Total Losses (dB)
Atoll calculates signal levels received from transmitters on each pixel of each transmitter service area. Where service
areas overlap the studied one, Atoll determines the best transmitter and evaluates total losses from the best transmitter.
A pixel of a service area is coloured if the total losses exceed (  ) the defined thresholds (pixel colour depends on total
losses). Coverage consists of several independent layers whose visibility in the workspace can be managed. There are
as many layers as defined thresholds. Each layer corresponds to an area where the total losses from the best server
exceed a defined minimum threshold.
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Number of Servers
Atoll evaluates how many service areas cover a pixel in order to determine the number of servers. The pixel colour
depends on the number of servers. Coverage consists of several independent layers whose visibility in the workspace can
be managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the number of
servers exceeds (  ) a defined minimum threshold.
Cell Edge Coverage Probability (%)
On each pixel of each transmitter service area, the coverage corresponds to the pixels where the signal level from this
transmitter fulfils signal conditions defined in Conditions tab with different Cell edge coverage probabilities. There is one
coverage area per transmitter in the explorer.
Best Cell Edge Coverage Probability (%)
On each pixel of each transmitter service area, the coverage corresponds to the pixels where the best signal level received
fulfils signal conditions defined in Conditions tab. There is one coverage area per cell edge coverage probability in the
explorer.
6.2
Definitions and Formulas
Input parameters and formulas used in simulations and predictions (coverage predictions and point analysis) are detailed
in the tables below.
6.2.1
Inputs
This table lists simulation and prediction inputs (calculation options, quality targets, active set management conditions,
etc.).
Name
Value
Unit
Description
F ortho
Clutter parameter
None
Orthogonality factor
Tx
Site equipment parameter
None
MUD factor
F MUD
Terminal parameter - HSDPA properties
None
MUD factor
ic
Frequency band parameter
None
Carrier number
AS_Th  Txi ic 
Cell parameter
None
Threshold for macro diversity
specified for a transmitter on a given
carrier ic
req
E
-----c-
Mobility parameter
 I 0  threshold
None
Ec/I0 target on downlink for the best
server
Global parameter
None
Pilot RSCP threshold for compressed
mode activation
Global parameter
None
Ec/I0 threshold for compressed mode
activation
E
-----b-
(Reception equipment, R99 bearer, Mobility) parameter
 N t  req
None
Eb/Nt target on downlink
Global parameter
None
Downlink Eb/Nt target increase due to
compressed mode activation
E
-----b-
(Reception equipment, R99 bearer, Mobility) parameter
 N t  req
None
Eb/Nt target on uplink
Global parameter
None
Uplink Eb/Nt target increase due to
compressed mode activation
F MUD
Term
Q pilot
CM – activation
RSCP pilot
CM – activation
Q pilot
DL
DL
Q req
DL
Q req
UL
UL
Q req
UL
Q req
CE – UL
 NI 
Site parameter
None
Number of channel elements available
for a site on uplink
CE – DL
 NI 
Site parameter
None
Number of channel elements available
for a site on downlink
N
CE – UL
 NI 
Simulation result
None
Number of channel elements of a site
consumed by users on uplink
N
CE – DL
 NI 
Simulation result
None
Number of channel elements of a site
consumed by users on downlink
N max
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N
Overhead – C E – UL
Site equipment parameter - UL overhead resources for common
channels/cell
None
Number of channel elements used by
the cell for common channels on
uplink
N
Overhead – C E – DL
Site equipment parameter - DL overhead resources for common
channels/cell
None
Number of channel elements used by
the cell for common channels on
downlink
N
R99 – T CH – C E – UL
(R99 Bearer, site equipment) parameter
None
Number of channel elements used for
R99 traffic channels on uplink
N
R99 – T CH – C E – DL
(R99 Bearer, site equipment) parameter
None
Number of channel elements used for
R99 traffic channels on downlink
HSUPA – C E
(HSUPA Bearer, site equipment) parameter
None
Number of channel elements
consumed by the HSUPA bearer on
uplink
UL
Site parameter
kbps
Maximum Iub backhaul throughput for
a site in the uplink
DL
Site parameter
kbps
Maximum Iub backhaul throughput for
a site in the downlink
UL
Simulation result
kbps
Iub backhaul throughput for a site in
the uplink
DL
Simulation result
kbps
Iub backhaul throughput for a site in
the downlink
Site equipment parameter
kbps
Iub throughput required by the cell for
common channels in the downlink
Site equipment parameter
%
HSDPA Iub backhaul overhead
Site equipment parameter
kbps
Throughput carried by an E1/T1/
Ethernet link
R99 – T CH – UL
(R99 Bearer, site equipment) parameter
kbps
Iub backhaul throughput consumed by
the R99 bearer in the uplink
R99 – T CH – DL
(R99 Bearer, site equipment) parameter
kbps
Iub backhaul throughput consumed by
the R99 bearer in the downlink
HSUPA
(HSUPA Bearer, site equipment) parameter
kbps
Iub backhaul throughput consumed by
the HSUPA bearer in the uplink
Simulation constraint
None
Maximum number of 512 bit-length
OVSF codes available per cell (512)
Simulation result
None
Number of 512 bit-length OVSF codes
used by the cell
Site equipment parameter - DL overhead resources for common
channels/cell
None
Number of 256 bit-length OVSF codes
used by the cell for common channels
N
T Iub –m ax  N I 
T Iub –m ax  N I 
T Iub  N I 
T Iub  N I 
Overhead – DL
T Iub
HSDPA
Overhead Iub
T E1  T1  Ethernet
T Iub
T Iub
T Iub
Codes
N max  Txi ic 
N
N
Codes
 Txi ic 
Overhead – C odes
Codes – HS PDSCH
 Txi ic 
Cell parameter (for HSDPA only)
None
Maximum number of 16 bit-length
OVSF codes available per cell for HSPDSCH
Codes – HS PDSCH
 Txi ic 
Cell parameter (for HSDPA only)
None
Minimum number of 16 bit-length
OVSF codes available per cell for HSPDSCH
NF term
Terminal parameter
None
Terminal Noise Figure
NF Tx
Transmitter parameter (user-defined or calculated from transmitter
equipment characteristics)
None
Transmitter Noise Figure
K
1.38 10-23
J/K
Boltzman constant
N max
N min
T
293
K
Ambient temperature
W
3.84 MHz
Hz
Spreading Bandwidth
Tx DL
Cell parameter
None
Inter-technology downlink noise rise
NR inter – techno log y
Tx UL
Cell parameter only used as input of the Monte-Carlo simulation
None
Inter-technology uplink noise rise
RF  ic ic adj 
Network parameter
If not defined, it is assumed that there is no inter-carrier interference
None
Interference reduction factor between
two adjacent carriers ic and ic adj
NR inter – techno log y
Tx m
ICP ic  ic
i
Network parameter
If not defined, it is assumed that there is no inter-technology downlink
interferences due to external transmitters
None
Inter-technology Channel Protection
between the signal transmitted by Tx
and received by m assuming the
frequency gap between ic i (external
network) and ic
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UL
X max
DL
%Power max
Simulation constraint (global parameter or cell parameter)
%
Maximum uplink load factor
Simulation constraint (global parameter or cell parameter)
%
Maximum percentage of used power
W
Thermal noise at transmitter
W
Thermal noise at terminal
bps
Chip rate
Tx UL
Tx
NF Tx  K  T  W  NR inter – techno log y
Term
NF Term  K  T  W  NR inter – techno log y
N0
N0
Rc
Tx DL
W  10
–3
W
UL
Site equipment parameter
None
Uplink rake receiver efficiency factor
DL
Terminal parameter
None
Downlink rake receiver efficiency
factor
R nominal
R99 bearer parameter
kbps
R99 bearer downlink nominal bit rate
F spreading  Active user 
R99 bearer parameter
None
Downlink spreading factor for active
users
DL
R99 bearer parameter
None
Downlink spreading factor for inactive
users
f rake efficiency
f rake efficiency
DL
DL
F spreading  Inactive user 
DL
R99 bearer parameter
None
ratio between DPCCH and DPCH
transmission duration on downlink
DPCCH and DPCH respectively refer
to the Dedicated Physical Control
Channel and Dedicated Physical
Channel
DL
Cell parameter
kbps
Maximum connection rate per user on
downlink
R99 bearer parameter
kbps
R99 bearer uplink nominal bit rate
UL
Service parameter
kbps
Uplink activity factor on E-DPCCH
channels
DL
Service parameter
kbps
Downlink Activity factor on A-DPCH
channel
UL
Service parameter
kbps
Minimum required bit rate that the
service should have in order to be
available in the uplink
DL
Service parameter
kbps
Minimum required bit rate that the
service should have in order to be
available in the downlink
rc
R max
UL
R nominal
f act –ADPCH
f act –ADPCH
R Guaranteed
R Guaranteed
UL
R99 bearer parameter
None
ratio between the DPCCH and DPCH
powers transmitted on uplink
DPCCH and DPCH respectively refer
to the Dedicated Physical Control
Channel and Dedicated Physical
Channel
UL
Cell parameter
kbps
Maximum connection rate per user on
uplink
DL
W
---------------------DL
R nominal
None
Service downlink processing gain
UL
W
---------------------UL
R nominal
None
Service uplink processing gain
T application
HSDPA study result
kbps
User application throughput on
downlink
R RLC – peak  I HSDPABearer 
HSDPA Bearer parameter
kbps
RLC peak rate supported by the
HSDPA bearer
kbps
RLC peak rate provided in the
downlink
rc
R max
Gp
Gp
DL
DL
HSDPA study result
DL
Without MIMO: R RLC – peak  Index HSDPABearer 
DL
R RLC – peak
DL
With MIMO (transmit diversity): R RLC – peak  Index HSDPABearer 
With MIMO (spatial multiplexing):
DL
R RLC – peak  Index HSDPABearer 
194
Max
  1 + f SM – Gain   G SM – 1  
AT281_TRG_E1
© Forsk 2009
Chapter 6: UMTS HSPA Networks
R Guaranteed
-------------------------------------------------------------------DL
R RLC – peak  I HSDPABearer 
%
HSDPA bearer consumption for a
packet (HSPA - Constant Bit Rate)
service user
HSDPA study result
kbps
RLC peak throughput supported by
the HSDPA bearer
T RLC – Av
HSDPA study result
kbps
Average RLC throughput supported
by the HSDPA bearer
R MAC
DL
HSDPA study result
kbps
MAC rate supported by the HSDPA
bearer
DL
HSDPA study result
kbps
MAC throughput supported by the
HSDPA bearer
T application
HSUPA study result
kbps
User application throughput on uplink
T application – Av
UL
HSUPA study result
kbps
User average application throughput
on uplink
R RLC – peak  I HSUPABearer 
HSUPA Bearer parameter
kbps
RLC peak rate supported by the
HSUPA bearer
kbps
RLC peak rate provided in the uplink
R Guaranteed
-------------------------------------------------------------------UL
R RLC – peak  I HSUPABearer 
%
HSUPA bearer consumption for a
packet (HSPA - Constant Bit Rate)
service user
UL
HSUPA study result
kbps
Minimum RLC throughput supported
by the HSUPA bearer
T RLC – Av
UL
HSUPA study result
kbps
Average RLC throughput supported
by the HSUPA bearer
R MAC
UL
HSUPA study result
kbps
MAC rate supported by the HSUPA
bearer
R
Service parameter (for HSDPA only)
kbps
Throughput offset
SF Rate
Service parameter (for HSDPA only)
%
Scaling factor
P max  Txi 
Transmitter parameter
W
Maximum shared power
Available only if the inter-carrier power
sharing option is activated
P SCH  Txi ic 
Cell parameter
W
Cell synchronisation channel power
P OtherCCH  Txi ic 
Cell parameter
W
P pilot  Txi ic 
Cell parameter
W
Cell pilot power
P HSDPA  Txi ic 
Cell parameter (user-defined or simulation result) (for HSDPA only)
P HS – PDSCH  Txi ic  + n HS – SCCH  P HS – SCCH  Txi ic 
W
Available cell HSDPA power
HSDPA: High Speed Downlink Packet
Access
P HS – PDSCH  Txi ic 
Simulation result (for HSDPA only)
W
Cell HS-PDSCH power
HS-PDSCH: High Speed Physical
Downlink Shared Channel
P HS – SCCH  Txi ic 
Cell parameter (for HSDPA only)
W
Cell HS-SCCH power
HS-SCCH: High Speed Shared
Control Channel
n HS – SCCH
Cell parameter (user-defined or simulation result) (for HSDPA only)
P Headroom  Txi ic 
Cell parameter (for HSDPA only)
W
Cell headroom power
P max  Txi ic 
Cell parameter
W
Maximum Cell power
P tch  Txi ic 
Simulation result
W
R99 traffic channel power transmitted
on carrier ic
min
R99 bearer parameter
W
Minimum power allowed on R99 traffic
data channel
P tch
max
R99 bearer parameter
W
Maximum power allowed on R99
traffic data channel
P HSUPA  Txi ic 
Cell parameter
W
Cell HSUPA power
HSUPA: High Speed Uplink Packet
Access
DL
C HSDPABearer
DL
T RLC – peak
DL
T MAC
UL
UL
HSUPA study result
UL
R RLC – peak
UL
R RLC – peak  I HSUPABearer 
UL
C HSUPABearer
T RLC – Min
P tch
© Forsk 2009
AT281_TRG_E1
Cell other common channels (except
CPICH and SCH) powera
number of HS-SCCH channels
managed by the cell
195
Technical Reference Guide
P tx –H SDPA  Txi ic 
Simulation result
W
Transmitter HSDPA power transmitted
on carrier ic
W
Transmitter R99 power transmitted on
carrier ic
Cell parameter or simulation result
P pilot  Txi ic  + P SCH  Txi ic  + P OtherCCH  Txi ic  +
P tx – R99  Txi ic 


P tch  Txi ic  +
tch(ic) used for
R99 users
DL
P tch  Txi ic   f act –ADPCH
tch(ic) used for
HSUPA users
P tx  Txi ic 
Simulation result
P tx – R99  Txi ic  + P tx –H SDPA  Txi ic  + P HSUPA  Txi ic 
W
Transmitter total power transmitted on
carrier ic
P term – R99
Simulation result
W
Terminal power transmitted to obtain
the R99 radio bearer
P term – HSUPA
Simulation result
W
Terminal power transmitted to obtain
the HSUPA radio bearer
P term
P term – R99  f act – ADPCH + P term – HSUPA for HSPA users
W
Total power transmitted by the
terminal
Simulation result
UL
P term – R99 for R99 users
P term
min
Terminal parameter
W
Minimum terminal power allowed
P term
max
Terminal parameter
W
Maximum terminal power allowed
 BTS
BTS parameter
%
Percentage of BTS signal correctly
transmitted
 term
Terminal parameter
%
Percentage of terminal signal correctly
transmitted

Clutter parameter
%
Percentage of pilot finger - percentage
of signal received by the terminal pilot
finger
G Tx
Antenna parameter
None
Transmitter antenna gain
G Term
Terminal parameter
None
Terminal gain
G Div
DL
R99 bearer parameter - Depends on the transmitter Tx diversity
None
Gain due to transmit diversity
UL
R99 bearer parameter - Depends on the transmitter Rx diversity
None
Gain due to receive diversity
G SM
Max
MIMO configuration parameter
dB
Maximum spatial multiplexing gain for
a given number of transmission and
reception antennas
G TD
DL
MIMO configuration parameter
dB
Downlink Transmit Diversity gain for a
given number of transmission and
reception antenna ports
f SM – Gain
Clutter parameter
None
Spatial multiplexing gain factor
G TD
Clutter parameter
dB
Additional diversity gain in downlink
L Tx
Transmitter parameter (user-defined or calculated from transmitter
equipment characteristics)
None
Transmitter lossb
L body
Service parameter
None
Body loss
L Term
Terminal parameter
None
Terminal loss
L indoor
Clutter and frequency band parameter
L path
Propagation model result
None
Path loss
M Shadowing – model
Result calculated from cell edge coverage probability and model
standard deviation
None
Model Shadowing margin
Only used in prediction studies
M Shadowing – Ec  Io
Result calculated from cell edge coverage probability and Ec/I0
standard deviation
None
Ec/I0 Shadowing margin
Only used in prediction studies
G Div
DL
DL
M Shadowing –  Eb  Nt 
196
npaths
G macro – diversity = M Shadowing – Ec  Io – M Shadowing – Ec  Io
DL
G macro – diversity
Indoor loss
None
n=2 or 3
DL
Result calculated from cell edge coverage probability and DL Eb/Nt
standard deviation
AT281_TRG_E1
None
DL gain due to availability of several
pilot signals at the mobile c.
DL Eb/Nt Shadowing margin
Only used in prediction studies
© Forsk 2009
Chapter 6: UMTS HSPA Networks
M Shadowing –  Eb  Nt 
Result calculated from cell edge coverage probability and UL Eb/Nt
standard deviation
UL
UL
npaths
G macro – diversity = M Shadowing –  Eb  Nt 
UL
G macro – diversity
UL
– M Shadowing – Eb  Nt 
n=2 or 3
Global parameter (default value)
UL
None
None
UL Eb/Nt Shadowing margin
Only used in prediction studies
UL quality gain due to signal diversity
in soft handoffd.
None
Random shadowing error drawn
during Monte-Carlo simulation
Only used in simulations
None
Transmitter-terminal total loss
P pilot  Txi ic 
----------------------------------LT
W
Chip power received at terminal
DL
P tch  Txi ic 
-------------------------------LT
W
Bit power received at terminal on
carrier ic
DL
P tx  Txi ic 
-----------------------------LT
W
Total power received at terminal from
a transmitter on carrier ic
W
Total power received at terminal from
traffic channels of a transmitter on
carrier ic
P term
-------------LT
W
Bit power received at transmitter on
carrier ic used by terminal
P term – R99
--------------------------LT
W
Bit power received at transmitter on
carrier ic used by terminal
W
Bit power received at transmitter on
DPDCH from a terminal on carrier ic
E Shadowing
Simulation result
In prediction studiese
For Ec/I0 calculation
L path  L Tx  L term  L body  L indoor  M Shadowing – Ec  Io
--------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
For DL Eb/Nt calculation
L path  L Tx  L term  L body  L indoor  M Shadowing –  Eb  Nt 
DL
-----------------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
LT
For UL Eb/Nt calculation
L path  L Tx  L term  L body  L indoor  M Shadowing –  Eb  Nt 
UL
-----------------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
In simulations
L path  L Tx  L term  L body  L indoor  E Shadowing
-------------------------------------------------------------------------------------------------------------------------------G Tx  G term
P c  Txi ic 
P b  Txi ic 
P tot  Txi ic 

DL
P traf  Txi ic 
tch  ic 
UL
P b  ic 
UL
P b – R99  ic 
UL
P tch  Txi ic 
-------------------------------LT
UL
P b – DPDCH  ic 
UL
P b – R99  ic    1 – r c 
a.
For the calculation of interference, P OtherCCH  Txi ic  also includes the MBMS SCCPCH channel power
when the optional MBMS feature is activated. You must modify the data structure for activating the optional MBMS feature.
For more information, see the Administrator Manual.
b.
L Tx = L total – UL on uplink and L Tx = L total – DL on downlink. For information on calculating transmitter
losses on uplink and downlink, see "UMTS HSPA, CDMA2000 1xRTT 1xEV-DO, and TD-SCDMA Documents" on
page 128.
c.
npaths
M Shadowing –Ec  Io corresponds to the shadowing margin evaluated from the shadowing error probability
density function (n paths) in case of downlink Ec/I0 modelling.
d.
npaths
M Shadowing –  Eb  Nt 
UL
corresponds to the shadowing margin evaluated from the shadowing error probability
density function (n paths) in case of uplink soft handoff modelling.
e.
In uplink prediction studies, only carrier power level is downgraded by the shadowing margin
( M Shadowing –  Eb  Nt  ). In downlink prediction studies, carrier power level and intra-cell interference are downgraded by
UL
the shadowing model ( M Shadowing –  Eb  Nt 
M Shadowing –  Eb  Nt 
6.2.2
DL
DL
or M Shadowing – Ec  Io ) while extra-cell interference level is not. Therefore,
or M Shadowing – Ec  Io is set to 1 in downlink extra-cell interference calculation.
Ec/I0 Calculation
This table details the pilot quality ( Q pilot or Ec  Io ) calculations.
© Forsk 2009
AT281_TRG_E1
197
Technical Reference Guide
Name
Value
P SCH  txi ic 
 DL
DL
P tot  txi ic  –  BTS     P tot  txi ic  – --------------------------------
L
DL
I intra  txi ic 
Unit
Description
W
Downlink intra-cell interference at
terminal on carrier ic
W
Downlink extra-cell interference at
terminal on carrier ic
W
Downlink inter-carrier interference at
terminal on carrier ic
T

DL
I extra  ic 
DL
P tot  txj ic 
txj j  i
 Ptot  txj icadj 
DL
DL
I inter – carrier  ic 
txj
 j
------------------------------------------------
RF  ic ic adj 
Tx
P Transmitted  ic i 
 -----------------------------------------Tx
Tx m
L
 ICP
DL
I inter – techno log y  ic 
ic i ic
total
ni
W
Downlink inter-technology interference
at terminal on carrier ic a
Without Pilot:
DL
DL
DL
DL
I intra  txi ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic 
Term
+ N0
DL
I 0  ic 
–  1 –     BTS  P c  txi ic 
DL
Total noise:
DL
W
Total received noise at terminal on
carrier ic
None
Quality level at terminal on pilot for
carrier ic
DL
P tot  txi ic  + I extra  ic  + I inter – carrier  ic 
DL
Term
+ I inter – techno log y  ic  + N 0
 BTS    P c  txi ic 
------------------------------------------------------DL
I 0  ic 
Ec
Q pilot  txi ic    ------
 I0 
a. In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the
fractional load.
6.2.3
DL Eb/Nt Calculation
Eb
DL
This table details calculations of downlink traffic channel quality ( Q tch or  ------- ). When the optional MBMS feature is
 Nt  DL
activated, the MBMS Eb/Nt is also calculated in the same manner. You must modify the data structure for activating the
optional MBMS feature. For more information, see the Administrator Manual.
Name
DL
I intra  txi ic 
Value
Unit
Description
P SCH  txi ic 
 DL
DL
P tot  txi ic  –  BTS  F ortho   P tot  txi ic  – --------------------------------
L
W
Downlink intra-cell interference at
terminal on carrier ic
W
Downlink extra-cell interference at
terminal on carrier ic
W
Downlink inter-carrier interference at
terminal on carrier ic
T

DL
I extra  ic 
DL
P tot  txj ic 
txj j  i
 Ptot  txj icadj 
DL
DL
I inter – carrier  ic 
txj
 j
------------------------------------------------
RF  ic ic adj 
Tx
P Transmitted  ic i 
 -----------------------------------------Tx
Tx m
L
 ICP
DL
I inter – techno log y  ic 
DL
N tot  ic 
DL
DL
ic i ic
total
ni
W
DL
Term
DL
I intra  ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
W
Downlink inter-technology interference
at terminal on carrier ic a
Total received noise at terminal on
carrier ic
Without useful signal:
DL
Eb
DL
Q tch  txi ic    ------
 N t  DL
 BTS  P b  txi ic 
DL
----------------------------------------------------------------------------------------------------------------  G DL
Div  G p
DL
DL
N tot  ic  –  1 – F ortho    BTS  P b  txi ic 
None
DL
 BTS  P b  txi ic 
DL
-  G DL
Total Noise: -----------------------------------------------Div  G p
DL
N tot  ic 
Q
198
DL
 ic 
DL
f rake efficiency


DL
Q tch  tx k
ic 
txk  ActiveSet
AT281_TRG_E1
None
Quality level at terminal on a traffic
channel from one transmitter on
carrier ic b
Quality level at terminal using carrier
ic due to combination of all
transmitters of the active set (Macrodiversity conditions).
© Forsk 2009
Chapter 6: UMTS HSPA Networks
DL
Q  ic 
---------------------------------------------------------DL
Q tch  BestServer ic 
DL
G SHO
None
Soft handover gain on downlink
W
Required transmitter traffic channel
power to achieve Eb/Nt target at
terminal on carrier ic
DL
Q req
--------------------  P tch  txi ic 
DL
Q  ic 
req
P tch  txi ic 
a. In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the
fractional load.
b. Calculation option may be selected in the Global parameters tab. The chosen option will be taken into account only in
simulations. In point analysis and coverage studies, Atoll uses the option “Total noise” to evaluate DL and UL Eb/Nt.
6.2.4
UL Eb/Nt Calculation
Eb
UL
This table details calculations of uplink traffic channel quality ( Q tch or  ------- ).
 Nt  UL
Name
UL intra
I tot
 Pb
UL
 txi ic 
UL extra
I tot
Value
term
txi

 txi ic 
term
txj j  i
 Pb
ic 
Description
W
Total power received at transmitter
from intra-cell terminals using carrier
ic
W
Total power received at transmitter
from extra-cell terminals using carrier
ic
W
Uplink inter-carrier interference at
terminal on carrier ic
W
Total received interference at
transmitter on carrier ic
W
Total noise at transmitter on carrier ic
(Uplink interference)
UL
P b  ic 
UL
UL
I inter – carrier  txi
 ic 
Unit
 ic adj 
term
txj j
--------------------------------------
RF  ic ic adj 
UL
I tot  txi ic 
UL extra
I tot
UL intra
Tx
 txi ic  +  1 – F MUD   term  I tot
UL
UL
N tot  txi ic 
UL
 txi ic + I inter – carrier  txi ic 
tx
I tot  txi ic  + N 0
Without useful signal:
UL
Eb
UL
Q tch  txi ic    ------
 N t  UL
 term  P b – DPDCH  ic 
UL
----------------------------------------------------------------------------------------------------------------  G UL
Div  G p
UL
Tx
UL
N tot  txi ic  –  1 – F MUD    term  P b  ic 
None
UL
 term  P b – DPDCH  ic 
UL
UL
 G Div  G p
Total noise: ---------------------------------------------------------UL
N tot  txi ic 
Quality level at transmitter on a traffic
channel for carrier ic a
UL
No HO: Q tch  txi ic 

UL
Softer HO: f rake efficiency 
UL
Q tch  tx k ic 
tx k  ActiveSet
 samesite 
Soft, softer/soft HO (No MRC):
UL
UL
Max  Q tch  tx k ic    G macro – diversity
Q
UL
tx k  ActiveSet
 ic 
Softer/soft HO (MRC):
Quality level at site using carrier ic due
to combination of all transmitters of
the active set located at the same site
and taking into account increasing of
None
the quality due to macro-diversity
(macro-diversity gain).


 UL

UL
UL
 f rake efficiency  Q tch  tx k ic  Q tch  tx l ic 
tx ,tx  ActiveSet
k l


tx  samesite 

tx k
k
Max
UL
In simulations G macro – diversity = 1 .

tx l  othersite
UL
 G macro – diversity
UL
UL
G SHO
© Forsk 2009
Q  ic 
---------------------------------------------------------UL
Q tch  BestServer ic 
AT281_TRG_E1
None
Soft handover gain on uplink
199
Technical Reference Guide
UL
Q req
--------------------  P term
UL
Q  ic 
req
P term  ic 
W
Required terminal power to achieve
Eb/Nt target at transmitter on carrier
ic
a.
Calculation option may be selected in the Global parameters tab. The chosen option will be taken into account
only in simulations. In point analysis and coverage studies, Atoll uses the option “Total noise” to evaluate DL and UL Eb/Nt.
6.3
Active Set Management
The mobile’s active set (AS) is the list of the transmitters to which the mobile is connected. The active set may consist of
one or more transmitters; depending on whether the service supports soft handover and on the terminal active set size.
The terminal frequency bands are taken into account and transmitters in the mobile’s active set must use a frequency band
supported by the terminal. Finally, the quality of the pilot (Ec⁄I0) is what determines whether or not a transmitter can belong
to the active set. The active set management is detailed hereafter. Cells entering a mobile’s active set must satisfy the
following conditions:
•
The best server (first cell entering active set)
The pilot quality from the best serving cell must exceed the Ec/I0 threshold. Best server cell is the one with the
highest pilot quality.
•
Other cells in the active set
-
6.4
Must use the same carrier as the best server,
The pilot quality difference between other candidate cells and the best server must be less than the AS
threshold specified for the best server,
Other candidate cells must belong to the neighbour list of the best server if it is located on a site where the
equipment imposes this restriction (the “restricted to neighbours” option selected in the equipment properties).
Simulations
The simulation process consists of two steps:
1. Obtaining a realistic user distribution
Atoll generates a user distribution using a Monte-Carlo algorithm, which requires traffic maps and data as input.
The resulting user distribution complies with the traffic database and maps provided to the algorithm.
Each user is assigned a service, a mobility type, and an activity status by random trial, according to a probability
law that uses the traffic database.
The user activity status is an important output of the random trial and has direct consequences on the next step
of the simulation and on the network interferences. A user may be either active or inactive. Both active and inactive
users consume radio resources and create interference.
Then, Atoll randomly assigns a shadowing error to each user using the probability distribution that describes the
shadowing effect.
Finally, another random trial determines user positions in their respective traffic zone and whether they are indoors
or outdoors (according to the clutter weighting and the indoor ratio per clutter class defined for the traffic maps).
2. Power control simulation
6.4.1
Generating a Realistic User Distribution
During the simulation, a first random trial is performed to determine the number of users and their activity status. Four activity status are modelled:
•
Active UL: the user is active on UL and inactive on DL
•
Active DL: the user is active on DL and inactive on UL
•
Active UL+DL: the user is active on UL and on DL
•
Inactive: the user is inactive on UL and on DL
The determination of the number of users and the activity status allocation depend on the type of traffic cartography used.
Note:
•
Atoll follows a Poisson distribution to determine the total number of users attempting a
connection in each simulation. In order for Atoll to use a constant total number of users
attempting a connection, the following lines must be added to the Atoll.ini file:
[CDMA]
RandomTotalUsers=0
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6.4.1.1
Simulations Based on User Profile Traffic Maps
User profile environment based traffic maps: Each pixel of the map is assigned an environment class which contains a list
of user profiles with an associated mobility type and a given density (number of subscribers with the same profile per km²).
User profile traffic maps: Each polygon and line of the map is assigned a density of subscribers with given user profile and
mobility type. If the map is composed of points, each point is assigned a number of subscribers with given user profile and
mobility type.
The user profile models the behaviour of the different subscriber categories. Each user profile contains a list of services
and their associated parameters describing how these services are accessed by the subscriber.
From environment (or polygon) surface (S) and user profile density (D), a number of subscribers (X) per user profile is
inferred.
X = SD
Notes:
•
When user profile traffic maps are composed of lines, the number of subscribers (X) per
user profile is calculated from the line length (L) and the user profile density (D) (nb of
subscribers per km) as follows: X = L  D
The number of subscribers (X) is an input when a user profile traffic map is composed of
points.
•
For each behaviour described in a user profile, according to the service, frequency use and exchange volume, Atoll calculates the probability for the user being active in uplink and in downlink at an instant t.
6.4.1.1.1
Circuit Switched Service (i)
User profile parameters for circuit switched services are:
•
•
The used terminal (equipment used for the service (from the Terminals table)),
The average number of calls per hour N call ,
•
The average duration of a call (seconds) d .
The number of users and their distribution per activity status is determined as follows:
Calculation of the service usage duration per hour ( p 0 : probability of a connection):
1.
N call  d
p o = --------------------3600
2.
Calculation of the number of users trying to access the service i ( n i ):
ni = X  p0
Next, we can take into account activity periods during the connection in order to determine the activity status of each user.
3.
Calculation of activity probabilities:
UL
DL
Probability of being inactive on UL and DL: p inactive =  1 – f act    1 – f act 
UL
DL
DL
UL
Probability of being active on UL only: p UL = f act   1 – f act 
Probability of being active on DL only: p DL = f act   1 – f act 
UL
DL
Probability of being active both on UL and DL: p UL + DL = f act  f act
UL
DL
Where, f act and f act are respectively the UL and DL activity factors defined for the circuit switched service i.
4.
Calculation of number of users per activity status:
inactive
Number of inactive users on UL and DL: n i
= n i  p inactive
Number of users active on UL and inactive on DL: n i  UL  = n i  p UL
Number of users active on DL and inactive on UL: n i  DL  = n i  p DL
Number of users active on UL and DL both: n i  UL + DL  = n i  p UL + DL
Therefore, a user when he is connected can have four different activity status: either active on both links, or inactive on
both links, or active on UL only, or active on DL only.
6.4.1.1.2
Packet Switched Service (j)
User profile parameters for packet switched services are:
•
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•
The average number of packet sessions per hour N sess ,
•
The volume (in kbytes) which is transferred on the downlink V DL and the uplink V UL during a session.
A packet session consists of several packet calls separated by a reading time. Each packet call is defined by its size and
may be divided in packets of fixed size (1500 Bytes) separated by an inter arrival time.
In Atoll, a packet session is described by following parameters:
UL
N packet –c all : Average number of packet calls on the uplink during a session,
DL
N packet –c all : Average number of packet calls on the downlink during a session,
UL
T packet – call : Average time (millisecond) between two packets calls on the uplink ,
DL
T packet – call : Average time (millisecond) between two packets calls on the downlink ,
UL
T packet : Average time (millisecond) between two packets on the uplink ,
DL
T packet : Average time (millisecond) between two packets on the downlink ,
UL
S packet : Packet size (Bytes) on uplink,
DL
S packet : Packet size (Bytes) on downlink.
Figure 6.1: Description of a Packet Session
The number of users and their distribution per activity status is determined as follows:
1.
Calculation of the average packet call size (kBytes):
V UL
V DL
UL
DL
- and S packet –c all = ------------------------------------------S packet –c all = ------------------------------------------UL
UL
DL
DL
N packet –c all  f eff
N packet – c all  f eff
UL
DL
Where f eff and f eff are the UL and DL efficiency factors defined for the packet switched service j.
Note:
UL
2.
DL
For packet (HSDPA) and packet (HSPA) services, f eff and f eff are set to 1.
•
Calculation of the average number of packets per packet call:
UL
DL
 S packet –c all 
 S packet –c all 
UL
- + 1 and N DL
- + 1
N packet = int  ----------------------------------packet = int  ---------------------------------- S UL

 S DL


1024
packet
packet  1024
Note:
•
3.
1kBytes = 1024Bytes.
Calculation of the average duration of inactivity within a packet call (s):
UL
UL
DL
DL
 N packet – 1   T packet
 N packet – 1   T packet
UL
DL
- and  D Inactivity  packet – call = ------------------------------------------------------------- D Inactivity  packet – call = -------------------------------------------------------------1000
1000
4.
Calculation of the average duration of inactivity in a session (s):
UL
UL
UL
DL
DL
DL
 D Inactivity  session = N packet –c all   D Inactivity  packet – call and  D Inactivity  session = N packet –c all   D Inactivity  packet – call
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5.
Calculation of the average duration of activity in a session (s):
UL
UL
DL
DL
N packet  S packet  8
N packet  S packet  8
UL
UL
DL
- and  D DL
 D Activity  session = N packet – c all  ----------------------------------------------------Activity  session = N packet – c all  ----------------------------------------------------UL
DL
R average  1000
R average  1000
UL
DL
Where R average and R average are the uplink and downlink average requested rates defined for the service j.
Therefore, the average duration of a connection (in s) is:
UL
UL
UL
DL
DL
DL
D Connection =  D Activity  session +  D Inactivity  session and D Connection =  D Activity  session +  D Inactivity  session
6.
Calculation of the service usage duration per hour (probability of a connection):
N sess
N sess
UL
UL
DL
DL
p Connection = --------------  D Connection and p Connection = --------------  D Connection
3600
3600
7.
Calculation of the probability of being connected:
UL
DL
p Connected = 1 –  1 – p Connection    1 – p Connection 
Therefore, the number of users who want to get the service j is:
n j = X  p Connected
As you can see on the picture above, we have to consider three possible cases when a user is connected:
•
1st case: At a given time, packets are downloaded and uploaded.
In this case, the probability of being connected is:
UL
DL
p Connection  p Connection
UL + DL
p Connected = ---------------------------------------------------------------p Connected
•
2nd case: At a given time, packet are uploaded (no packet is downloaded).
Here, the probability of being connected is:
UL
DL
p Connection   1 – p Connection 
UL
p Connected = -----------------------------------------------------------------------------p Connected
•
3rd case: At a given time, packet are downloaded (no packet is uploaded).
In this case, the probability of being connected is:
DL
UL
p Connection   1 – p Connection 
DL
p Connected = -----------------------------------------------------------------------------p Connected
Now, we have to take into account activity periods during the connection in order to determine the activity status of each
user.
8.
f
UL
Calculation of the probability of being active:
UL
DL
 D Activity  session
 D Activity  session
DL
- and f
= ----------------------------------------------------------------------------------------------------= ----------------------------------------------------------------------------------------------------UL
UL
DL
DL
  D Inactivity  session +  D Activity  session 
  D Inactivity  session +  D Activity  session 
Therefore, we have:
•
1st case: At a given time, packets are downloaded and uploaded.
The user can be active on UL and inactive on DL; this probability is:
1
p UL = f
UL
 1 – f
DL
UL + DL
  p Connected
The user can be active on DL and inactive on UL; this probability is:
1
p DL = f
DL
 1 – f
UL
UL + DL
  p Connected
The user can be active on both links; this probability is:
1
p UL + DL = f
UL
f
DL
UL + DL
 p Connected
The user can be inactive on both links; this probability is:
1
p inactive =  1 – f
•
UL
  1 – f
DL
UL + DL
  p Connected
2nd case: At a given time, packet are uploaded (no packet is downloaded).
The user can be active on UL and inactive on DL; this probability is:
2
p UL = f
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UL
 p Connected
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The user can be inactive on both links; this probability is:
2
p inactive =  1 – f
•
UL
UL
  p Connected
3rd case: At a given time, packet are downloaded (no packet is uploaded).
The user can be active on DL and inactive on UL; this probability is:
3
p DL = f
DL
DL
 p Connected
The user can be inactive on both links; this probability is:
3
p inactive =  1 – f
9.
DL
DL
  p Connected
Calculation of number of users per activity status
inactive
Number of inactive users on UL and DL: n j
1
2
3
= n j   p inactive + p inactive + p inactive 
1
2
1
3
Number of users active on UL and inactive on DL: n j  UL  = n j   p UL + p UL 
Number of users active on DL and inactive on UL: n j  DL  = n j   p DL + p DL 
1
Number of users active on UL and DL: n j  UL + DL  = n j  p UL + DL
Therefore, a user when he is connected can have four different activity status: either active on both links, or inactive on
both links, or active on UL only, or active on DL only.
Note:
•
6.4.1.2
The user distribution per service and the activity status distribution between the users are
average distributions. And the service and the activity status of each user are randomly
drawn in each simulation. Therefore, if you compute several simulations at once, the
average number of users per service and average numbers of inactive, active on UL, active
on DL and active on UL and DL users, respectively, will correspond to calculated
distributions. But if you check each simulation, the user distribution between services as
well as the activity status distribution between users is different in each of them.
Simulations Based on Sector Traffic Maps
Sector traffic maps can be based on live traffic data from OMC (Operation and Maintenance Centre). Traffic is spread over
the best server coverage area of each transmitter and each coverage area is assigned either the throughputs in the uplink
and in the downlink or the number of users per activity status or the total number of users (including all activity statuses).
6.4.1.2.1
Throughputs in Uplink and Downlink
When selecting Throughputs in Uplink and Downlink, you can input the throughput demands in the uplink and downlink
for each sector and for each listed service.
Atoll calculates the number of users active in uplink and in downlink in the Txi cell using the service (NUL and NDL) as
follows:
UL
DL
Rt
Rt
N UL = ---------------------and N DL = ---------------------UL
DL
R average
R average
UL
is the kbits per second transmitted in UL in the Txi cell to supply the service.
DL
is the kbits per second transmitted in DL in the Txi cell to supply the service.
Rt
Rt
DL
R average is the downlink average requested rate defined for the service,
UL
R average is the uplink average requested rate defined for the service.
NUL and NDL values include:
•
•
•
Users active in uplink and inactive in downlink (ni(UL)),
Users active in downlink and inactive in uplink (ni(DL)),
And users active in both links (ni(UL+DL)).
Atoll takes into account activity periods during the connection in order to determine the activity status of each user.
Activity probabilities are calculated as follows:
UL
DL
Probability of being inactive in UL and DL: p inactive =  1 – f act    1 – f act 
UL
DL
Probability of being active in UL only: p UL = f act   1 – f act 
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DL
UL
Probability of being active in DL only: p DL = f act   1 – f act 
UL
DL
Probability of being active both in UL and DL: p UL + DL = f act  f act
UL
DL
Where, f act and f act are respectively the UL and DL activity factors defined for the service i.
Note:
UL
DL
For packet (HSDPA) and packet (HSPA) services, f act and f act are set to 1.
•
Then, Atoll calculates the number of users per activity status:
We have:
 p UL + p UL + DL    n j  UL  + n j  DL  + n j  UL + DL   = N UL
 p DL + p UL + DL    n j  UL  + n j  DL  + n j  UL + DL   = N DL
Therefore, we have:
N UL  p UL + DL N DL  p UL + DL
Number of users active in UL and DL both: n i  UL + DL  = min  ------------------------------------- -------------------------------------
 p UL + p UL + DL p DL + p UL + DL 
Number of users active in UL and inactive in DL: n i  UL  = N UL – n i  UL + DL 
Number of users active in DL and inactive in UL: n i  DL  = N DL – n i  UL + DL 
inactive
Number of inactive users in UL and DL: n i
 n j  UL  + n j  DL  + n j  UL + DL  
= --------------------------------------------------------------------------------------  p inactive
1 – p inactive
Therefore, a connected user can have four different activity status: either active in both links, or inactive in both links, or
active in UL only, or active in DL only.
6.4.1.2.2
Total Number of Users (All Activity Statuses)
When selecting Total Number of Users (All Activity Statuses), you can input the number of connected users for each
sector and for each listed service ( n i ).
Atoll takes into account activity periods during the connection in order to determine the activity status of each user.
Activity probabilities are calculated as follows:
UL
DL
Probability of being inactive in UL and DL: p inactive =  1 – f act    1 – f act 
UL
DL
DL
UL
Probability of being active in UL only: p UL = f act   1 – f act 
Probability of being active in DL only: p DL = f act   1 – f act 
UL
DL
Probability of being active both in UL and DL: p UL + DL = f act  f act
UL
DL
Where, f act and f act are respectively the UL and DL activity factors defined for the service i.
Note:
•
UL
DL
For packet (HSDPA) and packet (HSPA) services, f act and f act are set to 1.
Then, Atoll calculates the number of users per activity status:
inactive
Number of inactive users in UL and DL: n i
= n i  p inactive
Number of users active in UL and inactive in DL: n i  UL  = n i  p UL
Number of users active in DL and inactive in UL: n i  DL  = n i  p DL
Number of users active in UL and DL both: n i  UL + DL  = n i  p UL + DL
Therefore, a connected user can have four different activity status: either active in both links, or inactive in both links, or
active in UL only, or active in DL only.
6.4.1.2.3
Number of Users per Activity Status
inactive
When selecting Number of Users per Activity Status, you can directly input the number of inactive users ( n i
), the
number of users active in the uplink ( n i  UL  ), in the downlink ( n i  DL  ) and in the uplink and downlink ( n i  UL + DL  ), for
each sector and for each service.
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Note:
•
6.4.2
The activity status distribution between users is an average distribution. In fact, in each
simulation, the activity status of each user is randomly drawn. Therefore, if you compute
several simulations at once, average numbers of inactive, active on UL, active on DL and
active on UL and DL users correspond to the calculated distribution. But if you check each
simulation, the activity status distribution between users is different in each of them.
Power Control Simulation
The power control algorithm simulates the way a UMTS network regulates itself by using uplink and downlink power
controls in order to minimize interference and maximize capacity.
HSDPA users (i.e., Packet (HSDPA), Packet (HSPA) and Packet (HSPA - Constant Bit Rate) service users) are linked to
the A-DPCH radio bearer (an R99 radio bearer). Therefore, the network uses a A-DPCH power control on UL and DL and
then it performs fast link adaptation on DL in order to select an HSDPA radio bearer. For HSUPA users (i.e., Packet
(HSPA) and Packet (HSPA - Constant Bit Rate) service users), the network first uses a E-DPCCH/A-DPCH power control
on UL and DL, checks that there is an HSDPA connection on downlink and then carries out noise rise scheduling in order
to select an HSUPA radio bearer on uplink. Atoll simulates these network regulation mechanisms with an iterative algorithm and calculates, for each user distribution, network parameters such as cell power, mobile terminal power, active set
and handoff status for each terminal. During each iteration of the algorithm, all the users (i.e., Circuit (R99), Packet (R99),
Packet (HSDPA), Packet (HSPA) and Packet (HSPA - Constant Bit Rate) service users) selected during the user distribution generation (1st step) attempt to connect one by one to network transmitters. The process is repeated until the network
is balanced, i.e., until the convergence criteria (on UL and DL) are satisfied.
Initialisation
R99 part
Mi Best Server Determination
Mi Active Set Determination
For HSDPA users, this part of
the algorithm is performed for
the A-DPCH bearer (R99 bearer)
For HSUPA users, this part is
performed for the E-DPCCH/ADPCH bearer (R99 bearer)
For each R99, HSDPA
and HSUPA mobile, Mi
UL Power Control
DL Power Control
UL and DL Interference Update
Congestion and Radio Resource Control
HSDPA part
For each HSDPA and
HSUPA mobile, Mi
Fast Link Adaptation
Mobile Scheduling
Radio Resource Control
HSUPA part
Admission Control
For each HSUPA
mobile, Mi
Noise Rise Scheduling
Radio Resource Control
Convergence Study
Figure 6.2: UMTS HSPA Power Control Algorithm
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As shown in Figure 6.2: on page 206, the simulation algorithm is divided in three parts. All users are evaluated by the R99
part of the algorithm. HSDPA and HSUPA bearer users, unless they have been rejected during the R99 part of the algorithm, are then evaluated by the HSDPA part of the algorithm. Finally, HSUPA bearer users, unless they have been
rejected during the R99 or HSDPA parts of the algorithm, are then evaluated by the HSUPA part of the algorithm.
The steps of this algorithm are detailed below.
6.4.2.1
Algorithm Initialization
The total power transmitted by the base station txi on the carrier ic m ,
P Tx  txi ic m  , is initialised to
P pilot  txi ic m  + P SCH  txi ic m  + P otherCCH  txi ic m  + P HSDPA  txi ic m  + P HSUPA  txi ic  . Uplink received powers by
UL intra
the base station txi on carrier ic m , I tot
UL extra
 txi ic m  , I tot
UL
 txi ic m  and I inter – carrier  txi ic m  are initialised to 0 W (i.e.
no connected mobile).
UL
I tot  txi ic m 
UL
- = 0
 X k  txi ic m  = --------------------------------UL
N tot  txi ic m 
6.4.2.2
R99 Part of the Algorithm
UL
The algorithm is detailed for any iteration k. Xk is the value of the X (variable) at the iteration k. In the algorithm, all Q req
DL
and Q req thresholds depend on the user mobility type and are defined in the R99 bearer property dialogue. All variables
are described in Definitions and formulas part.
Here, the rate downgrading is not taken into account.
The algorithm applies to single frequency band networks and to dual-band networks. Dual-band terminals can have the
following configurations:
-
Configuration 1: The terminal can work on f1 and f2 without any priority (select "All" as main frequency band
in the terminal property dialogue).
Configuration 2: The terminal can work on f1 and f2 but f1 has a higher priority (select "f1" as main frequency
band and "f2" as secondary frequency band in the terminal property dialogue).
For each mobile Mb
Determination of Mb’s Best Server
For each transmitter txi containing Mb in its calculation area and working on the main frequency band supported by the
Mb’s terminal (i.e. either f1 for a single frequency band network, or f1 or f2 for a dual-band terminal with the configuration
1, or f1 for a dual-band terminal with the configuration 2).
   BTS  P c  txi M b ic 
Calculation of Q pilot  txi ic Mb  = -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Term
k
DL
DL
DL
DL
P tot  txi ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
If user selects “without Pilot”
   BTS  P c  txi M b ic 
Q pilot  txi ic Mb  = ----------------------------------------------------------------------------------------------------------------------------------------------------------------------k
DL
DL
DL
 DL

 I intra  ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  


Term
+ N0
–  1 –     BTS  P c  txi M b ic 


Determination of the best transmitter, txBS, for each carrier ic.
For each carrier ic, selection of the transmitter with the highest Q pilot  txi M b ic  , tx BS  M b  .
k
Analysis of candidate cells, (txBS,ic).
For each pair (txBS,ic), calculation of the uplink load factor:
UL
I tot  tx BS ic 
UL
UL
- + X
X k  tx BS ic  = ---------------------------------UL
N tot  tx BS ic 
Rejection of bad candidate cells if the pilot is not received or if the uplink load factor is exceeded during the admission load
control (if simulation respects a loading factor constraint and Mb was not connected in previous iteration)
pilot
If Q pilot  tx BS M b ic   Q req  Mobility  M b   then (txBS,ic) is rejected by Mb
k
UL
UL
If X k  tx BS ic   X max , then (txBS,ic) is rejected by Mb
Else
Keep (txBS,ic) as good candidate cell
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For dual band terminals with the configuration 1 or terminals working on one frequency band only, if no good candidate
cell has been selected, Mb has failed to be connected to the network and is rejected.
For dual band terminals with the configuration 2, if no good candidate cell has been selected, try to connect Mb to transmitters txi containing Mb in their calculation area and working on the secondary frequency band supported by the Mb’s
terminal (i.e. f2). If no good candidate cell has been selected, Mb has failed to be connected to the network and is rejected.
For each NodeB having candidate cells, determination of the best carrier, icBS, within the set of candidate cells
of the NodeB.
If a given carrier is specified for the service requested by Mb
ic BS  M b  is the carrier specified for the service
Else the carrier selection mode defined for the site equipment is considered.
If carrier selection mode is “Min. UL Load Factor”
UL
ic BS  M b  is the cell with the lowest X k  tx BS ic 
Else if carrier selection mode is “Min. DL Total Power”
ic BS  M b  is the cell with the lowest P tx  tx BS ic  k
Else if carrier selection mode is “Random”
ic BS  M b  is randomly selected
Else if carrier selection mode is "Sequential"
UL
UL
ic BS  M b  is the first carrier where X k  tx BS ic   X max
Endif
max
(tx BS,ic BS) k  M b  is the best serving cell ( BestCell k  M b  ) and its pilot quality is Q pilot  M b 
k
In the following lines, we will consider ic as the carrier used by the best serving cell
Active Set Determination
For each station txi containing Mb in its calculation area, using ic , and, if neighbours are used, neighbour of
BestCell k  M b 
   BTS  P c  txi M b ic 
Calculation of Q pilot  txi M b ic  = -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------DL
DL
DL
DL
Term
k
P tot  txi ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
If user selects “without Pilot”
   BTS  P c  txi M b ic 
Q pilot  txi M b ic  = --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------k
DL
DL
DL
 DL

 I intra  txi ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  


Term
+ N0
–  1 –     BTS  P c  txi M b ic 


Rejection of txi from the active set if difference with the best server is too high
max
If Q pilot  M b  – Q pilot  txi M b ic   AS_Th  BestCell k  M b   then txi is rejected
k
k
Else txi is included in the Mb active set
Rejection of a station if the mobile active set is full
Station with the lowest Q pilot in the active set is rejected
k
EndFor
Uplink Power Control
R99 – req
Calculation of the terminal power required by Mb to obtain the R99 radio bearer: P term
 M b ic  k
For each cell (txi,ic) of the Mb active set
Calculation of quality level on Mb traffic channel at (txi,ic), with the minimum power allowed on traffic channel for the Mb
service
req
P term – R99  M b ic  k – 1
UL
P b – R99  txi M b ic  = --------------------------------------------------------L T  txi M b 
UL
UL
UL
P b – DPDCH  txi M b ic  = P b – R99  txi M b ic    1 – r c 
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UL
UL
UL
P b – DPCCH  txi M b ic  = P b – R99  txi M b ic   r c
UL
UL
UL
UL
UL
P b – R99  txi M b ic  = P b – DPCCH  txi M b ic  + P b – DPDCH  txi M b ic  if the user is active,
P b – R99  txi M b ic  = P b – DPCCH  txi M b ic  if the user is inactive,
UL
 term  P b – DPDCH  txi M b ic  k
UL
UL
-  G UL
Q tch  txi M b ic  k = -------------------------------------------------------------------------------------------------------------------------------------------------------p  Service  M b    G div
UL
Tx
UL
N tot  txi ic  –  1 – F MUD    term  P b – R99  txi M b ic  k – 1
If user selects "Total noise",
UL
 term  P b – DPDCH  txi M b ic  k
UL
UL
-  G UL
Q tch  txi M b ic  k = --------------------------------------------------------------------------------p  Service  M b    G div
UL
N tot  txi ic 
End For
If (Mb is in not in handoff)
UL
UL
Q k  M b  = Q tch  txi M b ic  k
Else if (Mi is in softer handoff)
UL
UL
Q k  M b  = f rake efficiency 

UL
Q tch  txi M b ic  k
txi  ActiveSet
Else if (Mb is in soft, or softer/soft without MRC)
UL
UL
UL
Q k  M b  = Max  Q tch  txi M b ic  k    G macro – diversity  2 links
txi  ActiveSet
Else if (Mb is in soft/soft)
UL
UL
UL
Q k  M b  = Max  Q tch  txi M b ic  k    G macro – diversity  3 links
txi  ActiveSet
Else if (Mb is in softer/soft with MRC)


 UL

UL
UL
UL
UL
Q k  M b  = Max  f rake efficiency 
Q tch  ic  Q tch  ic    G macro – diversity  2 links
other site


txi  ActiveSet


 samesite 

End If
UL
Q req  Service  M b  Mobility  M b  
req
req
P term – R99  M b ic  k = ------------------------------------------------------------------------------------------- P term – R99  M b ic  k – 1
UL
Qk  Mb 
If compressed mode is operated,
Note:
•
Compressed mode is operated if:
- Mi and Sj support compressed mode,
And
Resulting
- Either Q pilot
k
CM – activation
 txi M b ic   Q pilot
CM – activation
- Or P c  txi M b ic   RSCP pilot
UL
if the Ec/I0 Active option is selected,
if the RSCP Active option is selected.
UL
Q req  Service  M b  Mobility  M b    Q req   Service  M b  Mobility  M b   
req
-  P req
P term – R99  M b ic  k = -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------term – R99  M b ic  k – 1
UL
Qk  Mb 
req
min
req
max
req
min
If P term – R99  M b ic  k  P term  M b  then P term – R99  M b ic  k = P term  txi M b 
If P term – R99  M b ic  k  P term  M b  then Mb cannot select any cell and its active set is cleared
UL
UL
If R nominal  M b   R max  txi ic  then Mb cannot be connected
Endif
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Downlink Power Control
If (mobile does not use a packet switched service that is inactive on the downlink)
For each cell (txi,ic) in Mb active set
Calculation of quality level on (txi,ic) traffic channel at Mb with the minimum power allowed on traffic channel for the Mb
service
min
P tch  Service  M b  
DL
P b  txi M b ic  = ---------------------------------------------------L T  txi M b 
DL
 BTS  P b  txi M b ic  k
DL
DL
-  G DL
Q tch  txi M b ic  k = -----------------------------------------------------------------------------------------------------------------------------------p  Service  M b    G div
DL
DL
N tot  ic  –  1 – F ortho    BTS  P b  txi M b ic  k – 1
If the user selects the option "Total noise"
DL
 BTS  P b  txi M b ic  k
DL
DL
DL
Q tch  txi M b ic  k = ------------------------------------------------------------- G p  Service  M b    G div
DL
N tot  ic 
End For
DL
DL
Q k  M b  = f rake efficiency 

DL
Q tch  txi M b ic  k
txi  ActiveSet
Do
For each cell (txi,ic) in Mb active set
Calculation of the required power for DL traffic channel between (txi,ic) and Mb:
DL
Q req  Service  M b  Mobility  M b  
req
min
P tch  txi M b ic  k = ------------------------------------------------------------------------------------------- P tch  Service  M b  
DL
Qk  Mb 
If compressed mode is operated.
DL
DL
Q req  Service  M b  Mobility  M b    Q req   Service  M b  Mobility  M b   
req
-  P min
P tch  txi M b ic  k = -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------tch  Service  M b  
DL
Qk  Mb 
Note:
•
Compressed mode is operated if:
- Mi and Sj support compressed mode,
And
Resulting
- Either Q pilot
k
CM – activation
 txi M b ic   Q pilot
CM – activation
- Or P c  txi M b ic   RSCP pilot
req
max
if the Ec/I0 Active option is selected,
if the RSCP Active option is selected.
max
If P tch  txi M b ic  k  P tch  Service  M b   then  txi ic  is set to P tch
DL
max
Recalculation of a decreased Q req (a part of the required quality is managed by the cells set to P tch )
req
P tch  Service  M b  
DL
P b  txi M b ic  = --------------------------------------------------L T  txi M b 
DL
 BTS  P b  txi M b ic 
DL
DL
DL
Q tch  txi M b ic  k = -------------------------------------------------------------------------------------------------------------------------- G p  Service  M b    G div
DL
DL
N tot  ic  –  1 – F ortho    BTS  P b  txi M b ic 
DL
DL
DL
If the user is inactive, then his contribution to interference in the calculation of N tot  ic  is P b  txi M b ic   r c .
EndFor
DL
DL
Q k  M b  = f rake efficiency 

DL
Q tch  txi M b ic  k
txi  ActiveSet
While
DL
DL
Qk  Mb 

DL
Q req  Service  M b 
Mobility  M b   and Mb active set is not empty
DL
If R nominal  M b   R max  txi ic  then Mb cannot be connected
Endif
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Uplink and Downlink Interference Update
Update of interference on active mobiles only (old contributions of mobiles and stations are replaced by the new ones).
For each cell (txi,ic)
UL
Update of N tot  txi ic 
EndFor
For each mobile Mi
DL
Update of N tot  ic 
EndFor
EndFor
Control of Radio Resource Limits (OVSF Codes, Cell Power, Channel Elements, Iub Backhaul
Throughput)
For each cell (txi,ic)
P tx  txi ic  k
DL
While ------------------------------  %Power max
P max
Rejection of the mobile with the lowest service priority starting from the last admitted
EndFor
For each cell (txi,ic)
While N
Codes
Codes
 txi ic  k  N max  txi ic 
Rejection of the mobile with the lowest service priority starting from the last admitted
EndFor
For each NodeB, Ni
While N
CE – DL
CE – DL
 N i  k  N max
 Ni 
Rejection of the mobile with the lowest service priority starting from the last admitted
While N
CE – UL
CE – UL
 N i  k  N max
 Ni 
Rejection of the mobile with the lowest service priority starting from the last admitted
EndFor
For each NodeB, Ni
DL
DL
While T Iub  N I  k  T Iub –m ax  N I 
Rejection of the mobile with the lowest service priority starting from the last admitted
UL
UL
While T Iub  N I  k  T Iub –m ax  N I 
Rejection of the mobile with the lowest service priority starting from the last admitted
EndFor
Uplink Load Factor Control
For each cell (txi,ic) with X
UL
UL
 txi ic   X max
Rejection of the mobile with the lowest service priority starting from the last admitted
EndFor
While at least one cell with X
6.4.2.3
UL
UL
 txi ic   X max exists
HSDPA Part of the Algorithm
Packet (HSDPA) and packet (HSPA) service users active on DL as well as all packet (HSPA - Constant Bit Rate) service
users (i.e., active and incative), unless they have been rejected during the R99 part of the algorithm, are then evaluated
by the HSDPA part of the algorithm.
6.4.2.3.1
HSDPA Power Allocation
The total transmitted power of the cell ( P tx  ic  ) is the sum of the transmitted R99 power, the HSUPA power and the transmitted HSDPA power.
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P tx  ic  = P tx – R99  ic  + P tx –H SDPA  ic  + P HSUPA  ic 
•
In case of a static HSDPA power allocation strategy, Atoll checks in the simulation that:
DL
P tx  ic   P max  ic   %Power max
where:
DL
%Power max is the maximum DL load allowed.
Therefore, if the maximum DL load is set to 100%, we have:
P tx  ic   P max  ic 
•
In case of dynamic HSDPA power allocation strategy, Atoll checks in the simulation that:
DL
P tx – R99  ic  + P HSUPA  ic   P max  ic   %Power max
And it calculates the available HSDPA power as follows:
P HSDPA  ic  = P max  ic  – P Headroom  ic  – P tx – R99  ic  – P HSUPA  ic 
6.4.2.3.2
Number of HS-SCCH Channels and Maximum Number of HSDPA Bearer Users
The number of HS-SCCH channels ( n HS – SCCH ) is the maximum number of HS-SCCH channels that the cell can manage.
This parameter is used to manage the number of packet (HSDPA) and packet (HSPA) service users simultaneously
connected to an HSDPA bearer. This parameter is not taken into account for packet (HSPA - Constant Bit Rate) service
users as HS-SCCH-less operation (i.e., HS-DSCH transmissions without any accompanying HS-SCCH) is performed.
Each packet (HSDPA) and packet (HSPA) service user consumes one HS-SCCH channel. Therefore, at a time (over a
transmission time interval), the number of these users connected to an HSDPA bearer cannot exceed the number of HSSCCH channels per cell.
The maximum number of HSDPA users ( n max ) corresponds to the maximum number of HSDPA bearer users that the cell
can support. Here, all HSDPA bearer users, i.e., packet (HSDPA) service users, packet (HSPA) service users and packet
(HSPA - Constant Bit Rate) service users, are taken into consideration.
Let us assume there are 30 HSDPA bearer users in the cell:
•
•
10 packet (HSPA - Constant Bit Rate) service users with any activity status.
20 packet (HSDPA) and packet (HSPA) service users active on DL.
All users are connected to the A-DCH R99 bearer. Finally, the number of HS-SCCH channels and the maximum number
of HSDPA users respectively equal 4 and 25.
The scheduler manages the maximum number of users within each cell. Packet (HSPA - Constant Bit Rate) service users
have the highest priority and are processed first, in the order established during the generation of the user distribution.
After processing the packet (HSPA - Constant Bit Rate) service users, the scheduler ranks the remaining HSDPA bearer
users (i.e., packet (HSDPA) and packet (HSPA) service users) according to the selected scheduling technique. Users are
treated as described in the figure below.
Figure 6.3: Connection status of HSDPA bearer users
•
•
All packet (HSPA - Constant Bit Rate) service users may be served if there are enough HSDPA power, Iub backhaul throughput and OVSF codes available in order for them to obtain the lowest HSDPA bearer that provides a
RLC peak rate higher or equal to the guaranted bit rate defined for the service. In this case, they will be connected.
Else, they will be rejected.
Then, among the packet (HSDPA) and packet (HSPA) service users:
-
-
6.4.2.3.3
The first four users may be simultaneously served if there are enough HSDPA power, Iub backhaul throughput
and OVSF codes available in order for them to obtain an HSDPA bearer. In this case, they will be connected.
Else, they will be delayed.
The next eleven ones will be delayed since there are no longer HS-SCCH channels available. Their connection status will be "HS-SCCH Channels Saturation".
Finally, the last five users will be rejected beacuse the maximum number of HSDPA user has been fixed to
25. Their connection status will be "HSDPA Scheduler Saturation".
HSDPA Bearer Allocation Process
The HSDPA bearer allocation process depends on the type of service requested by the user. As explained before, packet
(HSPA - Constant Bit Rate) service users have the highest priority and are processed first, in the order established during
the generation of the user distribution. After processing the packet (HSPA - Constant Bit Rate) service users, the scheduler
ranks the remaining HSDPA bearer users (i.e., packet (HSDPA) and packet (HSPA) service users) and shares the cell
radio resources between them.
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Packet (HSPA - Constant Bit Rate) Service Users
Let us focus on the ten packet (HSPA - Constant Bit Rate) service users mentionned in the example of the previous paragraph "Number of HS-SCCH Channels and Maximum Number of HSDPA Bearer Users" on page 212. Fast link adaptation
is carried out on these users in order to determine if they can obtain an HSDPA bearer that provides a RLC peak rate
higher or equal to the service guaranteed bit rate. As HS-SCCH less operation is performed, only HSDPA bearers using
the QPSK modulation and two HS-PDSCH channels at the maximum can be selected and allocated to the users. The
users are processed in the order established during the generation of the user distribution and the cell’s available HSDPA
power is shared between them as explained below. Several Packet (HSPA - Constant Bit Rate) service users can share
the same HSDPA bearer. Then, Atoll calculates the HSDPA bearer consumption ( C in %) for each user and takes into
account this parameter when it determines the resources consumed by the user (i.e., the HSDPA power used, the number
of OVSF codes and the Iub backhaul throughput).
In the bearer allocation process shown below, the 10 packet (HSPA - Constant Bit Rate) service users are represented by
Mj, with j = 1 to 10. And, the initial values of their respective HSDPA powers is 0, i.e. PHSDPA(B(MX)) = 0, where X = 0 to
10. These power values are assigned one by one by the scheduler, so that with their allocated values, looped back to the
starting point, are used in successive steps.
For the user, Mj, with j varying from 1 to 10:
Figure 6.4: HSDPA Bearer Allocation Process for Packet (HSPA - Constant Bit Rate) Service Users
Packet (HSDPA) and Packet (HSPA) Service Users
After processing the packet (HSPA - Constant Bit Rate) service users, the scheduler share the cell’s remaining resources
between packet (HSDPA) and packet (HSPA) service users. Let us focus on the packet (HSDPA) and packet (HSPA) serv-
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ice users, especially on the first four users mentionned in the example of the previous paragraph, "Number of HS-SCCH
Channels and Maximum Number of HSDPA Bearer Users" on page 212. A new fast link adaptation is carried out on these
users in order to determine if they can obtain an HSDPA bearer. They are processed in the order defined by the scheduler
and the cell’s HSDPA power available after all Packet (HSPA - Constant Bit Rate) service users have been served is
shared between them as explained below.
In the bearer allocation process shown below, the 4 packet (HSDPA) and packet (HSPA) service users are represented
by Mj, with j = 1 to 4. And, the initial values of their respective HSDPA powers is 0, i.e. PHSDPA(B(MX)) = 0, where X = 0
to 4. These power values are assigned one by one by the scheduler, so that with their allocated values, looped back to
the starting point, are used in successive steps.
For the user, Mj, with j varying from 1 to 4:
Figure 6.5: HSDPA Bearer Allocation Process for Packet (HSDPA) and Packet (HSPA) Service Users
6.4.2.3.4
Fast Link Adaptation Modelling
Fast link adaptation (or Adaptive Modulation and Coding) is used in HSDPA. The power on the HS-DSCH channel is transmitted at a constant power while the modulation, the coding and the number of codes are changed to adapt to the radio
conditions variations. Based on the reported channel quality indicator (CQI), the node-B may change every 2ms the modulation (QPSK, 16QAM, 64QAM), the coding and the number of codes during a communication.
Atoll calculates for each user either the best pilot quality (CPICH Ec/Nt) or the best HS-PDSCH quality (HS-PDSCH Ec/
Nt); this depends on the option selected in Global parameters (HSDPA part): CQI based on CPICH quality or CQI based
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on HS-PDSCH quality (CQI means channel quality indicator). Then, it determines the HS-PDSCH CQI, calculates the best
bearer that can be used and selects the suitable bearer so as to comply with cell and terminal user equipment HSDPA
capabilities. Once the bearer selected, Atoll finds the highest downlink rate that can be provided to the user and may calculate the application throughput.
CQI Based on CPICH Quality
When the option “CQI based on CPICH quality” is selected, Atoll proceeds as follows.
1.
CPICH Quality Calculation
Ec
Let us assume the following notation:  -------  ic 
corresponds to the CPICH quality.
 Nt
 pilot
Two options, available in Global parameters, may be used to calculate Nt: option Without useful signal or option Total
noise.
Therefore, we have:
 BTS    P c  ic 
i
 Ec
-------  ic 
for the total noise option,
= --------------------------------------------- Nt
 pilot
DL
N tot  ic 
And
 BTS    P c  ic 
i
 Ec
-------  ic 
- for the without useful signal option.
= -------------------------------------------------------------------------------------- Nt
 pilot
DL
N tot  ic  –  1 –     BTS  P c  ic 
i
With
DL
DL
DL
DL
DL
term
N tot  ic  = I intra  ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
 DL
 DL
DL
P SCH  ic 
P SCH  ic 
DL
term
- –  BTS   P tot  ic  – ----------------------I intra  ic  = P tot  ic  +  BTS   1 – F MUD    1 –     P tot  ic  – ----------------------



LT
LT
txi
txi
txi





DL
I extra  ic  =
DL
P tot  ic 
txj j  i
 Ptot  icadj 
DL
DL
I inter – carrier  ic 
txj j
= -------------------------------------RF  ic ic adj 
icadj is a carrier adjacent to ic.
RF  ic ic adj  is the interference reduction factor, defined between ic and icadj and set to a value different from 0.
DL
I inter – techno log y  ic  is the inter-technology interference at the receiver on ic.
Tx
DL
I inter – techno log y  ic  =
P Transmitted  ic i 
 -----------------------------------------Tx
Tx m
L
 ICP
ni
ic i is the i
th
total
ic i ic
interfering carrier of an external transmitter
Tx m
ICP ic  ic is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming
i
the frequency gap between ic i (external network) and ic .
P pilot  ic 
P c  ic  = ----------------------i
LT
i
L path  L Tx  L term  L body  L indoor  E Shadowing 3
( )
L T = -------------------------------------------------------------------------------------------------------------------------------G Tx  G term
 BTS ,

term
and N 0
are defined in "Inputs" on page 192.
Note:
3.
In the HSDPA coverage prediction, L T is calculated as follows:
L path  L Tx  L term  L body  L indoor  M Shadowing – Ec  Io
-)
L T = -------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
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•
Atoll performs intra-cell interference computations based on the total power. You can
instruct Atoll to use maximum power by adding the following lines in the Atoll.ini file:
[CDMA]
PmaxInIntraItf = 1
In this case, Atoll considers the following formula:
P max  ic  – P SCH  ic 
P max  ic  – P SCH  ic 
P max  ic 
DL
term
- –  BTS   -----------------------------------------------------
- +  BTS  1 – F MUD  1 –    ----------------------------------------------------I intra  ic  = ---------------------



LT
LT
LT
2.
CPICH CQI Determination
Let us assume the following notation:  CQI  pilot corresponds to the CPICH CQI.  CQI  pilot is read in the table
Ec
 . This table is defined for the terminal reception equipment and the selected mobility.
 CQI  pilot = f   -------  ic 
  Nt
 pilot
3.
HS-PDSCH Quality Calculation
Atoll proceeds as follows:
1st step: Atoll calculates the HS-SCCH power ( P HS – SCCH ).
P HS – SCCH  ic  is the HS-SCCH power on carrier ic. It is either fixed by the user (when the option “HS-SCCH Power
Dynamic Allocation”in the cell property dialogue is unchecked) or dynamically calculated (when the option “HS-SCCH
Power Dynamic Allocation” is selected).
req
Ec
In this case, the HS-SCCH power is controlled so as to reach the required HS-SCCH Ec/Nt (noted  -------  ic 
). It
Nt
HS – SCCH
is specified in mobility properties.
We have:
 BTS  P c  ic 
i
 Ec
-------  ic 
for the total noise option,
= ----------------------------------- Nt
 HS – SCCH
DL
N tot  ic 
And
 BTS  P c  ic 
i
 Ec
-------  ic 
- for the without useful signal option.
= -------------------------------------------------------------------------------------------------------------------------------------- Nt
 HS – SCCH
DL
term
N tot  ic  –  1 – F ortho    1 – F MUD    BTS  P c  ic 
i
With
DL
DL
DL
DL
DL
term
N tot  ic  = I intra  ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
 DL
 DL
DL
P SCH  ic 
P SCH  ic 
DL
term
- –  BTS   P tot  ic  – ----------------------I intra  ic  = P tot  ic  +  BTS   1 – F MUD    1 – F ortho    P tot  ic  – ----------------------



LT
LT
txi
txi
txi





DL
I extra  ic  =
DL
P tot  ic 
txj j  i
 Ptot  icadj 
DL
DL
txj j
I inter – carrier  ic  = -------------------------------------RF  ic ic adj 
icadj is a carrier adjacent to ic.
RF  ic ic adj  is the interference reduction factor, defined between ic and icadj and set to a value different from 0.
DL
I inter – techno log y  ic  is the inter-technology interference at the receiver on ic.
Tx
DL
I inter – techno log y  ic  =
P Transmitted  ic i 
 -----------------------------------------Tx
Tx m
 ICP
L
ni
ic i is the i
th
total
ic i ic
interfering carrier of an external transmitter
Tx m
ICP ic  ic is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming
i
the frequency gap between ic i (external network) and ic .
P HS – SCCH  ic 
P c  ic  = -------------------------------------i
LT
i
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and
L path  L Tx  L term  L body  L indoor  E Shadowing 4
( )
L T = -------------------------------------------------------------------------------------------------------------------------------G Tx  G term
term
term
 BTS , F ortho , F MUD and N 0
are defined in "Inputs" on page 192.
Therefore,
req
DL
  Ec
-------  ic 
 N tot  ic 
 HS – SCCH
  Nt

P HS – SCCH  ic  =  ---------------------------------------------------------------------------  L T for the total noise option,
i



BTS


And
req
DL
 Ec


-------  ic 
 N tot  ic 
 Nt
 HS – SCCH


-  L T for the without useful signal option.
P HS – SCCH  ic  =  ---------------------------------------------------------------------------------------------------------------------------------------------------------req
i
term



 Ec-  ic 
 BTS   1 +  1 – F ortho    1 – F MUD    ----- HS – SCCH 
Nt
2nd step: Atoll calculates the HS-PDSCH power ( P HS – PDSCH ).
P HSDPA  ic  is the power available for HSDPA on the carrier ic. This parameter is either a simulation output, or a userdefined cell input.
P HSDPA  ic  = P HS – PDSCH  ic  + n HS – SCCH  P HS – SCCH  ic 
Therefore, we have:
P HS – PDSCH  ic  = P HSDPA  ic  – n HS – SCCH  P HS – SCCH  ic 
n HS – SCCH is the number of HS-SCCH channels.
3rd step: Then, Atoll evaluates the HS-PDSCH quality
Ec
Let us assume the following notation:  -------  ic 
corresponds to the HS-PDSCH quality.
 Nt
 HS – PDSCH
We have:
 BTS  P c  ic 
i
 Ec
-------  ic 
for the total noise option,
= ----------------------------------- Nt
 HS – PDSCH
DL
N tot  ic 
And
 BTS  P c  ic 
i
 Ec
-------  ic 
- for the without useful signal option.
= -------------------------------------------------------------------------------------------------------------------------------------- Nt
 HS – PDSCH
P c  ic 
DL
term
i
N tot  ic  –  1 – F ortho    1 – F MUD    BTS  ---------------n
Here, Atoll works on the assumption that five HS-PDSCH channels are used (n=5).
With
DL
DL
DL
DL
DL
term
N tot  ic  = I intra  ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
 DL
 DL
DL
P SCH  ic 
P SCH  ic 
DL
term
- –  BTS   P tot  ic  – ----------------------I intra  ic  = P tot  ic  +  BTS   1 – F MUD    1 – F ortho    P tot  ic  – ----------------------



LT
LT
txi
txi
txi




DL
I extra  ic   =

DL
P tot  ic 
txj j  i
 Ptot  icadj 
DL
DL
txj j
I inter – carrier  ic  = -------------------------------------RF  ic ic adj 
icadj is a carrier adjacent to ic.
RF  ic ic adj  is the interference reduction factor, defined between ic and icadj and set to a value different from 0.
4.
In the HSDPA coverage prediction, L T is calculated as follows:
L path  L Tx  L term  L body  L indoor  M Shadowing – Ec  Io
-)
L T = -------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
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DL
I inter – techno log y  ic  is the inter-technology interference at the receiver on ic.
DL
I inter – techno log y  ic  =

ni
ic i is the i
th
Tx
P Transmitted  ic i 
-----------------------------------------Tx
Tx m
L total  ICP ic  ic
i
interfering carrier of an external transmitter
Tx m
ICP ic  ic is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming
i
the frequency gap between ic i (external network) and ic .
P HS – PDSCH  ic 
P c  ic  = -----------------------------------------i
LT
i
And
L path  L Tx  L term  L body  L indoor  E Shadowing 5
( )
L T = -------------------------------------------------------------------------------------------------------------------------------G Tx  G term
term
term
 BTS , F ortho , F MUD and N 0
are defined in "Inputs" on page 192.
Note:
•
Atoll performs intra-cell interference computations based on the total power. You can
instruct Atoll to use maximum power by adding the following lines in the Atoll.ini file:
[CDMA]
PmaxInIntraItf = 1
In this case, Atoll considers the following formula:
P max  ic  – P SCH  ic 
P max  ic  – P SCH  ic 
P max  ic 
DL
term
- –  BTS  -----------------------------------------------------
-+  BTS  1 – F MUD   1 – F ortho   ----------------------------------------------------I intra  ic  = ---------------------



LT
LT
LT
4.
HS-PDSCH CQI Determination
The best bearer that can be used depends on the HS-PDSCH CQI. Let us assume the following notation:
 CQI  HS – PDSCH corresponds to the HS-PDSCH CQI. Atoll calculates  CQI  HS – PDSCH as follows:
 CQI  HS – PDSCH =  CQI  pilot – P pilot + P HS – PDSCH
5.
HSDPA Bearer Selection
Atoll selects the HSDPA bearer associated to this CQI (in the table Best Bearer=f(HS-PDSCH CQI) defined for the terminal
reception equipment and the user mobility) and compatible with the user equipment and cell capabilities.
HSDPA bearers can be classified into two categories:
•
HSDPA bearers using QPSK and 16QAM modulations: They can be selected for all users connected to HSPA and
HSPA+ capable cells. The number of HS-PDSCH channels required by the bearer must not exceed the maximum
number of HS-PDSCH codes available for the cell.
For packet (HSPA - Constant Bit Rate) service users, HS-SCCH-less operation (i.e., HS-DSCH transmissions
without any accompanying HS-SCCH) is performed. In this case, the UE is not informed about the transmission
format and has to revert to blind decoding of the transport format used on the HS-DSCH. Complexity of blind
detections in the UE is decreased by limiting the transmission formats that can be used (i.e., the HSDPA bearers
available). Therefore, only HSDPA bearers using the QPSK modulation and two HS-PDSCH channels at the maximum can be selected and allocated to these users. Additionally, the selected HSDPA bearer must provide a RLC
peak rate higher or equal to the guaranted bit rate defined for the service.
•
HSDPA bearers using 64QAM modulation (improvement introduced by the release 7 of the 3GPP UTRA specifications, referred to as HSPA+): These HSDPA bearers can be allocated to packet (HSDPA) and packet (HSPA)
users connected to cells with HSPA+ capabilities only. The number of HS-PDSCH channels required by the bearer
must not exceed the maximum number of HS-PDSCH codes available for the cell. These HSDPA bearers cannot
be allocated to packet (HSPA - Constant Bit Rate) service users.
Atoll considers an HSDPA bearer as compatible with the user equipment if:
•
•
•
5.
The transport block size does not exceed the maximum transport block size supported by the user equipment.
The number of HS-PDSCH channels required by the bearer does not exceed the maximum number of HS-PDSCH
channels that the terminal can use.
The modulation is supported by the user equipment.
In the HSDPA coverage prediction, L T is calculated as follows:
L path  L Tx  L term  L body  L indoor  M Shadowing – Ec  Io
-)
L T = -------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
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When there are several HSDPA bearers compatible, Atoll selects the HSDPA bearer that provides the highest RLC peak
rate. When several HSDPA bearers can supply the same RLC peak rate, Atoll chooses the HSDPA bearer with the highest
modulation scheme. Finally, if no HSDPA bearer is compatible, Atoll allocates a lower HSDPA bearer compatible with the
user equipment and cell capabilities which needs fewer resources.
Let’s consider the following examples.
Example1: One packet (HSDPA) user with category 13 user equipment and a 50km/h mobility.
The user equipment capabilities are:
•
•
•
•
Maximum transport block size: 35280 bits
Maximum number of HS-PDSCH channels: 15
Highest modulation supported: 64QAM
MIMO Support: No
Figure 6.6: HSDPA UE Categories Table
The cell to which the user is connected supports HSPA+ functionalities (i.e. 64QAM modulation in the DL and MIMO
systems) and the maximum number of HS-PDSCH channels is 15.
1st case: The CQI experienced by the user equals 26. Therefore, Atoll can choose between two HSDPA bearers, the
bearer indexes 26 and 31.
Characteristics of the bearer index 26 are:
•
•
•
•
Transport block size: 17237 bits
Number of HS-PDSCH channels used: 12
16QAM modulation is used
RLC Peak Rate: 8.32 Mb/s
Characteristics of the bearer index 31 are:
•
•
•
•
Transport block size: 15776 bits
Number of HS-PDSCH channels used: 10
64QAM modulation is used
RLC Peak Rate: 7.36 Mb/s
Both HSDPA bearers are compatible with the user equipment and cell capabilities. Atoll selects the HSDPA bearer that
provides the highest RLC peak rate, i.e. the bearer index 26.
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Figure 6.7: HSDPA Radio Bearers Table
2nd case: The CQI experienced by the user equals 27. Therefore, Atoll can choose between two HSDPA bearers, the
bearer indexes 27 and 32.
Characteristics of the bearer index 27 are:
•
•
•
•
Transport block size: 21754 bits
Number of HS-PDSCH channels used: 15
16QAM modulation is used
RLC Peak Rate: 10.24 Mb/s
Characteristics of the bearer index 32 are:
•
•
•
•
Transport block size: 21768 bits
Number of HS-PDSCH channels used: 12
64QAM modulation is used
RLC Peak Rate: 10.24 Mb/s
Both HSDPA bearers are compatible with the user equipment and cell capabilities and the RLC peak rate they provide is
the same. Atoll selects the HSDPA bearer using the highest modulation scheme, i.e. the bearer index 32.
Example 2: One packet (HSDPA) user experiencing a CQI of 26.
Therefore, Atoll can choose between two HSDPA bearers, the bearer indexes 26 and 31.
Characteristics of the bearer index 26 are:
•
•
•
•
Transport block size: 17237 bits
Number of HS-PDSCH channels used: 12
16QAM modulation is used
RLC Peak Rate: 8.32 Mb/s
Characteristics of the bearer index 31 are:
•
•
•
•
Transport block size: 15776 bits
Number of HS-PDSCH channels used: 10
64QAM modulation is used
RLC Peak Rate: 7.36 Mb/s
1st case: The user equipment category is 9. The cell to which the user is connected supports HSPA+ functionalities (i.e.
64QAM modulation in the DL and MIMO systems) and the maximum number of HS-PDSCH channels is 15.
The user equipment characteristics are the following:
•
•
•
•
Maximum transport block size: 20251 bits
Maximum number of HS-PDSCH channels: 15
Highest modulation supported: 16QAM
MIMO Support: No
The bearer index 31 cannot be selected because it requires a modulation scheme not supported by the terminal. Only the
bearer index 26 is compatible with the user equipment capabilities. Atoll selects it.
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2nd case: The user equipment category is 8. The cell to which the user is connected supports HSPA+ functionalities (i.e.
64QAM modulation in the DL and MIMO systems) and the maximum number of HS-PDSCH channels is 15.
The user equipment characteristics are the following:
•
•
•
•
Maximum transport block size: 14411 bits
Maximum number of HS-PDSCH channels: 10
Highest modulation supported: 16QAM
MIMO Support: No
Here, none of HSDPA bearers are compatible with the user equipment capabilities.
The bearer index 31 cannot be selected because it requires a modulation scheme not supported by the terminal. With the
bearer index 26, the number of HS-PDSCH channels (12) exceeds the maximum number of HS-PDSCH channels the
terminal can use (10), and the transport block size (17237 bits) exceeds the maximum transport block size (14411 bits)
the terminal can carried.
In the HSDPA Radio Bearer table, Atoll selects a lower HSDPA bearer compatible with cell and UE category capabilities.
It selects the bearer index 25.
•
•
•
The number of HS-PDSCH channels (10) does not exceed the maximum number of HS-PDSCH channels the terminal can use (10) and the maximum number of HS-PDSCH channels available at the cell level (15),
The transport block size (14411 bits) does not exceed the maximum transport block size (14411 bits) the terminal
can carried.
16QAM modulation is supported by the terminal and the cell.
3rd
case: The user equipment category is 13. The cell to which the user is connected supports HSPA functionalities and
the maximum number of HS-PDSCH channels is 15.
The user equipment capabilities are:
•
•
•
•
Maximum transport block size: 35280 bits
Maximum number of HS-PDSCH channels:15
Highest modulation supported: 64QAM
MIMO Support: No
The bearer index 31 cannot be selected because it requires a modulation scheme not supported by the cell. On the other
hand, the bearer index 26 is compatible with cell and UE category capabilities. Therefore, it is allocated.
6.
HS-PDSCH Quality Update
Once the bearer selected, Atoll exactly knows the number of HS-PDSCH channels. Therefore, when the method “Without
useful signal” is used, it may recalculate the HS-PDSCH quality with the real number of HS-PDSCH channels (A default
value (5) was taken into account in the first HS-PDSCH quality calculation).
CQI Based on HS-PDSCH Quality
When the option “CQI based on HS-PDSCH quality” is selected, Atoll proceeds as follows.
1.
HS-PDSCH Quality Calculation
Atoll proceeds as follows:
1st step: Atoll calculates the HS-SCCH power ( P HS – SCCH ).
P HS – SCCH  ic  is the HS-SCCH power on carrier ic. It is either fixed by the user (when the option “HS-SCCH Power
Dynamic Allocation”in the cell property dialogue is unchecked) or dynamically calculated (when the option “HS-SCCH
Power Dynamic Allocation” is selected).
req
Ec
In this case, the HS-SCCH power is controlled so as to reach the required HS-SCCH Ec/Nt (noted  -------  ic 
). It
Nt
HS – SCCH
is specified in mobility properties.
We have:
 BTS  P c  ic 
i
 Ec
-------  ic 
for the total noise option,
= ----------------------------------- Nt
 HS – SCCH
DL
N tot  ic 
And
 BTS  P c  ic 
i
 Ec
-------  ic 
- for the without useful signal option.
= -------------------------------------------------------------------------------------------------------------------------------------- Nt
 HS – SCCH
DL
term
N tot  ic  –  1 – F ortho    1 – F MUD    BTS  P c  ic 
i
With
DL
DL
DL
DL
DL
term
N tot  ic  = I intra  ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
 DL
 DL
DL
P SCH  ic 
P SCH  ic 
DL
term
- –  BTS   P tot  ic  – ----------------------I intra  ic  = P tot  ic  +  BTS   1 – F MUD    1 – F ortho    P tot  ic  – ----------------------



LT
LT
txi
txi
txi




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
DL
I extra  ic  =
DL
P tot  ic 
txj j  i
 Ptot  icadj 
DL
DL
txj j
I inter – carrier  ic  = -------------------------------------RF  ic ic adj 
icadj is a carrier adjacent to ic.
RF  ic ic adj  is the interference reduction factor, defined between ic and icadj and set to a value different from 0.
DL
I inter – techno log y  ic  is the inter-technology interference at the receiver on ic.
DL
I inter – techno log y  ic  =

ni
ic i is the i
th
Tx
P Transmitted  ic i 
-----------------------------------------Tx
Tx m
L total  ICP ic  ic
i
interfering carrier of an external transmitter
Tx m
ICP ic  ic is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming
i
the frequency gap between ic i (external network) and ic .
P HS – SCCH  ic 
P c  ic  = -------------------------------------i
LT
i
And
L path  L Tx  L term  L body  L indoor  E Shadowing 6
( )
L T = -------------------------------------------------------------------------------------------------------------------------------G Tx  G term
term
term
 BTS , F ortho , F MUD and N 0
are defined in "Inputs" on page 192.
Therefore,
req
DL
  Ec
-------  ic 
 N tot  ic 
 HS – SCCH
  Nt

P HS – SCCH  ic  =  ---------------------------------------------------------------------------  L T for the total noise option,
i



BTS


And
req
DL
 Ec


-------  ic 
 N tot  ic 
 Nt
 HS – SCCH


-  L T for the without useful signal option.
P HS – SCCH  ic  =  ---------------------------------------------------------------------------------------------------------------------------------------------------------req
i
term



 Ec-  ic 
 BTS   1 +  1 – F ortho    1 – F MUD    ----- HS – SCCH 
Nt
2nd step: Atoll calculates the HS-PDSCH power ( P HS – PDSCH )
P HSDPA  ic  is the power available for HSDPA on the carrier ic. This parameter is either a simulation output, or a userdefined cell input.
P HSDPA  ic  = P HS – PDSCH  ic  + n HS – SCCH  P HS – SCCH  ic 
Therefore, we have:
P HS – PDSCH  ic  = P HSDPA  ic  – n HS – SCCH  P HS – SCCH  ic 
n HS – SCCH is the number of HS-SCCH channels.
3rd step: Then, Atoll evaluates the HS-PDSCH quality
Ec
Let us assume the following notation:  -------  ic 
corresponds to the HS-PDSCH quality.
 Nt
 HS – PDSCH
Two options, available in Global parameters, may be used to calculate Nt: option Without useful signal or option Total
noise.
We have:
6.
In the HSDPA coverage prediction, L T is calculated as follows:
L path  L Tx  L term  L body  L indoor  M Shadowing – Ec  Io
-)
L T = -------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
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Chapter 6: UMTS HSPA Networks
 BTS  P c  ic 
i
 Ec
-------  ic 
for the total noise option,
= ----------------------------------- Nt
 HS – PDSCH
DL
N tot  ic 
And
 BTS  P c  ic 
i
 Ec
-------  ic 
- for the without useful signal option.
= -------------------------------------------------------------------------------------------------------------------------------------- Nt
 HS – PDSCH
P c  ic 
DL
term
i
N tot  ic  –  1 – F ortho    1 – F MUD    BTS  ----------------n
Here, Atoll works on the assumption that five HS-PDSCH channels are used (n=5). Then, it calculates the HS-PDSCH
CQI and the bearer to be used. Once the bearer selected, Atoll exactly knows the number of HS-PDSCH channels and
recalculates the HS-PDSCH quality with the real number of HS-PDSCH channels.
With
DL
DL
DL
DL
DL
term
N tot  ic  = I intra  ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
 DL
 DL
DL
P SCH  ic 
P SCH  ic 
DL
term
- –  BTS   P tot  ic  – ----------------------I intra  ic  = P tot  ic  +  BTS   1 – F MUD    1 – F ortho    P tot  ic  – ----------------------



LT
LT
txi
txi
txi





DL
I extra  ic   =
DL
P tot  ic 
txj j  i
 Ptot  icadj 
DL
DL
txj j
I inter – carrier  ic  = -------------------------------------RF  ic ic adj 
icadj is a carrier adjacent to ic.
RF  ic ic adj  is the interference reduction factor, defined between ic and icadj and set to a value different from 0.
DL
I inter – techno log y  ic  is the inter-technology interference at the receiver on ic.
DL
I inter – techno log y  ic  =

ni
ic i is the i
th
Tx
P Transmitted  ic i 
-----------------------------------------Tx
Tx m
L total  ICP ic  ic
i
interfering carrier of an external transmitter
Tx m
ICP ic  ic is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming
i
the frequency gap between ic i (external network) and ic .
P HS – PDSCH  ic 
P c  ic  = -----------------------------------------i
LT
i
And
L path  L Tx  L term  L body  L indoor  E Shadowing 7
( )
L T = -------------------------------------------------------------------------------------------------------------------------------G Tx  G term
term
term
 BTS , F ortho , F MUD and N 0
are defined in "Inputs" on page 192.
Note:
•
Atoll performs intra-cell interference computations based on the total power. You can
instruct Atoll to use maximum power by adding the following lines in the Atoll.ini file:
[CDMA]
PmaxInIntraItf = 1
In this case, Atoll considers the following formula:
P max  ic  – P SCH  ic 
P max  ic  – P SCH  ic 
P max  ic 
DL
term
- –  BTS  -----------------------------------------------------
-+ BTS 1 – F MUD  1 – F ortho  ----------------------------------------------------I intra  ic  = ---------------------



LT
LT
L
T
2.
HS-PDSCH CQI Determination
7.
In the HSDPA coverage prediction, L T is calculated as follows:
L path  L Tx  L term  L body  L indoor  M Shadowing – Ec  Io
-)
L T = -------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
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Let us assume the following notation:  CQI  HS – PDSCH corresponds to the HS-PDSCH CQI.  CQI  HS – PDSCH is read in
Ec
 . This table is defined for the terminal reception equipment and the
the table  CQI  HS – PDSCH = f   -------  ic 
  Nt
 HS – PDSCH
specified mobility.
3.
HSDPA Bearer Selection
The bearer is selected as described in "HSDPA Bearer Selection" on page 218.
6.4.2.3.5
MIMO Modelling
MIMO - Transmit Diversity
If the cell to which the user is connected supports HSPA+ with transmit diversity and if the user’s terminal HSDPA UE
category supports MIMO, we have:
Ec
DL
DL
 Ec
-------  ic 
=  -------  ic 
+ G TD + G TD in dB
 Nt
 HS – PDSCH
 Nt
 HS – PDSCH
Where
DL
G TD is the downlink transmit diversity gain (in dB) corresponding to the numbers of transmission and reception antenna
ports (respectively defined in the transmitter and terminal properties).
DL
G TD is the additional diversity gain in downlink (in dB). It is defined for the clutter class of the user.
MIMO - Spatial Multiplexing
DL
R RLC – peak  Index HSDPABearer  is the RLC peak rate that the selected HSDPA bearer ( Index HSDPABearer ) can provide.
It is read in the HSDPA Radio Bearer table.
If the cell to which the user is connected supports HSPA+ with spatial multiplexing and if the user’s terminal HSDPA UE
category supports MIMO, we have:
DL
DL
Max
R RLC – peak = R RLC – peak  Index HSDPABearer    1 + f SM – Gain   G SM – 1  
Where
Max
G SM is the maximum spatial multiplexing gain (in dB) for a given number of transmission and reception antennas (respectively defined in the transmitter and terminal properties).
f SM – Gain is the spatial multiplexing gain factor defined for the clutter class of the user.
6.4.2.3.6
Scheduling Algorithms
The scheduler manages the maximum number of users within each cell. Packet (HSPA - Constant Bit Rate) service users
have the highest priority and are processed first, in the order established during the generation of the user distribution.
After processing the packet (HSPA - Constant Bit Rate) service users, the scheduler ranks the remaining HSDPA bearer
users (i.e., packet (HSDPA) and packet (HSPA) service users) according to the selected scheduling technique.Three
scheduling algorithms are available , Max C/I, Round Robin and Proportional Fair. Impact they have on the simulation
result is described in the tables below.
Let us consider a cell with 16 packet (HSDPA) and packet (HSPA) service users. All of them are active on DL and
connected to the A-DCH R99 bearer. There is no packet (HSPA - Constant Bit Rate) service user in the cell and the
number of HS-SCCH channels and the maximum number of HSDPA users have been respectively set to 4 and 15.
•
224
Max C/I: 15 users (where 15 corresponds to the maximum number of HSDPA users defined) enters the scheduler
in the same order as in the simulation. Then, they are sorted in descending order by the channel quality indicator
(CQI), i.e. in a best bearer descending order.
Mobiles
Simulation Rank
Best Bearer
(kbps)
DL Obtained Rate
(kbps)
Connection
Status
M1
2
2400
2400
Connected
M2
15
2400
1440
Connected
M3
8
2080
160
Connected
M4
9
2080
3.4
Delayed
M5
10
2080
3.4
Delayed
M6
12
2080
3.4
Delayed
M7
13
2080
3.4
Delayed
M8
14
2080
3.4
Delayed
M9
7
1920
3.4
Delayed
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Chapter 6: UMTS HSPA Networks
•
•
M10
1
1600
3.4
Delayed
M11
3
1600
3.4
Delayed
M12
4
1600
3.4
Delayed
M13
5
1600
3.4
Delayed
M14
6
1600
3.4
Delayed
M15
11
1440
3.4
Delayed
M16
16
2080
0
Scheduler Saturation
Round Robin: Users are taken into account in the same order than the one in the simulation (random order).
Mobiles
Simulation Rank
Best Bearer
(kbps)
DL Obtained Rate
(kbps)
Connection
Status
M1
1
1600
1600
Connected
M2
2
2400
960
Connected
M3
3
1600
3.4
Delayed
M4
4
1600
3.4
Delayed
M5
5
1600
3.4
Delayed
M6
6
1600
3.4
Delayed
M7
7
1920
3.4
Delayed
M8
8
2080
3.4
Delayed
M9
9
2080
3.4
Delayed
M10
10
2080
3.4
Delayed
M11
11
1440
3.4
Delayed
M12
12
2080
3.4
Delayed
M13
13
2080
3.4
Delayed
M14
14
2080
3.4
Delayed
M15
15
2400
3.4
Delayed
M16
16
2080
0
Scheduler Saturation
Proportional Fair: 15 users (where 15 corresponds to the maximum number of HSDPA users defined) enters the
scheduler in the same order as in the simulation. Then, they are sorted in an ascending order according to a new
random parameter which corresponds to a combination of the user rank in the simulation and the channel quality
indicator (CQI).
For a user i, the random parameter RP i is calculated as follows:
Simu
RP i = 50  R i
CQI
+ 50  R i
Where,
Simu
is the user rank in the simulation.
Ri
CQI
Ri
is the user rank according to the CQI.
Note:
•
© Forsk 2009
You can change the default weights by editing the atoll.ini file. For more information, see
the Administrator Manual.
Mobiles
Simulation
Rank
CQI Rank
RP
M1
2
1
150
2400
2400
Connected
M2
1
10
550
1600
960
Connected
M3
8
3
550
2080
160
Connected
M4
9
4
650
2080
3.4
Delayed
M5
3
11
700
1600
3.4
Delayed
M6
10
5
750
2080
3.4
Delayed
M7
4
12
800
1600
3.4
Delayed
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(kbps)
Rate (kbps)
Connection
Status
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Technical Reference Guide
M8
7
9
800
1920
3.4
Delayed
M9
15
2
850
2400
3.4
Delayed
M10
5
13
900
1600
3.4
Delayed
M11
12
6
900
2080
3.4
Delayed
M12
6
14
1000
1600
3.4
Delayed
M13
13
7
1000
2080
3.4
Delayed
M14
14
8
1100
2080
3.4
Delayed
M15
11
15
1300
1440
3.4
Delayed
0
Scheduler
Saturation
M16
6.4.2.4
16
-
-
2080
HSUPA Part of the Algorithm
Packet (HSPA) service users active on UL as well as all packet (HSPA - Constant Bit Rate) service users (i.e., active and
incative), unless they have been rejected during the R99 or HSDPA parts of the algorithm, are then evaluated by the
HSUPA part of the algorithm. Atoll manages the maximum number of users within each cell. Packet (HSPA - Constant Bit
Rate) service users have the highest priority and are processed first, in the order established during the generation of the
user distribution. Then, Atoll considers packet (HSPA) service users in the order established during the generation of the
user distribution.
Let us assume there are 12 HSUPA bearer users in the cell:
•
•
3 packet (HSPA - Constant Bit Rate) service users with any activity status. All of them have been connected to an
HSDPA bearer.
9 packet (HSPA) service users active on UL. The first four packet (HSPA) have been connected to an HSDPA
bearer, the last one has been rejected and the remaining four have been delayed in the HSDPA part.
Finally, the maximum number of HSUPA users equals 10.
In this case, Atoll will consider the first ten HSUPA bearer users only and will reject the last two users in order not to exceed
the maximum number of HSUPA users allowed in the cell (their connection status is "HSUPA scheduler saturation").
6.4.2.4.1
HSDPA
Connection
Status
Evaluation by
the HSUPA
part of the
algorithm
Mobiles
Service
Simulation
Rank
M1
Packet (HSPA - Constant Bit Rate)
4
Connected
Yes
M2
Packet (HSPA - Constant Bit Rate)
7
Connected
Yes
M3
Packet (HSPA - Constant Bit Rate)
9
Connected
Yes
M4
Packet (HSPA)
1
Connected
Yes
M5
Packet (HSPA)
2
Connected
Yes
M6
Packet (HSPA)
3
Connected
Yes
M7
Packet (HSPA)
5
Connected
Yes
M8
Packet (HSPA)
6
Delayed
Yes
M9
Packet (HSPA)
8
Delayed
Yes
M10
Packet (HSPA)
10
Delayed
Yes
M11
Packet (HSPA)
11
Delayed
No
M12
Packet (HSPA)
12
Rejected
No
Admission Control
During admission control, Atoll selects a list of HSUPA bearers for each user. The selected HSUPA bearers have to be
compatible with the user equipment and capabilities of each HSUPA cell of the active set. For packet (HSPA - Constant
Bit Rate) service users, the list is restricted to HSUPA bearers that provide a RLC peak rate higher than the guaranteed
bit rate.
Let us focus on one packet (HSPA) service user with category 3 user equipment and a 50km/h mobility. This user is
connected to one cell only. The cell supports HSPA+ functionalities, i.e the cell supports QPSK and 16QAM modulations
in the UL.
HSUPA user equipment categories are provided in the HSUPA User Equipment Categories table. The capabilities of the
category 3 user equipment are:
•
•
•
•
•
226
Maximum Number of E-DPDCH codes: 2
TTI 2 ms: No so it supports 10 ms TTI
Minimum Spreading Factor: 4
Maximum Block Size for a 2ms TTI: no value
Maximum Block Size for a 10ms TTI: 14484 bits
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Chapter 6: UMTS HSPA Networks
•
Highest Modulation Supported: QPSK
Figure 6.8: HSUPA UE Categories Table
HSUPA bearer characteristics are provided in the HSUPA Bearer table. An HSUPA bearer is described with following characteristics:
•
•
•
•
•
•
•
Radio Bearer Index: The bearer index number.
TTI Duration (ms): The TTI duration in ms. The TTI can be 2 or 10 ms.
Transport Block Size (Bits): The transport block size in bits.
Number of E-DPDCH Codes: The number of E-DPDCH channels used.
Minimum Spreading Factor: The smallest spreading factor used.
Modulation: the modulation used (QPSK or 16QAM)
RLC Peak Rate (bps): The RLC peak rate represents the peak rate without coding (redundancy, overhead,
addressing, etc.).
HSUPA bearers can be classified into two categories:
•
HSUPA bearers using QPSK modulation: They can be selected for users connected to HSPA and HSPA+ capable
cells.
•
HSUPA bearers using 16QAM modulation (improvement introduced by the release 7 of the 3GPP UTRA specifications, referred to as HSPA+). These HSUPA bearers can be allocated to users connected to cells with HSPA+
capabilities only.
Atoll considers an HSUPA bearer as compatible with the category 3 user equipment if:
•
•
•
•
•
The TTI duration used by the bearer is supported by the user equipment (10 ms).
The transport block size does not exceed the maximum transport block size supported by the user equipment
(14484 bits):
The number of E-DPDCH channels required by the bearer does not exceed the maximum number of E-DPDCH
channels that the terminal can use (2).
The minimum spreading factor used by the bearer is not less than the smallest spreading factor supported by the
terminal (4).
The modulation required by the bearer is supported by the terminal.
The HSUPA bearers compatible with category 3 user equiment are framed in red:
Figure 6.9: HSUPA Radio Bearers Table
Then, during admission control, Atoll checks that the lowest compatible bearer in terms of the required E-DPDCH Ec⁄Nt
does not require a terminal power higher than the maximum terminal power allowed.
Atoll uses the HSUPA Bearer Selection table. Among the compatible HSUPA bearers, Atoll chooses the one with the
lowest required Ec/Nt threshold.
Here, this is the index 1 HSUPA bearer; the required Ec/Nt threshold to obtain this bearer is -21.7dB.
Ec req
req
Then, from the required Ec/Nt threshold,  -------
, Atoll calculates the required terminal power, P term – HSUPA .
 Nt  E – DPDCH
© Forsk 2009
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Technical Reference Guide
req
Ec
req
UL
P term – HSUPA =  -------
 L T  N tot
 Nt  E – DPDCH
With
UL
UL intra
tx
N tot  ic  =  1 – F MUD   term   I tot
UL extra
 ic  + I tot
UL
tx
 ic  + I inter – carrier  ic  + N 0
L path  L Tx  L term  L body  L indoor  E Shadowing 8
L T = -------------------------------------------------------------------------------------------------------------------------------( )
G Tx  G term
tx
UL intra
 term , F MUD , I tot
UL extra
, I tot
UL
tx
, I inter – carrier and N 0 are defined in "Inputs" on page 192.
Figure 6.10: HSUPA Bearer SelectionTable
req
Atoll rejects the user if the terminal power required to obtain the lowest compatible HSUPA bearer ( P term – HSUPA )
exceeds the maximum terminal power (his connection status is "HSUPA Admission Rejection").
At the end of this step, the number of non-rejected HSUPA bearer users is n HSUPA . All of them will be connected to an
HSUPA bearer at the end.
6.4.2.4.2
HSUPA Bearer Allocation Process
The HSUPA bearer allocation process depends on the type of service requested by the user. As explained before, packet
(HSPA - Constant Bit Rate) service users have the highest priority and are processed first, in the order established during
the generation of the user distribution. After the admission control on packet (HSPA - Constant Bit Rate) service users,
Atoll performs a noise rise scheduling, followed by a radio resource control. Then, it repeats the same steps on packet
(HSPA) service users.
Packet (HSPA - Constant Bit Rate) Service Users
Let us focus on the three packet (HSPA - Constant Bit Rate) service users mentionned in the example of the previous
paragraph "HSUPA Part of the Algorithm" on page 226. We assume that all of them have been admitted. Noise rise scheduling and radio resource control are carried out on each user in order to determine the best HSUPA bearer that the user
can obtain. Several Packet (HSPA - Constant Bit Rate) service users can share the same HSUPA bearer. Then, Atoll
calculates the HSUPA bearer consumption ( C in %) for each user and takes into account this parameter when it determines the resources consumed by the user (i.e., the terminal power used, the number of channel elements and the Iub
backhaul throughput).
8.
In the HSUPA coverage prediction, L T is calculated as follows:
L path  L Tx  L term  L body  L indoor  M Shadowing –  Eb  Nt 
UL
-)
L T = -----------------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
228
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Chapter 6: UMTS HSPA Networks
In the bearer allocation process shown below, the 3 packet (HSPA - Constant Bit Rate) service users are represented by
Mj, with j = 1 to 3.
For the user, Mj, with j varying from 1 to 3:
Figure 6.11: HSUPA Bearer Allocation Process for Packet (HSPA - Constant Bit Rate) Service Users
Packet (HSPA) Service Users
Let us focus on the seven packet (HSPA) service users mentionned in the example of the previous paragraph "HSUPA
Part of the Algorithm" on page 226. We assume that all of them have been admitted. Noise rise scheduling and radio
resource control are carried out on each user in order to determine the best HSUPA bearer that the user can obtain.
In the bearer allocation process shown below, the 7 packet (HSPA) service users are represented by Mj, with j = 1 to 7.
For the user, Mj, with j varying from 1 to 7:
Figure 6.12: HSUPA Bearer Allocation Process for Packet (HSPA) Service Users
6.4.2.4.3
Noise Rise Scheduling
Determination of the Obtained HSUPA Bearer
The obtained HSUPA radio bearer is the bearer that the user obtains after noise rise scheduling and radio resource control.
© Forsk 2009
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Packet (HSPA - Constant Bit Rate) service users have the highest priority and are processed first. Therefore, after the
admission control, the noise rise scheduling algorithm attempts to evenly share the remaining cell load between the packet
(HSPA - Constant Bit Rate) service users admitted in admission control; in terms of HSUPA, each user is allocated a right
UL
to produce interference. The remaining cell load factor on uplink ( X HSPA – CBR  txi ic  ) depends on the maximum load
factor allowed on uplink and how much uplink load is produced by the served R99 traffic. It can be expressed as follows:
UL
UL
UL
X HSPA – CBR  txi ic  = X max  txi ic  – X R99  txi ic 
Then, Atoll evenly shares the remaining cell load factor between the packet (HSPA - Constant Bit Rate) service users
admitted during the previous step ( n HSPA – CBR ).
UL
X HSPA – CBR  txi ic 
UL
X user  txi ic  = ------------------------------------------------------n HSPA – CBR
Ec max
From this value, Atoll calculates the maximum E-DPDCH Ec⁄Nt allowed (  -------
) for each packet (HSPA  Nt  E – DPDCH
Constant Bit Rate) service user. For further information on the calculation, see "Uplink Load Factor Due to One User" on
page 244.
max
1
 Ec
-------
= ------------------------------------------------ for the Without useful signal option
 Nt  E – DPDCH
UL
F  txi ic 
-------------------------------------- – 1
UL
X user  txi ic 
UL
max
X user
 Ec
-------
- for the Total noise option
= ---------------- Nt  E – DPDCH
UL
F
Then, it selects an HSUPA bearer. The allocation depends on the maximum E-DPDCH Ec⁄Nt allowed and on UE and cell
capabilities. Atoll selects the best HSUPA bearer from the HSUPA compatible bearers. This is the HSUPA bearer
UL
R RLC – peak  Index HSUPABearer 
( Index HSUPABearer ) with the highest potential throughput ( ------------------------------------------------------------------------------------ ) where:
N Rtx  Index HSUPABearer 
•
req
Ec max
 Ec
-------
  -------
 Nt  E – DPDCH  Nt  E – DPDCH
•
And P term – HSUPA  P term
max
req
req
Ec
When several HSUPA bearers are available, Atoll selects the one with the lowest  -------
.
 Nt  E – DPDCH
After the noise rise scheduling, Atoll carries out radio resource control, verifying if enough channel elements and Iub backhaul throughput are available for the HSUPA bearer assigned to the user. For information on radio resource control, see
"Radio Resource Control" on page 233.
After processing all packet (HSPA - Constant bit rate) service users, Atoll carries out noise rise scheduling and radio
resource control on packet (HSPA) service users. During the noise rise scheduling, Atoll distributes the remaining cell load
factor available after all packet (HSPA - Constant Bit Rate) service users have been served. It can be expressed as follows:
UL
UL
UL
UL
X HSPA  txi ic  = X max  txi ic  – X R99  txi ic  – X HSPA – CBR  txi ic 
The remaining cell load factor is shared equally between the admitted packet (HSPA) service users ( n HSPA ).
UL
X HSPA  txi ic 
UL
X user  txi ic  = ---------------------------------------n HSPA
max
Ec
From this value, Atoll calculates the maximum E-DPDCH Ec⁄Nt allowed (  -------
) as explained above and selects
 Nt  E – DPDCH
an HSUPA bearer for each packet (HSPA) service user. After the noise rise scheduling, Atoll carries out radio resource
control on packet (HSPA) service users. For information on radio resource control, see "Radio Resource Control" on
page 233.
Example: We have a cell with six packet (HSPA) service users and no packet (HSPA - Constant Bit Rate) user. All packet
(HSPA) service users have been admitted.
The remaining cell load factor equal to 0.6 is shared between the packet (HSPA) service users. Therefore, the UL load
factor alloted to each user is 0.1. Let’s take the cell UL reuse factor equal to 1.5. Atoll calculates the maximum E-DPDCH
Ec⁄Nt allowed (the Without useful signal option is selected).
Ec max
We have:  -------
= -11.5 dB
 Nt  E – DPDCH
Here, the obtained HSUPA bearer is the index 5 HSUPA bearer. It provides a potential throughput of 128 kbps and
requires E-DPDCH Ec⁄Nt of -13 dB (lower than -11.5 dB) and a terminal power lower than the maximum terminal power
allowed.
230
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Chapter 6: UMTS HSPA Networks
.
HSUPA Bearers
Index
Required Ec/Nt
Threshold (dB)
Nb of
Retransmissions
RLC Peak Rate
(kbps)
Potential
Throughput
(kbps)
1
-21.7
2
32
16
2
-19
2
64
32
3
-16.1
2
128
64
4
-13.9
2
192
96
5
-13
2
256
128
6
-10.1
2
512
256
7
-8
2
768
384
8
-7
2
1024
512
Noise Rise Scheduling in Soft Handover
With HSUPA, uplink soft handover impacts the scheduling operation. While HSDPA sends data from one cell only, with
HSUPA all cells in the active set receive the transmission from the terminal. Therefore, all the cells are impacted by the
transmission in terms of noise rise.
For each HSUPA capable cell of the active set  tx k ic  , Atoll calculates the maximum E-DPDCH Ec⁄Nt allowed
Ec max
 tx  ic  ) as explained in "HSUPA Bearer Allocation Process" on page 228.
(  -------
 Nt  E – DPDCH k
For each cell of the active set  tx k ic  , Atoll calculates the maximum terminal power allowed to obtain an HSUPA radio
max
bearer ( P term – HSUPA  tx k ic  ).
max
Ec
max
UL
max
P term – HSUPA  tx k ic  = min    -------
 tx  ic   L T  N tot   P term
   Nt  E – DPDCH k


With
UL
UL intra
tx
N tot  ic  =  1 – F MUD   term   I tot
UL extra
 ic  + I tot
UL
tx
 ic  + I inter – carrier  ic  + N 0
L path  L Tx  L term  L body  L indoor  E Shadowing 9
L T = -------------------------------------------------------------------------------------------------------------------------------( )
G Tx  G term
tx
UL intra
 term , F MUD , I tot
UL extra
, I tot
UL
tx
, I inter – carrier and N 0 are defined in "Inputs" on page 192.
As HSUPA bearer users in soft handover use the lowest granted noise rise, Atoll chooses the lowest of maximum terminal
power allowed for each cell of the active set  tx k ic  .
max
P term – HSUPA = min
txk  AS
max
 P term – HSUPA  tx k ic  
max
Once Atoll knows the selected maximum terminal power ( P term – HSUPA ), it recalculates the maximum E-DPDCH Ec⁄Nt
Ec max
allowed (  -------
 tx  ic  ) for each HSUPA capable cell of the active set.
 Nt  E – DPDCH k
max
max
P term – HSUPA
 Ec
-------
 tx  ic  = ---------------------------------- Nt  E – DPDCH k
UL
L T  N tot
Ec max
Then, Atoll calculates the maximum E-DPDCH Ec⁄Nt allowed (  -------
) after signal recombination of all HSUPA
 Nt  E – DPDCH
capable cells of the active set 10.
For softer (1/2) and softer-softer (1/3) handovers, we have:
9.
In the HSUPA coverage prediction, L T is calculated as follows:
L path  L Tx  L term  L body  L indoor  M Shadowing –  Eb  Nt 
UL
-)
L T = -----------------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
© Forsk 2009
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231
Technical Reference Guide
max
UL
 Ec
-------
= f rake efficiency 
 Nt  E – DPDCH

max
 Ec
-------
 tx  ic 
 Nt  E – DPDCH k
tx k  ActiveSet
 samesite 
Ec max
For soft (2/2) and soft-soft (3/3) handovers, we have:  -------
=
 Nt  E – DPDCH
max
tx
k
Ec
 tx  ic 
Max   -------

Nt E – DPDCH k
 ActiveSet
For softer-soft handover (2/3), it depends on if the MRC option is selected (option available in Global parameters). If selected, we have:
max
 Ec
-------
=
 Nt  E – DPDCH


 UL

Ec max
Ec max


 tx k ic  ------ tx l ic 
 f rake efficiency   -------


txk ,tx l  ActiveSet
Nt
Nt
E
–
DPDCH
E
–
DPDCH


tx k  samesite 

txk
Max

tx  othersite
l
max
max
Ec
=
Else, we have:  -------
 Nt  E – DPDCH
Ec
 tx  ic 
Max   -------

Nt E – DPDCH k
tx k  ActiveSet
Then, Atoll selects an HSUPA bearer as previously explained in "HSUPA Bearer Allocation Process" on page 228. The
allocation depends on the maximum E-DPDCH Ec⁄Nt allowed and on UE and cell capabilities. Atoll selects the best
HSUPA bearer from the HSUPA compatible bearers. This is the HSUPA bearer ( Index HSUPABearer ) with the highest poUL
R RLC – peak  Index HSUPABearer 
tential throughput ( ------------------------------------------------------------------------------------ ) where:
N Rtx  Index HSUPABearer 
req
Ec max
 Ec
-------
  -------
 Nt  E – DPDCH  Nt  E – DPDCH
•
10.
In HSUPA coverage predictions, we have the following:
max
Ec
UL
For softer (1/2) and softer-softer (1/3) handovers:  -------
= f rake efficiency 
 Nt  E – DPDCH

max
 Ec
-------
 tx  ic 
 Nt  E – DPDCH k
tx k  ActiveSet
 samesite 
Ec max
For soft handover (2/2):  -------
=
 Nt  E – DPDCH
max
tx
k
Ec
UL
 tx  ic    G macro – diversity  2links
Max   -------

Nt E – DPDCH k
 ActiveSet
max
Ec
=
For soft-soft handover (3/3):  -------
 Nt  E – DPDCH
tx
k
Ec max
UL
 tx k ic    G macro – diversity  3links
Max   -------

Nt
E
–
DPDCH
 ActiveSet
For softer-soft handover (2/3), it depends on if the MRC option is selected (option available in Global parameters). If selected, we have:
max
 Ec
-------
=
 Nt  E – DPDCH


 UL

Ec max
Ec max


 tx k ic  ------ tx l ic 
 f rake efficiency   -------


tx ,tx  ActiveSet
Nt
Nt
k l
E – DPDCH
E – DPDCH


tx  samesite 

txk
k
Max

tx l  othersite
UL
  G macro – diversity  2links
Ec max
=
Else, we have:  -------
 Nt  E – DPDCH
232
max
tx
k
Ec
UL
 tx  ic    G macro – diversity  2links
Max   -------

Nt E – DPDCH k
 ActiveSet
AT281_TRG_E1
© Forsk 2009
Chapter 6: UMTS HSPA Networks
req
Ec
When several HSUPA bearers are available, Atoll selects the one with the lowest  -------
.
 Nt  E – DPDCH
Determination of the Requested HSUPA Bearer
The requested HSUPA radio bearer is selected from the HSUPA bearers compatible with the user equipment. Atoll determines the HSUPA bearer the user would obtain by considering the entire remaining load of the cell. The user is treated as
if he is the only user in the cell. Therefore, if we go on with the previous example, the maximum E-DPDCH Ec⁄Nt allowed
is equal to -1.8 dB and the requested HSUPA bearer is the index 7 HSUPA bearer. It requires E-DPDCH Ec⁄Nt of -8 dB
(lower than -1.8 dB) and a terminal power lower than the maximum terminal power allowed.
6.4.2.4.4
Radio Resource Control
Atoll checks to see if enough channel elements are available and if the Iub backhaul throughput is sufficient for the HSUPA
bearer assigned to the user (taking into account the maximum number of channel elements defined for the site and the
maximum Iub backhaul throughput allowed on the site in the uplink). If not, Atoll allocates a lower HSUPA bearer ("downgrading") which needs fewer channel elements and consumes lower Iub backhaul throughput. If no channel elements are
available, the user is rejected. On the same hand, if the maximum Iub backhaul throughput allowed on the site in the uplink
is still exceeded even by using the lowest HSDPA bearer, the user is rejected.
6.4.2.5
Convergence Criteria
The convergence criteria are evaluated for each iteration, and can be written as follow:
DL
  max P tx  ic  k – P tx  ic  k – 1
 max N DL


user  ic  k – N user  ic  k – 1
Stations
Stations
-  100 
 DL = max  int  --------------------------------------------------------------------------------------- 100  int  ---------------------------------------------------------------------------------------------------DL
 


P tx  ic  k

N user  ic  k



UL
UL

 max N UL

  max I UL
tot  ic  k – I tot  ic  k – 1
user  ic  k – N user  ic  k – 1
Stations
Stations
-  100  int  ----------------------------------------------------------------------------------------------------  100 
 UL = max  int  --------------------------------------------------------------------------------------UL
UL



 
I tot  ic  k
N user  ic  k



 
Atoll stops the algorithm if:
1st case: Between two successive iterations,  UL and  DL are lower (  ) than their respective thresholds (defined when
creating a simulation).
The simulation has reached convergence.
Example: Let us assume that the maximum number of iterations is 100, UL and DL convergence thresholds are set to 5.
If  UL  5 and  DL  5 between the 4th and the 5th iteration, Atoll stops the algorithm after the 5th iteration. Convergence
has been reached.
2nd case: After 30 iterations,  UL and/or  DL are still higher than their respective thresholds and from the 30th iteration,
 UL and/or  DL do not decrease during the next 15 successive iterations.
The simulation has not reached convergence (specific divergence symbol).
Examples: Let us assume that the maximum number of iterations is 100, UL and DL convergence thresholds are set to 5.
1. After the 30th iteration,  UL and/or  DL equal 100 and do not decrease during the next 15 successive iterations:
Atoll stops the algorithm at the 46th iteration. Convergence has not been reached.
2. After the 30th iteration,  UL and/or  DL equal 80, they start decreasing slowly until the 40th iteration (without going
under the thresholds) and then, do not change during 15 successive iterations: Atoll stops the algorithm at the 56th
iteration without reaching convergence.
3rd case: After the last iteration.
If  UL and/or  DL are still strictly higher than their respective thresholds, the simulation has not reached convergence
(specific divergence symbol).
If  UL and  DL are lower than their respective thresholds, the simulation has reached convergence.
6.4.3
Results
6.4.3.1
R99 Related Results
This table contains some R99 specific simulation results provided in the Cells and Mobiles tabs of the simulation property
dialogue.
© Forsk 2009
AT281_TRG_E1
233
Technical Reference Guide
Name
Value
Nb E1  T1  Ethernet
Unit
DL
UL
RoundUp  Max  T Iub  N I   T E1  T1  Ethernet T Iub  N I   T E1  T1  Ethernet   None
 DL
P SCH  txi ic 
 P  txi ic  – --------------------------------DL
P tot  txi ic  – F ortho   BTS   tot

LT
txi


DL
I intra  txi ic 
Description
Number of E1/T1/Ethernet links
required by the site
None
Downlink intra-cell interference at
terminal on carrier ic
W
Downlink extra-cell interference at
terminal on carrier ic
W
Downlink inter-carrier interference at
terminal on carrier ic
DL
–  1 – F ortho    BTS  P b  txi ic 

DL
I extra  ic 
DL
P tot  txj ic 
txj j  i
 Ptot  txj icadj 
DL
DL
I inter – carrier  ic 
txj
 j
------------------------------------------------
RF  ic ic adj 

DL
I inter – techno log y  ic 
ni
DL
DL
I tot  ic 
DL
UL extra
i
I tot  ic  + N 0
W
Total received noise at terminal on
carrier ic
 Pb
W
Total power received at transmitter
from intra-cell terminals using carrier
ic
W
Total power received at transmitter
from extra-cell terminals using carrier
ic
W
Uplink inter-carrier interference at
terminal on carrier ic
W
Total received interference at
transmitter on carrier ic
W
Total noise at transmitter on carrier ic
(Uplink interference)
None
Cell uplink load factor on carrier ic
Term
UL

UL
P b  ic 
term
txj j  i
 Pb
UL
UL
I inter – carrier  txi
 ic 
term
txi
 txi ic 
ic 
at terminal on carrier ic a
Total effective interference at terminal
on carrier ic (after unscrambling)
DL
DL
ic 
Downlink inter-technology interference
W
DL
DL
I tot
W
I intra  ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic 
N tot  ic 
UL intra
I tot
 txi
Tx
P Transmitted  ic i 
-----------------------------------------Tx
Tx m
L total  ICP n  ic
 ic adj 
term
txj j
--------------------------------------
RF  ic ic adj 
UL
I tot  txi ic 
UL extra
I tot
UL intra
Tx
 txi ic +  1 – F MUD   term  I tot
UL
UL
N tot  txi ic 
UL
 txi ic  +I inter – carrier  txi ic 
tx
I tot  txi ic  + N 0
UL
X
UL
 txi ic 
I tot  txi ic 
----------------------------UL
N tot  txi ic 
F
UL
 txi ic 
I tot  txi ic 
------------------------------------------------------------------------------------------UL intra
Tx
I tot
 txi ic    1 – F MUD   term 
None
Cell uplink reuse factor on carrier ic
E
UL
 txi ic 
1
-----------------------------UL
F  txi ic 
None
Cell uplink reuse efficiency factor on
carrier ic
None
Downlink load factor on carrier ic
UL
Simulation result available per cell
DL
 I extra  ic 
DL
+ I inter – carrier  ic    L T
---------------------------------------------------------------------------------------- + 1 – F ortho   BTS
DL
P Tx  txi ic 
-------------------------------------------------------------------------------------------------------------------------------------------1
------------- +  1 – F ortho   BTS 
tch
DL
CI req

X
DL
 txi ic 
DL
Q req
DL
with CI req = ----------DL
Gp
Simulation result available per mobile
DL
I tot  ic 
-------------------DL
N tot  ic 
234
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© Forsk 2009
Chapter 6: UMTS HSPA Networks
DL
F
DL
I tot  ic 
------------------------------DL
I intra  txi ic 
 txi ic 
None
Downlink reuse factor on a carrier ic
NR
DL
 txi ic 
– 10 log  1 – X
DL
 txi ic  
dB
Noise rise on downlink
NR
UL
 txi ic 
– 10 log  1 – X
UL
 txi ic  
dB
Noise rise on uplink
a. In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the
fractional load.
6.4.3.2
HSPA Related Results
At the end of the R99 part, packet (HSDPA), packet (HSPA) and packet (HSPA - Constant Bit Rate) service users can be:
•
•
Either connected and in this case, they obtain the requested R99 bearer,
Or rejected exactly for the same reasons as R99 users.
Only connected packet (HSDPA), packet (HSPA) and packet (HSPA - Constant Bit Rate) service users are considered in
the HSDPA part. At the end of the HSDPA part, packet (HSDPA) and packet (HSPA) service users can be:
•
•
•
Either connected if they obtain an HSDPA bearer,
Or rejected if the maximum number of HSDPA users per cell is exceeded,
Or delayed in case of lack of resources (HSDPA power, HS-SCCH power, HS-SCCH channels, OVSF codes).
Packet (HSPA - Constant Bit Rate) service users can be:
•
•
Either connected if they obtain an HSDPA bearer,
Or rejected for the following reasons: the maximum number of HSDPA users per cell is exceeded, the lowest
HSDPA bearer the user can obtain does not provide a RLC peak rate higher than the guaranted bit rate, the HSSCCH signal quality is not sufficient, there are no more OVSF codes available, the maximum Iub backhaul
throughput allowed on the site in the downlink is exceeded.
In the HSUPA part, Atoll processes packet (HSPA) service users and packet (HSPA - Constant Bit Rate) service users
who are connected to an HSDPA bearer or were delayed in the previous step. At the end, they can be:
•
•
6.4.3.2.1
Either connected if they obtain an HSUPA bearer,
Or rejected for the following reasons: the maximum number of HSUPA users per cell is exceeded, the terminal
power required to obtain the lowest compatible HSUPA bearer exceeds the maximum terminal power, there are
no more channel elements available, the maximum Iub backhaul throughput allowed on the site in the uplink is
exceeded, the lowest compatible HSUPA bearer they can obtain does not provide a RLC peak rate higher than
the guaranted bit rate (only for packet (HSPA - Constant Bit Rate) service users).
Statistics Tab
In the Statistics tab, Atoll displays as results:
•
•
•
The number of rejected users.
The number of delayed users.
The number of R99 bearer users connected to a cell (result of the R99 part). This figure includes R99 users as
well as HSDPA and HSUPA bearer users since all of them request an R99 bearer.
-
The number of R99 bearer users per frequency band.
The number of R99 bearer users per activity status.
-
The downlink and uplink rates ( R R99 and R R99 ) generated by their connection to R99 bearers. Only active
DL
UL
users are considered.
DL
R R99 =

DL

UL
R nominal  R99 Bearer  and R R99 =
Active
users
UL
R nominal  R99 Bearer 
Active
users
DL
UL
R nominal  R99 Bearer  is the downlink nominal rate of the user R99 radio bearer and R nominal  R99 Bearer  is the uplink
nominal rate of the user R99 radio bearer.
•
The number of connected users with an HSDPA bearer (result of the HSDPA part) and the downlink rate they generate. Packet (HSDPA), packet (HSPA) and packet (HSPA - Constant Bit Rate) service users are considered since
they all request an HSDPA bearer. On the other hand, only active users are taken into consideration in the downDL
link rate calculation ( R HSDPA ).
DL
R HSDPA =

DL
R RLC – peak
Active
users
DL
R RLC – peak is the RLC peak rate provided in the downlink.
•
© Forsk 2009
The number of connected HSUPA bearer users (result of the HSUPA part). Only packet (HSPA) and packet
(HSPA - Constant Bit Rate) service users are considered.
AT281_TRG_E1
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Technical Reference Guide
In addition, Atoll indicates the uplink data rate generated by active users connected with an HSUPA bearer
UL
( R HSUPA ):
UL
R HSUPA =

UL
R RLC – peak
Active
users
UL
R RLC – peak is the RLC peak rate provided in the uplink.
6.4.3.2.2
Mobiles Tab
In the Mobiles tab, Atoll indicates for each user:
•
UL
DL
The uplink and downlink total requested rates in kbps (respectively, R requested  M b  and R requested  M b  )
For circuit and packet (R99) service users, the DL and UL total requested rates correspond to the DL and UL nominal rates
of the R99 bearer associated to the service.
DL
DL
UL
UL
R requested  M b  = R nominal  R99 Bearer 
R requested  M b  = R nominal  R99 Bearer 
For packet (HSDPA) service users, the uplink requested rate corresponds to the nominal rate of ADPCH R99 radio bearer
and the downlink requested rate is the sum of the ADPCH radio bearer nominal rate and the RLC peak rate that the
selected HSDPA radio bearer can provide. Here, the user is treated as if he is the only user in the cell and then, Atoll determines the HSDPA bearer the user would obtain by considering the entire HSDPA power available of the cell.
DL
DL
UL
UL
DL
R requested  M b  = R nominal  ADPCH R99 Bearer  + R RLC – peak
R requested  M b  = R nominal  ADPCH R99 Bearer 
For HSUPA bearer users (i.e., packet (HSPA) and packet (HSPA - Constant Bit Rate) service users), the uplink requested
rate is equal to the sum of the ADPCH-EDPCCH radio bearer nominal rate and the RLC peak rate of the requested HSUPA
radio bearer. The requested HSUPA radio bearer is selected from the HSUPA bearers compatible with the user equipment. Here, the user is treated as if he is the only user in the cell and then, Atoll determines the HSUPA bearer the user
would obtain by considering the entire remaining load of the cell. The downlink requested rate is the sum of the ADPCHEDPCCH radio bearer nominal rate and the RLC peak rate that the requested HSDPA radio bearer can provide. The
requested HSDPA radio bearer is determined as explained in the previous paragraph.
DL
DL
DL
UL
UL
UL
R requested  M b  = R nominal  ADPCH – EDPCCH R99 Bearer  + R RLC – peak
R requested  M b  = R nominal  ADPCH – EDPCCH R99 Bearer  + R RLC – peak
•
UL
DL
The uplink and downlink total obtained rates in kbps (respectively, R obtained  M b  and R obtained  M b  )
For circuit and packet (R99) service users, the obtained rate is the same as the requested rate if he is connected without
being downgraded. Otherwise, the obtained rate is lower (it corresponds to the nominal rate of the selected R99 bearer).
If the user is rejected, the obtained rate is zero.
For a packet (HSDPA) service connected to an HSDPA bearer, the uplink obtained rate equals the requested one and the
downlink obtained rate corresponds to the instantaneous rate; this is the sum of the A-DPCH radio bearer nominal rate
and the RLC peak rate provided by the selected HSDPA radio bearer after scheduling and radio resource control. If the
user is delayed (he is only connected to an R99 radio bearer), uplink and downlink obtained rates correspond to the uplink
and downlink nominal rates of ADPCH radio bearer. Finally, if the user is rejected either in the R99 part or in the HSDPA
part (i.e., because the HSDPA scheduler is saturated), the uplink and downlink obtained rates are zero.
For a connected packet (HSPA) service user, on uplink, if the user is connected to an HSUPA bearer, the obtained uplink
rate is the sum of the ADPCH-EDPCCH radio bearer nominal rate and the RLC peak rate provided by the selected HSUPA
radio bearer after noise rise scheduling. On downlink, if the user is connected to an HSDPA bearer, the obtained downlink
rate corresponds to the instantaneous rate. The instantaneous rate is the sum of the ADPCH-EDPCCH radio bearer nominal rate and the RLC peak rate provided by the selected HSDPA radio bearer after scheduling and radio resource control.
If the user is delayed, the obtained downlink rate corresponds to the downlink nominal rate of ADPCH-EDPCCH radio
bearer. If the user is rejected, the obtained uplink and downlink rates are "0."
For a connected packet (HSPA - Constant Bit Rate) service user, the uplink and downlink total obtained rates are the sum
of the ADPCH-EDPCCH radio bearer nominal rate and the guaranteed bit rate defined for the service. If the user is
rejected, the uplink and downlink total obtained rates are "0".
•
The mobile total power ( P term )
UL
P term = P term – R99  f act – EDPCCH + P term – HSUPA for packet (HSPA) service users
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UL
P term = P term – R99  f act – EDPCCH + P term – HSUPA  C HSDPABearer for packet (HSPA - Constant Bit Rate) service users
Note:
UL
For packet (HSPA - Constant Bit Rate) service users, f act –EDPCCH = 0.1 .
And
P term = P term – R99 for circuit and packet (R99) service users and packet (HSDPA) service users
•
DL
The HSDPA application throughput in kbps ( T application  M b  )
This is the net HSDPA throughput without coding (redundancy, overhead, addressing, etc.).
DL
R obtained  M b    1 – BLER HSDPA   SF Rate – R
DL
T application  M b  = ----------------------------------------------------------------------------------------------------------------------------------TTI
Where:
BLER HSDPA is read in the quality graph defined for the triplet “reception equipment-selected bearer-mobility” (HSDPA
Quality Graphs tab in the Reception equipment properties). This graph describes the variation of BLER as a function of
the measured quality (HS-PDSCH Ec/Nt). Knowing the HS-PDSCH Ec/Nt, Atoll calculates the corresponding BLER.
SF Rate and R respectively represent the scaling factor between the application throughput and the RLC (Radio Link
Control) throughput and the throughput offset. These two parameters model the header information and other supplementary data that does not appear at the application level. They are defined in the service properties.
TTI is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user
equipment category properties.
•
The number of OVSF codes
This is the number of 512-bit length OVSF codes consumed by the user.
•
The required HSDPA power in dBm (  P HSDPA  required )
It corresponds to the HSDPA power required to provide the HSDPA bearer user with the downlink requested rate. The
downlink requested rate is the data rate the user would obtain if he was the only user in the cell. In this case, Atoll determines the HSDPA bearer the user would obtain by considering the entire HSDPA power available of the cell.
 P HSDPA  required =  P HS – PDSCH  used + n HS – SCCH  P HS – SCCH
 P HS – PDSCH  used is the HS-PDSCH power required to obtain the selected HSDPA bearer (in dBm). If the HSDPA bearer
allocated to the user is the best one,  P HS – PDSCH  used corresponds to the available HS-PDSCH power of the cell. On
the other hand, if the HSDPA bearer has been downgraded in order to be compliant with cell and UE capabilities or for
another reason,  P HS – PDSCH  used will be lower than the available HS-PDSCH power of the cell.
•
The served HSDPA power in dBm (  P HSDPA  served )
This is the HSDPA power required to provide the HSDPA bearer user with the downlink obtained rate. The downlink
obtained rateis the data rate experienced by the user after scheduling and radio resource control.
 P HSDPA  served =  P HS – PDSCH  used + n HS – SCCH  P HS – SCCH for packet (HSDPA) and packet (HSPA) service users
And
 P HSDPA  served =  P HS – PDSCH  used  C HSDPABearer for packet (HSPA - Constant Bit Rate) service users
Where
 P HS – PDSCH  used is the HS-PDSCH power required to obtain the selected HSDPA bearer.
•
The No. of HSUPA Retransmissions (Required)
The maximum number of retransmissions in order to have the requested HSUPA radio bearer with a given BLER.
•
The No. of HSUPA Retransmissions (Obtained)
The maximum number of retransmissions in order to have the obtained HSUPA radio bearer with a given BLER.
•
UL
The HSUPA application throughput in kbps ( T application  M b  )
This is the net HSUPA throughput without coding (redundancy, overhead, addressing, etc.).
UL
R obtained  M b    1 – BLER HSUPA   SF Rate – R
UL
T application  M b  = ----------------------------------------------------------------------------------------------------------------------------------N Rtx
Where:
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BLER HSUPA is the residual BLER after N Rtx retransmissions. It is read in the quality graph defined for the quartet “reception equipment-selected bearer-number of retransmissions-mobility” (HSUPA Quality Graphs tab in the Reception equipment properties). This graph describes the variation of BLER as a function of the measured quality (E-DPDCH Ec/Nt).
Knowing the E-DPDCH Ec/Nt, Atoll calculates the corresponding BLER.
SF Rate and R respectively represent the scaling factor between the application throughput and the RLC (Radio Link
Control) throughput and the throughput offset. These two parameters model the header information and other supplementary data that does not appear at the application level. They are defined in the service properties.
N Rtx is the maximum number of retransmissions for the obtained HSUPA bearer. This figure is read in the HSUPA Bearer
Selection table.
The following columns appear if, when creating the simulation, you select "Detailed information about mobiles":
•
The uplink and downlink requested RLC peak rates (kbps)
Downlink and uplink requested RLC peak rates are not calculated for circuit and packet (R99) service users.
For packet (HSDPA) service users, the uplink RLC peak rate is not calculated and the downlink requested RLC peak rate
is the data rate that the selected HSDPA radio bearer can provide. Here, the user is treated as if he is the only user in the
cell and then, Atoll determines the HSDPA bearer he would obtain by considering the entire HSDPA power available of
the cell.
For HSUPA bearer users (i.e., packet (HSPA) and packet (HSPA - Constant Bit Rate) service users), the requested uplink
RLC peak rate is the data rate of the requested HSUPA radio bearer. The requested HSUPA radio bearer is selected from
the HSUPA bearers compatible with the user equipment. Here, the user is treated as if he is the only user in the cell and
then, Atoll determines the HSUPA bearer the user would obtain by considering the entire remaining load of the cell. If the
user is connected to an HSDPA bearer in the downlink, the downlink requested RLC peak rate is the rate that the
requested HSDPA radio bearer can provide. The requested HSDPA radio bearer is determined as explained in the previous paragraph.
•
The uplink and downlink obtained RLC peak rate (kbps)
Downlink and uplink obtained RLC peak rates are not calculated for circuit and packet (R99) service users.
For a packet (HSDPA) service user connected to an HSDPA bearer, the uplink obtained RLC peak rate is not calculated,
and the downlink obtained RLC peak rate is the rate provided by the selected HSDPA radio bearer after scheduling and
radio resource control.
For a connected packet (HSPA) service user, on uplink, if the user is connected to an HSUPA bearer, the obtained uplink
RLC peak rate is the rate provided by the selected HSUPA radio bearer after noise rise scheduling. On downlink, if the
user is connected to an HSDPA bearer, the downlink obtained RLC peak rate is the rate provided by the selected HSDPA
radio bearer after scheduling and radio resource control.
For a connected packet (HSPA - Constant Bit Rate) service user, the uplink and downlink obtained RLC peak rates are
the uplink and downlink guaranteed bit rates defined for the service.
6.4.3.2.3
Cells Tab
In the Cells tab, Atoll gives:
•
The available HSDPA power in dBm ( P HSDPA  ic  )
This is:
-
Either a fixed value in case of a static HSDPA power allocation strategy,
Or a simulation result when the option "HSDPA Power Dynamic Allocation" is selected. We have:
P HSDPA  ic  = P max  ic  – P Headroom  ic  – P tx – R99  ic  – P HSUPA  ic 

with P tx – R99  ic  = P pilot  ic  + P SCH  ic  + P OtherCCH  ic  +
P tch  ic  +
tch used for
R99 users
•

DL
P tch  ic   f act – ADPCH
tch used for
HSPA users
The transmitted HSDPA power in dBm ( P tx –H SDPA  ic  )
It corresponds to the HSDPA power used to serve HSDPA bearer users.
P tx – H SDPA  cell  =

 P HSDPA  M b   served
M b  cell
•
The number of HSDPA users in the cell
They are the connected and delayed HSDPA bearer users. This figure includes packet (HSDPA), packet (HSPA) and
packet (HSPA - Constant Bit Rate) users.
•
The number of simultaneous HSDPA users in the cell ( n M )
b
It corresponds to the number of connected HSDPA bearer users that the cell supports at a time, i.e. within one transmission time interval. All these users are connected to the cell at the end of the HSDPA part of the simulation; they have a
connection with the R99 bearer and an HSDPA bearer.
•
238
DL
The instantaneous HSDPA rate in kbps ( R Inst  cell  )
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Chapter 6: UMTS HSPA Networks
This is the number of kilobits per second that the cell supports on downlink to provide simultaneous connected HSDPA
bearer users with an HSDPA bearer.
DL
R Inst  cell  =

DL
R obtained  M b 
M b  cell
DL
The instantaneous HSDPA MAC Throughput in kbps ( T MAC  cell  )
•
DL
T MAC  cell  =

M b  cell
S block  M b 
------------------------------------------T TTI   TTI  M b 
Where,
S block  M b  is the transport block size (in kbits) of the HSDPA bearer selected by the user; it is defined for each HSDPA
bearer in the HSDPA Radio Bearers table.
TTI  M b  is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal
user equipment category properties.
–3
T TTI is the TTI duration, i.e. 2 10 s (2000 TTI in one second). This value is specified by the 3GPP.
DL
The average instantaneous HSDPA rate in kbps ( R Av – Inst  cell  )
•

DL
R obtained  M b 
M  cell
DL
b
R Av – Inst  cell  = -------------------------------------------------------nM
b
DL
The HSDPA application throughput in kbps ( T application  cell  )
•

DL
Either T application  cell  =
DL
T application  M b  if the scheduling algorithm is Round Robin or Proportional Fair,
M b  cell
DL
DL
Or T application  cell  = T application  M b  maxC  I   if the scheduling algorithm is Max C/I.
M b  maxC  I  is the user with the highest C  I in the cell.
•
DL
The minimum HSDPA RLC peak rate in kbps ( min  R obtained  M b   )
M b  cell
It corresponds to the lowest of RLC peak rates obtained by HSDPA bearer users connected to the cell.
•
The maximum HSDPA RLC peak rate in kbps (
DL
max  R obtained  M b   )
M b  cell
It corresponds to the highest of RLC peak rates obtained by HSDPA bearer users connected to the cell.
•
The number of HSUPA users in the cell ( n M ):
c
They are the HSDPA bearer users connected to the cell.
•
UL
The HSUPA application throughput in kbps ( T application  cell  )
UL
T application  cell  =

UL
T application  M b 
M b  cell
•
UL
The uplink cell load factor due to HSUPA traffic ( X HSUPA  cell  ):
UL
 I tot  cell   HSUPA
UL
X HSUPA  cell  = -------------------------------------------UL
N tot  cell 
Where
UL
 I tot  cell   HSUPA is the total interference at transmitter received from HSUPA bearer users.
6.4.3.2.4
Sites Tab
In the Sites tab, Atoll displays:
•
© Forsk 2009
DL
The instantaneous HSDPA rate carried by the site in kbps ( R Inst  site  )
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
DL
R Inst  site  =
DL
R Inst  cell 
cell  site
•
DL
The instantaneous HSDPA MAC Throughput carried by the site in kbps ( T MAC  site  in kbps)
DL
T MAC  site  =

DL
T MAC  cell 
cell  site
•
R
UL
The HSUPA rate carried by the site in kbps ( R
 site  =

UL
 site  )
UL
R obtained  M c 
M c  site
6.4.4
Appendices
6.4.4.1
Admission Control in the R99 Part
During admission control of the R99 part of the simulation, Atoll calculates the uplink load factor of a considered cell
assuming the mobile concerned is connected with it. Here, activity status assigned to users is not taken into account. So
even if the mobile is not active on UL, it can be rejected due to cell load saturation. To calculate the cell UL load factor,
either Atoll takes into account the mobile power determined during power control if mobile was connected in previous iteration, or it estimates a load rise due to the mobile and adds it to the current load. The load rise ( X
follows:
X
6.4.4.2
6.4.4.2.1
UL
UL
) is calculated as
1
= -------------------------------------------------W
1 + ---------------------------------------UL
UL
Q req  R nominal
Resources Management
OVSF Codes Management
OVSF codes are managed on the downlink during the simulation since this resource is downlink limited only. Atoll checks
the availability of this resource during the simulation, first in the R99 part and then in the HSDPA part. It determines the
number of codes that will be consumed by each cell.
OVSF codes form a binary tree. Codes of longer lengths are generated from codes of a shorter length. Length-k OVSF
codes are generated from length-k/2 OVSF codes. Therefore, if one channel needs 1 length-k/2 OVSF code, it is equivalent to use 2 length-k OVSF codes, or 4 length-2k OVSF codes and so on.
512 512-bit-length codes per cell are available in UMTS HSPA projects.
In the R99 part, during the resource control, Atoll determines the number of 512 bit-length codes that will be consumed for
each cell.
If the cell supports HSUPA, Atoll allocates codes for the DL channels used for HSUPA:
•
•
A 128 bit-length code for the E-HICH and E-RGCH channels (i.e. four 512 bit-length OVSF codes), for each cell.
Therefore, Atoll will take four 512-bit-length codes,
A 256 bit-length code for the E-AGCH channel (i.e. two 512 bit-length OVSF codes), for each cell. Therefore, Atoll
will take two 512-bit-length codes,
If the cell supports HSDPA, Atoll reserves for potential HSDPA bearer users:
•
Codes – HS – PDSCH
The minimum number of HS-PDSCH codes defined for the cell, N min
. They are 16-bit length OVSF
Codes – HS – PDSCH
codes (i.e. thirty-two 512 bit-length OVSF codes). Therefore, Atoll will take 32  N min
•
512-bit-
length codes,
A 128 bit-length code per HS-SCCH channel (i.e. four 512 bit-length OVSF codes), for each cell. Therefore, Atoll
will take 4  n HS – SCCH 512-bit-length codes,
Then, it allocates to the cell OVSF codes to support R99 bearers required by users:
•
A 256 bit-length code per common channel (i.e. two 512 bit-length OVSF codes), for each cell. Therefore, Atoll will
•
take 2  N
512-bit-length codes,
A code per cell-receiver link, for TCH (traffic channels). The length of code to be allocated, Code_Length, depends
on the user activity. We have:
Overhead – Codes
DL
Either Code_Length = F spreading  Active user  when the user is active,
DL
Or Code_Length = F spreading  Inactive user  if the user is inactive.
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The number of 512 bit-length OVSF codes needed N
as follows:
N
Codes-TCH
Codes-TCH
is calculated from the length of the code to be allocated
512
= -----------------------------------Code_Length
Figure 6.13: OVSF Code Tree Indices (Not OVSF Code Numbers)
The OVSF code allocation follows the “Buddy” algorithm, which guarantees that:
•
•
If a k-length OVSF code is used, all of its children with lengths 2k, 4k, …, cannot be used as they will not be orthogonal.
If a k-length OVSF code is used, all of its ancestors with lengths k/2, k/4, …, cannot be used as they will not be
orthogonal.
Example: We consider a user with a service requiring the UDD64 R99 radio bearer. This user is active on DL while
connected to a cell (which does not support HSDPA). The spreading factor for active users has been set to 64 and site
equipment requires four overhead downlink channel elements per cell. Atoll will consume four 256 bit-length OVSF codes
for common channels (i.e. eight 512 bit-length OVSF codes) and a 64 bit-length OVSF code for traffic channels (i.e. eight
additional 512 bit-length OVSF codes).
Notes:
•
In the R99 part, the OVSF code allocation follows the mobile connection order (mobile
order in the Mobiles tab).
•
The OVSF code and channel element management is differently dealt with in case of
“softer” handover. Atoll allocates OVSF codes for each cell-mobile link while it globally
assigns channel elements to a site.
In the HSDPA part, packet (HSDPA), packet (HSPA) and packet (HSPA - Constant Bit Rate) service users) are assigned
an HSDPA bearer (Fast link adaptation). Therefore, Atoll allocates to the cell:
•
16-bit length OVSF codes per cell-HSDPA receiver, for HS-PDSCH. This figure depends on the HSDPA bearer
assigned to the user and on the type of service.
For packet (HSDPA) and packet (HSPA) service users, Atoll needs 32  N
for each user connected to the cell. N
HSDPA bearer.
Codes – HS – PDSCH
512-bit-length codes
is the number of HS-PDSCH channels required by the
For packet (HSPA - Constant Bit Rate) service users, Atoll needs 32  N
bit-length codes for each user connected to the cell. N
required by the HSDPA bearer.
Codes – HS – PDSCH
Codes – HS – PDSCH
Codes – HS – PDSCH
 C HSDPABearer 512-
is the number of HS-PDSCH channels
Note:
•
When HSDPA bearer users (at least one) are connected to the cell, Atoll gives the cell back
Codes – HS – PDSCH
the minimum number of OVSF codes reserved for HS-PDSCH ( N min
). On
the other hand, if no HSDPA bearer user is connected, Atoll still keeps these codes and the
codes for HS-SCCH too. This is the same with HSUPA bearer users. Even if no HSUPA
bearer user is connected to the cell, Atoll still keeps the codes for E-HICH, E-RGCH and EAGCH channels.
6.4.4.2.2
Channel Elements Management
Channel elements are controlled in the R99 and the HSUPA parts of the simulation. Atoll checks the availability of this
resource in the uplink and downlink.
In the R99 part, during the resource control, Atoll determines the number of channel elements required by each site for
R99 bearer users in the uplink and downlink. Then, in the HSUPA part, Atoll carries out another resource control after allo-
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cating HSUPA bearers. It takes into account the channel elements consumed by HSUPA bearer users in the uplink and
recalculates the number of channel elements required by each site in the uplink.
In the uplink, Atoll consumes N
•
CE – UL
 j  channel elements for each cell j on a site NI. This figure includes:
Channel elements for R99 bearers:
-
Overhead – CE – UL
N
channel elements for control channels,
R99 – T CH – CE – UL
•
per cell-receiver link, for R99 TCH (traffic channels).
N
Channel elements for HSUPA bearers:
-
N
HSUPA – CE
N
HSUPA – CE
per cell-receiver link, for packet (HSPA) service users.
 C HSUPABearer per cell-receiver link, for packet (HSPA - Constant Bit Rate) service users.
Therefore, the number of channel elements required on uplink at the site level, N
N
CE – UL
N
 NI  =
CE – UL
CE – UL
 N I  , is:
j
j  NI
On downlink, Atoll consumes N
•
CE – DL
 j  channel elements for each cell j on a site NI. This figure includes:
Channel elements for R99 bearers
Overhead – CE – DL
channel elements for control channels (Pilot channel, Synchronisation channel, common
R99 – T CH – CE – DL
per cell-receiver link, for R99 TCH (traffic channels).
-
N
channels),
-
N
Therefore, the number of channel elements required on downlink at the site level, N
N
CE – DL
 NI  =
N
CE – DL
CE – DL
 N I  , is:
j
j  NI
Note:
•
6.4.4.2.3
In case of “softer” handover (the mobile has several links with co-site cells), Atoll allocates
channel elements for the best serving cell-mobile link only.
Iub Backhaul Throughput
The Iub backhaul throughput is controlled in the R99, the HSDPA and the HSUPA parts of the simulation. Atoll checks the
availability of this resource in the uplink and downlink.
In the R99 part, during the resource control, Atoll determines the Iub throughput required by each site for R99 bearer users
in the uplink and downlink. Then, in the HSDPA part, Atoll performs a resource control in the downlink after allocating
HSDPA bearers. It takes into account the Iub backhaul throughput consumed by HSDPA bearer users in the downlink and
recalculates the Iub backhaul throughput required by each site in the downlink. Finally, in the HSUPA part, Atoll carries
out a resource control in the uplink after allocating HSUPA bearers. It takes into account the Iub backhaul throughput
consumed by HSUPA bearer users in the uplink and updates the Iub backhaul throughput required by each site in the
uplink.
UL
In the uplink, the Iub backhaul throughput consumed by each cell j on a site NI, T Iub  j  , includes:
•
The Iub backhaul throughput required for R99 bearers:
-
•
R99 – T CH – UL
T Iub
per cell-receiver link, for R99 TCH (traffic channels).
The Iub backhaul throughput required for HSUPA bearers:
HSUPA
-
T Iub
-
HSUPA
T Iub
per cell-receiver link, for packet (HSPA) service users.
 C HSUPABearer per cell-receiver link, for packet (HSPA - Constant Bit Rate) service users.
UL
Therefore, the Iub backhaul throughput required on uplink at the site level, T Iub  N I  , is:
UL
T Iub  N I  =
 TIub  j 
UL
j  NI
DL
In the downlink, the Iub backhaul throughput consumed by each cell j on a site NI, T Iub  j  , includes:
•
•
242
The Iub backhaul throughput required for R99 bearers:
Overhead – DL
-
T Iub
for R99 control channels (Pilot channel, Synchronisation channel, common channels).
-
R99 – T CH – DL
T Iub
per cell-receiver link, for R99 TCH (traffic channels).
The Iub backhaul throughput required for HSUPA bearers:
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Chapter 6: UMTS HSPA Networks
HSDPA
-
T Iub
-
HSDPA
T Iub
per cell-receiver link, for packet (HSDPA) and packet (HSPA) service users.
 C HSDPABearer per cell-receiver link, for packet (HSPA - Constant Bit Rate) service users.
HSDPA
With T Iub
DL
HSDPA
= R RLC – peak + Overhead Iub
DL
 R RLC – peak
DL
Therefore, the Iub backhaul throughput required on downlink at the site level, T Iub  N I  , is:
DL
T Iub  N I  =
 TIub  j 
DL
j  NI
Note:
•
6.4.4.3
In case of “softer” handover (the mobile has several links with co-site cells), Iub backhaul
throughput is consumed by the best serving cell-mobile link only.
Downlink Load Factor Calculation
Atoll calculates a downlink load factor for each cell (available in the Cells tab of any simulation result) and each connected
mobile (available in the Mobiles tab of any given simulation result).
6.4.4.3.1
Downlink Load Factor per Cell
Approach for downlink load factor evaluation is highly inspired by the downlink load factor defined in the book “WCDMA
for UMTS by Harry Holma and Antti Toskala”.
DL
Q req
- be the required quality.
Let CI req = ----------DL
Gp
DL
Gp
DL
and Q req are the processing gain on downlink and the Eb/Nt target on downlink respectively.
In case of soft-handoff, required quality is limited to the effective contribution of the transmitter.
DL
P tx  ic  = P pilot  ic  + P SCH  ic  + P otherCCH  ic  +
 Ptch  ic 
tch
DL
ortho
nonOrtho
P tx  ic  = P CCH  ic  + P CCH
 ic  +
 Ptch  ic 
tch
where
ortho
P CCH  ic  = P pilot  ic  + P otherCCH  ic 
nonOrtho
P CCH
 ic  = P SCH  ic 
At mobile level, we have a required power, Ptch:
term
P tch  ic  = CI req   I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + I intra  ic  + N 0
DL
With r = 1 when the user is active on the downlink and r = r c
  LT  r
when the user is inactive. In case of an HSDPA bearer
DL
user, r = f act – ADPCH .


P tch  ic  = CI req  



I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic 
DL
nonOrtho
nonOrtho
 P tx  ic  – P CCH
 ic  – P tch  ic   P CCH
 ic 
term
- + N0
+  1 – F ortho   BTS   ---------------------------------------------------------------------------------------------- + ---------------------------------LT
LT


 L r
T



DL
 I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic    L T  r +  1 – F ortho   BTS   P tx  ic   r
+
nonOrtho
term
F ortho   BTS  P CCH
 ic   r + N 0
 LT  r
P tch  ic  = -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------1
---------------------- +  1 – F ortho   BTS 
CI req  r
I intra  ic  is the total power received at the receiver from the cell with which it is connected.
I extra  ic  is the total power received at the receiver from other cells.
I inter – carrier  ic  is the inter-carrier interference received at the terminal.
I inter – techno log y  ic  is the inter-technology interference received at the terminal from an external transmitter.
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We have:
ortho
nonOrtho
P CCH  ic  + P CCH
DL
P tx  ic 
DL
P tx  ic 
=
 ic 


 I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic    L T  r



DL
nonOrtho
term

1
F
+

–




P

ic


r
+
F



P

ic


r
+
N

L

r

ortho
BTS
tx
ortho
BTS
CCH
0
T

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+

1


--------------------+

–



1
F
ortho
BTS
tch 

CI req  r





 I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic    L T  r
-----------------------------------------------------------------------------------------------------------------------------------------------------------  P DL
tx  ic 
DL
P tx  ic 
= P ortho  ic  + P nonOrtho  ic  + ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- +
CCH
CCH
1
---------------------- +  1 – F ortho   BTS 
tch
CI req  r

DL
 1 – F ortho   BTS   P tx  ic   r
-----------------------------------------------------------------------------------+
1
tch ---------------------- +  1 – F ortho   BTS 
CI req  r

nonOrtho
term
F ortho   BTS  P CCH
 ic   r + N 0
 LT  r
---------------------------------------------------------------------------------------------------------------------------1
---------------------- +  1 – F ortho   BTS 
tch
CI req  r

 I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic    L T  r
---------------------------------------------------------------------------------------------------------------------------------------------------------- + 1 – F ortho   BTS  r 
DL


P

ic

DL
tx
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------   P DL
P tx  ic  –
tx  ic 


1
---------------------- +  1 – F ortho   BTS 

tch 

r
CI
req



ortho
nonOrtho
= P CCH  ic  + P CCH
nonOrtho
 ic  +
F ortho   BTS  P CCH
term
 ic   r + N 0
 LT  r
 ---------------------------------------------------------------------------------------------------------------------------1
---------------------- +  1 – F


tch
CI req  r
nonOrtho
ortho
BTS
term
F ortho   BTS  P CCH
 ic   r + N 0
 LT  r
---------------------------------------------------------------------------------------------------------------------------1
---------------------- +  1 – F ortho   BTS 
tch
CI req  r
DL
P tx  ic  = -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic    L T  r
----------------------------------------------------------------------------------------------------------------------------------------------------------- + 1 – F ortho   BTS  r 
DL


P tx  ic 
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1–


1
---------------------- +  1 – F ortho   BTS 

tch 
CI req  r


ortho
nonOrtho
P CCH  ic  + P CCH
 ic  +


Therefore, the downlink load factor can be expressed as:
X
DL
 I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic    L T  r
----------------------------------------------------------------------------------------------------------------------------------------------------------- + 1 – F ortho   BTS  r
DL
P tx  ic 
=
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------1
---------------------- +  1 – F ortho   BTS 
tch
CI req  r

The downlink load factor represents the signal degradation in relation to the reference interference (thermal noise plus
synchronisation channel power).
6.4.4.3.2
Downlink Load Factor per Mobile
Atoll evaluates the downlink load factor for any connected mobile as follows:
X
6.4.4.4
DL
DL
I tot  ic 
= ------------------DL
N tot  ic 
Uplink Load Factor Due to One User
UL
This part details how Atoll calculates the contribution of one user to the UL load factor ( X k ).
In this calculation, we assume that the cell UL reuse factor ( F
UL
 txi ic  ) is constant.
The result depends on the option used to calculate Nt (Without useful signal or Total noise that you may select in Global
parameters).
Without Useful Signal Option
UL
 P b  k   req
W
UL
-  ------------------------------------------------------------------------------------------------------------------------Q req  k  = ----------------------------UL
UL
tx
R nominal  k  I intra –  P b  k   req + I extra + I inter – carrier + N 0
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Chapter 6: UMTS HSPA Networks
UL
 P b  k   req
W
UL
-  ------------------------------------------------------------------------------Q req  k  = ----------------------------UL
UL
UL
tx
R nominal  k  I intra  F –  P b  k   req + N 0
UL
UL
R nominal  k 
R nominal  k 

UL
UL
UL
UL
tx
 P b  k   req   1 + Q req  k   ------------------------------ = Q req  k   ------------------------------   I intra  F + N 0 
W
W


UL
UL
R nominal  k 
R nominal  k 
UL
UL
UL
tx
Q req  k   ------------------------------  I intra  F
Q req  k   ------------------------------  N 0
W
W
= -------------------------------------------------------------------------------------------- + -----------------------------------------------------------------------UL
UL
R nominal  k 
R nominal  k 
UL
UL
1 + Q req  k   -----------------------------1 + Q req  k   -----------------------------W
W
UL
 P b  k   req
UL
req
R nominal  k 
Ec
UL
We note  -------  k 
= Q req  k   ----------------------------- Nt  E – DPDCH
W
UL
tx
N0
I intra  F
UL
- + ------------------------------------------------------------ P b  k   req = ------------------------------------------------------------
 


 

1
1
+ 1  ---------------------------------------------- + 1
 ---------------------------------------------req
Ec  req
  Ec





- k
- k
  -----   -----
Nt  E – DPDCH
Nt  E – DPDCH
  Pb
UL
As I intra =
 k   req , we have:
K
I intra = I intra  F
UL

1
K
tx
N0 
1
- + N 0   ------------------------------------------------------------- ------------------------------------------------------------



tx


1
+ 1
 ---------------------------------------------req
  Ec

-  k 
  -----
Nt  E – DPDCH
K


1
+ 1
 ---------------------------------------------req
  Ec

-  k 
  -----
Nt  E – DPDCH
1
 ------------------------------------------------------------



1
+ 1
 ---------------------------------------------req
  Ec


- k
  -----
Nt  E – DPDCH
= -----------------------------------------------------------------------------------------------UL
1
1–F 
-------------------------------------------------------------


K 
1
+ 1
 ---------------------------------------------req
  Ec

-  k 
  -----
Nt  E – DPDCH
K
I intra

tx
UL
N0  F
I intra = -----------------------------------------------------------------------------------------------1
--------------------------------------------------------------------------------------- – 1
UL
1
F 
-------------------------------------------------------------


K 
1
---------------------------------------------+
1


req
  Ec

-  k 
  -----

Nt
E – DPDCH

X
UL
UL
I intra + I extra + I inter – carrier
I intra  F
1
- = -------------------------------------= -----------------------------------------------------------------------------------= -----------------------------------------tx
UL
tx
tx
I intra  F + N 0
N0
I intra + I extra + I inter – carrier + N 0
1 + --------------------------UL
I intra  F
Therefore, we have:
X
UL
= F
UL

1
 ------------------------------------------------------------

K


1
+ 1
 ---------------------------------------------req
Ec
  ------- 

  Nt  k 

E – DPDCH
So, we can conclude that the contribution of one user to the UL load is defined as:
UL
X k
© Forsk 2009
= F
UL
1
 -------------------------------------------------------------



1
+ 1
 ---------------------------------------------req
  Ec


- k
  -----
Nt  E – DPDCH
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Total Noise Option
UL
 P b  k   req
W
UL
-  -----------------------------------------------------------------------------------Q req  k  = ----------------------------UL
tx
R nominal  k  I intra + I extra + I inter – carrier + N 0
UL
 P b  k   req
W
UL
-  -----------------------------------------Q req  k  = ----------------------------UL
UL
tx
R nominal  k  I intra  F + N 0
UL
R nominal  k 
UL
UL
UL
tx
 P b  k   req = Q req  k   ------------------------------   I intra  F + N 0 
W
UL
req
R nominal  k 
Ec
UL
We note  -------  k 
= Q req  k   ----------------------------- Nt  E – DPDCH
W
req
Ec
UL
UL
tx
 P b  k   req =  -------  k 
  I intra  F + N 0 
 Nt  E – DPDCH
  Pb
UL
As I intra =
 k   req , we have:
K
I intra =  I intra  F
UL
tx
+ N0  
Ec
req
-  k 
  -----Nt  E – DPDCH
K
tx
N0 
Ec
req
-  k 
  -----Nt  E – DPDCH
K
I intra = --------------------------------------------------------------------UL
1–F
X
UL
I intra + I extra + I inter – carrier
I intra  F
1
- = -------------------------------------= -----------------------------------------------------------------------------------= -----------------------------------------UL
tx
tx
tx
I intra  F + N 0
N0
I intra + I extra + I inter – carrier + N 0
1 + --------------------------UL
I intra  F
UL
Therefore, we have:
X
UL
= F
UL

Ec
req
-  k 
  -----Nt  E – DPDCH
K
So, we can conclude that the contribution of one user to the UL load is defined as:
UL
X k
6.4.4.5
= F
UL
req
Ec
  -------  k 
 Nt  E – DPDCH
Inter-carrier Power Sharing Modelling
Inter-carrier power sharing enables the network to dynamically allocate available power from R99-only and HSDPA carriers among HSDPA carriers.
In this part, we will consider the most common scenario, a network consisting of an R99-only carrier (c1) and an HSDPA
carrier with dynamic power allocation (c2) (c2 does not support HSUPA).
As explained in The User Manual, the maximum power of the HSDPA cell must be set to the same value as the maximum
shared power in order to use power sharing efficiently. In this case, the HSDPA cell can use 100% of the available power,
i.e, all of the R99-only cell’s unused power can be allocated to the HSDPA cell.
Let’s take the following example to measure the impact of the inter-carrier power sharing.
•
1st case: Inter-carrier power sharing is not activated
On c1, we have: P max  Tx c 1  = 43dBm and P tx – R99  Tx c 1  = 39.1dBm .
On c2, we have: P max  Tx c 2  = 43dBm , P tx – R99  Tx c 2  = 36.1dBm and P Headroom  Tx c 2  = 0dB .
Therefore, P HSDPA  Tx c 2  = P max  Tx c 2  – P tx – R99  Tx c 2  – P Headroom  Tx c 2  = 42dBm
•
2nd case: Inter-carrier power sharing is activated and P max  Tx  = 46dBm
On c1, we have: P max  Tx c 1  = 43dBm and P tx – R99  Tx c 1  = 39.1dBm .
On c2, we have: P max  Tx c 2  = 46dBm , P tx – R99  Tx c 2  = 36.1dBm and P Headroom  Tx c 2  = 0dB .
Therefore, P HSDPA  Tx c 2  = P max  Tx  – P tx – R99  Tx c 1  – P tx – R99  Tx c 2  – P Headroom  Tx c 2  = 44.4dBm
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Chapter 6: UMTS HSPA Networks
6.4.4.6
Best Server Determination in Monte Carlo Simulations - Old Method
Before Atoll 2.8.0, best server determination used to be performed by selecting the best carrier within transmitters according to the selected method (site equipment) and then the best transmitter using the best carrier. To switch back to this
method, add the following lines in the Atoll.ini file:
[CDMA]
MultiBandSimu = 0
The method is described below:
For each station txi containing Mb in its calculation area and using the main frequency band supported by the Mb’s terminal
(i.e. either f1 for a single frequency band network, or f1 or f2 for a dual-band terminal without any priority on frequency
bands, or f1 for a dual-band terminal with f1 as main frequency band).
Determination of BestCarrier k  txi M b  .
If a given carrier is specified for the service requested by Mb and if it is used by txi
BestCarrier k  txi M b  is the carrier specified for the service.
Else the carrier selection mode defined for txi is considered.
If carrier selection mode is “Min. UL Load Factor”
For each carrier ic used by txi, we calculate current loading factor:
UL
I tot  txi ic 
UL
UL
- + X
X k  txi ic  = ----------------------------UL
N tot  txi ic 
EndFor
UL
BestCarrier k  txi M b  is the carrier with the lowest X k  txi ic 
Else if carrier selection mode is “Min. DL Total Power”
BestCarrier k  txi M b  is the carrier with the lowest P tx  txi ic  k
Else if carrier selection mode is “Random”
BestCarrier k  txi M b  is randomly selected
Else if carrier selection mode is "Sequential"
UL
UL
BestCarrier k  txi M b  is the first carrier so that X k  txi ic   X max
Calculation of
   BTS  P c  txi M b BestCarrier 
Q pilot  txi BestCarrier  = -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------k
DL
DL


P tot  txi BestCarrier k  txi M b   + I extra  BestCarrier k  txi M b   +


 DL
DL
Term 
 I inter – carrier  BestCarrier k  txi M b   + I inter – techno log y  BestCarrier k  txi M b   + N 0

If user selects “without Pilot”
   BTS  P c  txi M b BestCarrier 
Q pilot  txi BestCarrier  = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------k


DL
DL
P tot  txi BestCarrier k  txi M b   + I extra  BestCarrier k  txi M b  




DL
DL
 +I
 BestCarrier k  txi M b   + I inter – techno log y  BestCarrier k  txi M b   
inter
–
carrier


Term


+ N0
–  1 –     BTS  P c  txi M b BestCarrier 


Rejection of station txi if the pilot is not received
pilot
If Q pilot  txi M b BestCarrier   Q req  Mobility  M b   then txi is rejected by Mb
k
max
If Q pilot  txi M b BestCarrier   Q pilot  M b 
k
k
Admission control (If simulation respects a loading factor constraint and Mb was not connected in previous iteration).
UL
UL
If X k  txi BestCarrier  txi M b    X max , then txi is rejected by Mb
Else
max
Q pilot  M b  = Q pilot  txi M b BestCarrier 
k
k
Tx BS  M b  = txi
© Forsk 2009
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Endif
EndFor
If no TxBS has been selected and Mb’s terminal can work on one frequency band only, Mb has failed to be connected to
the network and is rejected.
If no TxBS has been selected and Mb’s terminal can work on another frequency band.
Determination of BestCarrier k  txi M b  for each station txi containing Mb in its calculation area and using another
frequency band supported by the Mb’s terminal (i.e. f1 or f2 for a dual-band terminal without any priority on frequency
bands, or f2 for a dual-band terminal with f2 as secondary frequency band)
If a given carrier is specified for the service requested by Mb and if it is used by txi
BestCarrier k  txi M b  is the carrier specified for the service.
Else the carrier selection mode defined for txi is considered.
If carrier selection mode for txi is “Min. UL Load Factor”
For each carrier ic used by txi, we calculate current loading factor:
UL
I tot  txi ic 
UL
UL
- + X
X k  txi ic  = ----------------------------UL
N tot  txi ic 
EndFor
UL
BestCarrier k  txi M b  is the carrier with the lowest X k  txi ic 
Else if carrier selection mode is “Min. DL Total Power”
BestCarrier k  txi M b  is the carrier with the lowest P tx  txi ic  k
Else if carrier selection mode is “Random”
BestCarrier k  txi M b  is randomly selected
Else if carrier selection mode is "Sequential"
UL
UL
BestCarrier k  txi M b  is the first carrier so that X k  txi ic   X max
Calculation of
   BTS  P c  txi M b BestCarrier 
Q pilot  txi BestCarrier  = -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------k
DL
DL



txi

BestCarrier

txi

M


+
I

BestCarrier

txi

M


+
P
tot
k
b
extra
k
b


 DL
DL
Term 
 I inter – carrier  BestCarrier k  txi M b   + I inter – techno log y  BestCarrier k  txi M b   + N 0

If user selects “without Pilot”
   BTS  P c  txi M b BestCarrier 
Q pilot  txi BestCarrier  = ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------k


DL
DL
P tot  txi BestCarrier k  txi M b   + I extra  BestCarrier k  txi M b  




DL
 + I DL
 BestCarrier k  txi M b   + I inter – techno log y  BestCarrier k  txi M b   
inter
–
carrier


Term


+ N0
–  1 –     BTS  P c  txi M b BestCarrier 


Rejection of station txi if the pilot is not received
pilot
If Q pilot  txi M b BestCarrier   Q req  Mobility  M b   then txi is rejected by Mb
k
max
If Q pilot  txi M b BestCarrier   Q pilot  M b 
k
k
Admission control (If simulation respects a loading factor constraint and Mb was not connected in previous iteration).
UL
UL
If X k  txi BestCarrier  txi M b    X max , then txi is rejected by Mb
Else
max
Q pilot  M b  = Q pilot  txi M b BestCarrier 
k
k
Tx BS  M b  = txi
Endif
EndFor
If no TxBS has been selected, Mb has failed to be connected to the network and is rejected.
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Chapter 6: UMTS HSPA Networks
6.5
UMTS HSPA Prediction Studies
6.5.1
Point Analysis
6.5.1.1
AS Analysis Tab
Let us suppose a receiver with a terminal, a service and a mobility type. This receiver does not create any interference.
You can make the prediction for a specific carrier or for all carriers of the main frequency band for the selected terminal.
If you have selected a dual-band terminal, you can make the coverage prediction on a specific carrier or on all carriers of
any frequency band for the selected terminal, or for all the carriers of all the frequency bands. The analysis is based on
the following parameters:
•
•
•
The uplink load factor and the downlink total power of cells,
The available HSDPA power of the cell in case of an HSDPA bearer user,
The cell UL reuse factor, the cell UL load factor due to HSUPA and the maximum cell UL load factor for HSUPA
bearer users.
These parameters can be results of a given simulation, average values calculated from a group of simulations, or userdefined cell inputs. In the last case, when no value is defined in the Cells table, Atoll uses the following default values:
•
•
•
•
•
Total transmitted power = 50% of the maximum power (i.e, 40 dBm if the maximum power is set to 43 dBm)
Uplink load factor = 50%.
Uplink reuse factor = 1
Uplink load factor due to HSUPA = 0%
Maximum uplink load factor = 75%
On the other hand, no default value is used for the HSDPA power; this parameter must be defined by the user.
6.5.1.1.1
Bar Graph and Pilot Sub-Menu
We can consider the following cases:
1st case: Analysis based on a specific carrier
The carrier that can be used by transmitters is fixed. In this case, for each transmitter i containing the receiver in its calculation area and using the selected carrier, Atoll calculates the pilot quality at the receiver on this carrier. Then, it determines
the best serving transmitter using the selected carrier ic.
2nd case: Analysis based on all carriers
Atoll determines the best carrier for each transmitter i which contains the receiver in its calculation area and uses a
frequency band supported by the receiver’s terminal. The best carrier selection depends on the option selected for the site
equipment (UL minimum noise, DL minimum power, random, sequential). Then, Atoll calculates the pilot quality at the
receiver from these transmitters on their best carriers (ic) and defines the best server (on its best carrier).
3rd case: Analysis based on all carriers of any frequency band (for dual-band terminals with priority defined on frequency
bands only)
The frequency band that can be used is fixed. Atoll determines the best carrier for each transmitter i containing the receiver
in its calculation area and using the selected frequency band. The best carrier selection depends on the option selected
for the site equipment (UL minimum noise, DL minimum power, random, sequential). Then, Atoll calculates the pilot quality
at the receiver from these transmitters on their best carriers (ic) and defines the best server (on its best carrier).
Ec/I0 (or Q pilot  ic  ) Evaluation
Let us assume that ic is either the best carrier or the selected carrier of a transmitter i containing the receiver in its radius
calculation and icadj is another carrier adjacent to ic. An interference reduction factor, RF  ic ic adj  , is defined between ic
and icadj and set to a value different from 0.
Two ways may be used to calculate I0.
Option Total noise: Atoll considers the noise generated by all the transmitters and the thermal noise.
Option Without pilot: Atoll considers the total noise deducting the pilot signal.
Calculation option may be selected in Global parameters.
Therefore, we have:
 BTS    P c  i ic 
Q pilot  i ic  = ------------------------------------------------DL
I 0  ic 
With,
DL
DL
DL
DL
DL
term
I 0  ic  = P tot  i ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
for the total noise option,
And
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DL
DL
DL
DL
DL
term
I 0  ic  = I intra  ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
–  1 –    BTS  P c  i ic  for the without
pilot option.
1st step: P c  i ic  calculation for each cell (i,ic)
P c  i ic  is the pilot power of a transmitter i on carrier ic at the receiver.
P pilot  i ic 
P c  i ic  = --------------------------LT
I
L T is the total loss between transmitter i and receiver.
I
L Tx  L path  L term  L body  L Indoor  M Shadowing – Ec  Io
L T = -------------------------------------------------------------------------------------------------------------------------------------------------I
G Tx  G term
DL
DL
DL
2nd step: P tot  j ic  , P tot  i ic  and P tot  j ic adj  calculations
We have:
DL
I extra  ic  =

DL
P tot  j ic 
txj j  i
P SCH  ic 
DL
DL
DL
I intra  ic  = P tot  i ic  –  BTS     P tot  i ic  – ----------------------

L
T
 Ptot  j icadj 
DL
DL
txj j
I inter – carrier  ic  = ------------------------------------------RF  ic ic adj 
and
Tx
DL
I inter – techno log y  ic  =
P Transmitted  ic i 
 -----------------------------------------Tx
Tx m
L
 ICP
ni
ic i ic
total
DL
For each transmitter of the network, P tot  ic  is the total power received at the receiver from the transmitter on the best
carrier ic of the transmitter i.
P Tx  ic 
DL
P tot  ic  = -----------------LT
P Tx  ic  is the total power transmitted by the transmitter on the best carrier. Total power transmitted by each cell is either
a simulation result (provided in Simulation properties (Cells tab)) or a value user-defined in Cell properties.
DL
For each transmitter of the network, P tot  ic adj  is the total power received at the receiver from the transmitter on the
carrier icadj. This carrier is adjacent to ic.
P Tx  ic adj 
DL
P tot  ic adj  = ------------------------LT
P Tx  ic adj  is the total power transmitted by the transmitter on the carrier icadj. Total power transmitted by each cell is either
a simulation result (provided in Simulation properties (Cells tab)) or a value user-defined in Cell properties.
term
3rd step: N 0
term
N0
calculation
Tx DL
= NF Term  K  T  W  NR inter – techno log y
DL
4th step: I 0  ic  and Q pilot  i ic  evaluation using formulas described above
DL
5th step: G macro – diversity calculation
DL
The macro-diversity gain, G macro – diversity , models the decrease in shadowing margin due to the fact there are several
available pilot signals at the mobile.
DL
npaths
G macro – diversity = M Shadowing – Ec  Io – M Shadowing – Ec  Io
npaths
M Shadowing – Ec  Io is the shadowing margin when the mobile receives n pilot signals (not necessarily from transmitters
belonging to the mobile active set).
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Chapter 6: UMTS HSPA Networks
Note:
•
This parameter is determined from cell edge coverage probability and Ec/I0 standard
deviation. When the Ec/I0 standard deviation is set to 0, the macro-diversity gain equals 0.
6th step: Determination of active-set
Atoll takes the transmitter i with the highest Q pilot  i ic  and calculates the best pilot quality received with a fixed cell edge
Resulting
coverage probability, Q pilot
Resulting
Q pilot
 ic  .
DL
 ic  = G macro – diversity  max  Q pilot  i ic  
Resulting
req
Resulting
 Q pilot , it means pilot quality at the receiver exceeds Q pilot
If Q pilot
 ic  x% of time (x is the fixed cell edge cover-
age probability). The cell whose Q pilot  i ic  is the highest one enters the active set as best server ( Q pilot  BS ic  ) and
the best carrier (icBS) of the best server, BS, will be the carrier used by other transmitters of the active set (when active
set size is greater than 1). Pilot is available.
Resulting
If Q pilot
req
 Q pilot , no cell (i,ic) can enter the active set. Pilot is unavailable.
Then, pilot qualities at the receiver from transmitters i (except the best server) on the best carrier of the best server, icBS,
are recalculated to determine the entire receiver active set (when active set size is greater than 1). Same formulas and
DL
calculation method are used to update I 0  ic BS  value and determine Q pilot  i ic BS  .
We have:
 BTS    P c  i ic 
Q pilot  i ic  = ------------------------------------------------DL
I 0  ic 
With,
DL
DL
DL
DL
DL
term
I 0  ic  = P tot  i ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
for the total noise option,
And
DL
DL
DL
DL
DL
term
I 0  ic  = I intra  ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
–  1 –     BTS  P c  i ic  for the without
pilot option.
Other cells (i,icBS) in the active set must satisfy the following criteria:
Q pilot  i ic BS  – Q pilot  BS ic BS   AS_threshold  i BS ic BS 
 i ic BS   neighbour list  i BS ic BS  (optionally)
Number of Cells in Active Set
This is a user-specified input in the Terminal properties. It corresponds to the active set size.
Thermal Noise
This parameter is calculated as described above (3rd step).
I0 (Best Server)
I0 (Best server) is the total noise received at the receiver on icBS. The notation “Best server” refers to the best server of
active set. This is relevant when using the calculation option “Without pilot”. In this case, it informs that the pilot signal of
the best server (BS,icBS) is deducted from the total noise.
Downlink Macro-Diversity Gain
This parameter is calculated as described above (5th step).
6.5.1.1.2
Downlink Sub-Menu
The Downlink sub-menu may contain R99-related results and HSDPA-related results when an HSPA bearer user is
modelled.
•
R99-related Results
Atoll calculates the traffic channel quality from each cell (k,icBS) of the receiver’s active set at the receiver. No power
control is performed as in simulations. Here, Atoll determines the downlink traffic channel quality at the receiver for the
maximum allowed traffic channel power per transmitter. Then, after combination, the total downlink traffic channel quality
is evaluated and compared with the specified target quality.
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Eb/Nt Target
DL
Eb/Nt target ( Q req ) is defined for a given R99 bearer, a mobility type and a reception equipment. This parameter is available in the R99 Bearer Selection table.
Notes:
•
Compressed mode is operated when:
- A mobile supporting compressed mode is connected to a cell located on a site with a
compressed-mode-capable equipment
And
- Either the received Ec/I0 is lower than the Ec/I0 activation threshold (Global parameters):
Resulting
Q pilot
CM – activation
 Q pilot
,
- Or the pilot RSCP is lower than the pilot RSCP activation threshold (Global parameters):
CM – activation
P c  RSCP pilot
•
.
When compressed mode is activated, the downlink Eb/Nt target is increased by the value
DL
user-defined for the DL Eb/Nt target increase field (Global parameters), Q req .
Required transmitter power on traffic channels
req
The calculation of the required transmitter power on traffic channels ( P tch ) may be divided into three steps.
DL
1st step: Q max  k ic BS  evaluation for each cell
DL
Let us assume the following notation: Eb/Nt max corresponds to Q max
Therefore, for each cell (k,icBS), we have:
DL
 BTS  P b – max  k ic BS 
DL
DL
-  G DL
Q max  k ic BS  = ------------------------------------------------------------p  G Div
DL
N tot  ic BS 
max
P tch
DL
With P b – max  k ic BS  = -----------LT
k
DL
DL
DL
DL
DL
term
and N tot  ic BS  = I intra  ic BS  + I extra  ic BS  + I inter – carrier  ic BS  + I inter – techno log y  ic BS  + N 0
Where
max
P tch is the maximum power allowed on traffic channels. This parameter is user-defined in the R99 Radio Bearers table.
DL
N tot  ic BS  is the total noise at the receiver on the best carrier of the best server.
DL
I intra  ic BS  is the intra-cell interference at the receiver on the best carrier of the best server.
P SCH  k ic BS 
DL
I intra  ic BS  = P DL  k ic  –  BTS  F ortho   P DL  k ic  – ----------------------------------- tot

tot
BS
BS
L
T
DL
I extra  ic BS  is the extra-cell interference at the receiver on the best carrier of the best server.
DL
I extra  ic BS  =
 Ptot  j icBS 
DL
j j  k
DL
I inter – carrier  ic BS 
is the inter-carrier interference at the receiver on the best carrier of the best server.
 Ptot  j icadj 
DL
DL
I inter – carrier  ic BS 
txj j
= ------------------------------------------RF  ic BS ic adj 
icadj is a carrier adjacent to icBS.
RF  ic BS ic adj  is the interference reduction factor, defined between ic and icadj and set to a value different from 0.
DL
I inter – techno log y  ic BS  is the inter-technology interference at the receiver on the best carrier of the best server.
DL
I inter – techno log y  ic BS  =
Tx
P Transmitted  ic i 
 L---------------------------------------------Tx
Tx m
 ICP
ni
252
total
ic i ic BS
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Chapter 6: UMTS HSPA Networks
ic i is the i
Tx m
ICP ic  ic
i
BS
th
interfering carrier of an external transmitter
is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming
the frequency gap between ic i (external network) and ic BS .
2nd step: Calculation of the total traffic channel quality
DL
Q MAX is the traffic channel quality at the receiver on icBS after signal combination of all the transmitters k of the active set.
On downlink, if there is no handoff, we have:
DL
DL
Q MAX  ic BS  = Q max  k ic BS 
For any other handoff status, we have:
DL
DL
Q MAX  ic BS  = f rake efficiency 
 Qmax  k icBS 
DL
k
Where
DL
f rake efficiency is the downlink rake efficiency factor defined in Terminal properties.
req
3rd step: P tch calculation
DL
Q req
req
-  P max
P tch = ------------------------------tch
DL
Q MAX  ic BS 
Notes:
•
Compressed mode is operated when:
- A mobile supporting compressed mode is connected to a cell located on a site with a
compressed-mode-capable equipment
And
- Either the received Ec/I0 is lower than the Ec/I0 activation threshold (Global parameters):
Resulting
Q pilot
CM – activation
 Q pilot
.
- Or the pilot RSCP is lower than the pilot RSCP activation threshold (Global parameters):
CM – activation
P c  RSCP pilot
•
When compressed mode is activated, the downlink Eb/Nt target is increased by the value
DL
user-defined for the DL Eb/Nt target increase field (Global parameters), Q req . In this
DL
DL
Q req  Q req
req
-  P max
case, we have: P tch = --------------------------------tch
DL
Q MAX  ic BS 
Eb/Nt Max for Each Cell of Active Set
For each cell (k,icBS), we have:
DL
 BTS  P b – max  k ic BS 
DL
DL
-  G DL
Q max  k ic BS  = ------------------------------------------------------------p  G Div
DL
N tot  ic BS 
max
P tch
DL
With P b – max  k ic BS  = -----------LT
k
DL
DL
DL
DL
DL
term
N tot  ic BS  = I intra  ic BS  + I extra  ic BS  + I inter – carrier  ic BS  + I inter – techno log y  ic BS  + N 0
max
req
P SCH  k ic BS 
P tch – P tch
DL
- –  1 –  BTS   max (-----------------------------I intra  ic BS  = P DL  k ic  –  BTS  F ortho   P DL  k ic  – ------------------------------------,0)
 tot

tot
BS
BS
L
L
T
DL
I extra  ic BS  =
Tk
 Ptot  j icBS 
DL
j j  k
 Ptot  j icadj 
DL
DL
txj j
I inter – carrier  ic BS  = ------------------------------------------RF  ic BS ic adj 
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Tx
DL
I inter – techno log y  ic BS  =
P Transmitted  ic i 
 L---------------------------------------------Tx
Tx m
 ICP
ni
ic i ic BS
total
Where
req
P tch is the required transmitter power on traffic channels.
Eb/Nt Max
DL
Q MAX is the traffic channel quality at the receiver on icBS after signal combination of all the transmitters k of the active set.
On downlink, if there is no handoff, we have:
DL
DL
Q MAX  ic BS  = Q max  k ic BS 
For any other handoff status, we have:
DL
DL
Q MAX  ic BS  = f rake efficiency 
 Qmax  k icBS 
DL
k
Where
DL
f rake efficiency is the downlink rake efficiency factor defined in Terminal properties.
DL
DL
DL
DL
DL
Therefore, the service on the downlink traffic channel is available if Q MAX  ic BS   Q req (or Q MAX  ic BS   Q req  Q req
when compressed mode is activated).
Effective Eb/Nt
DL
Q eff is the effective traffic channel quality at the receiver on icBS.
DL
DL
DL
DL
DL
DL
DL
Q eff = min  Q MAX Q req  (or Q eff = min  Q MAX Q req  Q req  when compressed mode is activated).
Downlink Soft Handover Gain
DL
G SHO corresponds to the DL soft handover gain.
DL
Q MAX  ic BS 
DL
G SHO = ----------------------------------------------------DL
max  Q max  k ic BS  
DL
DL
max  Q max  k ic BS   corresponds to the highest Q max  k ic BS  value.
•
HSDPA-related Results
Atoll determines the best HSDPA bearer that the user can obtain. The HSDPA bearer user is processed as if he is the only
user in the cell i.e. he uses the entire HSDPA power available in the cell.
For further information on the fast link adaptation modelling, see "Fast Link Adaptation Modelling" on page 214.
HS-PDSCH Ec/Nt
Atoll calculates the best HS-PDSCH quality (HS-PDSCH Ec/Nt). The way of calculating it depends on the selected option
in the transmitters global parameters (HSDPA part): CQI based on CPICH quality or CQI based on HS-PDSCH quality.
For further details on the HS-PDSCH quality calculation, see either "HS-PDSCH Quality Calculation" on page 216 if the
selected option is "CQI based on CPICH quality" or "HS-PDSCH Quality Calculation" on page 221 if the selected option
is "CQI based on HS-PDSCH quality".
HS-SCCH Ec/Nt
When the HS-SCCH power allocation strategy is dynamic, this parameter corresponds to the HS-SCCH Ec/Nt threshold
defined for the selected mobility type.
When the HS-SCCH power allocation strategy is static, the HS-SCCH Ec/Nt is calculated from the fixed HS-SCCH power.
We have:
 BTS  P c  ic 
i
 Ec
-------  ic 
for the total noise option,
= ----------------------------------- Nt
 HS – SCCH
DL
N tot  ic 
And
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 BTS  P c  ic 
i
 Ec
-------  ic 
- for the without useful signal option.
= -------------------------------------------------------------------------------------------------------------------------------------- Nt
 HS – SCCH
DL
term
N tot  ic  –  1 – F ortho    1 – F MUD    BTS  P c  ic 
i
With
DL
DL
DL
DL
DL
term
N tot  ic  = I intra  ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
 DL
 DL
DL
P SCH  ic 
P SCH  ic 
DL
term
- –  BTS   P tot  ic  – ----------------------I intra  ic  = P tot  ic  +  BTS   1 – F MUD    1 – F ortho    P tot  ic  – ----------------------



LT
LT
txi
txi
txi





DL
I extra  ic  =
DL
P tot  ic 
txj j  i
 Ptot  icadj 
DL
DL
txj j
I inter – carrier  ic  = -------------------------------------RF  ic ic adj 
icadj is a carrier adjacent to ic.
RF  ic ic adj  is the interference reduction factor, defined between ic and icadj and set to a value different from 0.
DL
I inter – techno log y  ic  is the inter-technology interference at the receiver on ic.
DL
I inter – techno log y  ic  =

ni
ic i is the i
th
Tx
P Transmitted  ic i 
-----------------------------------------Tx
Tx m
L total  ICP ic  ic
i
interfering carrier of an external transmitter
Tx m
ICP ic  ic is the inter-technology Channel Protection between the signal transmitted by Tx and received by m assuming
i
the frequency gap between ic i (external network) and ic .
P HS – SCCH  ic 
P c  ic  = -------------------------------------i
LT
i
And
L path  L Tx  L term  L body  L indoor  M Shadowing – Ec  Io
L T = -------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
term
term
 BTS , F ortho , F MUD and N 0
are defined in "Inputs" on page 192.
CQI
It corresponds to the HS-PDSCH CQI. The way of calculating it depends on the selected option in the transmitters global
parameters (HSDPA part): CQI based on CPICH quality or CQI based on HS-PDSCH quality.
For further details on the HS-PDSCH quality calculation, see either "HS-PDSCH CQI Determination" on page 218 if the
selected option is "CQI based on CPICH quality" or "HS-PDSCH CQI Determination" on page 223 if the selected option is
"CQI based on HS-PDSCH quality".
RLC Peak Rate
Knowing the HS-PDSCH CQI, Atoll calculates the best HSDPA bearer that can be used and selects a bearer compatible
with cell and terminal user equipment HSDPA capabilities. Once the bearer selected, Atoll determines the RLC peak rate
DL
that can be provided to the user, R RLC – peak .
For further details of the HSDPA bearer selection, see "HSDPA Bearer Selection" on page 218.
Bearer Consumption
Atoll provides this result for packet (HSPA - Constant Bit Rate) service users only. The minimum bit rate required by the
service is allocated to these users. Therefore, they parly consume the HSDPA bearer. The bearer consumption expressed
in %, C HSDPABearer , is calculated as follows:
DL
R Guaranteed
C HSDPABearer = -------------------------------------------------------------------DL
R RLC – peak  I HSDPABearer 
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6.5.1.1.3
Uplink Sub-Menu
The Uplink sub-menu may contain R99-related results and HSUPA-related results when an HSPA bearer user is modelled.
•
R99-related Results
For each cell (k,icBS) in the receiver’s active set, Atoll calculates uplink traffic channel quality from receiver. No power
control is performed as in simulations. Here, Atoll determines the uplink traffic channel quality at the cell for the maximum
terminal power allowed. Then, the total uplink traffic channel quality is evaluated with respect to the receiver handover
status. From this value, Atoll calculates the terminal power required to obtain the R99 bearer and compares it to the maximum terminal power allowed.
Max Terminal Power
max
Max terminal power ( P term ) is an input user-defined for each terminal. It corresponds to the terminal’s maximum power.
Required Terminal Power
req
The calculation of the terminal power required to obtain an R99 bearer ( P term – R99 ) may be divided into three steps.
UL
1st step: Q max  k ic BS  evaluation for each cell
For each cell (k,icBS) in the receiver’s active set, we have:
UL
 term  P b – max  k ic BS 
UL
UL
-  G UL
Q max  k ic BS  = -------------------------------------------------------------p  G Div
UL
N tot  k ic BS 
max
UL
P term   1 – r c 
UL
With P b – max  k ic BS  = -----------------------------------------LT
k
UL
N tot  k
ic BS  is the total noise at the transmitter on the best carrier of the best server. This value is calculated from the
cell uplink load factor X
UL
 k ic BS  .
tx
N0
UL
N tot  k ic BS  = ----------------------------------------UL
1 – X  k ic BS 
tx
N 0 is the transmitter thermal noise.
2nd step: Calculation of the total traffic channel quality
UL
Q MAX  ic BS  is the traffic channel quality at the transmitter on icBS after signal combination of all the transmitters k of the
active set.
UL
UL
If there is no handoff (1/1): Q MAX  ic BS  = Q max  k ic BS 
For soft handoff (2/2):
UL
UL
UL
Q MAX  ic BS  =  G macro – diversity  2 links  max  Q max  k ic BS  
UL
 G macro – diversity  2 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage
probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected
(Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters.
UL
UL
max  Q max  k ic BS   corresponds to the highest Q max  k ic BS  value.
For soft-soft handoffs (3/3):
UL
UL
UL
Q MAX  ic BS  =  G macro – diversity  3 links  max  Q max  k ic BS  
UL
 G macro – diversity  3 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage
probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected
(Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters.
For softer and softer-softer handoffs (1/2 and 1/3):
UL
UL
Q MAX  ic BS  = f rake efficiency 
  Qmax  k icBS  
UL
k
For softer-soft handoffs (2/3), there are two possibilities. If the MRC option is selected (option available in Global parameters), we have:
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 UL
UL
UL
Q MAX  ic BS  =  G macro – diversity  2 links  max  f rake efficiency 


UL
UL
 Q max  k ic BS   Q max
k on the same site
k on the same site

 k ic BS 

Else,
UL
UL
UL
Q MAX  ic BS  =  G macro – diversity  2 links  max  Q max  k ic BS  
req
3rd step: P term – R99 calculation
req
P term – R99 is the required terminal power.
UL
Q req
req
-  P max
P term – R99 = ------------------------------term
UL
Q MAX  ic BS 
UL
Q req is the uplink traffic quality target defined by the user for a given reception equipment, a given R99 bearer and a given mobility type. This parameter is available in the R99 Bearer Selection table.
Notes:
•
Compressed mode is operated when:
- A mobile supporting compressed mode is connected to a cell located on a site with a
compressed-mode-capable equipment, and
- The received Ec/I0 is lower than the Ec/I0 activation threshold (Global parameters):
Resulting
Q pilot
CM – activation
 Q pilot
.
- The pilot RSCP is lower than the pilot RSCP activation threshold (Global parameters):
CM – activation
P c  RSCP pilot
•
When compressed mode is activated, the uplink Eb/Nt target is increased by the value
UL
user-defined for the UL Eb/Nt target increase field (Global parameters), Q req . In this
UL
UL
Q req  Q req
req
-  P max
case, we have: P term – R99 = --------------------------------term
UL
Q MAX  ic BS 
req
max
Therefore, the service on the uplink traffic channel is available if P term – R99  P term .
Eb/Nt Max
For each cell (k,icBS) in the receiver’s active set, we have:
UL
 term  P b – max  k ic BS 
UL
UL
-  G UL
Q max  k ic BS  = -------------------------------------------------------------p  G Div
UL
N tot  k ic BS 
max
UL
P term   1 – r c 
UL
With P b – max  k ic BS  = -----------------------------------------LT
k
UL
N tot  k ic BS  is the total noise at the transmitter on the best carrier of the best server. This value is calculated from the
cell uplink load factor X
UL
 k ic BS  .
tx
max
req
N0
P term – P term – R99
UL
- +  1 –  term   max (----------------------------------------------N tot  k ic BS  = -----------------------------------------,0)
UL
LT
1 – X  k ic BS 
k
tx
N 0 is the transmitter thermal noise.
UL
Q MAX  ic BS  is the traffic channel quality at the transmitter on icBS after signal combination of all the transmitters k of the
active set.
UL
UL
If there is no handoff (1/1): Q MAX  ic BS  = Q max  k ic BS 
For soft handoff (2/2):
UL
UL
UL
Q MAX  ic BS  =  G macro – diversity  2 links  max  Q max  k ic BS  
UL
 G macro – diversity  2 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage
probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected
(Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters.
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UL
UL
max  Q max  k ic BS   corresponds to the highest Q max  k ic BS  value.
For soft-soft handoffs (3/3):
UL
UL
UL
Q MAX  ic BS  =  G macro – diversity  3 links  max  Q max  k ic BS  
UL
 G macro – diversity  3 links is the uplink macro-diversity gain. This parameter is determined from the fixed cell edge coverage
probability and the uplink Eb/Nt standard deviation. When the option “Shadowing taken into account” is not selected
(Prediction properties), Atoll considers the uplink macro-diversity gain defined by the user in Global parameters.
For softer and softer-softer handoffs (1/2 and 1/3):
UL
UL
Q MAX  ic BS  = f rake efficiency 
  Qmax  k icBS  
UL
k
For softer-soft handoffs (2/3), there are two possibilities. If the MRC option is selected (option available in Global parameters), we have:
 UL
UL
UL
Q MAX  ic BS  =  G macro – diversity  2 links  max  f rake efficiency 


UL
UL
 Q max  k ic BS   Q max
k on the same site
k on the same site

 k ic BS 

Else,
UL
UL
UL
Q MAX  ic BS  =  G macro – diversity  2 links  max  Q max  k ic BS  
Effective Eb/Nt
UL
Q eff is the effective traffic channel quality at the transmitter on icBS.
UL
UL
UL
UL
UL
UL
UL
Q eff = min  Q MAX Q req  (or Q eff = min  Q MAX Q req  Q req  when compressed mode is activated).
Uplink Soft Handover Gain
UL
G SHO corresponds to the uplink soft handover gain.
UL
Q MAX  ic BS 
UL
G SHO = ----------------------------------------------------UL
max  Q max  k ic BS  
UL
UL
max  Q max  k ic BS   corresponds to the highest Q max  k ic BS  value.
•
HSUPA-related Results
Atoll determines the best HSUPA bearer that the user can obtain. The HSUPA bearer user is processed as if he is the only
user in the cell i.e. he uses the entire remaining load of the cell.
For further information on the HSUPA bearer selection, see "HSUPA Bearer Allocation Process" on page 228.
Required E-DPDCH Ec/Nt
req
Ec
It corresponds to the E-DPDCH Ec/Nt required to obtain the HSUPA bearer (  -------
). This value is defined for an
 Nt  E – DPDCH
HSUPA bearer ( Index HSUPABearer ) and a number of retransmissions ( N Rtx ) in the HSUPA Bearer Selection table.
Required Terminal Power
req
Ec
req
From  -------
, Atoll calculates the terminal power required to obtain the HSUPA bearer, P term – HSUPA .
 Nt  E – DPDCH
Ec req
req
UL
P term – HSUPA =  -------
 L T  N tot
 Nt  E – DPDCH
With
UL
UL intra
tx
N tot  ic  =  1 – F MUD   term   I tot
UL extra
 ic  + I tot
UL
tx
 ic  + I inter – carrier  ic  + N 0
L path  L Tx  L term  L body  L indoor  M Shadowing –  Eb  Nt 
UL
L T = -----------------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
tx
UL intra
 term , F MUD , I tot
258
UL extra
, I tot
UL
tx
, I inter – carrier and N 0 are defined in "Inputs" on page 192.
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RLC Peak Rate
Atoll selects the best HSUPA bearer from the HSUPA compatible bearers. This is the HSUPA bearer with the highest poUL
R RLC – peak  Index HSUPABearer 
tential throughput ( ------------------------------------------------------------------------------------ ) where:
N Rtx  Index HSUPABearer 
•
req
Ec max
 Ec
-------
  -------
 Nt  E – DPDCH  Nt  E – DPDCH
•
And P term – HSUPA  P term
max
req
With
max
 Ec
-------
: the maximum E-DPDCH Ec⁄Nt allowed.
 Nt  E – DPDCH
max
P term : the maximum terminal power allowed.
UL
After selecting the HSUPA bearer, Atoll determines the corresponding RLC peak rate, R RLC – peak .
Application Throughput
UL
Atoll displays the provided application throughput ( T application ). The application throughput represents the net throughput
after deduction of coding (redundancy, overhead, addressing, etc.). This one is calculated as follows:
UL
R RLC –p eak   1 – BLER HSUPA   SF Rate – R
UL
T application  M b  = -------------------------------------------------------------------------------------------------------------------------N Rtx
Where:
BLER HSUPA is the residual BLER after N Rtx retransmissions. It is read in the quality graph defined for the quartet “reception equipment-selected bearer-number of retransmissions-mobility” (HSUPA Quality Graphs tab in the Reception equipment properties). This graph describes the variation of BLER as a function of the measured quality (E-DPDCH Ec/Nt).
Knowing the E-DPDCH Ec/Nt, Atoll finds the corresponding BLER.
SF Rate and R respectively represent the scaling factor between the application throughput and the RLC (Radio Link
Control) throughput and the throughput offset. These two parameters model the header information and other supplementary data that does not appear at the application level. They are defined in the service properties.
Bearer Consumption
Atoll provides this result for packet (HSPA - Constant Bit Rate) service users only. The minimum bit rate required by the
service is allocated to these users. Therefore, they parly consume the HSUPA bearer. The bearer consumption expressed
in %, C HSUPABearer , is calculated as follows:
UL
R Guaranteed
C HSUPABearer = -------------------------------------------------------------------UL
R RLC – peak  I HSUPABearer 
6.5.2
Coverage Studies
Let us assume each pixel on the map corresponds to a probe receiver with a terminal, a mobility type and a service. This
receiver does not create any interference. You can make the coverage prediction for a specific carrier or for all carriers of
the main frequency band for the selected terminal. If you have selected a dual-band terminal, you can make the coverage
prediction on a specific carrier or on all carriers of any frequency band for the selected terminal, or for all the carriers of all
the frequency bands. Coverage predictions are based on parameters that can be either simulation results, or user-defined
cell inputs.
6.5.2.1
Pilot Reception Analysis
For further details of calculation formulas and methods, please refer to Definitions and formulas part, and Point analysis
– AS analysis tab – Pilot sub-menu part.
We consider the following cases:
1st case: Analysis Based on a Specific Carrier
The carrier that can be used by transmitters is fixed. In this case, for each transmitter i containing the receiver in its calculation area and using the selected carrier, Atoll calculates the pilot quality at the receiver on this carrier icgiven. Then, it
determines the best serving transmitter BS using the carrier icgiven ( Q pilot  ic given  ) and calculates the best pilot quality
BS
received with a fixed cell edge coverage probability,
Resulting
Q pilot
 ic given 
.
Atoll displays the best pilot quality received with a fixed cell edge coverage probability.
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2nd case: Analysis Based on All Carriers
Atoll proceeds as in point predictions. It determines the best carrier of each transmitter i containing the receiver in its calculation area and using a frequency band supported by the receiver’s terminal. The best carrier selection depends on the
option selected for the site equipment (UL minimum noise, DL minimum power, random, sequential) and is based on the
UL load percentage and the downlink total power of cells (simulation results or cell properties). Atoll calculates the pilot
quality at the receiver from these transmitters on their best carriers and determines the best serving transmitter BS on its
best carrier icBS ( Q pilot  ic BS  ). Then, it calculates the best pilot quality received with a fixed cell edge coverage probaBS
bility,
Resulting
Q pilot
 ic BS 
.
Atoll displays the best pilot quality received with a fixed cell edge coverage probability.
3rd case: Analysis based on all carriers of any frequency band (for dual-band terminals with priority defined on frequency
bands only)
The frequency band that can be used is fixed. Atoll determines the best carrier of each transmitter i containing the receiver
in its calculation area and using the selected frequency band. The best carrier selection depends on the option selected
for the site equipment (UL minimum noise, DL minimum power, random, sequential) and is based on the UL load percentage and the downlink total power of cells (simulation results or cell properties). Then, Atoll calculates the pilot quality at
the receiver from these transmitters on their best carriers and determines the best serving transmitter BS on its best carrier
icBS ( Q pilot  ic BS  ). Then, it calculates the best pilot quality received with a fixed cell edge coverage probability,
BS
Resulting
Q pilot
 ic BS 
.
Atoll displays the best pilot quality received with a fixed cell edge coverage probability.
6.5.2.1.1
Prediction Study Inputs
The Pilot Reception Analysis depends on the downlink total transmitted power of cells. This parameter can be either a
simulation output, or a user-defined cell input. In the last case, when no value is defined in the Cells table for the total
transmitted power, Atoll considers 50% of the maximum power as default value (i.e. 40 dBm if the maximum power is set
to 43 dBm).
6.5.2.1.2
Study Display Options
Single colour
Resulting
Atoll displays a coverage if Q pilot
req
 ic   Q pilot . Coverage consists of a single layer with a unique colour
req
( ic = ic BS or ic given ). Q pilot is a target value defined in the Mobility table by the user.
Colour per transmitter
Resulting
Atoll displays a coverage if Q pilot
req
 ic   Q pilot ( ic = ic BS or ic given ). Coverage consists of several layers with asso-
ciated colours. There is a layer per transmitter with no intersection between layers. Layer colour is the colour assigned to
the best serving transmitter BS.
Colour per mobility
In this case, receiver is not completely defined and no mobility is assigned.
Coverage consists of several layers with a layer per user-defined mobility defined in Mobility sub-folder. For each layer,
Resulting
area is covered if Q pilot
req
 ic   Q pilot ( ic = ic BS or ic given ). Each layer is assigned a colour and displayed with inter-
sections between layers.
Colour per probability
This display option is available only if analysis is based on all simulations in a group (i.e. if you select a group of simulations
and the “All” option in the Simulation tab of prediction properties). Coverage consists of several layers with a layer per
user-defined probability level defined in the Display tab (Prediction properties). For each layer, area is covered if
Resulting
Q pilot
req
 ic   Q pilot ( ic = ic BS or ic given ) in the required number of simulations. Each layer is assigned a colour and
displayed with intersections between layers.
Colour per cell edge coverage probability
Coverage consists of several layers with a layer per user-defined cell edge coverage probability, p, defined in the Display
Resulting
tab (Prediction properties). For each layer, area is covered if Q pilot
req
 ic p   Q pilot ( ic = ic BS or ic given ). Each layer
is assigned a colour and displayed with intersections between layers.
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Colour per quality level (Ec/I0)
Coverage consists of several layers with a layer per user-defined quality threshold defined in the Display tab (Prediction
Resulting
properties). For each layer, area is covered if Q pilot
 ic    Q pilot  threshold ( ic = ic BS or ic given ). Each layer is
assigned a colour and displayed with intersections between layers.
Colour per quality margin (Ec/I0 margin)
Coverage consists of several layers with a layer per user-defined quality margin defined in the Display tab (Prediction propResulting
erties). For each layer, area is covered if Q pilot
req
 ic  – Q pilot   Q pilot m arg in ( ic = ic BS or ic given ). Each layer is
assigned a colour and displayed with intersections between layers.
6.5.2.2
Downlink Service Area Analysis
As in point predictions, Atoll calculates traffic channel quality at the receiver for each cell (k,ic) (with ic=icBS or icgiven) in
the receiver’s active set. No power control is performed as in simulations. Here, Atoll determines downlink traffic channel
quality at the receiver for a maximum allowed traffic channel power for transmitters. Then, the total downlink traffic channel
DL
quality ( Q MAX  ic  ) is evaluated after recombination.
Note:
•
Best server and active set determination is performed as in point prediction (AS analysis).
Atoll displays traffic channel quality at the receiver for transmitters in active set on the carrier ic ( ic BS or ic given ).
For further details of calculation formulas and methods, see "Downlink Sub-Menu" on page 251.
6.5.2.2.1
Prediction Study Inputs
The Downlink Service Area Analysis depends on the downlink total transmitted power of cells. This parameter can be
either a simulation output, or a user-defined cell input. In the last case, when no value is defined in the Cells table for the
total transmitted power, Atoll considers 50% of the maximum power as default value (i.e. 40 dBm if the maximum power
is set to 43 dBm).
6.5.2.2.2
Study Display Options
Single colour
DL
DL
DL
DL
DL
Atoll displays a coverage with a unique colour if Q MAX  ic   Q req (or Q MAX  ic   Q req  Q req if compressed mode is
activated).
DL
Q req is the downlink traffic quality target defined by the user for a given reception equipment, a given R99 bearer and a
given mobility type. This parameter is available in the R99 Bearer Selection table.
DL
Q req is the DL Eb/Nt target increase; this parameter is user-defined in the Global parameters.
Colour per transmitter
DL
DL
DL
DL
DL
Atoll displays a coverage if Q MAX  ic   Q req (or Q MAX  ic   Q req  Q req if compressed mode is activated). Coverage
consists of several layers with associated colours. There is a layer per transmitter with no intersection between layers.
Layer colour is the colour assigned to best serving transmitter.
Colour per mobility
In this case, receiver is not completely defined and no mobility is assigned. Coverage consists of several layers with a
DL
DL
layer per user-defined mobility defined in Mobility sub-folder. For each layer, area is covered if Q MAX  ic   Q req (or
DL
DL
DL
Q MAX  ic   Q req  Q req if compressed mode is activated). Each layer is assigned a colour and displayed with intersections between layers.
Colour per service
In this case, receiver is not completely defined and no service is assigned. Coverage consists of several layers with a layer
DL
DL
per user-defined service defined in Services sub-folder. For each layer, area is covered if Q MAX  ic   Q req (or
DL
DL
DL
Q MAX  ic   Q req  Q req if compressed mode is activated). Each layer is assigned a colour and displayed with intersections between layers.
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Colour per probability
This display option is available only if analysis is based on all simulations in a group (i.e. if you select a group of simulations
and the “All” option in the Simulation tab of prediction properties). Coverage consists of several layers with a layer per
user-defined probability level defined in the Display tab (Prediction properties). For each layer, area is covered if
DL
DL
Q MAX  ic   Q req in the required number of simulations. Each layer is assigned a colour and displayed with intersections
between layers.
Colour per cell edge coverage probability
Coverage consists of several layers with a layer per user-defined cell edge coverage probability, p, defined in the Display
DL
DL
DL
DL
DL
tab (Prediction properties). For each layer, area is covered if Q MAX  ic p   Q req (or Q MAX  ic   Q req  Q req if
compressed mode is activated). Each layer is assigned a colour and displayed with intersections between layers.
Colour per maximum quality level (max Eb/Nt)
Coverage consists of several layers with a layer per user-defined quality threshold defined in the Display tab (Prediction
DL
properties). For each layer, area is covered if Q MAX  ic   Threshold . Each layer is assigned a colour and displayed with
intersections between layers.
Colour per effective quality level (Effective Eb/Nt)
Coverage consists of several layers with a layer per user-defined quality threshold defined in the Display tab (Prediction
DL
properties). For each layer, area is covered if Q eff  ic   Threshold . Each layer is assigned a colour and displayed with
DL
DL
DL
DL
DL
DL
DL
intersections between layers. Q eff  ic  = min  Q MAX  ic  Q req  (or Q eff  ic  = min  Q MAX  ic  Q req  Q req  when
compressed mode is activated).
Colour per quality margin (Eb/Nt margin)
Coverage consists of several layers with a layer per user-defined quality margin defined in the Display tab (Prediction propDL
DL
DL
DL
DL
erties). For each layer, area is covered if Q MAX  ic  – Q req  M arg in (or Q MAX  ic  – Q req  Q req  M arg in when
compressed mode is activated). Each layer is assigned a colour and displayed with intersections between layers.
Colour per required power
req
Atoll calculates the downlink required power, P tch  ic  , as follows:
DL
Q req
req
-  P max
P tch  ic  = -----------------------tch
DL
Q MAX  ic 
Where
DL
Q req is the Eb/Nt target on downlink. This parameter, available in the R99 Bearer Selection table, is user-defined for a
given R99 bearer, a given reception equipment and a mobility type.
max
P tch is a user-defined input for each bearer related to a service. It corresponds to the maximum allowable traffic channel
power for a transmitter.
DL
DL
Q req  Q req
req
-  P max
When compressed mode is activated, we have: P tch  ic  = --------------------------------tch .
DL
Q MAX  ic 
Coverage consists of several layers with a layer per user-defined required power threshold defined in the Display tab
req
(Prediction properties). For each layer, area is covered if P tch  ic   Threshold . Each layer is assigned a colour and
displayed with intersections between layers.
Colour per required power margin
Coverage consists of several layers with a layer per user-defined power margin defined in the Display tab (Prediction propreq
max
erties). For each layer, area is covered if P tch  ic  – P tch  M arg in . Each layer is assigned a colour and displayed with
intersections between layers.
6.5.2.3
Uplink Service Area Analysis
As in point prediction, Atoll calculates uplink traffic channel quality from receiver for each cell (k,ic) (with ic=icBS or icgiven)
in receiver active set. No power control simulation is performed. Atoll determines uplink traffic channel quality at the trans-
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UL
mitter for the maximum terminal power allowed. Then, the total uplink traffic channel quality ( Q MAX  ic  ) is evaluated with
respect to receiver handover status.
Note:
•
Best server and active set determination is performed as in point prediction (AS analysis).
Atoll displays traffic channel quality at transmitters in active set on the carrier ic ( ic BS or ic given ) received from the
receiver.
For further details of calculations formulas and methods, see "Uplink Sub-Menu" on page 256.
6.5.2.3.1
Prediction Study Inputs
The Uplink Service Area Analysis depends on the UL load factor of cells. This parameter can be either a simulation output,
or a user-defined cell input. In the last case, when no value is defined in the Cells table for the uplink load factor, Atoll uses
50% as default value.
6.5.2.3.2
Study Display Options
Single colour
UL
UL
UL
UL
UL
Atoll displays a coverage if Q MAX  ic   Q req (or Q MAX  ic   Q req  Q req if compressed mode is activated). Coverage
colour is unique.
UL
Q req is defined for a reception equipment, a R99 bearer and a mobility type. This parameter is available in the R99 Bearer
Selection table.
UL
Q req is the UL Eb/Nt target increase; this parameter is user-defined in the Global parameters.
Colour per transmitter
UL
UL
UL
UL
UL
Atoll displays a coverage if Q MAX  ic   Q req (or Q MAX  ic   Q req  Q req if compressed mode is activated). Coverage
consists of several layers with associated colours. There is a layer per transmitter with no intersection between layers.
Layer colour is the colour assigned to best server transmitter.
Colour per mobility
In this case, receiver is not completely defined and no mobility is assigned. Coverage consists of several layers with a
UL
UL
layer per user-defined mobility defined in Mobility sub-folder. For each layer, area is covered if Q MAX  ic   Q req (or
UL
UL
UL
Q MAX  ic   Q req  Q req if compressed mode is activated). Each layer is assigned a colour and displayed with intersections between layers.
Colour per service
In this case, receiver is not completely defined and no service is assigned. Coverage consists of several layers with a layer
UL
UL
per user-defined service defined in Services sub-folder. For each layer, area is covered if Q MAX  ic   Q req (or
UL
UL
UL
Q MAX  ic   Q req  Q req if compressed mode is activated). Each layer is assigned a colour and displayed with intersections between layers.
Colour per probability
This display option is available only if analysis is based on all simulations in a group (i.e. if you select a group of simulations
and the “All” option in the Simulation tab of prediction properties). Coverage consists of several layers with a layer per
user-defined probability level defined in the Display tab (Prediction properties). For each layer, area is covered if
UL
UL
UL
UL
UL
Q MAX  ic   Q req (or Q MAX  ic   Q req  Q req if compressed mode is activated) in the required number of simulations.
Each layer is assigned a colour and displayed with intersections between layers.
Colour per maximum quality level (Max Eb/Nt)
Coverage consists of several layers with a layer per user-defined quality threshold defined in the Display tab (Prediction
UL
properties). For each layer, area is covered if Q MAX  ic   Threshold . Each layer is assigned a colour and displayed with
intersections between layers.
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Colour per effective quality level (Effective Eb/Nt)
Coverage consists of several layers with a layer per user-defined quality threshold defined in the Display tab (Prediction
UL
properties). For each layer, area is covered if Q effective  ic   Threshold . Each layer is assigned a colour and displayed
with intersections between layers.
UL
UL
UL
UL
UL
UL
UL
Q eff  ic  = min  Q MAX  ic  Q req  (or Q eff  ic  = min  Q MAX  ic  Q req  Q req  when compressed mode is activated).
Colour per quality margin (Eb/Nt margin)
Coverage consists of several layers with a layer per user-defined quality margin defined in the Display tab (Prediction propUL
UL
UL
UL
UL
erties). For each layer, area is covered if Q MAX  ic  – Q req  M arg in (or Q MAX  ic  – Q req  Q req  M arg in if
compressed mode is activated). Each layer is assigned a colour and displayed with intersections between layers.
Colour per required power
Coverage consists of several layers with a layer per user-defined power threshold defined in the Display tab (Prediction
req
properties). For each layer, area is covered if P term – R99  ic   Threshold . Each layer is assigned a colour and displayed
with intersections between layers.
Colour per required power margin
Coverage consists of several layers with a layer per user-defined power margin defined in the Display tab (Prediction propreq
max
erties). For each layer, area is covered if P term – R99  ic  – P term  M arg in . Each layer is assigned a colour and displayed
with intersections between layers.
Colour per soft handover gain
Coverage consists of several layers with a layer per soft handover gain value defined in the Display tab (Prediction propUL
erties). For each layer, area is covered if G SHO  Threshold . Each layer is assigned a colour and displayed with intersections between layers.
6.5.2.4
Downlink Total Noise Analysis
Atoll determines the downlink total noise generated by cells.
 Ptot  icadj 
DL
DL
N tot  ic  =

txj j
DL
 j
--------------------------------------+
P tot  ic  + txj
RF  ic ic adj 

ni
Tx
P Transmitted  ic i 
term
+ N0
-----------------------------------------Tx
Tx m
L total  ICP ic  ic
i
DL
Downlink noise rise, NR DL  ic  , is calculated from the downlink total noise, N tot , as follows:
term
 N0 
-
NR DL  ic  = – 10 log  ------------ N DL

tot
6.5.2.4.1
Study Inputs
The Downlink Total Noise Analysis depends on the downlink total transmitted power of cells. This parameter can be either
a simulation output, or a user-defined cell input. In the last case, when no value is defined in the Cells table for the total
transmitted power, Atoll considers 50% of the maximum power as default value (i.e. 40 dBm if the maximum power is set
to 43 dBm).
6.5.2.4.2
Analysis on All Carriers
If all the carriers are selected, Atoll determines DL total noise for all the carriers. Then, allows the user to choose different
colours.
Colour per minimum noise level
Coverage consists of several layers with a layer per user-defined noise level defined in the Display tab (Prediction propDL
erties). For each layer, area is covered if minN tot ic   Threshold . Each layer is assigned a colour and displayed with
ic
intersections between layers.
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Colour per maximum noise level
Coverage consists of several layers with a layer per user-defined noise level defined in the Display tab (Prediction propDL
erties). For each layer, area is covered if maxN tot ic   Threshold . Each layer is assigned a colour and displayed with
ic
intersections between layers.
Colour per average noise level
Coverage consists of several layers with a layer per user-defined noise level defined in the Display tab (Prediction propDL
erties). For each layer, area is covered if averageN tot ic   Threshold . Each layer is assigned a colour and displayed
ic
with intersections between layers.
Colour per minimum noise rise
Atoll displays bins where minNR DL ic   Threshold . Coverage consists of several areas with an area per user-defined
ic
noise rise threshold defined in the Display tab. Each area is assigned a colour with intersections between areas.
Colour per maximum noise rise
Atoll displays bins where maxNR DL ic   Threshold . Coverage consists of several areas with an area per user-defined
ic
noise rise threshold defined in the Display tab. Each area is assigned a colour with intersections between areas.
Colour per average noise rise
Atoll displays bins where averageNR DL ic   Threshold . Coverage consists of several areas with an area per useric
defined noise rise threshold defined in the Display tab. Each area is assigned a colour with intersections between areas.
6.5.2.4.3
Analysis on a Specific Carrier
When only one carrier is analysed, Atoll determines DL total noise or DL noise rise on this carrier. In this case, the
displayed coverage is the same for any selected display per noise level (average, minimum, maximum) or any display per
noise rise (average, minimum, maximum).
Colour per noise level
Coverage consists of several layers with a layer per user-defined noise level defined in the Display tab (Prediction propDL
erties). For each layer, area is covered if N tot  ic   Threshold . Each layer is assigned a colour and displayed with intersections between layers.
Colour per noise rise
Atoll displays bins where NR DL  ic   Threshold . Coverage consists of several areas with an area per user-defined noise
rise threshold defined in the Display tab. Each area is assigned a colour with intersections between areas.
6.5.2.5
HSDPA Prediction Study
When calculating the HSDPA coverage prediction, either you can take all the possible HSDPA radio bearers into consideration, or you can study a certain HSDPA radio bearer. Then, available display options depend on what you have
selected.
When considering all the HSDPA radio bearers, you can set display parameters:
•
•
•
To analyse the uplink and downlink A-DPCH qualities on the map,
To analyse the HS-SCCH quality/power,
To model fast link adaptation for a single HSDPA bearer user or for a defined number of HSDPA bearer users.
When studying a certain HSDPA radio bearer, you can display areas where a certain RLC peak rate is available with different cell edge coverage probabilities (i.e. the probability of having a certain RLC peak rate).
Let us assume each pixel on the map corresponds to one or several users with HSDPA capable terminal, mobility and
HSDPA service. Each user may be using a specific carrier or all of them. Moreover, he does not create any interference.
Note that the HSDPA service area is limited by the pilot quality and the A-DPCH quality.
6.5.2.5.1
Prediction Study Inputs
Parameters used as input for the HSDPA prediction study are:
•
•
•
© Forsk 2009
The available HSDPA power of the cell,
The downlink total transmitted power of the cell,
The number of HSDPA users within the cell if the study is calculated for several users.
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These parameters can be either simulation outputs, or user-defined cell inputs. In the last case, when no value is defined
in the Cells table for the total transmitted power and the number of HSDPA users, Atoll uses the following default values:
•
•
Total transmitted power = 50% of the maximum power (i.e, 40 dBm if the maximum power is set to 43 dBm)
Number of HSDPA users = 1
On the other hand, no default value is used for the available HSDPA power; this parameter must be defined by the user.
6.5.2.5.2
Study Display Options
When considering all the HSDPA radio bearers, several display options are available in the study properties dialogue.
They can be regrouped in four categories according to the objective of the study:
•
•
•
•
To analyse the uplink and downlink A-DPCH qualities on the map,
To analyse the HS-SCCH quality/power,
To model fast link adaptation for a single HSDPA bearer user
To model fast link adaptation for a defined number of HSDPA bearer users.
When studying a certain HSDPA radio bearer, only one display option is available. It allows you to display where a certain
RLC peak rate is available with different cell edge coverage probabilities.
Analysis of UL And DL A-DPCH Qualities
•
Colour per Max A-DPCH Eb/Nt DL
DL
Atoll displays the A-DPCH quality at the receiver ( Q MAX  ic  ) for the best server on the carrier ic ( ic BS or ic given ). No
power control is performed as in simulations. Here, Atoll determines downlink traffic channel quality at the receiver for a
maximum traffic channel power allowed for the best server.
For further details of calculation formulas and methods, please refer to Prediction studies: Point analysis – AS analysis tab
– Downlink sub-menu part.
Coverage consists of several layers with a layer per user-defined quality threshold defined in the Display tab (Prediction
DL
properties). For each layer, area is covered if Q MAX  ic   Threshold . Each layer is assigned a colour and displayed with
intersections between layers.
•
Colour per Max A-DPCH Eb/Nt UL
UL
Atoll displays the A-DPCH quality at the best server ( Q MAX  ic  ) on the carrier ic ( ic BS or ic given ). No power control is
performed as in simulations. Here, Atoll determines uplink traffic channel quality at the receiver for a maximum terminal
power allowed.
For further details of calculations formulas and methods, please refer to Point analysis – AS analysis tab – Uplink submenu part.
Coverage consists of several layers with a layer per user-defined quality threshold defined in the Display tab (Prediction
UL
properties). For each layer, area is covered if Q MAX  ic   Threshold . Each layer is assigned a colour and displayed with
intersections between layers.
Analysis of The HS-SCCH Quality/Power
•
Colour per HS-SCCH Power
This display option is relevant in case of dynamic HS-SCCH power allocation only. In this case, Atoll displays on each pixel
the HS-SCCH power per HS-SCCH channel. Coverage consists of several layers with a layer per threshold. For each
layer, area is covered if P HS – SCCH  ic   Threshold . Each layer is assigned a colour and displayed with intersections
between layers.
•
Colour per HS-SCCH Ec/Nt
This display option is relevant in case of static HS-SCCH power allocation only. In this case, Atoll displays on each pixel
the HS-SCCH quality per HS-SCCH channel. Coverage consists of several layers with a layer per threshold. For each
Ec
layer, area is covered if  -------  ic 
 Threshold . Each layer is assigned a colour and displayed with intersections
 Nt
 HS – SCCH
between layers.
Fast Link Adaptation Modelling For A Single User
When you calculate the study with the following display options, Atoll considers one user on each pixel and determines
the best HSDPA bearer that the user can obtain. On each pixel, the user is processed as if he is the only user in the cell
i.e. he uses the entire HSDPA power available in the cell.
For further information on the fast link adaptation modelling, see "Fast Link Adaptation Modelling" on page 214.
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•
Colour per HS-PDSCH Ec/Nt
Atoll displays on each pixel the HS-PDSCH quality. Coverage consists of several layers with a layer per threshold. For
Ec
each layer, area is covered if  -------  ic 
 Threshold . Each layer is assigned a colour and displayed with inter Nt
 HS – PDSCH
sections between layers.
•
Colour per CQI
Atoll displays either the CPICH CQI (see the calculation detail in "CPICH CQI Determination" on page 216) when the
selected option in Global parameters (HSDPA part) is CQI based on CPICH quality, or the HS-PDSCH CQI (see the calculation detail in the section 10.7.1.2.2) when considering the CQI based on HS-PDSCH quality option.
Coverage consists of several layers with a layer per CQI threshold (  CQI  threshold ). For each layer, area is covered if
CQI   CQI  threshold . Each layer is assigned a colour and displayed with intersections between layers.
•
Colour per MAC Rate
DL
Atoll displays the MAC rate ( R MAC ) provided on each pixel. The MAC rate is calculated as follows:
S block
DL
R MAC = --------------T TTI
Where,
S block is the transport block size (in kbits) of the selected HSDPA bearer; it is defined for each HSDPA bearer in the
related table.
–3
T TTI is the TTI duration, i.e. 2 10 s (2000 TTI in one second). This value is specified by the 3GPP.
DL
Coverage consists of several layers with a layer per possible MAC rate ( R MAC ). For each layer, area is covered if the
MAC rate exceeds the user-defined thresholds. Each layer is assigned a colour and displayed with intersections between
layers.
•
Colour per MAC Throughput
DL
Atoll displays the MAC throughput ( T MAC ) provided on each pixel. The MAC throughput is calculated as follows:
S block
DL
T MAC = -----------------------------T TTI   TTI
Where,
S block is the transport block size (in kbits) of the selected HSDPA bearer; it is defined for each HSDPA bearer in the
HSDPA Radio Bearers table.
TTI is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user
equipment category properties.
–3
T TTI is the TTI duration, i.e. 2 10 s (2000 TTI in one second). This value is specified by the 3GPP.
DL
Coverage consists of several layers with a layer per possible MAC throughput ( T MAC ). For each layer, area is covered if
the MAC throughput exceeds the user-defined thresholds. Each layer is assigned a colour and displayed with intersections
between layers.
•
Colour per RLC Peak Rate
DL
After selecting the bearer, Atoll reads the corresponding RLC peak rate ( R RLC –p eak  I HSDPABearer  ). This is the highest
DL
rate that the bearer can provide on each pixel. Then, it determines the RLC peak rate provided in the downlink, R RLC –p eak .
DL
Coverage consists of several layers with a layer per possible RLC peak rate ( R RLC –p eak ). For each layer, area is covered
if the RLC peak rate can be provided. Each layer is assigned a colour and displayed with intersections between layers.
•
Colour per RLC Peak Throughput
DL
Atoll displays the RLC peak throughput ( T RLC –p eak ) provided on each pixel. The RLC peak throughput is calculated as
follows:
DL
R RLC – p eak
DL
T RLC –p eak = --------------------------TTI
Where TTI is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user equipment category properties.
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DL
Coverage consists of several layers with a layer per possible RLC peak throughput ( T RLC –p eak ). For each layer, area is
covered if the RLC peak throughput exceeds the user-defined thresholds. Each layer is assigned a colour and displayed
with intersections between layers.
•
Colour per Average RLC Throughput
DL
Atoll displays the average RLC throughput ( T RLC – Av ) provided on each pixel. The average RLC throughput is calculated
as follows:
DL
R RLC – p eak   1 – BLER HSDPA 
DL
T RLC – Av = ---------------------------------------------------------------------------------TTI
Where,
BLER HSDPA is read in the quality graph defined for the triplet “reception equipment-selected bearer-mobility” (HSDPA
Quality Graphs tab in the Reception equipment properties). This graph describes the variation of BLER as a function of
the measured quality (HS-PDSCH Ec/Nt). Knowing the HS-PDSCH Ec/Nt, Atoll finds the corresponding BLER.
TTI is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user
equipment category properties.
DL
Coverage consists of several layers with a layer per possible average RLC throughput ( T RLC – Av ). For each layer, area
is covered if the average RLC throughput exceeds the user-defined thresholds. Each layer is assigned a colour and
displayed with intersections between layers.
•
Colour per Application Throughput
DL
Atoll displays the application throughput ( T application ) provided on each pixel. The application throughput represents the
net throughput after deduction of coding (redundancy, overhead, addressing, etc.). This one is calculated as follows:
DL
R RLC –p eak   1 – BLER HSDPA   SF Rate – R
DL
T application = -------------------------------------------------------------------------------------------------------------------------TTI
Where:
BLER HSDPA is read in the quality graph defined for the triplet “reception equipment-selected bearer-mobility” (HSDPA
Quality Graphs tab in the Reception equipment properties). This graph describes the variation of BLER as a function of
the measured quality (HS-PDSCH Ec/Nt). Knowing the HS-PDSCH Ec/Nt, Atoll finds the corresponding BLER.
SF Rate and R respectively represent the scaling factor between the application throughput and the RLC (Radio Link
Control) throughput and the throughput offset. These two parameters model the header information and other supplementary data that does not appear at the application level. They are defined in the service properties.
TTI is the minimum number of TTI (Transmission Time Interval) between two TTI used; it is defined in the terminal user
equipment category properties.
DL
Coverage consists of several layers with a layer per possible application throughput ( T application ). For each layer, area is
covered if the application throughput exceeds the user-defined thresholds. Each layer is assigned a colour and displayed
with intersections between layers.
Fast Link Adaptation Modelling For Several Users
When you calculate the study with the following display options, Atoll considers several users per pixel and determines
the best HSDPA bearer that each user can obtain. In this case, the cell available HSDPA power is shared between HSDPA
bearer users. When the coverage prediction is not based on a simulation, the number of HSDPA bearer users is taken
from the cell properties. The displayed results of the coverage prediction will be an average result for one user.
For further information on the HSDPA bearer allocation process when there are several users, see "HSDPA Bearer Allocation Process" on page 212 For further information on the fast link adaptation modelling, see "Fast Link Adaptation
Modelling" on page 214.
•
Colour per MAC Throughput Per Mobile
DL
Atoll displays the average MAC throughput per mobile (  T MAC  average ) provided on each pixel. The average MAC
throughput per mobile is calculated as follows:
n HSDPA
DL

DL
T MAC  x 
x=1
 T MAC  average = --------------------------------------n HSDPA
Where,
n HSDPA is the number of HSDPA users within the cell.
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T MAC  x  is the MAC throughput of each HSDPA bearer user. For further information on the calculation of the MAC
throughput, see "Colour per MAC Throughput" on page 267.
DL
Coverage consists of several layers with a layer per possible average MAC throughput per mobile (  T MAC  average ). For
each layer, area is covered if the average MAC throughput per mobile exceeds the user-defined thresholds. Each layer is
assigned a colour and displayed with intersections between layers.
•
Colour per RLC Throughput Per Mobile
DL
Atoll displays the average RLC throughput per mobile (  T RLC  average ) provided on each pixel. The average RLC throughput per mobile is calculated as follows:
n HSDPA
DL

DL
T RLC – p eak  x 
x=1
 T RLC  average = ---------------------------------------------------n HSDPA
Where,
n HSDPA is the number of HSDPA users within the cell.
DL
T RLC –p eak  x  is the RLC peak throughput of each HSDPA bearer user. For further information on the calculation of the
RLC peak throughput, see "Colour per RLC Peak Throughput" on page 267.
DL
Coverage consists of several layers with a layer per possible average RLC throughput per mobile (  T RLC  average ). For
each layer, area is covered if the average RLC throughput per mobile exceeds the user-defined thresholds. Each layer is
assigned a colour and displayed with intersections between layers.
•
Colour per ApplicationThroughput Per Mobile
DL
Atoll displays the average application throughput per mobile (  T application  average ) provided on each pixel. The average
application throughput per mobile is calculated as follows:
n HSDPA
DL

DL
T application  x 
x=1
 T application  average = ----------------------------------------------------n HSDPA
Where,
n HSDPA is the number of HSDPA users within the cell.
DL
T application  x  is the application throughput of each HSDPA bearer user. For further information on the calculation of the
application throughput, see "Colour per Application Throughput" on page 268.
Coverage consists of several layers with a layer per possible average application throughput per mobile
DL
(  T application average ). For each layer, area is covered if the average application throughput per mobile exceeds the userdefined thresholds. Each layer is assigned a colour and displayed with intersections between layers.
Probability of Having a Certain RLC Peak Rate
This result can be obtained only if you have selected an HSDPA radio bearer in the Condition tab.
•
Colour per Cell Edge Coverage Probability
Atoll shows areas where the selected HSDPA radio bearer is available with different cell edge coverage probabilities.
Coverage consists of several layers with a layer per cell edge coverage probability defined in the Display tab. For each
layer, area is covered if the selected HSDPA radio bearer is available. Each layer is assigned a colour and displayed with
intersections between layers.
6.5.2.6
HSUPA Prediction Study
A dedicated HSUPA study is available with different calculation and display options. Atoll determines on each pixel the
best HSUPA bearer that can be obtained; it can consider either a single HSUPA bearer user or several ones on each pixel.
For further information on the HSUPA bearer selection, see "HSUPA Bearer Allocation Process" on page 228. By caclulating this study with suitable display options, it is possible:
•
•
•
To analyse the power required by the selected terminal,
To analyse the required E-DPDCH quality,
To analyse rates and throughputs.
Let us assume each pixel on the map corresponds to one or several users with HSUPA capable terminal, mobility and
HSUPA service. Each user may be using a specific carrier or all of them. Moreover, he does not create any interference.
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6.5.2.6.1
Prediction Study Inputs
Parameters used as input for the HSUPA prediction study are:
•
•
•
•
•
The cell UL load factor,
The cell UL reuse factor,
The cell UL load factor due to HSUPA,
The maximum cell UL load factor,
The number of HSUPA users within the cell if the study is calculated for several users.
These parameters can be either simulation outputs, or user-defined cell inputs. In the last case, When no value is defined
in the Cells table, Atoll uses the following default values:
•
•
•
•
•
6.5.2.6.2
Uplink load factor = 50%
Uplink reuse factor = 1
Uplink load factor due to HSUPA = 0%
Maximum uplink load factor = 75%
Number of HSUPA users = 1
Calculation Options
Atoll can calculate the HSUPA coverage prediction in one of two ways:
•
•
6.5.2.6.3
HSUPA resources can be dedictated to a single user: On each pixel, the user is processed as if he is the only
user in the cell i.e he will use the entire remaining load after allocating capacity to all R99 users.
HSUPA resources can be shared by HSUPA users defined or calculated per cell: Atoll considers several
HSUPA bearer users per pixel. After allocating capacity to all R99 users, the remaining load of the cell will be
shared equally between all the HSUPA bearer users. When the coverage prediction is not based on a simulation,
the number of HSUPA users is taken from the cell properties. The displayed results of the coverage prediction will
be an average result for one user.
Display Options
The following display options are available in the prediction property dialogue.
Colour per Required E-DPDCH Ec/Nt
Atoll displays on each pixel the E-DPDCH Ec/Nt required to obtain the selected HSUPA bearer. Coverage consists of
Ec req
 Threshold . Each layer is
several layers with a layer per threshold. For each layer, area is covered if  -------
 Nt  E – DPDCH
assigned a colour and displayed with intersections between layers.
Colour per Required Terminal Power
Atoll displays on each pixel the terminal power required to obtain the selected HSUPA bearer. The required terminal power
is calculated from the required E-DPDCH Ec/Nt. Coverage consists of several layers with a layer per threshold. For each
req
layer, area is covered if P term  Threshold . Each layer is assigned a colour and displayed with intersections between
layers.
Colour per MAC Rate
UL
Atoll displays the MAC rate ( R MAC ) provided on each pixel. The MAC rate is calculated as follows:
UL
S block
UL
R MAC = --------------T TTI
Where,
UL
S block is the transport block size (in kbits) for the selected HSUPA bearer; it is defined for each HSUPA bearer in the
HSUPA Radio Bearers table.
T TTI is the duration of one TTI for the selected HSUPA bearer; it is defined for each HSUPA bearer in the HSUPA Radio
Bearers table.
UL
Coverage consists of several layers with a layer per possible MAC rate ( R MAC ). For each layer, area is covered if the
MAC rate exceeds the user-defined thresholds. Each layer is assigned a colour and displayed with intersections between
layers.
Colour per RLC Peak Rate
After selecting the HSUPA bearer, Atoll reads the corresponding RLC peak rate. This is the highest rate that the selected
HSUPA bearer can provide on each pixel.
UL
Coverage consists of several layers with a layer per possible RLC peak rate ( R RLC –p eak ). For each layer, area is covered
if the RLC peak rate can be provided. Each layer is assigned a colour and displayed with intersections between layers.
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Colour per Minimum RLC Throughput
UL
Atoll displays the minimum RLC throughput ( T RLC – Min ) provided on each pixel. The minimum RLC throughput corresponds to the RLC throughput obtained for a given BLER and the maximum number of retransmissions. It is calculated as
follows:
UL
R RLC –p eak   1 – BLER HSUPA 
UL
T RLC – Min = ---------------------------------------------------------------------------------N Rtx
Where,
BLER HSUPA is the residual BLER for the selected uplink transmission format (HSUPA bearer with N Rtx retransmissions). It is read in the quality graph defined for the quartet “reception equipment-selected bearer-number of retransmissions-mobility” (HSUPA Quality Graphs tab in the Reception equipment properties). This graph describes the variation of
BLER as a function of the measured quality (E-DPDCH Ec/Nt). Knowing the E-DPDCH Ec/Nt, Atoll finds the corresponding
BLER.
N Rtx is the maximum number of retransmissions for the selected HSUPA bearer. This figure is read in the HSUPA Bearer
Selection table.
DL
Coverage consists of several layers with a layer per possible minimum RLC throughput ( T RLC – Min ). For each layer, area
is covered if the minimum RLC throughput exceeds the user-defined thresholds. Each layer is assigned a colour and
displayed with intersections between layers.
Colour per Average RLC Throughput
When HARQ (Hybrid Automatic Repeat Request) is used, the required average number of retransmissions is smaller and
UL
the RLC throughput is an average RLC throughput ( T RLC – Av ). This is the RLC throughput obtained for a given BLER and
the average number of retransmissions. It is calculated as follows:
UL
R RLC – p eak   1 – BLER HSUPA 
UL
T RLC – Av = --------------------------------------------------------------------------------- N Rtx  av
BLER HSUPA is the residual BLER for the selected uplink transmission format (HSUPA bearer with N Rtx retransmissions). It is read in the quality graph defined for the quartet “reception equipment-selected bearer-number of retransmissions-mobility” (HSUPA Quality Graphs tab in the Reception equipment properties). This graph describes the variation of
BLER as a function of the measured quality (E-DPDCH Ec/Nt). Knowing the E-DPDCH Ec/Nt, Atoll finds the corresponding
BLER.
The average number of retransmissions (  N Rtx  av ) is determined from early termination probabilities defined for the
selected HSUPA bearer (in the HSUPA Bearer Selection table). The Early Termination Probability graph shows the probability of early termination ( p ) as a function of the number of retransmissions ( N Rtx ). Atoll calculates the average number
of retransmissions (  N Rtx  av ) as follows:
 N Rtx 
max

 p  N Rtx  – p  N Rtx – 1    N Rtx
N Rtx = 1
 N Rtx  av = -----------------------------------------------------------------------------------------------------p   N Rtx  max 
DL
Coverage consists of several layers with a layer per possible average RLC throughput ( T RLC – Av ). For each layer, area
is covered if the minimum RLC throughput exceeds the user-defined thresholds. Each layer is assigned a colour and
displayed with intersections between layers.
Colour per Application Throughput
UL
Atoll displays the application throughput ( T application ) provided on each pixel. The application throughput represents the
net throughput after deduction of coding (redundancy, overhead, addressing, etc.). This one is calculated as follows:
UL
UL
T application  M b  = T RLC – Min  SF Rate – R
Where:
SF Rate and R respectively represent the scaling factor between the application throughput and the minimum RLC
(Radio Link Control) throughput and the throughput offset. These two parameters model the header information and other
supplementary data that does not appear at the application level. They are defined in the service properties.
UL
Coverage consists of several layers with a layer per possible application throughput ( T application ). For each layer, area is
covered if the application throughput exceeds the user-defined thresholds. Each layer is assigned a colour and displayed
with intersections between layers.
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Colour per Average Application Throughput
UL
Atoll displays the average application throughput ( T application – Av ) provided on each pixel. It is calculated as follows:
UL
UL
T application – Av  M b  = T RLC – Av  SF Rate – R
Where:
SF Rate and R respectively represent the scaling factor between the average application throughput and the average
RLC (Radio Link Control) throughput and the throughput offset. These two parameters model the header information and
other supplementary data that does not appear at the application level. They are defined in the service properties.
UL
Coverage consists of several layers with a layer per possible average application throughput ( T application – Av ). For each
layer, area is covered if the average application throughput exceeds the user-defined thresholds. Each layer is assigned
a colour and displayed with intersections between layers.
6.6
Automatic Neighbour Allocation
Atoll permits the automatic allocation of intra-technology neighbours in the current network. Two allocation algorithms are
available, one dedicated to intra-carrier neighbours and the other for inter-carrier neighbours.
The intra-technology neighbour allocation algorithms take into account all the cells of TBC transmitters. It means that all
the cells of TBC transmitters of your .atl document are potential neighbours.
The cells to be allocated will be called TBA cells. They must fulfil following conditions:
•
•
•
•
They are active,
They satisfy the filter criteria applied to the Transmitters folder,
They are located inside the focus zone,
They belong to the folder on which allocation has been executed. This folder can be either the Transmitters folder
or a group of transmitters or a single transmitter.
Only TBA cells may be assigned neighbours.
Note:
•
If no focus zone exists in the .atl document, Atoll takes into account the computation zone.
In this section, the following are explained:
•
•
•
6.6.1
"Neighbour Allocation for All Transmitters" on page 272.
"Neighbour Allocation for a Group of Transmitters or One Transmitter" on page 276.
"Importance Calculation" on page 276.
Neighbour Allocation for All Transmitters
We assume that we have a reference, cell A, and a candidate neighbour, cell B. When the automatic neighbour allocation
starts, Atoll checks the following conditions:
1.
2.
The distance between both cells must be less than the user-definable maximum inter-site distance. If the distance
between the reference cell and the candidate neighbour is greater than this value, then the candidate neighbour
is discarded.
The calculation options,
Carriers: This option enables you to select the carrier(s) on which you want to run the allocation. You may choose one or
more carriers. Atoll will allocate neighbours to cells using the selected carriers.
Force co-site cells as neighbours: This option enables you to force cells located on the reference cell site in the candidate
neighbour list. This constraint can be weighted among the others and ranks the neighbours through the importance field
(see after).
Force adjacent cells as neighbours (only for intra-carrier neighbours): This option enables you to force cells geographically
adjacent to the reference cell in the candidate neighbour list.This constraint can be weighted among the others and ranks
the neighbours through the importance field (see after).
Notes:
•
272
Adjacence criterion: Let CellA be a candidate neighbour cell of CellB. CellA is considered
adjacent to CellB if there exists at least one pixel in the CellB Best Server coverage area
where CellA is Best Server (if several cells have the same best server value) or CellA is the
second best server that enters the Active Set (respecting the HO margin of the allocation).
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•
When this option is checked, adjacent cells are sorted and listed from the most adjacent to
the least, depending on the above criterion. Adjacence is relative to the number of pixels
satisfying the criterion.
Force neighbour symmetry: This option enables user to force the reciprocity of a neighbourhood link. Therefore, if the reference cell is a candidate neighbour of another cell, this one will be considered as candidate neighbour of the reference cell.
Force exceptional pairs: This option enables you to force/forbid some neighbourhood relationships. Therefore, you may
force/forbid a cell to be candidate neighbour of the reference cell.
Delete existing neighbours: When selecting the Delete existing neighbours option, Atoll deletes all the current neighbours
and carries out a new neighbour allocation. If not selected, the existing neighbours are kept.
There must be an overlapping zone ( S A  S B ) with a given cell edge coverage probability:
3.
•
Intra-carrier neighbours: intra-carrier handover is a soft handover.
The reference cell A and the candidate cell B are located inside a continuous layer of cells with carrier c1 (c1 is the selected
carrier on which you run the allocation).
SA is the area where the cell A is the best serving cell. It means that the cell A is the first one in the active set.
-
The pilot signal received from the cell A is greater than the minimum pilot signal level.
The pilot quality from A exceeds a user-definable minimum value (minimum Ec/I0).
The pilot quality from A is the best.
SB is the area where the cell B can enter the active set.
-
The pilot signal received from the cell B is greater than the minimum pilot signal level.
The pilot quality from B is greater than the pilot quality from A minus the Ec/I0 margin. The Ec/I0 margin has
the same meaning as the AS-threshold defined in the Cell properties. So, it should logically have the same
value.
Figure 6.14: Overlapping Zone for Intra-carrier Neighbours
•
© Forsk 2009
Inter-carrier neighbours: inter-frequency handover is a hard handover. It is needed in a multi-carrier W-CDMA network:
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-
To balance loading between carriers and layers (1st case),
-
To make a coverage reason handover from micro cell frequency to macro cells (2nd case).
1st case: the reference cell A is located inside a continuous layer of cells with carrier c1 (c1 is the selected carrier on which
you run the allocation) and the candidate cell B belongs to a layer of cells with carrier c2.
SA is the area where the cell A is not the best serving cell of its layer but can enter the active set.
-
The pilot signal received from the cell A is greater than the minimum pilot signal level.
The pilot quality from A exceeds a user-definable minimum value (minimum Ec/I0).
The pilot quality from A is not the highest one. It is strictly lower than the best pilot quality received and greater
than the best pilot quality minus the Ec/I0 margin.
SB is the area where the cell B is the best serving cell of its layer.
-
The pilot signal received from the cell B is greater than the minimum pilot signal level.
The pilot quality from B exceeds a user-definable minimum value (minimum Ec/I0).
The pilot quality from B is the highest one.
Figure 6.15: Overlapping Zone for Inter-carrier Neighbours - 1st Case
2nd case: the reference cell A is located on the border of a layer with carrier c1 (c1 is the selected carrier on which you run
the allocation) and the candidate cell B belongs to a layer of cells with carrier c2.
SA is the area where the pilot quality from the cell A starts significantly decreasing but the cell A is still the best serving cell
of its layer (since it is on the border).
-
The pilot signal received from the cell A is greater than the minimum pilot signal level.
The pilot quality from A is the highest one
The pilot quality from A is lower than a user-definable minimum value (minimum Ec/I0) plus the Ec/I0 margin.
SB is the area where the cell B is the best serving cell of its layer.
-
The pilot signal received from the cell B is greater than the minimum pilot signal level.
The pilot quality from B exceeds a user-definable minimum value (minimum Ec/I0).
The pilot quality from B is the highest one.
Note:
•
Two ways enable you to determine the I0 value:
1 - Global Value: A percentage of the cell maximum power is considered. If the % of
maximum power is too low, i.e. if %  P max  P pilot , Atoll takes into account the pilot power
of the cell. Then, I0 represents the sum of values calculated for each cell.
2 - Defined per Cell: Atoll takes into account the total downlink power defined per cell. I0
represents the sum of total transmitted powers.
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Figure 6.16: Overlapping Zone for Inter-carrier Neighbours - 2nd Case
SA  SB
Atoll calculates the percentage of covered area ( ----------------------  100 ) and compares this value to the % minimum covered
SA
area. If this percentage is not exceeded, the candidate neighbour B is discarded.
4.
The importance of neighbours.
For information on the importance calculation, see "Importance Calculation" on page 276.
Importance values are used by the allocation algorithm to rank the neighbours according to the allocation reason. Atoll
lists all neighbours and sorts them by importance value so as to eliminate some of them from the neighbour list if the maximum number of neighbours to be allocated to each transmitter is exceeded. If we consider the case for which there are
15 candidate neighbours and the maximum number of neighbours to be allocated to the reference cell is 8. Among these
15 candidate neighbours, only 8 (having the highest importance values) will be allocated to the reference cell. Note that
specific maximum numbers of neighbours (maximum number of intra-carrier neighbours, maximum number of inter-carrier
neighbours) can be defined at the cell level (property dialogue or cell table). If defined there, this value is taken into account
instead of the default one available in the Neighbour Allocation dialogue.
In the Results part, Atoll provides the list of neighbours, the number of neighbours and the maximum number of neighbours allowed for each cell. In addition, it indicates the importance (in %) of each neighbour and the allocation reason.
Therefore, a neighbour may be marked as exceptional pair, co-site, adjacent, coverage or symmetric. For neighbours
accepted for co-site, adjacency and coverage reasons, Atoll displays the percentage of area meeting the coverage conditions and the corresponding surface area (km2), the percentage of area meeting the adjacency conditions and the corresponding surface area (km2). Finally, if cells have previous allocations in the list, neighbours are marked as existing.
Notes:
•
No simulation or prediction study is needed to perform an automatic neighbour allocation.
When starting an automatic neighbour allocation, Atoll automatically calculates the path
loss matrices if not found.
•
Even if no specific terminal, mobility or service is selected in the automatic allocation, it is
interesting to know that the algorithm works such as finding the maximum number of
neighbours by selection the multi-service traffic data as follows:
Service: selection of the one with the lowest body loss.
Mobility: no impact on the allocation, no specific selection.
Terminal: selection of the one with the greatest (Gain - Loss) value, and, if equal, the one
with the lowest noise figure.
•
The neighbour lists may be optionally used in the power control simulations to determine
the mobile's active set.
•
A forbidden neighbour must not be listed as neighbour except if the neighbourhood
relationship already exists and the Delete existing neighbours option is unchecked when
you start the new allocation. In this case, Atoll displays a warning in the Event viewer
indicating that the constraint on the forbidden neighbour will be ignored by algorithm
because the neighbour already exists.
•
The force neighbour symmetry option enables the users to consider the reciprocity of a
neighbourhood link. This reciprocity is allowed only if the neighbour list is not already full.
Thus, if the cell B is a neighbour of the cell A while the cell A is not a neighbour of the cell
B, two cases are possible:
1st case: There is space in the cell B neighbour list: the cell A will be added to the list. It will
be the last one.
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2nd case: The cell B neighbour list is full: Atoll will not include cell A in the list and will
cancel the link by deleting cell B from the cell A neighbour list.
6.6.2
•
When the options “Force exceptional pairs” and “Force symmetry” are selected, Atoll
considers the constraints between exceptional pairs in both directions so as to respect
symmetry condition. On the other hand, if neighbourhood relationship is forced in one
direction and forbidden in the other one, symmetry cannot be respected. In this case, Atoll
displays a warning in the Event viewer.
•
In the Results, Atoll displays only the cells for which it finds new neighbours. Therefore, if a
TBA cell has already reached its maximum number of neighbours before starting the new
allocation, it will not appear in the Results table.
Neighbour Allocation for a Group of Transmitters or One
Transmitter
Atoll allocates neighbours to:
•
•
•
TBA cells,
Neighbours of TBA cells marked as exceptional pair, adjacent and symmetric,
Neighbours of TBA cells that satisfy coverage conditions.
Automatic neighbour allocation parameters are described in "Neighbour Allocation for All Transmitters" on page 272.
6.6.3
Importance Calculation
Importance values are used by the allocation algorithm to rank the neighbours according to the allocation reason, and to
quantify the neighbour importance.
6.6.3.1
Importance of Intra-carrier Neighbours
As indicated in the table below, the neighbour importance depends on the neighbourhood cause; this value varies between
0 and 100%.
Neighbourhood cause
When
Importance
value
Existing neighbour
Only if the Delete existing neighbours option is not selected
and in case of a new allocation
Existing
importance
Exceptional pair
Only if the Force exceptional pairs option is selected
100 %
Co-site transmitter
Only if the Force co-site cells as neighbours option is selected
IF
Adjacent transmitter
Only if the Force adjacent cells as neighbours option is
selected
IF
Neighbourhood relationship that fulfils
coverage conditions
Only if the % minimum covered area is exceeded
IF
Symmetric neighbourhood
relationship
Only if the Force neighbour symmetry option is selected
IF
Except the case of forced neighbours (importance = 100%), priority assigned to each neighbourhood cause is determined
using the Importance Function (IF). The IF considers three factors for calculating the importance:
•
•
•
The co-site factor (C) which is a Boolean
The adjacency factor (A) which deals with the percentage of adjacency
The overlapping factor (O) meaning the percentage of overlapping
The IF is user-definable using the Min importance and Max importance fields.
Factor
Min importance
Default value
Max importance
Default value
Overlapping factor (O)
Min  O 
1%
Max  O 
30%
Adjacency factor (A)
Min  A 
30%
Max  A 
60%
Co-site factor (C)
Min  C 
60%
Max  C 
100%
The IF evaluates importance as follows:
Neighbourhood
cause
276
IF
Resulting IF using the
default values from the
table above
Co-site
Adjacent
No
No
Min  O  +   O   O 
1% + 29%  O 
No
Yes
Min  A  +   A   Max  O   O  +  100% – Max  O    A  
30% + 30%  30%  O  + 70%  A  
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Yes
Min  C  +   C   Max  O   O  +  100% – Max  O    A  
Yes
60% + 40%  30%  O  + 70%  A  
Where   X  = Max  X  – Min  X 
Notes:
•
If there is no overlapping between the range of each factor, the neighbours will be ranked
by neighbourhood cause. Using the default values for minimum and maximum importance
fields, neighbours will be ranked in the following order:
i.
Co-site neighbours
ii. Adjacent neighbours
iii. Neighbours based on coverage overlapping
6.6.3.2
•
If the ranges of the importance factors overlap, the neighbours may not be ranked
according to the neighbourhood cause.
•
The ranking between neighbours from the same category depends on the factors (A) and
(O).
•
The default value of Min(O) = 1% ensures that neighbours selected for symmetry will have
an importance greater than 0%. With a value of Min(O) = 0%, neighbours selected for
symmetry will have an importance field greater than 0% only if there is some coverage
overlapping.
Importance of Inter-carrier Neighbours
As indicated in the table below, the neighbour importance depends on the neighbourhood cause; this value varies between
0 to 100%.
Neighbourhood cause
When
Importance
value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing
importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter
If the Force co-site cells as neighbours option is selected
IF
Neighbourhood relationship that fulfils
coverage conditions
If the % minimum covered area is exceeded
IF
Symmetric neighbourhood
relationship
If the Force neighbour symmetry option is selected
IF
Except the case of forced neighbours (importance = 100%), priority assigned to each neighbourhood cause is determined
using the Importance Function (IF). The IF considers two factors for calculating the importance:
•
•
The co-site factor (C) which is a Boolean
The overlapping factor (O) meaning the percentage of overlapping
The IF is user-definable using the Min importance and Max importance fields.
Factor
Min importance
Default value
Max importance
Default value
Overlapping factor (O)
Min  O 
1%
Max  O 
60%
Co-site factor (C)
Min  C 
60%
Max  C 
100%
The IF evaluates importance as follows:
Co-site Neighbourhood cause
IF
Resulting IF using the default
values from the table above
No
Min  O  +   O   O 
1% + 59%  O 
Yes
Min  C  +   C   O 
60% + 40%  O 
Where   X  = Max  X  – Min  X 
Notes:
•
If there is no overlapping between the range of each factor, the neighbours will be ranked
by neighbourhood cause. Using the default values for minimum and maximum importance
fields, neighbours will be ranked in the following order:
i.
Co-site neighbours
ii. Neighbours based on coverage overlapping
•
© Forsk 2009
If the ranges of the importance factors overlap, the neighbours may not be ranked
according to the neighbourhood cause.
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6.7
•
The ranking between neighbours from the same category depends on the factor (O).
•
The default value of Min(O) = 1% ensures that neighbours selected for symmetry will have
an importance greater than 0%. With a value of Min(O) = 0%, neighbours selected for
symmetry will have an importance field greater than 0% only if there is some coverage
overlapping.
Primary Scrambling Code Allocation
Downlink primary scrambling codes enable you to distinguish cells from one another (cell identification).
By default, there are 512 primary scrambling codes numbered (0...511).
The cells to which Atoll allocates scrambling codes are referred to as the TBA cells (cells to be allocated). TBA cells fulfil
following conditions:
-
They are active,
They satisfy the filter criteria applied to the Transmitters folder,
They are located inside the focus zone,
They belong to the folder on which allocation has been executed. This folder can be either the Transmitters
folder or a group of transmitters or a single transmitter.
Note:
•
If no focus zone exists in the .atl document, Atoll takes into account the computation zone.
6.7.1
Automatic Allocation Description
6.7.1.1
Options and Constraints
The scrambling code allocation algorithm can take into account following constraints and options:
1.
Neighbourhood between cells,
You may consider:
•
•
•
First order neighbours: The neighbours of TBA cells listed in the Intra-technology neighbours table,
Second order neighbours: The neighbours of neighbours,
Third order neighbours: The neighbour’s neighbour’s neighbours.
Notes:
2.
•
In the context of the primary scrambling code allocation, the term "neighbours" refers to
intra-carrier neighbours.
•
Atoll can take into account inter-technology neighbour relations as constraints to allocate
different scrambling codes to the UMTS neighbours of a GSM transmitter. In order to
consider inter-technology neighbour relations in the scrambling code allocation, you must
make the Transmitters folder of the GSM .atl document accessible in the UMTS .atl
document. For information on making links between GSM and UMTS .atl documents, see
the User Manual.
•
Atoll considers symmetry relationship between a cell, its first order neighbours, its second
order neighbours and its third order neighbours.
Cells fulfilling a criterion on Ec/I0 (option “Additional Overlapping Conditions”),
For a reference cell “A”, Atoll considers all the cells “B” that can enter the active set on the area where the reference cell
is the best server (area where (Ec/I0)A exceeds the minimum Ec/I0 and is the highest one and (Ec/I0)B is within a Ec/I0
margin of (Ec/I0)A).
Note:
•
3.
Atoll considers either a percentage of the cell maximum powers or the total downlink power
used by the cells in order to evaluate I0. In this case, I0 equals the sum of total transmitted
powers. When this parameter is not specified in the cell properties, Atoll uses 50% of the
maximum power.
Reuse distance,
Notes:
•
278
Reuse distance is a constraint on the allocation of scrambling codes. A code cannot be
reused at a cell that is not at least as far away as the reuse distance from the cell allocated
with the particular code.
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•
4.
5.
Scrambling code reuse distance can be defined at cell level. If this value is not defined,
then Atoll will use the default reuse distance defined in the Scrambling Code Automatic
Allocation dialogue.
Exceptional pairs,
Domains of scrambling codes,
Note:
•
6.
When no domain is assigned to cells, Atoll considers the 512 primary scrambling codes
available.
The number of primary scrambling codes per cluster. In Atoll, we call "cluster", a group of scrambling codes as
defined in 3GPP specifications. 3GPP specifications define 64 clusters consisting of 8 scrambling codes (in this
case, clusters are numbererd from 0 to 63). However, you can define another value (e.g. if you set the number of
codes per cluster to 4, scrambling codes will be distributed in 128 clusters).
When the allocation is based on a Distributed strategy (Distributed per Cell or Distributed per Site), this parameter
can also be used to define the interval between the primary scrambling codes assigned to cells on a same site.
The defined interval is applied by adding the following lines in the Atoll.ini file:
[PSC]
ConstantStep = 1
For more information about setting options in the atoll.ini file, see the Administrator Manual.
7.
The carrier on which the allocation is run: It can be a given carrier or all of them. In this case, either Atoll
independently plans scrambling codes for the different carriers, or it allocates the same primary scrambling code
to each carrier of a transmitter if the option "Allocate carriers identically" is selected.
The possibility to use a maximum of codes from the defined domains (option "Use a Maximum of Codes"): Atoll
will try to spread the scrambling code spectrum the most.
The "Delete All Codes" option: When selecting this option, Atoll deletes all the current scrambling codes and
carries out a new scrambling code allocation. If not selected, the existing scrambling codes are kept.
8.
9.
In addition, it depends on the selected allocation strategy. Allocation strategies can be:
•
•
•
•
Clustered allocation: The purpose of this strategy is to choose for a group of mutually constrained cells, scrambling
codes among a minimum number of clusters. In this case, Atoll will preferentially allocate all the codes within the
same cluster.
Distributed per cell allocation: This strategy consists in using as many clusters as possible. Atoll will preferentially
allocate codes from different clusters.
One cluster per site allocation: This strategy allocates one cluster to each site, then, one code from the cluster to
each cell of each site. When all the clusters have been allocated and there are still sites remaining to be allocated,
Atoll reuses the clusters as far as possible at another site.
Distributed per site allocation: This strategy allocates a group of adjacent clusters to each site, then, one cluster
to each transmitter on the site according to its azimuth and finally, one code from the cluster to each cell of each
transmitter. The number of adjacent clusters per group depends on the number of transmitters per site you have
in your network; this information is required to start allocation based on this strategy. When all the groups of adjacent clusters have been allocated and there are still sites remaining to be allocated, Atoll reuses the groups of
adjacent clusters as far as possible at another site.
In the Results table, Atoll only displays scrambling codes allocated to TBA cells.
6.7.1.2
Allocation Process
For each TBA cell, Atoll lists all cells which have constraints with the cell. They are referred to as near cells. The near cells
of a TBA cell may be:
•
•
•
•
•
•
Its neighbour cells: the neighbours listed in the Intra-technology neighbours table (options “Existing neighbours”
and "First Order"),
The neighbours of its neighbours (options “Existing neighbours” and “Second Order”),
The third order neighbours (options “Existing neighbours” and “Third Order”),
The cells that fulfil Ec/I0 condition (option “Additional Overlapping Conditions”),
The cells with distance from the TBA cell less than the reuse distance,
The cells that make exceptional pairs with the TBA cell.
Additional constraints are considered when:
•
•
The cell and its near cells are neighbours of a same GSM transmitter (only if the Transmitters folder of the GSM
.atl document is accessible in the UMTS .atl document),
The neighbour cells cannot share the same cluster (for the "Distributed per site" allocation strategy only).
These constraints have a certain weight taken into account to determine the TBA cell priority during the allocation process
and the cost of the scrambling code plan. During the allocation, Atoll tries to assign different scrambling codes to the TBA
cell and its near cells. If it respects all the constraints, the cost of the scrambling code plan is 0. When a cell has too many
constraints and there are not anymore scrambling codes available, Atoll breaks the constraint with the lowest cost so as
to generate the scrambling code plan with the lowest cost. For information on the cost generated by each constraint, see
"Cell Priority" on page 281.
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6.7.1.2.1
Single Carrier Network
The allocation process depends on the selected strategy. Algorithm works as follows:
Strategies: Clustered and Distributed per Cell
Atoll processes TBA cells according to their priority. It allocates scrambling codes starting with the highest priority cell and
its near cells, and continuing with the lowest priority cells not allocated yet and their near cells. For information on calculating cell priority, see "Cell Priority" on page 281.
Strategy: One Cluster per Site
All sites which have constraints with the studied site are referred to as near sites.
Atoll assigns a cluster to each site, starting with the highest priority site and its near sites, and continuing with the lowest
priority sites not allocated yet and their near sites. When all the clusters have been allocated and there are still sites
remaining to be allocated, Atoll reuses the clusters at another site. When the Reuse Distance option is selected, the algorithm reuses the clusters as soon as the reuse distance is exceeded. Otherwise, when the option is not selected, the algorithm tries to assign reused clusters as spaced out as possible.
Then, Atoll allocates a primary scrambling code from the cluster to each cell located on the sites (codes belong to the
assigned clusters). It starts with the highest priority cell and its near cells and goes on with the lowest priority cells not
allocated yet and their near cells.
For information on calculating site priority, see "Site Priority" on page 283. For information on calculating cell priority, see
"Cell Priority" on page 281.
Strategy: Distributed per Site
All sites which have constraints with the studied site are referred to as near sites.
Atoll assigns a group of adjacent clusters to each site, starting with the highest priority site and its near sites, and continuing
with the lowest priority sites not allocated yet and their near sites. When all the groups of adjacent clusters have been
allocated and there are still sites remaining to be allocated, Atoll reuses the groups of adjacent clusters at another site.
When the Reuse Distance option is selected, the algorithm reuses the groups of adjacent clusters as soon as the reuse
distance is exceeded. Otherwise, when the option is not selected, the algorithm tries to assign reused groups of adjacent
clusters as spaced out as possible. Then, Atoll assigns each cluster of the group to each transmitter of the site according
to the transmitter azimuth and selected neighbourhood constraints (options "Neighbours in Other Clusters" and "Secondary Neighbours in Other Clusters"). Then, Atoll allocates a primary scrambling code to each cell located on the transmitters
(codes belong to the assigned clusters). It starts with the highest priority cell and its near cells and goes on with the lowest
priority cells not allocated yet and their near cells.
For information on calculating site priority, see "Site Priority" on page 283. For information on calculating cell priority, see
"Cell Priority" on page 281.
Determination of Groups of Adjacent Clusters
In order to determine the groups of adjacent clusters to be used, Atoll proceeds as follows: It defines theoretical groups of
adjacent clusters, independently of the defined domain, considering the 512 primary scrambling codes available and the
specified number of codes per cluster (if this one is set to 8, 64 clusters are supposed to be available). It starts the division
in group from the cluster 0 (hard coded) and takes into account the maximum number of transmitters per site user-specified
in order to determine the number of clusters in each group and then, the number of possible groups.
Let us assume that the number of codes per cluster is set to 8 and the maximum number of transmitters per site in the
network is 3. In this case, we have the following theoretical groups:
Group 1
Group 2
Group 3
Group 4
...
Group 21
Cluster 0
Cluster 1
Cluster 2
Cluster 3
Cluster 4
Cluster 5
Cluster 6
Cluster 7
Cluster 8
Cluster 9
Cluster 10
Cluster 11
...
Cluster 61
Cluster 62
Cluster 63
If no domain is assigned to cells, Atoll can use all these groups for the allocation. On the other hand, if a domain is used,
the tool compares adjacent clusters really available in the assigned domain to the theoretical groups and only keeps adjacent clusters mapping the theoretical groups.
Let us assume that we have a domain consisted of 12 clusters: clusters 1 to 8 and clusters 12 to 15.
Therefore, Atoll will be able to use the following groups of adjacent clusters:
•
•
•
•
Group 2 with cluster 3, 4 and 5,
Group 3 with cluster 6, 7 and 8,
Group 6 with cluster 12, 13 and 14.
The clusters 1, 2 and 15 will not be used.
If a domain does not contain any adjacent clusters, the user is warned through the 'Event Viewer'.
6.7.1.2.2
Multi-Carrier Network
In case you have a multi-carrier network and you run the scrambling code allocation on all the carriers, the allocation process depends on the allocation strategy as detailed above and in addition, wether the option "Allocate Carriers Identically"
is selected or not.
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When the option is not selected, algorithm works for each strategy, as explained above. On the other hand, when the
option is selected, allocation order changes. It is no longer based on the cell priority but depends on the transmitter priority.
All transmitters which have constraints with the studied transmitter will be referred to as near transmitters.
In case of a "Per cell" strategy (Clustered and Distributed per cell), Atoll starts scrambling code allocation with the highest
priority transmitter and its near transmitters and continues with the lowest priority transmitters not allocated yet and their
near transmitters. The same scrambling code is assigned to each cell of the transmitter.
In case of the "One cluster per site" strategy, Atoll assigns a cluster to each site and then, allocates a scrambling code to
each transmitter. It starts with the highest priority transmitter and its near transmitters and continues with the lowest priority
transmitters not allocated yet and their near transmitters. The same scrambling code is assigned to each cell of the transmitter.
In case of the "Distributed per site" strategy, Atoll assigns a group of adjacent clusters to each site, then a cluster to each
transmitter and finally, allocates a scrambling code to each transmitter. It starts with the highest priority transmitter and its
near transmitters and continues with the lowest priority transmitters not allocated yet and their near transmitters. The same
scrambling code is assigned to each cell of the transmitter.
For information on calculating transmitter priority, see "Transmitter Priority" on page 283.
Note:
•
6.7.1.3
6.7.1.3.1
When cells, transmitters or sites have the same priority, processing is based on an
alphanumeric order.
Priority Determination
Cell Priority
Scrambling code allocation algorithm in Atoll allots priorities to cells before performing the actual allocation. Priorities
assigned to cells depend upon how much constrained each cell is and the cost defined for each constraint. A cell without
any constraint has a default cost, C , equal to 0. The higher the cost on a cell, the higher the priority it has for the scrambling
code allocation process.
There are six criteria employed to determine the cell priority:
•
Scrambling Code Domain Criterion
The cost due to the domain constraint, C i  Dom  , depends on the number of scrambling codes available for the allocation.
The domain constraint is mandatory and cannot be broken.
When no domain is assigned to cells, 512 scrambling codes are available and we have:
C i  Dom  = 0
When domains of scrambling codes are assigned to cells, each unavailable scrambling code generates a cost. The higher
the number of codes available in the domain, the less will be the cost due to this criterion. The cost is given as:
C i  Dom  = 512 – Number of scrambling codes in the domain
•
Distance Criterion
The constraint level of any cell i depends on the number of cells (j) present within a radius of "reuse distance" from its
centre. The total cost due to the distance constraint is given as:
C i  Dist  =
 Cj  Dist  i  
j
Each cell j within the reuse distance generates a cost given as:
C j  Dist  i   = w  d ij   c dis tan ce
Where
w  d ij  is a weight depending on the distance between i and j. This weight is inversely proportional to the inter-cell distance.
For a reuse distance of 2000m, the weight for an inter-cell distance of 1500m is 0.25, the weight for co-site cells is 1 and
the weight for two cells spaced out 2100m apart is 0.
c dis tan ce is the cost of the distance constraint. This value can be defined in the Constraint Cost dialogue.
•
Exceptional Pair Criterion
The constraint level of any cell i depends on the number of exceptional pairs (j) for that cell. The total cost due to exceptional pair constraint is given as:
C i  EP  =
 cEP  i – j 
j
Where
c EP is the cost of the exceptional pair constraint. This value can be defined in the Constraint Cost dialogue.
•
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Neighbourhood Criterion
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The constraint level of any cell i depends on the number of its neighbour cells j, the number of second order neighbours k
and the number of third order neighbours l.
Let’s consider the following neighbour schema:
Figure 6.17: Neighbourhood Constraints
The total cost due to the neighbour constraint is given as:

Ci  N  = 






 Cj  N1  i   +  Cj – j  N1  i   +   Ck  N2  i   +  Ck – k  N2  i   +   Cl  N3  i   +  Cl – l  N3  i  
j
j
k
k
l
l
Each first order neighbour cell j generates a cost given as:
C j  N1  i   = I j  c N1
Where
I j is the importance of the neighbour cell j.
c N1 is the cost of the first order neighbour constraint. This value can be defined in the Constraint Cost dialogue.
Because two first order neighbours must not have the same scrambling code, Atoll considers the cost created by two first
order neighbours to be each other.
C j  N1  i   + C j  N1  i  
C j – j  N1  i   = ---------------------------------------------------------2
Each second order neighbour cell k generates a cost given as:
C k  N2  i   = Max ( C j  N1  i    C k  N1  j   , C j  N1  i    C k  N1  j   )  c N2
Where
c N2 is the cost of the second order neighbour constraint. This value can be defined in the Constraint Cost dialogue.
Because two second order neighbours must not have the same scrambling code, Atoll considers the cost created by two
second order neighbours to be each other.
C k  N2  i   + C k  N2  i  
C k – k  N2  i   = ------------------------------------------------------------2
Each third order neighbour cell l generates a cost given as:
 C  N1  i    C k  N1  j    C l  N1  k   C j  N1  i    C k  N1  j    C l N1  k  
C l  N3  i   = Max  j
  c N3
  C j  N1  i    C k  N1  j     C l N1  k  C j  N1  i    C k  N1  j    C l N1  k  
Where
c N3 is the cost of the third order neighbour constraint. This value can be defined in the Constraint Cost dialogue.
Because two third order neighbours must not have the same scrambling code, Atoll considers the cost created by two third
order neighbours to be each other.
C l  N3  i   + C l  N3  i  
C l – l  N3  i   = ---------------------------------------------------------2
Note:
• Atoll considers the highest cost of both links when a neighbour relation is symmetric and the
importance value is different.
In this case, we have:
C j  N1  i   = Max  I i – j I j – i   c N1
And
C k  N2  i   = Max (C j  N1  i    C k  N1  j  ,C j  N1  k    C i  N1  j  )  c N2
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•
GSM Neighbour Criterion
This criterion is considered when the co-planning mode is activated (i.e. the Transmitters folder of the GSM .atl document
is made accessible in the UMTS .atl document) and inter-technology neighbours have been allocated. If the cell i is neighbour of a GSM transmitter, the cell constraint level depends on how many cells j are neighbours of the same GSM transmitter. The total cost due to GSM neighbour constraint is given as:
C i  N 2G  =
 cN
2G
 j – Tx 2G 
j
Where
cN
2G
is the cost of the GSM neighbour constraint. This value can be defined in the Constraint Cost dialogue.
•
Cluster Criterion
When the "Distributed per Site" allocation strategy is used, you can consider additional constraints on allocated clusters
(one cell, its first order neighbours and its second order neighbours must be assigned scrambling codes from different clusters). In this case, the constraint level of any cell i depends on the number of first and second order neighbours, j and k.
The total cost due to the cluster constraint is given as:
C i  Cluster  =
 Cj  N1  i    cCluster +  Ck  N2  i    cCluster
j
k
Where
c Cluster is the cost of the cluster constraint. This value can be defined in the Constraint Cost dialogue.
Therefore, the total cost due to constraints on any cell i is defined as:
C i = C i  Dom  + C i  U 
With
C i  U  = C i  Dist  + C i  EP  + C i  N  + C i  N 2G  + C i  Cluster 
6.7.1.3.2
Transmitter Priority
In case you have a multi-carrier network and you run scrambling code allocation on "all" the carriers with the option "allocate carriers identically", algorithm in atoll allots priorities to transmitters. Priorities assigned to transmitters depend on how
much constrained each transmitter is and the cost defined for each constraint. The higher the cost on a transmitter, the
higher the priority it has for the scrambling code allocation process.
Let us consider a transmitter Tx with two cells using carriers 0 and 1. The cost due to constraints on the transmitter is given
as:
C Tx = C Tx  Dom  + C Tx  U 
With C Tx  U  =
Max  C  U   and C  Dom  = 512 – Number of scrambling codes in the domain
i
Tx
i  Tx
Here, the domain available for the transmitter is the intersection of domains assigned to cells of the transmitter. The
domain constraint is mandatory and cannot be broken.
6.7.1.3.3
Site Priority
In case of "Per Site" allocation strategies (One cluster per site and Distributed per site), algorithm in Atoll allots priorities
to sites. Priorities assigned to sites depend on how much constrained each site is and the cost defined for each constraint.
The higher the cost on a site, the higher the priority it has for the scrambling code allocation process.
Let us consider a site S with three transmitters; each of them has two cells using carriers 0 and 1. The cost due to
constraints on the site is given as:
C S = C S  U  + C S  Dom 
With C S  U  =
Max  C  U   and C  Dom  = 512 – Number of scrambling codes in the domain
Tx
S
Tx  S
Here, the domain considered for the site is the intersection of domains available for transmitters of the site. The domain
constraint is mandatory and cannot be broken.
6.7.2
Allocation Examples
6.7.2.1
Allocation Strategies and Use a Maximum of Codes
In order to understand the differences between the different allocation strategies and the behaviour of algorithm when
using a maximum of codes or not, let us consider the following sample scenario:
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Figure 6.18: Primary Scrambling Codes Allocation
Let Site0, Site1, Site2 and Site3 be four sites with 3 cells using carrier 0 whom scrambling codes have to be allocated out
of three clusters consisted of 8 primary scrambling codes. This implies that the domain of scrambling codes for the four
sites is from 0 to 23 (cluster 0 to cluster 2). The reuse distance is supposed to be less than the inter-site distance. Only
co-site neighbours exist.
The following section lists the results of each combination of options with explanation where necessary.
6.7.2.1.1
Strategy: Clustered
Since the restrictions of neighbourhood only apply to co-sites with the same importance and sites distances are greater
than reuse distances, every cell has the same priority. Then, scrambling code allocation to cells is performed in an alphanumeric order.
Without ‘Use a Maximum of Codes’
With ‘Use a Maximum of Codes’
Atoll starts allocating the codes from the start of cluster 0 at As it is possible to use a maximum of codes, Atoll starts
each site.
allocation at the start of a different cluster at each site.
When a cluster is reused, and there are non allocated
codes left in the cluster, Atoll first allocates those codes
before reusing the already used ones.
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6.7.2.1.2
Strategy: Distributed
Since the restrictions of neighbourhood only apply to co-sites with the same importance and sites distances are greater
than reuse distances, every cell has the same priority. Then, scrambling code allocation to cells is performed in an alphanumeric order.
Without ‘Use a Maximum of Codes’
With ‘Use a Maximum of Codes’
Atoll allocates codes from different clusters to each cell of Atoll allocates codes from different clusters to each site’s
the same site. Under given constraints of neighbourhood cells. As it is possible to use a maximum of codes, Atoll alloand reuse distance, same codes can be allocated to each cates the codes so that there is least repetition of codes.
site’s cells.
6.7.2.1.3
Strategy: ‘One Cluster per Site
Since the restrictions of neighbourhood only apply to co-sites with the same importance and sites distances are greater
than reuse distances, every site has the same priority. Then, cluster allocation to sites is performed in an alphanumeric
order.
Without ‘Use a Maximum of Codes’
With ‘Use a Maximum of Codes’
In this strategy, a cluster of codes is limited to be used at When it is possible to use a maximum of codes, Atoll can
just one site at a time unless all codes and clusters have allocate different codes from a reused cluster at another
been allocated and there are still sites remaining to be allo- site.
cated. In this case Atoll reuses the clusters as far as possible at another site.
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6.7.2.1.4
Strategy: ‘Distributed per Site
Since the restrictions of neighbourhood only apply to co-sites with the same importance and sites distances are greater
than reuse distances, every site has the same priority. Then, the group of adjacent clusters allocation to sites is performed
in an alphanumeric order.
Without ‘Use a Maximum of Codes’
With ‘Use a Maximum of Codes’
In this strategy, a group of adjacent clusters is limited to be When it is possible to use a maximum of codes, Atoll can
used at just one site at a time unless all codes and groups allocate different codes from a reused group of adjacent
of adjacent clusters have been allocated and there are still cluster at another site.
sites remaining to be allocated. In this case (here only one
group of adjacent clusters (clusters 0, 1 and 2) is available),
Atoll reuses the group at another site.
6.7.2.2
Allocate Carriers Identically
In order to understand the behaviour of algorithm when using the option "Allocate Carriers Identically" or not, let us
consider the following sample scenario:
Let Site0, Site1, Site2 and Site3 be four sites with 3 cells using carrier 0 and 3 cells using carrier 1. Scrambling codes have
to be allocated out of 3 clusters consisted of 8 primary scrambling codes. This implies that the domain of scrambling codes
for the five sites is from 0 to 23 (cluster 0 to cluster 2). The reuse distance is supposed to be less than the inter-site
distance. Only co-site neighbours exist. Allocation algorithm will be based on the "One Cluster per Site" strategy and the
option "Use a Maximum of Codes" is selected.
Without ‘Allocate Carriers Identically’
With ‘Allocate Carriers Identically’
Atoll allocates one cluster at each site as detailed in the In this case, Atoll allocates one cluster at each site and
previous section. Then, it allocates a code from the cluster then, one code to each transmitter so as to use a maximum
to each cell of the site so as to use a maximum of codes. of codes. Then, the same code is given to each cell of the
transmitter.
In both cases (with and without ’Allocate Carriers Identically’), every site has the same priority. Then, cluster allocation to
sites is performed in an alphanumeric order.
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6.8
Automatic GSM-UMTS Neighbour Allocation
6.8.1
Overview
You can automatically calculate and allocate neighbours between GSM and UMTS networks. In Atoll, it is called inter-technology neighbour allocation.
Inter-technology handover is used in two cases:
•
•
When the UMTS coverage is not continuous. In this case, the UMTS coverage is extended by UMTS-GSM
handover into the GSM network,
And in order to balance traffic and service distribution between both networks.
Note that the automatic inter-technology neighbour allocation algorithm takes into account both cases.
In order to be able to use the inter-technology neighbour allocation algorithm, you must have:
•
•
An .atl document containing the GSM network, GSM.atl, and another one describing the UMTS network,
UMTS.atl,
An existing link on the Transmitters folder of GSM.atl into UMTS.atl.
The external neighbour allocation algorithm takes into account all the GSM TBC transmitters. It means that all the TBC
transmitters of GSM.atl are potential neighbours. The cells to be allocated will be called TBA cells which, being cells of
UMTS.atl, satisfy following conditions:
•
•
•
•
They are active,
They satisfy the filter criteria applied to Transmitters folder,
They are located inside the focus zone,
They belong to the folder for which allocation has been executed. This folder can be either the Transmitters folder
or a group of transmitters subfolder.
Only UMTS TBA cells may be assigned neighbours.
6.8.2
Automatic Allocation Description
The allocation algorithm takes into account criteria listed below:
•
•
•
•
The inter-transmitter distance,
The maximum number of neighbours fixed,
Allocation options,
The selected allocation strategy,
Two allocation strategies are available: the first one is based on distance and the second one on coverage overlapping.
We assume we have a UMTS reference cell, A, and a GSM candidate neighbour, transmitter B.
6.8.2.1
Algorithm Based on Distance
When automatic allocation starts, Atoll checks following conditions:
1.
The distance between the UMTS reference cell and the GSM neighbour must be less than the user-definable
maximum inter-site distance. If the distance between the UMTS reference cell and the GSM neighbour is greater
than this value, then the candidate neighbour is discarded.
Candidate neighbours are sorted in descending order with respect to distance.
Note:
•
2.
Transmitter azimuths are taken into account to evaluate the inter-transmitter distance (for
further information on inter-transmitter distance calculation, please refer to "Calculation of
Inter-Transmitter Distance" on page 290)
The calculation options,
Carriers: This option enables you to select the carrier(s) on which you want to run the allocation. You may choose one or
more carriers. Atoll will allocate neighbours to cells using the selected carriers.
Force co-site cells as neighbours: It enables you to automatically include GSM transmitters located on the same site as
the reference UMTS cell in the candidate neighbour list. This option is automatically selected.
Force exceptional pairs: This option enables you to force/forbid some neighbourhood relationships. Therefore, you may
force/forbid a GSM transmitter to be candidate neighbour of the reference UMTS cell.
Delete existing neighbours: When selecting the Delete existing neighbours option, Atoll deletes all the current neighbours
and carries out a new neighbour allocation. If not selected, existing neighbours are kept.
3.
The importance of neighbours.
Importance values are used by the allocation algorithm to rank the neighbours according to the allocation reason. Atoll
lists all neighbours and sorts them by importance value so as to eliminate some of them from the neighbour list if the maximum number of neighbours to be allocated to each cell is exceeded. If we consider the case for which there are 15 candidate neighbours and the maximum number of neighbours to be allocated to the reference cell is 8. Among these 15
candidate neighbours, only 8 (having the highest importance values) will be allocated to the reference cell. Note that the
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maximum number of inter-technology neighbours can be defined at the cell level (property dialogue or cell table). If defined
there, this value is taken into account instead of the default one available in the Neighbour Allocation dialogue.
As indicated in the table below, the neighbour importance depends on the neighbourhood cause; this value varies between
0 to 100%.
Neighbourhood cause
When
Importance
value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing
importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter
If the Force co-site cells as neighbours option is selected
100 %
Neighbourhood relationship that fulfils
distance conditions
If the maximum distance is not exceeded
d
1 – -----------d max
Where d is the distance between the UMTS reference cell and the GSM neighbour and d max is the maximum inter-site
distance.
In the Results part, Atoll provides the list of neighbours, the number of neighbours and the maximum number of neighbours allowed for each cell. In addition, it indicates the importance (in %) of each neighbour and the allocation reason.
Therefore, a neighbour may be marked as exceptional pair, co-site, or distance. For neighbours accepted for distance
reasons, Atoll displays the distance from the reference cell (m). Finally, if cells have previous allocations in the list, neighbours are marked as existing.
6.8.2.2
Algorithm Based on Coverage Overlapping
When automatic allocation starts, Atoll checks following conditions:
1.
The distance between the UMTS reference cell and the GSM neighbour must be less than the user-definable
maximum inter-site distance. If the distance between the UMTS reference cell and the GSM neighbour is greater
than this value, then the candidate neighbour is discarded.
Note:
•
2.
Here, real inter-transmitter distance is considered.
The calculation options,
Carriers: This option enables you to select the carrier(s) on which you want to run the allocation. You may choose one or
more carriers. Atoll will allocate neighbours to cells using the selected carriers.
Force co-site cells as neighbours: It enables you to automatically include GSM transmitters located on the same site as
the reference UMTS cell in the candidate neighbour list. This option is automatically selected.
Force exceptional pairs: This option enables you to force/forbid some neighbourhood relationships. Therefore, you may
force/forbid a GSM transmitter to be candidate neighbour of the reference UMTS cell.
Delete existing neighbours: When selecting the Delete existing neighbours option, Atoll deletes all the current neighbours
and carries out a new neighbour allocation. If not selected, existing neighbours are kept.
3.
There must be an overlapping zone ( S A  S B ) with a given cell edge coverage probability.
Four different cases may be considered for SA:
-
1st case: SA is the area where the cell A is the best serving cell of the UMTS network.
- The pilot signal received from A is greater than the minimum pilot signal level,
- The pilot quality from A exceeds a user-definable minimum value (minimum Ec/I0) and is the highest one.
In this case, the Ec/I0 margin must be equal to 0dB and the max Ec/I0 option disabled.
-
2nd case: SA represents the area where the pilot quality from the cell A strats decreasing but the cell A is still
the best serving cell of the UMTS network.
The Ec/I0 margin must be equal to 0dB, the max Ec/I0 option selected and a maximum Ec/I0 user-defined.
-
-
The pilot signal received from A is greater than the minimum pilot signal level,
The pilot quality from A exceeds the minimum Ec/I0 but is lower than the maximum Ec/I0.
The pilot quality from A is the highest one.
3rd case: SA represents the area where the cell A is not the best serving cell but can enter the active set.
Here, the Ec/I0 margin has to be different from 0dB and the max Ec/I0 option disabled.
-
-
288
The pilot signal received from A is greater than the minimum pilot signal level,
The pilot quality from A is within a margin from the best Ec/I0, where the best Ec/I0 exceeds the minimum
Ec/I0.
4th case: SA represents the area where:
- The pilot signal received from A is greater than the minimum pilot signal level,
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Chapter 6: UMTS HSPA Networks
-
The pilot quality from A is within a margin from the best Ec/I0 (where the best Ec/I0 exceeds the minimum
Ec/I0) and lower than the maximum Ec/I0.
In this case, the margin must be different from 0dB, the max Ec/I0 option selected and a maximum Ec/I0 userdefined.
Two different cases may be considered for SB:
-
1st case: SB is the area where the cell B is the best serving cell of the GSM network.
In this case, the margin must be set to 0dB.
-
-
The signal level received from B on the BCCH TRX type exceeds the user-defined minimum threshold and
is the highest one.
2nd case: The margin is different from 0dB and SB is the area where:
- The signal level received from B on the BCCH TRX type exceeds the user-defined minimum threshold and
is within a margin from the best BCCH signal level.
SA  SB
Atoll calculates the percentage of covered area ( ----------------------  100 ) and compares this value to the % minimum covered
SA
area. If this percentage is not exceeded, the candidate neighbour B is discarded.
Candidate neighbours fulfilling coverage conditions are sorted in descending order with respect to % of covered area.
Guidelines for the automatic allocation
When the automatic allocation is based on coverage overlapping, we recommend you to perform two successive automatic allocations:
- A first allocation in order to find handovers due to non-continuous UMTS coverage. In this case, you have to select the
max Ec/I0 option and define a high enough value.
- A second allocation in order to complete the previous list with handovers motivated for reasons of traffic and service
distribution. Here, the max Ec/I0 option must be disabled.
4.
The importance of neighbours.
Importance values are used by the allocation algorithm to rank the neighbours according to the allocation reason. Atoll
lists all neighbours and sorts them by importance value so as to eliminate some of them from the neighbour list if the maximum number of neighbours to be allocated to each cell is exceeded. If we consider the case for which there are 15 candidate neighbours and the maximum number of neighbours to be allocated to the reference cell is 8. Among these 15
candidate neighbours, only 8 (having the highest importance values) will be allocated to the reference cell. Note that the
maximum number of inter-technology neighbours can be defined at the cell level (property dialogue or cell table). If defined
there, this value is taken into account instead of the default one available in the Neighbour Allocation dialogue.
As indicated in the table below, the neighbour importance depends on the cause; this value varies between 0 to 100%.
Neighbourhood reason
When
Importance
value
Existing neighbour
If the Delete existing neighbours option is not selected
Existing
importance
Exceptional pair
If the Force exceptional pairs option is selected
100 %
Co-site transmitter
If the Force co-site cells as neighbours option is selected
IF
Neighbourhood relationship that fulfils
coverage conditions
If the % minimum covered area is exceeded
IF
Except the case of forced neighbours (importance = 100%), priority assigned to each neighbourhood cause is determined
using the Importance Function (IF). The IF considers two factors for calculating the importance:
•
•
The co-site factor (C) which is a Boolean
The overlapping factor (O) meaning the percentage of overlapping
The IF is user-definable using the Min importance and Max importance fields.
Factor
Min importance
Default value
Max importance
Default value
Overlapping factor (O)
Min  O 
1%
Max  O 
60%
Co-site factor (C)
Min  C 
60%
Max  C 
100%
The IF evaluates importance as follows:
Co-site neighbourhood reason
IF
Resulting IF using the default
values from the table above
No
Min  O  +   O   O 
1% + 59%  O 
Yes
Min  C  +   C   O 
60% + 40%  O 
Where   X  = Max  X  – Min  X 
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Notes:
•
If there is no overlapping between the range of each factor, the neighbours will be ranked
by neighbourhood cause. Using the default values for minimum and maximum importance
fields, neighbours will be ranked in the following order:
i.
Co-site neighbours
ii. Neighbours based on coverage overlapping
•
If the ranges of the importance factors overlap, the neighbours may not be ranked
according to the neighbourhood cause.
•
The ranking between neighbours from the same category depends on the factor (O).
In the Results part, Atoll provides the list of neighbours, the number of neighbours and the maximum number of neighbours allowed for each cell. In addition, it indicates the importance (in %) of each neighbour and the allocation reason.
Therefore, a neighbour may be marked as exceptional pair, co-site or coverage. For neighbours accepted for co-site and
coverage reasons, Atoll displays the percentage of area meeting the coverage conditions and the corresponding surface
area (km2). Finally, if cells have previous allocations in the list, neighbours are marked as existing.
Notes:
•
No prediction study is needed to perform an automatic neighbour allocation. When starting
an automatic neighbour allocation, Atoll automatically calculates the path loss matrices if
not found.
•
A forbidden neighbour must not be listed as neighbour except if the neighbourhood
relationship already exists and the Delete existing neighbours option is unchecked when
you start the new allocation. In this case, Atoll displays a warning in the Event viewer
indicating that the constraint on the forbidden neighbour will be ignored by algorithm
because the neighbour already exists.
•
In the Results, Atoll displays only the cells for which it finds new neighbours. Therefore, if a
TBA cell has already reached its maximum number of neighbours before starting the new
allocation, it will not appear in the Results table.
6.8.2.3
Appendices
6.8.2.3.1
Delete Existing Neighbours Option
As explained above, Atoll keeps the existing inter-technology neighbours when the Delete existing neighbours option is
not checked. We assume that we have an existing allocation of inter-technology neighbours.
A new TBA cell i is created in UMTS.atl. Therefore, if you start a new allocation without selecting the Delete existing neighbours option, Atoll determines the neighbour list of the cell i.
If you change some allocation criteria (e.g. increase the maximum number of neighbours or create a new GSM TBC transmitter) and start a new allocation without selecting the Delete existing neighbours option, it examines the neighbour list of
TBA cells and checks allocation criteria if there is space in their neighbour lists. A new GSM TBC transmitter can enter the
TBA cell neighbour list if allocation criteria are satisfied. It will be the first one in the neighbour list.
6.8.2.3.2
Calculation of Inter-Transmitter Distance
When allocation algorithm is based on distance, Atoll takes into account the real distance ( D in m) and azimuths of antennas in order to calculate the effective inter-transmitter distance ( d in m).
d = D   1 + x  cos  – x  cos  
where x = 0.5% so that the maximum D variation does not exceed 1%.
Figure 6.19: Inter-Transmitter Distance Computation
The formula above implies that two cells facing each other will have a smaller effective distance than the real physical
distance. It is this effective distance that will be taken into account rather than the real distance.
Note:
•
290
This formula is not used when allocation algorithm is based on coverage overlapping. In
this case, real inter-transmitter distance is considered.
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Chapter 7
CDMA2000 1xRTT 1xEV-DO Networks
This chapter provides descriptions of all the algorithms for calculations, analyses, automatic allocations,
simulations and prediction studies available in CDMA2000 projects.
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Chapter 7: CDMA2000 Networks
7
CDMA2000 Networks
7.1
General Prediction Studies
7.1.1
Calculation Criteria
Three criteria can be studied in point analysis (Profile tab) and in common coverage studies. Study criteria are detailed in
the table below:
Study criteria
Formulas
Signal level ( P rec ) in dBm
Signal level received from a transmitter on a carrier (cell)
P rec  ic  = EIRP  ic  – L path – M Shadowing – model – L Indoor + G term – L term
L path = L model + L ant
Path loss ( L path ) in dBm
Total losses ( L total ) in dBm
Tx
L total =  L path + L Tx + L term + L indoor + M Shadowing – model  –  G Tx + G term 
where,
EIRP is the effective isotropic radiated power of the transmitter,
ic is a carrier number,
L model is the loss on the transmitter-receiver path (path loss) calculated by the propagation model,
L ant
Tx
is the transmitter antenna attenuation (from antenna patterns),
M Shadowing – model is the shadowing margin. This parameter is taken into account when the option “Shadowing taken into
account” is selected,
L Indoor are the indoor losses, taken into account when the option “Indoor coverage” is selected,
L term are the receiver losses,
G term is the receiver antenna gain,
G Tx is the transmitter antenna gain,
L Tx is the transmitter loss ( L Tx = L total – DL ). For information on calculating transmitter loss, "UMTS HSPA, CDMA2000
1xRTT 1xEV-DO, and TD-SCDMA Documents" on page 128.
Notes:
•
For CDMA2000 1xRTT systems, EIRP  ic  = P pilot  ic  + G Tx – L Tx (where, P pilot  ic  is
the cell pilot power).
•
For CDMA2000 1xEV-DO systems, EIRP  ic  = P max  ic  + G Tx – L Tx (where P max  ic 
is the maximum cell power).
•
It is also possible to analyse all the carriers at once. In this case, Atoll displays the best
signal level received from a transmitter. Therefore, if the network consists of 1xRTT and
1xEV-DO carriers, Atoll takes the highest power of both cells for each transmitter (i.e. the
highest value between the pilot power of the 1xRTT cell and the maximum power of the
1xEV-DO cell) to calculate the received signal level.
•
Atoll considers that G term and L term equal zero.
7.1.2
Point Analysis
7.1.2.1
Profile Tab
Atoll displays either the signal level received from the selected transmitter on a carrier ( P rec  ic  ), or the highest signal
level received from the selected transmitter on all the carriers.
Note:
•
For a selected transmitter, it is also possible to study the path loss, L path , or the total
losses, L total . Path loss and total losses are the same on any carrier.
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7.1.2.2
Reception Tab
Analysis provided in the Reception tab is based on path loss matrices. So, you can study reception from TBC transmitters
for which path loss matrices have been computed on their calculation areas.
For each transmitter, Atoll displays either the signal level received on a carrier, ( P rec  ic  ), or the highest signal level
received on all the carriers.
Reception bars are displayed in a decreasing signal level order. The maximum number of reception bars depends on the
signal level received from the best server. Only reception bars of transmitters whose signal level is within a 30 dB margin
from the best server can be displayed.
Note:
•
For a selected transmitter, it is also possible to study the path loss, L path , or the total
losses, L total . Path loss and total losses are the same on any carrier.
•
7.1.3
You can use a value other than 30 dB for the margin from the best server signal level, for
example a smaller value for improving the calculation speed. For more information on
defining a different value for this margin, see the Administrator Manual.
Coverage Studies
For each TBC transmitter, Txi, Atoll determines the selected criterion on each bin inside the Txi calculation area. In fact,
each bin within the Txi calculation area is considered as a potential (fixed or mobile) receiver.
Coverage study parameters to be set are:
•
•
7.1.3.1
The study conditions in order to determine the service area of each TBC transmitter,
The display settings to select how to colour service areas.
Service Area Determination
Atoll uses parameters entered in the Condition tab of the coverage study property dialogue to predetermine areas where
it will display coverage.
We can distinguish three cases:
7.1.3.1.1
All Servers
The service area of Txi corresponds to the bins where:
Txi
Txi
Txi
Minimum threshold  P rec  ic   or L total or L path   Maximum threshold
7.1.3.1.2
Best Signal Level and a Margin
The service area of Txi corresponds to the bins where:
Txi
Txi
Txi
Minimum threshold  P rec  ic   or L total or L path   Maximum threshold
And
Txi
Txj
P rec  ic   Best  P rec  ic   – M
ji
M is the specified margin (dB).
Best function: considers the highest value.
Notes:
•
If the margin equals 0 dB, Atoll will consider bins where the signal level received from Txi is
the highest.
•
If the margin is set to 2 dB, Atoll will consider bins where the signal level received from Txi
is either the highest or 2dB lower than the highest.
•
If the margin is set to -2 dB, Atoll will consider bins where the signal level received from Txi
is 2dB higher than the signal levels from transmitters, which are 2nd best servers.
7.1.3.1.3
Second Best Signal Level and a Margin
The service area of Txi corresponds to the bins where:
Txi
Txi
Txi
Minimum threshold  P rec  ic   or L total or L path   Maximum threshold
And
Txi
P rec  ic   2
294
nd
Txj
Best  P rec  ic   – M
ji
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Chapter 7: CDMA2000 Networks
M is the specified margin (dB).
2nd Best function: considers the second highest value.
Notes:
•
If the margin equals 0 dB, Atoll will consider bins where the signal level received from Txi is
the second highest.
•
If the margin is set to 2 dB, Atoll will consider bins where the signal level received from Txi
is either the second highest or 2dB lower than the second highest.
•
If the margin is set to -2 dB, Atoll will consider bins where the signal level received from Txi
is 2dB higher than the signal levels from transmitters, which are 3rd best servers.
7.1.3.2
Coverage Display
7.1.3.2.1
Plot Resolution
Prediction plot resolution is independent of the matrix resolutions and can be defined on a per study basis. Prediction plots
are generated from multi-resolution path loss matrices using bilinear interpolation method (similar to the one used to evaluate site altitude).
7.1.3.2.2
Display Types
It is possible to display the transmitter service area with colours depending on any transmitter attribute or other criteria
such as:
Signal Level (in dBm, dBµV, dBµV/m)
Atoll calculates signal level received from the transmitter on each bin of each transmitter service area. A bin of a service
area is coloured if the signal level exceeds (  ) the defined minimum thresholds (bin colour depends on signal level).
Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many
layers as transmitter service areas. Each layer shows the different signal levels available in the transmitter service area.
Best Signal Level (in dBm, dBµV, dBµV/m)
Atoll calculates signal levels received from transmitters on each bin of each transmitter service area. Where other service
areas overlap the studied one, Atoll chooses the highest value. A bin of a service area is coloured if the signal level
exceeds (  ) the defined thresholds (the bin colour depends on the signal level). Coverage consists of several independent
layers whose visibility in the workspace can be managed. There are as many layers as defined thresholds. Each layer
corresponds to an area where the signal level from the best server exceeds a defined minimum threshold.
Path Loss (dB)
Atoll calculates path loss from the transmitter on each bin of each transmitter service area. A bin of a service area is
coloured if path loss exceeds (  ) the defined minimum thresholds (bin colour depends on path loss). Coverage consists
of several independent layers whose visibility in the workspace can be managed. There are as many layers as service
areas. Each layer shows the different path loss levels in the transmitter service area.
Total Losses (dB)
Atoll calculates total losses from the transmitter on each bin of each transmitter service area. A bin of a service area is
coloured if total losses exceed (  ) the defined minimum thresholds (bin colour depends on total losses). Coverage
consists of several independent layers whose visibility in the workspace can be managed. There are as many layers as
service areas. Each layer shows the different total losses levels in the transmitter service area.
Best Server Path Loss (dB)
Atoll calculates signal levels received from transmitters on each bin of each transmitter service area. Where other service
areas overlap the studied one, Atoll determines the best transmitter and evaluates path loss from the best transmitter. A
bin of a service area is coloured if the path loss exceeds (  ) the defined thresholds (bin colour depends on path loss).
Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many
layers as defined thresholds. Each layer corresponds to an area where the path loss from the best server exceeds a
defined minimum threshold.
Best Server Total Losses (dB)
Atoll calculates signal levels received from transmitters on each bin of each transmitter service area. Where service areas
overlap the studied one, Atoll determines the best transmitter and evaluates total losses from the best transmitter. A bin
of a service area is coloured if the total losses exceed (  ) the defined thresholds (bin colour depends on total losses).
Coverage consists of several independent layers whose visibility in the workspace can be managed. There are as many
layers as defined thresholds. Each layer corresponds to an area where the total losses from the best server exceed a
defined minimum threshold.
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Number of Servers
Atoll evaluates how many service areas cover a bin in order to determine the number of servers. The bin colour depends
on the number of servers. Coverage consists of several independent layers whose visibility in the workspace can be
managed. There are as many layers as defined thresholds. Each layer corresponds to an area where the number of servers exceeds (  ) a defined minimum threshold.
Cell Edge Coverage Probability (%)
On each bin of each transmitter service area, the coverage corresponds to the pixels where the signal level from this transmitter fulfils signal conditions defined in Conditions tab with different Cell edge coverage probabilities. There is one coverage area per transmitter in the explorer.
Best Cell Edge Coverage Probability (%)
On each bin of each transmitter service area, the coverage corresponds to the pixels where the best signal level received
fulfils signal conditions defined in Conditions tab. There is one coverage area per cell edge coverage probability in the
explorer.
7.2
Definitions and Formulas
7.2.1
Parameters Used for CDMA2000 1xRTT Modelling
7.2.1.1
Inputs
This table lists simulation and prediction inputs (calculation options, quality targets, active set management conditions,
etc.)
Name
Value
Unit
Description
F ortho
Clutter parameter
None
Orthogonality factor
F MUD
Tx
Site equipment parameter
None
MUD factor
ic
Frequency band parameter
None
Carrier number
req
Q pilot  txi ic  + Q pilot
min
req
req
None
Active set upper threshold
(used to determine the best server in
the active set)
Q pilot  txi ic  + Q pilot
min
min
None
Active set lower threshold
(used to determine other members of
the active set)
req
Min. Ec/I0 - Cell parameter
None
Minimum Ec/I0 required from the cell
to be the best server in the active set
min
T_Drop - Cell parameter
None
Minimum Ec/I0 required from the cell
not to be rejected from the active set
req
Delta Min. Ec/I0 - Mobility parameter
None
Variation of the minimum Ec/I0
required from the cell to be the best
server in the active set
min
Delta T_Drop - Mobility parameter
None
Variation of the minimum Ec/I0
required from the cell not to be
rejected from the active set
None
Eb/Nt target for FCH channel on
downlink
None
Eb/Nt target for SCH channel on
downlink
None
Eb/Nt target for FCH channel on
uplink
None
Eb/Nt target for SCH channel on
uplink
None
Number of channel elements available
for a site on uplink
Q pilot
Q pilot
Q pilot  txi ic 
Q pilot  txi ic 
Q pilot
Q pilot
DL
 Q req  FCH
E
-----b-
 N t  req
FCH – DL
(Service, Terminal, Mobility) parameter
E
-----b-
 N t  req
SCH – DL
DL
 Q req  SCH
(Service, Terminal, Mobility, SCH rate multiple) parameter
UL
 Q req  FCH
E
-----b-
 N t  req
FCH – UL
(Service, Terminal, Mobility) parameter
E
-----b-
 N t  req
SCH – UL
UL
 Q req  SCH
(Service, Terminal, Mobility, SCH rate multiple) parameter
CE – U L
N max
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Site parameter
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CE – D L
 NI 
Site parameter
None
Number of channel elements available
for a site on downlink
N
CE – U L
 NI 
Simulation result
None
Number of channel elements of a site
consumed by users on uplink
N
CE – D L
 NI 
Simulation result
None
Number of channel elements of a site
consumed by users on downlink
N max
N
Overhead – C E – UL
Site equipment parameter
None
Number of channel elements used by
the cell for common channels on
uplink
N
Overhead – C E – DL
Site equipment parameter
None
Number of channel elements used by
the cell for common channels on
downlink
N
FCH – C E – UL
(Terminal, site equipment) parameter
None
Number of channel elements used for
FCH on uplink
N
FCH – C E – DL
(Terminal, site equipment) parameter
None
Number of channel elements used for
FCH on downlink
Simulation constraint
None
Maximum number of Walsh codes
available per cell (128)
Simulation result
None
Number of Walsh codes used by the
cell
NF term
Terminal parameter
None
Terminal Noise Figure
NF Tx
Transmitter parameter (user-defined or calculated from transmitter
equipment characteristics)
None
Transmitter Noise Figure
K
1.38 10-23
J/K
Boltzman constant
T
293
K
Ambient temperature
W
1.23 MHz
Hz
Spreading Bandwidth
Tx DL
Cell parameter
None
Inter-technology downlink noise rise
NR inter – techno log y
Tx UL
Cell parameter
None
Inter-technology uplink noise rise
RF  ic ic adj 
Network parameter
If not defined, it is assumed that there is no inter-carrier interference
None
Interference reduction factor between
two adjacent carriers ic and ic adj
Codes
N max  txi ic 
N
Codes
 txi ic 
NR inter – techno log y
Tx m
ICP ic  ic
i
Network parameter
If not defined, it is assumed that there is no inter-technology downlink
interferences due to external transmitters
None
Inter-technology Channel Protection
between the signal transmitted by Tx
and received by m assuming the
frequency gap between ic i (external
network) and ic
UL
X max
DL
%Power max
Simulation constraint (global parameter or cell parameter)
%
Maximum uplink load factor
Simulation constraint (global parameter or cell parameter)
%
Maximum percentage of used power
W
Thermal noise at transmitter
Tx UL
Tx
NF Tx  K  T  W  NR inter – techno log y
Term
NF Term  K  T  W  NR inter – techno log y
W
Thermal noise at terminal
Rc
W
bps
Chip rate
f rake efficiency
UL
Equipment parameter
None
Uplink rake receiver efficiency factor
DL
Terminal parameter
None
Downlink rake receiver efficiency
factor
Frate SCH
Simulation result
None
SCH rate factor (drawn following the
SCH probabilities of the service)
R FCH
DL
Terminal parameter
bps
Downlink FCH nominal rate
DL
R FCH  Frate SCH
bps
Downlink SCH bit rate
Frate SCH
Simulation result
None
SCH rate factor (drawn following the
SCH probabilities of the service)
UL
Terminal parameter
bps
Uplink FCH nominal rate
N0
N0
f rake efficiency
DL
R SCH
UL
R FCH
© Forsk 2009
Tx DL
DL
DL
AT281_TRG_E1
297
Technical Reference Guide
UL
UL
UL
R FCH  Frate SCH
bps
Uplink SCH bit rate
W
-------------DL
R FCH
None
Downlink service processing gain on
FCH
W
-------------DL
R SCH
None
Downlink service processing gain on
SCH
W ------------UL
R FCH
None
Uplink service processing gain on
FCH
W
-------------UL
R SCH
None
Uplink service processing gain on
SCH
DL
Service parameter
None
Downlink activity factor on FCH
AF FCH
UL
Service parameter
None
Uplink activity factor on FCH
P Sync  txi ic 
Cell parameter
W
Cell synchronisation channel power
P paging  txi ic 
Cell parameter
W
Cell other common channels (except
CPICH and SCH) power
P pilot  txi ic 
Cell parameter
W
Cell pilot power
P max  txi ic 
Cell parameter
W
Maximum cell power
M pooling  txi ic 
Cell parameter
dB
Maximum amount of power reserved
for pooling
P FCH
min
Service parameter
W
Minimum power allowed for FCH
P FCH
max
Service parameter
W
Maximum power allowed for FCH
P SCH
min
Service parameter
W
Minimum power allowed for SCH
P SCH
max
Service parameter
W
Maximum power allowed for SCH
P FCH  txi ic tch 
Simulation result including the term AFFCH  Serv 
W
Cell FCH power for a traffic channel
on carrier ic
W
Total FCH power on carrier ic
Simulation result
W
Transmitter SCH power for a traffic
channel on carrier ic

W
Total SCH power on carrier ic
W
Transmitter total transmitted power on
carrier ic
R SCH
FCH – DL
Gp
SCH – DL
Gp
FCH – UL
Gp
SCH – UL
Gp
AF FCH
P FCH  txi ic 
DL

P FCH  txi ic tch 
tch  FCH  ic  
P SCH  txi ic tch 
P SCH  txi ic 
P SCH  ic tch 
tch  SCH  ic  
P tx  txi ic 
+ P FCH  txi ic 
P term
min
Terminal parameter
W
Minimum terminal power allowed
max
Terminal parameter
W
Maximum terminal power allowed
P term
FCH
Simulation result including the term AFFCH  Serv 
W
Terminal FCH power transmitted in
carrier ic
P term  ic 
SCH
Simulation result
W
Terminal SCH power transmitted on
carrier ic
 BTS
BTS parameter
%
Percentage of BTS signal correctly
transmitted
 term
Terminal parameter
%
Percentage of terminal signal correctly
transmitted

Clutter parameter
%
Percentage of pilot finger - percentage
of signal received by the terminal pilot
finger
G Tx
Antenna parameter
None
Transmitter antenna gain
G Term
Terminal parameter
None
Terminal gain
P term  ic 
298
P pilot  txi ic  + P Sync  txi ic  + P paging  txi ic  + P SCH  txi ic 
UL
AT281_TRG_E1
© Forsk 2009
Chapter 7: CDMA2000 Networks
L Tx
Transmitter parameter (user-defined or calculated from transmitter
equipment characteristics)
None
Transmitter lossa
L body
Service parameter
None
Body loss
L Term
Terminal parameter
None
Terminal loss
L indoor
Clutter and frequency band parameter
L path
Propagation model result
None
Path loss
f
Terminal parameter
None
Number of fingers
p
Terminal parameter
%
Pilot power percentage
M Shadowing – model
Result calculated from cell edge coverage probability and model
standard deviation
None
Model Shadowing margin
Only used in prediction studies
M Shadowing – Ec  Io
Result calculated from cell edge coverage probability and Ec/I0
standard deviation
None
Ec/I0 Shadowing margin
Only used in prediction studies
DL
Indoor loss
npaths
G macro – diversity = M Shadowing – Ec  Io – M Shadowing –Ec  Io
DL
G macro – diversity
None
n=2 or 3
M Shadowing –  Eb  Nt 
DL
M Shadowing –  Eb  Nt 
UL
pilot signals at the mobile b.
Result calculated from cell edge coverage probability and DL Eb/Nt
standard deviation
None
DL Eb/Nt Shadowing margin
Only used in prediction studies
Result calculated from cell edge coverage probability and UL Eb/Nt
standard deviation
None
UL Eb/Nt Shadowing margin
Only used in prediction studies
UL
UL
G macro – diversity
DL gain due to availability of several
npaths
G macro – diversity = M Shadowing –  Eb  Nt 
UL
– M Shadowing – Eb  Nt 
n=2 or 3
Global parameter (default value)
E Shadowing
UL
None
UL quality gain due to signal diversity
in soft handoffc.
None
Random shadowing error drawn
during Monte-Carlo simulation
Only used in simulations
None
Transmitter-terminal total loss
P pilot  txi ic 
--------------------------------LT
W
Chip power received at terminal
Simulation result
In prediction studiesd
For Ec/I0 calculation
L path  L Tx  L term  L body  L indoor  M Shadowing – Ec  Io
--------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
For DL Eb/Nt calculation
L path  L Tx  L term  L body  L indoor  M Shadowing –  Eb  Nt 
DL
-----------------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
LT
For UL Eb/Nt calculation
L path  L Tx  L term  L body  L indoor  M Shadowing –  Eb  Nt 
UL
-----------------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
In simulations
L path  L Tx  L term  L body  L indoor  E Shadowing
-------------------------------------------------------------------------------------------------------------------------------G Tx  G term
P c  txi ic 
FCH – DL
 txi ic tch 
P FCH  txi ic tch 
---------------------------------------------LT
W
Bit received power at terminal for FCH
on carrier ic
SCH – DL
 txi ic tch 
P SCH  txi ic tch 
---------------------------------------------LT
W
Bit received power at terminal for SCH
on carrier ic
W
Bit received power at terminal for
FCH+SCH on carrier ic
W
Total received power at terminal from
a transmitter on carrier ic
W
Total power received at terminal from
traffic channels of a transmitter on
carrier ic
W
Bit received power at transmitter for
FCH on carrier ic
Pb
Pb
DL
P b  txi ic tch 
FCH – DL
Pb
DL
FCH – UL
Pb
© Forsk 2009
 txi ic tch 
P tx  txi ic 
---------------------------LT
DL
P tot  txi ic 
P traf  txi ic 
SCH – DL
 txi ic tch  + P b

tch  ic 
P FCH  txi ic  + P SCH  txi ic 
--------------------------------------------------------------------------LT
FCH
 ic 
P term
-------------LT
AT281_TRG_E1
299
Technical Reference Guide
SCH – UL
Pb
SCH
P term
-------------LT
 ic 
W
Bit received power at transmitter for
SCH on carrier ic
UL
Pb
 ic 
W
Bit received power at transmitter for
SCH+FCH on carrier ic
UL
P b  ic 
UL
UL
P b  ic  + P c  ic  = ------------------1 – p
W
Total power transmitted by the
terminal on carrier ic
UL
p  P tot  ic 
W
Chip received power at transmitter
FCH – UL
P b  ic 
SCH – UL
 ic  + P b
UL
P tot  ic 
UL
P c  ic 
a.
L Tx = L total – UL on uplink and L Tx = L total – DL on downlink. For information on calculating transmitter
losses on uplink and downlink, see "UMTS HSPA, CDMA2000 1xRTT 1xEV-DO, and TD-SCDMA Documents" on
page 128.
b.
npaths
M Shadowing –Ec  Io corresponds to the shadowing margin evaluated from the shadowing error probability
density function (n paths) in case of downlink Ec/I0 modelling.
c.
npaths
M Shadowing –  Eb  Nt 
UL
corresponds to the shadowing margin evaluated from the shadowing error probability
density function (n paths) in case of uplink soft handoff modelling.
d.
In uplink prediction studies, only carrier power level is downgraded by the shadowing margin
( M Shadowing –  Eb  Nt  ). In downlink prediction studies, carrier power level and intra-cell interference are downgraded by
UL
the shadowing model ( M Shadowing –  Eb  Nt 
M Shadowing –  Eb  Nt 
7.2.1.2
DL
DL
or M Shadowing – Ec  Io ) while extra-cell interference level is not. Therefore,
or M Shadowing – Ec  Io is set to 1 in downlink extra-cell interference calculation.
Ec/I0 Calculation
This table details the pilot quality ( Q pilot or Ec  Io ) calculations.
Name
Value
DL
DL
I intra  txi ic 
P tot  txi ic 

DL
I extra  ic 
DL
P tot  txj ic 
Unit
Description
W
Downlink intra-cell interference at
terminal on carrier ic
W
Downlink extra-cell interference at
terminal on carrier ic
W
Downlink inter-carrier interference at
terminal on carrier ic
txj j  i
 Ptot  txj icadj 
DL
DL
I inter – carrier  ic 
txj
 j
------------------------------------------------
RF  ic ic adj 
Tx
P Transmitted  ic i 
 -----------------------------------------Tx
Tx m
L
 ICP
DL
I inter – techno log y  ic 
ni
DL
I 0  ic 
Ec
Q pilot  txi ic    ------
 I0 
DL
DL
W
ic i ic
total
DL
DL
Term
I intra  txi ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
 BTS    P c  txi ic 
------------------------------------------------------DL
I 0  ic 
W
None
Downlink inter-technology interference
at terminal on carrier ic a
Total received noise at terminal on
carrier ic b
Quality level at terminal on pilot for
carrier ic
a. In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the
fractional load.
Term
b. In an active set, N 0
7.2.1.3
is calculated for all its members with Inter-technology downlink noise rise of the best server.
DL Eb/Nt Calculation
Eb
DL
This table details calculations of downlink traffic channel quality ( Q tch (tch could be FCH or SCH) or  ------- ).
 Nt  DL
Name
DL
I intra  txi ic 
300
Value
Unit
Description
 1 –  BTS  F ortho   P DL  txi ic 
tot
W
Downlink intra-cell interference at
terminal on carrier ic
AT281_TRG_E1
© Forsk 2009
Chapter 7: CDMA2000 Networks

DL
I extra  ic 
DL
P tot  txj ic 
W
Downlink extra-cell interference at
terminal on carrier ic
W
Downlink inter-carrier interference at
terminal on carrier ic
txj j  i
 Ptot  txj icadj 
DL
DL
I inter – carrier  ic 
txj
 j
------------------------------------------------
RF  ic ic adj 

DL
I inter – techno log y  ic 
ni
DL
N tot  ic 
DL
DL
Tx
P Transmitted  ic i 
-----------------------------------------Tx
Tx m
L total  ICP ic  ic
W
i
DL
Term
DL
I intra  ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic  + N 0
W
Downlink inter-technology interference
at terminal on carrier ic a
Total received noise at terminal on
carrier ic
Without useful signal:
FCH – DL
E b DL
DL
Q FCH  txi ic    ------
 N t  FCH
DL
Q FCH  ic 
 BTS  P b
 txi ic tch 
– DL
----------------------------------------------------------------------------------------------------------------  G FCH
p
DL
DL
N tot  ic  –  1 – F ortho    BTS  P b  txi ic 
None
FCH channel on carrier ic b
FCH – DL
 BTS  P b
 txi ic tch 
– DL
-  G FCH
Total noise: --------------------------------------------------------------------------p
DL
N tot  ic 

DL
f rake efficiency 
DL
Q FCH  tx k ic 
Quality level at terminal on a traffic
channel from one transmitter for a
None
txk  ActiveSet  FCH 
Quality level at terminal for FCH using
carrier ic due to combination of all
transmitters of the active set (Macrodiversity conditions).
Without useful signal:
SCH – DL
E b DL
DL
Q SCH  txi ic    ------
 N t  SCH
DL
Q SCH  ic 
 BTS  P b
 txi ic tch 
– DL
----------------------------------------------------------------------------------------------------------------  G SCH
p
DL
DL
N tot  ic  –  1 – F ortho    BTS  P b  txi ic 
None
SCH channel on carrier icc
SCH – DL
 BTS  P b
 txi ic tch 
– DL
-  G SCH
Total noise: --------------------------------------------------------------------------p
DL
N tot  ic 

DL
f rake efficiency 
DL
Q SCH  tx k ic 
None
Quality level at terminal for SCH using
carrier ic due to combination of all
transmitters of the active set (Macrodiversity conditions).
None
Downlink soft handover gain for FCH
channel on carrier ic
None
Downlink soft handover gain for SCH
channel on carrier ic
W
Required transmitter FCH traffic
channel power to achieve Eb/Nt target
at terminal on carrier ic
W
Required transmitter SCH traffic
channel power to achieve Eb/Nt target
at terminal on carrier ic
W
Required transmitter traffic channel
power on carrier ic
txk  ActiveSet  SCH 
DL
DL
 G SHO  FCH
Q FCH  ic 
------------------------------------------------------------DL
Q FCH  BestServer ic 
DL
DL
 G SHO  SCH
Q SCH  ic 
------------------------------------------------------------DL
Q SCH  BestServer ic 
DL
req
P FCH  txi ic 
 Q req  FCH
---------------------------  P FCH  txi ic 
DL
Q FCH  ic 
DL
req
P SCH  txi ic 
req
P tch  txi ic 
 Q req  SCH
---------------------------  P SCH  txi ic 
DL
Q SCH  ic 
req
req
P FCH  txi ic  + P SCH  txi ic 
Quality level at terminal on a traffic
channel from one transmitter for a
a. In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the
fractional load.
b. Calculation option may be selected in the Global parameters tab. The chosen option will be taken into account only in
simulations. In point analysis and coverage studies, Atoll uses the option “Total noise” to evaluate DL and UL Eb/Nt.
c. Calculation option may be selected in the Global parameters tab. The chosen option will be taken into account only in
simulations. In point analysis and coverage studies, Atoll uses the option “Total noise” to evaluate DL and UL Eb/Nt.
7.2.1.4
UL Eb/Nt Calculation
Eb
UL
This table details calculations of uplink traffic channel quality ( Q tch (tch could be FCH or SCH) or  ------- ).
 Nt  UL
© Forsk 2009
AT281_TRG_E1
301
Technical Reference Guide
Name
UL intra
I tot
  Pb
UL
 txi ic 
UL extra
I tot
Value

UL
term
txj j  i
UL
UL
I inter – carrier  txi ic 
W
Total power received at transmitter
from intra-cell terminals using carrier
ic
W
Total power received at transmitter
from extra-cell terminals using carrier
ic
W
Uplink inter-carrier interference at
terminal on carrier ic
W
Total received interference at
transmitter on carrier ic
UL
 P b  ic  + P c  ic  
  Pb
Description
UL
 ic  + P c  ic  
term
txi
 txi ic 
Unit
UL
 ic adj  + P c  ic adj  
term
txj
 j
-----------------------------------------------------------------------------
RF  ic ic adj 
UL
I tot  txi ic 
UL extra
I tot
UL intra
Tx
 txi ic  +  1 – F MUD   term I tot
UL
UL
N tot  txi ic 
UL
 txi ic  +I inter – carrier  txi ic 
tx
I tot  txi ic  + N 0
W
Total noise at transmitter on carrier ic
(Uplink interference) a
Without useful signal:
FCH – UL
Eb
UL
Q FCH  txi ic    ------
 N t  UL
 term  P b
 ic 
– UL
----------------------------------------------------------------------------------------------------------------  G FCH
p
UL
Tx
UL
N tot  txi ic  –  1 – F MUD    term  P b  ic 
None
Quality level at transmitter on a traffic
channel for the FCH channel on
carrier icb
FCH – UL
 term  P b
 ic 
– UL
-  G FCH
Total noise: -----------------------------------------------------p
UL
N tot  txi ic 
Without useful signal:
SCH – UL
Eb
UL
Q SCH  txi ic    ------
 N t  UL
 term  P b
 ic 
– UL
----------------------------------------------------------------------------------------------------------------  G SCH
p
UL
Tx
UL
N tot  txi ic  –  1 – F MUD    term  P b  ic 
None
Quality level at transmitter on a traffic
channel for the SCH channel on
carrier icc
SCH – UL
 term  P b
 ic 
– UL
-  G SCH
Total noise: -----------------------------------------------------p
UL
N tot  txi ic 
UL
No HO: Q tch  txi ic 

UL
Softer HO: f rake efficiency 
UL
Q tch  tx k ic 
tx k  ActiveSet
 samesite 
Soft, Softer/Soft HO (No MRC):
UL
UL
Max  Q tch  tx k ic    G macro – diversity
txk  ActiveSet
UL
Q tch  ic 
Softer/Soft HO (MRC):
Quality level at site using carrier ic due
to combination of all transmitters of
the active set located at the same site
and taking into account increase of the
None quality due to macro-diversity (macrodiversity gain).
tch could be FCH or SCH


 UL

UL
UL
f rake efficiency  Q tch  tx k ic  Q tch  tx l ic 

tx k ,txl  ActiveSet


txk  samesite 

tx k
Max
UL

In simulations, G macro – diversity = 1 .
tx  othersite
l
UL
 G macro – diversity
UL
UL
 G SHO  FCH
Q FCH  ic 
------------------------------------------------------------UL
Q FCH  BestServer ic 
None
Uplink soft handover gain for FCH
channel on carrier ic
None
Uplink soft handover gain for SCH
channel on carrier ic
W
Required terminal power to achieve
Eb/Nt target at transmitter for FCH on
carrier ic
UL
UL
 G SHO  SCH
Q SCH  ic 
------------------------------------------------------------UL
Q SCH  BestServer ic 
UL
FCH – req
P term
302
 ic 
 Q req  FCH
---------------------------  P FCH
term  ic 
UL
Q FCH  ic 
AT281_TRG_E1
© Forsk 2009
Chapter 7: CDMA2000 Networks
W
Required terminal power to achieve
Eb/Nt target at transmitter for SCH on
carrier ic
W
Required terminal power on carrier ic
UL
SCH – req
P term
 Q req  SCH
--------------------------  P SCH
term  ic 
UL
Q SCH  ic 
 ic 
req
FCH – req
P term  ic 
P term
SCH – req
 ic  + P term
 ic 
tx
a. In an active set, N 0 is calculated for all its members with Inter-technology uplink noise rise of the best server.
b. Calculation option may be selected in the Global parameters tab. The chosen option will be taken into account only in
simulations. In point analysis and coverage studies, Atoll uses the option “Total noise” to evaluate DL and UL Eb/Nt.
c. Calculation option may be selected in the Global parameters tab. The chosen option will be taken into account only in
simulations. In point analysis and coverage studies, Atoll uses the option “Total noise” to evaluate DL and UL Eb/Nt.
7.2.1.5
Simulation Results
This table contains some simulation results provided in the Cells and Mobiles tabs of the simulation property dialogue.
Name
Value
DL
DL
P tot  txi ic  – F ortho   BTS  P tot  txi ic 
DL
I intra  txi ic 
–  1 – F ortho   BTS  

DL
I extra  ic 
DL
P b  txi
Unit
Description
None
Downlink intra-cell interference at
terminal on carrier ic
W
Downlink extra-cell interference at
terminal on carrier ic
W
Downlink inter-carrier interference at
terminal on carrier ic
ic 
DL
P tot  txj ic 
txj j  i
 Ptot  txj icadj 
DL
DL
I inter – carrier  ic 
txj
 j
------------------------------------------------
RF  ic ic adj 

DL
I inter – techno log y  ic 
ni
DL
DL
I tot  ic 
DL
DL
DL
Term
I tot  ic  + N 0
  Pb
UL
 txi ic 
UL extra
I tot
i
DL
DL
UL intra

UL
term
txj j  i
  Pb
UL
ic 
at terminal on carrier ic a
Total effective interference at terminal
on carrier ic (after unscrambling)
W
Total received noise at terminal on
carrier ic
W
Total power received at transmitter
from intra-cell terminals using carrier
ic
W
Total power received at transmitter
from extra-cell terminals using carrier
ic
W
Uplink inter-carrier interference at
terminal on carrier ic
W
Total received interference at
transmitter on carrier ic
W
Total noise at transmitter on carrier ic
(Uplink interference)
None
Cell uplink load factor on carrier ic
UL
 P b  ic  + P c  ic  
Downlink inter-technology interference
W
UL
 ic  + P c  ic  
term
txi
 txi ic 
UL
I inter – carrier  txi
W
I intra  ic  + I extra  ic  + I inter – carrier  ic  + I inter – techno log y  ic 
N tot  ic 
I tot
Tx
P Transmitted  ic i 
-----------------------------------------Tx
Tx m
L total  ICP ic  ic
UL
 ic adj  + P c  ic adj  
term
txj
 j
-----------------------------------------------------------------------------
RF  ic ic adj 
UL
I tot  txi ic 
UL
N tot  txi ic 
UL extra
I tot
UL intra
Tx
 txi ic  +  1 – F MUD   term I tot
UL
UL
 txi ic  +I inter – carrier  txi ic 
tx
I tot  txi ic  + N 0
UL
 txi ic 
I tot  txi ic 
----------------------------UL
N tot  txi ic 
F
UL
 txi ic 
I tot  txi ic 
------------------------------------------------------------------------------------------UL intra
Tx
I tot
 txi ic    1 – F MUD   term 
None
Cell uplink reuse factor on carrier ic
E
UL
 txi ic 
1
-----------------------------UL
F  txi ic 
None
Cell uplink reuse efficiency factor on
carrier ic
P tx  txi ic  
 --------------------------------  100
 P max  txi ic 
None
Percentage of max transmitter power
used.
X
UL
UL
%Power
© Forsk 2009
DL
 txi ic 
AT281_TRG_E1
303
Technical Reference Guide
Simulation result available per cell
DL
 I extra  ic 
DL
+ I inter – carrier  ic    L T
---------------------------------------------------------------------------------------- + 1 – F ortho   BTS
P tx  txi ic 
------------------------------------------------------------------------------------------------------------------------------------------1
------------- +  1 – F ortho   BTS 
tch
DL
CI req

X
DL
 txi ic 
with
DL
CI req
SCH – DL
FCH – DL
None
Downlink load factor on carrier ic
None
Downlink reuse factor on a carrier ic
Q req
Q req
= ------------------------+ -----------------------SCH – DL
FCH – DL
Gp
Gp
DL
I tot  ic 
Simulation result available per mobile: -------------------DL
N tot  ic 
DL
F
DL
I tot  ic 
------------------------------DL
I intra  txi ic 
 txi ic 
NR
DL
 txi ic 
– 10 log  1 – X
DL
 txi ic  
dB
Noise rise on downlink
NR
UL
 txi ic 
– 10 log  1 – X
UL
 txi ic  
dB
Noise rise on uplink
a. In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the
fractional load.
7.2.2
Parameters Used for CDMA2000 1xEV-DO Modelling
7.2.2.1
Inputs
This table lists simulation and prediction inputs (calculation options, quality targets, active set management conditions,
etc.)
Name
Value
Unit
Description
F ortho
Clutter parameter
None
Orthogonality factor
F MUD
Tx
Site equipment parameter
None
MUD factor
ic
Frequency band parameter
None
Carrier number
req
Q pilot  txi ic  + Q pilot
min
req
req
None
Active set upper threshold
(used to determine the best server in
the active set)
Q pilot  txi ic  + Q pilot
min
min
None
Active set lower threshold
(used to determine other members of
the active set)
req
Min. Ec/I0 - Cell parameter
None
Minimum Ec/I0 required from the cell
to be the best server in the active set
min
T_Drop - Cell parameter
None
Minimum Ec/I0 required from the cell
not to be rejected from the active set
req
Delta Min. Ec/I0 - Mobility parameter
None
Variation of the minimum Ec/I0
required from the cell to be the best
server in the active set
Q pilot
min
Delta T_Drop - Mobility parameter
None
Variation of the minimum Ec/I0
required from the cell not to be
rejected from the active set
E
-----c-
 N t  min
Mobility parameter for 1xEV-DO Rev. 0 users
Parameter read in the 1xEV-DO Rev. A Radio Bearer Selection
(Uplink) table for 1xEV-DO Rev. A users
None
Minimum pilot quality level on uplink
n SF
1xEV-DO Rev. A Radio Bearer Selection (Uplink) table
None
Number of subframes associated to
uplink 1xEV-DO Rev. A bearer
R RLC – peak
Uplink 1xEV-DO Rev. A Radio Bearer table
None
Uplink RLC peak rate provided by the
1xEV-DO Rev. A bearer
E
-----c-
 N t  min
Mobility parameter for 1xEV-DO Rev. 0 users
Parameter read in the 1xEV-DO Rev. A Radio Bearer Selection
(Downlink) table for 1xEV-DO Rev. A users
None
Minimum pilot quality level required to
obtain a data rate on downlink
n TS
1xEV-DO Rev. A Radio Bearer Selection (Downlink) table
None
Number of timeslots associated to
downlink 1xEV-DO Rev. A bearer
Q pilot
Q pilot
Q pilot  txi ic 
Q pilot  txi ic 
Q pilot
UL
UL
DL
304
AT281_TRG_E1
© Forsk 2009
Chapter 7: CDMA2000 Networks
DL
R RLC – peak
None
Downlink RLC peak rate provided by
the 1xEV-DO Rev. A bearer
EVDO – CE
 NI 
Site parameter
None
Number of EVDO channel elements
available for a site on uplink and
downlink
EVDO – CE
 NI 
Simulation result
None
Total number of EVDO channel
elements of a site consumed by users
on uplink and downlink
(Terminal, site equipment) parameter
None
Number of channel elements used for
TCH on uplink
N max
N
Downlink 1xEV-DO Rev. A Radio Bearer Table
N
TCH – C E – UL
MacIndexes
 txi ic 
Simulation constraint
None
Maximum number of MAC indexes
available per cell (59)
MacIndexes
 txi ic 
Simulation result
None
Number of MAC indexes used by the
cell
Simulation constraint (cell parameter)
None
Maximum number of EVDO users that
can be connected to the cell
Simulation result
None
Number of EVDO users connected to
the cell
NF term
Terminal parameter
None
Terminal Noise Figure
NF Tx
Transmitter parameter (user-defined or calculated from transmitter
equipment characteristics)
None
Transmitter Noise Figure
K
1.38 10-23
J/K
Boltzman constant
T
293
K
Ambient temperature
W
1.23 MHz
Hz
Spreading Bandwidth
Tx DL
Cell parameter
None
Inter-technology downlink noise rise
NR inter – techno log y
Tx UL
Cell parameter
None
Inter-technology uplink noise rise
RF  ic ic adj 
Network parameter
If not defined, it is assumed that there is no inter-carrier interference
None
Interference reduction factor between
two adjacent carriers ic and ic adj
N max
N
EVDO
n max  txi ic 
n
EVDO
 txi ic 
NR inter – techno log y
Tx m
ICP ic  ic
i
Network parameter
If not defined, it is assumed that there is no inter-technology downlink
interferences due to external transmitters
None
Inter-technology Channel Protection
between the signal transmitted by Tx
and received by m assuming the
frequency gap between ic i (external
network) and ic
UL
X max
Simulation constraint (global parameter or cell parameter)
Tx UL
%
Maximum uplink load factor
W
Thermal noise at transmitter
Tx
NF Tx  K  T  W  NR inter – techno log y
Term
NF Term  K  T  W  NR inter – techno log y
W
Thermal noise at terminal
Rc
W
bps
Chip rate
f rake efficiency
Equipment parameter
None
Uplink rake receiver efficiency factor
Simulation result
bps
Uplink data rate
R TCP – ACK
Simulation result
bps
Uplink data rate due to TCP
aknowledgements
R BCMCS
Cell parameter
bps
Downlink data rate for Broadcast/
Multicast services
DL
Simulation result
bps
Downlink maximum data rate supplied
to the terminal
DL
Simulation result
bps
Downlink average cell data rate
N0
N0
UL
R
UL
UL
R max
R avg
DL
Tx DL
DL
R application
SF rate  R max – R
bps
Downlink user application throughput
SF Rate
Service parameter
%
Scaling factor
© Forsk 2009
AT281_TRG_E1
305
Technical Reference Guide
R
Service parameter
kbps
Offset
Gp
W
---------UL
R
None
Uplink service processing gain on
FCH
G idle – power
Cell parameter
None
Idle power gain
G MU
Cell parameter
None
Multi user gain
P max  txi ic 
Cell parameter
W
Max cell power
P tx  txi ic b pilot 
P max  txi ic 
W
Pilot burst transmitted by the
transmitter on carrier ic.
W
Traffic burst transmitted by the
transmitter on carrier ic.
UL
P max  txi ic  if users to support
P tx  txi ic b traffic 
ER DRC
Cell parameter
%
Error rate on the DRC channel
TS BCMCS
Cell parameter
%
Pourcentage of EVDO timeslots
dedicated to Broadcast/Multicast
services
TS EVDO – CCH
Cell parameter
%
Pourcentage of EVDO timeslots
dedicated to control channels
P term  ic 
Simulation result
W
Terminal power transmitted on carrier
ic
P term
min
Terminal parameter
W
Minimum terminal power allowed
P term
max
Terminal parameter
W
Maximum terminal power allowed
 BTS
BTS parameter
%
Percentage of BTS signal correctly
transmitted
 term
Terminal parameter
%
Percentage of terminal signal correctly
transmitted

Clutter parameter
%
Percentage of pilot finger - percentage
of signal received by the terminal pilot
finger
G Tx
Antenna parameter
None
Transmitter antenna gain
G Term
Terminal parameter
None
Terminal gain
L Tx
Transmitter parameter (user-defined or calculated from transmitter
equipment characteristics)
None
Transmitter lossa
L body
Service parameter
None
Body loss
L Term
Terminal parameter
None
Terminal loss
L indoor
Clutter and frequency band parameter
L path
Propagation model result
None
Path loss
G ACK
Terminal parameter
None
Acknowledgement Channel gain
G RRI
Terminal parameter (for 1xEV-DO Rev A terminals only)
None
Reverse Rate Indicator Channel gain
G DRC
Terminal parameter
None
Data Rate Control Channel gain
G Auxiliary – pilot
Terminal parameter (for 1xEV-DO Rev A terminals only)
None
Auxiliary Pilot Channel gain
G TCH
Terminal parameter
None
Traffic data Channel gain
M Shadowing – model
Result calculated from cell edge coverage probability and model
standard deviation
None
Model Shadowing margin
Only used in prediction studies
M Shadowing – Ec  Io
Result calculated from cell edge coverage probability and Ec/I0
standard deviation
None
Ec/I0 Shadowing margin
Only used in prediction studies
DL
G macro – diversity
306
P max  txi ic   G idle – power if no user to support
DL
Indoor loss
npaths
G macro – diversity = M Shadowing – Ec  Io – M Shadowing – Ec  Io
n=2 or 3
AT281_TRG_E1
None
DL gain due to availability of several
pilot signals at the mobile b.
© Forsk 2009
Chapter 7: CDMA2000 Networks
M Shadowing –  Eb  Nt 
Result calculated from cell edge coverage probability and UL Eb/Nt
standard deviation
UL
UL
npaths
G macro – diversity = M Shadowing –  Eb  Nt 
UL
G macro – diversity
UL
– M Shadowing – Eb  Nt 
n=2 or 3
Global parameter (default value)
UL
None
None
UL Eb/Nt Shadowing margin
Only used in prediction studies
UL quality gain due to signal diversity
in soft handoffc.
None
Random shadowing error drawn
during Monte-Carlo simulation
Only used in simulations
None
Transmitter-terminal total loss
P tx  txi ic b pilot 
-------------------------------------------LT
W
Pilot burst received at terminal from a
transmitter on carrier ic
P tx  txi ic b traffic 
----------------------------------------------LT
W
Traffic burst received at terminal from
a transmitter on carrier ic
P term
-------------LT
W
Bit received power at transmitter on
carrier ic
Cell parameter
dB
Cell uplink noise rise threshold
Cell parameter
dB
Cell uplink noise rise upgrading/
downgrading delta
E Shadowing
Simulation result
In prediction studiesd
For Ec/I0 and Ec/Nt calculations
L path  L Tx  L term  L body  L indoor  M Shadowing – Ec  Io
--------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
For UL Eb/Nt calculation
L path  L Tx  L term  L body  L indoor  M Shadowing –  Eb  Nt 
UL
-----------------------------------------------------------------------------------------------------------------------------------------------------------G Tx  G term
LT
In simulations
L path  L Tx  L term  L body  L indoor  E Shadowing
-------------------------------------------------------------------------------------------------------------------------------G Tx  G term
DL
P tot  txi ic b pilot 
DL
P tot  txi ic b traffic 
UL
P b  ic 
UL
NR threshold  txi ic 
UL
NR threshold  txi ic 
a.
L Tx = L total – UL on uplink and L Tx = L total – DL on downlink.
b.
M Shadowing –Ec  Io corresponds to the shadowing margin evaluated from the shadowing error probability
npaths
density function (n paths) in case of downlink Ec/I0 modelling.
c.
npaths
M Shadowing –  Eb  Nt 
UL
corresponds to the shadowing margin evaluated from the shadowing error probability
density function (n paths) in case of uplink soft handoff modelling.
d.
In uplink prediction studies, only carrier power level is downgraded by the shadowing margin
( M Shadowing –  Eb  Nt  ). In downlink prediction studies, carrier power level and intra-cell interference are downgraded by
UL
the shadowing model ( M Shadowing – Ec  Io ) while extra-cell interference level is not. Therefore, M Shadowing – Ec  Io is set to
1 in downlink extra-cell interference calculation.
7.2.2.2
Ec/I0 and Ec/Nt Calculations
Ec
Ec
Ec
This table details ------  txi ic b pilot  , ------  txi ic b pilot  and ------  txi ic b traffic  calculations.
I0
Nt
Nt
Name
Value
Unit
Description

txi ic
DL 
I intra 

 b pilot or b traffic 
0
W
Downlink intra-cell interference at
terminal on carrier ic (only one mobile
is served at a time)
W
Downlink extra-cell interference based
on pilot at terminal on carrier ic
DL
I extra  ic b pilot 
DL
I extra  ic b traffic 

P tot  txj ic b pilot 

P tot  txj ic b traffic 
W
Downlink extra-cell interference based
on traffic at terminal on carrier ic
 Ptot  txj icadj bpilot 
W
Downlink inter-carrier interference
based on pilot at terminal on carrier ic
DL
txj j  i
DL
txj j  i
DL
DL
I inter – carrier  ic
b pilot 
txj
 j
-----------------------------------------------------------------
RF  ic ic adj 
© Forsk 2009
AT281_TRG_E1
307
Technical Reference Guide
 Ptot  txj icadj btraffic 
DL
DL
I inter – carrier  ic b traffic 
W
txj
 j
--------------------------------------------------------------------
RF  ic ic adj 
Tx
P Transmitted  ic i 
 -----------------------------------------Tx
Tx m
L
 ICP
DL
I inter – techno log y  ic 
DL
ic i ic
total
ni
W
DL
DL
P tot  txi ic b pilot  + I extra  ic b pilot  + I inter – carrier  ic b pilot 
DL
I 0  ic b pilot 
+
DL
W
Total noise based on traffic received
at terminal on carrier ic
I extra  ic b pilot  + N 0
W
Total noise based on pilot received at
terminal on carrier ic
DL
W
Total noise based on traffic received
at terminal on carrier ic
None
Pilot quality level at terminal on carrier
ic
None
Pilot quality level at terminal on carrier
ic
None
Traffic quality level at terminal on
carrier ic
+
DL
term
N0
DL
DL
I inter – techno log y  ic 
DL
N tot  ic b pilot 
DL
N tot  ic b traffic 
+
term
N0
term
term
I extra  ic b traffic  + N 0
Q pilot  txi ic 
DL
 BTS    P tot  txi ic b pilot 
--------------------------------------------------------------------------DL
I 0  ic b pilot 
Ec
 ------  txi ic b pilot 
I0
at terminal on carrier ic a
Total noise based on pilot received at
terminal on carrier ic
DL
+
Downlink inter-technology interference
W
DL
I inter – techno log y  ic 
P tot  txi ic b traffic  + I extra  ic b traffic  + I inter – carrier  ic b traffic 
DL
I 0  ic b traffic 
Downlink inter-carrier interference
based on traffic at terminal on carrier
ic
DL
Ec
------  txi ic b pilot 
Nt
 BTS    P tot  txi ic b pilot 
-----------------------------------------------------------------------------------------------------------------------DL
DL
N tot  ic b pilot  +  1 –  BTS   P tot  txi ic b pilot 
Ec
------  txi ic b traffic 
Nt
 BTS    P tot  txi ic b traffic 
------------------------------------------------------------------------------------------------------------------------------DL
DL
N tot  ic b traffic  +  1 –  BTS   P tot  txi ic b traffic 
DL
a. In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the
fractional load.
7.2.2.3
UL Eb/Nt Calculation
This table details calculations of uplink quality ( Q
Name
UL intra
I tot
 txi
UL extra
I tot
UL
Eb
or  ------- ).
 Nt  UL
Value
 Pb
UL
ic 

 txi ic 
term
txj j  i
 Pb
ic 
Description
W
Total power received at transmitter
from intra-cell terminals using carrier
ic
W
Total power received at transmitter
from extra-cell terminals using carrier
ic
W
Uplink inter-carrier interference at
terminal on carrier ic
W
Total received interference at
transmitter on carrier ic
W
Total noise at transmitter on carrier ic
(Uplink interference)
UL
P b  ic 
UL
UL
I inter – carrier  txi
 ic 
term
txi
Unit
 ic adj 
term
txj j
--------------------------------------
RF  ic ic adj 
UL
I tot  txi ic 
UL
N tot  txi ic 
308
UL extra
I tot
UL intra
Tx
 txi ic  +  1 – F MUD   term I tot
UL
UL
 txi ic  +I inter – carrier  txi ic 
tx
I tot  ic  + N 0
AT281_TRG_E1
© Forsk 2009
Chapter 7: CDMA2000 Networks
Without useful signal:
UL
Q
UL
 term  P b  ic 
----------------------------------------------------------------------------------------------------------------  G UL
p
UL
Tx
UL
N tot  txi ic  –  1 – F MUD    term  P b  ic 
Eb
 txi ic    ------
 N t  UL
None
UL
 term  P b  ic 
-  G UL
Total noise: --------------------------------------p
UL
N tot  txi ic 
No HO: Q
Softer HO:
UL
f rake efficiency
UL


UL
Q tch  tx k ic 
Soft, Softer/Soft HO (No MRC):
UL
UL
Max  Q tch  tx k ic    G macro – diversity
tx  ActiveSet
k
UL
ica
 txi ic 
tx k  ActiveSet
 samesite 
Q total  ic 
Quality level at transmitter on carrier
Softer/Soft HO (MRC):
Quality level at site using carrier ic due
to combination of all transmitters of
the active set located at the same site
and taking into account increase of the
None quality due to macro-diversity (macrodiversity gain).



Max  UL
UL
UL
f

Q

tx

ic


Q

tx

ic

 rake efficiency

tch
k
tch
l
tx ,tx  ActiveSet
k l


txk  samesite 

tx k

UL
In simulations, G macro – diversity = 1 .
tx  othersite
l
UL
 G macro – diversity
UL
Q total  ic 
--------------------------------------------------------UL
Q  BestServer ic 
UL
G SHO
None
Uplink soft handover gain on carrier ic
None
Eb/Nt target on uplink
W
Required terminal power to achieve
Eb/Nt target at transmitter on carrier ic
For 1xEV-DO Rev 0 terminal
UL
E
-----c-
 G p   1 + G ACK + G DRC + G TCH 
 N t  min
UL
UL
Q req
For 1xEV-DO Rev A terminalb
When the acknoledgement signal is considered
UL
E
-----c-
 G p   1 + G ACK + G RRI + G DRC + G TCH + G Auxiliary – Pilot 
 N t  min
UL
When the acknoledgement signal is not considered
UL
E
UL
c
 ------
 G p   1 + G RRI + G DRC + G TCH + G Auxiliary – Pilot 
 N t  min
UL
req
P term  ic 
Q req
----------------------- P term
UL
Q total  ic 
a.
Calculation option may be selected in the Global parameters tab. The chosen option will be taken into account
only in simulations. In point analysis and coverage studies, Atoll uses the option “Total noise” to evaluate DL and UL Eb/Nt.
b.
In simulations, the uplink Eb/Nt target is calculated whithout considering the aknoledgement signal.
7.2.2.4
Simulation Results
This table contains some simulation results provided in the Cells and Mobiles tabs of the simulation property dialogue.
Name
Value
I intra  txi ic b traffic 
 1 – F ortho   BTS   P tot  txi ic b traffic  = 0
DL
DL
I extra  ic b traffic 
DL

DL
P tot  txj ic b traffic 
Unit
Description
W
Downlink intra-cell interference at
terminal on carrier ic (only one mobile
is served at a time)
W
Downlink extra-cell interference based
on traffic at terminal on carrier ic
W
Downlink inter-carrier interference
based on traffic at terminal on carrier
ic
txj j  i
 Ptot  txj icadj btraffic 
DL
DL
I inter – carrier  ic b traffic 
txj
 j
--------------------------------------------------------------------
RF  ic ic adj 
DL
I inter – techno log y  ic 

ni
© Forsk 2009
Tx
P Transmitted  ic i 
-----------------------------------------Tx
Tx m
L total  ICP n  ic
i
AT281_TRG_E1
W
Downlink inter-technology interference
at terminal on carrier ic a
309
Technical Reference Guide
DL
DL
N tot  ic b traffic 
UL intra
I tot
+
DL
term
I tot  ic b traffic  + N 0
 Pb
UL
 ic 
term
txi

 txi ic 
 Pb
UL
UL
Total effective interference based on
traffic at terminal on carrier ic (after
unscrambling)
W
Total noise based on traffic received
at terminal on carrier ic
W
Total power received at transmitter
from intra-cell terminals using carrier
ic
W
Total power received at transmitter
from extra-cell terminals using carrier
ic
W
Uplink inter-carrier interference at
terminal on carrier ic
W
Total received interference at
transmitter on carrier ic
UL
P b  ic 
term
txj j  i
I inter – carrier  txi ic 
W
DL
DL
I inter – techno log y  ic 
 txi ic 
UL extra
I tot
DL
I intra  ic b traffic  + I extra  ic b traffic  + I inter – carrier  ic b traffic 
DL
I tot  ic b traffic 
 ic adj 
term
txj j
--------------------------------------
RF  ic ic adj 
UL
UL extra
I tot  txi ic 
I tot
UL intra
Tx
 txi ic  +  1 – F MUD   term I tot
UL
 txi ic  +I inter – carrier  txi ic 
N tot  txi ic 
I tot  txi ic  + N 0
W
Total noise at transmitter on carrier ic
(Uplink interference)
N mobiles  txi ic 
Simulation result
None
Number of mobiles connected to
transmitter txi on carrier ic
None
Cell downlink load factor on carrier ic
None
Cell uplink load factor on carrier ic
UL
UL
tx
DL
X
DL
 txi ic 
I tot  ic b traffic 
--------------------------------------DL
N tot  ic b traffic 
X
UL
 txi ic 
I tot  txi ic 
----------------------------UL
N tot  txi ic 
F
UL
 txi ic 
I tot  txi ic 
------------------------------------------------------------------------------------------UL intra
Tx
I tot
 txi ic    1 – F MUD   term 
None
Cell uplink reuse factor on carrier ic
E
UL
 txi ic 
1
-----------------------------UL
F  txi ic 
None
Cell uplink reuse efficiency factor on
carrier ic
UL
UL
NR
DL
 txi ic 
– 10 log  1 – X
DL
 txi ic  
dB
Noise rise on downlink
NR
UL
 txi ic 
– 10 log  1 – X
UL
 txi ic  
dB
Noise rise on uplink
a. In the case of an interfering GSM external network in frequency hopping, the ICP value is weighted according to the
fractional load.
7.3
Active Set Management
The mobile active set is the list of the transmitters to which the mobile is connected. The active set may consist of one or
more transmitters; depending on whether the service supports soft handoff and on the terminal active set size. The terminal frequency bands are taken into account and transmitters in the mobile active set must use a frequency band with which
the terminal is compatible.
It is, however, the quality of the pilot (Ec⁄I0) that finally determines whether or not a transmitter can belong to the active set.
Cells entering the mobile’s active set must fulfill the following conditions:
1.
The best server (first cell entering active set)
In order for a given transmitter to enter the mobile active set as best server, the quality of this transmitter’s pilot
must be the highest one and it must exceed an upper threshold equal to the sum of the minimum Ec/I0 defined in
the properties of the best serving cell and the Delta minimum Ec/I0 defined in the properties of the mobility type.
The upper threshold is set for the carrier as defined in the cell properties and can also take into account the user
mobility type if the Delta minimum Ec/I0 defined in the mobility type is different from 0.
2.
310
In order for a transmitter to enter the active set (other cells of active set):
- They must use the same carrier as the best server cell,
- The pilot quality from other candidate cells must exceed a lower threshold. The lower threshold depends both
on the type of carrier and the mobility type. It is equal to the sum of T_Drop defined in the properties of the
best server and the Delta T_Drop defined in the properties of the mobility type.
AT281_TRG_E1
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Chapter 7: CDMA2000 Networks
-
7.4
If you have selected to restrict the active set to neighbours, the cell must be a neighbour of the best server
(the restricted to neighbours” option is selected in the equipment properties).
Simulations
The simulation process is divided into two steps:
1. Obtaining a realistic user distribution
Atoll generates a user distribution using a Monte-Carlo algorithm, which requires traffic maps and data as input.
The resulting user distribution complies with the traffic database and maps provided to the algorithm.
Each user is assigned a service, a mobility type, and an activity status by random trial, according to a probability
law that uses the traffic database.
The user activity status is an important output of the random trial and has direct consequences on the next step
of the simulation and on the network interferences. A user may be either active or inactive. Both active and inactive
users consume radio resources and create interference.
Additionally, each 1xEV-DO Rev. 0 user is assigned a transition flag ("True" or "False") for each possible data rate
transition (from 9.6 to 19.2 kbps, 19.2 to 38.4 kbps, 38.4 to 76.8 kbps, and 76.8 to 153.6 kbps for data rate upgrading and from 153.6 to 76.8 kbps, 76.8 to 38.4 kbps, 38.4 to 19.2 kbps, and 19.2 to 9.6 kbps for data rate downgrading). These transition flags are based on the data rate downgrading and upgrading probabilities. If a transition
flag is "True," the user data rate can be downgraded or upgraded if necessary.
Then, Atoll randomly assigns a shadowing error to each user using the probability distribution that describes the
shadowing effect.
Finally, another random trial determines user positions in their respective traffic zone and whether they are indoors
or outdoors (according to the clutter weighting and the indoor ratio per clutter class defined for the traffic maps).
2. Modelling the network regulation mechanism
This algorithm depends on the network. Atoll uses a power control algorithm in case of CDMA2000 1xRTT
networks and a different algorithm, which mixes data rate control on downlink and power control on uplink, for
CDMA2000 1xEV-DO networks.
7.4.1
Generating a Realistic User Distribution
7.4.1.1
Number of Users, User Activity Status and User Data Rate
During the simulation, a first random trial is performed to determine the number of users and their activity status. The determination of the number of users and the activity status allocation depend on the type of traffic cartography used.
Note:
•
Atoll follows a Poisson distribution to determine the number of total connected users before
each simulation. In order to make Atoll use a constant number of total connected users, the
following lines must be added to the Atoll.ini file:
[CDMA]
RandomTotalUsers=0
7.4.1.1.1
Simulations Based on User Profile Traffic Maps
User profile environment based traffic maps: Each pixel of the map is assigned an environment class which contains a list
of user profiles with an associated mobility type and a given density (number of subscribers with the same profile per km²).
User profile traffic maps: Each polygon and line of the map is assigned a density of subscribers with given user profile and
mobility type. If the map is composed of points, each point is assigned a number of subscribers with given user profile and
mobility type.
The user profile models the behaviour of the different subscriber categories. Each user profile contains a list of services
and their associated parameters describing how these services are accessed by the subscriber.
From environment (or polygon) surface (S) and user profile density (D), a number of subscribers (X) per user profile is
inferred.
X = SD
Notes:
•
•
© Forsk 2009
In case of user profile traffic maps composed of lines, the number of subscribers (X) per
user profile is calculated from the line length (L) and the user profile density (D) (nb of
subscribers per km) as follows: X = L  D
The number of subscribers (X) is an input when a user profile traffic map is composed of
points.
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For each behaviour described in a user profile, according to the service, frequency use and exchange volume, Atoll calculates the probability for the user being connected in uplink and in downlink at an instant t.
1.
Calculation of the service usage duration per hour ( p 0 : probability of a connection):
N call  d
p 0 = --------------------3600
where N call is the number of calls per hour and d is the average call duration (in second).
Then, Atoll calculates the total number of users trying to access a certain service.
Calculation of the number of users trying to access the service j ( n j ):
2.
nj = X  p0
The next step determines the activity status of each user.
3.
Calculation of number of users per activity status:
This steps depends on the type of service (Voice, 1xRTT data, 1xEV-DO data…).
•
CDMA2000 1xRTT Services
Activity status of voice and data service users is determined as follows.
Users are always active on FCH in both directions, uplink and downlink. Therefore, we have:
Probability of being active on UL: p UL = 0
Probability of being active on DL: p DL = 0
Probability of being active both on UL and DL: p UL + DL = 1
Probability of being inactive: p inactive = 0
Thus, for voice and data services, we have:
Number of inactive users: n j  inactive  = n j  p inactive = 0
Number of users active on UL: n j  UL  = n j  p UL = 0
Number of users active on DL: n j  DL  = n j  p DL = 0
Number of users active on UL and DL both: n j  UL + DL  = n j  p UL + DL = n j
n j = n j  UL  + n j  DL  + n j  UL + DL  + n j  inactive  = n j  UL + DL 
-
Voice Users
Voice users are active on uplink and downlink. However, the FCH can have inactivity periods on both links. This is
UL
DL
modelled by the FCH activity factor, AF FCH and AF FCH . Therefore, all voice service users try to access the service with
UL
UL
DL
DL
the following FCH rates, R FCH  AF FCH on uplink and R FCH  AF FCH on downlink.
UL
DL
R FCH and R FCH are respectively the uplink and downlink FCH nominal rates.
-
Data Users
Data service users are active on uplink and downlink. FCH is always allocated but can have inactivity periods on both links;
UL
DL
this is modelled by the FCH activity factor, AF FCH and AFFCH . SCH may be allocated with four possible rates (2x, 4x,
8x and 16xFCH nominal rate).
Therefore, data service users can access the service with different rates. Possible rates are detailed in the table below:
Allocated rates
SCH rate factor r k
Only FCH is used
-

UL
AF FCH
On DL
DL
R FCH
DL
 AF FCH
UL
UL
R FCH   AF FCH + 2 
UL
UL
R FCH   AF FCH + 4 
UL
UL
R FCH   AF FCH + 8 
2x
R FCH   AF FCH + 2 
4x
R FCH   AF FCH + 4 
8x
R FCH   AF FCH + 8 
16x
R FCH   AF FCH + 16 
Both FCH and SCH are used
UL
On UL
UL
R FCH
UL
UL
DL
DL
DL
DL
DL
DL
DL
DL
R FCH   AF FCH + 16 
DL
R FCH and R FCH are respectively the uplink and downlink FCH nominal rates.
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Chapter 7: CDMA2000 Networks
Then, Atoll determines the distribution of users between the different possible rates.
UL
In case of a data service, j, several data rate probabilities, P k
DL
and P k , can be assigned to different rate factors, r k , for
SCH channel.
Note:
•
For non-data services, these probabilities are 0.
For data service users, a random trial compliant with data rate probabilities is performed for each link in order to determine
the rate for each user.
On uplink, we have:
rk
UL
UL
For each SCH rate factor, r k , the number of users n j with the data rate R FCH   AF FCH + r k  is calculated as follows,
rk
UL
nj = Pr
k
 nj
FCH
Therefore, the number of users n j
FCH
nj
= nj –
UL
UL
with the data rate, R FCH  AF FCH , is:
rk
 nj
rk
On downlink, we have:
rk
DL
DL
For each SCH rate factor, r k , the number of users, n j with the data rate, R FCH   AF FCH + r k  , is calculated as follows,
rk
DL
nj = Pr
k
 nj
FCH
Therefore, the number of users n j
FCH
nj
= nj –
DL
DL
with the data rate, R FCH  AF FCH , is:
rk
 nj
rk
•
CDMA2000 1xEV-DO Services
As power control is performed on uplink only, 1xEV-DO data service users will be considered either active on uplink or
inactive. 1xEV-DO data Rev. 0 service users can access the service with uplink rates of 9.6, 19.2, 38.4, 76.8 and 153.6
kbps. 1xEV-DO data Rev. A service users can access the service with uplink rates of 4.8, 9.6, 19.2, 38.4, 76.8, 115.2,
153.6, 230.4, 307.2, 460.8, 614.4, 921.6, 1,228.8 and 1,848.2 kbps.
UL
UL
For each service, j, several data rate probabilities, P k , can be assigned to different rates R k . The number of users
active on uplink ( n j  UL  ) and the number of inactive users ( n j  inactive  ) are calculated as follows:
Probability of being active on UL: p UL =
 Pk
UL
UL
 Rk 
UL
Rk
Probability of being inactive: p inactive = 1 –
 Pk
UL
UL
 Rk 
UL
Rk
Probability of being active on DL: p DL = 0
Probability of being active on UL and DL both: p UL + DL = 0
Therefore, we have:
Number of users active on UL: n j  UL  = n j  p UL
Number of inactive users: n j  inactive  = n j  p inactive
Number of users active on DL: n j  DL  = n j  p DL = 0
Number of users active on UL and DL both: n j  UL + DL  = n j  p UL + DL = 0
n j = n j  UL  + n j  DL  + n j  UL + DL  + n j  inactive  = n j  UL  + n j  inactive 
UL
Then, Atoll determines the distribution of users between the different possible rates, R k . The number of users with the
UL
UL
data rate R k , n j  R k  , is calculated as follows:
UL
UL
nj  Rk  = Pk  nj
Inactive users have a requested data rate equal to 0.
© Forsk 2009
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Technical Reference Guide
Notes:
•
The user distribution per service is an average distribution and the service of each user is
randomly drawn in each simulation. Therefore, if you compute several simulations at once,
the average number of users per service will correspond to the calculated distribution. But if
you check each simulation, the user distribution between services is different in each of
them.
It is the same for the SCH rate distribution between 1xRTT data service users and the
traffic data rate distribution between 1xEV-DO data service users.
•
In calculations detailed above, we assume that the sum of data rate probabilities is less
than or equal to 1. If the sum of data rate probabilities exceeds 1, Atoll considers

normalised data rate probabilities values, P r  
k


 Pr  , instead of specified data rate
k
rk
probabilities P r .
k
7.4.1.1.2
Simulations Based on Sector Traffic Maps
Sector traffic maps can be based on live traffic data from OMC (Operation and Maintenance Centre). Traffic is spread over
the best server coverage area of each transmitter and each coverage area is assigned either the throughputs in the uplink
and in the downlink, or the number of users per activity status or the total number of users (including all activity statuses).
CDMA2000 1xRTT Services
•
Voice Service (j)
For each transmitter, Txi, Atoll proceeds as follows:
-
UL
When selecting Throughputs in Uplink and Downlink, you can input the throughput demands in UL ( R t
and DL
DL
( Rt
)
) for each sector.
Atoll calculates the number of users active in UL and DL using the voice service in the Txi cell as follows:
UL
DL
Rt
Rt
- and N DL = --------N UL = --------UL
DL
Rj
Rj
Where,
UL
Rt
is the number of kbits per second transmitted in UL in the Txi cell to provide the service j to the users
(user-defined value in the traffic map properties)
DL
Rt
is the number of kbits per second transmitted in DL in the Txi cell to provide the service j to the users
(user-defined value in the traffic map properties).
UL
Rj
DL
and R j
correspond to the UL and DL rates of a user. FCH is always allocated to active users but can
UL
have inactivity periods on both links. Therefore, we have R j
UL
UL
UL
UL
= R FCH  AF FCH (where R FCH is the service
FCH nominal rate on UL and
AF FCH
DL
Rj
is the service FCH nominal rate on DL and AFFCH corresponds to the
=
DL
R FCH

DL
AF FCH
(where
DL
R FCH
corresponds to the FCH activity factor on UL) and
DL
FCH activity factor on DL).
Users are always active on FCH for both links. Therefore, we have following activity probabilities.
Probability of being active in UL: p UL = 0
Probability of being active in DL: p DL = 0
Probability of being active in UL and DL both: p UL + DL = 1
Probability of being inactive: p inactive = 0
Then, Atoll calculates the number of users per activity status:
Number of users active in UL and DL both: n j  UL + DL  = max (N UL,N DL)
Number of users active in UL and inactive in DL: n j  UL  = 0
Number of users active in DL and inactive in UL: n j  DL  = 0
inactive
Number of inactive users in UL and DL: n j
314
AT281_TRG_E1
= 0
© Forsk 2009
Chapter 7: CDMA2000 Networks
Therefore, all connected voice users ( n j ) are active in both links.
-
When selecting Total Number of Users (All Activity Statuses), you can input the number of connected users
for each sector ( n j ).
Users are always active on FCH for both links. Therefore, we have following activity probabilities.
Probability of being active in UL: p UL = 0
Probability of being active in DL: p DL = 0
Probability of being active in UL and DL both: p UL + DL = 1
Probability of being inactive: p inactive = 0
Then, Atoll calculates the number of users per activity status:
inactive
Number of inactive users in UL and DL: n j
= n j  p inactive = 0
Number of users active in UL and inactive in DL: n j  UL  = n j  p UL = 0
Number of users active in DL and inactive in UL: n j  DL  = n j  p DL = 0
Number of users active in UL and DL both: n j  UL + DL  = n j  p UL + DL = n j
Therefore, all connected users ( n j ) are active in both links.
-
When selecting Number of Users per Activity Status, you can directly input the number of users active in
the uplink and downlink ( n j  UL + DL  ), for each sector.
UL
UL
DL
DL
Voice service users try to access the service with the FCH rates, R FCH  AF FCH on uplink and R FCH  AF FCH on downlink.
All user characteristics determined, a second random trial is performed to obtain their geographical positions.
•
Data Service Users (j)
FCH is always allocated to active users but can have inactivity periods on both links. This is modelled by the FCH activity
UL
DL
factors, AF FCH and AF FCH . SCH may be allocated with four possible rates (2x, 4x, 8x, 16xFCH nominal rate). Several
UL
data rate probabilities, P k
DL
and P k , can be assigned to different rates factor, r k , for SCH channel.
Note:
•
For non-data services, these probabilities are 0.
For each transmitter, Txi, Atoll proceeds as follows:
-
UL
When selecting Throughputs in Uplink and Downlink, you can input the throughput demands in UL ( R t
and DL
DL
( Rt
)
) for each sector.
Atoll calculates the number of users active in UL and DL using the service in the Txi cell as follows:
UL
DL
Rt
Rt
- and N DL = --------N UL = --------UL
DL
Rj
Rj
Where,
UL
Rt
is the number of kbits per second transmitted in UL in the Txi cell to provide the service j to the users
(user-defined value in the traffic map properties)
DL
Rt
is the number of kbits per second transmitted in DL in the Txi cell to provide the service j to the users
(user-defined value in the traffic map properties).
UL
and R j
UL
=
Rj
Rj
DL
correspond to uplink and downlink rates of a user.
  rk + AFFCH   RFCH  Pr
k
  rk + AFFCH   RFCH  Pr
k
UL
UL
UL
rk
DL
Rj
=
DL
rk
© Forsk 2009
DL
DL

+ 1 –

 Pr

+ 1 –

 Pr
AT281_TRG_E1
UL
k
rk
DL
rk
k
UL
UL
DL
DL
  R FCH  AF FCH

  R FCH  AF FCH

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Technical Reference Guide
UL
DL
R FCH and R FCH are the uplink and downlink FCH nominal rates respectively.
Note:
•
In calculations detailed above, we assume that the sum of data rate probabilities is less
than or equal to 1. If the sum of data rate probabilities exceeds 1, Atoll considers

normalised data rate probabilities values, P r  
k


 Pr  ,
k
instead of specified data rate
rk
probabilities P r .
k
Users are always active on FCH for both links. Therefore, we have following activity probabilities.
Probability of being active in UL: p UL = 0
Probability of being active in DL: p DL = 0
Probability of being active in UL and DL both: p UL + DL = 1
Probability of being inactive: p inactive = 0
Then, Atoll calculates the number of users per activity status and the total number of users:
Number of users active in UL and DL both: n j  UL + DL  = max (N UL,N DL)
Number of users active in UL and inactive in DL: n j  UL  = 0
Number of users active in DL and inactive in UL: n j  DL  = 0
inactive
Number of inactive users in UL and DL: n j
= 0
Therefore, all connected users ( n j ) are active in both links.
-
When selecting Total Number of Users (All Activity Statuses), you can input the number of connected users
for each sector ( n j ).
Users are always active on FCH for both links. Therefore, we have following activity probabilities.
Probability of being active in UL: p UL = 0
Probability of being active in DL: p DL = 0
Probability of being active in UL and DL both: p UL + DL = 1
Probability of being inactive: p inactive = 0
Then, Atoll calculates the number of users per activity status:
inactive
Number of inactive users in UL and DL: n j
= n j  p inactive = 0
Number of users active in UL and inactive in DL: n j  UL  = n j  p UL = 0
Number of users active in DL and inactive in UL: n j  DL  = n j  p DL = 0
Number of users active in UL and DL both: n j  UL + DL  = n j  p UL + DL = n j
Therefore, all connected users ( n j ) are active in both links.
-
When selecting Number of Users per Activity Status, you can directly input the number of users active in
the uplink and downlink ( n i  UL + DL  ), for each sector.
As explained above, data service users can access the service with different rates. Possible rates are detailed in the table
below:
SCH rate factor r k
Only FCH is used
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Allocated rates
On UL
UL
R FCH

UL
AF FCH
On DL
DL
R FCH
DL
 AF FCH
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Chapter 7: CDMA2000 Networks
UL
UL
R FCH   AF FCH + 2 
UL
UL
R FCH   AF FCH + 4 
UL
UL
R FCH   AF FCH + 8 
2x
R FCH   AF FCH + 2 
4x
R FCH   AF FCH + 4 
8x
R FCH   AF FCH + 8 
16x
R FCH   AF FCH + 16 
Both FCH and SCH are used
UL
UL
DL
DL
DL
DL
DL
DL
DL
DL
R FCH   AF FCH + 16 
Atoll determines the distribution of users with the different possible rates. A random trial compliant with data rate probabilities is performed for each link in order to determine the data rate of each user.
On uplink, we have,
rk
UL
UL
For each SCH rate factor, r k , the number of users n j with the data rate R FCH   AF FCH + r k  is calculated as follows,
rk
UL
nj = Pr
k
 nj
FCH
Therefore, the number of users n j
FCH
nj
= nj –
UL
UL
with the data rate, R FCH  AF FCH , is,
rk
 nj
rk
On downlink, we have,
rk
DL
DL
For each SCH rate factor, r k , the number of users, n j with the data rate, R FCH   AF FCH + r k  , is calculated as follows,
k
DL
nj = Pk  nj
FCH
Therefore, the number of users n j
FCH
nj
= nj –
DL
DL
with the data rate, R FCH  AF FCH , is,
rk
 nj
rk
CDMA2000 1xEV-DO Services
As power control is performed on uplink only, 1xEV-DO data service users will be considered either active on uplink or
inactive. 1xEV-DO data Rev. 0 service users can access the service with uplink rates of 9.6, 19.2, 38.4, 76.8 and 153.6
kbps. 1xEV-DO data Rev. A service users can access the service with uplink rates of 4.8, 9.6, 19.2, 38.4, 76.8, 115.2,
153.6, 230.4, 307.2, 460.8, 614.4, 921.6, 1,228.8 and 1,848.2 kbps.
UL
UL
For each service, j, several data rate probabilities, P k , can be assigned to different uplink rates R k . The number of
users active in uplink ( n j  UL  ) and the number of inactive users ( n j  inactive  ) are calculated into several steps. First of
all, Atoll determines the number of users active in UL using the service j in the Txi cell.
For each transmitter, Txi, and each service j:
-
UL
When selecting Throughputs in Uplink and Downlink, you can input the throughput demands in UL ( R t
)
for each sector.
Atoll calculates the number of users active in UL using the service j in the Txi cell as follows:
UL
Rt
N UL = --------UL
Rj
Where:
UL
Rt
is the number of kbits per second transmitted on UL in the Txi cell to provide the service j (user-defined
value in the traffic map properties).
UL
corresponds to the uplink data rate for a user.
UL
=
Rj
Rj
 Pk
UL
UL
 Rk
k
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Note:
•
In calculations detailed above, we assume that the sum of data rate probabilities is less
than or equal to 1. If the sum of data rate probabilities exceeds 1, Atoll considers

normalised data rate probabilities values, P r  
k


 Pr  , instead of specified data rate
k
rk
probabilities P r .
k
We have the following activity probabilities:
Probability of being active in UL: p UL =
 Pk
UL
UL
 Rk 
UL
Rk
Probability of being inactive: p inactive = 1 –
 Pk
UL
UL
 Rk 
UL
Rk
Probability of being active in DL: p DL = 0
Probability of being active in UL and DL both: p UL + DL = 0
Therefore, we have:
Number of users active in UL: n j  UL  = N UL  p UL
Number of inactive users: n j  inactive  = N UL  p inactive
Number of users active in DL: n j  DL  = 0
Number of users active in UL and DL both: n j  UL + DL  = 0
Total number of connected users: n j = n j  UL  + n j  inactive 
-
When selecting Total Number of Users (All Activity Statuses), you can input the number of connected users
for each sector ( n j ).
We have the following activity probabilities:
Probability of being active in UL: p UL =
 Pk
UL
UL
 Rk 
UL
Rk
Probability of being inactive: p inactive = 1 –
 Pk
UL
UL
 Rk 
UL
Rk
Probability of being active in DL: p DL = 0
Probability of being active in UL and DL both: p UL + DL = 0
Therefore, we have:
Number of users active in UL: n j  UL  = n j  p UL
Number of inactive users: n j  inactive  = n j  p inactive
Number of users active in DL: n j  DL  = 0
Number of users active in UL and DL both: n j  UL + DL  = 0
-
When selecting Number of Users per Activity Status, you can directly input the number of inactive users
( n j  inactive  ) and the number of users active in the uplink ( n j  UL  ), for each sector.
The total number of connected users ( n j ) is calculated as follows
n j = n j  UL  + n j  inactive 
Then, Atoll determines the distribution of users with the different possible rates. The number of users with the data rate
UL
UL
R k , n j  R k  , is calculated as follows:
UL
UL
nj  Rk  = Pk  nj
Inactive users have a requested data rate equal to 0.
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Chapter 7: CDMA2000 Networks
Note:
•
7.4.1.2
The user distribution per service is an average distribution and the service of each user is
randomly drawn In each simulation. Therefore, if you compute several simulations at once,
the average number of users per service will correspond to the calculated distribution. But if
you check each simulation, the user distribution between services is different in each of
them.
It is the same for the SCH rate distribution between 1xRTT data service users and the
traffic data rate distribution between 1xEV-DO data service users.
Transition Flags for 1xEV-DO Rev.0 User Data Rates
For 1xEV-DO Rev. 0 services supporting data rate downgrading, you can define the probability of the service being
UL
UL
UL
UL
UL
upgraded ( P Upg – k  R k  ) or downgraded ( P Downg – k  R k  ) on the uplink (reverse link) for each data rate ( R k ). The
probabilities are taken into account in order to determine if a user with a certain data rate can be upgraded or downgraded.
User data rate downgrading and upgrading occur during congestion control when the cell is over- or underloaded.
The following table shows the data rate changes that are possible when a data rate is upgraded or downgraded. The probabilities are defined with a number from 1 to 255 for each data rate.
Possible Data Rate Changes
During Upgrading
From
To
Possible Data Rate Changes
During Downgrading
From
To
9.6 kbps
19.2 kbps
153.6 kbps
76.8 kbps
19.2 kbps
38.4 kbps
76.8 kbps
38.4 kbps
38.4 kbps
76.8 kbps
38.4 kbps
19.2 kbps
76.8 kbps
153.6 kbps
19.2 kbps
9.6 kbps
During the generation of the user distribution, each 1xEV-DO Rev. 0 user is assigned a random number between 1 and
255 for each possible data rate transition. When this number is lower or equal to the value of the probability, the transition
flag for this data rate transition is set to "True" meaning that this data rate transition can be performed if necessary.
UL
The number of 1xEV-DO Rev. 0 users with a certain data rate that can be downgraded ( n j  R k  Downg ) and upgraded
UL
( n j  R k  Upg ) are calculated as follows:
UL
UL
UL
P Upg – k  R k   n j  R k 
UL
n j  R k  Upg = -------------------------------------------------------------255
And
UL
UL
UL
P Downg – k  R k   n j  R k 
UL
n j  R k  Downg = -------------------------------------------------------------------255
Note:
•
7.4.1.3
The number of users with a certain data rate that can be downgraded or upgraded is an
average. Therefore, if you compute several simulations at once, the average number of
users with a certain data rate that can be downgraded or upgraded will correspond to the
calculated value. But if you check each simulation, this number is different in each of them.
User Geographical Position
Once all the user characteristics determined, another random trial is performed to obtain their geographical positions and
whether they are indoors or outdoors according to the percentage of indoor users per clutter class defined for the traffic
maps.
7.4.2
Network Regulation Mechanism
7.4.2.1
CDMA2000 1xRTT Power Control Simulation Algorithm
CDMA2000 1xRTT network automatically regulates itself using traffic driven uplink and downlink power control on the
fundamental and supplemental channels (FCH and SCH respectively) in order to minimize interference and maximize
capacity. Atoll simulates this network regulation mechanism with an iterative algorithm and calculates, for each user distribution, network parameters such as base station power, mobile terminal power, active set and handoff status for each
terminal.
The power control simulation is based on an iterative algorithm, where in each iteration, all the mobiles selected during
the user distribution generation (1st step) try to connect to network active transmitters with a calculation area. The process
is repeated from iteration to iteration until convergence is achieved. The algorithm steps are detailed below.
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Technical Reference Guide
Figure 7.1: CDMA2000 1xRTT Power Control Algorithm
7.4.2.1.1
Algorithm Initialization
Total power on carrier ic, P Tx  ic  , of base station Sj is initialised to P pilot  ic  + P sync  ic  + P paging  ic  .
UL intra
Uplink received powers on carrier ic, I tot
UL extra
 ic  , I tot
UL
 ic  and I inter – carrier  ic  , at base station Sj are initialised to 0 W
(no connected mobile).
UL
I tot  S j ic 
UL
- = 0
 X k  S j ic  = ---------------------------UL
N tot  S j ic 
7.4.2.1.2
Presentation of the Algorithm
UL
The algorithm is detailed for any iteration k. Xk is the value of the variable X at the iteration k. In the algorithm, all Q req
DL
and Q req thresholds depend on user mobility type and are defined in Service and Mobility parameters tables. All variables
are described in Definitions and formulas part.
The algorithm applies to single frequency band networks and to dual-band networks. Dual-band terminals can have the
following configurations:
-
Configuration 1: The terminal can work on f1 and f2 without any priority (select "All" as main frequency band
in the terminal property dialogue).
Configuration 2: The terminal can work on f1 and f2 but f1 has a higher priority (select "f1" as main frequency
band and "f2" as secondary frequency band in the terminal property dialogue).
For each mobile Mi
Determination of Mi’s Best Server (SBS(Mi))
For each transmitter Sj containing Mi in its calculation area and working on the main frequency band supported by the Mi’s
terminal (i.e. either