LTE RF System Design Procedure With_Atoll

LTERF System Design Procedure for use with Atoll Revision 1.3 Atoll Version 2.8.0 LTE PLANNING AND DESIGN IPROTECT: INTERNAL © Copyright 2010 Motorola, Inc. All Rights Reserved LTE RF System Design Procedure - Atoll This page is intentionally left blank. Revision 1.3 iProtect: Internal Page 2 LTE RF System Design Procedure - Atoll Table of Contents 1. INTRODUCTION................................................................................................ 17 1.1. LTE RF SYSTEM DESIGN PROCEDURE ............................................................... 17 1.2. PROCEDURE FLOW CHART ................................................................................ 17 1.2.1. Budgetary RF System Design Process Flow............................................ 18 1.2.2. RF System Capacity Analysis .................................................................. 20 1.2.3. Detailed RF System Design Process Flow ............................................... 22 2. LTE RF LINK BUDGET ...................................................................................... 25 2.1. ML-CAT .......................................................................................................... 26 3. LTE SYSTEM CAPACITY CALCULATION ........................................................ 29 3.1. USING ML-CAT FOR LTE CAPACITY ANALYSIS ................................................... 29 4. INSTALLING ATOLL .......................................................................................... 30 4.1. COMPUTER CONFIGURATION .............................................................................. 30 4.2. INSTALLATION AND UPGRADE PROCEDURES ......................................................... 30 4.2.1. Installation ................................................................................................ 30 4.2.2. Removing Atoll ......................................................................................... 33 4.3. INSTALLING MOTOROLA TEMPLATE INFORMATION ................................................ 33 5. CREATING PROJECTS/DOCUMENTS IN ATOLL............................................ 34 5.1. WORKING WITH ATOLL PROJECTS ...................................................................... 34 5.1.1. Starting a New Atoll Project...................................................................... 34 5.1.2. Saving, Opening, and Sharing an Atoll Project......................................... 40 5.1.3. Creating a Project Archive........................................................................ 40 5.2. WORKING WITH LTE BASE STATIONS ................................................................. 43 5.2.1. Placing a Base Station Using a Station Template via the Map................. 43 5.2.2. Placing Multiple Base Stations Using a Station Template via the Map..... 44 5.2.3. Hexagonal Design .................................................................................... 45 5.2.4. Importing a Group of Base Stations.......................................................... 46 5.2.5. Moving Sites............................................................................................. 47 5.2.6. Deleting Sites ........................................................................................... 48 5.2.7. Display Hints ............................................................................................ 49 Revision 1.3 iProtect: Internal Page 3 LTE RF System Design Procedure - Atoll 5.2.8. Managing Station Templates.................................................................... 49 6. IMPORTING GEOGRAPHIC DATA AND ANTENNA PATTERNS .................... 53 6.1. TERRAIN DATA.................................................................................................. 54 6.2. LAND USE / LAND COVER DATA ......................................................................... 57 6.2.1. Clutter Classes ......................................................................................... 57 6.2.2. Clutter Heights.......................................................................................... 60 6.3. DISPLAYING VECTOR AND RASTER DATA ............................................................ 64 6.3.1. Road Data ................................................................................................ 64 6.3.2. Building data............................................................................................. 66 6.4. GEOGRAPHIC DATA FILES, DIRECTORIES, AND NAMING CONVENTIONS.................. 70 6.4.1. Using “Index”, “MapProjectionFile”, and “Menu” Files .............................. 71 6.4.2. Creating Index Files from Header Files .................................................... 72 6.5. OBTAINING GEOGRAPHIC DATA .......................................................................... 75 6.6. ANTENNA PATTERN DATA .................................................................................. 76 6.6.1. BTS Antennas .......................................................................................... 78 6.6.2. Subscriber Antennas ................................................................................ 78 6.6.3. New Antennas .......................................................................................... 79 7. SETTING ATOLL SITE/NETWORK/SUBSCRIBER/CLUTTER CLASS INPUTS82 7.1. SITE/SECTOR LEVEL INPUTS .............................................................................. 82 7.1.1. Sites ......................................................................................................... 82 7.1.2. Transmitters ............................................................................................. 85 7.2. NETWORK LEVEL PARAMETERS........................................................................ 108 7.2.1. Global Transmitter Parameters .............................................................. 108 7.2.2. Network Settings .................................................................................... 110 7.2.3. Equipment Settings ................................................................................ 124 7.2.4. Cell Settings ........................................................................................... 143 7.3. SUBSCRIBER (TERMINAL) PARAMETERS ............................................................ 147 7.3.1. 7.4. CPE Antenna Variations......................................................................... 150 CLUTTER CLASS PARAMETERS ........................................................................ 155 8. SETTING PROPAGATION INPUTS ................................................................ 160 8.1. PROPAGATION MODELS ................................................................................... 160 8.1.1. Revision 1.3 Available Propagation Models ................................................................ 160 iProtect: Internal Page 4 LTE RF System Design Procedure - Atoll 8.1.2. SPM Parameter Settings ........................................................................ 162 8.1.3. Clutter Heights, Losses and Clearance .................................................. 163 8.1.4. Base Station Antennas Below Clutter..................................................... 165 8.2. PROPAGATION MODEL TUNING......................................................................... 168 8.2.1. Collecting Drive Test Data...................................................................... 168 8.2.2. Post processing RSS.............................................................................. 175 8.2.3. Filtering the Drive-test Data.................................................................... 176 8.2.4. Running the Calibration .......................................................................... 180 8.2.5. Validating the Optimized Model.............................................................. 185 8.3. PROPAGATION ZONES ..................................................................................... 188 8.3.1. Creating and Editing Zones .................................................................... 189 8.3.2. Filtering Zone ......................................................................................... 191 8.3.3. Computation Zone .................................................................................. 191 8.3.4. Focus & Hot Spot Zones ........................................................................ 193 8.3.5. Printing Zone .......................................................................................... 195 8.3.6. Coverage Export Zone ........................................................................... 195 9. GENERATING COVERAGE STUDIES............................................................ 197 9.1. SUBSCRIBER ANTENNA HEIGHT SELECTION ...................................................... 197 9.2. HOW TO GENERATE STUDIES IN GENERAL ........................................................ 199 9.2.1. Creating a New Prediction...................................................................... 199 9.2.2. Generating Predictions with Lognormal Fade Margin............................. 203 9.3. PROPAGATION PREDICTION IMAGES ................................................................. 208 9.3.1. Coverage and RSSI Images................................................................... 208 9.3.2. Additional Design Images....................................................................... 214 9.4. INTERPRETING IMAGES .................................................................................... 224 9.4.1. Tips and Hints for Evaluating Images ..................................................... 224 9.4.2. Evaluating Coverage and Interference ................................................... 226 9.4.3. Use of Profile Analysis Feature in Evaluation......................................... 233 9.4.4. Coverage Range Limitations .................................................................. 241 9.5. GENERATING PROPAGATION PREDICTION STATISTICS ........................................ 242 9.5.1. Reports................................................................................................... 242 9.5.2. Histograms ............................................................................................. 244 9.6. GENERATING PATH LOSS FILES ....................................................................... 244 Revision 1.3 iProtect: Internal Page 5 ...... 266 10......................................... DEFINING USER PROFILES .......6.3.............. OVERVIEW OF MIMO SETTINGS ........... 257 10......2..................................3 iProtect: Internal Page 6 ......................................................... 262 10............... 274 10......... 291 Revision 1......3..... Throughput Reduction Associated with Additional HARQ Gain................................1......2.. ACCOUNTING FOR HARQ GAIN IN ATOLL .......6................... TXAA MODELING IN ATOLL ... MIMO SETTINGS IN ATOLL .........................................................4........ 254 10.....................................8..............................2............................... Coverage Predictions based on Simulation Results .......... 289 12...................................3........................ DEFINING SERVICES .... 254 10................................................. 285 11..... User Profile and Environment Traffic Maps ........... 272 10.........4.......................1............. INCORPORATING ADDITIONAL HARQ GAIN IN ATOLL.... 247 10................ 273 10.............3. DEFINING TERMINALS .....1.........................4. 286 11.......6...............................7...................................................... 253 10...............................1................7.3.. DEFINING MOBILITY TYPES ........................... 268 10...............................................2................................LTE RF System Design Procedure ............3..... Simulation Output Statistics............ 282 10.. SIMULATION PROCESS ............... 246 10. CAPACITY ANALYSIS...... MIMO MODELING IN ATOLL .............. TRAFFIC MAPS AND SUBSCRIBER LISTS . Displaying Traffic Distributions . Subscriber Lists ....................... 274 10.......................7............ 289 12........... ADDITIONAL HARQ GAIN MODELING APPROACH IN ATOLL ......8......2...............................6...4......................... 285 11................................ 277 10......... 285 11......... Applying Coverage Constraint to Density Map ...................3............ PROCEDURE FOR CAPACITY ANALYSIS ................................8.................................8.................................................... 287 12........................................................ 264 10................. DETERMINING IF ADDITIONAL HARQ GAIN IS REQUIRED ... 288 12................................ 261 10.1.........6.. 275 10..Atoll 10............................................................ DEFINING ENVIRONMENTS .3. 282 11.. Sector Traffic Maps .......1......... Post-processing Simulation Statistics..............3.............................................. MIMO AND TXAA MODELING ...................7.......................... Assumptions for Quick Assessment of Capacity ........................1.............2......................................7.......................... Adjusting the Bearer Threshold Values for Traffic Channel Studies......... How to Run Simulations ................................................5............... User Density Maps ................. 289 12........................................3.......................... Adjusting Image Thresholds to Include HARQ for Traffic Channel Studies 291 12.............................................. 267 10................ 288 12.............2.. ........... 293 14............... REFERENCES.............. 294 Revision 1.................................................................3 iProtect: Internal Page 7 ..................Atoll 13........................... GLOSSARY ............................LTE RF System Design Procedure ......................... ............. 288 Revision 1......................... 110 Table 6: Max MIMO Gains ................................................................................................................... 96 Table 4: Diversity support.................................... 139 Table 8: Lognormal Fade Margin (CINR) ....LTE RF System Design Procedure ...................................................................................... 94 Table 3: TDD configurations.... 137 Table 7: DL MIMO Parameter Settings ......... bearer selection thresholds) ...................e...............................................................................3 iProtect: Internal Page 8 ........................................................... 30 Table 2: Max Power (dBm)............ 251 Table 14: HARQ Gain Effective Data Rate Impact ................................. 204 Table 9: Downlink/Uplink kTB Values.. 229 Table 10: DL Effective SNR Values (i.................Atoll List of Tables Table 1: Recommended Workstation Configuration .................. 249 Table 13: Highest Bearer Settings ....... 230 Table 11: UL Effective SNR Values (i..............e........................................................................................... 97 Table 5: PUCCH RB's ................................... bearer selection thresholds) ............................................................................................................................ 231 Table 12: Template Services Parameters ................................................................................................................................................................................... ............................... 38 Figure 10: Units Tab from Options Dialog .............................................................................................. 51 Figure 19: Accessing the Station Templates Table . 54 Figure 21: Data Types................................................................ 46 Figure 17: Hexagon Group of Sites ....................... 52 Figure 20: Open ................ 44 Figure 15: Site 12 Positioned via Map........ 60 Figure 29: Clutter height definition ....................................................................................................... 36 Figure 8: Coordinate Systems Dialog (Find In list showing) ..................................................................................................................................................................................3 iProtect: Internal Page 9 ...... 39 Figure 11: Auto Backup Configuration... 61 Figure 30: Data Types.................................................................................................... 58 Figure 27: Clutter Classes Image.... 41 Figure 13: Save As Settings for Saving GIS Data within a Computation Zone........... 57 Figure 25: Data Types................................................................ 55 Figure 23: Digital Terrain Image......................................................................................................................................................................................................................................................................................................................................... 35 Figure 7: Coordinates Tab from Options Dialog ......... 42 Figure 14: Base Station Templates .................................................................................. 56 Figure 24: Digital Terrain Model properties ...................................................................................................... 24 Figure 5: ML-CAT GUI ........................................................................................................................... 37 Figure 9: Coordinate Systems Dialog (both Cartesian/geographic coordinates showing) ............................. 27 Figure 6: Project Templates .......Atoll List of Figures Figure 1: Budgetary Process Flow Chart.......................................................................... 62 Revision 1........................................................................................................................................................................................................................................................................................ 55 Figure 22: Digital Terrain Model ....................... 23 Figure 4: Detailed System Design Flow Chart (B) . 58 Figure 26: Clutter Classes.Import .................................................................. 21 Figure 3: Detailed System Design Flow Chart (A) ................LTE RF System Design Procedure ......................... 59 Figure 28: Clutter Classes properties ........................................................................................................ 40 Figure 12: Saving GIS Data within a Computation Zone ...................................... 20 Figure 2: ML-CAT Capacity Process Flow Chart.......................................... 46 Figure 18: Properties Dialog for Station Templates......................................................................................................................................... 44 Figure 16: Hexagon Radius for Site and Sector ................... .. 69 Figure 40: Building data properties ......................................... 105 Figure 61: Transmitters Display Parameters ..................................... 85 Figure 53: Transmitter Properties ............................................................................... 106 Figure 63: Accessing the Transmitters Table . 72 Figure 43: “menu” File Example ...................................................Transmitter Tab .................................................................................................................... 67 Figure 38: Building data ....3 iProtect: Internal Page 10 ........................................................................................ 86 Figure 54: Transmitter Properties ............................. 77 Figure 49: Example Antenna Properties Window ................................................................................................................................................................................................................................................................... 65 Figure 36: Road data Image....... 106 Figure 62: Changing the Transmitter Display Symbol ............................................................................................................................. 73 Figure 46: Example Header File Information............LTE RF System Design Procedure ............ 87 Figure 55: Example Antenna Parameters .............. 84 Figure 52: Accessing Transmitter Sector Properties .................. 76 Figure 48: Antennas properties ........... 79 Figure 50: Site Properties Window ................................................................................................................................ 68 Figure 39: Building data Image .............Display Tab..........................................................................................General Tab...............................Atoll Figure 31: Clutter Heights ........ 72 Figure 44: Format for “index” File ..........................................General Tab ................................................................................................................... 73 Figure 45: Map File Reference Grid ..........................................................................................Cells Tab ... 63 Figure 33: Clutter Heights properties..................................................................................... 83 Figure 51: Site Properties Window ..................................... 104 Figure 59: Selecting Transmitters Properties ................................................. 102 Figure 58: Transmitter Properties ................................................................................................................................................................................................ 105 Figure 60: Transmitter Properties Automatic Display ....................... 65 Figure 35: Road data........... 70 Figure 41: “index” file............................... 74 Figure 47: Antennas label ............... 66 Figure 37: Vector Import...................................................................................................................................................... 62 Figure 32: Clutter Heights Image ....................... 92 Figure 57: Transmitter Properties ...................................................................................................... 89 Figure 56: Transmitter Properties ............................................................................... 107 Revision 1............... 71 Figure 42: “MapProjectionFile” file .....................Display Tab............................................................ 64 Figure 34: Vector Import.......Propagation Tab ..................................................................................... ...............................3 iProtect: Internal Page 11 ......... 124 Figure 81: TMA Equipment Window......... 131 Figure 89: Quality Graph .................................................................................................... 122 Figure 78: Accessing Station Templates Table . 134 Figure 92: Example Downlink Path Represented in MIMO Tab ...................................................................................................... 118 Figure 74: Schedulers Window ................................................................................... 142 Figure 96: Accessing the Cells Table ........................ 130 Figure 87: LTE Equipment Window.. 141 Figure 95: Example MIMO Gain Graph .................................................................................................................................................. 127 Figure 84: Accessing BTS Equipment Parameters ...................................................................................................................................................................LTE RF System Design Procedure ....................................................................................................................................................................................................... 128 Figure 85: BTS Equipment Window .......................................................................................................................Atoll Figure 64: Example Transmitters Table ................ 114 Figure 70: DL Bearers Dialog Window ............................................................................................................................................. 129 Figure 86: Accessing LTE Equipment Parameters......................... 123 Figure 79: Station Template Table ................................ 120 Figure 77: Bearer Selection Criterion ........................... 123 Figure 80: Accessing TMA Equipment Parameters..................... 125 Figure 82: Accessing Feeder Equipment Parameters ................................... 132 Figure 90: Effective MPR ................................. 111 Figure 68: Frequency Bands Table ............................................. 116 Figure 72: Accessing Quality Indicators ................... 108 Figure 66: Global Transmitter Parameters Interface ....... 130 Figure 88: LTE UE Reception Equipment Window – Bearer Selection Thresholds........................... 107 Figure 65: Accessing Global Transmitter Parameters ....................................... 112 Figure 69: Accessing the LTE Bearer Parameters .......................................................................... 115 Figure 71: UL Bearers Dialog Window ..... 135 Figure 93: Example Uplink Path Represented in MIMO Tab............... 120 Figure 76: Example of PD Scheduling...................................................................................................................................................................................................... 144 Revision 1...................... 140 Figure 94: LTE Reception Equipment – MIMO Tab .. 117 Figure 73: Quality Indicators ............................................................. 109 Figure 67: Accessing Frequency Band Information....................................................... 126 Figure 83: Feeder Equipment Window .............................................................. 133 Figure 91: Example Downlink and Uplink Paths between eNB and CPE ....................................... 119 Figure 75: Example of PF Scheduling (~Full Buffer) ............................................................... ........ 173 Figure 117: Example of Uniform Drive Routes ..................................................................................... 156 Figure 106: Sample Clutter Classes Properties Window............................. 164 Figure 110: Isolated High Clutter..................................... 166 Figure 112: Measured versus Predicted Pathloss in Dense Urban Area Using Hata .........................................................................................LTE RF System Design Procedure ................... 177 Figure 120: Example of Filtered Drive-test Data ................................................................................................. 165 Figure 111: Signal Strength with Base Station Antenna Height Below Clutter ............................. 187 Figure 128: Mean prediction error per test site.......................................................................................... 172 Figure 116: Weighted Drive Data with Least Squares Trendline................................... 189 Revision 1................................................................. 181 Figure 125: Final Model Tuning Configuration ................................... 146 Figure 100: Accessing Terminal Parameters .............................................. 168 Figure 114: Pathloss versus Foliage Density ............ 156 Figure 107: Atoll Propagation Models ........................................................................................... 174 Figure 118: Antenna Viewpoint Photos ...3 iProtect: Internal Page 12 ............Atoll Figure 97: Example Cells Table ...................................................................................................................................................................................... 167 Figure 113: Settings for Uniform Cost-231 Hata ..................................................................................................................... 171 Figure 115: Drive Data with Least Squares Trendline ............................................... 146 Figure 99: Example Neighbours Table ................................................... 153 Figure 105: Accessing the Clutter Class Parameters .................. 186 Figure 127: Example of Model with Low Slope ................................................................................................................................................................................................... 148 Figure 102: CPE Device Properties.... 179 Figure 124: Default Model Calibration Interface ......... 163 Figure 109: Recommended Clutter Parameters............ 179 Figure 123: Maximum Distance Filter to Avoid Clipping ...................................... 178 Figure 122: Issue with Minimum Signal Strength Filter ....... 188 Figure 129: Propagation Zones Folder.............................................................. 151 Figure 103: Reducing Antenna Gain by AGCF .... 145 Figure 98: Accessing the Neighbours Table... 161 Figure 108: Motorola Recommended 2..................... 177 Figure 121: Example of Measurements at the Receiver Noise Floor ................................ 175 Figure 119: Example of Unfiltered Drive Test Data ........... 152 Figure 104: Alternate Way of Incorporating AGCF .... 147 Figure 101: Example Terminal Properties Window ....................5 GHz Parameter Settings .............................................................................................................. 185 Figure 126: Predicted and Measured Signal Strength.......................................................... ........................................................................ 207 Figure 150: Clutter Class Default Values ......... 190 Figure 131: Menu Options for Editing a Zone............................................ 196 Figure 137: Predictions Properties – Subscriber Antenna Height ......................................................................................................... 217 Figure 158: Sample Coverage by Transmitter Image................................................................................................................. 198 Figure 139: Selecting New Predictions...................... 200 Figure 142: Predictions Condition Tab ..................... 205 Figure 147: Shadow Fade Margin Calculator CINR .............................................................................. 208 Figure 151: Setting Condition Tab............................................................................. 191 Figure 132: Example of Filter Zone and Computation Zone.......................................................................................... 218 Figure 159: Sample Coverage by Transmitter Image with Margin .. 199 Figure 140: Selecting Prediction Type........................................... 209 Figure 152: Setting Throughput Display Information ................... 206 Figure 149: Clutter Class Standard Deviation ......................................... 220 Figure 161: Sample Coverage by Best Bearer Image – DL ........................................ 211 Figure 154: Effective Signal Analysis – DL – Options ...................... 215 Figure 157: Sample Coverage by C/(I+N) Level Image – DL ............... 194 Figure 135: Focus & Hot Spot Zone Reports .................................... 210 Figure 153: Sample Coverage by Throughput – DL – Peak.. 219 Figure 160: Best Bearer Modulation Scheme............................LTE RF System Design Procedure ............. 213 Figure 156: Coverage by Throughput – DL – Options.... 200 Figure 141: Predictions General Tab.........................................................................................................3 iProtect: Internal Page 13 ........... 204 Figure 146: Shadow Fade Margin Calculator for RSSI...... 221 Figure 162: Atoll generated best bearer ranges ................................................................................................................................................................................ 197 Figure 138: Propagation Model Properties – Clutter ....................................................................... 203 Figure 145: Accessing the Shadow Fade Margin Calculator......................................................................... 212 Figure 155: Sample Effective Signal Analysis Best Traffic Signal – DL.......Atoll Figure 130: Menu Options for Creating or Importing Zones .................................................. 222 Revision 1............................ 193 Figure 134 : Focus & Hot Spot Zone Polygons ....................................................................................................................... 195 Figure 136: Exporting a Coverage Prediction....................... 205 Figure 148: Accessing the Clutter Classes Properties .................................................................................. 201 Figure 143: Predictions Display Tab....................................... 202 Figure 144: Predictions Condition Tab with Shadowing for RSSI................... 192 Figure 133 : Propagation Zone and Computation Zone ........... .................................... 248 Figure 183: Example Services GUI Window (FTP) ............ 241 Table 177: Maximum Cell Range Due to PRACH Timing ........ 226 Figure 167: Path Profile..................... 223 Figure 164: Sample Overlapping Zones Image....... 236 Figure 170: Path Profile Reception .............................................................. 239 Figure 174: Downlink Window... 234 Figure 168: Path Profile Analysis Properties .......................................................................3 iProtect: Internal Page 14 ......................................................LTE RF System Design Procedure .......................................................................... 263 Figure 193: Environment Properties (example).................................................................................................................................... 253 Figure 185: Example Mobility Types GUI Windows (PB3) .................................................................................................................................................................. 237 Figure 171: Path Signal Analysis ...................... 243 Figure 180: Coverage by Best Signal Level Report ....................... 242 Figure 179: Generate Report Data ....................................... 260 Figure 191: New Traffic Map ......................................................................................... 241 Figure 178: Predictions – Generate Report.................................................................................................................................................................... 239 Figure 173: SCH & PBCH Reception Window ................................................................................................... 240 Figure 176: Path Profile Results......................... 255 Figure 188: Accessing Environments Parameters ............................................................................................................................................................. 224 Figure 165: Tip Text Display ......................... 244 Figure 182: Accessing Services Parameters.......................................................... 238 Figure 172: Preamble Reception Strength Bars.. 225 Figure 166: Tip Text Display Properties ..................................................... 235 Figure 169: Path Profile Link Budget............ 254 Figure 186: Accessing User Profiles Parameters................................................................. 261 Figure 192: User Profile Traffic Map Properties ......Atoll Figure 163: Import best bearer plot configuration........................................... 264 Figure 194: Sector Traffic Map Properties.......................................... 250 Figure 184: Accessing Mobility Types ...................................... 255 Figure 187: Example User Profiles Window (Business User)....................................................................................... 258 Figure 189: Example Environments Window (Urban) – General Tab..... 258 Figure 190: Example Environments Window (Urban) – Clutter Weighting Tab .............................................................................................................................. 266 Revision 1....................................................................................................................................................................................... 243 Figure 181: Histogram of Best Signal Level ......................... 265 Figure 195: Sector Traffic Map Table ........... 240 Figure 175: Uplink Window ............................................. ..............................LTE RF System Design Procedure .. 292 Figure 203: Example Post-HARQ PHY Data Rate ...................................................... 281 Figure 201: Bearer Threshold Information without Additional HARQ Gain....... 292 Revision 1...................................... 280 Figure 200: Key Mobile Chart Examples .......... 290 Figure 202: Example PHY Data Rates not Accounting for HARQ Gain ........................................................................................................................ 267 Figure 197: Simulation Process Flowchart ..................................................................................................... 273 Figure 199: Summary Statistics (post-processed)..........Atoll Figure 196: Density Map Properties ....................................3 iProtect: Internal Page 15 .................. 269 Figure 198: Simulation (Drop) Statistics ..... 2).Atoll Revision History Atoll Release Revision 2. 1.8.2.0.0 Aug 31-2009 SSE Released for general use 2.3 Dec 17-2010 P&D Modified reliable coverage assessment to focus on “shadowing” and coverage by throughput images.2.8.2 Sept 22-2009 SSE Updated UL bearer selection thresholds (Table 8) 2.com/go/316936464 ).4. refer to the “Supplement – Atoll 2.1.1 Features for LTE and WiMAX RF System Design Procedure” document (http://compass. 2. Updates to Sections 7.LTE RF System Design Procedure .1.3 iProtect: Internal Page 16 .4. and Section 12. For an overview of significant Atoll 2.8.1 changes.03 1.mot.0.8. refer to the “Supplement – Atoll 2. Document location: http://compass.8.2.01 1.2 changes.2 Nov 2-2010 P&D Incorporated DL MIMO modeling (see Section 7.8. For an overview of significant Atoll 2.2.2.02 1.0 1.3.0 1.1. 1. 2. 2 In Rev.4.0.8.3.3 Sep 29-2009 SSE Updated connector losses for Frame Based and RRH base stations 2.1 Apr 19-2010 P&D Incorporated capacity analysis using Monte Carlo simulations (new Section 10) and summary chapter on MIMO/TxAA (new Section 11).8.com/go/318588510 1 In Rev.8.2.0 Date Author Description 1. new sections reference Atoll release 2.8.com/go/316936464 ).mot.mot. Revision 1.8.8. 7. new material references Atoll release 2.2 Features for LTE and WiMAX RF System Design Procedure” document (http://compass. ML-CAT should be chosen (see Section 1. When describing the detailed design process using Atoll.).3) and are the main focus for this document. 1.Atoll 1. Revision 1. some of the information and text in this document is taken directly from the Forsk Atoll manuals. etc.2. but based on the composition of the building. These guideline documents do not address contract issues or the commitments that should or should not be made to the operator.LTE RF System Design Procedure . For budgetary designs. this document assumes that the Atoll RF planning tool will be used in the design process. The LTE RF System Design Procedure and ML-CAT guide are documents that describe how to design a system using the various planning tools (procedures.3 iProtect: Internal Page 17 .1.2. Budgetary designs are characterized by short turn around time and limited input data. Procedure Flow Chart There are two fundamental LTE RF system design processes defined in this document.1 below) for estimating a site radius and to perform a capacity study. The two process flow diagrams are described in the following sections. how to interpret the results. An allowance can be made in the design for a set building loss. but both terms are referring to the same thing. In the case of detailed designs. proper settings of values. Throughout this document the terms base station (BS) and eNodeB (eNB) may be used. LTE RF System Design Procedure This document describes the procedure to follow and the tools used in producing an LTE RF system design. These designs may be produced for contract purposes and final system deployment designs. and angle and distance from the base stations the penetration of the signal into one building will be different than into some other building. The RF system designers need to stress to any individuals that are making the commitments to the customer that there should not be any commitment made for in-building coverage. There should be no commitments to any in-building coverage unless studies and specific testing are done for a specific building and then the commitments to coverage would only apply within that specific building. The tools and procedures to follow will depend on the output and detail required.2. Detailed RF system designs will rely upon the Atoll RF design tool (see Section 1. Introduction 1. System site requirements = the sum of the site counts for each neighborhood within the service area. 1. see ML-CAT Guide document.3 Neighborhoods are subdivided portions of a system service area. (See Figure 1: Budgetary Process Flow Chart ) NOTES: Note. These neighborhoods exhibit homogeneous topography and land use characteristics. COST-231 Hata) may be used within Atoll.g. Subdivide service area into geographic neighborhoods (see Note 1 below) 4. 9. Determine the number of sites required by each neighborhood (neighborhood total area divided by the per site area for the neighborhood) 8.2. Define the system service area 3. http://compass. Producing a budgetary RF system design using ML-CAT takes the following ten steps: 1. They have no relationship to political boundaries.Atoll 1. Atoll may be used in conjunction with ML-CAT.1. Multiple neighborhood definitions will be used for each System.mot. Revision 1. Neighborhoods should be defined with iProtect: Internal Page 18 .com/go/310448858 If an image is required to show the coverage for a budgetary design. Produce report For details on the use of ML-CAT. Compute the area covered by a site within each defined neighborhood using the tool 7. This allows a uniform eNodeB placement to be used throughout the neighborhood. Budgetary RF System Design Process Flow Budgetary RF system designs are a balance between the time available to produce the study. Multiple areas throughout the city may be assigned the same neighborhood definition. The exact site location and end deployment details are not required at this step. the availability of market data. Determine area of each neighborhood (see Note 2 below) 5. Enter system parameters and appropriate propagation model data into ML-CAT 6. For budgetary designs. Gather customer requirements 2. Review results 10. The RF propagation characteristics should be consistent over the surface area of each neighborhood.LTE RF System Design Procedure . Using MLCAT can quickly produce results that meet these requirements (see Section 2). and accuracy of the end results. a statistical propagation model (e. Approximate site counts with correct bill of materials is the primary goal of a budgetary study. 5. All areas specified by the customer for coverage will then be assigned one of the neighborhood definitions. Note. Lakes. Density and placement of buildings 3. The type of structures (residential. A finite number of neighborhood definitions (5 to 10 definitions) should serve most system designs.g. Neighborhoods will only be defined where the user population is present. open barren land. Revision 1. iProtect: Internal Page 19 . rail road switching yard) will likely be excluded from assignment to a neighborhood. dense forests. high-rise buildings) 2. ravines.Atoll sufficient surface area to accommodate four or more sites (10 Km2 minimum surface area is a typical minimum neighborhood size). unpopulated industrial and agricultural areas (e. rivers.LTE RF System Design Procedure .3 A separate tool (such as Google Earth) is needed to determine the surface area of each neighborhood. Width of streets. Proportions of block length to width. Density and placement of trees and foliage 4. The presence of parking lots 6. industrial. Characteristics to take into account when defining neighborhoods are: 1. 2. 7. business. Presence of open ally ways. RF System Capacity Analysis The capacity and throughput of an RF system is calculated for each cell for a given neighborhood along with the site radii while using ML-CAT tool as described in Section 1. This tool utilizes the site information entered into ML-CAT and assumes that each cell is operating with a full buffer (fully loaded). Revision 1.Atoll Figure 1: Budgetary Process Flow Chart ML-CAT 1.LTE RF System Design Procedure .1.) Calculating a system throughput and capacity using ML-CAT tool takes the following five steps: 1. (Refer to Section 2.2. Calculate the number of users supported by each cell within a neighborhood based on ML-CAT and multiplying that value by the number of cells within the neighborhood.3 iProtect: Internal Page 20 .2.2. Produce report. see ML-CAT Guide document. 5.com/go/310448858 (See Figure 2: ML-CAT Capacity Process Flow Chart) Figure 2: ML-CAT Capacity Process Flow Chart Start Determine Site capacity using ML-CAT Calculate total Subscribers supported Review Results Produce Report End Revision 1. 4. 3. Repeat step 1 for each neighborhood within the system.mot. Combine the results for each neighborhood to determine the system throughput and capacity.LTE RF System Design Procedure . adjust the number of cells and average cell coverage area and repeat steps 1 through 3.Atoll 2. Review results. For details on the use of ML-CAT.3 iProtect: Internal Page 21 . http://compass. If results do not meet customer requirements. 9. If coverage and interference criteria are not met or locations exist where there may be too much site coverage overlap.6*R^2. 6. 10. Repeat steps 6 through 9 for each of the neighborhoods defined in step 5 making sure the boundary between neighborhoods is properly covered. additional eNB’s. Analyze coverage and interference results to determine if requirements are met. Position this grid to include as many preferred customers sites as possible. Producing a detailed RF system design using Atoll requires the following steps: 1.). Repeat steps 13 through 15 until all coverage and interference issues are resolved.3 iProtect: Internal Page 22 . Dense Urban High-Rise. Enter system/site parameters into Atoll. etc.LTE RF System Design Procedure . 5. Gather customer preferred or mandatory site locations list. aerial photography) for the system along with Building and Road data files if available.3. Run coverage studies in Atoll. Identify likely eNB locations within remaining unoccupied grid elements using a search ring which is 25% or less of the grid element radius located in the center of the grid. 13. where R is the average cell radius). 8.Atoll 1. The results of the detailed design should provide the exact location of base sites. if unavoidable. then identify the sites most closely associated with the problem location. Gather Geographic input data files (Terrain. Suburban-hills. Define the system service area. 4. 7. 16. Revision 1. etc. equipment configurations. or. 3. computer processes. Create a Base Station (BS) placement grid for the area using Hexagons for 3 sector sites (the grid area is 2. 15. 14. 11. Make adjustments to these associated sites by antenna adjustments.). 12. Re-run RF predictions for the area being adjusted to verify the effectiveness of the changes. Detailed RF System Design Process Flow The level of detail an RF system design can contain is dependant on the availability of detailed input data and allotted design time and the number of resources available (e. manpower.2. and system coverage performance. Urban Tract Housing. Land Use / Land Cover Data. Run 3 to 4 “sample” RF propagation predictions using Atoll for a neighborhood chosen in step 5 and determine an average cell radius for the area. relocation. Gather customer requirements for system performance and deployment constraints.g. Use aerial photography to subdivide service area into geographic neighborhoods (Suburban. 2. Atoll 17. the propagation model that is used to produce the predictions should be tuned prior to completing the design. 18. Refer to Sections 8. The initial predictions can be done with a more generic propagation model. (See Figure 3: Detailed System Design Flow Chart (A)) Figure 3: Detailed System Design Flow Chart (A) Revision 1.2 for further discussion on the propagation models and their tuning.1 and 8. 19.3 iProtect: Internal Page 23 . Produce report Though not explicitly mentioned in the steps above.LTE RF System Design Procedure . If a coverage and interference solution does not result from this effort. but this model may not properly address the specific characteristics of the given market. consider revisiting step 7 utilizing a different grid orientation. Review design. LTE RF System Design Procedure .Atoll Figure 4: Detailed System Design Flow Chart (B) B Enter system/site parameters Run and analyze coverage study Coverage Requirements Met? N Make any required design adjustments Y END Revision 1.3 iProtect: Internal Page 24 . 3 iProtect: Internal Page 25 . Typical items within an LTE RF link budget are: Uplink and Downlink • Antenna gain • Transmit power • Diversity gain • Noise Figure • Receiver Sensitivity • EIRP Other • Lognormal Fading • Fast Fading • Interference margin • Number of resource elements • Power per resource element • Building loss • Vehicle loss • Body loss • Target SNR Refer to the LTE RF Planning Guide (http://compass. The specific link budget values used for any given study need to be incorporated within ML-CAT or in the Atoll application. The two tools discussed within this document for LTE RF planning (ML-CAT and Atoll) use these link budget values in conjunction with a propagation model to estimate coverage.LTE RF System Design Procedure . Revision 1.mot. RF prediction tools rely upon values within the link budget for pathloss modeling. These values are used to determine the maximum allowable pathloss between the base site and the subscriber.com/go/310442223) for further information on the LTE RF link budget and these parameters. LTE RF Link Budget An RF link budget is the sum of all RF system gains and losses in the RF path (downlink or uplink).Atoll 2. it can account for interference and traffic load in its predictions. it also incorporates terrain and clutter information to provide a better prediction of coverage.Atoll 2.3 iProtect: Internal Page 26 . This stand alone tool estimates the site coverage given the equipment selected and base site height and other user supplied settings. The information to be supplied by the user is entered through the User Interface tab of the spread sheet (see Figure 5). The Atoll RF planning tool can be used to produce a more detailed design. However. It provides a user interface that accepts similar link budget inputs as ML-CAT. (Further detailed discussion on using Atoll for designing LTE systems starts at Section 4 and continues to the end of this document. Additionally. ML-CAT ML-CAT is a spreadsheet application that automates the management of the RF link budget.) ML-CAT enables the user to estimate the coverage of an LTE base site configured with specific base site and subscriber equipment. Revision 1. This can be utilized for budgetary estimates for a design scenario.LTE RF System Design Procedure .1. LTE RF System Design Procedure .Atoll Figure 5: ML-CAT GUI Within this window are several smaller user input windows: 1.3 iProtect: Internal Page 27 . RF Design Inputs 2. Effective Link Budget 5. Mobile or Nomadic Devices 7. Edge Throughput Rate Inputs 6. Customer Premise Equipment Revision 1. Base Station Inputs 3. Subscriber Inputs 4. The latest version of ML-CAT can also be found at http://compass. The results of the selections are continually refreshed showing the impacts of different input selections.LTE RF System Design Procedure .mot.3 iProtect: Internal Page 28 . an interference (i. Revision 1.mot. The link budget results are based on a noise limited design. For further information.Atoll The user enters the relevant data into each sub-window.com/go/310448858.com/go/310448858.e. C/(I+N)) analysis is not performed. refer to the ML-CAT User Guide document available at http://compass. LTE RF System Design Procedure .com/go/310442223). LTE System Capacity Calculation ML-CAT combines capacity analysis capability with the link budget analysis in one spreadsheet tool (see Section 2.3 iProtect: Internal Page 29 .mot.1. Additional information concerning the factors that influence LTE capacity can be found in the LTE RF Planning Guide (http://compass.1).Atoll 3. The capacity related inputs essentially index into the tables of simulation results. 3.2.2. ML-CAT capacity analysis is based on a set of previously run simulation results. • For further information.com/go/310448858 link. Revision 1.mot. The capacity analysis assumes that the sector is operating with a full buffer (maximum capacity). Using ML-CAT for LTE Capacity Analysis The high level design procedure for using ML-CAT to produce LTE capacity results is described in Section 1. refer to the ML-CAT User Guide document available at the http://compass. Computer configuration Atoll documentation provides the following requirements for workstations intended for working with Atoll.com/go/Atoll and appropriate release from the Atoll Releases folder download the Or: Revision 1. The last subsection in this chapter provides information on how to access and install Motorola-specific template information for use with Atoll. Installing Atoll The Atoll application runs on PC work stations under Windows 2000. Installation To install Atoll: • Quit all programs • Then either: • Go to http://compass.1. 4.2.Atoll 4.1. This template provides configuration information that is specific to Motorola equipment. Installation and upgrade procedures 4. as well as installation and upgrade procedures.mot.2. XP. or Windows 2003 Server.3 iProtect: Internal Page 30 .LTE RF System Design Procedure . The first two subsections below provide configuration requirements. Table 1: Recommended Workstation Configuration Hardware/Software Minimum Recommended Processor Intel® Pentium® III Intel® Pentium® IV or Xeon® RAM 512 MB 2 GB Hard disk space 10 GB free hard disk space More than 10 GB (according to the geographic database) Graphics 1280 x 1024 with 64000 colors Higher Operating System Microsoft® Windows® 2000 SP4 or XP SP1 (SP2 supported) Additional Software Microsoft® Office 2000 or XP Ports 1 Parallel port (25 pins) or 1 USB port required to plug-in the license key 4. All information in these subsections is taken from Atoll documentation. LTE RF System Design Procedure .3 Select the type of installation desired: iProtect: Internal Page 31 . edit directly the appropriate box during the installation. the Atoll installation directory path is C:\Program Files\Forsk\Atoll (or the last directory in which the Atoll application was installed).Atoll • Insert the CD-ROM in the appropriate drive and follow the instructions on the screen • Double-click the Setup application. • Revision 1. Or: By default. To define another directory path. LTE RF System Design Procedure . Development kit • Compact: Atoll application only • Custom: select the desired options to install • Select the destination of the application in the Start menu folder • Click the Install button to run the installation process.Atoll • Full: Atoll application. Notes: - Help files are automatically installed during Setup - The User Manual is provided with the software In some instances. Atoll calculation server application. the following error window may be seen during the installation process: Revision 1.3 iProtect: Internal Page 32 . Dongle driver for fixed license. mdb”) from the compass location http://compass.mot-solutions.3. The template can be further customized by opening an existing template. Retrieve the template file (“LTE_MOTOv282.2. Install the project template as follows: 1. 4. select Atoll in the list.com/go/364172907. and then click Control Panel • Double click the Add/Remove Programs icon • In the Install/Uninstall tab. etc. Revision 1.LTE RF System Design Procedure .2. Removing Atoll To remove the Atoll application: • Quit all programs • Click the Windows Start button. To save the template. 2. and then click Add/Remove • Follow the instructions on the screen 4. point to Settings. quality curves. It also contains radio data (bearer selection thresholds. Click OK and continue. making the changes necessary to meet the needs and then saving it as a new template.Atoll If multiple licenses are not sharing processing power. Place the mdb file into the Atoll project templates folder: C:\Program Files\Forsk\Atoll\templates Note: assumes that Atoll was installed under “C:\Program Files”. this is not an issue.3 iProtect: Internal Page 33 . use File>Database>Export and place the file in the Atoll project templates folder. The use of this custom project template will facilitate Motorola-specific system design work.) based on development input. Installing Motorola Template Information LTE Planning & Design has created a custom LTE project template which contains information specific to Motorola radio equipment. 1. Pre-assemble required data for the project All data required for the project should be pre-assembled. the process by which Atoll projects. Information on how to populate and place sites within the project is also supplied. Creating Projects/Documents in Atoll In this section. called “documents”.1. Geographic (or “geo”) data such as terrain. 4.1. Create a new Atoll “document” from a template. The project template is called "LTE_MOTOv282" and its use will facilitate Motorola-specific system design work. The steps for creating a new project are summarized as follows: 1. 3.1. Also described is the process by which documents are saved. are created will be described.Atoll 5. Sufficient lead time is required to order the data from the geo data source provider. Import required geographic data. Also. and shared. 5. but non-default site specific information should be readily available. Revision 1. Each step will now be described in more detail. Note: Atoll allows for creating a project from a database which allows for several users to share the same data while managing data consistency. Starting a New Atoll Project When a new Atoll project is started.1. 5. Working with Atoll Projects In this section.3 iProtect: Internal Page 34 . clutter.LTE RF System Design Procedure . coordination with a server administrator may be required to have the data loaded in the appropriate folders.” Several project templates are supplied with Atoll including one for LTE. Once the new project is started. Configure the basic parameters. quality curves) based on development input. Pre-assemble required data for the project.1. already incorporated into the Motorola LTE project template. 2. This alternative configuration can be explored in the Atoll User Manual under “Working in a Multi-User Environment. 5. opened. It also contains radio data (bearer selection thresholds. the network parameters can be modified to meet the project’s particular needs. 5. it is based on a project template that has the data and folder structure necessary for the technology being used. LTE Planning & Design has created a custom LTE project template which contains information specific to Motorola radio equipment. and roads should be available to use in the project. Activate autosave. information is provided on how to start an Atoll project. to a significant degree. Radio equipment and channel data is. 1.2. such as basic measurement units. The geographic data files describe a curved surface (the earth). but the projection and display coordinate systems must be selected. The Atoll map window is a flat rectangular view of the system under design. the basic parameters of the Atoll document are configured. the Motorola-specific LTE template. Atoll creates a new document based on the template selected. Note: Select “LTE_MOTOv282".LTE RF System Design Procedure .1.1. Select File > New > From a Document Template.3 iProtect: Internal Page 35 . Atoll enables the user to select the projection parameters for data processing purposes and for viewing purposes.1. Each data point of this curved environment must be “projected” onto the flat display surface for processing and viewing.Atoll 5. The Project Templates dialog appears. Create a new Atoll “document” from a template The process of creating a new Atoll “document” (i. The default values for some parameters. 1. may be accepted “as is”. project) from a template is very simple. Configure the basic parameters Once a new Atoll document has been created.3. Figure 6: Project Templates 2.e. Revision 1. 5. Select the template on which to base the document and click OK. Then. Browse buttons (“…”) bring up a Coordinate Systems dialog box (Figure 8). a catalog is selected from the Find In pull-down list.Atoll Figure 7: Coordinates Tab from Options Dialog Figure 7 shows the Options dialog box from which the coordinate systems and the measurement units can be specified. It is accessible via Tools> Options.3 iProtect: Internal Page 36 . a coordinate system can be selected from the list that appears. Revision 1. only cartographic coordinate systems will be available for selection.LTE RF System Design Procedure . Within this dialog box. For Projection. LTE RF System Design Procedure . For convenience. Revision 1. Also. both cartographic and geographic coordinate systems are available for selection.3 iProtect: Internal Page 37 . the display coordinate system defaults to the selected projection coordinate system.Atoll Figure 8: Coordinate Systems Dialog (Find In list showing) For Display. if a geographic coordinate system is selected for Display. then the Degree Format field will be enabled within the Options window and the user can select from one of four format options for displaying the coordinates. but it can be selected to display a system different from the projection coordinate system. The Units tab within the Tools-Options window (Figure 10) allows the user to modify the measurement units from their defaults.Atoll Figure 9: Coordinate Systems Dialog (both Cartesian/geographic coordinates showing) NOTES: - The icon next to a projection name identifies it as a Cartesian projection and will result in the map window rulers displaying position in X-Y coordinates. refer to the Atoll User Manual under “Projection and Display Coordinate Systems”. - The icon next to a projection name identifies it as a geographic projection and will result in the map window rulers displaying position in Latitude and Longitude. - All imported raster geographic files must use the same cartographic system.LTE RF System Design Procedure . Revision 1.3 iProtect: Internal Page 38 . For more information on coordinate systems. Atoll provides a basic autosave functionality which is configured via File>Configure Auto Backup. Atoll recognizes the file format and suggests the appropriate folder on the Geo tab of the Explorer window for placement.5. The time between auto backups can be specified by one input and the other input is a checkbox that permits the user to indicate whether or not they should be informed prior to Atoll performing an auto backup.1. When a new geo data file is imported. The geographic data (terrain.3 iProtect: Internal Page 39 . Activate Auto Backup.1. 5. Atoll supports a variety of both raster and vector file formats. the other two inputs become enabled. Geo data files can be embedded in the Atoll document while importing them or subsequent to importing them. When working with large projects.4.Atoll Figure 10: Units Tab from Options Dialog 5. clutter. When the “Activate Auto Backup” check box is selected. it is advisable to protect against the loss of work by regularly saving the document. Refer to Figure 11. Import required geographic data. Revision 1.1. Refer to Section 6 for more detail on the subject of Geo data.LTE RF System Design Procedure . etc.) should be imported via File>Import. roads.1. the document will save immediately. the pathloss files and all external GIS files. Atoll permits for saving the entire project as a single file by embedding the geo data within the atl file. NOTE: In general. invoke File>Open (or Ctrl+O) and select the file from within the interface. If the document has previously been named. Opening. The suffix for the Atoll project file will be “atl”. vector. The Project Archive can be found at Atoll > File > Add to Archive Revision 1.3 iProtect: Internal Page 40 . This can be accomplished by selecting the Embed in Document check box in the File Import or Vector Import dialog.1.g. This allows the project information to be easily ported or shared. Creating a Project Archive The project archive function is used for storing a complete project. less than 100 MB). This function will create a zip file that will contain the project ATL file. embedding geographic. Note that externally linked files can still be embedded by selecting Embed on the General tab of the Properties dialog for the particular data file (right-click on file under Geo tab of Explorer and select Properties). Saving. simply invoke File>Save (or Ctrl+S). To open the existing document.1. This represents a method for sharing the project. If it is the first time that the save has been invoked.LTE RF System Design Procedure . The project can also be linked to external files. or pathloss data is not recommended as it typically produces a very large project file. The Save interface is a standard Windows interface.3. and Sharing an Atoll Project To save an Atoll project. then an interface will appear that will allow for specifying the name and location of the document. Embedding data is only for cases where the combined size of the data is relatively small (e.2. 5.Atoll Figure 11: Auto Backup Configuration 5. ATL • \PATHLOSS • \GEO • Elevation File • Clutter Classes • Clutter Height • Image Files • Vector Files If there is a large GIS data file (land use or elevation).3 iProtect: Internal Page 41 .LTE RF System Design Procedure . the extents of the GIS data files can be reduced by doing the following • Create a computation zone around the area to be archived or shared • Right click within the map display window and select “Save As” Figure 12: Saving GIS Data within a Computation Zone Revision 1. If only a portion of the entire project area needs to be shared.Atoll The zip file will contain Zip File: • *. some of the data files may need to be removed so that the zip file is not too large. 3 Once both the elevation and clutter class files have been saved.e.zip. Enter the desired file name for the saved data and click on “Save”.LTE RF System Design Procedure .grc)” from the “Save as type” pull-down list (as seen in the figure below). Select the appropriate resolution of the data and then click “OK”.Atoll • The Save As window will pop up.grd. • Another window will appear. Select “Vertical Mapper Files (*. iProtect: Internal Page 42 . Select the appropriate region to save (i. *. “The Computation Zone” would be selected to only save the data within the Computation Zone). This is done by modifying the Project Archive File *. the larger GIS elevation and clutter files need to be replaced with the newly created smaller elevation and clutter class files that are within the computational zone. Figure 13: Save As Settings for Saving GIS Data within a Computation Zone • Revision 1. Working with LTE Base Stations In Atoll. move the pointer over the map to where the new station is to be placed. a base station refers to a site with its associated transmitters and cells. The Motorola project template used to create the project contains within it numerous base station templates which reflect Motorola LTE products. In an LTE project. and cells) will also be created and placed into their respective folders in the Explorer window. The base station will appear within the map and its objects (site. select a template from the list.LTE RF System Design Procedure . transmitters. This section will describe how to integrate sites into the project including the placement of single or multiple base stations using both map and database methods. Once a site has been created. band. a site is defined as a geographical point where one or more transmitters are located. and number of sectors. In Atoll. Also described is how to move and delete base stations. Using a station template. In Figure 14. such as the TMA.1.2. NOTE: Geographic data needs to be brought into a project before placing sites.3 iProtect: Internal Page 43 . In the Radio toolbar. In Atoll. 2. or create several at once by creating a station template. a transmitter is defined as the antenna and any other additional equipment. The exact coordinates of the pointer’s current location are visible in the Status bar.2. 3. Placing a Base Station Using a Station Template via the Map A single base station can be created leveraging the station template and positioned via the map as follows: 1. feeder cables. or cell at a time. Please see Section 6 regarding importing geographic data. transmitter. channel bandwidth. Revision 1. the user can create one or more base stations at the same time. In the map window. cells must also be added to each transmitter. Note the presence of various Motorola products labeled by product name. 5. 4. Click to place the station.Atoll 5. Click the New Base Station button ( ) in the Radio toolbar. etc. The balance of this explanation assumes the use of these station templates as the most efficient means of establishing a baseline from which any required customization can be performed. transmitters can be added to it. A cell refers to the characteristics of an RF channel on a transmitter. Atoll lets the user create one site. the drop-down menu for base station templates is shown. This is done by defining an area on the map to place the base stations. Click the Hexagonal Design button ( ). Atoll displays a tool tip with the base station’s exact coordinates.2.3 iProtect: Internal Page 44 . Revision 1. to the left of the template list. select a template from the list. allowing the user to verify that the location is correct (refer to Figure 15). In the Radio toolbar. Placing Multiple Base Stations Using a Station Template via the Map A series of base stations can also be placed using a station template. Alternatively.5).LTE RF System Design Procedure . Atoll calculates the placement of each base station according to the defined hexagonal cell radius in the station template. 2. a base station can be placed more accurately by opening the Site properties window for the particular site and typing the exact coordinates into the General tab. A hexagonal design is a group of base stations created from the same station template. To place the base station more accurately. Figure 15: Site 12 Positioned via Map 5.2. To place a series of base stations within a defined area: 1.2.Atoll Figure 14: Base Station Templates With the pointer resting over the base station. zoom in (use Ctrl+A or ) on the map prior to placing the new station or moving an already placed station (see Section 5. transmitter) and. draw a zone (polygon) delimiting the area in which to place the series of base stations. Atoll fills the delimited zone with new base stations and their hexagonal shapes. This can serve as the basis for a study based on a uniform distribution of sites or.e. Using the mouse. Atoll can produce a group of base stations which are uniformly distributed per a hexagonal grid layout. then the following are true: Rsite = 3 × Rsector DISTANCEsite − to − site = 3 × Rsector = 3 × Rsite Revision 1.2.3 iProtect: Internal Page 45 .3. alternatively.LTE RF System Design Procedure . Base station objects such as sites and transmitters are also created and placed into their respective folders in the Explorer window. 3. Consequently. If Rsector is used to represent the Atoll “sector” hexagonal radius and Rsite is used to represent the Motorola “site” hexagonal radius. “Group 1” in Figure 17). it can serve as the starting place for a real system design. For more information on the benefits of hexagonal design refer to Section 5. It should be noted that the hexagonal radius employed within Atoll refers to a hexagon used to represent the coverage area of a single sector (i. described above. 5.2. Hexagonal Design As stated in the previous section.g. will all be associated with a newly created hexagon group (e.Atoll Note: Sites produced using the Hexagonal Design button as. some conversion will be required. is different from the usage employed within Motorola where the hexagon is used to represent site coverage. thus. The hexagonal radius used to create the layout is specified within the base station template and can be modified by the user prior to employing the template for base station creation.3. 2.g.g. if desired. Refer to Section 5. having position or bearing changed) and still remain a member of the same hexagon group. 5. The hexagon group can be selected via the map which can facilitate repositioning the entire group. Importing a Group of Base Stations If the project is large and data already exists.4. “Group 1” in Figure 17).LTE RF System Design Procedure .3 iProtect: Internal Page 46 .2. Whenever a hexagon group’s check box is checked under Hexagon Design. then its sectors will all display their hexagons.8 on Managing Station Templates to learn how to modify the station templates. another benefit of hexagonal design is that the sites produced will all be associated with a newly created hexagon group (e. Figure 17: Hexagon Group of Sites In addition to the benefit associated with being able to lay out a grid of 3-sector sites.Atoll Figure 16: Hexagon Radius for Site and Sector Rsite DISTANCE site-to-site Rsector The tilt of the hexagonal grid layout is controlled by the first sector azimuth of the base station template employed. Revision 1. then this data can be imported into the current Atoll document to create a group of base stations. Individual base stations can be modified (e. see "Exporting Tables to Text Files" and "Importing Tables from Text Files" in the Atoll User Manual. it can be imported into the tables of the current document. The first step is to create a base station or base stations using the template of interest. the order of the source must match the order of the site data table. Atoll allows users to map input columns to destination columns.LTE RF System Design Procedure . To move a site using the mouse: 1. the coordinate system of the imported data must match the display coordinate system used in the document. When importing. then it may be most efficient to first create a group of base stations using the base station template. For information on importing and exporting table data. the locations can be modified either by copy-pasting or importing new position information into the sites table overriding the existing information. These files can be imported into Excel and used as the basis for forming a custom database that can be imported back into Atoll. The benefit of this approach is that there is no need to bother with transmitter or cell data tables. or by using the mouse. Then. Base station data can be imported in the following ways: • Copying and pasting data: If base station data is available in table form. transmitter. If only site locations need to be customized. 5. To facilitate importing data.2. the display coordinate system of the Atoll document can be temporarily changed to match the source data. For the copy-paste to work. either in another Atoll document or in a spreadsheet.3 iProtect: Internal Page 47 . Important: The source and destination of the copy-paste must have the same dimensions and column order. If the coordinate system of the source data cannot be changed. Moving Sites A site can be moved by editing the coordinates on the General tab of the Site Properties dialog. The site names must be identical to those of the created sites for the import to work. Whether data is brought in via copy-paste or import. If the data is in another Atoll document. and cell data into the Cells table. export the site.5. the exact coordinates of the pointer’s current location are visible in the Status bar. a copy-paste into the data tables of the current Atoll document can be performed.Atoll NOTE: When data is imported. As the site is dragged. transmitter data into the Transmitters table. and cell databases. • Importing data: If base station data is available in text or comma-separated value (CSV) format. site data must be entered into the Sites table. it may be efficient to create an external database that leverages the base station template. Then. Revision 1. Click and drag the site to the desired position. in that order. it can first be exported in text or CSV format and then imported into the tables of the current Atoll document. adjusting them appropriately. To delete a site: 1. then re-positioning them is as simple as moving a single site. Within the Sites data table.Atoll 2. in terms of reception and transmission. 2. Release the site to place it. Select Move to a Higher Location.2. 2. Deleting Sites Sites. copying the locations out to Excel. enter the radius of the area in which Atoll should search and click OK. and pasting them back in). If the delete key is held down during this process. More precise positioning can be obtained via the database (e. If the sites are adjacent within the table. Atoll moves the site to the highest point within the specified radius. 5. it quickly deletes the selected site and all sites listed below it in the Explorer window. While the mouse method allows the user to place a site quickly.3 iProtect: Internal Page 48 . To have Atoll move a site to a higher location: 1. with all associated transmitters and cells. Click Yes to confirm. By default. they can be selected similar to the single site by first clicking on one Revision 1. To improve the location of a site. 3. With the hexagon group checkbox selected. Note that when a site is selected from the Explorer window.6. If a group of sites needs to be moved and the sites all belong to the same hexagon group. In the Move to a Higher Location dialog. Atoll asks the user to confirm the move. it can also be deleted by hitting the delete key. Atoll can find a higher location within a specified radius from the current location of the site.LTE RF System Design Procedure . Right-click the site in the map window. Select Delete from the context menu. 3. the user can select a single site by clicking to the left of the desired site name. Multiple sites can also be selected.g. the hexagon group is selected within the map and dragged to its new location. Right-click the site either in the Explorer window or on the map. The context menu appears. the location can be adjusted more precisely by editing the coordinates on the General tab of the Site Properties dialog. The selected site is deleted. Sites can be deleted from within the sites data table by first double-clicking on the Sites folder. Deleting all the sites of a hexagon group is accomplished by selecting the hexagon group via the map (hexagon group check box must be enabled) and then performing Right-click>Delete. Note: A site which is part of a hexagon group will still remain part of the group after being moved to a higher location. Atoll locks the position of a site. can be deleted from either the Explorer window or the map. When the position of a site is locked. The context menu appears. The following tools can be used to display information about base stations: • Label: Information can be displayed about each object. This enables the user not only to display selected information. Once the site or sites are selected. Atoll bases it on the station template selected in the Station Template Properties dialog. • Transmitter symbol: One of several symbols can be selected to represent transmitters. Managing Station Templates Users may modify existing station templates or create new ones. filtering. The label is always displayed. Double-clicking on the Sites folder would now bring up only those sites. only the parameters that differ need to be modified. then the user can select the sites using the controlclick functionality.2.3 iProtect: Internal Page 49 . Station template changes/modifications described here only apply to the active project (i.3). If the desired sites are not adjacent within the table.e. For the new set of station templates. they need to be saved as part of a new project template (refer to Section 4. can be displayed in the form of a tooltip that is only visible when the pointer is placed over the object. To create or modify a station template: Revision 1. When a new station template is created. by right-clicking on the Sites folder.2. • Transmitter color: The transmitter color can be set to display information about the transmitter. to be accessible to other new projects. Therefore. Multiple methods exist for looking at subsets of a data file (e. and symbols. sorting. such as each site or transmitter. after which using Ctrl-A (select all) and then hitting the Delete key would discard them all. tooltips.7. a user can select “Filter Inside a Polygon>Draw” and then draw a polygon around the sites to be deleted (which can be a very irregular shape). such as each site or transmitter. Display Hints Atoll allows the user to display information about base stations in a number of ways.8. • Tooltips: Information about each object. For information on defining labels. 5. Select “Remove the Polygon Filter” (by right-clicking on the Sites folder) to return to the normal view. 5. by selecting the existing station template that most closely resembles the station template to be created. For example. lists). colors. reflecting the changes/modifications. are saved into the project’s atl file). refer to “Display Properties of Objects” in the Atoll User Manual. The new station template starts with the same parameters as the one it is based on. but also to distinguish base stations at a glance.g. they can be deleted by clicking the Delete key on the keyboard.Atoll site and then dragging the cursor to include all of the desired sites. in the form of a label that is displayed with the object.LTE RF System Design Procedure . group by. and 7.2. Sectors. The Hexagon Radius is the theoretical radius of the hexagonal area covered by this base sector.2. 3. iProtect: Internal Page 50 . The Station Template Properties dialog appears. Transmitter.3 When finished with setting the parameters for the station template.To create a new station template: Under Station Templates. refer to Sections 7. The Properties dialog appears. select the station template whose properties are to be modified and click Properties.3. More specifically. 7.2.LTE RF System Design Procedure . respectively. LTE. . Create a new station template or modify an existing one: . 5.2. Name. Refer to Figure 18 for an example of the Station Template Properties dialog box. refer to Section 7. The Sectors field refers to the number of Sectors associated with this base station template.To modify an existing station template: Under Station Templates.4.1. each with a transmitter. and Other tabs of the Properties dialog.2. as appropriate. select the station template that most closely resembles the station template to be created and click Add. cell. Select Manage Templates from the list.1. In the Radio toolbar. and propagation parameters.1. Modify fields. click the arrow to the right of the Station Template list. and Hexagon Radius. click OK to close the dialog and save the changes. The Name field refers to the name of the station template. The Other tab will only appear if there are user-defined fields. namely.1. within the General. The General tab of the Properties dialog contains three fields which are unique to this interface. 4. Revision 1. 2.1. The Properties dialog appears. for transmitter.1. For descriptions of all other fields found within the Properties dialog.Atoll 1.1. Atoll Figure 18: Properties Dialog for Station Templates Alternatively.5. deleted.2.3 iProtect: Internal Page 51 . Further information regarding the Station Template table can be found in Section 7.2. This table can be accessed through the Data tab by right-clicking on the Transmitters folder then selecting Network Settings and then Station Templates. or changed) through the Station Template table. as seen in the figure below. the Base Station Template parameters can also be modified (added.LTE RF System Design Procedure . Revision 1. LTE RF System Design Procedure .Atoll Figure 19: Accessing the Station Templates Table Revision 1.3 iProtect: Internal Page 52 . 3 iProtect: Internal Page 53 . This topic is covered in Section 5. It is not connected to the geography of the service area. Please see Section 5. The following subsections describe the process used for working with NetPlan formatted geographic data.Atoll 6.a. a. the following terrain and clutter files are also supported within Atoll: • GeoTiff (*.1. The building data and road data can be used as visual location reference aids in displaying Atoll predictions. Antenna pattern data is also discussed in this section. Studies can be run using only terrain and land use / land cover (LULC.1. Clutter) data. but needs to be present for a propagation run. Importing Geographic Data and Antenna Patterns Atoll requires a foundation of geographic data for the area over which propagation studies will be performed.LTE RF System Design Procedure .BIL) • Erdas Imagine (*.grc for clutter files) Revision 1.k.img) • Vertical Mapper (*. The proper mapping projection must be used with the geographic data.2 for further information regarding site placement. NOTE: Geographic data needs to be brought into a project before placing sites.grd for terrain files and *. It provides information concerning the horizontal and vertical patterns of the specific antenna. This section describes four types of geographic data that are used within Atoll: • Terrain Data • Land Use / Land Cover Data • Building Data • Road Data The terrain and land use/land cover data are used within the propagation modeling. The process of importing these databases is similar (and sometimes less involved) to importing NetPlan formatted data.tif) • Binary Interlaced Files (*. In addition to the NetPlan / Planet data format. Atoll is able to work with several different formats of geographic data. The projection describes how the data samples (taken from the curvature of the earth) are to be projected onto the flat map window of Atoll. both of these files need to be renamed to just “index”. Terrain Data Terrain data defines the elevation of the land used in the Atoll document.3 iProtect: Internal Page 54 . Revision 1. If this data is to be used in Atoll.LTE RF System Design Procedure . This also requires that the files be put into two different directories. a terrain directory and a clutter directory.Import Navigate the directories and select the file named “index” located in the directory where the NetPlan terrain/elevation data is stored for the current document. Figure 20: Open . select File > Import.1. The following steps describe how to import terrain data into Atoll: From the main tool bar. since the two files will now have identical names.Atoll 6. Click the “Open” button. This opens up the Open window. This will open the Data Types window. NOTE: NetPlan formatted data that is used in Hydra uses a file name of “d_index” for the terrain file and “l_index” for the clutter file. Atoll Figure 21: Data Types Click on the “Altitudes” button and click “OK”. Revision 1.LTE RF System Design Procedure . Atoll will load the terrain data and place an entry in the Explorer window under the Geo tab named Digital Terrain Model. Figure 22: Digital Terrain Model The terrain image will be displayed in the map window once the terrain data has been successfully imported.3 iProtect: Internal Page 55 . Right clicking on the Digital Terrain Model label and selecting “properties” opens the Digital Terrain Model Properties window.3 iProtect: Internal Page 56 . Revision 1.LTE RF System Design Procedure . The precedence of which digital terrain file is used when two or more terrain files overlap in areas is a function of the order in which they appear under the Digital Terrain Model label.Atoll Figure 23: Digital Terrain Image Expanding the Digital Terrain Model folder within the Explorer window displays the individual digital terrain files included in the terrain “index” file. The files listed higher on the list take precedence over those further down the list. Dragging and dropping a listed file to a different location within this list is the method of changing the data file’s precedence status for the document. forest. If this data is to be used in Atoll. water.) is present over a given location. This opens up the Open window. Land Use / Land Cover Data Land use / land cover (Clutter) data defines the usage of the land in the Atoll document.Atoll Figure 24: Digital Terrain Model properties The shading.2. The following steps describe how to import and display the clutter data into Atoll: 6. since the two files Revision 1. both of these files need to be renamed to just “index”. Clutter Classes Clutter Classes define what type of land cover (building. Navigate the directories and select the file named “index” located in the directory where the NetPlan LULC/Clutter data is stored for the current document. 6.2. select File > Import. NOTE: NetPlan formatted data that is used in Hydra uses a file name of “d_index” for the terrain file and “l_index” for the clutter file.3 iProtect: Internal Page 57 . This also requires that the files be put into two different directories. a terrain directory and a clutter directory.LTE RF System Design Procedure .1. colors and transparencies of the terrain image are adjusted using this window. From the main tool bar. Refer to the Atoll User Manual for more information on how to modify the display properties of objects. etc. Atoll displays two images associated with cutter data (Clutter Classes and Clutter Heights). These two images are created from the same clutter data files. Each unique clutter designation is assigned a random color. Click the “Open” button. Additionally. Atoll will load the clutter data and place an entry in the Explorer window under the Geo tab named Clutter Classes. Revision 1.Atoll will now have identical names.3 iProtect: Internal Page 58 . This will open the Data Types window.txt file that is used with Hydra NetPlan data.LTE RF System Design Procedure . there is a clutter_menu. This file needs to be renamed to “menu” and placed in the same directory as the clutter index file to be used within Atoll. Figure 26: Clutter Classes The Clutter Classes image will be displayed in the map window once the clutter data has been successfully imported. Figure 25: Data Types Click on the “Clutter Classes” button and click “OK”. These colors can be adjusted by the user. Right clicking on the Clutter Classes label and selecting “properties” opens the Clutter Classes Properties window.LTE RF System Design Procedure . The precedence of which digital clutter file is used when two or more clutter files overlap in areas is a function of the order in which they appear under the Clutter Classes label. The files listed higher on the list take precedence over those further down the list. Dragging and dropping a listed file to a different location within this list is the method of changing the data file’s precedence status for the document.3 iProtect: Internal Page 59 .Atoll Figure 27: Clutter Classes Image Expanding the Clutter Classes label within the Explorer window displays the individual clutter files included in the clutter “index” file. Revision 1. 1.LTE RF System Design Procedure .4. Clutter Heights Clutter heights are typically defined as an average value per clutter class in the Clutter Classes properties interface as shown in Figure 29.2.) Revision 1.Atoll Figure 28: Clutter Classes properties The shading.3 for details regarding clutter heights that should be used with the recommended propagation models.3 iProtect: Internal Page 60 . Please see Section 8. (Further information regarding Clutter Classes properties can be found in Section 7. 6. colors and transparencies of the clutter class image are adjusted using this window.2. Atoll Figure 29: Clutter height definition Alternatively.3 iProtect: Internal Page 61 . select File > Import.LTE RF System Design Procedure . Click the “Open” button to open the Data Types window. Revision 1. This opens up the Open window. if a clutter height file is available. From the main tool bar. The steps for importing the clutter heights data is much the same as for importing the cutter classes. then the height of land cover present over a given location can be defined by the Clutter Heights data. Navigate the directories and select the file named “index” located in the directory where the NetPlan LULC/Clutter data is stored for the current document. 3 iProtect: Internal Page 62 . Revision 1.LTE RF System Design Procedure . Atoll will load the clutter height data and place an entry in the Explorer window under the Geo tab named Clutter Heights.Atoll Figure 30: Data Types Click on the “Clutter Heights” button and click “OK”. Figure 31: Clutter Heights The Clutter Heights image will be displayed in the map window once the clutter data has been successfully imported. The precedence of which digital clutter file is used when two or more clutter files overlap in areas is a function of the order in which they appear under the Clutter Heights label.3 iProtect: Internal Page 63 . Right clicking on the Clutter Heights label and selecting “properties” opens the Clutter Heights Properties window Revision 1.Atoll Figure 32: Clutter Heights Image Expanding the Clutter Heights label within the Explorer window displays the individual clutter files included in the clutter “index” file.LTE RF System Design Procedure . The files listed higher on the list take precedence over those further down the list. Dragging and dropping a listed file to a different location within this list is the method of changing the data file’s precedence status for the document. Only the road data file with the suffix (.3. and roads for the Atoll document. 6. Revision 1. All the files associated with this shapefile will be imported.LTE RF System Design Procedure . Navigate the directories and select the road data file.3. The following subsections describe how to import and display these data types. This will open the Vector Import window. Road Data Road data are vector files which represent the highways.shp) will appear on the menu.1. Displaying Vector and Raster Data Vector and Raster data incorporate useful information such as Roads and Buildings.Atoll Figure 33: Clutter Heights properties The shading colors and transparencies of the clutter height image are adjusted using this window.3 iProtect: Internal Page 64 . 6. From the main tool bar. streets. This opens up the Open window. Click the “Open” button. select File > Import. Revision 1. Figure 35: Road data The Road data image will be displayed in the map window once the road data has been successfully imported. Click the “Import” button when these settings are correct. Atoll will load the road data and place an entry in the Explorer window under the Geo tab with the name of the shape file used.3 iProtect: Internal Page 65 .Atoll Figure 34: Vector Import Verify that the Coordinate System settings used for the document are represented in the two boxes or make the appropriate adjustments in these boxes to match the projection used for the document.LTE RF System Design Procedure . Atoll Figure 36: Road data Image Right clicking on the Road data label and selecting “properties” opens the Road data Properties window. The weighting of the road lines can be adjusted using this window.2. Building data Building data are vector files which represent outlines and heights of buildings for the Atoll document.3. 6.3 iProtect: Internal Page 66 .LTE RF System Design Procedure . This opens up the Open window. From the main tool bar. select File > Import. Revision 1. Only the building data file with the suffix (. All the files associated with this shapefile will be imported. Click the “Open” button. Revision 1.Atoll Navigate the directories and select the building data file. Click the “Import” button when these settings are correct. This will open the Vector Import window. Figure 37: Vector Import Verify that the Coordinate System settings used for the document are represented in the two boxes to match the projection used for the document. Atoll will load the building data and place an entry in the Explorer window under the Geo tab with the name of the shape file used.3 iProtect: Internal Page 67 .LTE RF System Design Procedure .shp) will appear on the menu. Atoll Figure 38: Building data The Building data image will be displayed in the map window once the building data has been successfully imported.LTE RF System Design Procedure .3 iProtect: Internal Page 68 . Revision 1. 3 iProtect: Internal Page 69 . Revision 1.LTE RF System Design Procedure .Atoll Figure 39: Building data Image Right clicking on the building data label and selecting “properties” opens the Building data Properties window. and Naming Conventions All geographic data is addressed by absolute directory path within Atoll. all users must either be on the same workstation or have access to the same folders across a network. Various information files can be provided along with NetPlan formatted terrain and clutter files (binary data).Atoll Figure 40: Building data properties The shading colors and transparencies of the building data image are adjusted using this window. To share geographic data. It also provides details on the naming conventions and directory Revision 1. an “index” and “MapProjectionFile” can be provided with the terrain and clutter data. Section 6. For example.LTE RF System Design Procedure . This allows the data to be placed anywhere within the computer directory structure and facilitates sharing common geographic data between multiple users.4.3 iProtect: Internal Page 70 .1 provides details on the type of information that is contained within these files. There are no naming restrictions or directory placement restrictions for Building data or Road data. The following subsection provides naming restrictions and directory placement restrictions regarding terrain and clutter data.4. Geographic Data Files. as well as a “Menu” file provided with the clutter data. Directories. 6. and “Menu” Files Files named “index” and “MapProjectionFile” are provided along with NetPlan formatted terrain data.LTE RF System Design Procedure .4. Please see Section 6. However.3 iProtect: Internal Page 71 . Using “Index”.bil) and a header file (*. These two files (along with a third file named “menu”) must have these names and must reside in the same directory as the clutter data. Figure 41: “index” file l_mexico_mwz. The individual binary terrain and clutter data files are not restricted in naming convention. If this is the case. These two files must have these names and must reside in the same directory as the terrain data. The header and binary file can be imported directly into Atoll (please see Sections 6.bin 473149 483999 2151801 2166006 5 The “MapProjectionFile” file is an ASCII file that contains geographic projection parameters for the NetPlan binary data.Atoll placement restrictions that are important when using these “index”. NetPlan formatted data can also be provided in the form of a binary file (*. Revision 1. files with the same names (“index” and “MapProjectionFile”) are provided along with NetPlan formatted clutter data. then an “index” file can be created from the header file. “MapProjectionFile”.2 for details on how to create an “index” file from a header file. NetPlan formatted raster data for terrain and clutter data must be placed in separate directories because the “index” files for the terrain and clutter hold different information yet have identical names.4.2 for further details).1.1 and 6. sometimes the header file cannot be interpreted correctly.hdr). Similarly. 6. “MapProjectionFile” and Menu” files within Atoll. The “index” file is an ASCII file that contains a list of all terrain/clutter data files for the Atoll document along with the Cartesian coordinates within each file. 00 ctN_MeridCntr -99.Atoll Figure 42: “MapProjectionFile” file ctN_Radius 6378137.9996 ctN_NorthingCntr 0. Creating Index Files from Header Files In cases where the header file cannot be interpreted by Atoll.00 ctN_EastingCntr 500000.2. The following provides details on how to create an “index” file from a header (*.hdr) file.00 ctN_Eccentricity 0.3 iProtect: Internal Page 72 . an “index” file can be created from the header file information and the “index” file can be used instead.00 The “menu” file is an ASCII file that contains clutter codes and names for the NetPlan binary clutter data. Revision 1.LTE RF System Design Procedure . Figure 43: “menu” File Example 1 Dense Urban-Commercial 2 Urban-High Density 3 Urban-Low Density 4 Suburban-High-Density-Residential 5 Suburban-Low-Density-Residential 6 Suburban-Dense Vegetation 7 Industrial-Low-Density 13 Inland Water 16 Quasi-open/roads/barren 18 Forest 19 Low-trees/Low-density_woodland 20 Agriculture/Rangeland/Grasses 21 Village 6.00 ctN_ScaleCntr 0.4.081819191 ctN_ParaCntr 0. Atoll As shown in Figure 41.bil Xmin Xmax Ymin Ymax PixelSize The following image provides an example of a binary map file layout. The layout of the 6 items of information within the “index” file is shown in the figure below. The reference grid shows how the information within the “index” file relates to the map file.3 iProtect: Internal Page 73 . Figure 44: Format for “index” File BinaryFileName.LTE RF System Design Procedure . The following figure contains an example of data from a header file. The information in this file helps define the projection of the binary map file. the “index” file is made up of 6 items that are space delimited. Figure 45: Map File Reference Grid Pixel Size The information from the header file can be used to determine the proper settings to create an “index” file. Revision 1. The remaining two values that are needed within the “index” file. can be calculated using the information from the header file.3 iProtect: Internal Page 74 . and the PixelSize (XDIM or YDIM.500000 + ( 8800 * 5) LRLXMAP = 503002.5 Revision 1.Atoll Figure 46: Example Header File Information ULXMAP 459002. since these are both the same). which equates to the maximum Y value XDIM = resolution or pixel dimension in the X direction YDIM = resolution or pixel dimension in the Y direction NROWS = number of rows (or Y entries) within the map file NCOLS = number of columns (or X entries) within the map file NBITS = number of bits.000000 YDIM 5. ULXMAP). the header file contains some of the information needed in the “index” file: the Xmin value (i. which equates to the minimum X value ULYMAP = upper left Y map location. It is important that this value be 16 for use in Atoll As shown in the information above. use the following formula: LRXMAP = ULXMAP + ( NCOLS * XDIM) Using the header information shown above.000000 BYTEORDER M LAYOUT BIL NROWS 8200 NCOLS 8800 NBANDS 1 NBITS 16 Where: ULXMAP = upper left X map location. this value would be calculated as: LRXMAP = 459002.e. To calculate the Xmax value (lower right X map location). ULYMAP).500000 XDIM 5.e. the Ymax value (i.LTE RF System Design Procedure . the Xmax and the Ymin values (which define the lower right corner of the map).500000 ULYMAP 4442997. contact [email protected] 4442997.bil” would be replaced by the name of the specific file (*.5 503002. The United States Geological Service offers 30 meter resolution Ultra High-Res Terrain.5 Once these values have been calculated. this value would be calculated as: LRYMAP = 4442997. the propagation model should be tuned for the given area. A full listing of the supported data formats is given in the Atoll Users Manual under the Supported Geographic Data Formats section. Building files can be purchased from GDS (http://gds. and TIGER 2000/2006 shapefile Roads data for the United States free of charge. the “index” file can be created. The time required by GDS to produce high resolution geographic data should be factored into the total time required for the RF design project. Atoll users may acquire geographic data from the Motorola Graphical Data Services organization (GDS). Higher resolution data is obtained by GDS from other sources requiring more time to process which incurs higher expenses.3 iProtect: Internal Page 75 . Obtaining Geographic Data Atoll supports several geographic data formats including NetPlan and Planet. The GDS organization can quickly convert this data into Atoll compatible formats for a minimal charge.760.( NROWS * YDIM) Using the header information shown above.com).LTE RF System Design Procedure . 6. To ensure further propagation prediction accuracy.2560 [email protected] Xmin Xmax Ymin Ymax PixelSize Using the information from the above header file.mot.com. the index file should look like the following: BinaryMapFile. Higher resolution geographic data produces propagation predictions of greater accuracy (assuming that the data itself is accurate) and is recommended for all but urgent budgetary RF studies. Within this file is a single line consisting of the following data: BinaryFileName.Atoll To calculate the Ymin value (lower right Y map location).5.5 5 Where “BinaryMapFile. use the following formula: LRYMAP = ULYMAP . The vector building data should be in Revision 1.com) or from CyberCity LLC (contact name Jacqui Swartz 310.5 4401997. NLCD Land Cover. GDS can convert many forms of existing geographic data into data formats supported by Atoll.com). This is done by creating a text file named “index”.500000 .bil) that contains the binary map data.bil 459002. contact maps@motorola.( 8200* 5) LRYMAP = 4401997. LTE RF System Design Procedure . either for free or for a nominal charge.DWG files. Census 2000 TIGER/Line Data (free download only in the United States).MIF files. base height and building height. peak antenna gain. However. AutoCAD *. click on the Data tab at the top of the Explorer window and expand the “Antennas” label. Freeware and commercial GIS file translators exist that generate shapefiles from most formats. etc. horizontal antenna response pattern. Figure 47: Antennas label Revision 1. ArcInfo *.) can also be found using an Internet search.6. Internet search engines can locate sources using search keywords such as “shapefile" & your location. and vertical antenna response pattern. A wide variety of shapefile data is available on the Internet.shp) format and include fields describing each buildings perimeter. Vector shapefiles depicting detailed state & county boundaries and highways for the United States.com or maps@motorola. To view the available antennas embedded within the Motorola LTE template. these generic patterns should be replaced with the actual antenna patterns that are planned for use in the system being designed.3 iProtect: Internal Page 76 . Antenna Pattern Data The base station and the subscriber terminals require the presence of antenna performance data for RF predictions to run. and similar data for Canada & Mexico can also be provided by the Motorola GDS organization.e00 files.mot.com). This data is in the form of frequency of operation. Generic 70 degree Antenna patterns are included in the LTE template that was selected when creating the LTE document (see Section 5). 6. This data is contained in a single text file called the antenna pattern file. A starting point is ESRI's web site.Atoll “shapefile” (.DXF or *. Contact GDS for advice (http://gds. Mapping data in other GIS formats (for example. MapInfo *. right click on the antenna label and select the “Properties” option.Atoll To view the antenna data for a given antenna model.3 iProtect: Internal Page 77 . Figure 48: Antennas properties Revision 1.LTE RF System Design Procedure . This opens the antenna properties window. 6. the front to back ratio (isolation). Once the antenna is chosen. The system designer must make sure that appropriate antennas are selected for the deployment design goals.3) 6.1.2. with suffix for the CPE antenna indicating the antenna gain. It is also important to note that the effective gain of the antenna at the CPE device may be less than the antenna gain specification due to the placement of the CPE in a nonline-of-sight scattering environment and non-optimal orientation of the device.3. Subscriber Antennas The last two antennas listed in Figure 47 are for use with the subscriber devices. For some CPEs. and frequency of operation. The parameters would include the number of antennas encapsulated within the panel (ports) to support the number of transmit and receive antennas needed by the base site.3 iProtect: Internal Page 78 . Revision 1. the gain of the antenna. antenna gain referred to an isotropic source.LTE RF System Design Procedure . the frequency of operation.Atoll 6. Antenna patterns for Smart Antenna have not been defined as of the release of this document The antennas used with the various base stations are ordered as ancillary equipment and not included with the FNE equipment package. the vertical beam width and any fixed electrical downtilting required. To edit the subscriber antenna gain for a given antenna model. BTS Antennas The base station antenna names listed in Figure 47 depict the horizontal beam width. the antenna gain may vary depending upon the frequency of operation and model.6. Section 7. This opens the antenna properties window as seen in the figure below.6. • CPE Antenna – 7 dBi • MS Antenna – 0 dBi The names of these antenna selections match the two categories of subscriber devices. the horizontal Beamwidth. its pattern data must be entered as a new antenna into the Atoll project (see section 6.1 provides further discussion on adjustments that should be made to address the CPE antenna gain correction factor and orientation loss. right click on the antenna label and select the “Properties” option. This will bring up a pop up window.3.1.6.Atoll Figure 49: Example Antenna Properties Window Enter the appropriate antenna gain into the “Gain” field.1.LTE RF System Design Procedure .6. Within the General tab of the Antenna Properties window. as seen in Figure 49. then Right click on the Antennas folder. New Antennas Antennas can be created from Tabular data or imported from an antenna pattern that is in Planet format. If the CPE is located in a nonline-of-sight scattering environment or has a non-optimal device orientation. 6. enter information into the following fields: Revision 1.3 iProtect: Internal Page 79 . Click “OK” to apply this gain value. 6. It is important to note that when an antenna is imported or created. Click on the Data tab. It is recommended that the user enter comments to document the gain selection to avoid future confusion. Select “New” to open the Antenna Properties window. the antenna will have to be imported again if it is desired to use this pattern within the new project.3. the antenna pattern is stored with the ATL file.3. Creating Antenna Pattern The following steps describe how to create a new antenna pattern for a project. then the antenna gain may need to be reduced by the antenna gain correction factor and orientation loss depending on whether the engineer desires to account for these adjustments as described in Section 7. If a new project is created from the Motorola Template. then Right click on the Antennas folder. Select “Import” to bring up the “Open” interface. Within the Other Properties tab. the user can define the beamwidth and frequency range for the antenna. The following steps describe how to do this.6. Attenuation values can also be defined for angles other than integer values from 0° to 359°.3. Atoll allows horizontal and vertical pattern attenuations (respectively) to be entered for as many as 720 angles. The antenna patterns are correctly aligned when: • The horizontal pattern attenuation at 0° is the same as the vertical pattern attenuation at the pattern electrical tilt angle. This will bring up a pop up window. The following is a list of the antenna information that can be defined in this tab: • Beamwidth • FMin: Minimum frequency for the pattern • FMax: Maximum frequency for the pattern • Frequency: the design frequency of the antenna • V WIDTH: the vertical beamwidth of the antenna • H_WIDTH: the horizontal beamwidth of the antenna • FRONT_TO_BACK: the front to back ratio of the antenna • TILT Atoll checks whether the vertical and horizontal patterns are correctly aligned at the extremities. as well as other antenna parameters. These fields are used for filtering and not used in any calculations. 6.Atoll • Name • Manufacturer • Gain • Pattern Electrical Tilt • Comments : Any other information Within the Horizontal Pattern and Vertical Pattern tabs.3 iProtect: Internal Page 80 . If the horizontal and vertical pattern data is in spreadsheet or text documents. the data can be copied directly from the source files into the Atoll horizontal or vertical pattern tables.LTE RF System Design Procedure . and • The horizontal pattern attenuation at 180° is the same as the vertical pattern attenuation at the 180° less the pattern electrical tilt angle. Importing Antenna Data Atoll can import Planet formatted antenna patterns.2. Revision 1. Click on the Data tab. The antenna patterns will be imported and made available in the Antennas window. Revision 1. The antenna patterns are correctly aligned when: • The horizontal pattern attenuation at 0° is the same as the vertical pattern attenuation at the pattern electrical tilt angle. Atoll checks whether the vertical and horizontal patterns are correctly aligned at the extremities. select “Planet 2D Antenna Files (index)” from the “Files of type” drop-down menu.Atoll From within the “Open” interface.3 iProtect: Internal Page 81 . In the “File name” field. select the “index” file from the directory that contains the Planet formatted antenna patterns and then click “Open”. and • The horizontal pattern attenuation at 180° is the same as the vertical pattern attenuation at the 180° less the pattern electrical tilt angle.LTE RF System Design Procedure . There are three tabs within the Site Properties window: General. It is recommended that the Motorola specific LTE template be used within Atoll since many of these parameters are set within the template based on Motorola products. etc. The following sections include information regarding the parameter values that are set within the templates and which parameters are likely to need modification. this value will not be appropriate in all situations. it is important to review the parameters (e.g. and the system or network configurations. This section provides descriptions of the parameters. 7. the subscriber configurations. antenna heights. a base station is defined through site. and cell parameters. Sites The site information defines the geographic location of the site.Atoll 7. The following figure shows an example of the parameters within the General tab. etc. Site/Sector Level Inputs Within Atoll. or by right-clicking on the object in the map window. “Frame Based eNB”.) and modify them as necessary for the specific market that is being designed. many site/sector configuration parameters can be set by choosing one of the provided base station templates (e.1. by right clicking on a Site and selecting Properties). For example.3 iProtect: Internal Page 82 .g. Setting Atoll Site/Network/Subscriber/Clutter Class Inputs This section discusses the parameters that need to be set to define a system within Atoll.1. the associated equipment. However. When using the Motorola template.). the default site antenna height used in the template is 30 m.e. “Remote Radio Head”. Revision 1. This includes parameters that define the site/sector configurations. For example. 7. as well as recommended settings. Most of the input windows can be accessed in two ways: either through selection from the Explorer window under the Data tab. and Display. where possible.LTE RF System Design Procedure . azimuths. The site parameters can be found in the Site’s Properties dialog window (i.1. The site parameters define the location of the site. Pylon (used with microwave studies and will not be discussed further in this document). transmitter. while the transmitter and cell parameters define the details of the site such as the antenna and equipment parameters as well as the characteristics of an RF channel on a transmitter. if desired. 4. 2. 3. This Name field allows the user to change the name.e. If desired. is given as the DTM setting.LTE RF System Design Procedure .Atoll Figure 50: Site Properties Window . then Atoll will use this value for calculations. The following figure shows an example of the parameters that can be set within the Display tab of the Site Properties window. It is recommended to use the DTM setting for this field.General Tab 1 3 2 4 NOTES: Note. please see the Atoll Administrator Manual. Revision 1. The Altitude field is composed of a Real and a DTM setting. Atoll automatically enters a default name for each new site. if desired.) Note. the user can define another altitude under the Real setting.3 iProtect: Internal Page 83 .) Note. (The example figure above shows the longitude and the latitude of the site. not the height of the antennas). The Comments text box allows the user to enter comments regarding this site. If the Real setting has a specified altitude. Note. as defined by the Digital Terrain Map. the elevation at the base of the site. The Position field provides the X and Y coordinates for the site. 1. The altitude of the site (i. (If it is desired to change the default name that Atoll gives to new sites. If the checkbox is selected. the name will appear in the display.3 iProtect: Internal Page 84 . The Display Radial Grid checkbox allows the user control over whether they wish to display a radial grid around the site. The Display Name with Style checkbox allows the user control over whether or not to display the site name. 1. 2. Note.Display Tab 1 2 3 NOTES: Note. the spacing between the circles. Revision 1. This is done by defining the maximum radius for the grid. a radial grid will appear around the selected site. The AaBbYyZz box allows the user to modify the font and style that is used when displaying the Site name in the display. and the angle between the radials. The Symbol Style allows the user to modify the style of the symbol that is used to represent the site in the display.LTE RF System Design Procedure . 3. If this checkbox is selected. The Parameters… option allows the user to define the number of radials and circles that will appear in the radial grid. Note. This feature can be used in conjunction with a coverage image to get a quick distance estimate of the coverage range around a site.Atoll Figure 51: Site Properties Window . as shown in the next figure.2. The parameters in each of these tabs will be described below. Transmitters The Transmitters Properties windows define the specific parameters for each sector (e.1. Cells. Propagation. losses.2.g. Entering Transmitter Data The Transmitter Properties dialog window can be found from the Data tab by rightclicking on a Transmitter and selecting Properties. Figure 52: Accessing Transmitter Sector Properties The Transmitter Properties window consists of 5 tabs: General.1. power levels. etc. 7. These parameters can be found in the Transmitters Properties dialog windows or in the Transmitters Table (Transmitters Æ Open Table). gains.1. Revision 1.General Tab The General tab in the Transmitter Properties window provides information regarding the name and location of a sector relative to the associated site. Transmitter Properties .3 iProtect: Internal Page 85 .LTE RF System Design Procedure . Transmitter. antenna parameters. and Display.1.1.). 7.Atoll 7.2.1. Note. Note. 1. please see the Atoll Administrator Manual. if desired. The Name of the transmitter (sector) is automatically assigned by Atoll.) Note. 4. The Comments text box allows one to enter comments regarding this transmitter. The Site parameter indicates the site with which this transmitter is associated. Revision 1. if a site is located on a rooftop and it is desired to locate one of the sector antennas on the opposite side of the roof from the other antennas. this parameter can be used to position the antenna.Atoll Figure 53: Transmitter Properties .3 iProtect: Internal Page 86 . The “…” button to the right of this field allows the user to access the properties of the site on which the transmitter is located. However. it is recommended to let Atoll assign the name.LTE RF System Design Procedure . (If it is desired to change the default name that Atoll gives to new transmitters. for the sake of consistency. rather than entering X-Y offsets into these fields. 3. 2.General Tab 1 2 3 4 NOTES: Note. For example. This field allows the user to enter a different name for the transmitter. it is generally easier to position the antennas relative to the site by dragging and dropping them in the map display. if desired. The Position relative to the site field allows the user to modify the transmitter’s location relative to the site. However. these parameters need to be reviewed to make sure that the settings are appropriate for the given market.Transmitter Tab 1 2 5 3 4 6 7 9 8 10 11 12 NOTES: Revision 1. If the Motorola base station templates are used to create sites. then many of these parameters are set automatically. and downtilt may not be appropriate for a specific transmitter and will need to be modified.2.Transmitter Tab The Transmitter tab within the Transmitter Properties window provides information regarding transmission/reception gains and losses. azimuth. Transmitter Properties . the default settings for parameters such as the antenna height.1.1. Figure 54: Transmitter Properties . However.LTE RF System Design Procedure .3 iProtect: Internal Page 87 . as well as providing information regarding the antennas that are associated with this transmitter.Atoll 7.2. For example. This feature allows the user to model the impact of neighboring networks by including these sites as interferers but not sources within a design. The Total losses (Real) field allows the user to enter the total transmission loss or total reception loss for the eNB. Revision 1. 6. The checkboxes only affect what sites are displayed in the Atoll workspace. not a server.5 dB for RRH. transmission line equipment). so it is likely that it will need to be modified to something other than 3 dB for Frame Based and 0. (Please note that the checkboxes in the Explorer window next to each site/sector do not affect what sites are included in a prediction study. Note.3 The Antennas Height/Ground entry defines the height of the antenna above the ground. This value needs to be adjusted to correspond to the actual line and connector loss for the sector. Note. 1. if the transmitter is defined as an “Extra-network (Interferer Only)”. which is the typical noise figure for Motorola eNB products. Note. The Motorola base station templates do not use these detailed equipment input windows to calculate the Total losses or BTS Noise Figure.g. Only active transmitters are taken into consideration during calculations. connector losses. The Transmission/Reception portion of the window allows the user to enter or have the tool calculate the Total losses and BTS Noise Figure associated with the sector. 2. The BTS Noise Figure (Real) field allows the user to enter the noise figure value associated with the given BTS. etc. The Motorola template for Frame Based eNB products include a 3 dB loss setting. it will only be modeled as an interfering source. (If the transmitter is located on top of a building. The Transmitter Type field allows the user to define how the transmitter will be modeled by selecting between two types: “Intra-network (Server and Interferer)” or “Extra-network (Interferer Only)”. 5. The Details button then displays the calculation for the total uplink loss. It then uses this information to calculate the associated losses and noise figure information.LTE RF System Design Procedure .) Note. This field would include losses such as transmission line loss. The Equipment and Details buttons are used if the tool is to calculate these values. The Motorola base station template sets this value to 0. The Active checkbox allows the user to select whether this transmitter will be considered active. The Equipment button allows the user to enter the relevant information regarding the site equipment (e. filter losses. 4.Atoll Note. However. If the transmitter is defined as an “Intra-network (Server and Interferer)”. this height must include the height of the building. 3. the transmitter will be modeled as both a transmitting and interfering source. Note.) iProtect: Internal Page 88 .5 dB for the Remote Radio Head eNB. which are then displayed as the Computed values for the Total losses and BTS Noise Figure. The Motorola eNB templates have this set to 4 dB. This value needs to be reviewed and modified as necessary for the particular market being designed. This generic antenna pattern should be replaced with the actual antenna pattern that is planned for use in the system deployment. the Mechanical Downtilt and Additional Electrical Downtilt parameters associated with the main antenna. The Main Antenna portion of the Transmitter tab dialog window allows the user to define the Model.Atoll If a Motorola base station template was used to place the site within the system. as seen in the following figure.LTE RF System Design Procedure . Revision 1. the Azimuth. Figure 55: Example Antenna Parameters If the Motorola base station template is used within Atoll. please note that this template uses a default of 30 m for the base station antenna heights. then a generic antenna model is provided based on the selected site configuration.3 iProtect: Internal Page 89 . Refer to Section 6.6. The Model is selected from a pull-down list.3 for information on creating new antenna patterns in Atoll. Note. 7. The “…” button allows the user to access the properties of a given antenna. which is the percentage of power reserved for this particular antenna. Note. Doing this opens the “LTE Equipment” window which lists the BTS configurations available. Any further use of the previous practice of referencing 1 receive antenna in place of 8 at the eNB should be discontinued. Problems were experienced when predicting UL capacity correctly when utilizing the older approach. 9. a value of 4 should be selected for Transmission and Reception.1 (build 3095 and later). for a transmitter with one secondary antenna. these parameters are set automatically to 2 Tx and 2 Rx antennas. to model a Remote Radio Head product with 4 Tx and 4 RX antennas.3 iProtect: Internal Page 90 . and % Power.Atoll Note. These downtilt parameters that are defined for the main antenna are also used for the calculations using the smart antenna equipment. For example. Note. Note. The Azimuth field allows the user to set the orientation of antenna. This can be found by clicking Transmitters Æ Equipment Æ LTE Equipment.1 template has been updated accordingly. 60% is available for the main antenna. Selecting the MIMO tab in this window will display the number of TX and TX ports associated with the chosen BTS equipment. In order to model a configuration other than 2 Tx and 2 RX antennas. The Motorola base station templates assume that the antennas are not downtilted. 8. This will result in the correct indexing into the MIMO configuration table when Atoll applies MIMO gains. 10.8. Note: In Atoll 2. so the parameter will need to be updated in cases where downtilting is desired. Mechanical Downtilt. 210. Selecting the appropriate BTS name and double clicking on the arrow next to the name will open the properties window for that BTS. Additional Electrical Downtilt. The Mechanical Downtilt and Additional Electrical Downtilt fields allow the user to define any downtilting that is required for the antenna. For example. and 330 degrees for 3-sector sites. The Number of Antenna Ports portion of the Transmitter tab allows the user to define the number of transmission and reception antennas that will be used for MIMO. The Motorola base station templates assume a sector orientation of 90. Revision 1. 8 receive antennas can be specified. The Motorola 2. the appropriate number of TX and RX antennas must be entered.LTE RF System Design Procedure .8. These values determine which MIMO configuration will be used. 11. if 40% of the total power is reserved for the secondary antenna. When using the Motorola base station templates. The Secondary Antennas portion of the Transmitters tab allows the user to select one or more secondary antennas in the Antenna column and enter their Azimuth. If the user selects the Motorola specific LTE template. The user can either move to the beginning or end of the transmitter list or move one by one through the list in the backwards or forwards direction by using these buttons.3.). (For information on working with data tables.3 iProtect: Internal Page 91 .Atoll This portion of the GUI window will not typically be used. “>>”. The “|<”. “<<”. 12. 7. many of these parameters are set based on Motorola equipment. The parameters that appear in the Cells tab are dependent upon the technology that was chosen when the user opens a new project. power levels.2.) Note.LTE RF System Design Procedure . The following describes the parameters associated with the Cells tab. etc.1. noise rise. >|” buttons allow the user to easily navigate from the properties window for one transmitter sector to the properties window for another. please see the Atoll Users Guide. Transmitter Properties .Cells Tab The Cells tab provides detailed information regarding various LTE parameters and RF channel characteristics associated with the sector (such as the frequency. traffic load. Revision 1.1. Cells Tab NOTES: Note. 1. is filled in by Atoll to name the cell after its transmitter. for consistency sake.3 iProtect: Internal Page 92 . it is recommended this name field be assigned by the Atoll tool. adding a suffix in parenthesis. The Name entry. by default.Atoll Figure 56: Transmitter Properties . (If it is desired to change the default name that Atoll gives to new cells.) Revision 1. This field allows the user to change the cell name.LTE RF System Design Procedure . please see the Atoll Administrator Manual. However. The available channels in the pull-down list are dependent upon the frequency band that has been selected for the study. Physical Cell ID Status is the status of the physical cell ID currently assigned to the cell for use with automated cell ID planning. concrete product plans have not been established regarding supported frequency bands and bandwidths. The box must be checked to make the cell active. For information regarding automated cell ID planning. The Channel Allocation Status is the status of the current channel allocated to the cell for use with the AFP. It is an integer value from 0 to 503. The AFP is a separate module within Atoll. An S-SCH ID is thus uniquely defined by a number in the range of 0 to 167. The physical cell IDs are defined in the 3GPP specifications. 3. Note. Note. whether the cell will be included in calculations).1 for additional information on frequency band numbering. Note. See Section 7. with each group containing 3 unique identities (called P-SCH IDs in Atoll). 4. This field needs to be set by the user to correspond to the channel that will be used in this sector. For information regarding the AFP. please see the Atoll User’s Manual. The Frequency Band field allows the user to enter the sector’s frequency band from the Frequency Band list. then this field is set to a default band that must be changed to the correct band for the system being designed. Note.Atoll Note. it is necessary to check with WiBB Product Management for actual or planned availability of eNBs’ supporting the frequency band and channel bandwidth being considered for the design. Note. Physical Cell ID is the physical cell ID of the cell. therefore. The drop down menu contains a list of the most likely bands to be supported by Motorola products. please see the Atoll User’s Manual. The Min Reuse Distance (m) field is used by the Automatic Frequency Plan (AFP) algorithm to determine the minimum distance between this cell and when the channel assigned to this cell can be used again.LTE RF System Design Procedure .2.e. The Channel Number field allows the user to enter the channel from the list of available channels. The AFP is a separate module within Atoll. The Active field designates whether this cell is active (i.3 iProtect: Internal Page 93 . Automated cell ID planning functionality is not covered in this document. 8. The physical cell IDs are grouped into 168 unique cell ID groups (called S-SCH IDs in Atoll). 6. 5. please see the Atoll User’s Manual. Revision 1. 7. Each cell’s reference signals transmit a pseudo-random sequence corresponding to the physical cell ID of the cell. For information regarding the AFP. as of the writing of this document. 2. If the Motorola base station templates are used to place the sites. However. Note. and a PSCH ID is defined by a number in the range of 0 to 2. There are 504 unique physical-layer cell identities.2. Atoll Note.3 iProtect: Internal Page 94 . The PDSCH & PDCCH EPRE Offset / RS (dB) is the difference in the energy of a resource element belonging to the PDSCH or the PDCCH with respect to the energy of a reference signal resource element.26 46. By setting the Max Power (dBm) values as shown in the table and setting the two EPRE Offset values to 0.26 49 46 46 46 46 46 46 SC7224 43 UBS 43 Note. The two EPRE Offset values are set to 0 in the template. the PDSCH power used in signal strength and CINR predictions will be as shown in the table (PDSCH Power (dBm)). If using the Motorola template. The following table shows the Max Power (dBm) values contained in the template. this value will be set to 0 dB. where the number of resource elements is determined internally by Atoll. Note.26 46. Motorola’s design procedure involves analysis of the PDSCH. rather. Max Power (dBm) will be set for the selected eNB product assuming two transmit antennas. This value is Revision 1. The calculated power also depends on the values of SCH & PBCH EPRE Offset/RS (dB) (described in Note. Motorola’s design procedure is focused on the PDSCH and setting the EPRE Offset to 0 will ensure that the correct output power is used for the PDSCH. 10. The Max Power (dBm) Values in the template include 3 dB of TX diversity gain. Atoll uses this power value as a starting point for calculating power levels for each of several different channel types. then an additional 3 dB should be added to Max Power (dBm). 11. again assuming 2 TX antennas. If using the Motorola template.26 46.26 46. Note that the power entered here is not the exact power used in computing the base station EIRP for signal strength prediction. Table 2: Max Power (dBm) LTE AP Product eNB Tx Power per antenna (dBm) TX Combining Gain Max Power (dBm) PDSCH Power (dBm) Frame Based 46 2x2 RRH 43 4x4 RRH 40 4x8 RRH 40 Horizon II 43 3 3 6 6 3 3 3 49.26 46. The SCH & PBCH EPRE Offset / RS (dB) is the difference in the energy of a resource element belonging to the SCH or the PBCH with respect to the energy of a reference signal resource element. Max Power (dBm) is the cell’s maximum transmission power.26 46. 9. If 4 TX are to be used. This value is used to calculate the transmission power corresponding to the primary and secondary synchronization channels and the physical broadcast channel. 10 below) and PDSCH & PDCCH EPRE Offset / RS (dB) (described in Note. 12 below).LTE RF System Design Procedure . The calculated power level used in signal strength prediction depends on the number of resource elements for the given channel type. The reception equipment parameters are used in uplink calculations. this field is set to -20 dB. or D-UDD D-UDD can be selected in Atoll v2. “U” being an uplink subframe. this field is set to Proportional Fair by default. this field is automatically set to “Motorola eNB Reception (UL)”. D-UUD D-UUD. This field is used in the simulation process and setting this to null disables it from serving as an upper limit on users being scheduled. The choice of TDD Frame Configuration determines the number of DL and UL subframes per frame. please see the Atoll User’s Manual.8.LTE RF System Design Procedure . Refer to Section 10. The TDD Frame Configuration is the frame configuration used when the selected frequency band for the cell is designated as a TDD band in the Transmitters Æ Network Settings Æ Frequencies Æ Bands interface. a frame configuration of type D-UUU D-UUU.3 iProtect: Internal Page 95 . Note. This parameter acts as a boundary threshold for the downlink and uplink coverage area. 14. The Reference Signal C/N Threshold (dB) defines the minimum reference signal C/N required for a user to be connected to this sector. The LTE Equipment field specifies the reception equipment from an LTE Equipment list. Note. Motorola’s design procedure is focused on the PDSCH and setting the EPRE Offset to 0 will ensure that the correct output power is used for the PDSCH.) If the Motorola base station templates are used.0. 16. If the Motorola base station templates are used. where the pattern represents subframe usage with “D” being a downlink subframe. Revision 1. The Scheduler field defines the scheduler that is used by the sector for resource allocation during Monte Carlo simulations. If using the Motorola template. this value will be set to 0 dB. If the C/(I+N) level at a pixel is below this threshold. The appropriate scheduler is chosen from a Scheduler list.7 for more information. A setting of -20 dB ensures that the Reference Signal C/N Threshold will not override the Prediction coverage threshold. When using the Motorola base station templates. Note. (For more information regarding scheduler lists. Note. which impacts the DL and UL throughput values that are displayed in the throughput plots as well as the throughput values reported in Monte Carlo simulation results. The Motorola base station template sets this field to null which is the recommended setting.Atoll used to calculate the transmission power corresponding to the physical downlink shared channel (PDSCH) and the physical downlink control channel (PDCCH). 12. 13. Note. 15. The Max Number of Users field defines the maximum number of simultaneous users supported by the sector. If the network’s switching point periodicity is set to "0-Half Frame" in the TransmittersÆ Properties Æ Global Parameters interface. the pixel will not be included in the C/(I+N) coverage area. 8. If the system being designed is TDD. the TDD frame configuration field is left blank. within Atoll.3 iProtect: Internal Page 96 . those DL & UL percentages are 54. Note: Both ML-CAT and Atoll estimate TDD capacity by taking FDD capacity and scaling it by DL and UL factors which represent the number of subframes (and consequently the fraction of subframes) utilized by the particular direction. The choice of frame configuration should also consider coexistence requirements with other non-LTE TDD systems. Channel throughput estimations will be scaled on the basis of the TDD configuration selection according to the number of subframes for the direction. then the appropriate TDD Frame Configuration must be selected and the frequency band for the cell must be a TDD band (refer to Section 7. the DL & UL percentages are both 40%.2.LTE RF System Design Procedure .3% and 40%. This corresponds to 4 subframes for the UL and 4 subframes for the DL plus a fraction of the special subframes for the DL as well (that number is 10 symbols out of 14 corresponding to special subframe configuration #7).e. i. which is D-UUU D-UUD. 5ms and 10ms) is to accommodate coexistence between a TDD LTE system and other non-LTE TDD systems. Table 3: TDD configurations TDD Configuration DL%/UL% Split D-UUU D-UUU D-UUD D-UUD D-UDD D-UDD D-UUU D-UUD (Atoll v2. for TDD config #1.e.8. If the network’s switching point periodicity is set to "1-Frame".1 for further information on configuring frequency bands). D-UUD DDDDD. no special consideration is given Revision 1.2. The choice of TDD frame configuration should coincide with the actual expected DL/UL traffic usage as dictated by the planned services for the network.1) D-UUU DDDDD D-UUD DDDDD D-UDD DDDDD 25/75 50/50 75/25 37/63 67/33 78/22 89/11 If using the Motorola template.Atoll and “-“ for a special subframe with guard period. Atoll 2. a frame configuration of type D-UUU DDDDD. But. Within ML-CAT. or D-UDD DDDDD can be selected. respectively. The purpose for having two different DL/UL switching point periodicities (i.1 is currently scheduled to add one more selection option for the half frame periodicity. indicating FDD as the default operation. The associated DL/UL split percentages for these configurations are as shown in the following table. 1.LTE RF System Design Procedure .36 (for TDD configuration #1.0. The recommended setting is a function of the transmission mode being modeled (refer to Table 7). or AMS) supported by the sector in the downlink. Transmit Diversity. If the reference signal CINR is below the AMS & MU-MIMO Threshold (dB). i.3%). Note that Atoll will only apply the selected eNB TX scheme in an analysis if the selected terminal for the analysis has its diversity support set to MIMO (refer to Section 7. Diversity Support (DL) is the type of antenna diversity technique (None.Atoll the fraction of DL traffic that can fit into the special subframes. Note. Until the fix arrives. special sub-frame configuration #7). then the Diversity Gain (dB) value from the Equipment MIMO interface is applied to the C/(I+N) calculations. then the MIMO Gain curve from the Equipment MIMO interface is applied to Tput calculations. it is reasonable to take the resultant DL TDD capacity from Atoll and scale it up to account for the special subframes. The following table describes the impact of this selection. SU-MIMO. This means the DL traffic within Atoll is scaled down too much (40% instead of only 54.3/40 or 1. Diversity Gain (dB) is not applied to the CINR calculations. iProtect: Internal Page 97 . AMS If the reference signal CINR is above the AMS & MU-MIMO Threshold (dB) from the Cells interface. Table 4: Diversity support Revision 1.3 for information on terminal settings). This field is set to a single appropriate value for both coverage and capacity analysis.3 Diversity Support (DL) Effect on Analysis Transmit Diversity Diversity Gain (dB) value from the Equipment MIMO interface is applied to the C/(I+N) calculations SU-MIMO MIMO Gain curve from the Equipment MIMO interface is applied to Tput calculations. 17.e. Forsk has acknowledged this scaling inaccuracy (FR #24542) and the fix is planned for v3. scale by 54. None No gain is applied to either the Tput or CINR calculations. In uplink throughput calculations. This is the recommended setting for coverage analysis. 19.Atoll Note. Note. by default. The MU-MIMO Capacity Gain (UL) field defines the uplink capacity gain due to multi-user (collaborative) MIMO. so that the system design is based on modeling a fully loaded system. If the cell traffic load is limited by this value. then the MU-MIMO Capacity Gain value from the Cells interface (refer to Note. the MU-MIMO gain is set to a value of 1.) Note. If the Motorola template is used. Note. indicating no gain. Note. MU-MIMO is the one additional option for the uplink as compared to the selection options described in the table above. 22. the cell will not be allowed to have a downlink traffic load greater than this maximum traffic load. SU-MIMO. This limit can be taken into account during Monte Carlo simulations. Diversity Support (UL) is the type of antenna diversity technique (None. (If the Motorola base station templates are not used. If the cell traffic load is limited by this value. (For more information on Adaptive MIMO switching. the cell will not be allowed to have an uplink traffic load greater than this maximum traffic load.3 iProtect: Internal Page 98 . If MU-MIMO is selected. or MU-MIMO) supported by the cell in uplink. in this value must be changed to something greater than 1. Receive Diversity. The Traffic Load (UL) (%) field defines the uplink traffic load percentage. If it is desired to include MU-MIMO gain. Further information regarding MU-MIMO gain we’ll be forthcoming in a subsequent release of this document. SU-MIMO and AMS is not supported in the UL. please see the Atoll User’s Manual. 20 below for additional information on MU-MIMO Capacity Gain) will be used to scale the uplink throughput. 21. then the diversity support field will be set to Receive Diversity. The recommended setting is a function of the transmission mode being modeled (refer to Table 7). Atoll sets the uplink traffic load to 100%.) Revision 1. In the case of AMS. This limit can be taken into account during Monte Carlo simulations. 18. 20. since the subscriber equipment typically only has one transmitter. Within the Motorola template. the AMS & MU-MIMO Threshold (dB) field defines the reference signal threshold for switching from spatial multiplexing and Transmit Diversity as the reference signal conditions get worse than the given value.LTE RF System Design Procedure . Max Traffic Load (UL) (%) is the uplink traffic load not to be exceeded. 23. The MU-MIMO option can be selected if the goal is to scale the uplink throughput to model UL spatial division multiple access. AMS. the throughput will be multiplied by this gain at the pixels where MU-MIMO is used. The Motorola base station templates assume 100% as the default. Max Traffic Load (DL) (%) is the downlink traffic load not to be exceeded. Note. it is up to the end user to define the level of interference received. and the uplink noise rise can be set manually to actual network values or the values computed during Monte Carlo simulations can be used. The Traffic Load (DL) (%) field defines the downlink traffic load percentage. however. Unique and more accurate per-cell values of UL noise rise can be taken from capacity simulation outputs (see Section 10. refer to the Section 10 introduction and Section 10.7.1).2. and the uplink noise rise can be set manually to actual network values or the values computed during Monte Carlo simulations can be used. (If the Motorola base station templates are not used.7. The UL Noise Rise (dB) field defines the uplink noise rise in dB used for the UL interference when running static plots. for static UL CINR plots.4). Monte Carlo simulation results can be stored in the cells by clicking the Commit Results button in the simulation results dialog.1.3 iProtect: Internal Page 99 . as such. The allocation of RBs will depend on the selected scheduler parameters (see Section 7. The Motorola base station templates assume 100% as the default. consequently. Atoll does not compute interference from co-channel UE’s when running static UL CINR plots since the UE locations are not known. Note. 25. this is only an estimate and.7. Revision 1.Atoll Note: The values for uplink and downlink traffic loads. By default. Atoll automatically accounts for the number of UL RBs used on the UL while the recommended approach of producing throughput images to represent system coverage is being followed (see Section 9.) Note: The values for uplink and downlink traffic loads. The Motorola base station templates assume a setting of 3 dB. the downlink traffic load is set to 100%.3. For further information regarding values derived from Monte Carlo simulations.4). 24. Note. Monte Carlo simulation results can be stored in the cells by clicking the Commit Results button in the simulation results dialog. It reflects its source which is either Monte Carlo simulations or userspecified values. Atoll sets the downlink traffic load to 100%. Note: For further information regarding values derived from Monte Carlo simulations. Rather. so that the system design is based on modeling a fully loaded system.2. the UL CINR plot must be considered as approximate only. by default. refer to the Section 10 introduction and Section 10.LTE RF System Design Procedure . Note: This field is an output and. purely informational. The UL noise rise is impacted by the number of UL Resource Blocks being used for the UEs. this field is automatically set to the Motorola recommended value of 32. this field is automatically set to the Motorola recommended value of 32. 26. This dialog window is accessed by clicking on the browse button (“…”). This value is automatically assigned when creating a new cell.1. Transmitter Properties .3 iProtect: Internal Page 100 . The Max Number of Intra-technology Neighbors field defines the maximum number of neighbors from within the same Atoll document (project) that the sector can have. The effect of these downlink interferences can be seen in the predictions for which downlink interferences may have an effect. The Comments field allows the user to enter comments regarding this sector. Note. This value represents the downlink interferences from external mobiles on the mobiles in the system. but can be modified afterwards. if desired.LTE RF System Design Procedure .Propagation Tab The Propagation Tab within the Transmitter Properties window defines the propagation models that are associated with the given sector. The effect of this uplink interference can be seen in any prediction for which uplink interferences may have an effect. 27. 29. This noise rise is added to any calculation of the mobile downlink interferences. This value is normally set at the template default of 0 dB. The Inter-technology DL Noise Rise (dB) field defines the downlink noise rise that will be used in the calculations of downlink inter-technology interference. The Inter-technology UL Noise Rise (dB) field defines the uplink noise rise that will be used in the calculations of uplink inter-technology interference. The Layer field defines the order of the cell among all the cells of the transmitter. The order is used during calculations for selecting the service cell. Additional information regarding Serving Cell Selection can be found in the section on Global Transmitter Parameters (Section 7.) 7. This noise rise is added to any calculation of uplink interference.2. Note. 30. please see the Atoll User Manual. Note. 28.Atoll Note. Note.1. The Max Number of Inter-technology Neighbors field defines the maximum number of neighbors from other technology documents (projects) that the cell can have. (For information regarding defining neighbors. The browse button will appear if Apply is clicked. Note. If the Motorola base station templates are used. This value represents the uplink interference from external transmitters or mobiles. This must be a positive integer value. 32. Note that the browse button may not be visible in the Neighbors box if this is a new cell.1). If the Motorola base station templates are used. This value is normally set at the template default of 0 dB. 31. Atoll uses the propagation model Revision 1.4.2. Note. The Neighbors field provides access to a dialog window where the intratechnology and inter-technology neighbors can be set. Atoll either calculates the path loss at any point of the map in real time (e. Atoll uses the prediction minimum threshold to define the calculation radius for each transmitter. Atoll allows the user to calculate high resolution path loss matrices closer to the transmitter with one propagation model. and resolution) are defined for the extended matrix. If the calculation radius for the main propagation model is not defined and if the extended propagation model is not defined. (See Section 9 for more information regarding coverage resolution. the user can define a coverage resolution that is different from the resolution defined for the path loss matrices. calculation radius.Atoll defined for each transmitter to calculate losses along the transmitter-receiver path.3 iProtect: Internal Page 101 . By using two sets of calculation parameters. The path loss matrix contains a set of path loss values calculated on each pixel over a specified area. However. Atoll limits the scope of calculations to a defined area.) Revision 1. this can lead to lengthy calculation times. while reducing calculation time and storage size by using an extended matrix with a lower resolution and another propagation model further from the site. Point Analysis calculations) or it calculates a path loss matrix for each transmitter that will be considered in predictions. It is calculated based on a set of three parameters defined for the transmitter: o The propagation model o The calculation radius o The resolution By using the calculation radius. Note that when creating coverage predictions. Atoll will calculate the extended matrix only if all three parameters (propagation model.g. Atoll enables calculations to be made for two path loss matrices: a main matrix and an extended matrix.LTE RF System Design Procedure . Propagation Tab 4 1 2 3 5 NOTES: Note. The Propagation Model pull-down menu allows the user to choose the appropriate propagation model from the list of available models. This model takes terrain elevation and clutter into account. 1.LTE RF System Design Procedure . For cases where drive test data is not yet available to tune the model. For best results. Radius and Resolution for the main propagation matrix.3 iProtect: Internal Page 102 .Atoll Figure 57: Transmitter Properties . a set of default parameters for use with the SPM model has been developed. the SPM should be tuned to the particular environment of the market that is being designed. The Main Matrix portion of the Propagation tab defines the Propagation Model. These default parameter settings are incorporated into several different propagation model options that are included in the Motorola Revision 1. The recommended propagation model for use in most LTE designs is the “Standard Propagation Model (SPM)” or a version of this SPM model. Atoll template. (Further information regarding these propagation models can be found in Section 8. Other propagation models are also available within Atoll. Then. Note. Revision 1. Erceg-Greenstein (SUI). Note. If the Motorola base station templates are used. initial coverage estimates. the radius needs to be large enough to adequately model the coverage and interference surrounding the site. only the main matrix settings are given by default. The Extended Matrix portion of the Propagation tab defines the Propagation Model.). If the Motorola base station templates are used.) The Motorola base station templates include a propagation model for a default frequency band.g. this parameter is set to 25 m resolution. The use of one of these Motorola models is recommended until drive-test data is available to tune the SPM model for the given market. the use of both the main matrix and extended matrix allows the use of higher resolution closer to the site location and lower resolution farther out from the site. the resolution can be set to match the terrain resolution. The smaller the site radius. encompassing 2-3 rings of sites) or based on speed if trying to just get a quick estimate of RSSI values. Within the Motorola base station templates. 2.LTE RF System Design Procedure . However.g. for more detailed or final studies. the default radius is set to 5 km. etc. This can be used as a technique to improve the speed of the calculations. This default model in the template will need to be changed if the frequency for the system under design is different than the default. such as several statistical models that the user can select when running budgetary coverage studies (e. Cost-Hata. the faster the speed. As mentioned above.3 iProtect: Internal Page 103 . This value affects the speed with which Atoll results are generated. A separate model is included for each LTE frequency band.) Note.1. This value can be modified as required. The Resolution field defines the resolution corresponding to the path loss calculations within Atoll. 3. This value will need to be adjusted based on the expected cell range required to get accurate C/(I+N) calculations (e. 4. It may be advantageous to use higher values in this resolution field for quick. The Radius field allows the user to specify a maximum cell range. (Please see Section 8 of this document and the Atoll User Manual for further information regarding the propagation models. Radius and Resolution for the extended propagation matrix. LTE RF System Design Procedure - Atoll Note. 5. Atoll automatically checks the validity of the path loss matrices before calculating any coverage prediction. The Available Results portion of this window reports the results of this validity check. For further information on this topic, please see the Atoll User Manual. 7.1.2.1.5. Transmitter Properties - Display Tab The Display Tab within the Transmitter Properties window defines how the sector will be displayed. Figure 58: Transmitter Properties - Display Tab As can be seen in the figure above, the Display tab provides the access to the display parameters for this sector. The Display Parameters dialog window allows the user to change the color, size, and symbol for the object that represents the sector within the display. Atoll can be set to automatically use different colors for the sectors (transmitters) in a system. Automatically setting the transmitter colors helps in displaying the sites since each transmitter will have a different color (though colors from one site to another may be reused). Also, setting the transmitter colors before running images ensures that the images will also be colored (rather than shades of gray), such as the Coverage by Transmitter image. The following steps can be used to automatically set the coloring of all transmitters: 1. Right-click the Transmitters folder and select Properties, as seen below. Revision 1.3 iProtect: Internal Page 104 LTE RF System Design Procedure - Atoll Figure 59: Selecting Transmitters Properties 2. Select the Display tab and set the Display type to Automatic, as seen in the following figure. Figure 60: Transmitter Properties Automatic Display 3. This step and the following two steps are not required for automatically coloring the transmitters. However, these steps are included to show how to change the transmitter display symbol, if desired. Click on the symbol shown under the Display Type and a Display parameters dialog window will appear. Revision 1.3 iProtect: Internal Page 105 LTE RF System Design Procedure - Atoll Figure 61: Transmitters Display Parameters 4. In the Symbol pull-down list, select the last symbol from the list (i.e. the beamwidth related transmitter symbol). Figure 62: Changing the Transmitter Display Symbol 5. Click OK within the Display parameters. 6. Click OK within the Transmitter parameters window. 7.1.2.2. Making Global Changes to Transmitter Data As seen in the previous subsections, the parameters for a specific site can be changed through the Transmitter Properties window for that specific site/sector. However, if the user wants to make global changes to the parameters for several sites/sectors at once, then it is necessary to open the Transmitters and/or Cells Tables. This section will provide information regarding making changes to the Transmitters Table. Similar types of changes can be made to the Cells Table, which is discussed further in Section 7.2.4.1. Revision 1.3 iProtect: Internal Page 106 LTE RF System Design Procedure - Atoll To open the Transmitters Table, right-click on the Transmitters folder and select Open Table, as seen in the following figure. Figure 63: Accessing the Transmitters Table This opens up the Transmitters Table as seen in the following figure. Figure 64: Example Transmitters Table As can be seen in this figure, the transmitter related fields (not including the cell table fields) are contained within this table. This table is especially useful when making global changes to a field or when making changes for a group of sectors. For example, if it is desired to change the height of all of the antennas, the user can change the antenna height of the first sector within the table and then copy this value to all of the other sectors. Similar to Excel spreadsheets, a shortcut method to copy the first value in a column of an Atoll table to the rest of the rows is to click in the column heading field to select the column and then hit Ctrl-d. Revision 1.3 iProtect: Internal Page 107 LTE RF System Design Procedure - Atoll For information on how to more easily make group changes, refer to “Copying and Pasting in Tables” and “Grouping, Sorting, and Filtering Data” in the Atoll User Manual. 7.2. Network Level Parameters Various LTE parameters are set on a network level within Atoll. These parameters define information such as the network frequencies, bearer information, quality indicators, schedulers, MIMO configurations, cell information, and equipment settings. The Motorola template contains default settings for these parameters. 7.2.1. Global Transmitter Parameters The Global Transmitter Parameters define the frame structure, TDD, and Power Control parameters for the system. The Motorola template contains default settings for these parameters. However, these settings need to be reviewed and updated by the user to ensure that they are set appropriately for the given market configuration. The Transmitter Global Parameters are accessed by right-clicking on the Transmitters folder and selecting Properties, as shown in the following figure. Figure 65: Accessing Global Transmitter Parameters This opens up the Transmitters Properties dialog window. The following figure shows the Global Parameters tab within this dialog window. All of the values in the Frame Structure section of this interface impact the estimated throughput values that are produced by Atoll. Revision 1.3 iProtect: Internal Page 108 normal cyclic prefix results in 7 OFDM symbols per slot being used in the throughput calculations whereas selecting the extended cyclic prefix results in only 6 OFDM symbols per slot being used in the throughput calculations.3 iProtect: Internal Page 109 . PHICH. 2. Note. In Atoll.Atoll Figure 66: Global Transmitter Parameters Interface 1 2 3 4 5 6 7 8 NOTES: Note. Using the default. PDCCH overhead is set to a default value of 3. Revision 1. Their corresponding overheads are hard-coded in Atoll in accordance with the 3GPP specifications. When using the Motorola template. The PBCH. LTE supports two cyclic prefix types: normal and extended. The Physical Downlink Control Channel (PDCCH) can take up to 3 symbol durations for PDCCH Overhead in each subframe in the downlink. 1. and PCH as well.LTE RF System Design Procedure . The Default Cyclic Prefix is set to 0 – Normal in the Motorola template. and the downlink reference signals consume a fixed amount of resources in the downlink. P-SCH. S-SCH. the PDCCH is considered to include the PCFICH. which is the initial cyclic prefix supported by Motorola LTE eNodeB’s. Revision 1. 7. 5. for safety against fast fading. Uplink Power Control Margin is the margin (in dB) that will be added to the bearer selection threshold.LTE RF System Design Procedure . The following table contains recommended typical values of PUCCH overhead as a function of bandwidth. and MIMO configurations). 3.e. The following global parameters are accessed via the Advanced button.4 1 3 2 5 4 10 8 15 12 20 16 Note. quality indicators. Note. Their corresponding overheads are hard-coded in Atoll in accordance with the 3GPP specifications. bearer information. The Adaptive MIMO Switching Criterion is set to Reference Signal C/(I+N).e. Note. The uplink demodulation and sounding reference signals consume a fixed amount of resources in the uplink. The Reference Signal EPRE is set to 0 in the template to specify that its value is derived from Max Power and EPRE Offsets. Note. for each cell according to the selected switching point periodicity.. frequency band. The Switching Point Periodicity (TDD only) can either be after each halfframe or each frame.3 iProtect: Internal Page 110 . the configuration of uplink and downlink subframes in a frame. 7. the end user must directly enter the PUCCH overhead. 4. Most of these parameters are set within the Motorola template and should not need to be changed.2. You can select the frame configuration.Atoll Note. Table 5: PUCCH RB's Bandwidth (MHz) PUCCH RB’s 1. The Serving Cell Layer Selection Method is set to Random. However. Network Settings The following subsections describe the input settings that define the network (i. i.2. when performing power control in the uplink. 8. schedulers. PUCCH Overhead is the number of resource blocks in the uplink that are used for the Physical Uplink Control Channel (PUCCH). 6. Note. Revision 1. However.Atoll 7. as of the time of writing this document the product plans for frequency band support have not been solidified. Frequencies The Frequency Band information is accessed by right-clicking on Transmitter folder in the Data tab and selecting Network Settings Æ Frequencies Æ Bands. as seen in the following figure.2. Figure 67: Accessing Frequency Band Information This opens up the Frequency Bands dialog window. These values should not need to be changed.3 iProtect: Internal Page 111 .1.LTE RF System Design Procedure . The following figure shows the window with the values that are set within the Motorola template.2. please contact PdM to check on the availability of eNB equipment in the desired frequency band for the system being designed. therefore. If the Motorola template is used within Atoll. the values for the frequency band parameters are set according the Motorola eNB product road map. 1. Note. Since each LTE frequency band has a specific channel bandwidth.LTE RF System Design Procedure .3 iProtect: Internal Page 112 . The Channel Width (MHz) field defines the channel bandwidth for the given frequency band. The Name field provides the name of the frequency band. a dialog window for that particular band can be opened by double-clicking in the column that precedes that frequency. This name will appear in other dialog windows where a frequency band is selected. if the user desires to update one frequency band. Alternately. 2.Atoll Figure 68: Frequency Bands Table 1 2 3 4 5 6 7 8 9 10 11 The input for the frequency bands can be entered directly into this table. NOTES: Note. Check with WiBB Product Management for actual or planned availability dates as the AP’s supported bands and channel bandwidths may change over time. it is recommended that the channel bandwidth be included as part of the frequency band name. Revision 1. Note. The recommended setting for the first channel is 0. The start frequency is determined by adding ½ the bandwidth from the edge of the frequency band. Note.3 GHz (i. If the Motorola template is used with Atoll. This value is set to default provided by Forsk of 28. The Number of Frequency Blocks (RB) field defines the number of 180 KHz wide frequency blocks contained within the channel bandwidth. 8. The values in the Motorola template are set according to the LTE specifications and should not need to be changed. Note. This method is chosen from the duplexing method list (FDD or TDD). If the frequency band has only one carrier. The Excluded Channels field defines the channel numbers which do not constitute the frequency band. For example. 4.LTE RF System Design Procedure . 5. 10.23 dB in the Motorola template. this value does not affect the results. Note. The Duplexing Method field defines the duplexing method used in the frequency band. Note. Revision 1. The FDD: UL Start Frequency (MHz) field defines the uplink start frequencies for FDD frequency bands. The TDD: Start Frequency. if the frequency band is 2. 9. The Adjacent Channel Suppression Factor (dB) field defines the adjacent channel interference suppression factor in dB. this value is already set for the given bands that are supported by Motorola equipment. 11. This value should be set accordingly for the system being designed. then the start frequency is 2300 MHz + 5 MHz. 3. The Sampling Factor field defines the sampling factor for converting the channel bandwidth into the sampling frequency. The Last Channel field defines the number of the last channel in the given frequency band. 6. Note. enter the same number as entered in the First Channel field.Atoll Note. FDD: DL Start Frequency (MHz) field defines the start frequency for TDD frequency bands and the downlink start frequencies for FDD frequency bands. this value is already set correctly for each frequency band.e. Note. Note. and since there is no overlap. this value is set appropriately. 7. If using the Motorola template with Atoll. 2300 MHz at the lower edge) and the channel bandwidth is 10 MHz.3 iProtect: Internal Page 113 . Interference received from adjacent channels is reduced by this factor during the calculations. or 2305 MHz. This value only impacts channel overlap. If using the Motorola template. this value is already set based on the LTE specifications. If using the Motorola template within Atoll. if any. The First Channel field defines the number of the first channel in the given frequency band. The first set of bearers is numbered 1 – 29 for the downlink and the second set of bearers is numbered 30 – 58 for the uplink. The information in the following figure is based on the Motorola template settings and is for the downlink bearers. each row represents a separate bearer. as seen in the following figure. therefore. In this window. Figure 69: Accessing the LTE Bearer Parameters This accesses the following LTE Bearers parameters dialog window.3 iProtect: Internal Page 114 . Revision 1. The LTE Bearers parameters are accessed by right-clicking on the Transmitter folder in the Data tab and selecting Network Settings Æ LTE Bearers.2. the values for the LTE bearer parameters are set within the tool to match what is supported by Motorola products.2. If the Motorola template is used within Atoll. The coding rates are slightly different on the downlink as compared to the uplink for LTE. LTE Bearers The LTE bearer table defines the modulation and coding schemes that are used within Atoll for uplink and downlink. the LTE bearer table contains two sets of bearers with 29 bearers in each set.2.Atoll 7.LTE RF System Design Procedure . 3. The Name field provides the name given to the specific bearer. 1. Note. 4. The Radio Bearer Index field provides the index that is used to identify the bearer in other tables (e. 2.Atoll Figure 70: DL Bearers Dialog Window 1 2 3 4 5 NOTES: Note. Revision 1. Note.LTE RF System Design Procedure . The Modulation field provides the modulation that is used for the bearer (QPSK.3 iProtect: Internal Page 115 . Note. The Channel Coding Rate field provides the coding rate for the bearer. the bearer selection thresholds and the quality graphs in the LTE reception equipment tables). This name appears in other dialog windows and results. 16 QAM or 64 QAM).g. assuming that BLER=0. The Bearer Efficiency (bits/symbol) field provides the number of useful bits that the bearer can transfer in a symbol.117188 * Log2(4) = 0.3 iProtect: Internal Page 116 . The information in the following figure is based on the Motorola template settings and is for the uplink bearers. The Bearer Efficiency is calculated using the following formula: Bearer Efficiency = (1-BLER) * r * Log2(M) where BLER is the block error rate. As an example.LTE RF System Design Procedure . the bearer efficiency of a QPSK 0. Figure 71: UL Bearers Dialog Window Revision 1.Atoll Note.12 bearer is (1-0)*0. 5. r is the channel coding rate. This information is used in throughput calculations. and M is the modulation rate.234375 bits/symbol. BLER is synonymous with FER. The values in this table should not need to be changed. Figure 72: Accessing Quality Indicators This accesses the Quality Indicators table as shown in the following figure.3.3 iProtect: Internal Page 117 . If the Motorola template is used within Atoll.LTE RF System Design Procedure . Quality Indicators Quality indicators are used in Atoll as part of the Effective MAC Channel Throughput Calculation. Revision 1.2. The Quality Indicators table can be accessed by right-clicking on the Transmitter folder in the Data tab and selecting Network Settings Æ Quality Indicators. as seen in the following figure.Atoll 7. the values for the Quality Indicator parameters are set within the tool to match what is supported by Motorola products.2. Only the BLER row is included in the template. The Quality Indicators table lists the quality indicators that are used in Atoll. The Used for Voice Services field checkbox indicates whether this quality indicator is used for voice services.7. 7. Note. Within Atoll. 3. frame error rate. The Used for Data Services field checkbox indicates whether this quality indicator is used for data services. If this checkbox is selected. and determine the fraction of the channel capacity that the user will be allowed to consume. Different scheduling methods and parameters influence how the allocation of resources is performed and the resultant capacity. this quality indicator is used for data services. The Name field provides the name of the Quality Indicator (bit error rate.6 of the Atoll 2.LTE RF System Design Procedure . Basic definitions for all scheduler parameters along with detailed procedures for accessing and modifying the scheduler table are found in “Defining LTE Schedulers” (Section 12. assign bearers. packet error rate). In the UL direction.1 User Manual).3 iProtect: Internal Page 118 . Revision 1. If this checkbox is selected. schedulers perform resource allocation. the scheduler will prioritize users. The balance of this section will provide Motorola recommendations/suggestions for the various parameters. this quality indicator is used for voice services. Schedulers In Atoll.2. 2.8. 1. the scheduler will also allocate the number of frequency blocks and transmit power to be used.Atoll Figure 73: Quality Indicators 1 2 3 NOTES: Note.4. Note. block error rate.2. a harmonic mean across the MPR/CINR distribution). resource elements) across users. note how the PF scheduler. PF will yield a capacity that is a mix of PD (for MinTD) and PF (for MaxTD).Atoll The Schedulers table can be accessed by right-clicking on the Transmitter folder in the Data tab and selecting Network Settings Æ Schedulers.3 iProtect: Internal Page 119 . then the resultant capacity from invoking PF would approximate a Full Buffer model and would represent an upper bound on capacity.e. The Max Aggregate Throughput method is not recommended for use inasmuch as it prioritizes users solely on the basis of signal quality and. the resultant capacity can be seen as a lower bound on capacity. it will be too detrimental to cell edge performance.e.LTE RF System Design Procedure . very low MinTD and high MaxTD). a user with an MPR of 5 would enjoy a throughput that is 5 times better than that of user with an MPR of 1. but only after satisfying the Min Throughput Demand (MinTD). When invoked. As an estimation of real-world modeling of capacity. the fraction of total resources) in a fairly uniform fashion across all the bearers (represented by their DL Channel Throughput (CTP) values). is filled with the default template values. effectively. Figure 74: Schedulers Window Names/Scheduling Method The names found within the template are created to match the scheduling method. Scheduling methods are applied in the effort to satisfy the Max Throughput Demand (MaxTD). as shown below. although this would yield a high capacity. When invoked. the use of the PF scheduler method in conjunction with realistic service parameters for MinTD and MaxTD is recommended. Proportional Fair (PF) is a scheduling method that seeks to equalize the number of resources (i. Proportional Demand (PD) is a scheduling method that seeks to equalize throughput across users regardless of signal quality (i. parameterized to approximate Full Buffer. allocates resources (%Res. PD is the scheduling method automatically used in satisfying the MinTD. In the following figure.e. Revision 1. The table. Note that. With this method. Were the services parameters to be set as non-constraining (i. 000 CTP (kbps) Target Throughput for Voice Services & Target Throughput for Data Services In defining the services parameters Max Throughput Demand (MaxTD).000 10.000 30. it is only here in the scheduler definition that we specify the layer to which these target throughputs apply. This means that target throughputs can be specified at any layer within the services as long as the corresponding layer is identified Revision 1.000 20.000 25.000 15.Atoll Figure 75: Example of PF Scheduling (~Full Buffer) DL CTP vs %Res 9% 8% 7% %Res 6% 5% 4% 3% 2% %Res Avg %Res 1% 0% 0 5.000 25.000 35.LTE RF System Design Procedure .000 35.000 10. throughput values were specified. the fraction of total resources) in a non-uniform fashion across bearers (represented by their DL Channel Throughput values) in an effort to equalize user throughputs.000 30. But.000 CTP (kbps) In the figure below. Figure 76: Example of PD Scheduling DL CTP vs %Res 20% %Res 18% Avg %Res 16% 14% %Res 12% 10% 8% 6% 4% 2% 0% 0 5. note how the PD scheduler allocates resources (%Res.000 15.3 iProtect: Internal Page 120 . Min Throughput Demand (MinTD). and Average Requested Throughput (ART).000 20. i. The candidate bearers would be those that a) are less than or equal to the highest bearer specified for the service and b) have bearer selection thresholds that are lower than the CINR that the subscriber experiences (assuming use of all frequency blocks). there is a difference at the lowest bearer where HARQ gain is being employed and Peak and Effective throughputs diverge beyond 10%. The three options available include: Bearer Index. With that in mind.2 + 3. Although. The default of Peak RLC Throughput is proposed for use. Of the candidates. Uplink Bandwidth Allocation Target The three options available include: Full Bandwidth. the same bearer is chosen as best. The default (template) value of Best Bearer is recommended for use in conjunction with the Peak RLC Throughput bearer selection criterion. Peak RLC Throughput. there would be no real significant difference regardless of which option is selected. Refer to the description below of UL Bandwidth Allocation Target for additional information related to this topic. and Effective RLC Throughput.2 kbps may be directly specified as the target throughput as long as an appropriate Application Throughput Scaling Factor is specified to account for the overheads between Layer 1 and the application layer (e. no matter which option is selected. extend or “maintain” coverage. it is not only possible but likely that a lower bearer with a larger bandwidth allocation will actually achieve a higher throughput than a higher bearer with a smaller bandwidth allocation. the difference between Peak and Effective throughputs is a fixed 10%. On the other hand. be utilized by the subscriber. therefore.2 kbps or ~8 bytes of overhead). all frequency blocks. The Best Bearer (BB) option performs like the MC option. therefore. in this manner.LTE RF System Design Procedure .g. The Full Bandwidth option is not to be used. This is because both the peak and effective throughputs are increasing with CINR and the bearer indices are also chosen to increase in number with increased bearer efficiency.2 / (12.Atoll here. but also evaluates whether a higher order bearer with fewer frequency blocks can be preferred to a lower Revision 1. The choice must be consistent across all voice type services and across all data type services. The Application layer may be specified to make the target throughputs more recognizable or to be closer in value to those throughputs specified by the customer. for the full rate AMR (Adaptive Multi-rate) vocoder. Full Bandwidth requires that the entire bandwidth. the “best” bearer is selected based on the criterion specified via this scheduler parameter.3 iProtect: Internal Page 121 . Maintain Connection. It is strongly recommended that the Bearer Index not be used as the Bearer Selection Criterion.e. it is recommended that Peak targets not be used for specifying data services. For example. For the downlink. generally.2) = 21% would be sufficient to account for 3. the coding rate of 12. Bearer Selection Criterion Bearer selection involves first establishing a set of candidate bearers. the difference for the UL can be very significant. and Best Bearer. This is because the bandwidth allocation on the UL can vary (depending on the option selected for UL Bandwidth Allocation Target) and. This Full Bandwidth requirement will drive subscribers on the cell edge into outage unnecessarily as the devices will not be allowed to trade off Frequency Blocks to increase power-per-subcarrier and. a scaling factor of 3. This is exactly what is accomplished with the Maintain Connection (MC) option. LTE RF System Design Procedure .000 CTP (kbps) 7.000 4.2.000 12.000 14.000 16.8 described how the user can access and modify the base station parameters using the Station Template Properties dialog. as seen in the following figure. Revision 1.000 8. the user can also access the base station template parameters through the Station Templates table. Figure 77: Bearer Selection Criterion UL CTP vs FB 60 50 40 FB UL CTP vs FB 60 30 FB Avg FB 50 20 40 10 FB FB 0 0 2. the chart in the lower right shows Best Bearer in conjunction with the Bearer Index selection method.2.000 4.000 18. Conversely.000 20 10 0 0 2.000 CTP (kbps) 12.000 10.000 18.000 8. BB is the only option that can search bearers beyond the original set of candidates.000 6.Atoll order bearer with more frequency blocks.2. The Station Templates table can be accessed by right-clicking on the Transmitter folder in the Data tab and selecting Network Settings Æ Station Template.000 16.000 6. Section 5. Note how the highest order UL MCS (represented by the high Channel Throughput) has been allocated in nearly all of the cases. In the figure below.000 14. This is because the set was formed on the assumption of the entire bandwidth being utilized and the BB option changes this assumption. However. Station Templates As discussed in Section 5.2.5.000 Avg FB 30 10. there are several LTE Base Station templates within Atoll that allow the user to set the parameters for various base stations so that the user can then create new sites with these specific parameters.3 iProtect: Internal Page 122 . the chart in the upper left shows Best Bearer with Peak Throughput selection method. This last distribution is more realistic and leads to the recommendation to use this combination. 3 iProtect: Internal Page 123 .Atoll Figure 78: Accessing Station Templates Table This accesses the following Station Templates table. Figure 79: Station Template Table When using the Motorola-specific project template. Product management should be consulted to determine eNB availability for the specific frequency band and configuration desired. please note that product availability is subject to change.LTE RF System Design Procedure . However. Revision 1. the base station template table reflects the Motorola AP products. 3 iProtect: Internal Page 124 . The TMA Equipment interface can be accessed by rightclicking on the Transmitter folder in the Data tab and selecting Equipment Æ TMA Equipment.Atoll 7.2.3. When using the Motorola template. the losses and noise figures are defined and not calculated from the parameters within the TMA.LTE RF System Design Procedure . TMA Equipment If tower mounted amplifiers are being used. Equipment Settings Several dialog windows within Atoll allow the user to define the base station and associated equipment (e. the equipment needs to be defined in the TMA Equipment interface. These properties can be automatically calculated by Atoll from the properties of the components or they can be defined by the user. 7. or BTS equipment configuration windows. Atoll uses the associated equipment properties to calculate the downlink and uplink losses and BTS noise figure of the transmitter. Figure 80: Accessing TMA Equipment Parameters This opens up the TMA Equipment dialog window as seen in the following figure: Revision 1.g. as seen in the following figure.2. tower mounted amplifier and feeder cables).3. feeder.1. 3 iProtect: Internal Page 125 . then the user needs to define this equipment and associated cable lengths within the appropriate dialog windows.Atoll Figure 81: TMA Equipment Window 1 2 3 4 NOTES: Note.e. Note. 1. The Name field provides the name of the TMA equipment. Note. 2. 3.LTE RF System Design Procedure .e. The following figure shows how to access the Feeder Equipment dialog window (i. Note. The Noise Figure (dB) field provides the noise figure associated with the TMA equipment. A positive value must be entered in this field. insertion loss) for the TMA equipment. Revision 1.2. 4. Feeder Equipment If the user desires to have Atoll automatically calculate the feeder losses based on specific feeder equipment and cable lengths. The Reception gain (dB) field provides the reception (uplink) gain for the TMA equipment. This name will appear in other dialog windows when selecting TMA equipment. The Transmission loss (dB) field provides the transmission (downlink) losses (i. A positive value must be entered in this field.2.3. by right-clicking on the Transmitter folder in the Data tab and selecting Equipment Æ Feeder Equipment). The Motorola template contains typical cable loss values for various cable diameters in the LTE frequency bands. Otherwise. 7. the user can define the overall losses for the feeder cables. LTE RF System Design Procedure .3 iProtect: Internal Page 126 .Atoll Figure 82: Accessing Feeder Equipment Parameters This opens up the Feeder Equipment dialog window as seen in the following figure: Revision 1. This value will be used in conjunction with the user-defined cable lengths to calculate the feeder loss values. 1. AVA650 1-1/4”. and AVA7-50 1-5/8” .LTE RF System Design Procedure . The Name field provides the name of the Feeder Equipment. This name will appear in other dialog windows when selecting Feeder Equipment.3 iProtect: Internal Page 127 . AVA5-50 7/8”. The Loss per length (dB/m) field provides the loss per meter associated with the specified feeder cable. A positive value must be entered in this field.Atoll Figure 83: Feeder Equipment Window 1 2 3 4 NOTES: Note. 2. Revision 1. Note. These loss rates are based on the following Andrew Heliax cables: LDF4-50A 1/2”. as seen in the following figure. Figure 84: Accessing BTS Equipment Parameters This opens up the BTS Equipment dialog window as seen in the following figure: Revision 1. A positive value must be entered in this field.LTE RF System Design Procedure . This interface can be accessed by right-clicking on the Transmitter folder in the Data tab and selecting Equipment Æ BTS Equipment.Atoll Note. 7.3. 4.2. The Connector transmission loss (dB) field provides the connector loss associated with the transmission (downlink) path. BTS Equipment The BTS equipment is modeled using the BTS Equipment dialog window. Note. 3. A positive value must be entered in this field.3.3 iProtect: Internal Page 128 . The Connector reception loss (dB) field provides the connector loss associated with the reception (uplink) path. 1. The Name field provides the name of the BTS Equipment. please see the Atoll User Manual. Note.1.3 iProtect: Internal Page 129 . Note. This name will appear in other dialog windows when selecting BTS Equipment. This field is not used at this time. For further information on this parameter. the typical Noise Figure for Motorola eNBs is 4 dB. Note. 5.2.Atoll Figure 85: BTS Equipment Window 1 2 3 4 5 NOTES: Note. The Downlink Losses due to the configuration (dB) field provides the losses on the downlink based on the BTS configuration. 1. Note. The Uplink Losses due to the configuration (dB) field provides the losses on the uplink based on the BTS configuration. 4. 3. As described in Section 7.LTE RF System Design Procedure . The Noise Figure (dB) field provides the noise figure associated with the specified BTS equipment. Revision 1. 2.2. The Rho factor enables Atoll to take into account self-interference produced by the BTS. The Rho factor (%) field provides the Rho factor associated with the BTS equipment as a percentage. 2.4. This figure and the remainder of figures in this section assume the use of the Motorola template. Figure 86: Accessing LTE Equipment Parameters The LTE Equipment interface provides the reception characteristics of cells and user terminals. as seen in the following figure.LTE RF System Design Procedure . The main LTE Equipment window is shown in the following figure. Figure 87: LTE Equipment Window Revision 1.Atoll 7.3. channel quality indicator graphs. Bearer selection thresholds. and MIMO configuration information are defined in the reception equipment. LTE Equipment The LTE Equipment interface can be accessed by right-clicking on the Transmitter folder in the Data tab and selecting Equipment Æ LTE Equipment.3 iProtect: Internal Page 130 . The information in the Motorola template is based on the bearer threshold information and includes AWGN SNR + fast fading for the specific mobility profile.2.1.LTE RF System Design Procedure .3 iProtect: Internal Page 131 .e. and MIMO.4. Bearer Selection Thresholds and Quality Graphs The Bearer Selection Thresholds tab provides Bearer Selection Thresholds for different mobility types. Double clicking on the area to the left of the “Name” column for any one of the LTE Equipment entries will open up the reception equipment properties dialog window for the selected equipment. A bearer is selected for data transfer at a given pixel if the received C/(I+N) ratio is higher than its selection threshold. 7. CPE and MS) contained in the Motorola template. The reception equipment properties window has three tabs: Bearer Selection Thresholds.Atoll The “Motorola UE Reception (DL)” contains the reception characteristics of the default subscriber terminals (i. The Bearer Selection Thresholds interface for the “Motorola UE Reception (DL)” is shown in the figure below. Quality Graphs. Figure 88: LTE UE Reception Equipment Window – Bearer Selection Thresholds A graph showing the C/(I+N) thresholds for each of the bearers can be accessed from the Bearer Selection Thresholds tab by clicking on the mobility type that is of interest Revision 1. as shown in Figure 88. The “Motorola LTE Reception (UL)” contains the reception characteristics of the eNodeB’s.3. 2.2). Figure 89 below shows a single example. within Atoll.3 iProtect: Internal Page 132 .1) at the bearer selection threshold CINR of 3.LTE RF System Design Procedure . when specifying mobility types for Monte Carlo simulations. These BLER curves are customized to the specific bearers and mobility types involved. The C/(I+N) Thresholds window shows both a chart and a graph of the C/(I+N) thresholds that are associated with each bearer.2.0194 dB. the BLER have been adjusted to scale the static peak efficiencies to effective efficiencies (see MPR versus EFF curves in Figure 90). the mobility type PB3 will access the coverage set while the mobility type PB3_Capacity will access the capacity set. Section 7. But.e. users should not be surprised to find some negative BLER values and also instances where the effective efficiency exceeds the peak efficiency. 0. In particular. The Quality Indicator Graphs are used in the computation of Effective MAC Channel Throughput. The capacity set is distinguished by having the suffix “_Capacity” appended to its mobility type name. The BLER begins at 10% (i. Figure 89: Quality Graph Revision 1.Atoll and then clicking on the Best Bearer Thresholds button. the capacity sets ought to be invoked. The bearers are listed by the bearer index (as discussed in the LTE Bearers interface. The graphs show the relationship of CINR to BLER for each bearer within each mobility type. The BLER then decreases as CINR increases. Each mobility type has two sets of bearer selection thresholds provided. BLER would ideally be 10% for most values of CINR (see Ideal MPR versus EFF curves in Figure 90). For example. one for coverage and one for capacity. Because of this translation. 2.2.7 Ideal MPR EFF > MPR (negative BLER) 0. At the lowest bearer (MCS0).1.4. Revision 1. Spatial multiplexing gains are modeled in Atoll using MIMO configurations.e.3.0 6.2. MIMO Configurations The third tab within the LTE reception equipment properties is the MIMO tab.0 10.8 EFF 0.9 MPR 0.0 8. radio bearer index and Max BLER). The MIMO capacity gain (Max SU- 3 The correlation to RS CINR as opposed to RS C/N is dependent on the setting of a transmitter global parameter. NOTE: If new bearer thresholds are needed. mobility type. then the Planning & Design group should be contacted to assist in the creation of new customized BLER curves. This BLER range is only used by the DL capacity curves which automatically include HARQ gain. Each row in this tab represents a different downlink or uplink path configuration with an associated Max MIMO and Diversity gain.0 CINR (dB) It is expected that BLER values will deviate from ideal 10% values for the lowest and highest bearers. perhaps for a new mobility type. At the highest bearer.0 5. increased CINR reduces BLER below 10% and eventually down to 0%.0 9. the BLER curves reflect a HARQ gain which correlates to an increase in BLER above 10% as increased retransmissions and de-rated effective throughput is traded for extended coverage.0 7.Atoll Figure 90: Effective MPR Effective MPR Efficiency (bits/symbol) 1. specific combinations of number of transmission and reception antennas.5 4.LTE RF System Design Procedure .3 iProtect: Internal Page 133 . Refer to Section 7. 7.0 EFF = (1-10%) x Ideal MPR 0.6 0. This tab defines MIMO and Diversity gains that will be applied depending on the specific equipment configuration for a given downlink or uplink path (i. A MIMO configuration contains MIMO graphs of capacity gain versus RS C/(I+N)3 for different numbers of transmission and reception antennas. Atoll MIMO gain) is defined as the increase in channel capacity compared to a SISO system (i. The row that represents the downlink path for this example is seen in the following figure. while the CPE subscriber has 1 transmission antenna and 2 reception antennas. The associated Max MIMO and Diversity gains for this path would be represented in the Motorola UE Reception (DL) equipment properties MIMO table in a row that contains 2 transmission antennas and 2 reception antennas. The Frame Based eNB has 2 transmission antennas and 2 reception antennas. When using the Motorola template.LTE RF System Design Procedure .3 iProtect: Internal Page 134 . Figure 91: Example Downlink and Uplink Paths between eNB and CPE Frame Based eNB Example 2 – TX antennas 2 – RX antennas Downlink case: 2 TX antennas at eNB. the increase in throughput due to MIMO). 2 RX antennas at sub Uplink case: 1 TX antennas at sub. as seen in the figure below. Take the case between a Frame Based eNB and a CPE subscriber. The structure of this MIMO tab can be illustrated further with an example. 2 RX antennas at eNB CPE Example 1 – TX antennas 2 – RX antennas Given this example. the Diversity gain field is used to represent Rx Diversity (MRC) gain.e. the downlink path from the eNB to the CPE contains 2 transmission antennas (at the eNB) and 2 reception antennas (at the subscriber). Revision 1. Atoll Figure 92: Example Downlink Path Represented in MIMO Tab In the DL. mobility. These values must be set by the user on the basis of the transmission mode. The complete set of 8 cases along with instructions for copying them into the project’s database can be found in the spreadsheet “AtollR282Params. processing as a single stream (“rank 1”) is assumed. and number of Tx antennas. Following are some notes pertinent to the use of this table.xls” located at Revision 1. • The table only shows a subset of the actual table sets. Table 6 below shows some example Max MIMO Gains specifications. means that 32% of the theoretical maximum is being obtained or 32% of the time rank 2 processing is being performed. When 2 data streams are being transmitted simultaneously using the same symbol resources (termed “rank 2” processing). mobility (PB3 and VA30). the use of both Diversity Gain and Max MIMO Gain fields requires that the terminal type be specified to support MIMO. The 4 combinations shown below correspond to the more likely scenarios because the performance of TM3 is best for vehicular mobility while TM4 is best for pedestrian.3 iProtect: Internal Page 135 . How much of the theoretical 2X maximum benefit is being captured for any particular RS CINR? A value of 1. • The R7 release of this design procedure represents Motorola’s first use of the Max MIMO Gain field to model MIMO’s capacity benefit. Consequently. The use of Max MIMO Gains also requires that the cell’s DL Diversity Support indicate “AMS”. and number of Tx antennas (2Tx and 4Tx). The gain values in the table are throughput scalars.LTE RF System Design Procedure .32. then the CINR is said to be “shared”. for example. While 68% of the time. The complete set represents 8 combinations transmission modes (TM3 and TM4). the DL Diversity Gain field will almost always be used. com/go/318588510.mot-solutions.3 iProtect: Internal Page 136 . • Atoll’s interface and database structure doesn’t facilitate the specification of different MIMO gain curves to reflect different mobilities for the same path configuration (e.Atoll http://compass.LTE RF System Design Procedure . user entering of these table values is needed. Refer to sheet “MIMO Tput Scalars”. PB3 and VA30 for 2x2 MIMO). For this reason.g. • The tables represent gain curves that have been derived from Minisim simulations. Revision 1. Revision 1.3 iProtect: Internal Page 137 . Following are some notes pertinent to the use of this table. • Four fields (highlighted in orange) correspond to Atoll parameters which must be specified per the antenna configuration desired. mobility.LTE RF System Design Procedure . and number of Tx antennas. Also included are the recommended values for Diversity Support and AMS Threshold. o Diversity Support (DL) is found in the Cells database.Atoll Table 6: Max MIMO Gains Table 7 below shows the recommended Diversity Gain settings for different combinations of transmission mode. • The tables represent values adjusted from the standard 3 dB and have been calibrated based on Minisim simulations to obtain alignment of CINR distributions. It is not the same as true 4x2 MIMO. for coverage purposes. a customer is interested in either Beamforming (TM7) or MIMO (TM3/4) (highlighted in green).g. i. 3 dB +/. o Mobility. under the Traffic tab of the traffic map properties window. • 2x2 MIMO implemented on 4Tx using CSD (Drop D) should be considered equivalent to 2x2 MIMO. • A difference between TM6 and TM7 is that TM7 utilizes UE-specific RS while TM6 uses cell-specific RS. • TM3/4Tx/PB3 (highlighted in grey) is a poor performing scenario and the scheduler. Generally.Atoll o AMS Threshold (dB) [more fully termed "AMS & MU-MIMO Threshold" within Atoll] is found in the Cells database. • Consult with PdM on which Transmission Modes (TM) are available and to be used. o Diversity Gain (dB) is found under the MIMO tab of the "Motorola UE Reception (DL) properties" window o Mobility. don't select this option. e. for traffic (Monte Carlo) purposes.LTE RF System Design Procedure . will select TM4 in preference. o Generally. Open Loop (OL) MIMO (TM3) performs better at vehicular speeds (VA30) while Closed Loop (CL) MIMO performs better at pedestrian speeds (PB3).3 iProtect: Internal Page 138 . Revision 1.e.1 dB. TM 6 (pre-coded beamforming) and TM 7 (beamforming) both show somewhat higher diversity gains which CINR improvement is consistent with a TxAA like benefit. o When the choice is MIMO. is specified under the Conditions tab of the prediction properties window. Beamforming could be considered as a special case of the extremely generic notion of (channel dependent) precoding. TM7 applies more classical beamforming (strives to form 1 localized beam in physical space) while TM6 applies the newer concept of pre-coded beamforming (where weights are chosen to form a beam in vector space). when given the freedom to mode switch. is specified in various manners. The adjustments are generally modest. Atoll Table 7: DL MIMO Parameter Settings Continuing with this example. Revision 1. the uplink path from the CPE to the eNB contains 1 transmission antenna (at the subscriber) and 2 reception antennas (at the eNB). The associated Max MIMO and Diversity gains for this path would be represented in the Motorola eNB Reception (UL) equipment properties MIMO table in a row that contains 1 transmission antenna and 2 reception antennas. The row that represents the uplink path for this example is seen in the following figure.LTE RF System Design Procedure .3 iProtect: Internal Page 139 . LTE RF System Design Procedure .3 iProtect: Internal Page 140 .Atoll Figure 93: Example Uplink Path Represented in MIMO Tab The following figure shows the MIMO tab for the Motorola UE Reception (DL) properties window. Revision 1. for a set antenna combination.). This field is set to “All” in the Motorola template since the MIMO and Diversity gains will be applied for all of the radio bearer index settings. Note. The parameter values are applied regardless of the radio bearer index. 1. vary based on mobility. the user will need to change these parameters manually.Atoll Figure 94: LTE Reception Equipment – MIMO Tab 1 2 3 4 5 6 7 NOTES: Note. The Number of Transmission Antenna Ports field provides the number of transmission antennas that are used for MIMO. but.3 iProtect: Internal Page 141 . given constraints in Atoll’s interface and database structure. This field is set within the Motorola template. This field allows the user to set up different MIMO and Diversity gain parameters based on different mobility settings.. Note.LTE RF System Design Procedure . This means that the MIMO and Diversity parameters are not set based on different radio bearer index settings (i. in fact. PB3. This field is set to “All” in the Motorola template since the MIMO and Diversity gains will be applied for all of the mobility settings. This field allows the user to set up different MIMO and Diversity gain parameters based on different radio bearer index settings. there is not a separate set of parameters for each radio bearer index). etc. 3. The Mobility field provides the corresponding mobility type from a pulldown menu (e.e. VA30. Revision 1. as required. 2. The Radio Bearer Index field provides the corresponding radio bearer index from a pull-down menu. MIMO and Diversity gain parameters will.g. This means that the MIMO and Diversity parameters are not set based on different BLER settings (i. This field allows the user to set up different MIMO and Diversity gain parameters based on different maximum BLER settings. The Max BLER field provides the corresponding Max BLER setting. all BLER settings). Revision 1. 4.e.e. The Max MIMO Gain field provides the maximum MIMO gain values that correspond to specific RS C/(I+N) levels for the given number of transmit and receive MIMO antennas. This field is set within the Motorola template. the UL Diversity Support will only specify Receive Diversity). Figure 95: Example MIMO Gain Graph Note. The following figure shows an example of one of these graphs.e. for a set antenna combination. there is not a separate set of parameters for various maximum BLER settings). The parameter values are applied regardless of the BLER setting. The MIMO Gain graphs can be seen by clicking on a specific row in the MIMO table and then clicking the “Max MIMO Gain Graphs” button. Note. This field is set to “1” in the Motorola template since the MIMO and Diversity gains will be applied for BLER settings up to a maximum of 1 (i.Atoll Note. The Number of Reception Antenna Ports field provides the number of reception antennas that are used for MIMO. these curves are not expected to be used since current product doesn’t support UL MIMO (i. Note: In the UL. 5. The MIMO Gain graphs provide an easier way to view this information.LTE RF System Design Procedure . 6. This field impacts the throughput results. Refer to Table 6 for recommended values.3 iProtect: Internal Page 142 . Revision 1. The Diversity Gain (dB) field allows the user to provide a receive diversity gain for the path with the specified number of MIMO transmission and reception antennas. For the uplink path. MRC) gain. it will not produce the desired results when doing Monte Carlo simulations. Refer to Table 7 for recommended values. as well as the specified mobility. the Diversity Gain field is used to incorporate the eNB Rx diversity gain so that it will impact the C/(I+N) calculations appropriately (since the Diversity gain field affects the C/(I+N) calculations in both the images and Monte Carlo simulations). Although this will produce the desired results for UL C/(I+N) and throughput images.4. the gain will impact the C/(I+N) calculations in both the images and Monte Carlo simulations. the information from the Cells Table and the Neighbors table can be accessed. the number of MIMO transmission antennas will represent the number of antennas at the eNB and the number of MIMO reception antennas will represent the number of antennas at the subscriber. The UL C/(I+N) image.LTE RF System Design Procedure . does not calculate interference from other subscribers. depending on the environment. A TxAA gain is included under TM 7. 7.e. The use of the base station diversity gain (negative loss) will result in higher signal strength and higher C/(I+N) images values.2. 7. that field only adjusts the total transmit losses by adding a negative loss. It uses the user-defined uplink noise rise.Atoll Note. radio bearer index. Although Atoll includes a specific field for entering base station diversity gain in the Transmitter Æ Equipment interface. In the cases where this MIMO table is representing an uplink path. However. The spatial transmit diversity gain is not included here. the number of MIMO transmission antennas will represent the number of antennas at the subscriber and the number of MIMO reception antennas will represent the number of antennas at the eNB. Cell Settings Within the Transmitter folder. and Max BLER settings. When using the Motorola template. the uplink noise rise is calculated by incorporating the interference from each subscriber. the Diversity gain field is used to represent Rx diversity (i. By incorporating the base station Rx diversity gain into the Diversity gain field of the MIMO interface. The Diversity Gain (dB) field can be adjusted to account for TXAA. when running Monte Carlo simulations. In the cases where this MIMO table is representing a downlink path. which also drives the throughput images. The following sections discuss these tables briefly. but is included in the transmit power.3 iProtect: Internal Page 143 . including diversity gain. as seen in the following figure. this table allows the user to easily make changes to settings in multiple sites/sectors. Revision 1.3 iProtect: Internal Page 144 .1.1. Similar to the Transmitters Table (discussed in Section 7.LTE RF System Design Procedure . right-click on the Transmitters folder and select Cells Æ Open Table. To open the Cells Table. This table provides the Cells parameter values for all of the sectors in the project.Atoll 7. Figure 96: Accessing the Cells Table This opens up the Cells Table as seen in the following figure. Cells Table All of the information that was seen in the Cells tab of the Transmitters Properties window (see Section 7.4.2).2.2.1.2.1.3) can be accessed in the Cells Table. ) Revision 1. (Although the Neighbors table is not required in the RF system design process. Neighbors The Neighbors table is accessed by right-clicking on the Transmitters folder and selecting Cells Æ Neighbors and then either Intra-technology Neighbors or Intertechnology Neighbors.LTE RF System Design Procedure . This table is especially useful when making global changes to a field or when making changes for a group of sectors.4.3 iProtect: Internal Page 145 .2. 7. the fields from the Cells tab of the Transmitter Properties are contained within this table.Atoll Figure 97: Example Cells Table As can be seen in this figure.2. as seen in the following figure. a brief description is included here for reference. Revision 1. if desired. Further information on the creation and use of neighbors can be found in the Atoll User Manual.Atoll Figure 98: Accessing the Neighbours Table This opens up the Neighbors Table as seen in the following figure. The neighbor relation between sites can be set up as symmetric. Figure 99: Example Neighbours Table The Neighbors table allows the user to specify the neighbors for each sector.LTE RF System Design Procedure .3 iProtect: Internal Page 146 . 3. the properties dialog window for that terminal will open.3 iProtect: Internal Page 147 . Each subscriber type is listed separately within the Terminals folder and has its own set of parameters. To access the subscriber parameter information.Atoll 7. This table contains the parameters for all of the terminals that are included in the project. as seen in the following figure. expand the Terminals folder within the LTE Parameters folder in the Data tab and then choose the desired terminal type. Subscriber (Terminal) Parameters The parameters associated with the subscriber units are located in the Terminals portion of the Data tab. The parameters can also be accessed by right-clicking on the Terminals folder and selecting Open Table. Figure 100: Accessing Terminal Parameters By selecting a specific terminal type. This section will go through the parameters that are associated with a subscriber unit. Revision 1. It also includes information regarding adjustments that may need to be made to the subscriber antenna gain due to the placement of the CPE in a non-line-of-sight environment and non-optimal orientation of the device. as seen in the figure below.LTE RF System Design Procedure . The Motorola template contains to default subscriber units (CPE and MS) along with their recommended parameter settings. Note. Note. 5. Note. 1. This name will appear in other dialog windows when selecting terminal equipment.3.Atoll Figure 101: Example Terminal Properties Window 1 2 3 4 5 6 7 8 9 10 11 12 NOTES: Note. These values should be changed if necessary for the specific UE equipment in accordance with the system being designed. as described in Section 7. The Name field provides the name of the terminal. Within the Motorola template. Within the Motorola template. The Losses field allows the user to enter any losses associated with this terminal. assuming that the subscriber antenna gain has not been Revision 1.LTE RF System Design Procedure . 3.1. 4. Within the Motorola template.3 iProtect: Internal Page 148 . The Max Power field provides the maximum power level associated with this terminal. the minimum power level for the terminals are set to 63 dB below the maximum power level to provide a range of 63 dB for power control. no losses are associated with any of the subscriber equipment. the noise figure values are set to representative values for the specific terminal equipment . Note. The Noise Figure field provides the noise figure that is associated with this terminal. 2. This field can also be used to account for antenna gain correction factors and orientation losses. The Min Power field provides the minimum power level associated with this terminal. Within the Motorola template. the maximum power levels are set to the representative values for the generic terminal equipment. Atoll modified to account for these factors.LTE RF System Design Procedure . 9. The Antenna Model field specifies the antenna model that is associated with this terminal. Note. Note. The “|<”. This parameter should be changed to the actual antenna model being used in the system design. Terminals capable of certain antenna diversity (i. be applied on a per-service basis (refer to Figure 183.1. Within the Motorola template. “>>”. The Number of Antenna Ports Reception field specifies the number of antennas that will be used by the subscriber terminal for reception with MIMO.e. Note. In either case.3.3 iProtect: Internal Page 149 . 8. this field is set to a representative antenna pattern.3. care should be taken to avoid double counting the body loss. 7. The Antenna Gain field shows the gain that is associated with the selected Antenna Model. Within the Motorola template. 12. Note 10).1 provides further discussion on adjustments that should be made to address the CPE antenna gain correction factor and orientation loss. 11. Within the Motorola template. As discussed in Section 7. Note.2. Note. so that the Rx diversity gain values will be used from the Diversity Gain fields in the MIMO table (see Section 7. 6. Within the Motorola template. 10. The subscriber antenna gain value that is set within the Motorola template is a representative value and should be changed to the actual antenna gain for the device being modeled.3 for additional information on importing to patterns in Atoll. Note. this value is set to 2 to represent a typical diversity receive device. Within the Motorola template. this value is set to 1 for all terminals since the signal is typically only transmitted on one antenna for the subscribers. MIMO was selected as the antenna diversity support for all terminals.4).4. The LTE Equipment field specifies the reception equipment for this terminal. The Number of Antenna Ports Transmission field specifies the number of antennas that will be used by the subscriber terminal for transmission with MIMO. preferentially. None or MIMO) will be allocated to cells that support the same type of antenna diversity. “<<”. these adjustments can be made to the antenna gain or to the terminal Losses field. >|” buttons allow the user to easily navigate from the properties window for one terminal type to the properties window for Revision 1. The Antenna Diversity Support field specifies the type of antenna diversity technique that is supported by the terminal.6. Section 7. Note.3.2.3.2). Body losses may be incorporated here on a per-terminal basis or. It is also important to note that the effective gain of the antenna at the CPE device may be less than the antenna gain specification due to the placement of the CPE in a non-line-of-sight scattering environment and non-optimal orientation of the device. Please refer to Section 6. this field is set to “Motorola UE Reception (DL)” (refer to Section 7. the CPE’s effective antenna gain in Atoll should be reduced by the AGCF provided above.com/go/310442223) provides details regarding this topic. Antenna Gain Correction Factor The Antenna Gain Correction Factor (AGCF) is a reduction of the antenna gain due to the installation of the subscriber antenna in an NLOS scattering environment.1. Variations between different CPE devices and how they are placed within the system may require an adjustment to the antenna gain.3. This section describes the antenna gain correction factor. The RF Planning Guide (http://compass. orientation.) Revision 1. 7. and lognormal fade margin standard deviation.mot.3 iProtect: Internal Page 150 .86 dB (i. 7 – 2. the user needs to open the specific antenna that is associated with the subscriber device and modify the gain. In order to reduce the antenna gain. the antenna orientation loss and the lognormal fade margin standard deviation adjustments that may be necessary to model the CPEs within the system.3.LTE RF System Design Procedure . The effective gain of the antenna at the CPE device may be less than the antenna specification due to the placement of a CPE in a non-line-ofsight (NLOS) scattering environment and non-optimal orientation of the device. Using the example above.86 could be entered in the terminal’s Losses field or the antenna gain should be reduced by 2.1. The user can either mover to the beginning or end of the terminal list or move one by one through the list in the backwards or forwards direction by using these buttons.1. This can be accomplished either by adding the AGCF value in the Losses field of the terminal or by modifying the gain associated with the antenna. CPE Antenna Variations Within a system design.86 dB). If a CPE antenna is placed within a NLOS scattering area. if a CPE antenna is placed in a NLOS scattering environment then a value of 2. 7. one must consider the antenna characteristics of the CPE and where the CPE will be located. where the antenna model is set to “CPE Antenna – 7dBi” with a gain of 7 dBi. (The figure below shows the properties of the CPE. For example.e.Atoll another terminal type. the user would need to reduce the antenna gain of the “CPE Antenna” model. 3 iProtect: Internal Page 151 . the user would then reduce the antenna gain for the CPE Antenna model by 2.Atoll Figure 102: CPE Device Properties Continuing this example. as seen in the figure below.LTE RF System Design Procedure .86 dB. Revision 1. as seen in the figure below.LTE RF System Design Procedure .86.86 dB to the losses associated with the CPE device. instead of reducing the antenna gain by the AGCF. To follow the example above. Revision 1.Atoll Figure 103: Reducing Antenna Gain by AGCF Alternatively. the user could add 2. instead of reducing the antenna gain by 2. the user could add this AGCF to the losses associated with the subscriber device and achieve the same results.3 iProtect: Internal Page 152 . • RF environment is likely to change. etc.e.e. This primarily applies to the case of a fixed CPE that has some directionality to the antenna pattern (i.Atoll Figure 104: Alternate Way of Incorporating AGCF If a non-Motorola subscriber device is being used. further information regarding this device and its antenna will be required to determine the appropriate antenna gain correction factor to be applied to the design. 7.3.3 • New sites added which could change optimal orientation • New construction or changes in foliage which may change optimal orientation • Changes in nearby obstructions (e. Antenna orientation loss should be included in the RF design if: • Devices are being randomly installed (i.) iProtect: Internal Page 153 . the device can be rotated or moved).LTE RF System Design Procedure .g. not perfectly omni).2.e. furniture. Antenna Orientation Loss The antenna orientation loss is a reduction in the performance of the antenna due to the antenna not being oriented in an optimal direction. • Devices are not fixed to the installed location (i. people.1. not optimally placed to insure orientation for maximum performance). Revision 1. com/go/310442223) provides details regarding this topic. 7. 7 – 2. if the antenna orientation loss is used in the design. As described in the previous section. then the CPE antenna gain should be reduced by 2 dB in addition to the reduction for the AGCF (i.e. See the previous section for further details on how to adjust the antenna gain or the subscriber device losses.3.LTE RF System Design Procedure .1. the mean values are used directly to reduce the CPE antenna gain parameter. a typical value of antenna orientation loss is 1 dB with 2 dB standard deviation. if a an with 2 dB of orientation loss is not optimally oriented within a system. σ xyz 2 = σ x 2 + σ y 2 + σ z 2 + 2 ρ xyσ xσ y + 2 ρ xzσ xσ z + 2 ρ yzσ yσ z Where σx Lognormal fading margin standard deviation σy Antenna gain correction factor standard deviation σz Orientation loss standard deviation ρ xy Correlation of lognormal fading margin and antenna gain correction factor ρ xz Correlation of lognormal fading margin and orientation loss Revision 1. The following calculation can be used to derive a joint lognormal fade margin standard deviation that incorporates the antenna gain correction factor and the orientation loss.mot. either the CPE antenna gain within Atoll is reduced by this orientation loss or this orientation loss is added to the Losses field of the terminal. For example. In order to quantify the antenna orientation loss. or the AGCF and antenna orientation losses can be added to the losses associated with the subscriber device. the antenna gain can be reduced for the specific antenna that is associated with the subscriber device.com/go/310442223).3.Atoll The RF Planning Guide (http://compass. The following information regarding adjusting the lognormal fade margin standard deviation due to subscriber antenna gain correction factor and the antenna orientation loss is taken from the RF Planning Guide (http://compass. Similar to the antenna gain correction factor.86 – 2 dB) or the 2 dB should be added to the terminal’s Losses field. As seen above.3 iProtect: Internal Page 154 . To account for the standard deviation is not as straightforward. A new lognormal fade margin can be obtained after a new standard deviation is calculated using the following equation. however. Lognormal Fade Margin Standard Deviation Both the antenna gain correction factor and the antenna orientation loss parameters have a mean and standard deviation. measurements are required for each antenna type.mot. 4.84 dB If the CPEs are optimally placed: σ xy 2 = 82 + 1.85) = 781. Clutter Class Parameters The clutter class parameters must also be defined before running coverage studies.25)(8)(1.3 iProtect: Internal Page 155 . as seen in the following figure. For further information regarding the lognormal fade margin.5 (a moderate negative correlation) If the CPEs are randomly placed: σ xyz 2 = 82 + 1.85) + 2(− 0.25 (a weak positive correlation) ρ yz -0.5)(1. Revision 1.Atoll ρ yz Correlation of Antenna gain correction factor and orientation loss σ xyz Joint probability standard deviation Example: Device CPE σx 8 dB ρ xy 0.4 σ xyz = 8..25)(8)(1.042 + 2(0.LTE RF System Design Procedure .04 )(1. The parameters for the Clutter Classes can be accessed in the Geo tab by double clicking on the Clutter Classes field.32 dB This new standard deviation along with the desired area reliability can be used to determine a new lognormal fade margin that addresses slow fade.25)(8)(1.25 (a weak positive correlation) ρ xz 0.04 ) + 2(0. antenna gain correction and orientation loss.04) = 69. please see Section Error! Reference source not found.852 + 2(0.042 + 1. 7.24 σ xyz = 8. The Code field contains the clutter class code. The Name field provides a descriptive name of the clutter class field. Note. Further information regarding setting the clutter class heights can be found in Section 8. 2.3. Figure 106: Sample Clutter Classes Properties Window 1 2 3 4 5 6 7 8 9 NOTES: Note. 1.1. Note. 3. Revision 1.LTE RF System Design Procedure . as seen in the following figure. The Height (m) field provides the average height for the clutter class.Atoll Figure 105: Accessing the Clutter Class Parameters This opens the Clutter Classes Properties window.3 iProtect: Internal Page 156 . 2).3 iProtect: Internal Page 157 . (refer to Section 9. then the default value within the default tab) is used for coverage predictions. For capacity simulations. Note. Note. As mentioned in the model standard deviation note above.2). disable its use (since standard deviations are always applied within Atoll simulations). The per-clutter C/I standard deviation value for this parameter (if not defined. effectively. The per-clutter model standard deviation value (if not defined. and direction from the base station. It is recommended that whenever possible. 7. 6.Atoll Note. and Monte Carlo simulations. disable its use (since standard deviations are always applied within Atoll simulations). For capacity simulations. actual field data for the particular environment be used to determine the building penetration loss. as related to the user-defined “Cell Edge Coverage Probability” parameters within the prediction parameters. no model standard deviation is desired and the model standard deviation value must be zero (0) to. The C/I Standard Deviation (dB) field provides the standard deviation that is used when computing shadowing losses on the C/(I+N) values. Building penetration loss is highly variable and is a function of items such as construction material. This value is only used when the “Shadowing taken into account” and “Cell Edge Coverage Probability” parameters are used when generating predictions.LTE RF System Design Procedure . If it is desired to apply a specific building loss throughout a coverage area. 4. Note. The Model Standard Deviation (dB) field provides the standard deviation value that is used when computing the shadow loss portion of the path loss. 5. point analysis. user location inside the building. building layout. then this loss would be included in each clutter class. effectively. the C/I Standard Deviation value is used when the “Shadowing taken into account” and “Cell Edge Coverage Probability” parameters are set.2. The Indoor Loss (dB) field allows the user to provide a building penetration loss value for the clutter class. then the default value within the default tab) is used when the “Shadowing taken into account” and “Cell Edge Coverage Probability” parameters are set (refer to Section 9. no model standard deviation is desired and the C/I standard deviation value must be zero (0) to. This value is applied to the path loss and is used in coverage predictions.2. proximity to the base station. The SU-MIMO Gain Factor field provides a factor that is applied to the spatial multiplexing gain value that is obtained from the Max MIMO Gain graphs in the MIMO tab within the LTE Equipment Reception properties. Revision 1. e.41 kbps (i. the throughput would be 1105. 8. The user needs to enter a value between 0 and 1. the throughput would be 1210. SU-MIMO Gain Factor = 0. In this case. assume that the CINR at a pixel is 15 dB and the MAC channel throughput without including MIMO considerations is 1000 kbps. and a value between 0 and 1 is used for a mixture of LOS and NLOS.Atoll The SU-MIMO Gain Factor is used to adjust the Max MIMO Gain.4.e. then an SU-MIMO gain between the maximum SU-MIMO gain from the Max MIMO Gain curve and no SU-MIMO gain would be applied to the throughput results.82kbps (i. the MRC diversity is handled in the MIMO tab of the LTE Equipment Reception properties interface (within the Diversity Gain Revision 1. 1000 * (1 + 0 * (1. As discussed in Section 7.5. A 0 indicates that no SUMIMO gain will be included and a 1 indicates that the maximum SU-MIMO gain from the curve will be included.21082-1))).e. This is set to 0 dB in the Motorola template and should not need to be changed.21082-1))). Based on the information in the MIMO tab of the LTE Equipment Reception properties interface.5 * (1. This gain is then adjusted by the SU-MIMO Gain Factor that is associated with the clutter class of the given pixel. the CINR of 15 dB equates to a Max MIMO Gain of 1. Note.21082-1))). as demonstrated below: SU-MIMO Gain Factor = 1 If the SU-MIMO Gain Factor for that pixel is 1. A 0 is used for mainly LOS cases (such as in a rural environment). In this case.3. then no SU-MIMO gain would be applied to the throughput. The Additional Transmit Diversity Gain (dB) field provides a value that is added to the user’s downlink C/(I+N) in cases where the user and its reference cell support Diversity.LTE RF System Design Procedure .21082. then the maximum SUMIMO gain from the Max MIMO Gain curve would be incorporated into the throughput results. 1000 * (1 + 1 * (1.5 If the SU-MIMO Gain Factor for that pixel is 0. SU-MIMO Gain Factor = 0 If the SU-MIMO Gain Factor for that pixel is 0. 1000 * (1 + 0. The Max MIMO Gain and the SU-MIMO Gain factor are used in the Atoll throughput calculations. a 1 is used for NLOS cases (such as in a dense urban environment).3 iProtect: Internal Page 158 . The throughput is adjusted by the following factor: [1 + SU-MIMO Gain Factor * (Max MIMO Gain – 1)] For example.2.2. resulting in a throughput of 1000 kbps (i. Note: Factor = 1 is the default for all clutter and is the recommended setting. 9. Revision 1. This is set to 0 dB in the Motorola template and should not need to be changed.3.3 iProtect: Internal Page 159 .LTE RF System Design Procedure .Atoll settings) so additional Diversity gain offset is not needed in the clutter table. The Additional Receive Diversity Gain (dB) field provides a value that is added to the user’s uplink C/(I+N) in cases where the user and its reference cell support Diversity. As discussed in Section 7.2. Note. the MRC diversity is handled in the MIMO tab of the LTE Equipment Reception properties interface (within the Diversity Gain settings) so additional Diversity gain offset is not needed in the clutter table.2.4. 3 describes the various propagation zones that are used to identify propagation and analysis extents.1 describes the available propagation models and provides recommendations for the default parameter settings for the Atoll “Standard Propagation Model”. The available propagation models are accessed under the Modules tab of the Explorer window as shown in Figure 107. Propagation Models The propagation model selected for a prediction can have a large impact upon how closely the results of the prediction will match what is actually seen in the field. the following subsections provide information on the recommendations for a propagation model prior to collecting data from the field and tuning a model specific for the market. Section 8.1. To minimize the difference between prediction and field results. Next. Revision 1.Atoll 8.2.3 iProtect: Internal Page 160 . 8.1. First. Section 8.LTE RF System Design Procedure .2 describes a number of considerations in tuning the propagation prediction model with drive-test data. Finally. please see Section 8. Available Propagation Models Atoll offers a number of propagation models to choose from. (For information regarding model tuning. Setting Propagation Inputs This section of the document pertains to the propagation models in Atoll and running propagation. Section 8.) 8.1. 3 iProtect: Internal Page 161 . All of these models use the Atoll SPM configured with Motorola’s recommended parameter settings. the recommendation is to start with the SPM model. Reasonable default parameter settings can be used for the earlier phases of system design where drive-test data is typically not available. Since model tuning will eventually be needed during the design process.e. <2 dB mean error and <8.5 dB error standard deviation).1. The default parameters described in this section of the document are only recommended for use in the initial phases of system design to obtain budgetary results.LTE RF System Design Procedure . Revision 1.4 provides some options for predicting pathloss when the base station antennas are below the clutter height. These default settings are saved in the LTE Motorola template as the eight different propagation model options highlighted in Figure 107. The purpose of this section of the document is to describe a set of default parameters for use with the SPM when drive test data is not available. As noted earlier. A separate model is available for each of the LTE bands of interest. Section 8.Atoll Figure 107: Atoll Propagation Models The primary Atoll model that can be automatically tuned using drive-test data is the Standard Propagation Model (SPM). Model tuning is required for a commercial system design in order to produce accurate signal strength estimates (i. Using the prescribed default parameters in the Motorola versions of the SPM model will result in reasonable propagation predictions when the base station antenna heights are above the height of the surrounding clutter. Atoll model tuning with drive-test data is required for accurate commercial system design. This section of the document does not cover all the available propagation models or even all of the details of the SPM. the rationale behind the selection of the default parameter settings. 8.2. The Forsk documents entitled “Atoll User Manual” and “Atoll Technical Reference Guide” can be referenced for additional detail on the available propagation models. which is unique to each band.1. Pathloss predictions may be on the order of 20 dB too high if the base station antenna is below the surrounding clutter.3 iProtect: Internal Page 162 .2 of this document also provides additional guidelines on propagation model tuning. The diffraction loss component of the overall pathloss is also a function of the operating frequency and will therefore be inherently different for the various LTE bands of interest. If drive-test data is available. these parameters are only valid when the base station antenna is above the clutter. then it should be used to tune the SPM employing the procedure found in the Forsk document entitled “Measurements and Model Calibration Guide”.5 GHz band. SPM Parameter Settings The following image shows the recommended parameter settings for the 2. Please refer to the internal document entitled “Atoll Propagation Model Parameter Settings and Validation” for additional information on the SPM equation. The SPM is not designed for below-rooftop propagation prediction. and the results of accuracy validation testing.LTE RF System Design Procedure . Settings for the other bands are the same with the exception of the k1 intercept related parameter. As previously noted. Revision 1. Section 8. Clutter Heights.1.Atoll Figure 108: Motorola Recommended 2.5 GHz Parameter Settings 8. Losses and Clearance A set of clutter parameters that produce reasonable results is shown in Figure 109. Note that the clutter heights are in parentheses next to the clutter category name.3 iProtect: Internal Page 163 .3.LTE RF System Design Procedure . Revision 1. clutter loss for foliage categories deserves additional consideration. Other parameters related to the exponent-based loss are set to values that will produce reasonable pathloss estimates when the clutter height is 0 for open areas. so there is an increased loss associated with tree categories. the “Forest” category in Figure 109 is set to a clutter height (i. Part of configuring and running the SPM is to check the clutter data using Google Earth and local knowledge of the area being designed. It is important to leave the clearance at 10m. and again. accurate clutter data. This is consistent with Forsk’s recommendations when using clutter heights in diffraction (i. The clutter heights for the open categories such as “Low Vegetation”. However. “OpenBarren_Land”. then Atoll’s clutter editor feature can be used to modify the classifications. “Clutter taken into account in diffraction” set to yes as seen in Figure 109).LTE RF System Design Procedure . Unfortunately. it is necessary to tune the model with drive test data in order to obtain more accurate results. which is typically desirable. “Water Bodies” and “Transportation_Infrastructure” should be set to 0. in the case where the signal must propagate through a significant distance of foliage between the transmitter and receiver.3 iProtect: Internal Page 164 .e. additional loss on the order of 5 – 8 dB should be added to the foliage clutter categories. The foliage categories do not typically require additional loss because Atoll treats foliage the same as other clutter categories and computes diffraction loss over the foliage. The clutter heights themselves may also need to be adjusted based on Revision 1. As an example. It is important to use high quality. Changing the clearance distance requires a coordinated change of other parameters in order to obtain valid results.e. 8 m) that is greater than most of the other solid clutter categories. Please refer to the Atoll User Manual for information on using the clutter editor feature. The clutter losses shown in Figure 109 are all set to zero. However. this is not an exact science.Atoll Figure 109: Recommended Clutter Parameters The clearance shown in Figure 109 must be set to 10m. This can be as simple as a visual check comparing land use in Google Earth to the clutter image in Atoll. If there are inconsistencies in the clutter classifications. LTE RF System Design Procedure - Atoll local knowledge of the areas being modeled. The predicted pathloss scales directly with clutter height, so increasing clutter height will increase predicted pathloss and conversely decreasing clutter height will reduce the predicted pathloss. 8.1.4. Base Station Antennas Below Clutter As noted earlier, the SPM is designed for modeling pathloss when the base station antenna height is above the clutter height. To illustrate the issue, Figure 110 shows a site where several isolated areas of high clutter (circled in red) have been added using Atoll’s clutter editor. The height of the base station is 30m and the height of the isolated high clutter is 50m. Figure 111 shows the resulting signal strength prediction plot. As seen in this image, long shadows are cast beyond the high clutter height obstructions. These predicted diffraction shadows are typically unrealistic, given the amount of reflection that occurs off of surrounding clutter. The SPM is not capable of considering the reflections in detail, so the pathloss prediction has significant error when the base station antenna height is below the clutter height. Figure 110: Isolated High Clutter Revision 1.3 iProtect: Internal Page 165 LTE RF System Design Procedure - Atoll Figure 111: Signal Strength with Base Station Antenna Height Below Clutter A possible solution for modeling systems where the base station height is below the surrounding clutter height is to use one of the third party ray-tracing add-in modules that are available for Atoll. Siradel Volcano and WaveCall WaveSight are the primary options for ray-tracing. These tools do consider reflections in detail and would presumably do a much better job of predicting signal strength for low antenna height, micro-cellular, dense urban systems. Unfortunately, evaluation of these tools has not been prioritized at this time. As such, a recommendation for which ray-tracing tool to select has not been decided and this procedure will not provide any detail on using a ray-tracing propagation model. Recommendations and design procedures for raytracing will be available in a future release of this document, once the ray-tracer evaluation is prioritized. In the meantime, until a full evaluation of ray-tracing tools is complete, there needs to be some way of making a reasonable estimate of pathloss in dense urban environments with below rooftop base station antennas when drive-test data is not available. As such, the recommendation for now is to use Atoll Hata – Metropolitan Center for predicting pathloss in uniform, dense urban environments where the base station antenna is below the surrounding clutter height. To obtain more accurate results, drive-test data should Revision 1.3 iProtect: Internal Page 166 LTE RF System Design Procedure - Atoll be collected from the dense urban areas and used to tune an SPM for this specific scenario. The Atoll Hata – Metropolitan center approach was employed to analyze measured pathloss versus predicted pathloss for six sites in downtown Chicago. The mean prediction error was -2.1 dB and the prediction error standard deviation was 8.1 dB for all six sites combined together. Figure 112 illustrates the use of Atoll Hata – Metropolitan center for predicting pathloss in downtown Chicago. The plot is for one of the six sites where data was collected and shows the relatively close match between the Atoll Hata predictions and the measured data. Please refer to the document entitled “Atoll Cost-231 Hata Urban Prediction Accuracy Analysis for Downtown Chicago” for additional information on the Chicago propagation pathloss analysis. Figure 112: Measured versus Predicted Pathloss in Dense Urban Area Using Hata Cost-231 Hata for a given environment can be applied over the entire coverage area by setting the formula for every clutter class to the same Hata environment as seen in Figure 113. In this case, “Metropolitan center” was used everywhere. This was applicable because the cell sites were immersed in a uniform dense urban environment. The goal was to model pathloss with a straight Hata formula and not vary the formula according to clutter class. If the cell sites are in a uniform, dense urban environment with base station antenna heights below the clutter, then using Atoll’s Cost-Hata model configured as in Figure 113 should produce reasonable results. The results will definitely be better than using an un-tuned SPM with clutter heights in the diffraction. Note that the first parameter in Lu is set to 46.3. This is 3 dB lower than the default Revision 1.3 iProtect: Internal Page 167 LTE RF System Design Procedure - Atoll value of 49.3 that Atoll uses. 49.3 corresponds to COST-231 Hata Dense Urban whereas 46.3 corresponds to Urban. For the Chicago testing described above, Urban, using 46.3, was the best fit. Figure 113: Settings for Uniform Cost-231 Hata 8.2. Propagation Model Tuning Forsk maintains a detailed model tuning document entitled “SPM Calibration Guide”. The purpose of this section of the document is not to replicate all of the information in Forsk’s manual; rather, it is meant to augment Forsk’s manual with additional information and guidelines, as well as, to stress some of the key aspects of the model tuning procedure that have a significant impact on the results. Please refer to Forsk’s “SPM Calibration Guide” for the model tuning procedure and to this document for the additional required information. 8.2.1. Collecting Drive Test Data The next several sections provide information on collecting the drive-test data that will be used in model tuning. 8.2.1.1. CW Versus Test CPE The SPM can be tuned using either Continuous Wave (CW) data or RSS from an LTE test CPE. The recommendation is to use narrowband CW test equipment for model tuning. CW test equipment is the best choice for the following reasons: - The signal strength averaging algorithm is controlled by the end user and can be set to ensure collection of local mean signal strength using the Lee criteria (i.e. Revision 1.3 iProtect: Internal Page 168 LTE RF System Design Procedure - Atoll >=50 samples over 40 wavelengths). In contrast, the RSS logged by a test UE uses an averaging algorithm that is proprietary to the LTE chip manufacturer. Since the signal processing algorithms are proprietary, the exact meaning of what the RSS represents may not be known. It can only be assumed that it is meant to reflect local mean signal strength. - Accurate CINR prediction is very important for modeling LTE coverage, throughput, etc. In order to tune the propagation model for interference, it is necessary to collect drive-test data at the locations where the LTE signal from the test location would interfere with signals from other LTE base stations. These areas are at relatively further distances from the cell site than just the cell site’s best server area. Using a test UE may limit the range over which the RSS measurements can be taken if the test UE is handing off between base stations. The test UE will also typically be less sensitive than a narrow band CW receiver, which again will limit the range over which the RSS measurements can be made. The Gator transmitter and Coyote receiver products from Berkely Varitronics have proven to be good tools for transmitting and receiving the required CW test signals for propagation measurement. See the link below for additional information on these tools. http://www.bvsystems.com/Products/LTE/LTE.htm If a test UE is used, then there are several important considerations: - UE’s are typically diversity receive. If both antennas are used during the drivetest, then this adds uncertainty in the measurement result because the diversity gain is variable as a function of the environment. As such, only one antenna port of the UE should be used and the other antenna port should be terminated with a 50 ohm load. - The UE antenna may not be perfectly omni-directional and may also be a high gain antenna with a compressed vertical pattern. Furthermore, the antenna is typically connected to the UE directly, which is not ideal for drive-testing. As such, the recommendation is to use a separate external low gain (e.g. 0 dBd) omni-directional antenna that is connected by a cable to the UE, which resides in the drive-test vehicle. The omni antenna should be a mag-mount that is specifically designed to operate on the vehicle roof. - There are additional considerations regarding the interpretation of the RSS values stored in the drive test log file. These considerations are addressed in the post processing section of this document, Section 8.2.2. Revision 1.3 iProtect: Internal Page 169 However.1. a minimum of approximately 8 sites are required per area type for model tuning. The site to the south in Figure 114 is clearly in a more densely foliaged area than the nearby site to the north. it is likely that some of the sites will be deemed unacceptable after analyzing the collected data. and terrain flatness.LTE RF System Design Procedure . Figure 114 illustrates the need for separate models based on foliage density. so it is highly recommended to gather drive test data from at least 10 sites per area type. Separate propagation models should be tuned for each unique area type within the service area.Atoll 8.2. Selecting Sites As per the Forsk guidelines. As an example. street width. foliage heights and density. Characteristics that should be considered in identifying the area types are building heights and density. for propagation prediction in Atoll. Then. The graphs of measured pathloss for these two sites show a large difference in the slope and intercept of the measured pathloss best-fit lines. the appropriate tuned model is selected on a per sector basis within Atoll. In order to accurately account for this large difference in pathloss. separate tuned propagation models would be needed for sites in the densely foliaged areas and for sites in the less densely foliaged areas Revision 1.2.3 iProtect: Internal Page 170 . This document is aimed at the typical LTE use case of UE antennas at approximately first floor window height.Atoll Figure 114: Pathloss versus Foliage Density Propagation pathloss is a function of antenna height. Other scenarios will need to be addressed on a case-by-case basis. then test locations should be selected that include a 20m antenna height. 8. the propagation pathloss will also depend on the subscriber station antenna height. Drive Routes Atoll’s propagation model auto-tuner uses a linear least squares error algorithm to fit a pathloss versus distance line to the collected pathloss data.3 iProtect: Internal Page 171 . As such.3. it is important to collect equal amounts of drive-test data near the site and far from the site. If there is only a small number of data points collected near the site. if the base station antenna heights within a given area type are expected to range between 20 and 65 meters. For example.LTE RF System Design Procedure . a 65m antenna height. The reason is that the least squares error algorithm will always result in a solution that minimizes the mean square error between the best fit line and the collected data points. In addition to the dependence on the base station antenna height. so it is important to select sites that cover the full range of expected antenna heights for the base stations to be deployed.2.1. and additional sites that equally cover the range of antenna heights between 20 and 65 meters. then the result of the best fit Revision 1. The calculated slope shown in the legend is 29.2 db/decade versus 33.2 dB to 33. Figure 115: Drive Data with Least Squares Trendline The graph in Figure 116 shows the case where the dataset of Figure 115 is used. As such. While the difference of 29. as clearly seen by the lower density of blue points at smaller distances.3 iProtect: Internal Page 172 .9 dB/decade may not seem overly significant. the trendline will be biased towards areas where there are more sample points. The calculated slope of the trendline shown in the legend has increased from 29. which also seems low given that this data was collected in a dense urban area. Looking at Figure 115. which is more consistent with expectations for a dense urban area. Near the site. In the first image. the slope of the least squares trendline appears shallow as compared to a visual inspection of the data. The trendline appears to be getting pulled towards data points at greater distances and away from data points closer to the site.LTE RF System Design Procedure . only the measured drive-test points are used to create the graph. This often results in a tuned model with a slope that is lower than it should be. there are fewer samples. the trendline is being skewed towards points at greater distances. The following two graphs illustrate the issue in accurately calculating the pathloss slope using the least squares method. the predicted CINR is extremely Revision 1. each drive test point at a distance of 400m or less was replicated 100 times to increase the “weight” of those points near the site.9 dB. Since the trendline is calculated to minimize the mean square error between all of the measured points and the trendline itself.Atoll algorithm will be weighted more heavily towards the data points collected far from the site.2 dB/decade. but in this case. The trendline in Figure 116 now appears to do a better job of fitting the entire dataset from near to the site all the way to the furthest range from the site. ). it will be possible to segregate the drive data according to area type or other differentiating factors. etc. During post processing. building height/density. The next consideration in selecting drive routes is that it is important to uniformly sample the test area. the drive routes are evenly spaced. the best approach for collecting the data is to collect everywhere and then leave the filtering to the post processing steps described in Section 8.LTE RF System Design Procedure . The goal is to uniformly sample the entire testing area.2. Figure 117 gives a good example of how drive routes should be configured. As such. As seen in the image. equally cover north-south and east-west streets. The preferred approach is to configure the drive routes to collect approximately equal amounts of data as a function of distance from the test site. and cover the entire service area.3 iProtect: Internal Page 173 . street width. Figure 116: Weighted Drive Data with Least Squares Trendline The above example illustrates the need to either collect approximately equal amounts of data across all distances between the site and the outer edge of the drive routes or when post processing the data to add weight to areas where fewer points have been collected. The pathloss is impacted by the environment (including foliage density. terrain height. Revision 1. This difference in slope would translate into a significant reduction in predicted CINR. The drive test routes should be configured to equally cover cross streets and parallel streets. extending as far as possible until reaching the noise floor of the measurement equipment. Collecting data in only a small part of the coverage area will bias the results to those particular areas.3.Atoll sensitive to slope. etc.1. The pictures should capture a 360 degree view from the site.Atoll Figure 117: Example of Uniform Drive Routes 8. These photographs will help in analyzing the drive-test data to determine if some of the data should be filtered. For example.2.3 iProtect: Internal Page 174 . it is necessary to create a log sheet for each site tested to record all pertinent information that will be needed later when processing the data to obtain the tuned model. the pictures may help to recommend removing areas that are blocked by equipment. Revision 1.4. on the roof where the test transmitter is deployed.LTE RF System Design Procedure . Additional Deliverable Data As described in the Forsk model tuning document. Pictures similar to those shown in Figure 118 should also be included in the information to obtain for each site tested. 2. The RSS that is recorded in the log file may represent different values depending on the UE being used.Atoll Figure 118: Antenna Viewpoint Photos 8.3 iProtect: Internal Page 175 . there are additional factors that must be properly accounted for. Post processing RSS In order to produce a valid propagation model from the drive-test data.LTE RF System Design Procedure . It must be understood exactly what the RSS measurement represents and make sure to either setup Atoll to match this or post Revision 1.2. Atoll must predict received signal strength that is consistent with the measured received signal strength. Typical gains and losses that must be properly accounted for include: - TX Power - TX Cable/Connector Loss - TX Antenna Gain - RX Antenna Gain - RX Cable/Connector Loss When using data collected from a test UE. This means that the predicted and measured signal strength take the same end-to-end gain and loss components into consideration. these areas have potential to introduce error in the optimization result. again.3. There will also often be groups of points that are offset from the main trend towards lower measured signal strength.1. Prior to filtering. These points should be filtered from the analysis to avoid error.2. The issue is that the clutter database is typically not accurate enough to consistently identify line-of-sight versus non line-ofsight areas. 2. the points circled and labeled “Note 1” are near the site and deviate significantly from the best-fit line.2. they should be removed from the optimization since. If there are only a few such places. The goal is not to optimize the model for these few small areas. The equipment manufacturer for the specific UE used for data collection will need to be contacted to find the required information on RSS measurement. the antenna pattern has high attenuation and high variability near the site.3. These areas are associated with higher than typical loss such as in densely foliaged areas. Revision 1. Note. When there are only small areas like this. In order for the algorithm to work properly. Filtering the Drive-test Data One of the most important steps in the model tuning process is filtering the collected drive-test data. Note. As such. the goal is to optimize for the majority of the area where the CPE units will actually be deployed. rather. There will often be groups of points that appear to be offset from the main trend. then they are likely associated with an area that has line-of-sight or near lineof-sight to the base station. There are a number of candidates for filtering that are circled on the graph in red and described as follows: Note. Atoll uses a linear least squares algorithm to calculate a best-fit line to the collected drive-test data. Some key points are as follows. 1. The tuned model will likely be in error if the drive-test points are not properly filtered prior to running the automated model tuning algorithm. it’s best to filter them out of the optimization. 8. Even a small number of erroneous or outlier points can cause the results of the tuning algorithm to be non-optimal. therefore. the goal is to optimize for the majority of locations where UE’s will be deployed.1. An approximate best-fit line has been drawn on the graph for reference. 8.3 iProtect: Internal Page 176 .2.Atoll process the collected RSS to match Atoll’s implementation. Filtering for Linear Least Squares Analysis As noted earlier in Section 8. 3.LTE RF System Design Procedure . the drive-test data will most likely not have linear pathloss versus logdistance. Refer to Forsk’s model tuning document for detailed information regarding the filtering requirements. Figure 119 shows an example of measured RSS versus log-distance prior to filtering. A high gain omni-directional base station antenna was used to collect this data. the input data must have approximately linear pathloss versus log-distance.3. If the points have significantly higher signal strength than the trend. As seen in the image. As shown circled in this image.3 iProtect: Internal Page 177 . Figure 120: Example of Filtered Drive-test Data Revision 1.Atoll Figure 119: Example of Unfiltered Drive Test Data Note 1 Note 2 Note 3 Figure 120 shows the same drive-test data after filtering.LTE RF System Design Procedure . about 5% of the data has been filtered leaving the remaining 95% of the data that most closely follows the linear trend. if a Min Measurement filter of -107 dBm is used. One approach that is often used to account for the receiver sensitivity is to apply a minimum signal strength filter. The yellow dashed line in Figure 122 depicts a possible solution to the least squares best fit when the input data is filtered for minimum signal strength. However. Figure 121: Example of Measurements at the Receiver Noise Floor As an example. then the remaining sample points would be as shown in Figure 122. the issue with this approach is that it tends to skew the optimization results towards higher signal strength or. which is skewed towards higher signal levels at further distances because of the minimum signal strength filter. The yellow dashed line is in error because of the missing data.2.Atoll 8. The solid light blue line shows a possible solution that might be obtained if the additional data points in the red triangular area were available.2. lower loss. The yellow dashed line has a shallower slope because it is being fit to the available data.3. it can see that the remaining sample points do not accurately reflect the expected distribution of points between the two red vertical lines. Revision 1. The red triangular area between the vertical lines depicts an area on the graph where drive-test points would intuitively be expected if the Min Measurement filter was not in place and the receiver was capable of measuring at lower signal levels. which is 10 dB above the measurement floor of -117 dBm.LTE RF System Design Procedure .3 iProtect: Internal Page 178 . Filtering for Receiver Noise Floor Figure 121 shows an example where the RSS at a given distance has reached the minimum measurement level of the receiver. equivalently. The difference between these two solutions illustrates the impact of using the minimum signal strength filter. Looking at this graph. Figure 123 shows the correct filter distance as indicated by the red vertical line to the right.3 iProtect: Internal Page 179 . enter a distance in the Min Distance box) where the distance is selected to ensure that the low end of the signal strength versus distance is not being clipped by the receiver minimum measurement threshold. Figure 123: Maximum Distance Filter to Avoid Clipping Revision 1.LTE RF System Design Procedure .e. This is the distance at which the receiver’s minimum measurement threshold has just been reached.Atoll Figure 122: Issue with Minimum Signal Strength Filter A more accurate solution is to filter on distance (i. therefore.5 GHz (SPM) V2” model and will be slightly different for the other frequencies. for example. The antenna pattern typically changes rapidly away from the main beamwidth which results in high prediction error that tends to introduce additional error in model tuning. if there was a large equipment penthouse on the roof where the test transmitter is located. After selecting the drive-test data to be used in the calibration.2. Next. Running the Calibration Calibration results are dependent on the starting values for the tuning parameters. Filtering on angle is also advisable when there is an obstruction near the test antenna.2. Also note that the status of the check boxes in this image are based on the Atoll defaults and need to be changed as described in the following sections. Note that the starting parameters in this image are for the “Motorola 2.4.4. For example. then the filter to select the points in the dense urban clutter categories should be used.3. 8. Revision 1.LTE RF System Design Procedure .2. the recommendation is to make a duplicate of the Motorola model by right clicking the model and selecting “Duplicate”. the preferred approach is to use the Filtering Assistant tool in Atoll to view the graph of pathloss versus distance and select a minimum distance such that the remaining data has essentially linear pathloss versus distance.4. 8. Filtering for Minimum Distance As noted earlier. Filtering on Angle of Arrival If a directional antenna is used for the transmitter under test. As such.3. Filtering Clutter Classes As described next in Section 8. rather than just selecting a fixed minimum filter distance. it is not recommended to tune clutter losses per clutter category when using clutter heights in the diffraction loss calculation. the vertical antenna pattern typically changes rapidly near the site. filtering clutter categories is not so much based on the number of samples per clutter category as it is on filtering clutter categories that do not match with your model tuning goals. begin the calibration of this model by right clicking and selecting “Calibration”.5. therefore.3.3 iProtect: Internal Page 180 . the following screen in Figure 124 will be presented. 8. However.3. then it is important to apply an angle filter to ensure that only drive-test points within the main beamwidth of the antenna are included in the analysis. if the drive route includes both urban and dense urban areas and the goal is to tune a model for urban areas.Atoll 8. Double click this copy and rename it to reflect an appropriate name for the tuned model. it is necessary to filter test points that are within approximately 200 to 250m from the site.2.2. 4.LTE RF System Design Procedure . The recommendation is to fix the approach to “Deygout with correction (ITU526-5)”. where the virtual height is the same as the actual height of the antenna above ground level.3 iProtect: Internal Page 181 . when clutter heights are Revision 1. The “Diff.1. method” checkbox should be unchecked for calibration so that the selection remains at the Motorola default of “Deygout with correction (ITU526-5). HTx Method Atoll offers a number of options for calculating the virtual base station antenna height that is used in computing the exponent based pathloss.3.2.4. This range makes sense when clutter heights are not used in diffraction. respectively.Atoll Figure 124: Default Model Calibration Interface 8. therefore. for the exponent based loss portion of the overall pathloss. Diff. Some of the methods use a single knife edge approach and others use a multiple Knife-Edge approach. The Motorola models use clutter height in diffraction. the recommendation is to use the “Height above the ground” method. This is a multiple-knife-edge diffraction method with an additional distance based correction factor.4.2. Method Atoll offers a number of methods for computing diffraction loss. These are the primary factors to be adjusted by the auto-tuner. 8.2. The default range for K1 is 0 – 100. K1 and K2 K1 and K2 are the intercept and slope related parameters. however. however. may produce unexpected results in areas where drive-test data was not collected. 8. The “HTx method” checkbox should be unchecked for model tuning.2. Allowing Atoll to optimize with the HTx method may result in slightly better accuracy in the areas with the drive-test data. These various methods primarily apply when clutter heights are not used in the diffraction calculation. The default range for K2 is 20 – 70 and is acceptable as a starting point. The issue with optimizing K4 is that the Atoll auto-tuner will often adjust K4 down to a low value such as 0. This may result in good prediction error standard deviation. K4 K4 is a multiplication factor for the calculated diffraction loss. The K1 and K2 checkboxes should be checked for calibration. that follows. A K4 value of 0. As noted above. Therefore. as noted in Section 8. that K2 did not get erroneously tuned to such a low value that the slope of the predicted pathloss versus distance is lower than the measured slope.5. The default range of -20 to +20 is acceptable for this parameter. etc). The range for K1 is set by clicking in the K1 row and then clicking “Define Range …”. 8. then the calculated diffraction loss over the hill will be too low. the goal in selecting a value for K4 is to achieve a balance between the errors at high K4 and the errors at low K4.2.LTE RF System Design Procedure . However. however. for example. lower K4 values are also an issue because.4.3 iProtect: Internal Page 182 .6 has been deemed to be an optimal choice to reach the desired balance. All values between 0 and 1 will serve to scale the calculated diffraction loss from 0 to its full value. the diffraction loss errors associated with the database are magnified at higher K4 values. then the K3 checkbox should be unchecked for model tuning and the default Motorola value should be used. The prediction error standard deviation increases with increasing K4 because the databases have only approximate clutter heights and the clutter classification itself has limited accuracy.Atoll used in diffraction. then K1 can be even less than 0 due to the extra diffraction loss associated with the clutter. The K4 checkbox should be unchecked for calibration. As noted above. the recommended range for K1 is -20 to 100. low K4 will produce unrealistic predictions for shadowed areas (such as behind hills. for example.2.1. therefore. selecting the “Height above the ground” HTx method means that the base station virtual height is actually the height above ground level. However. where 0 means that no diffraction loss will be included in the overall pathloss result and 1 means that the full calculated value of diffraction loss will be included in the overall pathloss result. The valid range is 0 to 1. If the measured RSS data was collected from sites where the antenna heights do not cover the expected range of antenna heights for the final deployment. the model tuning results will need to be validated to ensure.2. will result in ever increasing prediction error standard deviation when using the typical clutter databases that are available at reasonable cost. High values of K4.4. above 0. if there is a large hill in the service area and K4 is set very low. K3 K3 adjusts the exponent based loss intercept as a function of the log of the base station virtual height.5. 8. Therefore. this parameter should only be tuned if the input data was collected at multiple base station antenna heights that cover the full range of antenna heights expected for the final system deployment.4. Revision 1. as is the case with the Motorola models.6. 2. The default range of -10 to 0 is acceptable for this parameter. Conversely. as is the case with the Motorola settings.Atoll 8. If the input data does not cover the full range of antenna heights.8. As is the case with K3. If desired. Clutter Losses If the Clutter Losses checkbox is checked. An iterative process of manually adjusting clutter heights.2. for example above the clutter. The mean prediction error and standard deviation per clutter category are displayed after running the prediction calculations for the drive routes by right clicking on CW Measurements and selecting to display statistics.9. the diffraction loss will increase as the receiver height relative to the base station antenna height and clutter is reduced.4. This parameter is mainly applicable when the SPM is being configured as a statistical propagation model without clutter heights used in diffraction.4. K7 K7 adjusts the exponent based loss intercept as a function of the log of the effective receiver height.7. This is consistent with Forsk’s recommendation to not use clutter losses when clutter heights are included in diffraction loss. where the effective height of the receiver is calculated as the difference between the ground level at the transmitter and the ground level at the receiver plus the height above ground of the receiver antenna itself. where the effective receiver height is calculated as the difference between the ground level at the transmitter and the ground level at the receiver plus the height above ground of the receiver antenna itself. there is an inherent accounting of the effect of the receiver height in the diffraction loss calculation. then the K5 checkbox should be unchecked for calibration. 8. and calculating statistics to view the impact on the mean prediction error and standard deviation can be done to optimize the prediction error and standard deviation. running the model tuner.4.2. 8. K6 K6 is a straight multiplier to the receiver effective height. then the diffraction loss will be low. Revision 1.2. K6 should be set at the default of 0 and the K6 checkbox should be unchecked for calibration.4. then Atoll will automatically optimize the clutter loss per clutter category.6. While better results would likely be possible if the clutter heights could be automatically tuned per clutter category. If the receiver height is high. K7 should be set at the default of 0 and the K7 checkbox should be unchecked for calibration. clutter heights can be manually adjusted in an effort to reduce the mean prediction error and standard deviation. When clutter heights are used in diffraction. K5 should only be tuned if the input data includes data from base station antennas that cover the full range of heights expected for the final system deployment. 8.LTE RF System Design Procedure . tuning K1 and K2 does a good job of producing a nearly optimal result. The recommendation is to leave the Clutter Losses checkbox unchecked during calibration. K5 K5 scales the slope of the exponent based loss as a function of the log of the base station antenna height.3 iProtect: Internal Page 183 . However. Right click on CW Measurements and select to Refresh Geo Data. then K3 and K5 would also be unchecked.3 iProtect: Internal Page 184 . then this road issue can be overcome by reclassifying the drive-test points that are on the roads. the vast majority of collected drive-test data ends up being ascribed to the road category. There may be little or no correlation in pathloss versus distance for the data points in the road category. This is done by selecting the desired clutter category in the clutter editor interface and drawing polygons around the drive-test data. the final configuration screen for the model tuning run will be as depicted in Figure 125. as such. the drive-test classification will not change until select Refresh Geo Data is performed again. The idea of tuning per clutter category is that there should be some correlation in pathloss versus distance as a function of the clutter category. the correct propagation predictions will be obtained. the drive-test points will have been reclassified according to the clutter classes drawn using the clutter editor. 8. By following these steps. as well as. the new classifications will remain in effect until another refresh of the geo data is performed. If data was not collected across various antenna heights. the desired classification of drivetest points. Use Atoll’s clutter editor tool to change the clutter coding for the roads where the drive-test data is located. c. In the end.4. Deleting the drawn clutter polygons as in Step “c”. Even if new clutter data is loaded or additional clutter edits made. Once the drive-test geo data has been refreshed. ensures that the proper clutter classification is used for the propagation predictions. This is for the case where drive-test data was collected for various test transmitter heights that cover the full range of expected antenna heights for the final deployment. however.LTE RF System Design Procedure .2. this typically does not apply with the road category because it passes through numerous other types of clutter.10. Select all of the clutter polygons that were drawn in Step 1 and delete them. if there is a desire to tune per clutter category. b. The procedure to do this is as follows: a. Final Model Tuning Configuration After following the above procedures. However. removing the clutter polygons will have no affect on the drive-test point classification. Revision 1. This leads back to the procedure of simply tuning K1 and K2 and not focusing on trying to tune per clutter category.Atoll One key issue with tuning on a per clutter category basis is that the newer clutter databases typically have roads burned into the clutter and. If the prediction error is significantly outside of this range. Rather.2.5 dB. The main issues are related to the input data used to tune the model and whether or not the data was properly gathered. post processed.1. 8.LTE RF System Design Procedure . Revision 1. it is necessary to analyze the prediction results.3 iProtect: Internal Page 185 . and filtered.5. or other area that will need to be investigated. In order to validate that the tuned model is working correctly.2.5 dB and the standard deviation should be approximately 8. Analyzing Prediction Error for Validation Sites As described in the Forsk model tuning document. These two sites would not have been used in the model tuning. The prediction error should typically be within +/. Validating the Optimized Model There are many things that can go astray in tuning the propagation model. at least two sites per area type should be used to validate the results of model tuning.5. filtering of the data. the tuned model is applied to these two sites and then the resulting prediction error statistics are reviewed (please refer to the Forsk “SPM Calibration Guide” for the steps required to generate the validation statistics). then there is likely some anomaly in the input data.2.Atoll Figure 125: Final Model Tuning Configuration 8. While it is more conventional to see propagation model equations in terms of logarithm base 10. the Excel output is still useful for comparing the relative slope between predicted and measured pathloss. Excel’s trendline function produces an equation that is in the form of Aln(x) + B. If the slope in terms of log base 10 is desired.LTE RF System Design Procedure . Excel allows the user to select the data series.303 to convert from natural log to log base 10. and choose to have a trendline added to the graph. then multiply Excel’s trendline slope by 2.5. The trendlines in this plot are useful to show how closely the slope of the predictions match with the measured data. For example. the predicted trend matches closely with the measured.2. In this case. Plotting RSS versus Distance A good way to validate the tuned model is to plot the predicted RSS versus distance on a graph. Figure 126: Predicted and Measured Signal Strength Revision 1. One of the main things to look for on this graph is whether or not the slope of the predictions matches closely with the slope of the measured RSS versus distance. right click. where “A” is the slope of the natural logarithm and “B” is the 1 m intercept. Figure 126 shows an example where the measured and predicted RSS is plotted using Microsoft Excel’s X-Y scatter plot.2.3 iProtect: Internal Page 186 . This can be done by exporting the drive test table after calculating predictions using the tuned propagation model and then analyzing the data with a data analysis tool ( please refer to the Forsk “SPM Calibration Guide” for more information on working with drive test data tables). This result serves to validate that the tuned model is working correctly. The goal is to determine if the slope of the measured RSS versus distance is at least close to the slope of the predicted RSS versus distance.Atoll 8. Questions should be asked. using a bar graph in Excel for example. and the various other concerns that have been raised in this propagation model tuning section of this document. due to dense foliage.3 iProtect: Internal Page 187 . Analyzing Per-Transmitter Statistics Looking at combined statistics for all transmitters used in model tuning will typically show 0 dB mean error and low standard deviation. such as. It illustrates that there are several sites Revision 1. It is useful to plot prediction error separately for each transmitter. are there parts of the service area where data should be filtered out (e. hills.). water.g. then that would warrant additional investigation into the model tuning results and the input data itself.3. Figure 128 shows an example of a plot of mean prediction error versus test site number. in order to see how the mean error varies from site-to-site.e.Atoll Figure 127 shows an example using a different statistical analysis tool to plot the predicted pathloss versus measured pathloss along with the associated trendlines and reference lines for the Hata and free space loss propagation models.LTE RF System Design Procedure . is there enough data near the site or are the results being skewed towards data further from the site.2.7 dB/decade for the predicted). This result would serve to invalidate the tuned model and would be cause for further investigation into the model tuning process. 39. Figure 127: Example of Model with Low Slope 8. open areas.6 dB/decade for measured and only 27. Please refer to the Forsk “SPM Calibration Guide” for information on generating error statistics per transmitter. was the drive data collected uniformly across the service area. etc. have proper distance filters been applied to avoid erroneous data under the base station antenna and to avoid data clipping at the edge of the receiver’s sensitivity.5. This example shows a case where the predicted slope is much lower than the measured slope (i. If there are sites with a large mean prediction error. Focus Zone.LTE RF System Design Procedure . as seen in the figure below.3.3 iProtect: Internal Page 188 . these zones will be covered later. Revision 1.Atoll with a high prediction error. These sites should be investigated further to better understand the cause of the prediction error. in the Zones folder. The Printing and Coverage Export zones are used in the generation of presentations. Computational Zone and Hot Spot Zone. The Propagation zones can be found under the Geo tab. The Propagation zones are the Filtering Zone. Propagation Zones There a four Propagation Zones that are used by Atoll. Each zone has a specific purpose that will be explained below. Figure 128: Mean prediction error per test site 8. Shape. etc). such as: 1.3. Make sure the imported data shares the same coordinate system as the project. an administrative boundary map) within the project (except Hot Spot Zone) 3. DXF.LTE RF System Design Procedure .1.Atoll Figure 129: Propagation Zones Folder 8. Fitting a zone to the Map Window size 4. Drawing a zone using the polygon tool 2.3 iProtect: Internal Page 189 . Revision 1. Importing a polygon from a variety of sources (MIF. Using an existing polygon (e. Creating and Editing Zones Each of the different zones can be created using a variety of methods.g. LTE RF System Design Procedure . it can be modified by two methods. It is possible to copy the coordinates of one zone/polygon and paste them into another zone/polygon via the properties window.e. Important: Zones are taken into account whether or not they are visible on the Atoll display (i. then select the Properties.3 iProtect: Internal Page 190 . A Properties window will be revealed with the coordinates for each point in the zone. Atoll provides several different ways of editing computation. This action will highlight the intersection points. the computation. and filtering zones. even if the display checkbox is not selected in the Zones folder of the Geo tab).Atoll Figure 130: Menu Options for Creating or Importing Zones Once a zone has been created. The second method is to have the desired zone selected in the Zone Folder. Revision 1. For example. focus. refer to “Using Polygon Zone Editing Tools” in the Atoll User Manual. as seen in the following figure. two zones/polygons can share the exact same shape. Modifying the location of the points will change the shape and area of the zone. several polygons can be combined. By this means. and then left click on the zones line within the display. hot spot. Also. For more information on these special editing features. The first method is to right click on the desired zone. allowing the user to insert/move/delete a point and move/delete the zone. focus and filter zone polygons can be made to contain holes. One use of the Filtering Zone would be to run a study of a portion of the system. Figure 132 shows a prediction study where sites outside of the Computation Zone still impact the study. coverage studies. only the sites that are within the zone are displayed and active). The calculations in the Computation Zone include predictions from base stations which are active.2. One could define a Filtering Zone around this portion of the system and then only the sites within that zone would be included in any study that is run while the filter is included (i. etc. Filtering Zone A Filtering Zone (represented with a Blue Line) can be defined from the Geo tab. it is sufficient for Revision 1. filtered (i. Refer to Figure 132 for an example.Atoll Figure 131: Menu Options for Editing a Zone 8. A Filtering Zone restricts the objects displayed on the map and on the Data tab of the Explorer window to only include the objects that are within the Filtering Zone. Pixels outside the zone are not included.LTE RF System Design Procedure . For a site to be included in the Computation Zone calculations.3.3.).) will be performed.3 iProtect: Internal Page 191 . If the user later wants to run a study of the entire system.e. 8. filtered “in”). A propagation zone for a site is bounded by a square centered on the site with an area of 2R x 2R where R is the maximum radius specified for the propagation model (as seen in Figure 133). Pixels within the Computation Zone are included in the calculations.e. the Filtering Zone definition can be deleted and all active sites would once again be included in a subsequent study. and whose propagation zone intersects a rectangle containing the Computation Zone. It also restricts which objects are used in calculations (such as coverage predictions. etc. simulations. Computation Zone A Computation Zone (represented with a Red Line) defines a region where calculations (path loss matrices.3. the dashed green line represents the rectangle that encompasses the red Computation Zone polygon. Refer to Figure 133. Atoll will use all active transmitters in its calculations. Figure 132: Example of Filter Zone and Computation Zone sites outside Filter Zone are not seen in map or explorer window and do not influence studies prediction study is performed inside computation zone Revision 1. If there is no Computation Zone specified.3 sites outside the computation zone may impact the prediction study iProtect: Internal Page 192 .LTE RF System Design Procedure . the propagation zone does not necessarily need to intersect the Computation Zone polygon).e. Use of Computation Zones is recommended for studies involving large networks to reduce the time needed for calculations. All of the sites whose blue propagation zone squares intersect this green rectangle would be included in the Computation Zone calculations.Atoll its propagation zone to intersect the rectangle encompassing the Computation Zone (i. Within this figure. Hot Spot Zones (represented with a Black Line) are similar to Focus zones in most respects. the blue polygons represent the propagation zones for each of the individual sites. a specific set of base stations can be included in the report. 8. If there is no Focus Zone defined. This opens a context window from which “Export” is selected.LTE RF System Design Procedure . the red polygon represents the Computation Zone. as seen in the following figure) allows the selection of areas of coverage predictions or other calculations on which reports.Atoll Figure 133 : Propagation Zone and Computation Zone Within this figure. Revision 1. statistics and results are generated.3.3 iProtect: Internal Page 193 . Figure 134 below shows a Focus Zone and two Hot Spot Zones within it. There can only be ONE Focus Zone per project. By using a Focus Zone for the report. except that there can be multiple Hot Spot Zones throughput the project.4. Export the zone to a file. and selecting the recently saved polygon file. and the green rectangle represents the rectangle that encompasses the Computation Zone. then the Computational Zone will be used. selecting “Import” from context window. Focus & Hot Spot Zones A Focus Zone (represented with a Green Line. The exported file can then be imported as a new Hot Spot zone by right clicking on the Hot Spot icon. An existing polygon can also be used as a Hot Spot Zone by selecting the original polygon under the Geo tab of the Explorer window and right clicking on the zone type. Atoll instead of creating a report for every site that has been calculated.3 iProtect: Internal Page 194 . Figure 134 : Focus & Hot Spot Zone Polygons Focus Zone Hot Spot Zones Computation Zone Revision 1. Figure 135 shows that the generated report includes statistics for the Focus Zone and each of the Hot Spot Zones.LTE RF System Design Procedure . by a transmitter attribute. the Print Setup should be run to select the layout of the project (File > Print Setup). In this case. Once the area has been delimited. Coverage Export Zone The Coverage Export Zone (represented with a Purple line) is used to export only a portion of the coverage prediction to a raster or vector file. coverage predictions with the display type set by transmitter. if the coverage prediction was made per transmitter (e. For example. In the example below. If no print area is defined. if “Coverage by Transmitter” is selected and exported.3 iProtect: Internal Page 195 . only the coverage area of a single transmitter can be exported in raster format.g. by signal level. or by total losses). only certain types of coverage predictions can be exported in raster format. then it cannot be exported in raster format. 8.Atoll Figure 135: Focus & Hot Spot Zone Reports 8.3. Printing Zone The Printing Zone (represented with a Light Blue line) will define the area that is shown when the user selects the Print Option. If a user chooses to print. However. If “Site0_1” is selected (from within the expansion of the Revision 1.6. the user can export the area. All coverage types can be exported. by path loss.3.LTE RF System Design Procedure .5. by default the Computation Zone will be used. the results will be a vector based file. To export the coverage.Atoll “Coverage by Transmitter” prediction folder). then the Predictions Folder. This brings up another window where the user can select the export type desired. the user is able to export the results as either a vector or raster based file. Figure 136: Exporting a Coverage Prediction Revision 1.LTE RF System Design Procedure .3 iProtect: Internal Page 196 . Right click to bring up the menu and select “Export the Coverage”. select the DATA tab. Expand the prediction of interest. then right-clicking on the “Predictions” folder and selecting the “Properties” option.1. It also includes a section regarding the use of the Profile Analysis Feature in the image evaluation process. Additionally. please use the logo. This section describes how to generate the images and includes descriptions of some of the images that are most important in the LTE system design process.Atoll 9. One important setting is the height of the subscriber antenna. The subscriber antenna height can be set globally by clicking on the “Data” tab at the top of the “Explorer” window. This opens the “Predictions properties” window.bmp file that is located at http://compass.com/go/267706168. Subscriber Antenna Height Selection Image generation is impacted by many user settings.3 iProtect: Internal Page 197 . Figure 137: Predictions Properties – Subscriber Antenna Height Revision 1.mot. NOTE: When printing an image from Atoll. 9. Generating Coverage Studies Atoll has the ability to generate numerous images which can be utilized in evaluating the RF performance of a system design. there is information provided regarding the generation of reports and histograms based on the predictions.LTE RF System Design Procedure . The subscriber antenna height can be set globally or for each clutter type (depending on the propagation model being used). To include the Motorola logo instead. the Forsk logo is included by default. as well as information regarding how to evaluate these images. This file needs to be placed within the following directory: C:\Program Files\Forsk\Atoll. This opens the properties window for the propagation model.Atoll Click on the “Receiver” tab at the top of the “Predictions properties” window.LTE RF System Design Procedure . The subscriber antenna height can be set based on each clutter classification when using the “Standard Propagation Model” or propagation models based on the SPM Click on the “Modules” tab at the top of the “Explorer” window and expand the “Propagation Models” folder (click on the [+] box next to the folder) to display the propagation models. The user may now enter an antenna height to be globally applied to all the subscriber units throughout the system. Revision 1. Right click on a propagation model (this needs to be an SPM based model) and select the “Properties” option. Figure 138: Propagation Model Properties – Clutter Click on the “Clutter” tab at the top of the propagation model properties window. The user may now enter antenna heights in the Rx Height (m) field for each of the clutter classifications.3 iProtect: Internal Page 198 . Figure 139: Selecting New Predictions 2.2 provides further information concerning two approaches for applying a lognormal fade (i. Revision 1.Atoll 9.2.1 provides general information on creating a new prediction study.LTE RF System Design Procedure .2. 9. 1. Section 9.2. How to Generate Studies in General The following provides the process that is followed when generating propagation images. Select “New” and the Study Types dialog box appears. slow fade or shadowing) margin to the prediction results. Right-click the Predictions folder in the Data tab to obtain the context menu. Creating a New Prediction The following provides a brief discussion on the windows that are to be populated when a new prediction is created. Refer to the Atoll manuals for further information. Section 9.2.1.3 iProtect: Internal Page 199 . Select the desired coverage image type from the Study Types dialog.e. LTE RF System Design Procedure .3 iProtect: Internal Page 200 .) Figure 141: Predictions General Tab Revision 1. Under the Configuration section. 4. as well as the storage folder location for the prediction. Once the desired coverage image type is selected.Atoll Figure 140: Selecting Prediction Type 3. if desired. a dialog window will appear with three tabs: General. (For further information regarding grouping. the user can create a Filter to select which sites to display in the results. please see the Atoll manuals. These dialogs change slightly depending on which image was selected. From within this tab the user can change the default Name and Resolution of the coverage prediction image. Click on the General tab. and Display. filtering and sorting functionality in the prediction generation process. the process for setting up these images is very similar and will be explained here. Condition. However. The user can also add Comments. e. For example. and can be defined separately for each coverage prediction. - For some predictions. prediction) that has been selected. Under the Condition tab. the user can define the signals that will be considered for each pixel. Revision 1. the user needs to select the Terminal. - For some predictions. as well as defining the load conditions (i. The following figure shows the different views that can be observed. based on simulations or data in the cells table). The Condition window will be different based on the study type (i.e.3 iProtect: Internal Page 201 .LTE RF System Design Procedure . the Server line allows the user to determine what servers to consider: All. This range is typically based on Signal Level. Selecting “All” or “Best signal level” will provide the same results because Atoll displays the results of the best server in either case.Atoll The coverage prediction resolution does not have to be the same as the resolution of the path loss matrices or the geographic data. the first line of the Condition window allows the user to set the range that will be considered. whereas a second study may assume the MS device for an outdoor prediction. prediction) could assume the CPE device for an indoor prediction. Best Signal Level. 5. one study (i. Mobility and Service settings to reflect the prediction that is being made. but the user can also select to have the range set by Path Loss or Total Loss.e. or Second Best Signal Level. Figure 142: Predictions Condition Tab - For some predictions. 1. - The Cell Edge Coverage Probability allows the user to select the probability for the cell edge coverage. such as Coverage by Transmitter) is used to specify an amount (i. The indoor losses are defined per clutter class.2. Condition.) Revision 1. and Display windows and the user has clicked OK. Refer to Sections 9.3 iProtect: Internal Page 202 .LTE RF System Design Procedure . To execute the prediction.e. Once the prediction properties have been set within the General.e. - The Indoor Coverage check box can be selected to add indoor losses to the prediction.4. Figure 143: Predictions Display Tab The Actions button lets the user further define the scale and shading used. (Force Calculate will regenerate the pathloss files needed for the images. 7. Refer to Section 7. This field is enabled when the previous checkbox is checked. right-click the Predictions folder to obtain the context menu. thus defining how the image will be displayed on the screen. Refer to Section 9. dB) of coverage overlap between sectors. shadow) margin in the coverage plots in accordance with the selected Cell Edge Coverage Probability and the user defined lognormal standard deviations per clutter category. Then select either “Calculate” or “Force Calculate” to start generation of the images.Atoll - Turning on the “Shadowing taken into account” checkbox causes Atoll to include a lognormal (i.2.4 for further information concerning the levels to be set for various predictions. 6. This option is recommended and will be discussed further in Section 9.2.2.3 and 9. the predictions are ready to be run. The Display dialog window allows the user to define the thresholds.1 for further discussion. - Selecting “With a Margin” (which is available for certain prediction images. Note: If shadowing is employed for coverage predictions. no standard deviations are desired and the value must be zeroed to.2. The user should first check the “Shadowing taken into account” box. A second option is to not apply a lognormal fade margin and produce images that represent the average levels. Generating Predictions with Lognormal Fade Margin The recommended approach to generating predictions is to apply a lognormal (i.2. then model and CINR standard deviations should be reset to 0 prior to performing any capacity analysis. shadow) fade margin when specifying the Conditions for the prediction image by checking the “Shadowing taken into account” box.3 iProtect: Internal Page 203 . 9. effectively.2.e. 9.Atoll Further details regarding creating prediction images can be found in the Atoll User Manual. disable their use (since standard deviations are always applied within Atoll simulations). The values for model and CINR standard deviations are located within the Clutter Classes Properties interface (see Figure 149 and Figure 150 ).1. this will activate the Cell Edge Coverage Probability percentage as shown in the following figure. several additional steps must be taken for the appropriate lognormal margin to be applied.LTE RF System Design Procedure . Lognormal Fade Margin Set in Prediction Properties If the user elects to check the “Shadowing taken into account” box. Figure 144: Predictions Condition Tab with Shadowing for RSSI Revision 1. .2. For simulations. Right mouse click on Predictions > Shadow Margins). Figure 145: Accessing the Shadow Fade Margin Calculator The Shadow Fade Margins are calculated independently for the Model and C/I standard deviations (set in the Clutter Classes Properties interface) but using the same Cell Edge Coverage Probability value. a cell edge reliability value is used for obtaining a lognormal fading value. whereas in Atoll. the user supplies an area reliability value for deriving the lognormal fading value.22 dB/decade slope and 60 degrees antennas).3 iProtect: Internal Page 204 . The margin values shown in the following two figures are matched to those calculated by ML-CAT (assuming a 90% area reliability. 8 dB standard deviation. Table 8: Lognormal Fade Margin (CINR) Area Reliability Cell Edge Coverage Probability Standard Deviation: From Model Standard Deviation: C/I Lognormal Fade Margin (CINR) 90% 76.LTE RF System Design Procedure . The Cell Edge Coverage Probability percentage is incremented or decremented until the margin is at the desired level. Revision 1.6 dB 1. Note: In ML-CAT. 35.6% 5. Thus the area reliability percentage can not be taken directly from ML-CAT and used in the Cell Edge Coverage Probability field.81 dB 1 dB 1 dB 95% 87.Atoll The percentage displayed can be calculated using the Shadow Fade Margin calculator (Atoll > Explorer > Data > Predictions.16 dB 1. See following table for 90% and 95% area reliability.4% 9.6 dB Note: these values are based on an 8dB lognormal standard deviation. 3 iProtect: Internal Page 205 .standard_deviation) Where Probability = Cell Edge Coverage Probability Mean = zero (0) Revision 1.Atoll Figure 146: Shadow Fade Margin Calculator for RSSI Figure 147: Shadow Fade Margin Calculator CINR The formula for the Shadow Fade Margin calculator can be found in the Atoll Technical Reference Guide in the section on Shadow Margin Calculation.LTE RF System Design Procedure . If the desired Cell Edge Coverage Probability and standard deviation are known.mean. the approximate fade margin value can be obtained using the following formula inside Microsoft Excel = NORMINV(probability. mean. Revision 1. This will provide a 1 dB lognormal margin when the Cell Edge Coverage Probability is set to 76.LTE RF System Design Procedure . The C/I value can be changed based on local market needs and customer inputs.Atoll Standard deviation = value from the Clutter Classes description (see below) If the desired margin and standard deviation are known. By default the Atoll tool puts in a value of 7 dB for both of the Model and C/I standard deviations. no standard deviations are desired and the value must be zeroed to.standard_deviation. Figure 148: Accessing the Clutter Classes Properties In the Clutter Class properties window. then model and CINR standard deviations should be reset to 0 prior to performing any capacity analysis. select the Description tab to find the fields for the Model and C/I standard deviations.3 iProtect: Internal Page 206 . For simulations.6 dB lognormal margin when the Cell Edge Coverage Probability is set to 87.6%.4 dB be used for the C/I standard deviation (assuming 90% area reliability is desired). Note: If shadowing is employed for coverage predictions. 95% area reliability can be modeled providing a 1. It is recommended that a value of 1. The Model (RSSI) standard deviation should be changed to a value of 8 dB or a value that matches what was assumed in ML-CAT. = NORMDIST(x. the edge probability can be obtained using the following Microsoft Excel formula.TRUE) Where x = amount of fade margin desired Mean = zero (0) Standard deviation = value from the Clutter Classes description The Shadow Fade Margin calculator uses two fields from the Clutter Classes properties interface (Atoll > Explorer > Geo > Clutter Classes. Right mouse click > Properties).4%. Best Bearer) use the shadow margin resulting from the C/I standard deviation. please make sure to verify Shadow Fade Margin with the built in calculator.3 iProtect: Internal Page 207 .Atoll effectively. Figure 149: Clutter Class Standard Deviation The standard deviation values will also need to be modified in the Default Values tab.g.e. The following two figures illustrate where the Model and C/I standard deviation values are set. Signal Level. Once the adjustment has been made. Be aware that some images (e.LTE RF System Design Procedure . disable their use (since standard deviations are always applied within Atoll simulations). shadow fade).g. Traffic C/(I+N). the user will have to modify the clutter class Model and C/I standard deviations in the Clutter Class table on a clutter class basis. Revision 1. Signal Quality) use the shadow margin resulting from the Model standard deviation and other images (e. Should a customer require that individual clutter classes have different lognormal fade margins (i. 3 iProtect: Internal Page 208 . Lognormal Fade Margin). and best bearer images. The second image that is included in this section is the Effective Signal Analysis image. please see the Atoll User Guide and the Atoll Technical Reference Guide. The first image described is the Coverage by Channel Throughput. For further details regarding these images.1.3. This image will be used to show the RSSI levels for a design.Atoll Figure 150: Clutter Class Default Values The lognormal shadow margin will be different between the CINR and RSSI based images due to the different Model and C/I standard deviation values that are used. Coverage and RSSI Images This section describes two images that will be used most often in the system design process. The second subsection includes descriptions of several other images that can be helpful in the design process. 9.e. Once the user has decided on which Model and C/I standard deviation values to have in the Clutter Class table. such as best server images. Revision 1. Propagation Prediction Images This section provides descriptions and sample plots of some of the prediction coverage images. The first subsection focuses on the images that will be used the most in the evaluation of coverage and RSSI. the Cell Edge Coverage Probability should be adjusted so that the desired Shadow Fade Margin is calculated (i. If the standard deviation values are set the same there will be no difference in the resulting shadow margin that is applied to the images. 9. throughput images.LTE RF System Design Procedure .3. This image will be used to evaluate the coverage of a system. If the user wishes that the lognormal fading is taken into account. Atoll calculates the Peak RLC Channel Throughputs from the information provided in the Global Parameters (see Section 7.3) for the terminal and mobility selected in the coverage prediction (see Figure 151).1. The coverage by throughput image can be displayed by Peak RLC Channel Throughput. Figure 151: Setting Condition Tab Atoll determines the bearer at each pixel and multiplies the bearer efficiency by the number of symbols in the frame to determine the Peak RLC Channel Throughputs. Refer to Section 9.3 iProtect: Internal Page 209 .2 on how to adjust for lognormal fading via this method. The Coverage by Throughput image will use the C/I Standard Deviation from the Clutter Classes for the calculation of the lognormal fading margin.2. Refer to Figure 153.LTE RF System Design Procedure .3.1) and in the terminal and mobility properties (see Section 7.2.1. the “Shadowing taken into account” must be turned on. Revision 1. The Peak RLC Channel Throughput image does not allow the user to set a threshold to include a margin for the lognormal fading. Coverage by Channel Throughput – DL and UL Downlink and uplink channel throughput coverage predictions calculate and display the median channel throughputs based on C/(I+N) and bearer calculations for each pixel.Atoll 9. 2.3 iProtect: Internal Page 210 . as seen below.Atoll The Peak RLC Channel Throughput image displays areas colored by throughput in kbps increments set in the Display tab of the Coverage by Throughput properties window. Figure 152: Setting Throughput Display Information An example downlink Peak RLC throughput image that results from settings such as these is seen in the following figure.1. Revision 1. For the image to incorporate reliability.1 and 9.3.9.2. The image Display tab should be set so the lowest throughput displayed is the targeted edge rate of the system design. the “Shadowing taken into account” check box should be selected.2.LTE RF System Design Procedure .1. Effective throughput images (post-HARQ) and Application throughput images are covered in Sections.3. Typically. such P-SCH.1.2. S-SCH. RSSI Images – Effective Signal Analysis – DL and UL Downlink and uplink Effective Signal Analysis plots display the signal levels of different types of LTE signals.3. PDSCH. These images are recommended for use in the design process to show RSSI levels throughout the system.LTE RF System Design Procedure . it is recommended to set the “Field” to the Best PDSCH Signal Level (DL) (dBm). As seen in the following figure. in the part of the network being studied.Atoll Figure 153: Sample Coverage by Throughput – DL – Peak 9. PUSCH etc. the system design will focus on the PDSCH (traffic) signal. Revision 1..3 iProtect: Internal Page 211 . When generating these images to show the RSSI for a given design. the “Field” menu is used to define the type of signal that is used in the Effective Signal Analysis image. Atoll calculates the best server for each pixel depending on the downlink signal level. Then it calculates the effective signal level (received carrier power (C) or carrier-to noise ratio (C/N)). Revision 1. The following figure shows an example Effective Signal Analysis (DL) image for the Best Traffic Signal.Atoll Figure 154: Effective Signal Analysis – DL – Options In the downlink direction.3 iProtect: Internal Page 212 . Pixels are colored if the display threshold condition is met.LTE RF System Design Procedure . The following equation should be used to determine the proper RSSI threshold for the downlink direction: RSSI Threshold (DL) = kTB + NF + SNR + Fast Fade Margin – Diversity Gain – Adaptive Array Gain + Interference Margin The lognormal fade margin will be based on the Cell Edge Coverage Probability percentage and the Model Standard Deviation of the clutter classes. Revision 1. it is essential that this legend be modified to reflect the specific signal levels that are applicable for the given design. The diversity gain is subtracted here because it is not included in the RSSI image. the adaptive array gain is subtracted since it is not included in the RSSI image.2).e.Atoll Figure 155: Sample Effective Signal Analysis Best Traffic Signal – DL The RSSI legend that is shown in this figure is just an example. The diversity gain and adaptive array gain (which are included in the Diversity Gain in the Atoll MIMO configurations interface) are only applied to the C/(I+N) image. which depicts the percent of area at or above a given threshold.3 iProtect: Internal Page 213 .LTE RF System Design Procedure . When evaluating an RSSI image for a system. in 100% of the service area). in cases of TXAA configurations.2. The Cell Edge Coverage Probability value that provides the desired model margin result from the Shadow Margin Calculator should be entered into the Cell Edge Coverage Probability box in the prediction’s Condition window (refer to Section 9. the system designer needs to show that the RSSI values meet or exceed the desired threshold value throughout the customer’s desired service area (i. Note that the coverage area reliability is taken into account by looking at the “% of covered area” results of an image. Similarly. When evaluating an RSSI image. the lognormal fade margin is based on the Cell Edge Coverage Probability percentage and the Model Standard Deviation of the clutter classes. Revision 1. and the Overlapping Zones image provides the number of transmitting servers for each area. Application Channel Throughput. Additional Design Images This section describes several other images that can be helpful in the system design process since they provide additional perspectives on the design. the Coverage by Transmitter provides a best server perspective.2. For example.3 iProtect: Internal Page 214 .1.3) for the terminal and mobility selected in the coverage prediction. Effective RLC Cell Capacity.Atoll The same equation is used on the uplink.1) and in the terminal and mobility properties (see Section 7.3. which can assist in interference analysis.1) can be generated. These coverage images display Effective RLC Channel Throughput. the Coverage by Best Bearer provides the achieved bearer rates. The Cell Edge Coverage Probability value that provides the desired model margin result from the Shadow Margin Calculator should be entered into the Cell Edge Coverage Probability box in the prediction’s Condition window. Coverage by Channel Throughput – DL and UL (Additional Images) Additional channel throughput images (other than the Peak RLC Channel Throughput described in Section 9.1. except that there is no adaptive array gain included and the values used for various parameters are different for uplink than for downlink.3. or Application Cell Capacity. Please see Section 9.2.2.3. Peak RLC Cell Capacity. Downlink and uplink channel throughput coverage predictions calculate and display the channel throughputs based on C/(I+N) and bearer calculations for each pixel. RSSI Threshold (UL) = kTB + NF + SNR + Fast Fade Margin – Diversity Gain + Interference Margin Again.LTE RF System Design Procedure . 9. the Coverage by Channel Throughput image provides the throughput results in the system. Atoll calculates the channel throughputs from the information provided in the Global Parameters (see Section 7.4 for further information regarding evaluating images and recommended values to use in these RSS coverage thresholds. 9. or the Block Error Rate (BLER).2. The overheads such as PDU/SDU header information.4).3. Effective MAC Channel Throughput The Effective RLC Channel Throughputs are the Peak RLC throughputs reduced by retransmission due to errors. 9. Revision 1. coding all reduce the available throughput. padding.2.3 iProtect: Internal Page 215 . Atoll uses the block error rate curves of the reception equipment defined in the selected terminal reception equipment of the cell of the serving transmitter (see Section 7.1. encryption. Each uniquely configured device could have a different Effective RLC Channel Throughput rate for a given location.2.1. 9.1. Application Channel Throughput The Application Channel Throughput is the Effective RLC Throughput reduced by the overheads of the different layers between the RLC and the Application layers.LTE RF System Design Procedure .2.Atoll Figure 156: Coverage by Throughput – DL – Options The following subsections also include information on how to display throughput levels.3.3. 2. Atoll automatically accounts for the number of UL RBs used on the UL. Coverage by C/(I+N) Level – DL and UL The Coverage by C/(I+N) level images show the C/(I+N) for each pixel.2.3. Effective RLC Allocated Bandwidth Throughput. The relationships of Effective RLC Cell Capacity to Effective RLC Channel Throughput and Application Cell Capacity to Application Channel Throughput are comparable to that described above for Peak RLC Cell Capacity to Peak RLC Channel Throughput.1.3 iProtect: Internal Page 216 . 9. The Maximum Traffic Load is defined in the Cells table as Max Traffic Load (UL) % and Max Traffic Load (DL) %.3.2.4. 9. Revision 1. It is not recommended that a value of less than 100% be used for these fields.2.Atoll 9. The allocation of RBs will depend on the selected scheduler parameters (see Section 7. Atoll calculates the best server for each pixel depending on the downlink signal level. Then it calculates the interference from other cells.4) For the image to incorporate reliability. For the downlink.3. or Application Allocated Bandwidth Throughput. The color of the pixel depicts the C/(I+N) level of that pixel. The following figure shows an example Coverage by C/(I+N) Level – DL image. Allocated Bandwidth Throughput .1. This image can be run either for the downlink or uplink perspective. The predictions consist of Peak RLC Allocated Bandwidth Throughput. The allocated bandwidth throughputs are the throughputs corresponding to the number of frequency blocks allocated to the terminal at different locations.3. and finally calculates the C/(I+N).3.2. Cell Capacity The Peak RLC Cell Capacity will generate the same image as the Peak RLC Channel Throughput as long as the Maximum Traffic Load is set to 100 percent.1).UL The Allocated Bandwidth throughputs are only available in the uplink. For the image to incorporate reliability.1.LTE RF System Design Procedure . the “Shadowing taken into account” check box should be selected.2. the “Shadowing taken into account” check box should be selected. The system coverage is defined using the Peak RLC Throughput image (see Section 9. 3 iProtect: Internal Page 217 .2).2. The UL Resource Blocks at the cell edge for C/(I+N) is computed depend on the selected scheduler parameters (see Section 7.4 for further information regarding evaluating images and recommended values to use in this CINR coverage threshold. in 100% of the service area).Atoll Figure 157: Sample Coverage by C/(I+N) Level Image – DL The C/(I+N) legend that is shown in this figure is just an example. Note that the Coverage by C/(I+N) Level image includes the Diversity gain from the MIMO table within the LTE Equipment interface. it is essential that this legend be modified to reflect the specific C/(I+N) levels that are applicable for the given design. which is automatically computed by Atoll as part of its UL subchannelization algorithm.2. It is best to use the Noise Rise results produced by Monte Carlo simulations though estimated values for Uplink Noise Rise are given in Section 7. The noise component “N” of C/(I+N) depends on the noise bandwidth.2.e.1. the system designer needs to show that the C/(I+N) values meet or exceed the desired threshold value (refer to Table 10 and Table 11) throughout the customer’s desired service area (i. When evaluating coverage for a system. The lognormal fade margin will be based on the Cell Edge Coverage Probability percentage and the C/I Standard Deviation of the clutter classes.3. Please see Section 9. The Cell Edge Coverage Probability value that provides the desired C/I margin result from the Shadow Margin Calculator should be entered into the Cell Edge Coverage Probability box in the prediction’s Condition window (refer to Section 9. Atoll sets the interference component “I” of C/(I+N) according to the userdefined Uplink Noise Rise (traffic interference).1.LTE RF System Design Procedure .2. For the uplink. When evaluating a C/(I+N) image.4) Revision 1. g. that has the strongest reference signal for each pixel.4). 9.3 iProtect: Internal image (see Figure may occur since it dependent on the could be triggered Page 218 .3.) Figure 158: Sample Coverage by Transmitter Image If the option of using a margin was selected when generating the 142). Refer to Table 11 for selecting the proper UL C/(I+N) threshold.1. This is network definition of handover and the criteria (e.3. it is possible to define the potential areas where a handover depicts the overlap between sectors by a given margin. the “Shadowing taken into account” check box should be selected.7. Coverage by Transmitter (Best Server) The coverage prediction by transmitter is basically a best server image. via varying colors. See Section 7. rather than shades of gray.2.2. as seen in the following example figure.1. (Please note that in order to see varying colors in this image.Atoll For the image to incorporate reliability. Revision 1. the handover based on a C/(I+N) level or an RSSI level) for it to take place. the user needs to set the automatic coloring of the transmitters. Running a Monte Carlo simulation using multiple drops can provide the UL noise rise required for each cell in a detailed system study (see Section 10.5 for further information on setting the transmitter color display. This image shows the transmitter.LTE RF System Design Procedure . 3. The legend seen in Figure 161 refers to the Radio Bearer Index value and modulation name as shown in Figure 160.2. please look for Bearer Determination in the Atoll Technical Reference Guide.3. The Best Bearer refers modulation and coding scheme used in the prediction.3 iProtect: Internal Page 219 . Figure 159: Sample Coverage by Transmitter Image with Margin 9. For more information. The Coverage by Best Bearer image uses the C/I Standard Deviation from the Clutter Classes for the calculation of the lognormal fading when “shadowing” is checked at the time the image is generated.2. The Coverage by Best Bearer generates a CINR image (Section 9.4.LTE RF System Design Procedure .4).3.Atoll The following figure is identical to the previous figure except that a 5 dB margin was supplied. Revision 1. The settings for the scheduler determine method used to arrive at the best bearer for each pixel. Coverage by Best Bearer – DL and UL The downlink and uplink best radio bearer coverage predictions calculate and display the best LTE radio bearers based on the C/(I+N) for each pixel.2.2) and then compares it against the Bearer Selection Thresholds (Section 7. 3 iProtect: Internal Page 220 .Atoll Figure 160: Best Bearer Modulation Scheme Revision 1.LTE RF System Design Procedure . which is why there are 29 separate entries in the template for each link direction. Revision 1. The modulation and coding scheme combinations are slightly different on the uplink as compared to the downlink. Atoll populates the image ranges to include all of the bearers in the bearer table.LTE RF System Design Procedure . This creates somewhat of an issue in Atoll when plotting the best bearer image. 29 for the downlink and 29 for the uplink.3 iProtect: Internal Page 221 . When using the default configuration for the best bearer image. The legend automatically includes the bearer index number and the modulation and coding scheme as illustrated in Figure 162.Atoll Figure 161: Sample Coverage by Best Bearer Image – DL There are a total of 58 bearers and the Motorola template. however.LTE RF System Design Procedure . Configuration files have been created for the standard UL and DL best bearer plots and can be downloaded from the following link: http://compass. one work around to facilitate the best bearer plot creation is to store the desired plot configuration information in an Atoll configuration file and then import this configuration when creating the best bearer plot. once the range is changed. as illustrated in Figure 163. only the bearer index is shown as seen in Figure 161.3 iProtect: Internal Page 222 . Another approach might be to select the rows for the bearers to be excluded from the plot and choose Actions Æ Delete. if the goal is to display only a subset of the bearers.com/go/326569766 To use the configuration file. Revision 1. However. In the meantime. for example to plot only 1 – 29 for the DL bearers. rather. Atoll no longer displays the modulation and coding scheme in the legend.Atoll Figure 162: Atoll generated best bearer ranges However. This issue has been reported to Forsk and is in their bug database to be fixed. This would delete the undesired bearers while retaining the detailed legend information. the resulting color scheme is not ideal. and browse to the appropriate configuration file (UL or DL). select ActionsÆConfigurationÆImport.mot. then it would seem straightforward to simply change the image range for the plot to 1 – 29. path loss or total losses within a defined range. The colors within the image indicate the number of transmitters that are covering a given pixel. This image can be based on reference signal level. based on the conditions defined when the image is generated.Atoll Figure 163: Import best bearer plot configuration 9. The images generated to show Overlapping Zones may be used to help evaluate adequate coverage and determine if there are too many interferers that appear in various locations of the network design.LTE RF System Design Procedure .2. Overlapping Zones The Overlapping Zones coverage image provides an indication of the number of transmitting servers that cover a pixel.3 iProtect: Internal Page 223 .5.3. Revision 1. Additionally.Atoll Figure 164: Sample Overlapping Zones Image .1. the tip box will display the values for all the coverage layers that Revision 1. This section also provides information regarding the use of Atoll’s Profile Analysis Feature. the system designers need to apply their own skills and make deployment decisions to arrive at the final design. Interpreting Images LTE images produced by Atoll provide powerful tools for system designers. They are not intended to be totally inclusive as designers will find their own set of images that provide insights to unique design situations encountered.LTE RF System Design Procedure . this section provides information regarding coverage range limitations that should be kept in mind when evaluating images. 9. Tips and Hints for Evaluating Images The Tip Text for Coverage Predictions can be used to help analyze coverage or determine problems by displaying the coverage values at specific points. but do not automate the design process. The images do not warn the designers of existing problems or direct them to the solutions. Ultimately. The images provide visual feedback on the RF performance of the system design in its current state.4. This feature is useful when evaluating and gathering detailed information regarding an image. for use in the LTE design process will be suggested below. The Tip Text works by displaying the values of the coverage layers that are turned on.3 iProtect: Internal Page 224 . Interpreting the system performance feedback given through the Atoll images is a part of the process. Some images or combination of images. 9. If more than one layer is turned on.4. The geographic layers of elevation. it may be necessary to adjust the transparency via the slide control. In order to see the underlying coverage predictions. Moving the transparency slide control to the right makes the display more transparent and moving it to the left makes it less transparent. By moving the cursor over specific points of interest. clutter heights and clutter classes are not displayed when there is a coverage layer displayed. Figure 165: Tip Text Display The amount of information that is displayed in the Tip Text pop up can be controlled from the display properties for each prediction layer.LTE RF System Design Procedure . as seen in the figure below. In the figure below. the pop up display will show the values for the selected coverage layers.Atoll are turned on (as seen in the following figure). the tip text setting is showing default values of the Prediction Name and Legend.3 iProtect: Internal Page 225 . Other values can be selected from the tip text box for display. Revision 1. foliage. The design goal is to provide coverage over a desired region knowing these small shadows will exist. there will be regions that are essential to cover and other regions where coverage is not required. the design goal is to ensure that 100% of the service area is covered with adequate signal strength (i. at or above the RSSI threshold throughout the service area) and that there is no significant interference (i.3 iProtect: Internal Page 226 . buildings.e. This Revision 1. By nature. the service area). Since the coverage area reliability is taken into account by including the lognormal fade margin by specifying a Cell Edge Coverage Probability.e. there are often regions within the customer’s service area that are essential to cover and other regions where coverage is not required. As mentioned above.2. The goal of providing coverage in a design is to ensure all desired geographic locations within the service area are given RF coverage at performance levels that meet or exceed the customer’s coverage and throughput expectations. Evaluating Coverage and Interference A good understanding of the customer’s expectations is primary to planning LTE system coverage.LTE RF System Design Procedure . Attempting to provide RF coverage to every square meter of a region (outdoor and indoor) is cost prohibitive and beyond the scope of reasonable LTE deployment. setting their expectations and gaining their acceptance of the design. The designer will need to explain the coverage to the customer.g. an LTE system design will typically have some small coverage shadows behind obstructions (e. and abrupt geographic features).e. For example.4. it is important to understand the area that the customer wants to cover (i. Often within the customer’s defined service area. at or above the CINR threshold throughout the service area). The coverage and interference images need to be reviewed to ensure that the service area is covered with adequate signal strength and that there is no significant interference.Atoll Figure 166: Tip Text Display Properties 9. • Adjusting antenna azimuth to address coverage or interference issues • Selecting a different site deployment pattern or using alternate site locations for key sites that affect the coverage problem area. Coverage Images As mentioned in Section 9. then only the colored area meets the coverage area reliability value. It can be used to examine the signals from the surrounding sites and to examine possible obstructions in the area.e. not just 90% of the service area. (See Section 9. the Coverage by Channel Throughput images are used to evaluate the coverage of a system. Then when the resulting Coverage Throughput image and Effective Signal Analysis for the Best Traffic Signal Level image are evaluated.1.1. Verify the “Shadowing taken into account” option was checked in the prediction’s Condition window. then only 95% of the area would be considered as 90% reliable. if a system is being designed for 90% coverage reliability. then system design adjustments need to be examined.LTE RF System Design Procedure . Poor C/(I+N) performance may be due to shadowing by large obstructions in the signal’s path. • Adding sites to fill the coverage hole. 9.4. It may also be caused by an unusually strong signal from the neighboring sites. the user needs to show that the entire service area is at or above the calculated thresholds.3 iProtect: Internal Page 227 . the lognormal fade margin values that are used in the Coverage Throughput image and RSSI threshold (assuming the lognormal fade margin is being accounted for in the threshold settings and not based on the Cell Edge Coverage Probability) would be based upon 90% coverage reliability. When evaluating this image. The Lognormal fade margin will be Revision 1.1.2. downtilting the offending sector’s antenna is typically the best approach to controlling the interference problem. (If a percentage of area less than 100% is shown. For example.2. such as: • Adjusting antenna downtilt in sites/sectors to address coverage or interference issues. in 100% of the service area). If this is the case. The Point Analysis Tool within Atoll can be used in the evaluation and troubleshooting process to help determine which sites/sectors are associated with a coverage problem area. If relatively large areas between sites lack coverage or show high interference.) The following subsections will describe how to determine the proper signal strength thresholds to use when evaluating the images. For example.3 and the Atoll manuals for further information on the use of the Point Analysis Tool).Atoll design goal is to show adequate signal strength and no significant interference in all of the required regions within the service area.2.3. the system designer needs to show that the downlink and uplink meet or exceed the desired cell edge throughput value throughout the customer’s service area (i. as described in Section 9. if 95% of the service area meets the calculated threshold level which includes a lognormal fade margin for 90% reliability.4.1. The system designer needs to show that the RSSI values meet or exceed the desired RSSI threshold throughout the customer’s service area (i.3. 9. The following equations are used to determine the downlink and uplink RSSI thresholds: RSSI Threshold (DL) = kTB + NF + SNR + Fast Fade Margin – Diversity Gain – Adaptive Array Gain + Interference Margin RSSI Threshold (UL) = kTB + NF + SNR + Fast Fade Margin – Diversity Gain + Interference Margin Verify the “Shadowing taken into account” option was checked in the prediction’s Condition window.1.4.2.LTE RF System Design Procedure .2. RSS Images As mentioned in Section 9.4. 9. The following subsections provide values for these parameters based on various configurations. the adaptive array gain is subtracted from the downlink threshold since it is not included in the RSSI image.3 iProtect: Internal Page 228 .Atoll based on the Cell Edge Coverage Probability percentage and the Model Standard Deviation of the clutter classes.2.2 the Effective Signal Analysis images for the Best Traffic Signal Level are used to evaluate the traffic signal levels within a system.3 to determine the values to use in this equation. The lognormal fade margin will be based on the Cell Edge Coverage Probability percentage and the Model Standard Deviation of the clutter classes.2.3. kTB kTB is calculated as follows: Downlink kTB = kT + 10log(Resource Element bandwidth * DL occupied Resource Elements) Uplink kTB = kT + 10log(UL Resources Blocks * 180 kHz ) Revision 1.3.1.4. 9.2.2. in 100% of the service area).4.2. Please see Section 9. The diversity gain and adaptive array gain (which are incorporated in the Diversity Gain in the Atoll MIMO configurations interface) are only applied to C/(I+N) images. Similarly. as described in Section 9.1. in cases of TXAA configurations.e. The values used in these equations depend upon the given design configuration. The diversity gain is subtracted because it is not included in the RSSI image. RSSI Threshold Parameter Values The previous sections provide equations to use in calculating the RSSI thresholds. which will alter the uplink kTB value (as seen in the equation above). The minimum number of uplink Resource Blocks should not be less than two. Table 9: Downlink/Uplink kTB Values Channel Bandwidth.2 15 -174 15000 900 75 63 -102.3 iProtect: Internal Page 229 .Atoll And kT (dBm/Hz) = -174 The following table contains downlink and uplink kTB values for the different channel bandwidths.7 -110.4 Maximum Maximum Resource DL Number of UL kT element Occupied UL Occupied (dBm/Hz) Bandwidth. Resource Resource Resource Hz Elements Blocks Blocks -174 15000 72 6 5 Downlink kTB (dBm) Uplink kTB (dBm) * -113. it is possible that a smaller allocation of Resource Blocks will be used.7 -114. The uplink kTB value will need to be modified (using the equation above) based on the number of UL Resource Blocks that are assumed per user for the given market. Revision 1.5 -108.2 * Assumes that all Resource Blocks are used for a subscriber.5 -105.5 20 -174 15000 1200 100 84 -101.4 -102. However.LTE RF System Design Procedure .7 -103.5 3 -174 15000 180 15 13 -109. MHz 1.3 5 -174 15000 300 25 21 -107.2 10 -174 15000 600 50 42 -104. LTE RF System Design Procedure - Atoll 9.4.2.3.2. Noise Figure (NF) In the downlink direction, the Subscriber Noise Figure is used in the RSSI threshold calculation. The subscriber noise figure should be available from the UE vendor. In the uplink direction, the eNB Noise Figure is used in the RSSI threshold calculation. For Motorola base stations, the Noise Figure is typically 4 dB. 9.4.2.3.3. Effective SNR The RSSI threshold equation includes the SNR + Fast Fade Margin terms, so the Effective SNR value can be used for the combination of these two parameters within this equation. The following tables provide the Effective SNR for both the DL and UL. The first table provides the downlink effective SNR values and the second table provides the uplink effective SNR values. The values in these tables are the same as the bearer selection threshold values found within Atoll (see Section 7.2.3.4). The values in Table 10 are the same as the values in the Motorola UE Reception (used for DL), the values in Table 11 are the same as the values in the Motorola eNB Reception (used for UL). Table 10: DL Effective SNR Values (i.e. bearer selection thresholds) Bearer Index 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 Revision 1.3 Modulation QPSK 0.12 QPSK 0.15 QPSK 0.19 QPSK 0.25 QPSK 0.30 QPSK 0.37 QPSK 0.44 QPSK 0.51 QPSK 0.59 QPSK 0.66 16 QAM 0.33 16 QAM 0.37 16 QAM 0.42 16 QAM 0.48 16 QAM 0.54 16 QAM 0.60 16 QAM 0.64 64QAM 0.43 64QAM 0.46 64QAM 0.50 64QAM 0.55 64QAM 0.60 64QAM 0.65 PB3 -5.3 -4.3 -3.3 -2.0 -0.9 0.3 1.5 2.7 3.7 4.6 4.6 5.3 6.4 7.6 9.0 10.0 10.8 10.8 11.4 12.5 13.6 14.5 15.4 iProtect: Internal VA30 -5.3 -4.3 -3.3 -2.0 -0.9 -0.2 1.8 3.1 4.1 5.0 5.0 5.8 6.8 8.2 9.5 10.8 11.5 11.6 12.3 13.4 14.4 15.3 16.2 VA30R1 -5.3 -4.3 -3.3 -2.0 -0.9 -0.2 1.6 3.0 4.0 4.9 4.9 5.8 7.3 9.1 10.7 12.1 12.8 12.9 13.6 14.5 15.4 16.5 17.4 Page 230 LTE RF System Design Procedure - Atoll 23 24 25 26 27 28 64QAM 0.70 64QAM 0.75 64QAM 0.80 64QAM 0.85 64QAM 0.89 64QAM 0.93 16.2 17.0 19.2 40.0 40.0 40.0 16.8 17.8 19.8 40.0 40.0 40.0 18.1 18.9 19.9 40.0 40.0 40.0 Note: These DL values have been calibrated with Minisim simulations. The R282 template (Nov10) contains the bearer selection curves for all mobilities. Should an existing project need to be updated with the new curves, the complete set along with instructions for copying them into the project’s database can be found in the spreadsheet “AtollR282Params.xls” located at http://compass.mot-solutions.com/go/318588510. Refer to sheet “BST” (for Bearer Selection Thresholds). Table 11: UL Effective SNR Values (i.e. bearer selection thresholds) BEAREX INDEX Revision 1.3 Modulation 30 QPSK 0.10 31 QPSK 0.13 32 QPSK 0.16 33 QPSK 0.21 34 QPSK 0.25 35 QPSK 0.31 36 QPSK 0.37 37 QPSK 0.43 38 QPSK 0.49 39 QPSK 0.56 40 QPSK 0.62 41 16 QAM 0.31 42 16 QAM 0.35 43 16 QAM 0.40 44 16 QAM 0.45 45 16 QAM 0.50 46 16 QAM 0.54 47 16 QAM 0.57 48 16 QAM 0.63 49 16 QAM 0.69 iProtect: Internal PB3 -0.088 VA30 & VA30R1 0.612 0.981 1.681 1.743 2.409 2.909 3.109 4.235 5.134 5.192 6.050 5.950 6.687 6.577 7.431 7.145 8.068 7.771 8.511 8.285 8.921 8.285 8.921 8.993 9.688 9.857 10.405 10.516 11.114 11.383 12.032 12.097 12.322 12.393 12.634 12.899 13.306 13.676 14.263 Page 231 LTE RF System Design Procedure - Atoll 50 16 QAM 0.75 51 64QAM 0.50 52 64QAM 0.54 53 64QAM 0.59 54 64QAM 0.63 55 64QAM 0.67 56 64QAM 0.71 57 64QAM 0.74 58 64QAM 0.77 14.634 15.160 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0 Note: These UL values have been calibrated with Minisim simulations. The R282 template (Dec10) contains the bearer selection curves for all mobilities. Should an existing project need to be updated with the new curves, the complete set along with instructions for copying them into the project’s database can be found in the spreadsheet “AtollR282Params.xls” located at http://compass.mot-solutions.com/go/318588510. Refer to sheet “BST (UL)” (for Bearer Selection Thresholds). 9.4.2.3.4. Diversity Gain Diversity gain is not included in the RSSI images (i.e. Effective Signal Analysis images). As mentioned previously, the diversity gain needs to be accounted for in the RSSI threshold value. In the downlink direction, the diversity gain is determined by the subscriber equipment and the receive diversity type that is supported by that equipment, as well as the MCS and channel profile assumptions. Similarly, for the uplink direction, the diversity gain is determined by the base station receive diversity type and the MCS and channel profile assumptions. UL Diversity gain is currently modeled in the Atoll LTE template as 10*Log10(Num Rx Antennas), so 3 dB gain for two-branch RX diversity, 6 dB for four-branch RX diversity, and 9 dB for eight-branch. For DL Diversity gain recommendations, refer to Table 7. (Receive diversity gain values are included in the Diversity Gain fields within the MIMO table of the LTE Equipment interface, which are incorporated in the C/(I+N) images.) 9.4.2.3.5. Adaptive Array Gain The adaptive array gain needs to be incorporated into the RSSI threshold value in the downlink direction. This is only a factor in systems where smart antennas are used. A TxAA array gain of 2 to 5 dB is included, depending on the environment being modeled (i.e. 2 dB is used in dense urban settings with a high degree of scattering, 3 to 4 dB is used in urban or suburban settings with a medium degree of scattering, and 5 dB is used in rural or suburban settings with a low degree of scattering). Further information regarding the TxAA gain can be found in the LTE RF Planning Guide (http://compass.mot.com/go/310442223) or in the LTE ML-CAT User Guide (http://compass.mot.com/go/310448858). Revision 1.3 iProtect: Internal Page 232 LTE RF System Design Procedure - Atoll 9.4.2.3.6. Interference Margin The topic of Interference Margin is described within the UL Noise Rise discussion in Section 7.1.2.1.3. The noise rise values discussed in this section represent the interference margin that can be used for the uplink or downlink interference margin in the RSSI threshold calculations. 9.4.2.4. Additional Image Evaluations In addition to evaluating coverage and signal strength within a system, other performance aspects of the system need to be evaluated. Various other images are available to assist with this evaluation, such as: • Coverage by Channel Throughput is used in evaluating throughput results in the system • Coverage by C/(I=N) is used in evaluating regions of high interference. • Coverage by Best Bearer provides information regarding the achieved bearer rates in the system. • Coverage by Transmitter provides a best server analysis of the system • Overlapping Zones interference areas. can provide additional insight into possible Further information regarding these images can be found in Section 9.3.2 and in the Atoll manuals. 9.4.3. Use of Profile Analysis Feature in Evaluation The Point Analysis Tool can be useful in the process of evaluating or troubleshooting a design. The Point Analysis Tool is activated by clicking on the Point Analysis Tool button in the Atoll toolbar, as shown below. This will open the Point Analysis window. Revision 1.3 iProtect: Internal Page 233 LTE RF System Design Procedure - Atoll 9.4.3.1. Path Profile Analysis The Point Analysis Tool is useful to see the path profile that includes the pathloss, terrain elevations, and clutter losses / obstructions. Figure 167: Path Profile 2 3 4 7 5 1 6 In the profile window (item “1” in the previous figure), the “Transmitter” field (item “2”) specifies the source of the signal from which the path is generated. The numbers adjacent to it (item “3” above) are the received signal strength of the transmitter, the Propagation Model that was used, and the distance from the Transmitter. Also, if the “Shadowing taken into account” field is checked in the Analysis Properties interface, then the shadow margin and the cell edge coverage probability used for calculating the shadow fade margin are also shown here. The blue ellipsoid indicates the Fresnel zone and the green line indicates the Line of Site between the transmitter and the receiver. (Note that when there is an obstacle along the path, the green line is drawn from the transmitter to the obstacle.) The angle Revision 1.3 iProtect: Internal Page 234 3 iProtect: Internal Page 235 . (as seen in Figure 168). The Link Budget details window will show the various values that are being reported at the location of the cursor. if the signal meets an obstruction. the elevation value and the clutter type. or Link Budget details (as seen in Figure 169). The total attenuation is displayed in the profile (item “5” in the figure above). The values shown below the Profile window (item “6” in the figure above) provide the Latitude / Longitude. the diffraction is displayed by a red vertical line (assuming the propagation model used takes diffraction into account). the path profile will change due to variations in terrain and clutter values.Atoll of the LOS read from the vertical antenna pattern is also displayed (item “4” in the figure above). Right Clicking in the Profile window allows the user to bring up the Properties. As the cursor is dragged around the map. Checking the “Geographic profile” box (item “7” in the figure above) turns off all of the propagation reporting in the profile tab window and only shows the blue Fresnel zone ellipsoid and the geographic information (terrain and clutter) between the transmitter and the receiver. Along the profile.LTE RF System Design Procedure . Figure 168: Path Profile Analysis Properties Revision 1. The information in the Link Budget window will change as the cursor is dragged around the map. The analysis point will remain in a fixed location by releasing the left mouse button. This can be useful for determining most likely interferers in areas with high C/(I+N). Reception Analysis The Reception tab.Atoll Figure 169: Path Profile Link Budget 9.3 iProtect: Internal Page 236 .3.4. displays the signal strength levels of the surrounding transmitters. Multiple arrows connecting the cursor location to each transmitter will be displayed and colored the same as the transmitter color. The cursor can then be moved (do not depress the mouse buttons) to any of the connection lines on the display to reveal the transmitter identification associated with the connection line. As the cursor is dragged around the map. 2nd tab of the Point Analysis window.2.LTE RF System Design Procedure . the reception values will vary as the distance from the transmitter changes. Revision 1. bearers. 3rd tab of the Point Analysis window. Signal Analysis The Signal Analysis tab. Revision 1. downlink traffic.4.3. Only the best server link will have a black arrow between the measurement point and the serving cell as seen in the following figure.3 iProtect: Internal Page 237 .LTE RF System Design Procedure . C/(I+N). shows information on the reference signal.Atoll Figure 170: Path Profile Reception 9.3. and throughputs. and uplink signal levels. 3. The Service field pull-down allows the user to select the subscriber application being used for the analysis (from the list of defined services). 4. Uplink and Downlink at the selected point. This area of the Point Analysis window shows the connection status of the SCH & PBCH. The solid portions of the reference signal reception bars indicate signal levels above the preamble C/N threshold. Note. The Mobility field pull-down allows the user to select the subscriber mobility model being used for the analysis (from the list of defined mobility types). A green to any of these titles indicates a working connection.Atoll Figure 171: Path Signal Analysis NOTES: Note. Note. a red of these titles indicates a bad connection. Note. The Load Conditions field allows the user to define whether the load is from the Cells Table or from simulations (if simulations have been run). The Terminal field pull-down allows the user to select the subscriber equipment used for the analysis (from the list of all available terminal types). 1. 6.LTE RF System Design Procedure . Revision 1. 2. The clear portions indicate signal levels below the preamble C/N threshold.3 iProtect: Internal next next to any Page 238 . Note. The reference signal strength bars are shown with the best server at the top and the interfering cells below in descending order. Note. 7. 5. Note. LTE RF System Design Procedure .Atoll A reference signal reception strength bar will be shown for all links which have signal levels above the reference signal C/N threshold (see below). and Uplink portion of the Signal Analysis window (see note 7 above) offers additional information about each of these links.3 iProtect: Internal Page 239 . Figure 173: SCH & PBCH Reception Window Revision 1. Figure 172: Preamble Reception Strength Bars The SCH & PBCH. Double clicking on any of these names will bring up a data window with information about that link at that measurement location (see the following three figures). Downlink. LTE RF System Design Procedure .3. while the Point Analysis window shows a table of numeric signal strength “C (dBm)” values and distances to each transmitter from the analysis point as seen in the following figure. Revision 1.Atoll Figure 174: Downlink Window Figure 175: Uplink Window 9. the 4th tab of the Point Analysis window.3 iProtect: Internal Page 240 .4. Results Analysis The Results tab.4. displays multiple arrows connecting the cursor location to each transmitter. as well as other technologies.3 iProtect: Internal Maximum Cell Radius (km) Page 241 .88 6.67 100.53 1 2 684.13 96.67 77.25 14.38 515.LTE RF System Design Procedure . the PRACH for FDD and TDD Systems as well as the guard period for TDD systems serve to limit the cell range.16 Revision 1.88 6. Table 177: Maximum Cell Range Due to PRACH Timing Preamble Format Number of Allocated Subframes CP Duration (μs) GT Duration (μs) Max Delay Spread (μs) 0 1 103. Coverage Range Limitations Coverage range in an LTE system.34 2 2 203.Atoll Figure 176: Path Profile Results 9. For LTE.63 16.25 29.63 16.53 3 3 684.13 196. The following table provides the cell radius limitation as a function of the PRACH configuration. can be limited by timing considerations.4.4.38 715. (See Section 8. Reports The Reports are generated from previously created Predictions.1. 9. azimuth or downtilt changes) and the addition or removal of sites within the system.com/go/310442223). These zones can be created from existing polygons or drawn onto the project area.3 iProtect: Internal Page 242 .Atoll The TDD guard time can be configured to accommodate cell ranges up to the prescribed 100 km requirement for LTE.) To generate prediction statistics for a given service area.5. Generating Propagation Prediction Statistics Propagation prediction statistics are generated for the Focus and / or Hot Spot Zones.4) corresponding to the service area before generating predictions.LTE RF System Design Procedure . Right click on a generated prediction and select Generate Report. Please refer to the LTE RF Planning guide for additional information on the topic of timing based coverage limitations (http://compass. On the Data tab click on Predictions to expand it. the reports will be generated for the Computation Zone. The prediction statistics are useful in determining if changes that the user has made have improved the overall system performance.5. If Focus or Hot Spot Zones do not exist.3. Figure 178: Predictions – Generate Report Revision 1.g.3 for further information regarding zones. 9. The most typical uses would be for sector modifications (e. it is recommended to generate a Focus zone (see Section 8.mot. when evaluating a Coverage by C/(I+N) image. a calculated CINR threshold is used.g. This CINR threshold includes the lognormal fade margin (whether applied as a margin to the threshold or selected by checking “Shadowing taken into account” when the prediction is performed) that accounts for the market-specific coverage area reliability percentage. focus zone) is at or above the Revision 1. In this case. the statistics for a given image can provide some indication as to the coverage of the service area. As mentioned in previous sections. the table can be copied into Excel by selecting all the columns and rows and then copying and pasting them into Excel. data) are to be reported. the report will be generated.LTE RF System Design Procedure . Figure 180: Coverage by Best Signal Level Report For further analysis. Figure 179: Generate Report Data Once the desired columns have been selected.3 iProtect: Internal Page 243 . the design goal is to show that 100% of the service area (i.Atoll Once the Generate Report option has been selected. a new window will open allowing the user to select which columns (e. If a Focus Zone has been created to match the customer’s desired service area.e. 9. 9. Each transmitter will generate its own pathloss plane. the design goal for an Effective Signal Analysis for Best Traffic Signal Level is to show that 100% of the service area (i. Figure 181: Histogram of Best Signal Level The histogram can also be viewed as a CDF or as an Inverse CDF (refer to the Atoll User Manual for further information).5. Similarly.LTE RF System Design Procedure .6. there will be statistics generated in the box below the Histogram. Histograms The Histograms are generated from previously created Predictions.Atoll CINR threshold value. Revision 1. When exported. the pathloss planes will be in the projection system defined in the Atoll project and the Displayed Map Projection. Right click on a generated prediction and select Histograms. On the Data tab click on Predictions to expand it.3 iProtect: Internal Page 244 . Depending on the Type of Prediction that was generated. Generating Path Loss Files The pathloss planes of Atoll can be exported as either a binary (bil) or as a text file (Tab or comma delimited). focus zone) is at or above the RSSI threshold.2.e. In the table within the Propagation tab. select Export and the “Calculation Results Export” window will open.Atoll In the Data tab of the Explore window. In this new window. A new window will open with the Transmitter Properties. and dBuV/m). and then select the properties. Finally. the user can specify if they would like to have pathloss planes as a Binary Format (BIL) or as a Text formatted (tab or comma delimited). Then right click again. right click and Select All. The values inside the planes can be defined (dB. Revision 1.LTE RF System Design Procedure . the user can specify the path in which to write the pathloss planes.3 iProtect: Internal Page 245 . right click on the Transmitter folder. dBuV. dBm. in a manner that satisfies the Minimum Throughput Demand (aka Minimum Reserved Rates) for the services. The resultant statistics are reviewed to verify that the system (including each individual sector) can carry its load (i. Optimizing system capacity may also involve adjusting the system design around limiting sites. Each simulation has a load of active subscribers “dropped” into the simulation. Also. d. Should the exit criteria not be met. in their average across simulations. the maximum load persector that the system can carry). the probabilities established via the traffic maps for subscriber density. but reflect. the systems designer can look at alternatives such as improving site capacity (e.e. mixture of services. These are reflected in the resultant statistics and constitute capacity “outages”. b. remaining capacity is distributed among users according to the manner that reflects the scheduler. Capacity Analysis This section describes the process by which Monte Carlo simulations are used to derive DL and UL Traffic Loads and UL Noise Rise. Secondly. simulation results are used to verify that the capacity criterion for the system design is met. “maximum throughput”.g. First. i. The number and position are determined randomly. A “Group” of “Simulations” are made. The overall process of assessing system capacity is outlined at a high level as follows: 1. Note: “Resource Saturation” occurs whenever the Minimum Throughput Demands of the users cannot be satisfied.e. optimizing antenna tilt and azimuth. Subscriber lists may be used to characterize fixed subscribers. adopting a different antenna technology) or increasing the site count. ii. This constitutes an exit criterion. Different system capacities can be defined including “maximum user”. and “available”. Sectors (channels) will be loaded with traffic.3 iProtect: Internal Page 246 . c.LTE RF System Design Procedure . Mobility. and probabilities of activity. Revision 1. Create Traffic Map(s) These will describe the subscriber density and define the load being offered to the system. These simulation outputs can be fed back into coverage predictions. 3. Define Services. and Schedulers 2. Resource Saturation is at acceptable levels). Run Monte Carlo Simulations a. Resultant statistics are produced. This process verifies that the projected system load can be supported. Terminals. 4. It may also be desirable to determine the system capacity (i.Atoll 10. Mobility Types.3.2. ¾ Section 10.2. This is only true for capacity curves.1 through 10.1.7.1).8 describes the overall recommended Motorola procedure including checks to perform.8.2).2 summarizes the assumptions to adopt in making a quick assessment of capacity. The DL MCS0 bearer threshold is lowered to allow for up to 2. The type of services that Revision 1. This section describes how the Services are defined within Atoll. Defining Services Services. ¾ Section 10. 10.1. BLER curves (relating CINR to BLER on a per-mobility. The capacity curves have been calibrated (aligned) with Minisim simulations.4. traffic map displays (Section 10.3 describe Services.4. SU-MIMO Gains (a function of CINR) are defined for 2x2 and 4x2 DL antenna schemes.4.5 dB of additional HARQ gain.3 iProtect: Internal Page 247 .7. Refer to Section 7.2.8. This should be useful when detailed customer inputs are lacking.LTE RF System Design Procedure . ¾ Sections 10.3.Atoll There are a few noteworthy changes that accompany the introduction of the capacity analysis. and Terminals.2.5 describe User Profiles and Environments.2. and post-processing of statistics (Section 10.6 describes the Traffic Maps and Subscriber Lists. per-bearer basis) are introduced to de-rate peak throughputs to effective throughputs.4 describes Schedulers.2 and Section 7.3) and method of applying load conditions to coverage images (Section 10.7 describes the fundamental Atoll simulation process including the algorithm.2. ¾ Section 7. ¾ Section 10.4). ¾ Section 10. output statistics (Section 10. need to be defined to produce Monte Carlo simulations that characterize the traffic load submitted to the system. need to be disabled (zeroed) for simulation work.4 through 10. in general. ¾ Sections 10.8.1). Refer to Section 7. together with Mobility Types and Terminals. Model (RSS) and CINR standard deviations.7. The following list provides the sections where settings that will impact the simulations are discussed in further depth.2.3. These changes are highlighted here: • • • • • The bearer selection thresholds associated with the definition of LTE Equipment (refer to Section 7. Refer to Section 9. procedure (Section 10.7.3 outlines the procedure for generate a density traffic map constrained by coverage.4) are expanded to include a set of capacity curves to be used in Monte Carlo simulations. definition of capacities and exit criteria. ¾ Section 10. 3 iProtect: Internal Page 248 .Atoll are available to the user can be either voice or data services. the Motorola template defines four Services: FTP Download. and the application throughput parameters. VoIP. the upper limit bearer. the average requested throughput. as seen in the following figure.LTE RF System Design Procedure . and Web Browsing. The Services within Atoll are accessed through the Services folder within the LTE Parameters folder in the Data tab. Video Conferencing. They are simply placeholders. are shown in the following table. These services then are defined further by parameters that set the priority. Note: The “Video Conferencing” service parameters should not be considered recommended. Revision 1. the maximum and minimum throughput. Figure 182: Accessing Services Parameters As seen within this figure. along with their default values. The parameters that are used in defining these services. 2 1000 2200 Min Throughput Demand (kbps) 64 100 64 64 64 100 12.2 12.3 iProtect: Internal Page 249 .5 1 1 Highest Bearer 50 29 50 29 50 29 50 29 50 29 Max Throughput Demand (kbps) 256 1000 64 64 256 1000 12.Atoll Table 12: Template Services Parameters Name Full FTP Video Web Download Conf Browsing Data Voice Data Voice Data 0 2 1 3 1 Type Priority VoIP Buffer UL DL UL DL UL DL UL DL UL DL Activity Factor 1 1 0.2 0 0 Average Requested Throughput (kbps) 180 360 64 64 180 180 12.2 12.2 12.5 1 1 0.LTE RF System Design Procedure .5 0.2 360 360 Application Throughput Scaling Factor (%) 95 95 95 74 95 Application Throughput Offset (kbps) 0 0 0 0 0 Body Loss (dB) 0 0 0 2 0 The following figure shows an example of the GUI window set up for an FTP service. Revision 1.5 0. The Priority field allows the user to define the priority associated with the service (0 being the lowest priority). followed by the Video Conferencing service. Note.3 iProtect: Internal Page 250 . Revision 1. Note 4. Note 4. and that the FTP Download and Web Browsing share the lowest priority.LTE RF System Design Procedure . refer to Figure 187. The Type field allows the user to define the type of service as either Voice or Data. For further explanation of how the Activity Factor impact simulations. the probability of activity for voice type services. Note. For further explanation of how the selection of voice or data types impact simulations. These fields are not utilized for data services. by direction. 1. Note. The Activity Factor field will appear within the interface when Voice is selected. Note that the template default values are set so that the VoIP service has the highest priority. 4. refer to Figure 187. The Activity Factor fields define. 3.Atoll Figure 183: Example Services GUI Window (FTP) 1 3 2 4 5 6 7 8 9 9 10 NOTES: Note. The Name field allows the user to provide a name for the given service. 2. and Average Requested Throughput (ART). Min Throughput Demand (MinTD). Nevertheless. This establishes an upper limit that is used during bearer determination. Specifically. by direction. it is only in the scheduler definition that the layer to which these target throughputs apply is specified. Refer to the scheduler description for more detail (Section 7. refer to Figure 187. The Average Requested Throughput fields define. 64QAM 0.LTE RF System Design Procedure . For further explanation of how the Average Requested Throughput impacts simulations. The Min Throughput Demand fields define.4). The choice must be consistent across all voice type services and across all data type services.3 iProtect: Internal Page 251 . 64QAM 0. Note. it is never applied for data services.2. The default values match. the maximum MCS and coding rate levels. This represents the highest bearer supported in Motorola’s initial LTE product offering. But. Note: In defining the services parameters Max Throughput Demand (MaxTD). the maximum throughput that the service can demand. by direction. the UL is constrained to bearer index 50 which corresponds to MCS 20 (16QAM with coding rate of 0. Table 13: Highest Bearer Settings Highest Bearer Template Future Uplink 50 (MCS 20. 5.75). by direction. the minimum throughput that the service can demand. 16QAM 0.Atoll Note: The field may or may not appear for data services depending on the release. throughput values are specified. the average requested throughput. This means that target throughputs can be specified at any layer within the services as long as the corresponding layer is identified in the scheduler. 7. 6. Note. The Highest Bearer fields define. by direction. It is anticipated that a future product release will extend UL support to 64QAM. Revision 1.93) 29 (MCS 28. These values are used in the simulation during user distribution to calculate the number of users attempting a connection.93) Note. The Max Throughput Demand fields define. by direction.75) 58 (MCS 28. Note 4.2. The Motorola template includes the same default settings across all defined services. 8. Note.77) Downlink 29 (MCS 28. the highest bearer that can be used by the service. 64QAM 0. Be careful not to double count the loss. The Body Loss field allows the user to account for the body loss at the subscriber device on a per-service basis. Revision 1.g. Note 5). 9. then a body loss (e. the loss would be applied across all services employing the terminal. this loss could be moved from this field and incorporated into the Losses field of the Terminal properties instead (refer to Figure 101.3 iProtect: Internal Page 252 . exhibit a different body loss. The application level channel throughput is calculated in Atoll as follows: Application Level Channel Throughput = Effective Channel Throughput * (Application Throughput Scaling Factor/100) – Application Throughput Offset Note. Note: Alternatively. the same handheld device acting as a modem may be used to access email and. In this case. 10. These fields are used to account for overhead associated with protocol headers as well as any other factors which may lead to de-rating of the throughput. For example. The Application Throughput Scaling Factor and Offset fields allow the user to enter parameters to be used when calculating the application throughput from the effective throughput. Conversely. 2 dB) would be entered to account for the head of the person holding the subscriber device.Atoll Note. consequently. if a handheld device was used for a voice call.LTE RF System Design Procedure . This section describes how the Mobility Types are defined within Atoll. Typical designs use the PB3 mobility type which is appropriate even for a fixed CPE scenario. The properties window is accessed by double-clicking on the Mobility Type or by rightclicking on Mobility Types and selecting “New” for a new Mobility Type. it will require adding new curves. for capacity purposes. etc. Defining Mobility Types Mobility Types.).3 iProtect: Internal Page 253 . Note that there are “_Capacity” versions of each of these mobility types. as seen in the following figure. The Mobility Types within Atoll are accessed through the Mobility Types folder within the LTE Parameters folder in the Data tab. together with Services and Terminals. which can be accessed by right-clicking on Mobility Types and selecting “Open Table”. The following figures show example Mobility Types interfaces within Atoll. Revision 1. This information can also be viewed for all Mobility Types at the same time by looking within the Mobility Types table. VA30 (for TM 3/4) and VA30R1 (for TM2/6/7) are for systems that are mobile. another set of bearer selection thresholds and quality scalars. VA30 and VA30R1 (Vehicular A @ 30 kmph). the Motorola template defines three basic mobility types: PB3 (Pedestrian B @ 3 kmph).Atoll 10. Figure 184: Accessing Mobility Types As seen within this figure. vehicles passing. The primary purpose for defining Mobility Types is as a means for indexing the appropriate bearer selection threshold and quality curves. Note that should a new mobility type need to be defined.LTE RF System Design Procedure . Systems which contain both pedestrian and vehicular traffic should be characterized by whichever mobility type is limiting. need to be defined to produce Monte Carlo simulations that characterize the traffic load submitted to the system. They are identical to their counterparts in their speed and exist so as to be able to access.2. as there will be movement in the environment (trees swaying. It allows the user to enter the Name and associated Average Speed with each defined Mobility Type. Atoll Figure 185: Example Mobility Types GUI Windows (PB3) The parameters that are used in defining these Mobility Types are described below. 10.3. The Average Speed field allows the user to define the average speed that will be associated with that particular Mobility Type. NOTES: Note. 10. etc. Each service/terminal pair is then correlated to a specific per-user load (arrival rate and voice average hold time or session data volume). Note. 2. it is just provided for information. Each service is paired with a specific terminal type which permits for defining. then the use of User Profile traffic maps would be very appropriate. The systems designer is responsible for setting inputs to correspond to the actual customer traffic projections.LTE RF System Design Procedure .6. The Terminal properties define how the subscriber equipment is modeled within Atoll (power level. Note: It should be understood that the parameters characterizing the default User Profiles found within the template are simply placeholders. The Name field allows the user to provide a name for the given Mobility Type.).) Note: To utilize Subscriber Lists.4 for further information on Subscriber Lists. Defining Terminals Terminals. for example. 1. need to be defined to produce Monte Carlo simulations that characterize the traffic load submitted to the system. antenna parameters. Defining User Profiles User Profiles characterize subscribers in terms of their service usage. together with Services and Mobility Types. Revision 1. Terminals are described in Section 7.3. it is required that an associated Mobility Type of “Fixed” be defined. The Atoll LTE Parameters within the Data tab also include Terminals. When marketing-based traffic data is available for the system design. (This speed is not used in any calculations.3 iProtect: Internal Page 254 . web browsing to be done assuming a modem card while a VoIP call might assume a handheld device.4. noise figure. Refer to Section 10. The parameters that are used in defining these services are described below. Names can be easily changed and new user profiles easily added. 1. as seen in the following figure.LTE RF System Design Procedure . there are two user profiles that are included in the Motorola template: Business User and Standard User. The Name field allows the user to provide a name for the given User Profile. Revision 1. This allows for defining a typical user and a second. Figure 187: Example User Profiles Window (Business User) 2 3 4 5 6 7 1 NOTES: Note. Figure 186: Accessing User Profiles Parameters As seen in the figure above. more demanding user.3 iProtect: Internal Page 255 .Atoll The User Profiles within Atoll are accessed through the User Profiles folder within the LTE Parameters folder in the Data tab. a service with type “voice”).6% probability of being active (bursting) in the DL direction (assuming an average requested throughput of 180 kbps.Atoll Note. In Figure 187 above. the sum of activity probabilities must be lower than 1. For example. In the case of an interactive service like web browsing. the Web Browsing service shows 0.3% probability for use of the voice service. the CPE terminal is associated with each of the Services except VoIP which is associated with the MS terminal. scaled to bits. VoIP. this field is used to define the busy hour session attempts (or session arrival rate). it yields the probability of being active (bursting) in each direction. and normalized by average requested throughput (defined for the data service) and 3600 (seconds in the sample period). In Figure 187 above. this field is used to define the busy hour call attempts (or call arrival rate).013 Erlangs or a 1.LTE RF System Design Procedure . that for Monte Carlo simulations. The Terminal field describes the type of terminal that is associated with the Service listed for this given User Profile. The Terminals that are available for this field are defined in the Terminals interface (as described in Section 10. Note. Note.e. 3. the voice activity factor defined for the VoIP service will also be applied to determine the probability of being active (bursting) in each direction. When multiplied by the duration (or average hold time) and normalized by 3600 (seconds within the sample period).1). Voice Conferencing. the data activity factor is low and it is likely the session data volume assumed above is distributed over several separate downloads corresponding to different web pages with significant “think time” or “reading time” in between downloads. In the case of a voice service (i.3 iProtect: Internal Page 256 . In the case of a data service (i. When multiplied by the data volume (kB/session attempt). see Table 12).3). and Web Browsing. a service with type “data”).e.1 x 4500 x 8 / 3600 / 180 kbps) or a ~0. the VoIP service shows 0. The Services that are available for this field are defined in the Services interface (as described in Section 10. Note furthermore.1 busy hour session attempts and 4500 kBytes/session attempt which yields 0. in the figure above. 4. Expressing this differently. Note: In order for all the services defined for a User Profile to be taken into account during traffic scenario elaboration. in the figure above. it yields the Erlangs of voice traffic which is also the probability of use of the service. 2. For example. the Business User Profile is made up of four different Services: FTP Download.0055 (0. The Calls/hour field has a different meaning depending upon whether it is used with a voice or data service. The Service field allows the user to define the service or services that are associated with the given User Profile.3 and Section 7. Atoll doesn’t model a Revision 1.2 busy hour call attempts and a 240 second average hold time which yields 0. The UL Volume (Kbytes) field is only used for data services. environment traffic maps can easily be created by drawing a polygon and associating an environment with it. then the load per user. Should it become significant to model simultaneous services (e. The Environments within Atoll are accessed through the Environments folder within the LTE Parameters folder in the Data tab. If the given service is a data service. Note: It should be understood that the parameters characterizing the default Environments found within the template are simply placeholders. When marketing-based traffic data is available for the system design. If the given service is a voice service. 7. 5. Note. correspondingly scaled up so that the total offered load remains the same. Note. The Duration (sec.e. then the use of Environment traffic maps will be best. then this field is left blank. should be scaled down to the point where the probability of activity is now less than 1 and the user density. This field provides the average duration of a call (in seconds) for the given type of service. The DL Volume (Kbytes) field is only used for data services. Each environment class corresponds to a mix of user profiles where each profile is associated with a mobility type and user density (i. 6.) field is only used for voice services. as represented in traffic map. The systems designer is responsible for setting inputs to correspond to the actual customer traffic projections. subscribers/km2). This field provides the average uplink volume per session (in kilobytes) for the given type of service.Atoll user employing two different services simultaneously. 10.3 iProtect: Internal Page 257 . Options exist to further specify the user distribution on the basis of clutter and indoor/outdoor. a CPE with multiple VoIP lines that sustains greater than 1 Erlang of busy hour voice traffic). Note.LTE RF System Design Procedure . then this field is left blank. Defining Environments Environment classes are defined to facilitate the creation of environment traffic maps. If the given service is a voice service. In this manner.5. Revision 1. then this field is left blank.g. This field provides the average downlink volume per session (in kilobytes) for the given type of service. as seen in the following figure. as represented within the user profile. Urban. Figure 189: Example Environments Window (Urban) – General Tab 2 3 4 1 Revision 1. Suburban. along with their default values.3 iProtect: Internal Page 258 . There are two tabs within the Environments properties interface: a General tab and a Clutter Weighting tab. The following figure describes the parameters within the General tab.LTE RF System Design Procedure . and Rural. are described below. there are four Environments that are included in the Motorola template: Dense Urban.Atoll Figure 188: Accessing Environments Parameters As seen within this figure. The parameters that are used in defining these environments. The Clutter Classes that are listed in this tab are defined in the Clutter Class properties as described in Section 7. This assumes equal subscriber density for these two user profiles. and Rural environments. Note. For example. The Name field allows the user to provide a name for the given Environment. Business Users are associated with the Dense Urban and Urban environments.3 iProtect: Internal Page 259 . 4. The systems designer is responsible for setting inputs to correspond to the actual customer traffic projections. Note. The Mobility field defines the Mobility type that is associated with the selected User Profile for the given Environment. (Within the Motorola template. The Density (Subscribers/km2) field defines the user density associated with the selected User Profiles for the given Environment. both the Business User and Standard User profiles are associated with the Urban environment.4. the PB3_Capacity Mobility Type is associated with both the Business User and Standard User profiles. the subscriber density for both the Business User and Standard User profiles is 400 subscribers per square kilometer. Suburban. 3. in the figure above. Urban. 1. The User field defines the User Profile(s) associated with the given environment. Standard Users are associated with the Dense Urban. Revision 1. but for a specific design the assumptions could be that there will be twice as many business users as standard users. The density settings characterizing the default Environments found within the template are simply placeholders. For example. the “_Capacity” mobility types need to be selected in producing traffic maps so that the correct bearer thresholds are indexed. The following figure describes the parameters within the Clutter Weighting tab.Atoll NOTES: Note.) Note. Note that for capacity studies. 2. in the figure above. For example. in the figure above.LTE RF System Design Procedure . 000 subscribers in the Dense Forest clutter class and 36. This would equate to 40.4). Given these weightings. using the clutter classes shown in the figure above.000 subscribers in the area. The user may adjust these to represent the distribution for the market being modeled. then the user distribution would have 9 times the users in the High Density Urban area than in the Dense Forest area. Note that the Motorola template provides equal weighting to each clutter class – using the default setting of 1. The % Indoor field allows the user to specify the percentage of indoor subscribers for each clutter class. Note. Further assume that this area is made up of only High Density Urban and Dense Forest clutter classes and that these clutter classes have been assigned weights as previously mentioned (9 for High Density Urban and 1 for Dense Forest).3 iProtect: Internal Page 260 . 1. an additional indoor loss will be added to the indoor users. if a weight of 1 is used for Dense Forest and a weighting of 9 is used for High Density Urban. if desired. as seen in the figure above and within all Environments specified in the Motorola template.LTE RF System Design Procedure .Atoll Figure 190: Example Environments Window (Urban) – Clutter Weighting Tab 1 2 NOTES: Note. Assume a given area is 50 square kilometers with a user density of 800 subscribers per square kilometer. this would equate to 4. Revision 1. In the Monte-Carlo simulations. For example. The default setting for this field is 0%. This additional indoor loss is specified within the Clutter Class properties (as described in Section 7. The Weight field allows the user to assign a weight to each clutter class to adjust the user distribution.000 subscribers in the High Density Urban clutter class. 2. LTE RF System Design Procedure - Atoll 10.6. Traffic Maps and Subscriber Lists To perform Monte Carlo simulations as part of a traffic study, it is required to derive the number of active (bursting) users in any given region. Deriving this number is accomplished via traffic maps. Users also need to be characterized by their services, mobility type, and terminals. Procedures for creating or importing traffic maps, definitions of map parameters, as well as procedures for accessing and modifying map parameters are to be found within the Atoll user manual (see Section 12.3.2 of the Atoll 2.8.1 User Manual). This section does not reproduce these Atoll user manual descriptions, but assumes that the reader is already familiar with them. The balance of this section will describe the various traffic maps available and their use. The use of subscriber lists is also described in this section (see Section 12.3.4 of the Atoll 2.8.1 User Manual for detailed creating, accessing, and modifying procedures). Figure 191: New Traffic Map The New Traffic Map interface is accessed by right-clicking on the Traffic folder under the Geo tab and selecting New Map. Three traffic map classes, as shown in the figure above, are made available and include: user profile, sector, and user density. The user profile class is further sub-divided into user profile (“user profile densities”) and environments (“user profile environments”). Some general comments on traffic maps include the following: • Generally, the geometry of traffic maps are best specified via imported data files supplied by the customer. Raster file formats are used for environment and user density traffic maps while vector file formats are used for user profile traffic maps. Sector maps utilize the Atoll geo data file format. Alternatively, vector editing tools within Atoll allow for manually creating and modifying polygons. Revision 1.3 iProtect: Internal Page 261 LTE RF System Design Procedure - Atoll • Within the Motorola template, mobility types used in traffic maps should be selected from those which index capacity curves, i.e. have the suffix “_Capacity”. • Reference to “active” users typically refers to bursting users. Any exceptions in this section will be explicitly noted. 10.6.1. User Profile and Environment Traffic Maps The first class of traffic maps are those based on user profiles. The user profile class is sub-divided into user profile (“user profile densities”) and environment (“user profile environments”) traffic maps. Options to create either type are available in the pull-down menu associated with the “User profile traffic map” selection of the “New traffic map” window (see Figure 191). These maps have the following characteristics. • User profile traffic maps are well suited towards traffic projections which are marketing-based. • The subscriber density, i.e. subscribers / km2, should be known for the service region(s). • One or more user profiles are defined which characterize the services, terminals, and offered load. (Refer to Section 10.4 for details on defining user profiles.) The probability of activity for a service is derived from the load parameters within the user profile together with parameters which characterize the service. • A single user profile can be mapped to a region (polygon) in a user profile traffic map. Alternatively, a set of user profiles can be mapped to a region via the use of environment traffic map. (Refer to Section 10.5 for details on defining environments.) • Population databases, which correlate regions to subtending populations (e.g. census geo datasets) can be leveraged to create user profile traffic maps. Additional fields can be added to the database that allow for scaling the population by a target penetration to magnitudes that correspond more directly to the number of active subscribers. This approach can be readily applied to user profile traffic maps because they accept vector file formats (e.g. shp or mif). The user profile traffic map properties window, shown in the figure below, provides an example of basic map parameters. In this example, both the “Business User” user profile and the “PB3_Capacity” mobility type have been specified globally for the traffic map (i.e. they have been selected “by value” from a pull-down menu of available choices). The density is user-specified via the Density field within the traffic map table. Each row of the traffic map table corresponds to a polygon and each polygon may have a different density value. Revision 1.3 iProtect: Internal Page 262 LTE RF System Design Procedure - Atoll Figure 192: User Profile Traffic Map Properties An option exists for differentiating the probability of user distribution within the region based on clutter type (although, typically, all weights are set to 1 and no clutter differentiation is used). Similarly, the option exists to specify the average percentage of indoor users on a per clutter class basis. The environment traffic map may be the option best suited to system design work when marketing information is available. Regions, such as in the “Urban” environment properties window seen below, are defined by specifying the subscriber density, i.e. subscribers / km2, of user profiles and mobility pairings. The user profiles themselves specify the mix of services and terminals. The environment traffic map allows users to label regions (polygons) by environment (e.g. Urban, Suburban, etc.). When creating an environment map, Atoll supplies an Environment Map Editor specifically for this task. Environment traffic map tables are not accessible. This means that once a polygon is assigned a particular environment (e.g. Suburban) at creation, it cannot be changed to be a different environment. It must be deleted and re-created. The geometry (shape) of polygons may be modified. Subscriber densities are specified as part of the environment definitions and not within the environment traffic map directly. Revision 1.3 iProtect: Internal Page 263 LTE RF System Design Procedure - Atoll Figure 193: Environment Properties (example) 10.6.2. Sector Traffic Maps The second class of traffic maps are those based on sector traffic. The sector traffic maps have the following characteristics. • Sector traffic maps are well suited towards traffic projections which are “live data”-based, i.e. where a network management system provides empirical insight into the actual load being carried by the system. • To exploit this traffic map, it is likely that the system has already gone commercial and is past initial system design. But, this is not necessarily the case. In instances where the LTE broadband system is being layered on top of an older technology, the “live” statistics from the incumbent technology can be used to derive insight into the traffic distribution to be expected on the new system. Although the magnitude of the traffic may require scaling, the traffic proportions among the sectors would be correct. This approach, of course, depends on the validity of the assumption that the two systems have comparable traffic distributions. • Sector traffic maps require best server images corresponding to the sectors for which traffic is available. • Sector coverage is mapped to specific per-sector traffic specifications. The number of active users is specified on a per-service, per-direction basis. The distribution (probability) of mobility types and terminals is globally specified across all sectors. To use this means of traffic specification, select “Number of users per activity status” in the pull-down menu associated with the “Sector traffic map” selection of the “New traffic map” window (see Figure 191). • Alternatively, throughput demand can be used to specify the load instead of specifying active users directly. In this case, the demand is normalized by the average requested throughput for the service to derive the number of active users. To use this means of traffic specification, select “Throughputs in uplink Revision 1.3 iProtect: Internal Page 264 LTE RF System Design Procedure - Atoll and downlink” in the pull-down menu associated with the “Sector traffic map” selection of the “New traffic map” window (see Figure 191). The sector traffic map properties window, shown below, provides an example of basic map parameters. In this example, the distribution of terminals and mobility types are specified globally as 100% CPE and 100% PB3_Capacity. As with user profile based traffic maps, options exist for differentiating based on clutter class and indoor/outdoor. Figure 194: Sector Traffic Map Properties Referring to the example sector traffic map table below, the density is user-specified for each sector by specifying the number of active users on a per-service, per-direction basis. Note that for a service such as VoIP, a realistic distribution would have some traffic for downlink, uplink, and uplink + downlink. The services present within the table automatically reflect all defined services (found under the Services folder of the Data tab, refer to Section 10.1). Revision 1.3 iProtect: Internal Page 265 both uplink and downlink. note that user profile based maps specify a density that corresponds to all users and then the number of active users for each direction is determined based on probabilities derived from the service characteristics and the offered load per user. • Multiple user density maps can be defined and simultaneously employed to fully characterize the traffic load. The user density maps have the following characteristics. unless there are only a few polygons.LTE RF System Design Procedure . The user density map properties allow for classifying the user’s activity status as downlink-only. • All users are considered active. and mobility types. also.3 iProtect: Internal Page 266 .Atoll Figure 195: Sector Traffic Map Table As a point of contrast. the aggregate of all directions). • The distribution (probability) of services. • Although the user density map can be created internally by specifying polygons and assigning them densities. The activity status of users is specified at the time of creating the traffic map (via the pull-down menu associated with the “User density traffic map” selection of the “New traffic map” window.3. terminals. see Figure 191). the users will be decomposed into the various directions based on activity factors derived from the services definitions.e. and terminals is globally specified for each user density map. When “All activity statuses” is selected. This is different from sector traffic maps where the number of active users is supplied directly. uplink-only. User Density Maps The third class of traffic maps are those based on user density. 10. • User density maps are a logical choice should the customer supply a geo data set where the number of subscribers is specified on a per-pixel basis. The input file must be in a raster file format (either 16 or 32 bit). It is preferable to leverage user profile traffic maps where greater flexibility is present. this is not recommended. Revision 1. but can be changed at any time within the properties window. mobility types.6. Note: The activity status of “inactive” present in the interface is ignored for LTE. specifying non-globally the mix of services. or “all” (i. User profile traffic maps allow for importing vector file formats and. terminals.4. i. Both the subfolder and table are labeled “density values” by default. they are to be applied to commercial markets where the user locations are established. the mix of services and terminals (likely to be a single terminal for fixed users) is specified via a user profile. Creating a User Density Traffic Map. is expected to be named “Fixed”. • Subscriber lists define the exact number and location of subscribers as opposed to a random distribution based on a mean probability as with traffic maps. Density values that are imported within a raster file are not visible since they are variable on a per-pixel basis. Subscriber lists have the following characteristics. For manually created polygons. Each row of the table corresponds to a polygon and each polygon may have a different density value.2. • For simulations. Calculations can be performed in Revision 1.e.3. shown below. • Subscriber lists may be used in conjunction with traffic maps.2. • Since subscriber lists depend on real. For greater detail. In the case of a user density map. provides an example of basic map parameters. Figure 196: Density Map Properties 10. once polygons are created.3 iProtect: Internal Page 267 . • The mobility for subscriber lists is not specified by the user. but. fixed locations. Subscriber Lists Atoll also includes a subscriber database for modeling fixed user distributions in a network. rather.Atoll The user density traffic map properties window. of the Atoll User Manual.6.LTE RF System Design Procedure . review Section 12. services. The subfolder only appears once the map is edited.e. and mobility) is specified globally. the distribution of all the attributes (i.3. the density is supplied on a user per km2 basis via a Density field within a table which is accessed via a subfolder of the user density map. Atoll the absence of simulations and. right-clicking on the Subscribers folder and selecting New List. Revision 1. refer to the section titled “Simulation Process”). Refer to the Atoll User Manual for further discussion on subscriber lists. refer to the section titled “LTE Traffic Simulation Algorithm”) and a detailed description within the Atoll Technical Reference (within the LTE chapter. The subscriber list will then appear in the Subscribers folder. in this case. • Each individual user can be characterized as indoor or outdoor. or a list can be imported. 10. • Pathloss calculations are performed independently for each subscriber because antenna heights can be subscriber-specific.3 iProtect: Internal Page 268 . the overall simulation process is represented in the following flow chart. In this case.LTE RF System Design Procedure . Simulation Process A description of the Monte Carlo simulation process is provided within the Atoll User Manual (within the LTE chapter.7. This is in contrast to the treatment of mobiles dropped from traffic maps. Subscriber lists can be created by going to the Data tab. the service and terminal type are specified separately within the database. For reference. antenna heights are fixed for the simulation and all mobiles dropped leverage the pathloss matrices that are generated for the simulation. User profiles provide insight into the probability of using a particular service and/or of being active in a particular direction within a service. the Revision 1.LTE RF System Design Procedure . some key aspects of the simulation process will be highlighted. the actual number of users employing a service or exhibiting an activity status will vary about the mean across drops. a realistic user distribution is obtained as a function of the traffic map(s) supplied as input for the simulation. consider the following voice and data examples: o Assume a voice service with 2 busy hour call attempts of 180 seconds each and a voice activity factor in each direction of 40%. consequently.Atoll Figure 197: Simulation Process Flowchart In the balance of this section. • As an example of deriving probabilities of activity. Then. The overall number of users is obtained from density and surface area.3 iProtect: Internal Page 269 . Randomness is also present in determining locations within the service area (as a function of different weightings per clutter) and in assigning whether the subscriber device is indoor or outdoor. • During the initialization phase. Note that these probabilities of activity are used as means for random draws. A failure to connect to the system corresponds to a coverage outage. Multiplying R by η yields bits per frame and dividing by the frame duration. channel throughputs are derived. The percentage of users in outage corresponds to a probability of coverage and will not increase with load.LTE RF System Design Procedure . i. The formula can be seen to take the kilobits transferred in the busy hour (0. there is a 24% probability [40% x (1-40%)] of being DL (and the same for UL) while there is a 16% probability [40% x 40%] of being active in both directions (which leaves a 36% probability [(1-40%) x (1-40%)] of being inactive). then bearers must be allocated in each direction.3 iProtect: Internal Page 270 . The basic formula for peak channel throughput is: CTP = R x η / D. or both DL and UL and the probability of being in one state or the other is based on the voice activity factor. Effective throughput is derived by scaling by (1 – BLER) and application throughput takes the effective throughput and applies a user-defined scalar and Revision 1. The probability of being active in the DL direction is 1.Atoll probability of using the voice service would be 10% (= 2 x 180 / 3600).1 Erlangs).4). o Assume a data service with 0.1 busy hour data sessions pushing 15.1 x 15000 kB x 8 bits/byte / 200 kbps / 3600 sec/hr]. The variable η represents the peak efficiency (bits per resource element) associated with the specific bearer. of being active.000 kBs DL each session with an average requested throughput of 200 kbps.1 x 15000 x 8) and dividing this by the average throughput (200 kbps) to derive the busy hour bursting seconds (60s). rather. When this is divided by 3600s. the scheduler parameters Bearer Selection Criterion and Uplink Bandwidth Allocation Target are important (refer to Section 7. For this determination. D (0. • If a subscriber cannot connect to the system even at the lowest bearer.2. When CINR standard deviation is enabled. Subscribers are classified as either bursting DL. CINRs are derived and best bearers determined. UL. Subscribers are required to have a connection for each direction in which they are active. yields bps. reference signals. • For each subscriber dropped into the simulation. even though associated with a service. have been discounted in deriving “R”. The overheads for control channels. but.2. For example. then it is given a connection status of “No Service”.e. then “No Service” statistics should correspond to expectations for coverage reliability established via coverage predictions. It is the normal practice to disable CINR standard deviations for capacity studies and to establish coverage reliability via coverage predictions. The variable “R” corresponds to the number of resource elements available for use by the shared channel. etc. In this case. This also corresponds to the Erlangs of traffic (0.67% [0. if a subscriber has an activity status of “DL+UL”. don’t show up in the resultant statistics from simulations since they don’t transfer any data. this yields the probability of bursting. will converge with greater accuracy. Note: Inactive subscribers. • Once bearers are selected.01 sec/frame). For the uplink.LTE RF System Design Procedure . • A large set of statistics are output from the simulations. it is considered advisable to simply produce coverage predictions while retaining the assumption of 100% TL.e. These are reflected in the resultant statistics and constitute capacity “outages”.e. For UL coverage predictions. Each subscriber is classified with a connection status indicating the direction of activity (i. Max Number of Users (refer to Section 7. Revision 1. Without the benefit of simulations to generate realistic UL NR values. or UL+DL). Subscribers that are excluded due to this limit are said to be in “Scheduler Saturation” and are not deemed “connected”. UL.3 iProtect: Internal Page 271 . “No Service”.2. For this reason. the UL Noise Rise (NR) is used to generate UL calculations. or the cause for lack of connection (i. the allocated bandwidth throughput (ABTP = CTP x allocated frequency blocks) is also derived and represents the upper bound on what the subscriber can achieve on the UL. remaining capacity is distributed among users according to the manner that reflects the scheduler method selected. Subscribers that satisfy the MinTD are. First.1. UL Traffic Load. Refer to Section 7. is purely informational. UL coverage predictions depend on user-specified values which are likely to exhibit greater error.1. Secondly. It is recommended that the Max Number of Users parameter be null so as not to apply any limit.4 for a description of the Proportional Fair and Proportional Demand scheduling methods. DL.2. • The primary outputs of the simulation process are the DL Traffic Load.3). sectors (channels) are loaded with traffic. • As part of RRM. • Radio Resource Management (RRM) is next performed to determine how resources are allocated among users. “Scheduler Saturation”. in a manner that satisfies the Minimum Throughput Demand (aka Minimum Reserved Rates) for the services. therefore. if connected. For the DL Traffic Load. and the UL Noise Rise.Atoll offset. Note that the channel throughput assumes the use of the entire available bandwidth even in the uplink. or “Resource Saturation”). by definition. Instead. “Resource Saturation” occurs whenever the Minimum Throughput Demands of the users cannot be satisfied. These resultant values can be fed back into coverage predictions. it is recommended that simulations be performed and that the resultant UL NR values be applied and UL coverage reevaluated. subscribers can be excluded immediately due to limits on the number of simultaneous users supported by the scheduler.2. “connected”. Potentially. These statistics will be used to establish whether or not the capacity criterion has been met and also to derive system and sector capacities. the ABTP is preferred to CTP. The UL Traffic Load is not actually employed in UL calculations and. This is represented by the Cells parameter. Once this offered load is determined to be carried by the system. Note that the smaller the sample size. some load which establishes a sector or group of sectors as limiting any further load increase). It is recommended to continue employing the original. the larger the number of iterations required to achieve convergence. Forsk modified their internally hard-coded convergence parameter defaults to different values. integer value. Note: Beginning in R282. How to Run Simulations Refer to the LTE chapter of the Atoll user manual under the heading “Creating Simulations” for a detailed description of the procedure to run simulations. then it is likely that the simulation didn’t converge. Key elements are highlighted here. This will require manually setting these values for each simulation.1. and 1 dB for UL Noise Rise Convergence Threshold. Number of Simulations In specifying the Number of Simulations.3 iProtect: Internal Page 272 . then the GSF can be increased to identify a system capacity (i.0% for the traffic load thresholds and 2 dB for the UL noise rise) in an Revision 1. If simulation statistics show that all 50 iterations. It is not clear how this parameter corresponds to any limiting mechanism within the product. Max Traffic Load DL and UL Max Traffic Loads should be globally set to 100%. Average statistics can be produced for the group of simulations. but capable of being duplicated. In this manner. Convergence The recommended Convergence parameter values are 50 for Max Number of Iterations. the number of drops can be increased (~10 to 30) to obtain a larger sample and greater confidence in the results.Atoll 10. quicker feedback can be obtained upon which to assess whether adjustments in the design need to take place.g.LTE RF System Design Procedure . It is unusual for simulations to require as many as 50 iterations to converge. namely.2% for DL and UL Traffic Load Convergence Threshold.7. Assuming that the offered load established via the traffic map properly reflects the customer’s projection. the results will be random. 0. Global Scaling Factor The Global Scaling Factor (GSF) is used to scale the number of users in the simulation either up or down. 1. 100 for Max Number of Iterations and 5% for DL and UL Traffic Load Convergence Thresholds. the convergence parameters above should be relaxed (e. then the GSF would be 1.e. In this manner. The number should always be set to a consistently applied non-zero. Generator Initialisation The generator initialization parameter establishes the seed for random number generation during the simulation. employ only a single drop. tighter constraints. Later. Under these circumstances. 3 iProtect: Internal Page 273 . A summary is provided here along with some highlighting of key elements. DL. The details for all statistics found are described in the LTE chapter of the Atoll user manual under the heading “Displaying the Results of a Single Simulation”.2. “Results” (carried) traffic statistics are provided. Stop Calculations Any calculations in progress may be stopped by clicking the Stop Calculations button ( ) in the toolbar. and UL+DL). The properties. The number and percentage of rejected users is provided in the aggregate Revision 1. Figure 198: Simulation (Drop) Statistics In the top section of the Statistics tab. In the bottom section of the Statistics tab. 10.7. These statistics are provided overall for the computation zone and also broken down on a per-service basis. contain 5 tabs. each simulation (drop) has a corresponding set of statistics produced. Simulation Output Statistics Within a group of simulations. Each service definition contains minimum and maximum throughput demands and these are aggregated across all dropped subscribers within the simulation to provide boundaries for the offered load.LTE RF System Design Procedure . These statistics are accessed by opening the simulation properties.Atoll effort to reduce the time of simulation and to identify more appropriate bounds for the simulation. The number of users “trying to connect” reflects the random draw of active subscribers for this simulation and the breakdown is given by direction (UL. as shown in the following figure. “Request” (offered) traffic statistics are provided. and applications levels are also provided in both the DL and UL directions.7. 10. it is advisable to produce coverage predictions while retaining the assumption of 100% TL. Percent “Resource Saturation” should be reviewed to verify that system blocking is at an acceptable level (<2%). These statistics are provided overall for the computation zone and also broken down on a per-service basis. All tabs are recreated as discussed above except for the Mobiles tab. Without the benefit of simulations Revision 1. and application levels by direction (DL and UL) and in the aggregate as well as by-service.e. the number of subscribers rejected for each cause is provided. The Sites tab statistics provide. effective. A specific Mobiles statistic (e. The Initial Conditions tab summarizes the parameters used for the simulation. on a per-site basis. (Note that the statistics made available for selection are constrained by the choice of display type.) By this means. but on a cell (i. In addition. e. a user can easily display all mobiles with the activity status uniquely color-coded. Coverage Predictions based on Simulation Results The primary outputs of the simulation process are the DL Traffic Load.3 iProtect: Internal Page 274 . Discrete values). DL/UL CINRs.7. To accomplish this. DL/UL peak/effective/application channel and user throughputs. the DL Traffic Load (%).3. the UL Noise Rise (NR) is used to generate UL calculations. UL Traffic Load. DL/UL bearers. Information includes. The UL Traffic Load is not actually employed in UL calculations and. refer to the LTE chapter of the Atoll User Manual under the section called “Displaying the Traffic Distribution on the Map”. For the DL Traffic Load. The number of connected users is then given. The percentage of users rejected for “No Service” should be reviewed to verify that it corresponds to an acceptable or expected level of system coverage outage. and UL Noise Rise (dB) are provided. The aggregate user throughputs at the peak. UL Traffic Load (%). and the UL Noise Rise. Additionally. These resultant values can be fed back into coverage predictions. 10.g. The Mobiles tab statistics provide detailed information on the location and state of each active mobile (subscriber) dropped in the simulation. global scaling factor. sector) basis.LTE RF System Design Procedure . first access the display properties for the “LTE Simulations” folder and then select a display type (e.4. Instead. in the aggregate and by direction. For further details. effective. No scheduler saturation is expected (with Max Users set to null).g. Connection Status. max number of iterations.g. and the traffic map(s) employed. is purely informational. but is not limited to: Activity Status. convergence parameters. The Cells tab statistics provide the same statistics as the Sites. A set of average statistics representing the average for a group of simulations can be viewed by right-clicking on the group folder and selecting Average Simulation. therefore. Connection Status) can be selected for display on the map from the Field menu.Atoll and by cause. Displaying Traffic Distributions Atoll allows for graphically displaying Mobiles statistics from simulations on the map. throughputs at peak. and allocated bandwidth (UL only). Default template Revision 1. This will always require customization. Select the Commit Results button found on the Cells tab of simulation properties (either for an individual drop or for a group average). the fields are “committed”. The level at which throughput parameters for services are defined (i. FTP. To leverage the simulation results when producing. Procedure for Capacity Analysis What follows is a Motorola recommended procedure for performing LTE capacity analysis.4).2. the services may still require further customization.3). 10.4. then a Fixed mobility type will need to be added. this assumes 100% Traffic Load.1). simply specify the simulation group for the Load Condition under the Condition tab. this assumes user defined UL noise rise. a.8. Needed Terminals should be defined (Section 10.e.2. a service approximating full buffer is provided. Scheduler should be defined (Section 7. Furthermore. For the UL. and Web Browsing. the Proportional Fair scheduler and associated default template parameters should be sufficient. or Application) should correspond to the target throughputs defined for voice and data services within the Scheduler. Prior to running simulations.6). Needed Services should be defined (Section 10. a Coverage by C/(I+N) Level prediction. For the DL. UL coverage can be re-evaluated after more realistic UL noise rise values are produced via simulations. 2. Generally.Atoll to generate realistic UL NR values. To actually carry the simulation results into the Cell table fields on a permanent basis. An initial assessment of coverage reliability should have already been established. e. Although the template is intended to provide a realistic set of parameters for VoIP. If Subscriber Lists are to be employed. User Profiles and Traffic Map(s) should be defined (Sections 10. Needed Mobility Types should be defined (Section 10. verify that all inputs have been defined. 10.3 iProtect: Internal Page 275 .5. UL coverage predictions depend on user-specified values which are likely to exhibit greater error. Mobility types explicitly intended for use in capacity simulations are included within the template. and 10. Peak. d.LTE RF System Design Procedure . For this reason. b. It is advisable that final UL NR values produced from Monte Carlo simulations should come from averages across a larger number of drops.2). Effective. it is recommended that simulations be performed and that the resultant UL NR values be applied and UL coverage re-evaluated. 1. c. for example. ) should be explored. • If it appears that relieving the congestion for just a few limiting sites/sectors will allow for sufficiently increased system capacity to justify it. The limiting sector is that which blocks with the highest %RS.8. should be disabled (zeroed). Run Monte Carlo simulations. f. • Identify the limiting sector. cell splitting. either Atoll’s or post-processed.1. therefore. Note that within simulations. other traffic map types (environment.Atoll definitions for user profiles cannot be accepted as appropriate. This result is considered the minimal exit criterion for capacity. Different insights into capacity can be obtained via simulations and these are discussed below. the subscriber population can be scaled upwards to model the system closer to full loading. Alternatively. Vary the system load (through use of the global scaling factor). Model and CINR standard deviations. then this indicates that the system capacity is sufficient to satisfy the traffic load requirements for the planning period. standard deviations are always applied. If the statistics show that the percentage of rejections due to Resource Saturation (%RS) for all sectors is ≤2%. A single simulation can be employed for initial assessments and more simulations (10-30) for greater confidence in final work. disable them. iProtect: Internal Page 276 . Review the simulation statistics. to determine whether simulation goals have been achieved.LTE RF System Design Procedure . Export and post-process the simulation statistics. effectively. assume the traffic map and services reflect the projected load for a planning period (e.g. a. their values must be set to zero (as they are in the template) to. b. both default and per-clutter class. a spreadsheet (AtollStatsTemplate. For some design work. Consider the following: Revision 1. The traffic maps will define the user profile density (users per km2) for the service area(s). A detailed description is provided in Section 10. Repeat steps 3 and 4. 3. down-tilting. density) can be employed. 4.xls) is provided with associated macros. etc.3 • The GSF may act as an oversubscription factor (OSF) to scale a total subscriber population down to the active subscriber population. For the following explanation. 5. Conversely. The maps will also associate with the user profile the appropriate capacity mobility type. EOY2010). as required. sector. then relief options (e.g. it may be sufficient to establish that the projected load is satisfied and no further capacity analysis is required. but it is more likely that some better and more accurate definition of the system capacity is desired. To facilitate the postprocessing of simulation statistics. The user profiles will establish the voice and data service loads exhibited by typical users in accordance with customer inputs for the traffic load. 6. Under heavier user load. 2. that leverages the Note: Excel’s limit of ~65K rows (Excel 2003 and earlier) for the worksheet size may constrain the ability of post-processing the statistical data via this method. the scheduler behavior will move towards being completely PD. This will allow for verifying UL coverage reliability using the more accurate UL noise rise from the Monte Carlo simulation. is located at: http://compass.3 iProtect: Internal Page 277 . Reporting the system capacity without explicitly acknowledging this can be misleading by underestimating the available system capacity.2.Atoll • Trade-offs between sector capacity and average or edge user throughput can be observed as user load is modified. 1. 3. Within Atoll. consequently. Conversely. Note: For a TDD frame configuration.LTE RF System Design Procedure . The available sector capacity is derived via post-processing and statistics are termed “Throughput Capacity”. Copy-paste the data from the properties window over to the spreadsheet as follows: Revision 1. To approximate the available system capacity. This contains the 5 tabs with statistics. the DL scaling applied within Atoll is in not optimal.3 for details. Once simulations are complete. requires further adjustment.1.1. Atoll scales DL and UL throughputs.1. as user load lightens. sector loading is divided by the sector %traffic load to derive available sector capacity and then these are summed across sectors of the system. This spreadsheet. Refer to Note. Mobile statistics are not included with Atoll’s average statistics. and. Note: All derived data and charts dependent upon Mobiles data described herein will not be generated when the source data comes from a set of Average simulation statistics. c. Currently. open the simulation properties window.xls spreadsheet.8. the UL CINR coverage prediction can be re-run with the simulation referenced as the Load Condition (rather than the Cells Table).mot. Post-processing Simulation Statistics The procedure for post-processing simulation statistics AtollStatsTemplate. For real-world scenarios where traffic is very non-uniform. it is likely that many sectors will be exhibiting traffic loading at levels less than 100%. a greater influence of PF allocation will be noted.com/go/318588510. 10.xls spreadsheet is described below. with the latest version macros. 16 in Section 7. Open the AtollStatsTemplate. Excel 2007’s limit is ~1M rows (which doesn’t present a problem). Note: It is likely that interaction will take place across platforms where the spreadsheet will be on a desktop compute while Atoll will be running remotely on a server. • Summary statistics are provided for each numerical data field. This makes it possible to look at subsets of the rows of data based on different user-defined filtering criteria. a click and drag approach to selecting all of the data will be needed. it is advisable to close any other open spreadsheets. A Ctrl+A will not work to capture all the data within a section. These include Average. This data is copied for informational purposes and to have a complete record within the spreadsheet. This facilitates filtering based upon site and sector numbers. • From the “Cells” tab in Atoll to the “Sheet3” tab in Excel. Count. but it will not be post-processed. Note that due to the size of the data. Prior to invoking the macro. • From the “Initial Conditions” tab in Atoll to the “Sheet5” tab in Excel. • New data fields have been derived for each of the data sets as follows: Revision 1. Max. Note: Atoll provides export options for its statistical data. the copy may take a few seconds.LTE RF System Design Procedure . The following functions will be performed by the FmtAll macro. Also. These statistics can represent the system when the filtered rows correspond to the entire system. 4. Min. • A “Zone” field is added that is arbitrarily set to the value 1. The 10th and 90th percentiles are also provided across all data rows (no filtering). • The numerical site and sector identifications are extracted from their alphanumeric representations and provided in their own separate fields. but it will not be post-processed. and “Init Conds”. A Ctrl+C will copy the data and a Ctrl-V into the upper-left corner (cell A1) of the Excel sheet will paste the data. Atoll will provide progress of the copy on the status bar. Within the spreadsheet. Separate transfers for the “Request” and “Results” data will be needed. perform a “Save As” to rename. the spreadsheet to reflect the assumptions under which the data was generated. “Mobiles”. but the approach outlined here is just as expeditious as any.3 iProtect: Internal Page 278 . • From the “Mobiles” tab in Atoll to the “Sheet4” tab in Excel. This new field can be user-defined and is intended to be used in creating special filters. • Sheets 1 through 5 will be renamed to “Atoll Stats”. “Sites”. appropriately. following the same process used for Sites data. following the same process used for Sites data. A Ctrl+A will work to capture all the data within a section. “Sectors”. • From the “Sites” tab in Atoll to the “Sheet2” tab in Excel. Select the upper-left corner of the table will select the entire set of statistics (as in Excel).Atoll • From the “Statistics” tab in Atoll to the “Sheet1” tab in Excel. This data is copied for informational purposes and to have a complete record within the spreadsheet. rather. • Auto-filtering is enabled. and Sum all of which dynamically reflect the filtered rows. invoke the FmtAll macro by using the shortcut Ctrl+”a” (for “all”). Peak Throughput Capacity (UL). • Peak Throughput Capacity (DL). • The four site charts generated at the sector level. • %No Svc and %Res Sat – The percentage of users rejected for “No Service” or “Resource Saturation”.Atoll • For Mobiles • • • • • DL %Resources and UL %Resources – The percentage of the channel resource consumed by the user.3 iProtect: Internal Page 279 . For Sectors & Sites • DL Connected Users • Avg User Tput (DL) and Avg User Tput (UL) • Edge User Tput (DL) and Edge User Tput (UL) – The 5th percentile user throughput. Sectors. An example is provided in the following figure. Revision 1.LTE RF System Design Procedure . These statistics are dynamically linked to reflect. and Mobiles data. Four Site charts (found on sheet “Site Charts”) show key statistics across all sites of interest (which reflect filtering dynamically). Effective Throughput Capacity (DL). in general. • DL & UL Peak Tputs • DL & UL Avg User Tputs • “%No Svc” & “%Res Sat” • Connected Users Six Sector charts (found on sheet “Sector Charts”) show key statistics across all sectors of interest (which reflect filtering dynamically). • DL & UL Traffic Load (%) • UL Noise Rise (dB) A “Summary” sheet brings together key statistics. and Effective Throughput Capacity (UL). the average values across all filtered rows among the Sites. Prior to invoking the macro. and Mobiles sheets. it is possible to filter on rows where the Zone field equals 1 when a function has been introduced into the Zone column that returns a 1 whenever the row belongs to a site of interest determined per some lookup table. Eleven charts with accompanying data tables are produced to reflect various key distributions and relationships. Sectors. The “Zone” field is provided as a placeholder to facilitate more complex or custom filtering. they will not change when filtering is changed on the Mobiles sheet). As an example.e. then the appropriate filtering ought to be introduced to the Sites. This data reflects the particular mobiles of interest selected at the time of their generation.Atoll Figure 199: Summary Statistics (post-processed) 5. If statistics are desired for any subset of sectors or sites. The tables and charts are statically generated (i. it may represent a single sector. or the entire system.e. i.LTE RF System Design Procedure .e.3 iProtect: Internal Page 280 . The new charts and data tables. where statistics names are provided) and invoke the KeyMobileCharts macro by using the shortcut Ctrl+”m” (for “mobiles”). are classified as follows: • “No Service” CINR distributions (DL and UL) • CINR distributions for Connected Users (DL and UL) • Bearer distributions (DL and UL) • CTP (Channel Throughput) vs FB (Frequency Blocks allocated) (UL only) • CTP (Channel Throughput) vs UTP (User Throughput) (DL and UL) • CTP (Channel Throughput) vs %Res (%Resources) (DL and UL) Revision 1. a group of sites. Within the Mobiles sheet. 6. The macro can be invoked again to produce a new set of charts when filtering is changed should the user so desire. select any cell on the header row (i. row 8. The following functions will be performed by the KeyMobileCharts macro. it is advisable to close any other open spreadsheets. Second. of a user throughput) for a particular bearer allocation. both idle and active users may be or may not be represented among the load offered to the system depending on the traffic map selected. To invoke this macro.g. select the cell containing the statistic’s name (at the head of the column of data) and apply the shortcut Ctrl+”g” (for “generic”). The macro will automatically select appropriate bins based on data type. it will automatically choose the number and size of bins. Finally. Each vertical band of data corresponds to the distribution (e. can be interpreted as separate bearers. A macro named GenericDist can be invoked to generate distribution charts for any column of data on the Sites. idle users are not represented among the Mobile statistics nor any statistic derived from them. as is the practice within QCAT. Connected Users. Sectors. or Mobiles sheets. statistical data is provided for both PDF and CDF charts for both counts as well as percentages. it will create bins that correspond to all the valid bearers.Atoll Figure 200: Key Mobile Chart Examples For distributions. First. as found in various X-Y charts. it should be considered normal practice to de-rate the estimate of user Revision 1. it will automatically report on all values present.LTE RF System Design Procedure . e.g. The data collected represents both CDF and PDF of absolute and relative (percentage) values. the following should be considered. For numerical data. 7.3 iProtect: Internal Page 281 . For string data (such as Activity Status). For Bearer data (a special type of string data). Note that the use of CTP (Channel Throughput). With respect to assessing capacity in terms of numbers of subscribers. then an estimate could be based on 1 active subscriber per MHz of bandwidth per sector. Do not specify per-clutter weightings so as to exclude certain areas from getting dropped mobiles. Right-click for "Export the Coverage…".3 for details on how to accomplish this. 1. The results are unpredictable. This could still use the rule-of-thumb of 1 user per MHz of bandwidth per sector.Atoll capacity to account for additional overhead messaging not already considered within the modeling. 10.8. Applying Coverage Constraint to Density Map Here is an outline of how to get a density traffic map to reflect a coverage image. 10. Revision 1. The subscriber loading can be derived from total number of subscribers and area being served. the customer has provided little in terms of detailing the mix of services or the load per user upon which to make an assessment of capacity. Assumptions for Quick Assessment of Capacity In many circumstances. verify that the system can carry the predicted load and report the available sector and system capacity. Consequently. 2. b. Here are a recommended set of assumptions to adopt.8. You might need to change the display coordinate system if there is a mismatch between the coverage and traffic map geometries. A sector traffic map is roughly uniform. like a sector traffic map. An initial estimate of sectors is needed. Assume the Full Buffer service.2. a. Don't change the projection coordinate system (there is no need). refer to Section 10. 5.3. In reviewing the resultant simulation statistics. 3.3 iProtect: Internal Page 282 . In presenting results. The difference between a sector traffic map and the user density map is that the user density map can generate a spatially uniform traffic distribution. For a sector traffic map. specifies active users. If the customer has not supplied an overall target subscriber population for the service area. Note that a density map. the use of “split-in-cells” can take the coverage image and split it into different cells which can then be used to generate a sector traffic map. The coverage image should already exist.LTE RF System Design Procedure . the traffic should be scaled within the Monte Carlo simulation through use of the GSF to reflect the over-subscription factor. all assumptions should be caveated to the customer. Alternatively. Constrain the traffic map to only include covered areas. Create a user density traffic map that supplies a fixed users/km^2. but only to the degree that sector coverage is uniform.8. a sector traffic map could be employed that directly specifies the number of active users per sector. 4. 1) Export the coverage image as a mif file. For a user density traffic map. Overwrite with all the data previously copied from the other map (using Ctrl-V). Cancel 6) Open the polygon properties of the user density traffic map. of users/km^2) All activity statuses Create Note: Set fields on General. Geo>Traffic>New Map… User density traffic map (no. This map has been created only to leverage its polygon properties. Deselect the editing tool (so that you get a pointer on the map). Geo>Traffic>New Map… User profile traffic map User profile densities "Import" the mif file Note: The fields of the "properties" window that opens are not important. Traffic. 75%. Right-click on user density traffic map Select Edit. OK 3) Create a user density traffic map using Create. and smoothing. Select the polygon within the map image (you might need to make it visible). 5) Open polygon properties of the user profile traffic map. 2) Create a user profile traffic map using user profile densities. OK 4) Create a simple polygon for the density traffic map. respectively.3 iProtect: Internal Page 283 . try 50m.LTE RF System Design Procedure .Atoll For resolution. The process of exporting takes time. Right-click properties Select all of the data (Ctrl-A) from the Geometry tab. Right-click properties Copy all of the data (Ctrl-A) from the Geometry tab. Select the polygon within the map image (you might need to make it visible). Revision 1. and 50%. Use the Vector Edition toolbar to create a simple polygon. filtering. Allow ~5 minutes. and Display tabs as appropriate (you can always come back to revise these settings). Revision 1.Atoll OK. Select the polygon within the map image (you might need to make it visible). Delete 8) Specify the user density value for the polygon set.LTE RF System Design Procedure . 7) Delete the user profile traffic map.3 iProtect: Internal Page 284 . Right-click on the sub-folder and select Open Table. Alternatively. Right-click the user profile traffic map folder. Specify the Traffic Density field within the table. open the Density values sub-folder under the user density traffic map. Right-click properties Specify the Traffic Density field on the General tab. in sections for the specific input parameters). Refer to Table 7 for the recommended setting for DL Diversity Support as a function of transmission mode.LTE RF System Design Procedure .2. it is summarized here to show the overall process for MIMO and TXAA modeling. SU-MIMO: A throughput gain related to CINR and is modified using a user-defined capacity multiplier per clutter category.g. 11. AMS: If the reference signal CINR is above the AMS & MU-MIMO Threshold (dB) from the Cells interface. then the Diversity Gain (dB) value from the Equipment MIMO interface is applied to the C/(I+N) calculations. the MIMO throughput gain related to CINR is set through the Max MIMO Gain field in the MIMO Configurations interface.Atoll 11. Although this information is contained in other portions of this LTE RF System Design Procedure (e. MIMO and TXAA Modeling The purpose of this section of the document is to summarize the procedures for modeling MIMO and TXAA with Motorola’s LTE products in Atoll. 11.3 iProtect: Internal Page 285 . The user-defined capacity multiplier is set per clutter category through the Clutter Classes SU-MIMO Gain Factor parameter. then the MIMO Gain curve from the Equipment MIMO interface is applied to Tput calculations. If the reference signal CINR is below the AMS & MU-MIMO Threshold (dB). Overview of MIMO Settings Several aspects of a MIMO system design that must be considered when setting the input parameters and modeling approach are: • Subscriber device MIMO capabilities (MIMO or None) • Base station and subscriber MIMO configuration settings (both need to be configured for MIMO in order for MIMO to be accounted for in the modeling) • Number of MIMO transmit antennas at the base station Revision 1.1. Within Atoll. MIMO Modeling in Atoll Atoll supports three TX Diversity/MIMO modes as follows: TX Diversity: A Diversity Gain (dB) value from the Equipment MIMO interface is applied to the C/(I+N) calculations. 4. Ensure that the DL Diversity Support is set correctly per Table 7. the number of MIMO Rx antennas depends on the terminal type and was set based on general assumption of two receive antennas. Ensure the proper subscriber terminal settings for MIMO. 2 eNB transmit and 2 subscriber receive antennas: the 2x2 case). Ensure the Diversity Gain is set correctly per Table 7. 3. Configure the number of AP MIMO transmit antennas in the Transmitters. b.2 for further information regarding MIMO Configurations settings. Ensure that the number of MIMO Rx antennas is set properly.2.6.2. Ensure the proper entry within the MIMO Configurations table for the number of transmit and receive antennas (i. This threshold is represented in Atoll as the AMS Threshold in the cell properties. a.3 for further information. c.LTE RF System Design Procedure .3. See Section 6.1.2. See Section 7. See Section 7.3 iProtect: Internal Page 286 . Ensure that cell property parameters are set correctly. This increase will depend on the level of interference and scattering in the region. Ensure that the CINR threshold for switching between TX Diversity and SU-MIMO is set. See Section 7.3. Ensure the SU-MIMO throughput gain related to CINR is set through the Max MIMO Gain field in the MIMO Configurations interface. Within the Motorola template.1. Revision 1.2 for further details.2. Ensure that the subscriber terminal Antenna Diversity Support is set to MIMO. b. Further details can be found in Section 7.1.1. b. Ensure that the MIMO Configurations table is properly set. 11. a.3.e.Atoll • Number of MIMO receive antennas at the subscriber device • Threshold for switching between TX Diversity and SU-MIMO The expected result of accounting for these MIMO parameters in the system design is: • Increased downlink traffic channel per-user and per-sector throughput based on the SU-MIMO parameters. 2.4. MIMO Settings in Atoll This section outlines the settings within Atoll that are used to account for TX Diversity and SU-MIMO and points to the section in this document containing additional details. a. 1. The Motorola template does not inherently contain additional TXAA gain. This is because downlink beamforming requires channel information that is measured on the uplink.Atoll 5.4 for further information. Motorola’s approach to modeling TXAA in Atoll for LTE is to account for the expected increase in CINR that is associated with beamforming.2 for additional information on setting Diversity Gain. TXAA Modeling in Atoll TXAA for LTE is only available in the TDD product. a. Therefore.3 iProtect: Internal Page 287 . Adjust the Clutter Class Parameters as needed.4. depending on the environment. 11. Refer to Table 7 for recommended values of Diversity Gain for TM 7 that will reflect the TxAA gain. This channel information would not be valid for FDD because of the large difference in operating frequency between the uplink and downlink for FDD. the Diversity Gain (dB) field in the MIMO configuration interface can be adjusted by increasing the default value by 2 – 5 dB.4. the process of generating coverage images is the same as what is discussed in Section 9. See Section 7.2. 2 dB would be appropriate for dense urban environments and 5 dB would be used for open areas. to account for TXAA gain. Please refer to Section 7. Enter the appropriate SU-MIMO Gain Factor to adjust the Max MIMO Gain for SU-MIMO.LTE RF System Design Procedure . Once the system has been configured with MIMO settings.3. Revision 1. Incorporating Additional HARQ Gain in Atoll This section describes a set of input parameters and procedures for modeling additional HARQ gain in Atoll.0 70% 43% 2. so this tradeoff needs to be evaluated. The following table shows the data rate reduction that is associated with different HARQ gains: Table 14: HARQ Gain Effective Data Rate Impact Revision 1.3 Additional HARQ Gain Effective PHY Rate Retransmissions 0 91% 10% 0.5 83% 20% 1.e. such that additional HARQ gain can be assumed.5 73% 36% 2. Determining if Additional HARQ Gain is Required As is discussed in the LTE ML-CAT User Guide.0 78% 29% 1. 12. it is important to understand that additional HARQ gain will reduce the cell edge data rates for MCS0.6 66% 50% iProtect: Internal Page 288 . From this initial design. there will be a benefit (e. no HARQ gain beyond what is assumed in the SNR values). The HARQ gain is obtained by combining the first transmission with the retransmission. The SNR values within ML-CAT and within the Motorola template for Atoll assumes a level of HARQ gain that is associated with a 10% BLER threshold that assumes a single HARQ re-transmission which results in an effective BLER of less than 1%.g.LTE RF System Design Procedure . obtain the range and edge data rates. any additional HARQ gain will reduce the cell edge peak physical data rate (as shown in the PostHARQ PHY data rates within ML-CAT). it is recommended that a link budget design be done assuming no additional HARQ gain for the purposes of increasing the coverage range (i. where each retransmission repeats the first transmission or part of it. If the resulting CINR coverage in Atoll is less than the customer’s requirement. increase in CINR coverage) if additional HARQ gain is added to the Atoll threshold for MCS0. However. HARQ gain accounts for the benefit of retransmissions. However.Atoll 12.1. There can be up to four retransmissions. Within Atoll. 12.1. any additional HARQ gain needs to be incorporated into the appropriate parameters so that it is accounted for in the results. For cases where non-traffic channel studies are being run.3 for further details. Within Atoll. The following subsections provide details regarding these settings. When additional HARQ gain is included in a study. 2. 12.3.e. See Section 12. See Section 12. 2. The details of these parameter adjustments are provided in the following subsections. Adjusting the Bearer Threshold Values for Traffic Channel Studies When running traffic channel studies.12)) need to be adjusted to incorporate the additional HARQ gain. When evaluating the images that are generated with the additional HARQ gain incorporated. the resulting throughput images need to be adjusted to reduce the throughput for MCS0 accordingly. Accounting for HARQ Gain in Atoll This section outlines the settings within Atoll that are used to account for additional HARQ gain. See Section 12. when analyzing the traffic channels. 3. Additional HARQ Gain Modeling Approach in Atoll HARQ gain is only applied to the downlink and uplink traffic channels.3 iProtect: Internal Page 289 . the image thresholds for MCS0 need to include this same additional HARQ gain.1 for further details. 3. If the design scenario is being limited by one of the overhead channels. the lowest order modulation and coding scheme (QPSK 0. when analyzing non-traffic channels. the Bearer Threshold tables for MCS0 (i.2. Revision 1.3. there will be no improvement to the overall coverage of a site by adding HARQ gain. to see the affect of the additional HARQ gain on the downlink and uplink traffic channels. the MCS0 Bearer Threshold values need to be adjusted to account for any additional HARQ gain that is to be included in the study. The image thresholds do not need to include this same additional HARQ gain. since the additional HARQ gain only impacts the traffic channels: 1. No adjustments need to be made to the resulting throughput images to reduce the throughput.LTE RF System Design Procedure .3.Atoll 12. For cases where traffic channel studies are being run: 1.3. However.3. No adjustments are required to the Bearer Threshold tables to incorporate any additional HARQ gain.2 for further details. these parameters are not adjusted for the additional HARQ gain. Figure 201: Bearer Threshold Information without Additional HARQ Gain In order to incorporate additional HARQ gain into the bearer selection thresholds.Atoll Assume that a traffic channel study is being run for a pedestrian environment using the PB3 channel model. The following figure shows the Bearer Threshold values when no additional HARQ gain is incorporated. assume that 2. A different HARQ gain could be assumed for the uplink as compared to the downlink and therefore each of the C/(I+N) Thresholds tables would need to be modified accordingly.669472 – 2 = -1.0 dB of additional HARQ gain is to be used in the design (i. The lowest order modulation and coding scheme. 2. Revision 1. If the HARQ gain is assumed to be on both the downlink and uplink. the MCS0 C/(I+N) value would need to be reduced by the additional HARQ gain.e.0 dB HARQ gain in addition to the HARQ gain that is included in the SNR values). would be reduced by 2 dB. then the C/(I+N) thresholds need to be set for the Motorola eNB Reception (UL) and the Motorola UE Reception (DL). identified as Best Bearer 1 in Figure 201.LTE RF System Design Procedure . The new value to enter into the table for Best Bearer 1 would be 0.3 iProtect: Internal Page 290 .330528. For example. and evaluation of images.Diversity Gain Additional HARQ Gain + Interference Margin For further information regarding images. Therefore. if 2. the image threshold equations are modified as follows: The downlink Signal Quality Analysis (DL) threshold is given as follows: RSSI Cutoff (DL) = kTB + NF + SNR + Fast Fade Margin . 12. this is associated with 70% effective PHY rate (per Table 14).TXAA Gain . please see Sections 9.2.4.3.0 dB of additional HARQ gain is being assumed in the design. Revision 1. Throughput Reduction Associated with Additional HARQ Gain When additional HARQ gain is included in a study.LTE RF System Design Procedure . thresholds. The following uses a ML-CAT example to show how the throughput legend values would change to incorporate an additional HARQ gain.2. please see Section 7.4.3.Atoll The bearer thresholds can be adjusted by typing in the new C/(I+N) values directly in its chart value location as shown in the figure above.1 and 9. For further information regarding setting Bearer Thresholds. the image thresholds must be adjusted by the additional HARQ gain. the user needs to manually reduce the MCS0 throughput level within the legend based on the effective PHY rate that is associated with the specific additional HARQ gain that is being used in the design.3.3.3 iProtect: Internal Page 291 . In cases where additional HARQ gain is used. 12. For example. the throughput levels in the throughput image legend for MCS0 would be reduced to 70% of the PHY rate value.Additional HARQ Gain + Interference Margin The uplink Signal Quality Analysis (UL) threshold is given as follows: RSSI Threshold (UL) = kTB + NF + SNR + Fast Fade Margin . Table 14 shows the effective PHY rates that are associated with different additional HARQ gains and retransmission numbers. In order to account for additional HARQ gain within the throughput images.2. the resulting throughput images need to be adjusted to reduce the throughput accordingly.Diversity Gain . Adjusting Image Thresholds to Include HARQ for Traffic Channel Studies When generating images for traffic channels in cases where additional HARQ gain is used.3. 0 dB of additional DL HARQ gain is used. Figure 202: Example PHY Data Rates not Accounting for HARQ Gain The figure below shows a Post-HARQ PDSCH data rates and Information Rate under the link budget tab in ML-CAT. which corresponds to 2 dB of HARQ gain.g. The Post HARQ rate accounts for the reduction in the throughput rate due to the additional HARQ gain. As seen in Table 14.3 iProtect: Internal Page 292 .LTE RF System Design Procedure . 43% retransmissions is entered by the user. this figure shows that the Post-HARQ PHY data rate is 70% of the downlink PHY data rate before the HARQ gain is incorporated (e.Atoll The following image shows an example ML-CAT screenshot where 2. As expected. Figure 203: Example Post-HARQ PHY Data Rate Revision 1. 1393 kbps * 70% = 975 kbps). 2 Features http://compass.8.mot.com/go/atolldo cs LTE ML-CAT http://compass.8. 2.0 LTE ML-CAT User Guide http://compass. 3. 6.com/go/31693 for LTE and WiMAX RF System 6464 Design Procedure Revision 1.0 Supplement – Atoll 2.mot.com/go/lteplan Version 1.mot.LTE RF System Design Procedure .mot. 5.mot.com/go/lteplan Version 1. Title Atoll User Manual Location/Version http://compass.mot. 7.2 LTE RF Planning Guide http://compass. 4.mot.Atoll 13.1 Features http://compass.3 iProtect: Internal Date - Author(s) Forsk - Forsk Aug-2009 Aug-2009 Aug-2009 Jan-2010 Oct-2010 LTE Planning and Design LTE Planning and Design LTE Planning and Design LTE Planning and Design LTE Planning and Design Page 293 .com/go/atolldo cs Atoll Technical Reference Guide http://compass.com/go/31693 for LTE and WiMAX RF System 6464 Design Procedure Supplement – Atoll 2.1. References 1.com/go/lteplan R2. Atoll 14. Glossary Acronym Meaning AAS Adaptive Antenna System AMS Adaptive MIMO Switching AP EnodeB BE Best Effort BS Base Site BSID Base Station ID CATP Coverage Acceptance Test Plan CDF Cumulative Distribution Function CINR Carrier to interference plus noise ratio CPE Customer Premises Equipment CTP Channel Throughput DAP Diversity EnodeB DL Downlink dB Decibel dBi Decibels relative to an isotropic radiator EFS Effective Faded Sensitivity ERP Effective Radiated Power GAP Ground mounted EnodeB GSF Global Scaling Factor IAP Intelligent ENodeB Kbps Kilobits per second LOS Line-of-sight MAC Medium Access Control layer MAP Mobile Application Part.3 iProtect: Internal Page 294 .LTE RF System Design Procedure . Media Access Protocol MaxTD Max Throughput Demand Mbps Megabits per second MCS Modulation and Coding Scheme MIMO Multiple Input Multiple Output MinTD Min Throughput Demand Revision 1. Atoll MMSE Minimum Mean Square Error MPR Modulation and coding Product Mbits Megabits NLOS Non-line-of-sight nrtPS Non-Real Time Polling Service PD Proportional Demand PDU Protocol Data Unit PF Proportional Fair RLC Radio Link Control RTG Receive Transition (or Time) Gap TXAA Smart Antenna ENodeB SDMA Spatial Division Multiple Access SDU Service Data Unit SM Spatial Multiplexing SNR Signal to Noise Ratio SISO Single Input Single Output TDD Time Division Duplexing TMA Tower Mounted Amplifier TTG Transmit Transition (or Time) Gap Tx Transmit TxAA Transmit Adaptive Antenna UL Uplink VOIP Voice Over Internet Protocol Revision 1.LTE RF System Design Procedure .3 iProtect: Internal Page 295 .