Performance Enhancements in a Frequency Hopping GSM Network

Performance Enhancements in a Frequency Hopping GSM Network

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English

Description

Due to the explosive global growth in the number of mobile subscribers, as well as the growth predicted in the mobile data segment, the need for improved spectrum efficiency on the radio interface becomes more and more important. Frequency hopping (FH) is an effective method for improving the spectrum efficiency. One of the advantages of FH is that it can be combined with other spectral efficiency improving features like power control, handover and reuse partitioning.
Performance Enhancements in a Frequency Hopping GSM Network covers FH and some of the additional features in detail. It begins with an in-depth description of the basic concept of FH on link level as well as on system level. Different methods have been used for analysis, such as link level simulations, network level simulations and classic tele-traffic theory.
Special features of Performance Enhancements in a Frequency Hopping GSM Network:
Combines the practical experiences of operator and vendor with more theoretical research methods. An in-depth treatment of prevailing problems in GSM networks;
Presentation of a new method, computer-aided network design (CAND), which has been developed to analyse the complex network structures of a GSM network. CAND provides the possibility for more realistic performance evaluations than conventional methods;
Provides GSM-specific analysis of functionality improvements in power control, discontinuous transmission, and several handover algorithms;
Explanation of the quality and capacity gains of features like the combination of FH and reuse partitioning, referred to as intelligent frequency hopping;
A frequency planning method for FH GSM networks is presented. This method exploits the benefits from FH directly in the allocation process, increasing the overall frequency plan.

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Published by
Published 01 January 2000
Reads 13
EAN13 0306473135
License: All rights reserved
Language English

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Contents
PREFACE
ACKNOWLEDGEMENTS
1
2
INTRODUCTION
1.Digital SystemsEvolution of
2.Performance of a Mobile Network
3.The aim of the book
PERFORMANCE ENHANCING STRATEGIES AND EVALUATION METHODS 1.Radio Performance Enhancements 1.1the Network InfrastructureEngineering of 1.2Radio Interface Channel Allocation Techniques 1.3Techniques to Limit the Influence of Interference 1.4Data Services for GSM 1.5Closing Comments on Performance Enhancements
2.Computer Aided GSM network Design 2.1The Simulation Tool
3.Classic Traffic Theory
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7 7 8 10 13 15 16
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vi Performance Enhancements in a Frequency Hopping GSM Network
4.Network Field Trials
3.A BRIEF INTRODUCTION TO THE GSM SYSTEM
1.GSM System Structure
2.Multiple Access Scheme in GSM
3.Channel Types in GSM
4.Mapping Logical to Physical Channels
5.Modulation Scheme in GSM
6.Typical Cell Architecture
7.Measurement Reporting in GSM
8.Frequency Hopping in GSM
9.Discontinuous Transmission in gsm
10.The Dropped Call Algorithm
4.LINK MODELLING AND LINK PERFORMANCE
1.The GSM Link 1.1The Channel Coding 1. 2Interleaving
2.The GSM Link Simulator 2.1Structure of the Link Simulator 2.2Output Parameters from the Link Simulator
3.Influence of Frequency Hopping on the Link Performance 3.1Aim of Frequency Hopping 3.2Link Simulation Reference Conditions 3.3Link Simulation Results 3.4Performance Comparison to Existing GSM Mobiles
4.Predicting the BER/FER with FH 4.1The FER/BER Prediction Method 4.2Accuracy of the BER/FER Prediction Method
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35 35 36
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43 44 50
Preface
5.Summary and Conclusions
5.COMPUTER AIDED NETWORK DESIGN
1.Introduction to Computer Aided Network Design
2.Network Modelling by CAPACITY 2.1 The General Program Structure
3.Available Output Parameters
4.Dropped Call Algorithm comparison
5.Accuracy of simulation results
6.Default simulation Parameters
6.INFLUENCE OF FH ON A GSM SYSTEM
1.Capacity Limits of a FH GSM Network 1.1Defining Coverage 1.2Determining the Hard Blocking 1.3Determining the Soft Blocking
2.Network Simulation Results 2.1Introduction to the Network Simulations 2.2The CAPACITY Network Simulation Results 2.3Alternative Network Topologies
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3.Interaction between Network Quality Parameters 3.1Simulations on Dropped Calls versus RXQUAL 3.2Live Network Measurements on Dropped Calls versus RXQUAL 3.3FER on the SACCH versus FER on the TCH
4.Using Frequency Hopping in Band Limited One Layer Networks 4.1The Basic Problem 4.2The MAIO-Management Concept 4.3Soft Capacity versus MAIO-Management 4.4Network Simulation Results using CAPACITY 4.5Concluding Remarks on MAIO-Management
5.Exploiting Frequency Hopping in a LIVE Network 5.1Introduction 5.2Frequency Hopping Trial Results
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88 88 89 92 93 94
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Performance Enhancements in a Frequency Hopping GSM Network
5.3Summary on Live Frequency Hopping Trial
6.Summary and Conclusions
7.POWER CONTROL AND DTX IN A FH GSM SYSTEM
1.An introduction to power control 1.1Previous Work Concerning Power Control 1.2The Potential Gain from Power Control
2.Introduction to Discontinuous TransmissionA Brief
3.The GSM Power Control Algorithm 3.1Introduction 3.2The Simplified Power Control Algorithm 3.3Performance of the Simplified PC Algorithm 3.4the GSM PC AlgorithmNetwork Simulations of 3.5Trial Results of Downlink Power Control and DTX in a FH Network
4.Discontinuous Transmission in GSM 4.1The Basic Functionality of DTX in GSM 4.2RXQUAL Estimation Accuracy with DTX 4.3The Gain From DTX in a FH GSM Network
5.Conclusion on Power Control and DTX in a FH GSM network
8.HANDOVER ALGORITHMS IN A GSM SYSTEM
1.Introduction 1.1Handover Basics 1.2Literature Study 1.3Chapter Outline
2.The Simulation Model 2.1Modelling and Implementation in CAPACITY 2.2Simulation Results 2.3Live Network Measurements 2.4Frequency Hopping in Relation to Handovers
3.Theoretical Handover Modelling 3.1Simple theoretical analysis of handover probability 3.2Birth Dead Model
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137 137 138 146
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155 155 160 164 166
168 168 172
Preface
3.3Multiple cells scenario 3.4Mobility Dependency
4.Handover Improvements 4.1Channel Reservation for Handover Traffic 4.2Channel Reservation Combined with Queuing 4.3Traffic Reason Handover 4.4Dynamic HO Margin
5.Summary on handover algorithms in a gsm network
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9.COMBINING REUSE PARTITIONING AND FREQUENCY HOPPING IN A GSM NETWORK
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179 179 184 189 197
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1.Introduction to Frequency Reuse Partitioning204 1.1Reuse Partitioning in a Cellular Communication System like GSM205 1.2Previous Frequency Reuse Partitioning Studies206 1.3Idealised Frequency Reuse Partitioning Considerations207 1.4Practical Considerations Concerning Reuse Partitioning212
2.The Intelligent Underlay-Overlay Algorithm 2.1Estimating C/Iin GSM 2.2Practical Frequency Planning Difficulties of IUO 2.3Estimating the Hard Blocking Limit of an IUO Cell 2.4Remarks on the IUO Algorithm
3.The Capacity Enhancement Proposal
4.Preliminary Simulation Studies of IUO with Frequency Hopping 4.1Problems Discovered with the Original IUO Algorithm and FH 4.2Improvements to Enhance the IUO Algorithm
5.The Improved IUO Algorithm 5.1Improved Handover Characteristics with IUO 5.2Hard Blocking Traffic Model of the Improved IUO
6.Implementation of IUO in CAPACITY 6.1The IUO Input Parameter List 6.2Implementation of the Handover Algorithm
7.Outline for CAPACITY Simulations Concerning IUO 7.1IUO Parameter Settings 7.2Network Parameter Settings
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x PerformanceEnhancements in a Frequency Hopping GSM Network
8.CAPACITY Simulation Results 8.1the Functionality of IUO and FHSimulations of 8.2CAPACITY Simulations of IUO and Baseband FH
9.IUO and FHLive Network Trials Related to the combination of
10.Concluding Comments on the Combination of IUO and FH for GSM 10.1Analytical Calculations and Network Simulations 10.2Ideas for Future Improvements of IFH
10.FREQUENCY PLANNING OF FREQUENCY HOPPING NETWORKS
1.Introduction 1.1The Frequency Planning Problem 1.2Existing Techniques 1.3Chapter Outline
2.The Frequency Allocation Principle 2.1Propagation Prediction Input 2.2in FH NetworksFrequency Planning 2.3Broadcast Channels versus Traffic Channels 2.4The Frequency Planning Method
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274 275 275 277 279
3.Performance of the FH Planning Tool297 3.1Performance of the Search Algorithm297 3.2Evaluation Method for a Frequency Plan with Frequency Hopping303 3.3Results from Live Network307
4.Other Parameters to be planned 4.1Frequency Hopping Parameters 4.2Training Sequences
5.Conclusions and Improvements 5.1Summary 5.2Future Improvements
REFERENCES
INDEX
308 308 309
312 312 314
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