Microwave Line of Sight Link Engineering

A comprehensive guide to the design, implementation, and operation of line of sight microwave link systems

The microwave Line of Sight (LOS) transport network of any cellular operator requires at least as much planning effort as the cellular infrastructure itself. The knowledge behind this design has been kept private by most companies and has not been easy to find. Microwave Line of Sight Link Engineering solves this dilemma. It provides the latest revisions to ITU reports and recommendations, which are not only key to successful design but have changed dramatically in recent years. These include the methodologies related to quality criteria, which the authors address and explain in depth.

Combining relevant theory with practical recommendations for such critical planning decisions as frequency band selection, radio channel arrangements, site selection, antenna installation, and equipment choice, this one-stop primer:

• Describes the procedure for designing a frequency plan and a channel arrangement structure according to ITU current standards, illustrated with specific application examples

• Offers analytical examples that illustrate the specifics of calculations and provide order of magnitude for parameters and design factors

• Presents case studies that describe real-life projects, putting together the puzzle pieces necessary when facing a real design created from scratch

Microwave Line of Sight Link Engineering is an indispensable resource for radio engineers who need to understand international standards associated with LOS microwave links. It is also extremely valuable for students approaching the topic for the first time.

Auteur

PABLO ANGUEIRA, PhD, is an Associate Professor in the
Department of Communication Engineering of the University of the
Basque Country UPV/EHU. He has been involved in radio
communications research and teaching activities for more than
fifteen years. He is author of several contributions to the ITU-R
WP3 and WP6 groups as well as many journal and international
conference papers. He is Associate Editor of the IEEE
Transactions on Broadcasting journal.

JUAN ANTONIO ROMO, PhD, is an Associate Professor
teaching fixed, mobile, and satellite radio systems in the
Department of Communication Engineering of the University of the
Basque Country UPV/EHU. He has twenty-five years' experience in
diverse areas of radio communications, in both manufacturing and
network operations.

Contenu
PREFACE xix ACRONYMS xxiii

1 INTRODUCTION TO MICROWAVE LOS LINK SYSTEMS 1

1.1 Introduction 1

1.2 Historic Evolution of Radio Links 3

1.3 Point-to-Point Fixed Communication Technologies 5

1.4 Field of Application and Use Cases 13

1.5 Basic Structure of a Fixed Service Microwave Link 18

1.6 Spectrum Management Aspects 21

1.7 First Approach to the Design of a Microwave LOS Link 26

1.8 Link Budget Basics 28

1.9 Noise 36

1.10 Interferences 39

2 LOSS AND FADING ASSOCIATED WITH TROPOSPHERE PROPAGATION PHENOMENA 42

2.1 Introduction 42

2.2 Influence of Refraction on Propagation in the Troposphere 43

2.3 Terrain Diffraction Losses: Fresnel Zones 59

2.4 Vegetation Attenuation 60

2.5 Atmospheric Gas and Vapor Absorption 61

2.6 Hydrometeors 62

2.7 Reflection 65

2.8 Distortion due to Propagation Effects 67

3 FREQUENCY PLAN FOR A FIXED SERVICE MICROWAVE LINK 72

3.1 Frequency Planning Overview 72

3.2 Bandwidth and Capacity of a Microwave LOS Link 74

3.3 ITU-R Frequency Plans 79

3.4 Assignment of Radio-frequency Channels 93

3.5 Comments on the Frequency Band Choice 97

4 EQUIPMENT AND SUBSYSTEM TECHNOLOGY ASPECTS: A RADIO LINK DESIGNER APPROACH 100

4.1 Introduction 100

4.2 Basic Block Diagrams 102

4.3 Transport Technologies 107

4.4 Baseband Unit 114

4.5 Modulation and Demodulation 123

4.6 Transceiver Unit 139

4.7 Antenna Coupling Elements 142

4.8 Antennas 147

4.9 Redundancy Arrangements 166

4.10 System Monitoring and Management 171

5 PERFORMANCE OBJECTIVES AND CRITERIA FOR FIXED SERVICE MICROWAVE LINKS 174

5.1 Introduction 174

5.2 Error Performance Objectives and Criteria Based on Recommendation ITU-T G.821 176

5.3 Error Performance Objectives and Criteria Based on Recommendations ITU-T G.826 and ITU-T G.828 179

5.4 Availability Criteria 188

5.5 Availability Objectives for Microwave LOS Links Designed Before 2005 190

5.6 Availability Objectives for Microwave LOS Links Designed After 2005 192

5.7 ITU Error Performance and Availability Usage Guidelines 194

5.8 Degradation due to Interferences 195

6 LINK PATH ENGINEERING 207

6.1 General Considerations on Link Path Engineering 207

6.2 Site Selection Criteria 209

6.3 Digital Terrain Databases 211

6.4 Profile Extraction, Clearance, and Obstructions 212

6.5 Optimum Choice of Antenna Heights 216

7 PROPAGATION CALCULATION METHODS ACCORDING TO ITU-R P SERIES RECOMMENDATIONS 227

7.1 General Considerations on Propagation Calculation Methods 227

7.2 Fading Definition 228

7.3 Reflection on Earth's Surface 230

7.4 Attenuation Due to Atmospheric Gases 236

7.5 Diffraction Fading 237

7.6 Multipath Flat Fading 245

7.7 Distortion Due to Multipath Propagation Effects Under Clear Sky 250

7.8 Attenuation due to Hydrometeors 255

7.9 Reduction of Cross-Polar Discrimination (XPD) 262

7.10 ITU-R Databases for Tropospheric Propagation Studies 265

8 LINK ENGINEERING ACCORDING TO AVAILABILITY AND ERROR PERFORMANCE CRITERIA 271

8.1 Introduction 271

8.2 Design According to Availability and Error Performance 272

8.3 Microwave LOS Link Design According to Availability Criteria 281

8.4 Microwave LOS Link Design According to Error Performance Objectives 285

8.5 Design in Problematic Propagation Environments 294

8.6 Quality and Availability Calculation Guidelines in Real Links 304

8.7 Interferences 306

8.8 Link Engineering Summary Procedure 319

9 LINK OPERATION AND MONITORING 321

9.1 Introduction 321 9.2 Reference Performance Objec...