Microwave Line of Sight Link Engineering

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 Objectives (RPO) 322 9.3 Bringing into Service (BIS) 325 9.4 Maintenance 328 Bibliography 333 APPENDIX 335 INDEX 378