Digital Microwave Communication: Engineering Point-to-Point Microwave Systems

The first book to cover all engineering aspects of microwave communication path design for the digital age Fixed point-to-point microwave systems provide moderate-capacity digital transmission between well-defined locations. Most popular in situations where fiber optics or satellite communication is impractical, it is commonly used for cellular or PCS site interconnectivity where digital connectivity is needed but not economically available from other sources, and in private networks where reliability is most important. Until now, no book has adequately treated all engineering aspects of microwave communications in the digital age. This important new work provides readers with the depth of knowledge necessary for all the system engineering details associated with fixed point-to-point microwave radio path design: the why, what, and how of microwave transmission; design objectives; engineering methodologies; and design philosophy (in the bid, design, and acceptance phase of the project). Written in an easily accessible format, Digital Microwave Communication features an appendix of specialized engineering details and formulas, and offers up chapter coverage of: A Brief History of Microwave Radio Microwave Radio Overview System Components Hypothetical Reference Circuits Multipath Fading Rain Fading Reflections and Obstructions Network Reliability Calculations Regulation of Microwave Radio Networks Radio Network Performance Objectives Designing and Operating Microwave Systems Antennas Radio Diversity Ducting and Obstruction Fading Digital Receiver Interference Path Performance Calculations Digital Microwave Communication: Engineering Point-to-Point Microwave Systems will be of great interest to engineers and managers who specify, design, or evaluate fixed point-to-point microwave systems associated with communications systems and equipment manufacturers, independent and university research organizations, government agencies, telecommunications services, and other users.

Table of Contents:
Preface xv Acknowledgments xvii About the Author xix 1 A Brief History of Microwave Radio Fixed Point-to-Point (Relay) Communication Systems 1 1.1 In the Beginning 1 1.2 Microwave Telecommunications Companies 7 1.3 Practical Applications 10 1.4 The Beat Goes On 14 References 16 2 Regulation of Microwave Radio Transmissions 20 2.1 Radio Frequency Management 21 2.2 Testing for Interference 28 2.3 Radio Paths by FCC Frequency Band in the United States 29 2.4 Influences in Frequency Allocation and Utilization Policy within the Western Hemisphere 30 2.5 FCC Fixed Radio Services 36 2.6 Site Data Accuracy Requirements 41 2.7 FCC Antenna Registration System (ASR) Registration Requirements 42 2.8 Engineering Microwave Paths Near Airports and Heliports 44 References 47 3 Microwave Radio Overview 48 3.1 Introduction 48 3.2 Digital Signaling 50 3.3 Noise Figure Noise Factor Noise Temperature and Front End Noise 50 3.4 Digital Pulse Amplitude Modulation (PAM) 53 3.5 Radio Transmitters and Receivers 58 3.6 Modulation Format 60 3.7 QAM Digital Radios 65 3.8 Channel Equalization 68 3.9 Channel Coding 70 3.10 Trellis Coded Modulation (TCM) 72 3.11 Orthogonal Frequency Division Multiplexing (OFDM) 75 3.12 Radio Configurations 76 3.13 Frequency Diversity and Multiline Considerations 82 3.14 Transmission Latency 85 3.15 Automatic Transmitter Power Control (ATPC) 87 3.16 Current Trends 87 References 90 4 Radio Network Performance Objectives 96 4.1 Customer Service Objectives 96 4.2 Maintenance Objectives 96 4.3 Commissioning Objectives 98 4.4 Design Objectives 98 4.5 Differences Between North American and European Radio System Objectives 99 4.6 North American Telecommunications System Design Objectives 100 4.7 International Telecommunications System Design Objectives 100 4.8 Engineering Microwave Paths to Design Objectives 102 4.9 Accuracy of Path Availability Calculations 106 4.10 Impact of Flat Multipath Variability 108 4.11 Impact of Outage Measurement Methodology 108 4.12 Impact of External Interference 109 4.13 Conclusion 109 References 110 5 Radio System Components 114 5.1 Microwave Signal Transmission Lines 115 5.2 Antenna Support Structures 121 5.3 Tower Rigidity and Integrity 127 5.4 Transmission Line Management 127 5.5 Antennas 127 5.6 Near Field 137 5.7 Fundamental Antenna Limitations 143 5.8 Propagation 143 5.9 Radio System Performance as a Function of Radio Path Propagation 145 5.10 Radio System Performance as a Function of Radio Path Terrain 149 5.11 Antenna Placement 153 5.12 Frequency Band Characteristics 155 5.13 Path Distances 157 5.A Appendix 159 References 172 6 Designing and Operating Microwave Systems 175 6.1 Why Microwave Radio? 175 6.2 Radio System Design 175 6.3 Designing Low Frequency Radio Networks 179 6.4 Designing High Frequency Radio Networks 182 6.5 Field Measurements 185 6.6 User Data Interfaces 185 6.7 Operations and Maintenance 202 6.8 Maintaining the Network 210 References 217 7 Hypothetical Reference Circuits 220 7.1 North American (NA) Availability Objectives 220 7.2 North American Quality Objectives 225 7.3 International Objectives 225 7.4 International Telecommunication Union Quality Objectives 236 7.5 Error-Performance Relationship Among BER BBER and SESs 245 References 247 8 Microwave Antenna Theory 249 8.1 Common Parameters 251 8.2 Passive Reflectors 252 8.3 Circular (Parabolic) Antennas 256 8.4 Square Flat Panel Antennas 274 8.5 Regulatory Near Field Power Density Limits 290 8.6 Practical Near Field Power Calculations 290 8.7 Near Field Antenna Coupling Loss 296 8.A Appendix 307 References 318 9 Multipath Fading 320 9.1 Flat and Dispersive Fading 329 9.A Appendix 338 References 344 10 Microwave Radio Diversity 348 10.1 Space Diversity 350 10.2 Dual-Frequency Diversity 354 10.3 Quad (Space and Frequency) Diversity 357 10.4 Hybrid Diversity 358 10.5 Multiline Frequency Diversity 358 10.6 Crossband Multiline 365 10.7 Angle Diversity 366 10.A Appendix 372 References 380 11 Rain Fading 384 11.1 Point (Single-Location) Rain Loss (Fade) Estimation 386 11.2 Path Rain-Fade Estimation 390 11.3 Point-to-Path Length Conversion Factor 398 11.4 Single-Location Rain Rate R 398 11.5 City Rain Rate Data for North America 407 11.6 New Rain Zones 430 11.7 Worst-Month Rain Rates 430 11.8 Point Rain Rate Variability 439 11.9 Examples of Rain-Loss-Dominated Path Designs 441 11.10 Conclusions 444 11.A Appendix 446 References 458 12 Ducting and Obstruction Fading 461 12.1 Introduction 461 12.2 Superrefraction (Ducting) 465 12.3 Subrefraction (Earth Bulge or Obstruction) 469 12.4 Minimizing Obstruction Fading 471 12.5 Obstruction Fading Model 477 12.6 Obstruction Fading Estimation 479 12.7 Bell Labs Seasonal Parameter Charts 483 12.8 Refractivity Data Limitations 484 12.9 Reviewing the Bell Labs Seasonal Parameter Charts 485 12.10 Obstruction Fading Parameter Estimation 486 12.11 Evaluating Path Clearance Criteria 487 12.A Appendix: North American Refractivity Index Charts 490 12.B Appendix: Worldwide Obstruction Fading Data 491 References 511 13 Reflections and Obstructions 514 13.1 Theoretical Rough Earth Reflection Coefficient 514 13.2 Scattering from Earth Terrain 517 13.3 Practical Earth Reflection Coefficient 519 13.4 Reflection Location 519 13.5 Smooth Earth Divergence Factor 522 13.6 Reflections from Objects Near a Path 523 13.7 Fresnel Zones 525 13.8 Antenna Launch Angle (Transmit or Receive Antenna Takeoff Angle) 527 13.9 Grazing Angle 527 13.10 Additional Path Distance 528 13.11 Estimating the Effect of a Signal Reflected from the Earth 528 13.12 Flat Earth Obstruction Path Loss 529 13.13 Smooth Earth Obstruction Loss 529 13.14 Knife-Edge Obstruction Path Gain 530 13.15 Rounded-Edge Obstruction Path Gain 531 13.16 Complex Terrain Obstruction Losses 532 13.A Appendix 536 References 555 14 Digital Receiver Interference 559 14.1 Composite Interference (T/T ) Criterion 559 14.2 Carrier-to-Interference Ratio (C/I) Criterion 560 14.3 Measuring C/I 560 14.4 Estimating C/I 561 14.5 Threshold to Interference (T/I) Criterion 562 14.6 Why Estimate T/I 563 14.7 T/I Estimation—Method One 564 14.8 T/I Estimation—Method Two 565 14.9 Conclusion 569 14.A Appendix 569 14.B Appendix: Receiver Parameters 571 References 572 15 Network Reliability Calculations 573 15.1 Hardware Reliability 574 15.2 System Reliability 577 15.3 Communication Systems 579 15.4 Application to Radio Configurations 580 15.5 Spare Unit Requirements 580 15.6 BER Estimation 583 References 585 16 Path Performance Calculations 587 16.1 Path Loss 588 16.2 Fade Margin 589 16.3 Path Performance 589 16.4 Allowance for Interference 590 16.5 North American (NA) Path Performance Calculations 590 16.6 International Telecommunication Union—Radiocommunication Sector (ITU-R) Path Performance Calculations 604 16.7 Rain Fading and Obstruction Fading (NA and ITU-R) 614 16.8 Comparing the North American and the ITU-R Flat-Fading Estimates 614 16.9 Diffraction and Vegetation Attenuation 621 16.10 Fog Attenuation 622 16.11 Air Attenuation 624 16.A Appendix 631 References 649 A Microwave Formulas and Tables 653 A.1 General 653 Table A.1 General 653 Table A.2 Scientific and Engineering Notation 654 Table A.3 Emission Designator 655 Table A.4 Typical Commercial Parabolic Antenna Gain (dBi) 656 Table A.5 Typical Rectangular Waveguide 656 Table A.6 Typical Rectangular Waveguide Data 657 Table A.7 Typical Copper Corrugated Elliptical Waveguide Loss 657 Table A.8 Typical Copper Circular Waveguide Loss 658 Table A.9 Rectangular Waveguide Attenuation Factors 659 Table A.10 CommScope Elliptical Waveguide Attenuation Factors 659 Table A.11 RFS Elliptical Waveguide Attenuation Factors 660 Table A.12 Elliptical Waveguide Cutoff Frequencies 660 Table A.13 Circular Waveguide Cutoff Frequencies 661 Table A.14 Typical Coaxial Microwave Connectors 663 Table A.15 Coaxial Cable Velocity Factors 664 Table A.16 50 Ohm Coaxial Cable Attenuation Factors 664 Table A.17 Frequency Bands General Users 665 Table A.18 Frequency Bands Fixed Point to Point Operators 665 Table A.19 Frequency Bands Radar Space and Satellite Operators 666 Table A.20 Frequency Bands Electronic Warfare Operators 666 Table A.21 Frequency Bands Great Britain Operators 666 Table A.22 Signal-to-Noise Ratio for Demodulator 10−6 BER 667 A.2 Radio Transmission 668 A.3 Antennas (Far Field) 675 A.4 Near-Field Power Density 682 A.5 Antennas (Close Coupled) 683 A.6 Path Geometry 687 A.7 Obstruction Loss 693 A.8 Mapping 698 A.9 Towers 700 A.10 Interpolation 702 B Personnel and Equipment Safety Considerations 709 B.1 General Safety Guidelines 709 B.2 Equipment Protection 711 B.3 Equipment Considerations 712 B.4 Personnel Protective Equipment 713 B.5 Accident Prevention Signs 713 B.6 Tower Climbing 713 B.7 Hand Tools 715 B.8 Electrical Powered Tools 715 B.9 Soldering Irons 715 B.10 Ladders 716 B.11 Hoisting or Moving Equipment 716 B.12 Batteries 717 B.13 Laser Safety Guidelines 717 B.14 Safe Use of Lasers and LED in Optical Fiber Communication Systems 718 B.15 Optical Fiber Communication System (OFCS) Service Groups (SGs) 718 B.16 Electrostatic Discharge (ESD) 719 B.17 Maximum Permissible Microwave Radio RF Exposure 720 B.18 Protect Other Radio Users [FCC] 720 B.19 PAUSE (Prevent all Unplanned Service Events) and Ask Yourself (Verizon and AT&T Operations) 721 B.20 Protect Yourself (Bell System Operations) 721 B.21 Parting Comment 721 Index 723

About the Author :
GEORGE KIZER is a telecomm consultant specializing in microwave radio engineering and training. Before retiring from Alcatel North America's Wireless Transmission Division in 2001, he worked at Collins Radio and Rockwell International's Microwave Division of the Collins Radio Group. Mr. Kizer also served as chairman of the TIA's Fixed Microwave Section from 1991 to 1996.