Description
Book SynopsisThe 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 acceptanc
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
