Implementing 802.11, 802.16, and 802.20 Wireless Networks

frankppk

Implementing 802.11, 802.16,
and 802.20 Wireless Networks
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Implementing 802.11, 802.16,
and 802.20 Wireless Networks
Planning, Troubleshooting and Operations
by Ron Olexa
AMSTERDAM • BOSTON • HEIDELBERG • LONDON
NEW YORK • OXFORD • PARIS • SAN DIEGO
SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO
Newnes is an imprint of Elsevier
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v
Contents
Preface ........................................................................................ix
Introduction ............................................................................... xiii
What’s on the CD-ROM? ............................................................ xix
Chapter 1: High-Speed Wireless Data: System Types,
Standards-Based and Proprietary Solutions ............................ 3
Fixed Networks ............................................................................................4
Nomadic Networks ......................................................................................5
Mobile Networks .........................................................................................6
Standards-Based Solutions and Proprietary Solutions .................................6
Overview of the IEEE 802.11 Standard .......................................................7
Overview of the IEEE 802.16 Standard .....................................................14
10−66 GHz Technical Standards ...............................................................16
2−11 GHz Standards ..................................................................................16
Overview of the IEEE 802.20 Standard .....................................................17
Proprietary Solutions .................................................................................18
Chapter 2: Basic Radio and RF Concepts ....................................... 27
RF Energy ..................................................................................................27
RF Generation and Transmission ...............................................................30
Oscillator ....................................................................................................30
Power Amplifiers .......................................................................................34
Antennas and Feedlines .............................................................................35
RF Reception .............................................................................................41
Modulation of RF Signals ..........................................................................44
Amplitude Modulation ...............................................................................44
Frequency Modulation ...............................................................................46
Complex Modulation .................................................................................47
Duplexing ...................................................................................................54
vi
Contents
Frequency Division Duplexing ..................................................................54
Time Division Duplexing ...........................................................................55
Multiple Access Techniques .......................................................................55
Spread-Spectrum Modulation ....................................................................58
OFDM ........................................................................................................62
Ultra Wideband ..........................................................................................64
Chapter 3: Propagation, Path Loss, Fading and Link Budgets .......... 69
Path Loss and System Coverage ................................................................79
Frequency Reuse ........................................................................................85
Chapter 4: Propagation Modeling and Measuring ........................... 95
Predictive Modeling Tools .........................................................................95
Spreadsheet Models ...................................................................................96
Terrain-Based Models ................................................................................97
Effectively Using a Propagation Analysis Program ...................................98
Using a Predictive Model .........................................................................104
The Comprehensive Site Survey Process .................................................106
Survey Activity Outline ...........................................................................110
Identification of Requirements .................................................................112
Identification of Equipment Requirements ..............................................113
The Physical Site Survey .........................................................................114
Determination of Antenna Locations .......................................................115
RF Site Survey Tools ...............................................................................117
The Site Survey Checklist ........................................................................119
The RF Survey .........................................................................................120
Data Analysis ...........................................................................................123
Chapter 5: System Planning ....................................................... 131
System Design Overview .........................................................................131
Location and Real Estate Considerations ................................................132
System Selection Based Upon User Needs ..............................................139
Identification of Equipment Requirements ..............................................140
Identification of Equipment Locations .....................................................143
Channel Allocation, Signal-to-Interference, and Reuse Planning ...........151
Network Interconnect and Point-to-Point Radio Solutions .....................155
vii
Costs .........................................................................................................159
The Five C’s of System Planning .............................................................159
Chapter 6: System Implementation, Testing
and Optimization ............................................................ 163
Real-World Design Examples ..................................................................163
Example One: Local Coffee House .........................................................163
Example Two: Office LAN Deployment .................................................165
2.4 GHz RF Coverage Results .................................................................169
5.6 GHz RF Coverage Results .................................................................170
Capacity Requirements ............................................................................171
System Design Analysis ...........................................................................171
NEC, Fire, and Safety Code Concerns .....................................................174
Example Three: Community WISP .........................................................176
Community: A Garden Style Apartment Complex ..................................177
RF Considerations ....................................................................................178
Backhaul ..................................................................................................181
Weatherproofing .......................................................................................183
Grounding and Lightning Protection .......................................................184
Community: A Small Area Subdivision ...................................................185
Equipment Selection ................................................................................185
System Planning ......................................................................................187
Community: An Urban or Suburban Area Serving Business Users .........188
Spectrum Issues .......................................................................................188
Design Considerations .............................................................................190
Community: A Small Town System for Consumer and Business Users .191
Summary ..................................................................................................191
Example Four: Mobile Broadband Network ............................................192
Initial Modeling .......................................................................................192
Preliminary Information ...........................................................................193
Coverage Modeling ..................................................................................194
Capacity Modeling ...................................................................................194
Cost Modeling ..........................................................................................195
Designing in the Real World ....................................................................195
Chapter Summary ....................................................................................197
Contents
viii
Contents
Chapter 7: Back Office System Requirements ............................... 201
Network Systems Required ......................................................................201
Customer Authorization System ..............................................................202
Billing Data Collection ............................................................................203
Network Monitoring and Control ............................................................203
Billing System ..........................................................................................204
Trouble Ticketing .....................................................................................205
Customer Service Systems .......................................................................206
Design Considerations and Requirements ...............................................208
Chapter 8: Network Performance Testing and Troubleshooting ...... 213
Low RSSI and Noise Levels in a Single Area ..........................................215
High Noise or Interference Levels ...........................................................216
Throughput Problems Unrelated to Signal or Noise ................................218
Repeater Mode ........................................................................................219
Multiple Channel Reuse in a Close Area .................................................220
Near/Far Problems ...................................................................................220
Hidden Node Problems ............................................................................220
Client Card “Roam” .................................................................................221
Viruses and Trojans ..................................................................................221
Troubleshooting Summary .......................................................................222
About the Author ..................................................................... 223
List of Acronyms ....................................................................... 225
Index ..................................................................................... 229

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