ByJack Unger
Transcript of ByJack Unger
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Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
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Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
all brands of broadband wireless equipment and explains the principles upon which all wireless
equipment is based. Inside, you'll find step-by-step instructions and crystal-clear explanations
that walk you through initial planning stages and onto full wireless network operation. End-of-
chapter review questions reinforce important concepts.
Whether you're an IT director, ISP engineer, network architect, or field technician, Deploying
License-Free Wireless W ide-Area Networks is your essential reference. With practical, in-depth
coverage of the real-world challenges of outdoor, license-free wireless WAN deployment, this
book provides a comprehensive, vendor-neutral guide to successful wireless network design andoperation.
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Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Copyright
About the Author
About the Technical Reviewers
Acknowledgments
Sample of Physical Site Survey Data Form
Introduction
Who This Book Is For
How to Use This Book
Chapter1. An Introduction to Broadband License-Free Wireless Wide-Area Networking
Differences Between Wired Networks and Wireless Networks
Wireless Terminology and Evolution Advantages of License-Free Wireless Networks
Challenges of License-Free Wireless Networks
Review Questions
Chapter2. Understanding Wireless Fundamentals
Wireless Propagation
Wireless Frequency
Wireless Wavelength
Attenuation
Free-Space Waves
Reflected Waves
Diffraction
Weather and Other Atmospheric Effects
Working with Wireless Power
Antenna Characteristics
Antenna Beamwidth
Obtaining Wireless Line-of-Sight Paths
Wireless Link Budget
Tips for Planning Long Wireless Links
Review Questions
Chapter3. Choosing Your Network Architecture
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Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
Point-to-Point Architecture
Cellular Architecture
Mesh Architecture
Selecting the Preliminary Network Architecture
Review Questions
Chapter4. Performing Site Surveys
Physical Site Surveys
Radio Frequency (RF) Site Surveys Negotiating a Site Lease
Review Questions
Chapter5. Selecting Antenna Systems
Using Antennas to Focus Power and Reduce Interference
Surveying Common Antenna Types
Combining Antenna Systems
Isolating Antenna Systems
Sector Antenna Systems
Other Antenna System Components
Feed Systems
Review Questions Chapter6. Evaluating and Selecting Wireless Equipment
Overview of the Equipment Selection Process
OSI and TCP/IP Reference Models
Physical Layer Wired-Interface Features
Physical Layer Wireless-Interface Features
Data Link Layer Features
Network Layer Features
Application Layer Features
Major Network Feature Decisions
Review Questions
Chapter7. Installing Outdoor Wireless Systems
Preparing for Outdoor Wireless Installations
Verifying the Installation Documentation
Installing Tower-Mounted Antenna Systems
Installing Rooftop-Mounted Antenna Systems
Testing Wireless Systems
Review Questions
Chapter8. Solving Noise and Interference Problems
Understanding SNR
Maximizing the Signal Level
Minimizing the Noise and Interference Level Using Direction-Finding Techniques to Locate Noise Sources
Review Questions
Chapter9. Providing Broadband Wireless Internet Access
Planning for WISP Success
Designing Reliable Networks
Deploying Stable Networks
Managing Network Throughput
Enhancing Network Security
Coexisting with Other Wireless Networks
Living with the FCC
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Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
Anticipating Emerging Trends
Avoiding B lack Holes
Review Questions
AppendixA. Wireless Standards Summary
AppendixB. Wireless Hardware, Software, and Service Provider Organizations
Wireless Hardware
Low-Cost 802.11b Access Point Hardware
Wireless Hotspot Hardware Free Space Optical Hardware
Security Hardware and Software
Antenna Systems
Coaxial Cable
Towers and Antenna Mounting Hardware
Lightning-Protection Equipment
Grounding Equipment
Test Equipment
Peripheral Equipment Distributors
Wireless Software
Services Suggested Books for Further Reading
Online Magazines
WISP Industry Organizations
E-Mail Lists
FCC Rules and Regulations
Wireless Standards
Locating a WISP
Community Networks and Wireless User Groups
AppendixC. Answers to Chapter Review Questions
Answers to Chapter 1 Review Questions
Answers to Chapter 2 Review Questions
Answers to Chapter 3 Review Questions
Answers to Chapter 4 Review Questions
Answers to Chapter 5 Review Questions
Answers to Chapter 6 Review Questions
Answers to Chapter 7 Review Questions
Answers to Chapter 8 Review Questions
Answers to Chapter 9 Review Questions
Index
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Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
Copyright
Copyright 2003 Cisco Systems, Inc.
Publishedby:
CiscoPress201West103rdStreetIndianapolis,IN46290USA
All rights reserved. No part of this book may be reproduced or transmitted in any form or by any
means, electronic or mechanical, including photocopying, recording, or by any information
storage and retrieval system, without written permission from the publisher, except for the
inclusion of brief quotations in a review.
Printed in the United States of America 2 3 4 5 6 7 8 9 0
Second Printing June 2003
Library of Congress Cataloging-in-Publication Number: 2001098196
Warning and Disclaimer
This book is designed to provide information about license-free wireless wide-area networks.
Every effort has been made to make this book as complete and as accurate as possible, but no
warranty or fitness is implied.
The information is provided on an "as is" basis. The author, Cisco Press, and Cisco Systems, Inc.
shall have neither liability nor responsibility to any person or entity with respect to any loss or
damages arising from the information contained in this book or from the use of the discs or
programs that may accompany it.
The opinions expressed in this book belong to the author and are not necessarily those of Cisco
Systems, Inc.
Trademark Acknowledgments
All terms mentioned in this book that are known to be trademarks or service marks have been
appropriately capitalized. Cisco Press or Cisco Systems, Inc. cannot attest to the accuracy of this
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At Cisco Press, our goal is to create in-depth technical books of the highest quality and value.
Each book is crafted with care and precision, undergoing rigorous development that involves the
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Readers' feedback is a natural continuation of this process. If you have any comments regardinghow we could improve the quality of this book, or otherwise alter it to better suit your needs,
you can contact us through e-mail at [email protected]. Please make sure to include the
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8/14/2019 ByJack Unger
7/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
book title and ISBN in your message.
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We greatly appreciate your assistance.
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8/14/2019 ByJack Unger
8/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
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All other trademarks mentioned in this document or Web site are the property of their respective
owners. The use of the word partner does not imply a partnership relationship between Cisco
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8/14/2019 ByJack Unger
9/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
and any other company. (0303R)
Printed in the USA
Dedications
I dedicate this book to my mother, Virginia Blossom Kaufman-Unger-London and to my father,Milton Unger. Thank you both for loving me unconditionally.
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8/14/2019 ByJack Unger
10/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
About the Author
Jack Unger, the founder and president of Wireless InfoNet, Inc., is a pioneer in the broadband
fixed-wireless industry. Since founding Wireless InfoNet in 1993, he has personally designed and
installed hundreds of license-free outdoor broadband wireless network sites and consulted on
countless others. In 1995, he designed and deployed one of the world's first public outdoorwireless Internet access points-of-presence. This wireless POP is still in service today in Palo
Alto, California. In 2001, based on his wireless ISP experiences, Jack created the world's first
vendor-neutral wireless ISP training seminar. To date, in this seminar, he has personally trained
more than 800 ISP personnel across the United States.
Prior to founding Wireless InfoNet, Jack worked for 14 years in the Silicon Valley
telecommunications industry for ROLM, IBM, Siemens, and NEC. Prior to that, Jack worked for 7
years selling wireless communications equipment, including television and radio station
broadcast equipment. He has a total of 45 years of wireless experience since his "initiation" into
the wireless world as an amateur radio operator at the age of 11. Jack has received A.A., A.S.,
and B.A. degrees and has completed extensive work in the U.C. Berkeley Extension
Telecommunications Engineering Program. He holds FCC Amateur Extra and GeneralRadiotelephone licenses as well as an FAA Private Pilot license. He also served as a volunteer
firefighter for 11 years in the mountains of Santa Cruz County, California.
Jack is an experienced technical writer who has written numerous telecommunications hardware
and software manuals and close to 100 Cisco IOS Release Notes for the Cisco 2600, 3600, 3810,
4000, and IAD2420 router product lines. Deploying License-Free Wireless Wide-Area Networks isthe industry's first book written specifically to help wireless ISPs and corporate IT department
personnel successfully deploy outdoor, license-free, wireless WANs and broadband wireless
Internet access. Jack welcomes your comments, suggestions, corrections, and questions via e-mail. You are invited to contact him at [email protected].
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11/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
About the Technical Reviewers
Jim Geier is the founder and principal consultant of Wireless-Nets, Ltd., a consulting firm that
assists companies with the development and deployment of wireless LAN products and systems.
His 20 years of experience includes the analysis, design, software development, installation, and
support of numerous client/server and wireless network-based systems for retail, manufacturing,warehousing, healthcare, and airline industries throughout the world. Jim is the author of
several books: 802.11 Unleashed,Wireless LANs,Wireless Networking Handbook, and NetworkReengineering, as well as numerous articles. He is a voting member within the Wireless Ethernet
Compatibility Alliance (WECA), responsible for certifying interoperability of 802.11 (Wi-Fi)
wireless LANs. He served as chairman of the Institute of Electrical and Electronic Engineers
(IEEE) Computer Society, Dayton Section, and chairman of the IEEE International Conference on
Wireless LAN Implementation. He has been an active member of the IEEE 802.11 Working
Group, responsible for developing international standards for wireless LANs. Jim's educationincludes B.A. and M.A. degrees in electrical engineering and an M.A. degree in business
administration. You can contact Jim [email protected] or visit his website atwww.wireless-nets.com.
H. Paul Shuch, Ph.D. is the aerospace engineer who is credited with designing the world's first
commercial home satellite TV receiver. Paul has served as executive director of the grassroots,
nonprofit SETI League, Inc. since its inception eight years ago.
The author of more than 300 publications, Paul holds a Ph.D. degree in engineering from the
University of California, Berkeley and has taught on various campuses for 30 years. His teaching
and research have won several international awards. Paul is a Fellow of the Radio Club of
America and a Fellow of the British Interplanetary Society; he has served on the boards of
directors of several nonprofit organizations.
A licensed commercial pilot and instrument flight instructor, Paul serves as an accident
prevention counselor for the FAA, as a military program evaluator for the American Council onEducation, and as a lecturer for the Air Safety Foundation. He is listed in Who's Who in Aviation
and Aerospace,Who's Who in California,Who's Who of American Inventors,Who's Who inScience and Engineering,American Men and Women of Science,Who's Who in Amer icanEducation , and the International Directory of Distinguished Leadership.
Paul lives on a radio-quiet hilltop in central Pennsylvania with his biologist wife, five of their
seven recombinant DNA experiments, three motorcycles, two radio telescopes, and an antique
MG-TD. He can be found on the web at http://drseti.com.
Jack Unger, the author of this book, is Paul's former student, former employee, fellow radio
amateur, and lifelong friend.
http://drseti.com/ -
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Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
Acknowledgments
Literally thousands of people have made indirect contributions to this book.
First, thanks to all of my public school teachers (from kindergarten through college) who
patiently helped me, encouraged me, and taught me how to learn. Next, thanks to the manymembers of the amateur radio community who showed me how to actually make wireless
equipment work. Further, I extend my thanks to the many members of the wireless ISP
community who shared their experiences and their ideas with me. Next, thanks to my
colleagues, J.V. Rudnick, Bob Fike, and Phil Marcelis, who many times showed me a better way
to erect an antenna, route a cable, or configure a wireless router. Last but certainly not least, I'd
like to thank my Cisco Press editors, Michelle Grandin and Christopher Cleveland, and my
technical reviewers, Dr. Paul Shuch, Jim Geier, and Greg DesBrisay, for graciously contributing
their energy, their experience, and their knowledge to this book.
Finally, allow me to make a gentle request of you, the reader. If you find this book helps you to
learn more about and to experience the magic of wireless, please feel free to generously pass
your new learning along to others who share your interest in wireless.
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8/14/2019 ByJack Unger
13/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
Sample of Physical Site Survey Data Form
Surveyor Name Phone/ E-Mail
Site Address Site Owner Site Manager Phone/ E-Mail
Facility Manager Phone/ E-Mail
Existing W ireless Equipment Existing Antenna L ocations
New Equipment Location Power Source
Path Length Fresnel Zone Clearance
Roof Height Roof Access Location
Antenna Location Antenna Height AboveGround
Antenna Mounting Hardw are
Needed Antenna Heading/ Tilt
Nearby Obstructions Distant Obstructions
Cable Type and Length Cable Entry Point
Cable Rou te
Grounding Locations (Mast and
Building Entrance)
Ground Wire Route (Mast and
Building Entrance)
Lightning Protection Description Lightning P rotection Location
Site Evaluation Good Acceptab le Not
Acceptable
Comments and
Recommendations
Follow-Up Is sues
Drawings Attached
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15/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
Who This Book Is For
This book is for you, if you
Find yourself intrigued by the magic of wireless
Want to advance your knowledge and want to learn practical wireless networking skills
Want to advance in your career and in the wireless field
Are interested in providing broadband wireless service to others in their community
Want to save money, have fun, and be creative
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16/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
How to Use This Book
The chapters in the book are arranged in a logical order. If you have never been exposed to
wireless ("exposed to wireless" "radio-active"you get it?), you can start reading at Chapter1 and read right through to Chapter 9. On the other hand, if you just want to look up oneparticular topic, use the index or the table of contents, locate the topic, and go directly to that
page or chapter. Here are the topics covered by each chapter:
Chapter 1, "An Introduction to Broadband License-Free Wireless Wide-Area Networking,"presents basic broadband wireless terminology and history. It outlines the advantages and
the challenges of working with outdoor networks. Finally, it discusses the safety issues that
you need to address.
Chapter 2, "Understanding Wireless Fundamentals," helps you understand wirelessfundamentals. Even if you have never worked with wireless before, you can be successful if
you take the time to learn these fundamentals.
Chapter 3, "Choosing Your Network Architecture," describes the four basic wireless networkarchitectures, including the advantages and disadvantages of each architecture.
Chapter 4, "Performing Site Surveys," discusses physical site surveys and wireless sitesurveys. Site surveys are an important step in building a reliable wireless network.
Chapter 5, "Selecting Antenna Systems," describes how antennas work and how to usethem. Proper antenna selection and use is vital to successful wireless WAN operation.
Chapter 6, "Evaluating and Selecting Wireless Equipment," helps you to understand therange of features available in wireless equipment. When you understand the features and
how they determine your network capabilities, you can select the best equipment for your
network.
Chapter 7, "Installing Outdoor Wireless Systems," explains the techniques to safely install,ground, and test your outdoor wireless systems.
Chapter 8, "Solving Noise and Interference Problems," discusses the causes of noise andinterference and explains the techniques that you can use to minimize noise and
interference problems. This chapter also provides some suggestions about how you can
cooperate and coordinate with other wireless network operators to reduce interference
between your networks.
Chapter 9, "Providing Broadband Wireless Internet Access," provides extra tips andtechniques for those of you who want to be wireless Internet Service Providers (WISPs) and
provide wireless Internet access service to your communities.
Appendix A, "Wireless Standards Summary," provides a summary table of the 802.11standards. It also includes related standards, such as 802.1x and 802.16.
Appendix B, "Wireless Hardware, Software, and Service Provider Organizations," contains alisting of organizations that provide wireless hardware, software, peripherals, and services.
Appendix C, "Answers to Chapter Review Questions," provides answers to the reviewquestions that appear at the end ofChapters 1 through 9.
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17/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
Chapter 1. An Introduction to BroadbandLicense-Free Wireless Wide-AreaNetworking
This chapter introduces broadband wireless networking terms, summarizes license-free wireless
history, and describes both the advantages and the challenges of deploying license-free wireless
wide-area networks (WANs).
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18/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
Differences Between Wired Networks and Wireless
Networks
Most of the time, users of a broadband wireless network do not experience a difference between
using a wireless network and using a wired network. Your experiences as you design and build a
wireless network, however, will be quite different compared to your experiences when youdesign and install a wired network. Table 1-1 summarizes the differences that you need to beaware of.
Tab le 1-1. Differences Between Wired and W ireless Networks
Network
Characteristic
Wired Network Wireless Network
Visualdetermination ofnetwork
connectivity
If you can see the network cable
going to a location, that location
can be connected to the network.
Wireless networks sometimes
connect locations that you cannot
visibly see. Additionally, wireless
networksmight not connectlocations that you can see visibly.
Visibility node-to-node on the same
network
All of the nodes on a wired
network can hear all other nodes.
Many nodes on a wireless network
cannot hear all of the other wireless
nodes on the same network.
Visibility network-to-network
Wired networks are invisible to
other wired networks. The
presence of one wired network hasno effect on the performance of
another wired network.
Wireless networks are often visible
to other wireless networks. One
wireless network can affect theperformance of other wirelessnetworks.
Atmosphericproperties
Wired network performance is not
affected by the properties of the
atmosphere.
Wireless network performance can
be affected by the properties of the
atmosphere.
Terrain properties Wired network performance is notaffected by the properties of the
earth's terrain.
Wireless network performance is
strongly affected by the properties ofthe earth's terrain.
User connectivity
and mobility
Connectivity is possible only to or
from those physical locationswhere the network cablingextends.
Connectivity is possible beyond the
bounds of physical network cabling.
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19/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
Wireless Terminology and Evolution
Today, you can design and build wireless networks that possess three characteristics that were
not available in the past. These characteristics are broadband capability, wide-area coverage,
and license-free operation. The definition of these terms is somewhat vague; therefore, it is
important to define the terms clearly. The following sections provide these definitions as well as
some wireless history.
Broadband
Broadband is a subjective term that has been used in various ways throughout the
communications industry. Broadband is used when new communications technologies are
developed that provide enough additional bandwidth for the user experience to feel substantially
faster than it felt before.
Most Internet users today have experienced dialing into the Internet at bandwidths ranging from
28,800 bits per second (28.8 kbps) up to 56,000 bits per second (56 kbps). They perceive afaster Internet connection, such as a 1.5 million bit per second (1.5 Mbps) connection, as a
broadband connection.
Some users have access to the Internet using a web browser on a cell phone. Their connection
bandwidth ranges from 9.6 kbps to 14.4 kbps. Comparing the cell phone connection speed to a
dialup 28.8-kbps connection, the cell phone connection feels slow. It certainly doesn't feel like
broadband; in fact, it feels like "narrowband."
For the remainder of this book, any wireless connection that has a bandwidth of 128,000 bits per
second (128 kbps) will be defined as broadband. Given the Internet experiences of users who
have either browsed the Internet using a cell phone or dialed into the Internet, a 128-kbps
connection is perceived as broadband.
Wide-Area Network
There is no absolute line between the definition of a local-area network (LAN) and the definition
of a wide-area network (WAN). Both terms have been used somewhat loosely. Here's how this
book defines them:
LA N A network that connects stations contained within a single building
WAN A network that connects stations located in different buildings or in different partsof a city
NOTE
Some books use the term MAN to indicate a metropolitan-area network or, in other
words, a citywide network. This book refers to a citywide network as a WAN.
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20/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
History of License-Free Wireless Networking
The purpose of this book is to help you deploy broadband wireless WANs without needing to
apply to the Federal Communications Commission (FCC) for a license. The following sections
provide a historical overview of some of the events that led to the present privilege of using
some broadband wireless equipment without needing to obtain a license.
History of Wireless Licensing
Wireless technology has passed through several regulatory phases during its history. In the late
1800s and early 1900s, there were many wireless scientists, experimenters, and hobbyists. In
these early days, transmitting distances were limited and population density was low; it was
unnecessary to require a license for transmitting. As more wireless stations came on the air,
interference between stations became a serious problem. In 1921, the United States government
began requiring licenses for all transmitters, including commercial broadcast transmitters,
experimental transmitters, and amateur radio transmitters.
Radio system usage continued to grow rapidly during the remainder of the 20th century. The
U.S. government continued to regulate radio transmissions and to license radio transmitters.
These licensing regulations played a useful role because they allowed many different radio
systems to share the available radio frequencies without interfering with each other.
The downside to governmental regulation was that it took both time and money to obtain a
license to transmit on a specific frequency. This limited the use of broadband wireless equipment
to those companies or individuals who could afford the cost of obtaining the FCC license and
purchasing the rather expensive wireless equipment.
In 1985, the U.S. Federal Communications Commission (FCC) issued regulations that, for the
first time, allowed the use of broadband wireless transmitting equipment without the need to
apply for, pay for, and wait for a license. To operate license free, the wireless equipment had to
do the following:
Operate at low power levels
Use spread spectrum modulation
Transmit within three specified frequency bands
Broadband license-free wireless equipment began to be manufactured and sold at a much lower
cost than the licensed broadband wireless equipment.
Table 1-2 provides an outline of the wireless events that led full-circle from the days whenlicensing was not required, to the days when licensing was required, to today, when broadband
wireless equipment can be deployed license free.
Table 1-2. Brief History of Wire less Development
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21/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
Year Event
1600 Dr. Will iam Gilbert detects electromagnetic activity in the human body and describes itas "electricity."
1837 Samuel F.B. Morse invents the Morse telegraph and sends messages over wires by usingMorse code.
1865 Scientists, inventors, and hobbyists begin performing experiments with wireless.
1867 Scottish mathematician and physicist James Clerk Maxwell develops the theory thatpredicts the existence of electro-magnetic waves.
1886 German physicist Heinrich Hertz is the first person to demonstrate the existence ofelectromagnetic waves as predicted by James Clerk Maxwell.
1896 Italian Guglielmo Marconi demonstrates electric-wave telegraphy.
1901 Marconi transmits the letter "s" in Morse code across the Atlantic Ocean from England toCanada.
1906 Professor Reginald Fessenden broadcasts voice and music in Massachusetts.
1910 The U.S. government requires all ships to be equipped with a wireless telegraph.1912 The "unsinkable" Titanic ocean liner sinks after striking an iceberg in the North Atlantic.
The wireless telegraph is used to summon help from other ships in the area.
1912 The regulation of radio broadcasting is started by the U.S. Department of Commerce,Bureau of Navigation. Transmitting stations simply had to supply the government with a
description of their transmitting equipment.
1912 Radio station KQW makes frequent broadcasts from San Jose, California.
1920 Radio station KDKA begins regular commercial broadcasting from Pittsburgh,Pennsylvania.
1921 The U.S. government requires all broadcasting stations to apply for a broadcastinglicense.
1927 The responsibility for regulating radio transmission is transferred to the Federal RadioCommission.
1934 The Communications Act of 1934 establishes the FCC. The responsibility for regulatingradio transmission is transferred to the FCC.
1985 The FCC authorizes license-free spread spectrum transmission in three industrial,scientific, and medical (ISM) bands at 900 megahertz (MHz), 2.4 gigahertz (GHz), and
5.8 GHz. Maximum legal transmitter output power is 1 watt (1W).
1994 The FCC begins using spectrum auctions. Corporations bid hundreds of thousands tomillions of dollars to buy the right to use specific wireless frequency bands.
1997 The FCC authorizes license-free transmission in three 5.1 to 5.8 GHz Unlicensed-National Information Infrastructure (U-NII) subbands. Maximum legal transmitter
output power ranges from 50 milliwatts (50 mW) to 1 W.
History of Spread Spectrum
Modulation is the process of adding information or intelligence to a wireless signal.
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Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
NOTE
In the wireless world, the term intelligence sometimes has no discernable relationship
to the process of using one's brain to make a wise decision.
A modulated wireless signal carries intelligence to the receiver where the intelligence is removed
and used. The intelligence might be voice, music, data, or video. For example, the process of
amplitude modu lation adds voice and music to AM broadcast station signals. The process of
frequency modulation adds voice and music to FM broadcast station signals. The process of
spread spectrum modu lation adds data to broadband license-free wireless signals.
The development of spread spectrum modulation began during World War II. Hedy Lamar (the
actress) is credited for inventing spread spectrum modulation. The story goes that she was
opposed to the actions of the German military during the war and decided to find a way to
transmit and receive messages that would remain undetected by the German military. She
devised the spread-spectrum principle of frequency hopping. Frequency hopping changes the
transmitter frequency rapidly to prevent the transmitted messages from being detected byanyone except the person intended to receive the messages. The spread spectrum receiver
knows the proper sequence of frequency changes and follows them to decode (demodulate) the
transmitted message.
Two different types of spread spectrum modulation are in general use today, both of which
spread the signal out over a broad band of frequencies:
Frequency hopp ing spread spectrum (FHSS) Changes frequency from 8 to 32 times
each second
Direct sequence spread spectrum (DSSS) Stays on one center frequency but spreadsout the signal at low power over a wide frequency band
The resulting transmitted signal simply looks like weak noise. Only a receiver that knows how to
despread the signal can demodulate it and recover the original intelligence.
Development of License-Free Spread Spectrum
Prior to 1985, the FCC permitted low power, short-range devices such as baby monitors and
garage door openers to operate license free. These devices operated indoors or with short-range
transmitters and did not cause interference problems with other wireless systems. In 1985, the
FCC considered the following points and then decided to allow the operation of license-freespread spectrum systems:
Spread spectrum signals spread their wireless energy over the frequency spectrum rather
than concentrating it all on one frequency. By spreading out the energy, the signals are lesslikely to cause interference to other spread spectrum and non-spread spectrum systems.
Spread spectrum signals are less susceptible to being inter fered with than non-spreadspectrum signals.
Low power spread spectrum transmitters operating in the ISM bands will be limited to line-
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8/14/2019 ByJack Unger
23/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
of-sight operation. The signals will not carry very far; therefore, many spread spectrum
systems can operate in the same general area without causing significant interference to
each other.
Many spread spectrum systems will be used indoors. The building walls will absorb much of
the wireless energy before it can go very far and cause interference problems.
The first license-free spread spectrum wireless systems were short-range, indoor LANs. These
systems were used for applications such as retail price marking and inventory management.
Next, wireless equipment manufacturers began to offer spread spectrum equipment with
improved antenna systems that could be used for longer-distance outdoor point-to-point links
between buildings. These outdoor links offered a low-cost alternative to the expensive leased-line connections offered by the local telephone companies. Soon, cities, school districts, and
corporations began to use this outdoor equipment in point-to-multipoint network configurations.
By 1995, the first few Internet service providers (ISPs) began to use the technology to provide
license-free broadband wireless Internet access to the public. The era of the license-free
broadband wireless WAN had begun.
NOTE
Although spread spectrum systems are unlicensed, it does not mean that they areunregulated. The FCC specifies the rules and regulations that govern the manufacture
of spread spectrum systems. Equipment manufacturers are responsible for
manufacturing equipment that complies with the FCC regulations. Equipment installers
are responsible for installing the wireless equipment properly so that it does not violate
FCC regulations.
License-Free Wireless Frequencies
In 1985, the FCC authorized the use of license-free spread spectrum wireless equipment in the
following three ISM bands in the United States:
900 to 928 MHz (900 MHz range)
2.4 to 2.483 GHz (2.4 GHz range)
5.725 to 5.850 GHz (5 GHz range)
Further, in 1997, the FCC authorized the use of license-free low-power non-spread-spectrum
wireless equipment in the following three U-NII bands:
5.15 to 5.25 GHz
5.25 to 5.35 GHz
5.725 to 5.825 GHz
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8/14/2019 ByJack Unger
24/399
Table of Contents
IndexDeploying License-Free W ireless Wide-Area Networks
ByJackUnger
Publisher: Cisco Press
Pub Date: February 26, 2003
ISBN: 1-58705-069-2
Pages: 352
Best practices for planning and deployment of broadband WWANs.
Learn insider tips from an experienced wireless industry leader
Understand the principles that underlie the operation of all wireless systems
Learn how to provide profitable and reliable wireless Internet access
Select the most effective equipment and antenna systems for your area
Avoid common pitfalls encountered by new wireless network operators
Minimize the effects of noise and interference on your network
Enjoy the satisfaction of providing wireless Internet access to your community
Practice the business principles used by successful wireless ISPs (WISPs)
Use 802.11a, 802.11b, and 802.11g equipment more successfully in your own home, office,
or outdoor environment
Choose the right network architecture for your wireless network
Conduct physical site surveys and radio-frequency (RF) site surveys
License-free broadband wireless wide-area networks (WWANs) provide fast deployment of low-
cost, high-speed "last-mile" wireless Internet access. License-free wireless technology delivers
these benefits without requiring the use of products or services provided by local telephone or
cable companies. WWANs enable Internet service providers (ISPs) and corporate IT managers to
deploy their own cost-efficient broadband networks that deliver high-speed access for buildings
and areas where traditional wired connectivity is either completely unavailable or is cost-
prohibitive.Deploying License-Free Wireless Wide-Area Networks is the first book that providescomplete, real-world "start-to-finish" design, installation, operation, and support information for
wireless ISPs and other organizations deploying outdoor wireless WANs-including coverage of
802.11a, 802.11b, 802.11g, and proprietary-protocol networks. This vendor-neutral book covers
Advantages of License-Free Wireless Networks
Following are the advantages of deploying a license-free broadband wireless WAN:
Cost savings
Fast deployment speed
Network architecture flexi