CWTS E-Book

Robert J. Bartz

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 629

Veröffentlichungsjahr: 2010

Beschreibung

About the BookThis Official Study Guide for the CWTS exam features completecoverage of the exam objectives, as well as hands-on exercises,Real World Scenarios, chapter review questions, a detailedglossary, objective map, and a pre-assessment test. The enhanced CDincludes two bonus exams, 150 flashcards, Case Studies, and demosoftware.Exam coverage includes:* Wi-Fi Technology, Standards, and Certifications* Hardware and Software* Radio Frequency (RF) Fundamentals* Site Surveying and Installation* Applications, Support, and Troubleshooting* Security & ComplianceAbout the CWTS CertificationThe Certified Wireless Technology Specialist (CWTS) is avendor-neutral certification administered by CWNP. This brand newcertification is the only entry-level vendor neutral wirelesscertification for IT Professionals, and was developed for ITsupport staff who work with wireless technologies. It is aspringboard to the foundation-level Certified Wireless NetworkAdministrator (CWNA), and more advanced Certified Wireless SecurityProfessional (CWSP) and Certified Wireless Network Expert (CWNE)certifications. The exam is offered in over 100 countries throughboth Prometric and Pearson VUE testing centers. The cost of theexam is $125.Note: CD-ROM materials for eBook purchases can bedownloaded from CWNP's website at www.cwnp.com/sybex

Leseprobe

Table of Contents

Title Page

Copyright Page

Dedication

Acknowledgments

About the Author

List of Tables

Foreword

Introduction

About CWNP

CWNP Learning Resources

How to Become a CWTS

Who Should Buy this Book?

How to Use this Book and the CD

Exam Objectives

CWNP Exam Terminology

Assessment Test

Answers to Assessment Test

Chapter 1 - Introduction to Wireless Local Area Networking

Common WLAN Deployment Scenarios

Radio Frequency Regulatory Domain Governing Bodies

IEEE and Wireless LAN Standards

Interoperability Certifications

Summary

Key Terms

Exam Essentials

Review Questions

Answers to Review Questions

Chapter 2 - Wireless LAN Infrastructure Devices

OSI Model Basics

Access Points (AP)

Power over Ethernet (PoE)

Summary

Exam Essentials

Key Terms

Review Questions

Answers to Review Questions

Chapter 3 - Wireless LAN Client Devices

PCMCIA

ExpressCard

USB 1.0, USB 1.1, and USB 2.0

CompactFlash (CF) Devices

Secure Digital (SD)

Peripheral Component Interconnect (PCI)

Mini-PCI and Mini-PCIe (Mini-PCI Express)

Workgroup Bridges

Client Device Drivers

Client Utility Software

Summary

Exam Essentials

Key Terms

Review Questions

Answers to Review Questions

Chapter 4 - Radio Frequency (RF) Fundamentals for Wireless LAN Technology

Understanding Radio Frequency (RF)

Coverage and Capacity

RF Range and Speed

Basic Units of RF Measurement

Summary

Exam Essentials

Key Terms

Review Questions

Answers to Review Questions

Chapter 5 - Access Methods, Architectures, and Spread Spectrum Technology

Network Access Methods

Spread Spectrum Technology

Summary

Exam Essentials

Key Terms

Review Questions

Answers to Review Questions

Chapter 6 - WLAN Antennas and Accessories

Basic RF Antenna Concepts

WLAN Antenna Types

RF Cables and Connectors

Factors in Antenna Installation

Combating Effects of Wind and Lightning on Wireless Connections

Installation Safety

Antenna Mounting

Maintaining Clear Communications

Summary

Exam Essentials

Key Terms

Review Questions

Answers to Review Questions

Chapter 7 - WLAN Terminology and Technology

Wireless LAN Modes of Operation

Connecting to a Wireless Network

Distribution System (DS)

Data Rates

Throughput

Dynamic Rate Switching (DRS)

WLAN Roaming

Power Saving Operation

Protection Mechanisms

Summary

Exam Essentials

Key Terms

Review Questions

Answers to Review Questions

Chapter 8 - Planning a WLAN Site Survey

Wireless LAN Site Surveys

Gathering Business Requirements

Interviewing Managers and Users

Defining Physical and Data Security Requirements

Gathering Site-Specific Documentation

Documenting Existing Network Characteristics

Identifying Infrastructure Connectivity and Power Requirements

Understanding RF Coverage and Capacity Requirements

Client Connectivity Requirements

Antenna Use Consideration

Summary

Exam Essentials

Key Terms

Review Questions

Answers to Review Questions

Chapter 9 - Performing a WLAN Site Survey

The Physical Site Survey Process

RF Spectrum Analysis

Performing a Manual Site Survey

Performing a Predictive Site Survey

Protocol Analysis

Documenting Existing Network Characteristics

RF Coverage Requirements

Infrastructure Hardware Selection and Placement

Infrastructure Connectivity and Power Requirements

Received Signal Strength

Antenna Use Considerations

Channel Architectures

Installation Limitations

Site Survey Report

Summary

Exam Essentials

Key Terms

Review Questions

Answers to Review Questions

Chapter 10 - WLAN Security

Introduction to Wireless Security

Wireless LAN Threats and Intrusion

IEEE 802.11 Standards Security

Early WLAN Security Mechanisms

Authentication and Encryption

SOHO and Enterprise Security Solutions

PIN-Based or Push-Button Configuration (PBC) Wireless Security

Passphrase-Based Security

User-Based Security

Encryption: WEP/TKIP/CCMP

Role-Based Access Control (RBAC)

Virtual Private Networking (VPN)

Wireless Intrusion Prevention Systems (WIPS)

Regulatory Compliance

Summary

Exam Essentials

Key Terms

Review Questions

Answers to Review Questions

Chapter 11 - Troubleshooting and Maintaining Wireless Networks

Identifying Wireless LAN Problems

Optimizing Wireless Networks

Summary

Exam Essentials

Key Terms

Review Questions

Answers to Review Questions

Appendix - About the Companion CD

Glossary

Index

CWTS: Certified Wireless Technology Specialist Official Study Guide

List of Tables

TABLE 1.1 ITU-R Regions, Geographic Locations and Website URLs

TABLE 1.2 Summary of 802.11 Communications Standards and Amendments

TABLE 1.3 DETAILS OF THE WPA AND WPA 2.0 CERTIFICATIONS

TABLE 2.1 Classes of Powered Device Described in the PoE amendment to the Ethernet standard, 802.3-2005 clause 33.

TABLE 3.1 Features of the Three Types of PCMCIA Card

TABLE 3.2 Characteristics and Uses of CF Cards

TABLE 3.3 Features of Mini-PCI and Mini-PCIe Cards

TABLE 4.1 Typical Radio Transmission Wavelengths for WLANs

TABLE 4.2 Local RF Regulatory Bodies

TABLE 4.3 IEEE 802.11 Frequency and Channel Allocations

TABLE 4.4 Absolute and Relative Measures of Power

TABLE 5.1 2.4 GHz ISM Band Consists of 14 Available Channels

TABLE 5.2 5 GHz UNII Band Channels

TABLE 6.1 Omnidirectional Antenna Specifications

TABLE 6.2 Flat Patch Antenna Specifications

TABLE 6.3 90° Sector Panel WLAN Antenna Specifications

TABLE 6.4 15 dBi Yagi Antenna Specifications

TABLE 6.5 2.4 GHz 30 dBi Grid Parabolic Dish Antenna Specifications

TABLE 7.1 DATA RATES BASED ON SPREAD SPECTRUM TYPE

TABLE 9.1 Examples of Minimum Received Signal Strengths Required for Specific Data Rates

TABLE 10.1 Features of the Two Types of WEP Keys

TABLE 10.2 Details of the WPA and WPA 2.0 Certifications

Acquisitions Editor: Jeff Kellum Development Editor: Stef Jones Technical Editors: Bryan Harkins and Marcus Burton Production Editor: Rachel McConlogue Copy Editor: Lunaea Hougland Production Manager: Tim Tate Vice President and Executive Group Publisher: Richard Swadley Vice President and Publisher: Neil Edde Media Project Manager 1: Laura Moss-Hollister Media Associate Producer: Angie Denny Media Quality Assurance: Josh Frank Book Designers: Judy Fung and Bill Gibson Compositor: Craig W. Johnson, Happenstance Type-O-Rama Proofreader: Publication Services, Inc. Indexer: Nancy Guenther Project Coordinator, Cover: Lynsey Stanford Cover Designer: Ryan Sneed

Copyright © 2009 by Wiley Publishing, Inc., Indianapolis, Indiana

Published simultaneously in Canada

ISBN: 978-0-470-43889-3

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Library of Congress Cataloging-in-Publication Data

Bartz, Robert J., 1959-

p. cm.

1. Wireless LANs—Examinations—Study guides. 2. Telecommunications engineers—Certification—Study guides. I. Title. II. Title: Certified wireless technology specialist official study guide (PW0-070).

TK5105.78.B37 2009

621.384076—dc22

2009010840

TRADEMARKS: Wiley, the Wiley logo, and the Sybex logo are trademarks or registered trademarks of John Wiley & Sons, Inc. and/or its affiliates, in the United States and other countries, and may not be used without written permission. CWTS is a trademark of CWNP, Inc. All other trademarks are the property of their respective owners. Wiley Publishing, Inc., is not associated with any product or vendor mentioned in this book.

Dear Reader,

Thank you for choosing CWTS: Certified Wireless Technology Specialist Official Study Guide. This book is part of a family of premium-quality Sybex books, all of which are written by outstanding authors who combine practical experience with a gift for teaching.

Sybex was founded in 1976. More than thirty years later, we’re still committed to producing consistently exceptional books. With each of our titles we’re working hard to set a new standard for the industry. From the paper we print on to the authors we work with, our goal is to bring you the best books available.

I hope you see all that reflected in these pages. I’d be very interested to hear your comments and get your feedback on how we’re doing. Feel free to let me know what you think about this or any other Sybex book by sending me an email at [email protected], or if you think you’ve found a technical error in this book, please visit http://sybex.custhelp.com. Customer feedback is critical to our efforts at Sybex.

Best regards,

Neil Edde Vice President and Publisher Sybex, an Imprint of Wiley

To my mother Kathryn, who taught me and my 11 brothers and sisters the meaning of hard work, honesty, and loyalty. At 86 years young she is still a great inspiration to me. I want to say thanks, Mom.

Acknowledgments

I would like to thank my wife, Jeannie, and two young adult children, Ashley and Jason, and to say how much I appreciate the support I received during the writing process of this book. This book was a huge task that took hundreds of hours and kept me locked away for days at a time. They made completing this project much easier for me because of their support, patience, and understanding.

I would also like to thank all the people at Sybex who helped with the creation of this book, including Acquisitions Editor Jeff Kellum, Production Editor Rachel McConlogue, Copy Editor Lunaea Hougland, Editorial Assistant Connor O’Brien and Editorial Manager Pete Gaughan. I owe all these individuals a ton of gratitude for their patience while working with me on this project, including having to deal with a few unexpected delays.

A very special thanks goes to the Development Editor Stef Jones for all her hard work in helping me with the editing, organization, and suggestions that allowed me to complete this book and still maintain my sanity. Her knowledge, expertise, and attention to detail were an enormous help to me.

The Technical Editor of this book is Bryan Harkins. I want to thank Bryan for his timely reviews, comments, and suggestions that helped make this book a valuable reference source for sales and technical support people. His years of experience as a technical trainer, engineer, and security specialist were a great contribution in creating a book I hope you will enjoy reading.

I would like to thank the thousands of students who have taken the time to attend the networking classes I was given the opportunity to teach. Educating, mentoring, and entertaining so many of these individuals gave me the inspiration and motivation to author this book.

Of course, this book would not exist if it were not for the people at CWNP. This group of individuals I have known for many years includes Kevin Sandlin, Scott Williams, Devin Akin, and Scott Turner as well as some of the newer members of the team, Cary Chandler, Marcus Burton, Trish Bruce, Abbey Cole, and all the others. They have realized the need for vendor-neutral wireless LAN training and certification and have done a great job of building a brand over the years that is now known worldwide.

Finally, a thank you to all the manufacturers, vendors, organizations, and individuals that provided the subject matter, allowing me the technology and tools needed to write this book.

Aerohive -www.aerohive.comStephen Philip and Adam Conway AirMagnet -www.airmagnet.comJoe Kuo and Dilip Advani Aruba Networks -www.arubanetworks.comBrad Day and Michael Tennefoss Broadcom Corporation -www.broadcom.comCisco Systems -www.cisco.comCompactFlash Association -www.compactflash.orgCWNP -www.cwnp.comDevin Akin and Marcus Burton HP ProCurve (Colubris Networks) -www.procurve.comIEEE -www.ieee.orgIntel -www.intel.comL-com Global Connectivity -www.l-com.comJim Corcoran Linksys -www.linksys.comMetaGeek -www.metageek.netMark Jensen and Ryan Woodings Motorola -www.motorola.comTim Brophy and Bryan Harkins Netgear -www.netgear.comNetwork Stumbler -www.netstumbler.comPCI-SIG -www.pcisig.comPCMCIA Association -www.pcmcia.orgMary Hain, Hain Communications Proxim Wireless -www.orinocowireless.comPsiber Data Systems -www.psiber.comBruce Nelson SD Association -www.sdcard.orgTamoSoft -www.tamos.comMichael Berg TerraWave Solutions -www.terrawave.comJennifer Haltom Trapeze Networks -www.trapezenetworks.comUSB Implementers Forum, Inc. -www.usb.orgWi-Fi Alliance -www.wi-fi.orgWildPackets -www.wildpackets.comXirrus -www.xirrus.comDouglas Haider

About the Author

Robert Bartz is a technical trainer and computer networking consultant. He is a graduate of California State University Long Beach, School of Engineering, with a Bachelor of Science degree in Industrial Technology. Prior to becoming a computer networking engineer and trainer, Robert was employed as an aerospace test engineer working with radar systems and satellite communications. He has attained many technical certifications over the years, including Master Certified Novell Engineer (MCNE), Certified Novell Instructor (CNI), Microsoft Certified Systems Engineer (MCSE), Microsoft Certified Trainer (MCT), CWNP Certified Wireless Network Administrator (CWNA), Certified Wireless Security Professional (CWSP), and Certified Wireless Network Trainer (CWNT), to name a few. He has been involved with the CWNP program since its inception and has taught this technology to thousands of people from various industries and markets across the United States and abroad.

Robert is the founder of Eight-O-Two Technology Solutions, LLC, a computer networking technical training and consulting services company providing education and services to various organizations both local and around the country. He spends his spare time learning new technology, working outside, and enjoying the beauty of his surroundings at his home in Monument, Colorado. Robert hopes one day to semi-retire and be the proprietor of a neighborhood eating and drinking establishment in a warm sunny beach community. He can be contacted by e-mail at [email protected].

Foreword

Manufacturers, value added resellers (VARs), and end-user organizations are now seeing the value of training and certifying not only “techies,” but account managers, sales representatives, project managers, help desk professionals, and others with similar roles on Wi-Fi technology. For maximum ROI, it’s important that this Wi-Fi training and certification be appropriate to these specific job roles. The Wi-Fi landscape is continually changing, and keeping abreast of trends, terminology, and technology has never been more important.

With all of this change, how can an organization be sure to train and certify its people on relevant and position-appropriate material? How can an organization provide an upwardly mobile learning path should its people change positions? How can an organization be sure that the training being provided to its people will continue to be relevant should they decide to partner with a different or additional vendor? These are valid concerns faced by large organizations every day, and CWNP has the answer. CWNP’s new Certified Wireless Technology Specialist (CWTS™) certification has been targeted at these user groups with the modus operandi “what it is, not how it works.” For example, in most organizations it’s clear that a Wi-Fi account manager needs to understand what an RF site survey is and why it’s important in given circumstances, but it’s also clear why the account manager doesn’t need to understand every nuance of performing an RF site survey in order to accomplish his or her own sales functions. The same applies to a plethora of topics, from understanding Wi-Fi equipment types to Wi-Fi security.

Wi-Fi terminology is a world of confusion in and of itself, but the confusion can be greatly reduced with even a minimal amount of targeted education. It doesn’t help that marketing departments at various manufacturers create a new marketing term for every new technology offering, often changing their own terminology for the purpose of differentiation. Most technologies, devices, equipment features, architectures, and the like have industry-standard names. Such standardized naming conventions are facilitated by the IEEE, Wi-Fi Alliance, and by CWNP. For example, when implementing a single channel architecture (a term that also has various marketing terms in the industry) system, each channel is called a ________. This could be a span, stack, layer, blanket, channel, or perhaps something new in the near future. They all mean the same thing. How is the customer to compare apples-to-apples when Wi-Fi terminology is all over the map? This is where trained people make all the difference.

The book you now hold in your hand is an important step in studying for the CWTS certification. The CW TS: Certified Wireless Technology Specialist Official Study Guide covers the CWTS exam objectives step-by-step in a concise manner. It’s a no-nonsense approach to obtaining a certification that will differentiate you from your peers and help you wins sales, better support your customers, and most of all, grow in your career.

Robert Bartz has been part of the CWNP program since day 1, when in our very first class in November 2001 he sat front-left paying close attention while I was explaining RF behavior. Thereafter, he very quickly passed the CWNA exam and moved on to become one of our first instructors. He has participated in CWNP in a variety of ways over the years and has added significant value to the program as a whole. He has taught CWNP classes at every level and to diverse audiences around the globe since 2001, and it’s easy to give both Robert and his new book a big thumbs-up. I would also like to thank Sybex for producing such high-quality books for CWNP. They are a class act through and through, and we look forward to working with them more in the future. Now, what are you waiting for? Stop reading this foreword, and get on to Chapter 1. Your future in Wi-Fi awaits!

Devin Akin Chief Technology OfficerThe CWNP Program

Introduction

This book is intended to provide an introduction to the exciting and emerging world of wireless LAN technology. This technology continues to expand at a phenomenal pace with constant improvements in speed, reliability, and security. Reading this book will teach you the fundamentals of standards-based technology, giving you an overview of the design, communication, hardware components, and maintenance associated with wireless LAN technology, commonly referred to as Wi-Fi™.

In addition to providing an overview of the technology, this book will help you prepare for the Certified Wireless Technology Specialist (CWTS) certification exam available from the CWNP program. CWTS is an entry-level enterprise wireless LAN certification, and is recommended prior to the Certified Wireless Network Administrator (CWNA) certification. CWTS is designed as a replacement for the Wireless# Certification. This certification is geared specifically toward both wireless LAN (WLAN) sales and support staff for those in the enterprise WLAN industry.

Not only will this book help you prepare for the CWTS Certification exam, it will give you the fundamental knowledge, tools, and terminology to more effectively sell and support enterprise WLAN technologies. The main goal of this book is for you to learn “what it is,” not “how it works.” The “how” part comes later in other CWNP Study Guides and instructor-led courses. After reading this book and completing all the available practice exam tools included, you will have the knowledge needed to take the CWTS certification exam.

Finally, the CD included with this book contains evaluation software you can install in order to become familiar with RF spectrum analysis, perform some limited packet analysis, and explore site survey tools.

For more information about the CWTS and other vendor-neutral wireless LAN certifications from the CWNP program, visit www.cwnp.com.

About CWNP®

CWNP is the abbreviation for Certified Wireless Network Professional and is the industry standard for vendor-neutral, enterprise wireless LAN certifications. CWNP currently offers five levels of enterprise WLAN certifications, from novice to expert. The goal of CWNP is to provide educational resources and certifications that are recognized worldwide to information technology (IT) and sales professionals in the field of wireless networking technology. By acquiring this knowledge, these professionals will be able to enter any business and sell, design, install, manage, and support the wireless LAN infrastructure regardless of which manufacturer’s solution is used.

In addition to CWTS, there are four other wireless certifications currently offered from CWNP:

CWNA®: Certified Wireless Network Administrator The CWNA® (Certified Wireless Network Administrator) certification is the foundation-level enterprise wireless LAN certification for the CWNP program. The CWNA certification will validate one’s skills to successfully administer enterprise-class wireless LANs. Passing the CWNA exam will earn one credit toward the more advanced CWNP certifications. The CWNA exam measures one’s ability to understand the fundamentals of RF behavior and to describe the features and functions of various WLAN components. Passing the PW0-104, Wireless LAN Administration certification exam will satisfy the requirement to become CWNA certified.

CWSP®: Certified Wireless Security Professional The CWSP® (Certified Wireless Security Professional) certification is an advanced-level WLAN certification offered by the CWNP program. Acquiring this certification will prove one’s ability to successfully apply the most up-to-date wireless LAN security solutions to an organization’s wireless LAN. This certification will ensure that the successful candidate understands the security weaknesses inherent in wireless LANs, the solutions available to address those weaknesses, and the steps necessary to implement a secure and manageable wireless LAN in an enterprise environment. Successfully passing two exams is required to become CWSP certified:

• Exam PW0-104 - Wireless LAN Administration

• Exam PW0-200 - Wireless LAN Security

CWNE®: Certified Wireless Network Expert The CWNE® credential is the final certification step in the CWNP program. By successfully completing the CWNE requirements, one will have demonstrated that they have the most advanced skills available in today’s wireless LAN market. CWNE assures that the skills mastered include the ability to administer, install, configure, troubleshoot, and design wireless network systems. Additional skills include protocol analysis, intrusion detection and prevention, performance and QoS analysis, spectrum analysis, and WLAN management.

In order to become CWNE certified, one must pass the PW0-104, PW0-200, and PW0-300 exams, and hold a valid CWSP certification at the time of application for CWNE. Successfully passing these exams is not all that is required. To maintain CWNE certification, the following criteria must be met:

• Pass all three exams, PW0-104, PW0-200, and PW0-300

• Professional experience

• Three letters of endorsement

• 60 points in the CWNE points schedule

• Continuing education requirement

For additional information on the details required for CWNE certification, visit www.cwnp.com

CWNT®: Certified Wireless Network Trainer Certified Wireless Network Trainers (CWNT®) are qualified instructors certified by the CWNP program to deliver CWNP training courses to IT professionals. CWNTs are technical and instructional experts in wireless technologies, products, and solutions. CWNP Training Partners are required to use CWNTs when delivering training using Official CWNP Courseware.

To become a CWNT, the requirements include:

• Attend an official class for the CWNP level to be taught

• Pass the appropriate level exam with a minimum score of at least 80%

• A minimum of 12 months of documented IT industry training experience

CWNP Learning Resources

There are a variety of resources available from CWNP to help one learn vendor-neutral wireless LAN technology. Listed are some of these resources:

• Self-study materials

• Official study guides from Sybex

• Online practice exams from www.cwnp.com

• Instructor-led training

• Online training

• Computer-based training (CBT)

• CWNP website

• CWNP forums

• CWNP blog

• CWNP learning center, 1,000+ white papers

How to Become a CWTS

To become a CWTS, you must complete the following two steps:

• Agree that you have read and will abide by the terms and conditions of the CWNP confidentiality agreement

• Pass the CWTS PW0-070 certification exam.

A copy of the CWNP confidentiality agreement can be found online at the CWNP website.

When you take the exam, you will be required to accept the confidentiality agreement before you can continue to complete the exam. After you have agreed, you will be able to continue with the exam. When you pass the exam with a score of 70 percent or higher, you will have met the requirements to become CWTS certified.

The information for the CWTS exam is as follows:

• Exam name: Certified Wireless Technology Specialist

• Exam number: PW0-070

• Cost: $125.00 (USD)

• Duration: 90 minutes

• Questions: 60

• Question types: Multiple choice/multiple answer

• Passing score: 70 percent (80 percent for instructors)

• Available languages: English

• Renewal: None—lifetime certification. Recommended prior to CWNA.

• Availability: Register at Pearson VUE (www.vue.com/cwnp)

When you schedule the exam, you will receive instructions regarding appointment and cancellation procedures, ID requirements, and information about the testing center location. In addition, you will receive a registration and payment confirmation e-mail. Exams can be scheduled weeks in advance or, in some cases, even as late as the same day.

After you have successfully passed the CWTS exam, the CWNP program will award you the lifetime certification. If the e-mail contact information you provided the testing center is correct, you will receive an e-mail from CWNP recognizing your accomplishment and providing you with a CWNP certification number. After you earn any CWNP certification, you can request a certification kit. The kit includes a congratulatory letter, a certificate, and a wallet-sized personalized ID card. You will need to log in to the CWNP tracking system, verify your contact information, and request your certification kit.

Who Should Buy this Book?

This book is intended to provide an overview of wireless LAN technology for sales and technical support professionals. This book is written with the CWTS exam objectives in mind and “what it is,” not “how it works.” The exam objectives were designed based on the skill set the intended audience should need in order to perform their job functions or roles in an organization. One thing to keep in mind is that this book will introduce and teach you a technology, a combination of local area networking and radio frequency.

If you follow the exam objectives, perform the hands-on exercises, and utilize all the available exam questions and practice exams included with the CD and on www.cwnp.com, this book should be enough to effectively prepare you to pass the CWTS certification exam. It will also serve as a stepping-stone to more advanced books that teach the technology in more depth as well as a reference guide for the technology.

How to Use this Book and the CD

This book includes a CD-ROM with exam questions and flashcards. These are designed to test your knowledge on the information you have learned from reading the book and performing the exercises. Although there is no guarantee you will pass the certification exam if you use this book and CD, you will have the tools necessary that effectively prepare you to do so.

Before you begin At the beginning of the book (right after this introduction) is an assessment test you can use to check your readiness for the certification exam. Take this test before you start reading the book; it will help you determine the areas you may need to brush up on. The answers to the assessment test appear on a separate page after the last question of the test. Each answer includes an explanation and describes why the other options are incorrect.

Chapter review questions To test your knowledge as you progress through this book, there are review questions at the end of each chapter. As you finish each chapter, answer the review questions and then check your answers—the correct answers appear on the page following the last review question. You can go back and revisit the section that deals with each question you answered wrong to ensure that you understand the material and answer correctly the next time you are tested on that topic.

Electronic flashcards You will find flashcard questions on the CD for on-the-go review. These are short questions and answers, just like other flashcards you may be familiar with. You can answer them on your PC or download them onto a Palm device for quick and convenient reviewing.

Test engine The CD also contains the Sybex Test Engine. With this custom test engine, you can identify weak areas up front and then develop a solid studying strategy that includes each of the robust testing features described previously. The readme file on the CD will walk you through the quick, easy installation process.

In addition to the assessment test and the chapter review questions, you will find two bonus exams. Use the test engine to take these practice exams just as if you were taking the actual exam (without any reference material). When you have finished the first exam, move on to the next one to solidify your test-taking skills. After you get a high percentage of the answers correct, it is an indication you are ready to take the actual certification exam.

Labs and exercises Several chapters in this book have exercises that use evaluation software that is either provided on the CD-ROM included with this book or downloadable from the manufacturer’s website. These exercises will provide you with a broader learning experience by providing hands-on experience and step-by-step problem solving.

White papers Several wireless networking white papers are also provided on the CD-ROM included with this book or available for download. These white papers serve as additional reference material for preparing for the CWTS or other CWNP certification exams.

The CWTS Certification Exam (PWO-070) Is Based on the Exam Objectives

It is important to note that in order to pass the certification exam you should study from the currently posted exam objectives. Use this book as an learning aid to understand the exam objectives. For the most up-to-date certification exam objectives, visit the CWNP website at www.cwnp.com.

Exam Objectives

The Certified Wireless Technology Specialist (CWTS) certification, covering the current objectives, will certify that successful candidates know the fundamentals of RF behavior, can describe the features and functions of wireless components, and have the skills needed to install and configure wireless network hardware components. A typical candidate should have a basic understanding of data networking concepts.

The skills and knowledge measured by this examination are derived from a survey of wireless networking experts and professionals. The results of this survey were used in weighing the subject areas and ensuring that the weighting is representative of the relative importance of the content.

The following chart provides the breakdown of the exam, showing you the weight of each section:

Subject Area% of ExamWi-Fi Technology, Standards, and Certifications15%Hardware and Software25%Radio Frequency (RF) Fundamentals15%Site Surveying and Installation15%Applications, Support, and Troubleshooting15%Security and Compliance15%Total100%

Wireless Technologies, Standards, and Certifications—15%

1.1. Define the roles of the following organizations in providing direction and accountability within the wireless networking industry

• IEEE

• Wi-Fi Alliance

• Regulatory Domain Governing Bodies

1.2. Define basic characteristics of Wi-Fi technology

• Range, coverage, and capacity

• requencies/channels used

• Channel reuse and co-location

• Active and passive scanning

• Power saving operation

• Data rates and throughput

• Dynamic rate switching

• Authentication and association

• The distribution system and roaming

• Infrastructure and ad hoc modes

• BSSID, SSID, BSS, ESS

• Protection mechanisms

1.3. Summarize the basic attributes and advantages of the following WLAN standards, amendments, and product certifications

• Wi-Fi certification

• 802.11a

• 802.11b

• 802.11g

• 802.11n

• Wi-Fi Multimedia (WMM) certification

• WMM Power Save (WMM-PS) certification

• Wi-Fi Protected Setup (WPS) certification

• Push-button

• PIN-based

• Wi-Fi Protected Access (WPA/WPA2) certification

• Enterprise

• Personal

Hardware and Software—25%

2.1 Identify the purpose, features, and functions of the following wireless network components. Choose the appropriate installation or configuration steps in a given scenario.

• Access points

• Lightweight

• Autonomous

• Mesh

• Wireless LAN routers

• Wireless bridges

• Wireless repeaters

• WLAN controller/switch

• Distributed AP connectivity

• Direct AP connectivity

• Layer 2 and Layer 3 AP connectivity

• Power over Ethernet (PoE) devices

• Midspan

• Endpoint

2.2. Identify the purpose, features, and functions of the following client devices. Choose the appropriate installation or configuration steps in a given scenario.

• PC cards (ExpressCard, CardBus, and PCMCIA)

• USB2, CF, and SD devices

• PCI, Mini-PCI, and Mini-PCIe cards

• Workgroup bridges

• Client utility software and drivers

2.3. Identify the purpose, features, and functions of and the appropriate installation or configuration steps for the following types of antennas

• Omnidirectional/dipole

• Semidirectional

• Highly directional

Radio Frequency (RF) Fundamentals—15%

3.1 Define the basic units of RF measurements

• Milliwatt (mW)

• Decibel (dB)

• dBm

• dBi

3.2 Identify factors that affect the range and speed of RF transmissions

• Line-of-sight requirements

• Interference (baby monitors, spread spectrum phones, microwave ovens)

• Environmental factors

3.3 Define and differentiate between the following Physical layer wireless technologies

• HR / DSSS

• OFDM

• MIMO

3.4 Define concepts that make up the functionality of RF and spread spectrum technology

• OFDM and HR/DSSS channels

• Co-location of HR/DSSS and OFDM systems

• Adjacent-channel and co-channel interference

• WLAN/WPAN co-existence

• CSMA/CA operation - half duplex

3.5 Identify RF signal characteristics and the applications of basic RF antenna concepts

• Passive gain

• Beamwidths

• Simple diversity

• Polarization

3.6 Describe the proper locations and methods for installing RF antennas

• Pole/mast mount

• Ceiling mount

• Wall mount

3.7 Identify the use of the following WLAN accessories and explain how to select and install them for optimal performance and regulatory domain compliance

• RF cables

• RF connectors

• Lightning arrestors and grounding rods

Site Surveying and Installation—15%

4.1 Understand and describe the requirements to gather information prior to the site survey and do reporting after the site survey

• Gathering business requirements

• Interviewing managers and users

• Defining physical and data security requirements

• Gathering site-specific documentation

• Documenting existing network characteristics

• Identifying infrastructure connectivity and power requirements

• Understanding RF coverage requirements

• Client connectivity requirements

• Antenna use considerations

4.2 Define and differentiate between the following WLAN system architectures and understand site survey concepts related to each architecture. Identify and explain best practices for access point placement and density.

• Multiple channel architecture (MCA)

• Single channel architecture (SCA)

4.3 Define the need for and the use of a manual site survey tool and differentiate between the following manual site survey types

• Active surveys

• Passive surveys

4.4 Differentiate between manual and predictive site surveys

• Advantages and disadvantages of each site survey methodology

4.5 Define the need for and use of a protocol analyzer in a manual site survey as it relates to the following

• Identifying, locating, and assessing nearby WLANs

4.6 Differentiate between site surveys involving networks with and without a mesh access layer

4.7 Define the need for and use of a spectrum analyzer in a manual site survey

• Identification and location of interference sources

• Differentiation of Wi-Fi and non-Wi-Fi interference sources

4.8 Identify limitations on hardware placement

• Areas where APs or antennas cannot be placed

• Areas beyond Ethernet distance limitations

4.9 Understand industry best practices for optimal use of directional and omnidirectional antennas in site surveys

Applications, Support, and Troubleshooting—15%

5.1 Identify deployment scenarios for common WLAN network types

• Small office/home office (SOHO)

• Extension of existing networks into remote locations

• Building-to-building connectivity

• Public wireless hotspots

• Mobile office, classroom, industrial, and health care

• Municipal and law-enforcement connectivity

• Corporate data access and end-user mobility

• Last-mile data delivery, wireless ISP

• Transportation networks (trains, planes, automobiles)

5.2 Recognize common problems associated with wireless networks and their symptoms, and identify steps to isolate and troubleshoot the problem. Given a problem situation, interpret the symptoms and the most likely cause. Problems may include:

• Decreased throughput

• Intermittent or no connectivity

• Weak signal strength

• Device upgrades

5.3 Identify procedures to optimize wireless networks in specific situations

• Infrastructure hardware selection and placement

• Identifying, locating, and removing sources of interference

• Client load balancing

• Analyzing infrastructure capacity and utilization

• Multipath and hidden nodes

Security and Compliance—15%

6.1 Identify and describe the following WLAN security techniques

• SSID hiding

• Legacy security mechanisms: WEP and MAC filtering

• User-based security: 802.1X/EAP and RADIUS authentication

• Passphrase-based security

• Push-button or PIN-based wireless security

• Encryption: TKIP/CCMP

• Role-based access control (RBAC)

• Virtual private networking (VPN)

• Wireless intrusion prevention systems (WIPS)

• Captive Portal

6.2 Regulatory Compliance

• PCI compliance

• HIPAA compliance

• Enforcing compliance with WIPS

CWNP Exam Terminology

The CWNP program uses specific terminology when phrasing the questions on any of the CWNP exams. The terminology used most often mirrors the language that is used in the IEEE 802.11-2007 standard. While technically correct, the terminology used in the exam questions often is not the same as the marketing terminology that is used by the Wi-Fi Alliance or the manufacturers of WLAN equipment.

The most current IEEE version of the 802.11 standard is the IEEE 802.11-2007 document, which includes all the amendments that have been ratified prior to the document’s publication. Standards bodies such as the IEEE often create several amendments to a standard before “rolling up” the ratified amendments (finalized or approved versions) into a new standard.

For example, you might already be familiar with the term 802.11g, which is a ratified amendment that has now been integrated into the IEEE 802.11-2007 standard. The technology that was originally defined by the 802.11g amendment is called Extended Rate Physical (ERP). Although the name 802.11g effectively remains the more commonly used marketing terminology, exam questions may use the technical term ERP instead of 802.11g. A document with exam terms is available from the CWNP website. At the time of this writing, the URL to access this document is www.cwnp.com/exams/exam_terms.html.

Assessment Test

1. Which amendment to the standard operates in the 2.4 GHz ISM band and supports data rates up to 54 Mbps?

a. 802.11a

b. 802.11b

c. 802.11g

d. 802.11n

2. The access method that an IEEE 802.11a wireless network would use to get control of the wireless medium in order to transmit data is called what?

a. CSMA /CD

b. FHSS

c. HR / DSSS

d. CSMA/CA

e. CSMA / DSSS

3. What will a protocol analyzer do during a manual site survey?

a. Perform a RF analysis of the proposed area

b. Help locate sources of RF interference

c. Identify existing wireless networks

d. Describe security requirements of the wireless LAN

4. IEEE 802.11g wireless networks can operate in which unlicensed RF band?

a. 902 - 928 MHz ISM

b. 2.400 - 2.500 GHz UNII

c. 5.725 - 5.825 GHZ UNII

d. 5.250 - 5.350 GHz UNII

e. 2.400 - 2.500 GHz ISM

5. What could be the cause of intermittent connectivity for a wireless client device in an IEEE 802.11g wireless network?

a. A weak received signal strength on the client

b. A signal-to-noise ratio of 35 dB

c. The access point power is set too high and overpowering the client device

d. The radio in the client device is disabled

6. Which statement is accurate regarding mesh access points and mesh technology?

a. Mesh is a legacy technology and the priority should be to select an appropriate upgrade path.

b. In a full mesh network, all nodes connect together with at least two paths for every node.

c. Mesh access points are unreliable communications and represent a single point of failure.

d. Mesh access points require a separate radio for communications and therefore can be costly to implement.

7. PIN-based wireless LAN security is ________ .

a. Addressed in the Wi-Fi Protected Setup certification

b. Required by the 802.11i amendment

c. Best used in enterprise wireless networks

d. A multifactor authentication mechanism for WLANs

8. Open system authentication is _________in an IEEE 802.11 wireless network.

a. Flawed

b. Optional

c. Secure

d. Required

9. The amount of output power and useable frequency ranges for wireless devices is determined by which organization?

a. Wireless Ethernet Compatibility Alliance

b. Wi-Fi Alliance

c. Institute of Electrical and Electronics Engineers

d. Regulatory domain governing bodies

10. Which IEEE 802.11 standard or amendment can use three radio chains per band and multiple input/multiple output (MIMO) to transmit data?

a. 802.11

b. 802.11a

c. 802.11g

d. 802.11h

e. 802.11n

11. What can contribute to voltage standing wave ratio (VSWR) in an IEEE 802.11g wireless LAN circuit?

a. Output power of the access point

b. Impedance mismatch

c. Gain of an antenna

d. Attenuation value of cable

12. Wireless repeaters are devices in wireless networking that are __________.

a. Used to extend the radio frequency cell

b. Used to repeat and strengthen the RF signal for better performance

c. Used as a backup solution in the event of an access point failure

d. Used to increase the bandwidth of the WLAN

13. What does the term authenticator identify in an IEEE 802.1X secure network?

a. The RADIUS server

b. The access point

c. The client device

d. The RAS server

14. An independent basic service set requires a minimum of how many access points?

a. 0

b. 1

c. 2

d. 3

15. An HR/DSSS channel used to transmit data an IEEE 802.11g wireless LAN is _______ wide.

a. 2.412 GHz

b. 5.160 GHz

c. 11 MHz

d. 22 MHz

16. What is the horizontal angle of measurement in degrees of an omnidirectional antenna with a gain of 2.2 dBi?

a. 90

b. 180

c. 270

d. 360

e. 0

17. You are a wireless LAN engineer hired to perform a predictive analysis site survey for a 150,000-square-foot office building. This space includes walled offices as well as cubicles. What is an advantage of a predictive modeling site survey over a manual survey in this specific application?

a. A predictive site survey is the most accurate available.

b. The amount of time required for accurate results is much less than a complete manual walkthrough.

c. Because of an extensive attenuation database, a predictive modeling site survey will be able to determine the interference values of any obstacles.

d. A predictive modeling site survey will allow you to experiment with different access point criteria, including power settings, channels, and locations, without the need for a physical visit.

18. Which RF channels are considered non-overlapping for an IEEE 802.11g network?

a. 1 and 4

b. 6 and 9

c. 1 and 6

d. 3 and 7

e. 11 and 13

19. The Service Set Identifier (SSID) in an IEEE 802.11 wireless LAN is also known as what?

a. The name of the wireless network

b. The media access control address of the radio

c. The name of the access point

d. The wireless medium identifier

20. What Layer 2 security mechanisms are weak and should not be used with IEEE 802.11 wireless LANs? (Choose three.)

a. SSID hiding

b. WPA

c. VPN

d. WEP

e. WPA 2.0

f. RBAC

g. MAC filter

21. If an autonomous access point is set to what is commonly referred to as root mode, it will be able to perform which function?

a. Connect to a distribution system and allow client devices to send information to other devices

b. Connect to a distribution system as a root bridge and allow two or more LANs to connect wirelessly

c. Connect to a distribution system but is seldom used as this mode requires extensive configuration

d. Connect to a distribution system as a repeater which allows the RF cell to be extended

22. What could cause low throughput in an 802.11g wireless network?

a. Access point output power is too high

b. Too many associated client devices

c. Load-balancing features are moving clients

d. The clients are too close to the access points and are overpowered

23. Some common wireless personal network (WPAN) devices such as Bluetooth use a communication technology that has the potential to interfere with IEEE 802.11g wireless LANs. What is the name for this technology?

a. FHSS

b. DSSS

c. HR / DSSS

d. HR/FHSS

e. ERP-OFDM

24. A virtual private network (VPN) operates at what layer of the OSI model?

a. Physical, Layer 1

b. Data Link, Layer 2

c. Network, Layer 3

d. Transport, Layer 4

e. Application, Layer 7

25. An antenna will propagate RF energy in specific radiation patterns, both horizontal and vertical. How do antenna manufacturers identify the horizontal radiation patterns?

a. Elevation

b. Azimuth

c. Dipole

d. Longitude

26. Wi-Fi Protected Access 2 (WPA 2.0) requires ____ for the cipher suite and ____ for the encryption mechanism.

a. TKIP, RC4

b. TKIP, RC5

c. WEP, RC4

d. CCMP, RC4

e. CCMP, AES

27. Antenna diversity will _____ .

a. Provide an RF signal additional range

b. Reduce the effects of multipath

c. Increase the effects of VSWR

d. Provide active gain

28. The manual site survey process allows the site surveyor to perform the survey in one of two modes. What are these two modes? (Choose two.)

a. Passive

b. Visual

c. Predictive

d. Active

e. Placement

29. A beacon is an example of what type of frame used in an IEEE 802.11 wireless LAN?

a. Control

b. Management

c. Data

d. Null function

30. What can have a negative effect on the capacity of an IEEE 802.11g wireless LAN access point?

a. Reflections caused by furnishings

b. Frequency range in use

c. Number of associated users

d. Output power of access point

Answers to Assessment Test

1. C. The IEEE 802.11g amendment to the standard and the 802.11a amendment both support up to 54 Mbps maximum data rates. However, of the two only 802.11g operates in the 2.4 GHz ISM band. 802.11b also operates in the 2.4 GHz ISM band but only supports a maximum data rate of 11 Mbps. The IEEE 802.11n amendment currently in draft supports up to 300 Mbps but eventually 600 Mbps. For more information, see Chapter 1.

2. D. CSMA/CA stands for Carrier Sense Multiple Access/Collision Avoidance and is used as an access method for wireless LANs to share the communication medium, which is the air. CSMA/CD is Carrier Sense Multiple Access Collision/Detection Avoidance and is used with Ethernet networks. FHSS and HR/DSSS are spread spectrum technologies used with some standards or amendments. CSMA/DSSS does not exist. For more information, see Chapter 5.

3. C. A protocol analyzer will help identify existing wireless networks in an area and provide other information about these networks that can be used in the site survey/design process. An RF analysis is performed by a spectrum analyzer, which will also help locate sources of RF interference. A protocol analyzer can help identify security-related issues from existing wireless networks but will not describe security requirements of a new wireless LAN. For more information, see Chapter 9.

4. E. IEEE 802.11g networks operate in the 2.4 GHz ISM band. 802.11a networks operate in the 5 GHz UNII band. IEEE standards-based wireless networks do not use the 900 MHz ISM band or the 2.4 GHz UNII band. For more information, see Chapter 4.

5. A. The received signal strength represents how much of a transmitted signal is being received. If this signal is weak, the difference between the signal and noise may not be high enough to recover the data. If the power on an access point is high, it would provide more received signal. A signal-to-noise ratio of 35 dB is more than adequate. If the radio on the client was disabled, it would not be able to connect at all. For more information, see Chapter 11.

6. B. In a full mesh network, all nodes connect together with at least two paths for every node. This technology is on the increase in outdoor installations and starting to appear in indoor installations as well. It is common in metropolitan area networks and campus area networks. Many access points and wireless LAN switches/controllers have the capability built in. For more information, see Chapter 2.

7. A. PIN-based security is designed for home networks or small office installations to help ease the burden of setting up wireless LAN security. The IEEE 802.11i amendment to the standard requires CCMP/AES and is used in enterprise installations. Enterprise installations use more sophisticated solutions such as user-based and 802.1X/EAP. Multifactor authentication requires at least two parts to be authenticated, such as something you have and something you know. A bank automated teller machine (ATM) card is an example of multifactor authentication. For more information, see Chapter 10.

8. D. Open system authentication is addressed in the original IEEE 802.11 standard and requires a wireless client device to authenticate to an access point in order to associate. Shared key authentication is legacy and flawed and either cannot or should not be used. Open system authentication is a “null” authentication, is automatic and not secure. For more information, see Chapter 7.

9. D. Regulatory domain governing bodies manage the RF spectrum used in both unlicensed and licensed applications. The IEEE creates standards and the Wi-Fi Alliance certifies devices for interoperability. Wireless Ethernet Compatibility Alliance is the former name of the Wi-Fi Alliance. For more information, see Chapter 1.

10. E. 802.11n and MIMO will use up to three radios in either the 2.4 GHz ISM or the 5 GHz UNII band. 802.11a/g uses one radio per band but can use two antennas for diversity. 802.11h is for spectrum management. For more information, see Chapter 5.

11. B. An impedance mismatch between connections in a WLAN system will cause VSWR. The gain of an antenna is a relative value that has to do with the size or shape of the RF pattern emitted. Attenuation of cable adds to the overall loss of the system. For more information, see Chapter 6.

12. A. A wireless repeater—which in most cases is a function of an access point—will extend the RF cell to allow users at a greater distance to connect. This will have an impact on throughput for users connected to the repeater and this solution is recommended only when necessary. For more information, see Chapter 2.

13. B. 802.1X is for port-based access control and the terminology for the access point is authenticator. The RADIUS server is the authentication server and the client device is a supplicant. The RAS server is the predecessor to RADIUS. For more information, see Chapter 10.

14. A. An independent basic service set (IBSS) is an ad hoc network that is used for peer-to-peer communications. No access points are used in an IBSS implementation. For more information, see Chapter 7.

15. D. Both DSSS and HR/DSSS channels are 22 MHz wide. 2.412 GHz and 5.160 GHz is the center frequency of some channels used. For more information, see Chapter 5.

16. D. An omnidirectional antenna has a horizontal radiation pattern of 360 degrees. For more information, see Chapter 6.

17. B. A predictive analysis site survey will minimize the time required on-site for testing and analysis. This site survey will be accurate if the information about the location input is accurate. A manual site survey requires a walkthrough on the area and can be time consuming. For more information, see Chapter 9.

18. C. To be considered non-overlapping, channels in the 2.4 GHz ISM band need to be separated by 5 or 25 MHz. For more information, see Chapter 4.

19. A. The SSID is the name that identifies a wireless network. The MAC address of the access point radio is the BSSID. For more information, see Chapter 7.

20. A,D,G. SSID hiding, WEP, and MAC filtering are legacy security mechanisms for IEEE 802.11 wireless networks and should not be used. WPA and WPA 2.0 are Wi-Fi certifications and are more advanced. Virtual private network (VPN) is a Layer 3 security solution typically used for remote access. RBAC is role-based access control. For more information, see Chapter 10.

21. A. Most enterprise-level autonomous access points have the capability to operate in root, repeater, or bridge modes. Root mode is the most common. Root mode allows devices to authenticate, associate, and access network resources and services. For more information, see Chapter 2.

22. B. Low throughput may occur when too many client devices are associated to an access point and cause overloading. Load balancing would help to solve this problem. Because of DRS, the closer the client device is to an access point, the better the throughput. For more information, see Chapter 11.

23. A. Some wireless personal networks (WPANs), such as Bluetooth, use FHSS for communications. This will potentially interfere with IEEE 802.11 wireless networks. DSSS, HR/ DSSS, ERP-OFDM are all used in wireless LANs. HR/FHSS does not exist. For more information, see Chapter 5.

24. C. A virtual private network (VPN) is a Layer 3 (Network) security solution and is commonly used for remote access connectivity from unsecured networks such as hotspots. For more information, see Chapter 10.

25. B. The technical term for the horizontal radiation pattern is azimuth. The elevation is the vertical radiation pattern. For more information, see Chapter 6.

26. E. Wi-Fi Protected Access 2 (WPA 2.0) requires CCMP/AES. TKIP/RC4 is optional. WEP/ RC4 is legacy and should not be used. It cannot be used with a robust secure network. RC5 is a stream cipher and not used with IEEE 802.11 wireless LANs. CCMP uses AES, not RC4. For more information, see Chapter 1.

27. B. Antenna diversity will reduce the effects of multipath caused by reflections. An antenna will provide additional coverage and range based on the gain. VSWR is caused by an impedance mismatch, and active gain is provided by amplifiers and other powered devices. For more information, see Chapter 6.

28. A,D. Passive and active are the two modes in which a manual site survey can be performed. Passive mode monitors all RF, and active mode requires a client association. For more information, see Chapter 9.

29. B. A beacon frame is a management frame and is used to advertise information about the wireless LAN. For more information, see Chapter 7.

30. C. The number of associated users will affect the capacity of an access point. The frequency range will affect the propagation as well as the output power. Reflections will cause multipath. For more information, see Chapter 4.

Chapter 1

Introduction to Wireless Local Area Networking

THE FOLLOWING CWTS EXAM OBJECTIVES ARE COVERED IN THIS CHAPTER:

• Identify deployment scenarios for common WLAN network types

• Small office/home office (SOHO)

• Extension of existing networks into remote locations

• Building-to-building connectivity

• Public wireless hotspots

• Mobile office, classroom, industrial, and healthcare

• Municipal and law-enforcement connectivity

• Corporate data access and end-user mobility

• Last-mile data delivery: wireless ISP

• Transportation networks (trains, planes, automobiles)

• Define the roles of the following organizations in providing direction and accountability within the wireless network ing industry

• IEEE

• Wi-Fi Alliance

• Regulatory Domain Governing Bodies

• Summarize the basic attributes and advantages of the WLAN standards, amendments, and product certifications

• Wi-Fi certification

• 802.11a

• 802.11b

• 802.11g

• 802.11n

• Wi-Fi Multimedia (WMM) certification

• WMM Power Save (WMM-PS) certification

• Wi-Fi Protected Setup (WPS) certification

• Push-button

• PIN-based

• Wi-Fi Protected Access (WPA / WPA2) certification

• Enterprise

• Personal

Wireless computer networks have taken computer communication to a new level. This communication technology is the combination of computer local area networking (LAN) and radio frequency (RF) technology. By combining these two technologies, computer users have the opportunity to access and share information in ways that would seem unattainable a few years ago.

This chapter will look at various ways in which wireless local networks are used and deployed. We will also cover organizations responsible for managing and creating wireless LAN standards. Details of the 802.11 standard and amendments will be discussed illustrating the communications and functional aspects. Finally, we will discuss interoperability certifications available for communications, quality of service, and security of IEEE 802.11 wireless networks.

Common WLAN Deployment Scenarios

The availability of wireless LAN technology has increased while the cost continues to decrease, making wireless LANs a viable solution for many business models, including small offices, home offices, and personal use. This chapter will look at scenarios in which wireless networking is used, and provide an overview of standards-based solutions and interoperability certifications. The following are some common applications utilizing wireless local area networks (WLANs):

• Small office/home office (SOHO)

• Enterprise: corporate data access and end-user mobility

• Extension to remote locations

• Mobile office

• Public wireless hotspots

• Classroom

• Healthcare

• Last-mile data delivery: wireless Internet service provider (ISP)

• Industrial

• Municipal and law-enforcement connectivity

• Transportation networks

• Building-to-building connectivity

Small Office/Home Office (SOHO)

Many small office/home office (SOHO) businesses have the same needs as those of larger businesses with regard to technology, computer networking, and communication. Computer networking technology is common regardless of the size of the business. Whether there are 1 or 100 employees or even more, many are categorized as small businesses. Wireless LANs can play a major role in small businesses. Many of these locations will have a high speed Internet connection such as DSL (digital subscriber line) or cable modem for access outside the local network.

With the number of work-at-home professionals continuing to grow at a very high rate, the need for wireless networking in this environment is also continuing to grow. The same goes for the small office environment. Deployments such as these typically involve a small number of users. Therefore, the equipment used may be consumer brands sold in consumer electronics and department stores.

Figure 1.1 shows a SOHO configuration with a wireless LAN router connected to an Internet service provider allowing access to the necessary network/Internet resources.

FIGURE 1.1 Example of a SOHO wireless LAN configuration

Enterprise Deployments: Corporate Data Access and End-User Mobility

Enterprise organizations have used wired local area networks for many years. With the increased need for mobility, wireless LANs within enterprise organizations have also increased in popularity. In earlier years, due to lack of interoperability and security features, many enterprise organizations limited wireless LAN deployments to extensions of networks where wired connectivity was either not feasible or too costly. Because of advancements in wireless LAN technology over the recent years, deployments in enterprise organizations are now growing at a rapid pace.

Wireless LANs in the enterprise are used with—but not limited to—client workstation connectivity (desktop and notebook), printers, barcode scanners, voice handsets, and location services. The cost of this technology has decreased while capabilities, performance, and security have increased, making wireless a very attractive solution for many enterprise organizations. The cost savings over hard-wired solutions are enormous, adding to the attractiveness. Finally, wireless connectivity is the only option in some cases, such as mobile Voice over Wi-Fi handsets for voice communications.

Extending Existing Networks with Wireless LAN

Early wireless networking technology was typically deployed to allow an extension of an existing wired network infrastructure. For example, some users who required access to the computer network exceeded the distance the IEEE 802.3 Ethernet standard allowed for a copper-wired connection, therefore other solutions were needed to provide connectivity. Other wired technology, such as fiber optics and leased lines, were sometimes cost prohibitive or not logistically feasible. Wireless local area networks were an excellent alternative.

Mobile Office and Public Wireless Hotspots