Introduction
This book is intended to provide an introduction to the exciting and emerging world of IEEE 802.11 wireless LAN technology. This technology continues to expand at a phenomenal pace, with constant improvements in speed, performance, reliability, and security. Reading this book will teach you the fundamentals of IEEE 802.11 standards-based wireless technology, giving you an overview of the hardware and software components, radio frequency communication principals, terminology overview, and support 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 Certified Wireless Network Professional (CWNP) program. CWTS is an entry-level enterprise wireless LAN certification, and is recommended as preparation for the Certified Wireless Network Administrator (CWNA) certification. This certification is geared specifically toward wireless local area network (WLAN) support staff, sales and marketing personnel, or anyone who wants to become more familiar with 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 IEEE 802.11 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.
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. The CWNP program develops courseware and certification exams for IEEE 802.11 WLAN technologies in the computer networking industry.
CWNP offers several 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 IEEE 802.11 wireless networking technology. By acquiring this knowledge, these professionals will be able to enter any business and sell, design, install, manage, and support a wireless LAN infrastructure regardless of which manufacturer's solution is used.
In addition to CWTS, there are five other wireless certifications currently offered from CWNP:
- Exam PW0-105 – Certified Wireless Network Administrator
- Exam PW0-204 – Certified Wireless Security Professional
- Exam PW0-105 – Certified Wireless Network Administrator
- Exam PW0-250 – Certified Wireless Design Professional
- Exam PW0-105 – Certified Wireless Network Administrator
- Exam PW0-270 – Certified Wireless Analysis Professional
- Exam PW0-105 – Certified Wireless Network Administrator
- Exam PW0-204 – Certified Wireless Security Professional
- Exam PW0-250 – Certified Wireless Design Professional
- Exam PW0-270 – Certified Wireless Analysis Professional
- Three years of documented enterprise Wi-Fi implementation experience
- Three professional endorsements
- Two other current, valid professional networking certifications
- Documentation of three enterprise Wi-Fi projects in which you participated or led in the form of 500 word essays
- Re-certification every three years by passing the most current version of either the CWSP, CWAP, or CWDP exam
CWNP Learning Resources
There are a variety of resources available from CWNP to help 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 classroom training
- Online live training
- Computer-based training (CBT)
- CWNP website
- CWNP forums
- CWNP blog
- CWNP learning center, offering 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 PW0-071 certification exam.
When you take the CWTS certification 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: PW0-071
- Cost: $125.00 (USD)
- Duration: 90 minutes
- Questions: 60
- Question types: Multiple choice/multiple answer
- Passing score: 70 percent
- 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 from CWNP. 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?
Reading this book will provide you with an overview of IEEE 802.11 WLAN technology. 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 computer 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 at the book's companion website (www.sybex.com/go/cwts2e) and at 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 Companion Website
Several testing features are in this book, and an exam engine that contains flashcards and additional practice exams is available on the book's companion website (www.sybex.com/go/cwts2e). These are designed to test your knowledge of 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 the additional online material, you will have all the tools necessary that effectively prepare you to do so.
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 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.
As of this writing the most current IEEE version of the 802.11 standard is the IEEE 802.11-2012 document, which includes all the amendments that have been ratified since the IEEE 802.11-2007 standard. 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 802.11-2012 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.
CWTS 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.
CWTS: Certified Wireless Technology Specialist Official Study Guide has been written to cover every CWTS exam objective at a level appropriate to its exam weighting. The following tables provide a breakdown of this book's exam coverage, showing you the weight of each section and the chapter where each objective or subobjective is covered.
| Wi-Fi Technology, Standards, and Certifications | 25% |
| Hardware and Software | 20% |
| Radio Frequency (RF) Fundamentals | 20% |
| Site Surveying and Installation | 10% |
| Applications, Support, and Troubleshooting | 15% |
| Security and Monitoring | 10% |
| Total | 100% |
| Wireless Technologies, Standards, and Certifications—25% | |
| 1.1. Define the roles of the following organizations in providing direction and accountability within the wireless networking industry. | |
| IEEE | 2 |
| Wi-Fi Alliance | 2 |
| Local regulatory authorities | 2 |
| 1.2. Define basic characteristics of and concepts relating to Wi-Fi technology. | |
| Range, coverage, and capacity | 6 |
| Frequencies/channels used | 6 |
| Channel reuse and co-location | 6 |
| Infrastructure and ad hoc modes | 8 |
| BSSID, SSID, BSS, ESS, BSA, IBSS | 8 |
| Network discovery via active and passive scanning | 8 |
| 802.11 authentication and association | 8 |
| Data rates and throughput | 8 |
| The distribution system and roaming | 8 |
| Protection mechanisms | 8 |
| Power saving operation | 8 |
| Dynamic rate switching | 8 |
| 1.3. Summarize the basic attributes of the following WLAN standards, amendments, and product certifications. | |
| 802.11a | 2 |
| 802.11b | 2 |
| 802.11g | 2 |
| 802.11n | 2 |
| Wi-Fi Multimedia (WMM) certification | 2 |
| WMM Power Save (WMM-PS) certification | 2 |
| Wi-Fi Protected Access (WPA/WPA2) certification | 2 |
| Enterprise | 2 |
| Personal | 2 |
| 1.4 Explain the role of Wi-Fi as a network access technology. | |
| WPAN, WLAN, WMAN, WWAN | 2 |
| The OSI reference model | 1 |
| Hardware and Software—20% | |
| 2.1 Identify the purpose, features, and functions of the following wireless network components. Choose the appropriate implementation or configuration steps in a given scenario. | |
| Access points | 3 |
| Controller-based | 3 |
| Autonomous | 3 |
| Cooperative | 3 |
| Mesh | 3 |
| Wireless LAN routers | 3 |
| Wireless bridges | 3 |
| Wireless repeaters | 3 |
| WLAN controller | 3 |
| Distributed and centralized data forwarding | 3 |
| Power over Ethernet (PoE) devices | 3 |
| 802.3af and 802.3at | 3 |
| Midspan | 3 |
| Endpoint | 3 |
| 2.2. Identify the purpose, features, and functions of the following client device types. Choose the appropriate installation or configuration steps in a given scenario. | |
| PC cards (ExpressCard, CardBus, and PCMCIA) | 4 |
| USB2 | 4 |
| PCI, Mini-PCI, Mini-PCIe and Half Mini PCIe cards | 4 |
| Workgroup bridges | 4 |
| Client utility software and drivers | 4 |
| 2.3. Identify the purpose, features, and proper implementation of the following types of antennas. | |
| Omni-directional/dipole | 7 |
| Semi-directional | 7 |
| Highly-directional | 7 |
| 2.4 Describe the proper locations and methods for installing RF antennas. | |
| Internal and external (to the AP) antennas | 7 |
| Pole/mast mount | 7 |
| Ceiling mount | 7 |
| Wall mount | 7 |
| Radio Frequency (RF) Fundamentals—20% | |
| 3.1 Define the basic units of RF measurements, identify when they are used, and perform basic unit conversion. | |
| Watt (W) and Milliwatt (mW) | 6 |
| Decibel (dB) | 6 |
| dBm | 6 |
| dBi | 6 |
| RSSI | 6 |
| SNR | 6 |
| 3.2 Identify and explain RF signal characteristics. | |
| Frequency | 6 |
| Wavelength | 6 |
| Amplitude | 6 |
| Phase | 6 |
| 3.3 Identify factors which affect the range and rate of RF transmissions. | |
| Line-of-sight requirements | 6 |
| Interference (Wi-Fi and non-Wi-Fi) | 6 |
| Environmental factors, including building materials | 6 |
| Free space path loss | 6 |
| 3.4 Define and differentiate between the following physical layer wireless technologies. | |
| 802.11b HR/DSSS | 6 |
| 802.1g ERP | 6 |
| 802.11a OFDM | 6 |
| 802.11n HT | 6 |
| 3.5 Define concepts which make up the functionality of RF and spread spectrum communication. | |
| 802.11 channels | 5 |
| Co-location of 802.11a/b/g/n systems | 5 |
| Adjacent-channel and co-channel interference | 5 |
| WLAN/WPAN co-existence | 5 |
| CSMA/CA operation | 5 |
| Half duplex communications | 5 |
| 3.6 Understand and apply basic RF antenna concepts. | |
| Passive gain | 7 |
| Beamwidth | 7 |
| Simple diversity | 7 |
| Polarization | 7 |
| 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 | 7 |
| RF connectors | 7 |
| Lightning arrestors and grounding rods | 7 |
| Site Surveying and Installation—10% | |
| 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 | 10 |
| Interviewing stakeholders | 10 |
| Gathering site-specific documentation including existing network characteristics | 10 |
| Identifying infrastructure connectivity and power requirements | 10 |
| Understanding RF coverage requirements | 10 |
| Understanding application requirements | 10 |
| 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) | 11 |
| Single channel architecture (SCA) | 11 |
| 4.3 Describe the primary purpose and methodology of manual and predictive site surveys. | 11 |
| 4.4 Define the need for and the use of a manual site survey tool and differentiate between the following manual site survey types. | |
| Active surveys | 11 |
| Passive surveys | 11 |
| 4.5 Differentiate between manual and predictive site surveys. | |
| Advantages and disadvantages of each site survey methodology | 11 |
| 4.6 Define the need for and use of site survey software or a protocol analyzer in a manual site survey as it relates to identifying, locating, and assessing nearby WLANs. | 11 |
| 4.7 Differentiate between site survey methods for indoor and outdoor wireless service. | 11 |
| 4.8 Define the need for and use of a spectrum analyzer in a site survey. | |
| Identification and location of interference sources | 11 |
| Differentiation of Wi-Fi and non-Wi-Fi interference sources | 11 |
| 4.9 Understand industry best practices for optimal use of directional and omnidirectional antennas in site surveys. | 11 |
| Applications, Support, and Troubleshooting—15% | |
| 5.1 Identify deployment scenarios for common WLAN network types and suggest best practices for these scenarios. | |
| Small Office/Home Office (SOHO) | 2 |
| Extension of existing networks into remote locations | 2 |
| Building-to-building connectivity | 2 |
| Public wireless hotspots | 2 |
| Carpeted office, education, industrial, and healthcare | 2 |
| Last-mile data delivery – wireless ISP | 2 |
| High density environments | 2 |
| 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. | |
| Throughput problems | 12 |
| Connectivity problems | 12 |
| Interference from Wi-Fi or non-Wi-Fi sources | 12 |
| Application performance problems | 12 |
| RF performance problems, such as multipath and hidden nodes | 12 |
| 5.3 Identify procedures to optimize wireless networks. | |
| Infrastructure hardware selection and placement | 12 |
| Identifying, locating, and removing sources of interference | 12 |
| Client load-balancing and infrastructure redundancy | 12 |
| Analyzing infrastructure capacity and utilization | 12 |
| Security and Monitoring—10% | |
| 6.1 Identify and describe the following legacy WLAN security technologies. | |
| SSID hiding | 9 |
| WEP | 9 |
| MAC Filtering | 9 |
| 6.2 Understand the basic operation of and implementation best practices for the following WLAN security technologies. | |
| WPA and WPA-2 Personal | 9 |
| WPA and WPA-2 Enterprise | 9 |
| 802.1X/EAP | 9 |
| AAA and RADIUS | 9 |
| Encryption: TKIP/CCMP | 9 |
| 6.3 Understand the basic functions and implementation best practices for the following WLAN security technologies. | |
| Role-based access control (RBAC) | 9 |
| Virtual private networking (VPN) | 9 |
| Wireless intrusion prevention systems (WIPS) | 9 |
| Captive portal | 9 |
| Network management and monitoring systems | 9 |