CWNA Certified Wireless Network Administrator Study Guide

Exam CWNA-107

David D. Coleman, David A. Westcott

• Éditeur: Sybex
• Année: 2018
• ISBN:
  9781119477501
• Édition: 5
• Sujet: Computer Science
• Sous-sujet: Certification Guides in Computer Science

The bestselling CWNA study guide, updated for the latest exam

The CWNA: Certified Wireless Network Administrator Study Guide is the ultimate preparation resource for the CWNA exam. Fully updated to align with the latest version of the exam, this book features expert coverage of all exam objectives to help you internalize essential information. A pre-assessment test reveals what you already know, allowing you to focus your study time on areas in need of review, while hands-on exercises allow you to practice applying CWNA concepts to real-world scenarios. Expert-led discussion breaks complex topics down into easily-digestible chucks to facilitate clearer understanding, and chapter review questions help you gauge your progress along the way. You also get a year of free access to the Sybex online interactive learning environment, which features additional resources and study aids including bonus practice exam questions.

The CWNA exam tests your knowledge of regulations and standards, protocols and devices, network implementation, security, and RF site surveying. Thorough preparation gives you your best chance of passing, and this book covers it all with a practical focus that translates to real on-the-job skills.

• Study 100% of the objectives for Exam CWNA-107
• Assess your practical skills with hands-on exercises
• Test your understanding with challenging chapter tests

• Access digital flashcards, white papers, bonus practice exams, and more

The CWNA certification is a de facto standard for anyone working with wireless technology. It shows employers that you have demonstrated competence in critical areas, and have the knowledge and skills to perform essential duties that keep their wireless technology functioning and safe. The CWNA: Certified Wireless Network Administrator Study Guide gives you everything you need to pass the exam with flying colors.

Chapter 1
Overview of Wireless Standards, Organizations, and Fundamentals

IN THIS CHAPTER, YOU WILL LEARN ABOUT THE FOLLOWING:

• 
  History of wireless local area networks
• 
  Standards organizations
  • Federal Communications Commission
  • International Telecommunication Union Radiocommunication Sector
  • Institute of Electrical and Electronics Engineers
  • Internet Engineering Task Force
  • Wi-Fi Alliance
  • International Organization for Standardization
• 
  Core, distribution, and access
• 
  Communications fundamentals
  • Communication terminology
  • Carrier signals
  • Keying methods

Wireless local area network (WLAN) technology has a long history that dates back to the 1970s, with roots as far back as the 19th century. This chapter will start with a brief history of WLAN technology. Learning a new technology can seem like a daunting task. There are so many new acronyms, abbreviations, terms, and ideas to become familiar with. One of the keys to learning any subject is to learn the basics. Whether you are learning to drive a car, fly an airplane, or install a wireless computer network, there are basic rules, principles, and concepts that, once learned, provide the building blocks for the rest of your education.

The Institute of Electrical and Electronics Engineers (IEEE) 802.11 technology, more commonly referred to as Wi-Fi, is a standard technology for providing local area network (LAN) communications using radio frequencies (RFs). The IEEE designates the 802.11-2016 standard as a guideline to provide operational parameters for WLANs. Numerous standards organizations and regulatory bodies help govern and direct wireless technologies and the related industry. Having some knowledge of these various organizations can provide you with insight as to how IEEE 802.11 functions and sometimes even how and why the standards have evolved the way they have.

As you become more knowledgeable about wireless networking, you may want or need to read some of the standards documents that are created by the different organizations. Along with the information about the standards bodies, this chapter includes a brief overview of their documents.

In addition to reviewing the various standards organizations that guide and regulate Wi-Fi, this chapter discusses where WLAN technology fits in with basic networking design fundamentals. Finally, this chapter reviews some fundamentals of communications and data keying that are not part of the CWNA exam but that may help you better understand wireless communications.

History of Wireless Local Area Networks

In the 19th century, numerous inventors and scientists, including Michael Faraday, James Clerk Maxwell, Heinrich Rudolf Hertz, Nikola Tesla, David Edward Hughes, Thomas Edison, and Guglielmo Marconi, began to experiment with wireless communications. These innovators discovered and created many theories about the concepts of electrical magnetic radio frequency (RF).

Wireless networking technology was first used by the U.S. military during World War II to transmit data over an RF medium using classified encryption technology to send battle plans across enemy lines. The spread spectrum radio technologies often used in today’s WLANs were also originally patented during the era of World War II, although they were not implemented until almost two decades later.

In 1970, the University of Hawaii developed the first wireless network, called ALOHAnet, to wirelessly communicate data between the Hawaiian Islands. The network used a LAN communication Open Systems Interconnection (OSI) layer 2 protocol called ALOHA on a wireless shared medium in the 400 MHz frequency range. The technology used in ALOHAnet is often credited as a building block for the Medium Access Control (MAC) technologies of Carrier Sense Multiple Access with Collision Detection (CSMA/CD) used in Ethernet and Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) used in 802.11 radios. You will learn more about CSMA/CA in Chapter 8, “802.11 Medium Access.”

In the 1990s, commercial networking vendors began to produce low-speed wireless data networking products, most of which operated in the 900 MHz frequency band. The Institute of Electrical and Electronics Engineers (IEEE) began to discuss standardizing WLAN technologies in 1991. In 1997, the IEEE ratified the original 802.11 standard that is the foundation of the WLAN technologies you will be learning about in this book.

This legacy 802.11 technology was deployed between 1997 and 1999 mostly in warehousing and manufacturing environments for the use of low-speed data collection with wireless barcode scanners. In 1999, the IEEE defined higher data speeds with the 802.11b amendment. The introduction of data rates as high as 11 Mbps, along with price reductions, ignited the sales of wireless home networking routers in the small office, home office (SOHO) marketplace. Home users soon became accustomed to wireless networking in their homes and began to demand that their employers also provide wireless networking capabilities in the workplace. After initial resistance to 802.11 technology, small companies, medium-sized businesses, and corporations began to realize the value of deploying 802.11 wireless networking in their enterprises.

If you ask the average user about their 802.11 wireless network, they may give you a strange look. The name that people often recognize for the technology is Wi-Fi. Wi-Fi is a marketing term, recognized worldwide by millions of people as referring to 802.11 wireless networking.

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What Does the Term Wi-Fi Mean?

Many people mistakenly assume that Wi-Fi is an acronym for the phrase wireless fidelity (much like hi-fi is short for high fidelity), but Wi-Fi is simply a br...