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CHAPTER 1

Introduction to Wireless
Networking Concepts
Perhaps this is the first time you have ever delved into the world of wireless networking.
Or maybe you have been in networking for some time and are now beginning to see the
vast possibilities that come with wireless networking. Either way, this chapter can help
you understand topics that are not only tested on the CCNA Wireless exambut provide a
good foundation for the chapters to come. If you are comfortable with the available frequency bands, the modulation techniques used in wireless LANs, and some of the standards and regulatory bodies that exist for wireless networking, you may want to skip to
Chapter 2, “Standards Bodies.”
This chapter provides a brief history of wireless networks and explores the basics of radiotechnology, the modulation techniques used, and some of the issues seen in wireless LANs.
You should do the “Do I Know This Already?” quiz first. If you score 80 percent or higher,
you might want to skip to the section “Exam Preparation Tasks.” If you score below 80
percent, you should spend the time reviewing the entire chapter. Refer to Appendix A,
“Answers to the ‘Do I Know This Already?’Quizzes” to confirm your answers.

“Do I Know This Already?” Quiz
The “Do I Know This Already?” quiz helps you determine your level of knowledge of this
chapter’s topics before you begin. Table 1-1 details the major topics discussed in this chapter and their corresponding quiz questions.

Table 1-1

“Do I Know This Already?” Section-to-Question Mapping

Foundation Topics SectionQuestions

Wireless Local-Area Networks

1–2

How Bandwidth Is Achieved from RF Signals

3–6

Modulation Techniques and How They Work

7–10

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CCNA Wireless Official Exam Certification Guide
1. Which of the following accurately describes the goal of RF technology?
a.

To send as much data as far as possible and as fast as possible

b.

To send secure data to remote terminalsc.

To send small amounts of data periodically

d.

To send data and voice short distances using encryption

2. Which of the following is a significant problem experienced with wireless networks?
a.

Infection

b.

Policing

c.

Transmission

d.

Interference

3. Which two of the following are unlicensed frequency bands used in the United
Stated? (Choose two.)
a.

2.0MHz

b.

2.4 GHz

c.

5.0 GHz

d.

6.8 GHz

4. Each 2.4-GHz channel is how many megahertz wide?
a.

22 MHz

b.

26 MHz

c.

24 MHz

d.

28 MHz

5. How many nonoverlapping channels exist in the 2.4-GHz ISM range?
a.

9

b.

3

c.

17

d.

13

6. The 5.0-GHz range is used by which two of the following 802.11 standards?
(Choose two.)
a.

802.11b.

802.11b/g

c.

802.11n

d.

802.11a

Chapter 1: Introduction to Wireless Networking Concepts
7. Which three of the following modulation techniques do WLANs today use?
(Choose three.)
a.

OFDM

b.

AM

c.

FM

d.

DSSS

e.

MIMO

8. DSSS uses a chipping code to encode redundant data into the modulated signal.
Which two of the following are examples ofchipping codes that DSSS uses?
(Choose two.)
a.

Barker code

b.

Baker code

c.

Complementary code keying (CCK)

d.

Cypher block chaining (CBC)

9. DSSS binary phase-shift keying uses what method of encoding at the 1-Mbps data rate?
a.

11-chip Barker code

b.

8-chip CCK

c.

11-chip CCK

d.

8-chip Barker code

10. With DRS, when a laptop operating at 11 Mbpsmoves farther away from an access
point, what happens?
a.

The laptop roams to another AP.

b.

The laptop loses its connection.

c.

The rate shifts dynamically to 5.5 Mbps.

d.

The rate increases, providing more throughput.

7

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CCNA Wireless Official Exam Certification Guide

Foundation Topics

Wireless Local-Area Networks
Although wireless networking began to...