Network+ Guide to Networks, 8th Edition 6-1
Chapter 6
Wireless Networking
At a Glance
Instructor’s Manual Table of Contents
• Overview
• Objectives
• Teaching Tips
• Quick Quizzes
Network+ Guide to Networks, 8th Edition 6-2
Lecture Notes
Overview
This chapter first looks at how wireless transmissions work, regardless of the type of wireless
technology used. These wireless characteristics apply to satellite, Bluetooth, Wi-Fi, cellular, and
Chapter Objectives
After reading this chapter and completing the exercises, the student will be able to:
• Identify and describe various types of wireless networking characteristics
• Explain the various wireless standards that support the Internet of Things
• Explain 802.11 standards and innovations
• Secure a Wi-Fi network
• Troubleshoot a Wi-Fi network
Teaching Tips
Characteristics of Wireless Transmissions
2. Describe the characteristics wireless transmissions have in common with wired
The Wireless Spectrum
1. Define the term wireless spectrum as the frequency range of electromagnetic waves used
for data and voice communication.
3. Use Figure 6-1 to illustrate the wireless spectrum and the major wireless services
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Channel Management
1. Explain that most wireless devices implement one of two technologies to take advantage
of the frequencies within it band:
a. FHSS (frequency hopping spread spectrum)
b. DSSS (direct sequence spread spectrum)
The FCC Wireless Telecommunications Bureau (WTB) handles nearly all FCC
2. Discuss the following wireless standards in the 2.4 GHz range and the band it uses:
a. Wi-Fi uses DSSS
3. Use Figure 6-2 to discuss how Bluetooth frequency hopping avoids a busy Wi-Fi
Antennas
1. Introduce the concept of an antenna noting that each type of wireless service requires an
antenna specifically designed for that service.
2. Define the term radiation pattern.
3. Define the term unidirectional antenna and provide examples of its use. Note that this
type of antenna may also be called a directional antenna.
4. Define the term omnidirectional antenna and provide examples of its use.
Signal Propagation
1. Introduce the concept of signal propagation noting that ideally, a wireless signal would
travel directly in a straight line from its transmitter to its intended receiver.
2. Define and explain LOS (line-of-sight) propagation.
3. Explain the options available when an obstacle stands in a signal’s way.
a. The signal may pass through the object.
4. Note that the object’s geometry governs which of these three phenomena occurs.
5. Discuss the following phenomena and its effect on wireless signals:
a. fading
6. Define multipath signals noting the advantage and disadvantage they present.
7. Use Figure 6-5 to illustrate multipath signals caused by reflection, diffraction, and
Wireless Standards for the IoT (Internet of Things)
1. Introduce students to the acronym IoT (Internet of Things). Point out that this term
applies to any device that can be connected to the Internet.
3. Define and discuss a wireless personal area network, also known as a WPAN.
ZigBee
1. Introduce students to ZigBee, a low-powered battery-conserving wireless technology
designed to handle small amounts of data.
2. Point out that ZigBee is used in IoT devices for the following purposes:
a. building automation
Z-Wave
1. Explain that Z-Wave is a smart home protocol that provides two basic types of functions:
2. Discuss the use of a Z-Wave network controller to control various smart devices on a
Bluetooth
1. Discuss the very common wireless technology known as Bluetooth. Point out that most
3. Use Table 6-2 to discuss Bluetooth power classes.
4. Discuss the pairing process that is required in order for two Bluetooth devices to connect:
a. Turn on the Bluetooth antenna for each device
5. Discuss the security risks involved when using Bluetooth devices.
ANT+
1. Discuss the ANT+ protocol, which is used to gather and track information from sensors
RFID (Radio Frequency Identification)
2. Discuss the three general types of RFID tag and reader combinations:
3. Point out that RFID is commonly used for inventory management and can also be used
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NFC (Near-Field Communication)
1. Explain that near-field communication (NFC) is a form of radio communication that
transfers data wirelessly over very short distances.
Wireless USB
2. Use Figure 6-12 to demonstrate how a mouse can use wireless USB to communicate with
a computer.
IR (Infrared)
1. Explain that IR technology has found new life in the world of IoT.
2. Point out that IR sensors are used to collect information such as:
a. Presence or level of liquid
Quick Quiz 1
1. True or False: All wireless signals are carried through the air by electromagnetic waves.
2. The frequency range of electromagnetic waves used for data and voice communication is
known as which of the following?
a. antenna
b. band
c. wireless spectrum
d. spread
3. ____________________ are used for both the transmission and reception of wireless
signals.
4. What type of signals follow a number of different paths to their destination because of
reflection, diffraction, and scattering?
a. Multipath
b. Opened
c. Closed
d. Variable
5. Which of the following uses FSSS technology in order to avoid interference?
a. Wi–Fi
b. Bluetooth
c. ZigBee
d. ANT+
802.11 WLAN Standards
1. Introduce 802.11 WANs, and note that they operate at Layers 1 and 2 of the OSI model.
2. Introduce Wi-Fi (wireless fidelity) standards.
3. Point out that the 802.11 standards vary at the Physical layer. Point out that 802.11n and
later standards modify the way frames are used at the MAC sublayer.
Access Method
1. Note the significance of using the same physical addressing scheme as Ethernet.
2. Explain the CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) access
method.
3. Describe the RTS/CTS (Request to Send/Clear to Send) protocol.
4. Use Figure 6-15 to demonstrate CSMA/CA with the optional RTS/CTS protocol.
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Association
1. Introduce the concept of association by noting that association involves a number of
packet exchanges between an access point and a computer.
a. Note that association is another function of the MAC sublayer described in the
802.11 standard.
2. Define the term scanning.
3. Describe active scanning and passive scanning.
5. Define the BSS (basic service set) and explain its significance.
7. Use Figure 6-16 to illustrate a network with a single BSS.
8. Use Figure 6-17 to illustrate a network encompassing multiple BSSs that form an ESS.
9. Define and explain reassociation.
10. Note that on a network with multiple access points, network managers can take advantage
Teaching
Tip
Explain why it is considered best practice to use access points manufactured by the
same company when designing an 802.11 network.
IEEE 802.11 Frames
1. Review the types of overhead required to manage access to the 802.11 wireless networks.
3. Compare a basic 802.11 data frame with an Ethernet_II (DIX) frame (Figure 6-18).
4. Describe the significant fields in an 802.11 data frame contributing to data frame
802.11 Innovations
1. Explain that beginning with 802.11n, several innovations have been implemented that
contribute to making later 802.11 standards much faster and much more reliable. Discuss
each of the following:
• MIMO
2. Note that not all of the above techniques are used in every 802.11n or 802.11ac
Implementing a Wi-Fi Network
1. Introduce the topics covered in this section:
a. Designing a small WLAN
Wireless Topologies
1. Explain why wireless networks are not laid out using the same topologies as wired
networks.
2. Describe an ad hoc WLAN. Use Figure 6-22 to illustrate an ad hoc WLAN.
3. Describe an infrastructure WLAN and define a wireless access point and provide
alternative names for it.
5. Note that it is common for a mesh WLAN to include several access points.
6. Use Figure 6-11 to illustrate a mesh WLAN.
7. Discuss the use of a wireless controller for centralized wireless management. Wireless
8. Point out that wireless controllers can be used to detect the presence of unauthorized APs
9. Explain why wireless technology can be used to connect two different parts of a LAN or
Determining the Design
1. Explain that an AP in a home or small office network often combines switching, routing,
2. Use Figure 6-28 to illustrate a home or small office WLAN arrangement.
3. Discuss the following factors when deciding where to install a WLAN’s AP:
a. distance
5. Define and describe a site survey.
7. Point out the enterprise-wide WLAN design considerations found on pages 341-342 of
the text.
Configure Wi-Fi Connectivity Devices
1. Review the steps to configure an access point.
Configure Wi-Fi Clients
1. Explain that wireless access configuration varies from one type of client to another.
2. Explain that configuring clients for wireless access on an enterprise network involves a
3. Review the section on how to configure a Linux/UNIX client using the iwconfig
4. Use Figure 6-32 to illustrate output from the iwconfig command.
Wi-Fi Network Security
1. Explain that the 802.11 standard does not offer any security and the client only needs to
3. Define and explain the term encryption.
4. Emphasize to the students that the purpose of encryption is to keep information private.
5. Explain that many forms of encryption exist with some being more secure than others.
Legacy Networking: WEP (Wired Equivalent Privacy)
1. Briefly discuss the various flaws of WEP and mention that WEP was replaced with a
WPA/WPA2 (Wi-Fi Protected Access)
1. Describe the WPA wireless security protocol.
2. Explain that the encryption protocol in WPA was replaced by a stronger encryption
protocol for the updated version, called WPA2.
3. Point out some additional security options:
Security Threats to Wi-Fi Networks
1. Discuss the following security threats to wireless networks:
Network+ Guide to Networks, 8th Edition 6-12
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Troubleshooting Wireless LANs
1. Point out that cable-testing tools covered in Chapter 5 will tell you nothing about wireless
Wi-Fi Network Tools
1. Discuss the two types of software every network administrator should have in their
toolkit:
2. Describe the specific capabilities common to most wireless network testing tools.
Avoid Pitfalls
1. Discuss the following wireless configuration pitfalls to avoid:
• wrong SSID
• security types mismatch
• wrong passphrase
• overlapping channels or mismatched frequencies
• mismatched standards
Quick Quiz 2
1. Which type of wireless network consists of wireless nodes that transmit directly to each
other via wireless NICs without an intervening connectivity device?
a. mesh WLAN
b. infrastructure WLAN
c. ad hoc WLAN
d. AP WLAN
2. BSSes that belong to the same ESS share a special identifier. What is the identifier
called?
a. SSID
b. BSSID
c. BESSID
d. ESSID
3. True or False: 802.11 networks use the same access method as Ethernet networks.
4. The 802.11 standard specifies a frame type at which of the following?
a. MAC sublayer
b. Physical layer
c. LLC sublayer
d. Network layer
5. Which of the following best describes an innovation where two adjacent 20-MHz
channels can be combined to make a 40-MHz channel?
a. MIMO
b. MU-MIMO
c. channel bonding
d. frame aggregation
Class Discussion Topics
1. Take a student poll of Wi-Fi use (802.11b, 802.11a, 802.11g, 802.11n, and 802.11ac).
Which standard is used the most by the class? Have the class discuss their experiences
2. As a class, discuss the implications of security breaches on technology adoption. Are
people hesitant to use the Internet or wireless technology for purchases due to security
concerns? Are people hesitant to use technology because of privacy concerns? Are these
concerns warranted and are they influenced by age, race, or gender?
Additional Projects
1. Have students research the AT&T network of hot spots across the nation. Each student
should write a report summarizing his or her findings.
Additional Resources
1. The ABCs of securing your wireless network
2. How to Minimize Wireless Problems
3. Bluetooth Special Interest Group
4. Introduction to Wireless Network Security
5. How WiFi Works
Key Terms
For definitions of key terms, see the Glossary near the end of the book.
➢ 802.11a
➢ beacon frame
➢ Bluetooth
➢ brute force attack
➢ BSS (basic service set)
➢ BSSID (basic service set identifier)
➢ ESSID (extended service set identifier)
➢ evil twin
➢ fading
➢ FHSS (frequency hopping spread spectrum)
➢ frequency hopping
➢ MAC sublayer
➢ mesh
➢ MIMO (multiple input-multiple output)
➢ MU-MIMO (multiuser MIMO)
➢ NFC (near-field communication)
➢ refraction
➢ remote wipe
➢ RFID (Radio Frequency Identification)
➢ rogue access point
➢ RTS/CTS (Request to Send/Clear to Send)
➢ Wi-Fi
➢ Wi-Fi analyzer
➢ wireless bridge
➢ wireless controller
➢ wireless range extender