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Chapter 8: Wireless LANs
Core Idea
This chapter focuses on the use of wireless technology to connect to local and distant networks.
Instructor Focus
The focus of this topic is on wireless connection terminology and the techniques for sharing the
wireless bandwidth. Make sure to review the 802.11 set of standards for radio frequency
Network+ Exam Objectives in this Chapter/Lesson
o 4.3 Given a scenario, secure a basic wireless network
Terminology
Make an effort to define the following terms for the designated areas. After defining these,
calling on the students for repeat definitions as you progress through the slide deck will help
them retain the terminology.
Wireless Technology Elements:
x Wireless access point (AP)
x Wireless router
Frequency Sharing:
x Carrier sense multiple access collision avoidance (CSMA/CA)
x Direct-sequence spread spectrum (DSSS)
x Frequency-hopping spread spectrum (FHSS)
x Orthogonal frequency-division multiplexing (OFDM)
Wireless Standards:
x 802.11a
x 802.11g
x 802.11ac
General Wireless Concepts:
x Multiple input, multiple output (MIMO)
x Channel bonding
x Warchalking
Wireless Service Sets:
x Independent basic service set (IBSS)
x Basic service set (BSS)
Wireless Security:
x Wired Equivalent Privacy (WEP)
x Wi-Fi Protected Access (WPA)
x Wi-Fi Protected Access version 2 (WPA2)
Focus Questions
x How do various wireless LAN technologies function, and what wireless standards are in
common use?
x What are some of the most important WLAN design considerations?
x What WLAN security risks exist, and how can those risks be mitigated?
Icebreaker Discussion
Choose one or both of the following:
1. What are the benefits of connecting to a network wirelessly?
This should be a fairly straightforward discussion, but it will get your students focused on
the topic and why it is important. This is probably the fastest growing area of local
2. What are the difficulties associated with wireless network connections?
This should also be a general discussion that will be expanded as the lesson continues.
Establish here what the main issues are in terms of communicating wirelessly. Specifically,
Icebreaker Activity
1. Give an example of a home wireless network; what devices are likely to use this network and
why is it more beneficial than a wired home network?
This is an expansion of the discussions where you will get to specific devices that benefit
from wireless technologies. You will specifically focus on the incorporation of wireless
technology in a home network. A wireless router will often serve as a gateway to a
Chapter 8: Network Simulator Activities
x Matching Wireless Standards and Terminology
x Wireless Antenna Placement
Main Activities
1. Wireless Advantages
For this lesson, you will show what is needed to wire a home with a traditional LAN and the
benefit provided by using a WLAN instead. Also mention how this expands on the subscriber line
In this scenario, the WAN connection is in the same room with one of the stationary computers
and one of the primary use places for a laptop. However, there is another stationary computer
in a room upstairs and a second room that is another place for laptop usage. All of these rooms
would have to be wired in a LAN configuration, but they are all centralized on one side of the
2. Wireless AP Placement
This lesson focuses on the placement of overlapping wireless access points (APs). Consider the
overlapping channel issue here (where a channel must be at least five channels away to prevent
crossover) when planning for the number of APs that will be utilized. Eventually, you will
establish a wireless network with seven APs that bound each other. The available channels to
WAN
Connection
If two cells with the same channel overlap, you will get interference. This comes down to a
spacing issue that will have to be tested in practice, but you can see from the example that it is
possible to have up to three overlapping AP cells. Now challenge your students to plan coverage
of seven AP cells that border each other. One possible solution is shown here.
Quiz Questions
You can ask the following questions either in class for a group discussion or for individual practice. If
you ask them for individual practice, review in class to make sure everyone properly understands
the content.
1. What is the difference between omnidirectional antennae and unidirectional antennae? When
are each used?
11
11
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2. Briefly compare the following standards: 802.11a, 802.11b, and 802.11g.
802.11b: Supports speeds up to 11 Mbps on the 2.4-GHz band, DSSS transmission method
3. Briefly define the WLAN types IBSS, BSS, and ESS.
IBSS: Independent basic service set: This is used for temporary or ad hoc connections between
4. What is the likely result if a wireless client is using WEP attempts to connect using the correct
username/password to a wireless network using WPA2?
5. Why is security so important to wireless networks? Give two examples of defense measures that
should be taken to enhance wireless security.
Wireless networks need to be secured to prevent unauthorized use, eavesdropping of legitimate
use, and compromise of the connected networks. Several common defense mechanisms can be
used:
x MAC filtering: This instructs the AP to filter out any unauthorized MAC addresses from
using the AP.
