Chapter 6: Wireless Networking

Which Wi-Fi frequency band offers 24 unlicensed communications channels in the United States?

5 GHz

Which 802.11 standard functions in both the 2.4-GHz and 5-GHz bands?

802.11n

What feature of a site survey maps the Wi-Fi signals and other noise in your location?

Heat maps

Which one of the following wireless transmission types requires a clear LOS to function?

Infrared

What is the lowest layer of the OSI model at which wired and wireless transmissions share the same protocols?

Layer 3

Which Bluetooth class has the highest power output?

Class 1

Which Carrier Sense technology is used on wireless networks to reduce collisions?

CSMA/CA

You just settled in for some study time at the local coffee shop, and you pause long enough to connect your smartphone to the WiFi so you can listen to some music while you study. As you're about to sign in, you realize that you clicked on an SSID called "Free Coffee and Internet." What kind of security trap did you almost fall for?

Evil twin

What technology does Bluetooth use to take advantage of the 79 channels allocated to the Bluetooth band?

FHSS (frequency hopping spread spectrum)

You've just completed a survey of the wireless signals traversing the airspace in your employer's vicinity, and you've found an unauthorized AP with a very strong signal near the middle of the 100- acre campus. What kind of threat do you need to report to your boss?

Rogue AP

Why do wireless networks experience a greater reduction in throughput compared with wired networks?

Wireless networks operate at half duplex while wired networks can operate in full duplex which causes throughput to be lower in wireless connections then what is advertised for them. Also in the 802.11 data frame the Sequence Control field that handles packet fragmentation is error checked and handled at the Data link layer rather than the Networking Layer which slows down transmission more.

802.11ac provides an advantage over 802.11n by incorporating increased channel bonding capabilities. What size bonded channels does 802.11ac support?

802.11ac supports 20-,40-,60-MHz channels with optional use of 160-MHz channels.

To exchange information, two antennas must be tuned to the same ______________.

frequency

You're setting up a home network for your neighbor, who is a music teacher. She has students visiting her home regularly for lessons and wants to provide Internet access for their parents while they're waiting on the children. However, she's concerned about keeping her own data private. What wireless feature can you configure on her AP to meet her requests?

A guest network with a captive portal.

Which kind of antenna is used in a point-to-point link, especially over long distances?

A unidirectional antenna

Which IoT wireless standard is used to sync data from a smartwatch, bike computer, and smart phone to a single user account?

ANT+

A hacker takes advantage of an open Bluetooth connection to send a virus to a user's smartphone. What kind of security breach has occurred?

Bluejacking

A user swipes her smartphone across a tag on a poster to obtain showtimes for a movie she wants to see later that evening. What wireless technology transmitted the data?

NFC

Signals traveling through areas in which many wireless communications systems are in use will exhibit a lower _________ due to the higher proportion of noise.

SNR(signal-to-noise ratio)

When a wireless signal encounters a large obstacle, what happens to the signal?

The wave may pass through the object if the object allows otherwise the signal may experience certain phenomena, depending on the object such as fading, attenuation, interference, refraction, reflection, scattering or diffraction