Chapter 5-6 review (homework telecommunication)

Suppose you're assisting with a cable installation using fiber-optic cabling that will support Gigabit Ethernet. You're approved to install segments up to 4000 m in length. What kind of cable are you using?

- 1000Base-LX- SMF (Single mode fiber)

What is the difference between short circuits and open circuits?

- A short circuit is an unwanted connection, such as when exposed wires touch each other. - An open circuit is one where needed connections are missing, such as when a wire breaks.

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 kind of cable uses BNC connectors? Which connector is likely to be used by cable TV? A.Coaxial cable, F-connector B. Twisted-pair cable, RJ-11 C. Copper cable, RJ-45 D. Fiber-optic cable, MTRJ

A

Which fiber connector contains two strands of fiber in each ferrule? A.MTRJ B. SC C. ST D. LC

A

Which fiber transceiver is the same size as SFP transceivers, but can support network speeds over 10 Gbps?

SFP+

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+

Which kind of multiplexing assigns slots to nodes according to priority and need? A.WDM (wavelength division multiplexing) B. STDM (statistical time division multiplexing) C. TDM (time division multiplexing) D .CWDM (coarse wavelength division multiplexing)

B

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

What is the earliest twisted-pair cabling standard that meets the minimum requirements for 10GBase-T transmissions? A. Cat 5e B. Cat 5 C. Cat 6a D. Cat 7

C

What type of fiber cable problem is caused when pairing a 50-micron core cable with a 62.5-micron core cable? A. Dirty connectors B. Wavelength mismatch C. Fiber type mismatch D. TX/RX reverse

C

Which of these categories of twisted-pair cable can support Gigabit Ethernet? A.Cat 5, Cat 6, Cat 7 B .Cat 5e, Cat 6, Cat 3 C. Cat 5e, Cat 6a, Cat 7 D. Cat 6, Cat 7a, Cat 5

C

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

CSMA/CA

What kind of tool can measure the distance to the location of damage in a cable?

Cable Performance Tester

Which Bluetooth class has the highest power output?

Class 1

What characteristic of optical transmissions is primarily responsible for distance limitations

Cost and Optical loss

Which kind of crosstalk occurs between wire pairs near the source of the signal? A.Alien B. TX/RX reverse C. FEXT D. NEXT

D

Which transmission characteristic is never fully achieved? A.Latency B.Throughput C.Bit rate D.Bandwidth

D

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)

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 fiber is used in fiber-optic cabling to protect the inner core and prevent the cable from stretching?

Kevlar (a polymeric fiber)

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

Layer 3

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

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

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)

Why is SMF more efficient over long distances than MMF?

Signals traveling over multi-mode fiber experience greater attenuation than those traversing single-mode fiber.

How is latency measured, and in what unit?

The brief delay of electrons between the instant when data leaves the source and when it arrives at its destination. -Measured in milliseconds RTT (Round-trip-time) The time it takes to go from sender to receiver then back to sender.

Why do APC ferrules create less back reflection than UPC ferrules?

The end faces are placed at an angle to each other.

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

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.

What is a twist ratio, and why is it important?

- The number of twists per meter or foot. - Affects the reduction or increase of attenuation. -The more twist per meter, the more it is resistant to cross-talk.

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.

Suppose you're creating patch cables to be used in a government office. What color wire goes in the first pin? A.White/orange B. White/green C. Brown D. Blue

A

Which part of a toner and probe kit emits an audible tone when it detects electrical activity on a wire pair? A.TDR B. Tone generator C. Tone locator D. Toner

C