Chapter 3

Question 1

What are the two categories of communications media.

Answer 1

• physical or conducted media
• radiated or wireless media

Question 2

Conducted media includes what cables.

Answer 2

-Twisted pair wire
- Coaxial cable
- Fiber-optic cable

Question 3

What cable comes as two or more pairs of single-conductor copper wires that have been twisted around each other.

Answer 3

twisted pair wire

Question 4

What cable has 7 categories

Answer 4

Twisted pair wire

Question 5

Why are the wires in twisted pair twisted.

Answer 5

It helps eliminate electromagnetic interface between the two wires.

Question 6

the most common form of twisted pair; none of the wires in this form is wrapped with a metal foil or braid.

Answer 6

Unshielded twisted pair (UTP)

Question 7

a form in which a shield is wrapped around each wire individually, around all the wires together, or both.

Answer 7

shielded twisted pair (STP)

Question 8

a single wire (usually copper) wrapped in a foam insulation, surrounded by a braided metal shield, and then covered in a plastic jacket.

Answer 8

Coaxial cable

Question 9

What are the two major coaxial cable technologies.

Answer 9

-Baseband
- Broadband

Question 10

Which coaxial technology uses digital signaling in which the cable carries only one channel of digital
data.

Answer 10

Baseband

Question 11

Which coaxial technology typically transmits analog signals and is
capable of supporting multiple channels of data simultaneously.

Answer 11

Broadband

Question 12

the electronic distortion that a
signal passing through a metal wire experiences when a stray magnetic field passes over it.

Answer 12

Electromagnetic interference

Question 13

a thin glass cable, a little thicker than a human hair, surrounded by a plastic coating.

Answer 13

Fiber-optic cable (or optical fiber)

Question 14

Explain how a fiber-optic cable works

Answer 14

A photo diode or laser generates pulses of light which travel down the fiber optic cable and are received by a photo receptor

Question 15

the main connecting cable that runs from one end of the installation to another

Answer 15

backbone

Question 16

What transmission systems transmit tightly focused beams of radio signals from one ground-based microwave transmission antenna to another.

Answer 16

Terrestrial microwave

Question 17

What are the two most common application areas of terrestrial microwave?

Answer 17

• Telephone communications
• Business intercommunications

Question 18

Microwave transmissions do not what?

Answer 18

Microwave transmissions do not follow the curvature of the Earth, nor do they pass through solid objects.

Question 19

What means that to receive and transmit a signal, each antenna must be in sight of the next antenna

Answer 19

line-of-sight transmission

Question 20

Which transmission system signal travels from a ground station on Earth to a satellite and back to another ground station on Earth, thus achieving much greater distances than Earth-bound line-of-sight transmissions.

Answer 20

Satellite microwave transmission

Question 21

What is a wireless technology that uses low-power, short-range radio frequencies to communicate between two or more devices.

Answer 21

The Bluetooth protocol

Question 22

A small network like this with eight or fewer devices is called a what?

Answer 22

piconet

Question 23

Multiple piconets can be interconnected form a what?

Answer 23

scatternet

Question 24

What is a special form of radio transmission that uses a focused ray of light in the infrared frequency range (1012–1014 MHz)?

Answer 24

Infrared transmission

Question 25

a relatively new wireless technology supported by the IEEE 802.15.4 standard.

Answer 25

ZigBee