Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Networking > Chapter 3 82-87 > Flashcards

Chapter 3 82-87 Flashcards

1
Q

What is data modulation?

A

converting analog to digital signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what modulates data in your home?

A

the modem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is a carrier wave?

A

a wave with preset properties (frequency, amplitude, phase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How is data transferred

A

another wave is combined with the carrier wave to create a new wave, then another data wave is added to this. The modem separates them when the message arrives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how much is modified by the information wave?

A

only one property of the wave is modified by the information wave when added to the carrier wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is FM

A

FM is frequency modulation.The data wave must conform to a certain frequency.The carrier wave’s frequency is modified by a data signal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is AM

A

AM is amplitude modulation, the amplitude of the carrier wave is modified by the data wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Simplex

A

one way communication, cannot get a message back

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Half-duplex

A

two way communication, but only one way at a time (walkie talkies)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Duplex

A

full duplex, phone lines, two way communication at the same time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a channel?

A

a channel is a distinct transportation path

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

multiplexing?

A

allowing multiple signals to travel simultaneously over one medium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Sub-channel

A

a medium’s channel is divided into subchannels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is a mux and demux

A

the device that separates the signals or combines the signals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

multiplexer

A

at the transmission end of the signal, combines many signals on a channel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

demultiplexer

A

At the receiving end separates the signals on the channel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the purpose of multiplexing?

A

multiplexing allows more data to be transmitted in a given span of time over a given bandwidth

18
Q

TDM

A

Time division multiplexing

19
Q

what is TDM

A

channel is divided into intervals of time,or time slots. Each node on the network gets its own slot.

20
Q

Why can TDM be inefficient?

A

because if all nodes are not transmitting data, then that spot is wasted it is not shared with other users

21
Q

What is statistical multiplexing?

A

slots are assigned according to priority or need

22
Q

How is statistical multiplexing different from TDM?

A

when a node is not using its slot, the space is reassigned to a node that can use it.

23
Q

What is a benefit of statistical multiplexing?

A

it maximizes available bandwidth on a network

24
Q

what is FDM

A

Frequency division multiplexing

25
Q

What happens in FDM?

A

a unique frequency band is assigned to each communication sub channel

26
Q

When was FDM used?

A

in the earth 20th C for telephone lines rather than stringing a line per house, they merged the signals

27
Q

How many signals were sent on telephone wire?

A

24

28
Q

How are telephone wires used differently these days?

A

we can only hear 300-3400 MHz, so they use the remaining bandwidth to send other signals

29
Q

What happens when the telephone signal gets to your house?

A

It is demultiplexed into only your signal

30
Q

What is WDM?

A

Wavelength division multiplexing

31
Q

What does WDM do?

A

uses fiber optic cable,

32
Q

How many conversations can a WDM signal carry?

A

20000

33
Q

How does WDM work?

A

a beam of light, divided into 40 carrier waves with different wavelengths, thus different colours

34
Q

What can each WDM carry?

A

10Gbps on one channel

35
Q

What happens to the data?

A

Each channel is given its data signal, then a mutliplexer combines all the waves into one white light. Like a prism

36
Q

What happens to the WDM signal when it arrives?

A

a demultiplexer separates it into channels again

37
Q

What can boost the signal?

A

an amplifier might boost a weak signal

38
Q

What is DWDM?

A

Dense wavelength division multiplexing

39
Q

What does DWDM do?

A

a single fiber in a fiber optic cable can carry 80-160 channels

40
Q

How does DWDM get so much signal?

A

DWDM uses more wavelength for signals

41
Q

when is DWDM used?

A

between ISP providers and their providers, very long distance WAN for high bandwidth uses

Networking (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions