Data Transmission Basics

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Questions and Answers

What type of data is characterized by having discrete states and values?

Composite data

Analog data

Continuous data

Digital data (correct)

Which type of signal can be composed of multiple sine waves?

Non-periodic analog signal

Digital signal

Simple periodic analog signal

Composite periodic analog signal (correct)

What is the bandwidth of a composite signal defined as?

The frequency of the digital signal

The difference between the highest and lowest frequencies (correct)

The total number of signal levels

The average frequency of the signal

In Baseband transmission, how is data sent through the media?

As digital signals through a single channel using entire bandwidth Signup and view all the answers

How many bits per level are needed for a digital signal with eight levels?

3 bits Signup and view all the answers

Which statement about Baseband communication is true?

It utilizes the entire bandwidth for a single channel. Signup and view all the answers

Which of the following best describes Digital signals?

Composite analog signals with frequencies between zero and infinity Signup and view all the answers

What is the characteristic of periodic analog signals?

They can be either simple or composite. Signup and view all the answers

What is the relationship between bandwidth and bit rate in baseband transmission?

Bandwidth is proportional to bit rate. Signup and view all the answers

Which of the following best describes broadband transmission?

It requires separate frequencies for sending and receiving data. Signup and view all the answers

What does attenuation refer to in the context of signal transmission?

The loss of signal energy as it travels through a medium. Signup and view all the answers

What causes phase differences in a composite signal?

Different frequency components have varying propagation speeds. Signup and view all the answers

Which of the following measures the relative strengths of two signals?

Decibel (dB) Signup and view all the answers

What effect does distortion have on a signal?

It alters the signal's form or shape. Signup and view all the answers

Which type of communication relies on the concept of frequency-division multiplexing?

Broadband transmission Signup and view all the answers

Which of the following is NOT a cause of signal impairment?

Amplification Signup and view all the answers

What does a high signal-to-noise ratio (SNR) indicate about a signal?

The signal is less corrupted by noise. Signup and view all the answers

Which calculation is used to determine the theoretical maximum bit rate for a noiseless channel?

Bit Rate = 2 × bandwidth × log2 L Signup and view all the answers

What factors influence the data rate in data communications?

Available bandwidth, quality of the channel, signal level Signup and view all the answers

Which of the following correctly defines Shannon capacity?

The theoretical maximum bit rate of a noisy channel Signup and view all the answers

How is the signal-to-noise ratio expressed in decibels?

SNRdB = 10 log10 SNR Signup and view all the answers

What is a practical limitation when increasing the number of signal levels in data transmission?

Reduced reliability of the communication system Signup and view all the answers

What is the role of bandwidth in networking?

It refers to the range of frequencies a channel can pass. Signup and view all the answers

What is the main reason for modulating an analog signal?

To enable transmission over a band pass channel Signup and view all the answers

Which technique is commonly used for converting an analog signal to digital data?

Pulse Code Modulation Signup and view all the answers

In terms of bandwidth, what does an increase in hertz imply?

Increased data transmission speed in bits per second. Signup and view all the answers

What is the primary difference between guided and unguided transmission media?

Guided media uses physical conductors while unguided does not Signup and view all the answers

Which of the following is NOT a type of un-guided transmission media?

Coaxial cable Signup and view all the answers

Which of the following techniques may not always be needed in digital-to-digital conversion?

Block coding Signup and view all the answers

How many types of guided transmission media are explicitly mentioned?

Four Signup and view all the answers

Which application is a common example of analog-to-digital conversion?

Video transmission Signup and view all the answers

What is the role of line coding in digital-to-digital conversion?

To represent digital data with digital signals Signup and view all the answers

What does baud rate refer to in data transmission?

The signal rate, or how many signal changes are transmitted per second. Signup and view all the answers

Which statement correctly describes the relationship between baud rate and bit rate during analog transmission of digital data?

Baud rate is less than or equal to bit rate. Signup and view all the answers

What does throughput measure in the context of data transmission?

The actual speed of data transmission through a network. Signup and view all the answers

How is the throughput different from bandwidth?

Throughput represents an actual measurement while bandwidth represents potential capacity. Signup and view all the answers

What is the purpose of Digital-to-Analog Conversion?

To allow digital data to be transmitted over analog communication links. Signup and view all the answers

Which of the following is NOT a type of encoding mentioned?

Analog-to-Digital Transmission Signup and view all the answers

What is the formula that describes the relationship between baud rate (S), bit rate (N), and the ratio of data elements (r)?

S = N x 1 / r Signup and view all the answers

Which device is an example of a technology that uses Digital-to-Analog Conversion?

Modem Signup and view all the answers

What is the maximum bandwidth of twisted pair cables?

0 - 100 MHz Signup and view all the answers

Which type of twisted pair cable is mostly used indoors?

UTP (Unshielded Twisted Pair) Signup and view all the answers

What distinguishes UTP from STP cables?

STP cables are shielded to reduce interference, whereas UTP cables are not. Signup and view all the answers

What is a major advantage of fiber-optic cables over twisted pair cables?

Fiber-optic cables can transmit data over longer distances. Signup and view all the answers

What is the consequence of using stranded cable instead of solid cable?

Stranded cable has a smaller bend radius, making it easier for tight corners. Signup and view all the answers

What is the role of coaxial cables in data communications?

They are outdated and not commonly used. Signup and view all the answers

Which cable type provides the highest bandwidth?

Optical Fiber Cable Signup and view all the answers

What is a characteristic of thick net coaxial cables?

They require special equipment to connect to a network. Signup and view all the answers

Study Notes

Data Transmission on Physical Media

Data can be analog or digital. Analog data are continuous, digital data have discrete states.
Signals can be analog (infinite values) or digital (limited values).
Periodic analog signals can be simple (sine wave) or composite (multiple sine waves).
Bandwidth is the difference between highest and lowest frequencies in a composite signal.
Digital signals can have multiple levels, enabling more than one bit per level.
Sending 1 bit per level vs. sending multiple bits for a level in a digital signal.
Bit rate is the number of bits sent per second, baud rate is the number of signal changes per second.

Transmission Impairments

Signal impairment occurs due to imperfections in the transmission medium.
Three main causes of impairment are: attenuation, distortion, and noise.
Attenuation is loss of signal energy; to compensate for loss, amplifiers are used.
Distortion is change in the signal's form; it occurs due to different propagation speeds of signal components.
Noise is unwanted signals that corrupt the desired signal (thermal, crosstalk, impulse noise).
Signal-to-noise ratio (SNR) is the ratio of signal power to noise power; a higher SNR indicates less signal corruption.
SNR is often expressed in decibels (dB).

Transmission Methods

Baseband transmission uses the entire bandwidth of the medium as a single channel for digital signals.
It is bi-directional (can send and receive simultaneously).
It cannot use frequency-division multiplexing.
Broadband transmission uses multiple frequencies in a channel, enabling multiple transmissions at once.
It is unidirectional by default (send and receive on separate pathways) or two channels for transmission and reception,
It is possible to utilize frequency-division multiplexing (FDM).
Bandwidth is proportional to the bit rate for baseband transmission.

Data Rate Calculation

Nyquist bit rate (noiseless channel) defines the theoretical maximum bit rate: Bit Rate = 2 x bandwidth x log2 L
Shannon capacity (noisy channel) defines the theoretical maximum bit rate for a noisy channel: Bit Rate = bandwidth x log2(1 + SNR)
Bandwidth can be measured in Hertz (frequencies) or bits per second (speed of transmission).
Baud rate (signal rate): the number of signal changes per second. Baud rate is related to the bit-rate.

Encoding

Data (signal) encoding can be of four types: digital-to-analog, analog-to-analog, analog-to-digital, and digital-to-digital conversion.
Digital-to-analog conversion allows sending digital information over analog channels. Includes techniques like ASK, FSK, PSK, QAM.
Modulation is a technique to convert analog signal to a higher frequency band if the media or channel is a limited band-pass channel.
Analog-to-digital conversion changes an analog signal to digital data.
Digital-to-digital conversion changes one form of digital data to another form of digital data (e.g. line coding to increase the rate).

Transmission Media Categories

Transmission media are categorized as guided (wired) or unguided (wireless).
Guided media include twisted-pair cable, coaxial cable, fiber-optic cable, and twisted pair.
Unguided media include radio waves, microwaves, and infrared waves.
Each media type has different bandwidth capabilities and physical properties.

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Description

Explore the fundamentals of data transmission on physical media in this insightful quiz. Learn about analog and digital signals, bandwidth, and the various impairments that can affect signal quality. Test your knowledge on key concepts such as bit rate and transmission causes.