Question 1

The basic way to perform compression is to look for some common pattern in the data and replace each data pattern with a symbol or symbols that will consume less space during transmission or storage.

Accepted Answer

This is indeed the basic concept of data compression.

Question 2

Under normal circumstances, the synchronous time division multiplexor maintains a simple ____ sampling order of the input devices.
A)round-robin
B)FIFO
C)LIFO
D)FILO

Accepted Answer

The synchronous time division multiplexor maintains a simple round-robin sampling order of the input devices, meaning that each device is sampled one after the other in a cyclical order. This ensures that each input device receives equal time and avoids any device being given priority over others. Therefore, the best choice is A) round-robin.

Question 3

The human ear can hear sounds only within a certain range, which for an average person is 10 Hz to 40 kHz (40,000 Hz).

Accepted Answer

The human ear can hear sounds within a range of 20 Hz to 20 kHz.

Question 4

____ gives each incoming source signal a turn to be transmitted, proceeding through the sources in round-robin fashion.
A)Statistical time division multiplexing (Stat TDM)
B)Empirical time division multiplexing (ETDM)
C)Synchronous time division multiplexing (Sync TDM)
D)Fixed time division multiplexing (FTDM)

Accepted Answer

Synchronous time division multiplexing (Sync TDM) gives each incoming source signal a turn to be transmitted in a round-robin fashion. The timing of transmission is synchronized among the sources, ensuring that each source gets a dedicated time slot for transmission. Therefore, choice C is the best option.

Question 5

The Lempel-Ziv algorithm can be fairly effective in compressing data.

Accepted Answer

The Lempel-Ziv algorithm is a well-known lossless data compression algorithm that is widely used in various applications due to its effectiveness in compressing data.

Question 6

The MP3 encoder produces a data stream that has a much faster data rate than that of conventional CD-quality music.

Accepted Answer

The MP3 encoder reduces the data rate compared to conventional CD-quality music by using lossy data compression to discard parts of the audio not typically heard by the human ear, resulting in a smaller file size and slower data rate.

Question 7

Presently, a medium can be divided in three basic ways: a division of ____, a division of time, and a division of transmission codes.
A)frequencies
B)amplitudes
C)wavelength
D)direction

Accepted Answer

The division of frequencies refers to the range of frequencies that can be used to transmit information through a medium. This includes the commonly used radio frequency spectrum and other specialized frequencies used for specific purposes such as satellite communication or medical imaging.

Question 8

To allow multiple users to share a single medium, FDM assigns each user a separate ____.
A)time slot
B)transmission code
C)channel
D)amplitude

Accepted Answer

FDM (Frequency Division Multiplexing) assigns each user a separate channel within the spectrum, allowing multiple users to share a single communication medium by dividing it into frequency bands.

Question 9

Code division multiplexing is based upon a class of modulation techniques known as spread spectrum technology.

Accepted Answer

Code division multiplexing (CDM) is a type of spread spectrum technology that allows multiple users to share the same frequency band by assigning unique codes to each user's signal.

Question 10

The device that is attached to the receiving end of the medium and splits off each signal to deliver it to the appropriate receiver is called the second multiplexor, or ____.
A)multiplexor
B)endplexor
C)splitxor
D)demultiplexor

Accepted Answer

The device that splits off each signal to deliver it to the appropriate receiver is called a demultiplexor. It is the opposite of a multiplexor, which combines multiple signals into one. Therefore, the best choice is D, demultiplexor.

Question 11

Code division multiplexing, while using a fairly wide bandwidth of frequencies and a complex technology, is scalable like WDM.

Accepted Answer

Code division multiplexing (CDM) is indeed scalable like WDM (wavelength division multiplexing) as both technologies allow for multiple signals to be transmitted over a single channel, providing increased bandwidth and efficiency. CDM utilizes the spreading of signals over a wide range of frequencies using unique codes to differentiate each signal, while WDM utilizes different wavelengths of light to transmit multiple signals simultaneously.

Question 12

Since time division multiplexing was introduced, it has split into two roughly parallel but separate technologies: synchronous time division multiplexing and ____ time division multiplexing.
A)fixed
B)statistical
C)inverse
D)empirical

Accepted Answer

Synchronous time division multiplexing (STDM) and statistical time division multiplexing (TDM) are the two main types of TDM. STDM is based on fixed time slots and is used primarily in circuit-switched systems. Statistical TDM, on the other hand, uses variable time slots and is used primarily in packet-switched systems. Therefore, the correct choice is B, statistical time division multiplexing.

Question 13

DSL is capable of achieving speeds into the millions of bits per second.

Accepted Answer

DSL (Digital Subscriber Line) technology is capable of achieving speeds into the millions of bits per second (Mbps), making it one of the fastest and most reliable forms of internet connection available to consumers.

Question 14

The big advantage of frequency division multiplexing over synchronous TDM is the lower noise due to the use of digital signals during transmission.

Accepted Answer

The advantage of frequency division multiplexing is that it allows multiple signals to be transmitted simultaneously over different frequencies, but it does not necessarily have an advantage in terms of lower noise or the use of digital signals. Synchronous TDM can also use digital signals and can provide low noise if properly implemented.

Question 15

First-generation cellular telephone systems allocated channels using frequency ranges within the 800 to ____ megahertz (MHz) spectrum.
A)830
B)900
C)930
D)960

Accepted Answer

First-generation cellular telephone systems allocated channels using frequency ranges within the 800 to 900 MHz spectrum.

Question 16

____ is the assignment of nonoverlapping frequency ranges to each "user" of a medium.
A)Time division multiplexing (TDM)
B)Transmission code multiplexing (TCM)
C)Amplitude division multiplexing (ADM)
D)Frequency division multiplexing (FDM)

Accepted Answer

Frequency division multiplexing (FDM) is the assignment of nonoverlapping frequency ranges to each "user" of a medium.

Question 17

In FDM, ____ take up frequencies that might be used for other data channels, thus introducing a certain level of wastefulness.
A)guard bands
B)channels
C)multiplexors
D)demultiplexors

Accepted Answer

Guard bands are used to prevent interference between adjacent channels, but they also take up frequencies that could potentially be used for additional channels or data transmission. This results in a certain level of wastefulness or inefficiency in FDM.

Question 18

Synchronous time division multiplexing does not require as high-speed a line as statistical time division multiplexing does.

Accepted Answer

This statement is false. Synchronous time division multiplexing requires a higher-speed line because it requires each channel to be assigned a fixed time slot, regardless of whether there is data to transmit or not. Statistical time division multiplexing, on the other hand, can dynamically allocate time slots to the channels that have data to transmit, which can result in a more efficient use of the available line bandwidth.

Question 19

A video device displays multiple (typically 30) frames per second.

Accepted Answer

Most video devices, such as cameras or monitors, display 30 frames per second (fps) or even higher for smoother motion.

Question 20

Three types of synchronous time division multiplexing that are popular today are T-1 multiplexing, ____ multiplexing, and SDH.
A)EIA-232F
B)IPS/SPX
C)SONET
D)RS-232

Accepted Answer

T-1 and SDH are both mentioned as examples, leaving only C as the remaining option.

Quiz 5: Making Connections Efficient: Multiplexing and Compression

The basic way to perform compression is to look for some common pattern in the data and replace each data pattern with a symbol or symbols that will consume less space during transmission or storage.

Under normal circumstances, the synchronous time division multiplexor maintains a simple ____ sampling order of the input devices.

The human ear can hear sounds only within a certain range, which for an average person is 10 Hz to 40 kHz (40,000 Hz).

____ gives each incoming source signal a turn to be transmitted, proceeding through the sources in round-robin fashion.

The Lempel-Ziv algorithm can be fairly effective in compressing data.

The MP3 encoder produces a data stream that has a much faster data rate than that of conventional CD-quality music.

Presently, a medium can be divided in three basic ways: a division of ____, a division of time, and a division of transmission codes.

To allow multiple users to share a single medium, FDM assigns each user a separate ____.

Code division multiplexing is based upon a class of modulation techniques known as spread spectrum technology.

The device that is attached to the receiving end of the medium and splits off each signal to deliver it to the appropriate receiver is called the second multiplexor, or ____.

Code division multiplexing, while using a fairly wide bandwidth of frequencies and a complex technology, is scalable like WDM.

Since time division multiplexing was introduced, it has split into two roughly parallel but separate technologies: synchronous time division multiplexing and ____ time division multiplexing.

DSL is capable of achieving speeds into the millions of bits per second.

The big advantage of frequency division multiplexing over synchronous TDM is the lower noise due to the use of digital signals during transmission.

First-generation cellular telephone systems allocated channels using frequency ranges within the 800 to ____ megahertz (MHz) spectrum.

____ is the assignment of nonoverlapping frequency ranges to each "user" of a medium.

In FDM, ____ take up frequencies that might be used for other data channels, thus introducing a certain level of wastefulness.

Synchronous time division multiplexing does not require as high-speed a line as statistical time division multiplexing does.

A video device displays multiple (typically 30) frames per second.

Three types of synchronous time division multiplexing that are popular today are T-1 multiplexing, ____ multiplexing, and SDH.