Question 1

At a higher level of utilization a larger buffer is needed to hold the backlog.

Accepted Answer

As the utilization increases, the backlog tends to increase as well, which means that a larger buffer is needed to hold and manage the backlog effectively. So, the statement is true.

Question 2

The ________ accepts the multiplexed data stream,separates the data according to channel,and delivers data to the appropriate output lines.
A)high capacity fiber
B)coaxial link
C)multiplexer
D)demultiplexer

Accepted Answer

The device that separates the data according to channel and delivers it to the appropriate output lines is a demultiplexer. A multiplexer is used to combine multiple input channels into one output line. High capacity fiber and coaxial links are types of transmission media and do not perform the function described in the question.

Question 3

Synchronous time division multiplexing can be used with ________ signals.
A)analog
B)digital signals or analog signals carrying digital data
C)digital
D)digital signals carrying digital data

Accepted Answer

Synchronous time division multiplexing (TDM) is a technique used to combine multiple signals into a single transmission medium by dividing the available bandwidth into time slots. This technique can be used with digital signals or analog signals carrying digital data, but not with pure analog signals. Therefore, option B is the best choice as it covers both digital signals and analog signals carrying digital data.

Question 4

Large numbers of voice and data transmissions can be carried simultaneously using multiplexing.

Accepted Answer

Multiplexing is a technique that allows multiple signals to be transmitted over a single communication channel. This enables large numbers of voice and data transmissions to be carried simultaneously.

Question 5

With time division multiplexing,modulation equipment is needed to move each signal to the required frequency band and multiplexing equipment is needed to combine the modulated signals.

Accepted Answer

Time Division Multiplexing (TDM) does not require modulation equipment to move each signal to a specific frequency band; it works by dividing the available time into slots and assigning each signal a specific slot, thus combining them into one signal without changing their frequencies.

Question 6

Synchronous time division multiplexing is possible when the achievable data rate of the medium exceeds the data rate of digital signals to be transmitted.

Accepted Answer

Synchronous time division multiplexing is a technique where multiple digital signals are combined into a single signal by assigning each signal a fixed time slot. This technique can only be used when the achievable data rate of the medium (such as a copper wire or an optical fiber) is greater than the combined data rate of the signals to be transmitted. This ensures that each signal has enough time to be transmitted within its allotted time slot. Therefore, the statement is true.

Question 7

________ multiplexing is commonly used for multiplexing digitized voice streams and data streams.
A)Time division
B)Frequency division
C)Statistical time division
D)Synchronous time division

Accepted Answer

The answer of ________ multiplexing is commonly used for multiplexing...

Question 8

FDMA is a technique used to share the spectrum among multiple stations.

Accepted Answer

FDMA stands for Frequency Division Multiple Access, which is a technique used to divide the available frequency spectrum into multiple channels or sub-bands to enable multiple stations to share the same spectrum without interfering with each other. Each station is assigned a unique frequency or channel to transmit and receive data. Therefore, Option A is correct.

Question 9

Flow control and error control can be provided on a per-channel basis by using a data link control protocol such as HDLC.

Accepted Answer

HDLC is a data link control protocol that provides flow control and error control on a per-channel basis. Therefore, the statement is true.

Question 10

The true potential of optical fiber is fully exploited when multiple beams of light at different frequencies are transmitted on the same fiber.

Accepted Answer

This statement is true. The technique used to achieve this is called wavelength division multiplexing (WDM). Different wavelengths of light can be used to carry different data signals simultaneously on the same fiber, greatly increasing the capacity and efficiency of the system.

Question 11

The long distance carrier system provided in the US and throughout the world was designed to transmit voice signals over high capacity transmission links such as optical fiber,coaxial cable,and microwave.

Accepted Answer

The statement is true. The long distance carrier system was designed to transmit voice signals over high capacity transmission links such as optical fiber, coaxial cable, and microwave.

Question 12

The multiplexer combines data from the input lines and transmits over a lower capacity data link.

Accepted Answer

A multiplexer combines multiple input signals into one output signal, but it does not necessarily transmit over a lower capacity data link; it selects one of the inputs to pass through to the output.

Question 13

Typically two communicating stations will not utilize the full capacity of a data link.

Accepted Answer

Two communicating stations will not use the full capacity of a data link because there are other factors that affect the transmission rate such as noise, latency, and network congestion. The transmission rate is also influenced by the protocols and technologies used to establish and manage the connection. Therefore, it is common for communication channels to operate below their maximum capacity.

Question 14

Frequency division multiplexing can be used with ________ signals.
A)digital signals carrying digital data
B)analog signals carrying digital data
C)analog
D)digital

Accepted Answer

Frequency division multiplexing is a technique used to divide the bandwidth of a communication channel into several sub-channels, each dedicated to a separate signal. It is commonly used with analog signals. Although it is possible to use it with digital signals, it is more commonly done with analog signals that carry voice, video or other types of analog data. Therefore, the best choice is (C) analog.

Question 15

Multiplexing allows several transmission sources to share a larger transmission capacity.

Accepted Answer

Multiplexing is a technique that combines multiple signals into a single signal that can be transmitted over a shared communication medium. This allows several transmission sources to share a larger transmission capacity, making more efficient use of the available bandwidth. Multiplexing is commonly used in telecommunications systems, such as telephone networks and cable television systems, to transmit multiple channels of information over a single transmission line.

Question 16

In TDD,data are transmitted in both directions at the same time.

Accepted Answer

In TDD (Time Division Duplexing), data is transmitted in one direction at a time. The transmitter and receiver switch roles at a specific interval, enabling bidirectional communication.

Question 17

The higher the data rate,the least cost-effective the transmission facility.

Accepted Answer

Higher data rates typically allow for more efficient use of a transmission facility, spreading the fixed costs over more data and potentially reducing the cost per bit transmitted.

Question 18

An individual cable modem subscriber may experience access speeds from 500 kbps to 1.5 Mbps or more,depending on the network architecture and traffic load.

Accepted Answer

The access speeds for an individual cable modem subscriber can vary depending on the network architecture and traffic load, typically ranging from 500 kbps to 1.5 Mbps or more.

Question 19

The ________ multiplexing is the most heavily used.A familiar example is broadcast and cable television.
A)statistical time division
B)time division
C)frequency division
D)synchronous time division

Accepted Answer

The given example of broadcast and cable television indicates that the most heavily used type of multiplexing is frequency division multiplexing (FDM). This is because different channels are allocated different frequencies which are then combined and transmitted over a single communication channel. Statistical time division multiplexing (STDM) and synchronous time division multiplexing (TDM) are also used, but not as commonly as FDM.

Question 20

Synchronous TDM is called synchronous because synchronous transmission is used.

Accepted Answer

Synchronous TDM is called synchronous because it allocates fixed time slots to each channel in a repeating sequence, not because synchronous transmission is used.

Quiz 8: Multiplexing