quiz 3

___________ is not a type of digital signaling technique.

Data rate signaling

A physical circuit refers to the transmission characteristics of the connection.

False

ASCII is the least popular code for data communications.

False

______________ refers to the time it takes for a signal to travel from sender to recipient (highly exaggerated with satellite transmission).

Propagation delay

With which type of digital signaling does the signal always return to zero volts after each bit?

Return-to-zero signaling

Data compression can increase the throughput of a communication link.

True

Time division multiplexing is more efficient that frequency division multiplexing because the guardbands used in the frequency division multiplexing or not needed.

True

Which is not true about point-to-point circuits?

point-to-point circuits reduce the amount of cable required and use the circuit more efficiently than multipoint circuits.

_________ is the basic physical layout of the circuit.

circuit configuration

Having a conversation with someone using a cellular phone is an example of _________ transmission.

full-duplex

If each sample uses 16 bits and the number of samples taken each second is 8000; then the transmission speed on the circuit is?

128 Kbps

When sending four bits at a time using frequency modulation, the number of different frequency levels that would be needed would be _______.

16

The typical range of human hearing is:

20 to 14,000 Hz

____________ refers to the transmission characteristics of the circuit.

logical circuit

__________ is a line-of-sight type of wireless media.

microwave

____________ refers to changing the shape of the sound wave in different ways to represent a 1 or a 0.

modulation

The acronym, Modem, stands for _________________.

modulator-demodulator

The earliest type of fiber optic systems were:

Multimode

Which of the following statements is correct?

Serial transmission is slower than parallel transmission.

___________ refers to the spreading of the signal that different parts of the signal arrive at different times at the destination.

dispersion

Microwave transmission

all of the above

Another term for the weakening of a signal over distance is:

attenuation

The _____________ of a circuit determines a circuit's capacity.

bandwidth

Which type of digital signaling would experience fewer errors because it has more distinct signals?

bipolar

Transmission speeds:

differ widely among media

In general, networks designed to transmit primarily computer data are likely to be ________.

digital

A codec converts an incoming digital signal to an analog signal for transmission over an analog network.

false

Baud rate is the number of bits transmitted per second.

false

Digital transmission occurs when the signal sent over the transmission media constantly varies among an infinite number of states.

false

Digital transmission produces more errors than analog transmission.

false

Fiber optic cable carries signals in traditional electrical form

false

Frequency division multiplexing divides the circuit into a set of different time slots.

false

Frequency modulation refers to the changing of the height of the sound wave.

false

In a multipoint circuit configuration, each computer can use the circuit at the same time.

false

Multimode fiber is capable of longer transmission distances than single mode fiber.

false

Multitasking means to break one high-speed physical communication circuit into several lower-speed logical circuits so that different devices can simultaneously use it.

false

Nonreturn to zero is a type of unipolar signaling

false

Propagation delay is negligible with satellite transmission.

false

The cabling that runs from the telecommunications closet to each LAN is called backbone cabling.

false

With nonreturn to zero signaling, the voltage alternates between zero and a positive or negative voltage.

false

Radio, microwave and satellite are all examples of guided media.

fasle

Which of the following is the most secure wired media?

fiber optic cable

Which of the following media can best withstand harsh environmental conditions?

fiber optic cable

A(n) __________ circuit is another name for a multipoint configuration.

shared

In which type of modulation is a 1 distinguished from a 0 by shifting the direction in which the wave begins?

phase modulation

____________ is a modulation technique that combines two different amplitude combinations with eight different phase combinations modulation to send four bits per symbol.

quadrature amplitude modulation

_____________ refers to the difference between the original analog data and the approximation of that data using the techniques for translating from analog data to digital signals.

quantizing error

When all bits of a character are transferred one after another, the bits are transferred in ___________ mode.

serial

The room that contains the cable termination points and the distribution frames is referred to as

telecommunications closet

Coding schemes are groups of bits that translate into the "alphabet" of any given system.

true

Ethernet, a common LAN technology, uses Manchester encoding.

true

In full-duplex transmission, two stations can send and receive simultaneously.

true

One form of interference with satellite transmission is called raindrop attenuation in which the transmissions are absorbed by heavy rain.

true

Statistical time division multiplexing does not require the capacity of the circuit to be equal to the sum of the combined circuits.

true

The medium is the physical matter or substance that carries the voice or data transmission.

true

The predominant method of transferring information internally in a computer is via parallel mode.

true

WDM is a version of FDM used in fiber-optic cables.

true

The type of media usually installed on homes and businesses by the telephone company is called ____________.

twisted pair