MIS 140 Chapter 3
A codec converts an incoming digital signal to an analog signal for transmission over an analog network. True False
False
A physical circuit refers to the transmission characteristics of the connection, such as the speed at which data is being sent through the connection. True False
False
ASCII is the least popular code for data communications. True False
False
Based on the TIA/EIA 568-B structured cabling standard, the cabling that runs from the telecommunications closet to each work area is called backbone cabling. True False
False
Baud rate is the number of bits transmitted per second. True False
False
Coaxial cable costs less and offers less shielding to electrical interference than twisted pair cable. True False
False
Digital transmission occurs when the signal sent over the transmission media constantly varies among an infinite number of states. True False
False
Digital transmission produces more errors than analog transmission. True False
False
Fiber optic cable can only be used on LANs. True False
False
In simplex transmission, the data flows in both directions at the same time True False
False
Multimode fiber is capable of longer transmission distances than single mode fiber. True False
False
Multiplexing increases the cost of provisioning network circuits. True False
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. True or False?
False
Newer telephone circuits, built during the last decade, offer higher quality because they were built using analog transmission. True False
False
The amount of time it takes to switch between sending and receiving in half-duplex transmission is called the propagation delay. True False
False
Wavelength division multiplexing can only used with copper cables. True False
False
With modem communications, the receiving modem converts the incoming digital signal from the telephone line into an analog signal that can be understood by the computer. True False
False
With nonreturn to zero signaling, the voltage alternates between zero and a positive or negative voltage. True False
False
Coding schemes are groups of bits that translate into the "alphabet" of any given system. True False
True
Computers produce digital data whose values are binary: 0 or 1. True False
True
Data compression can increase the throughput of a communication link. True False
True
Ethernet, a common LAN technology, uses Manchester encoding. True False
True
Frequency is the number of cycles per second and is expressed in Hertz. True False
True
One form of interference with satellite transmission is called raindrop attenuation in which the transmissions are absorbed by heavy rain. True False
True
One way to reduce quantizing errors is to increase the sampling rate of the analog signal. True False
True
Radio data transmission requires that each device has a radio receiver/transmitter and uses a specific frequency. True False
True
The predominant method of transferring information internally in a computer is via parallel mode. True False
True
Time division multiplexing is more efficient that frequency division multiplexing because the guardbands used in the frequency division multiplexing or not needed. True False
True
WDM is a version of FDM used in fiber-optic cables. True False
True
A coding scheme that uses 10 bits to represent each character is capable of representing _________ different characters. a. 256 b. 20 c. 200 d. 512 e. 1024
e. 1024
When converting analog voice data to digital signals, Pulse Code Modulation typically samples the incoming voice signal _______ times per second. 8,000 8 18,000 64 256
8,000
The medium is the physical matter or substance that carries the voice or data transmission. True False
True
_____________ can be thought of as dividing the circuit horizontally. a. Frequency division multiplexing b. Statistical frequency division multiplexing c. Statistical time division multiplexing d. Time division multiplexing e. Wavelength division multiplexing
a. Frequency division multiplexing
With which type of digital signaling does the signal always return to zero volts after each bit? a. Non-return-to-zero signaling b. Unipolar signaling c. Return-to-zero signaling d. Data rate signaling e. Huffman encoding signal
c. Return-to-zero signaling
The height of a sound wave is called its: a. frequency b. phase c. amplitude d. bandwidth e. furlong
c. amplitude
Which of the following statements is true? a. the longer the distance of a telephone wire between sender and recipient, the lower the bandwidth across that wire b. the shorter the distance of a telephone wire between sender and recipient, the lower the bandwidth across that wire c. bandwidth is constant across any wire, therefore distance is not relevant to its capacity d. the longer the distance of a telephone wire between sender and recipient, the higher the bandwidth across that wire e. bandwidth is not a term that can be used when discussing telephone transmissions
c. bandwidth is constant across any wire, therefore distance is not relevant to its capacity
Which type of digital signaling would experience fewer errors because it has more distinct signals? a. unipolar b. serial c. bipolar d. attenuation e. Huffman encoding signal
c. bipolar
_________ is the basic physical layout of the circuit. a. point-to-point configuration b. configuration c. circuit configuration d. circuit design e. circuit plan
c. circuit configuration
Equipment used to transform analog voice signals to digital signals and digital signals to analog signals. a. voice converter b. modem c. codec d. multiplexer e. demodulator
c. codec
___________ refers to the spreading of the signal that different parts of the signal arrive at different times at the destination. a. turnaround time b. propagation delay c. dispersion d. insulation e. attenuation
c. dispersion
____________ refers to changing the shape of the sound wave in different ways to represent a 1 or a 0. a. digitizing. b. sampling c. modulation d. demodulation e. shaping
c. modulation
The direction in which the sound wave begins is known as: a. amplitude, which our ears detect as loudness b. frequency, which our ears detect as pitch c. phase d. bandwidth e. furlong
c. phase
The type of media usually installed on homes and businesses by the telephone company is called ____________. a. fiber optic cable b. coaxial cable c. twisted pair d. phone cable e. phone wire
c. twisted pair
Fiber optic cable carries signals in traditional electrical form. True False
False
Frequency division multiplexing divides the circuit into a set of different time slots. True False
False
Frequency modulation refers to the changing of the height of the sound wave. True or False?
False
Guided media refers to the type of media in which the message is broadcast through the air. True False
False
In a multipoint circuit configuration, each computer can use the circuit at the same time. True False
False
In a multipoint circuit configuration, each computer has a dedicated circuit between itself and each of the other computers in the network. True False
False
Nonreturn to zero is a type of unipolar signaling True False
False
Propagation delay is negligible with satellite transmission. True False
False
Serial mode transmission is much faster than parallel mode transmission. True False
False
In full-duplex transmission, two stations can send and receive simultaneously. True False
True
Statistical time division multiplexing does not require the capacity of the circuit to be equal to the sum of the combined circuits. True False
True
The "local loop" refers to the wires that run from the customer premises to the telephone switch of the telephone company. True False
True
A walkie-talkie is an example of half-duplex transmission. True or False?
True
Amplitude, frequency and phase are all characteristics of a sound wave. True False
True
If each sample uses 16 bits and the number of samples taken each second is 8000; then the transmission speed on the circuit is? a. 128 Kbps b. 64 Kbps c. 12800 bps d. 96 Kbps e. 32000 bps
a. 128 Kbps
____________ is one of the most commonly used coding schemes used in data transmission. a. ASCII b. ISDN c. MAU d. ATM e. FDM
a. ASCII
A _________ is an FDM device that splits the physical circuit into three logical circuits (phone, upstream data, downstream data). a. DSL modem b. cable modem c. wireless router d. V.44 modem e. Serial modem
a. DSL modem
When sending four bits at a time using frequency modulation, the number of different frequency levels that would be needed would be _______. a. 24 b. 16 c. 2 d. 8 e. 4
b. 16
______ is a modem standard that uses Lempel-Ziv encoding to compress data. a. V.22 b. V.44 c. V.32bis d. V.34 e. RS 232
b. V.44
____________ is used by IM and other applications that provide voice services over lower-speed digital circuits. a. pulse code modulation b. adaptive differential pulse code modulation c. Voice conversation d. code modulation e. phase modulation
b. adaptive differential pulse code modulation
Having a conversation with someone using a cellular phone is an example of _________ transmission. a. simplex b. full-duplex c. half-duplex d. analog e. digital
b. full-duplex
The two basic types of media are: a. statistical and frequency b. guided and wireless (radiated) c. local and wide area d. attenuator and Gaussian e. duplexed and non-duplexed
b. guided and wireless (radiated)
__________ is a line-of-sight type of wireless media. a. coaxial cable b. microwave c. radio d. twisted pair e. fiber optic
b. microwave
A(n) ___________ divides one high-speed communication circuit into several lower speed circuits for the primary reason of saving communication line costs. a. transponder b. multiplexer c. inverse multiplexer d. codec e. intelligent terminal
b. multiplexer
The ability to transmit in both directions, but only in one direction at a time is an example of _______________ transmission. a. simplex b. full-duplex c. half-duplex d. analog e. digital
c. half-duplex
Frequency division multiplexing: a. operates by statistically time slicing the signal b. operates by dividing the signal into different frequencies c. uses a codec that divides signals into different channels d. operates by time slicing the signal e. operates by light dividing the signal
b. operates by dividing the signal into different frequencies
Time (non-statistical) division multiplexing differs from frequency division multiplexing because it: a. does not share a communication circuit b. splits the communication circuit vertically (with time slots) instead of horizontally c. increases the wavelength and phase angles of the baseband frequency used for transmission d. moves the baseband of a circuit by shifting it to a higher frequency e. reduces baseband signal velocity more than frequency division multiplexing
b. splits the communication circuit vertically (with time slots) instead of horizontally
The typical range of human hearing is: a. 0 to 4,000 Hz b. 0 to 1,200 Hz c. 20 to 14,000 Hz d. 0 to 300 Hz e. 0 to 56,000 Hz
c. 20 to 14,000 Hz
If the highest frequency of a circuit is 10KHZ and the lowest frequency is 900 Hz, the bandwidth available for this circuit is : a. 890 Hz b. 8900 HZ c. 9100 Hz d. 9Khz e. 890 KHz
c. 9100 Hz
With respect to converting digital data into analog signals, AM stands for: a. Asynchronous Manchester b. Analog Multimode c. Amplitude Modulation d. Anomaly Multiplexing e. Analytical Mosaic
c. Amplitude Modulation
The earliest type of fiber optic systems were: a. Graded index multimode b. Attenuated c. Multimode d. Single mode e. Step mode
c. Multimode
Which of the following statements is correct? a. Parallel transmission is most often used for sending data on a circuit that is made up of one wire. c. Parallel transmission is distinguished from serial transmission by the fact that the transmitting device sends a single bit, then a second bit, and so on, until all the bits are transmitted. c. Parallel transmission is only used for analog data. d. Serial transmission is slower than parallel transmission. e. Parallel transmission is the same as serial transmission.
d. Serial transmission is slower than parallel transmission.
Transmission speeds: a. are the same among all media b. are not a factor in selecting a media because all media have more than enough speed to serve current communication demands c. are a constant, 56Kbps, for all media types d. differ widely among media always have a direct correlation with security
d. differ widely among media
Two fundamentally different types of data are: a. DSL and ADSL b. asymmetric and symmetric c. Microsoft and IBM d. digital and analog e. local area and wide area
d. digital and analog
Which of the following is the most secure wired media? a. coaxial cable b. unshielded twisted pair c. shielded twisted pair d. fiber optic cable e. infrared
d. fiber optic cable
Which of the following media has the lowest error rates and the highest transmission speeds? a. Coaxial cable b. unshielded twisted pair c. shielded twisted pair d. fiber optic cable e. infrared
d. fiber optic cable
____________ refers to the transmission characteristics of the circuit. a. handshaking b. virtual circuit c. bonding d. logical circuit e. physical circuit
d. logical circuit
Which of the following would be considered a type of wireless media? a. unshielded twisted pair b. shielded twisted pair c. coaxial cable d. microwave e. fiber optics
d. microwave
Microwave transmission: a. is a type of high frequency radio communication b. requires a clear line-of-sight path c. is typically used for long distance data transmission d. does not require the laying of any cable e. all of the above
e. all of the above
In general, older networks and local loops designed to transmit voice data are likely to be ________. a. international b. level 2 c. numeric d. digital e. analog
e. analog
Another term for the weakening of a signal over distance is: turnaround time a. turnaround time b. propagation delay c. dispersion d. insulation e. attenuation
e. attenuation
In general, networks designed to transmit primarily computer data are likely to be ________. a. international b. level 1 c. numeric d. analog e. digital
e. digital
Which of the following media can best withstand harsh environmental conditions? a. shielded twisted pair b. unshielded twisted pair c. Cat 5 twisted pair d. coaxial cable e. fiber optic cable
e. fiber optic cable
Radio, microwave and satellite are all examples of guided media. True False
false
Digital transmission permits higher maximum transmission rates when compared to analog. True False
true
Manchester encoding is a special type of bipolar signaling in which the signal is changed from high to low or from low to high in the middle of the signal. True False
True
Microwave transmissions require a line of sight between any two points. True False
True
Of all the media available, fiber optic provides the highest transmission speeds. True False
True
Signal bandwidth is the difference between the highest and lowest frequencies in a band. True False
True
Which of the following is not a key advantage of digital transmission? a. It permits only low transmission rates. b. It is more efficient. c. It is simpler to integrate voice, video, and data on the same circuit. d. It is more secure. e. It produces fewer errors.
a. It permits only low transmission rates.
The _ of a circuit determines a circuit's capacity. frequency a. bandwidth b. phase c. amplitude d. loudness
a. bandwidth
The representation of the character A by the group of 8 bits, 01000001, is an example of: a. digital coding b. phase modulation c. binary modulation d. analog transmission e. pitch variation
a. digital coding
To get more "bandwidth" in a digital transmission, you must: a. increase the range of frequencies available for a transmission b. increase the loudness per transmission c. decrease the bits per second transmission speed d. increase the phase shifts per transmission e. decrease the baud rate per transmission
a. increase the range of frequencies available for a transmission
Which of the following is a characteristic of sound waves that can be modulated to convert digital data into analog signals? a. phase b. attenuation c. bipolar d. bandwidth e. codec
a. phase
Data is physically transmitted from one computer or terminal to another in the ________ layer. a. physical b. transport c. application d. terminal e. data link
a. physical
Which of the following is not an important factor to consider when selecting media to be used in a network? a. prestige value of the type of media b. type of network c. cost d. transmission distance e. security
a. prestige value of the type of media
____________ is a modulation technique that combines two different amplitude combinations with eight different phase combinations modulation to send four bits per symbol. a. quadrature amplitude modulation b. time division multiplexing c. synchronous digital line control d.pulse code modulation e.baseband signaling
a. 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. a. quantizing error b. handshaking phase c. modulating frequency d. POTS anomaly e. amplitude Trellis effect
a. quantizing error
When all bits of a character are transferred one after another, the bits are transferred in ___________ mode. a. serial b. frequency division c. multiplexing d. parallel e. full complex
a. serial
When you send an email from the US to Europe, it likely is transmitted from one continent to another through one of the ______ that connect America and Europe. a. submarine cables b. satellites c. telephone lines d. boats e. modems
a. submarine cables
_____________ is not a form of modulation used to transform digital data into analog signals. a. synchronous time division b. amplitude shift keying c. amplitude modulation d. frequency modulation e. phase modulation
a. synchronous time division
The room that contains the cable termination points and the distribution frames is referred to as a. telecommunications closet b. equipment room c. building entrance d. backbone room e. work area
a. telecommunications closet
The type of multiplexer that divides the circuit horizontally into different light frequencies that are transmitted simultaneously across many channels is a: a. wavelength division multiplexer b. time division multiplexer c. statistical time division multiplexer d. frequency division multiplexer e. statistical frequency division multiplexer
a. wavelength division multiplexer
The acronym, Modem, stands for _________________. a. multiplexing/demultiplexing b. more/demote c. Mode-M technique d. modulator/demodulator e. Mod emulation technique
d. modulator/demodulator
In which type of modulation is a 1 distinguished from a 0 by shifting the direction in which the wave begins? a. bandwidth modulation b. amplitude modulation c. frequency modulation d. phase modulation e. codec modulation
d. phase modulation
Which is not true about point-to-point circuits? a. point-to-point circuits are dedicated to the use of the two computers. b. point-to-point circuits are more expensive than multipoint circuits. c, point-to-point circuits are called dedicated circuits. d. point-to-point circuits reduce the amount of cable required and use the circuit more efficiently than multipoint circuits. e. point-to-point circuits are used when the computers generate enough traffic to fill the capacity of the communication circuit.
d. point-to-point circuits reduce the amount of cable required and use the circuit more efficiently than multipoint circuits.
A(n) __________ circuit is another name for a multipoint configuration. a. analog b. dedicated c. point-to-point d. shared e. simplex
d. shared
How many bits are required to sample an incoming signal 4000 times per second using 64 different amplitude levels? a. 64 b. 32 c. 16 d. 8 e. 6
e. 6
___________ is not a type of digital signaling technique. a. Non-return-to-zero signaling b. Unipolar signaling c. Manchester encoding d. Return-to-zero signaling e. Data rate signaling
e. Data rate signaling
______________ refers to the time it takes for a signal to travel from sender to recipient (highly exaggerated with satellite transmission). a. Line-of-sight effect b. Multimode index c. Saturation effect d. Raindrop attenuation e. Propagation delay
e. Propagation delay
