Q&A Hero

Communication

Q: The __________ d(v1, v2) between two n -bit binary sequencesv1 and v2 is the number of bits in which v1 and v2 disagree. A) check bits B) FCS C) ECC D) Hamming distance
Q: The ratio of redundant bits to data bits, (n " k)/k , is called the __________ of the code. A) redundancy B) coding gain C) code rate D) fixed parity
Q: The _________ is a string of 1-bit storage devices with each device having an output line, which indicates the value currently stored, and an input line. A) shift register B) parity C) digital logic D) none of the above
Q: The __________ is the reduction, in decibels, to achieve a specified BER of an error-correcting coded system compared to an uncoded system using the same modulation. A) FEC B) Hamming distance C) coding gain D) checksum
Q: The __________ is a measure of how much additional bandwidth is required to carry data at the same data rate as without the code.A) burst rateB) code rateC) stream rateD) idle rate
Q: In ________ transmission systems, an error occurs when a bit is altered between transmission and reception. A) analog B) digital C) idle D) guided
Q: The use of coding allows a reduction, referred to as the ________, and defined as the reduction in decibels to achieve a specified BER of an error correcting coded system compared to an uncoded system using the same modulation. A) code rate B) fixed coding C) coding gain D) block code
Q: Error correction works by adding ________ to the transmitted message. A) decoding B) clarification C) error burst D) redundancy
Q: Correction of errors using an error detecting code requires that block of data to be ________. A) skipped over B) deleted C) retransmitted D) streamed
Q: A ___________ is an isolated error condition that alters one bit but does not affect nearby bits. A) parity error B) burst error C) single-bit error D) streaming error
Q: In __________ transmission systems, an error occurs when a binary 1 is transmitted and a binary 0 is received, or a binary 0 is transmitted and a binary 1 is received. A) analog B) digital C) parallel D) none of the above
Q: In a(n) ________ there is a cluster of bits in which a number of errors occur, although not necessarily all of the bits in the cluster suffer an error. A) error burst B) single-bit error C) idle state D) error detection
Q: In ________ transmission each block of data is formatted as a frame that includes a starting and an ending flag. A) parallel B) asynchronous C) analog D) synchronous
Q: A ________ error can occur in the presence of white noise when a slight random deterioration of the signal to noise ratio is sufficient to confuse the receiver's decision of a single bit. A) burst B) idle C) single-bit D) digital
Q: ________ is one of the most fundamental requirements in the transmission of a stream of bits from one device to another. A) Standardization B) Digitalization C) Synchronization D) Configuration
Q: The characteristics that distinguish various data link configurations are topology and whether the link is half duplex or full duplex.
Q: The use of Manchester encoding is a form of synchronization.
Q: Error correction is best used with wireless applications.
Q: The simplest error detecting scheme is to append a parity bit to the end of a block of data.
Q: Modulo 2 arithmetic uses binary addition with no carries, which is just the exclusive-OR (XOR) operation.
Q: CRC-32 is not used in IEEE 802 LAN standards.
Q: Error correction works by adding sufficient redundancy to the transmitted message.
Q: The ratio of data bits to total bits is called the code rate .
Q: Error detection found in data link control protocols such as HDLCis not a useful technique.
Q: The Internet checksum is considerably less effective than the CRC.
Q: Single bit errors are more common and more difficult to deal with.
Q: Burst errors can be caused by impulse noise.
Q: An error detection code simply detects the presence of an error.
Q: Redundant bits are not used by the receiver for error detection.
Q: Regardless of the design of the transmission system, there will be errors, resulting in the change of one or more bits in a transmitted block of data.
Q: The simplest error-detecting scheme is to append a __________ bit to the end of a block of data.
Q: In an __________ , there is a cluster of bits in which a number of errors occur, although not necessarily all of the bits in the cluster suffer an error.
Q: A __________ error can occur in the presence of white noise.
Q: An ___________ is a group of bits in which two successive erroneous bits are always separated by less than a given number x of correct bits.
Q: Forward error correction schemes are frequently used in __________ transmission, where retransmission schemes are highly inefficient and error rates may be high.
Q: The ________ is a measure of how much additional bandwidth is required to carry data at the same data rate as without the code.
Q: The ratio of redundant bits to data bits is called the ________ of the code.
Q: A way of viewing the CRC process is to express all values as ________ in a dummy variable X with binary coefficients.
Q: The ________ is a measure of how much additional bandwidth is required to carry data at the same data rate as without the code.
Q: A ________ error is an isolated error condition that alters one bit but does not affect nearby bits.
Q: The data, plus preamble, postamble and control information are called a ________.
Q: FEC codes are designed not just to detect but correct errors, avoiding the need for __________.
Q: Redundant bits are used by the _________ for the purpose of error detection or correction.
Q: ___________ operates in a fashion similar to error detection but is capable of correcting certain errors in a transmitted bit stream.
Q: Three approaches are in common use for coping with data transmission errors: error-detection codes, error-correction codes, and __________ protocols.
Q: The parameter known as the ________ is the ratio of the amplitude of the input signal to the carrier.
Q: There are two important parameters in a delta modulation scheme: the size of the step assigned to each binary digit and the ________ rate.
Q: The process of converting analog data into digital data is known as ________.
Q: A popular analog signaling technique that is used in the asymmetric digital subscriber line is ________ modulation.
Q: In the differential ________ scheme a binary 0 is represented by sending a signal burst of the same phase as the previous signal burst sent. A binary 1 is represented by sending a signal burst of opposite phase to the preceding one.
Q: The three basic encoding or modulation techniques for transforming digital data into analog signals are amplitude shift keying, phase shift keying, and ________.
Q: A distinction needs to be made between data rate (expressed in bits per second and ________ rate )expressed in baud when signal encoding techniques are used.
Q: There is a transition at the middle of each bit period in the ________ biphase coding technique. The midbit transition serves as a clocking mechanism and also as data. A low-to-high transition represents a 1, and a high-to-low transition represents a 0.
Q: In the ________ scheme, a binary 0 is represented by no line signal and a binary 1 is represented by a positive or negative pulse. The binary 1 pulses must alternate in polarity.
Q: NRZI is an example of ________ encoding.
Q: The ________ rate, expressed in baud, is the rate at which the signal level is changed.
Q: In ________ signaling one logic state is represented by a positive voltage level and the other by a negative voltage level.
Q: Multiple signals, each at a different position on the spectrum, sharing the same transmission medium, is known as frequency division ________.
Q: All modulation techniques involve operation on one or more of the three fundamental frequency domain parameters: amplitude, phase and _____.
Q: The basis for ________ signaling is a continuous constant frequency signal known as the carrier signal.
Q: A coding scheme that is commonly used in Europe and Japan is the ________. A) B8ZS B) AMI C) amplitude shift keying D) HDB3
Q: Frequency modulation and phase modulation are special cases of ________ modulation. A) PM B) FM C) angle D) amplitude
Q: The device used for converting analog data into digital form for transmission, and subsequently recovering the original analog data from the digital, is a ________. A) modem B) ASK C) PAM D) codec
Q: A common encoding technique in which each of the two modulated streams is a BPSK signal at half the data rate of the original bit stream is ________. The combined signals have a symbol rate that is half the input bit rate. A) MPSK B) MFSK C) QPSK D) QAM
Q: In ________ the phase of the carrier signal is shifted to represent data. A) MFSK B) ASK C) FSK D) PSK
Q: The ________ code has been specified for the IEEE 802.3 (Ethernet) standard for baseband coaxial cable and twisted pair bus LANs. A) Manchester B) HDB3 C) differential Manchester D) NRZ
Q: The binary 1 represented by the absence of a line signal and the binary 0 by alternating positive and negative pulses is ________. A) pseudoternary B) NRZ-L C) bipolar-AMI D) differential Manchester
Q: Because of their simplicity and relatively low frequency response characteristics, ________ codes are commonly used for digital magnetic recording. A) NRZ B) AMI C) VSES D) B8ZS
Q: If digital signaling elements all have the same algebraic sign, all positive or all negative, then the signal is ________. A) polar B) unipolar C) baseband D) differential
Q: Analog data in electrical form can be transmitted as ________ signals easily and cheaply with voice transmission over voice grade lines. A) carrier B) broadband C) baseband D) modulating
Q: In ________ signaling an analog or digital data source is encoded into a digital signal. A) polar B) carrier C) analog D) digital
Q: In ________, the two binary values are represented by two different amplitudes of the carrier frequency. Commonly, one of the amplitudes is zero. One binary digit is represented by the presence, at constant amplitude, of the carrier, the other by the absence of the carrier. A) amplitude shift keying B) phase shift keying C) frequency shift keying D) high density bipolar-3 zeros
Q: A scrambling coding technique based on bipolar-AMI and commonly used in North America is ________. A) HDB3 B) ASK C) MFSK D) B8ZS
Q: A ________ converts digital data to analog signal so that it can be transmitted over an analog line. A) modem B) satellite C) router D) receiver
Q: The simplest form of digital encoding of ________ is to assign one voltage level to binary- one and another to binary-zero. A) digital data B) carrier data C) AM data D) analog data
Q: Modulation does not permit frequency division multiplexing.
Q: PCM starts with a continuous time, continuous amplitude signal from which a digital signal is produced.
Q: Bandwidth efficiency measures the efficiency with which bandwidth can be used to transmit data.
Q: More efficient use of bandwidth can be achieved if each signaling element represents one bit.
Q: Amplitude shift keying is less susceptible to error than binary frequency shift keying.
1 2 3 … 617

Subjects

Accounting Anthropology Archaeology Art History Banking Biology & Life Science Business Business Communication Business Development Business Ethics Business Law Chemistry Communication Computer Science Counseling Criminal Law Curriculum & Instruction Design Earth Science Economic Education Engineering Finance History & Theory Humanities Human Resource International Business Investments & Securities Journalism Law Management Marketing Medicine Medicine & Health Science Nursing Philosophy Physic Psychology Real Estate Science Social Science Sociology Special Education Speech Visual Arts