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
Question
Used for amateur radio, CB radio, and international broadcasts such as BBC and Voice of America, ________ propagation is a signal from an earth based antenna reflected from the ionosphere back down to earth.Answer
This answer is hidden. It contains 7 characters.
Related questions
Q:
Amplitude shift keying is less susceptible to error than binary frequency shift keying.
Q:
A single orbiting satellite will operate on a number of frequency bands called ________ channels.
Q:
Often used in LANs, ________ transmission has a higher refractive index at the center which makes the light rays moving down the axis advance more slowly than those near the cladding.
Q:
A communication ________ is a microwave relay station used to link two or more ground based microwave transmitter/receivers known as earth stations.
A) transmitter
B) transponder
C) dish
D) satellite
Q:
The two different types of light source used in fiber optic systems are the ________.
A) single mode and the multimode
B) LID and the DEL
C) TIR and the GIM
D) light-emitting diode and the injection laser diode
Q:
The parabolic reflective antenna is a type of antenna used in terrestrial microwave and satellite applications.
Q:
The most commonly used medium in the telephone network is twisted pair.
Q:
Guided media employ an antenna for transmitting through air, vacuum, or water.
Q:
The transmission media that are used to convey information can be classified as guided or unguided.
Q:
________ noise is noncontinuous, consisting of irregular pulses or noise spikes of short duration and of relatively high amplitude. It is generated from a variety of causes such as lightning and faults and flaws in the communications system.
Q:
A means of transmitting analog signals without regard to their content is ________ transmission.
Q:
The simplest sort of signal is a ________ signal, in which the same signal pattern repeats over time.
Q:
________ is generated by terminals. computers, and other data processing equipment and then converted into digital voltage pulses for transmissions.
A) Voice
B) Audio
C) Binary data
D) Text
Q:
A(n) ________ signal is a continuously varying electromagnetic wave that may be propagated over a variety of media, depending on spectrum. Examples are wire media and fiber optic cable.
A) digital
B) periodic
C) aperiodic
D) analog
Q:
A guided transmission medium is ________ if it provides a direct link between two devices and those are the only two devices sharing the medium.
A) multipoint
B) simplex
C) point-to-point
D) wireless
Q:
Delay distortion occurs because the velocity of propagation of a signal through a guided medium varies with frequency.
Q:
An analog signal can be transmitted only a limited distance before attenuation, noise, and other impairments endanger the integrityof the data.
Q:
A familiar example of analog data is audio, which, in the form of acoustic sound waves, can be perceived directly by human beings.
Q:
It is necessary to impose a layer of control in each communicating device that provides functions such as flow control, error detection, and error control.
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 ratio of data bits to total bits is called the code rate .
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:
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:
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:
Multiple signals, each at a different position on the spectrum, sharing the same transmission medium, is known as frequency division ________.
Q:
In ________ the phase of the carrier signal is shifted to represent data.
A) MFSK
B) ASK
C) FSK
D) PSK
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