1 of 20
Term
What is oversampling?
Give this one a try later!
Voice over IP is commonly used to transmit phone conversations over the digital
networks. VoIP uses digital phones with built-in codecs to convert analog to
digital.
For voice digitization, one typically samples at twice the highest frequency
transmitted, or a minimum of 8,000 times a second. Sampling more
frequently than this will improve signal quality. For example, CDs sample at
44,100 times a second and use 16 bits per sample to produce almost error-
free music.
, The use of standards makes it much easier to develop software and hardware
that link different networks because software and hardware can be developed
one layer at a time. The software or hardware defined by the standard at one
network layer can be easily updated, as long as the interface between that layer
and the ones around it remains unchanged.
the representation of one set of symbols by another set of symbols. In data
communications, this coding is a specific arrangement of binary 0s and 1s used to
represent letters, numbers, and other symbols that have meaning.
Don't know?
2 of 20
Term
What is a modem?
Give this one a try later!
For voice digitization, one typically samples at twice the highest frequency
transmitted, or a minimum of 8,000 times a second. Sampling more frequently
than this will improve signal quality. For example, CDs sample at 44,100 times a
second and use 16 bits per sample to produce almost error-free music.
Modem is an acronym for MOdulator/DEModulator. A modem takes the
digital electrical pulses received from a computer, terminal, or
microcomputer and converts them into a continuous analog signal that is
needed for transmission over an analog voice grade circuit. Modems are
either internal (i.e., inside the computer) or external (i.e., connected to the
computer by a cable).
, With cloud computing, a company contracts with another firm to provide
software services over the Internet, rather than installing the software on its own
servers. The company no longer buys and manages its own servers and software,
but instead pays a monthly subscription fee or a fee based on how much they
use the application.
Quantizing error is the difference between the replicated analog signal and its
original form, shown with jagged "steps" rather than the original, smooth flow.
Voice transmissions using digitized signals that have a great deal of quantizing
error will sound metallic or machinelike to the human ear
Don't know?
3 of 20
Term
How do information bits differ from overhead bits?
Give this one a try later!
One popular technique is quadrature amplitude modulation (QAM). QAM
involves splitting the symbol into eight different phases (three bits) and two
different amplitudes (one bit), for a total of 16 different possible values. Thus, one
symbol in QAM can represent four bits.
Forward error correction uses codes containing sufficient redundancy to prevent
errors by detecting and correcting them at the receiving end without
retransmission of the original message. The redundancy, or extra bits required,
varies with different schemes. It ranges from a small percentage of extra bits to
100 percent redundancy, with the number of error detecting bits roughly
equaling the number of data bits.
Term
What is oversampling?
Give this one a try later!
Voice over IP is commonly used to transmit phone conversations over the digital
networks. VoIP uses digital phones with built-in codecs to convert analog to
digital.
For voice digitization, one typically samples at twice the highest frequency
transmitted, or a minimum of 8,000 times a second. Sampling more
frequently than this will improve signal quality. For example, CDs sample at
44,100 times a second and use 16 bits per sample to produce almost error-
free music.
, The use of standards makes it much easier to develop software and hardware
that link different networks because software and hardware can be developed
one layer at a time. The software or hardware defined by the standard at one
network layer can be easily updated, as long as the interface between that layer
and the ones around it remains unchanged.
the representation of one set of symbols by another set of symbols. In data
communications, this coding is a specific arrangement of binary 0s and 1s used to
represent letters, numbers, and other symbols that have meaning.
Don't know?
2 of 20
Term
What is a modem?
Give this one a try later!
For voice digitization, one typically samples at twice the highest frequency
transmitted, or a minimum of 8,000 times a second. Sampling more frequently
than this will improve signal quality. For example, CDs sample at 44,100 times a
second and use 16 bits per sample to produce almost error-free music.
Modem is an acronym for MOdulator/DEModulator. A modem takes the
digital electrical pulses received from a computer, terminal, or
microcomputer and converts them into a continuous analog signal that is
needed for transmission over an analog voice grade circuit. Modems are
either internal (i.e., inside the computer) or external (i.e., connected to the
computer by a cable).
, With cloud computing, a company contracts with another firm to provide
software services over the Internet, rather than installing the software on its own
servers. The company no longer buys and manages its own servers and software,
but instead pays a monthly subscription fee or a fee based on how much they
use the application.
Quantizing error is the difference between the replicated analog signal and its
original form, shown with jagged "steps" rather than the original, smooth flow.
Voice transmissions using digitized signals that have a great deal of quantizing
error will sound metallic or machinelike to the human ear
Don't know?
3 of 20
Term
How do information bits differ from overhead bits?
Give this one a try later!
One popular technique is quadrature amplitude modulation (QAM). QAM
involves splitting the symbol into eight different phases (three bits) and two
different amplitudes (one bit), for a total of 16 different possible values. Thus, one
symbol in QAM can represent four bits.
Forward error correction uses codes containing sufficient redundancy to prevent
errors by detecting and correcting them at the receiving end without
retransmission of the original message. The redundancy, or extra bits required,
varies with different schemes. It ranges from a small percentage of extra bits to
100 percent redundancy, with the number of error detecting bits roughly
equaling the number of data bits.
