Cisco Optical Hub and Hub-Node Installation Guide
Glossary
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C/N or CNR
carrier-to-noise ratio. The ratio, in decibels, of the carrier to that of the noise in a receiver's IF
bandwidth after specified band limiting and before any nonlinear process such as amplitude
limiting and detection takes place.
bandwidth after specified band limiting and before any nonlinear process such as amplitude
limiting and detection takes place.
C/T
carrier-to-noise temperature ratio.
CISC
Complex Instruction Set Computer. A computer that uses many different types of instructions
to conduct its operations, i.e., IBM PCs, Apple Macintosh’s, IBM 370 mainframes.
to conduct its operations, i.e., IBM PCs, Apple Macintosh’s, IBM 370 mainframes.
compression
The non-linear change of gain at one level of a signal with respect to the change of gain at
another level for the same signal. Also, the elimination of redundant information from an
audio, data, or video signal to reduce transmission requirements.
another level for the same signal. Also, the elimination of redundant information from an
audio, data, or video signal to reduce transmission requirements.
CW
continuous wave.
CWDM
coarse wave-division multiplexing. CWDM allows a modest number of channels, typically
eight or less, to be stacked in the 1550 nm region of the fiber called the C-Band. This capacity
is greater than WDM (wave-division multiplexing) and lesser than DWDM (dense wave-
division multiplexing).
eight or less, to be stacked in the 1550 nm region of the fiber called the C-Band. This capacity
is greater than WDM (wave-division multiplexing) and lesser than DWDM (dense wave-
division multiplexing).
D
dB
decibel. One tenth of a bel, the number of decibels denoting the ratio of two amounts of
power being ten times the common logarithm of this ratio.
power being ten times the common logarithm of this ratio.
dBc
decibels relative to a reference carrier.
dBi
decibels of gain relative to an isotropic radiator.
dBm
decibels relative to 1 milliwatt.