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TRANSMISSION AND SWITCHING: CORNERSTONES OF A NETWORK
medium). The modulation plan usually is a diagram showing the necessary mixing,
local oscillator mixing frequencies, and the sidebands selected by means of the triangles
described previously in a step-by-step process from voice channel input to line frequency
output. The CCITT has recommended a standardized modulation plan with a common
terminology. This allows large telephone networks, on both national and multinational
systems, to interconnect. In the following paragraphs the reader is advised to be careful
with terminology.
4.5.2.3.2
Formation of the Standard CCITT Group
. The standard group, as defined
by the CCITT, occupies the frequency band of 60 kHz to 108 kHz and contains 12 voice
channels. Each voice channel is the nominal 4-kHz channel occupying the 300-Hz to
Figure 4.19
Formation of the standard CCITT group.
Summary :
The standard group, as defined by the CCITT, occupies the frequency band of 60 kHz to 108 kHz and contains 12 voice channels. Each voice channel is the nominal 4-kHz channel occupying the 300-Hz to Figure 4.19 Formation of the standard CCITT group.
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ccitt,standard,oice,group,channel,terminology,formation,plan,frequency,modulation,khz,mixing,cornerstones