Telecom Glossary D3
Dial Tone
Ready To Place/Originate A Call. When the off hook
indication is received at a central office, a dial tone
signal is sent to the originating caller on a switched
network to indicate that the switch is ready to accept
a number.
Dialer
Equipment that pulses out a standard dial protocol
signal.
Digital
A device or method that uses discrete variations in
voltage, frequency, amplitude, location, etc. to encode,
process, or carry binary (zero or one) signals for sound,
video, computer data or other information. For example,
a digital clock displays the time as discrete numeric
values, rather than angular displacement of analog hands.
Digital communications technology generally permits
higher speeds of transmission with a lower error rate
than can be achieved with analog technology. When analog
signals are received and amplified at each repeater
station, any noise is also amplified. A digital signal,
however, is detected and regenerated (not amplified).
Unlike amplification, any noise (less than a valid signal)
is eliminated by digital regeneration.
Digital Television (DTV)
A new technology for transmitting and receiving
broadcast television signals. DTV provides clearer
resolution and improved sound quality.
Long Distance Glossary
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