Tiernan TE3000, Инструкция по установке и эксплуатации, Страница: 108 / 114

98 Glossary
carrier offset
The frequency difference in Hertz measured between the programmed receive frequency
and the actual frequency received.
channel A single path for transmitting electric or electromagnetic signals.
CPS Cells per second
CSA Canadian Standards Association—The Canadian counterpart of the U.S. Underwriters
Laboratories.
data
Typically refers to the information content of a signal including video, audio, graphic, or
character-based information.
data bits Within a data packet, the bits which represent the information content of a packet. See also
Data.
dB
Decibel—A unit of measure of signal strength, usually the relation between a transmitted
signal and a standard signal source. An increase of 3 dB results in a doubling of the signal
strength. An increase of 6 dB results in a quadrupling of the signal strength. Conversely, a
decrease of 3dB and 6 dB results in a reduction in signal strength by one half and three
quarters, respectively.
decode
To convert a coded signal into its original form.
demod
Demodulation. See Demodulate.
demodulate
To retrieve an electrical signal from a carrier signal or wave.
DS3
A commercial leased line format that has the capacity to handle up to 44.763Mbps of
digital information; North American standard digital interface.
dsec Deci-seconds—A measurement of time that is equal to 0 .1 seconds. For example, 15 dsec
is equal to 1 .5 seconds.
DTE
Data Termination Equipment—A generic name for any device that generates information
to be transmitted to another device or over a transmission system. For example, visual
display units, computers, and office workstations.
DVB
Digital Video Broadcast— A set of standards providing the specifications for transmission
and reception of digitally processed broadcasting signals.
E
b
/N
o
Eb=Energy per information bit; No=Noise energy per Hertz—Signal energy with respect
to noise, expressed in energy per bit/noise in 1Hz bandwidth.
E-3
European standard 34.368 Mbps digital interface.
fault
A disturbance that impairs or disrupts normal operations.
FIFO
First In, First Out—A type of data buffer.
FPGA
Field Programmable Gate Array —A chip that can be reprogrammed for various uses.
G.703
ITU-T Recommendation G.703, “Physical/Electrical Characteristics of Hierachical
Digital Interfaces.”— An interface protocol used for terrestrial transmissions that operates
at multiples of 64 kbps PCM.
Hz
Hertz—A measurement of frequency in cycles of a waveform occurring in one second.
One Hertz is one cycle per second.
HPA High power amplifier— A device which provides the high power necessary to transmit
radio signals from an earth terminal to a satellite.
IEC
International Electrotechnical Commission— A Geneva-based organization that sets
international electrical and electronics standards and includes national committees from
over 40 countries.