Glossary - CityCom 202 10001 Bedienungsanleitung

Glossary

Glossary
Antenna
•
A device that collects and radiates electromagnetic waves. Includes a satellite dish and
abroadband antenna.
Forward Error Correction (FEC)
•
A system of error control for data transmission.
Frequency
•
The number of cycles or events per one second, which is expressed in the unit of Hertz(Hz).
Intermediate Frequency (IF)
•
A frequency to which a carrier frequency is shifted as an intermediate step in transmission or
reception.
Low Noise Block (LNB) Downconverter
•
A low noise microwave amplifier and converter which downconverts a range of frequencies
to IF range.
Packet Identifier (PID)
•
A set of numbers that idenitifies transport stream packets containing data from a single data
stream.
Polarisation
•
Characteristic of an electromagnetic wave determined by the orientation of the electricfield
vector.
Quaternary Phase Shift Keying (QPSK)
•
Phase-shift keying in which four different phase angles are used.
Service
•
A channel to which a decoder or TV is tuned.
Transponder
•
An automatic device that receives, amplifies and retransmits a signal on a different frequency.
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