SAB Explorer User Manual - page 6
Glossary
Antenna
A device that collects and radiates electromagnetic waves.
Includes a satellite dish and a broadband 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 identifies transport stream packets containing data from
a single data stream.
Polarization
Characteristic of an electromagnetic wave determined by the orientation of
the electric field vector.
Quaternary Phase Shift Keying (QPSK)
Phase-shift keying in which four different phase angles are used.
Transponder
Equipment in a satellite which receives a single uplink channel from a satellite
Earth station, amplifies it, converts the frequency and changes the
polarization, then rebroadcasts it back to Earth.
Transport Stream
The bit stream formed prior to transmission of signals by combining the video,
audio and data streams of one service. It consists of fixed length packets of
188 bytes of data.`
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