Ross DVB-S 5010 - Page 22

(11) Packet Identier (PID)
Asetofnumbersthatidentiestransportstreampacketscontainingdatafromasingle
data stream
(12) Polarization
Satellite waves are polarized. They can be linear or circular. Linear polarity is Vertical
or Horizontal, circular polarity is Right-hand and Left-hand circular polarity.
(13) Quadrature Phase Shift Keying (QPSK) Modulation
Phase-shift keying in which four different phase angles are used.
(14) RF
A frequency that is useful for radio transmission, usually between10KHz and
300,000Mhz.
(16) STB
Set Top Box, another common name for a Digital Satellite Receiver, because it would
usually be put on top of a TV. This acronym is common worldwide.
(17) Symbol Rate
The amount of data transmitted every second.
(18) Transponder (TP)
Equipment in a satellite which receives a single uplink channel from a satellite earth
station,ampliesit,convertsthefrequencyandchangesthepolarization,thenbroad-
casts it back to earth.
(19) 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xedlengthpacketsof188bytesof
data.
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