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NTSC - National Television Standards Committee. This is a shorthand description for
the standard 525-line, 30-frames-per-second analog baseband television signal format
used in the US
MPEG, MPEG Transport Stream - Moving Picture Experts Group. This catchall
abbreviation is used to describe the digital compression (redundancy reduction) of
linearly-digitized audio and video signals as well as the mode of multiplexing and
transporting that compressed data. The Transport stream is a packetized system
consisting of a sequence of 188-byte packets, each with a sync-byte and a specific
payload identified by a payload ID (or PID). The stream contains packets not only for
the compressed audio and video, but also auxiliary data, program information and
allocation data, and conditional access information.
PID - Payload Identifier (or ID). See "MPEG."
QPSK - Quadrature Phase Shift Keying. This is a popular mode of transmitting digital
information by varying the phase of a radio-frequency carrier.
SCPC - Single-Channel-Per-Carrier. Only one service or program is present on a
particular radio-frequency carrier.
SETTINGS TABLE - An internal table of alternate carrier/program settings stored in the
IRDs non-volatile memory (remembered through power cycles). This table may be
used in the following ways: (1) If an IRD is unable to acquire the commanded carrier,
then it will, after an appropriate time-delay, search for and lock onto any carriers in the
table it may be able to find. (2) If local control is enabled, a user, may, through the
front-panel or terminal command, tune the IRD to a new setting found in the table using
the shorthand of the Settings Table entry number.
UTY4000-003
C-2
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