Harmonic Ellipse 3000, Руководство пользователя, Страница: 391 / 403

Glossary
Numerics
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© 2013 Harmonic Inc. 391 Ellipse 3000 r.3.0, Rev. B
PSIP
Program and System Information Protocol
PTS
Presentation Time Stamp. An MPEG-2 defined field that can be present in the
PES
packet
header to indicate the time the access unit is to be presented (displayed) to the viewer.
PW
Password.
Q
QAM
Quadrature Amplitude Modulation. Transmits 4 bits (16 QAM) to 8 bits (64 QAM) at the same
time by varying the phase and amplitude of a signal.
See also
QPSK
.
QPSK
Quaternary Phase Shift Keying. QPSK transmits 2 bits at the same time by varying the phase
of the signal.
See also
QAM
.
R
RAID
Redundant Array of Independent Disks
RCA connector
A plug and socket for a two-wire coaxial cable used to connect consumer audio and video
components.
Redundancy
A back-up system of Harmonic components that ensures uninterruptible service in the event
of a
component
failure.
Reed-Solomon decoder
A device that performs error correction on the incoming data stream.
reference clock
The 27-MHz abstract clock from which various physical clocks are instantiated. The encoder
maintains a 27 MHz encoder clock, and via correct placement of PCR values into the
Transport Stream, the decoder is able to reconstruct the reference clock in the form of a
decoder clock.
reference level
Reference level is the nominal level to which all parts of an audio signal chain are aligned. This
is co4 dBu or 0 dBu for analog audio systems. It is measured in an out of service
measurement where a sine-wave tone of the nominal level is introduced at the entrance of