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Program
Programme
P
P
R
PS
PSI
PSIP
PSK
PSR
PSU
QAM
QoS
QPSK
QSIF
Quantise
RAM
RAS
EN/LZT 790 0005 R7A
PC - A sequence of instructions for a computer.
TV - A concept having a precise definition within ISO 13818-1
(MPEG-2). For a transport stream, the timebase is defined by the
PCR. The use of the PCR for timing information creates a virtual
channel within the stream.
A linking of one or more events under the control of a broadcaster.
For example, football match, news, film show. In the MPEG-2
concept, the collection of elementary streams comprising the
programme, have a common start and end time. A series of
programmes are referred to as events.
Analogue Color difference signals. Refer to C
B
Program Stream: A combination of one or more PESs with a
common timebase.
Program Specific Information: Consists of normative data, which is
necessary for the de-multiplexing of transport streams and the
successful regeneration of programs (see also: SI).
Program System Information Protocol: The ATSC equivalent of SI
for DVB.
Phase Shift Keying: A method of modulating digital signals
particularly suited to satellite transmission.
Professional Satellite Receiver: See also: IRD.
Power Supply Unit.
Quadrature Amplitude Modulation: A method of modulating digital
signals, which uses combined techniques of phase modulation and
amplitude modulation. It is particularly suited to cable networks.
Quality of Service. A common term for a set of parameters
describing the quality you get from an IP network: Throughput,
availability, delay, jitter and packet loss.
Quadrature Phase Shift Keying: A form of phase shift keying
modulation using four states.
Quarter Screen Image Format.
A process of converting analogue waveforms to digital information.
8-bit quantization as set out in ITU-R Rec. 601. Uses 256 levels in
the range 0 – 255 to determine the analogue waveform value at any
given point. The value is then converted to a digital number for
processing in the digital domain.
Random Access Memory: A volatile storage device for digital data.
Data may be written to, or read from, the device as often as
required. When power is removed, the data it contains is lost.
Remote Authorization System: An Ericsson AB proprietary public-
key encryption system used to prevent unauthorized viewing of a TV
programme or programmes.
Glossary
C
for an explanation.
R
B
A-15
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