TANDBERG TT1260 Reference Manual page 105

Network
NICAM
NIT
nm
NTSC
NVOD
NVRAM
ODU
OFDM
OPPV
OSD
Packet
PAL
PAT
PCM
PCR
PDC
Reference Guide: TT1260 Contribution Receiver
ST.RE.E10100.3
In the context of broadcasting: a collection of MPEG-2 transport stream multiplexes
transmitted on a single delivery system, for example, all digital channels on a specific cable
system.
Near Instantaneously Companded Audio Multiplex: Official name is NICAM 728. Used for
digital stereo
sound broadcasting in the UK employing compression techniques to deliver very near CD
quality audio.
728 refers to
the bitrate in kbit/s.
Network Information Table: Part of the service information data. The NIT provides
information about the physical organisation of each transport stream multiplex, and the
characteristics of the network itself (such as the actual frequencies and modulation being
used).
Nanometre: a unit of length equal to one thousand millionth (10
National Television Systems Committee: The group, which developed analogue standards
used in television broadcast systems in the United States. Also adopted in other countries
(e.g. Mexico, Canada, Japan). This system uses 525 picture lines and a 59.97 Hz field
frequency.
Near Video On Demand: Method of offering multiple showings of movies or events. The
showings are timed to start at set intervals, determined by the broadcaster. Each showing of a
movie or event can be sold to subscribers separately.
Non-volatile Random Access Memory: Memory devices (permitting random read / write
access) that do not lose their information when power is removed. Stores the default
configuration parameters set by the user.
Outdoor Unit
Orthogonal Frequency Division Multiplex: A modulation technique used for digital TV
transmission in Europe, Japan and Australia; more spectrally efficient than FDM. In OFDM,
data is distributed over a large number of carriers spaced apart at precise frequencies. The
carriers are arranged with overlapping sidebands in such a way that the signals can be
received without adjacent channel interference.
Order ahead Pay Per View: An advance purchase of encrypted one-time events with an
expiry date.
On-screen display: Messages and graphics, typically originating from the SMS, and
displayed on the subscriber's TV screen by the IRD, to inform the subscriber of problems or
instruct the subscriber to contact the SMS.
A unit of data transmitted over a packet-switching network. A packet consists of a header
followed by a number of contiguous bytes from an elementary data stream.
Phase Alternating Line:
the R-Y colour-difference signal is inverted on every alternate line to average
out errors providing consistent colour reproduction.
Program Association Table: Part of the MPEG-2 Program Specific Information (PSI) data
and is mandatory for MPEG-2 compliance. The PAT points (maps) to the PMT.
Pulse Code Modulation: A process in which a signal is sampled, each sample is quantised
independently of other samples, and the resulting succession of quantised values is encoded
into a digital signal.
Program Clock Reference: A time stamp in the transport stream from which the Decoder
timing is derived.
Program Delivery Control: A Teletext service allowing simple programming (i.e. VideoPlus)
of VCR recording times. If the desired program is rescheduled, PDC updates the
programming information in the VCR.
A colour TV broadcasting system where the phase of
Glossary
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) of a metre.
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