TANDBERG TT1260 Reference Manual page 103

IRD
IRE
ISDN
ISO
ISOG
ITS
ITT
ITU-R
ITU-T
JPEG
kbit/s
Kbit
Ku-band
LAN
L-band
LED
LNB
LO
lsb
Luminance
Reference Guide: TT1260 Contribution Receiver
ST.RE.E10100.3
Integrated Receiver Decoder: The Receiver with an internal MPEG Decoder, which is
connected to the subscriber's TV. The IRD is responsible for receiving and de-multiplexing all
signals. The unit receives the incoming signal and if CA is active, decodes the signal when
provided with a control word by the viewing card.
Domestic IRDs are also known as Set-Top Units or Set-Top Boxes.
Institute of Radio Engineers: No longer in existence but the name lives on as a unit of video
amplitude measurement. This unit is 1% of the range between blanking a peak white for a
standard amplitude signal.
Integrated Services Digital Network: The basic ISDN service is BRI (Basic Rate Interface),
which is made up of two 64 kbit/s B channels and one 16 kbit/s D channel (2B+D). If both
channels are combined into one, called bonding, the total data rate becomes 128 kbit/s and
is four and a half times the bandwidth of a V.34 modem
(28.8 kbit/s).
The ISDN high-speed service is PRI (Primary Rate Interface). It provides 23 B channels and
one 64 kbit/s D channel (23B+D), which is equivalent to the 24 channels of a T1 line. When
several channels are bonded together, high data rates can be achieved. For example, it is
common to bond six channels for quality videoconferencing at 384 kbit/s. In Europe, PRI
includes 30 B channels and one D channel, equivalent to an E1 line.
International Standards Organisation.
Inter-union Satellite Operations Group.
Insertion Test Signal: A suite of analogue test signals placed on lines in the VBI. Also known
as VITS.
Invitation To Tender.
International Telecommunications Union - Radiocommunications Study Groups (was
CCIR).
International Telecommunications Union - Telecommunications Standardisation Sector
(was CCITT).
Joint Photographic Experts Group: ISO/ITU standard for compressing still images. It has a
high compression capability. Using discrete cosine transform, it provides user specified
compression ratios up to around 100:1 (there is a trade-off between image quality and file
size).
1000 bits per second.
1024 bits, usually refers to memory capacity or allocation.
The portion of the electromagnetic spectrum, which spans the frequency range of
approximately 12 GHz to 14 GHz. Used by communications satellites. Preferred for DTH
applications because this range of frequency is less susceptible to interference.
Local Area Network: A network, which provides facilities for communications within a defined
building or group of buildings in close proximity.
The frequency band from 950 MHz to 2150 MHz, which is the normal input-frequency-range
of a domestic IRD. The incoming signal from the satellite is down-converted to L-band by the
LNB.
Light Emitting Diode.
Low Noise Block Down-Converter: The component of a subscriber satellite transmission
receiving dish which amplifies the incoming signal and down-converts it to a suitable
frequency to input to the IRD (typically 950 MHz - 1600 MHz).
Local Oscillator.
Least significant bit.
The television signal representing brightness, or the amount of light at any point in a picture.
The Y in YC C
R B.
Glossary
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