TANDBERG E5780, Справочное руководство

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Glossary
Page A-6 Reference Guide: evolution 5000 E5780 and E5782 Encoder
ST.RE.E10135.4
ISDN
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.
ISO International Standards Organisation.
ISOG Inter-union Satellite Operations Group.
ITS Insertion Test Signal: A suite of analogue test signals placed on lines in the VBI. Also known as VITS.
ITT Invitation To Tender.
ITU-R International Telecommunications Union - Radiocommunications Study Groups (was CCIR).
ITU-T International Telecommunications Union - Telecommunications Standardisation Sector (was CCITT).
JPEG 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).
JVT The Joint Video Team (JVT ) is a partnership between ISO/IEC and ITU to develop the new video compression
standard MPEG-4 Part 10 from the original ITU-T H.26L project.
kbit/s 1000 bits per second.
Kbit 1024 bits, usually refers to memory capacity or allocation.
Ku-band 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.
LAN
Local Area Network: A network, which provides facilities for communications within a defined building or group of
buildings in close proximity.
LATM Low-overhead Audio Transport Multiplex is part of the method to encapsulate MPEG-4 HE-AAC into transport
stream. It is used in conjunction with LOAS.
L-band 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.
LED Light Emitting Diode.
LNB 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).
LO Local Oscillator.
LOAS Low-overhead Audio Stream is part of the method to encapsulate MPEG-4 HE-AAC into transport stream. It is
used in conjunction with LATM.
LSB Least significant bit.
Luminance The television signal representing brightness, or the amount of light at any point in a picture. The Y in YC
R
C
B.
LVDS Low Voltage Differential Signal: LVDS is a generic multi-purpose Interface standard for high speed / low power
data transmission. It was standardised in ANSI/TIA/EIA-644-1995 Standard (aka RS-644).
Macroblock A 16x16-pixel area of the TV picture. Most processing within the MPEG domain takes place with macro blocks.
These are converted to four 8x8 blocks using either frame DCT or field DCT. Four 8 x 8 blocks of luminance data
and two (4:2:0 chrominance format), four (4:2:2) or eight (4:4:4) corresponding 8 x 8 blocks of chrominance data
coming from a 16 x 16 section of the luminance component of the picture. Macroblock can be used to refer to the
sample data and to the coded representation of the sample values and other data elements.
Mbit/s Million bits per second.
MCC Multiplex Control Computer: A component of a System 3000 compression system. The MCC sets up the
configuration for the System 3000 Multiplexers under its control. The MCC controls both the main and backup
Multiplexer for each transport stream.
MCPC Multiple Channels Per Carrier.
MEM Multiplex Element Manager: A GUI-based control system, part of the range of TANDBERG Television
compression system control element products. The evolution 5000 MEM holds a model of the system hardware.
Using this model, it controls the individual system elements to configure the output multiplexes from the incoming
elementary streams. The MEM monitors the equipment status and controls any redundancy switching.