TANDBERG M2/TT1220CIF/D, Инструкция по эксплуатации

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Glossary
Page A-4 Instruction Manual: Professional Decoder
ST.TM.TT1220.1
FEC
Forward Error Correction. The amount of redundancy available in the Input Signal. This redundancy is used by the
Forward Error Correction routine to detect and correct channel errors.
Also:
Future ECM Computer: responsible for preparation of FECMs from Programme Information.
FFT (Fast Fourier
Transformation) A fast algorithm for performing a discrete Fourier transform.
FIFO (First In, First Out) A type of buffer.
Footprint The area of the Earth’s surface covered by a satellite’s downlink transmission. Also (generally) the area from which
the satellite can receive uplink transmissions.
FTP File Transfer Protocol.
G.703 The ITU-T standard which defines the physical and electrical characteristics of hierarchical digital interfaces.
GOP (Group of Pictures) MPEG video compression works more effectively by processing a number of video frames as a block. The NDS
System Encoder normally uses a 12 frame GOP, every twelfth frame is an I frame.
GUI Graphical User Interface.
HDTV High Definition Television.
HPA (High Power Amplifier) Used in the signal path to amplify the modulated and up-converted broadcast signal for feeding to the uplink antenna.
Hub
A device in a multipoint network at which branch nodes interconnect.
ICAM (Integrated
Conditional Access Module) Embedded in the IRD and responsible for descrambling and packet filtering and reception. It also contains the
physical interface to the subscriber’s viewing card.
IEC International Electrotechnical Committee.
IF (Intermediate Frequency) Usually refers to the 70 MHz or 140 MHz output of the modulator in satellite and cable transmission applications.
Interframe Coding
Predictive coding where values for prediction are taken from the previous and the current frame. That is, coding
exploits temporal redundancy by using forward or backward prediction to produce P or B Frames.
Intraframe Coding Coding of a macroblock or picture that uses information only from that macroblock or picture. Exploits spatial
redundancy by using DCT to produce I Frames.
IP Internet Protocol.
I-picture; I-frame
(Intracoded Picture/Frame) A picture/frame which is coded using purely intra coding, with reference to no other field or frame information. The I
frame is used as a reference for other compression methods.
IPPV (Impulse Pay Per
View) One-time events that the subscriber purchases ‘on impulse’ using pre-arranged credit from the SMS, not as part of a
subscription.
IRD (Integrated Receiver
Decoder) The receiver with an internal 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 decodes it when provided with a control
word by the viewing card. (Domestic IRDs are also known as Set-Top Units or Set-Top Boxes.)
IRE (Institute of Radio
Engineers) IRE Unit: An arbitrary unit used to describe the amplitude characteristics of a video signal.
Pure white is defined to be 100 IRE and the blanking level is defined to be 0 IRE.
ISDN (Integrated Services
Digital Network) An ISDN line usually refers to a 64 kbit/s data line.
ISO International Standards Organisation.
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) An ISO/IEC international standards group developing an image compression algorithm for continuous tone still colour
pictures.
Kbps / kbps 1024 bits per second / 1000 bits per second.
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.
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.