Glossary
Page A-8
Instruction Manual: Professional Decoder
ST.TM.TT1220.1
SNMP
Simple Network Management Protocol.
Spatial Redundancy
Information repetition due to areas of similar luminance and/or chrominance characteristics within a single frame.
Removed using DCT and Quantisation (Intra-Frame Coding).
SPI
Synchronous Parallel Interface.
Statistical Redundancy
Data tables are used to assign fewer bits to the most commonly occurring events, thereby reducing the overall
bit-rate. Removed using Run Length Coding and Variable Length Coding.
STB (Set-Top Box)
See: IRD.
TAXI (Transparent
Asynchronous Tx/Rx
Interface)
A proprietary multiplexer interface.
TCP/IP (Transmission
Control Protocol/Internet
Protocol)
A set of communications protocols that may be used to connect different types of computers over networks.
TDM (Time Division
Multiplex)
One common, physical communications channel for a number of signals, each with its own allotted time slot.
TDT (Time and Date Table) Part of the Service Information. The TDT gives information relating to the present time and date.
Temporal Redundancy
Information repetition due to areas of little or no movement between successive frames. Removed using motion
estimation and compensation (Inter-Frame Coding).
Time-stamp
A term that indicates the time of a specific action such as the arrival of a byte or the presentation of a presentation
unit.
Transport Stream
A set of packetised elementary data streams and SI streams which may comprise more than one programme, but
with common synchronisation and error protection.
The data structure is defined in ISO/IEC 13818-1 [1] and is the basis of the ETSI Digital Video Broadcasting
standards.
Transport Stream Packet
Header
A data structure used to convey information about the transport stream payload.
TS
Transport stream. A combination of one or more fixed length PESs with independent timebases into a single stream.
TSP
Transport Stream Processor.
U
44.45 mm (rack height standard).
UART (Universal
Asynchronous Receiver
Transmitter)
A device providing a serial interface for transmitting and receiving data.
Upconvert/ Downconvert
The process by which the frequency of a broadcast transport stream is shifted to a higher (lower) frequency range.
Uplink
The part of the communications satellite circuit that extends from the Earth to the satellite.
UPS (Uninterruptable
Power Supply)
A device that conditions the power supply to equipment to ensure continuous power and the avoidance of power
surges. It also provides power from batteries, for a short time, in case of mains failure.
UTC
Universal Time, Co-ordinated (previously Greenwich Mean Time or GMT).
Also
Unique Title Code.
Vitterbi
A filter optimized to correct errors caused by evenly distributed noise. (Band limited White Noise)
VITS
Vertical Interval Test Signal. See: ITS.
VPS
Video Programming System.
WSS (Wide Screen
Switching)
Data used in wide-screen analogue services which enables a receiver to select the appropriate display mode.
WST
World System Teletext.
XILINX
A type of programmable Integrated Circuit.
Y (Luminance)
Defines the brightness of a particular point on a TV line.
