TANDBERG Voyager E5784, Справочное руководство

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Glossary
Page A-4 Reference Guide: Voyager E5784 and E5788 HD DSNG Encoder
ST.RE.E10137.3
DVB-PI DVB-Professional Interfaces: TTV Lan search shows – DVB Physical Interfaces
Earth Technical Earth: Ensures that all equipment chassis within a rack are at the same potential, usually by
connecting a wire between the Technical earth terminal and a suitable point on the rack. This is sometimes known
as a Functional earth.
Protective Earth: Used for electric shock protection. This is sometimes known as a safety earth.
EBU European Broadcast Union.
ECM Entitlement Control Message.
EDI
Ethernet Data Input
EIA Electronics Industries Association (USA) .
EIT Event Information Table: Equipment: A component of the DVB-Service Information (SI) stream generated within
an Encoder, containing information about events or programmes such as event name, start time, duration, etc.
System: EIT (Present/Following) contains the name of the current and next event. It may include an optional
descriptor (synopsis) giving brief details of content. EIT (Schedule) is used to produce a full EPG. The EIT is the
only DVB-SI table, which can be encrypted.
Elementary Stream A generic term for a coded bit-stream, be it video, audio or other.
EMC Electromagnetic Compatibility.
EMM Entitlement Management Message.
Encryption Encoding of a transmission to prevent access without the appropriate decryption equipment and authorisation.
EPG Electronic Programme Guide: On-screen programme listing using thumbnail pictures and/or text.
Ethernet The most widely used local area network (LAN) defined by the IEEE as the 802.3 standard. Transmission speeds
vary according to the configuration. Ethernet uses copper or fibre-optic cables.
ETS European Telecommunications Standard.
ETSI European Telecommunications Standards Institute.
FCC Federal Communications Commission.
FDM
Frequency Division Multiplex: A common communication channel for a number of signals, each with its own
allotted frequency.
FEC Forward Error Correction: A method of catching errors in a transmission. The data is processed through an
algorithm that adds extra bits and sends these with the transmitted data. The extra bits are then used at the
receiving end to check the accuracy of the transmission and correct any errors.
FFT Fast Fourier Transformation: A fast algorithm for performing a discrete Fourier transform.
FIFO
First In, First Out: A data structure or hardware buffer from which items are taken out in the same order they
were put in. Also known as a shelf from the analogy with pushing items onto one end of a shelf so that they fall off
the other. A FIFO is useful for buffering a stream of data between a sender and receiver that are not synchronised
- i.e. they not sending and receiving at exactly the same rate.
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: A protocol used to transfer files over a TCP/IP network (Internet, UNIX, etc.). For
example, after developing the HTML pages for a Web site on a local machine, they are typically uploaded to the
Web server, using FTP. Unlike e-mail programs in which graphics and program files have to be attached, FTP is
designed to handle binary files directly and does not add the overhead of encoding and decoding the data.
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 TANDBERG Television Encoder normally uses a 12 frame GOP; every twelfth frame is an I frame.
GPI General Purpose Interface. A TANDBERGTV card used to control various specific functions of TTV encoders
using a contact closure input. In addition contact closure outputs are provided.
GUI Graphical User Interface: The use of pictures rather than just words to represent the input and output of a
program. A program with a GUI runs under a windowing system and has a screen interface capable of displaying
graphics in the form of icons, drop-down menus and a movable pointer. The on-screen information is usually
controlled / manipulated by a mouse or keyboard.
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.
HSYNC Horizontal (line) SYNCs.
Hub A device in a multipoint network at which branch nodes interconnect.