* Aspect Ratio :
It is the ratio of the width of the screen to the height. The two relevant digital TV formats are
16:9 (widescreen) or 4:3 (the traditional screen ratio). 16:9 is more ergonomically suitable for human's eye.
* Bandwidth :
Frequency range allows for carrying a certain radio signal. The speed of data transmission
depends on the available bandwidth of the transmission channel.
* Coaxial Cable :
A type of cable used to transmit high frequency signals e.g. from the VHF/UHF antenna to the
terrestrial Digital TV receiver.
* Composite Video :
There are three elements of the video system : First - the " active video" which means the
picture to be displayed on the screen and its associated colors. Second - the " sync" decides where to place
each pixel on the screen. Third - the " blanking" tells the display when to turn off the electron beam so no
retrace across the screen. These three elements combined together is called " composite video" when
connecting to a display through connectors.
* ATSC:
Abbreviation for "Advanced Television System Committee". The Advanced Television Systems
Committee, Inc. (ATSC), is an international, non-profit membership organization developing voluntary
standards for the entire spectrum of advanced television systems. They stipulate the standard for terrestrial
Digital TV broadcast which is also called ATSC.
* EPG :
Abbreviation for "Electronic Program Guide". A software that enable viewers to navigate through the
large number of channels offered by digital TV broadcaster and select the desired services.
* Frequency :
The property of a signal which is measured in cycles per second(=Hertz).
* Letterbox :
The picture with aspect ratio 16:9 in a 4:3 TV screen with blank lines on top and bottom. It is the
means to watch a wide screen TV program on a 4:3 TV screen.
* Megahertz (MHz) :
Millions of cycles per second, which describes frequencies of radio wave or electric current.
* OSD
: Abbreviation of "On Screen Display", used in digital set top box. OSD is comprised of a main menu and
many submenu with lots of options of functions inside.
* NTSC :
Stands for "National Television System Committee", the U.S. video standard which includes the image
format of 4: 3, 525 horizontal lines (only 480 lines active among them, 60 Hz and a total 6 MHz channel width.
* PID :
Stands for "Packet Identifier". It is a code used for identifying video, audio PCR and other elements that
form a particular service in the transport stream.
* RF Channel :
Radiated Frequency Channel, one RF channel may carry 4 to 6 subchannels 2-1,2-2,2-3.etc.
* S-Video (also called Y/C) :
The standard for the way a video signal is carried on the cable. Y represents
brightness and C represents color. S-Video cables have separate wires for the color and brightness so it offers
a better picture quality than the composite video.
* VHF :
Stands for "Very High Frequency", starts from 30 to 300 MHz corresponding to channels 5-12,including
Bands I, II and III.
*
UHF :
Stands for "Ultra High Frequency", starts from 300 to 3000 MHz corresponding to channels 28-69,
including Bands IV and V.
*
Y/Pb/Pr :
Component Video Output. It is better than S-Video and Composite Video output in terms of picture
quality. Y/Pb/Pr is the standard HDTV connector.
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APPENDIX 3 GLOSSARY
