Digital TV Lingo Explained

<body topmargin=0 leftmargin=0 marginheight=0 marginwidth=0> <table cellpadding=0 cellspacing=0 border=0 height="100%"><tr> <td valign="top" width=150 BGCOLOR="#000066" TEXT="#F7F7FF" background="03fd6c00dkbliw.jpg"> <div> <I><B>Don's TV Service</B></I></div> <div> <I><B>155 N. Second </B></I></div> <div> <I><B>Porterville</B></I></div> <div> <I><B>CA 93257</B></I></div> <bR> <div> <I><B>559-782-3409</B></I></div> <bR> <div> <A HREF="index.htm" TARGET="_top" TITLE=" Welcome to Dons TV Service"><U><B>Home</B></U></A></div> <div> <A HREF="id17.htm" TARGET="_top" TITLE="The Shop"><U><B>The Shop</B></U></A></div> <div> <A HREF="id18.htm" TARGET="_top" TITLE="Parts"><U><B>Parts</B></U></A></div> <div> <A HREF="id19.htm" TARGET="_top" TITLE="Info Page"><U><B>Info Page</B></U></A></div> <div> <A HREF="id21.htm" TARGET="_top" TITLE="Contact Us"><U><B>Contact Us</B></U></A></div> <div> <A HREF="transfer_home_movies_to_dvd.htm" TARGET="_top" TITLE="Transfer Service"><U><B>Transfer Service</B></U></A></div> <bR> </td> <td valign="top" BGCOLOR="#FFFFFF" TEXT="#080000"> <div> <FONT SIZE="5" COLOR="#0066FF" FACE="Arial" ><B>      Welcome to Don's TV Service</B></FONT><FONT SIZE="1" COLOR="#333399" FACE="Arial" >    </FONT> |     <A HREF="index.htm" TARGET="_top" TITLE=" Welcome to Dons TV Service"><U>home</U></A></div> <div> <A HREF="id19.htm" TARGET="_top" TITLE="Info Page"><U>Back to Info Page</U></A></div> <div> Digital TV Lingo Explained</div> <bR> <div> <B> <TABLE BORDER="0" CELLPADDING="2" CELLSPACING="1" WIDTH="497" BORDERCOLORLIGHT="#C0C0C0" BORDERCOLORDARK="#808080" FRAME="VOID" RULES="NONE" HSPACE="0" VSPACE="0" > <tR> <tD VALIGN=TOP HEIGHT= 87 WIDTH="289"><IMG BORDER="0" SRC="1x1.gif" HEIGHT="87" ALIGN="bottom" WIDTH="289" HSPACE="0" VSPACE="0"></tD> <tD VALIGN=TOP WIDTH="197"><div> <A HREF="transfer_home_movies_to_dvd.htm" TARGET="_top" TITLE="Transfer Service"><U><IMG SRC="14664510.jpg" border=0 width="100" height="81" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></U></A></div> </tD> </tR> </TABLE></B></div> <bR> <div> <B>Analog</B></div> <div> Conventional analog television uses a system of varying wavelengths to represent picture elements. By comparison, digital television (DTV) handles data much the way a computer does. For example, each element in a frame (a complete video picture) is converted to a binary word composed of 1s and 0s for transmission (see graph below). You can convert an analog signal to a digital signal by using an analog to digital converter (A to D). </div> <bR> <div> <IMG SRC="084a0660.png" border=0 width="160" height="102" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> <bR> <div> <B>Back Channel</B></div> <div> A means of communication from users to content providers. Today, a common type of back channel is an Internet connection using a modem. </div> <bR> <div> <B>Bit</B></div> <div> The smallest increment of digital information. A bit may be either a one or a zero. For the purposes of digital television signals, bits are counted in groups of a million each (Megabits, or Mb). Digital television signals use a data rate of 20 Megabits per second (Mb/s). </div> <bR> <div> <B>Cliff Effect</B></div> <div> When approaching the fringes of reception, analog TV pictures begin to degrade by becoming "snowy." By contrast, when in a weak digital signal area, a relatively small change in received power may cause the DTV picture to abruptly change from perfect to nothing; hence the name, "cliff effect." </div> <bR> <div> <B>Compression</B></div> <div> The technique of reducing the amount of data needed to represent a video or audio signal (by reducing the size of digital data files). Compression makes it possible to transmit DTV signals containing high-quality pictures, high-quality sound and data using the same amount of bandwidth (spectrum) as the existing analog television service. Compression can be accomplished in two ways: by removing redundant information in the files (called "lossless" compression) or by removing non-critical data (called "lossy" compression). In the United States, the DTV signal is reduced to 19.4 million bits per second. </div> <bR> <div> <B>Datacasting</B></div> <div> While broadcasting in HDTV or multicasting in SDTV, digital technology allows broadcasters to use leftover bandwidth to transmit additional program material or non-program related resources, such as video, audio, text, graphics, maps and services, to specially equipped computers, cache boxes, set-top boxes, or DTV receivers. This is called datacasting. DTV's broader bandwidth channel allows information to be downloaded at a transmission rate currently 600 times that of a personal computer modem. </div> <bR> <div> <B>Digital Television</B> (DTV)</div> <div> The umbrella term for the new broadcasting system adopted by the Federal Communications Commission in 1996. Analog television, which was developed in the 1940s, receives one continuous electronic signal. In contrast, DTV works on the same principle as a computer or a digitally recorded compact disc. It uses binary code, a series of ones and zeros, rather than a continuous signal. </div> <bR> <div> <B>Enhanced Television</B></div> <div> Term used for certain digital on-air programming (usually educational) that includes additional resources downloaded to viewers. Viewers will be able to simultaneously watch an enhanced TV production and, in the background, receive hundreds of megabytes of additional video, audio, text, images and other data related to the program. Some forms of enhanced TV allow live interaction; other forms are not visible on-screen until later recalled by viewers. Enhanced television (also known as "datacasting" or "interactive television") is still based on a broadcast technology, meaning that one source sends out information to many recipients. Users can only interact with the content provider directly when there is a back channel.</div> <bR> <div> <B>Flat Screen Display</B></div> <div> New TV screen technology will reduce the depth of TV sets to that of a framed picture. The TV screens on today's larger sets use bulky cathode ray tubes (CRTs), which are made of a glass envelope and use a controlled beam of electrons striking light-emitting material to display the picture. Flat screen displays are currently in development, and are beginning to show up in some TV sets and computer monitors. For now, CRTs are believed to be the first choice for DTV, but future development will make large DTV and current analog flat-screen displays practical. </div> <bR> <div> <B>High-Definition Television</B> (HDTV)</div> <div> The ultimate digital TV technology, HDTV uses twice as many lines as traditional television screens, and is broadcast in the wide-screen (16:9) format also found in movie theaters. The image quality is therefore significantly improved. You must have a high-definition television set in order to receive all the benefits of HDTV. </div> <bR> <div> <B>Interactive Television</B></div> <div> See Enhanced Television. </div> <bR> <div> <B>Multicasting</B></div> <div> Because digital television allows you to pack much more information into the allotted signal, we can transmit multiple channels on the same bandwidth instead of just one. Think of a broadcasting bandwidth as a multi-lane freeway. You can run a big, flashy, wide-load truck carrying HDTV and take up all of the lanes, or you can send multiple compact cars down the same freeway, each carrying specialized programming. When not broadcasting KCTS-DT HDTV on the majority of the bandwidth, KCTS multicasts three SDTV program streams on its digital channel 41: KCTS-DT, KCTS-DT Plus, and KCTS-DT Learns. These channels are broadcast in standard definition television (SDTV) programming. </div> <bR> <div> <B>NTSC</B></div> <div> "National Television Systems Committee"; also the name of the current analog transmission standard used in the U.S., which the committee created many decades ago. </div> <bR> <div> <B>SDTV-Standard Definition Television</B></div> <div> These are digital formats that do not achieve the video quality of high-definition television (HDTV), but are at least equal, or superior to, NTSC pictures. KCTS' three multicast channels are broadcast in SDTV. SDTV may have either "regular" (4:3) or "wide-screen" (16:9) aspect ratios, and it includes surround sound. Variations of fps (frames per second), lines of resolution, and other factors of 480p and 480i make up the 12 SDTV formats in the ATSC standard. </div> <bR> <div> <B>Spectrum</B></div> <div> Called "the invisible highway", spectrum is the collection of radio frequencies used by analog television broadcasters. Other users of spectrum include police and fire department radios, air traffic control, satellite transmissions, microwave ovens, cell phones and baby monitors. Intense overcrowding and competition for spectrum sparked a 10-year effort involving broadcasters, government agencies, scientists and engineers to reinvent television broadcast technology.  This effort has brought us digital television, which will not only allow a more efficient use of available spectrum, but offers benefits that will revolutionize the way we watch and enjoy TV. </div> <bR> <bR> <DIV ALIGN="LEFT"></DIV> <div> <B>© 2004  Don's TV Service </B></div> <bR> <bR> </td> </tr></table></body>