Tuesday, October 19, 2010

What Is The History Behind Digital TV?

By Adriana Noton

The modern era has seen sweeping changes in telecommunications. The industries of portable phones and internet have been created, improved, and re-imagined. Television, though an older technology, has not been immune from technological advancements. On the contrary, digital TV is one of the biggest paradigm shifts in television's history.

First, let's understand the difference between the older analog system, and the new digital medium. Analog systems have picture and sound information encoded in a transmission signal. Before digital television every TV worked this way. Digital TV receives the same audio and picture information digitally, meaning it works less like listening to music on the radio and more like hearing a CD. Digital TV has two distinct formats, HDTV and STV. The confusing thing is that there are shades of grey between them. HDTV stands for High Definition Television, but this varies depending on the aspect ratio (width to height). Though there are varying degrees of quality to HDTV, it reaches a height unsurpassed in analog, or in any other form of digital TV. STV fits between analog and HDTV in terms of quality, but this too can vary since broadcasters change quality depending on the broadband strength of the host country.

Actually, the requirements for digital television have been around since the mid eighties. Like so many things, there was corporate disagreement about how the public would best be served. Though it's hard to believe, it actually took over twenty years to reach consensus.

Digital TV is replacing analog in many industrialized countries. Basically, it is so superior that it makes sense for the shift to be mandated in law. Here's why. Because digital TV takes up less bandwidth, cable providers have a great deal of flexibility and options. Digital providers now offer interactive menus and games, things which create additional revenue for cable providers that was previously impossible to obtain. Things like electronic programming guides and multi-lingual subtitles are possible. The bandwidth efficiency also allows for more programs being shown in the same space, so an increase in channels is possible. Moreover, interference doesn't affect digital TV the way it did analog. A crossing of signals might produce the fuzzing of images or a breakdown in sound quality. With digital cable, the audio and video are synchronized more fully, so unless there is an utter breakdown (something that happens far less often than even a modest glitch in analog) your program will show in better quality.

The first program to be shown publicly in HDTV was launch of Space Shuttle mission STS-95. The feed was free for any broadcaster who could receive the signals. What an appropriate way to begin the launching of such a superior technology! Still, its rise to prominence was far from immediate. Actually, there were many interlocking problems which stymied digital television. Manufacturers couldn't stock many HDTV's because consumers didn't show enough interest. The broadcasters didn't want to spend so much money on expensive feeds with so few televisions out there. Consumer's weren't buying it immediately because there weren't many programs. All these factors kept the cost high. But in the end, common sense prevailed and the better technology won out. Today, wireless internet has also made it possible to watch shows and movies that you would usually watch on TVs. - 33366

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