HDTV Broadcasts - HDTV Signals - Digital TV Signal
When talking about HDTV, most discussions of centre on the receiver, which in reality is the most visible part.
However, to be able to work to it's full potential, that high definition TV has to have something to receive in the
form of a digital TV signal.
HDTV sets display 1080 lines of pixels which is around twice the traditional number. The actual TV screens
themselves typically have an aspect ratio of 16:9 rather than the standard 4:3. That means, even though the
dimensions of the sets vary, the ratio of width to height is always 16 to 9 vs 4 to 3 for standard sets.
Traditional TV signals were broadcast in analog fashion. Avoiding some complicated technical discussion, that
just means the radio waves composing TV signals are modulated in different ways. Those modulations make variations
that the television receiver can process into moving images.
Digital signals, by contrast, make those changes by varying the pattern of digital 1's and 0's that form every
kind of digital source such as DVD, TV, and MP3.
Whether the signal is broadcast via satellite, via cable or even directly into your PC or TV via DVD player or
over the Internet the basics are the same. Make a changing pattern of digital 1's and 0's and translate that into a
series of moving images.
Advantages of Digital TV Signals
One advantage just hinted at is the ability to transmit movies to PCs. That is becoming an ever more popular
since, among other things, it enables people to see more kinds of content on their PC - such as movies from a
library on a pay per view basis. People aged 16-24 (or even those around the 50 mark like yours truly!) throughout
the world now spend more time on a PC than they ever do watching television.
Another is the ability to deliver not just better quality images, but vastly superior sound quality. Though it
has long been possible to hook up your TV to your stereo system, the actual quality of broadcast audio left a
little to be desired. Now Dolby Digital 5.1 surround sound is commonly broadcast along with standard HDTV video
signals, making the investment in a full surround sound home entertainment system much more attractive.
Digital broadcasts will, in the long run, lower broadcasters costs. Currently, they are supporting two different
technologies. That eats into revenue that could be used elsewhere. Converting to digital only broadcasts, which is
currently scheduled for 2009, enables them to invest more in programming content and other things consumers
Broadcasting a digital tv signal makes it much more feasible to eliminate different kinds of interference. With
the advent of digital cable and DVD, many of the older problems such as snowy or rolling pictures are now history.
However, digital broadcasts eliminate even more sources of trouble.