Other Benefits of digital TV

There are benefits to digital TV other than the obvious ones of improved picture and sound quality.
Multicasting Just as a DVD can contain several different programs on a single disc, so can a DTV broadcast contain several TV programs on the same channel. This technique is called multicasting, and it allows the broadcaster to serve several different audiences at the same time. Or a cable system operator can use channel space more efficiently by carrying multiple digital cable programs on one channel.

Here’s a real-world example. A local TV station elects to send out three DTV programs. The first program offers HDTV shows and sports, while the second offers SD versions of the same programming. Finally, a third program carries continuous local weather information. Your digital TV set-top receiver or integrated TV will automatically find all of these programs for you and identify each with a unique channel number.

In this case, the first program (HDTV) would appear as channel 6-1. The second program would come up as channel 6-2, and the 24/7 weather programming would show up as 6-3.

The digital TV or external set-top receiver knows how many of these TV programs are on each channel by reading the digital program data packets. For a better understanding of how this works, think of the TV channel as a “digital shoebox.”

Multicasting allows you to choose from up to four images on the same channel.
Datacasting Another benefit of digital TV is datacasting. The broadcaster sends out data separate from any TV programs. That data could be anything from prices and delivery information on a home shopping channel to interactive text and graphics on an educational channel.

In the cable world, this process is used to order video-on-demand (VOD) programs. It could also be used to provide high-speed Internet access to the user, with a slower connection going back to the broadcaster or satellite operator.
Datacasting allows broadcasters to supplement a TV program with information screens similar to Web pages.

Digital AudioJust as a DVD will offer multiple soundtracks, you’ll find that many digital TV broadcasts let you listen in single-channel (mono), two-channel (stereo), or even surround-sound audio modes such as Dolby Digital 5.1. The latter, (DD 5.1 as it is called in industry shorthand) requires four speakers for surround sound effects, a center speaker for dialogue, and a sub-woofer for bass effects. There is provision for the mono audio track to be broadcast in multiple languages but that feature is not widely used at present.

With such a setup, you will feel more like you’re in a movie theater than at home watching TV programs. Surround sound is particularly effective with live sporting events such as auto racing, football, basketball, baseball, hockey, and soccer. Add in widescreen pictures and high definition, and you have a truly immersive TV viewing experience!