Digital Television

Digital Television is a digitally processed television signal transmission of audio & video which produces far higher quality as opposed to older analog TV. Because it utilizes digital signal, it uses binary concept, thus the result is either good picture or no picture at all (just like binary system: 1 or 0).

All countries use different Digital Television Terrestrial Broadcasting (DTTB) Standards to broadcast their programs. There are 4 DTTB standards currently in use:

• Advanced Television System Committee (ATSC): North America, South Korea.
• Digital Video Broadcasting-Terrestrial (DVB-T): Europe, Australia.
• Terrestrial Integrated Services Digital Broadcasting (ISDB-T): Japan, South America
• Digital Terrestrial Multimedia Broadcasting (DTMB): Republic of China

Source: Wikipedia

Formats in DTV

• HDTV (High-Definition TV). In 16:9 ratio: 1920×1080 (1080i) or 1280×720 (720p)

• SDTV (Standard-Definition TV). In 16:9 ratio: 720×480 (NTSC) or 720×576 (PAL), while in 4:3 ratio: 640×480 (NTSC) or 720×576 (PAL).

Comparisons of DTV and Analog TV

• Digital has definite crystal-clear picture, while analog’s picture can differ at times and largely depended to signal wave. Also if lacking, can result in ghosting image.
• Digital can provide HDTV service, interactivity, multiplexing, EPG, etc, while analog can only provide ‘television’; nothing more, nothing less.

Advantages of DTV

• Has precise, stable audio & video quality without any interference.
• Can provide high-definition contents.
• Multiplexing. Viewers can watch more than one program on the same channel simultaneously.
• Interactivity. Viewers can interact digitally with TV (such as polls) via internet.
• Electronic Program Guide (EPG). A feature which let viewers see program guide in a specific channel.
• Can provide additional languages and subtitles.
• More channels can fit on the same spectrum under digital transmission.
• Instance message is fastly received than analogue.

Disadvatages of DTV

• Sometimes can create artifacts in video caused by algorithm compression.
• Degrading antenna or weather-changing can cause garbled video in some hardware, while the others may show no picture at all. Known as Cliff Effect.
• TV sets with analog tuner can’t decode digital contents. To view it, need additional device: Set-Top Box (STB)
• Need a transition in all countries to globally adapting this new technology.
• An upgraded antenna installation may be required.
• Switching channels is slower because of the time delays in decoding digital signals.
• Interactive (red button) services are rarely provided, and most digital data such as schedule data is not provided by stations.

Digital Television Transition

Digital television transition is a process in which analog television broadcasting is converted and replaced with digital television. This process also involves conversion of analog terrestrial television to digital terrestrial. Many countries have begun the transition, although some, is still in progress. The switchover for each countries varies; in some countries it is being implemented in stages as in the United Kingdom for some years. While some others, have the whole country switches on one date, such as the Netherlands.

DTV in Indonesia
In Indonesia, although the global transition has not begun, many local TV stations have used DTV technology, but only limited to studio system and production-related things. The first station to launch digital telecast for testing purpose was TVRI on August 13, 2008, using DVB-T standard. Since Q1 2011 the authority has allowed digital television simulcast with analog television in some area. As for the complete analog-to-digital switchover in Indonesia, it will happen in 2018, supposedly.

In summary, DTV is a signal transmission received by television by means of digital. DTV has far superior image quality than analog TV. Many countries have gradually started its transition to digital. Although Indonesia has done experiments regarding the transition, it still has yet to officially started.