Digital television (DTV) could be the transmission of audio and video by digitally processed and multiplexed signal, as opposed to the totally analog and channel separated signals utilized by analog television. Digital TV can hold many enter in the same channel bandwidth. It is really an innovative service to display the initial significant evolution in television technology since color television inside the 1950s. Several aspects of the world are in different stages of adaptation and are implementing different broadcasting standards. Below are the various trusted digital television broadcasting standards (DTB):
- Digital Video Broadcasting (DVB) uses coded orthogonal frequency-division multiplexing (OFDM) modulation and supports hierarchical transmission. This standard has been adopted in Europe, New zealand and australia.
- Advanced Television System Committee (ATSC) uses eight-level vestigial sideband (8VSB) for terrestrial broadcasting. This standard has been adopted by six countries: United states of america, Canada, Mexico, Columbia, Dominican Republic and Honduras.
- Integrated Services Digital Broadcasting (ISDB) is a system made to provide good reception to fixed receivers and in addition portable or mobile receivers. It utilizes OFDM and two-dimensional interleaving. It supports hierarchical transmission up to three layers and uses MPEG-2 video and Advanced Audio Coding. This standard has been adopted in Japan and also the Philippines. ISDB-T International is definitely an adaptation of the standard using H.264/MPEG-4 AVC that been adopted generally in most of South usa and it is being embraced by Portuguese-speaking African countries.
- Digital Terrestrial Multimedia Broadcasting (DTMB) adopts time-domain synchronous (TDS) OFDM technology with a pseudo-random signal frame to serve because guard interval (GI) with the OFDM block and the training symbol. The DTMB standard has become adopted in the People's Republic of China, including Hong Kong and Macau.
- Digital Multimedia Broadcasting (DMB) is a digital radio transmission technology coded in Mexico contained in the national IT work for sending multimedia such as TV, radio and datacasting to cellular phones such as cellphones, laptops and Global positioning system systems.