Digital TV
History
In the United States, the National Television System Committee (for which the NTSC standard is named) standardized on 525 lines at 30 fps in 1940, with regular broadcasts starting on July 1, 1941.
NTSC standard was updated to include first a non-compatible 441-line color standard in 1950, which was replaced by a compatible 525-line, 29.97fps color standard approved in 1953 and used to this day.
Current high definition video standards were developed during the course of the advanced television process initiated by the Federal Communications Commission in 1987 at the request of American broadcasters
FCC process, led by the Advanced Television Systems Committee (ATSC) adopted a range of standards from interlaced 1080 line video with a maximum frame rate of 30 fps, and 720 line video, progressively scanned, with a maximum frame rate of 60 fps. The FCC officially adopted the ATSC transmission standard (which included both HD and SD video standards) in 1996, with the first broadcasts on October 28, 1998.
Who will be affected by DTV
Consumers who receive over-the-air television signals through antennas on television sets that are equipped with analog tuners – and who do not subscribe to cable, satellite or a telephone company television service provider – will be affected by the transition.
At least 19.6 million households receive over-the-air signals exclusively in their homes, and 14.9 million households have secondary over-the-air television sets in their bedrooms or kitchens. Overall, nearly 70 million television sets are at risk of losing their signals on February 17, 2009, if consumers do not make the transition to DTV.
Analog vs Digital
Analog TV – AM vestigial sideband
6 MHz of bandwidth per channel plus the audio
High power transmitters for coverage – 45 to 75KW Avg. Out
~300KW to 5MW ERP
Noise and multi-path interference common
Digital TV – 8VSB MPEG-2 Stream
6 Mhz Channel can produce multiple programs viewable with ATSC tuner
In the United States, the National Television System Committee (for which the NTSC standard is named) standardized on 525 lines at 30 fps in 1940, with regular broadcasts starting on July 1, 1941.
NTSC standard was updated to include first a non-compatible 441-line color standard in 1950, which was replaced by a compatible 525-line, 29.97fps color standard approved in 1953 and used to this day.
Current high definition video standards were developed during the course of the advanced television process initiated by the Federal Communications Commission in 1987 at the request of American broadcasters
FCC process, led by the Advanced Television Systems Committee (ATSC) adopted a range of standards from interlaced 1080 line video with a maximum frame rate of 30 fps, and 720 line video, progressively scanned, with a maximum frame rate of 60 fps. The FCC officially adopted the ATSC transmission standard (which included both HD and SD video standards) in 1996, with the first broadcasts on October 28, 1998.
Who will be affected by DTV
Consumers who receive over-the-air television signals through antennas on television sets that are equipped with analog tuners – and who do not subscribe to cable, satellite or a telephone company television service provider – will be affected by the transition.
At least 19.6 million households receive over-the-air signals exclusively in their homes, and 14.9 million households have secondary over-the-air television sets in their bedrooms or kitchens. Overall, nearly 70 million television sets are at risk of losing their signals on February 17, 2009, if consumers do not make the transition to DTV.
Analog vs Digital
Analog TV – AM vestigial sideband
6 MHz of bandwidth per channel plus the audio
High power transmitters for coverage – 45 to 75KW Avg. Out
~300KW to 5MW ERP
Noise and multi-path interference common
Digital TV – 8VSB MPEG-2 Stream
6 Mhz Channel can produce multiple programs viewable with ATSC tuner