ATSC(Advanced Television Systems Committee)
What is ATSC? ATSC is a set of standards developed by the Advanced Television Systems Committee for digital television transmission over terrestrial, cable, and satellite networks.
ATSC digital television standard is composed of four separate levels, and it has a clear interface between levels. The top one is the image layer, it is to determine the form of images, including pixel array, amplitude ratio and frame rate. Followed by image compression layer, the use of MPEG-2 compression standard. Further down the system multiplexing layer, specific data is compressed into a different package, it is used of MPEG-2 compression standard. Finally, the transport layer, it is can determine the modulation and channel coding scheme of the data transmission . For terrestrial broadcasting system, developed by Zenith 8-VSB transmission mode, the 6MHz terrestrial broadcast channels can be achieved 19.3Mb / s transfer rate. The standard also includes cable television system suitable for high data rate 16-VSB transmission mode can be achieved in the 6MHz cable channel 38.6Mb / s transfer rate. Two shared the following general data transmission. Determine the top two floors on the basis of data transmission in the general run of specific configuration, such as HDTV or SDTV; ATSC standard also identified the specific image format support, a total of 18 species (HDTV 6 species, SDTV 12 species), which uses progressive scan 14 way.
In 6 format of HDTV, because the 1920 × 1080 format does not fit within a 6MHz channel at 60 frames / second for progressive scan, it is replaced by interlaced scanning. SDTV's 640 × 480 VGA image format and the computer the same format, to ensure the applicability of the computer. In the 12 SDTV formats, there are 9 with progressive scan, leave 3 as a way to adapt the existing interlaced video system.
In addition, ATSC has also developed and adopted for use in countries with 50Hz frame rate of the prior standard. The pixel array HDTV format are the same, but the frame rate is 25Hz and 50Hz;the SDTV's lines of vertical resolution is 576,but the horizontal resolution is different; also contains 352 × 288 format, to adapt the set of window