Content-Type: text/html
DTV comes in two formats Standard Definition TV (SDTV) and High Definition TV (HDTV). SDTV uses 480x704 or 480x640 pixels; HDTV uses 1080x1920 or 720x1280 pixels. The signal can be in interlace? or [progressive scan]? mode. When broadcasting in SDTV mode, the bandwidth of a DTV channel can be subdivided into 6 sub-channels. The TV stations can use the other 5 subchannels to carry data, radio or any other signals.
US Congress mandates TV stations to convert to the Digital TV standard by 2003. Apparently, the plan is behind schedule. It is beleived that the sheer number of TV sets and broadcast equipment that require upgrade slow the momentum of the implementation.
Reference: [[ATSC]]