What is ATSC 3.0?

For the first 50+ years of terrestrial television broadcasting, the standards for video transmission in North and Central America, parts of South America, and a handful of African and Asian nations were governed by the National Television System Committee, or NTSC. 

The NTSC standard provided for 6MHz of bandwidth for each channel and was limited to 525 lines of interlaced video (480 active) at 30 frames per second. With the exception of the addition of stereo audio in the mid 1980’s, the NTSC standard remained largely unchanged in between 1953 and June 12, 2009, the day that broadcasters were forced to switch off their analog transmitters and begin digital-only transmission.    

The initial iteration of the ATSC (Advanced Television Systems Committee) standard provided the groundwork for digital television transmission by:

• Defining MPEG-2 as the compression method for transmission.
• Specifyinga transport stream bitrate of 19.39Mbps.
• Establishing 1920x1080 interlaced, 1280x720 progressive, and 640x480 interlaced as acceptable video resolutions.
• Providing for audio coding using Dolby AC-3. 
• Producing the criteria for the insertion of PSIP, a series of data tables necessary to identify the transmission source of a stream.
• Providing receivers with virtual channel tuning information, guide data, system time, and other metadata.

After much debate, ATSC 1.0 also established 8-VSB as the modulation scheme for terrestrial broadcasting. This modulation scheme was selected primarily due to its lower transmission power requirements. However, 8-VSB proved to perform poorly in multi-path situations, making it a sub-par choice for densely developed cities and mobile applications.   

By the time full-power analog television transmission ceased in 2009, the MPEG-2 codec used for ATSC was already 14 years old. While the quality of available encoding hardware and algorithms has improved over the years, the MPEG-2 codec itself had not changed substantially since its inception. 

The more efficient MPEG-4 codec was already in use for contribution and was being rolled out for distribution on cable and satellite, once again putting terrestrial broadcast at a competitive disadvantage. With 4K video on the horizon, the desire for a more efficient codec drove the push toward a revised ATSC standard. This codec would facilitate the transmission of higher resolution video, additional audio tracks, and data services outside of real time video and include HEVC as its standard for video encoding. With the move to HEVC, broadcasters will have the ability to distribute 4K, 8K, and HDR content. The more efficient use of bandwidth will also allow broadcasters to include additional subchannels, metadata, and non-real-time data and will allow for incentivized spectrum sharing among multiple licensees within a given market.