In the United States and most of North America, terrestrial television underwent a revolutionary transformation with the eventual acceptance of the NTSC standard for color television broadcasts in 1953. Later, Europe and the rest of the world either chose between the later PAL and SECAM color television standards, or adopted NTSC.
In addition to the threat from CATV, analog terrestrial television is now also subject to competition from satellite television and distribution of video and film content over the Internet. The technology of digital terrestrial television has been developed as a response to these challenges. The rise of digital terrestrial television, especially HDTV, may mark an end to the decline of broadcast television reception via traditional receiving antennae, which (if UHF capable), can receive over-the-air HDTV signals.
In North America, terrestrial broadcast television operates on TV channels 2 through 6 (VHF lo-band), 7 through 13 (VHF hi-band), and 14 through 69 (UHF television band). Channel numbers represent actual frequencies used to broadcast the television signal. Additionally, television repeaters can be used to rebroadcast a terrestrial TV signal using an otherwise unused UHF channel to cover areas with marginal reception. Once analog terrestrial broadcasts cease, the VHF television bands will no longer be used for television broadcasting in the United States. A chart showing the North American television bandplan can be found here.
See Lists of television channels, for lists by country and language.