Terrestrial television

Terrestrial television is the traditional method of television broadcast
signal delivery, by radio waves. Terrestrial television broadcasting dates
back to the very beginnings of television as a medium itself with the first
long distance public television broadcast from Washington, DC on April 7,
1927. In fact, there was virtually no other method of television delivery
until the 1950s with the advent of cable television, or community antenna
television (CATV). The first non-terrestrial method of delivering television
signals that in no way depended on a signal originating from a traditional
terrestrial source began with the use of communications satellites during
the 1960s and 1970s.

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.