Simulcasting is a term used to describe the simultaneous transmission of a television and/or radio signal over two or more networks or two or more stations. The most obvious example would be a major address by the President of the United States which might be carried simultaneously by three television networks (ABC, CBS, NBC), one or more cable networks (CNN, CNBC), and several radio networks.

The term has taken a different meaning during various periods in broadcasting. Initially, the term was applied to the simultaneous transmission of important events over two or more radio outlets. Later, it referred to the simultaneous transmission of programs on radio and television. This occurred during the 1960s when some of the most popular radio programs became television programs. but the audio portion was still simulcast on radio. This practice was short-lived, however, as the number of homes with TV sets increased and radio shifted to a more music-based programming.

The very slow growth in FM radio during the 1950s and 1960s was due, in part, to the simulcasting of radio programming over co-owned AM and FM stations. In 1964, the FCC (Federal Communications Commission) acted to force the independence of FM stations by severely restricting the number of hours that AM and FM stations could simulcast during any given broadcast day, although protests by radio station owners delayed implementation of the rule until 1 January 1967. (Ironically, the FCC removed the restrictions on AM-FM simulcasting a quarter of a century later so that struggling AM stations could simulcast the programming of their stronger FM sister stations.)

Simulcasting of musically-oriented programs by television and FM stations occurred on an occasional basis during the 1970s and 1980s. Sometimes these programs included opera or other classical presentations; on other occasions rock concerts were simulcast. The improved sound fidelity and stereo capability of newer television sets have diminished the need for such audio-enhancement simulcasting although some TV/FM simulcasting still occurs.

Currently the term simulcasting is most relevant to the development and adaptation of high definition television (HDTV). Both broadcasters and regulators realize that newer more advanced forms of television transmission will have to be phased in gradually since viewers with standard television receivers would not be willing to accept the immediate obsolescence of their current TV sets.

Proposals now under consideration would require television stations to simulcast two separate signals. One standard, or NTSC, analog signal suitable for reception by current receivers would be transmitted over the channels currently allocated to television stations; a second high definition, digital signal suitable for newer, more advanced receivers would be transmitted over a separate channel.

This type of simulcasting would require the allocation of additional broadcast frequencies to those television stations that transmit the second signal. While broadcasters have expressed an interest in acquiring second channels for various uses including HDTV, they resist the stipulation that links the second channel to the mandated simulcasting of NTSC and HDTV signals. Another point of controversy involves the time frame for simulcasting; i.e. how long would such transmissions be required and what requirement, if any, would have broadcasters return unused frequencies to the FCC for reallocation once simulcasting ended.

While this particular utilization of simulcasting is still under discussion the traditional simulcasting of major events by one or more television and/or cable outlets is a well established practice and one not likely to end in the near term.

-Norman Felsenthal


See also Music on Television; Public Television