![]() Historically, there have been several methods used for broadcasting electronic media audio and video to the general public: This is the information equivalent of 55 newspapers per person per day in 1986, and 175 newspapers per person per day by 2007. ![]() The world's technological capacity to receive information through one-way broadcast networks more than quadrupled during the two decades from 1986 to 2007, from 432 exabytes of (optimally compressed) information, to 1.9 zettabytes. Digital audio radio ( HD Radio, Digital Audio Broadcasting (DAB), Satellite radio and Digital Radio Mondiale (DRM) In general usage, broadcasting most frequently refers to the transmission of information and entertainment programming from various sources to the general public. Originally all broadcasting was composed of analog signals using analog transmission techniques but in the 2000s, broadcasters have switched to digital signals using digital transmission. Satellite broadcasting was initiated in the 1960s and moved into general industry usage in the 1970s, with DBS (Direct Broadcast Satellites) emerging in the 1980s. Television broadcasting started experimentally in the 1920s and became widespread after World War II, using VHF and UHF spectrum. By the early 1920s audio radio broadcasting became a household medium, at first on the AM band and later on FM. Audio radio broadcasting began experimentally in the first decade of the 20th century. This was particularly important for ship-to-ship and ship-to-shore communication, but it became increasingly important for business and general news reporting, and as an arena for personal communication by radio amateurs (Douglas, op. Morse therefore developed the forerunner to modern International Morse code. A code was needed to transmit natural language using only these pulses, and the silence between them. They developed an electrical telegraph system which sent pulses of electric current along wires which controlled an electromagnet that was located at the receiving end of the telegraph system. The earliest broadcasting consisted of sending telegraph signals over the airwaves, using Morse code, a system developed in the 1830s by Samuel Morse, physicist Joseph Henry and Alfred Vail. In the 2000s, transmissions of television and radio programs via streaming digital technology have increasingly been referred to as broadcasting as well. Transmissions using a wire or cable, like cable television (which also retransmits OTA stations with their consent), are also considered broadcasts but do not necessarily require a license (though in some countries, a license is required). Transmission of radio and television programs from a radio or television station to home receivers by radio waves is referred to as "over the air" (OTA) or terrestrial broadcasting and in most countries requires a broadcasting license. As defined, "transmitting" and "broadcasting" are not the same. For example, amateur ("ham") and citizens band (CB) radio operators are not allowed to broadcast. Private or two-way telecommunications transmissions do not qualify under this definition. Code of Federal Regulations, title 47, part 97 defines "broadcasting" as "transmissions intended for reception by the general public, either direct or relayed". The field of broadcasting includes both government-managed services such as public radio, community radio and public television, and private commercial radio and commercial television. The receiving parties may include the general public or a relatively small subset the point is that anyone with the appropriate receiving technology and equipment (e.g., a radio or television set) can receive the signal. Over the air broadcasting is usually associated with radio and television, though more recently, both radio and television transmissions have begun to be distributed by cable ( cable television). Examples applying it to "one-to-many" radio transmissions of an individual station to multiple listeners appeared as early as 1898. It was later adopted for describing the widespread distribution of information by printed materials or by telegraph. The term broadcasting evolved from its use as the agricultural method of sowing seeds in a field by casting them broadly about. ![]() ![]() ![]() Before this, all forms of electronic communication (early radio, telephone, and telegraph) were one-to-one, with the message intended for a single recipient. Broadcasting began with AM radio, which came into popular use around 1920 with the spread of vacuum tube radio transmitters and receivers. Broadcasting is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum ( radio waves), in a one-to-many model. ![]()
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