Broadcasting

• 1. Introduction

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  Broadcasting borrowed its name from a farmer's hand. The word once described the agricultural method of sowing seeds by casting them broadly across a field. Later it described the spread of information through printed materials and the telegraph. By 1898, the term was being applied to something new: the radio transmissions of a single station reaching many listeners at once. That shift from sowing seed to scattering signal carries a whole history inside it. Before broadcasting, most electronic communication was one-to-one. Early radio, the telephone, and the telegraph all sent a message intended for a single recipient. So how did a one-to-one world become a one-to-many one? What separates a broadcast from any other transmission? And how did a method of distribution grow until it could reach, in 2007, the information equivalent of 175 newspapers per person per day?

• 2. What Counts As Broadcasting

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  The U.S. Code of Federal Regulations, title 47, part 97, draws a sharp line. It defines broadcasting as transmissions intended for reception by the general public, either direct or relayed. That definition does real work. Private or two-way telecommunications transmissions do not qualify. Amateur operators, the ones known as ham radio operators, are not allowed to broadcast. Neither are citizens band, or CB, radio operators. By this standard, transmitting and broadcasting are not the same thing. The heart of the idea is access. Anyone with the appropriate receiving technology, a radio or a television set, can pick up the signal. The receiving parties may be the general public or a relatively small subset of it. What matters is that the door is open to whoever has the right equipment. The field spans both government-managed services and private commercial ones. It includes public radio, community radio, and public television alongside commercial radio and commercial television. Over-the-air broadcasting is usually associated with radio and television. More recently, both have begun to be distributed by cable. Transmission by radio waves from a station to home receivers is called over the air, or terrestrial, broadcasting. In most countries it requires a broadcasting license. Cable, which can also retransmit over-the-air stations with their consent, does not always require one.

• 3. From Marconi To Farnsworth

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  In 1894, the Italian inventor Guglielmo Marconi began developing wireless communication using the newly discovered phenomenon of radio waves. By 1901 he had shown that those waves could be transmitted across the Atlantic Ocean. This was the start of wireless telegraphy by radio. On the 17th of December 1902, a transmission from the Marconi station in Glace Bay, Nova Scotia, Canada, became the world's first radio message to cross the Atlantic from North America. In 1904, a commercial service began transmitting nightly news summaries to subscribing ships, which folded them into their onboard newspapers. War kept pushing the technology forward. World War I accelerated the development of radio for military communications. World War II again accelerated it, this time for aircraft and land communication, radio navigation, and radar. Television arrived through a separate lineage. On the 25th of March 1925, John Logie Baird demonstrated the transmission of moving pictures at the London department store Selfridges. His device relied on the Nipkow disk and became known as the mechanical television. It formed the basis of experimental broadcasts by the British Broadcasting Corporation beginning on the 30th of September 1929. For most of the 20th century, though, televisions depended on the cathode-ray tube invented by Karl Braun. The first version to show promise came from Philo Farnsworth, who demonstrated it to his family on the 7th of September 1927. Satellite broadcasting was initiated in the 1960s and moved into general industry usage in the 1970s, with Direct Broadcast Satellites emerging in the 1980s.

• 4. How The Signal Travels

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  A central high-powered broadcast tower stands at the start of the chain. It transmits a high-frequency electromagnetic wave to numerous receivers. That high-frequency wave is modulated with a signal carrying visual or audio information. The receiver tunes in to pick up the wave, and a demodulator retrieves the information hidden inside it. The signal itself can take two forms. An analog signal varies continuously with respect to the information it carries. In an analog audio signal, the instantaneous voltage varies continuously with the pressure of the sound waves. A digital signal instead encodes the information as a set of discrete values. It represents the time-varying quantity as a sampled sequence of quantized values, which imposes bandwidth and dynamic range constraints. Originally all broadcasting used analog signals and analog transmission techniques. In the 2000s, broadcasters switched to digital signals using digital transmission. The final leg of distribution is how the signal reaches the listener or viewer. It may come over the air to an antenna and radio receiver. It may arrive through cable television or cable radio. The Internet may bring internet radio or streaming media television to the recipient, with multicasting allowing the signal and bandwidth to be shared.

• 5. The Many Methods

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  Telephone broadcasting came first, running from 1881 to 1932. It began with the Théâtrophone, or Theatre Phone, a telephone-based distribution system that let subscribers listen to live opera and theatre performances over telephone lines. The French inventor Clément Ader created it in 1881. The form later grew to include telephone newspaper services for news and entertainment, introduced in the 1890s and located primarily in large European cities. These subscription services were the first examples of electrical broadcasting. Radio broadcasting ran experimentally from 1906 and commercially from 1920, sending audio signals through the air as radio waves. Radio stations can be linked into networks through broadcast syndication, simulcast, or subchannels. Television broadcasting, also called telecast, ran experimentally from 1925 and commercially from the 1930s, extending radio to include video signals. Cable radio arrived in 1928 and cable television in 1932, both carried via coaxial cable. Direct-broadcast satellite arrived around 1974 and satellite radio around 1990, aimed at direct-to-home programming. Webcasting of video and television streams began around 1993, and webcasting of audio and radio streams around 1994, offering a mix of traditional and dedicated internet programming.

• 6. Who Pays For It

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  Commercial broadcasting runs on advertising. These for-profit, usually privately owned stations and networks sell air time to advertisers for radio or television advertisements during or between programs. They often combine that revenue with cable or pay cable subscription fees. Public broadcasting takes a different path. Usually non-profit and publicly owned, these stations rely on license fees, government funds, grants from foundations, corporate underwriting, audience memberships, and contributions. In the United States, National Public Radio and the Public Broadcasting Service supplement membership subscriptions and grants with funding from the Corporation for Public Broadcasting. Congress allocates that funding bi-annually. The corporate and charitable grants are given in consideration of underwriting spots, which the FCC governs with specific restrictions. Those rules prohibit advocacy of a product or a call to action. Community broadcasting is owned, operated, or programmed by a community group to provide local programming. These stations are most commonly run by non-profit groups or cooperatives, though sometimes by a local college or university, a cable company, or a municipal government. Internet webcasting introduces a newer economy. The audience pays to recharge and buy virtual gifts for the anchor, and the platform converts the gifts into virtual currency, which the anchor withdraws. If the anchor belongs to a trade union, the union and the platform settle the payment, and the anchor gets a salary plus part of a bonus.

• 7. Recorded Or Live

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  The first regular television broadcasts started in 1937. From the start, broadcasts split into two kinds: recorded and live. Recording lets producers correct errors, remove undesired material, rearrange segments, and apply slow-motion and repetitions. Some live events borrow those techniques too, as when sports television inserts slow-motion clips of important goals or hits during the live telecast. American radio-network broadcasters habitually forbade prerecorded broadcasts in the 1930s and 1940s. Programs played for the Eastern and Central time zones had to be repeated three hours later for the Pacific time zone. The restriction was dropped for special occasions. One was the German dirigible airship Hindenburg disaster at Lakehurst, New Jersey, in 1937. During World War II, prerecorded broadcasts from war correspondents were allowed on U.S. radio, and American radio programs were recorded for playback by Armed Forces Radio stations around the world. Recording carries a cost. The public may learn the outcome of an event before the recording airs, which can spoil it. Prerecording could also keep announcers from deviating from an officially approved script, as happened with propaganda broadcasts from Germany in the 1940s and with Radio Moscow in the 1980s. Many events advertised as live are in fact recorded live, sometimes called live-to-tape. This holds for musical artists who visit a studio for an in-studio concert performance.

• 8. A Message Without A Reply

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  John Durham Peters framed broadcasting as an act of dissemination. In his essay he wrote that dissemination is a lens, sometimes a usefully distorting one, that helps us tackle basic issues such as interaction, presence, and space and time. Dissemination focuses on a message relayed from one main source to one large audience, without any exchange of dialogue in between. Once the source releases the message, it can be changed or corrupted by government officials. There is no way to predetermine how the audience will absorb it. They can choose to listen, analyze, or ignore it. The structure of the medium shapes the relationship. A disc jockey follows a script and talks into a microphone, gathering a large number of followers who tune in every day. They do not expect immediate feedback. The message travels across the airwaves throughout the community, but listeners cannot always respond at once, especially when the show was recorded before air time. Behind all of this sits broadcast engineering, a field of electrical engineering that now reaches into computer engineering and information technology. It covers both the studio and transmitter aspects, the entire airchain, as well as remote broadcasts. Every station has a broadcast engineer, though one may now serve an entire station group in a city. In small media markets, that engineer may work on a contract basis, moving between stations as each one needs.