RADIO

Radio includes a broad group of technologies that utilize electromagnetic radiation (also called radio waves) to transmit and/or receive information. Examples of radio technologies can be drawn from numerous industries, applications, and end users. A partial listing would include radio (and television) broadcasting, maritime communications, radio navigation, cellular telephony, satellite communications, numerous military applications, wireless computer networking, noncontact identification systems, military and meteorological radar, global positioning systems, and radio astronomy (see Figure 1).

What all these systems have in common is the conversion of electrical energy from one form into another, specifically, from electrical currents bound in conductive materials such as wires and cables into unbounded electromagnetic radiation that is free to propagate through space, the atmosphere, or another nonconducting medium. This is the process of radio transmission. Radio reception is the reverse process, in which incoming electromagnetic radiation is converted into electrical currents in the antennas, wires, and components of a radio receiver.

Historical Developments

The following material is a brief history of the development of radio technology with an emphasis on related ethical, political, and legal issues. This history draws on Christopher Sterling and John Michael Kittross's Stay Tuned (2002).

The background of radio was the earlier practical development of wired electronic signal transmission and reception, as in the telegraph (1830s and 1840s) and James Clerk Maxwell's electromagnetic theory (1860s), which was confirmed by Heinrich Hertz's laboratory experiments (1880s). It was his ability to draw on those previous achievements that enabled Guglielmo Marconi (1874–1937) (see Figure 2) to transmit and receive the first wireless telegraph messages in 1895, an experiment that he followed up with wireless transmissions across the English Channel (1899) and the Atlantic (1901).

The rapid development of radio led in 1910 to the Wireless Ship Act in the United States, which required a radio and an operator on all oceangoing passenger vessels. Through World War I the U.S. Navy continued to control radio facilities, while the U.S. Congress debated the future government role in relation to the new technology. Shortly after the war, in 1921, thirty broadcasting stations went on the air, using only two frequencies or channels.

In 1922 President Herbert Hoover hosted the first radio conference, which called for government regulation of radio technology, limited advertising, and classification of radio stations by the services they provided. Two years later the British physicist Sir Edward Victor Appleton conducted the first experiment with radio range-finding equipment, reflecting radio waves off the ionosphere to determine its height. This was an important step in the development of radar.

Later in the 1920s President Calvin Coolidge signed the Radio Act of 1927, establishing the Federal Radio Commission (FRC). In that decade the National Association of Broadcasters issued a code of radio advertising and programming ethics.

In 1932 the engineer Karl Jansky discovered a strong source of radio noise that later was discovered to originate outside the solar system; this marked the beginning of radio astronomy. In 1934 the Federal Communications Commission (FCC) was established to replace the FRC. Later in the decade, in 1937, the first practical mobile radio, the DR38a transmitter-receiver, was developed.

During World War II both Axis and Allied engineers made significant advances in land, mobile, maritime, and airborne radio as well as radar. After the war, in 1948, scientists at Bell Laboratories demonstrated the potential uses of the transistor. Between 1945 and 1960 numerous television stations began broadcasting coast to coast, linked by microwave radios.

The year 1958 marked the invention of the integrated circuit. In the 1960s the concept of a broadband mobile telephone system was outlined. In 1969 the first frequency-resuing commercial cellular system was used on trains running from Washington to New York. By the 1980s analog cellular telephone use had become widespread. Digital cellular systems with increased capacity were introduced in the 1990s. Another significant development was the FCC auction of spectrum for the Personal Communications Services (PCS) band.

The Radio Frequency Spectrum as a Limited Natural Resource

The electromagnetic spectrum contains frequencies from below 1 Hertz (one cycle per second) to above 1025 Hz. However, a much smaller subset of those frequencies lend themselves to terrestrial radio systems. Although there is not universal agreement on the boundaries, the "radio spectrum" is the subset of the electromagnetic spectrum with frequencies from 100,000 Hz to 100 GHz (105 to 1011 Hz).

The lower end of the radio spectrum is less suited for most communications applications. The rate at which information can be transmitted (the data rate) becomes lower as the frequency decreases. This does not mean that low-frequency waves travel through space more slowly because all electromagnetic radiation travels at the speed of light. However, the theoretical rate of information transfer decreases with decreasing frequency. This gives rise to a lower limit to the frequency band that can be used for most radio systems. Additionally, the ionosphere becomes opaque at lower frequencies, limiting some applications, although enhancing others.

At higher frequencies the entire atmosphere (not just the ionosphere) becomes opaque except for a few "windows" in which electromagnetic radiation is free to propagate without being absorbed significantly (see Figure 3). There is an optical window (the atmosphere is transparent to the frequencies human eyes can detect), and there is a radio window. Transmission of signals at frequencies above this window are absorbed or scattered rapidly by the atmosphere, similarly to the way fog limits visible frequencies. The opaque nature of the atmosphere at higher frequencies establishes an upper limit to the radio spectrum; thus, the radio spectrum is capped in its upper and lower ends. This means that the radio spectrum is a limited natural resource. Because of its immense importance and finite nature, the radio spectrum presents significant distributive justice issues.

Ethics, Politics, and Law

The ethical, political, and legal aspects of radio can be arranged in a four-fold taxonomy. Although there is significant overlap amongst the categories, they are useful in conceptualizing the major issues and highlighting the important ethical traditions pertaining to radio development and use.

First, there are issues surrounding the technological development of radio that pertain to topics in engineering ethics. For example, the use of radio for military applications and growing concerns about the health effects of electromagnetic frequencies present ethical challenges to engineers who are responsible for upholding the safety, health, and welfare of the public.

Second, radio content and use issues instantiate several aspects of broadcast journalism ethics as they place responsibilities on program directors, journalists, and radio managers. These obligations are traditionally formalized in codes of ethics such as the NAB code of radio advertising and program ethics and the Radio-Television News Directors Association (RTNDA) code of ethics, which states that electronic journalists ought to serve as trustees of the public reporting the truth with fairness, integrity, and independence.

Third, the broader cultural and societal impacts of radio raise issues explored in the philosophy of technology and the field of Science, Technology, and Society (STS) studies. Radio technologies reciprocally interact with various elements of culture to co-produce societal changes and personal life experiences. In the United States, for example, conservative talk radio programs have exerted massive influence over the political landscape and Christian programming has also come to dominate certain markets, which has influenced conceptions about religion in the public sphere. Such developments underscore the idea that radio is not a neutral medium, but rather an active agent that is used to selectively broadcast some voices and messages rather than others. It is a political and cultural force, albeit somewhat eclipsed by television. Interestingly, the rise of opinion and advocacy programs on radio seemed to foreshadow a general shift in media (furthered by the Internet and the "blogosphere") away from trust in a few supposedly neutral broadcast centers to a variegated spectrum of information streams.

Lastly, questions of how radio should be used and regulated raise fundamental issues from political philosophy such as distributive justice, the proper relationship between government and private enterprise, censorship and the proper limits to freedom of speech, and the concentration of corporate control over media.

As a common resource, it has been widely maintained that the radio spectrum must be centrally regulated to insure fairness and efficiency. For example, the International Telecommunication Union (ITU) is a regulatory body within the United Nations system that helps coordinate global telecommunications networks and services. Additionally, each country has its own national frequency allocation plan. In Germany, for example, each state exercises its own authority over radio broadcasting rather than a centralized federal entity. In the United States that plan is administered by the FCC. The FCC is an independent government agency, directly responsible to Congress, which plans, allocates, and monitors the use of the radio spectrum for nongovernment users. FCC rules pertaining to free speech and censorship tend to raise the most public controversy, especially those relating to indecency, obscenity, and profanity. These rules do not apply to satellite and cable broadcasting. The National Telecommunications and Information Administration (NTIA) is responsible for the allocation and assignment of frequencies for use by the federal government The national frequency allocation plan divides the spectrum into a multitude of frequency bands, reserving bits of spectrum for different types of users and reducing channel interference. It plays a vital role in balancing the often conflicting needs of commercial, military, scientific, and educational uses.

Although some level of government regulation may be necessary, many advocate further deregulation in order to capture the benefits of market competition and avoid inefficiency, corruption, or other unethical practices by centralized bureaucrats. Others, however, fear that deregulation will lead to further corporate monopolization of local markets. In the United States, concerns are developing that the increased corporate consolidation of radio diminishes its locality, threatens the democratizing value of free and independent communication, homogenizes music play lists, and undermines journalistic quality.

Similar debates about the proper roles of private and public or community radio sparked the 1967 creation of the U.S. Public Broadcasting Act, which established the Corporation for Public Broadcasting (CPB). The CPB receives annual appropriations from Congress to support independent local stations and National Public Radio (NPR), which was established in 1970. Although this helps defend the independence, integrity, and diversity of radio journalism, it also raises accountability issues about the use of federal funds.

College and community listener sponsored radio stations also attempt to secure independence and diversity at the fringes of corporate media conglomerations. In 2000, the U.S. government began issuing licenses for low-power (below 100 watts) radio stations partially to provide another avenue for local communities (especially low-income and minority) to obtain diverse, community-oriented information. Most of these licenses have been obtained by rural communities and churches, and they have not had the expected impact on urban areas that are most dominated by commercial radio. Concerns have been raised that Christian stations are monopolizing these markets, thus producing the same drawbacks from consolidation. There is also some concern that these stations interfere with broadcasts from bigger stations. Furthermore, many low-power radio broadcasts still operate illegally as "pirate" stations. Some of these stations are switching to internet broadcasts in attempts to avoid federal lawsuits.

Current Trends

As more uses of radio technologies are conceived, developed, and marketed (e.g., cell phones and wireless internet connections) and as demand for existing uses continues to grow, the radio spectrum will become increasingly crowded. Interference among users will become increasingly difficult to avoid and solve. Modulation schemes that are more tolerant of interference such as spread spectrum–based technologies should see increased use, as should hardware-based solutions such as more sophisticated filtering. Spectral crowding also will result in the continued migration toward higher frequencies despite the greater atmospheric attenuation and other technological obstacles. Finally, both the general public and those involved in the technical industries will be forced to become more aware of the limits of the radio spectrum, the importance of coordination and regulation, issues involving radio interference, and spectral crowding.

J. BRIAN THOMAS

SEE ALSO Advertising, Marketing, and Public Relations;Communication Ethics;Communication Systems;Entertainment;Networks.

BIBLIOGRAPHY

Kobb, Bennett. (2001). Wireless Spectrum Finder: Telecommunications, Government, and Scientific Radio Frequency Allocations in the U.S., 30 MHz–300 GHz, 6th edition. New York: McGraw-Hill.

Kraus, John D. (1986). Radio Astronomy, 2nd edition. Powell, OH: Cygnus-Quasar.

Radio Astronomy: Observing The Invisible Universe. (1999). Video. Produced by Dick Young Productions, New York, NY, for the National Science Foundation, USA.

Reed, Dana George, ed. (2001). The ARRL Handbook for Radio Amateurs. Newington, CT: American Radio Relay League.

Sterling, Christopher H., and John Michael Kittross. (2002). Stay Tuned: A History of American Broadcasting, 3rd edition. Mahwah, NJ: Lawrence Erlbaum.