Recent Advances in Telecommunications Technology

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This paper was originally prepared on 9 May 1994 for Dr. James A. Odom Jr., Harrisburg Area Community College. It was written to satisfy a course requirement in English Composition 101.

Ever since the beginning of human civilization, communication has been a staple of life for all people. Starting with primitive cave drawings, evolving to simple language and then to encoded messages sent via smoke signals and flashes of light, communications technologies have evolved greatly. Humans are social creatures, desperate to keep in touch with one another in order to keep informed. More recently, the greatest advances in telecommunications technology have taken place in the fields of radio and television, two media which can be received by anyone with the proper listening devices.

Radio

The year is 1873, and James Clerk Maxwell, a physics professor at Cambridge University, England, has recently published his theory of electromagnetism. This theory proves the existence of radio waves and also a description of how they should behave based on his observations of how light waves behave (Gross 50).

The first experiments to prove Maxwell's theory were undertaken by the German physics professor Heinrich Hertz during the 1880s. Hertz, who is honored by having his name referred to in frequency measurement, actually generated radio waves in his laboratory. The fact that Hertz was able to transmit the waves from one corner to another in his laboratory proved that radio waves acted in a similar manner to light waves. In 1888 he published a paper that served as a basis for the theory of modern radio transmission (Gross 50).

Guglielmo Marconi, the "Father of Radio," expanded upon the principles of Hertz and Maxwell. Marconi worked frantically in his workshop, until he was finally able to ring a bell with radio waves. Marconi then incorporated the Morse key into his system so that he could transmit messages with his radio using Morse code, the first time that radio was used for a practical purpose. Eventually he received financial backing and was able to start the Marconi Wireless Telegraph Company, Ltd. Marconi continued to improve on wireless, as it was called, and supplied equipment to ships (Gross 50-52).

The primary use of wireless was to transmit Morse code signals from ships at sea. More and more people were becoming intrigued by the idea of voice communication via wireless (Gross 52).

The first step toward voice transmission came with John Fleming's vacuum tube, which he invented in 1904. The tube was developed further by others, until in 1907 Lee De Forest invented the audion tube, which amplified sound to a higher degree than was ever possible before. This tube was a most crucial key to voice transmission (Gross 52).

It wasn't until 1921 that Frank Conrad, a physicist and employee of Westinghouse in Pittsburgh, began to regularly program radio shows as a hobby. Westinghouse saw a market in broadcasting, and created the first commercial radio station, assigned the call letters KDKA by the Department of Commerce. By 1923 radio licenses had been issued to more than six hundred stations, and receivers were in nearly one million homes (Gross 56-57).

Unfortunately, a major problem with early radio was that all stations broadcast on the same frequency -- 360 meters. Agreements were made between stations so that they could share the frequency by broadcasting as different times of the day (Gross 58).

As radio gained popularity, networks were formed to transmit programs nationwide. Telephone lines were used to distribute programming among network affiliates. The National Broadcasting Company was formed in 1926, Columbia Broadcasting System in 1927, Mutual Broadcasting Company in 1934, and American Broadcasting Company in 1945 (Gross 61-62).

Until this time, nearly all programming was performed live. In fact, both NBC and CBS had policies forbidding the use of recorded material for anything other than sound effects. Mutual used some recorded speech, and was considered second-rate for doing so.

Most recordings were on phonograph records, as the only other method of recording before World War II was the wire recorder, a highly cumbersome and primarily unusable machine. During the war, American troops entering German radio stations found that they were operating without any people. The broadcasting was being handled by a machine that used plastic tape. The recorders were confiscated and sent to America, where they later revolutionized programming procedures (Gross 77-78).

During the 1930s David Sarnoff, the president of RCA, had mentioned to Edwin H. Armstrong that someone should invent a black box to eliminate radio static. Rather than invent a box, Armstrong invented an entirely new broadcast system -- Frequency Modulation (FM). Although FM has a much higher fidelity than AM radio (the previous system), it did not catch on in radio broadcasting until the 1970s. This was primarily due to lack of concern for radio due to televisionÕs looming above the horizon, and the fact that most radio broadcasters simply programmed the same material on their AM and FM stations (Gross 81-83).

Television

The first experiments with television were performed by Paul Nipkow in Germany in 1884 using a mechanical scanning process. Even though the device could only scan small pictures, there were attempts to market it commercially. during the 1920s, Ernst F. W. Alexanderson began experimenting with mechanical television in GEÕs Schenectady, New York plant (Gross 90).

While mechanical scanning was being promoted, others were developing electronic scanning, the system that has since been adopted. The most prominent experiments with electronic scanning took place at RCA and were headed by Russian immigrant Vladimir K. Zworykin, a one-time Westinghouse employee. Zworykin had patented an electronic pickup tube called the iconoscope (Gross 91).

In 1932 experimental broadcasts took place from the Empire State building, emanating from a converted radio studio in Radio City. The first true programming was not to take place until 1939, although very few people had televisions to receive the programs (Gross 91-93).

In 1940 CBS began to experiment with color television, utilizing a mechanical color wheel of red, blue, and green. Unfortunately, the CBS color system was not compatible with the RCA black-and-white system or the proposed RCA color system. The Federal Communications Commission created the National Television System Committee (NTSC) to recommend standards for television so that no more conflicts would take place between developers of television technology. The NTSC declared in 1947 that the CBS color system would present a hardship to set owners because they would have to buy new sets. Therefore, it recommended the black-and-white compatible RCA system in 1953 (Gross 94-95). This system is still in use today (Gross 104).

Television networks had already existed before 1948 as offshoots of the radio networks. As early as 1945-1946 networks had been organized by NBC, CBS, and ABC. By 1952 there were sets in 15 million homes (Gross 95-96).

The earliest television was produced live, with no facility for editing or reruns. It wasn't until the "I Love Lucy" show that television was recorded on film using a Kinetoscope for later presentation. The Kinetoscope worked by simply recording an image from a studio monitor onto film. Film has been called the "medium within the medium," without which much of the early days of television would be little more than radio with a picture (Green 97).

Just the opposite of the Kinetoscope, the telecine camera allows filmed images to be converted to video signals for broadcast. In modern television production, telecine cameras are used primarily to transfer film to videotape for later broadcast. Films are generally not broadcast directly from the telecine camera (Zettl 315).

Videotape is used for a variety of reasons, the most obvious of which is convenience. As videotape is an electronic medium, it lends itself to convenient recording and editing of video and audio signals. When using film, additional steps are involved which add to the cost and complexity of production, while at the same time lowering the quality of the finished product.

Video tape recorders were invented in the 1950s but they did not become practical until the 1960s due to technical limitations (Gross 363). Since the 1960s however, videotape has become the dominant medium for the recording of video.

Television Transmission

There are several ways to get the television signal from here to there. One commonly used method is the cable. There are two types of cable: coaxial and fiber optic.

Coaxial cable has a central wire and a surrounding wire shield. The two are separated by flexible insulation. The cable transports the audio and video information on an electromagnetic carrier wave at a relatively low radio frequency (Yoakam 589).

A fiber optic cable consists of a great number of fiber-optic strands. Each of the strand is made of glass or plastic and is thinner than a human hair. Like the coaxial cable, the fiber-optic strand carries the audio and video information on a carrier wave at very high optical frequencies -- light (Yoakam 589). Using light makes transmissions less susceptible to electrical interference that coaxial cable (Gross 400). A single strand of fiber optic cable can carry a great deal more information than a larger coaxial cable (Yoakam 592).

The method used most frequently in electronic news gathering is the microwave link. The microwave link is essentially a wireless transmission system which utilizes a high-frequency radio signal. The signals carrying the video and audio information are transmitted from one point to another using antennae to send them, and "dishes" to catch them. There are no wires connecting the remote site with the television station (Yoakam 59-60). Most often, the microwave transmitter is located within a van located near the site. The same van that provides live coverage can also feed pre-taped material back to the station for use later (Yoakam 62).

When microwave transmission is impractical, communication satellites can be used. Communication satellites used for broadcast are positioned in a geosynchronous orbit 22,300 miles above the earth (Zettl 606). Television signals are sent to the satellite through an uplink, received and amplified by the satellite, and then rebroadcast by the satellite to be received to one or more earth stations, called downlinks. Similar to the microwave vans, there are satellite uplink vans that are capable of sending signals to satellites (Zettl 588).

The Future

With the advent of the so-called "Information Superhighway," broadcasting will not be anything like broadcasting as we know it today. Instead of watching or listening to shows which were programmed by an unknown person at a distant location, a menu will be provided listing available options -- films, music, news, etc. This "programming" will be an on- demand service, unlike the current system where the program is there, just waiting for you to turn it on.

Do today's broadcasters need to fear this change in technology? Probably not. Only the delivery system is changing -- the content will most likely remain the same -- and with a rumored capacity of 500 "channels," there may actually be a boom in the communications field.

Works Cited

Green, Maury. "Television News: Anatomy and Process". Belmont, California: Wadsworth Publishing Co., 1969.

Gross, Lynn S. "Telecommunications: An Introduction to Electronic Media". 4th ed. Dubuque, Iowa: Wm. C. Brown Publishers, 1983.

Yoakam, Richard D. and Cremer, Charles F. "ENG: Television News and The New Technology." Carbondale and Edwardsville, Illinois: Southern Illinois University Press, 1985.

Zettl, Herbert. "Television Production Handbook". 5th ed. Belmont, California: Wadsworth Publishing Co., 1992.