line.gif (45 bytes) CDMA spread spectrum

The birth of spread spectrum

How "The Bad Boy Of Music" And "The Most Beautiful 
Girl In The World" Catalyzed A Wireless Revolution--In 1941
By Anna Couey

cdma ics

Today, spread spectrum holds the potential to revolutionize wireless communications, because it renders radio spectrum--a resource currently deemed so precious that only the largest of corporations can afford to buy it--plentiful enough for all of us.

Spread spectrum is a highly efficient way of using radio waves to communicate, because it enables multiple users to share radio frequencies at the same time, without interfering with each other. Up until now, each radio station, for example, has been allocated a specific frequency over which to broadcast their programs. Since there are only so many bands of frequency within the entire radio spectrum, frequency bands are carefully allocated by the FCC for particular uses--such as commercial broadcasts, military communications, police radios, ham radios, etc.

Currently the US government licenses radio frequencies to the highest corporate bidder. Spread spectrum stands the concept of spectrum scarcity on its head, and just might rearrange who has access to radio waves in the future. For now, spread-spectrum radios provide high-speed wireless access to the Internet, with absolutely no telephone fees.

However, like many technology inventions, spread spectrum was designed for an entirely different purpose. The story of its birth and evolution is an epic drama of legendary proportions: World War II, avant-garde music and Hollywood all had a role in its creation.

At the center of the story is a beautiful young woman, whose creativity and intelligence led her to revolutionize communications technology into the 21st century.

The Road To Hollywood

Today, Hedy Lamarr lives in quiet seclusion in Florida. During World War II, however, she was a glamorous Hollywood star, "the most beautiful girl in the world." Her real-life story is arguably more alluring, and certainly more heroic, than any role she played on the silver screen.

Born Hedwig Maria Eva Kiesler in Vienna, Austria, sometime between 1913 and 1915 (history is not definitive on this point), Lamarr came to Hollywood shortly before World War II at the invitation of Louis B. Mayer and Otto Preminger to work for MGM. She had already made a memorable impression on the big screen for her revealing performance in Extase (Ecstasy), a 1933 art film that shocked societal sensibilities of the time for its frank sensuality.

Behind the star image lies a complex person who defies stereotypes. Lamarr married six times and, besides being an actress, painted abstract works of art and designed inventions. "People assume perhaps she wasn't intelligent because she was so beautiful. But she really had a mind...she held her own with anybody," says Peter Antheil, who remembers her visiting his parents' home when he was a child.

In Hollywood, the beautiful actress found success, and the world at her feet. But she didn't forget that World War II was brewing in Europe, and she was determined to do something about it. 

Technology And War

Lamarr had strong personal reasons to be against the war. She had recently escaped from her first husband, who was selling munitions to Hitler.

Fritz Mandl was one of Europe's largest armaments manufacturers. He had become the primary supplier of armaments to the Austrian army during World War I, when, it later turned out, he and Austria violated the Versailles Treaty by selling weapons to Hungary. Moreover, he appeared to be developing a reputation for selling "bombs and bullets and airplanes to Hitler and whoever else wanted to buy them," as Anthony Loder, Lamarr's son, describes it.

Lamarr and Mandl married in 1933. It was not a happy marriage, at least as far as Lamarr was concerned. Mandl was extremely possessive, and kept her "like a slave," she says, under the watchful eye of her maid. To the public, she was Mandl's showpiece, dazzling his clients and the cream of Austrian society. But Nazis were on the rise, and Lamarr had no use for them. She didn't just sit pretty.

Mandl was conducting research in weapons control systems. At the time, research was indicating that radio waves were better than wire for controlling weapons such as torpedoes. For one thing, it was hard to make a wire long enough (even ten miles was too short) to ensure that the communications channel between a commander and a torpedo would not break, leaving the torpedo to chart its own course. Radio waves solved the problem of needing a physical communication connection between commander and torpedo. But radio waves had a serious flaw: enemies could access the same radio wave and jam it.

As Mandl's wife, Lamarr was exposed to military technology ideas. By her own account, Mandl kept Lamarr at his side during his business meetings, a silent witness to technical discussions that foreshadowed World War II. Lamarr had no formal education in military technology, but she had a mind capable of understanding what she heard.

After four years of marriage to Mandl, Lamarr drugged her maid and left him forever. She made her way to London, where she came in contact with Louis B. Mayer of MGM, who arranged for her to come to the US. On the voyage across the Atlantic, Mayer gave her the name "Hedy Lamarr," in part inspired by the actress Barbara LaMar, and "...for the sea!," Lamarr's son, says.

Player Piano

Lamarr met George Antheil at a party in Hollywood, and they became friends.

"George was 5' 3" maybe, he was not very tall, but he was extremely charming--especially with women," says composer Charles Amirkhanian, who manages the George Antheil Archive.

Antheil had been at the forefront of experimental music in the 1920s, part of the first generation of artists that explored mechanical music as an expression of industrial society. "George was one of the first people to work with the player piano as a legitimate instrument for composed music," says Amirkhanian. Antheil's famous "Ballet Mecanique" was written for twelve player pianos, an airplane propeller and a symphony.

Antheil was quite famous in Europe, and had done a lot of creative work there. In the early 1930s, he had received a Guggenheim fellowship to go to Europe. But when Hitler began to close the German opera houses that presented modern music, Antheil returned to the US. Not only was his own source of work threatened (these very same institutions were among those who commissioned his compositions), Antheil "was very angry about Hitler's influence on the arts in Europe. He actually had to leave Europe because of Hitler, or felt he did," says Amirkhanian.

Antheil also emphatically opposed the Nazis. His son Peter remembers, "My father wanted to go into the army, but he couldn't; he was too old. But he wanted to do anything he could to help the war effort. I remember that they felt very strongly about it, both Hedy and my father, about war, and having to defeat the enemy."

In that context, Lamarr told Antheil about her idea for a Secret Communications System that could guide torpedoes to their target without being intercepted by the enemy, by sending messages between transmitter and receiver over multiple radio frequencies in a random pattern.

The message would move so quickly across the radio waves that anyone tuning in to a particular frequency would only hear a blip, and would be unable to intercept the message.

The only problem was how to ensure that the transmitter and receiver would stay in synchronization as they moved through the frequencies. Lamarr thought Antheil could help solve the synchronization problem. As a result of his musical experiments, Antheil had a good deal of experience with sound synchronization.

He did indeed hit on the solution for the invention to function: paper rolls perforated with a pseudo-random pattern would delineate the frequency path. Two rolls with the same pattern would be installed in the transmitter and receiver. If the two rolls were started at the same time, and one stayed at the launch point while the other was launched with the torpedo, and "if you had good rotary stability in the motor driving the paper rolls, you'd maintain the synchronization right on down to where the torpedo hit the ship," explains Dr. Robert Price of Consulting in Electronics Systems. Just like the player piano rolls in "Ballet Mecanique;" in fact, the two inventors designed their system to use eighty-eight frequencies--exactly the number of keys on a piano.

Patriotism And Barriers

Lamarr and Antheil knew they had something that could help win the war. They sent their invention to the recently established National Inventors Council, and Antheil claimed that Charles Kettering himself, director of the Council and research director at General Motors, encouraged them to patent it. The two inventors worked with an MIT electrical engineer to iron out some technical kinks, and submitted their patent proposal in 1941. On August 11, 1942, Lamarr and Antheil were awarded US Patent Number 2,292,387 for the Secret Communications System. Rather than develop the patent commercially, "they gave it away to the government for the war effort," says Peter Antheil. Despite the fact that they stood to gain financially by holding onto the patent--and Antheil in particular was always struggling financially--like many people in that time, they were both committed to helping to defeat the Nazis. "It was a totally different culture then. I can remember it even as a small child, and it was kind of a reflection of the way people felt in those days for George and Hedy to give the invention to the government to help win the war with...there was a tremendous feeling of patriotism," recalls the younger Antheil.

The Navy, however, refused to take the Secret Communication System seriously. Technologists questioned whether the paper rolls would hold without breaking, whether the rotary motor that synchronized the rolls would be accurate enough, and whether the paper rolls could be made small enough to fit inside a torpedo.

Despite Antheil's active lobbying and insistence that the US Navy needed the invention to compete with Germany's sophisticated military technology, the Secret Communications System was never used during World War II.

Antheil was convinced that the Navy's reticence was due to an anti-cultural bias: "In our patent Hedy and I attempted to better elucidate our mechanism by explaining that certain parts of it worked like the fundamental mechanism of a player piano. Here, undoubtedly, we made our mistake. The reverend and brass-headed gentlemen in Washington who examined our invention read no further than the words 'player piano.' 'My God,' I can see them saying, 'we shall put a player piano in a torpedo.'"

Not only was the invention rebuffed, but so were Lamarr's efforts to contribute her considerable technical abilities to the task of defeating Hitler. When she offered to come to Washington, D.C. and work at the National Inventors Council, she was told she'd be of greater service to the war effort by remaining in Hollywood and using her star status to raise war bonds. She did indeed raise $7 million for the war effort, but her intellectual talents remained untapped.

From Navy To Commerce

When the war ended, Lamarr and Antheil put the invention behind them. It was not to be implemented in Antheil's lifetime.

However, while seemingly inactive, the patent was not forgotten. Electronic technologies were beginning to develop, and in the 1950s, engineers from Sylvania Electronic Systems Division began to experiment with the ideas in the Secret Communication System patent, using digital components in place of the paper rolls. They developed an electronic spread-spectrum system that handled secure communications for the US during the Cuban Missile Crisis in 1962. By then, the Secret Communications System patent had expired.

It was in the early 1960s that the term "spread spectrum" began to be used. Today it refers to radio communications that employ cryptographic subsystems (like the pseudo-random patterns on the Secret Communications System's paper rolls), use a wide frequency spreading factor (much wider than typical voice telephone communications), and are not dependent on a particular type of tonality (such as a human voice) in the transmitting waveform.

"Hedy Lamarr and George Antheil were the first to satisfy all three ingredients," says Price. Their spread-spectrum technique is today called "frequency hopping" because the transmission jumps from frequency to frequency.

Initially, spread spectrum remained a military communications technology, and even today "the Defense Department of the United States has a huge investment in spread spectrum of a frequency-hopping type now, just like Hedy Lamarr's, which protects our assets all over the world," notes Price.

In the mid-1980s, the US military declassified spread-spectrum technology, and the commercial sector began to develop it for consumer electronics. Today, it's an increasingly important component of mobile telephony. CDMA (Code Division Multiple Access) technology uses spread spectrum. Spread spectrum has proven highly useful in cellular telephones, because its inherent encryption guarantees better privacy for cellular phone users. The technology has also proven to be an extremely efficient method for using radio waves. Rather than requiring each transmission to use its own frequency, spread spectrum enables people to simultaneously communicate over the same bands of spectrum without appreciable interference. Thus, as more people buy cellular phones, the increasing demand for spectrum can be accommodated by sharing the same frequencies.

For The Common Good

Once again, spread spectrum is in a position of potentially making a tremendous contribution to the public good. It's not exactly what Lamarr and Antheil had in mind when they invented the Secret Communications System, but, Anthony Loder says, his mother is glad that she "did something that could be good and useful for people, and for the country, and for the world."

And it has only taken 55 years for us to realize that the unlikely collaboration of a celebrated movie star and an avant-garde composer could possibly invent a communications system that is still at the forefront of telecommunications technology.

Copyright ©1997 by Anna Couey. All rights reserved.