Hedy Lamarr, born Hedwig Eva Maria Kiesler, was a Hollywood movie star who acted in dozens of films, most notably Algiers, released in 1938 and Samson and Delilah, in 1949. Alongside her acting career, she was also an inventor, working on everything from the shape of aircraft wings to dissolvable drink flavourings.
Most of her inventions were not widely used, but in the 1940s she wanted to create something that would help Allied forces fight the Nazis as part of the second world war – Lamarr, born to a Jewish family in Austria, fled to the US after the country was annexed by Germany in 1938.
Lamarr worked with composer George Antheil to develop a new way to steer torpedoes. She had already discovered that radio-signals used to control torpedoes could be jammed by the Nazis, making them miss their targets, and wanted to come up with an unjammable alternative.
The pair settled on a system that would randomly switch to different radio frequencies to get around jamming, known as frequency-hopping (FH) spread spectrum communication. It was controlled by a piano player mechanism of Antheil’s, meaning the system could switch between one of 88 different frequencies for each of the 88 black and white keys on a piano.
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It is often said that this patent means Lamarr helped to invent Wi-Fi, but the story is more complicated than that. Lamarr and Antheil patented their invention in 1942, but it was classified until 1981, and during that time only used in military technology such as sonar or satellite communications.
Before the patent was declassified, other spread spectrum techniques were invented independently, including direct-sequence (DS) spread spectrum, which spreads a signal across a range of frequencies, rather than hopping between one at a time.
When Wi-Fi standards were first defined in 1997, they allowed for both FH and DS systems, but DS quickly became the dominant system and there are no FH Wi-Fi devices in use today. So while Lamarr did invent the concept of spread spectrum communication, the direct line to Wi-Fi is murky. However, the Bluetooth standard, which is used to connect devices over short ranges, does use FH, and it is clear that Lamarr and Antheil’s invention had a large impact on the course of communications technology.
Key facts
Full name: Hedwig Eva Maria Kiesler
Born: 9 November 1914, Vienna
Died: 19 January 2000, Casselberry, Florida
Hedy Lamarr was an Austrian-American actor and inventor famous for developing a form of wireless communication still in use today.