Template:Frequency Hopping Technology
During World War II, Lamarr read that radio-controlled torpedoes had been proposed. However, an enemy might be able to jam such a torpedo's guidance system and set it off course. When discussing this with her friend the composer and pianist George Antheil, the idea was raised that a frequency-hopping signal might prevent the torpedo's radio guidance system from being tracked or jammed. Antheil succeeded by synchronizing a miniaturized player piano mechanism with radio signals. Antheil sketched out the idea for the frequency-hopping system, which was to use a perforated paper tape which actuated pneumatic controls (as was already used in player pianos).
Antheil was introduced to Samuel Stuart Mackeown, a professor of radio-electrical engineering at Caltech, whom Lamarr then employed for a year to actually implement the idea. Lamarr hired the Los Angeles legal firm of Lyon & Lyon to search for prior knowledge, and to craft the application for the patent which was granted as U.S. Patent 2,292,387 on August 11, 1942, under her married name Hedy Kiesler Markey.
It has been reported in many online publications that Antheil and Lamarr's work helped with the creation of Wi-Fi, Bluetooth, GPS and cellphones, however their work was never formally adopted anywhere.
Neither the US Navy nor that of any other nation were using radio-controlled torpedoes at the time, and electro-mechanical devices were soon to be made obsolete by purely electronic controls.
Furthermore, outside of incorporating the use of a miniaturized clockwork piano, their ideas on frequency-hopping were not new. As early as 1899, Guglielmo Marconi had experimented with frequency-selective reception in an attempt to minimize radio interference. The earliest mentions of frequency hopping in open literature are in US patent 725,605, awarded to Nikola Tesla on March 17, 1903, and in radio pioneer Jonathan Zenneck's book Wireless Telegraphy (German, 1908, English translation McGraw Hill, 1915). And Zenneck notes that Telefunken had already previously implemented it. In 1929, the Polish engineer and inventor Leonard Danilewicz further elaborated on the idea; and, in 1932, U.S. Patent 1869659A was issued to the Dutch inventor William Broertjes for his electromechanical device to encrypt radio transmissions by using frequency-hopping.
Frequency-hopping spread spectrum (FHSS) is not actually used by Wi-Fi, GPS or cellphones (they instead use DSSS), although a variation on the technology, known as adaptive frequency hopping (AFH), is employed by Bluetooth.