Frequency hopping patnet, 1941 locationsound.com
Frequency Hopping
In the words of Tracey Deutsch, “For Hedy Lamarr, inventing was more than just a hobby.” Of Lamarr's innumerable number of inventions, frequency hopping was by far the most paramount. Frequency hopping is the act of altering radio signals by rapidly changing the carrier frequency among many distinct frequencies occupying a large spectral band. The changes are controlled by a code known to both transmitter and receiver.
It was created for Navy use as a radio guidance transmitter and it let the torpedo's receiver to jump simultaneously from frequency to frequency, making it impossible for the enemy to locate and block a message before it had moved to another frequency. Later down the line frequency hopping played a huge role in the inventing of Wi-Fi, Bluetooth, and GPS. Hedy Lamarr may not have literally invented Wi-Fi, as that honor goes to Australian boffin John O'Sullivan, but she did discover a pretty important precursor.
