Ask most engineers who laid the groundwork for modern wireless and you will hear names like Marconi, Shannon, or the committees behind the IEEE 802.11 standard. Almost no one says Hedy Lamarr. Yet in 1942 the Hollywood movie star co-patented frequency hopping spread spectrum, the technique that quietly keeps your Wi-Fi, Bluetooth, and GPS working today. It is one of the best stories in wireless history, and it has a real lesson for anyone building connected devices.
A movie star, a composer, and a torpedo problem
Hedy Lamarr was born Hedwig Kiesler in Vienna and became one of MGM's biggest stars after fleeing Europe. Before Hollywood, she had been married to an Austrian munitions manufacturer who discussed military hardware openly at dinners, including the problem of radio-guided torpedoes being jammed by the enemy. Lamarr remembered all of it.
Working with the avant-garde composer George Antheil, she proposed a fix: instead of broadcasting a control signal on one fixed radio frequency that an enemy could find and jam, the transmitter and receiver would rapidly hop between many frequencies in a pattern only they shared. Jam one frequency and the signal had already moved. To keep both ends in sync, the pair borrowed a mechanism from a player piano, a perforated paper roll that stepped through 88 frequencies, one for each piano key.
On August 11, 1942, the US Patent Office granted patent 2,292,387 for a "Secret Communication System" to George Antheil and Hedy Kiesler Markey, Lamarr's legal name at the time.
Decades ahead of its time
The US Navy looked at the drawings, decided a movie star and a composer could not have invented anything useful, and filed it away. The idea sat unused through World War II. Spread-spectrum techniques only entered operational military systems around 1962, long after the patent had expired and the inventors saw no money from it.
What the Navy dismissed turned out to be foundational. The core insight, spreading a signal across many frequencies to resist interference and interception, is now everywhere:
- Bluetooth uses adaptive frequency hopping, jumping between channels up to 1,600 times per second to dodge congestion in the crowded 2.4 GHz band.
- Wi-Fi and CDMA cellular systems rely on related spread-spectrum methods to let many devices share the same spectrum without drowning each other out.
- GPS uses spread-spectrum coding so receivers can pull faint satellite signals out of the noise.
Every connected sensor, smart meter, and wearable that shares the airwaves owes something to that 1942 idea.
Why this matters for building IoT today
The story is charming, but there is a practical takeaway for embedded and IoT work. Wireless reliability is not free, and the 2.4 GHz band your ESP32 or BLE module lives in is a war zone of overlapping Wi-Fi, Bluetooth, Zigbee, and microwave-oven noise. The reason your devices keep working is decades of spread-spectrum engineering quietly fighting interference on your behalf.
When we design connected products, the wireless layer is where field failures hide. A prototype that works perfectly on the bench can fall apart in a factory full of motors and competing radios. Understanding how frequency hopping and channel selection work, rather than treating the radio as a black box, is what separates a demo from a product that survives deployment. For Philippine startups and thesis teams building IoT prototypes, this is often the difference between a board that passes a defense and one that ships.
It is also a reminder that good ideas get dismissed for bad reasons. The Navy rejected a working invention because of who proposed it. In engineering, the merit of an idea should outlive assumptions about its source.
Building on the foundations
At Fluidwire we build IoT and embedded systems from silicon to cloud, and the wireless stack is something we take seriously rather than assume. If you are designing a connected device and want the radio layer to hold up outside the lab, take a look at our services or get in touch. We are happy to talk through antenna choices, protocol selection, and the unglamorous interference testing that makes a product trustworthy.
Hedy Lamarr never profited from her patent, but she did receive recognition late in life, including the Electronic Frontier Foundation's Pioneer Award in 1997. Every time your earbuds pair without a hitch, that is her idea, eighty years on, still hopping.
