Analysis of Hedy Lamarr's Contribution to Spread-Spectrum Communication

It'd be much better to talk about Liskov, Goldberg, the women at Bluetooth SIG, or the countless other examples available.

‘Since the actual invention is a player-piano-like mechanism, and since experimental musician George Antheil had expertise in the inner workings of player pianos, and further since Hedy Lamarr evidently had no such expertise, it may be more appropriate to call the Lamarr-Antheil patent “Antheil’s patent.”’

are inappropriate and unjustified.

From the article: "A letter on 3 October 1941 from the Lyon and Lyon attorney to Lamarr and Antheil says '...we rather doubted at the time that method claim 7 would be considered patentable, since the invention appears to reside more in a new apparatus than in a new method.' Thus, the attorney representing the applicants agreed with the patent examiner that the evidence was against Lamarr-Antheil’s definitive method claim to FHSS, which was claim 7."

This analysis makes it pretty clear that EFF's 1997 assertion that she and Antheil "developed and [...] patented the concept of 'frequency-hopping' that is now the basis for the spread spectrum radio systems" is flatly untrue.

This isn't to say that she wasn't an inventor or innovator, or didn't put together existing known techniques in a new way to address a relevant and interesting problem.

A more convincing article would focus on purported prior art patents, and let the reader judge if really anticipated frequency hopping.

Nevertheless, while there have been a handful of earlier patents where the inventors had the same idea of using FHSS, those patents have remained unknown among the vast amount of useless patents so it is pretty certain that Hedy Lamarr has rediscovered FHSS independently.

After WWII, the evolution of FHSS in military communications has started from the patent of Hedy Lamarr, while the prior work has remained as obscure as before.

The HN hivemind on Jurgen Schmidhuber: he was only the first to think of the technique, not the first one to make it work.

Yes, I'm a big ol' meanie.

Here is the closest verbatim passage I found from Jonathan Zenneck’s *Wireless Telegraphy (1915), in the chapter “Methods for Preserving Secrecy of Messages.” The wording is slightly abridged due to the scan quality: “Furthermore, the apparatus can be so arranged that the wave-length is easily and rapidly changed, and then the wave-length varied in accordance with a pre-arranged programme, perhaps automatically. This method was adopted by the Telefunken Co. at one time.”

Note that the book was published in 1915, when Hedy Lamarr was less than one year old.

Anyone interested in the topic might also look at the work of Dr. Tony Rothman on the same question of Hedy's supposed invention. Tony was the scientific advisor to the filming of the PBS special called "Bombshell." He is a man of considerable standing, accomplishments, and qualifications.

Regarding Hedy's patent -- as I said in my paper, note bene: the application of a known technique (FHSS) for its intended purpose (security) does not constitute an invention. Hedy'a attorney tried to convey this message to her in his correspondence, but the message never sunk in.

Voice cryptosystems of the pre-WWII period included the Western Electric A-3 scrambler [1] There's one on eBay! [2] That split audio into a number of frequency bands, which were shifted and reassembled. At the receiving end, the process was reversed. The shift pattern changed periodically, on the order of tens of seconds. That was slow enough that keeping the thing in sync was possible with clockwork of the period. Note that this is working on the audio, not the RF; it's a scrambler, not a frequency hopper. This is what AT&T used for transatlantic commercial voice. Worked OK, mediocre security. Only 6 different frequency shift patterns were in use at a time. The Germans cracked it.

This is not the better known SIGSALY. That's a similar concept, but with a lot more audio channels, much more frequent changes, a one-time key for the changes, and more hardware than some mainframe computers. The A-3 was a desk-side wooden box. Neither system does frequency-hopping of the RF signal.

Hedy Lamarr's first husband was an arms manufacturer, and she apparently paid attention when visiting the factories. Hence the radio-controlled torpedo, which is close to Tesla's radio-controlled boat.

MARKEY (2,292,387) describes a cross between a radio-controlled boat and a set of synchronized player pianos. There's some handwaving around the sync problem. The trouble with syncing a frequency hopper is that you have trouble even finding the signal to get started. But if you're launching a torpedo or a bomb from a larger craft, both ends of the connection can be started in sync and will probably stay in sync long enough for the bombing run. Doing this with a player piano roll reader, vacuum pump and all, is probably not the right approach.

Trying to get things to sync up reliably has a long history. Edison's first useful invention was a way to get stock tickers to sync. There's a long history of clunky mechanisms, early ones involving flywheels or big tuning forks, and later electronic ones with too many screwdriver adjustments. Not until the invention of phase locked loops did it really Just Work. (I'm into restoring early Teletype machines, and I'm way too aware of the early days of sync problems.)

Markey was just too early. Reasonable idea, but not practical at the time due to lack of supporting technology.

[1] https://chris-intel-corner.blogspot.com/2012/02/intercepted-...

[2] https://www.ebay.com/itm/205373065319