Low tech sometimes succeeds where high tech fails – as one ingenious company is proving.
Chirp sends data over sound, a burst of audio that usually sounds like a bird's tweet. It doesn't transmit much data – 50 bytes – but it turns out you don't need much bandwidth to bridge the gaps between the real world and the digital world.
Chirp has already been put to use, and unusually for a small company, boasts hundreds of millions of users. Spun out of research at UCL, Chirp first stepped into the public eye four years ago with a consumer app. But it recently switched to a B2B model – licensing the technology for use in all kinds of cases via a software development kit.
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Sound has obvious disadvantages. One is that it needs to deal with noise interference, which is everywhere. And in the open, the range is short: 10 to 20 feet. But the big advantage is easy to miss: the audio bursts are a one-to-many, multidirectional transmission. So Chirps can be used as a signal – say a trigger, or a wake up call – for millions of digital devices at once. It can be played at a stadium, for example.
(Score: 2) by VLM on Friday November 11 2016, @01:11PM
I wonder how many patents they have on it.
Meanwhile, literally decades ago when PSK-31 was a new modulation method, ham radio guys would take their late 1990s laptops to demonstrations and they'd use the laptop and speaker and built in mic to demonstrate the bullet proof reliability of PSK-31 by talking across the room. Its mildly entertaining the first couple times.
With multimode software you can send SSTV pictures across the room, do TCP style error corrected packet communications, all manner of crazy stuff.
Note that PSK-31 sends very slowly but is very narrowband and bulletproof so "transmitting" at 20+ KHz would be quite inaudible to everyone but young little kids and dogs. From reading some papers on trying to do SONAR with laptop hardware, the sound card might be capable of it but speakers and amps roll off above audible range pretty quick so its a tradeoff.
(Score: 0) by Anonymous Coward on Friday November 11 2016, @05:40PM
inaudible to everyone but young little kids and dogs
Finally, a use for millennials!