High-Speed Communications Under Water #Science #Oceans #Europa

Chengzhi Shi checks the connections between the transducer array and the digital circuit. The experimental setup showed the potential of generating independent channels onto a single frequency to expand acoustic communications underwater. 

Credit: Marilyn Chung/Berkeley Lab


Low frequency acoustics is the option that remains for long-range underwater communication. Applications for sonar abound, including navigation, seafloor mapping, fishing, offshore oil surveying, and vessel detection.

However, the tradeoff with acoustic communication, particularly with distances of 200 meters or more, is that the available bandwidth is limited to a frequency range within 20 kilohertz. Frequency that low limits the rate of data transmission to tens of kilobits per second, a speed that harkens back to the days of dialup internet connections and 56-kilobit-per-second modems, the researchers said.

Note:  here at the Rockhouse we remember 300 baud modems and that wasn't communication; that was comedy although not so much at the time.  Actually, at the time it was a lot like magic.

Phys.org:  Study finds way to pack more data in single acoustic beam for underwater communications


There's all the physics the fun-loving student may want in the source article but we want the punchline.

"We modulated the amplitude and phase of each transducer to form different patterns and to generate different channels on the orbital angular momentum," said Shi. "For our experiment we used eight channels, so instead of sending just 1 bit of data, we can send 8 bits simultaneously. In theory, however, the number of channels provided by orbital angular momentum can be much larger."

- PO

While an eight times increase over 56K probably won't be blowing you back to Buffalo, the potential could be real within the audiences they have suggested.  The audience probably is not military since I gather submarines need to surface to send what I suppose must be large volumes of data.  Whatever way they really do it is probably more highly-classified than who killed Jimmy Hoffa.

Note:  see ... that information is so classified you don't even know who Jimmy Hoffa was.


We're not getting a strong vibe for the sci fi extension on this.  All of us see an eight times boost to communication speed is going to be a big tingle for those who use it but the audience isn't that exciting ...

until ...

we use this device on a robo which goes undersea on Europa.  How about that, mates.  Maybe a current robo finds the Coolest Thing in Creation ... but ... it uses the old way for communication and it can't convey sufficient information quickly enough to be useful.  With the new way, we even get pictures, albeit somewhat slowly.

That's kind of thin but the Rockhouse is going with it since maybe this new technology will make for cooler robos on Europa as they find whatever they will down there.