Next frontier: Aquatic IoT

New software-defined marine acoustic modems could help bring the Internet of Things underwater.

Underwater Wi-Fi Internet of Things IoT
Credit: iStockphoto

Underwater communications networks are excruciatingly slow, and that's hampering oil and gas exploration and scuba communications, among other businesses.

The communications technology needs upgrading to more closely match high-speed, through-air radio networks, say experts.

One answer may be to adapt software-defined radios and couple them with special underwater acoustic modems, according to electrical engineers at the University of Buffalo.

Radio too slow

Sound-waves—like those used by whales and dolphins—as opposed to radio-waves, are the best media for communicating underwater, the scientists say.

Traditional radio methods don't work properly. The problem is that radio doesn't function well underwater. Commercial underwater modems are slow, and voice solutions are limited by distance and clarity, the scientists say.

However, the engineers believe sound waves could be a better solution. That is, of course, if they can get around some of the problems.

It would be faster, for one thing.

Doppler

"The trouble is that sound waves encounter such obstacles as path loss, delay and Doppler which limit their ability to transmit," says a University of Buffalo news release about the work.

The Doppler shift effect occurs when a wave's frequency changes as parties move closer or away from each other. It's common in sound. A good example is how a train horn sounds different when it's moving, compared to when the train is standing still.

That can be a problem if you need to interpret the sounds.

Plus, "underwater communication is also hindered by the architecture" of systems, which "lack standardization, are often proprietary and not energy-efficient," the university continues.

Software-defined

The key to the solution, they think, is to use software-defined acoustic modems. The engineers say their modem prototype can achieve high data rates in underwater acoustic links.

The "real-time reconfigurable capabilities" allow the underwater networks to be efficient and provide a "high data rate," an IEEE abstract says. The electrical engineering society published the study in November 2015.

Traditional Software Defined Radio is radio equipment that can have its frequencies shifted by computer, rather than by physical means.

"Applying software-defined radio to acoustic modems could vastly improve underwater data transmission rates," the university's release says.

Testing

And the Buffalo engineers report success.

In tests at Lake Erie, they were able to boost data transmission rates "by ten times what today's commercial underwater modems are capable of," the university says.

Uses

It's not just scuba divers and oil and gas exploration that benefit from better underwater communications. The Coast Guard might detect marine drug smugglers more easily or coordinate search-and-rescue missions better, for example. The technology could also have an effect on pollution monitoring. 

In fact, it's in that last one, sensor deployment, such as those used in tsunami warning systems, where this technology might play a significant role.

Aqua-IoT sensors

Just as with the land-based Internet of Things, an aquatic Internet of Things could allow better eco-monitoring. Around 71% of the earth's surface is water.

"The remarkable innovation and growth we've witnessed in land-based wireless communications has not yet occurred in underwater sensing networks, but we're starting to change that," Dimitris Pados, of the School of Engineering and Applied Sciences at Buffalo, a co-author of the study, said in the news release.

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