A new era of digital underwater communications

Imagine a scuba diver approaching the surface, being made aware of nearby boating activity; or a submarine communicating with a land-based command post; or an underwater robot sending a warning to an oil rig after a leak is detected – the possible applications of underwater communications are limitless.

It could be used in many areas: for harbour protection, maritime surveillance, mine detection, surveying offshore wind farms and pipelines, or even underwater archaeology.

The NATO Science and Technology Organization’s Centre for Maritime Research and Experimentation (CMRE, see below for more info) has developed a standard for underwater acoustic communications called JANUS, which is recognised as a NATO standard by all NATO Allies since 24 March 2017. This marks the first time that a digital underwater communication protocol has been acknowledged at international level and opens the way to develop many exciting underwater communication applications.

A network of marine robots

CMRE is working to support effective underwater communication networks to allow undersea robots to work together and report back home (see the infographic on Digital Underwater Networked Communications).

"Robots can behave intelligently and act as a team," says João Alves, Principal Scientist and Project Leader at CMRE. “For example, one of the robots could find some interesting feature and call the rest of the team.”

With effective undersea communication, this can all happen in an autonomous way, without requiring direct human intervention. If needed, the operation can be managed by land-based engineers who monitor all the communications from a command and control room ashore. The connection to land is made through gateway buoys on the surface of the water equipped with radio links to local support platforms or satellites.

“This is particularly important for search-and-rescue operations,” says John Potter, a scientist at the CMRE Strategic Development Office. “Autonomous vehicles are relatively inexpensive and of course unmanned, so they can be sent to do dirty, dangerous jobs.”

“Sound is known to have an impact on marine life,” said João Alves.  Aware of this risk, the Centre works with biologists and other scientists to protect the marine environment. 

Much of this development work is carried out on the Littoral Ocean Observatory Network, or LOON (see below for more info). The LOON is a test facility, installed in the harbour of La Spezia, Italy that plays a central role in NATO projects, many of which are developed in partnership with the European Commission. 

CMRE uses the LOON to develop and test communication solutions that contribute to the protection and monitoring of oceans and rivers by underwater robots.

JANUS, the standard underwater language

To be able to communicate with each other, underwater assets need common standards. “In the air we can simply connect our gadgets to any WiFi hotspot without having to worry about the compatibility,” says João Alves. “Until now, there wasn’t anything even remotely similar for the underwater domain.”

As with the industry standard for WiFi communication, an undersea communication standard has to be defined in order to guarantee the interoperability between equipment from different manufacturers.

For the past ten years, CMRE has been working on the development of the first international digital underwater communication protocol, known as JANUS, which is now an approved NATO standard.

“JANUS was a Roman god of openings and gateways,” says John Potter. “That’s why it is called JANUS, because this language opens the portal between two domains, two different operating paradigms, through which they can talk.”  

“It is a digital underwater signalling system that can be used to contact underwater devices using a common format; announce the presence of a device to reduce conflicts; and enable a group of underwater devices (that can be underwater robots, submarines, divers or any other equipment operating under the surface) to organise themselves into a network,” adds John Potter.

Adopted globally, JANUS can make military and civilian, NATO and non-NATO devices interoperable, providing them all with a common language with which to communicate and arrange to cooperate.

JANUS has been extensively tested at sea in exercises involving a number of partners (universities, industries and research institutions) covering a range of application scenarios. Close collaboration with NATO Allies has been particularly fruitful in developing JANUS for use in cases that may improve the safety of maritime operations.

For example, the Portuguese Navy has been working with CMRE to develop new concepts to support the exchange of crucial information with submarines (typically only available at the surface via radio) such as the location of nearby ships. Digital data exchanges to support rescue operations in case of a submarine incident are currently also being developed.