JANUS (also known as ANEP-87) is a communication standard for undersea telecom, this modem maximizes interoperability with the outside world. Janus was developed at the Centre for Maritime Research and Experimentation (CMRE) https://www.cmre.nato.int/ with the collaboration of academia, industry and government.

In any communication system, standardization is fundamental. A common mechanism or language must be followed on both ends of the system for successful data transmission. In March 2017, NATO released ANEP-87 Digital Underwater Signaling Standard for Network Node Discovery and Interoperability (JANUS). It is the first underwater communications standard to be defined by an international body. JANUS is the first step toward the “internet of underwater things.” Equipment includes such applications as underwater autonomous vehicles, diver and ship communication systems, smart buoys, and intelligent sensors.

JANUS utilizes acoustic sound waves at an 11.52 kHz carrier frequency to transmit information wirelessly through the water. A transmitter and receiver can be separated several kilometers and still maintain successful communication acoustically through the water. Although the data rate is low (80 bps) compared to internet standards, this information rate is more than adequate for most marine applications.

Popoto Modem has an easy to use implementation of the JANUS standard.  It is off-the-shelf and available now as an OEM boardset for manufacturers or as a complete standalone solution for ship board or submerged operation.