High-speed underwater communications system developed with defense funds

October 31, 2017

TOKYO- The Japan Agency for Marine-Earth Science and Technology, or JAMSTEC, has developed an underwater wireless communications system that enables high-speed data transmissions by using light.

The project was funded by the Defense Ministry under its program to promote the development of technology for national security, which the Science Council of Japan has criticized.

Military application of the new system in the future cannot be ruled out, an expert noted.

An official of the ministry said it is yet to be known what will result from the basic scientific research. But the official pointed to the possibility of the epoch-making undersea communications technology being used in submarines.

According Takao Sawa, chief researcher at JAMSTEC, acoustic communications technology has been used for underwater data transmissions. But the transmission rate is low. High-speed transmissions will be possible if cables are used. However, it is difficult to use underwater cable communications systems in areas where ocean currents are moving fast.

On the other hand, visible-light with certain wavelength is an excellent medium for application in underwater wireless communications, Sawa said in a past report.

In the research project, he and colleagues created an optical communications system and tested it in water 700-800 meters deep near the entrance of Sagami Bay. Then they succeeded in transmitting data at 20 megabits per second, about 1,000 times the acoustic system's transmission speed, at a distance of 120 meters.

"The technology can be used for various purposes, including remote-controlling separately located computers under water," Sawa said.

The JAMSTEC team has received a total of 65 million yen from the ministry for the project for three years through March 2016.

In March this year, the council said in a statement that the ministry's grant program contains many problems, including the government's significant interference with research projects. Jiji Press