Shimadzu underwater optical wi-fi system completes open water test

Shimadzu Corporation has been working on the practicality of an underwater optical Wi-Fi system using underwater optical wireless communication technology, which was selected as a research theme for the "Nippon Foundation-DeepStar joint research and development program for Offshore Oil and Natural Gas". In the final test of the program, the team was able to demonstrate that the underwater optical Wi-Fi system under open water environment. In the test, Shimadzu conducted the tests of "measurement of communication distance and speed" and "demonstration of handover function among multiple Wi-Fi base stations" on the coast of Nagasaki Prefecture from 12 - 15 December, 2022. The tests were conducted during the day and at night at a location off the coast of Nagasaki prefecture, Japan and 30 meters deep in the ocean.

 

The test was conducted using the following configuration. The two base stations of the Wi-Fi system communicate with MC500＊１ (Middle range underwater wireless communication device manufactured by Shimadzu Corp) mounted on the ROV (Remotely Operated Vehicle). Each base station emits a green laser and the MC500 emits a blue laser, which enables full-duplex communication. In this test, we measured the distance at which full-duplex communication was ensured.

Shimadzu's Wi-Fi System was able to achieve the following communication distances. Communication was considered to have been achieved when 95% or more of the data volume was received relative to the volume of data transmitted.

 

 

As a result of this sea trial, we were able to confirm that an omni-directional optical wireless Wi-Fi area could be constructed in actual sea conditions and that the communication area could be extended by adding optical fiber. On the other hand, we also learned about the effects of ambient light and the challenges of beam alignment to have aligning the optical axis on the ROV side, which was the base station's communication partner. Shimadzu will utilize the results of this test for future development aimed at actual operation.