A statement from NEC said it would provide the optical submarine cable system as a turnkey solution. The system is scheduled to start operations in April 2020.
Under the contract, NEC will design, engineer, supply, install, test and implement the system.
The 760-km cable system will be connected to Nago City in Okinawa Prefecture and Hioki City in Kagoshima Prefecture and will be installed at a maximum depth of 1200 metres.
It will also meet the demand for communications between the Okinawa, Kyushu and Honshu regions, which is expected to continue growing due to data centre construction in Okinawa and the launch of 5G services.
NEC has been building submarine cable systems for more than 50 years and has laid more than 300,000 km of cable.
It provides all aspects of submarine cable operations, including production of optical transmission terminal stations, optical submarine repeaters, optical submarine cables, ocean surveys and route designs, installation of equipment and cable installation, and training and delivery testing.
NEC's subsidiary, OCC Corporation, manufactures this cable, and is the sole company in Japan that can manufacture optical submarine cables capable of withstanding the water pressure at 8000 metres.