Japan-Singapore subsea cable project set to cost USD $1bn

NTT DATA, Sumitomo Corporation and JA Mitsui Leasing have set up a new company to build and run a submarine cable system linking Japan, Malaysia and Singapore, with planned extensions to other Asian markets.

The partners said the new venture, Intra-Asia Marine Networks, will construct and operate the Intra-Asia Marine Cable. The system will create a new Japan-Singapore cable route via Malaysia. It will link to landing stations in Chiba, Mie and Fukuoka.

The consortium expects the project to cost about USD $1 billion. The planned system length is about 8,100 kilometres.

Regional route

The companies said the cable will connect Japan, Malaysia and Singapore at launch. They also set out plans for additional connectivity to South Korea, the Philippines and Taiwan.

The project adds a long-haul route across Asia at a time when operators and cloud providers continue to expand cross-border traffic flows. Subsea cables carry the majority of international data transfers and remain central to the region's connectivity map.

NTT DATA positioned the new route as part of a broader build-out of subsea infrastructure in Asia. It said the new system complements its MIST cable, which links Singapore, Malaysia, Thailand and India.

Capacity plans

The partners said the I-AM Cable will deliver an initial total capacity of around 320Tbps. They linked demand expectations to AI workloads, cloud services and rising international data traffic.

The project will use Wavelength Selective Switch functionality. The companies said this allows remote adjustment of wavelength bandwidth for each route.

The cable will also adopt Space Division Multiplexing technology. The partners said the design can accommodate up to 16 fibre pairs, or 32 cores, per cable.

The companies said the cable design and route selection focus on reliability and resilience. They described the system as a new route that strengthens network resilience for technology companies and telecom operators operating across the region.

Japan hub

The consortium described Japan as a data hub between Asia and the United States. It said the new system will secure routes from the three Japanese landing stations to Malaysia and Singapore.

The companies also linked the project to resilience against natural disasters. They said the new system provides robustness in the region through route diversity.

New operator

Intra-Asia Marine Networks will oversee the project from planning through to the sale of communication circuits, according to the partners. It will manage the commercialisation of capacity for customers that include telecom operators and large technology companies.

The announcement expands a broader push by Japanese groups into regional digital infrastructure, where subsea links have drawn interest from investors and operators as Asia's data centre footprint grows. Singapore continues to attract cable landing activity given its role in regional connectivity and interconnection.

One context point the companies highlighted is the continuing need for additional routes as traffic increases between Northeast Asia and Southeast Asia. They also pointed to the importance of alternate paths when incidents disrupt existing systems.

"The launch of I-AM NW marks a significant step in strengthening Asia's digital infrastructure," said Yoshio Sato, CEO at I-AM NW. "This project reflects our commitment to delivering reliable, flexible connectivity solutions that empower businesses and drive digital transformation across the Asia-Pacific region."

The partners said they plan further connectivity additions beyond the initial Japan, Malaysia and Singapore route, including links to South Korea, the Philippines and Taiwan.