Japan Launches a $1B Cable That Thinks on Its Feet

A consortium led by NTT DATA plans an 8,100-kilometer subsea cable designed to reroute and future-proof digital traffic across Asia Pacific

6 Mar 2026

A consortium of three Japanese companies announced plans in January to build a billion-dollar submarine cable spanning much of East and Southeast Asia, a project that underscores the intensifying race to keep pace with the region's surging demand for data. The system, called the Intra-Asia Marine Cable, would stretch roughly 8,100 kilometers from Japan to Malaysia and Singapore, with branches to South Korea, the Philippines and Taiwan, and is expected to enter service in early 2029.

The venture, known as Intra-Asia Marine Networks, brings together NTT DATA, the global technology services firm; Sumitomo Corporation, a major Japanese trading house; and JA Mitsui Leasing, which specializes in infrastructure finance. Alcatel Submarine Networks, one of the world's leading cable manufacturers, will supply the system, while OMS Group, a marine services provider, will handle installation.

What distinguishes the I-AM Cable from conventional builds, according to its developers, is a pair of advanced technologies. Space Division Multiplexing allows the cable to carry up to 16 fiber pairs within a single sheath, yielding an initial capacity of roughly 320 terabits per second. Wavelength Selective Switch technology, meanwhile, enables operators to reallocate bandwidth across individual routes remotely, without dispatching a repair vessel. Together, the features are intended to let the system adapt in near real time as traffic patterns shift.

The cable's planned path through the South China Sea is also notable. As shown in routing maps released by NTT, the system avoids areas within China's claimed nine-dash line and includes no Chinese landing points, a choice consistent with several other recent regional cable projects. Within Japan, three geographically dispersed landing stations in Chiba, Mie and Fukuoka are designed to reduce vulnerability to earthquakes and other natural disasters.

The project arrives during an extraordinary period of investment in undersea infrastructure. According to TeleGeography, the research firm, approximately $6 billion worth of new cable systems are forecast to enter service in 2026, roughly double the $3.2 billion recorded the previous year. Much of that spending is driven by cloud computing providers and the growing computational demands of artificial intelligence. Whether the I-AM Cable's capacity to reconfigure itself on the fly proves as transformative as its backers suggest may not be clear for years, but the scale of the wager reflects a conviction that Asia's appetite for bandwidth is only beginning.