Asia’s New Mega Cable Ignites a Connectivity Revolution

A powerful new subsea cable boosts Asia’s data capacity as AI driven demand accelerates across the region

17 Nov 2025

A new subsea cable connecting Singapore and Japan has entered service, adding a major route through Southeast and East Asia at a time when digital traffic is rising and pressure on existing paths is increasing.

The Southeast Asia Japan Cable 2 system, developed by a consortium including China Mobile International, Chunghwa Telecom and KDDI, provides about 126 terabits of capacity across more than 10,000km. The line connects Thailand, Vietnam, Taiwan and the Philippines, creating an additional corridor for cloud services and artificial intelligence workloads that have strained older networks.

Consortium members view the project as both a strategic investment and a safeguard for regional resilience. China Mobile International has described the cable as an essential part of Asia’s core network. Chunghwa Telecom expects the system to strengthen Taiwan’s role as a regional hub as computing needs grow. KDDI engineers say design changes aim to improve protection against natural hazards that have disrupted other cables in nearby waters.

The launch comes during a broader cycle of investment in regional connectivity. Operators across Asia are modernising older infrastructure, acquiring assets and planning new systems to support demand from data centres and cross-border digital services. Industry analysts, however, note that the region continues to face slow regulatory approvals, higher construction costs and increasing security concerns around subsea networks.

As more activity depends on these cables, experts argue that stronger safeguards against outages and cyber risks are becoming essential. Governments in the region have been reviewing frameworks for network protection, though progress remains uneven.

Even with these constraints, investment momentum continues. The activation of SJC2 expands available capacity, raises expectations for network performance and allows its backers to reinforce their positions in a competitive connectivity market.

For industry observers, the cable’s entry into service reflects a wider shift as Asia builds the infrastructure required for the next phase of global data exchange. Additional projects are planned, supported by growth in cloud computing, e-commerce and cross-border digital trade. While the system runs deep underwater, its introduction signals a further step in the region’s drive to upgrade its digital foundations.