AWS to build 420 Tbps transpacific subsea cable by 2029

Amazon Web Services has announced plans to construct a new transpacific subsea cable system, Sta’O’Nuk, which will connect Washington state in the United States to Japan. The project is designed to provide an alternative geographic route for international data traffic, addressing concerns about over-reliance on established cable corridors in California, Oregon, and specific regions of Japan. With a planned capacity of 420 terabits per second, the system is expected to enhance AWS’s network resilience and support a range of workloads, including distributed AI training, financial transactions, and video delivery. The cable is scheduled to become operational in 2029, though AWS has noted that this timeline and the stated performance metrics remain targets rather than guarantees at this stage.

Route and technical design

The Sta’O’Nuk cable will use 20 fiber pairs and will land in locations that AWS describes as less concentrated than traditional subsea cable gateways. On the U.S. side, it will be the first international subsea cable to land in Washington state in nearly three decades. The Japanese landing points have not been disclosed in detail, but the route is intended to mitigate risks associated with geographic concentration, such as earthquakes, fishing activity, or anchoring damage, which can disrupt multiple cables simultaneously. Nearshore sections of the cable will be armored and buried at depths of up to 1,500 meters to further reduce the risk of physical damage.

AWS has incorporated multiple layers of security into the system’s design. Optical encryption at Layer 1, described as quantum-safe, will be complemented by MACsec at Layer 2, with additional protection provided by TLS/SSL or QUIC at higher layers. The project also involves collaboration with the Quinault Indian Nation, which has authorized AWS to use the name Sta’O’Nuk, translated as “lightning serpent,” for the system. Toptana, the Nation’s Indigenous-owned subsea cable landing-station and backhaul venture, will play a role in the Washington landing.

Strategic context and industry trends

The announcement reflects a broader trend among hyperscale cloud providers to invest directly in subsea cable infrastructure. Companies like AWS are increasingly seeking to control the physical pathways for international data traffic, rather than relying solely on third-party cable operators. This shift is driven by the growing demand for capacity, particularly for AI and machine learning workloads, as well as the need for redundant and geographically diverse routes to ensure network reliability.

Recent years have seen a surge in new subsea cable projects. For example, the SJC2 cable, which entered service in Asia in July 2025, offers over 126 terabits per second of capacity, while the Candle system, connecting Japan to Southeast Asia, is expected to become operational in 2028. These projects highlight the industry’s focus on both expanding capacity and diversifying routes to reduce single points of failure.

Regulatory and operational considerations

The Sta’O’Nuk project will proceed under a revised U.S. regulatory regime for subsea cables. Earlier this year, the Federal Communications Commission adopted new licensing rules aimed at addressing national-security risks while encouraging cable deployment. Key provisions of the updated framework will take effect on September 25, 2026, which may influence the permitting and operational timeline for the project. AWS has not disclosed specific details about how the new rules will impact Sta’O’Nuk, but the regulatory changes are expected to streamline certain aspects of the approval process while introducing additional security-related requirements.

The project’s success will depend on coordination with multiple stakeholders, including the Quinault Indian Nation, local authorities in Washington state, and Japanese regulatory bodies. AWS has emphasized the importance of geographic diversity in its network strategy, and Sta’O’Nuk is positioned as a critical component of that approach. However, the system’s actual performance and resilience will only be tested once it becomes operational in 2029.