Petabit-Scale Transatlantic Link Announced

Meta has revealed Petal, a transformative 7,000-kilometer (4,300 miles) transatlantic submarine cable linking the United States directly to France's Atlantic coast. Scheduled to enter service in 2029, this system achieves 1 Petabit per second (1 Pbps / 1,000 Tbps) of total design capacity—representing the most significant single generational advancement in subsea cable capacity ever deployed. The architecture doubles the bandwidth of existing 24 fiber-pair systems, such as Meta's Anjana cable, without requiring proportional increases in physical cable dimensions or shore power draw.

Industrial Partners and System Design

Realizing a petabit-class transoceanic system demanded a complete overhaul of subsea manufacturing and engineering across three primary collaborators:

NEC Corporation

NEC serves as the turnkey supplier, managing overall system design, optical repeater engineering, wet-plant manufacturing, and ocean installation. The company engineered a single-body 96-amplifier repeater and the complete 2-core Spatial Division Multiplexing (SDM) system architecture.

Sumitomo Electric

Sumitomo Electric provides the "2C Z-PLUS ULL" ultra-low-loss 2-core fiber strands. The company achieved the technical feat of embedding two independent light-guiding cores within a standard 125 µm outer cladding diameter while maintaining practically negligible crosstalk.

Orange

Orange functions as the landing partner on France's Atlantic coast, overseeing Cable Landing Station (CLS) operations, environmental permitting, and direct optical backhaul connectivity into major European data center hubs.

Core Engineering Innovations

Conventional subsea capacity expansion relied on adding more physical fiber pairs within a cable. However, exceeding 24 fiber pairs introduces severe constraints around mechanical handling, physical weight, and electrical power consumption. Petal addresses these limitations through three fundamental engineering advances:

  • 2-Core Multi-Core Fiber (MCF) at Scale: Rather than expanding cable thickness to accommodate 48 physical fiber pairs, Petal integrates two distinct light-guiding cores inside each fiber strand while preserving the industry-standard 125 µm outer diameter. This approach maintains standard cable manufacturing, armored protection, and shipboard handling procedures while effectively doubling spatial capacity.
  • Single-Body 96-Amplifier Repeater with FIFO Interfaces: A 7,000 km route demands roughly 100 subsea repeaters to regenerate optical signals. To amplify 96 spatial cores within a single repeater housing, NEC incorporated Fan-In/Fan-Out (FIFO) optical interfaces. Within each repeater, FIFO divides the 2-core fiber into two single-core paths for efficient single-core amplification before recombining them back into 2-core fiber upon exit.
  • Power Feeding Efficiency (18 kV Boundary): By leveraging high-efficiency SDM pump-sharing repeaters combined with low-loss Sumitomo fiber, Petal operates within existing 18-kilovolt (kV) Power Feeding Equipment (PFE) specifications. This avoids the extended engineering and safety requalification cycles necessary for ultra-high voltage shore power infrastructure.

Implications for AI Infrastructure and Global Networks

Petal transitions multi-core fiber from research settings into operational commercial subsea deployment. By establishing a functioning 2-core supply chain, Meta creates an open technical framework that the broader subsea cable industry can leverage for future transoceanic projects.

Generative AI training and distributed GPU clusters depend on extensive data replication spanning continents. The 1 Pbps capacity enables real-time synchronization of large-scale neural networks and hyperscale availability zones between the U.S. and Europe.

Meta's Expanding Subsea Infrastructure Strategy

Meta has positioned itself as a leading private investor in submarine cable systems, backing more than 20 global subsea projects. These include major initiatives such as 2Africa (45,000+ km circumnavigating Africa), Project Waterworth (50,000+ km multi-ocean system), Candle (APAC region), and Malbec (South America).

Within the strategically critical North Atlantic corridor, Petal represents the culmination of a three-phase capacity expansion roadmap. The system establishes a new technological benchmark for subsea infrastructure by successfully industrializing 2-core multi-core fiber alongside NEC, Sumitomo Electric, and Orange—effectively doubling transatlantic data pipelines to 1 Petabit per second and setting the standard for undersea connectivity in the AI era.