Meta Plans Petal Subsea Cable to Carry 1 Petabit per Second

Meta is developing Petal, a 7,000-kilometer subsea cable connecting France and the United States, scheduled to enter service in 2029. Built in partnership with NEC, Sumitomo Electric, and Orange, the system is designed to achieve an aggregate capacity of 1 petabit per second. This rate, equivalent to 1,000 terabits per second or a theoretical 125 terabytes per second, doubles the 0.5 Pbps target of Meta's previous Anjana cable system.

To achieve this capacity without increasing the physical cable size, Petal deploys multi-core fiber at scale. The system uses 24 fiber pairs of Sumitomo's 2C Z-PLUS ULL two-core fiber, yielding 96 optical cores. Each fiber maintains the industry-standard 125-micrometer outer diameter, allowing compatibility with existing manufacturing equipment. To amplify the signals over the transoceanic route, NEC single-body repeaters with 96 amplifier channels use fan-in and fan-out components to split the two-core fibers into single-core paths for amplification via standard erbium-doped fiber amplifiers, keeping the system voltage under the established 18-kilovolt limit.

For AI practitioners and cloud engineers, Petal addresses the soaring demand for cross-region data transfers. Training large-scale models requires moving massive datasets, model checkpoints, production weights, backup replicas, and real-time inference traffic between American and European data centers. By shifting from spectral efficiency to spatial division multiplexing, Meta's architecture demonstrates how operators can scale bandwidth across oceans without exceeding power budgets or redesigning terrestrial landing stations, which Orange will connect to the European backbone.