🌊 The data that brought you this page most likely crossed a seabed, not a satellite. In September 2026, Meta announced Petal, linking the US and France over about 7,000 km. It is being built with Japan's NEC and Sumitomo Electric Industries and designed for 1 petabit per second. The trick behind that number is modest: two light paths in each strand of glass, in a field where labs have already gone past a dozen.

The internet runs along the ocean floor

According to the International Telecommunication Union (ITU), submarine cables carry about 99% of the world's internet traffic. Inside them are glass fibers, each about 125 micrometers wide, roughly the width of a hair.

Meta posted the announcement on September 21, 2026 (US time); Sumitomo Electric's release is dated September 22 in Japan. Petal will connect the US with France's Atlantic coast and is due to start service in 2029 (as of September 2026). Meta is paying for the system and will run it. NEC is the turnkey supplier, handling design, repeaters, manufacturing and installation. Sumitomo Electric supplies the fiber, which it calls 2C Z-PLUS Fiber ULL. The French operator Orange supports the landing in France.

As of September 22, 2026, the tech site Cyber Kendra noted that the cost, the US landing site and the exact French landing site had not been disclosed.

How big is a petabit?

One petabit per second is 1,000 terabits per second. Meta estimates that is enough for about 75% of the world's population to stream music at once (about 6.25 billion streams at 160 kbps each). It is still a design target: the cable has not been laid.

Meta's own Atlantic cables make a better yardstick. Marea had 8 fiber pairs, Amitié 16. Anjana, a 7,121 km NEC-built cable between Myrtle Beach, South Carolina, and Santander, Spain, has 24 pairs and about 0.5 Pbps. Petal doubles Anjana and comes to 5.5 times Marea. An Orange executive quoted by Meta noted that it arrives 25 years after the transatlantic terabit mark.

Two roads inside one strand of glass

An optical fiber carries light through a narrow channel called a core, and standard fiber has one. Subsea systems use fibers in pairs, one for each direction.

Sumitomo's fiber puts two cores inside the same 125-micrometer glass, with light running in opposite directions in each, so one strand does the work of a pair. The opposite directions keep crosstalk, the leakage between cores, practically immeasurable, and Meta says performance is nearly identical to single-core fiber. A cable with 24 fiber pairs therefore acts like one with 48.

Meta says it considered two other ways to double capacity: 48 conventional fiber pairs, or adding the L-band (another slice of the light spectrum) to 24 pairs.

The real ceiling was electricity

Adding fibers runs into a less visible limit: power.

Light fades as it travels, so repeaters on the seabed amplify it along the way. Meta says a 7,000 km cable typically needs about 100 of them. They run on electricity sent from shore through the cable itself, and every extra fiber means more amplifiers to feed.

NEC spelled out this limit in 2022 when it announced JUNO, a cable between Japan and California. Until then, according to NEC, trans-Pacific cables had been capped at 16 fiber pairs (32 fibers) by the power available to repeaters. JUNO reached 20 pairs with lower-power repeaters.

Petal's answer sits in the repeater. Each one packs 96 amplifiers into a single body. A fan-in/fan-out interface splits the two-core fiber into two ordinary single-core paths, amplifies them and merges them back. With shared pump lasers and low-loss fiber, Meta says Petal stays within existing power feeding equipment rated up to 18 kV. Going higher would have meant requalifying the whole subsea ecosystem.

The partners also say the design enables single-end feeding, with power supplied from one shore only. According to Converge Digest, this keeps the cable resilient if the supply from one shore fails.

Labs have 19 cores; the ocean gets two

Petal's "world first" comes with conditions. Japanese labs had already gone well beyond two cores.

In March 2024, NEC and NTT sent signals 7,280 km over 12-core fiber in a lab experiment, aiming for practical use in the 2030s. In the same release, NEC noted it was already working on a long-haul subsea cable project using 2-core fiber. In April 2025, Japan's National Institute of Information and Communications Technology (NICT) and Sumitomo Electric reached 1.02 Pbps over 1,808 km with 19-core fiber. In March 2026, NTT unveiled a subsea cable system using 4-core fiber with 192 cores, aiming for deployment around 2029 (we covered it here).

So Sumitomo and NICT have already reached a petabit in a lab. Petal aims for the same figure over nearly four times the distance, with fewer cores per fiber and more fibers in parallel.

Petal is not the first subsea cable to adopt multi-core fiber either. In September 2023, Google and NEC announced what they called the industry's first adoption of it, on the Taiwan-Philippines-U.S. cable. Meta's claim is narrower and holds up on its own terms: Petal would be the first ocean-crossing cable built for a petabit, and the first to use multi-core fiber on this scale.

NICT's own release explains why the lab and the seabed differ. Its 19-core fiber is a "coupled" type, which relies on heavy signal processing (MIMO) at the receiver to undo interference between cores. The fibers being developed for early practical use are uncoupled 2-core and 4-core designs. Our reading is that Meta chose two cores because it is the conservative option: optical performance stays close to ordinary fiber, and power stays under the existing limit.

Who pays, and who builds

Meta, which reports stakes in over 20 subsea cable builds, owns Petal; NEC and Sumitomo are suppliers. The same split held for Anjana, which Meta owns outright and NEC built. We looked at NEC's position against its US and French rivals in an earlier piece.

Japanese companies do sit on the ownership side elsewhere, as in the NTT-led venture for a Japan-Asia cable. On Petal, Japan's part is the fiber and the hardware that keeps light alive across 7,000 km.

Do you know where the cables serving your country come ashore, and which coast is on the other end?

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