Meta's Petal transatlantic fiber optic cable project connecting the US and France allows 75% of the world's population to listen to music online at the same time without congestion, expected to operate in 2029.

Live Science reported on October 17 that Meta - the parent company of Facebook, Instagram, and WhatsApp, announced a 7,000 km long submarine fiber optic cable project called Petal, with a design bandwidth of up to one petabit/second, equivalent to one million gigabits/second. At this speed, the Internet cable line can transmit about 125 terabytes (TB) of data in just one second, or 25,000 HD quality movies (each movie has a capacity of 5GB) or allow 3/4 of the world's population to listen to music online at the same time without congestion. Petal's data transfer speeds will be approximately 3.3 million times faster than the average US household's Internet connection, based on average broadband speeds.

When in operation, this will be the first transoceanic fiber optic cable to achieve petabit-level data transmission speeds, twice as fast as current undersea cable systems of the same length. Petal is also the first commercial submarine cable to use multi-core fiber optic technology. While conventional optical fibers contain only a single core, Petal uses two cores that transmit optical signals in opposite directions, providing the same capacity as a single core fiber pair. Each optical fiber is as thick as a human hair with a diameter of 125 micrometers. The Petal cable will contain 24 pairs of double-core optical fibers, for a total of 96 fiber cores.

Japanese technology company NEC will be responsible for the design and construction of Petal while Sumitomo Electric is in charge of providing the fiber.

According to the International Telecommunications Union, the United Nations agency on digital technology, undersea fiber optic cables are one of the most important layers of Internet infrastructure, carrying about 99% of global traffic. Installing thousands of kilometers of cables under the seabed is a technological feat, but ensuring the cables can transmit tiny pulses of infrared light carrying data over huge distances without affecting performance is equally challenging. Engineers use amplifiers and equipment installed at regular intervals along the cable route to enhance optical signals with lasers. Meta representatives said the 7,000 km project requires about 100 such amplifiers.

Petal submarine cable will apply channel merging/separating technology (fan-in/fan-out). When the double-core fiber enters the amplifier, the optical interface routes the signal from each core into a separate single-core fiber for independent enhancement. After strengthening, the signal will be combined back into the two cores of the double-core optical fiber to continue transmission. Thanks to this solution, Petal can double the data transmission capacity without having to consume correspondingly more electricity.

According to Tech Radar, communications traffic is constantly increasing as artificial intelligence tools and everyday digital services require connections between continents to be more resilient and reliable. That's why Meta continuously expands undersea cables across many regions by investing in more than 20 projects connecting every continent except Antarctica. Petal is one of many recent Meta subsea cable projects, including Marea in 2018, Amitie in 2023 and Anjana in 2025. Marea, the company's first transatlantic fiber optic cable, supports 192 terabits per second, one-fifth that of Petal.

Fortune said Meta's most ambitious subsea cable project is Waterworth, announced in February 2025. Meta said this system will stretch nearly 50,000 km, longer than the circumference of the Earth, connecting the US, Brazil, South Africa, India and other regions on five continents. Some sections will be placed about 7 km below the sea surface to protect against ship anchors and other hazards.

An Khang summary