China's CICT Unveils 24-Core Fiber Carrying 3.2 Pbps Over 10.3 km

China Information and Communication Technologies (CICT), a Chinese state-owned company, says it has pushed 3.2 petabits of data per second through a single optical fiber. The test covered 10.3 km and used a newly developed fiber with 24 cores.

To put the figure in perspective, 3.2 Pbps equals roughly 20,000 HD films downloaded in one second. At that rate, the volume of digital data humanity stored in 2007 could in theory be transferred in just over 12 minutes. A petabit is a thousand terabits, or a million billion bits.

Not a record, but in real time

Most fibers in today's networks have a single glass core, with capacity that can reach a few hundred terabits per second depending on the technology. CICT's multi-core design multiplies that potential considerably.

The result is not an absolute record. Japan's national institute NICT reached 22.9 Pbps over 13 km, but in an offline experiment without real-time encoding and decoding of the signal. CICT's signal, by contrast, was encoded and decoded in real time, which makes the demonstration closer to real-world conditions.

Why it matters for AI and 6G

The technology targets a growing problem: data center capacity. According to CICT engineers, a next-generation AI computing center needs five to ten times more optical fibers than a conventional data center. As AI usage grows, so does the pressure on the links that connect servers.

The fiber could also support the rollout of 6G, whose commercial deployment is expected around 2030.

The technology is not yet mature, however. The test spanned only 10.3 km, and CICT will need to maintain such throughput, or more, over much longer distances if the goal is to cover cities. Even so, the demonstration marks a notable step forward for high-capacity optical networks.