ItInsightsWorld Analysis: 24-Core Fiber Reaches 3.2 Pb/s in a 10.3 km Trial, While Scale-Out Still Needs Engineering

What was demonstrated

The result comes from a test over 10.3 kilometers of 24-core fiber. Using space-division multiplexing together with the three S, C, and L bands, the system built thousands of parallel transmission channels. It reached 3.2 Pb/s, which is 3200 Tb/s. This does not mean that current home broadband or ordinary single-core fiber already delivers that capacity.

How the speed scales

Per wavelength, the S band achieved 400 Gb/s, while each wavelength in the C and L bands reached 1.2 Tb/s. Commercial coherent optical modules and higher-order probabilistic shaping were part of the setup, and the fiber cores were arranged to reduce inter-core crosstalk. The team also used self-developed optical modules for real-time transmission verification.

Why the number matters

Researchers estimate that the total rate could, in theory, transfer more than 20,000 4K movies in one second or carry about 3.2 million gigabit-broadband households simultaneously. These are illustrative conversions: the dedicated 24-core test fiber and its 10.3 km span are not a deployed access network.

Where deployment still must catch up

Traditional commercial G.652 single-mode fiber has a C- and L-band capacity ceiling of about 100 Tb/s, making the multi-core aggregate approximately 32 times larger. Multiple cores in one fiber may help data-center interconnects, backbone networks, and future 6G transport, but the work remains experimental. Earlier studies achieved higher rates with non-commercial equipment and signal-processing schemes; this result instead checked a more commercial-like architecture in real time. It was accepted at the 2026 International Conference on Optical Fiber Communication (OFC) as a highly rated paper, and the team was invited to submit to the Journal of Lightwave Technology.