Japan sets world record for internet speed with 1.02 million GB/s data transmission
NICT breaks barriers with fastest long-distance fibre transmission ever
DUBAI: Japan has broken the world record for internet speed, transmitting a staggering 1.02 million gigabytes per second over a distance of 1,808 kilometres.
The milestone was achieved by a team led by the National Institute of Information and Communications Technology (NICT), in collaboration with Sumitomo Electric Industries. The demonstration used a 19-core optical fibre with a standard cladding diameter of 0.125 mm – comparable in size to conventional fibres used today.
This feat marks the first successful transmission of over 1 petabit per second across more than 1,000 km using standard-diameter fibre. It is expected to shape the future of long-distance, high-capacity optical communications amid rising global data demands.
World record fibre technology
The 19-core fibre used in this study acts like a 19-lane expressway for data, dramatically increasing bandwidth without altering the fibre’s diameter. Each core transmits data independently, enabling massive throughput. The fibre was paired with advanced optical amplifiers designed to boost signals simultaneously across all cores and two frequency bands: the C-band and L-band.
The setup included 19 recirculating transmission loops, simulating long-distance travel by passing the data through the 86.1 km loop 21 times. This brought the total transmission length to 1,808 km – roughly the same as the distance from Sapporo to Fukuoka or Berlin to Naples.
Breakthrough in long-distance internet speed
While petabit-level speeds have been recorded before, they were typically limited to short distances. NICT’s success lies in extending the range while maintaining speed, thanks to reduced fibre loss and precise amplification. The final result was a record-breaking capacity-distance product of 1.86 exabits per second-kilometre – the highest ever recorded using standard cladding diameter fibre.
Signals were received by a 19-channel receiver equipped with a MIMO-based processor, which removed interference and calculated data rates in real time. The clean, synchronised signals confirmed the success of the transmission across all 19 cores.
Implications for future networks
This development lays the foundation for scaling up global fibre networks without replacing existing infrastructure. Previous 19-core fibres were only able to transmit over distances under 100 km. Now, with amplified cores and robust signal recovery, NICT has demonstrated that ultra-fast, long-distance networks are possible using existing fibre sizes.
Presented at the 48th Optical Fiber Communication Conference (OFC 2025) in San Francisco, the study has been praised as a landmark achievement. As data consumption surges with AI, IoT, and 6G on the horizon, innovations like this are essential to future-proof communication systems.