China Telecom, YOFC and ZTE test hollow-core fibre: 128 Tbit/s over a line of more than a thousand km

Chinese researchers have presented an optical fibre technology that carries data faster than ordinary cables, according to MK (science), citing South China Morning Post. Thanks to the unusual design, signal delay over a distance of more than a thousand kilometres fell by about 30% mk.ruМК (наука)mk.ruOpen source ↗. The experiment involved China Telecom, Yangtze Optical Fibre and Cable (YOFC) and ZTE.

Hollow core instead of solid glass

The main difference of the new fibre is its core. In traditional cables, light passes through glass at a speed of about 200 thousand kilometres per second. The Chinese specialists replaced the solid glass core with a microscopic channel filled with air. As a result, light propagates at a speed close to 300 thousand kilometres per second.

Test results and limits

The researchers set up simultaneous transmission in two directions at 64 terabits per second in each. The total throughput reached 128 terabits per second. For comparison, this is equivalent to simultaneously downloading and uploading 160 full-length 4K films every second.

Over a distance of more than a thousand kilometres, the signal took only 3.4 milliseconds, while conventional optical fibre needs about five milliseconds mk.ruМК (наука)mk.ruOpen source ↗. The developers announced a world record for data transmission distance over hollow-core fibre. The experiment was run on a specially assembled line of hundreds of spools, not on an operating telecommunications network.

Specialists note that remote data centres must constantly exchange very large volumes of information, and faster links could improve their efficiency and reduce equipment costs. Hollow-core fibre has already begun to be used on a limited basis in commercial projects, including a financial communications line between Shenzhen and Hong Kong.