China Mobile Pushes 1.6 Terabits per Second Down One Laser Beam for 960 km of Ordinary Fiber

China Mobile said on Nov. 11 that it had sent 1.6 terabits per second down a single laser wavelength over 960 kilometers (about 600 miles) of ordinary backbone fiber, in real time. Xinhua reported it as the longest single-wavelength 1.6T transmission China Mobile has done. IT Home, a Chinese tech outlet, called it the industry's first long-haul 1.6T test built on 230-gigabaud technology. Those "first" and "record" labels come from China Mobile and media reports. No paper or independent test data has been published yet.

How the internet's highways work

Streaming video, using AI and syncing data between cities all depend on a carrier's backbone network. That backbone is mostly fiber-optic cable buried underground or laid on the seabed. One fiber can carry many beams of laser light at different colors, or wavelengths, and each beam works like a lane on a highway. To make the network faster, you either add lanes or make each lane faster.

How fast is 1.6 Tb/s? One terabit is 1,000 gigabits, so 1.6 terabits per second works out to roughly 200 gigabytes per second, or dozens of HD movies every second. Many backbones today still run 400G per wavelength. China Mobile only finished its first large-scale rollout of a 400G all-optical backbone in 2024. Standards groups such as the ITU-T and the Optical Internetworking Forum treat 1.6T as the next target speed after 400G.

What's new: 230 gigabaud

Baud rate is how many times per second the laser changes its signal. Each change carries one symbol. With the same encoding, a higher baud rate packs more data into each second. 230 gigabaud means 230 billion symbols per second.

IT Home reports that China Mobile mainly used 130 gigabaud for its 400G rollout in 2024. When it later trialed 1.2T on a metro network, it concluded that 130 gigabaud fell well short of what long-haul backbone links need. The company then made speeds above 200 gigabaud a priority and spent two years getting from 130 to 230. For comparison, the single-carrier 1.6T system that Canadian equipment maker Ciena announced earlier runs at 200 gigabaud and mainly targets metro distances.

The fiber matters too. The test used G.652.D, the ordinary single-mode fiber that makes up most of the world's installed backbone, not a specialty fiber built for extreme speeds. If the technology matures, much of the fiber already in the ground could in principle be upgraded to 1.6T by swapping the equipment at each end, without digging up roads to lay new cable. And 960 kilometers is a bit shorter than the flying distance from New York to Chicago, edging toward the 1,000-kilometer mark.

What we don't know

Xinhua's report says only that China Mobile ran the test "with partners." It doesn't name the equipment vendors or give engineering details like error rates or channel count. It also doesn't say whether this was a lab setup or a live network, or when the technology might be deployed commercially. China Mobile itself noted that new kinds of optical impairments from approaches like subcarrier designs still need more research. Going from a successful trial to wide deployment usually takes mature equipment, lower costs and finished standards.

On standards, IT Home reports that in July 2026 China Mobile led completion of the first phase of G.709.5, a core terabit-era standard, at a plenary of the ITU-T's Study Group 15. Work has also started on G.696.1, a 1.6T optical-layer standard for long-haul links, and the 960-kilometer results will feed into it as test data.

What it means for you

Your home broadband and phone won't suddenly get faster, since the bottleneck is usually the "last mile" to your door. But the backbone is the internet's main highway. Training and running large AI models means moving huge amounts of data between distant data centers, and traffic from video and cloud gaming keeps growing. Faster lanes that can reuse old fiber would let carriers add capacity more cheaply. Over time, that could lower the cost of moving data between regions and make online services more reliable. According to Xinhua, China Mobile framed the goal as cutting the overall cost of carrying traffic such as links between data centers.

Original sources published: Xinhua, Nov 11, 2026, 19:39 Beijing time / 6:39 AM EST; IT Home, Nov 12, 2026, 07:56 Beijing time / Nov 11, 2026, 6:56 PM EST