China Mobile activates world's first 3-band fibre link in Qingdao
Synopsis
China Mobile has activated the world's first commercial three-band optical fibre link in Qingdao, enabling a single fibre to carry more than five times conventional traffic — a potential game-changer for AI backbone networks globally.
Key Takeaways
China Mobile and Hengtong Optic-Electric activated the world's first commercial S-band + C-band + L-band optical fibre system in Qingdao, Shandong in early June 2026 .
A single fibre on the new system can carry more than five times the traffic of conventional fibre, with per-core transmission capacity rising by nearly half .
The live link spans 35km (21.7 miles) and connects major computing facilities in Qingdao , serving as a commercial test bed.
The S-band — previously too noisy and unstable for commercial use — was made viable by combining ultra-low-loss transmission with multi-core fibre technology.
The project supports China's Eastern Data, Western Computing national strategy and could reduce the cost of AI network upgrades by maximising existing infrastructure.
China Mobile, in partnership with Hengtong Optic-Electric, activated the world's first commercial three-band optical fibre communication system in Qingdao, Shandong province, early in June 2026 — a breakthrough the project team says could multiply the data-carrying capacity of future AI and computing networks without laying new cable.
What the technology does
The system simultaneously uses three transmission windows — the S-band, C-band, and L-band — within a single conventional optical fibre. According to the project team, a single fibre can carry more than five times the traffic of conventional systems, while transmission capacity per core increases by nearly half. China Mobile likened the approach to expanding 'a two-lane motorway into a three-lane highway' without building an entirely new road.
The engineering challenge solved
Most long-haul fibre networks globally rely primarily on the C-band and, increasingly, the L-band. The S-band has historically been excluded from commercial use due to signal amplification difficulties, noise, and transmission instability. The new system addresses this by extending ultra-low-loss transmission capabilities into the S-band while combining them with multi-core fibre technology, according to the development team.
The deployment: a 35km commercial test bed
The 35km (21.7-mile) link connects major computing facilities within Qingdao and functions as a commercial test bed for next-generation optical networking, according to a June 3 report by Shanghai Securities News. The project was jointly developed by state-owned China Mobile and industry partners including Hengtong Optic-Electric, both key players in China's fibre infrastructure ecosystem.
Why it matters for AI infrastructure
The deployment is directly relevant to China's Eastern Data, Western Computing strategy, which routes data workloads from data-hungry eastern cities to computing centres in the country's less-developed west. As AI model training and inference push bandwidth demands to new highs, the ability to triple usable spectrum on existing fibre could defer or reduce the cost of physical network upgrades. The technology, if scaled, could reshape the economics of backbone connectivity not just in China but in markets across Asia, Europe, and the United States where legacy fibre infrastructure is already strained.
What's next
The Qingdao link currently serves as a live commercial test bed, meaning wider rollout depends on performance data gathered from this deployment. Industry analysts will be watching whether China Mobile and Hengtong Optic-Electric can replicate the results over longer distances and in more complex network topologies. The outcome could determine how quickly three-band transmission moves from a Chinese-first milestone to a global networking standard.
Point of View
And it sidesteps the supply-chain friction that has complicated hardware procurement amid ongoing export controls. What mainstream coverage tends to underplay is the role of Hengtong Optic-Electric: a domestic champion now positioned to export three-band technology to belt-and-road markets where fibre upgrades are overdue. The real test is distance — the 35km Qingdao loop is controlled-environment proof-of-concept, and long-haul S-band amplification at scale remains an open engineering problem. If China Mobile publishes reproducible results, it could force network operators in Europe, Japan, and the United States to accelerate their own multi-band roadmaps much sooner than planned.
NationPress
29 Jul 2026
Frequently Asked Questions
What is the world's first three-band optical fibre system?
China Mobile and Hengtong Optic-Electric activated the world's first commercial optical fibre link that simultaneously uses the S-band , C-band , and L-band transmission windows in a single fibre. The 35km system went live in Qingdao, Shandong in early June 2026 and allows a single fibre to carry more than five times the data of conventional systems.
Why does the S-band matter for optical fibre?
The S-band is a portion of the light spectrum that has historically been too noisy and difficult to amplify for commercial fibre use. By solving those amplification and stability challenges, the new system unlocks a third transmission 'lane' alongside the already-commercial C-band and L-band , dramatically increasing usable spectrum on existing cables.
How does this affect AI network capacity?
The technology directly addresses the bandwidth bottleneck created by large-scale AI model training and inference. Because the upgrade works on existing fibre infrastructure — China Mobile compared it to widening a motorway without building a new road — it could allow operators to scale AI backbone capacity at a fraction of the cost of new cable deployment.
Who built the Qingdao three-band fibre link?
The project was jointly developed by state-owned China Mobile and its industry partners, prominently including Hengtong Optic-Electric . The 35km link in Qingdao serves as a live commercial test bed for next-generation optical networking, according to a June 3 report by Shanghai Securities News .
Will three-band optical fibre be adopted globally?
Wider adoption depends on whether the technology can perform reliably over longer distances and in more complex network environments beyond the controlled 35km Qingdao test bed. If results hold, network operators in Europe , the United States , and Japan — where legacy fibre is already strained — could face pressure to accelerate their own multi-band upgrade roadmaps.
