China launches first three‑band optical fiber system to accelerate AI data traffic

China has activated the world’s first three‑band optical fiber network, a 35‑kilometre pilot installed in Qingdao, Shandong province. The project, carried out by China Mobile together with partners such as Hengtong Optic‑Electric, uses three frequency windows (S, C and L) and four independent cores within a standard‑diameter fiber. According to the developers, the line can transmit up to five times the traffic of conventional systems and boosts per‑core capacity by roughly 50%, effectively widening a data “highway” from two to three lanes without replacing existing cables.

The technology is positioned as a strategic upgrade for the massive data‑transfer needs of artificial‑intelligence training and inference, enabling faster, more efficient movement of large model datasets. Researchers also claim the approach overcomes previous limitations of the short‑wave S band, opening the possibility of applying the method to submarine cables and broader internet backbones.

The breakthrough follows earlier laboratory records in Europe, the United States and Japan, but represents the first commercial‑scale deployment, signalling China’s push to strengthen its digital infrastructure ahead of ever‑larger AI models.