China activates world's first commercial three-band optical fiber system to boost network capacity

China has achieved a significant technological milestone with the activation of the world's first commercial three-band optical fiber communication system. This innovation, developed by state-owned telecommunications giant China Mobile and its industry partners, promises to dramatically expand the carrying capacity of future networks, particularly those supporting artificial intelligence.

The newly operational system, located in Qingdao in the eastern province of Shandong, utilizes a 35km link connecting major computing facilities. It represents a leap forward by enabling a single optical fiber to handle more than five times the traffic of traditional systems, while simultaneously increasing transmission capacity per core by nearly half. This advancement was achieved by combining ultra-low-loss transmission capabilities into the S-band, a part of the light spectrum previously deemed too unstable for commercial use, with multi-core fiber technology.

Developers liken the approach to expanding a two-lane highway into a three-lane one without constructing an entirely new road. While most long-haul fiber systems globally rely on the C-band and increasingly the L-band, technical hurdles have historically limited the use of other spectrum parts. China Mobile's breakthrough overcomes these challenges by simultaneously employing three transmission windows, the S-band, C-band, and L-band, within a conventional optical fiber, thereby maximizing data flow through existing infrastructure.