In early June 2026, the world's first S+C+L tri-band (short-wave, conventional communication, and long-wave bands) ultra-low-loss multi-core optical cable line was completed and launched in Qingdao, Shandong. This new type of optical cable line breaks through the transmission capacity limits of traditional optical fibers, marking a new stage of commercialization for China's space-division multiplexing fiber and multi-band integration technologies.
Traditional optical fibers are constrained by the number of cores and available bandwidth, creating significant bottlenecks in capacity. China Mobile innovatively adopted a four-core fiber structure, integrating four independent signal channels within a fiber as thin as a human hair. By extending ultra-low-loss and large-effective-area characteristics from the C and L bands to the S band, the system achieves "tri-band parallel transmission." This is akin to widening an information highway from two lanes to three; single-core bandwidth increases by nearly 50%, and the capacity of a single fiber reaches more than five times that of traditional fibers, fully meeting future demands for AI-driven intelligent computing and terabit-level ultra-high-speed transmission.
The greatest challenge in implementing multi-core optical cables lies in the precise alignment and splicing of multiple cores. Facing challenges such as environmental vibration, complex terrain, and extremely high precision requirements for splicing, China Mobile collaborated with partners to develop multi-core splicing algorithms. These achieved high-precision alignment and splicing within minutes, enabling successful, high-quality deployment under live network conditions.
Measured data shows that the cable's performance comprehensively surpasses current commercial network standards. Using this line, China Mobile has completed real-time transmission tests across the full S+C+L spectrum, achieving stable transmission with zero errors and low jitter—marking a critical leap for the technology from laboratory settings to live network trials.
China Mobile stated that the launch of this world-first tri-band multi-core optical cable line marks a significant milestone in China's optical communication technology, shifting from "following" to "leading." It also provides a mature and viable new solution for interconnecting intelligent computing centers, high-capacity submarine cables, and the national integrated computing power network. Moving forward, China Mobile will accelerate the large-scale deployment of next-generation optical fiber technologies to build an intelligent optical transmission network characterized by higher speeds, lower latency, and greater capacity.
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