Key undersea cable makes HK touchdown

A new high-capacity international submarine cable system — the Asia Link Cable, or ALC — successfully landed in Hong Kong on Thursday, marking a major milestone for the project's anticipated full commercial operation later this year.

Jointly built by a consortium of 12 domestic and international telecom operators including China Unicom and China Telecom, the ALC is the first international submarine cable to land in China during the country's 15th Five-Year Plan (2026-30) period.

Spanning approximately 6,100 kilometers, the cable covers key digital hubs including China's Hong Kong Special Administrative Region, China's Hainan province, Singapore, Vietnam, the Philippines, Malaysia and Brunei, serving as a critical digital artery linking China with Southeast Asia.

In the modern information age, undersea cables have become a strong foundation for digital connectivity, Tomas Lamanauskas, deputy secretary-general of the International Telecommunication Union, said in an interview with UN News.

Trillions of dollars in transactions in the global economy and the continuous accessibility of information pass through the cables. About 99 percent of international internet traffic goes through submarine cables, he said.

"People know the visible access points, such as mobile networks, satellites and fixed internet, but the underlying infrastructure that supports them is the vast network of submarine cables — our digital highways," he added.

China Unicom said the ALC features the world's first adoption of intelligent optical network submarine cable scheduling. Together with the SEA-H2X cable — which landed in Hong Kong in November 2025 and in which China Unicom also took part — the two cables establish a "dual-landing at three locations via diverse routes" architecture across Hong Kong, Hainan and Singapore.

This innovative design enables millisecond-level automatic link switching and achieves 99.999 percent ultra-high reliability, China Unicom said.

In terms of performance, the ALC's single-fiber capacity reaches 27 terabits per second, with the Hong Kong-Hainan-Singapore backbone latency optimized to 32 milliseconds, the company added.

China Unicom underlined that by industry-equivalent flow calculation, the cable can transmit more than 80 billion tokens per second — enough to efficiently support cross-border real-time scheduling, cross-border inference and global computing coordination for large-scale AI applications.

The move came as China's appetite for artificial intelligence data is exploding at a scale that is beginning to reshape the economy, with daily token usage soaring from just over 1 trillion at the start of 2025 to 100 trillion by year-end, showing "exponential growth", Chinese officials said.

The figure rose further to 140 trillion by March this year, according to Liu Liehong, head of the National Data Administration, underscoring the accelerating value of data as a production factor and the rapid emergence of new forms of the "intelligent economy".

Gan Quan, deputy general manager of China Unicom's Hainan provincial branch, said that in May 2025, the main structure of China Unicom's Hainan Lingshui International Submarine Cable Landing Station — located in Lingshui Li autonomous county — was completed after 80 days of construction. The station served as a critical hub for both the SEA-H2X and ALC cable systems.

"The integration of these submarine cables is set to significantly reduce network latency between Hainan and Southeast Asia by approximately 9 milliseconds," Gan said.

"This millisecond-level ultralow latency will provide a robust boost to industries such as international trade, finance, technological innovation, e-commerce and cross-border data flow, enhancing Hainan's competitiveness in the global digital economy."

The successful landing of the ALC enables China Unicom to form a multi-layer network architecture in the Asia-Pacific region, comprising three traditional submarine cables — alongside three new-generation cables. This further reinforces China's network advantages in the global internet landscape.

Contact the writers at masi@chinadaily.com.cn