China Telecom collaborates with ZTE to complete world's first C+L band integrated 80×800G WDM trial on live network

• The trial achieved flexible adjustment of wavelengths within a 12 THz ultra-wide spectrum, and demonstrated live network rerouting with wavelength switching in approximately 30 seconds
• China Telecom and ZTE will continue to collaborate to accelerate the application of extended C+L band WDM technology

Barcelona, Spain, 5 March 2025 - ZTE Corporation (0763.HK / 000063.SZ), a global leading provider of integrated information and communication technology solutions, has successfully completed the world's first extended C+L band integrated 80×800 Gbps WDM trial in collaboration with China Telecom. This groundbreaking trial achieved flexible adjustment of wavelengths within a 12 THz ultra-wide spectrum, and the achievement was unveiled at MWC Barcelona 2025. 

This breakthrough provides important reference for future network deployment and optimization, and promotes the development of optical transport networks toward a more efficient and flexible direction.

In the digital era, network traffic is experiencing explosive growth. The single-wavelength transmission rate of optical networks has gradually increased to 400 Gbps and is now advancing towards 800 Gbps. The evolution towards extended C+L band transmission has become the mainstream technology direction in the industry. As early as 2023, China Telecom proposed that all-optical ROADM networks should be built using the extended C+L band, and has continuously promoted the implementation of key boards and components. In 2024, China Telecom successfully completed the laboratory verification of the 400 Gbps ultra-long-haul (ULH) extended C+L integrated optical module.

The trial was conducted on China Telecom's ongoing ROADM all-optical switching backbone network. Based on the extended C+L integrated optical layer platform, the trial comprehensively verified:

·The service transport capability of extended C+L integrated 800 Gbps OTU module，

·The optical-electrical scheduling capability within the 12 THz ultra-wide spectrum，

·The wavelength recovery capability of the Wavelength Switched Optical network (WSON). 

In the live network environment, the trial successfully completed two service rerouting operations, demonstrating flexible switching of any wavelength within the extended C+L ultra-wide spectrum, with each wavelength switch completed in approximately 30 seconds. This marks a key step towards the commercialization of the extended C+L integrated all-optical switching system.

Moving forward, China Telecom will continue to collaborate with ZTE and global industry partners to accelerate the application and development of extended C+L band integrated WDM technology, while also continuously exploring the development and application of high-speed, multi-band technologies. This collaboration aims to build more efficient, flexible, and reliable optical network infrastructure, and drive the comprehensive development of the global digital economy.

For more information, please visit the ZTE booth (3F30, Hall 3, Fira Gran Via) at MWC Barcelona 2025 or explore: https://www.zte.com.cn/global/about/exhibition/mwc25.html