With the continuous growth of data traffic, the data transmission and bandwidth pressure of the bearer network are also increasing, and the transmission rate of the backbone network will be continuously upgraded from 100G to 200G/400G and other higher rates. In addition, 400G is the basic rate of the next-generation OTN network after 100G. It is reported that at present, domestic and foreign standards organizations have developed a series of relevant standards. CCSA has completed the establishment of two core standards for long-distance 400G optical modules and systems, and mainstream international standards organizations have completed medium and short-term standards. The 400G standard has been formulated, and 800G research has been initiated.

There is no doubt that 400G+ will become the mainstream application of super 100G networks. From the perspective of the backbone network, single-wave 400G is about to open and enter a long cycle. Wei Leping, executive deputy director of the Communication Science and Technology Commission of the Ministry of Industry and Information Technology and director of the China Telecom Science and Technology Commission, also pointed out last year that the 400G era has begun.

According to the analysis of market research agency Omdia, data centers (DCs) are the first to start the transition to 400G and have begun to apply in 2019. 400G sales are expected to dominate the data center market by 2023.

Just how far is 400G from real commercial use?

Recently, Lv Kai, an engineer at the Research Institute of China Telecom Co., Ltd., said that it is expected that the backbone long-distance 400G industry will be capable of large-scale deployment in 2024. China Unicom also finally said that it will launch a 400G new technology trial network this year.

China Telecom: It is expected that the 400G industry will have large-scale deployment capabilities in 2024

A few days ago, Lv Kai, an engineer at the Research Institute of China Telecom Co., Ltd., said at the "2022 China Optical Communication High-Quality Development Forum - 400G Technology Special Session": "It is expected that 400G prototypes or commercial equipment will appear in 2023, and backbone long-distance equipment will appear in 2024. The 400G industry is capable of large-scale deployment. At that time, operators will promote network construction based on 400G service drivers.”

China Telecom also carried out 400G live network test very early. In April 2017, it completed the 400G live network test based on WSS all-optical scheduling on the second plane of Shanghai Telecom OTN, the largest and most complex local network in the country.

On September 17, 2021, China Telecom Shanghai-Guangzhou G.654.E project with a total length of 1970 kilometers was officially completed, and the new optical cable was used to complete the first 400Gb/s ultra-long on G.654E optical cable in China. The test of the existing network of commercial equipment for WDM transmission has achieved more than 1900 kilometers of non-electric relay transmission.

China Unicom: Launch 400G new technology trial network in 2022

Tang Xiongyan, vice president and chief scientist of China Unicom Research Institute, said that in recent years, operators have been carrying out verification tests of single-wavelength 400G WDM technology to promote the gradual maturity of long-distance 400G technology in backbone networks. The 100G interface on the client side will continue to be applied on a large scale, and 400G will become the main interface on the client side beyond 100G. In order to cope with the surge in metro traffic, the metro optical network will be the first to introduce 400G and beyond 400G WDM technology.

Regarding the time point of 400G commercial use, China Unicom has also talked about it many times before. Finally, Wang Guangquan, director of the Network Technology Research Center of China Unicom Research Institute and a professor-level senior engineer recently revealed: "China Unicom will launch a 400G new technology trial network in 2022."

As early as 2016, China Unicom deployed 400G existing network pilots in Shandong and Xinjiang: two 400G optical cables were built in Xinjiang and Shandong respectively. Xinjiang is 140 kilometers long from Hami to Balikun, and Shandong is from Jinan to Qingdao. 420 km.

In April 2018, Shandong Unicom built China Unicom's first 400G WDM ring in Jinan. Currently, Shandong Unicom has planned to deploy more than ten waves of dual-carrier 400G in Jinan. The dual-carrier 400G solution used in the existing network can coexist with 100G channels. The existing network 100G system can be upgraded to 400G system only by expanding the 400G channel, which can effectively relieve the pressure on slot and channel resources, and finally achieve full network coverage.

In addition, in recent years, China Unicom has been actively carrying out the standardization, industrialization and test demonstration of G.654.E optical fiber in conjunction with the industrial chain. G.654.E optical fiber can significantly increase the distance of no electric relay of ultra-high-speed transmission systems, lay the foundation for the construction of ultra-high-speed, ultra-long-distance, and large-capacity backbone optical networks, and better serve the implementation of the "East and West" strategy.

China Mobile: G.654E optical fiber and cable centralized procurement results released 800G research has been started

Today, China Mobile has built the world's largest 100G OTN network, and continues to conduct research and verification on super-100G technology, and has deployed 200G in some areas. In 2021, the 16QAM-PCS 400G laboratory and the existing network pilot will be completed, the 400G (16QAM-PCS) transmission capacity will be increased from 600 kilometers to 1,000 kilometers, and the intergenerational evolution of the trunk line rate from 100G to 400G will be promoted.

In addition, last year, China Mobile carried out research on 800G OTN system solutions and key technologies, and completed laboratory technology verification tests to realize single-carrier 800G 1000km transmission for the first time.

At present, G.652 optical fiber is the mainstream optical fiber used in long-distance communication trunk lines, accounting for more than 95%. With the rapid and continuous growth of global Internet traffic, as well as the interconnection of massive 5G devices and the emergence of video services as the mainstream, information transmission continues to move towards larger capacity, higher speed, longer relay and transmission distance. The traditional G.652 fiber has gradually been unable to meet the needs of communication trunk lines, and the ultra-low loss and large effective area G.654.E fiber that meets the two characteristics of ultra-low loss and large effective area at the same time is the best choice for 400G/1T systems. A few days ago, China Mobile announced the results of G.654E optical fiber and cable centralized procurement, which is also the first time China Mobile has started G.654E optical fiber and cable centralized procurement.