How far is 400G from true commercial deployment?

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

There is no doubt that 400G+ will become the mainstream application of super 100G networks. From the perspective of backbone networks, single-wavelength 400G is about to be launched and will enter a long period. Wei Leping, executive deputy director of the Communications Technology Committee of the Ministry of Industry and Information Technology and director of the Technology Committee of China Telecom, also pointed out last year that the 400G era has begun.

According to the analysis of market research organization Omdia, data centers (DCs) took the lead in transitioning to 400G and began to apply it in 2019. It is expected that by 2023, sales of 400G will dominate the data center market.

But how far is 400G from real commercial use?

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

China Telecom: It is expected that the 400G industry will have the ability to deploy on a large scale by 2024

Recently, Lv Kai, an engineer at the Research Institute of China Telecom Co., Ltd., said at the "2022 China Optical Communications High-Quality Development Forum - 400G Technology Special Session": "It is expected that 400G prototypes or commercial equipment will appear in 2023, and the backbone long-distance 400G industry will have the ability to deploy on a large scale in 2024. By then, operators will promote network construction based on 400G business drivers."

China Telecom also conducted 400G live network testing very early. In April 2017, it completed 400G live network testing 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, the 1,970-kilometer China Telecom Shanghai-Guangzhou G.654.E project was officially completed. The newly built optical cable was used to complete the country's first 400Gb/s ultra-long-distance WDM transmission commercial equipment live network test on the G.654E optical cable, achieving more than 1,900 kilometers of electrical relay-free transmission.

China Unicom: Launching 400G new technology test network in 2022

Tang Xiongyan, deputy director and chief scientist of China Unicom Research Institute, said that in recent years, all operators have been conducting verification tests of single-wavelength 400G WDM technology, promoting the gradual maturity of long-distance 400G technology in backbone networks. The client-side 100G interface 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 sharp increase in metropolitan area traffic, metropolitan area optical networks will take the lead in introducing 400G and beyond 400G WDM technology.

China Unicom has discussed the timing of 400G commercialization many times before. Finally, recently, Wang Guangquan, director of the Network Technology Research Center of China Unicom Research Institute and professor-level senior engineer, revealed: "China Unicom will launch a 400G new technology test network in 2022."

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

In April 2018, Shandong Unicom built the first 400G wavelength division ring in China in Jinan. Currently, Shandong Unicom has planned to deploy more than ten dual-carrier 400G wavelengths in Jinan. The dual-carrier 400G solution used in the existing network can coexist with 100G channels. In the later stage, only the 400G channel capacity needs to be expanded to upgrade the existing 100G network to a 400G system, which can effectively alleviate the pressure on slot and channel resources and ultimately achieve full network coverage.

In addition, in recent years, China Unicom has also actively carried out G.654.E optical fiber standardization, industrialization and trial demonstration in the joint industry chain. G.654.E optical fiber can significantly increase the non-powered relay distance of ultra-high-speed transmission systems, lay the foundation for building ultra-high-speed, ultra-long-distance, large-capacity backbone optical networks, and better serve the implementation of the "East Data West Computing" strategy.

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

Today, China Mobile has built the world's largest 100G OTN network and continues to research and verify super-100G technologies. 200G has been deployed in some areas. In 2021, the 16QAM-PCS 400G laboratory and live network pilot will be completed, and the 400G (16QAM-PCS) transmission capacity will be increased from 600 kilometers to 1,000 kilometers, promoting the generational evolution of trunk line rates from 100G to 400G.

In addition, last year China Mobile carried out research on 800G OTN system solutions and key technologies, and completed laboratory technical verification tests to achieve 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 is constantly moving towards larger capacity, higher speed, longer relay and transmission distance. Traditional G.652 optical 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 optical fiber that meets the two characteristics of ultra-low loss and large effective area is the best choice for 400G/1T systems. Recently, China Mobile announced the results of the centralized procurement of G.654E optical fiber and cable. This is also the first time that China Mobile has started the centralized procurement of G.654E optical fiber and cable.