400G backbone network is imperative: it is too difficult for commercial use

With the advent of the 5G and cloud era, ultra-broadband has gradually become the cornerstone of the Internet of Everything in the intelligent era. 400G, as the new generation of mainstream high-speed Ethernet interfaces for ultra-broadband, has gradually become the basic capability of IP network infrastructure and has begun its vigorous development. .

With the advent of the 5G and cloud era, ultra-broadband has gradually become the cornerstone of the Internet of Everything in the intelligent era. 400G, as the new generation of mainstream high-speed Ethernet interfaces for ultra-broadband, has gradually become the basic capability of IP network infrastructure and has begun its vigorous development.

Recently, at the "400G Scale Commercial Path Analysis" roundtable forum held concurrently with the China Optical Expo in 2021, Dr. Li Junjie, chief expert of China Telecom's optical transmission specialty, Dr. Wang Dong, project manager and senior engineer of the Institute of Basic Network Technology, China Mobile Research Institute, and Bai Zhongqiang, vice president of Huawei's optical transmission field, discussed the issue of large-scale commercial use of 400G.

400G continues to burst out of value, with great promise in the future

With the strong drive of future broadband transmission demand such as cloud computing, the Internet of Things, and the new Internet, 400G has gradually moved from behind-the-scenes technical research to a commercial front-end, especially in the past two years, where it has developed more rapidly in China. However, at present, 100G is still in its prime, 800G is also about to move, and the volume of 400G in the middle is getting smaller.

 

Li Junjie believes that 400G is not a short-lived technology, it will be the most important technology hub in the next decade. 400G technology is now mature and can achieve full coverage. Although 800G technology is very hot recently, based on the current technology level, it is difficult to achieve full coverage of 800G. It may be the technology of metropolitan area network or access network.

 

Wang Dong said that from 2013 to the present, 100G has experienced a life cycle of nearly ten years and has achieved great success in commercial deployment. Although 800G is now a hot spot in the industry, from the perspective of the industrial structure, whether it is optical devices or optical transmission capabilities, there is still a long way to go from commercialization and long-distance applications. 400G is the basic consensus of operators, and it will become a very important technology for the next generation.

As a representative of an equipment manufacturer, Bai Zhongqiang believes that, on the whole, 400G key technologies are making breakthroughs and are expected to reach the level of trial commercial use in about 1-2 years. There are still many key technologies of 800G that have not broken through, including the core devices of the laboratory that are still under study. It is expected that 800G will have a long way to go before it can be commercialized.

In 2010, the IEEE formally approved the IEEE 802.3ba standard, and the operator's IP backbone network entered the era of the 100G platform. 100G routers are widely deployed in the backbone network and metropolitan area networks of operators. This year, the Ministry of Industry and Information Technology proposed to promote the deployment of backbone network 200G/400G transmission on demand. Entering the backbone network from the metropolitan area network is also the ultimate destiny of 400G, but for now, the road ahead for 400G is a bit bumpy.

 

In this regard, Li Junjie replied: If a technology wants to be mature and commercialized, it faces the problem of cost performance, and the cost performance is sufficient to be able to operate. Therefore, from the perspective of performance and price, at this stage, the implementation of 400G on the backbone network is still more difficult.

 

He added that, looking at it now, the single-wavelength 400G transmission technology has certain shortcomings in the backbone network in terms of performance. The other is cost. Cost is an unavoidable problem. 400G has not yet been launched on a large scale. The main problem is high cost. If the cost of 400G is higher than four 100Gs, the deployment power of operators is insufficient in this case.

Wang Dong said that the current channel spacing based on 75GHz can basically meet the needs of the metropolitan area network, and there is still a big gap in the demand for the backbone network for thousands of kilometers or more than 1,500 kilometers. Only by further increasing the transmission distance can operators better promote 400G from the metropolitan area to the backbone network, and meet the business needs more quickly.

 

Upstream and downstream linkage accelerates the maturity of the 400G industry chain

In Li Junjie's view, the 400G industry chain has basically matured, and it has been almost ten years since the establishment of the 400G standard. 400G applications in data centers have been three to four years, and the industry chain is currently relatively mature. Among them, the biggest shortcoming is the control of high-end technology.

 

According to him, many high-precision components are currently in the hands of foreign companies, such as adjustable lasers, analog and digital circuits, and so on. Hope to have Chinese manufacturers in this field, so as to create a mature and healthy industrial chain.

 

Li Junjie emphasized that, first of all, it is very important for the industrial chain to join hands. Secondly, the issue of diversification of technical routes and the issue of non-focusing of technology should be paid more attention to. More importantly, in terms of standardization, the entire industrial chain needs to be interoperable as soon as possible. "As an operator, China Telecom hopes that the standard technology can be interconnected. China Telecom will work with suppliers to accelerate the standard focus of 400G technology and accelerate its maturity as soon as possible, and transform 400G technology into productivity as soon as possible.".

 

Regarding the current 400G industrial chain, Wang Dong believes that for metropolitan area networks, 400G has built a very complete industrial chain and has the conditions for deployment. Facing the backbone network, the equipment and equipment technical solutions of various mainstream equipment manufacturers have been initially capable of transmission for one thousand kilometers.

Wang Dong pointed out that operators especially hope that the industry chain can reach a unified solution, and work together to make the technology more mature, and the performance and price of the products are more convenient for operators to use and deploy. He hopes to use the domestic CCSA platform and the industry to work together to promote the development of 400G technology. "Whether it is an optical component manufacturer, an optical module manufacturer or an amplifier manufacturer, etc., it is necessary to have clear index definitions and a path for research and development. This will reduce the cost of R&D investment, and ultimately be able to focus more on technical routes and quickly meet the needs of operators. Demand."

 

Bai Zhongqiang said that in the field of metropolitan area networks, foreign industrial chains are gradually becoming mature. In contrast, domestic companies are still under the control of others. He hopes that the domestic industrial chain can follow up as soon as possible; in the field of backbone networks, there is still an urgent need for breakthroughs in China. Key technologies, including electrical layer, optical layer and system.

At the end of the round table, the three experts all talked about the outlook for 400G technology. Li Junjie said that for 400G, he not only hopes to be more localized in high-precision components, but also hopes that the industry can seize the time to reserve next-generation technologies. Wang Dong called on industry, academia and research institutes to work together to advance the exploration of basic research on 400G applications, promote my country's research in optical devices, optical modules, or some relatively more cutting-edge technologies, and achieve overall results in the entire industry. Bai Zhongqiang hopes that my country's upstream and downstream industrial chain will increase investment and strive to become a global leader in the future.