“F5G represented by the Gigabit Optical Network has entered the fast lane, combining cloud and AI to realize the optical connection of everything and stimulate new kinetic energy in the digital economy.” On March 29, the “Gigabit Optical Network Helps Digital At the “New Economic Growth” forum, Wei Leping, executive deputy director of the Electronic Science and Technology Committee of the Ministry of Industry and Information Technology, said.

The gigabit optical network is very popular recently. The government work report of the two sessions in 2021 proposed to “intensify the construction of 5G and gigabit optical network and enrich the application scenarios”. It is reported that the number of users with access rates of 1000M and above in my country has grown rapidly, reaching 8.03 million.

Since then, the industry has been hoping to analyze the impact of this policy on the optical industry, including the current development of gigabit optical networks in the home and industry. How does the gigabit optical network support the development of operators’ cloud-network integration?

Wei Leping is a Taishan Beidou-level figure in the field of communications, and has devoted himself to the research of optical network for many years. This time, Wei Leping introduced the status and development of gigabit optical network in detail, including toC and toB of gigabit optical network, all-optical network 2.0, 10G PON/50G PON, etc., which are worthy of our study and analysis.

01. How to read the first mention of “Gigabit Optical Network” in the government report

“Gigabit optical network” was written into the government work report for the first time, and the industry’s attention to “all-optical network” has been pushed to a new height. The goals and tasks of the “14th Five-Year Plan” point out that it is necessary to “accelerate digital development, create new advantages in the digital economy, coordinately promote digital industrialization and industrial digital transformation, and accelerate the pace of building a digital society”, and to “promote and upgrade gigabit fiber optic networks.”

Many people wonder why the country attaches so much importance to gigabit optical networks? Combined with Wei Leping’s point of view, the author summarizes as follows.

First, the gigabit optical network is the foundation for the development of the digital economy. The digital economy has become the main theme of economic growth, and the digital transformation of thousands of industries has become the main topic of the moment. World Bank research shows that every 10% increase in broadband penetration will lead to an average GDP growth of 1.38%.

In my country, according to “China’s Digital Economy Development and Employment White Paper 2019”, China’s 180 million fiber optic cable network supports the development of 31.3 trillion digital economy. This shows that the construction of gigabit optical network has a very obvious driving effect on the social economy.

Specifically, the vigorous development of the digital economy is inseparable from the super-strong capacity built by the “gigabit optical network” and the super-strong computing power based on the “cloud”. The chemical reaction generated by the integration of the two will directly affect the digital economy. Strength; the construction of smart city intelligence requires ultra-high-speed and highly reliable network coverage, providing a solid network foundation for innovation in thousands of industries and maximizing the value of urban resources.

Second, my country’s gigabit optical network has made outstanding achievements and will further move towards integrated development. As early as 2013, my country began to promote the plan of “Optical Entry into Copper Retreat” and vigorously promote the “Broadband China” strategy. Up to now, the penetration rate of optical fiber networks in the country has exceeded 98%, and the proportion of users with bandwidths above 100M has exceeded 90%. “Fiber to the home and 100M to the home” have been basically realized.

Regarding the “gigabit optical network” mentioned in the government work report, Wei Leping believes that we can understand the two aspects of gigabit access and all-optical network: “From a short-term perspective, the generalized gigabit optical network is a combination of access and transmission. To form an end-to-end optical network, the access side faces the scale expansion and extension of gigabit optical access, and the transmission side faces the comprehensive strategic upgrade and expansion to all-optical network 2.0. In the long run, access and transmission are gradually integrated as a An end-to-end transparent large optical network.”

In Wei Leping’s view, through the integration of the access network and the transmission network, end-to-end quality assurance is finally achieved, allowing gigabit experience to enter every home, every enterprise, and every machine, thereby providing new momentum for the country’s digital economy. .

Third, the gigabit optical network is driven by the needs of innovative services and conforms to the evolution trend of optical networks. As Wei Leping concluded, in terms of home broadband, with the increasing number of applications such as 4K/8K ultra-high-definition video, cloud gaming, distance education, telemedicine, and smart homes, home broadband has evolved from 10Mbps to 100Mbps, and gradually upgraded to 1Gbps .

In terms of government and enterprise broadband, with the acceleration of government and enterprise digital transformation and cloudification, the bandwidth of enterprises and institutions has evolved from 10/100Mbps to 1/10/100Gbps. The continuous growth of demand-side traffic has made the supply-side backbone network capacity continue to increase, which has evolved from Tbps-level capacity to Pbps-level capacity.

In order to enhance the value of services and applications, operators must be able to provide a large amount of end-to-end bandwidth, provide super transport capacity for the digital economy, build a solid foundation for smart cities, and maximize cloud computing power. “At present, metro access is still the bottleneck of the entire network bandwidth.” Wei Leping said.

02. Not only high-quality home broadband, but also gigabit optical network extends to industrial interconnection

At present, in the toC field of the gigabit optical network, my country is promoting the optical fiberization of incoming lines and even houses, desktops, and terminals. In the toB field, it has also begun to promote the optical fiberization of parks, factories, and workshops.

Regarding how to realize the rapid coverage and popularization of gigabit networks in my country, Wei Leping emphasized the key to upgrading multiple technologies and network innovations, including the upgrade of optical node equipment (OLT).

“OLT equipment, as a unified access platform, is the key network element to realize full-service intelligent bearing.” Wei Leping pointed out that the industry should adopt a distributed architecture, separate control and transfer, and ensure service forwarding; flexible OLT slicing/VxLAN functions should be provided to improve the Full-service carrying capacity and network quality of optical access; resource boards with distributed computing capabilities must be supported.

As we all know, in the access network part of the three major operators, 10G PON is the mainstream Gigabit broadband access technology, and it needs to be continuously upgraded and evolved to 50G PON in the future.

We see that some leading operators are optimizing 10G PON: on the one hand, in cities and key townships, they are deploying 10G PON optical line terminal (OLT) equipment on a large scale, and continue to optimize OLT uplink networking; on the other hand, in old communities , industrial parks and other weak fiber-to-the-home areas, carry out the transformation and upgrading of the optical distribution network (ODN), and promote the further extension of the all-optical access network to the user end.

Of course, in addition to the home market, another important trend of gigabit optical networks is the application of industrial Internet. Operators are also vigorously promoting the development of industrial PON.

Wei Leping said that in the traditional factory network, the communication protocol “seven countries and eight systems” has formed an information island, the application environment is complex, there is a lot of electromagnetic interference, and the products are mainly customized by foreign manufacturers. The industrial PON can adapt the traditional PON as a standardized product after adaptation, which has the characteristics of high industrial application compatibility, high localization degree and high reliability.

It can be seen that industrial PON can promote the development of gigabit all-optical networks in various industrial parks and realize the comprehensive interconnection of people, machines and things, which is worthy of vigorous development in the industry.

Talking about promoting the development of 50G PON in the future, Wei Leping proposed that the industry should ensure that the 10G PON network has the ability to continuously evolve and upgrade:

A set of systems to support unified upgrade from 10G PON to 50G PON;

The coexistence of the second generation ensures that 10G PON and 50G PON can coexist in the existing ODN network and achieve smooth upgrade;

Five times the bandwidth, five times the downlink bandwidth, and uplink multi-rate access (12.5/25/50Gbps).

03. The era of all-optical network 2.0 is fully opened

As early as 2019, the author heard Wei Leping talk about the development trend of the backbone network of operators, that is, the evolution from the all-optical network 1.0 (all-optical network) to the new era of all-optical network 2.0 (all-optical automatic scheduling). Now two years have passed, all-optical network 1.0 has covered 85% of households, and the era of all-optical network 2.0 has been fully opened.

“The provincial trunk line and large-scale metropolitan area network have also begun or will soon start large-scale application (all-optical 2.0), and the ordinary metropolitan area and access network still need to further reduce the cost before large-scale application is expected.” Wei Leping said.

It is reported that the all-optical network has the characteristics of ultra-large available spectrum (>10THz), ultra-large capacity (~100Tbit/s), ultra-high speed (1Tbps), ultra-large capacity node (Pbit/s), ultra-low latency (5us/km), etc. , which determines that the all-optical network is the ideal carrier network base for realizing cloud-network integration and smart cities.

In terms of the practical effect of all-optical network 2.0, according to the author’s knowledge, China Telecom’s all-optical backbone network is currently the largest in the world in coverage and scale, with 470 ROADM nodes and a total network capacity of 620T. The network architecture is flat, realizes the integration of primary and secondary trunk lines, and greatly improves service configuration efficiency; all-optical switching scheduling based on 20/32-dimensional OXC realizes direct end-to-end optical layer with the lowest delay; enables WSON optical layer recovery and Dynamic rerouting, recovery time in minutes.

According to Wei Leping, China Telecom has built my country’s first backbone ROADM network (the middle and lower reaches of the Yangtze River), which has roughly reduced costs by 30-50%, energy consumption and space by about 50% since its operation, greatly improved service configuration efficiency and low latency. The wavelength of light can be reached directly in one hop.

Talking about the overall development of all-optical network 2.0, Wei Leping believes that the current CTC backbone transport network has been fully upgraded from a point-to-point chain DWDM system to an all-optical network with dynamic mesh networking, so as to fully move towards the backbone transport network level. The all-optical network 2.0 era in which the optical layer can be automatically scheduled.

Of course, the development of all-optical networks cannot rely on waiting, and the industry needs to be more proactive in solving deployment problems. Wei Leping also admitted that although there are currently more than 8 million gigabit home access users, it is still far from the goal, and 50G PON also faces technical challenges in terms of power budget and dispersion cost compensation. These all require the joint efforts of the industry to continue to work hard to solve them.

Although there are many uncertainties in the future, the author can say with certainty that gigabit optical network is an important development direction for our communicators in the next few years. Broadband, all-optical network, cloud network integration and other goals, build high-quality communication infrastructure, on the other hand serve the society and people’s livelihood, enable the digital transformation of thousands of industries, and accelerate the sustainable development of the digital economy.