At the recently held “2022 China Optical Communications High-Quality Development Forum”, Tang Xiongyan, vice president and chief scientist of China Unicom Research Institute, said that only by realizing the synergy between optical network and 5G can the industrial Internet be better empowered! We should seize the development opportunity of the industrial Internet, give full play to the advantages of optical communication, carry out industrial optical network technology innovation such as industrial PON, promote the application of fiber-to-machine and optical network technology in the industrial Internet, and realize the integration of industrial optical network, industrial Ethernet, 5G and other technologies Networking, laying a solid foundation for industrial computing networks.
Industrial Internet needs 5G and optical network synergy
“Industrial Internet” is an important starting point of the strategy of building a strong country and a strong manufacturing country. It has been highly valued by the Chinese government and has been included in the government work report for five consecutive years since 2017. The Industrial Internet has also created new development space for optical communications. In Tang Xiongyan’s view, the industrial-grade optical network is an important opportunity for optical communication to integrate into the development trend of the industrial Internet.
At present, the industrial Internet network faces many challenges:
One is the network separation of different areas and links such as industrial parks, offices, and production, and the isolation of systems and information;
Second, the traditional networking method is not flexible enough, and network adjustment, upgrade, and expansion are limited;
The third is that network operation and maintenance and management and control lack intelligence, and the management and control system of network, computing and application is not unified;
Fourth, the industrial environment is complex, the industrial application scenarios are diverse, and some scenarios have large electromagnetic interference, making it difficult to adapt to wireless access methods.
“Traditional industrial Internet networks need to be changed urgently, and to build high-quality network facilities for industrial Internet application scenarios needs to have five characteristics.” Tang Xiongyan said:
One is the ultra-large connection to realize the access of massive industrial equipment;
The second is ultra-low latency, ensuring end-to-end low-latency communication and meeting industrial control requirements;
The third is the enhancement of computing power, which realizes the integration of edge computing and computing network by enhancing the computing power of the gateway;
Fourth, edge-cloud collaboration empowers industrial big data and industrial intelligence;
Fifth, it is safe and reliable, building highly secure and highly reliable industrial networks and systems.
Industrial optical network is the combination of industrial network and optical network. It adopts optical network technology to interconnect all production factors of industrial enterprises, realizes unified access of production control, factory area monitoring, and office business, and realizes all-round high-quality interconnection of people, machines, and things. Tang Xiongyan emphasized that the industrial Internet requires both 5G and optical networks, and the two complement each other, each with its own advantages and applicable scenarios.
In the industrial optical network, industrial PON, industrial OTN and industrial optical bus are relatively key technologies. In particular, industrial PON can be widely used in industrial parks, factories and sites, and has many advantages:
Large connection and large bandwidth, which can well meet the large-scale connection requirements of human-machine objects in the industrial Internet and the large-bandwidth business requirements such as 3D machine vision;
Low latency and low jitter, the downlink broadcast mechanism of industrial PON can ensure stable low-latency transmission, the downlink latency can be lower than 100 microseconds, the upstream latency can be lower than 200 microseconds, and the time can be further improved through technological innovation Latency down to 10 microseconds;
High reliability and high security, optical access naturally has the characteristics of anti-electromagnetic interference and high stability, which can meet the security and reliability requirements of the industrial Internet;
Flexibility and scalability. The access bandwidth and number of users of the PON system can be flexibly expanded. In addition to the transmission capacity, computing power can also be enhanced to achieve computing-network collaboration and better carry industrial applications.
Because of the unique advantages of industrial PON, China Unicom expects to build a super-connected, ultra-low-latency, safe and reliable industrial PON network. Through the basic technology of industrial PON with large connections and low latency, industrial computing that integrates connection and computing Network system and enhanced safety and reliability guarantee mechanism to build a solid foundation for the development of the Industrial Internet.
The “Seven Keys” of Industrial PON Technology Innovation
As the person in charge of the 2021 National Key R&D Project, Tang Xiongyan is undertaking the project research of “Ultra-low latency, ultra-large connection, safe and reliable industrial passive optical network architecture and system research and application demonstration”.
According to reports, the project focuses on the application of PON in industrial Internet scenarios, researches and proposes a new generation of optical access network architecture with ultra-large connections, ultra-low latency, and safety and reliability, and develops low-cost optical access system devices, modules, and equipment. Create an industrial optical network operation and maintenance management and control system with edge-cloud collaboration, carry out application demonstrations, and promote the expansion of PON from carrier-grade to industrial-grade. The subject will carry out technological innovation in the following areas.
One is to build a super-connected optical access network through TDM+WDM+SDM multi-dimensional multiplexing.
The mainstream 10G TDM-PON technology of industrial PON has high technology maturity and a complete industrial chain. One OLT device can realize the connection of more than 10,000 terminals, which meets the super-large connection demand of the industrial Internet. At the same time, based on the needs of the industrial Internet, it will also be upgraded to 50G PON to meet the needs of higher bandwidth services. WDM is an important direction for further upgrading of PON. It has development potential, and the industrial chain is gradually maturing. WDM-PON has greater connection and bandwidth capabilities. In the future, through the combination of multi-carrier and multi-core optical fiber, wavelength division, space division and multi-dimensional Multiplexing, a single PON port can realize the connection of thousands of ONUs.
The second is to realize the ultra-low latency industrial PON system.
Through the FBA fixed bandwidth mechanism, the uplink burst is shortened, and mechanisms such as out-of-band windowing reduce the PON system delay, achieving a downlink delay of 75 microseconds and an uplink time delay of 200 microseconds. At the same time, the project is still researching the ultra-low-latency industrial PON system. By using wavelength division and coherent technology, the PON delay can be controlled to within 10 microseconds.
The third is to build a highly reliable and secure PON network.
PON has complete protection switching, such as PON optical link protection can adopt TYPE D mode (OLT double PON ports, ONU double PON ports, trunk fiber, optical splitter and distribution fiber are all dual redundant), to ensure the system High reliability; the signal sent by the OLT in the PON system can be received by all ONUs, and a complete ONU access security mechanism and encryption algorithm are required to ensure high security of the system and data.
The fourth is to develop a new industrial gateway for computing and network integration.
In view of the characteristics of various industrial communication data interfaces, complex protocols, and mutual incompatibility, a multi-protocol conversion system based on ONU edge computing capabilities is designed to realize transparent data transmission across the transport layer. For deterministic low-latency and low-jitter bearer requirements, edge computing capabilities are downgraded to on-site ONUs. The key technologies of the industrial PON fusion gateway include: single-frame multi-burst low-latency technology, airtight, anti-corrosion and electromagnetic isolation technology, computing power based on virtualization/containerization to enhance the ONU hardware architecture, multi- Protocol conversion.
The fifth is to realize flexible slicing of industrial PON.
The industrial PON network is capable of network slicing. One physical OLT device can be virtualized into multiple logical OLT device slices. The network resource allocation and system management rights between each slice are independent of each other. On the premise of realizing the sharing of physical resources, the independent management and control of services is realized.
The sixth is to build an industrial computing power network with cloud-edge-end collaboration.
The industrial computing network with cloud-edge-device collaboration can undertake various industrial applications, meet the diverse needs of industrial scenarios, and become the basic technology base of the Industrial Internet.
The seventh is to enhance the intelligent management and control capabilities of industrial networks.
Introduce artificial intelligence technology to enhance the intelligent management and control of industrial networks, realize rapid positioning and prediction of network faults, and incorporate third-party industrial Internet application platforms into the management and control system to achieve rapid integration of industrial Internet applications.
Industrial PON Application Scenarios
Tang Xiongyan pointed out that industrial PON can be applied to many scenarios of industrial Internet.
From the perspective of construction scenarios, it is suitable for new factory networks and factory network upgrades; from the perspective of construction coverage, the construction scope of industrial optical networks can cover industrial production networks in enterprises/parks, enterprise information networks, and outside enterprises/parks The backbone transmission network to build an end-to-end all-optical network interconnection system.
Industrial PON can be used in various industrial fields. For example, in mining scenarios, by deploying OLT active/standby protection, highly reliable industrial ONU connections can be realized; industrial PON networks can realize multi-service mixed bearer; pre-connected ODNs can realize rapid construction and reduce operational difficulty and risk.
In the manufacturing workshop scenario, industrial PON can effectively solve the problem of a large number of access terminals in the discrete manufacturing industry; solve the problem of real-time data collection at the field level; solve the problem of data transmission and interaction in different scenarios; solve the problem of complex environment Electromagnetic Interference Problems.
Industrial PON has begun to be applied on a large scale. In the case of an enterprise group in Hebei, the group realized the unified bearing of high-definition video surveillance, industrial information collection, intelligent manufacturing, cloud services, and massive data exchange by deploying a high-speed, integrated, and secure industrial PON network; In order to meet the needs of multiple scenarios, including automatic dust management, video surveillance + intelligent AI, remote tower cranes, employee personal intelligent supervision, construction site intelligent security system, and enterprise cloud platform, the smart construction site solution of PON+5G has greatly improved The scenario-based and customized capabilities of construction site operation and management have been improved; in an environmental protection intelligent monitoring station project in Zhejiang, problems such as difficult operation and maintenance of remote sites, low security, complex natural environment, multiple sites, and data collection and transmission needed to be solved. Through the application of industrial PON technology, the use of high anti-interference characteristics of optical fibers and the high reliability mechanism of industrial-grade PON satisfies the requirements for environmental adaptability.
From the perspective of industrial PON technology development, industrial PON1.0 mainly provides basic networking functions. PON equipment integrates various industrial interfaces such as Ethernet, RS232/485, and CAN, and realizes “fiber-to-machine” interface interconnection; industrial PON2. 0 realizes protocol conversion and data collection, integrates various mainstream industrial protocols, has industrial data collection/upload capabilities, and realizes “fiber-to-machine” protocol intercommunication. Tang Xiongyan pointed out that the next step towards industrial PON3.0 will be to pay more attention to the interoperability of systems and applications, realize the connection between PON equipment and industrial cloud platforms, support MEC, TSN, network AI, industrial security and other new-generation industrial Internet functions, and adapt to Equipped with industrial APP to realize “fiber to machine” application interoperability.