Next-Generation PON Technology Drives Gigabit Optical Network Evolution

At the OptiNet China Conference 2022 China held in Beijing, Zhang Dechao, Deputy Director of the Basic Network Technology Research Institute of China Mobile, delivered a keynote speech titled “Next-Generation PON Technology Drives Gigabit Optical Network Evolution”. Zhang Dechao said that under the strategic background of accelerating new infrastructure construction in the 14th Five-Year Plan and transforming China Mobile’s computing power network, the gigabit optical access network, as the first hop of “connection + computing power + capability”, needs to be comprehensively improved. 50G PON and FTTR are two key technologies that support integrated service bearer and home Wi-Fi, respectively. China Mobile will actively promote the maturity of the 50G PON industry and carry out pilot projects. In the FTTR field, China Mobile will accelerate the convergence and standardization of architectures and key technical solutions.

Gigabit Services and Various Application Scenarios Calls for Premium Access Networks

According to Mr. Zhang, optical access plays an important role in China Mobile’s computing power network transformation strategy. It provides committed computing power access and allows users to quickly obtain cloud computing power. As the broadband penetration rate and bandwidth increase, gigabit optical access networks extend from the consumer field to the vertical industry field to meet digital transformation requirements of various industries. Mr. Zhang said that the gigabit optical access network, as the first-hop of “connection + computing power + capability”, needs to be comprehensively improved on bandwidth and deterministic latency, and needs to integrate network awareness and slicing capabilities to support service-oriented differentiated bearing. The evolution from FTTH to FTTR enhances all-optical gigabit coverage, and enables operators’ network computing capabilities to directly reach users. In the future, 50G PON will multiply bandwidth, and innovative cross-layer synergy mechanisms will realize deterministic low-latency on optical access networks. In addition, all-optical intelligent awareness will be introduced to support intelligent evolution, service awareness, and network quality visualization, analysis, and optimization.

50G PON Is the Foundation of the Next-generation Optical Access Network

China Mobile uses 10G GPON, gigabit gateways, and Wi-Fi 6 to implement end-to-end gigabit fixed network capabilities. The next step is to evolve to 50G PON. Mr. Zhang introduced 50G PON and its standardization progress. As a key technology of the next-generation optical access system, 50G PON not only improves the bandwidth, but also meets new requirements on latency and time synchronization in multi-scenario integrated bearing. Currently, the asymmetric 50G PON international standard has been released, international standards for symmetric 50G PON are being formulated, and PON slicing and low-latency supplements that meet multi-scenario integrated bearing requirements are also under discussion. Mr. Zhang shared the key technologies and industry chain progress at the 50G PON physical layer. Currently, the performance of high-speed optoelectronic components at the transmit and receive ends needs to be further improved to meet the 32 dB power budget requirement of live optical distribution networks (ODNs). The industry chain of 50G PON optical modules is making fast progress. Samples of most 50G PON optoelectronic components are expected to be released this year. He called on the industry to continue to develop core technologies and incubate optoelectronic components to further improve the transmission performance and commercial use capability of 50G PON. Mr. Zhang said that China Mobile will work with system vendors to continuously improve 50G PON prototypes and promote the maturity of the 50G PON industry. China Mobile plans to continue to pilot the latest 50G PON prototypes on live networks in multiple regions this year to carry various services for in the campus, enterprise, video conference, and safe city scenarios.

FTTR further extends the computing capacity of gigabit optical networks to users.

To improve users’ gigabit experience and extend gigabit rates to rooms, FTTR development has become a trend and consensus in the industry. Currently, national and local policies have been issued to promote FTTR construction. FTTR series standards have been initiated in ITU and CCSA. Mr. Zhang believes that FTTR has three key aspects. First, among the P2MP FTTR and P2P FTTR technologies, we should choose the P2MP FTTR with higher scalability. Second, we should establish a new centralized management and control mechanism for FTTx and give full play to the scheduling advantages of the entire network. Third, we should build a Wi-Fi collaborative networking mechanism for FTTR, and move from single-point Wi-Fi to Wi-Fi networking to deliver optimal experience and performance. China Mobile Research Institute proposed the “321” FTTR architecture design concept for the first time in the industry to build enhanced management, control, and maintenance capabilities, ensure premium experience in high-value services, and support evolution to home network autonomy. For the enhanced management and control solution, China Mobile Research Institute proposed a new FTTR management and control architecture for the first time. This architecture builds a centralized master/slave FTTR network architecture to achieve optimal global real-time scheduling experience. The optical-layer OAM mechanism is introduced to implement FTTR management and control and fast fault recovery. Optical+Wi-Fi collaborative management implements E2E optimization and slicing capabilities, making full use of the advantages of optical access and home networks. When talking about key FTTR technology requirements for computing networks, Mr. Zhang said that service requirements and technology trends require home Wi-Fi to evolve to a single FTTR network architecture. To realize premium experience, home Wi-Fi needs to work with PON to form a single network to support seamless gigabit coverage. The core capability difference between FTTR and traditional networking modes lies in enhanced user experience. FTTR significantly improves user experience in ultra-broadband access, multi-connection, low latency, seamless handover between multiple hotspots, and imperceptible O&M.

At the end of his speech, Mr. Zhang called for strengthening industry collaboration; using 50G PON and FTTR as key technologies to comprehensively improve the bandwidth, latency, reliability, and network coverage of optical access networks; and integrating network awareness, network slicing, low latency, and all-optical access capabilities. The whole industry chain needs to jointly promote E2E experience assurance for computing network services, trial commercial use of 50G PON, rich application scenarios, and standardization of FTTR architecture and key technologies.