In August 2022, China Telecom Research Institute successfully completed the technical test of the 50G PON prototype supporting the ITU-T standard optical power budget, and the system performance fully met expectations.The 50G PON prototype adopts ITU-TG.The uplink and downlink wavelengths specified by the 9804.3 standard (officially released in 2021) support uplink and downlink 50Gbps/25Gbps line rates. After two-stage 1:8 optical splitter and 20km optical fiber transmission, the optical power budget exceeds 29dB, which conforms to the N1 optical fiber defined by the standard. The power budget index meets the requirements for smooth evolution and upgrade of the 10G-EPON system based on PR30 optical power budget level and the GPON/XG(S)-PON system based on Class B+/N1 to 50G PON in the current network of operators.China Telecom undertakes the key research and development plan of the Ministry of Science and Technology, takes the lead in the formulation of international standards for the next-generation optical access network 50G PON technology, and actively promotes the demonstration application of 50G PON prototypes in operators' existing networks.The project team actively benchmarked the technical requirements for the smooth evolution and upgrade of the existing network 10G PON (XG(S)-PON and 10G-EPON) to 50G PON in the future, and promoted key physical layers such as the MPM coexistence model (ie Combo mode) and the corresponding optical power budget. The parameters are included in ITU-TG.9804.3 standard to ensure that the 10G-EPON based on the IEEE standard system can be normalized and evolved to the ITU-T 50G PON.The 50G PON prototype technology test realized the registration and normal online of multiple ONUs in the ODN environment with two-level 1:8 optical splitter and 20 kilometers of optical fiber distance.Compared with the 50G PON prototype test in 2021, this test prototype has made key technological breakthroughs in key indicators such as system optical power budget and wavelength, and met the ITU-T standardization requirements, further promoting the development and maturity of the 50G PON industry chain.All Rights Reserved, Copyright 2004-2021 www.ctocio.com.cn