As we all know, mobile communication technology is divided between generations, from 1G, 2G, 3G to 4G, 5G.In fact, fixed-line broadband technology has also undergone intergenerational evolution. It has experienced the narrowband era (64Kbps) represented by PSTN/ISDN technology, the broadband era (10Mbps) represented by ADSL technology, and the ultra-broadband era represented by VDSL technology ( 30~200Mbps), the super 100M era represented by GPON/EPON technology (100~500Mbps), and the current gigabit ultra-broadband era represented by 10G PON technology.In March 2021, the Ministry of Industry and Information Technology announced the "Dual Gigabit Network Coordinated Development Action Plan (2021-2023)" (referred to as the "Action Plan"), in which the first phase of the goal is: by the end of 2021, 10G PON The number of ports and above exceeded 5 million, and the number of gigabit broadband users exceeded 10 million.Unexpectedly, one month after the "Action Plan" was released, in April 2021, the scale of my country's gigabit broadband users exceeded 10 million, reaching 10.94 million, which is called "superfast".At the end of July 2021, the goal of "more than 5 million ports of 10G PON and above" was also completed ahead of schedule.Especially with the development of new technologies such as WiFi 7 and millimeter-wave independent 5G, higher speeds will be brought to a wide range of people, and this requires the upgrade of optical fiber broadband technology to provide better support.Taking WiFi as an example, the current protocol standard is WiFi6, which was launched at the end of 2019, but the iteration process of WiFi is faster than people think. At present, some manufacturers have developed products that support the WiFi 7 standard, and the maximum speed can reach 40Gbps. The current 10G PON technology will become a bottleneck in the face of this.The same is true for millimeter-wave standalone 5G, which requires larger bandwidth for backhaul, which cannot be fully satisfied by current technology.Digital economy think tank IDATE DigiWorld believes that to achieve large-scale access of 5-10Gbps, not only EPON\GPON, but also 10G EPON\xG-PON is not enough, and higher-speed PON technology is needed.At present, there are many "candidates", including 25G PON, 50G PON, 100G PON, etc. Now, the two technical routes of 25G PON and 50G PON are mainly in the game, "100G PON is currently relatively advanced, and the industry chain The maturity is very low, for example, there are still many gaps in components." said Zhang Jun, a senior expert in the industry.Around the next generation of PON technology, the industry has been divided into two camps.The Chinese industry forces represented by the three telecom operators, Huawei, ZTE, etc. and many European telecom operators have made it clear that they have chosen 50G PON as the next-generation PON technology.The other camp is mainly represented by Nokia, as well as some operators in the United States, and chose the 25G PON route.In March last year, China Telecom successfully completed the industry's first 50G PON prototype technology test under the ODN simulation environment of the live network. Mega optical network, actively test and explore the introduction of 50G PON technology." In November last year, China Mobile clearly stated in its "14th Five-Year Network Evolution Technology White Paper": "In the future, China Mobile will actively introduce new technologies such as 50G PON and 400GOTN. technology."In addition, European telecom giants such as France's Orange, Swisscom, Telefonica, Turkey's Turkcell, etc., have made clear their positions and firmly follow the 50G PON technology route.The head of Orange's fixed access network said in March this year that 50G PON has become the industry's consensus choice for the next-generation PON.The relevant person in charge of Turkey Turkcell said that it plans to deploy 50G PON in 2024.Swisscom has carried out 50G PON technology laboratory and live network tests in 2020 and 2022, and said that it will launch this new technology to customers in 2025 at the latest.Under the joint proposal of China's PON industry, ITU-T (International Telecommunication Union Telecommunications Standards Branch) launched the 50G PON series of standards in 2018. In April 2021, the 50G PON international standard was officially approved.Under such circumstances, Nokia, which insisted on taking the 25G PON technology route, established its own technology club, the "25GS-PON MSA (Multi-Source Agreement) Organization", the American operator AT&T, the New Zealand fiber broadband service provider Chorus and Some industrial chain companies are involved.LightCounting, a well-known market research organization in the field of optical communication, has estimated the future shipments of 25G PON and 50G PON ONU (optical network unit equipment), and believes that the shipment of 50G PON ONU will significantly exceed that of 25G PON, and with the passage of time , the advantages of 50G PON are more obvious.The advantage of 25G PON is that the technology is relatively mature, and the deployment at this stage has a cost advantage.However, its shortcomings are also very obvious, and the intergenerational gap with the current 10G PON technology is not obvious, and it cannot meet the long-term needs of operators.In other words, soon after the deployment of 25G PON technology, operators are very likely to make new upgrades."Each generation of PON technology upgrades, the bandwidth increase is not less than 4-5 times. Compared with the current 10G PON, 25G PON does not show much advantage, so we do not track 25G PON, only focus on 50G PON", A provincial operator said.Zhang Jun also believes that from 10G PON to 25G PON, if it is a single wave, the intergenerational difference is too small."If you want to achieve 50G or 100G speed, you need to engage in multiple waves, such as 2*25G or 4*25G, but in this case, it is impossible for the network to evolve smoothly, and the splitters and other equipment have to be replaced, and the cost is too high. "And with the passage of time, driven by the industry chain, the price of 50G PON equipment will steadily decline. Market research firm IDATE DigiWorld predicts that the cost of 50G PON equipment will at least be reduced to the same price as 10G PON.In 2022, major manufacturers will basically launch 50G PON prototypes, "From a technical point of view, pilots can be carried out next year, and the construction of 10G OLT will be gradually launched in the year after, and if you want to become a leading operator, no later than 2025. 50G PON equipment should be introduced at the central office." Zhang Jun said.