Previous article (Link), Xiao Zaojun introduced the development history of broadband technology from ISDN, xDSL to 10G PON.
Today, let’s talk about the upcoming new generation of fiber optic broadband technology——50G PON.
Advertisement
█ F5G and F5G-A
Before introducing 50G PON, let’s talk about F5G and F5G-A.
In February 2020, ETSI (European Telecommunications Standards Institute) promoted a fixed communication network technology system based on 10G PON+FTTR, Wi-Fi 6, 200G optical transmission/aggregation, OXC and other technologies, and named it F5G is the fifth generation fixed network communication technology (The 5th generation Fixed networks).
F5G is the product of the fixed network industry’s “copying” from 5G. It simplifies the intergenerational naming method and packages some technologies to facilitate marketing and promotion.
Advertisement
Since last year, the entire communications industry has been discussing the half-generation evolution based on 5G – 5G-A. The fixed network industry also followed suit and created F5G-A as a small intergenerational evolution of F5G.
In November last year, ETSI officially released the “F5G Advanced Generation Definition”, clearly proposing the intergenerational standards and key features of F5G-A.
According to ETSI, F5G-A adds three new features (GAO, RRL, OSV) to the existing three features of F5G (eFBB, FFC, GRE). As shown below:
It is envisioned that F5G-A can bring a series of capability improvements such as 10 times bandwidth, 10 times fiber connection density, 10 times energy efficiency, 6 nines reliability, meter-level accurate sensing, sub-millisecond latency and L4 autonomous network. It can better meet users' broadband access needs and further realize “Fibre to Everywhere”.
█ Standard evolution of 50G PON
F5G-A is a very important evolution. 50G PON is the key enabling technology for this evolution.
In the previous article, we talked about the 10G PON era, which is our current gigabit broadband era.
10G is not the end of PON technology. As early as around 2012, the industry agreed that PON technology needed to evolve to higher rates.
There were two evolutionary ideas at that time. One wasImprove single wavelength ratethe other isUsing multi-wave superposition.
The IEEE (Institute of Electrical and Electronics Engineers) took the lead. They have developed an NG-EPON, which implements 25G downlink and 10/25G uplink on a single optical fiber, and is compatible with 10G EPON. 25Gbps, through multi-wavelength superposition and channel bonding technology, 50Gbps or even 100Gbps rates can be achieved.
In July 2015, IEEE launched the standard formulation of 25G/50G/100G EPON technology, named IEEE 802.3ca. Later, considering that 100G was too difficult, it was deleted and only 25G and 50G were retained.
Let’s look at FSAN (Full Service Access Network Alliance) and ITU-T (Telecommunications Standards Bureau of the International Telecommunication Union).
After the XG (S)-PON standard was formulated, FSAN quickly started the standard research of NG-PON2 (NG-PON1 is the previous 10G PON, including 10G GPON and 10G EPON), wanting to achieve 40G downlink and 40G/10G Upward.
At that time, the mainstream alternative technical solutions for NG-PON2 included: high-speed TDMA-PON, TWDM-PON, OFDM-PON and WDM-PON.
After analysis and comparison, in April 2012, FSAN decided to adopt TWDM-PON technology as the implementation solution for NG-PON2.
TWDM is TDM+WDM, time division multiplexing + wavelength division multiplexing. TWDM-PON adopts 4/8 wavelength superposition method and single-wavelength 10G TDM, which can achieve 4×10Gbps rate.
This solution was formulated by ITU-T as G.989.x The series of standards was finally completed in 2015.
After the standard was completed, few operators adopted this solution. Because this wavelength superposition method will bring high cost of tunable optical devices, and the system maturity of the solution is not enough.
Later, with the rapid maturity and large-scale application of the high-speed Ethernet industry chain, the overlay architecture of N*10G became increasingly unpopular. The industry has gradually strengthened its determination to develop in the direction of single-wavelength high-speed. In other words, no “TDM+WDM”, just “TDM”.
If it is a single wave, 100G is too difficult, and the improvement of 25G is not obvious (it will not take long to upgrade again, which is a waste of money and time). Then, the best choice is, of course, 50G.
In February 2018, under the joint suggestion of the Chinese industry, ITU-T SG15 Q2 officially launched the project for the single-channel 50G TDM PON series standards, named “G.HSP(G.Higher Speed PON)” It is planned to have commercial capabilities in 2025.
It is worth mentioning that Nokia is relatively persistent in 25G. After the ITU-T project was blocked, they ran to establish another one and established the 25G Symmetric PON Multi-Source Agreement (25GS-PON MSA) in October 2020. Many companies have joined, including large companies such as AT&T.
Let’s still talk about 50G PON.
When the 50G PON standard project was established, it mainly included four parts, as shown in the following table:
On April 23, 2021, the ITU-T SG15 plenary meeting adopted the standards for 50G PON, including: G.9804.1 Amd1 (requirements), G.9804.2 (general protocol layer), and G.9804.3 (physical layer standard).
In order to support the coexistence of multiple generations of PON technologies, ITU-T also tinkered with a G.9805 standard.
Taken together, as shown in the following table:
It corresponds to the table just now.G.hsp.TWDMpmd/ G.9804.4 is multi-wave and is not involved in China.
From 2021 to 2023, the 50G PON standards have successively completed research and revisions. In 2023, the ITU-T SG15 plenary meeting adopted G.9804.3 Amd.2, marking the completion of the 50G PON international standard system.
The multi-generation coexistence standard (G.9805) was also basically completed during this period, laying a standard foundation for the smooth evolution of different generations to 50G-PON. (50G PON supports the compatibility and coexistence of 10G EPON, which is conducive to the unification of IEEE routes and ITU-T routes, which is of great benefit to the industry chain. Although IEEE still hopes to stick to its own Ethernet route and not be “incorporated”, As the world's largest PON market, the will of China's industrial power is difficult to be violated, which is the general trend.)
In order to further enhance the capabilities of PON, two standards are in progress.One is for low latency G.Sup.PONLatencythe other one is for slicing G.Sup.PONSlicing.
In terms of domestic industry standards, CCSA TC6 is responsible for formulating them.
At present, the 50G PON overall, physical layer, TC layer and other series of industry standards have been released, and the test standards have been established and are expected to be formulated in 2024-2025; 50G-PON single-mode and 10G / 50G dual-mode industry standards have been submitted for approval, G / XG (S )/50G three-mode is expected to be formulated in 2024-2025.
All in all, the international standards and domestic industry standards for single-wavelength 50G PON (50G TDM PON) are basically in place, creating conditions for the upstream and downstream of the industry chain to comprehensively promote commercial use.
█ Application scenarios of 50G PON
50G PON brings 10G access speed, so you will definitely ask, what are its application scenarios?
At present, the industry’s definition of 50G PON application scenarios is still focused onhome broadband,Small, medium and micro enterprises,Park,industryWait for the scene.
For home broadband, it mainly meets the needs of 8K (and above) ultra-high-definition video, AR/VR/XR, and naked-eye 3D.
Generally speaking, the connection bandwidth of a single XR device is not high (around 380Mbps), and 10G PON is sufficient. The use of 50G PON is more aimed at multi-concurrency requirements, that is, multiple people using XR devices at the same time. For example, multiple family members can participate in XR game interactions.
For small, medium and micro enterprises, it is mainly used for cloud desktop office, video conferencing, enterprise cloud disk and other purposes. China is now promoting special actions to empower small, medium and micro enterprises in the digital field, and 50G PON can become the digital transformation base for small, medium and micro enterprises.
Park scenes, such as large enterprises, hospitals, schools, factories, ports, etc.
In the case of schools, there are dozens of students in a classroom, and multiple people using VR teaching at the same time will create demand for access bandwidth.
The hospital scene is more complex. In addition to traditional digital medical records, large-bandwidth networks also have some new applications.
For example, image viewing and digital reading. Hospital imaging equipment has a large amount of data, including multi-modal imaging, interventional imaging, etc. Through 10G optical networks such as 50G PON, it can help medical personnel view and transmit data.
Now operators are vigorously promoting FTTR. In the future, as access bandwidth increases, it may gradually enter the FTTD stage.
D stands for Device, which means that the optical fiber will be directly connected to user terminals (such as desktop computers, laptops, home appliances, etc.), completely eliminating network cables.
Then there is the industrial manufacturing scenario. This scenario is the current focus of 50G PON development, mainly targeting segmented scenarios such as data collection, industrial control, automation and human-computer interaction. These subdivided scenarios have strict requirements on network transmission delay and security and reliability.
In the industrial field, 50G PON may further promote optical fiber from daily office networks to production management networks and production site networks, and ultimately to internal machine connections.
It will bring about the transformation from FTTR to FTTM. M is Machine, that is, machine. It is somewhat similar to the FTTD mentioned just now. Now, FTTThing is also proposed, fiber to everything.
In addition to the above scenarios, using 50G PON for backhaul transport of 5G small base stations has also become an option (FTTCell, fiber to the base station).
If the light splitting ratio of 1:64 is allowed, the 8-port 50G PON line card can support 512 5G small base stations. If a single port is 40Gbps and each 5G small base station is 1Gbps, it means that a 50G PON single port can meet the backhaul needs of 40 5G small base stations. It is sufficient for general indoor coverage in buildings.
█ Commercial progress of 50G PON
In recent years, domestic operators have conducted some pilot work on 50G PON technology.
On March 27, 2023, China Telecom Research Institute completed the industry's first 50G-PON industrial application pilot in Jiangsu Yongding Optoelectronics, taking the lead in adopting 50G-PON / XG-PON dual-mode all-optical technology, verifying the application of 50G-PON in Industrial AOI (Automated Optical Inspection, automatic optical inspection) quality inspection and factory digital management business scenarios.
In November 2023, China Mobile successfully completed the world's first symmetrical 50G PON fixed-mobile access application demonstration on its live network in Nanjing, Jiangsu. China Unicom Beijing completed the verification of F5G-A 50G PON innovative applications. Beijing Telecom completed pilot project verification.
In March 2024, Shanghai Telecom took the lead in building F5G-A, the world's first 50G-PON-based “10 Gigabit Cloud Broadband Demonstration Community”, enabling 10 Gigabit access terminals to be used immediately on demand, and can provide 3D light sensing, 3D / A series of applications such as XR cloud live broadcast and ultimate cloud interaction.
In 2024-2025, 50G PON will enter the initial stage of commercial use. According to preliminary predictions, 50G PON will enter the stage of large-scale commercial use around 2027. By 2030, it will reach a peak.
According to Omdia's forecast, 50G PON port shipments will maintain a compound annual growth rate of 200% per year from 2024 to 2028, and will become a mainstream broadband technology in 2028.
Dell'Oro Group also predicts that total 50G PON equipment revenue will grow from less than US$3 million to US$1.5 billion from 2023 to 2027.
By the way, the next generation of 50G-PON is the ITU-T standard of B50G-PON (Super 50G PON) G.VHSP.sup(VHSP=Very High Speed PON), the project has been approved in September 2022 and is currently in the early advancement stage.
█ last words
Okay, the above is a basic introduction to 50G PON.
The development of 50G PON (F5G-A) is inseparable from user demand. At present, it seems that 50G PON, like 5G, lacks convincing hot-selling application scenarios, and it cannot be said to be a very needed technology.
Compared with 5G, the biggest advantage of 50G PON is cost. Although its cost will be significantly higher than 10G PON, it is still much lower than 5G. By matching with Wi-Fi 7, 50G PON can more easily provide users with low-cost, high-speed, and low-latency Internet access capabilities, making it easier to be accepted by the market.
Let time tell us whether 50G PON can take off.
In the next issue, we will talk about the key technologies of 50G PON, including compatibility and coexistence solutions, wavelength solutions, and optical module technology innovation. Stay tuned!
References:
1. “Progress in International Standards for High-Speed PON and FTTR”, Liu Dekun, Huawei;
2. “50G-PON Technology White Paper”, ZTE;
3. “China Unicom 50G PON Park Application Scenario White Paper”, China Unicom;
4. “50G-PON Technology and Application White Paper”, China Telecom;
5. “50G PON helps broadband networks move from Gigabit to 10G”, Liu Qian, Academy of Information and Communications Technology;
6. “50G PON development and foundation for 10G optical network”, Zhang Dechao, China Mobile;
7. “Discussion on the Development and Evolution of 50G PON Technology”, Zhang Dezhi, China Telecom;
8. “Analysis of 50G-PON Key Technologies and Application Requirements”, Shao Yan, China Unicom;
9. “50G PON, opening a new chapter in 10G access”, Wu Ying, ZTE;
10. ITU-T, IEEE official websites and related standard documents.