The Evolution of Fixed Networks: ETSI's Role and the Latest F5G-A Release

Since the establishment of the ETSI's Industry Specification Group (ISG) Fifth Generation Fixed Network (F5G) in 2020, ETSI has played a pivotal role in coordinating efforts among various standards development organizations (SDOs) for fixed networks. Just as mobile networks benefitted from ITU and 3GPP's unified standardization, fixed networks also benefit from cooperation and collaboration among SDOs. This article explores the advancements made by ETSI, particularly with the latest F5G Advanced (F5G-A), and the benefits this standardization brings to the fixed network industry.

Figure 1: F5G together with 5G as the two cornerstones for the new digital world

Aligning fixed networks and mobile networks

When initially establishing the ISG F5G, ETSI identified a critical need for cooperation among different SDOs. Also, fixed networks should have a comprehensive vision of generations, so that all the participants, such as operators, vendors, end customers, can speak the same technological language. Mobile networks set a good example, where unified generations like 3G, 4G, and 5G are well understood and adopted by users and technicians alike.

ETSI's goal is to create a similar generation system for fixed networks, with a unified technical architecture and cooperation platform. This would promote the adoption of existing technologies and explore new ones, thereby offering significant benefits to users.

The strategy and scope of the ISG F5G

The group's methodology begins with an evaluation of the use cases that could be expected to emerge with the available technologies. It then examines the gaps that hinder the implementation of these use cases and finally proposes a reference architecture that serves as a basis for implementations.

Furthermore, the group also focuses on the specificities inherent to the deployment of optical fiber technologies in certain environments. Thus, it has dedicated efforts to the use of PON technology in industrial settings. This approach, followed by 125 members and participants from all over the world, has produced more than 24 specifications and reports and continues to iterate the methodology for new releases.

Figure 2: ISG F5G release plan

Evolving from F5G to F5G Advanced

The recently published F5G-A Release 3 marks a significant milestone in the evolution of this approach. This release introduces a series of new features and capabilities, elevating fixed fiber networks to a new level.

In F5G-A Release 3, the "F5G Advanced Generation Definition" was unveiled, which not only enhances the three foundational characteristics of F5G (Enhanced Fixed Broadband (eFBB), Full Fiber Connection (FFC), and Guaranteed Reliable Experience (GRE)), but also introduces three new key characteristics: Green Agile Optical-network (GAO), Real-Time Resilient Link (RRL), and Optical Sensing and Visualization (OSV).

In terms of quantitative advancements, F5G-A delivers substantial improvements over all six of these characteristic dimensions. F5G-A is capable of delivering:

• eFBB: A tenfold increase in bandwidth (from gigabit to 10 gigabit)
• FFC: A tenfold increase in fiber connection density
• GRE: Improved quality of experience and L4 autonomous networks
• GAO: A tenfold improvement in energy efficiency
• RRL: Enhanced reliability from five nines (99.999%) to six nines (99.9999%)
• OSV: 99% accuracy and 1-meter location identification precision

F5G-A Release 3 also introduces 17 new use cases, which are driving the six characteristics of F5G-A. The use cases cover multiple domains including residential services, enterprises, vertical industries, network operations optimization, and end-to-end fixed infrastructure.

Figure 3: The six F5G-A characteristics and the use cases in F5G-A Release 3

The adoption of F5G and its advanced evolution, F5G-A, is gaining significant momentum among network operators and other sectors. This growing trend is driven by the substantial benefits these standards offer.

How standards lead to commercial deployment

In access networks, HKT met F5G-A standards with its broadband solutions, while China Unicom Beijing validated 50G PON technology to advance Beijing's "10G City" goals. Chile's Entel and Finland's Lounea innovated F5G-A applications based on 50G PON.

For optical transport networks, Saudi Arabia's Mobily and stc are building F5G-A-ready all-optical networks, supporting future-oriented applications. For vertical scenarios, F5G-A supports industrial digitization, such as Latin America's smart industries, China's first 10G rural product livestreaming park in Beijing, and high-speed infrastructure for the Asian Winter Games. These deployments highlight F5G-A's role in enabling 10 Gbps and above, low latency, and scalable solutions across smart cities, enterprises, and large-scale events, accelerating global digital transformation.

With the third iteration of the methodology, the group is gaining maturity, and the need for testing and validation of architectures is becoming apparent. Therefore, in 2024, the group created a dedicated working group for testing. The first planned specifications on fiber to the room (FTTR) architectures and the functional specifications of 50G PON are expected to appear within the year.

Embracing AI in optical architecture

Artificial intelligence (AI), along with the new forms of generative AI (GenAI) and large language model (LLM)-based solutions, has attracted significant attention from the industry, transforming how optical networks are designed, controlled, and operated.

The ETSI ISG F5G has started working on a whitepaper GenAI and LLMs for Optical Networks, aiming at providing guidelines and recommendations for the industry's future direction on AI for optical networks, specifically those GenAI and LLM-based technologies. It will also look into the use of new optical network technologies to better serve the AI deployments, including intra-DC connectivity and DC-to-DC connectivity.

Conclusions and future outlooks

The evolution of fixed networks, spearheaded by ETSI and its collaborative efforts with various SDOs, marks a transformative era for the telecommunications industry. The latest F5G-A Release 3 not only enhances existing fixed network capabilities but also introduces groundbreaking features that promise substantial improvements in bandwidth, reliability, energy efficiency, and precision. As network operators and verticals increasingly adopt these standards, the benefits of F5G-A are becoming evident across diverse applications, from residential services to industrial digitization and large-scale events.

ETSI's commitment to innovation continues as the group prepares for the next phase with F5G-A Release 4. New use cases are already in development, promising to further expand the capabilities and applications of fixed networks. This ongoing advancement ensures that fixed networks will play a crucial role in accelerating global digital transformation, offering users enhanced experiences and supporting the growing demands of modern connectivity.