Two 0520 1402x672

It Takes Two

May 1, 2020
Empowering Fixed Mobile Convergence and Transport for 5G — While 2019 marked the year 5G deployments finally came to fruition, this year, we are witnessing a much wider rollout of […]

Empowering Fixed Mobile Convergence and Transport for 5G —

While 2019 marked the year 5G deployments finally came to fruition, this year, we are witnessing a much wider rollout of this powerful technology as mass global rollout moves into high gear.

 This realization of 5G deployments will bring yet another surge in network traffic — which for years now has already been growing dramatically. As much more than the next generation of mobile technology, 5G technology promises to be a game-changer in terms of broadband reach and user experience, opening up new innovative use cases for consumers and businesses alike, and new applications from autonomous cars and smart communities to Industrial Internet of Things (IIoT), remote surgery, and immersive education.

However, to be successful, an entire ecosystem around 5G technology needs to be in place, from transport networks capable of handling increased network traffic and network slicing, to end devices that can seamlessly leverage the optimal technology available, to billing and management systems that seamlessly hand-off between these networks.

With 5G set to take off faster than either of its predecessors (CCS Insight predicts that there will be one billion users of 5G by 2023), operators are seeking ways to rapidly prepare for this powerful new technology. However, if operators are to support the requirements and demands of 5G, the way they build, operate, and use both their fixed and mobile networks must fundamentally change.

Food for Thought from Our 2022 ICT Visionaries

Marrying Fixed and Mobile

Since the introduction of mobile devices that include Wi-Fi, there has been an increasing interest in coordination and interworking among wireless and wireline networks across the industry — which has been further fueled by the rise in the use of smartphones at public hotspots.

As a result, an emerging ecosystem is taking shape where applications are developed largely independently of access types. There is an increased desire to provide network capabilities that offer better user experiences and more efficient network utilization for these devices as they handoff, roam, tether, and attach to wireline locations. Therefore, for operators wishing to provide superior user experiences, interworking between fixed and mobile networks is becoming crucial.

If operators are to cost-effectively support the growing use of multimedia applications and related traffic growth in both fixed and mobile environments, they require solutions that can constrain capital and operational expenditures. While network traffic continues to grow annually, it is unlikely to produce a commensurate increase in revenue in a competitive and regulated marketplace. Therefore, operators who own both fixed and wireless access networks are best positioned to consider converged solutions which can provide optimization of their network infrastructure.

To make this a reality, operators must have the tools at their disposal to enable sharing components between both their fixed and wireless networks, enabling them to align their service offerings and enhance user experience across both types of access technologies.

One Goal, One Network

The success of 5G and its ability to enable these new use cases and applications is dependent on the speed and reliability of both fixed and mobile networks. This means operators must leverage both fixed and mobile networks to unlock the full potential of new innovative services and applications, and to deliver a seamless experience for end users across all their devices.

To achieve this, operators must look to do 2 things:

1. Implement a converged and integrated core network. This is key to a converged services approach, which will ultimately enable operators to deliver a uniform experience to their customers irrespective of the access media type, technology, or appliance, they are using.

2. Enhance their transport network(s). The transport networks that interconnect the 5G RAN and core networks need to be enhanced to support the evolving 5G mobile architectures as well as the capacity and QoS performance demands of the 5G mobile network and its applications. Upgrading the 5G mobile equipment without the corresponding transport enhancements will not provide the full promise of 5G that end users expect.

Not a One-Man Mission

To address this challenge as 5G gathers pace, Broadband Forum is working to increase the synergy between wireless access technologies and wired access technologies, as well as that of wireless networking and wireline networking functions.

To ensure industry-wide collaboration, we are coordinating efforts with the 3rd Generation Partnership Project (3GPP) to provide an architectural framework for interworking between next-generation fixed and 3GPP wireless access. This work defines the business requirements, use cases, high-level functional architecture, and deployment options for interworking. It includes requirements on the regional access network and customer premises network to support interworking between Broadband Forum wireline access networks and 3GPP wireless networks, enabling the use of 3GPP User Equipment (UE) with wireline networks.

The organization contributed detailed recommendations to 3GPP as part of its Release 16 time frame, aligning their efforts in the development of a converged 5G core network. The suggestions addressed the common interfaces for access networks and 5G core networks to support the convergence of wireline and wireless networks. Detailed recommendations on a number of interfaces in the context of fixed 5G were also passed on to 3GPP, enabling its members to evaluate the interfaces that run between the 5G core and the fixed network. In addition to this, recommendations on signaling changes and enhancements were provided, addressing how fixed access can be fully integrated into the 5G core.

As part of its efforts to drive Fixed Mobile Convergence (FMC), the organization is also developing a specification for a 5G Access Gateway Function (AGF) which adapts fixed access onto the 5G core, specifications for 5G-capable Customer Premises Equipment (CPE), and specifications which address the interworking of existing fixed access subscribers, as well as deployed equipment into a 5G core that encompass a variety of deployment scenarios. This work is designed to empower operators to create powerful new converged service offerings, enabling them to gain additional revenues.

These initiatives leverage and integrate the newest technologies to ready the transport network for 5G while at the same time apply the transport network to the new 5G Radio Access Network (RAN) and mobile core architectures from 3GPP to fulfill the promises of 5G.

With 5G, 3GPP has split the traditional RAN and mobile core architecture exposing standard interfaces that were previously internal to the LTE equipment. The split allows a more dynamic and custom deployment of 5G equipment particularly for the RAN. The transport network, previously supporting only mobile backhaul, must support the volume of these new "fronthaul" interfaces.

However, these new interfaces are demanding not only in terms of the number that must be supported but also in terms of capacity and performance (e.g., latency, delay variation)

Focusing on capacity, performance, reliability, scalability and security, the scope of work on the transport network includes control, management, and data plane for the IP layer down to the physical layers.

Like this Article?

Subscribe to ISE magazine and start receiving your FREE monthly copy today!

A 5G Future

That’s why long-standing working relationships with organizations such as IEEE, IETF, and ITU-T are critical. We aim to leverage their work on timing and synchronization; OAM, routing, resiliency, scalability, and security into a comprehensive 5G Transport architecture that addresses the challenges of 5G; along with virtualization of the mobile transport infrastructure and enablement of software-driven networking.

All industry stakeholders can shape the future of broadband. When we work together to create a collaborative ecosystem, we provide a globally supported framework for operators worldwide to develop next-generation services and launch new, innovative, combined subscriber offerings.

For more information, please see CCS Insight Predicts 1 Billion Users of 5G by 2023, with More Than Half in China at

About the Author

Robin Mersh

Robin Mersh is CEO of the Broadband Forum. He joined the Broadband Forum as COO in July 2006, and was promoted to CEO in July 2010. He has authored multiple articles and has spoken at and chaired many broadband industry events. Robin has worked in the telecommunications industry for more than 18 years, and has worked in business development and alliance management for various OSS software companies in the US. For more information, please visit Follow the Broadband Forum on Twitter: @Broadband_Forum.