5G Fixed Mobile Convergence & 5G Transport

5G work in the BBF

The 5G Fixed-Mobile Convergence work investigates important issues that impact design, implementation, deployment and operations of 5G in the broadband ecosystem. These issues closely relate to significant business opportunites. The work is being done in collaboration with other industry bodies such as 3GPP. Your participation is strongly encouraged.

The 5G Transport work addresses the requirements and anticipated migration of the 5G transport network to accommodate the anticipated new demands generated by the introduction of 5G globally. 

For more information click on the tabs below
Many aspects of the BBF's key projects are closely woven into the successful deploment of 5G

Public Resources 

Members' Resources (login required)

  • SD-406 Network Slicing
  • SD-407/SD-420 5G Fixed Mobile Convergence Study
  • Other Member resources see wiki.broadband-forum.org for weekly 5G call schedules, JIRA 5G/WWC contributions, etc.

5G Fixed Mobile Convergence

5G Deployment Strategies

  • Coexistence strategy: enables stress-free, market-paced migration from installed to new services
  • Interworking: home access to 5G Core components
  • Direct access to 5G core – full operational integration

David Allan (Ericsson), BBF Work Area Director for Wireline-Wireless Convergence, talks about the latest BBF activities in accelerating 5G networks

5G Transport

  • 28bn devices and 6bn smartphones & 12(->50)k Petabytes per month in the broadband converged transport
  • BBF working Routing &Transport requirements to covering
    • Capacity, performance reliability & deterministic transport, scalability and security

Dave Sinicrope (Ericsson), BBF Work Area Director for Routing & Transport, talks about the latest BBF activties in transport for 5G

5G is usually thought of as a phenomenon in mobile broadband but the Broadband Forum is playing an important role to ensure that key role of the fixed networkis integrated seamlessly. David Allan, WWC director, introduces the work.

With industry talk surrounding radio and the new services and capabilities 5G will provide, the transport network is in danger of being overlooked. David Sinicrope, Vice President of the Broadband Forum, explains why transport is critical to the development of 5G. 

5G: "What's fixed got to do with it?"

The recordings of two recent 5G webinars being made available on the right. These recordings will be available for limited time. Recordings and presentations are also available on the BBF Wiki Marketing home page.

5G Fixed Mobile Convergence 

The purpose of this work is to investigate common interfaces for the Access Network and Core Network, to support converged wireline-wireless networks that use the 5G core network. It studies the N1, N2 and N3 interfaces in order to provide detailed feedback to 3GPP in the context of 5G Fixed networks (as recommended by the joint 3GPP-BBF 2017 Workshop) and to facilititae 3GPP work in this area as swiftly as possible. 

This project will specify of a 5G Access Gateway Function (AGF) that adapts fixed access onto the 5G core, and then consider and specify several architectural deployment options as well as the underlying infrastructure sharing aspects. It will also devise strategies and develop specifications to address operator requirements for interworking of existing fixed access subscribers and deployed equipment into a 5G core.

The study includes the examination of the following

  • Registration and Connection Management Procedures
  • Transport and Encapsulation in the Wireline Access of Control Plane (eg. NAS) and User Plane Traffic Exchanged with 5G Core
  • Regulatory Requirements
  • Operational Requirements
  • Resource Management in the Access
  • Session Management
  • Addressing for IPv4 and IPv6
  • Home LAN Support
  • IPTV and Multicast
  • Network Slice Selection
  • QoS and Policy Management

5G Transport

The foundation of the 5G network

5G is slated to support masses of new devices, upgraded mobile phones and require extraordinary bandwidth and matching investment by operators and equipment manufacturers. The questions that the Forum are investigating are the foillowing

  • Will the current transport network support the requirements of 5G?
  • What routing & transport enhancements will be required for 5G covering capacity, performance reliability & determinism?
  • What are the key recommendations should be made to the industry?
The forum's work is based on more than a decade of related work as the industry has migrated from mobile generation to mobile generation. This page touches briefly on those highlights

5G Requirements

  • Bandwidth, capacity
    • Gigabit speeds vs. megabit speeds
  • Performance
    • Latency
    • Loss
    • Delay variation
  • Reliability
    • Availability and resistance to failure
    • Isolation from interference
  • Scalability
    • Billion users and connected devices

The Transport network connects all the equipment together


New functionality

To meet needs of 5G these functions need to be integrated into what we have today
  • SDN
  • Segment Routing
  • Service Function Chaining
  • Ethernet VPN
  • Deterministic Transport
    • IEEE TSN
    • IETF DetNet
    • FlexE
  • Virtualization
  • Faster speeds, higher capacity
  • Intelligent management & orchestration

Member resources and further information on BBF work in progress

A full member video covering the work in progress is available on the members wiki marketing area

What's fixed got to do with it?

The following examines why the arrival of 5G is more important than ever that the Forum be involved in the world of mobile communications. In fact, by the end you may may share our conclusion that the success of many 5G use cases is critically dependent on the BBF's work - and that you will want to actively participate.

An expectation being set for 5G

With the digital society poised to enter the 5G era, we know that consumers and business users will expect a perfect seamless experience across all their devices - anytime, anywhere - regardless of the underlying network. With the proliferation of new connected devices, services and access types, seamless connectivity implies a context-driven, connected experience. In fact, they will expect it to match the highest fixed broadband quality.

5G is an end-to-end system that involves all aspects of the network, with an architecture that achieves a high level of convergence while leveraging today’s access mechanisms (and their evolution); this includes fixed, wireless, and cellular access. This is the vision for network-based Fixed Mobile Convergence (FMC). In fact, 5G can't meet the consumer expectation without a robust high performance and always-available fixed transport network.

Many new use cases and expectations

The NGMN envisages 5G operating in a heterogeneous environment characterized by multiple types of access, multi-layer networks, and a wide variety of device types and user interactions*. There is a need for 5G to provide a seamless and consistent customer experience across time and space, i.e. an experience which is the same regardless of the access type and end-device. This implies many new scenarios beyond the obvious ones such as the seamless use of compute, entertainment, IoT and mobile devices in the home and office. The age of the automated vehicle is fast approaching and there is likely to be an expectation that intense network and compute resources will be available everywhere.

A cornerstone of FMC is to have one view of the customer. Since the intelligence lies mainly in the network, the architecture will support devices from a wide range of manufacturers. The FMC approach has the potential to significantly improve customer experience by providing the most appropriate connectivity, regardless of location. There are market imperatives for service providers to find new network-enabled ways to deliver an enhanced, seamless experience.

Network operators also have a pressing need to improve network efficiency. This can be done by better utilization of their existing fixed and mobile assets, providing integrated-connectivity based offerings, and simplifying and automating network provisioning and operation. FMC improves infrastructure efficiency by the use of a common, access-independent core, and can benefit from the flexibility of virtualized network functions. 5G can only intensify this since the more 5G looks like the fixed high-speed internet the more the expectation will be for a free utility.

Today’s fixed and mobile networks have different architectures, access mechanisms and network functions, and typically use device-controlled network selection. FMC allows the pooling of access assets, and dynamic traffic steering could contribute to reduced access network costs, as well as converged connectivity service propositions. This can be achieved by sending traffic over the fixed or the mobile network as appropriate, or even both networks simultaneously. One thing is clear: there will need to be more compute intelligence and performance nearer to consumers so that delivery of these services is viable.

Another important aspect is support of the vast number of IoT devices which are expected in the near future. The majority of IoT devices are low-bandwidth and will have some form of short-range, low-power radio technology like Bluetooth, ZigBee or Z-Wave; others will use Wi-Fi. A new generation of devices with advanced capabilities will also emerge and operators must find ways of ensuring efficient delivery of services to vast numbers of new devices in the converged network architecture. The diversity of network requirements drives the need for logical networks with different properties. This renews the pressure on more intelligent home networking including Wi-Fi, better integration with the fixed and mobile access networks.

The need for a holistic approach - Enter the BBF

The more you look at what it will take to economically deliver on its expectations the more it becomes obvious that the industry is dependent on the expertise and experience of the BBF. Not only is the BBF working on key WWC projects but is also constantly supporting enhanced home networking, high speed access technologies enabling distributed networking with projects such as CloudCO, and virtualized network projects.

A range of new FMC Standards is required, which will involve several organizations, that need to find efficient ways of working together to avoid duplication of effort and incompatible systems. The converged network functions should, wherever possible, be based on the common 5G functions that can be configured to suit the application and customer needs, regardless of the access.

BBF is committed to developing technical specifications addressing the Fixed Broadband system evolution related to 5G, while considering migration and operational integration. This is being done in close cooperation with 3GPP and other select global organizations.

The Business Case for 5G and BBF use cases and projects

In recent times, the concept of NFV (Network finctions Virtualization) was born out the desire to reduce costs by simplifying and unifying the design of network devices its business justification has been in specific cases such as SD-WAN and vCPE. With the advent of new serivce opportunities it will be important to focues on those use cases for 5G the have the most immediate business impact and viability for those providers who must invest in the infrastructure. 

The BBF will clearly focus on those use cases which promise to bring the fastest return on investment. BBF members and non-members alike are encouraged to follow and actively participate in the cutting-edge work of the Forum in the area of 5G.

* from the Next Generation Mobile Networks (NGMN) published paper on 5G:

End-to-End Network Slicing

This work investigates the concept of network slicing with respect to the BBF architecture. Network slicing is considered as a fundamental enabler to migrate “one architecture fits all” to the logical “network per service”. Network slicing will enable value creation for vertical segments that lack physical network infrastructure, by offering network and cloud resources.In particular, this project has the following objectives:
  • Address business needs for network slicing
  • Identify and analyze potentially relevant slice types to be supported  in the BBF MSBN
  • Study existing work on network slicing of other industry bodies incl. ONF Architecture WG, 3GPP SA2/SA5, ITU-T, IETF, ETSI ISG NFV / MEC, 5GPPP Architecture WG, etc.
  • Provide the foundations to cooperate with other industry and standards developing organizations, particularly 3GPP SA2 and 3GPP SA5, as needed.
  • Identify specifications to address any potential gaps to support the identified network slice types provided on MSBN including any potential extensions to enable network slicing

This study explores network slicing considering a combined network and cloud resource allocation, customized to address specific business demands in a flexible and dynamic manner combining federated resources across multi-domains and transport/IP technologies. Various network slicing related operations should also be considered including for instance instantiation and orchestration procedures, multi-domain support as well as simultaneous connectivity to multiple network slices, without this list being exhaustive.

This work is intended to serve as a first step of a framework for enhancing the current MSBN in order to be able to accommodate end-to-end network slices across multiple administrative and/or heterogeneous transport/IP technology domains. From a BBF point of view, network slicing will be a significant capabilitiy for the delivery of innovative, ultra-fast, hyper-connected and valuable-added services supporting the BB20/20 vision.


The scope of this project is centered on the requirements for end-to-end network slicing including:

Identify umbrella use cases with relevance to the BBF MSBN, including the traditional and virtual RG/BG scenarios.

  • Identify relevant business entities
  • Identify relevant network slicing new entities and/or functions and assess their architectural impact
  • Identify transport and routing related operations, e.g. flexibility, on-demand provision, QoS, etc., and assess their architectural impact
  • Identify slicing-related security and privacy issues that may have to be resolved.
  • Identify network slice operation including, isolation e.g. at layer 2, extending VLAN tagging to the home
  • Consider how an SLA/business request shall be placed to enable a slice
  • Consider the components that support a slice request and how it should be mapped into network resources (e.g. using a slice template, via VNF/SDN means, via decomposing VNFs, i.e. Cloud CO, etc.)
The work relates closely to other BBF work since the 5G and fixed networking brings the promise of service protection and integrtion in the home and office.
Business Drivers and Impact:

5G design requirements and technology enablers drive both mobile and fixed developments.

The Next Generation (5G) System will support:

  • Simultaneous connection to different accesses, capability to access the services provided by the 5G network using non-3GPP access
  • Inter-system mobility between 3GPP and non-3GPP networks with optional session continuity,
  • Mobility between non-3GPP networks.
  • capability for the user equipment based on network control to discover and select the appropriate access,
  • A common authentication framework

5G-Fixed Mobile Convergence (5G-FMC) is one of the areas of high priority to be addressed, given that:

  • Seamless service experience is key for users and drives the need for full FMC
  • 5G services are to be deployed in an access-independent context across several access technologies (incl. wireless and wireline).
  • on-demand network services, e.g. different levels of mobility  may be required according to the application needs.
  • Multiple simultaneous attachments will be very common for certain devices and applications.
Please see previously published work on 3G and 4G on the Technical Reports page. These include


Technical Specifications for MPLS in Mobile Backhaul Networks



Energy Efficient Mobile Backhaul



Nodal Requirements for Interworking between Next Generation Fixed and 3GPP Wireless Access



Policy Convergence for Next Generation Fixed and 3GPP Wireless Networks



Hybrid Access Broadband Network Architecture:

  Recently published, TR-384 covers the following:
Bonding fixed broadband access and 3GPP access networks enables service providers to offer higher throughput and better Wide Area Network (WAN) reliability solutions to their customers. In this bonding scenario, advanced traffic distribution mechanisms are needed. This Working Text defines the architectural requirements and solutions for the connections of premises by means of both fixed broadband (DSL, GPON, P2P Fiber) and 3GPP WAN interfaces