New 5G Horizons for Telco Architectures

Bart Salaets, Senior Director of EMEA Solution Architects at F5, explores how a horizontal telco architecture can unlock greater control for networks and services

Increasing numbers of mobile operators are getting ready to roll out telco clouds and edge compute architectures for 5G core network functions and distributed application deployments. In doing so, many are grappling with a fundamental decision. Do they stick with the traditional approach and deploy vertically integrated stacks from different vendors for different use cases? Or should they be more radical and implement a horizontal architecture composed of distinct layers?

As technology progresses, the latter option is starting to resonate ever louder with forward-looking telcos.

In fact, there’s a strong case to be made that the realization of 5G’s full benefits and capabilities depends on a flexible, open, and transparent architecture. This is an approach starting to be adopted by some greenfield operators, such as Rakuten Mobile in Japan, that are looking to disrupt the telecoms market with a radical new cost structure.

A horizontal telco stack involves a complete decoupling between the server and network infrastructure and the different types of workloads that run on top of it. This kind of layered architecture is the norm among web-scale companies. But for telcos, it requires a change of mindset: they need to regard 5G as a use case that runs on top of a common telco cloud platform, rather than a vertical stack in its own right. 

Big business benefits for operators

From a business perspective, a horizontal telco cloud architecture has several advantages over more traditional approaches. First of all, it enables the telco to bring its telecoms and IT systems into a common infrastructure. That means that CapEx and OpEx investments are spread over telecoms and IT workloads, reducing costs.

Secondly, it provides the flexibility to deploy some elements of the 5G core, and the applications it supports, alongside network functions at the edge of the network, bringing them closer to end users. This makes them more responsive and improves the user experience. Expect to see significant and accelerated developments in this space in the coming years. As a case in point, F5 announced in January 2021 that it has acquired Volterra. The union is set to enable the creation of Edge 2.0, which will represent the first edge platform built for enterprises and service providers that will be security-first, multi-cloud enabled and app-driven, with unlimited scaling capabilities.

Finally, telcos with a horizontal architecture are less reliant on a single vendor. A horizontal architecture is more ‘open’ by nature and therefore makes it easier to mix and match different vendors in their 5G core. At the same time, telcos retain full visibility of traffic flows between the different 5G core components as provided by the underlying telco cloud platform. Furthermore, the architecture makes it possible to leverage a common platform to host telco and IT workloads. This minimizes the number of different hardware and platform components needed in the entire network. Telcos can also maintain their independence by partnering with major cloud providers, such as AWS and Microsoft Azure. This means they can deploy workloads in parts of the network that remain separate from the partnership with the cloud provider.

Unlike its predecessors, the 5G standard has been developed in a way that encourages operators to employ a horizontal architecture. The new generation of cellular technology has been designed to harness the service-based architecture that now permeates the IT sphere. It is also important to note that modern applications are composed of micro-services that perform specific functions and exchange information using the HTTP protocol and open application programming interfaces (APIs). The 5G service-based architecture relies on the exact same principles, leveraging HTTP-based APIs for interconnecting the different 5G functions.

The need for in-house expertise

Naturally, some operators will be better equipped to shift to a horizontal telco stack than others. Our conversations with 5G operators lead us to believe that there is growing appetite to move ahead with implementations, but they will likely progress at different speeds.

A key challenge moving ahead is that many service providers have limited in-house skills to start running a horizontal telco stack. A new architecture of this nature calls for a major organizational and technological shift, as vertical teams need to be reorganized into horizontal teams.

Consequently, some operators might begin with a hybrid approach where they gradually move specific vendors’ functions from a vertical to a horizontal stack. The initial moves are likely to focus on IT applications, with the telco team running a specific stack for their use cases, at least in the near-term.

For some use cases, applications and network functions must be deployed closer to end users to meet stringent bandwidth and latency requirements. As a result, we’re starting to see momentum building for edge computing initiatives that require telcos to deploy, secure, and manage cloud-native applications and 5G network functions across a large set of distributed Kubernetes clusters. This is exactly where F5 and Volterra aim to make a big difference by helping network and application teams to seamlessly deploy and manage their cloud-native workloads. Watch this space!

Clearly, there’s a lot of developments and innovations to digest but the overall direction of travel is clear. As they deploy standalone 5G networks and edge compute architectures, telcos across the world will start to realize the many benefits of deploying an open, transparent, and flexible architecture that gives full visibility and control of their networks.