How North American operators are unlocking the value of 5G: Making the leap to the standalone core
My team and I are working closely with a great many North American communications service providers (CSPs). One question comes up in every discussion: “How do we design and evolve (or build) our network to unlock the full potential of 5G and monetize 5G services?”
In this four-part blog series, I’m going to show that the answer may depend on implementing some fundamental enabling technologies that are already proven in the webscale world. I’ll also look at how 5G’s blending of traditionally well defined network and IT silos is going to allow CSPs to become true digital service providers (DSPs) — with an end-to-end approach to the network, operations and their business.
The core of the matter
CSPs are investing billions to launch 5G and realize its significant improvements in capacity, connectivity, latency, reliability and openness. Combining these gains with the right enabling network and IT capabilities has the potential to unleash a range of new services for consumers and — more importantly — industry use cases.
To seize that potential, the network core has to be more scalable, high-performing and flexible than ever before. It needs to be able to connect millions of new devices and sensors, meet new traffic demands and diverse industry requirements, and extend any service over any access technology.
This basically necessitates a core with cloud-native capabilities, containerized micro services and an open, agile, distributed architecture that supports programmability, analytics and DevOps for rapid service definition and delivery. In other words, they require a 5G standalone (SA) core.
While cloud-native capabilities offer a range of benefits, CSPs are likely to approach and prioritize their 5G builds somewhat differently based on their size, complexity, time to market and choice of underlying cloud. In North America, some CSPs are prioritizing a uniform layer of infrastructure and operational tools across 5G functions in a multi-vendor environment. Others are prioritizing automation for software deployment from the outset to reduce operational costs. Still others are more concerned with time to market and having vendors vertically integrate network functions with their cloud infrastructure.
Toward a service-based architecture
The shift to a 5G SA core also requires adopting a service-based architecture (SBA), because the traditional peer-to-peer (P2P) network architectures that served CSPs for basic consumer voice, data and messaging services are rigid and struggle with scaling, redundancy and extensibility for rapid service innovation.
SBAs are centered on Network Functions that can advertise themselves as service producers and subscribe as service consumers or both. They’re built with web-based application programming interfaces (APIs) instead of legacy telecom-style point-to-point protocol interfaces — and because APIs are broadly available, development takes less effort.
Basically, with an open SBA, core elements become the building blocks for new features, which is key to enabling and creating new 5G services to be monetized. Some North American CSPs are focused on this standards based architecture and are taking the time to create a multi-vendor environment with best-of-breed 5G functions prioritizing over time to market.
Traditional applications come with their own signaling interfaces, which has led to inconsistent protocol adaptation, load balancing issues, overloads, tracing challenges and a lack of centralized control. (Who hasn’t witnessed the havoc caused by signaling storms in networks when certain devices or applications were launched at scale?) Webscale companies have addressed this by creating a reusable signaling microservice implemented as a “side-car proxy,” relieving the application from having to manage the signaling itself. When various network functions use these side-car proxies, the resulting network is a service mesh, which is ideally how 5G networks should evolve. Depending on the cloud stack selected, some CSPs are aiming to use uniform load balancers and service meshes based on open source infrastructure tools such as Envoy and Istio.
Unlocking the value of 5G with Standalone Core
Evolving to stateless and “data-less” applications
We’re seeing a number of deployment models for the 5G SA core in North America. Most CSPs are deciding to go fully cloud native with containers on bare metal from day one.
One thing this approach does is render the applications stateless and “data-less” by separating them from the signaling controls. This allows developers of 5G network functions to focus on business logic instead of on forging their own infrastructure tools. It frees CSPs to scale their networks for large numbers of subscribers, just as the webscale players do — and to configure, control and monitor distributed networks in a centralized, uniform way while providing the reliability and performance expected from a telco.
Separating application business logic from the corresponding data makes the business logic easier to build, deploy, operate and scale, using the full potential of automation and cloud-native capabilities. It also improves resiliency. Most large CSPs have taken this step, building front-end register applications in the cloud and keeping the back-end database in a hybrid mode. This ensures robust operations that can support 4G and 5G, with the goal of eventually migrating the database to the cloud as well.
Finding your path to the 5G core
While the approach to building a 5G core may vary, the fundamental characteristics are the same — cloud-native with a service-based architecture and stateless, data-less applications. It’s those characteristics that are key to unlocking 5G potential. T-Mobile US deserves congratulations as the first CSP to make this leap, announcing at the start of August 2020 its launch of the world’s first 5G standalone network — paving the way for other CSPs to follow suit.
Nokia is also helping make that transition possible with cloud-native products and solutions that rapidly and cost-effectively deploy diverse services across a range of access technologies (see https://www.nokia.com/networks/portfolio/5g-core).
In my next blog, I’ll take a look at how CSPs can drive 5G profitability through service exposure.
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