Mobile network cloudification: strategic guide

The evolution towards cloud-based network functions involves intricate decision-making for operators, with cloud infrastructure serving as a cornerstone. While offering abundant prospects, its execution presents complexities and puts operators in front of multidimensional strategic choices.

The transition towards network cloudification marks a significant transformation in the industry. In Europe, the cloudification is evolving to ensure compliance with emerging regulations aimed at protecting citizens, such as the NIS2 cybersecurity directive, Data Act, and AI Act.

The transition from virtualized to cloud-native network functions marks the initial step. Although it offers promising opportunities, operators face several challenges. These include meeting specific demands such as latency, throughput, and resilience, adapting to new operational methodologies like DevOps, and progressing at a suitable pace to protect essential enterprise services from risks associated with immaturity. Moreover, equipment manufacturers face a twofold challenge— overhauling existing function codes while innovating with new features, adding further complexity to the journey.

A progressive transformation

The process of network function cloudification follows a three-stage maturity model:

Virtualized: After the decoupling of hardware and software from network functions, virtualized network functions (VNFs) are deployed on standard servers. Today, most network functions are virtualized.
Cloud-Ready: This architecture, reimagined based off cloudification concepts, introduces automatic service and resource orchestration to enhance the flexibility and elasticity of the entire system. New players from the IT sector have started developing cloud ready VNFs.
Cloud-Native: This architecture grants access to disruptive technologies— network slicing, agile infrastructure, microservices, containers, and PaaS. VNFs are assembled flexibly, with network services released at any time. Network operations and maintenance, as well as service operations, are automated. All VNFs of a 5G core network will be cloud native.

The cloud infrastructure: a key player in network cloudification

Telco cloud infrastructure and the associated skills are of crucial importance for operators looking to launch new virtualized network services while remaining agile in response-tomarket developments. Choosing the appropriate infrastructure is critical for maintaining control over deployed computing resources, managing costs, and leveraging the benefits of network function disaggregation.
Most telecom operators are turning to ‘turnkey’ solutions, meaning that they choose the same supplier for both VNFs and server infrastructure. However, faced with this ‘vertical’ model offering a customized solution, Orange and other major operators are exploring a more flexible ‘horizontal’ model which entails sharing infrastructure among multiple providers (network equipment manufacturers, integrators, or trusted platforms like VMware).

A Complicated Decision

The industrial ecosystem surrounding cloud infrastructure presents a range of complexities. The multitude of options available can lead to significant expenses related to integration, orchestration, and automation. In response to these challenges, operators are exploring novel approaches, often constrained by European regulations. These include leveraging standardized reference architectures like Anuket from the Linux Foundation Networking (LFN) or embracing public cloud infrastructures.

Several emerging trends suggest a transformation in the virtualization ecosystem. This includes a shift from proprietary solutions to open-source alternatives like OpenStack,
the adoption of container-based hosting for more flexible infrastructure lifecycle management compared to traditional virtual machines (VMs), and the implementation of continuous development methodologies (CI/CD).

Criteria for selecting cloud solutions for VNF hosting

Evaluating the cloud readiness of VNFs, following the previously outlined cloudification process, remains a fundamental step in defining a migration strategy. Subsequently, the operator will incorporate various criteria to choose its cloud hosting solutions for VNFs.

Sovereignty, regulation, and security

Ensuring cloud sovereignty is vital to maintain geostrategic autonomy amidst dominant cloud powers, safeguard individual freedoms, and uphold enterprise data confidentiality. Prioritizing auditability, particularly for open-source software, and reducing reliance on publishers and solutions will be crucial steps forward.

In Europe, several legal frameworks will apply to operators, with specific regulations in France where, for example, equipment is subject to certification by the National Cybersecurity Agency (ANSSI) before operation. Alignment with European regulations is ongoing.

An optimal cloud solution will meet the needs of the national regulator by integrating key elements such as identity management, encryption protocols, and security key management methods.

Network performance

Data plane network functions, such as UPF for 5G, require optimal performance in terms of throughput and latency.

Distribution level

The industry is increasingly adopting remote sites to address network congestion issues related to the 5G core and meet the low latency needs of Open RAN.

Standardization and Open-Source Level

To optimize management, some players are adding elements to cloud infrastructures based on open-source components. Leveraging the advantages of hyperscalers with pre-integrated services can make them more dependent and slow down reversibility.
However, in the Anuket reference architecture, the certified Kubernetes version represents a design model that facilitates portability between different cloud solutions.

Financial considerations

Choosing between cloud solutions based on CapEx (private cloud) or OpEx (public cloud) models is strategic, especially for public networks, which are currently based on the CapEx model. Transitioning from one to the other requires careful analysis.

Pooling hardware and software resources in the cloud helps optimize costs and meet changing application needs, especially for central sites, where operators require flexibility for resource allocation and release.

Comparing different cloud solutions, assessing the total cost of ownership (TCO), and anticipating connectivity costs in a multi-cloud strategy are particularly complex tasks.

Service Catalog

Certain VNFs require specific services or functionalities on the target infrastructure, such as high-throughput storage for CDNs or real-time operating systems for Open RAN. During the decision-making process, evaluating the service catalog is crucial.

The deployment of network functions in cloud mode is becoming a reality for many enterprises. Telco cloud transformation promises revolutionary use cases and numerous opportunities for value creation, yet it comes with inherent risks.
Faced with new regulatory, technological, financial, and cultural challenges, companies will need to make decisive choices.