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Networks are transforming the world:
now we must transform the networks

Mohammad Arif Khan
May 31, 2024

Why MNOs need to transform their mobile networks, and how

These days CSPs are transforming their core networks for new businesses propositions and long-term business growth using new voice and data core for all network services such 2G,3G,4G,5G and 6G. CSPs are changing vendors or getting new solutions from existing vendors across the access and core network domain to migrate the existing customer and offer new business to the consumer/retail/enterprise market is the main objective of transformation. The network transform brings lot of challenges for CSPs but main is no “outage of network service”. CSPs are taking various approach and strategy to minimize the customer impact during network transformation such as well tested solution deployment, customer onboarding strategy, sustainability of solution and offloading of traffic in case of network collapse/full outage of sites.

At the end of 2023, 58% of the world’s population used mobile internet, equating to 4.7 billion users – an increase of 2.1 billion since 2015, according to the GSMA’s The Mobile Economy 2024. Another set of research, conducted by Ericsson, estimates total mobile data traffic to grow by a factor of around three between 2023 and 2029.

As is increasingly obvious, today’s consumers and enterprises expect greater variety and levels of service, facilitated by ultra-fast data speeds and high network uptime. The telecoms industry must deliver.

To deploy network services capable of meeting these needs, the long term business plans of mobile network operators (MNOs) compel them to transform their mobile networks through new infrastructure and technology.

But what is network transformation?

For the purposes of this article, we define mobile network transformation as the partial or complete change of a network’s core elements (the bits that manage the mobile network operation, such as user authentication, session management, data routing, and billing) or access elements (the bits that connect mobile devices to the core network via radio waves).

Transformation naturally involves implementing digital technologies into these parts of the network, which allow adaptive and automated control of physical mobile network infrastructure, and generate data driven insights that support that automation. Examples – which we will discuss – include cloud native containerized network functions (CNFs), virtual replacements to traditional physical network functions (PNFs) that offer greater scalability and adaptability. 

In search of this future, MNOs aim to ‘clean up’ existing networks, through a slow decommissioning and replacement of the existing legacy network. Here, operators switch out physical-only infrastructure with new ‘digital meets physical’ software-defined network technologies, and then migrate customers and services over to these new, improved mobile networks. 

However, such transformations are extremely complex, and face many challenges – not all of which are known. Worst case scenarios involve expensive transformations that fail, forcing MNOs to fall back to their legacy networks.

For the successful transformation of the core network, an accurate project planning and a mitigation strategy for all known risks is essential. These risks are the result of doing something that few, if any, have done before; such transformations are at the cutting edge of mobile network technology.

Thinking strategically

The goal is an improved network that operates without service outages or negative customer impacts. To this end, it is very important that the network solution and services be tested rigorously before we begin migrating customers. This must cover all types of testing – but most importantly load, performance and soak.

If the MNO’s business use case is not defined, there is the risk of high investment but low ROI. To prevent this, MNOs must build solid business use cases before attempting to transform their networks, so that the new network can properly deliver its promised user experience and revenue.

Project management is also a critical part of a mobile core network (MCN) transformation, and entails the completion and delivery of each phase/milestone on time and within budget. MCN transformation activity has many moving parts, so a lack of expertise in planning or delivery can impact heavily on milestone delivery, including delays to go live – along with potential financial and reputational consequences.

Network transformations can cost millions, including investments in new staff, training and vendor solutions. So, the key challenge is to properly plan and streamline project delivery.       

Challenges and risks

The known challenges or risks can largely be resolved by strategic planning, but unknown challenges or risks are very difficult to predict or measure. And these unknown challenges and risks can be critical blockers in the transformation journey.

Migrating customers from the legacy network to the new one is the ultimate goal of the transformation journey, and the migration strategy is crucial to ensure the smooth handover of customers. This is an area where MNOs must pay particular attention. They should be careful while selecting solution providers, solution integrators and technical resources for the MCN transformation journey. Indeed, the success of MCN projects depends on the correct selection of solutions from the vendor and the efforts of the MNO’s technical team to implement and integrate these solutions.

However, selecting the CNF/VNF and cloud infrastructure solution provider is just the beginning. MNOs also face various risks and challenges in their network transformations. These include the following:


  • Risks: if the network’s high level design (HLD) or low level design (LLD) is inaccurate or unsuited to network needs, lab and production deployment can fail.
  • Challenges: network service and network design misalignment in HLD or LLDs, design gaps (eg. gaps found during test and validation, or business requirements not being covered by the network), or a lack of suitable engineering, design and test resources.

Solution integration

  • Risks: if all the network’s parts, including devices, RANs, fixed networks and mobile core network components are not carefully planned in the integration strategy, new and legacy network interfaces may not properly integrate – causing network issues.
  • Challenges: if risks aren’t identified early in the integration strategy, then the solution may require redeployment. This can cause delays in the integration timeline. And if the deployment, redeployment or upgrades of the core network nodes aren’t planned accurately, we can expect further delays to test and validation timeframes in the lab, or during production.

Core network function/virtual network function (CNF/VNF) and cloud infrastructure

  • Risks: network stability and performance are at risk if network functions (NFs) aren’t fully certified and if services are not deployed and tested against the MNO’s desired network features.
  • Challenges: The main challenge is to ensure the network is stable and efficient for migrated customers, fulfilling all business use cases and the migration user journey. In short, the major challenge is to ensure the stability and optimized performance of cloud, microservices, pods and networking, to sustain the network’s traffic load.

Technical resource

  • Risks: if network design, test, integration and operation resources are inefficient or unable to understand design requirements, vendor solutions and integration points for various interfaces and features, there is the risk of the transformed network facing issues that were not identified and remediated in the design, integration and test phases.
  • Challenges: The MNO’s technical team must align itself with the company’s transformation requirements, especially if a new hardware and/or software vendor is introduced. If the MNO’s design, test and ops teams fail to acquire the expertise required to operate the solution independently, the MNO may struggle to properly utilize its newly transformed network.

Test and validation

  • Risks: if the MNO’s network services test and validation approach is not suited to the transformed network solution, there is a risk of testing being performed superficially, below the level of detail required to actually gather useful information.
  • Challenges: the effort put into the test strategy, along with the test methodology itself, determine how likely we are to find (and fix) major defects in the new network.

Customer migration challenges and risks

This is the last step in the network transformation journey, where the major risk is the failure of the customer migration. The challenge, then, is how to complete the migration as per the business plan.

  • Risks: a ‘big bang’ migration strategy (in which applications and data are migrated in one operation, at one point in time) can threaten the newly transformed network with frequent network outages and service failures. This can happen when new site capacity and performance are not proven to sustain the migrated customers’ traffic load. Ultimately, the critical risk is a negative customer experience caused by an unstable network or ineffective migration that could damage the MNO’s reputation.
  • Challenges: it is difficult to roll back customers from the newly transformed network to your legacy network. It is also very difficult to identify the cause of failure in network solutions and services, if the migration strategy of rollout and rollback is not strategic; neglecting important factors like use cases, customer types, traffic steering plans and the number (and order) of customers to be onboarded.


Network transformation is, of course, a means to an end. For network operators, that end empowers them to deliver superior services, unlock new revenue streams, and optimize operational efficiency – all while attracting and retaining subscribers. This is achieved through significantly higher data speeds, lower latency, and by offering increased network capacity to customers.

On a global level, the effort of MNOs contributes to something far more significant. By building the infrastructure that will enable 5G, the Internet of Things, and the ‘Fourth Industrial Revolution’, MNOs are helping to pave the way to a more interconnected, efficient and sustainable world of futuristic technologies; fully autonomous vehicles navigating complex urban environments, remote collaboration and telepresence technologies that transcend geographical boundaries, and a host of fantastic use cases as yet unimagined.

Considering or planning a core network transformation? Talk to our experts.

Meet our expert

Mohammad Arif Khan

Lead Connectivity & Networks, Capgemini Engineering
Arif has been dedicated to creating valuable digital experiences and enhancing customer relationships since 2003. Throughout his career, he has delivered numerous high-quality technical solutions within operator networks and worked with MNOs worldwide, including Vodafone UK, STC/STCS KSA, and Société Française du Radiotéléphone in France.