Do-It-Yourself eSIM RSP (part I)

eSIM – the digital transformation of the plastic SIM – is speeding up.

As adoption is set to scale globally from millions to billions, the use cases for players in the mobile telecom market to become an enabler of this game changing technology take on new urgency:

  • Infrastructure Providers – extending their solution stack with eSIM Management
  • Service Providers – adding eSIM Management to their service offering
  • Mobile Network Operators – managing eSIM subscriptions in-network

Although “eSIM-Management-as-a-Service” has been available for years from established SIM vendors, companies that deliver RSP services to their customers will need, in the long-term, commercial and technical independence to offer competitive products and services. And Mobile Network Operators (MNO) can have compelling reasons to fully control storage and processing of subscriber data “in-network”.

One alternative to the Software-as-a-Service model - developing the RSP software - is a huge project that demands deep knowledge of the embedded security domain and substantial development resources.

The second alternative - using “off-the-shelf” RSP software - eliminates the cost and risks of a development project and instead focusses efforts on building an RSP service that perfectly fits the business demands.

achelos offers a complete suite of RSP solutions covering the components specified by the GSMA (GSM Association) as well as solutions that go beyond the specified standards. As a software house we not only develop customised features and extensions for all products but also fully bespoke solutions.

To the challengers of the eSIM Management status quo, we deliver control:

  • Control of infrastructure and system configuration
  • Control of quality and costs
  • Control of regulatory compliance
  • Control of customer data retention
  • Control of integration with systems and processes
  • Control of customisation for a unique offering


In a series of articles, starting with this post, we want to give a detailed overview to help you determine which approach is right for you, “RSP-as-a-Service” or “Do-It-Yourself-RSP”.

You will find information about the essential components and, with a step-by-step description, how you can build an RSP service that you fully control and that is enabling your business strategy in the long-term.


But what took eSIM so long anyway? And why should this change?

Since the introduction of eSIM technology most known eSIM Management solutions, better known as Remote SIM Provisioning (RSP), have been offered as a service. It was seen, and largely still is, as an evolution of the traditional plastic SIM card business, inextricably linked to the manufacturing process of the secure hardware chip. The only difference being that the Mobile Network Operator (MNO) buys a "virtual" SIM instead of a physical one. However, the concept of eSIM actually enables very different models.

eSIM is separating the non-reprogrammable SIM chip from the MNO profile and transforms the profile into a truly digital asset. It becomes remotely manageable based on a purpose-build secure element, the eSIM chip. While the SIM was designed to be removable, the eSIM chip is a fixed component of the device with the capacity to store multiple MNO profiles.

Despite the obvious advantages of this approach, uptake of the technology has been slow. Mobile operators were sceptical to give their customers an easy way to “churn” and to sign up with competitors instantly by simply using an app on their mobiles. On the other hand, device manufacturers (OEM) were hesitant to increase their Bill of Materials, especially for low-cost devices, which would add a functionality that was neither understood nor demanded by customers. It created a chicken and egg situation that stalled the adoption of eSIM for years, leading to very limited usage where “eSIM Management-as-a-Service” from established manufacturers was the only option available and viable.

Times are changing, however, and fast, as you would expect from a disruptive digital technology. There is now no doubt throughout the industry that eSIM will largely replace the SIM in the not too distant future. 5G created significant momentum. Since its launch the major OEMs have been releasing an expanding range of 5G devices supporting eSIM. Mobile Network Operators have started to view eSIM as an opportunity to strengthen the customer relationship rather than as a thread to it. These developments are reflected in the latest numbers from GSMA itself, the global Association of Mobile Network Operators, that estimate eSIM connections to reach between 1.9 and 2.8 billion connections, the equivalent of 26%-40% of total market share, until 2025 alone.


Source: GSMA


In line with this forecast a growing amount of industry news is emerging, such as a Tier 1 MNO in Europe that will make eSIM the default subscription activation process and rumours that one of the leading mobile phone manufacturers is about to introduce “eSIM-only” models without the space consuming SIM slot. Besides the projected growth of eSIM usage, there is another major development that makes the operation of RSP services a lot more efficient – cloud.

Until very recently the traditional RSP service setup demanded substantial on-premise infrastructure within a certified high-security area. For innovative newcomers the entry barriers were largely too steep to surmount. Cloud, especially the GSMA security-certified, public cloud offered by MS Azure, AWS and Google across multiple sites and regions, has changed the game fundamentally. It reduces costs substantially while offering scalability combined with telco-grade reliability, enabling companies to host an RSP service that effortlessly expands in step with increasing demand.


In the next post we take a look at the different architectures specified by GSMA for eSIM RSP Management.

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