Interview on eSIM Profiles

Why Is Correctness Crucial for an eSIM Profile?

As many participants of the COMPRION RSP Advanced Trainings asked this question, COMPRION experts Andras and Olaf explain why.

First question: What is a profile on an eSIM or eUICC?

Andras: eUICC is the technical term for eSIM, which stands for embedded Subscriber Identify Module. The eSIM has your keys needed to access a mobile network. The latest smartphones, wearables, or tablets that lack a physical SIM slot use an eSIM for connecting. And, if it is to work in a mobile network, then there always must be a profile on it as well. This eSIM profile can be described as a set of data, applications, and file structures used for the cellular connections to your mobile network operator.


Question to Olaf

Why Have a Global Standard for It?

Why have a global standard?

Olaf: Standards make life much easier and cheaper. Here, the interoperability between profiles and an eSIM is key. This means any mobile network operator can use the eSIM in your device to store the necessary profile. Or, the other way round, any smartphone can work with any mobile network operator. To keep the promise that any eSIM works with any mobile network operator, the GSMA has created a Compliance Framework. Together with standardization bodies like Global Platform  or Trusted Connectivity Alliance, they define this so-called interoperability. For all involved it is simpler to have an independent confirmation, which proves that a specific eSIM is compliant and interoperable. Hence, the GSMA cooperates with certification bodies like GCF and PTCRB.

Question to Andras

What If the eSIM Profile Is Not Compliant to Standards?

What happens with incorrect eSIM profiles?

Andras: Indeed the eSIM rejects download attempts with syntax errors. However, its limited computing capability cannot detect inconsistent profile configurations. For example, the transfer of a PUK reference without PUK definition is not stopped. If an incorrectly formatted profile is installed, the result can be unpredictable. In a worst-case scenario, it can cause operational issues in the field: Access to some data can be blocked. So a related service is not available. Or OTA (over-the-air) remote access for changing data does not work due to wrong PINs. Ultimately, it can even prevent the eSIM from accessing the cellular network at all. This is, because the profile cannot be activated.

Of course, there is a plan B: If you use Wi-Fi, you can search for another eSIM profile; an IoT/M2M device switches to a fallback profile. But in any case, it takes time. More important for the service provider, it is costly to go back to plan A, not to mention the damage to the brand’s image.

Man with frustrated expression looking at clipboard

Question to Olaf

How to Avoid Unpredictable Results?

How to avoid unpredictable results?

Olaf: As a smart help, a tool is available that offers reliable profile validation: COMPRION’s eUICC Profile Manager uses a comprehensive set of more than 80 validation rules. Based on theses rules, it automatically checks generic requirements like the proper order of profile elements. Additionally, it evaluates specific dependencies such as conditional elements, for example, “if this field is present, it must contain that value”.

Maybe this does not sound complicated. And one could doubt there is a need for an extra tool? However, 27 different profile elements, each of them allowing up to 27 subelements, is quite a number. To verify all these elements and subelements manually takes time, and errors can quickly creep in. Simply put, eUICC Profile Manager effectively helps profile creators to validate a profile. Why is this so important? Well, quantity matters. Whereas a mobile network operator may not have many profiles, the number of installations is huge. So, any error that can happen related to the eSIM profile, will very probably happen.

The Experts

Ask the Experts for eSIM Profile and RSP

Andras Talas

As Technical Consultant he leads the eUICC Profile Testing Group within SIMalliance, now Trusted Connectivity Alliance. He joined COMPRION in 2012, and as a creator of test standards for M2M in the mobile industry, his Remote SIM Provisioning Trainings provide firsthand insight. Here, he answers all questions you may have around RSP and eUICC.Andras Talas Trainer and Expert for eSIM & RSP

Olaf Rethmeier

As Product Manager for eUICC-related solutions, Olaf is the person to ask for questions regarding testing the eUICC and Remote SIM Provisioning. He joined COMPRION in 2015. Before, he had been working for 10 years at a smart card manufacturer dealing with UICC developments. This makes him the perfect expert for any eSIM question.Olaf Rethmeier eSIM & RSP Compliance Expert

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