nuSIM: Our innovative iSIM solution

nuSIM is Deutsche Telekom’s iSIM solution for IoT devices, in which the SIM function is integrated directly into the mobile hardware. This means that no separate SIM card or additional SIM chip is required. nuSIM was developed specifically to meet the requirements of compact, energy-efficient and cost-effective IoT devices. The name ‘nuSIM’ is derived from ‘new SIM’ – meaning ‘new SIM’.

nuSIM addresses key requirements for IoT devices: low cost, low power consumption, compact form factors and easy integration. This enables module manufacturers to develop smaller and more energy-efficient products and to integrate SIM profiles at module level. Device manufacturers benefit from simpler device design and reduced effort in terms of storage, logistics and handling of separate SIM cards. 

nuSIM is Deutsche Telekom’s iSIM solution, in which the SIM function is integrated directly into the IoT device’s mobile communications hardware. Conventional SIMs – such as traditional SIM cards or permanently soldered MFF2 SIM chips – are, by contrast, separate components within the device and require additional space on the circuit board. With nuSIM, this separate component is no longer needed. This saves space, reduces the number of components and simplifies the device design.

Yes. The eSIM makes it possible, in particular, to add, activate and delete SIM profiles over-the-air. However, this makes it very complex and not suitable for all IoT applications – nor is it often necessary. nuSIM reduces the SIM to the bare essentials. As a result, the nuSIM is far less complex and is particularly suitable for IoT applications where switching between different SIM profiles is not required. The SIM function in nuSIM is integrated directly into the device’s mobile communications hardware. 

nuSIM is optimised for the IoT and therefore contains only those SIM functions that are essential for this application. As part of a rigorous streamlining process, features such as over-the-air access, the SIM toolkit, support for Java Card applets and unnecessary parts of the SIM file system have been removed. The result: manageable complexity, low memory requirements and very small profiles.
Another distinctive feature is that nuSIM is designed from the outset to foster an open and diverse ecosystem, in which the new technology is supported by as many partners as possible, each operating independently on the market with their own products. This fosters competition and provides our customers with the necessary freedom of choice.

Chip manufacturers can already add clear value to their components with the integrated nuSIM. For module manufacturers, this leads to smaller and more energy-efficient products, and they can work directly with mobile network operators to integrate the desired SIM profile at the module level. For device manufacturers, this brings design benefits and eliminates the entire burden of storing, transporting and handling separate SIM cards. And the end customer benefits when new devices work ‘out of the box’.

With nuSIM , the hardware, logistics and production costs that would otherwise be incurred by a separate SIM are eliminated. There is no longer a SIM holder, nor is there any need to open the device to insert the SIM card. The usual costs associated with procuring, storing and handling the physical SIM during production are also eliminated. This results in significant cost savings, particularly when dealing with large volumes. 

A set of binding specifications describes the function of the nuSIM, the interfaces for loading profiles and the cryptographic security processes. This ensures that any nuSIM profile can be loaded onto any nuSIM chip by any nuSIM Data Preparator. Compliance with the specifications is, of course, verified. To this end, nuSIM’s partner COMPRION, an established provider of SIM and eSIM test systems, has developed a comprehensive test suite.

nuSIM is particularly well-suited to cost-sensitive IoT applications involving small, energy-efficient devices that need to be ready for immediate use. These include, for example, asset tracking, smart parking, smart waste management and other sensor and monitoring applications. nuSIM is particularly relevant when devices are deployed in large numbers and the end user does not have to select or switch mobile network providers themselves.

All our partners are working to incorporate nuSIM into their product roadmaps. The nuSIM infrastructure is in place, and several chip prototypes are currently undergoing safety certification. The first nuSIM chips and modules will be launched shortly.

In principle, the nuSIM is compatible with any mobile communications technology. However, many of the nuSIM’s advantages stem from its reduced functionality, so we see its main applications in NB-IoT and LTE-M, as well as in multi-mode combinations with 2G. It will be interesting to see how the nuSIM develops in the future.

The mobile network operator’s data is provided as an encrypted nuSIM profile and securely transferred to the radio module. To do this, the nuSIM Loader Application (LA) requests the required profiles from the Data Preparator (DP), which creates and encrypts them on behalf of the mobile network operator. The profiles are stored in the Loader Application and then loaded into the radio modules. There, they are decrypted and installed. Once installed, the device is ready for mobile connectivity. The entire provisioning process is protected by cryptographic methods.

No. The nuSIM profile can also be loaded onto the wireless module by an upstream distributor. You will then receive the modules with the profile already installed and will not need to carry out the profile deployment yourself.

The partner responsible for loading the profile – usually the module or device manufacturer – must integrate and operate the nuSIM Loader Application within their production environment. Deutsche Telekom provides an open-source reference version free of charge for this purpose. Interested parties may further develop and market this tool under their own brand as required.

Much like an eSIM-SMDP(+), the Data Preparator creates the nuSIM profiles for a specific customer (module or device manufacturer) on behalf of a network operator and stores them until the relevant request is received from the customer’s Loader Application. It then transfers the profiles – in batches and individually encrypted – to the Loader Application, where they are stored for further use.

Any eSIM-SMDP(+) operator can become a Data Preparator for nuSIM with relative ease, as the processes for profile creation and provisioning are modelled on those of the GSMA eSIM. Interested companies are welcome to contact us.

Yes, the nuSIM can be assigned a profile at any stage of its lifecycle. If a profile is already loaded, the new profile simply replaces the existing one. This is also possible whilst the device is in use, for example as part of firmware updates (FOTA) or via Mobile Device Management (MDM), e.g. using the OMA Lightweight M2M (LwM2M) standard. OMA SpecWorks has standardised two nuSIM objects for this purpose, which represent the nuSIM and the nuSIM profiles as data elements that can be managed by an LwM2M server. A profile change in the field thus becomes a task for device management, whilst maintaining all necessary security aspects. This optional function is being implemented in collaboration with module and device manufacturers.

Every nuSIM implementation is independently tested and certified by TÜViT. Profiles are delivered using end-to-end encryption and via GSMA-SAS-accredited data preparation partners.