Beyond Traditional SIM Cards: Exploring the Benefits of iSIM for IoT

Istvan Lajtos

Head of Product Management

LinkedIn

Despite advances in cellular technologies and maturity in the ecosystem, there’s still more to do to realise the full potential of IoT. Integrated SIM technology can open up huge opportunities for expansion and innovation – once the challenges of adopting a new technology are overcome.

What is iSIM technology?

iSIM stands for “Integrated SIM” and is an evolution of SIM technology where cellular connectivity and subscriber identity management functionality are integrated into a System-on-Chip (SoC). Unlike traditional physical SIM cards that need to be inserted or embedded into a device, moving the SIM into a SoC reduces the footprint required on the device for connectivity components.

Benefits of iSIM

Built within a secure enclave in the SoC to GSMA specifications, iSIMs provide the same levels of identity authentication, security and seamless connectivity as embedded SIMs.

But the benefits of iSIM technology over SIMs of other form factors can also address issues that are holding IoT back.

Small size

Moving the cellular modem and SIM into a SoC reduces the footprint required on the device for these connectivity components.

Smaller devices can create new opportunities where size really matters. For example, smart labels can contain a device to track goods during shipping. Miniature devices can be embedded in wearables, such as smart glasses for VR/XR, to enhance their connectivity and functionality.

Power and performance

iSIM SoCs can deliver major improvements in device power usage and performance. The SIM itself requires less power to operate and that power is delivered to it more efficiently. Close integration of the components enables them to operate more effectively together.

For battery-powered devices, power conservation is key to success – particularly for those that need to operate in the field for many years. The combination of iSIM technology and the advances in Low Power Wide Area (LPWA) networks, such as LTE-M and NB-IoT, is ideal for deployments with low power, low bandwidth requirements.

Cellular connectivity becomes a viable option for many use cases where power usage had previously precluded it.

At the other end of the spectrum, some deployments require predictable and consistent performance with extremely low latency or high bandwidth. Examples include automated production lines, robotics, and autonomous vehicles. Using iSIM devices with 5G networks will deliver optimum performance for these solutions.

Ruggedised devices

Reducing the number of discrete components in a device reduces the risk of damage to the device, such as through water ingress.

Many IoT devices are located outdoors, sometimes in inhospitable terrain. These devices need to be ruggedised to withstand possible tampering, adverse weather and other environmental factors – often for many years. While embedded SIMs offer much better protection than removeable SIMs, with iSIM there are even fewer components to worry about.

Cost and complexity reduction

Cellular connectivity is often the best – if not the only – option for IoT deployments requiring global, ubiquitous connectivity.

But it’s not easy. Device manufacturers need relationships with module and SIM vendors, eUICC manufacturers, and connectivity providers. They need to ensure that their devices will operate as required in the field and gain certifications from relevant bodies.

With non-integrated SIMs, device manufacturers require separate supply chains for the SIMs and other device hardware. Using iSIM SoCs simplifies the Bill of Materials and supply chain management and enables a more streamlined process for device design, validation and certification.

Research from Transforma Insights shows that the cost of operating with eUICC embedded or iSIM devices can generate savings of 8-13%. Although initial hardware costs may be higher than for removeable SIMs, efficiencies in managing connectivity over the device lifetime can save considerable cost.

Support for secure and edge applications

The security inherent with an iSIM means it can be used as a secure Root of Trust (RoT) to provide authentication and security for other applications. This helps to reduce the overall attack surface of the device, making it more difficult for attackers to compromise the system or steal sensitive data.

One application for this is edge computing, where processing and data storage is performed on edge devices using local storage and compute resources rather than in a hyperscaler’s cloud facilities. Small applications can use the iSIM’s secure resources. If larger resources are required, the iSIM and device can act as a gateway to local edge applications that route into a private, public or hybrid cloud.

Keeping data localised can reduce bandwidth requirements, improve latency, extend battery life, and protect a company’s intellectual property (IP) and knowledge.

Challenges to iSIM development and adoption

Introducing a new technology that must meet stringent standards for security and operation is a huge challenge. The success of iSIMs relies on ensuring they comply with the industry-endorsed standards for cellular connectivity.

Adopting standards for assurance and interoperability

One of the challenges in the move to integrated SIMs is to ensure interoperability between all parties to ensure adoption and scalability. The cellular ecosystem is complex, with device manufacturers, mobile network operators (MNOs), mobile virtual network operators (MVNOs), cloud applications and others all requiring a secure and stable framework within which to operate.

SoC makers must gain certification in the approved standards and evaluation process to guarantee that the iSIM solution provides the required levels of security and ensure that the remote provisioning and switching solution will work seamlessly to ensure full interoperability.

eUICC manufacturing process

The eUICC production process is strictly controlled to ensure that sensitive assets are protected. eUICC manufacturers must operate secure production facilities that are audited to ensure compliance with GSMA requirements.

With iSIMs, eUICC manufacturers don’t have access to the SoC, as these are sent directly from the SoC manufacturer to the device manufacturer, who then needs to load the eUICC profiles onto the chips.

Requiring every device manufacturer to meet GSMA certification standards is not viable. Instead, eUICC manufacturers must create a key that is unique to each SoC to protect the sensitive data. This ensures that eUICC data can only be loaded onto the correct SoC and cannot be tampered with.

Remote provisioning and switching

The GSMA introduced two versions of the eSIM solution, one for consumers and one for IoT (M2M).

The consumer version enables devices to download network profiles when they need to switch. This uses the RSP pull mechanism.

The M2M version requires central systems to download profiles to devices using the RSP push mechanism and manage the profiles with over-the-air commands. Operators need to implement complex integrations with other operators’ systems to enable devices to switch from one network to another. Remote management operations are challenging for battery-operated IoT devices as they often connect for very short periods, which may not be long enough for operations to complete.

So, although iSIM builds on the eSIM solution, there’s no guarantee that enterprises can access global, ubiquitous connectivity with seamless network switching. Some MNOs haven’t fully embraced the eSIM remote switching technology, which means switching devices or whole deployments from one provider to another may be costly or impossible.

The GSMA has published a new standard (SGP.31) to extend the consumer version to IoT devices. There are challenges to adopting this standard, such as the time and cost involved, and the lack of interoperability with the M2M standard. Eventually, however, this solution will ensure greater choice and flexibility for organisations needing seamless, global connectivity for their IoT deployments.

Research indicates there could be 200 million iSIM-compliant devices in use by 2025. Initially, the growth is likely to be seen in use cases that need the efficient power use of iSIMs in combination with LPWA networks, such as LTE-M and NB-IoT. In addition, iSIM technology is likely to be adopted for devices, such as wearables, where space is at a premium.

It will take time for a wide selection of certified iSIM SoCs to be available. In general, however, iSIM technology is opening up opportunities to enhance existing applications and to present cellular connectivity as a viable option for a whole host of new applications and devices.

Connecting today

iSIM technology is the next exciting step in the evolution of SIMs – but iSIMs will be used alongside removeable and embedded SIMs for many years to come.

If you need to connect your IoT devices today, you don’t need to wait for iSIMs to be widely available. Talk to one of our IoT experts to find out how we can help with SIMs of any form factor…

Istvan Lajtos

Head of Product Management

LinkedIn

Istvan’s telecommunications career spans more than twenty years in a variety of roles, including product management, technical account management and marketing. Istvan leads on product management with expertise in communication technology strategy development, smart city technology and IoT, 4G to 5G mobile network evolution to secure content delivery.