Wiley's For Dummies Guide to eSIM and iSIM: By Kigen, 2nd Edition

Explore IoT RSP in this free eSIM and iSIM guide  

eSIM and iSIM with remote SIM provisioning is becoming the standard for cellular IoT devices.

IoT-connected devices are gaining traction due to the demand to digitalize operations from vertical sectors, governments and social initiatives. The world increasingly relies on IoT devices to manage an ever-growing number of functions such as smart energy, fleet management, sustainable transport, smart cities and healthcare wearables.  

Embedded SIM (eSIM)  and Integrated SIM (iSIM) unlock innovative product opportunities in building trusted, user-centric experiences which benefit from secure cellular connectivity. eSIM and iSIM technology enable trusted firmware and software updates over the air. This technology ensures the integrity of the device and the code within it throughout its lifespan. It is providing device makers with exciting opportunities for revenue generation without needing prior cellular expertise.   

Our free guide explores eSIM and iSIM technology, including the benefits, features and use cases. As well as the considerations for mobile network operators (MNOs), IoT providers and original equipment manufacturers (OEMs).  

Scalable security for cellular IoT  

Each connected device will need to be updated at some point. A key advantage of IoT devices is that they can receive software and firmware updates over the air. However, having the capacity only to allow authorized updates is crucial for manufacturers to ensure device and data integrity.   

Available choice of eSIM and iSIM solutions for scale  

All SIMs are built on universal integrated circuit card (UICC) technology. A secure computing device stores operator profiles that enable authentication on cellular networks. eSIM and iSIM are technologies used to authenticate subscribers and devices on mobile networks securely at enabling IoT to scale. 

Embedded SIM (eSIM) is soldered onto the device’s circuit board for protection from potential damage and theft.  

Integrated SIM (iSIM) doesn’t have to be soldered onto the device circuit board as it’s built into the chipset. iSIM is designed to meet the need for smaller, cheaper and more secure SIM cards. ISIM is integrated into the cellular module and is 98% smaller than an eSIM.  

Understanding eSIMs  

Embedded SIM (eSIM) is soldered into the device to incorporate new functionality needed to connect, store and manage profiles on IoT devices. The eSIM can store multiple network operator profiles which are remotely provisioned.  

 They can switch carriers and receive firmware updates over the air (OTA). It means you can deploy your device anywhere in the world without physically swapping out the SIM card for true scalability.   

Understanding iSIMs  

The integrated SIM (iSIM) moves the SIM from a separate chip into a secure enclave alongside the application processor and cellular radio on a purpose-built system on a chip (SoC). They are delivering these three building blocks in one embeddable component.   

The circuit board footprint is reduced, as are component sourcing and device manufacturing costs. It is energy efficient and can function where space is at a premium such as health devices, shipping labels and hair straighteners. A Secure Enclave reinforces chip-level security. iSIM is fully compliant with GSMA Remote SIM Provisioning standards and ETSI SIM specifications.  


SIM cards contain the operator subscription data, the authentication credentials and SIM-based software and applications. eSIM and iSIMs can hold multiple profiles. eUICC SIMs hold various profiles, each as a virtual SIM within the physical SIM container. However, only one profile can be enabled at any time. IoT devices such as vehicle fleets and container trackers must be provisioned for multiple regions.  


It is crucial for the trustworthiness of IoT data that security measures are easy to implement to protect credentials as they are transmitted from device to cloud. To this end, the OPEN IoT SAFE initiative mitigates the complex integration of security measures. They allow the exchange of any data across any network to exchange that data with a given enterprise securely.  

The zero-touch provisioning lowers the barriers to accessing hardware-based security for IoT deployments by effectively protecting credentials.  

Machine-to-machine remote SIM Provisioning (M2M RSP)  

Machine-to-machine RSP (Remote SIM provisioning) for eSIM and iSIM M2M RSP is the delivery and management of operator profiles within the eSIM. RSP takes place via the SM-SR (Subscription Manager Secure Routing) over cellular connectivity over the air using an out-of-the-box bootstrap. Kigen RSP for M2M and Consumer is certified under the GSMA Security Accreditation Scheme (SAS) with GSMA-accredited sites in the UK 

Understanding RSP: Consumer and M2M, to what’s better for IoT  

The new eSIM standard SGP.31 from the international GSMA organization allows IoT devices to use the eSIM operator switching model developed for consumer devices. It’s specifically designed for remote devices with eSIM and low bandwidth, such as smart meters which don’t have a user interface.  

IoT RSP overcomes challenges not covered today by consumer RSP or M2M RSP. It allows remote profile management from nominated trusted third-party platforms and supports profile download triggered via an activation code. It enables remote profile management on an individual or fleet of devices.  


IoT interoperability is the capacity for multiple devices in an IoT deployment to communicate and share data to achieve a joint outcome effectively. Organizations must be able to transmit and understand data throughout all the connections from devices to the cloud.  

Developments in IoT technology  

eSIM and iSIM, along with the capabilities of the public cloud for IoT data, edge compute platforms, the expansion of 5G networks and Low-cost, low-power devices. All provide new vertical-specific IoT possibilities tailored to the needs of specific sectors. The opportunity to develop and deploy applications enhanced by transformative eSIM and iSIM technology for smart cities, logistics tracking, micro-mobility, healthcare and security has never been more significant.  

Whether you are starting the eSIM and iSIM journey or looking to enhance IoT devices in your existing digital transformation, Kigen’s team of experts can support your decisions at all stages.   

We can help you simplify your deployment through our close ecosystem partnerships with leading MNOs, connectivity providers, device makers and chipset providers.  

Get in touch to find out more