The development of an Internet of Things solution typically includes the difficult task of choosing an appropriate communication medium. While LPWAN technologies such as LoRa and Sigfox offer Pro-IoT features such as low power and long-range, they are hampered by infrastructure and coverage challenges that force developers to consider cellular (2G, 3G, 4G, etc.) based communication, especially in applications where power is not a major concern.
In keeping with the unpredictable nature of communication protocols and the Internet of Things, cellular IoT has the proven infrastructure and coverage to support global deployment, but it is extremely difficult to manage at scale due to factors like the need for SIM cards and other obstacles.
The cellular communication organization GSMA began investigating the feasibility of software-based SIM cards in 2010 in part as a solution to this and similar problems with Smartphones and other consumer electronics products. The technical specification for eSIM, which eliminates the need for a physical SIM card in consumer devices, was announced by the consortium in 2016, and its adoption has since grown. Several manufacturers, including ARM with its new embedded SIM called ARM eSIM, and other consumer device giants, like Apple, have embedded the technology in various products.
What is an eSIM
Soft SIM, Virtual SIM, Embedded SIM, Electronic SIM, and Remote SIM are all different names for the same thing: an Embedded Universal Integrated Circuit Card (eUICC) with the ability to virtually support several network provider profiles.
Unlike traditional SIM cards, eSIMs can be re-written in software. This eliminates the need to physically exchange SIM cards and instead allows for its contents—including the international mobile subscriber identification (IMSI) and network carrier profiles—to be modified remotely using software.
The MFF2 SIM card pictured below is an example of an embedded SIM, however eSIM can also refer to less common removable plastic SIM cards, such as the 4FF form factor SIMs, on which an Embedded UICC software can be applied.
How does eSIM work?
When an electronic SIM card is put alongside a device, it allows the user or manufacturer to remotely add, update, extend, or uninstall numerous network operators.
Technically speaking, eSIMs consist of two parts, the integrated UICC (hardware) that is installed in the device during production, and a Subscription Management platform (SM), as detailed in the GSMA specifications. The two main components of the subscription management platform (SM) are the subscription management secure routing (SM-SR) and the subscription management data preparation (SM-DP).
SIMs are registered with the SM-SR by the eUICC’s maker or vendor (MNO, M2M Device, Consumer electronics manufacturer, etc.) during production or deployment, and the SM-SR keeps a constant, encrypted connection with the eUICC to handle subscription management. The SM-DP is in charge of converting MNO profiles into an eUICC-friendly format and relaying those directives from the vendor to the eUICC via the SM-SR.
The MNO sends a command to the SM-DP, which then downloads the MNO profile to the eUICC and provides an interface for the MNO to enable/disable a profile, usually in response to a user action (such as barcode scanning).
In the beginning, there was some disagreement over where exactly eSIMs would be used. Some companies, like Motorola, thought it was best suited for M2M industrial applications, while others, like Apple, saw no reason why it couldn’t be used in consumer goods. Probably as a direct result of this need to accommodate both uses, the consortium (GSMA) certified two distinct eSIM architectures;
- M2M eSIM Architecture
- Consumer Electronics eSIM Architecture
While both stacks allow eSIMs’ reprogrammability, they take distinct approaches to implementing the capability. The consumer electronics architecture adopts a client-controlled approach in which the device’s owner is in charge of remote network provisioning and operator profile management. However, the M2M design employs a server-controlled mechanism for mobile network provisioning and maintenance, allowing for remote access from the server in the backend. Because of the decreased need for human interaction at the M2M level and the central importance of remote upgrades and changes in IoT use cases, this makes perfect sense.
Key Features of eSIMs
eSIMs’ over-the-air re-programmability and the ability to navigate multiple profiles from different operators on the same device are widely regarded as its most appealing features. This eliminates the need for users to swap out hardware whenever they want to switch mobile network operators (MNOs). This, however, translates into a slew of other features that impact the device in a variety of ways (for the better, in my opinion). Among these characteristics are:
1. Cost Reduction
From the cost of the hardware like the SIM Tray and its supporting circuits to the cost of the SIMs themselves among others, the classical SIM Cards present a total cost that of ownership that is far greater than eSIMs.
2. Interoperability
All accredited partners in the GSMA ecosystem are expected to comply with the released standards and architecture, thus ensuring interoperability.
3. Small Form Factor
The shape, size, and need for an opening are requirements of classical SIM Cards that influences the form factor of the device in which they are used. With the chip-like nature of eSIMs, about half the size of Nano SIMs and don’t require a socket, designers will have more flexibility with the size and form factor of devices.
4. Power Efficiency
Even though they implement cellular communication which is not very power-friendly, eSiMs operate on less power compared to the Classical SIM Cards.
5. Security
One other obvious feature of eSIMs is their physical security. Having the chip embedded in the device makes it nearly impossible to tamper with or remove for misuse. Asides this, a comprehensive security accreditation scheme (SAS) is shipped along with the eSIM framework.
Potential Impact of eSIM on IoT
eSIMs will have a huge effect on the Internet of Things (IoT), but they will also alter the whole telecommunications business, from back-end processes to customer service.
eSIMs have the potential to affect three major subfields of cellular IoT:
1. Flexibility
This is undoubtedly the most problematic aspect of traditional SIM-based cellular IoT. While cellular connectivity provides worldwide coverage, the level of such coverage varies per mobile network operator (MNO). As a result, IoT solutions are constrained since users must go through the troublesome and logistically demanding activities of switching between SIM cards in order to fully use the connectivity characteristics of Cellular communications. But with eSIMs, IoT solution providers may make connectivity modifications based on parameters like signal quality, pricing, etc., and make those changes swiftly and securely Over-the-air.
2. Scalability
As the number of connected devices grows, it might become increasingly difficult to manage the SIM cards used by each one. This is easier to handle with eSIMs thanks to their adaptability and interoperability.
3. Reliability/Durability
Reliability issues arise when users choose to use a single SIM card from the network provider with the most coverage or when users physically swap SIM cards to increase coverage. Sim cards might be damaged or fail during the swapping procedure, and even the carrier with the widest coverage area might not have service where you’re stationed. Because eSIMs and OTA “SIM swaps” eliminate the need for physically changing the SIM card, the system is more reliable and durable.
Applications and Use cases for eSIM
While the impact of eSIMs is expected across every IoT application area, some sectors are expected to be huge beneficiaries. Some of these sectors include-
1. Automotive Industry
With the “connected car” Paradigm rapidly becoming mainstream, eSIMs have the potential to provide the seamless in-car Connectivity needed to allow users to enjoy all the features of the vehicles. Asides for connectivity, quick OTA updates could also potentially revolutionize how ownership transfer is implemented.
2. Agriculture
While most agriculture-related applications employ LPWAN protocols like LoRa, a connectivity backhaul like Cellular connectivity is often still required to get the data to the device cloud. Due to the location of most farms, the signal strength of MNOs may vary. With eSIMs, farmers can switch between MNOs without hassles.
3. Object Tracking
Sensors that track and monitor the conditions of different moving objects like cars, trucks, shipments, etc. can be made smaller have longer battery life, and unlimited coverage area (Switching between multiple MNOs), thanks to eSIMs.
Technically, every single IoT application that is better implemented with cellular IoT will experience performance increase, thanks to eSIMs.
iSIM
Like every new technology, adaptations of the eSIM technology are gradually coming to life with the most recent ones being iSIM.
iSIM (meaning Integrated SIM)
is a system that utilizes eSIM features. In contrast to traditional eSIMs, which consist of a separate chip that must be linked to the device’s CPU, the iSIM integrates both the CPU and eSIM functionality onto a single chip.
The purpose of its development was to reduce the size of SIM cards even further, and its integration with the CPU achieves this by making the device smaller and less expensive overall.
Although iSIM is still in its infancy, it appears to be the wave of the future for most applications, and some chip manufacturers are already jumping on the bandwagon, Qualcomm included, with the announcement of the Qualcomm® SnapdragonTM 855 SOC.
Conclusion
Although there is much left to do, eSIMs have the potential to pave the way for IoT solutions to take use of cellular networks’ extensive reach. eSIMs will prove useful in making sure IoT solutions take full use of the speed that 5G networks, which are now in development but are still some way off from providing universal coverage across all cities, are expected to deliver. New business models made possible by eSIMs’ introduction will also influence how IoT solution development is conducted, in addition to enhancing connectivity.