eSIM - keeping IoT connectivity simple - Quectel

July 14, 2022

eSIM (embedded SIM)
The embedded SIM (also called eSIM or eUICC) is a new secure element designed to remotely manage multiple mobile network operator subscriptions and be compliant with GSMA specifications. Available in various form factors, either plugged-in or soldered, the eSIM is easy to integrate in any kind of device.

SIM - Subscriber Identity Module

The subscriber identity module (SIM) in plastic card format has become the ubiquitous means of identifying a subscriber to a mobile network. It has provided an easy to use, globally-accepted way for mobile network operators (MNOs) to authorize and allow devices to connect to their networks, safe in the knowledge that they can bill the subscriber and they know what devices are connecting to their infrastructure. However, while plastic cards work well for consumer devices and many connected devices, the massive volumes associated with hyperscale IoT deployments means plastic SIMs are impractical.

There are several further drawbacks. A significant issue with the traditional plastic SIM is cost. This is cheap in the context of a human mobile subscriber but for IoT devices, the SIM has to be manufactured, distributed and installed and the IoT device needs to have the appropriate socket into which a card can be slid. This issue is compounded if a SIM needs to be replaced and causes huge expense in terms of truck roll as people go out into the field and swap SIMs over. This limits choice of mobile network and constrains the business case for many lower value IoT applications.

The SIM remains vital because it is a secure element, it contains user information and keys, and it simplifies the device activation and deployment process.

eSIM technology, what is it and why is it different from a physical SIM card?

Embedded SIM – or eSIM – builds on the simplicity of the plastic SIM card and enables remote provisioning with the SIM which is now a profile that is able to be downloaded into a secure element. This means there is no need for plastic cards and SIM sockets, through which dust and moisture can enter a device, and an eSIM can be preinstalled onto a device with upgrades and operator changes handled over the air.

eSIM, stands for Embedded Subscriber Identity Module, and it’s a form factor where the SIM is soldered directly onto the circuit board. While SIMs can come in many different form factors, such as micro, nano or mini – these usually need to be physically entered into a device. By using an embedded SIM, you’re protecting the card from hazards such as dust or water damage, and as the eSIM becomes part of the device, manufacturers get more flexibility to create thinner, more user-friendly devices, too.

eUICC, created by GSMA
eUICC stands for Embedded Universal Integrated Circuit Card and is a standard that was created by GSMA, the Telecoms trade body. It’s simply a SIM card that is capable of being remotely provisioned and comes in a variety of form factors. If your device supports eUICC within the eSIM, with the advent of remote SIM provisioning, these devices can be managed and controlled over-the-air (OTA). That means you can switch between different operator profiles, all from a single centralized location.

As eSIMs can withstand higher impact and wider temperature ranges, take less space on the electric circuit board and cannot be removed, you can see why eSIMs are a great choice anywhere an enterprise may need an IoT device to function.

Critically, eSIM is a GSMA global specification and it maintains the equivalent level of security and protection offered by traditional SIMs. On first connection, an eSIM utilizes a preloaded bootstrap profile and then connects to a mobile network operator to perform an initial profile transaction. In this way, eSIM enables greater design and deployment flexibility but there are still constraints because operators do not want to open their IT systems to outside control.

Remote provisioning therefore involves the exchange of sensible information and the business case for the mobile operator or mobile virtual operator is based on a closed subscription model. The full promise of remote provisioning has not been reached today because, even though that is technically possible, hurdles remain to be overcome for the business model.

There are several different SIM-related options now available to IoT organizations. These include the software SIM that runs SIM code inside and IoT module, chipset or MCU and emulates a physical SIM. These are also sometimes called virtual SIMs.

Integrated or iSIMs are now increasingly popular and as the name suggests, these are integrated into modules and chipsets that programmed at the factor and currently don’t support over-the-air (OTA) updates. iSIMs also rely on large order quantities of more than 200,000 per year. Developed by Kigen, an ARM company, iSIM is support by Quectel modules based on Sony Semiconductor IL (formerly Altair) chipsets, such as the Quectel BG770, for example.

Finally, the virtual SIM or vSIM is an ongoing development supported by Quectel modules based on Qualcomm and ASR chipsets. Similarly to iSIMs, vSIM need to have large order numbers and are programmed at the factory without OTA update capabilities.

How can IoT Solutions Benefit from eSIM Technology?

It’s with the rise of IoT that eSIMs are starting to meet their true potential. When you add eUICC compatibility to the mix, enterprises can set up security and compliance rules in a granular way without needing to manage or switch physical SIM cards in thousands of devices in the field to meet new and ever-changing requirements.

When devices land in the country in which they will connect, organizations can search for the best mobile network operator to trust, without physically being on the ground with the devices. Businesses can effortlessly meet local privacy requirements by connecting locally, and by using eSIMs they don’t have to worry about operator lock-in, since they can add profiles to the device as they need. This means at the point of manufacturing, they don’t even need to know which country is their final destination! As the eUICC-regulated eSIM has OTA provisioning and in-built security, data and communications are fully secured, according to your needs.

Ultimately the market will move to eSIM, utilizing embedded universal integrated circuit card (eUICC) technology to eventually enable OTA updates and enormous operational flexibility while still retaining the security aspects of traditional SIMs. The next few years will see sustained efforts to refine the business case and foster further standardization so eSIM can be used in global markets. Inevitably this will take time but the IoT market’s direction of travel away from plastic SIMs – whatever the form factor – is set.

eSIM for all devices



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