What is an eSIM?

An eSIM (embedded SIM) is a physical SIM but instead of being removable, it’s embedded permanently into a device. Authorized users can access and update profiles and other data on the eSIM via an over-the-air, remote SIM provisioning solution (RSP). eSIMs can store multiple network profiles allowing users to use services from multiple cellular networks with a single eSIM.

Physically removable SIM cards occupy a relatively larger physical area as the mechanism to add and remove the SIM also needs to be incorporated within the housing of the device. As IoT and connected consumer devices continue to shrink in size, it creates a design challenge for device makers that may need that space for other important features. Also, the fact that traditional SIM cards can be removed, causes other issues like the card can be dislodged, damaged or stolen. Even organizations that manage inventories of mobile devices face large costs and logistical complexities when tracking and managing every SIM card under its control. As SIM cards are used for deploying a large number of devices in industrial IoT, IoT logistics and smart cities applications, the cost and logistical complexity of managing these SIM cards make them untenable for deploying large numbers of devices.

eSIM technology offers an elegant, robust, and almost infinitely scalable solution to these legacy SIM challenges. The eSIM measures 5 × 6 mm and is approximately half the size of a Nano SIM card, which measures 12.0 × 8.8 mm. It is embedded into the device and doesn't need a SIM tray and a separate housing with a removable mechanism to be incorporated into the device. This size reduction gives device manufacturers more design flexibility and lowers their production costs. Using RSP technology, users can remotely manage profiles to change networks or update settings on almost any number of eSIM devices. Being non-removable components, eSIMs are tamper and theft proof. 

The global specification of eSIM is maintained by the GSMA. GSMA has defined eSIM as the SIM for the next generation of connected consumer devices. eSIM is a revolutionary innovation because it reduces the cost and management complexity of physical SIM cards. As a result, companies that deploy large numbers of IoT devices aren’t locked into their initial network operator or its pricing and access policies. 

Networking solutions using eSIM technology can be widely applied to various Internet of Things (IoT) scenarios, including connected cars (smart rearview mirrors, on-board diagnostics (OBD), vehicle Wi-Fi hotspots), artificial intelligence translators, MiFi devices, smart earphones, smart metering, GPS tracking units, DTU, bike-sharing, advertising players, video surveillance devices and many other devices.

Click here to download the eSIM white paper written by GSMA. This white paper provides both a primer to introduce the basics of Remote SIM Provisioning technology and an introduction to the detailed technical specifications.