eSIM vs iSIM: The eUICC Background

The world of connectivity has broadened significantly in the last decade due to the release of eUICC, or as it’s commonly known, eSIM. This carrier-agnostic SIM technology has created a single-SKU approach to connectivity that can be accessed around the globe. 

The eSIM Background

eUICC, the technology, is different than eSIM, which is the SIM card form factor. However, as eSIM is often used interchangeably with eUICC, for the sake of this article, I’ll refer to it mostly as eSIM. 

From a technology standpoint, however, eUICC stands for Embedded Universal Integrated Circuit Card. It’s a component of a Subscriber Identity Module (SIM) card that lets you switch Mobile Network Operators (MNOs). It’s a GSMA standard that was first created to provide a standard and simple means for customers to switch operator profiles when the embedded SIM (eSIM) was introduced.

Prior to eUICC, connected devices leveraged UICC, which contained a single mobile network operator (MNO) profile but the eUICC can manage multiple profiles within a single SIM card. 

This works through remote, or over-the-air (OTA) provisioning. Simply put, a device with an eSIM might initially deploy with a Telefonica profile but then move out of coverage and need to switch to a new network provider. With a UICC, this would have to take place by physically swapping the SIM card. But with eUICC, the organization using the eUICC device can use a remote SIM provisioning (RSP) platform (which may or may not be integrated with the connectivity providers’ connectivity management platform) to download the profile of the new network operator. 

All of this is done remotely and over-the-air, which allows deployed devices to access global connectivity at any time. 

Consumer eSIM vs M2M eSIM

Until recently, eSIM was segmented into consumer and M2M and this was mapped out in the SGP Release .21/.22. The consumer version was, of course, designed for a single-consumer use with the understanding that the end user would always have access to the device in order to download profiles. 

This is why the profile download is a “pull” model, where the consumer can select an operator via QR code or URL. The RSP module leverages SM-DP+ with a Local Profile Assistant (LPA) to make the switch. 

Conversely, the M2M version was designed with the understanding that there essentially is no end user and devices are deployed in large quantities and not user-by-user. This is why the profile download is a “push” model where the operator is selected by the organization. 

The RSP module leverages an SM-SR for managing the status of profiles on the eUICC. 

eSIM Release .31/.32

Recently, a new standard for eSIM was released – .31/.32, which blurs the lines between consumer and M2M. This standard uses a backend server – called the eSIM IoT Manager – to act as a proxy user interface that allows for a profile pull or profile push. 

This reduces complexities, streamlines downloading, and simplifies integrations between providers. 

In my next post on Thursday, I’ll show how eSIM and iSIM are much more similar and how both can help advance the adoption of carrier-agnostic, remote SIM technology.