What is eSIM, Embedded SIM, iSIM? Status of eSIM functionality in South Africa.

So many terms, and often some confusion around these terms within the Telecoms industry.
These terms can refer to the physical form of the SIM (form factor) or a set of SIM capabilities.

What is the Difference between eSIM, Embedded SIM and iSIM in IoT deployments?

A SIM (Subscriber Identity Module), also called a Universal Integrated Circuit Card or UICC, stores information that uniquely identifies a cellular subscription.  It holds the credentials and security keys necessary to identify a subscriber. That identity comes in the form of a so-called IMSI number, or International Mobile Subscriber Identity, which is unique for every user or device on or off the network. SIMs also run an application that passes that identity information to an onboard cellular modem. The modem in turn conducts the actual attachment operation to the network. The application that the SIM card runs, by the way, is also referred to as UICC; the acronym is often used synonymously with the card or chip itself.

The rightmost Embedded and Integrated ones look a little different – that’s because these are chips soldered directly onto your electronic circuit board that makes up your device, vs. the bigger versions you insert manually into a slot. This smaller form factor was needed for our ever-shrinking consumer and IoT devices. You could say it is “embedded” into a bigger circuit board.

--> Embedded (MFF2) SIM formats can be supplied by us for most local and global roaming mobile networks that we support.

So if the MFF2 form factor is “embedded”, is this what we call an “eSIM”? Unfortunately, not always. Some do call it that, but it’s imprecise. While the “e” in eSIM does stand for embedded (you will also find the reading “electronic SIM” out there), what is meant with eSIM is really a different “kind” of SIM (embedded or plastic).

What is an eSIM?

In simple terms, an eSIM is a SIM (embedded or plastic) that can load new carrier profiles digitally. For consumer devices, this needs to be done manually on the device (by scanning a QR code or inputting a numerical code), while unmanned IoT devices needs to conform to the new SGP.32 protocols for over-the-air provisioning (more on that below). 

In more technical terms, an eSIM is any piece of hardware that runs an application called eUICC, which has storage to hold multiple SIM profiles at the same time (but only one can be active), and can be provisioned manually (SGP.21/22) or remotely over the air (SGP.32).

An eSIM can therefore come in the form of any of the known form factors (2FF, 3FF, 4FF, MFF2, WLCSP) – and anyone can design their own hardware chip, as long as it runs an application that conforms to the GSM eUICC standard. 

--> eSIMs (manual activation SGP.21/22 standard) can be supplied by us for most local and global roaming mobile networks that we support.

Why is eSIM provisioning widely used in the consumer market, but not massively adopted in cellular IoT? 

Today there are three approaches to handle multiple MNO profiles in a single UICC, but by 2024/2025 a fourth option started becoming available, although adoption will take a few years.

These four options are:

1. Proprietary Multi-IMSI solutions: 

Typically, M(V)NO non-standard approaches that only work in a closed environment. A SIM is pre-loaded with 2 or 3 IMSI profiles that is rotated by the device firmware. These can not be changed remotely.

2. Existing GSMA-compliant RSP solutions:

M2M (GSMA SGP.01/.02): targeting M2M devices and applicable to non-end-user interactive environments. Here, profiles are pushed from the MNO. This standard was never widely adopted by MNO's due to cost and technical limitations.

3. Consumer (GSMA SGP.21/.22): Targeting Consumer devices (e.g., smartphones, tablets, wearables). In this case, profiles are manually pulled by the user (often using a QR code or app) and is not practical for IoT deployments. This is often used by travel SIM providers.

4. The new, emerging GSMA RSP standard (SGP.32):

This is specific to IoT applications and for network and UI constrained devices where eSIMS can not be manually activated. Adoption by MNOs and the wider ecosystem such as hardware providers is unlikely before 2026+. Full technical specs here. 

Once the “IoT” SGP.32 standard displaces the existing M2M standard, large-scale deployment of eSIM/iSIM in IoT deployments will become practically possible. For this to happen, the ecosystem needs to mature and develop so that GSMA certified devices, SIMs and RSP systems become readily available and in addition, local network operators making eSIM profiles readily available at reasonable prices.

eSIM management adds additional layers of technical platforms and providers, which may drive up costs. Be sure to fully understand the benefits eSIM deployments for IoT devices before embarking on this journey. Often the added complexity and cost does not justify the perceived benefits, and existing pain points can be adressed in other ways.  

Status of eSIM functionality in South Africa
Networks in South Africa (Vodacom, MTN, Telkom) only support consumer (SGP.21/22) eSIMs in approved devices. These eSIMs can be supplied and managed on SIMcontrol.

They need to be programmed/activated manually on the device (not Over The Air), typically by using an app or scanning a QR code. It is not currently possible to activate eSIMs on many IoT devices remotely. This will be possible once the new SGP.31/.32 standard is adopted by local network operators. So for IoT devices, no local remote eSIM activation support is available yet on South African networks.

--> Consumer eSIM (SGP.21) is available from us on the following networks:

 - Vodacom

 - Telkom

 - MTN (untested)
 - BICS IoT Roaming

Multi-IMSI SIMs

Multi-IMSI is a concept developed to overcome the single profile limitation set by UICC. The Multi-IMSI packages multiple MNO profiles (IMSI) in a single SIM card. The MNO profiles are managed by an applet running on the SIM. These are typically used for roaming between mobile networks.

--> Contact us for Multi-IMSI roaming options and data rates. 

What is an iSIM? 

The next revolution in the eSIM world wil be the iSIM (aka integrated SIM), a SIM that integrates directly into the device's processor. 

In essence, the iSIM enables devices to connect to a cellular network without needing a physical SIM card or soldered eSIM in a printed circuit board. 

Instead of using a separate physical SIM card, the iSIM technology embeds the SIM features directly into the device's hardware, allowing it to connect to the cellular network. Remote SIM provisioning (RSP) consists of loading and activating an MNO profile in an eUICC via over-the-air (OTA) download or other (manual) means.

The iSIM offers two key features: 

- It saves space by eliminating the need for a separate component.

- It requires significantly less power than eSIMs, making, for example, massive IoT use cases more operational.

Please contact us for eSIM, embedded SIM or Multi-IMSI SIM options for IoT deployments. 

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tags: eSIM, e-SIM, chip SIM, embedded SIM, multi-IMSI, eSIM Vodacom , eSIM MTN, eSIM South Africa, eSIM IoT, eUICC, SGP.32, SGP.21
Sources: Wikipedia, MyBroadband, Twillio, uBlox.