What’s an iSIM, and why should I know about it?

In this article, Amr Houssein, Managing Director of BSS telecom software developer Mobilise, offers his introduction to iSIM technology.

While a physical SIM card requires a dedicated slot on the smart device and eSIM demands a dedicated chip in order to initiate its set up, iSIM isn’t soldered onto the device’s circuit board. Instead, an iSIM has a dedicated space on the System on Chip (SoC) where it’s protected by a Tamper Resistant Element (TRE).

Just like eSIM, iSIM allows carriers to preload network profiles or remotely provision them on a user’s device without them needing to visit a store or acquire a physical SIM in any other way. There are, however, differences that bring benefits to several use cases.

The IoT space

iSIM is significantly smaller than eSIM – about 98% smaller, to be precise. Device real estate is a pretty valuable matter, and a standalone chip that’s dedicated for eSIM can take up precious space. This smaller size, alongside advancements in low-power silicon modules, opens the door for a number of IoT use cases.

For instance, iSIM brings heightened visibility to transport and logistics applications, helping businesses track the location and condition of products shipped worldwide. Smart labels embedded with a low-power connectivity module, an iSIM chip and a battery that can power the label for almost a year can form the basis of an IoT connectivity solution that takes up minimal space, yet provides major supply chain insight.

While it may look like any other label, a smart label has the ability to monitor and report on any disturbances to the delivery process. For instance, if there is a sudden change in temperature that would damage the goods, a notification is sent that triggers an action to resolve the situation.

Ultimately, iSIM changes the way device makers can access cellular capabilities for devices that couldn’t be served before. If we consider everyday consumer electronics, like hair straighteners for example, fitting an iSIM would add zero bulk to the appliance. What manufacturers could gain, however, is data on operational conditions and user behaviour that can help them improve their products.

Additionally, iSIM could also offer a digital interface that helps consumers control and manage their appliances themselves, adjusting parameters such as temperature based on their preferences.

The consumer space

A major boon of using iSIM for IoT applications is that it can save costs, with this iteration of SIM card technology looking to become the most affordable to date for many IoT devices. For consumer devices, however, this won’t make much of an impact on the overall cost of the device – though it certainly won’t drive prices up. Instead, there are other major benefits for these applications.

First, there’s the size of the chip. A 98% size reduction on eSIM is valuable to OEMs that are constantly looking to add more complexity to a device. With a smaller SIM, there’s more opportunity to add in something new.

Second, it introduces chip-to-cloud secure connection, heightening its security credentials.

A third major driver for iSIM in both the IoT and consumer space connects to the GSMA standards. Standard SGP.02/22, which defines a technical solution for the remote provisioning and management of eSIM in consumer devices, was separated from the standards and flows used for IoT applications. This made it challenging for service providers to build a unified solution to address the two sectors.

However, things look set to change with the introduction of standard SGP.31. This will leverage the benefits of existing GSMA eSIM remote provisioning specifications tailored to the machine-to-machine (M2M) and consumer markets and fill the gaps for IoT use cases. Its aim is to make the use of eSIM more widely available, but that’s encouraging for iSIM too.

We’re already seeing several consumer device OEMs begin to explore iSIM as a result of SGP.31. Already, many Android models are being tested with iSIM for both wearables and handheld devices. And, what’s even better for consumers, is that the transition from eSIM to iSIM can happen seamlessly, without introducing any changes to the user experience.

Let’s not get ahead

iSIM is undoubtedly the next generation of SIM technology and will apply cellular connectivity to the unconnected. It’s all part of an exciting future – but we mustn’t neglect the here and now.

eSIM adoption remains very much underway, and consumer appetite is real. Amdocs reports that 81% of consumers are actively in favour of an eSIM-only future for smartphones, driven by the prospect of being able to switch between plans seamlessly. But we’re still just scratching the surface of eSIM’s potential. We’ve seen major industry players, such as Apple and AT&T demonstrate their support for the technology this year, with the launch of an eSIM-only iPhone 14 acting as a catalyst for change.

For those operating in telecommunications, this uptake feels like it’s been five years in the making. So, while iSIM will undoubtedly offer many exciting benefits for manufacturers and consumers alike, benefits that we’ll all enjoy in the not-so-distant future, it’s clear industry is only just beginning to bask in the eSIM era.