Celebrating Qualcomm's Amazing Journey From eSIMs To iSIMs

Recall how in the early days of mobile phones the craze for swapping sim cards for every change of phone was something else. All that is about to change now.

At MWC 2023, Qualcomm announced a new advancement in SIM cards: the iSIM.

But how is an iSIM different from an eSIM? And what does it mean for mobile users? 

Simply put, an iSIM is a type of eSIM.

Usual eSIMs are small chips in a phone's motherboard. On the other hand, Qualcomm's iSIM is embedded into the processor.

As we can see, one of the interesting news from this year’s Mobile World Congress comes from Qualcomm.

According to this well-known chipset manufacturer, the Snapdragon 8 Gen 2 has been certified as the “world’s first commercial SoC with iSIM (Integrated SIM) support”.

But again, what the heck is iSIM? Didn’t we just switch from SIM to eSIM?

Right, but iSIM is better than eSIM.

The short answer is that iSIM is the next step in the ongoing march to reduce the size of SIM cards.

SIM cards are (in the smaller “nano” size) small 12×9 mm plastic cards that you physically insert into your smartphone.

The word SIM stands for “Subscriber Identity Module” and these cards mostly just identify you to your mobile operator, allowing your device to connect to it to provide the monthly service you pay for.

The idea is that if you buy a new smartphone or have several smartphones, you can simply move the SIM card between them if there are no compatibility issues, with the service correspondingly transferred from one phone to another.

In the past, these cards used to store some real data, such as contacts and messages, but with the advent of smartphones, all of this has been moved to the cloud.

Today, a SIM card can store up to 265KB of data on this 12×9mm sized card, which is an extremely small capacity when you consider that similarly sized MicroSD cards can go up to 1TB, or about 4, 2 million times more data.

SIM cards are a huge waste of space in an industry that is very aggressive about saving space, so they had to go.

With eSIMs, we have a new standard that does away with the physical, removable SIM card and instead places a tiny chip on your phone’s motherboard.

These came to Google’s Pixel line in 2017, the iPhone in 2018 and some Samsung phones in 2021 and, for some models, lived alongside physical SIMs.

A major turning point for most carriers was Apple killing off the physical SIM card in 2022 on iPhone 14s sold in America, which only accepts eSIMs.

An eSIM-only device has no removable card at all and therefore no card slot, simplifying the device design, saving space and removing a potential point for water ingress.

Instead of putting a piece of plastic on the phone, the user can connect to their carrier by completing a process that simply has a QR Code.

eSIMs save a lot of size compared to physical cards, and the smallest chips available measure around 2.5×2.3mm.

eSIMs are still a chip that takes up space on your motherboard, and that’s not ideal for manufacturers looking to squeeze every square millimetre of a phone’s space.

The next shrinking step is the iSIM – an integrated subscriber identity module.

Instead of a chip on the motherboard, iSIMs are integrated directly into the SoC.

SoC (system on a chip) integration is the technology that makes smartphones possible.

Instead of a thousand little chips that would handle the CPU, GPU, RAM, modem, and a bunch of other stuff, everything is bundled into a single piece of silicon that does everything.

Building everything on a chip, with the tiniest transistors you can muster, is the cheapest and most space- and energy-efficient way for industry, and now SIM cards are going to disappear inside that big block.

iSIMs will be measured in fractions of a millimetre and as part of the SoC, they will continue to shrink every year as chip process nodes reach smaller and smaller dimensions.

It looks like this is the final stage for SIM technology, and in addition to helping manufacturers, it will be great for devices with increasingly limited space, such as smartwatches.

Of course, carriers will need to agree to this, and that’s what Qualcomm’s announcement is mostly about.

The iSIM support in the Snapdragon 8 Gen 2 SoC that makes its appearance in recent android flagships has been certified by the GSMA or mobile operators worldwide.

Qualcomm says that “the new iSIM is fully compliant with the GSMA Remote SIM Provisioning standard – meaning its subscriptions can be managed remotely via any standard platforms”.

This is the same standard as eSIM and the same security requirements are met, so in theory any carrier working with eSIM should see no difference between an eSIM and an iSIM.

The iSIM is still just a piece of silicon that needs software to connect, and where silicon is present, it shouldn’t matter to your carrier.

Like many components of Qualcomm’s SoCs, the use of iSIM is optional, even though it is built into the chipset.

All current Snapdragon 8 Gen 2 smartphones use discrete eSIM chips instead of iSIMs.

However, now that the solution is certified, the next move is in the manufacturers’ camp.