Quick definition: An integrated Subscriber Identity Module (iSIM) is a SIM that’s built into a dedicated Tamper Resistant Element (TRE) on the System on Chip (SoC) and provides all the same functionality as an embedded SIM (eSIM). While an MFF2 embedded SIM has to be soldered onto the circuit board, iSIMs are a dedicated component of the chip. They’re also the smallest SIM currently available, measuring just 1mm by 1mm—a fraction of the size of an MFF2, which is already much smaller than standard SIM card form factors.
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What Types of SIMs are There? Different SIMs and Form Factors Explained
The humble SIM card has evolved far beyond its original design, becoming a critical component in ensuring seamless connectivity across devices and networks globally. From the traditional, physical SIMs to the innovative, embedded eSIMs, the technology has adapted to meet the diverse and expanding needs of IoT applications.
SIM, eSIM vs iSIM: What’s the Difference?
As you explore cellular components, at times you may hear several different terms for components that provide the same core function, such as a SIM, eSIM, and iSIM. The difference between these components could have a significant impact on your device’s future functionality, security, and scalability, so it’s important to understand the differences between them.
What is an eSIM?
Traditionally, if you wanted to switch your cellular device's carrier you had to replace the SIM with one from the new carrier. With phones and tablets, this is a simple task. However, for thousands of remotely deployed IoT devices, swapping out SIMs is problematic, especially for devices with embedded SIM form factors that are soldered. In such cases, the SIM is stuck in the device.