iSIM

iSIM

An iSIMiSIMApplicationSIMSIMApplicationSmart card for mobile network authentication.Click to view → integrated into device SoC.Click to view → (Integrated SIM) is a SIM implementation where the subscriber identity module functionality is built directly into a device's main system-on-chip (SoC), eliminating the need for a separate physical SIM card or even a discrete eSIM chip. The SIM application runs in a hardware-isolated secure partition within the SoC, achieving Secure Element grade protection while dramatically reducing the component count, board space, and cost per connected device.

iSIM Architecture

The iSIM integrates three traditionally separate components into one SoC:

The secure partition is enforced by hardware mechanisms — dedicated security logic, isolated memory regions, and a separate boot path that prevents the application processor from accessing SIM credentials. This is fundamentally different from a TEE, which relies on processor mode switching; the iSIM partition has its own cryptographic engine and tamper-detection circuits embedded in the SoC silicon.

iSIM vs eSIM vs Physical SIM

Use Cases

iSIM is designed for massive IoT deployments where cost, size, and power consumption per device must be minimized:

• Smart meters: Cellular-connected utility meters in the millions
• Asset trackers: Small GPS/LTE trackers for logistics
• Wearables: Compact devices where SIM tray or MFF2 space is unavailable
• Industrial sensors: Connected factory equipment with 10+ year lifecycles

Provisioning

iSIM uses the same GSMA Remote SIM Provisioning (RSP) infrastructure as eSIMeSIMApplicationProgrammable embedded SIM chip.Click to view →. The LPA (Local Profile Assistant) on the device communicates with the SM-DP+ server to download and activate operator profiles. Because the iSIM partition supports the same eUICCeUICCProvisioningReprogrammable SIM chip supporting remote profile switching.Click to view → interfaces as a discrete eSIM chip, existing RSP infrastructure works without modification.

Industry Status

Qualcomm's Snapdragon platforms and Samsung's Exynos modem SoCs have demonstrated iSIM capability. The GSMA's iSIM specification (based on SGP.22 consumer RSP) provides the standards framework, and GSMA SAS certification has been extended to cover SoC-integrated secure partitions.