SGP.32 explained: the eSIM standard for IoT
Updated
SGP.32 is the GSMA standard that brings consumer-style eSIM flexibility to IoT devices that have no screen and no user: a remote manager, the eIM, tells each device which operator profile to download, enable or delete, and an IoT Profile Assistant on the device carries it out. It replaces the older machine-to-machine model (SGP.02), where profile changes were driven by the network side and tied to platforms chosen at manufacturing.
Key takeaways
- Two documents. SGP.31 sets the requirements; SGP.32 is the technical specification.
- Three roles. The eIM orchestrates, the IPA executes on the device side, the operator’s SM-DP+ serves the profile.
- Built for constrained devices. Besides HTTPS, SGP.32 supports CoAP over UDP with DTLS, suited to LTE-M and NB-IoT links.
- Not retrofittable. An eUICC must be made for SGP.32; older SGP.02 devices generally cannot be converted.
How a profile change works
- The fleet owner decides, in the eIM, to move a group of devices to a new operator profile.
- The eIM instructs each device’s IoT Profile Assistant (IPA) to download the profile.
- The IPA fetches the profile from the operator’s SM-DP+ server and installs it on the eUICC.
- The eIM enables the new profile and, if wanted, disables or deletes the old one.
- The device reconnects on the new operator, without anyone visiting it.
SGP.32 vs SGP.02 vs SGP.22
| SGP.02 (M2M) | SGP.22 (consumer) | SGP.32 (IoT) | |
|---|---|---|---|
| Who starts a change | Network side (SM-SR) | The user (QR code, app) | The fleet owner, through the eIM |
| Device side | eUICC only | LPA in the phone | IPA in the device (IPAd) or on the eUICC (IPAe) |
| Profile server | SM-DP | SM-DP+ | SM-DP+ |
| Suits | Legacy M2M | Phones, watches, tablets | Headless IoT fleets |
IPAd or IPAe?
- IPAd runs in the device’s software (for example Linux or Android) and must be adapted to it.
- IPAe is hosted on the eUICC, so it works whatever the device software (Valid, 2024).
Constrained devices with simple firmware often favour IPAe; devices with a capable operating system can use IPAd.
Sources
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Frequently asked questions
What is SGP.32?
SGP.32 is the GSMA technical specification for remote SIM provisioning on IoT devices. It lets devices without a screen or a user download, enable, disable and delete operator profiles on their eUICC, under the control of a remote manager called the eIM.
What is the difference between SGP.31 and SGP.32?
SGP.31 sets the architecture and requirements of eSIM for IoT; SGP.32 is the technical specification that implements them.
What is an eIM?
The eIM (eSIM IoT remote Manager) is the server that tells devices which profile operations to perform. It manages fleets in bulk and can be a standalone platform or part of a connectivity management platform.
What is the difference between IPAd and IPAe?
Both are the IoT Profile Assistant that carries out profile operations on the device side. IPAd runs in the device's software and must be adapted to its operating system; IPAe is hosted on the eUICC itself, so it does not depend on the device.
Can an SGP.02 eUICC be upgraded to SGP.32?
Generally not by a simple update: the eUICC must be built and certified for SGP.32. Check with your eUICC and module suppliers before planning a migration.