What is Embedded Universal Integrated Circuit Card (eUICC)?

Ajit Thomas
Cavli Wireless
Published in
4 min readAug 19, 2024

Introduction

IoT deployments worldwide have used conventional SIM cards for a long time from the early 2000s, when it was first used in the Automated Meter Reading (AMR) project in Texas. But, as IoT deployments grew, there arose many difficulties in IoT Connectivity enablement and management.

Conventional SIM cards are carrier-specific. Locked into a single carrier, it will require physical SIM swaps to switch between networks, which obviously seems like an impractical thing to do. A single network SIM could lead to significant connectivity blackouts, especially in the below mentioned two scenarios

  • IoT-enabled deployments in mobility
  • Deployments are in remote locations, where that particular carrier may not have good coverage

Frequent human intervention and associated recurring costs to just maintain ‘Connectivity’ is not a smart proposition, and requires a technology upgrade/innovation to solve this problem. To address these shortcomings, the eUICC concept came into play.

Transitioning From UICC to eUICC

The transition from traditional UICC SIM cards to eUICC-enabled eSIMs

The UICC (Universal Integrated Circuit Card) is known as the mini-computer in the SIM ecosystem. It is a smart card technology that ensures the authentication and identification of SIM cards with designated MNOs.

What is eUICC?

eUICC or Embedded Universal Integrated Circuit Card is the architectural standard published by GSMA for eSIMs for establishing SIM capability. eUICC enables RSP (Remote SIM Provisioning) and OTA (Over-The-Air) updates for the SIM profiles, making it easier to

  • Manage multiple SIM profiles
  • Load new carrier profiles remotely
  • Seamlessly switch over different carrier profiles

Architecture of eUICC- Explained

Architectural overview of the eUICC security in eSIM

With tech growth, eUICC capability is now available in removable SIM cards and eSIMs. The key elements constituting the eUICC architecture are:

  • SM-DP
  • SM-SR
  • ISD-R
  • ECASD
eUICC remote provisioning components of an eSIM

The Subscription Manager (SM) of eUICC has two components:

  • SM-DP (SM- Data Preparation)
  • SM-SR (SM- Secure Routing)

SM-DP prepares and stores operator profiles, and installs them onto the eUICC. SM-SR manages profile status, enables/disables/or deletes profiles, and secures the link between eUICC and SM-DP during operator profile delivery.

Issuer Security Domain Root (ISD-R) is the in-build card component on SM-SR that manages SIM profiles. The ISD-P represents the UICC profiles. ECASD is also known as eUICC Controlling Authority Security Domain. It contains non-modifiable eUICC private keys, and root public keys for the establishment of new keysets in the ISD-P(s) and ISD-R. The Local Profile Assistant (LPA) component handles profile discovery, downloading profiles, and profile management.

Benefits of eUICC-Enabled eSIMs

eUICC SIM cards enable remote SIM provisioning

  • The remote provisioning of mobile network operator profiles helps switch between the network carrier profiles. This ensures flexibility and optimum coverage for IoT solutions deployed globally.

eUICC eSIMs offer remote device management with OTA updates

  • It is now easier for IoT engineers and manufacturers to connect and upgrade their IoT solutions deployed across the globe.

eSIM with eUICC capability enables localization

  • With OTA and RSP capability, eUICC SIM stores and manages updates of local network carrier profiles in which IoT solutions are deployed. Thus, it mitigates coverage and roaming difficulties making it cost-efficient for IoT solution providers.

Closing Notes

As the technology makes progress, there is more evolution occurring in this SIM field. The introduction of iUICC with iSIM invention is a topic in itself to discuss later on in the coming chapters. With xUICC ( eUICC & iUICC), it is evident that the connectivity issues in the M2M domain will be addressed to a great extent.

To learn more, visit us at https://www.cavliwireless.com/iot-modules/cellular-modules.html

Amusing Tech Chronicles

Facts and Anecdotes related to this edition of Wireless By Design

A Global Citizen Passport

eUICC is the passport of IoT devices. They allow devices to ‘travel’ internationally without the hassle of ‘visa applications’ (carrier negotiations and contracts) for each country.

Go Green

eUICC is environment-friendly. Fewer physical SIM cards mean less plastic waste, making a small but yet a significant green solution.

The Stamp Collector

eUICC is a stamp collector gathering stamps from different (carrier) countries in the world of connectivity.

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Ajit Thomas
Cavli Wireless

Ajit is a Marketing & Product management professional with experience across Technology & Industrial engineering. He is the Co-founder & CMO at Cavliwireless.