What is a SIM, eSIM, iSIM?
Last updated
Last updated
A SIM card, short for Subscriber Identity Module, is a crucial component developed in 1991, enabling Mobile Network Operators (MNOs) to identify and authenticate devices. It is standardized by the GSMA and acts as a bridge to the core network. The primary role of a SIM card is to securely store essential information such as:
ICCID (Integrated Circuit Card Identifier) - The serial number of the SIM card.
IMSI (International Mobile Subscriber Identity) - A unique network identifier.
Ki (Authentication Key) - A secret key used for network security purposes.
Algorithm - Used to securely identify and authenticate the SIM with the mobile network.
A SIM (Subscriber Identity Module) is a smart card designed to securely store subscriber-specific information used to authenticate and identify subscribers on mobile telephony devices. It's a critical component for connecting and accessing mobile networks.
Physical Form: Initially introduced as a physical card, it has evolved in size from standard to Nano-SIMs.
Core Information: Contains key information such as ICCID, IMSI, Ki (Authentication Key), and encryption algorithms.
Operator-Specific: Typically supports a single network operator profile, requiring physical replacement to switch networks.
Programmability: While not inherently reprogrammable, SIM cards can receive updates OTA (Over-the-Air) from the mobile network operator.
UICC and uSIM: With the advent of 3G, the term UICC (Universal Integrated Circuit Card) came into use, reflecting its broader application beyond merely mobile phones to other types of connected devices.
Different grades: Depending on the type of use, there are Commercial, Industrial, Automotive grades
This element of mobile technology has been instrumental in the secure and reliable operation of mobile networks globally.
An eSIM (Embedded SIM) represents a significant evolution from traditional SIM cards, offering enhanced flexibility and functionality. Here’s what sets the eSIM apart:
Embedded by design: Alongside physical SIM cards, eSIM can be soldered directly onto the device's motherboard, making it non-removable.
Remote provisioning: Users can switch operators without changing a physical SIM. This is done by remotely downloading the operator's profile onto the eSIM.
Multiple profiles support: An eSIM can store multiple operator profiles at once, though only one can be active at a time. This makes it easier to switch between networks or plans.
Ideal for a wide range of devices: Its small form factor and remote programmability make the eSIM suitable not only for smartphones but also for IoT devices, smart watches, and other connected consumer electronics.
Enhanced security: As with traditional SIMs, eSIMs provide secure authentication to network services but add an extra layer of security by being embedded in the device, making tampering more difficult.
When comparing eSIM technology for consumer devices versus Machine to Machine (M2M) applications, key differences emerge in their use case, deployment, and features.
M2M eSIM (GSMA SGP.02):
Target Devices: Designed for IoT devices, industrial sensors, automotive applications, and other machines that require connectivity. The device requires no specific software and works with constrained devices.
Deployment: M2M eSIMs are embedded during the manufacturing process, often not intended to be accessible by the end user.
Management: Provisioning and management are handled remotely through specialized platforms, catering to applications where manual intervention is impractical or impossible. Profiles can be pushed by campaign or using rules from network or CMS triggers
Profiles: KORE has a portfolio of native profiles available to provide local connectivity.
Consumer eSIM (GSMA SGP.22):
Target Devices: Aimed at smartphones, tablets, smartwatches, and other consumer electronics.
User Control: Allows consumers to manage their subscription and switch carriers via the device’s interface.
Remote Provisioning: Supports over-the-air (OTA) provisioning, enabling users to download and activate carrier profiles as needed.
LPA (Local Profile Assistant): The device must have a LPA, UI or camera to manage the profiles. Not easy to scale as each device must trigger profile management
Both consumer eSIMs and M2M eSIMs offer the benefits of flexibility and improved security but are tailored to fit the distinct needs and logistics of their respective fields.
An iSIM (Integrated SIM) represents the next step in SIM card technology evolution, building upon the foundation laid by eSIMs. Here are the key features of an iSIM:
Integrated functionality: Unlike the eSIM, which is soldered onto the device's motherboard, an iSIM is integrated into the processor chipset itself. This integration allows for even smaller device sizes and reduced manufacturing costs.
Remote provisioning and multiple profiles: Similar to eSIMs, iSIMs support remote provisioning by network operators and can store multiple operator profiles at once, with the ability to switch between them as needed.
Enhanced security and performance: By integrating the SIM functionality directly into the device's main processor, iSIMs potentially offer improved security and performance, benefiting from the processor's enhanced capabilities. Integrates into it’s own dedicated space on the System of Chip (SoC), where it is protected by a Tamper Resistant Element (TRE).
Wider range of applications: The smaller size and increased efficiency of iSIMs make them ideal for an even broader array of devices beyond smartphones, including IoT devices, wearable technology, and embedded applications in various sectors.
iSIM technology further simplifies device design and connectivity management, paving the way for future innovations in mobile and IoT ecosystems. iSIM is not a Soft SIM.
