IoT and eSIM, defined.

An embedded SIM (eUICC) soldered into a device whose operator profile can be downloaded and changed over the air, with no physical swap.

The hardware secure element behind an eSIM that securely stores one or more operator profiles and enforces remote provisioning.

The classic smart-card chip inside a removable SIM, the predecessor to the reprogrammable eUICC.

An integrated SIM built directly into the device modem or processor, even smaller and cheaper than an eSIM.

A fully software-based SIM that runs inside the modem or secure enclave, removing the need for any physical SIM or slot.

A solderable SIM and eSIM form factor rated for heat, shock and vibration, used in devices built to last 10+ years in the field.

The Mini-SIM, the largest of the modern removable SIM cut sizes.

The Micro-SIM, a smaller removable SIM cut that replaced the Mini-SIM in many devices.

The Nano-SIM, the smallest removable SIM cut used in most modern phones.

A SIM card pre-scored so it can be broken out to 2FF, 3FF or 4FF size to fit any slot.

A machine-to-machine SIM built for unattended devices, with industrial durability and remote management.

A SIM rated for extended temperature, vibration and a long lifespan, made for harsh deployments.

Integrated Circuit Card Identifier. The unique serial number printed on a SIM that identifies the card itself.

A small program running on the SIM that can add logic such as network steering or security on the card.

A tamper-resistant chip that stores keys and credentials, the foundation of SIM and eSIM security.

The GSMA standard for eSIM remote provisioning built specifically for IoT devices that have no screen or user, using an eIM to manage profiles at fleet scale.

The consumer eSIM remote-provisioning standard, designed for phones and wearables with a user interface to drive profile changes.

The original machine-to-machine eSIM standard, server-driven and used before SGP.32 for early M2M deployments.

Remote SIM Provisioning. The GSMA family of standards (SGP.22, SGP.32) for downloading and managing eSIM profiles over the air.

eSIM IoT Manager. The server that orchestrates profile download, enable and switch operations across a fleet of eUICCs under SGP.32.

Subscription Manager Data Preparation. The server that prepares and securely delivers eSIM profiles to a device.

Subscription Manager Discovery Server. The directory a device contacts to find which profiles are waiting for it.

eUICC Identifier. The unique serial number of an eSIM chip, used to target it for remote provisioning.

The operator subscription, keys and settings downloaded onto an eSIM to connect it to a network.

A minimal starter profile that gets a device online just long enough to download its real operational profile.

The full working subscription a device uses day to day once provisioned.

The global mobile operators association that publishes the eSIM and SIM standards the industry follows.

The standards body that defines the mobile radio and core network specifications from 2G through 5G.

The European standards institute behind many of the underlying SIM and telecom specifications.

International Mobile Subscriber Identity. The unique identifier a SIM presents to a mobile network to authenticate a subscription.

A SIM that holds several IMSIs and can switch between them over the air, behaving like multiple operator subscriptions on one piece of hardware.

International Mobile Equipment Identity. The unique serial number of the device hardware, used for IMEI locking to bind a SIM to a device.

A control that ties a SIM to a specific device so it stops working if moved to other hardware, deterring theft and fraud.

The phone number associated with a SIM, used for voice, SMS and some identification.

The secret authentication key stored on the SIM and the network that proves the SIM is genuine.

simsonic’s tamper-evident identity issued to every line at activation, letting a device cryptographically prove it is what it claims to be.

Over the air. Any update, configuration or profile change delivered to a SIM or device remotely over the network.

A list of approved destinations or endpoints a device is permitted to reach, blocking everything else by default.

Access Point Name. The gateway setting that tells a device which network path and IP space to use for data.

A dedicated, isolated APN that keeps a fleet off the public internet and inside a private network path.

A security model where no device or request is trusted by default, every connection is verified and least-privilege is enforced.

A protocol suite that encrypts and authenticates traffic through a secure tunnel between a device and a private network.

An open-source VPN protocol used to terminate device traffic securely into a private cloud or data centre.

A low-power wide-area radio with enough bandwidth for firmware updates and voice, supporting mobility, ideal for trackers and wearables.

Narrowband IoT. An ultra-low-power radio optimised for deep-indoor reach and massive device density, ideal for meters and fixed sensors.

An LTE device category offering moderate speeds suitable for many IoT applications that need more than NB-IoT.

A simplified single-antenna version of Cat-1, lower cost and popular for trackers and gateways.

Reduced Capability 5G, a lighter 5G profile designed for IoT devices that do not need full 5G speed.

The legacy GSM network, still used by some IoT devices but being switched off in many countries.

The older UMTS network generation, largely retired in favour of 4G and 5G.

The mainstream mobile network generation that carries most IoT and smartphone data today.

The latest mobile generation offering high speed, low latency and massive device density.

Reference Signal Received Power. A measure of cellular signal strength used to judge coverage quality.

Received Signal Strength Indicator. A general measure of how strong a received radio signal is.

The 4G LTE base station that connects devices to the core network.

The 5G base station that connects devices to the 5G core network.

Logic that moves a multi-IMSI SIM to the strongest or most cost-effective available network, with automatic fallback if one degrades.

Automatic switching to a backup network or path when the primary connection degrades or drops.

The geographic area and networks where a SIM can connect, shaped by roaming agreements and radio types.

Connecting through a network other than the SIM home operator, the basis of global IoT connectivity.

A device that roams indefinitely rather than briefly, which some countries restrict and which localisation solves.

Operator logic that pushes a roaming SIM towards preferred partner networks.

Giving a roaming device a local profile or IMSI so it behaves like a domestic subscriber and avoids permanent-roaming limits.

Using a local operator IMSI to gain compliant in-country access without holding a licence there.

The operator that issued the SIM and holds its primary subscription.

The partner network a SIM connects through while roaming away from home.

A commercial deal between operators that lets their subscribers use each other networks.

A SIM designed to connect across many countries and networks from a single profile.

Connectivity delivered through in-country profiles to meet regulation and improve performance.

Mobile Virtual Network Operator. A provider that sells connectivity over carriers it does not own, the layer simsonic operates at.

Mobile Network Operator. A carrier that owns and runs its own radio and core network.

Mobile Virtual Network Enabler. The platform layer that powers MVNOs with billing, provisioning and core services.

Connectivity Management Platform. The dashboard and API used to provision, monitor and control SIMs at scale.

The pricing and allowance rules applied to a SIM or group of SIMs.

A shared data allowance spread across many SIMs so heavy and light users balance out.

Billing where all SIMs draw from one combined data bucket rather than per-SIM limits.

Usage beyond an allowance, usually billed at a higher per-unit rate.

Application Programming Interface. The programmatic way to provision and manage connectivity without the dashboard.

An automated message your systems receive when an event happens, such as a SIM activating or hitting a usage limit.

Firmware Over The Air. Updating device firmware remotely over the cellular connection.

Remotely configuring, monitoring and updating fleets of connected devices.

The sensor and status data devices send back, the payload of most IoT deployments.

Activating and configuring a SIM or device so it can connect and be billed correctly.

A lightweight publish-subscribe messaging protocol widely used for low-bandwidth IoT telemetry.

Constrained Application Protocol. A compact web-style protocol for very constrained IoT devices.

Lightweight M2M. A device management protocol for provisioning, monitoring and updating IoT devices.

Transport Layer Security. The encryption that protects data in transit between devices and servers.

The actual data a device sends or receives, separate from headers and protocol overhead.

Data sent from the device up to the network or cloud.

Data sent from the network or cloud down to the device.

The delay between sending a request and receiving a response, critical for real-time control.

The amount of data that can be moved over a connection in a given time.

Quality of Service. Controls that prioritise certain traffic to guarantee performance.

A dedicated mobile core network that keeps a customer traffic, routing and policy fully isolated.

The central system that authenticates SIMs, routes traffic and enforces policy behind the radio.

Evolved Packet Core. The 4G LTE core network that handles data sessions and mobility.

The 5G Core, a cloud-native core network that runs 5G services and network slicing.

Home Location Register. The legacy database of subscribers and their permissions in a mobile network.

Home Subscriber Server. The 4G evolution of the HLR, storing subscriber identity and authentication data.

The signalling protocol that carries authentication and policy messages in 4G core networks.

The legacy signalling system still used for some roaming and interconnect functions.

Splitting one physical 5G network into isolated virtual networks tuned for different uses.

The maximum data capacity of a connection, often confused with throughput.