Diccionario práctico de conectividad IoT y M2M

What is eUICC

An eUICC (embedded Universal Integrated Circuit Card) is a programmable SIM chip that can hold several carrier profiles and switch between them over the air. It is the GSMA standard underpinning every modern eSIM, in phones, vehicles, and IoT devices.

What is a private APN

A private APN is a mobile network access point dedicated to a single company or project. Your IoT traffic never touches the public internet: it exits the carrier straight to your data center over a private tunnel, with your own IP plan, firewall rules, and routing.

What is Multi-IMSI

Multi-IMSI is a SIM technology that hosts several IMSIs (subscriber identifiers) on a single card and picks one based on country, signal quality, or cost. The device authenticates as a customer of carrier A in one place and as carrier B in another, with no hardware change.

What is permanent roaming

Permanent roaming is when a SIM connects continuously (beyond a few months) to a network other than its home carrier, never returning home. In IoT it is the norm, not the exception: a tracker deployed in Mexico can live for 10 years on Mexican networks with a Spanish-issued SIM.

What is LTE-M

LTE-M (also LTE Cat-M1) is an LTE variant designed for IoT: moderate bandwidth (up to 1 Mbps), very low power, voice support, and real cell-to-cell mobility. It is the sweet spot between NB-IoT (cheaper but static) and Cat-1 (faster but power-hungry).

What is NB-IoT

NB-IoT (Narrowband IoT) is a 4G/5G LPWA technology optimized for small messages from static, multi-year battery devices. It runs in a 200 kHz sub-band and prioritizes deep coverage and extreme power efficiency over throughput.

What is LTE Cat-1

LTE Cat-1 is the LTE device category targeted at general-purpose IoT: up to 10 Mbps down, 5 Mbps up, voice support, and works on any 4G network worldwide. Its Cat-1 bis variant runs on a single antenna, cutting hardware cost. It is the workhorse behind POS terminals, alarms, gateways, and low-bitrate CCTV.

What is MFF2

MFF2 (Machine-to-Machine Form Factor 2) is the solderable SIM: a 6x5 mm chip mounted directly on the PCB, no tray or socket. It is the de-facto standard in industrial IoT, automotive, and any device facing vibration, humidity, or extreme temperatures.

What is SGP.32

SGP.32 is the GSMA Remote SIM Provisioning standard built specifically for IoT, published in 2023. It supersedes SGP.02 (M2M) and removes the dependency on SGP.22 (Consumer) for headless devices. It introduces the IPA (IoT Profile Assistant) and a Pull model where the device requests profiles by country or event.

What are PSM and eDRX

PSM (Power Saving Mode) and eDRX (extended Discontinuous Reception) are 3GPP-defined mechanisms that let a cellular IoT device draw microamps while idle. PSM turns the modem off between long windows (up to days); eDRX spaces paging listening in short intervals (seconds to minutes) without losing network registration.

What is VPLMN

VPLMN (Visited Public Land Mobile Network) is the mobile network a SIM attaches to when away from its HPLMN (the home carrier's network). In international IoT, the VPLMN choice drives roaming cost, latency, and tech availability (LTE-M, NB-IoT) in each country.

ICCID, IMSI, and IMEI

ICCID identifies the physical SIM chip. IMSI identifies the subscriber on the mobile network. IMEI identifies the device (modem) holding the SIM. Three different identifiers, all three needed to manage an IoT fleet.

What is a CDR in IoT

A CDR (Call Detail Record) is the detailed record of every data, voice, or SMS session of a SIM. In IoT it is the source of truth for billing, fraud detection (anomalous traffic), and diagnostics (knowing why a device is silent).

What is MQTT

MQTT (Message Queuing Telemetry Transport) is a very lightweight publish/subscribe protocol designed for devices with little CPU, little RAM, and flaky links. It works against a central broker (Mosquitto, HiveMQ, EMQX, AWS IoT Core) and carries most modern industrial IoT traffic.

What is an IoT VPN

An IoT VPN is an encrypted tunnel between the carrier exit and the customer infrastructure. It lets devices on the cellular network reach private servers without going over the public internet. Typical options are IPSec, WireGuard, and L2TP/IPSec.

What is a static-IP IoT SIM

A static-IP SIM is an IoT card the carrier always assigns the same IP address to, instead of a different dynamic IP per session. It can be public (reachable from the internet) or private (reachable from your private APN or VPN). It is essential whenever a server needs to initiate the connection to the device.

What is iSIM

iSIM (integrated SIM) is a SIM whose silicon lives inside the modem or SoC, not as a separate chip. It shares the same eUICC logic and the same GSMA standards, but takes zero extra board space and trims bill of materials.

What is IoT eSIM

IoT eSIM is the eUICC SIM designed for headless devices. It inherits smartphone eSIM programmability but uses a Pull provisioning flow (SGP.32) where the device asks the server for a profile, without scanning a QR code or entering an activation code.