Welcome to the IoT Glossary of Terms
This IoT Glossary Of Terms is designed to help you understand key terms and technologies used in the world of IoT (Internet of Things), M2M (Machine-to-Machine), and mobile connectivity. Whether you’re exploring solutions involving eSIM, eUICC, multi-network SIMs, Roaming SIM cards, IoT SIM Cards, Fixed IP SIM Cards, remote SIM provisioning, or industrial 4G/5G routers, this guide explains the essential language that drives modern connected devices.
As eUICC and eSIM technology becomes central to flexible, secure, and scalable deployments, understanding the terminology behind IoT connectivity is more important than ever. Use this glossary as a reference point to navigate your way through the evolving ecosystem of intelligent, connected solutions.
2G / 3G / 4G / 5G
Generations of cellular technology offering increasing bandwidth and reduced latency. 2G (GSM) is nearly obsolete, 3G is being phased out, 4G is current mainstream, and 5G supports ultra-fast, low-latency, high-capacity connections.
Access Point Name (APN)
The gateway between a mobile network and another network (usually the internet). Used to configure data access for SIM-based devices.
Active Antenna
An antenna with a built-in amplifier to boost signal strength, typically requiring external power.
Antenna Gain
The increase in signal strength produced by an antenna, usually measured in dBi. Higher gain focuses signal more narrowly.
AT Commands
Text-based instructions used to control modems, commonly used for SIM management and router diagnostics.
Bandwidth
The capacity of a communication link to carry data, usually measured in Mbps or Gbps.
Bridge Mode
Router mode that disables NAT, passing the public IP directly to a connected device such as a firewall or server.
Cat 1 / Cat 4 / Cat 6 / Cat 12 / Cat 20
LTE categories defining speed and capability of modems. Cat 1 is slower but power efficient (used in IoT), Cat 20 is high speed (used in 5G routers).
Cellular Antenna
A device used to transmit/receive mobile signals. May be indoor, outdoor, directional, omnidirectional, or embedded.
CGNAT (Carrier-Grade NAT)
A method used by mobile networks to conserve IP addresses by placing many devices behind a single public IP.
Cloud Management Platform
Systems like Teltonika RMS that allow remote configuration, monitoring, and updating of IoT devices.
Coaxial Cable
Shielded cable used for RF connections between antennas and routers. Types include RG174, RG58, LMR200, etc.
Connector Types
Includes SMA, RP-SMA, TS9, CRC9, and N-type used to connect antennas to modems/routers.
Coverage
The geographic area where a mobile signal is available from a network provider.
Dashboard
A web-based interface to view status, analytics, and diagnostics of IoT devices.
Data Pool
A shared data allowance used across multiple SIM cards in an account or fleet.
Dual SIM Router
A router with two SIM slots for failover or load balancing.
eSIM (Embedded SIM)
A reprogrammable SIM soldered into a device. Supports over-the-air updates.
eUICC (Embedded Universal Integrated Circuit Card)
The software platform on a SIM or eSIM that enables remote provisioning and multiple operator profiles.
Failover
Automatic switch to a secondary connection when the primary fails.
Firmware Over-the-Air (FOTA)
Remote firmware updates for routers and IoT devices via wireless network.
Fixed IP SIM
A SIM card with a static IP address, either public or private, enabling remote access and device control.
Firewall
A network security system that monitors and controls incoming and outgoing traffic.
Gateway
A hardware device that connects different types of networks — such as cellular to Ethernet.
GPRS (General Packet Radio Service)
A legacy mobile data service used in early 2G networks.
GPS / GNSS
Location services supported by many IoT routers and devices for tracking and geofencing.
GSMA
Industry association representing mobile network operators and responsible for standards like eSIM.
ICCID
Unique serial number of a SIM card.
IMSI
International Mobile Subscriber Identity. A unique identifier that ties a SIM to a mobile network.
IP Passthrough
Router mode that forwards the SIM’s IP address to a connected LAN device.
IPSec VPN
A secure tunnel used to connect private networks over the internet, often used with private IP SIMs.
LAN (Local Area Network)
The internal network in a home or office, usually connected to a router.
Latency
The time delay between a request and its response, important for real-time IoT applications.
LoRa / LoRaWAN
Long-range, low-power wireless communication protocol for wide-area IoT networks.
LPWAN (Low-Power Wide-Area Network)
Category of networks optimized for low-bandwidth, long-distance IoT communication.
LTE-M (Cat-M1)
A 4G technology optimized for IoT. Offers better coverage and lower power consumption than standard LTE.
MAC Address
Unique hardware address of a network interface.
Modem
Device that modulates and demodulates data signals, often built into IoT routers.
Multi-Network SIM / Roaming SIM
SIMs that connect to multiple networks for better coverage and redundancy.
NAT (Network Address Translation)
The process of modifying IP address information to allow multiple devices to share a single public IP.
NB-IoT (Narrowband IoT)
Low-power wide-area network standard using existing cellular networks for low-throughput IoT devices.
NMS (Network Management System)
Software or platform used to oversee and manage a fleet of networked IoT devices.
Omnidirectional Antenna
An antenna that radiates signal in all directions equally.
OpenVPN
A common VPN protocol used to secure traffic between remote devices and central networks.
OTA (Over-the-Air)
Refers to remote configuration or updates delivered via the mobile network.
PCI Compliance
Standards required for payment processing devices, often needing private IP VPN-secured connectivity.
Plastic SIM (2FF / 3FF / 4FF)
Traditional removable SIM cards in various sizes: Mini, Micro, and Nano.
PoE (Power over Ethernet)
Allows Ethernet cables to carry power along with data to compatible devices.
Private APN
A mobile network access point used exclusively for a business, often secured with VPN and fixed IP routing.
Private IP SIM
A SIM assigned an internal network IP, requiring VPN for access — more secure and isolated.
Profile (SIM)
A mobile operator configuration loaded onto an eSIM/eUICC for connectivity.
Provisioning
Activating and configuring a SIM or device for use on a mobile network.
Public IP SIM
A SIM that provides a static, internet-routable IP address for direct access.
Redundancy
Backup systems or connections to ensure continuous operation during failure.
Remote SIM Management (RSP)
The ability to manage SIM profiles remotely using GSMA-compliant systems.
Router
A device that routes data between networks. In IoT, these often contain cellular modems and VPN support.
RS232 / RS485
Serial communication protocols used to connect industrial equipment to routers or controllers.
RSSI / RSRP / RSRQ / SINR
Signal strength and quality metrics used to assess cellular connection.
SCADA
Supervisory control and data acquisition — common industrial system type relying on M2M connectivity.
Signal Loss (dB)
Attenuation of signal strength due to cable length or poor antenna performance.
Signal Repeater / Booster
Device that amplifies weak mobile signal, often used where external antennas are not possible.
Single Board Computer (SBC)
Compact computers like Raspberry Pi used in embedded or edge IoT applications.
Smart Antenna
An adaptive antenna system that adjusts radiation pattern for better performance.
SMA / RP-SMA / TS9 / CRC9
Types of connectors used on antennas and modems for RF connections.
Static IP
Another term for fixed IP — an IP address that doesn’t change.
TCP/IP
Core internet protocols that define how devices communicate over networks.
Telemetry
Automated communications process by which measurements are collected and transmitted.
TR-069
Protocol used by ISPs to remotely manage routers and modems.
UICC
Universal Integrated Circuit Card — the chip on which SIM data is stored.
Unsteered Roaming
Roaming mode that connects to the strongest available network rather than a preferred one.
USB Tethering
Connecting a router or modem to a computer or SBC via USB for data transfer.
VPN Tunnel
A secure, encrypted connection between devices across the internet.
Watchdog Timer
A hardware or software function that resets a device if it becomes unresponsive.
WebUI
The local interface of a router used to configure and monitor settings.
Zigbee
Wireless mesh communication protocol often used in smart homes and industrial IoT.
Z-Wave
Another short-range wireless communication standard for IoT and smart devices.
Zero-Touch Provisioning
Enables automatic configuration of a device without manual intervention.