The glossary contains terms and acronyms that are used in this document.

Application Programming Interface (API)

A language and message format used by an application program to communicate with an operating system, application, or other service.



LTE-M User Equipment (UE) category with a single RX antenna, specified in 3GPP Release 13.


Narrowband Internet of Things (NB-IoT) User Equipment (UE) category with 200 kHz UE bandwidth and a single RX antenna, specified in 3GPP Release 13.

Development Kit (DK)

A development platform used for application development.


Device Firmware Update (DFU)

A mechanism for upgrading the firmware of a device.


Extended Discontinuous Reception (eDRX)

A method to conserve the battery of an IoT (Internet of Things) device by allowing it to remain inactive for extended periods.


Global Positioning System (GPS)

A satellite-based radio navigation system that provides its users with accurate location and time information over the globe.


Integrated Circuit Card Identifier (ICCID)

A unique serial number of a SIM card.


Integrated Development Environment (IDE)

A software application that provides facilities for software development.


International Mobile (Station) Equipment Identity (IMEI)

A unique code consisting of 14 digits and a check digit for identifying 3GPP-based mobile devices.



An open standard that is most suitable for medium throughput applications requiring low power, low latency, and/or mobility, like asset tracking, wearables, medical, POS, and home security applications. Also known as Cat-M1.

Narrowband Internet of Things (NB-IoT)

A narrowband technology standard with longer range, lower throughput, and better penetration in, for example, cellars and parking garages compared to LTE-M. NB-IoT is most suitable for static, low throughput applications like smart metering, smart agriculture, and smart city applications. Also known as Cat-NB1.


Non-access Stratum (NAS)

In telecom protocol stacks, the highest stratum of the control plane between the core network and User Equipment (UE). The layer is used to manage the establishment of communication sessions and for maintaining communications with the UE as it moves.


nRF Connect for Cloud

Nordic Semiconductor's platform for connecting IoT devices to the cloud, viewing and analyzing device message data, prototyping ideas that use Nordic Semiconductor chips, and more. It includes a public REST API that can be used for building IoT solutions. See nRF Connect for Cloud (

Personal Unblocking Key (PUK)

A digit sequence required in 3GPP mobile phones to unlock a Subscriber Identity Module (SIM) that has disabled itself after an in correct personal identification number has been entered multiple times.


Power Saving Mode (PSM)

A feature introduced in 3GPP Release 12 to improve battery life of IoT (Internet of Things) devices by minimizing energy consumption. The device stays dormant during the PSM window.


Protocol Configuration Options (PCO)

An element of Non-access Stratum (NAS) message used for transferring parameters between the UE and the P-GW (Packet Data Network Gateway).


SEGGER Embedded Studio (SES)

A cross-platform Integrated Development Environment (IDE) for embedded C/C++ programming with support for Nordic Semiconductor devices, produced by SEGGER Microcontroller.


Subscriber Identity Module (SIM)

A card used in UE containing data for subscriber identification.


System in Package (SiP)

A number of integrated circuits, often from different technologies, enclosed in a single module that performs as a system or subsystem.


Tracking Area Update (TAU)

A procedure initiated by the UE when moving to a new tracking area in the LTE (Long-term Evolution) system.


User Equipment (UE)

Any device used by an end-user to communicate. The UE consists of the Mobile Equipment (ME) and the Universal Integrated Circuit Card (UICC).