Glossary

Access Point Name (APN)

The name of a gateway between a mobile network and another computer network, usually the Internet.

APN

Application Identifier (appId)

A JSON field used to identify the type of data in a device message. It is used to categorize and filter messages, for example, when multiple data types share the same topic.

appId

Application Protocol Data Unit (APDU)

The communication unit between a terminal and smart card (Universal Integrated Circuit Card (UICC)).

APDU

AT command

A command used to control the modem.

AT command

Basic Service Set Identifier (BSSID)

The MAC address of a Wi-Fi access point or radio interface.

BSSID

Check Digit (CD)

The last one-digit number of the International Mobile (Station) Equipment Identity (IMEI) code used for error detection.

CD

DER

Distinguished Encoding Rules

DER

Device Firmware Update (DFU)

A mechanism for upgrading the firmware of a device.

DFU

Discontinuous Reception (DRX)

A method in mobile communication to conserve the battery of a mobile device by turning the RF modem in a sleep state.

DRX

Dynamic Host Configuration Protocol (DHCP)

A network management protocol used for automatic and centralized management of IP addresses within a network.

DHCP

EPS Mobility Management (EMM)

The Evolved Packet System (EPS) Mobility Management (EMM) sublayer in the Non-access Stratum (NAS) protocol provides mobility service to the User Equipment (UE).

EMM

E-UTRA Absolute Radio Frequency Channel Number (EARFCN)

LTE carrier channel number for unique identification of LTE band and carrier frequency.

EARFCN

Evolved Packet System (EPS)

A connection-oriented transmission network in LTE (Long-term Evolution) consisting of an EPC (Evolved Packet Core) and an E-UTRAN (Evolved Terrestrial Radio Access Network).

EPS

Evolved Terrestrial Radio Access Network (E-UTRAN)

The network architecture defined for the E-UTRA radio interface consisting of evolved Node Bs (eNB) and providing user plane and control plane protocol terminations towards the User Equipment (UE).

E-UTRAN

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.

eDRX

Firmware-Over-The-Air (FOTA)

A firmware update performed remotely over the air (OTA).

FOTA

General Packet Radio Services (GPRS)

A packet-based mobile data service for 2G and 3G mobile networks with data rates of 56-114 kbps/second and continuous connection to the Internet.

GPRS

General-Purpose Input/Output (GPIO)

A digital signal pin that can be used as input, output, or both. It is uncommitted and can be controlled by the user at runtime.

GPIO

IP Multimedia Services Identity Module (ISIM)

An application which resides on a mobile device's Subscriber Identity Module (SIM) card (UICC).

ISIM

Integrated Circuit Card Identifier (ICCID)

A unique serial number of a SIM card.

ICCID

International Mobile (Station) Equipment Identity (IMEI)

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

IMEI

International Mobile (Station) Equipment Identity, Software Version (IMEISV)

A unique code consisting of 16 decimal digits and two software version digits for identifying 3GPP-based mobile devices.

IMEISV

International Mobile Subscriber Identity (IMSI)

A unique code, usually 15 digits, used for the identification of a mobile subscriber and consisting of an Mobile Country Code (MCC), Mobile Network Code (MNC), and MSIN (Mobile Subscription Identification Number).

IMSI

Internet Protocol (IP)

The network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet.

IP

International Reference Alphabet (IRA)

A seven-bit coded character set for information exchange.

IRA

JSON Web Token (JWT)

An Internet-proposed standard for creating data with optional signature and optional encryption whose payload holds JSON that asserts some number of claims.

JWT

Long-Term Evolution (LTE)

A wireless broadband communication standard for mobile devices and data terminals, based on the GSM/EDGE and UMTS/HSPA technologies.

LTE

Media Access Control (MAC) address

A unique 12–character hexadecimal hardware address that identifies a network interface.

MAC address

Maximum Transmission Unit (MTU)

The largest packet or frame that can be sent in a single network layer transaction.

MTU

Mobile Country Code (MCC)

A unique three-digit part of an IMSI code identifying the country of domicile of the mobile subscriber. MCC is used together with the Mobile Network Code (MNC).

MCC

Mobile Equipment (ME)

The physical UE consisting of one of more Mobile Termination (MT) and one or more Terminal Equipment (TE).

ME

Mobile Network Code (MNC)

A code identifying the telecommunications network. The code is defined by ITU-T Recommendation E.212, consists of two or three decimal digits, and is used together with the Mobile Country Code (MCC).

MNC

Mobile Station International Subscriber Directory Number (MSISDN)

A number consisting of a maximum of 15 digits identifying a mobile subscriber by mapping the telephone number to the SIM card in a phone.

MSISDN

Mobile Termination (MT)

A component of the Mobile Equipment (ME) performing functions specific to management of the radio interface. The R interface between TE and MT uses the AT command set. The IMEI code is attached to the MT.

MT

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.

NAS

Non-access Stratum (NAS) Signalling Low Priority Indication (NSLPI)

Used by the network for NAS-level mobility management congestion control.

NSLPI

Non-volatile Memory (NVM)

Memory that can retrieve stored information even after having been power-cycled.

NVM

nRF 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 Cloud portal (nrfcloud.com).

Over-the-Air (OTA)

Refers to any type of wireless transmission. For Matter, OTA is synonymous with the Over-the-Air software update mechanism.

OTA

Packet Data Network (PDN)

A network that provides data services.

PDN

Packet Data Protocol (PDP)

A packet transfer protocol in wireless GPRS (General Packet Radio Services) and HSDPA (High-speed Downlink Packet Access) networks.

PDP

Packet Data Protocol (PDP) Context

In UMTS (Universal Mobile Telecommunications System) and GPRS (General Packet Radio Service), the record that specifies UE access to an external packet-switched network.

Paging Time Window (PTW)

The period of time during which the User Equipment (UE) attempts to receive a paging message.

Personal Identification Number (PIN)

An optional security feature in mobile devices used for identifying a user. PIN is a numeric code which must be entered each time a mobile device is started.

PIN

Personal Unblocking Key (PUK)

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

PUK

Power Management Unit (PMU)

A hardware block that manages power and clock resources in the system.

PMU

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.

PSM

Pre-shared Key (PSK)

A password authentication method, a string of text, expected before a username and password to establish a secured connection. Also known as a shared secret.

PSK

Protocol Configuration Options (PCO)

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

PCO

Protocol Data Unit (PDU)

Information transferred as a single unit between peer entities of a computer network and containing control and address information or data. PDU mode is one of the two ways of sending and receiving SMS messages.

PDU

Public Land Mobile Network (PLMN)

A network that provides land mobile telecommunications services to the public. A PLMN is identified by the MCC and MNC.

PLMN

Quality of Service (QoS)

The measured overall performance of a service, such as a telephony or computer network, a connection, or a cloud computing service.

QoS

Radio Resource Control (RRC)

A protocol used in UMTS, LTE, and 5G on the radio interface. It is an OSI model network layer 3 protocol used between the User Equipment and Base Station.

RRC

Received Signal Strength Indication (RSSI)

An indication of the power of a received radio signal.

RSSI

Reference Signal Received Power (RSRP)

The average power level received from a single reference signal in a Long-Term Evolution (LTE) network.

RSRP

Reference Signal Received Quality (RSRQ)

The quality of a single reference signal received in an LTE (Long-Term Evolution) network and calculated from Reference Signal Received Power (RSRP).

RSRQ

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.

SES

Serial Number (SNR)

A unique six-digit number part of the IMEI code identifying each equipment within each Type Allocation Code (TAC).

SNR

Service Set Identifier (SSID)

The unique name of a Wi–Fi network.

SSID

Software Version Number (SVN)

Part of the IMEI code identifying the revision of the software installed on a mobile device.

SVN

Subscriber Identity Module (SIM)

A card used in User Equipment (UE) containing data for subscriber identification.

SIM

Terminal Adapter (TA)

A device that connects a UE to a communications network. In mobile networks, the terminal adapter is used by the terminal equipment to access the mobile termination using AT commands.

TA

Terminal Equipment (TE)

Communications equipment at either end of a communications link, used to permit the stations involved to accomplish the mission for which the link was established.

TE

Tracking Area Code (TAC)

A unique code used to identify a tracking area within a particular network.

TAC

Tracking Area Update (TAU)

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

TAU

Transport Layer Security (TLS)

A cryptographic protocol that provides end-to-end security of data sent over a computer network.

TLS

Type Allocation Code (TAC)

The initial eight-digit part of an International Mobile (Station) Equipment Identity (IMEI) code used for identifying the model of a mobile phone.

TAC

Universal Asynchronous Receiver/Transmitter (UART)

A hardware device for asynchronous serial communication between devices.

UART

Universal Integrated Circuit Card (UICC)

A new generation Subscriber Identity Module (SIM) used in User Equipment (UE) for ensuring the integrity and security of personal data.

UICC

Universal Subscriber Identity Module (USIM)

A card used in UE containing data for subscriber identification.

USIM

Universal Subscriber Identity Module Application Toolkit (USAT)

A standard that provides mechanisms which allow applications in the Universal Subscriber Identity Module (USIM) to interact and operate with Mobile Equipment (ME).

USAT

Unsolicited Result Code (URC)

A result code sent by the modem independently of the direct response to an AT command.

URC

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).

UE

UUID

Universally Unique Identifier