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

16-state Quadrature Amplitude Modulation (16-QAM)

A digital modulation technique used for signals in which four bits are modulated at once by selecting one of 16 possible combinations of carrier phase shift and amplitude.


Access Point Name (APN)

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


Application Protocol Data Unit (APDU)

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


AT command

A command used to control the modem.

AT command

Bearer Independent Protocol (BIP)

A set of commands and events that allows a smart card to establish a communication channel with a terminal and through the terminal with a remote server or a remote device.


Binary Phase-Shift Keying (BPSK)

A digital modulation technique used for signals in which one bit is modulated by selecting one of two possible carrier phase shifts with a 180-phase difference.


Carrier Wave (CW)

A single-frequency electromagnetic wave that can be modulated in amplitude, frequency, or phase to convey information.



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


NB-IoT UE category with 200 kHz UE bandwidth and a single RX antenna, specified in 3GPP Release 13.


An upgraded version of Cat-NB1, specified in 3GPP Release 14.

Check Digit (CD)

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


Classless Inter-domain Routing (CIDR)

A method for allocating IP (Internet Protocol) addresses.


CS/PS Mode of Operation

A UE mode of operation. The UE may either register to packet-switched services, circuit-switched services, or both based on the mode of operation. If both are registered, the mode of operation also contains a preference for either of them.


A non-cellular radio standard included as part of the 5G standards by the ITU.


Dedicated File (DF)

A functional grouping of files consisting of a dedicated file and all files which contain the dedicated file in their parental hierarchy.


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.



Distinguished Encoding Rules


Dynamic Host Configuration Protocol (DHCP)

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


Electronic Serial Number (ESN)

A unique number embedded on a microchip for identifying mobile devices.


Enhanced Machine Type Communication (eMTC)

A low-power wide area network radio technology standard developed by 3GPP to enable a wide range of cellular devices and services.


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 UE.


E-UTRA Absolute Radio Frequency Channel Number (EARFCN)

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


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).


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).


Evolved Universal Terrestrial Radio Access (E-UTRA)

The air interface of LTE.


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.


Firmware-Over-The-Air (FOTA)

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


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.


Global Navigation Satellite System (GNSS)

A satellite navigation system with global coverage. The system provides signals from space transmitting positioning and timing data to GNSS receivers, which use this data to determine location.


Global Positioning System (GPS)

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


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.


Hybrid Automatic Repeat Request (HARQ)

Any combined Automatic Repeat Request (ARQ) and Forward Error Coding (FEC) method that saves failed decoding attempts for future joint decoding.


Integrated Circuit Card Identifier (ICCID)

A unique serial number of a SIM card.


IP Multimedia Services Identity Module (ISIM)

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


International Mobile (Station) Equipment Identity (IMEI)

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


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.


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).


Internet of Things (IoT)

Physical objects that are embedded with sensors, processing ability, software, and other technologies that connect and exchange data with other devices and systems of the Internet or other communications networks.


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.


International Reference Alphabet (IRA)

A seven-bit coded character set for information exchange.


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.


Low-Noise Amplifier (LNA)

In a radio receiving system, an electronic amplifier that amplifies a very low-power signal without significantly degrading its signal-to-noise ratio.


Long-Term Evolution (LTE)

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



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.

Maximum Transmission Unit (MTU)

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


MIPI RF Front-End Control Interface (RFFE)

A dedicated control interface for the RF front-end subsystem. MIPI Alliance


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).


Mobile Equipment (ME)

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


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).


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.


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.


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 or Cat-NB2.


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.


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

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


Non-volatile Memory (NVM)

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


Over-the-Air (OTA)

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


Packet Data Network (PDN)

A network that provides data services.


Packet Data Protocol (PDP)

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


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.


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.


Power Amplifier (PA)

A device used to increase the transmit power level of a radio signal.


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.


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.


Printed Circuit Board (PCB)

A board that connects electronic components.


Privacy Enhanced Mail (PEM)

A public key certificate defined in the X.509 cryptography standard and used to privately transmit email.


Production Test Image (PTI)

A modem firmware version used in the device manufacturing phase.


Protocol Configuration Options (PCO)

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


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.


PS Mode of Operation

A UE mode of operation. The UE registers only to EPS services.

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.


Quadrature Phase-Shift Keying (QPSK)

A digital modulation technique used for signals in which two bits are modulated at once, selecting one of four possible carrier phase shifts.


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.


Radio Policy Manager (RPM)

A radio baseband chipset feature that protects the mobile network from signaling overload.


Release Assistance Indication (RAI)

A 3GPP feature that allows an LTE-M or Narrowband Internet of Things (NB-IoT) device to indicate to the eNB that it has no more UL data and that the device does not anticipate receiving further DL data.


Reference Signal Received Power (RSRP)

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


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).


Resource Block (RB)

The smallest unit of resources that can be allocated to a user.



A message sent by the User Equipment to relay a notification to the network that the mobile has memory available to receive one or more short messages.

Serial Number (SNR)

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


Signal-to-Noise Ratio (SNR)

The level of signal power compared to the level of noise power, often expressed in decibels (dB).


Software Version Number (SVN)

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


Subscriber Identity Module (SIM)

A card used in UE containing data for subscriber identification.


System in Package (SiP)

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


System on Chip (SoC)

A microchip that integrates all the necessary electronic circuits and components of a computer or other electronic systems on a single integrated circuit.


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.


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.


Tracking Area Code (TAC)

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


Tracking Area Update (TAU)

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


Transport Layer Security (TLS)

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


Type Allocation Code (TAC)

The initial eight-digit part of an IMEI code used for identifying the model of a mobile phone.


Universal Asynchronous Receiver/Transmitter (UART)

A hardware device for asynchronous serial communication between devices.


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).


Universal Integrated Circuit Card (UICC)

A new generation SIM used in UE for ensuring the integrity and security of personal data.


Unique Slave Identifier (USID)

A unique address for identifying each slave device in an RFFE (RF Front-End) system.


Universal Subscriber Identity Module (USIM)

A card used in UE containing data for subscriber identification.


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).



Universally Unique Identifier