Telecom Terminology (EN)
Acronyms and abbreviations used in the telecommunications sector, with expansions and operational meaning for developers and teams building AI/RAG systems on telco domain data.
3GPP - 3rd Generation Partnership Project
International standardisation consortium producing technical specifications (TS) and reports (TR) for mobile networks: GSM, UMTS, LTE, 5G NR. URL: https://www.3gpp.org/
4G - Fourth Generation Mobile
LTE-based mobile standard (3GPP Release 8+). Peak theoretical: 1 Gbps DL (LTE-A). Frequencies vary by country (e.g., 800/1800/2600 MHz in Europe).
5G - Fifth Generation Mobile
3GPP Release 15+ standard. NSA (Non-Standalone) and SA (Standalone) modes. Frequency ranges: FR1 (sub-6 GHz) and FR2 (mmWave, 24.25–52.6 GHz). Source: 3GPP TS 38.101-1/2.
AMF - Access and Mobility Management Function
5G Core node for authentication, authorisation, mobility, UE registration. Functional equivalent of 4G MME. Source: 3GPP TS 23.501.
APN - Access Point Name
Identifier of the mobile data access point. DNS-structured name. Defines routing, authentication, QoS policy. Source: 3GPP TS 23.003.
ARPU - Average Revenue Per User
ARPU = total_revenue / avg_subscribers. Primary mobile operator KPI. Source: GSMA Intelligence.
BEREC - Body of European Regulators for Electronic Communications
EU body coordinating national telecom regulators (NRAs). Publishes net neutrality guidelines, roaming reports. URL: https://www.berec.europa.eu/
BSS - Business Support Systems
Customer-facing telco IT systems: CRM, billing, OMS, self-care. Integrated with OSS via TM Forum OpenAPI.
BTS - Base Transceiver Station
2G GSM radio base station. Equivalent terms: NodeB (3G), eNodeB (4G), gNodeB (5G). Source: ETSI GSM 04.08.
CA - Carrier Aggregation
LTE-A (Release 10) technique combining up to 5 component carriers for higher bandwidth. Source: 3GPP TS 36.300.
CDR - Call Detail Record
Record of call/session details (MSISDN, duration, timestamp, cell ID). Used for billing and traffic analysis.
CSCF - Call Session Control Function
IMS SIP session control. Variants: P-CSCF (Proxy), I-CSCF (Interrogating), S-CSCF (Serving). Source: 3GPP TS 23.228.
DPI - Deep Packet Inspection
Network traffic analysis technique examining IP packet payloads (not just headers) for application identification, traffic shaping, content filtering. Subject to GDPR/ePrivacy Directive.
EPC - Evolved Packet Core
4G LTE core network: MME (mobility), SGW, PGW, HSS, PCRF. Source: 3GPP TS 23.401.
ETSI - European Telecommunications Standards Institute
European TLC standardisation body producing EN and TS standards. URL: https://www.etsi.org/
EVS - Enhanced Voice Services
3GPP audio codec for VoLTE/VoNR providing HD voice and super-wideband audio. Source: 3GPP TS 26.441.
FR1 / FR2 - Frequency Range 1 / 2
3GPP 5G NR frequency classification. FR1: 450 MHz – 7125 MHz (sub-6 GHz). FR2: 24250 MHz – 52600 MHz (mmWave). Source: 3GPP TS 38.101-1 (FR1), 3GPP TS 38.101-2 (FR2).
GERAN - GSM/EDGE Radio Access Network
2G RAN (BSS, BSC, BTS). Source: 3GPP TS 45.001.
gNodeB (gNB)
5G NR radio base station. SA mode: connected to 5GC via NG interface. NSA mode: connected to eNodeB via Xn and to 4G EPC. Source: 3GPP TS 38.401.
GSMA - Global System for Mobile Communications Association
International association of mobile operators. Publishes eSIM SGP.22, roaming standards (IR.21, IR.34), VoLTE IR.92, RCS RCC.07, security guidelines (FS.11, FS.20). URL: https://www.gsma.com/
HLR / HSS - Home Location Register / Home Subscriber Server
HLR (2G/3G) and HSS (4G/IMS) are central subscriber databases: IMSI, MSISDN, service profile, authentication keys (Ki), VLR location. 5G equivalent: UDM. Source: 3GPP TS 29.002, TS 29.273.
IMEI - International Mobile Equipment Identity
15-digit unique device identifier (TAC + SNR + check digit). Used for device blacklisting.
IMSI - International Mobile Subscriber Identity
Unique subscriber identifier: MCC + MNC + MSIN (max 15 digits). Not visible to end users. Source: ITU-T E.212.
IoT - Internet of Things
Ecosystem of connected devices with limited compute. Mobile connectivity: NB-IoT, LTE-M. 5G mMTC optimised for massive IoT. Source: 3GPP TR 22.261.
IPX - IP eXchange
IP interconnection network between operators for international traffic (voice, data, SMS). Replaces legacy SS7/TDM. Source: GSMA IR.34.
ITU-T - International Telecommunication Union - Telecom Standardisation Sector
UN agency for TLC standardisation. Relevant recommendations: G.984 (GPON), G.9807 (XGS-PON), E.164 (numbering), E.212 (IMSI), Q.700 (SS7), Y.2001/Y.2011 (NGN), M.2083 (IMT-2020). URL: https://www.itu.int/en/ITU-T/
LI - Lawful Interception
Legal obligation to provide intercepted communications to authorised law enforcement. Architecture: ETSI ES 201 671 (HI1/HI2/HI3). Source: 3GPP TS 33.107, ETSI ES 201 671.
LTE - Long-Term Evolution
4G radio standard, 3GPP Release 8. OFDMA (DL), SC-FDMA (UL). Source: 3GPP TS 36.201.
MEC - Multi-access Edge Computing
Edge computing at the network margin (near base stations). Reduces latency for real-time apps. Source: ETSI GS MEC 003.
MME - Mobility Management Entity
4G EPC node for authentication (S6a–HSS), mobility (tracking area), SGW/PGW selection. Source: 3GPP TS 23.401.
mMTC - Massive Machine-Type Communications
5G use case for massive IoT (target 1M devices/km², ITU-R M.2083). Technologies: NB-IoT, LTE-M. Source: ITU-R M.2083.
MNC - Mobile Network Code
2-3 digit operator identifier within a country. Combined with MCC = PLMN ID. Source: ITU-T E.212.
MNO - Mobile Network Operator
Operator with own radio network and spectrum licence.
MNP - Mobile Number Portability
Service allowing subscribers to keep their number when switching operators. Source: GSMA PRD IR.26.
MPLS - Multiprotocol Label Switching
Label-based switching for IP/backbone networks. Used for corporate VPNs (L3VPN, L2VPN), QoS, TE. Standard: IETF RFC 3031.
MSISDN - Mobile Station International Subscriber Directory Number
Public subscriber phone number, E.164 format. Source: ITU-T E.164.
MVNO - Mobile Virtual Network Operator
Virtual operator without own radio network. Purchases wholesale from host MNO.
NB-IoT - Narrowband IoT
3GPP Release 13 LPWA standard, 180 kHz band. Source: 3GPP TS 36.211.
NFV - Network Functions Virtualisation
Virtual implementation of network functions on commodity hardware. Source: ETSI GS NFV 002.
NR - New Radio
5G radio standard abbreviation. Source: 3GPP TS 38.211.
OSS - Operations Support Systems
Technical network management systems: FCAPS. Standard: TM Forum eTOM, ITU-T M.3010.
PLMN - Public Land Mobile Network
Mobile network identified by MCC+MNC. Source: 3GPP TS 23.003.
PSM - Power Saving Mode
3GPP mechanism (Release 12+) enabling IoT devices to remain unreachable for extended periods to conserve battery. Used by NB-IoT and LTE-M. Source: 3GPP TS 23.682.
QCI / 5QI - QoS Class Identifier / 5G QoS Identifier
QoS classifier in 4G (QCI) and 5G (5QI). Defines latency, packet loss, priority. Source: 3GPP TS 23.203 (4G), 3GPP TS 23.501 (5G).
RAN - Radio Access Network
Network segment connecting UE to core network over the air interface. Source: 3GPP TS 38.300.
RCS - Rich Communication Services
Next-generation messaging protocol over IMS. Source: GSMA RCC.07.
SDN - Software-Defined Networking
Decouples control plane from data plane for programmable networks. Standard: ONF, IETF RFC 7426.
SIM - Subscriber Identity Module
Subscriber identification chip (IMSI + Ki). Variants: physical, eSIM (GSMA SGP.22), iSIM.
SLA - Service Level Agreement
Contract defining guaranteed service levels (uptime, latency, CIR bandwidth).
SMF - Session Management Function
5G Core node managing data sessions (PDU Session), UPF selection, APN, QoS. Equivalent of 4G PGW. Source: 3GPP TS 23.501.
SS7 - Signalling System 7
Legacy TDM/PSTN/GSM signalling protocol. Known security vulnerabilities (GSMA FS.11). Source: ITU-T Q.700.
SUCI - Subscription Concealed Identifier
5G privacy mechanism: IMSI encrypted with operator's public key (ECIES), preventing IMSI catchers. Source: 3GPP TS 33.501.
UDM - Unified Data Management
5G Core subscriber database (replaces HLR/HSS). Manages SUPI, 5G-AKA, session data. Source: 3GPP TS 29.503.
UPF - User Plane Function
5G Core data plane node (routing, NAT, QoS enforcement). Equivalent of 4G PGW. Source: 3GPP TS 29.244.
URLLC - Ultra-Reliable Low-Latency Communication
5G use case: ≤1 ms latency, ≥99.999% reliability. Source: 3GPP TS 22.261.
VoLTE - Voice over LTE
Voice calls over LTE via IMS. Source: 3GPP TS 22.173, GSMA IR.92.
VoNR - Voice over New Radio
Voice calls over 5G NR SA. Codec: EVS (3GPP TS 26.441). Source: 3GPP TS 23.501.
VoWiFi - Voice over Wi-Fi (Wi-Fi Calling)
Voice calls via Wi-Fi using VoLTE/IMS + IPSec tunnel (ePDG). Source: GSMA IR.51, 3GPP TS 24.302.
WRC - World Radiocommunication Conference
ITU-R conference updating Radio Regulations, including spectrum allocations for mobile (IMT). WRC-23 (Dubai 2023) discussed IMT-2030 (6G) bands. URL: https://www.itu.int/en/ITU-R/conferences/wrc/