OSS Acronyms / Glossary

The following table provides a list of nearly 1,000 acronyms / glossary for many commonly used terminologies in OSS/BSS and telco situations. Now includes 5G references.

Acronym Full Description Extra Details
3G Third generation cellular network  
3GPP Third-generation partnership program  Standards body for the cellular network industry
3GPP AAA EPCN3AI 3GPP Authentication, Authorization and Accounting Server  
3GPP AAA Proxy EPCN3AI 3GPP Authentication, Authorization and Accounting Proxy  
4G Fourth generation cellular network  
5G Fifth generation cellular network  
AAA Authentication Authorization and Accounting  
AAL ATM Adaption Layer  
AbisLink GSM Abis Link  
ACD Automatic Call Distribution  
ACE ATM Circuit Emulation  
ACELP Algebraic CELP Voice Compression Technology
ACM address complete message SS7 Notation
ACR Attenutation to Crosstalk Ratio Copper cabling measurement standard
ACS Access Control and Security  
active equipment  The electronic equipment that generates, transmits and receives signals to & from a telecommunications network.  
AD Active Directory  
ADM Add-drop Multiplexer SDH Equipment Type
ADM16 Add Drop Multiplexer (with a line rate of STM-16)  
ADPCM Adaptive Differential Pulse Code Modulation Voice Compression Technology
ADSL Asymmetric Digital Subscriber Line Information Transfer protocol. One style of transmitting information over a network
AF Application Function  
AGR Annual Growth Rate  
AGS Advanced Gaming Service  
AI Artificial Intelligence  
AIOps artificial intelligence for operations  
AIS Alarm Indication Signal  
AIU IM Antenna Inventory Unit  
Alarm Any detectable event/s within the Operational Network that requires an action by operational staff. This could include general Information alarms that need acknowledgement only, through to Critical alarms that need urgent attention. Alarms are generated by operational network devices / infrastructure or their associated management tools  
ALink Core A interface link  
AMF 5G Core Access and Mobility Management Function (AMF)  
AMFF Access & Mobility Management Function  
AMI Advanced Metering Infrastructure  
ANM answer message SS7 Notation
ANSI American National Standards Institute  
API Application Programming Interface  
APN AWS Partner Network  
APS Automatic Protection Switching  
AR Augmented Reality  
ARPU Average Revenue per user  
AS IMS Application Server (AS) providing call control and media transformation, such as a softswitch or media gateway
ASIC Application Specific Integrated Circuit  
ASN.1 Abstract syntax notation one  
Asset An asset is something that has intrinsic commercial value, generally where the assets are tracked from a financial perspective for financial calculations. Also sometimes refers to an inventory item or resource that’s stored in Inventory Management or CMDB solutions. This article provides a more detailed breakdown of the differences between asset and inventory management.  
ATC Adaptive Transform Coding Voice Compression Technology
ATM Asynchronous Transfer Mode Transmission protocol that segments user traffic into small fixed sized cells.  Cells are transmitted to their destination across various routes, and the original traffic is re-assembled.
ATSSS Access Traffic Steering, Switching and Splitting  
AU Administrative unit  
AUC Authentication Centre  
AUG AU group  
AUSF Authentication Server Function  
AV Anti-virus  
AWS Amazon Web Services  
AZ Availability Zones (for replication)  
B links bridge links SS7 Notation
B/OSS Business and Operational Support Systems  
BA Business Analyst  
Bandwidth The amount of data transmitted, usually referred to in units of bps)  
BAS Building Automation System  
BAU Business As Usual  
BBU Baseband Unit  
BCP Business Continuity Plan  
BDLA Bidirectional Line Amplifier  
BDSL Broadband Digital Subscriber Line   
BER Bit Error Rate  
BGF Border Gateway Functions  
BGP Border Gateway Protocol (for L3 routing)  
BGW Broadband Gateway  
BI Business Intelligence  
BIB backward indicator bit SS7 Notation
bits Discrete pieces of digital information  
BLSR Bidirectional Line Switched Ring  
BML Business Management Layer  
BoM Bill of Materials  
bps bits per second. The rate at which digital information is sent  
BR Bidirectional Ring  
BRA Basic Rate Access ISDN Type
BRD Business Requirements Document  
broadband services A telephone signal is considered a “narrowband” service, because only one signal transmits at a time. But if multiple signals are transmitted simultaneously as different “channels”, it is considered “broadband”  
BSC Base Station Controller  
BSF Binding Support Function  
BSN backward sequence number SS7 Notation
BSS Business Support System  
BSS GSM Base Station Subsystem (BSS)  
BTS GSM Base Transceiver Station  
BU Business Unit  
C&C Command & Control  
C2M Concept to Market  
C2S Complaint to Solution Workflow type
CaaS Container as a Service  
CAB Change Advisory Board   
CAC Carrier Access Code  
CAD Computer Aided Design  
CAGR Compound Annual Growth Rate   
CAN Customer Access Network  
CAPEX Capital Expenditure  
carriers  Also known as telecommunications carriers or telcos.  
CAT-5  (also CAT-6, CAT-7, etc) Category 5 unshielded twisted pair  is an industry standard for unshielded twisted copper wire capable of supporting high speed data traffic (up to 100 MHz for 100 ohm and 120 ohm balanced cables i.e. 100 Mbps LANs and ATM @ 155 Mbps) over short distances.
CATV  Common Antenna TeleVision (also known as Cable TV)  
CB Call Barring  
CB Citizen Band  
CBA Cost Benefit Analysis  
CBC Core Cell Broadcast Centre  
CBR  Constant Bit Rate Eg. Describes a quality of service on ATM networks
CBRS Citizens Broadband Radio Service enables enterprises to build their own private 4G/5G networks and result in improved 4G/5G offerings from service providers. 3.5GHz to 3.7GHz that the Federal Communications Commission has designated for sharing among three tiers of users: incumbent users, priority licensees and generally authorized, which is unlicensed.
CBT Computer Based Training  
CC Call Conferencing  
CC7 Common Channel Signalling # 7 TDM Domain
CCR Call Charging Record.  
CCS7 Common Channel Signalling # 7 TDM Domain
CCTV Closed Circuit Television  
CD Call Diversion  
CDMA Code Division Multiple Access  
CDN Content Delivery Network  
CDR Call Data Records  
CE Customer Edge (Router)  
CELP Code Excited Linear Predictive Voice Compression Technology
CEM Customer Experience Management  
CF Call Forwarding  
CGF Core Charging Gateway Function  
CGPOMU Carrier Grade Platform Operation and Management Unit  
CH/CW Call Hold / Call Waiting  
CHAP Cryptographic Handshake Authentication Protocol  
CHF Charging Function  
CI Configuration item. Can be physical, logical, virtual or even information assets that need to be recorded and/or tracked, usually for the purpose of delivering a service and/or operate a network/infrastructure. Usually stored in a CMDB  ITIL terminology
CI / CD Continuous Integration / Continuous Delivery (or Continuous Deployment)  
CIC Committee on Information and Communications  
CIF Cell in Frames ATM over Ethernet & Token Ring LANs
CLI Calling Line Identification Shows incoming caller number or ID
CLIP Calling Line Identification Presentation Shows incoming caller number or ID
CLIR Calling Line Identification Restriction  
CLNP Connection Less Network Protocol  
CM Configuration Management  
CMDB Configuration Management Database  
CMS Call Management Services  
CMS Content Management System  
CMTS Cellular Mobile Telephone Service  
CNM Customer Network Management  
CNNF Cloud Native Network Function  
CoC Cost of Capital  
conductor  A metallic wire designed to carry signals (eg copper telephone lines).  
CONS Connection-Mode Network service.  
CORBA Common Object Request Broker Architecture  System interface technique
CORD Central Office Re-architected as a Data Centre Typically cloud-centric data centres at the network edge
COTS Commercial Off The Shelf   
CP Connection point  
CP Control Plane  
CPE Customer Premises Equipment eg modems, routers, etc at customer premises
CPLD Complex Programmable Logic Device  
CPQ Configure, Price, Quote Workflow type
CPU Central Processing Unit  
CRAN C-RAN (Cloud-RAN), sometimes referred to as Centralised-RAN, is an architecture for cellular networks  
CRM Customer Relationship Management  
CS Caesium Clock Synch Domain
CS-ACELP Conjugate structure Algebraic CELP Voice Compression Technology
CSCF Cell Session Control Function  
CSMA/CD Carrier Sense Multiple Access with Collision Detection  
CSMGW Core Circuit Switched (CS) Media Gateway (MGW)  
CSN Control System Network  
CSP Communcations Service Provider  
CSTA Computer Supported Telecommunications Applications From ECMA. Defines application level CTI functions
CT Call Tracing  
CTIA Cellular Telecommunications Industry Association   
CTP Connection termination point  
CU Central Unit  
CUCP Central Unit (CU) Control Plane (CP)  
CU-CP Central Unit Control Plane  
CU-UP Central Unit User Plane  
D links diagonal links SS7 Notation
DA Domain Auhority – Predicts how well a website will rank on search engine result pages (SERPs)  
DAS Distributed Antenna System  
DB Database  
DC Data Centre or Direct Current depending on context  
DCF Dispersion Compensating Fibre  
DCG Dispersion Compensating Grating  
DCIM Data Centre Infrastructure Management  
DCME Digital Circuit Multiplication Equipment Voice Compression Technology
DCN Data Control Network A network used to carry network management traffic
DCS Digital Cross-connect System (qv. DXC)  
DDF Digital Distribution Frame For interconnection of cables at head-end.
DDS Digital Data Service  
DECT Digital Enhanced Cordless Telecommunications  
DES Data Encryption Software  
DEV/TEST/LAB  A non-production database for development, test or lab purposes  
DevOps Portmanteau for Development and Operations  
DHCP Dynamic Host Configuration Protocol  
DIU Digital Interface Unit TDM Domain
DLCI Data Link Connection Identifier ISDN “Circuit” identifier
DNS Domain Name Server  
DOCSIS Data Over Cable Service Interface Specification   
DOS Disk Operating System  
downstream  Transmission of information from the service provider to the customer  
DPC destination point code SS7 Notation
DPNSS Digital Private Network Signaling System  
DR Disaster Recovery  
DRA Diameter Routing Agent  
DRP Disaster Recovery Plan  
DS Digital section  
DS1 A bandwidth unit (1.5 Mbps), described when used for certain transfer protocols  
DS3 A bandwidth unit (45 Mbps), described when used for certain transfer protocols  
DSF Dispersion Shifted Fibre  
DSL Digital Subscriber Lines ADSL Domain
DSLAM Digital Subscriber Line Access Multiplexer ADSL Domain
DSR Diameter Signaling Router  
DSS Decision Support System  
DU Distribution Unit  
DVB Digital Video Broadcasting. Transmission of digital video signals  
DWDM Dense Wavelength Division Multiplexing DWDM Domain
DWH Data Warehouse  
DXC Digital Cross Connect  
E link extended link SS7 Notation
E1 A bandwidth unit (2.048 Mbps), described when used for certain transfer protocols  
E2E End to End  
E3 A bandwidth unit (34 Mbps), described when used for certain transfer protocols  
EA Equal Access TFN Service Type
easement Piece of land in which cables, conduits, etc can be placed.  
EC Error Correction.  
EC2 Amazon Elastic Compute Cloud  
EDFA Erbium Doped Fibre Amplifier  
EIR Core Equipment Identity Register  
EKS Elastic Kubernetes Service  
ELB Elastic Load Balancing  
ELK stack Elasticsearch, Logstash, and Kibana (Often referred to as Elasticsearch) and used for application / infrastructure log monitoring  
eMBB enhanced Mobile Broadband Network slice – provides higher speeds for applications such as web browsing, streaming and video conferencing
EMDF Enhanced Main Distribution Frame A LAN distribution frame where cables and LAN ports are patched.
EML Element Management Layer  
EMS Element Management System  
ENB LTE eNodeB  
EOI Expression of Interest  
EoL End of Life (of an asset)  
EoS End of Support (by the vendor of an asset type)  
EP_E1 NR End Point of the logical link, supporting E1 interface between gNB-CU-CP and gNB-CUUP  
EP_F1C NR End Point of the control plane interface (F1-C) between the DU and CU or CUUP  
EP_F1U NR End Point of the user plane interface (F1-U) between the DU and CU or CUUP  
EP_MAP_SMSC 5G Core End Point of MAP interfaceresource specification  
EP_N10 5G Core End Point of N10 interface (between SMF and UDM)resource specification  
EP_N11 5G Core End Point of N11 interface (between AMF and SMF)resource specification  
EP_N12 5G Core End Point of N12 interface (between AMF and AUSF)resource specification  
EP_N13 5G Core End Point of N13 interface (between AUSF and UDM)resource specification  
EP_N14 5G Core End Point of N14 interface (between two AMFs)resource specification  
EP_N15 5G Core End Point of N15 interface (between AMF and PCF)resource specification  
EP_N16 5G Core End Point of N16 interface (between two SMFs)resource specification  
EP_N17 5G Core End Point of N17 interface (between AMF and 5G-EIR)resource specification  
EP_N2 5G Core End Point of N2 interface (between (R)AN and AMF)resource specification  
EP_N20 5G Core End Point of N20 interface (between AMF and SMSF)resource specification  
EP_N21 5G Core End Point of N21 interface (between SMSF and UDM)resource specification  
EP_N22 5G Core End Point of N22 interface (between AMF and NSSF)resource specification  
EP_N26 5G Core End Point of N26 interface (between AMF and MME)resource specification  
EP_N27 5G Core End Point of N27 interfaceresource specification  
EP_N3 5G Core End Point of N3 interface (between (R)AN and UPF)resource specification  
EP_N31 5G Core End Point of N31 interfaceresource specification  
EP_N32 5G Core End Point of N32 interfaceresource specification  
EP_N4 5G Core End Point of N4 interface (between SMF and UPF)resource specification  
EP_N5 5G Core End Point of N5 interface (between PCF and AF)resource specification  
EP_N6 5G Core End Point of N6 interface (between UPF and DN)resource specification  
EP_N7 5G Core End Point of N7 interface (between SMF and PCF)resource specification  
EP_N8 5G Core End Point of N8 interface (between AMF and UDM)resource specification  
EP_N9 5G Core End Point of N9 interface (between two UPFs)resource specification  
EP_NgC NR End Point of the control plane interface (NG-C) between the gNB and NG-Core entity  
EP_NgU NR End Point of the NG user plane (NG-U) interface between the gNB and the UPGW  
EP_NLG 5G Core End Point of NLg interface (between AMF and GMLC)resource specification  
EP_NLS 5G Core End Point of NLs interface (between AMF and LMF)resource specification  
EP_RP_EPS EPC End Point (EP) of Reference Point (RP) in Evolved Packet System (EPS)  
EP_Rx 5G Core End Point of Rx interface (between PCF and AF)resource specification  
EP_S1U NR End Point of the logical link, supporting S1-U interface towards a S-GW node  
EP_S5C 5G Core End Point (EP) of S5-C interfaceresource specification  
EP_S5U 5G Core End Point (EP) of S5-U interfaceresource specification  
EP_SBI_IPX 5G Core End Point (EP) of Service Based Interface (SBI) IPXresource specification  
EP_SBI_X 5G Core End Point (EP) of Service Based Interface (SBI) Xresource specification  
EP_X2C NR End Point of the logical link, supporting X2-C application protocols  
EP_X2U NR End Point of the logical link, supporting the X2 user plane (X2-U) interface  
EP_XnC NR End Point of the logical link, supporting Xn Application protocols, to a neighbour gNB node  
EP_XnU NR End Point of a logical link supporting the Xn user plane (Xn-U) interface  
EPC Evolved Packet Core  
ePDG EPC evolved Packet Data Gateway  
EPS Evolved Packet System  
ERP Enterprise Resource Planning  
ET End Terminal DWDM Domain
Ethernet A local area network (LAN) protocol. One style of transmitting information over a local area network.  
ETL Extract, Transform, Load (of data)  
eTOM enhanced Telecom Operation Map  
eUICC embedded universal integrated circuit card aka eSIM
EUtranCellFDD LTE Frequency Division Duplex (FDD) radio cell  
EUtranCellTDD LTE Time Division Duplex (TDD) radio cell  
EVC Ethernet virtual connections   
F link fully associated link SS7 Notation
F&A Finance and Administration  
FAD Full Add Drop DWDM Domain
FAR Fixed Asset Register  
FAT Factory Acceptance Testing  
Fault A network or other issue that requires resolution. Resolution could be via automated controls or manual work order to a field technician.
Sometimes also known as an Alert, Incident or Event
 
FC Fully Compliant  
FCAPS Faults, Configuration, Accounting / Asset, Performance, Security management  
FDDI Fibre Distributed Data Interface  
FDP fibre distribution points. Point of interconnect of cables. Allows distribution of signal from head-end to a customer or customers.  
FE Fast Ethernet  
FEC Forward Error Correction  
FEP Front End Processor  
FERF Far end receive failure  
FIB forward indicator bit SS7 Notation
FISU fill in signal unit SS7 Notation
FM Facilities Management. Management and coordination of telecommunications equipment.  
FMS Fibre Monitoring System  
FOA Fixed Optical Attenuator  
FPGA Field Programmable Gate Array  
FR Frame Relay TFN Service Type
Frame Relay Information Transfer protocol. One style of transmitting information over a network  
FreeRTOS real-time operating system for microcontrollers  
FSAN Full Services Access Network. A network capable of carrying all forms of information with varying bandwidths and urgency of transmission.  
FSN forward sequence number SS7 Notation
FSP Fixed Line Service Provider  
FTAM File Transfer, Access and Management (ISO 8571).  
FTP File Transfer Protocol  
FTTC Fibre To The Curb. A style of cable network, where optical fibre carries signals from the head-end to the curb. From the curb to the home, the signal is carried by other cable types (eg normal copper telephone cables or coaxial cables).  
FTTdp Fibre to the Distribution Point. Similar to FTTC or FTTN, but closer to the customer premises and with a limited number of connections  
FTTH  Fibre To The Home. A style of cable network, where optical fibre carries signals from the head-end all the way to the home.  
FTTP Fibre to the Premises (same as FTTH)  
FTTx Fibre to the Anything (Node, Home, Premises, etc)  
GB Gigabyte  
Gbps  Gigabits per second (1,000,000,000 bps)  
GDPR General Data Protection Regulation  
GGSN Core Gateway GPRS Support Node  
Gigabit Ethernet Similar to 10BaseT Ethernet, except with a theoretical bandwidth of 1Gbps instead of 10Mbps.  
GIS Geographical Information Systems   
GNB gNodeB  
GNBCUCP 5G NR gNB Central Unit (CU) Control Plane (CP)  
GNBCUUP 5G NR gNB Central Unit (CU) User Plane (UP)  
GNBDU 5G NR gNB Distributed Unit (DU)  
GPON Gigabit Passive Optical Network  
GPRS General Packet Radio Service  
GPS Global Positioning System Synch Domain
GRE Generic Routing Encapsulation  
GSM Global System for Mobile Communications   
GsmCell GSM Radio Cell  
GST Goods and Services Tax  
GUI Graphical User Interface  
HA High Availability  
HDSL High-Bit-Rate Digital Subscriber Line   
HDTV High-Definition Television  The next generation of television. Provides greater picture resolution than current television signals.
HFC Hybrid Fibre / Coaxial  A style of cable network. Makes use of both optical fibre and coaxial cables to guide information from one point to another.
HLR Home Location Register  
HPA Higher order path adaptation  
HPC Higher order path connection  
HPT Higher order path termination  
HSS Home Subscriber Server  
HT Hub Terminal LMDS Domain
HTML Hypertext Markup Language  
HTTP HyperText Transfer Protocol  
HU Hub Unit LMDS Domain
HV High Voltage  
I2I Idea to Implementation Workflow type
IA Indirect adaptor  
IaaS Infrastructure as a Service   
IAC Cisco Intelligent Automation for Cloud  
IAM initial address message SS7 Notation
IBS Integrated Business System  
IC Integrated Circuit  
ICMP Internet Control Message Protocol  
ICSCF IMS Interrogating Call Session Control Function (I-CSCF)  
ICT Information and Communications Technology  
ID Identifier  
IDC Internet Data Centre  
IDS Intrusion Detection System  
IDU In-door Unit LMDS Domain
IEEE Institute for Electrical and Electronics Engineers   
IETF Internet Engineering Task Force   
IFL Interfacility Link LMDS Domain
iGWB Charging Gateway  
IITF Information Infrastructure Task Force   
ILD International Long Distance  
IM Inventory Management  
IMBE Improved MBE Voice Compression Technology
IMS IP Multimedia Subsystem  
IN Intelligent Network TDM Domain
integration of voice, video and data Previously the different types of signals were sent on different networks. However, integration was set up to use a single network infrastructure to carry all types of signals.  
IO Input / Output AMAS Domain
IOS Internetworking Operating System  
IoT Internet of Things  
IP Internet Protocol (RFC-791).  
IP/MPLS Internet Protocol / Multi-Protocol Label Switching  
IPAM IP Address Management  
IPS Intrusion Prevention System  
IPS / IDS Intrusion Prevention System / Intrusion Detection System  
IPSLA Internet Protocol Service Level Agreement  
IS Information Systems   
ISD International Subscriber Dialing  
ISDN Integrated Services Digital Network International standard that defines a digital end-to-end network that can support voice, data, image and video simultaneously
ISM Information Security Manual  
ISP Inside Plant  
ISP Internet Service Provider Allows customers access to the Internet and Internet facilities.
ISUP ISDN user part SS7 Notation
IT Information Technology  
ITIL Information Technology Infrastructure Library  
ITSM IT Service Management   
ITU-T International Telecommunication Union’s Telecommunication Standardization Sector   
ITU-TSS International Telecommunications   Union – Telecommunications Standards Sector  is the new name for CCITT which is an   international standards body which is a committee of the ITU, a U.N. treaty   organisation.
IubcLink Core Iu-bc interface link  
IubLink UMTS Iub Link  
IucsLink Core Iu-cs interface link  
IupsLink Core Iu-ps interface link  
IVR Interactive Voice Response  
JDBC A SUN JAVA standard for connecting client applications to external databases  
JIT Just in Time  
JSON JavaScript Object Notation  
JTAPI Java Telephony API From Sun Microsystems, Lucent, et al. Provides CTI in either 1st or 3rd party environment
kbps Kilobits per second (1,000 bps)  
KISS Keep it Simple Stupid  
km kilometre  
KPI Key Performance Indicator  
L2 Layer 2 (of the OSI stack)  
L2C Lead to Cash  
L3 Layer 3 (of the OSI stack)  
LAN Local Area Network Small networks of computers, usually in office or campus environments.
LAN interconnect services Allows communications between different information transfer protocols  
LAPB Link Access Procedure, Balanced Data link layer protocol in the X.25 protocol stack. LAPB is a bit-oriented protocol derived from HDLC
LC Logical Channel  
LDAP Lightweight Directory Access Protocol  
LDCA Long Distance Charge Area  
LD-CELP Low delay CELP Voice Compression Technology
LDS Leased Data Service TFN Service Type
LEC Local Exchange Carrier   
LEO Low Earth Orbit  Satellite
LES/BUS LAN Emulation Software & Broadcast Unknown Server  
LL Logical Link  
LLC Logical Link Control standards.  
LMF 5G Core Location Management Function  
LNI Logical Network Inventory  
LNS Layer 2 Tunneling Protocol (L2TP) Network Switch  
LocationService MEC Location Service  
LOF Loss of frame  
LOP Loss of pointer  
LOS Loss of signal  
LPA Lower order path adaptation  
LPC Lower order path connection  
LPT Lower order path termination  
LSP Label Switched Paths   
LSSU link status signal unit SS7 Notation
LTE Line Terminal Equipment  
LTG Line Trunk Group TDM Domain
LTU Line Trunk Unit TDM Domain
LVP Logical Virtual Path ADSL Domain
M2M Machine to Machine  
MaaP Messaging as a Platform  
MAC Media Access Control  
MACD Moves / Adds / Changes / Disconnects  
MAN Metropolitan Area Network   
MANO Management and Orchestration NFV functional component
MB Megabyte  
MBE Multiband Excitation Voice Compression Technology
Mbps Megabits per second  
MCC Mobile Country Code is used in wireless telephone networks such as GSM, CDMA, WCDMA or LTE in order to identify mobile user belongs to which country. MCC consists of 3 decimal digits.
MCN Media Conversion Node  
MCU Metered Call Unit  
MD Mediation Device.  
MDD Mediation Device Drivers   
MDF Main Distribution Frame For interconnection of cables at head-end.
MDN Mobile Directory Number  
ME Managed Element  
MEA Media Extension Adaptor Used to extend an adapter or card so that it fits inside a chassis.
MEA MEC Mobile Edge Application  
MEC Mobile Edge Core  
MEH MEC Mobile Edge Host Function  
MELT Metrics, Events, Logs, Traces Telemetry
MEPM MEC Mobile Edge Platform Manager  
MF multifrequency SS7 Notation
MFA Multi-Factor Authentication  
MGW Media Gateway  
MIB Management Information Base SNMP
MIS Management Information Systems   
ML Machine Learning  
MME Mobility Management Entity  
MML Man   Machine Language. An ITU-T recommendation for the   man-machine interface to operation and maintenance functions in telephone   exchange.
MMOF Multi-Mode Optical Fibre  
mMTC massive Machine Type Communications Network slice – extends LTE (Long Term Evolution) IoT (Internet of Things) capabilities to support a huge number of devices with enhanced coverage and long battery life
mmWave Millimeter wave  
MNC Mobile Network Code is also used in wireless telephone networks in order to identify mobile user belongs to which mobile network. MNC consists of 2 or 3 decimal digits.
MNIB Management Network Information Base.  
MNP-SRF Core Mobile Number Portability-Signaling Relay Function  
MOA Managed Object Agent  
MobileEdgePlatformService MEC Mobile Edge Platform Service  
MOR Multi-wavelength Optical Repeater  
MOS Mean Opinion Score A Measure Of Voice Quality
MPEG Motion Picture Experts Group  A standard method for compression of video signals
MPEG-1 One standard of the MPEG family. Typically used for computer video compression.  
MPEG-2 Another standard of the MPEG family. Typically used for broadcast video compression.  
MPLS Multiprotocol Label Switching   
MPLS-TE Multiprotocol Label Switching (MPLS) Traffic Engineering  
MPLS-TP Multi-Protocol Label Switching Transport Profile  
MP-MLQ Multi Pulse Maximum Likelihood Quantisation Voice Compression Technology
MR Mixed Reality  
MS Mobile Station Hand held Unit (mobile handset)
MS Multiplex section SDH Domain
MSC Mobile Switch Centre aka Mobile-service Switching Centre
MSOH Multiplexer Section Overhead  
MSP Multiplexer Section Protection  
MSP Maintenance Service Provider  
MSS Multiple Subscription Services  
MS-SPRING Multiplexer Section Shared Protection Ring  
MST Multiplex section termination  
MSU message signal unit SS7 Notation
MTBF Mean Time Between Failures  
MTBR Mean Time Between Repairs  
MTOSI Multitechnology Operations System Interface   
MTP message transfer part SS7 Notation
MTTF Mean Time To Failure  
multimedia services Transmission of multiple “media” (ie audio, video, data, image signals) over a single communication line  
MUX Multiplexer  
MVNO Mobile Virtual Network Operator  
MVP Minimum Viable Product  
N/A Not Applicable  
N3IWF Non-3GPP Interworking Function  
NaaS Network as a service   
NAP Network Access Point   
NAT Network Address Translation  
NBI Northbound Interface  
NBV Net Book Value (ie financial value remaining after depreciation is subtracted)  
NC Not Compliant  
NDIS Network Device Interface Specification  
NDSF Non-Dispersion Shifted Fibre  
NE Network Element Equipment in the Network
Near-RT RIC Near Real-Time RIC (RAN Intelligent Controller)  
NEF Network Exposure Function  
NEMS Network Element Management System Vendor Software to control network elements
NEXT Near End Crosstalk Copper cabling measurement standard
NFR Non-Functional Requirements  
NFS Network File System, (RFC-1094).  
NFV Network Function Virtualisation  
NFVI Network Function Virtualisation Infrastructure  
NFVO Network Function Virtualisation Orchestrator  
NGEIR 5G Core NG Equipment Identity Register  
NGOSS New Generation Operations Systems and Software  
NIC Network Interface Card  
NIST National Institute of Standards and Technology   
NLD National Long Distance  
NLDO National Long Distance Operator  
NLDSC National Long Distance Service Code  
NLR Natural Language Recognition  
NLSR Natural Language Speech Recognition  
NMC Network Management Control  
NML Network Management Layer  
NMS Network Management System Vendor Software to control network elements
NNI Network node interface  
NOC Network Operations Centre  
NodeB UMTS NodeB  
Non-RT RIC Non-RealTime RIC (RAN Intelligent Controller) Orchestration and Automation function described by the O-RAN Alliance for non-real-time intelligent management of RAN (Radio Access Network) functions
NPV Net Present Value  
NRCellCU 5G NR Cell Central Unit (CU)  
NRCellDU 5G NR Cell Distributed Unit (DU)  
NRF NF Repository Function Network Functions register themselves with the NRF, which maintains the overall inventory of active network functions. Other network functions can “discover” services and functions by interfacing with the NRF.
NRSectorCarrier 5G NR Sector Carrier  
nrt-VBR  Non Real Time Variable Bit Rate Describes a quality of service on ATM networks
NRZ Non Return to Zero  
NSN National Significant Number  
NSSF Network Slice Selection Function  
NTP National Telecom Policy  
NTP Network Time Protocol  
NTU Network Termination Unit  
NWDAF 5G Core Network Data Analytics Function  
NZDSF Non-Zero Dispersion Shifted Fibre  
O&M Operations and Maintenance  
O2A Order to Activate Workflow type
O2P Order to Payment Workflow type
O2S Order to Service Workflow type
OA Optical Amplifier DWDM Domain
OADM Optical Add-drop Multiplexer  
OAM Operation Administration and Maintenance  
OC-12 622M/b/s (SONET transmission rate)  
OC-192 10Gb/s (SONET transmission rate)  
OC-3 155Mb/s (SONET transmission rate)  
OC-48 2.5Gb/s (SONET transmission rate)  
OCH Optical Channel  
OCS Online Charging System  
OctopOSS I refer to OSS as The OctopOSS because an OSS can be like a giant octopus. Just when you think you have all the tentacles covered, another whacks you on the back of the head  
ODA Open Digital Architecture, framework by TM Forum. Blueprint for cloud-based open digital platforms  
ODBC Open Database Connectivity  
ODF Open Digital Framework, by TM Forum  
ODF Optical Distribution Frame  
ODN Open Data Network   
ODPR  Optical Dedicated Protection Ring  
ODS Operational Data Store  
ODU Out-door Unit LMDS Domain
OEM Original Equipment Manufacturer  
OH&S Operational Health and Safety  
OLA Optical Line Amplifier  
OLTE Optical Line Terminating Equipment  
OMAP operations, maintenance, and administration part SS7 Notation
OMC  Operation & Maintenance Centre  
OMS Optical Multiplexer Section  
OMSP Optical Multiplexer Shared Protection  
ONU Optical Network Unit.  Converts electrical signals to optical signals for transmission over optical fibres
OOB Out of Band Management traffic is carried via a separate network path to all other network traffic
OPC originating point code SS7 Notation
OPEX Operational Expenditure  
OPS Optical Protection Switching  
ORAN Open RAN  
OSC Optical Supervisory Channel  
OSI Open System Interconnection  
OSP Outside Plant  
OSS Operational Support System Software to control NEMS
OSSaaS OSS as a Service  
OT Operational Technology  
OT Operational Team  
OTAF Over The Air activation Function  
OTASP Over The Air Service Provisioning  
OTDR Optical Time Domain Reflectrometry Test equipment used to identify faults or degradations on optical fibre links
OTH Optical Transport Hierarchy  
OTR Optical Transport Repeater  
OTT Over the Top Method of delivering service over another service provider’s infrastructure (eg public Internet)
OXC Optical Cross Connect  
P2O Prospect to Order Workflow type
P2P Plan to Production Workflow type
PaaS Platform as a Service   
PABX  Private Automatic Branch Exchange Small telephone network/switch for customer premises. It provides local connectivity and switching coupled with connections to the public carrier network.
PAL Phase Alternation By Line   
PAP Password Authentication Protocol  
PBC Policy based charging  
PC Personal Computer   
PC  Partially Compliant  
PCF Policy Control Function  
PCI Peripheral Component Interconnect  
PCIA Personal Communications Industry Association   
PCM Pulse Code Modulation  
PCRF Policy Control and Charging Rules Function  
PCS Personal Communication Service   
PCSCF IMS Proxy Call Session Control Function (P-CSCF)  
PDA Personal Digital Assistant  
PDH Plesiochronous Digital Hierarchy  
PDSN Packet Data Switching Node  
PE Provider Edge (Router)  
PEE Power, Energy and Environmental (PEE)  
PFC Policy Feature Card  
PGW EPC PDN Gateway or Packet Gateway  
PLC Programmable Logic Control  
PLMN Public Land Mobile Network Identifier is a combination of MCC and MNC. It is unique value and globally used to identify the mobile network that a user subscribed.
PM Project Manager  
PM Project Management  
PM Performance Management  
PMBOK Project Management Body of Knowledge   
PMD Polarisation Mode Dispersion  
PMI Project Management Institute   
PMO Project Management Office  
PMP Project Management Plan  
PNF Physical Network Function  
PNI Physical Network Inventory  
PNNI Private Network to Network Interface  
PoC Proof of Concept  
POH Path overhead  
POI Point Of Interconnect Interconnect to other carriers’ networks
PON Passive Optical Network  
POP Point of Presence  
POTS Plain Old Telephone Service  Standard telephone lines. Originally designed to carry analogue information.
PP Path Protection  
PPP Point-to-Point Protocol  
PPV Pay Per View. The customer signs up for and pays for access to specific programming.  
PRA Primary Rate Access ISDN Type
PRINCE2  A project management methodology  
Problem A problem is the cause of one or more incidents / events. It is a data object that allows aggregation of related incidents / events, and is then used to coordinate further investigation and remediation effort.  
PROD Production database instance  
PROPEX Project OPEX Accounting mechanism used by some organisations
PRS Premium Rate Service TFN Service Type
PSTN Public Switched Telephone Network Telecommunications network
PSU Public Sector Unit  
PVC Permanent Virtual Circuit ATM Domain
PVP Permanent Virtual Path ATM Domain
Q2C Quote to Cash Workflow type
QA Quality Assurance  
QAM Quadrature Amplitude Modulation   
QoS Quality of Service  
R&D Research And Development   
R2A Request to Answer Workflow type
R2C Request to Change Workflow type
RADIUS Remote Authentication Dial In User Service  
RAM Random Access Memory  
RAN Radio Access Network  
RANCID Really Awesome New Cisco confIg Differ  
RAS Remote Access Server Equipment to allow remote dial-up access to a network
RBOC regional Bell operating company SS7 Notation
RCA Root Cause Analysis  
RCL release complete message SS7 Notation
RCS Residential Cabling System  
RCS Rich Communication Services This messaging service is designed to replace current short messages with a system that is richer, provides phonebook polling, and can transmit in-call multimedia. 5G may facilitate a shift away from basic SMS messaging, ushering in an era of RCS, where mobile messaging can become much more interactive and flexible, more akin to what we now know as iMessaging through platforms like Facebook and WhatsApp.
RDBMS Relational Database Management System  
RDN Relative distinguished name  
RDS Relational Database Service  
reach  the maximum distance over which a signal can be transmitted without significant degradation  
REL release message SS7 Notation
REST or RESTful Representational State Transfer REST is a form of API for transferring information between systems. Eg when used for web APIs, it leverages HTTP
RF Radio Frequency  
RFI Ready for Installation  
RFI Request for Information  
RFP Request for Proposal  
RFQ Request for Quote  
RIC RAN Intelligent Controller RIC  is a suite of Software Apps to enable SDN functionalities in open RAN networks. Responsible for all RAN operation and optimization procedure like radio connection management, mobility management, QoS management, edge services, and interference management, radio resource management, higher layer procedure optimization, policy optimization in RAN, and providing guidance, parameters, policies and AI/ML models to support the best effective network operation.
RNC UMTS Radio Network Controller  
RNI Radio Network Inventory  
R-NIB Radio-Network Information Base Used by RIC near-RT
RNP Radio Network Planning  
RO/RW Read Only / Read Write  
ROI Return on Investment   
ROM Read Only Memory  
ROM Rough Order of Magnitude  
ROS Robot Operating System  
RPC Remote Procedure Call (RFC-1057).  
RPE Regular Pulse Excited Voice Compression Technology
RRH Remote Radio Head  
RRP Recommended Retail Price  
RS Regenerator section  
RSOH Repeater Section Overhead  
RSP route set prohibited test message SS7 Notation
RSR restricted test message SS7 Notation
RSS Rapid Site Solution  
RST Regenerator section termination  
RSVP Resource Reservation Protocol  
RT Remote Terminal LMDS Domain
RTU Remote Testing Unit Fibre Monitoring
RTU Remote Terminal Unit  
RU Rack Units  
RU Remote Unit LMDS Domain
RX Receive/Receiver  
S3 Amazon Simple Storage Service  
SA Section adaptation  
SaaS Software as a Service   
SAN Storage Area Network  
SAR Segmentation And Re-assembly As used in network packets
SAT Site Acceptance Testing  
SAX Small Automatic Exchange Remote CDMA
SBC Session Border Controller  
SBS Stimulated Brillouin Scattering  
SCADA Supervisory Control and Data Acquisition  
SCCP signaling connection control part SS7 Notation
SCE Service Creation Environment IN Domain
SCP Service Control Point IN Domain / SS7 Notation
SCP Services Code Point  
SCP Service Communication Proxy provides a single point of entry for a cluster of a given type of Network Functions
S-CSCF IMS Serving Call Session Control Function  
SDCA Short Distance Charging Area  
SDDC Software Defined Data Centre  
SDH  Synchronous Digital Hierarchy ITU-TSS international standard for transmission of high capacity digital signals over optical fibre.
SDL Shared Data Layer  
SDM Space Division Multiplexing  
SDN Software Defined Network  
SDTV Standard Definition Television   
SEAL Substation Ethernet Access Link  
SECAM Sequential Couleur Avec Memoire  
SED Spatially Enabled Database  
SEO Search Engine Optimisation  
SEPP Security Edge Protection Proxy  
SES Simple Email Service  
SFVN Secure Fast Virtual Networking  
SGSN Serving GPRS Support Nodes  
SGW Serving Gateway  
SGW EPC Serving Gateway  
SGW Core Signalling Gateway (Sgw)  
SIA Service Imapact Analysis  
SID TM Forum’s Shared Information / Data model  
SIEM Security Information and Event Management  
SIM Subscriber Identity Module  
SIP Session Initiation Protocol a signalling protocol, widely used for setting up and tearing down multimedia communication sessions such as voice and video calls over the Internet. Other feasible application examples include video conferencing, streaming multimedia distribution, instant messaging, presence information and online games.
SIT Site Acceptance Testing  
SLA Service Level Agreement Contract to ensure certain service standards are met.
SLS signaling link selection SS7 Notation
SMDS Switched Multimegabit Data Service  
SME Small / Medium Enterprise   
SME Subject Matter Expert  
SMF Session Management Control Function  
SML Service Management Layer  
SMOF Single Mode Optical Fibre  
SMP Service Management Point IN Domain
SMPP Short Message Peer-to-Peer Protocol Supports transfer of short message data between External Short Messaging Entities (ESMEs), Routing Entities (REs) and SMSC
SMS Short Messaging Service  
SMSC Short Messaging Service Center  
SMSF Short Message Service Function  
SMTP Simple Mail Transfer Protocol  
SNCP Sub-Network Connection Protection  
SNMP Simple Network Management Protocol  
SNR Signal to Noise Ratio  
SNS Simple Notification Service  
SOC Security Operations Centre  
SOC Service Operations Centre  
SOE Standard Operating Environment  
SOH Section overhead  
SOHO Small Office / Home Office  
SONET Synchronous Optical NETwork   is an American National Standards Institute (ANSI) standard for transmission of high capacity digital signals over optical fibre, used in the USA and Canada.
SP-GW CP Service / Packet Gateway Control Plane  
SP-GW UP Service / Packet Gateway User Plane  
SPI SDH physical interface  
SPM Self Phase Modulation  
SPVP Switched or Soft Permanent Virtual Path ATM Domain
SQL Structured Query Language   
SQS Simple Queuing Service  
SRL Structural Return Loss Copper cabling measurement standard
SRS Stimulated Raman Scattering  
SS7 Signalling System # 7 SS7 Notation
SSO Single Sign-on  
SSP signal switching Point SS7 Notation
SSU Synchronisation Supply Unit Synch Domain
STB Set-Top Box   
STD Subscriber Trunk Dialing  
STM Synchronous transfer mode  
STM-1 155Mb/s (SDH transmission rate) SDH domain
STM-16 2.5Gb/s (SDH transmission rate) SDH domain
STM-4 622Mb/s (SDH transmission rate) SDH domain
STM-64 10Gb/s (SDH transmission rate) SDH domain
STP Signal Transfer Point SS7 Notation
STP Shielded Twisted Pair  is a generic name for any cable constructed with a pair of twisted wires surrounded by a metallic shield.
STT Set-Top Terminal  
STU Set Top Unit. The box at the   customer premises that decodes signals sent from the head-end.  
SU signal unit SS7 Notation
SWOT Strengths, Weaknesses, Opportunities, Threats  
T1 A bandwidth unit (1.5 Mbps), described when used for certain transfer protocols  
T2 Amazon compute instance  
T2C Termination to Confirmation Workflow type
T2R Trouble to Resolve  
T3 A bandwidth unit (45 Mbps), described when used for certain transfer protocols  
TAM TM Forum’s “The Application Map”  
TAPI Telephony Application Programming Interface From Microsoft & Intel. Provides first party CTI
TAS Telephony Application Server  
TB Terabyte  
TBC To Be Confirmed  
Tbps  Terabits per second (1,000,000,000,000 bps)  
TCAP transaction capabilities application part SS7 Notation
TCO Total Cost of Ownership   
TCP Transmission Control Protocol (RFC-793).  
TCP/IP Transmission Control Protocol / Internet Protocol  
TDM Time Division Multiplexing  
TDMA Time-Division Multiple Access   
telecommunications traffic Signals (information) being transmitted on telecommunications networks  
TFA transfer allowed message SS7 Notation
TFP transfer prohibited message SS7 Notation
TFR transfer restricted message SS7 Notation
TGNO Trunk Group Number TDM Domain
Ticket or Trouble Ticket A mechanism to assign tasks to different users and monitor performance of the user as well as the process.  
TM Forum Telemanagement Forum Standards body supporting the OSS/BSS / telco industry
TMA Tower Mounted Amplifier  
TMF Telemanagement Forum (TM Forum)  
TMN  Telecommunication Management Network.  Name of an area where standardisation bodies such an ANSI, ITU-T and ETSI are currently defining standards.
TNA Technology Neutral Architecture  
TNE Type of Network Element  
TNGF Trusted Non-3GPP Gateway Function  
TNMS Telecommunications Network Management System  
TNOC Telecommunications Network Operations Centre  
TOGAF The Open Group Architecture Forum  
ToIP Telephony over IP. A method of routing telephone calls through the Internet, rather than the PSTN (telecommunications networks).  
TOSCA Topology and Orchestration Specification for Cloud Applications  
TR Trouble Report  
TRA Trouble Report Answer  
TS Time Slot TDM Domain
TSAPI Telephony Service Application Program Interface From Novell & Lucent. Provides third party CTI in a LAN environment and which uses CSTA
TSG Time Stage Group TDM Domain
TT Trouble Ticket  
TTM Time to Market  
TTP Trail termination point  
TU Tributary unit  
TUG Tributary unit group  
TWAG Trusted Wireless Access Gateway  
TX Transmit/Transmitter  
U2C Usage to Cash Workflow type
U2P Usage to Payment Workflow type
UAT User Acceptance Testing   
UBR  Unspecified Bit Rate Describes a quality of service on ATM networks
UDM 5G Core Unified Data Management (UDM)  
UDM-FE Unified Data Management Front-end  
UDP Universal Demarcation Point Converts optical signals to electrical signals after transmission over optical fibres.
UDR United Data Repository  
UDSF Unstructured Data Storage Function The UDSF provides service interfaces to store, update, read and delete network function data. Allows other network functions such as the PCF, SMF and AMF to remain largely stateless.
UE User Equipment Mobile devices
UGW Universal Gateway  
UHF Ultra High Frequency  
UI User Interface  
UI / UX User Interface / User Experience  
ULR Useful Life Remaining  
ULR=0 Number of devices older than the useful life apportioned to the asset (in the case of Cumulus, assets are depreciated over a useful life of 5 years)  
UMTS Universal Mobile Telecommunications System  
UPF User-Plane Function  
UPS Uninterruptible Power Supply  
upstream Transmission of information from   the customer to the service provider  
UR Unidirectional Ring  
URL Universal Resource Locator   
uRLLC Ultra Reliable Low Latency Communications Network slice – enables mission-critical applications, industrial automation, new medical applications, and autonomous driving that require very short network traversal time
URSP UE (User Equipment) Route Selection Policies Helps device registration per subscriber, per slice
USCDB Unified Subscriber Center Database  
USN Unified Serving Node  
UTP Unshielded Twisted Pair  is a generic name for any cable consisting   of two twisted wires that are not surrounded by any shielding from the   potential effects of electromagnetic emissions.
UtranCellFDD UMTS Frequency Division Duplex (FDD) radio cell  
UtranCellTDDHcr UMTS Time Division Duplex (TDD) high chip rate (HCR) radio cell  
UtranCellTDDLcr UMTS Time Division Duplex (TDD) low chip rate (LCR) radio cell  
UX User Experience  
V.35, X.21, EIA-530 and G703/G.704 Information Transfer protocols. Styles of transmitting information over a network  
V5 Interface Type TDM Domain
VAN Value-Added Network   
VAR Value Added Reseller  
VAS Value Added Services  
VBR  Variable Bit Rate Describes a quality of service on ATM networks
VC Virtual Container SDH “payload”
VC Virtual Circuit ATM Domain
VC11 Virtual Container Carries T1 SDH “payload”
VC12 Virtual Container Carries E1 SDH “payload”
VC3 Virtual Container Carries T3 SDH “payload”
VC4 Virtual Container Carries STM1 SDH “payload”
VC4-4C Virtual Container Carries 4 x VC4 (to aggregate STM4) SDH “payload”
VCI Virtual Circuit Identifier ATM Domain
vCPU Virtual CPU (Central Processing Unit)  
vDC virtual Data Centre  
VDSL Very High Speed Digital   Subscriber Lines. Information Transfer protocol. One style of transmitting   information over a network. Similar to ADSL, but supports larger bandwidths.  
VHF Very High Frequency  
Video conference Transmission of video and audio signals over telecommunications networks.  
VIM Virtualised Infrastructure Manager  
VIP video information provider  
VIP Virtual IP (address)  
VLAN Virtual Local Area Network (LAN)  
VLR Visitor Location Register  
VM Virtual Machine  
VMS Voice Mail Service  
VNE Virtual Network Environment   
VNF Virtual Network Function  
VNFFG VNF Forwarding Graph Defines traffic flows between VNFs
VNFM Virtual Network Function Manager  
VoATM Voice over ATM  
VoD Video on Demand Video signal is transmitted over telecommunications network and allows the customer full control (fast forward, rewind, pause, etc). Allows the customer a selection of videos to choose from.
VoFR Voice over Frame Relay  
voice mail Records messages when someone is   not able to answer their phone.  
VoIP Voice over IP  
VP Virtual Path ATM Domain
VPC Virtual Private Cloud  
VPI Virtual Path Identifier ATM Domain
VPI/VCI Virtual Path Identifier / Virtual Circuit Identifier ATM Domain
VPLS Virtual Private LAN Service  
VPN Virtual Private Network  Segregates network for individual client groups.
VPRN Virtual Private Remote Network  Creates multi-protocol VPNs via the Internet
VR Virtual Reality  
VROOM Very Rough Order of Magnitude  
VSAT Very Small Aperture Terminal (Satellite)  
VSB Vestigial Side Band   
VT Virtual Tributary  
VXC Virtual Cross-Connect  
W-AGF Wireline Access Gateway Function  
WAN Wide Area Network  is a network which encompasses inter-connectivity between devices over a wide geographical area.  Such networks generally require access to the public network and operate over long distances.
WBS Work Breakdown Structure  
WC Will Comply  
WCS Wireless Control System   
WDM Wavelength Division Multiplexing  
WDV Written Down Value (ie the financial value of an asset after it has been depreciated Financial (depreciation) term
Web World Wide Web   
Web TV Allows access to the World Wide Web (an Internet service), using a television.  
WFM Workforce Management  
Wiki What I Know Is – a framework for collaborating on and storing information  
WIN Wireless Intelligent Network  
WINF WINForum; Wireless Information Networks Forum   
WLL Wireless in Local Loop  
WO Work Order Work Orders are a record of information about changes to network / infrastructure, including details of activities to be undertaken, primarily by field technicians. This could be work triggered by a Fault, project work or maintenance work.
WWW World Wide Web  
WYSIWYG What You See Is What You Get  
X.25 PLP X.25 Packet Level Protocol, layer 3 of ITU-T X.25.  
X.29  ITU-T X.29  recommendations for the interwork between a packet-mode DTE and a non packet-mode DTE in a packet switched transmission environment.
XaaS Anything as a Service  
xDSL Describes the family of DSL technologies (eg ADSL, VDSL, etc)  
XML eXtensible Markup Language  
XPM Cross Phase Modulation  
XR Extended Reality