In this article, I have compiled a list of common 5G Technical terms which are frequently used in the 5G Telecom domain.

1G: First generation of mobile network technology. It offered analog-based voice services.

2G: Second generation of mobile network technology. It offered digital voice and low-speed data services.

3G: Third generation of cellular network technology. It offered broadband data services.

4G: Fourth generation of cellular network technology, which offered high-definition digital voice and better data performance speed than 3G.

5G: Fifth generation of cellular network technology. It surpasses the 4G access speeds, latency, number of connected devices, coverage, availability, and energy consumption.

5G NR (New Radio): The 3GPP’s fifth-generation radio standard that leverages millimeter waves, enhanced small cells, Massive-Input Massive-Output (MIMO), beamforming, licensed/unlicensed spectrum, and full-duplex wireless technologies.

3GPP (3rd Generation Partnership Project): A group of [seven] telecommunications standard development organizations (ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, TTC), known as “Organizational Partners;” provides its members with a stable environment to produce the Reports and Specifications that define cellular telecommunications network technologies, including radio access, the core transport network, and service capabilities.

AAS (Active Antenna System): A 3GPP specified system that combines an Antenna Array with an Active Transceiver Unit Array and a Radio Distribution Network Unit.

AF (Application Function): An element offering applications that require dynamic policy and/or charging control over the IP CAN user-plane behavior. The AF communicates with the PCRF to transfer dynamic session information, required for PCRF decisions, as well as receive IP-CAN specific information and notifications about IP-CAN bearer-level events. One example of an AF is the P-CSCF of the IMS core network subsystem.

AMF (Access and Mobility Function): Provides UE-based authentication, authorization, registration, reachability, mobility management, and connection management functions. UE using multiple access technologies could be connected to a single AMF because the AMF is independent of the access technologies.

AN (Access Network): One of three major components of a 5G system, defining all equipment within the access part of the 5G network infrastructure.

AUSF (Authentication Server Function): Stores data for authentication of UE; used during the UE attachment sequence. For 5G, basic security mechanisms for 4G could be reused. However, as 5G enables new service and business models that will require many different security applications, AUSF will allow UE authentication using these different security application(s) in this new framework.

BBU (Base Band Unit): A unit of the telecom systems that processes baseband signals. It connects the core or backhaul network to one or more 4G RRHs. BBUs can be distributed (D-RAN) or centrally (C-RAN) deployed.

Beamforming: Uses multiple antennas to control the direction of a wavefront by appropriately weighting the magnitude and phase of individual antenna signals such that it become possible to provide better coverage to specific areas along the edges of cells. Beamforming algorithms can be used to reduce transmission interference from massive MIMO antennas by providing the precisely coordinated pattern through the air to each user, allowing the exchange of more data for multiple users at once.

CORD (Central Office Rearchitected as a Data Center): Transforms traditional central offices using data center technology for the purpose of virtualizing traditional telecoms network elements into a software construct.

CN (Core Network): One of three major components of the 3GPP 5G system defining all equipment within the core segment of the network.

Control Plane: The signaling function of a 3GPP system; largely deals with non-packet forwarding functions including mobility management, connection establishment, QoS control, etc. With Rel-14 and Rel-15, 3GPP aims to separate the user plane and control plane functions respectively for the EPC (Evolved Packet Core) in LTE and the NGC (Next Generation Core) in 5G.

CPRI (Common Public Radio Interface): Is a digitized and serial internal radio base station interface that establishes a connection between Radio Equipment Controller (REC), commonly known as Baseband Units (BBU), to the Radio Equipment (RE), commonly known as Remote Radio Heads (RRH), via single-hop and multi-hop topologies.

CU (Centralized Unit): A logical node hosting RRC, SDAP and PDCP sublayers of the gNB or ng-eNB; or RRC and PDCP sublayers of the en-gNB. It centralizes and controls the operation of one or more gNB-DUs, ng-eNB-DUs or en-gNB DUs. The CU terminates the Fronthaul High Layer Split (HLS) interface connected with the DUs.

CUPS (Control and User Plane Split): Refers to the separation of the Control and User Plane functions of a LTE EPC (Evolved Packet Core) packet-forwarding elements. These elements are the Serving Gateway (S-GW), the Packet Data Network (PDN), Packet Gateway (P-GW), and the Traffic Detection Function (TDF). With CUPS, a new control signal is also being defined between the control plane part and the user plane part of the split elements; this control signal is primarily used for session management purposes.

C-RAN (Centralized/Cloud-Radio Access Network): The centralization of Baseband Unit (BBU) or Distributed Unit (DU) processing, which improves cell coordination, scheduling, resource pooling, and load balancing.

DN (Data Network): The network hosting operator data-centric services, Internet, or third-party data-centric services.

D-RAN (Distributed Radio Access Network): A traditional RAN architecture where a standalone base station has both the Baseband Unit (BBU) and the Radio Unit (RU) installed at a cell site. Also, base stations with a D-RAN architecture are generally installed inside of a medium or large building for stable power supply and air conditioning needs. The D-RAN base station will have a backhaul interface into the core switching center, terminating to circuit-switching and/or packet-switching core network systems accordingly.

DU (Distributed Unit): A logical node hosting RLC, MAC, and PHY sublayers of the gNB, en-gNB, or ng-eNB. Its operation is partly controlled by the CU. One DU supports one or multiple cells. One cell is supported by only one DU. The DU terminates the Fronthaul High Layer Split (HLS) interface connected with the CU.

eCPRI (enhanced Common Public Radio Interface): The specification of an internal radio base station interface establishing a connection between eCPRI Radio Equipment Controller (eREC) and eCPRI Radio Equipment (eRE) via a packet-based transport network. Three different information flows are being defined in this specification including eCPRI User Plane Data, Control and Management Plane data, and Synchronization.

eMBB (Enhanced Mobile Broadband): One of the three subsets of 5G use cases, focusing on faster data speeds and better coverage. It’ll be perfect for data-hungry functions while on the go, like virtual or augmented reality. And a huge opportunity for businesses with new use cases built for 5G’s ten-times-faster data speeds.

en-gNB: A node providing NR user plane and control plane protocol terminations towards the UE, acting as Secondary Node in EN-DC.

EN-DC: E-UTRA (LTE) to NR Dual Connectivity. An architecture where both LTE eNodeB and NR gNB will be co-deployed, allowing the UE to simultaneously establish two radio bearers, each to the respective NodeBs.

Fronthaul: Defines the network segment connecting 3GPP Distributed Units (DUs) to Centralized Units (CUs) in a Centralized Radio Access Network (C-RAN) architecture. Fronthaul is further sub-categorized as Fronthaul HLS and Fronthaul LLS.

Fronthaul HLS (Higher Layer Split): Defines the open interconnection of a gNB-CU or ng-eNB-CU to a gNB-DU or ng-eNB-DU respectively, allowing the CUs or DUs to be supplied by different manufacturers. A Fronthaul HLS interface will have both the control plane part and the user plane part. 3GPP F1 interface is an example of a Fronthaul HLS interface.

Fronthaul LLS (Lower Layer Split): Defines the interconnection of a DU with that of a RU (Radio Unit). CPRI and eCPRI are both examples of a Fronthaul Low Layer Split interface. Specific to the eCPRI specification, the DU is being referred to as eREC, while the RU is being referred to as eRE.

gNB: A node providing NR user plane and control plane protocol terminations towards the UE, connected via the NG interface to the 5GC.

IMT-Advanced (International Mobile Telecommunications Advanced): Represents a secure all-IP mobile broadband system for wireless devices, going beyond mobile phones systems marketed as 3G; referenced as 4G or 4.5G.

IMT-2020 (International Mobile Telecommunications-2020): A program led by Working Party 5D of ITU’s Radio Communication Sector (ITU-R) to develop ‘IMT for 2020 and beyond;’ sets the stage for 5G research activities around the world. The detailed investigation of the key elements of 5G are being realized through successful partnerships between ITU-R and the mobile broadband industry, as well as with key stakeholders in the 5G community.

IP (Internet Protocol): Internet communications protocol suite for relaying data across network boundaries to enable internetworking; essentially establishes the Internet.

LTE (Long-Term Evolution): A 4G mobile communications standard whereby users of the LTE network should see data speeds up to 10 times faster than 3G networks.

LTE-A (Long-Term Evolution-Advanced): A mobile communication standard that brings major enhancements to the LTE standard; formally submitted to ITU-T in late 2009 as a candidate 4G system meeting the requirements of IMT-Advanced standard. LTE-A was standardized by the 3rd Generation Partnership Project (3GPP) in March 2011 as 3GPP Release 10.

M2M (Machine-to-Machine): Communications between machines, without human intervention.

MBH (Mobile Back Haul): The process of connecting cell sites (base stations) to network controller sites over wireline networks. Traffic engineering on such wireline networks is typically required to enforce the necessary quality of service.

Massive MIMO (Multiple-Input Multiple-Output): Refers to the large number of antennas in the base-station antenna array that enables multiple spatially separated users to be catered for by the antenna array in the same time and frequency resource.

MEC (Multi-Access Edge Computing): Cloud computing at the edge of the network, performing necessary tasks closer to the end-users. This environment is characterized by ultra-low latency and high bandwidth, as well as real-time access to radio network information that can be leveraged by applications to improve the overall end-user experience, man or machine.

MIMO (Multiple-Input Multiple-Output): Allows sending and receiving of more than one data signal on the same channel at the same time by using more than one antenna, thus improving the data rates between the transmitter and the receiver.

mmWave (millimeter wave): A high-frequency wave wedged between microwaves and infrared waves, in the millimeter band; considered to deliver faster, higher-capacity 5G services.

MNO (Mobile Network Operator): Provides wireless service(s) to wireless users by owning or leasing all components to sell and deliver wireless services over licensed wireless spectrum; MNOs include wireless service providers, wireless carriers, cellular companies, or mobile network carriers.

MTC (Machine Type Communications): Communications between machines (things).

mMTC (Massive Machine-Type Communications): Large number of machines (things) within a specific area and communicating with application servers residing in a core network.

M-CORD (Mobile-CORD): Focuses on a fully disaggregated and virtualized RAN and mobile core using open source collaboration, bringing the value of data center economics and cloud agility.

NEF (Network Exposure Function): A network entity that exposes 3GPP core network capabilities to third parties, non 3GPP environments. NEF also provides security when services or Application Functions (AFs) access 5G Core nodes. It can be thought of as a proxy, or API aggregation point, or translator into the Core Network.

NG (Next Generation): Typically referring to the new 5G systems or specifications.

NGC (Next Generation Core): Defines the mobile core elements of a 5G system.

ng-eNB: A node providing E-UTRA (LTE) user plane and control plane protocol terminations toward the UE, connected via the NG interface to the 5GC.

Network Slicing: Virtual slices of a physical network supporting specific performance guarantees.

NR (New Radio): Commonly used term to reference 3GPP 5G radio system.

NSA (Non-Standalone): One of two major 5G network architectures. In Non-standalone mode, 5G devices connect to the 4G LTE infrastructure for voice and data communication, and then use the 5G-NR infrastructure for additional data bandwidth. This architecture is predominant today, as it allows devices to use 4G and 5G seamlessly while carriers are building out their 5G networks.

PCF (Policy Control Function): A control plane function responsible for policy control; more specifically, managing the Quality of Service (QoS) of individual service data flows in a 3GPP 5G NGC. PCF enforces policies, usually based on usage volume reporting from the UPF (User Plane Function).

PDN-GW or P-GW (Packet Data Network Gateway): Provides access to Packet Data Networks; responsible for dictating QoS and BW parameters in LTE, acts as IP router to mobile-specific

tunneling and signaling protocols. This critical function will be replaced with UPF in 5G.

RAN (Radio Access Network): A combination of wireless network elements and wireline network elements connecting end-users, man and machine, to the network core delivering specific services. The network elements present in this segment of the network include the base stations, base station controllers, mobile backhaul transmission equipment, etc.

RRH (Remote Radio Head): A remote radio transceiver that connects to radio base station unit via electrical or wireless interface. The RRH is usually installed on a mast-top or tower top location and is physically some distance away from the base station hardware, which is often mounted in an indoor m the eNodeB to the P-GW. It is also the mobility anchor point for Inter-RAT handover between different generations of mobile networks such as 2G/3G. This critical function will be replaced with User Plane Function (UPF) in 5G.

SA (Stand-alone): One of two major 5G network architectures. In Stand-alone mode, 5G devices connect directly to the 5G-NR infrastructure for voice and data communication.

Small Cell: Low-powered cellular radio access nodes that operate in licensed and unlicensed spectrum, serving fewer users at high access speeds over a small geographic area.

SMF (Session Management Function): 5G NCG network entity handling the session establishment, modification, and release of the tunnel between UPF and AN node. It is also responsible for UE (User Equipment) IP address allocation and management; required to configure traffic steering capabilities at UPF to route traffic to their proper destination.

TSN (Time Sensitive Networking): IEEE 802.1 TSN is a collection of specifications that enhance the functionalities of IEEE 802.1Q, IEEE 802.1 and IEEE 802.3. These enhancements collectively enable the creation of a Deterministic Ethernet switched network where fixed latency, low packet error loss rate, zero congestion, and high availability network could be achieved.

UDM (Unified Data Management): Where all subscriber data, network service profiles, and network access policies are stored. The data in the UDM for specific subscribers could be accessed for verification of the subscriber during the initial network attachment sequence of the subscriber.

UE (User Equipment): One of three major components of a mobile network, defining all user devices connected to the network, man and machine.

UPF (User Plane Function): A core network function, where service functions like packet routing, and forwarding can be deployed in various locations or configurations. The UPF is the anchor point for any Intra-/Inter-RAT mobility. It also provides the Roaming Interface to a Visited Network UPF.

uRLLC (Ultra-reliable, Low-latency Communication): One of the three subsets of 5G use cases. This is for applications that need immediate responsiveness, and almost no latency. It might not be a lot of data, but often it needs to be sent in as close to real time as possible. Imagine self-driving cars or robots in a factory – they need instant feedback from their environment (and vice versa) to make split-second decisions.