Abbreviations

• SRVCC
  Single Radio Voice call Continuity is a level of functionality that is required within VoLTE systems to enable the packet domain calls on LTE to be handed over to legacy circuit switched voice systems like GSM, UMTS and CDMA 1x in a seamless manner.
• MME
  The MME (for Mobility Management Entity) deals with the control plane. It handles the signalling related to mobility and security for E-UTRAN access. The MME is responsible for the tracking and the paging of UE in idle-mode. It is the termination point of the Non-Access Stratum (NAS).
• ICS Gateway IMS Centralized Service Gateway (ICS GW)
  IMS Centralized Services Gateway (ICS GW) allows operators to connect their legacy 2G/3G radio access networks directly to IMS, which effectively replaces the existing legacy circuit-switched core network and enables consolidation of core network services for 2G/3G4G access domains onto the IMS core network.
• EPC Evolved Pacekt Core
  When designing the evolution of the 3G system, the 3GPP community decided to use IP (Internet Protocol) as the key protocol to transport all services. It was therefore agreed that the EPC would not have a circuit-switched domain anymore and that the EPC should be an evolution of the packet-switched architecture used in GPRS/UMTS. Traditional use of circuits to carry voice and short messages needed to be replaced by IP-based solutions in the long term.
• SAE
  SAE is the evolution of the GPRS Core Network, with some differences:
  • simplified architecture
  • all-IP Network (AIPN)
  • support for higher throughput and lower latency radio access networks (RANs)
  • support for, and mobility between, multiple heterogeneous access networks, including E-UTRA (LTE and LTE Advanced air interface), 3GPP legacy systems (for example GERAN or UTRAN, air interfaces of GPRS and UMTS respectively), but also non-3GPP systems (for example WiMAX or cdma2000)
• IMPI IP Multimedia Private Identity
  The IP Multimedia Private Identity (IMPI) is a unique permanently allocated global identity assigned by the home network operator, and is used, for example, for Registration, Authorization, Administration, and Accounting purposes. Every IMS user shall have one IMPI.
• IMPU IP Multimedia Public Identity
  The IP Multimedia Public Identity (IMPU) is used by any user for requesting communications to other users (e.g. this might be included on a business card). There can be multiple IMPU per IMPI. The IMPU can also be shared with another phone, so that both can be reached with the same identity (for example, a single phone-number for an entire family).
• UDR User Data Repository
  UDR provides a unique reference point to one or more Applications Front Ends, such as: one or more HSS/HLR/AuCFEs, and one or more AS- FEs. The reference point is named Ud. UDR shall provide support for multiple applications simultaneously.
• IMS IP multimedia subsystems
  The IP Multimedia Subsystem is an architectural framework for delivering IP multimedia services. It was originally designed by the wireless standards body 3GPP, as a part of the vision for evolving mobile networks beyond GSM. Its original formulation represented an approach to delivering „Internet services“ over GPRS. This vision was later updated by 3GPP, 3GPP2 and ETSI TISPAN by requiring support of networks other than GPRS, such as Wireless LAN, CDMA2000 and fixed lines. To ease the integration with the Internet, IMS uses IETF protocols wherever possible, e.g., SIP (Session Initiation Protocol). IMS is not intended to standardize applications, but rather to aid the access of multimedia and voice applications from wireless and wireline terminals, i.e., to create a form of fixed-mobile convergence (FMC). This is done by having a horizontal control layer that isolates the access network from the service layer. From a logical architecture perspective, services need not have their own control functions, as the control layer is a common horizontal layer. However in implementation this does not necessarily map into greater reduced cost and complexity.
• EPS Evolved packet system
  The Evolved Packet System (EPS) is purely IP based. Both real time services and datacom services will be carried by the IP protocol. The IP address is allocated when the mobile is switched on and released when switched off.
• HSS
  Home subscriber server is a database that contains user-related and subscriber-related information. It also provides support functions in mobility management, call and session setup, user authentication and access authorization. It is based on the pre-3GPP Release 4 – Home Location Register (HLR) and Authentication Centre (AuC).
• SLF subscription locator function
  SLF is an entity within an IP multimedia subsystem that provides information about the home subscriber server (HSS) that is associated with a particular user profile. It is generally implemented using a database. If the home domain contains more than one HSS, I-CSCF and S-CSCF will communicate with SLF and find the appropriate HSS based on user profile. CSCF communicates with the SLF using diameter Dx interface and the application server communicates with the SLF using Dh interface.
• ENUM E.164 Number to URI Mapping
  For an ENUM subscriber to be able to activate and use the ENUM service it needs to obtain three elements from a Registrar:
  A personal Uniform Resource Identifier (URI) to be used on the IP part of the network, as explained below.
  One E.164 regular personal telephone number associated with the personal URI, to be used on the PSTN part of the network.
  Authority to write their call forwarding/termination preferences in the NAPTR record accessible via the personal URI.
• UMTS Universal Mobile Telecommunications System
  WCDMA (Wideband Code Division Multiple Access) is an air interface standard found in 3G mobile telecommunications networks. It supports conventional cellular voice, text and MMS services, but can also carry data at high speeds, allowing mobile operators to deliver higher bandwidth applications including streaming and broadband Internet access. W-CDMA is the basis of Japan’s NTT DoCoMo‚s FOMA service and the most-commonly used member of the Universal Mobile Telecommunications System (UMTS) family and sometimes used as a synonym for UMTS. It uses the DS-CDMA channel access method and the FDD duplexing method to achieve higher speeds and support more users compared to most previously used time division multiple access (TDMA) and time division duplex (TDD) schemes. UMTS supports maximum theoretical data transfer rates of 42 Mbit/s
• GSM Global System for Mobile Communications 
• UPCC Unified Policy and Charging Controller
  The UPCC provides unified policy control in a variety of networks, including GSM, UMTS, LTE, CDMA, Wi-Fi, WIMAX, and fixed network. The UPCC enables operators to provide the following features to improve network operation efficiency and subscriber experience:
  • FUP
  • Limiting international roaming charges
  • Restricting access to certain websites
  • Reducing low-value data service volume
  • Guaranteeing quality of service (QoS) for high-value applications
• BRAS Broadband Remote Access Server
  routes traffic to and from broadband remote access devices such as digital subscriber line access multiplexers(DSLAM) on an Internet service provider‚s (ISP) network. BRAS can also be referred to as a Broadband Network Gateway (BNG). The BRAS sits at the core of an ISP’s network, and aggregates user sessions from the access network. It is at the BRAS that an ISP can inject policy management and IP Quality of Service(QoS).
  The specific tasks include:
  • Aggregates the circuits from one or more link access devices such as DSLAMs
  • Provides layer 2 connectivity through either transparent bridging or PPP sessions overEthernet or ATM sessions
  • Enforces quality of service (QoS) policies
  • Provides layer 3 connectivity and routes IP traffic through an Internet service provider’s backbone network to the Internet
• DPI Deep Packet Inspection
  DPI is a form of computer network packet filtering that examines the data part (and possibly also the header) of a packet as it passes an inspection point, searching for protocol non-compliance, viruses, spam, intrusions, or defined criteria to decide whether the packet may pass or if it needs to be routed to a different destination, or, for the purpose of collecting statistical information. There are multiple headers for IP packets; network equipment only needs to use the first of these (the IP header) for normal operation, but use of the second header (TCP, UDP etc.) is normally considered to be shallow packet inspection (usually called Stateful Packet Inspection) despite this definition.
  
  • Lawful interception
  • Policy definition and enforcement
  • Targeted advertising
  • Quality of service
  • Tiered services
  • Copyright enforcement
  • Statistics
• PDSN Packet data serving node
  The Packet Data Serving Node, or PDSN, is a component of a CDMA2000 mobile network.^[1] It acts as the connection point between the radio access and IP networks. This component is responsible for managing PPP sessions between the mobile provider’s core IP network and the mobile station (mobile phone). It is similar in function to the GGSN (GPRS Gateway Support Node) that is found in GSM and UMTS networks.
• HRPD High Rate Packet Data
  A novel method of architecting relay functions, within the paradigm of frequency division duplex based cellular networks, by modifying the Access Terminals (AT) to AT Relays (ATR) and enhancing HRPD Access Networks (AN) is proposed. Traditional applications such as spot/emergency coverage, and new applications related to network auto-configuration, optimization, and fault management are supported. Two bi-directional data streams are supported concurrently within a single AT radio aided by relatively simple enhancements to power and resource allocation mechanisms at the AT/AN, and interference cancellation at the AN to reduce blow-back to the data-sourcing ANs from the forwarding ATRs. A self-routing and self-configuring backhaul capability is created with a new flow type, and by adding a new request-response route-discovery protocol.
• HSGW HRPD serving gateway The HSGW is the entity that terminates the HRPD access network interface from the eAN/PCF. The HSGW functionality provides interworking of the AT with the 3GPP EPS architecture and protocols specified in 23.402 (mobility, policy control (PCC), and roaming). The HSGW supports efficient (seamless) inter-technology mobility between LTE and HRPD with the following requirements: Sub 300ms bearer interruption Inter-technology handoff between 3GPP E-UTRAN and HRPD Intra-technology handoff between an HSGW and an existing PDSN Support for inter-HSGW fast handoff via PMIPv6 Binding Update
• FUP Fair usage policy
  A bandwidth cap, also known as a band cap or a data cap, limits the transfer of a specified amount of data over a period of time. Internet service providerscommonly apply a cap when a channel intended to be shared by many users becomes overloaded, or may be overloaded, by a few users.
• PGW Provisioning Gateway
• UDC User Data Convergence
  • simplifies the overall network topology and interfaces
  • overcomes the data capacity bottleneck of a single entry point
  • avoids data duplication and inconsistency
  • reduces CAPEX and OPEX.
• UDB Unified DataBase
• PGW Proxy GateWay
• SDM Subscriber Data management
  Subscriber Data Management (SDM) seeks to provide centralized management of all subscriber data. It allows operators to reduce service innovation cycles by exploiting common subscriber data, thus reducing operating expenditure.
• UIM Unified Identity Management
• PCRF Policy Chargin Rule Function
  PCRF is the software node designated in real-time to determine policy rules in a multimedia network.As a policy tool, the PCRF plays a central role in next-generation networks. Unlike earlier policy engines that were added onto an existing network to enforce policy, the PCRF is a software component that operates at the network core and accesses subscriber databases and other specialized functions, such as a charging system, in a centralized manner
• IDM Identity Management
  Describes the management of individual principals, their authentication, authorization and privileges within or across system and enterprise boundaries^[2] with the goal of increasing security and productivity while decreasing cost, downtime and repetitive tasks.
• SSO Single-Sign-On 
• ENS Enhanced Name Server
  The ENS supports query for the following resources records:
  • Address (A): returns a 32–bit IPv4 address
  • IPv6 address (AAAA): returns a 128–bit IPv6 address
  • Naming authority pointer (NAPTR): allows regular expression based rewriting ofdomain names which can then be used as URIs and domain names
  • Name server (NS): delegates a DNS zone to use the given authoritative name servers
  • Service (SRV): specifies the location of the server for a specific protocol and domain
• SPR Subscriber profile
• USCDB Unified Subscriber Schema
• UID Unique identity
• SRV record
  A Service record is a specification of data in the Domain Name System defining the location, i.e. the hostname and port number, of servers for specified services.
• NAPTR
  A Name Authority Pointer is a type of resource record in the Domain Name System of the Internet.
• BSS Base Station Subsystem
• GGSN Gateway GPRS support node
• DPI Deep Packet Inspection
• UTRAN Universal Terrestrial Radio Access Network
• SGSN Serving GPRS support node
• UPCC Unified Policy and Charging Controller
• E-UTRAN Evolved universal terrestrial radio access network
• PDN Packet Data Network
• PDN GW – PDN Gateway
  The PDN GW is the point of interconnect between the EPC and the external IP networks. These networks are called PDN (Packet Data Network), hence the name. The PDN GW routes packets to and from the PDNs. The PDN GW also performs various functions such as IP address / IP prefix allocation or policy control and charging.
  • It is assigned to an IMS terminal before registration, and does not change for the duration of the registration.
  • It sits on the path of all signalling, and can inspect every signal; the IMS terminal must ignore any other unencrypted signalling.
  • It provides subscriber authentication and may establish an IPsec or TLS security association with the IMS terminal. This prevents spoofing attacks and replay attacks and protects the privacy of the subscriber.
  • It inspects the signaling and ensures that the IMS terminals do not misbehave (e.g. change normal signaling routes, do not obey home network’s routing policy).
  • It can also compress and decompress SIP messages using SigComp, which reduces the round-trip over slow radio links.
  • It may include a Policy Decision Function (PDF), which authorizes media plane resources e.g., quality of service (QoS) over the media plane. It is used for policy control, bandwidth management, etc. The PDF can also be a separate function.
  • It also generates charging records.
• P-CSCF – proxy-call session control function
  A Proxy-CSCF (P-CSCF) is a SIP proxy that is the first point of contact for the IMS terminal. It can be located either in the visited network (in full IMS networks) or in the home network (when the visited network is not IMS compliant yet). Some networks may use a Session Border Controller (SBC) for this function. The P-CSCF is at its core a specialized SBC for the User–network interface which not only protects the network, but also the IMS terminal. The use of an additional SBC between the IMS terminal and the P-CSCF is unnecessary and infeasible due to the signaling being encrypted on this leg. The terminal discovers its P-CSCF with either DHCP, or it may be configured (e.g. during initial provisioning or via a 3GPP IMS Management Object (MO)) or in the ISIM or assigned in the PDP Context (in General Packet Radio Service (GPRS)).
• S-CSCF Serving-CSCF
  A Serving-CSCF (S-CSCF) is the central node of the signalling plane. It is a SIP server, but performs session control too. It is always located in the home network. It uses Diameter Cx and Dx interfaces to the HSS to download user profiles and upload user-to-S-CSCF associations (the user profile is only cached locally for processing reasons only and is not changed). All necessary subscriber profile information is loaded from the HSS.
  • it handles SIP registrations, which allows it to bind the user location (e.g., the IP address of the terminal) and the SIP address
  • it sits on the path of all signaling messages of the locally registered users, and can inspect every message
  • it decides to which application server(s) the SIP message will be forwarded, in order to provide their services
  • it provides routing services, typically using Electronic Numbering (ENUM) lookups
  • it enforces the policy of the network operator
  • there can be multiple S-CSCFs in the network for load distribution and high availability reasons. It’s the HSS that assigns the S-CSCF to a user, when it’s queried by the I-CSCF. There are multiple options for this purpose, including a mandatory/optional capabilities to be matched between subscribers and S-CSCFs.
• I-CSCF
  An Interrogating-CSCF (I-CSCF) is another SIP function located at the edge of an administrative domain. Its IP address is published in the Domain Name System(DNS) of the domain (using NAPTR and SRV type of DNS records), so that remote servers can find it, and use it as a forwarding point (e.g., registering) for SIP packets to this domain.
  • it queries the HSS to retrieve the address of the S-CSCF and assign it to a user performing SIP registration
  • it also forwards SIP request or response to the S-CSCFUp to Release 6 it can also be used to hide the internal network from the outside world (encrypting parts of the SIP message), in which case it’s called a Topology Hiding Inter-network Gateway (THIG). From Release 7 onwards this „entry point“ function is removed from the I-CSCF and is now part of the Interconnection Border Control Function (IBCF). The IBCF is used as gateway to external networks, and provides NAT and firewall functions (pinholing). The IBCF is practically aSession Border Controller specialized for the NNI.
• LTE – Long Term Evolution
• xDSL – x digital subscriber line
• SGW
  The Serving GW is the point of interconnect between the radio-side and the EPC. As its name indicates, this gateway serves the UE by routing the incoming and outgoing IP packets. The gateways (Serving GW and PDN GW) deal with the user plane. They transport the IP data traffic between the User Equipment (UE) and the external networks.
• eHRPD evolved High Rate Packet Data
• HSGW HRPD serving gateway
• eAN ethernet Access Node
  An Access Node supporting Ethernet-based subscriber lines and uplinks to an Ethernet-based aggregation network and MAC-Forced Forwarding. For example, for xDSL access, the EAN is an      Ethernet-centric DSLAM. The EAN is a special type of filtering bridge that does not forward Ethernet broadcast and multicast frames originating on a subscriber line to other subscriber lines, but either discards them or forwards them upstream (towards the aggregation network). The EAN also discards unicast Ethernet frames that originate on a subscriber line and are not addressed to an AR.
• PCF Packet control function
• CDMA Code division multiple access
• BTS Base transceiver station
• BSC Base station controller
• PDSN Packet data serving node
• TDF Traffic Detection Function
• OSS Operations support system
• RCS Rich Communication Services
  Enhanced Phonebook: service capabilities and enhanced contacts information such as presence and service discovery
  Enhanced Messaging: enables a large variety of messaging options including chat, emoticons, location share and file sharing.
  Enriched Calls: enables multimedia content sharing during a voice call, video call and video sharing (see what I see)
• SGW (Serving Gateway): The SGW routes and forwards user data packets, while also acting as the mobility anchor for the user plane during inter-eNodeBhandovers and as the anchor for mobility between LTE and other 3GPP technologies (terminating S4 interface and relaying the traffic between 2G/3G systems and PGW). For idle state UEs, the SGW terminates the downlink data path and triggers paging when downlink data arrives for the UE. It manages and stores UE contexts, e.g. parameters of the IP bearer service, network internal routing information. It also performs replication of the user traffic in case of lawful interception.
• PGW (PDN Gateway): The PDN Gateway provides connectivity from the UE to external packet data networks by being the point of exit and entry of traffic for the UE. A UE may have simultaneous connectivity with more than one PGW for accessing multiple PDNs. The PGW performs policy enforcement, packet filtering for each user, charging support, lawful interception and packet screening. Another key role of the PGW is to act as the anchor for mobility between 3GPP and non-3GPP technologies such as WiMAX and 3GPP2 (CDMA 1X and EvDO).
• HSS (Home Subscriber Server): The HSS is a central database that contains user-related and subscription-related information. The functions of the HSS include functionalities such as mobility management, call and session establishment support, user authentication and access authorization. The HSS is based on pre-Rel-4Home Location Register (HLR) and Authentication Center (AuC).
• ANDSF (Access Network Discovery and Selection Function): The ANDSF provides information to the UE about connectivity to 3GPP and non-3GPP access networks (such as Wi-Fi). The purpose of the ANDSF is to assist the UE to discover the access networks in their vicinity and to provide rules (policies) to prioritize and manage connections to these networks.
• ePDG (Evolved Packet Data Gateway): The main function of the ePDG is to secure the data transmission with a UE connected to the EPC over an untrusted non-3GPP access. For this purpose, the ePDG acts as a termination node of IPsec tunnels established with the UE.
• SLF Subscriber Location Function
  SLF is an entity within an IP multimedia subsystem that provides information about the home subscriber server (HSS) that is associated with a particular user profile. It is generally implemented using a database. If the home domain contains more than one HSS, I-CSCF and S-CSCF will communicate with SLF and find the appropriate HSS based on user profile. CSCF communicates with the SLF using diameter Dx interface and the application server communicates with the SLF using Dh interface.

Source:
http://www.3gpp.org/technologies/keywords-acronyms
http://en.wikipedia.org/wiki/Spectral_efficiency#Comparison_table