3rd Generation Partnership Project System

Description

The term '3GPP system' denotes the complete telecommunications ecosystem standardized by the 3rd Generation Partnership Project (3GPP). It encompasses all components required for providing mobile communication services: one or more 3GPP core networks (e.g., EPC, 5GC), one or more 3GPP access networks (GERAN, UTRAN, E-UTRAN, NR), non-3GPP access networks such as WLAN, and User Equipment (UE). This definition, maintained in specification 21.905, serves as the foundational scope for all 3GPP technical work.

Architecturally, the 3GPP system is built on a modular, layered design. The core network handles session management, mobility, authentication, and policy control. Access networks provide the radio interface and connect UEs to the core. Non-3GPP access networks, like WLAN, can be integrated via interworking functions (e.g., ePDG, N3IWF) to offer seamless services. The system supports multiple radio access technologies (RATs) and allows inter-RAT handovers, ensuring service continuity.

Key components include the UE (mobile device with USIM), the radio access network (RAN) comprising base stations (NodeB, eNodeB, gNB), and the core network elements (e.g., MME, SGW, PGW, AMF, SMF, UPF). Interfaces between these components are standardized to ensure multi-vendor interoperability. The 3GPP system also defines security mechanisms, QoS frameworks, and charging functions.

Over releases, the definition has evolved to reflect technological advances. Initially limited to GERAN and UTRAN with a single core network, it expanded to include E-UTRAN (LTE) and later NR (5G), as well as non-3GPP accesses. The Rel-15 update introduced the concept of multiple core networks and access networks, aligning with 5G's service-based architecture and network slicing. This evolution ensures the term remains relevant across generations.

The 3GPP system is not a single product but a framework of specifications that enables global roaming, interoperability, and economies of scale. It is the basis for all mobile networks from 2G to 5G and beyond, and its definition continues to guide standardization efforts.

Purpose & Motivation

The concept of the '3GPP system' exists to provide a clear, standardized scope for the entire set of specifications developed by 3GPP. It defines the boundaries of what constitutes a compliant mobile network, ensuring that equipment from different vendors can interoperate. This is crucial for global roaming and multi-vendor deployments.

Historically, before 3GPP, regional standards bodies defined separate systems (e.g., GSM, IS-95), leading to fragmentation. 3GPP was created to unify these efforts, and the term '3GPP system' encapsulates that unified vision. It allows stakeholders to refer to a complete, end-to-end system rather than individual components, facilitating discussions on architecture, interfaces, and services.

The definition has been updated to accommodate new technologies like LTE and 5G, ensuring that the term remains inclusive of all access technologies and core network variants. This adaptability is essential as networks evolve towards heterogeneous deployments, network slicing, and convergence with non-3GPP accesses.