Description
A Mobile Network (MN) is the comprehensive, end-to-end system that enables wireless telecommunications services for user equipment (UE) such as smartphones and IoT devices. Architecturally, it is divided into two primary domains: the Radio Access Network (RAN) and the Core Network (CN). The RAN comprises the base stations (e.g., gNB in 5G, eNB in 4G, NodeB in 3G) and their controllers, which manage the radio interface, including radio resource management, handovers, and the initial processing of user data. The Core Network is the central brain, providing connectivity to external networks like the internet, enabling subscriber management, authentication, session management, mobility management, and policy enforcement. In 5G, this is the 5G Core (5GC), with key functions like the AMF, SMF, and UPF.
The network operates by establishing a secure, authenticated connection between the UE and the core. When a device powers on, it attaches to the network via procedures managed by the RAN and core network functions. The core network authenticates the subscriber using credentials stored in the Home Subscriber Server (HSS) or Unified Data Management (UDM). Once authenticated, a data session (Packet Data Unit session in 5G, PDN connection in 4G) is established, creating a tunnel for user plane traffic between the UE and a gateway that connects to the external data network. The network continuously manages the UE's mobility, seamlessly transferring its connection between cells as it moves, and applies policy rules to ensure Quality of Service (QoS) and charging.
Key components include the User Equipment, the RAN nodes, the core network control plane functions (for signaling), the user plane functions (for data forwarding), and the network management systems (OSS/BSS). Its role is to provide ubiquitous, reliable, and secure connectivity. The mobile network is not static; it evolves through generations (3G, 4G, 5G), with each generation introducing new architectural paradigms, such as the shift to an all-IP core in 4G and the service-based architecture with network slicing in 5G. It is the fundamental platform upon which all mobile services—from voice calls to massive IoT and ultra-reliable low-latency communications—are delivered.
Purpose & Motivation
The Mobile Network exists to provide wide-area, wireless communication services, solving the fundamental problem of enabling voice and data connectivity for people and devices on the move. Historically, it replaced fixed-line telephony for personal communication, offering unprecedented freedom and accessibility. Each generation of mobile network has been motivated by the need to overcome the limitations of its predecessor: 1G offered analog voice but was insecure and inefficient; 2G introduced digital voice and SMS; 3G aimed for mobile internet but with limited speed; 4G LTE was created specifically to provide a high-speed, all-IP broadband experience comparable to fixed lines.
The evolution to 5G and beyond addresses new sets of problems that 4G networks were not designed to handle efficiently. These include the massive scale of IoT deployments, which require support for millions of low-power, low-data-rate devices; applications demanding ultra-reliable low-latency communication (URLLC) such as industrial automation and remote surgery; and the need for enhanced mobile broadband (eMBB) with multi-gigabit speeds for AR/VR and 4K/8K video. The mobile network also solves critical business problems for operators, providing a managed, billable, and secure platform for service delivery, as opposed to unlicensed spectrum or best-effort Wi-Fi. Its continuous development is driven by societal and economic demands for ubiquitous digital connectivity as a utility.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (23 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
Studied in Rel-8, normative work from Rel-15.
In Release 15, the Mobile Network (MN) function was enhanced for Multi-RAT Dual Connectivity (MR-DC) operations, particularly in coordination with the Secondary Node (SN). Key introductions included support for PDU session split during inter-MN handover, mechanisms for MN-SN coordination on Automatic Neighbour Relations (ANR), and refined procedures for inter-node resource coordination and DRB ID alignment between the MN and SN.
- Support of PDU session split during inter-MN handover for MR-DC with 5GC TS 37.340CR0114
- MN-SN coordination for ANR in MR-DC TS 37.340CR0116
- Corrections on MN and SN inter-node resource coordination TS 37.340CR0123
- Allow MN to retrieve forwarding proposal from the source SN TS 37.340CR0135
- DRB ID co-ordination between MN and SN TS 37.340CR0174
In Release 16, enhancements to the Mobile Network (MN) function focused on refining Multi-Radio Dual Connectivity (MR-DC) operations. Key introductions included the Conditional PSCell (Primary SCell) addition and clarifications for inter-MN handovers without requiring a Secondary Node change. The release also brought corrections and improved coordination for MN-SN measurement procedures and configuration restrictions.
- Introduction of Conditional PSCell Change for intra-SN without MN involvement TS 37.340CR0210
- Correction on MN-SN measurements coordination in INM TS 37.340CR0208
- 37.340 correction for CHO early data forwarding in MN to eNB/gNB Change scenario TS 37.340CR0275
- Correction on MN-SN measurements coordination in INM TS 37.340CR0194
- CR on MN and SN configuration restriction coordination TS 37.340CR0256
- Clarification on inter-MN handover without SN change TS 37.340CR0300
In Release 17, enhancements were made to the Mobile Network (MN) function regarding conditional handover and reconfiguration procedures. Specifically, the release introduced support for Inter-MN RRC Resume without needing a Secondary Node change and provided clarifications on direct data forwarding for MN-initiated Conditional Primary Cell (CPC) changes. Additionally, corrections and modifications were applied to the handling of SCG reconfiguration during MN-initiated conditional reconfiguration and to the related procedural figures.
- Inter-MN RRC Resume without SN change [InterMNResume] TS 37.340CR0301
- Clarification on direct data forwarding for MN initiated CPC to TS37340 TS 37.340CR0346
- Correction on SCG reconfiguration when MN initiated conditional reconfiguration is prepared TS 37.340CR0366
- Modify the figures for MN/SN initiated CPC and CHO with SCG TS 37.340CR0368
In Release 18, key enhancements for the Mobile Network (MN) function included the introduction of support for mobile Integrated Access and Backhaul (IAB) nodes, enabling more flexible deployments. The release also specified the MN's involvement in new procedures for intra-SN subsequent Conditional Primary and Secondary Cell Addition/Change (CPAC) and intra-SN Single-Node CPAC (S-CPAC). Furthermore, corrections and refinements were made to the procedures, authorization, and migration for mobile IAB.
- Support for mobile IAB TS 38.401CR0308
- Support intra-SN subsequent CPAC in MN format TS 37.340CR0387
- Stage-2 updates for intra-SN S-CPAC with MN involvement TS 37.340CR0410
- Corrections on mobile IAB procedures TS 38.401CR0368
- Correction on mobile IAB-MT migration TS 38.401CR0381
- Correction on mobile IAB-node authorization TS 38.401CR0426
In Release 19, the specification introduced updates to the security handling procedures for scenarios where a Central Unit (CU) is acting as the Master Node (MN) while the Secondary Node (SN) remains unchanged. The changes specifically refine how security is managed in this particular CU-as-MN architectural configuration.
Explore further
Broader topics and technologies where MN plays a role.
Defining Specifications
3GPP specifications that define or reference MN, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 23.327 vd10 | 3GPP-WLAN Mobility Stage 2 Description | Rel-13 |
| TS 28.622 vk20 | Telecommunication Management; Generic NRM Information Service | Rel-20 |
| TS 29.273 vj10 | AAA Protocols for Non-3GPP Access in EPS & 5GS NSWO | Rel-19 |
| TS 32.422 vk00 | Telecom Management: Trace Control & Configuration | Rel-20 |
| TS 32.425 vj00 | E-UTRAN Performance Measurements | Rel-19 |
| TS 32.856 vf00 | Energy Efficiency Assessment for RAN OAM | Rel-15 |
| TS 33.107 vj00 | Lawful Interception Architecture & Functions | Rel-19 |
| TS 33.501 vk00 | 5G Security Architecture and Procedures | Rel-20 |
| TS 33.822 v1800 | Security Architecture for Inter-Access Mobility | Rel-8 |
| TS 33.825 vg01 | Security for 5G URLLC Services | Rel-16 |
| TS 37.340 vj00 | Multi-Connectivity Operation Overview | Rel-19 |
| TS 38.133 vj20 | 5G UE Radio Requirements for RRC_IDLE Mobility | Rel-19 |
| TS 38.306 vj00 | NR UE Radio Access Capability Parameters | Rel-19 |
| TS 38.401 vj10 | NG-RAN Architecture Specification | Rel-19 |
| TS 38.523 vj20 | 5G NR UE Conformance Testing: Idle/Inactive | Rel-19 |
| TR 38.804 ve00 | Study on New Radio Access Technology; Radio Interface Protocol Aspects | Rel-14 |