Description
The Network Status Continuous Report Request (NCR) is a network management mechanism introduced in 3GPP Release 13, allowing the network to request user equipment (UE) to continuously report various status parameters. It operates within the management plane, typically initiated by the network's management system or operations, administration, and maintenance (OAM) entities. NCR enables the collection of real-time data on radio conditions, mobility events, and UE performance, which is transmitted to the network for analysis. This function is part of the broader self-organizing network (SON) and minimization of drive tests (MDT) frameworks, aimed at automating network optimization and reducing operational costs.
Architecturally, NCR involves interactions between the OAM system, the radio access network (RAN), and the UE. The network sends an NCR request message to the UE, specifying the parameters to be reported, such as reference signal received power (RSRP), reference signal received quality (RSRQ), cell identities, and timing information. The UE then continuously monitors these parameters and sends reports back to the network at defined intervals or upon triggering events. The reports are aggregated and processed by network management systems to generate insights into network performance, coverage issues, and interference patterns.
How NCR works involves several steps: first, the network configures the UE with reporting criteria via RRC signaling or management protocols. The UE enters a continuous reporting mode, collecting data based on these criteria. Reports are formatted according to specified templates and transmitted using established signaling channels, often leveraging existing measurement reporting mechanisms but with enhanced continuity. The network uses this data for purposes like coverage optimization, handover parameter tuning, and identification of radio link failures. NCR supports both logged and immediate reporting modes, depending on network requirements.
Key components include the NCR configuration parameters, reporting triggers, and data structures for encapsulating status information. The mechanism integrates with existing measurement and reporting procedures in LTE and NR, extending them for continuous, network-requested monitoring. It plays a critical role in enabling proactive network management, allowing operators to detect and resolve issues before they impact users. By providing a standardized way to gather UE-side data, NCR enhances the efficiency of network optimization processes.
Purpose & Motivation
NCR was created to address the need for real-time, continuous network status monitoring from the UE perspective, which traditional drive tests and periodic reporting could not fully satisfy. Prior approaches, like manual drive tests, were costly, time-consuming, and provided only snapshot data. NCR enables automated, continuous data collection, solving problems related to dynamic network conditions and sporadic issues that intermittent measurements might miss. It supports the evolution toward self-optimizing networks by providing a rich dataset for analytics and automation.
Historical context includes the push for SON and MDT in 3GPP, which aimed to reduce operational expenses and improve network performance. NCR builds on earlier MDT features by allowing network-initiated continuous reporting, rather than relying solely on UE-triggered or logged measurements. This addresses limitations of previous methods, which often had gaps in data coverage or required UE cooperation only during specific events. NCR ensures that operators have a steady stream of information for ongoing optimization.
Motivations for NCR include the increasing complexity of networks with dense deployments and heterogeneous environments, where continuous monitoring is essential for maintaining quality of service. It solves challenges in detecting transient issues, optimizing mobility parameters, and enhancing user experience in real-time. By integrating with management systems, NCR facilitates data-driven decision-making, supporting advanced use cases like predictive maintenance and AI-based network optimization.
Classification
Release Timeline
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (49 CRs across 3 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 15, the NCR (Network Controlled Repeater) function was newly introduced, specifically enabling a target E-UTRA cell's NCR towards an NR cell for performing EN-DC. The support includes enhancements to UE Subscription data for NCR authorization and procedures where the AMF authorizes the NCR-MT during registration, providing the status to NG-RAN via the Initial UE Context Setup procedure. Furthermore, the AMF can update this authorization status in NG-RAN using the UE Context Modification procedure.
- Introducing a target E-UTRA cell's NCR towards an NR cell for performing EN-DC TS 36.300CR1228
In Release 18, the 3GPP specifications formally introduced the Network Controlled Repeater (NCR) function, defining it as an RF repeater node with an NCR-MT component that interacts with the 5G Core. The release established new performance, radio resource management (RRM), and demodulation test requirements for the NCR-MT, detailed across multiple technical specifications including TS 38.106 and TS 38.115-1. Furthermore, the core network procedures were enhanced to authorize NCR operation via subscription data checks during the UE Registration and Initial UE Context Setup procedures.
- Big CR to TS 38.106 Introduction of NCR TS 38.106CR0050
- Draft CR for TS38.106 on conducted performance requirements for NCR-MT TS 38.106CR0065
- Big CR to TS 38.106: the introduction of NCR RRM test case TS 38.106CR0081
- BigCR for introduction of performance requirements for NCR-MT in TS 38.115-1 TS 38.115CR0029
- Introduction of NCR in TS 38.304 TS 38.304CR0345
- CR to TS 38.106 on correction of requirement set applicability for NCR-MT TS 38.106CR0055
+ 37 more changes
In Release 19, the NCR (Network Controlled Repeater) function was enhanced with new core requirements and improvements for its Expected EIRP mask, along with the introduction of support for MIMO correlation matrices. Additionally, a correction was made regarding the configuration of the NCR-RNTI. These updates build upon the existing authorization framework where the AMF provides the NCR status to the NG-RAN via the Initial UE Context Setup and UE Context Modification procedures.
- CR to TS 38.106 for introduction of expected EIRP mask core requirement for NCR TS 38.106CR0112
- CR to TS 38.106 with improvements for EIRP mask for NCR TS 38.106CR0120
- CR on NCR Mimo Correlation Matrices in 38.106 TS 38.106CR0114
- CR on NCR Mimo Correlation Matrices in 38.115-1 TS 38.115CR0065
- Correction on NCR-RNTI configuration TS 38.331CR5623
Explore further
Broader topics and technologies where NCR plays a role.
Defining Specifications
3GPP specifications that define or reference NCR, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 23.501 vk00 | 5G System Architecture Stage 2 | Rel-20 |
| TS 28.313 vk00 | Management and orchestration; SON for 5G networks | Rel-20 |
| TS 28.658 vj00 | E-UTRAN NRM IRP Information Service | Rel-19 |
| TR 28.841 vi01 | Technical Report on IoT NTN Enhancements | Rel-18 |
| TS 29.153 vj00 | Ns Reference Point Protocol between SCEF and RCAF | Rel-19 |
| TS 32.511 vj00 | ANR Management Concepts & Requirements | Rel-19 |
| TS 36.300 vj00 | E-UTRAN Radio Interface Protocol Architecture Overview | Rel-19 |
| TS 38.106 vj20 | NR Repeater Radio Transmission and Reception | Rel-19 |
| TS 38.114 vj00 | EMC Requirements for NR Repeaters and NCR | Rel-19 |
| TS 38.115 vj20 | NR Repeater RF Conformance Testing Part 1 | Rel-19 |
| TS 38.201 vj00 | NR Physical Layer General Description | Rel-19 |
| TS 38.211 vj10 | NR Physical Channels and Modulation | Rel-19 |
| TS 38.212 vj10 | NR Multiplexing and Channel Coding | Rel-19 |
| TS 38.213 vj10 | NR Physical Layer Control Procedures | Rel-19 |
| TS 38.214 vj10 | NR Physical Layer Procedures for Data | Rel-19 |
| TS 38.300 vj00 | NG-RAN Overall Description | Rel-19 |
| TS 38.304 vj00 | UE RRC_IDLE and RRC_INACTIVE Procedures | Rel-19 |
| TS 38.306 vj00 | NR UE Radio Access Capability Parameters | Rel-19 |
| TS 38.321 vj00 | NR MAC Protocol Specification | Rel-19 |
| TS 38.331 vj00 | NR Radio Resource Control (RRC) Protocol Specification | Rel-19 |
| TR 38.867 vi00 | Technical Report | Rel-18 |