Description
The Trace Recording Session Reference (TRSR) is a critical identifier within the 3GPP's network management, specifically defined in the context of the Trace Control and Configuration Management Service (TCCMS) and the broader Management Data Analytics (MDA) framework. It serves as a unique key that unambiguously identifies an active or historical trace recording session initiated by the network operator. A trace recording session is a controlled process where specific network functions (e.g., Access and Mobility Management Function (AMF), Session Management Function (SMF), gNB) or User Equipment (UE) are instructed to collect and log detailed, granular data about signaling procedures, user plane activities, performance measurements, or specific events.
Architecturally, the TRSR is generated and managed by the Trace Control Function, often residing within the Operations, Administration and Maintenance (OAM) system or the Network Data Analytics Function (NWDAF). When an operator or an automated analytics function decides to initiate a trace—for example, to diagnose a service degradation for a specific subscriber or to monitor performance in a particular network slice—it sends a trace activation request. Upon successful activation, the managing function assigns a unique TRSR to this session. This TRSR is then included in all subsequent management communications related to this trace. It is used when the collecting network functions (trace collection entities) report the captured trace data (Trace Records) back to a central Trace Collection Entity. The TRSR allows the system to correctly associate all incoming trace records with the correct session context.
The TRSR works in conjunction with other trace parameters like Trace Reference, Trace Depth, and Interfaces To Trace. It is a cornerstone for trace session lifecycle management: activation, modification, deactivation, and retrieval. Logs and records stored in the trace collection archive are indexed by the TRSR, enabling efficient querying and analysis. In 5G service-based architecture, the TRSR is used in service operations defined in services like Nnrf_NFManagement, where NF service consumers can subscribe to trace data notifications filtered by TRSR. The identifier ensures data isolation and security, as trace data is often sensitive, containing subscriber-related information. Its structured format allows for scalability in large networks where thousands of concurrent trace sessions may be active across different domains (5GC, NG-RAN).
Purpose & Motivation
The TRSR was introduced to solve the problem of managing and correlating the vast amounts of diagnostic data generated by distributed trace sessions in modern, complex telecom networks. Prior to its formal definition, trace management was more ad-hoc and vendor-specific, making it difficult for operators to consistently activate traces across multi-vendor networks and to collate data from different network elements for a unified view of a service issue or subscriber journey.
Its creation was motivated by the need for standardized, automated network troubleshooting and optimization in 3GPP networks, particularly with the rollout of LTE and the increased complexity of the core network. The TRSR provides a standardized 'handle' that OAM systems and emerging analytics functions (like the NWDAF in 5G) can use to programmatically control and consume trace data. This is essential for implementing closed-loop automation, where the network can self-diagnose problems: an analytics function detects an anomaly, automatically activates a trace session (receiving a TRSR), collects the data, analyzes it, and then takes corrective action, all using the TRSR as the session identifier.
Furthermore, with the advent of network slicing in 5G, the ability to trace activities within a specific slice without interfering with others is crucial. The TRSR, used in conjunction with slice identifiers, enables slice-aware tracing. It also supports regulatory requirements like Lawful Interception (LI) by providing a managed framework for activating targeted traces, though LI uses its own specific identifiers and interfaces. In summary, the TRSR is a foundational enabler for efficient, scalable, and automated network observability and management in the 3GPP ecosystem.
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (35 CRs across 6 releases). Complements the general historical overview above with the evidence-based evolution of this function.
Studied in Rel-12, normative work from Rel-15.
In Release 15, the TRSR (Trace Recording Session Reference) function was newly introduced as the TraceJob Information Object Class (IOC) within the NRM IRP framework. This IOC formalizes the management of trace control and configuration parameters, enabling trace activation and deactivation through the creation and deletion of TraceJob instances by a management service consumer. It supports both file-based and stream-based trace reporting formats, with attributes for traceReference, jobId, and traceTarget to uniquely identify and scope the trace session.
- Remove references to Itf-N TS 28.622CR0024
In Release 16, the enhancements for the TRSR function included the addition and adaptation of Trace/MDT related parameters within the NRM framework, alongside corrections and clarifications for reporting within the TraceJob. Specifically, this involved introducing missing references and refining the trace control parameters for 5G systems to ensure proper configuration and management of trace sessions across network elements.
- Add trace control NRM fragment stage 2 TS 28.622CR0078
- Correct 5G trace parameter for trace control TS 28.622CR0094
- Addition, adaptation and cleanup of Trace/MDT related parameters (stage2) TS 28.622CR0100
- Correction and clarification of reporting in TraceJob (stage2) TS 28.622CR0115
- Adaptation and cleanup of Trace/MDT related parameters (stage2) TS 28.622CR0116
- Introduce missing references TS 28.622CR0121
In Release 17, the enhancements for the Trace Recording Session Reference (TRSR) function primarily involved refinements to the TraceJob Information Object Class (IOC). The changes included the addition of a new attribute to configure an identifier for a TraceJob and corrections for alignment and consistency of attribute names within the TraceJob IOC to match the stage 2 definitions in TS 32.422.
In Release 18, the TRSR (Trace Recording Session Reference) function was enhanced through corrections and alignment with the foundational trace specifications. Specifically, the `traceRecordingSessionReference` property was corrected and aligned with 3GPP TS 32.422, and the applicable notifications and attribute constraints for TraceJob were updated. Furthermore, the structure of TraceJob was redefined to include enhancements for UE-level measurements collection and to define name containment rules for signalling-based activation scenarios.
- Enhance the applicable notifications for Trace Job TS 28.622CR0270
- Re-structuring Trace job TS 28.622CR0273
- Enhance TraceJob for UE level measurements collection TS 28.622CR0326
- Name containment of Trace job in case of Signalling based activation TS 28.622CR0271
- Rel-18 CR TS 28.622 Fix references to non-existing attributes TS 28.622CR0349
- Rel-18 CR TS 28.622 Update Trace attributes TS 28.622CR0392
+ 8 more changes
In Release 19, the TRSR function was enhanced through corrections and clarifications to the TraceJob Information Object Class, including fixes for attributes like the MBSFN Area List and Area Configuration For Neighboring Cells. The release also introduced a missing definition for "trace metrics" and provided corrections for 5GC UE level measurements within the TraceJob model. These updates improved the precision of trace target constraints and cleaned up attribute descriptions for trace reporting.
- Rel-19 CR 28.622 Trace new RRC reports TS 28.622CR0438
- Rel-19 CR 28.622 Introduce missing definition of term “trace metrics” TS 28.622CR0491
- Rel-19 CR TS 28.622 Corrections on Trace Target TS 28.622CR0565
- Rel-19 CR TS 28.622 Update the wrong reference TS 28.622CR0409
- Rel-19 CR 28.622 Fix list of trace metrics attribute description TS 28.622CR0426
- Rel-19 CR 28.622 Cleanup of TraceJob TS 28.622CR0430
+ 4 more changes
In Release 20, the primary update for the TRSR (Trace Recording Session Reference) function was the introduction of a temporary suspension capability for a TraceJob. This is detailed in the Change Request for TS 28.622, which specifies that a MnS consumer can now temporarily suspend an active trace session without fully deactivating and deleting the corresponding TraceJob instance. This provides more granular control over trace session management compared to previous releases, which only supported full activation and deletion.
- Rel-20 CR TS 28.622 temporary suspension on TraceJob TS 28.622CR0573
Explore further
Broader topics and technologies where TRSR plays a role.
Defining Specifications
3GPP specifications that define or reference TRSR, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 28.622 vk20 | Telecommunication Management; Generic NRM Information Service | Rel-20 |
| TS 32.422 vk00 | Telecom Management: Trace Control & Configuration | Rel-20 |
| TS 32.836 vc00 | NM Centralized Coverage and Capacity Optimization Study | Rel-12 |