Description
In the context of 3GPP specifications, a Device Under Test (DUT) is not a specific technology but a fundamental concept in the testing and validation framework. It refers to the entity whose behavior, performance, or characteristics are being measured and evaluated against the normative requirements laid out in 3GPP technical specifications. The DUT can encompass a vast range of equipment: User Equipment (UE) such as smartphones and IoT modules, Radio Access Network (RAN) nodes like gNBs and eNBs, core network functions, or even entire systems. The specific identity of the DUT is defined by the scope of the particular test specification (e.g., TS 36.521-1 for UE radio transmission and reception).
The testing architecture involves the DUT, a test system (often comprising test equipment like channel emulators, signal generators, and protocol testers), and a precise test environment defined by the specification. The test system stimulates the DUT with controlled inputs (signals, messages, RF conditions) and measures its outputs (transmitted power, error rate, protocol messages, timing). The DUT's responses are then compared to the pass/fail criteria specified in the standard. Tests are categorized into areas like Radio Frequency (RF) conformance (e.g., output power, spectrum emission mask), radio resource management (RRM) (e.g., handover, cell selection), protocol conformance (e.g., RRC, NAS signaling), and performance testing (e.g., throughput, latency).
The role of the DUT is passive in the sense that it is the object of testing, but its configuration is critical. It must be set up in a defined reference state, often using specific test modes or firmware that enable reproducible measurements. For UE testing, the DUT typically has a Test Application or uses defined signaling to enter test loops. For base station testing, the DUT is configured with specific parameters and connected to test UEs. The comprehensive suite of DUT tests ensures that devices from different manufacturers interoperate seamlessly in live networks, deliver promised performance, and do not cause harmful interference.
Purpose & Motivation
The concept of the DUT is foundational to the 3GPP standardization process because it enables objective verification of implementation compliance. Without standardized testing procedures centered on a clearly defined DUT, interoperability between multi-vendor networks and devices would be unreliable, leading to dropped calls, failed handovers, and degraded service quality. The proliferation of DUT-related specifications across all releases underscores its role in ensuring network reliability and user experience.
Historically, as cellular technology evolved from GSM to UMTS, LTE, and now 5G NR, the complexity of the air interface and protocols increased exponentially. This made ad-hoc testing insufficient. The formalization of DUT-based conformance testing, starting robustly in 3GPP Release 6 and expanding thereafter, was motivated by the need to create a global certification ecosystem (e.g., through GCF and PTCRB). It addresses the limitations of proprietary testing by providing a common, unambiguous benchmark that all manufacturers must meet, fostering healthy competition and accelerating technology deployment while maintaining network integrity.
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (20 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
Studied in Rel-6, normative work from Rel-15.
In Release 15, the term "DUT" (Device Under Test) itself is newly introduced under change control for 3GPP specifications. This establishes a formal, standardized reference for test equipment terminology within the project's documentation. The introduction provides a precise vocabulary tool for technical work, categorizing DUT alongside other defined terms like "MTC Device" and "Repeater."
In Release 16, the "DUT" (Device Under Test) function was enhanced with new provisions for managing Machine Type Communication (MTC) Devices, which are UEs equipped for MTC, and their interactions with an MTC Server. The update also formalized requirements related to Service Continuity during radio access technology changes to maintain user experience. Furthermore, it introduced refined testing parameters for IP-CAN (IP-Connectivity Access Network) connectivity and the handling of localized services like LIPA (Local IP Access).
In Release 17, the DUT (Device Under Test) function was updated through the formalization of the specification under change control and revision control, resulting in the publication of version 17.0.0. These changes included the integration of small editorial updates to ensure clarity and consistency within the technical documentation. The process focused on finalizing and stabilizing the definitions and requirements, such as those for MTC Devices, Service Continuity, and Local IP Access (LIPA), as part of the broader 3GPP terminology framework.
- Approved by plenary – Rel-17 spec under change control TS 38.151
- Under change control TS 38.161
- put under revision control as v17.0.0 with small editorial changes TS 38.551
- put under revision control as v17.0.0 with small editorial changes TS 38.561
- Approved by plenary – Rel-17 spec under change control TS 38.834
In Release 18, the new developments for the Device Under Test (DUT) function specifically introduced standardized methodologies for Device Positioning for FR2 MIMO Over-the-Air (OTA) testing. This included enhancements detailed in the study item for NR FR2 OTA, which provided updated technical requirements and alignment procedures for testing the DUT in these high-frequency scenarios. These updates ensure precise vocabulary and testing conditions are defined for the DUT within the new FR2 MIMO OTA framework.
- Device Positioning for FR2 MIMO OTA Testing TS 38.551CR0031
- (FS_NR_FR2_OTA_enh) CR to TR 38.871 on DUT alignment figures TS 38.871CR0005
- Approved by plenary – Rel-18 spec under change control TS 38.751
- Approved by plenary – Rel-18 spec under change control TS 38.761
- Approved by plenary – Rel-18 spec under change control TS 38.870
- Approved by plenary – Rel-18 spec under change control TS 38.871
+ 1 more changes
In Release 19, the DUT (Device Under Test) function introduced new alternate test procedures for Total Radiated Power (TRP) and Tracking Reference Signal (TRS) specifically designed for XR devices. These procedures provide alternative measurement methodologies for evaluating the radio performance of these specialized user equipment. The updates were incorporated into the relevant technical specifications and reports for device conformance testing.
Explore further
Broader topics and technologies where DUT plays a role.
Defining Specifications
3GPP specifications that define or reference DUT, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TR 21.905 vj00 | 3GPP Technical Terms and Definitions | Rel-19 |
| TS 25.141 vj00 | UTRA FDD Base Station RF Conformance Testing | Rel-19 |
| TS 25.171 vj00 | A-GPS Minimum Performance Requirements for UTRA FDD UE | Rel-19 |
| TS 25.172 vj00 | A-GANSS UE Minimum Performance Requirements (FDD) | Rel-19 |
| TS 25.173 vj00 | A-GANSS Performance Requirements (TDD) | Rel-19 |
| TR 25.914 vj00 | 3G UE Radio Performance Test Methods | Rel-19 |
| TS 26.130 vj00 | RTP Payload Format Testing for 3GPP Codecs | Rel-19 |
| TR 26.921 vj00 | UE Performance in Ambient Noise | Rel-19 |
| TS 34.114 vc20 | Radiated Performance Test Procedure for UE/MS | Rel-12 |
| TS 36.117 vj00 | E-UTRA Relay RF Test Methods & Requirements | Rel-19 |
| TS 36.133 vj20 | E-UTRA RRM Requirements | Rel-19 |
| TS 36.141 vj00 | E-UTRA BS Conformance Testing | Rel-19 |
| TS 36.143 vj00 | E-UTRA FDD Repeater RF Testing | Rel-19 |
| TS 36.171 vj10 | A-GNSS Minimum Performance Requirements for UE | Rel-19 |
| TS 36.789 vd00 | LAA Multi-Node Coexistence Test Methodology | Rel-13 |
| TR 36.791 vg00 | E-UTRA 2.4 GHz TDD Band for US | Rel-16 |
| TS 37.144 vj00 | UE OTA Antenna Performance Requirements | Rel-19 |
| TS 37.145 vj10 | AAS Base Station Conducted Conformance Testing | Rel-19 |
| TS 37.544 vg70 | UE Radiated Performance Test Procedures | Rel-16 |
| TS 37.571 vj00 | UE Conformance for Positioning | Rel-19 |
| TS 37.842 vd30 | BS RF Requirements for Active Antenna Systems | Rel-13 |
| TR 37.843 vf70 | AAS BS Radiated RF Requirement Background | Rel-15 |
| TR 37.902 vj00 | OTA TRP/TRS Measurement for LTE Terminals | Rel-19 |
| TR 37.976 vj00 | MIMO OTA Test Methodology Study | Rel-19 |
| TR 37.977 vj00 | MIMO OTA Test Methodology | Rel-19 |
| TS 38.141 vj20 | NR Base Station RF Conformance Testing Part 1 | Rel-19 |
| TS 38.151 vj00 | NR UE MIMO OTA Performance Requirements | Rel-19 |
| TS 38.161 vj10 | NR UE TRP and TRS Requirements for FR1 | Rel-19 |
| TS 38.171 vj10 | 5G A-GNSS UE Positioning Requirements | Rel-19 |
| TS 38.551 vi30 | User Equipment (UE) Multiple Input Multiple Output (MIMO) Over-the-Air (OTA) performance | Rel-18 |
| TS 38.561 vj00 | UE Conformance for TRP/TRS FR1 | Rel-19 |
| TR 38.751 vi30 | Technical Report | Rel-18 |
| TS 38.761 vj00 | MIMO OTA Performance Measurements for UE | Rel-19 |
| TS 38.762 vj00 | Dynamic MIMO OTA Test Methodology for NR FR1 | Rel-19 |
| TS 38.771 vj00 | FR2-1 OTA Testing for STxMP UEs | Rel-19 |
| TR 38.803 ve40 | Study on Coexistence and RF Feasibility for 5G NR | Rel-14 |
| TR 38.810 vg70 | NR OTA Test Methods Study | Rel-16 |
| TS 38.817 | 3GPP TR 38.817 | Rel-6 |
| TR 38.834 vh20 | NR FR1 TRP/TRS Test Methodology | Rel-17 |
| TS 38.870 vj20 | Enhanced OTA Test Methods for NR FR1 TRP/TRS | Rel-19 |
| TR 38.871 vi20 | Technical Report | Rel-18 |
| TR 38.884 vi20 | Technical Report | Rel-18 |
| TR 38.903 vj00 | Test Tolerances & Measurement Uncertainties | Rel-19 |