5G UE Conformance Testing: OTA Tests & Equipment

This page delves into the world of 5G UE (User Equipment) Conformance Testing. We’ll explore the various 5G UE Over-The-Air (OTA) test cases and the equipment used to ensure these devices meet the necessary standards.

Introduction

A 5G network essentially comprises two key components: the UE (your mobile device) and the BTS (Base Transceiver Station, also known as gNB). Throughout the development of a 5G UE, rigorous testing is crucial to guarantee it aligns with the 3GPP specifications. 5G mobiles, or UEs, must adhere to these standards, which are meticulously published and maintained by 3GPP.

These conformance tests, defined by 3GPP, cover a range of areas including:

• RF (Radio Frequency): Testing the basic radio performance.
• RRM (Radio Resource Management): How the device manages connections and resources.
• Demodulation: The ability of the device to decode signals.
• Signaling: Testing the device’s communication with the network.

These specifications are detailed in 3GPP TS 38.101, split into:

• Part-1: Range 1 Standalone operation.
• Part-2: Range 2 Standalone operation.
• Part-3: Range 1 and Range 2 Interworking with other radio technologies.

The specifications cover both the transmission capabilities of the UE as well as its receiving abilities.

5G UE Conformance Testing

The table below offers a quick overview of the types of tests involved in 5G UE conformance. 5G UE Conformance testing touches every layer of the 5G protocol stack, from PHY (Physical Layer) up to RRC (Radio Resource Control), including MAC, RLC, and PDCP.

Global certification bodies such as GCF and PTCRB establish the framework for these 5G device certification tests.

5G UEs operate in diverse modes, such as SC (Single Carrier), CA (Carrier Aggregation), DC (Dual Connectivity), SUL (Supplementary Uplink), and UL MIMO (Uplink Multiple-Input Multiple-Output). As a result, testing must occur across numerous frequency bands, channel bandwidths (5MHz, 10MHz, 15MHz, 20MHz, 25MHz, 30MHz, 40MHz, 50MHz, 60MHz, 80MHz, 100MHz), and subcarrier spacing (15KHz, 30KHz, 60KHz) for each mode, all according to 3GPP guidelines.

Furthermore, R&D testing may involve OTA measurements like 2D/3D beam pattern analysis, cross-polarization isolation, and beam steering performance evaluations.

5G UE Transmitter Test Cases

Here’s a breakdown of the transmitter test cases, as defined in 3GPP TS 38.101:

• UE maximum output power
• UE maximum output power reduction (MPR)
• UE additional maximum output power reduction
• Configured transmitted power
• Transmitter power for CA/DC/SUL
• Output power dynamics (Minimum output power, Transmit OFF power etc.)
• Transmit ON/OFF time mask (for general slot, mini-slot, PRACH, PUCCH, SRS, PUSCH etc.)
• Power Control (absolute power tolerance, relative power tolerance, Aggregate power tolerance)
• Transmit Signal Quality (Frequency Error, modulation quality, EVM (Error Vector Magnitude), carrier leakage, In-band emissions, etc.)
• Output RF spectrum emissions (Occupied bandwidth, Out of band emission, Spectrum emission mask, Adjacent channel leakage ratio etc.)
• Spurious emissions (General, UE co-existence, Transmit intermodulation etc.)

5G UE Receiver Test Cases

The receiver test cases, also from 3GPP TS 38.101, include:

• Diversity tests
• Reference sensitivity power level (CA, DC, SUL modes)
• Maximum input level
• ACS (Adjacent channel selectivity)
• Blocking tests (In-band blocking, Out-of-band blocking, Narrow band blocking)
• Spurious emission tests
• Intermodulation tests

5G UE OTA Test Equipment

Several companies are at the forefront of developing 5G OTA test solutions and conformance

• EMITE (Spain): Offers comprehensive 5G OTA test solutions with Reverberation Chambers, Anechoic Chambers, and CATR Chambers.
• Anritsu: Developing test solutions for 5G mobile devices.
• Keysight: A major player in test and measurement equipment.
• ETS Lindgren: Provides a range of testing solutions, including OTA chambers.
• Rohde & Schwarz: Offers test solutions for a variety of communication technologies including 5G.

References

• TS 38.101 5G UE radio transmission and reception