Cellular device testing showcased at MWC 2021

High-throughput eMBB end-to-end testing

Enhanced mobile broadband (eMBB) is the use case of 5G NR that supports the ever-increasing end user data rate and system capacity, as mobile devices integrate more and more internet based services and applications.

At MWC21, Rohde & Schwarz demonstrates, together with VIAVI, its R&S CMX500 radio communication tester and the VIAVI TM500 network tester in a 5G NR eMBB end-to-end test scenario in 5G SA (standalone) mode, exceeding for the first time a high-speed data throughput of 7.5 Gbps.

This demonstration paves the way for upcoming data rates of 10 Gbps. In this scenario, the instruments simulate a standalone 5G cellular network with 8x downlink carrier aggregation in an NR dual connectivity (NR DC) setup, using one component carrier (1xCC) in FR1 and seven component carriers (7xCC) in FR2, with 256QAM applied to all carriers.

End-to-end testing evaluates the data throughput from the built-in simulated server and base station to the device under test in a well-defined network environment. For this scenario, the R&S CMX500 features an integrated FTP server which enables upload and download throughput tests for the file transfer protocol.

VoNR audio quality testing

Even with 5G, voice services will remain a key use case for mobile subscribers. Rohde & Schwarz has teamed up with HEAD acoustics to verify the quality of voice services over 5G NR.

At MWC21, the two companies demonstrate a test solution based on the latest generation of the R&S CMX500 radio communication tester, combined with the labCORE hardware platform from HEAD acoustics and their ACQUA measurement and analysis software.

The setup allows simulation of a voice connection in both 5G SA (VoNR) and 5G NSA (VoLTE) deployment scenarios. This enables manufacturers of 5G capable mobile devices to test their voice quality at an early stage before market introduction.

Conformance testing and carrier acceptance tests

Conformance testing is a crucial step in bringing mobile devices to the market. With the introduction of 5G NR, the number of test cases is growing exponentially due to the huge number of supported band combinations, deployment options and evolving standards.

Major 5G operators ask for additional carrier acceptance tests to ensure cellular devices function properly.

With an R&S CMX500 based test system, Rohde & Schwarz supports carrier acceptance tests such as performance quality analysis (PQA), network protocol tests (NPT) and LBS tests in 5G FR2. In all applications, the extremely compact R&S ATS800R CATR antenna test system for over-the-air (OTA) measurements is used.

Rohde & Schwarz will demonstrate a typical carrier acceptance test case: heat dissipation of a mobile device as a function of data throughput.

Multireflector compact antenna test range

5G NR devices equipped with mmWave antenna arrays, each consisting of a transceiver, frontend and phased array antenna, cannot be verified using conducted tests. Moreover, features such as beamforming can only be tested over the air.

Consequently, 3GPP specifies that all FR2 conformance tests need to be performed over the air under direct or indirect far-field conditions.

With the R&S ATS1800M, Rohde & Schwarz is introducing a CATR based mmWave test chamber that provides a multi-reflector setup with a small footprint to test with low measurement uncertainty.

This solution is ideal for characterising devices in the presence of multiple signals coming from different directions using a full black box test approach – a typical test scenario in radio resource management (RRM) testing that is made possible thanks to a total of four CATR reflectors in the R&S ATS1800M, each one providing a quiet zone with an unrivalled size of 30 cm in diameter.

mmWave testing on the factory floor

While the demand for manufacturing test solutions for 5G NR devices is growing, high-volume testing of devices operating in the mmWave range brings new challenges.

Since these devices have no RF connectors, DUT validation needs to take place in an OTA environment.

For this, Rohde & Schwarz has developed the R&S CMPQ test platform. Manufacturers setting up their production lines can configure the individual components and the overall system independently to create customised solutions for FR2 testing.

The R&S CMPQ consists of an R&S CMP200 radio communication tester, R&S CMPHEAD30 mmWave remote radio heads and an R&S CMQ200 shielding cube.

The platform comes from a single supplier and integrates all system components, including antennas, cables, feedthroughs and power sensors, to ensure optimal and stable system parameters for reliable and reproducible FR2 production tests.