Rohde & Schwarz has expanded the capabilities of its CMX500 radio communication tester to cover all non-terrestrial network (NTN) technologies; it will showcase the upgraded one-box tester at next week’s Mobile World Congress in Barcelona.

The CMX500 one-box signalling tester has evolved into a versatile, all-in-one platform for NTN testing, supporting NR-NTN, NB-NTN and direct-to-cell (D2C) technologies within a single unit. Users can now test all NTN technologies on both network and device level without the need for multiple instruments, thus accelerating development and ensuring quality of NTN services to be deployed.

As NTN matures alongside 5G and looks towards 6G, overcoming significant technical hurdles is key to realising its potential. Unlike terrestrial networks, NTNs present unique communication problems due to the dynamic nature of satellites. Rapid satellite movement causes frequent changes in signal characteristics, including Doppler frequency shifts, variable propagation delay and high path loss, requiring advanced channel emulation. Further complexity arises from the use of multiple orbits (LEO, MEO, GEO) and frequency bands, often necessitating frequency division duplex (FDD) instead of the time division duplex (TDD) common in terrestrial networks.

While the CMX500 is an established instrument in the 5G ecosystem, Rohde & Schwarz has recently expanded its functionalities significantly to address the specific complexities of satellite-based communication. It supports two primary testing configurations: full satellite access network (SAN) emulation for device manufacturers, simulating the complete NTN architecture for comprehensive device testing; and gNB and 5G core network emulation for satellite network operators, validating satellite network components against standards-compliant cellular technologies.

The constellation insight tool further enhances the instrument to support NTN testing scenarios. This software enables engineers to visualise satellite constellations in real time, manage mobility and observe trajectories, effectively creating a digital twin of the live sky. It allows for automated deployment and handovers, it integrates precise ephemeris data to simulate realistic mobility and impairment compensation, and it supports complex handover scenarios.

The German firm also offers an XLAPI Python test case package, which includes a range of Starlink LTE-DTC test scenarios. These cover, for example, LTE attach time and success rates in DTC mode, event A3 handover, cell reselection between intra-frequency LTE DTC cells, and recovery after radio link failure on LTE DTC cells. The ScriptAssist AI-powered script generation tool further acceleraties scripting for NTN-specific R&D protocol and application testing as well as instrument automation.

The instrument supports NTN conformance and carrier acceptance testing, offering the highest number of validated test cases for NR-NTN according to 3GPP Rel 17. Validations were conducted across all three critical test domains: protocol conformance testing (PCT), radio frequency (RF) and radio resource management (RRM).

It differentiates between propagation emulation and fading. It addresses space-to-ground effects, such as Doppler, delay and scattering, separately from terrestrial impairments, such as reflections and receiver-induced Doppler. This allows space-to-ground effects and terrestrial impairments to be modelled and controlled independently of each other, enabling more accurate and flexible testing of NTN scenarios.

“As NTN becomes an integral part of the 5G ecosystem, it brings a new level of complexity in validation and testing,” said Goce Talaganov, vice president at Rohde & Schwarz. “Our R&D teams have continuously invested in scaling up our CMX500 one-box tester to address exactly these technical hurdles. We’re excited to showcase this upgraded CMX500 one-box tester at MWC, which now fully supports all NTN technologies in a single, integrated platform. We look forward to engaging with our customers to discuss how this can help them with their NTN testing needs.”

Visitors to MWC (www.mwcbarcelona.com) can experience the NTN testing capabilities of the CMX500 (www.rohde-schwarz.com/cmx-ntn) on the Rohde & Schwarz (www.rohde-schwarz.com) stand 5A80 in hall 5 from March 2 to 5, 2026.