NTN automotive testing

NTN technology challenges

Automotive NTN connectivity introduces a range of RF, mobility and system-level challenges that must be addressed through rigorous testing:

• Large propagation distances and high pathloss: Unlike terrestrial networks with cell sizes of only a few hundred meters, NTN links span hundreds of kilometers to LEO satellites and roughly 36,000 km to GEO satellites. These extreme distances create significant pathloss and, in the case of GEO systems, substantial latency. High latency complicates timing synchronization and limits support for reactive automotive use cases.
• Low and variable satellite elevation angles: Maintaining a line-of-sight connection becomes difficult when satellites appear at low elevation angles, particularly for GEO systems viewed from high latitudes. Shadowing from terrain, foliage and the vehicle environment can further degrade service continuity. Antenna designers and OEMs must account for these conditions to ensure reliable operation across diverse driving scenarios.
• Signal distortion from atmospheric effects and multipath: Atmospheric fading and multipath reflections from the surrounding environment distort NTN signals, reducing link quality. These impairments influence NTN network design and must be addressed during chipset and vehicle-level integration.
• Satellite movement and Doppler effects: For non-geostationary earth orbit (NGEO) systems, the relative motion between the satellite and vehicle generates Doppler shifts and time-varying propagation delays. These effects introduce demanding synchronization and RF-channel challenges for the TCU and chipset. Vehicles may require active, beamforming antennas to continually track fast-moving LEO satellites, which are visible for only minutes at a time.
• Complex NTN mobility and handover procedures: NTN adds multiple mobility requirements beyond those of terrestrial networks, including inter-beam and inter-satellite handover, cell reselection, and transitions between NTN and TN networks. Particularly for LEO constellations, ensuring seamless mobility demands careful network design and testing of conditional handover parameters and trigger points at the vehicle level.
• Wide range of operating frequency bands: NTN systems operate from L and S bands up to Ku, K and Ka bands. While current automotive TCUs and antennas may already support lower bands, higher-frequency Ku/K/Ka operation introduces significantly more complex requirements for RF transceivers, TCUs and antennas.
• Space, power and thermal constraints: Beamforming-capable active antennas needed for high-frequency NTN operation increase size, weight, power consumption and thermal load. These constraints must be balanced against vehicle design, cost and integration considerations.

Master your automotive NTN test challenges

Realizing the always-connected vehicle also requires emulating complex NTN conditions and validating end-to-end performance:

• Flexible NTN network emulation: To evaluate chipset, TCU and vehicle-level performance over a wide range of NTN implementations, test systems must emulate LEO, MEO and GEO constellations, all relevant frequency bands and all appropriate mobility conditions.
• Standards-compliant protocol, RF and application testing: Chipsets and TCUs require testing against 3GPP NTN specifications - including NB-NTN and NR-NTN - to verify correct protocol behavior, RF performance and application-level operation. This ensures regulatory requirements are met and enables compatibility with other devices.
• Advanced channel emulation: To ensure correct operation on the road, pathloss, fading, shadowing, atmospheric effects and Doppler frequency shift must be replicated in the lab to emulate realistic NTN channel conditions.
• Timing and frequency synchronization verification: Accurate validation of timing behavior - especially under GEO latency and NGEO Doppler shift - is critical for ensuring correct operation of NTN communication systems.
• Emulation of realistic GNSS signals: As GNSS plays a central role in NTN positioning, timing and mobility procedures, test environments must emulate multiple GNSS satellites alongside NTN signals.
• Antenna and beamforming validation: Both passive and active automotive antennas require OTA lab and chamber testing to verify beam steering, gain, performance and robustness under varying elevation angles and satellite trajectories.
• Vehicle-level validation of NTN-based services: End-to-end services delivered over NTN, such as eCall, must be tested in integrated vehicle environments to ensure correct operation under real-world NTN conditions.

NTN implementations comparison

Our automotive NTN test solutions

• Multi-orbit support, covering LEO, MEO, GEO and GSO, as well as both inter- and intra-orbit handovers
• Multiband support covering all NTN frequency bands
• Dynamic Doppler shift emulation for both uplink and downlink signals
• Variable propagation delay and round-trip time (RTT) emulation, with the ability to assess the impacts of timing advance, HARQ retransmission process and overall latency
• NTN-specific fading profiles that incorporate effects such as atmospheric attenuation, rain fading and combined atmospheric/terrestrial fading
• Flexible GNSS signals emulation covering all global standards
• Complete active and passive antenna characterization solutions including far-field transformation
• Fast and efficient TCU production testing solutions
• Conformance testing of the TCU in accordance with the appropriate 3GPP release
• Full vehicle OTA testing to ensure end-to-end operation, co-existence and interference robustness