Keysight & KT SAT Achieve World-First Multi-Orbit NTN Live GEO / Emulated LEO Handover
Keysight Technologies and KT SAT have successfully demonstrated the industry’s first NR-NTN multi-orbit handover between a live Ku-band GEO link and an emulated LEO link, marking a major milestone for 3GPP Release-19 and early 6G NTN mobility.
The proof-of-concept was conducted using the KOREASAT-6A satellite at KT SAT’s Kumsan Satellite Network Operation Center in Korea, leveraging Keysight’s Network Emulator Solutions and UE emulation tools.
Unlike previous trials focused on single-orbit GEO links, this demonstration validates end-to-end session continuity during an orbit change from a real GEO satellite to a 3GPP-compliant LEO scenario.
This capability is viewed as essential for 6G’s vision of continuous, resilient space-ground coverage, enabling:
Multi-orbit service continuity (GEO ↔ LEO/MEO)
Dynamic resilience during outages or disasters
Optimized latency management (shift to LEO when needed)
Future direct-to-device NTN mobility
Early Ku-band NTN interoperability testing for Rel-19
The test used Ku-band DL ~12.3 GHz / UL ~14.4 GHz, the core band earmarked in 3GPP Rel-19 for NTN mobility, making the results directly relevant to upcoming commercial deployments.
During the test, the companies:
Ran a live GEO NR-NTN link over KOREASAT-6A
Emulated a LEO NTN link with full Doppler, delay, and mobility characteristics
Executed a seamless handover while maintaining session continuity
Validated timing, propagation, and mobility behaviors under standardized NR-NTN parameters
The test shows that operators and device vendors can now evaluate complex NTN mobility in the lab, avoiding the cost and uncertainty of early in-orbit trials.
The successful test provides operators with a practical way to develop real multi-orbit service strategies, chipset/device vendors with a test environment for NTN mobility without accessing physical LEO/GEO assets, standards bodies with input for ongoing Rel-19 and early Rel-20 NTN mobility work, the wider NTN industry with validated path toward seamless global coverage in 6G.