Keysight and KT SAT Achieve Industry-First Multi-Orbit NTN Handover Between GEO Satellite and Emulated LEO Link

Keysight Technologies, Inc. announced that in collaboration with KT SAT, it has demonstrated a successful non-terrestrial network (NTN) handover using the KOREASAT-6A satellite at KT SAT’s Kumsan Satellite Network Operation Center in Korea. In a controlled lab environment, the companies established the industry’s first1 NR-NTN multi-orbit handover between a commercial GEO satellite and an emulated LEO link. The demonstration was performed over a live Ku‑band GEO connection (DL ~12.3 GHz / UL ~14.4 GHz), marking a major milestone toward testing the newly standardized 3GPP Rel‑19 Ku‑band NTN spectrum. By incorporating Ku‑band operation into this multi-orbit mobility scenario, Keysight and KT SAT have validated NTN behaviors in a frequency range now central to emerging global standards and operator deployment strategies.

As the industry moves toward 6G, integrating satellite and terrestrial networks is essential to deliver continuous coverage and resilient service in remote or disaster-affected areas. Satellite links, however, introduce longer delays, Doppler effects, and dynamic link conditions that complicate mobility and handover across space and ground domains.

By moving beyond earlier demonstrations focused on single-orbit GEO connectivity, KT SAT and Keysight have shown how operators can evolve from point-to-point satellite links to continuous multi-orbit mobility, expanding KT SAT’s service capabilities toward resilient, always-on coverage across space and ground domains. This achievement also establishes an important technical milestone for KT SAT and Keysight in advancing Ku-band NTN mobility.

Using Keysight’s Network Emulator Solutions and UeSIM RAN Testing Toolset, the teams emulated the base station and user equipment, established a two-way link through KOREASAT-6A, and maintained service continuity during a handover from GEO to an emulated LEO connection. Operating the GEO link in Ku‑band ensures that these mobility insights directly map to the Rel‑19 NTN frequency bands now entering commercial planning, giving operators and device vendors earlier visibility into real‑world propagation, timing, and interoperability behaviors. As a result, KT SAT can now explore and validate advanced NTN mobility scenarios in the lab, before satellites or user devices are widely deployed, accelerating its roadmap and reducing the time and cost of bringing new multi-orbit services to market.

This collaboration shows how operators can extend coverage and resilience, while device and chipset vendors gain a lab-based path to validate NTN mobility without relying solely on expensive field trials. Insights from this work are intended to inform standards discussions and operator evaluations, helping the ecosystem shorten time-to-trial and de-risk commercialization.

Seo Young-soo, CEO of KT SAT, said: “As the only satellite communications service provider in Korea, KT SAT is progressively validating the applicability of NTN gNB and UE using our five operational GEO satellites. Building on the results of this trial, we will actively explore strengthening the competitiveness of our next-generation GEO satellite for the global market and delivering integrated multi-orbit communication services based on NTN systems, including traffic handover across our own GEO and future LEO/MEO constellations.”

Peng Cao, Vice President and General Manager of Keysight’s Wireless Test Group, Keysight, said: “This demonstration shows how emulation can bring future multi-orbit networks into the lab today. By combining a live GEO connection with emulated LEO conditions using NR-NTN parameters in Ku-band, Keysight gives operators and vendors a practical way to study NTN handover behavior, optimize mobility strategies, and reduce the cost and risk of early deployments.”