Bridging 5G and SatCom Beamforming for 5G-NTN: Transferability, Gaps, and a Selection Framework

The convergence of terrestrial 5G and satellite systems is driving the development of 5G Non-Terrestrial Networks (5G-NTN). In these networks, beamforming is a key technique to improve capacity and coverage and to manage interference, especially for LEO and MEO constellations. In practice, however, beamforming methods developed for terrestrial 5G do not transfer directly to NTN because of differences in channel dynamics (e.g., Doppler), CSI delay/aging, hardware calibration stability, and onboard resource constraints. This article bridges beamforming technologies used in terrestrial 5G and SatCom to identify what can be reused, what must be adapted,and what becomes impractical under 5G-NTN constraints. We propose a unified taxonomy across algorithms, architectures (digital/hybrid/analog), and procedures, and provide a compatibility matrix that labels key techniques as directly reusable, reusable with adaptation, or not suitable under representative NTN constraints. Building on this, we introduce a selection framework that maps deployment scenarios and constraints to recommended beamforming families and operational choices, summarized through an end-to-end beamforming pipeline. The paper concludes with a consolidated gap analysis and research directions toward practical and scalable beamforming solutions for 5G-NTN.