NTN Non-Terrestrial Network
A network that uses non-ground-based access nodes, such as satellites (GEO, MEO or LEO) or HAPS (High-Altitude Platform Stations), to deliver mobile connectivity across wide areas or to locations that terrestrial coverage cannot economically reach. NTN was first standardised for 5G NR (New Radio) in 3GPP Release 17, which specified only the transparent payload, also known as a bent pipe, where the satellite simply relays, amplifies and frequency-converts the signal while the serving gNB (Next Generation Node B) remains on the ground. Release 18 extended NTN into FR2 (Ku/Ka-band) for higher-bandwidth terminals and improved terrestrial-to-NTN mobility. Release 19 then added support for the regenerative payload, placing a complete gNB onboard the satellite so it can process signals rather than merely forward them, enabling inter-satellite routing over the Xn interface and reduced round-trip time.
