NR-NTN: satellite-based 5G, LEO/MEO/GEO access, 3GPP bands

NR Non-Terrestrial Network Architecture

NR-NTN extends 5G NR to satellite platforms defined in 3GPP TR 38.821. The architecture supports three orbital layers: Low Earth Orbit satellites at 300-1500 km altitude providing lowest latency but requiring large constellations, Medium Earth Orbit at 8000-20000 km balancing coverage and delay, and Geostationary at 35786 km covering one-third of Earth per satellite but with 270+ ms round-trip delay. The system uses transparent payloads (bent-pipe) where the satellite acts as an RF relay, or regenerative payloads with onboard gNB processing. Key challenges include Doppler compensation up to…