es of scale of the 5G ecosystem. There are several effects that have an impact on 5G standards that need to be handled in order to support NTN, as shown in Table 5.3.2 for HAPS, LEO, medium earth orbit (MEO), GEO, and high elliptical orbit (HEO) satellites. These depend on the considered NTN ref- erence scenarios (3GPP TR 38.811). In the present section we discuss these aspects in detail. 5.3.1 Key Ideas The definition of a global standard based on the 5G technology framework for all NTN platforms, whatever orbit, frequency band, or device, will enable a smooth integration of non-terrestrial networks into the 5G system. This will contribute to create new service capabilities critical for consistent service continuity, reliability, and availability, opening up access to various verticals and a decrease in the cost of network infrastructure and devices due to the economies of scale of the 5G ecosystem. 5.3 Non-terrestrial Networks Table 5.3.2 NR impacts to support the NTN reference scenarios. Medium Altitude earth earth stationary elliptical Platforms orbit orbit orbit orbit Effects (HAPS) (LEO) (MEO) (GEO) (HEO) Yes if beams Yes if beams Yes if beams Yes if beams are moving are moving are moving are moving Moving cell on earth on earth on earth on earth Motion of the pattern (hence high (hence high (hence high space/aerial speed)a speed) speed) vehicles No if beams No if beams No if beams No if beams are fixed on are fixed on are fixed on are fixed on earth earth earth earth Delay Highb Mediumb variation Doppler To be Highb Mediumb Negligible determined Altitude Latency Negligible Medium Cell size Differential Small Typically Typically Possibly Possibly delay relatively relatively relatively relatively medium medium Frequency selectiveness Propagation impairments channel Delay spread c impairments Duplex scheme Regulatory Frequency FDD and Only FDD Only FDD Only FDD constraints Division Possibly Duplexing (FDD) and possibly Division Duplexing (TDD) Assuming a fixed relation between beams and cells. Doppler and del