Improvements in and relating to non-terrestrial networks

摘要

Various methods of operating a non-terrestrial network (NTN) are disclosed. A method of operating a NTN comprising: configuring a Timing Advance, TA, value comprising a cell-specific TA and a residual TA, where the cell-specific common TA is broadcast by a satellite in a connection with a particular cell. The common TA may be determined on the basic of satellite ephemeris. The TA may include TA values associated with defined regions of the cell. Also disclosed is a method of using Adaptive Modulation and Coding (AMC) in an NTN, which may apply a lower modulation and coding rate than would otherwise be applied based on channel conditions. Also, a method of implementing either open-loop or closed-loop power control in the uplink in an NTN, which may be based on satellite ephemeris or location information of both satellite and UE. Also, a method of operating a NTN comprising splitting available resources between a feeder link and user link to achieve optimal spectral efficiency.