2. 3GPP standard introduces transparent satellites

This section presents the modifications to the 3GPP standard for the direct access use case (e.g. smartphone) for a usage frequency below 7 GHz and using the 5G NR waveform with satellites in non-geostationary orbit with a transparent satellite. The elements presented are also relevant for scenarios with higher usage frequencies.

The terminology "transparent" refers to the fact that the gNB as defined above (i.e., not including the RRU) is entirely on the ground, and the satellite performs no operations associated with modulating or decoding the received data. Different ways of slicing the physical layer are possible, and have been studied in study documents by 3GPP and the O-RAN consortium. The proposals made in the standard to introduce transparent satellites must be compatible with all levels of physical layer cuts. This architecture is illustrated in figure...