The 5G core is located after the eNB stack, so that would be in the ground-segment in the transparent architecture and in the regenerative architecture the 5G core can be placed either partially onboard the satellite along with the eNB or in the ground segment. Placing the eNB in the satellite alone reduces the propagation delay for AS messaging exchanges by half and rids you of the overhead of transmitting a copy of the RAN onto the feeder-link. (since the RAN is designed for radio access of cellular devices, and the feeder link involves massive satellite dishes in the ground segment, the copying of RAN onto feeder link is a very inefficient use of the feeder link). Placing some core network features onboard the satellite along with the eNB – such as MME and S-GW could allow for example the attachment and authorization of some UEs without the involvement of the ground-segment core network… this would reduce the overall delay for NAS procedures.