16.14.3.2.3 Satellite switch with re-synchronization

For transparent payload, upon both hard and soft satellite switch over in the quasi-Earth fixed scenario with the same SSB frequency and the same gNB, the satellite switch with re-synchronization procedure is supported. The satellite switch with re-sync avoids a L3 mobility for UEs in the cell by maintaining the same PCI on the geographical area covered by quasi-Earth fixed beam.

For soft satellite switch over, the UE can start synchronizing with the target satellite before the source satellite ends to serve the cell. It is not required for the UE to be connected to source satellite when the UE switches to target satellite.

For hard satellite switch over, the UE can only start synchronizing with the target satellite after the source satellite ends to serve the cell.

When both CHO and Satellite switch with re-synchronization are configured, it is up to UE implementation which procedure to initiate, if both of them are triggered simultaneously.

For the re-synchronization to the target satellite, random access can be triggered by a PDCCH order via the target satellite.