5.4.11.7 Tracking Area handling for NR satellite access

In the case of NR satellite access with moving cells, in order to ensure that each TA is Earth-stationary even if the radio cells are moving across the Earth's surface, the NG-RAN may change the TAC values that are broadcast in a cell's system information as the cell moves, as described in TS 38.300 [27] and TS 38.331 [28].

NG-RAN may broadcast in a cell a single TAC per PLMN and change that TAC value as the cell moves. Alternatively, the NG-RAN may broadcast in a cell more than one TAC for a PLMN and add or remove TAC values as the cell moves. The NG-RAN provides either the single broadcast TAI or all broadcast TAIs corresponding to the Selected PLMN as described in TS 38.413 [34] to the AMF as part of the ULI, whenever the ULI is included in the NGAP message as described in TS 38.413 [34]. The NG-RAN indicates, if known, also the TAI where the UE is geographically located. When supplying location information to another NF (e.g. SMF, PCF), the AMF shall include the TAI where the UE is located (if known) and the broadcast TAI(s), excluding all forbidden TAI(s).

NOTE: The AMF may take the TAI where the UE is geographically located into account to generate a suitable Registration Area for the UE.