Section: 4.11.1.5.5 5GS to EPS handover using N26 interface
Content: In step 3 of clause 4.11.1.2.1, the Forward Relocation Request may include new information Return Preferred. Return Preferred is an indication by the AMF of a preferred return of the UE to the last used 5GS PLMN at a later access change to a 5GS shared network. RFSP in Use ValidityTime is provided by the AMF to the MME if the AMF selects the RFSP Index in use identical to the authorized RFSP Index as specified in clause 5.4.3.4 of TS 23.501[ System architecture for the 5G System (5GS) ]  [2] and validity time is received from PCF as specified in clause 4.16.2.2 and in clause 6.1.2.1 of TS 23.503[ Policy and charging control framework for the 5G System (5GS); Stage 2 ]  [20]. The MME handles RFSP Index as specified in clause 4.11.1.5.8. The MME may store the last used 5GS PLMN ID in UE's MM Context. The MME may provide E-UTRAN with a Handover Restriction List taking into account the last used 5GS PLMN ID and the Return Preferred indication. The Handover Restriction List contains a list of PLMN IDs as specified by TS 23.251[ Network sharing; Architecture and functional description ]  [35].