Apparatus and method for supporting session continuity in wireless communication system
A method performed by a user equipment (UE) in a wireless communication system is provided. The method includes transmitting, to an access and mobility function (AMF), a registration request message for moving to a first public land mobile network (PLMN) from a second PLMN, receiving, from the AMF, a registration accept message including first single-network slice selection assistance information (S-NSSAI) corresponding to the first PLMN of the AMF, determining whether second S-NSSAI associated with a protocol data unit (PDU) session established for the UE matches to the first S-NSSAI, wherein the second S-NSSAI corresponds to the second PLMN, and locally updating the PDU session based on a result of the determining.
1. A method performed by a user equipment (UE) in a wireless communication system, the method comprising:
identifying a first single-network slice selection assistance information (S-NSSAI) associated with a protocol data unit (PDU) session for a first public land mobile network (PLMN);
transmitting, to an access and mobility management function (AMF) entity, a registration request message for a second PLMN;
receiving, from the AMF entity, a registration accept message including allowed network slice selection assistance information (NSSAI), wherein the allowed NSSAI includes second mapped S-NSSAI and second S-NSSAI, and wherein the second S-NSSAI corresponds to the second mapped S-NSSAI;
identifying whether the first S-NSSAI associated with the PDU session matches to the second mapped S-NSSAI; and
updating the first S-NSSAI associated with the PDU session to the second S-NSSAI in case that the first S-NSSAI matches to the second mapped S-NSSAI.
2. The method of claim 1 , further comprising:
establishing the PDU session in the first PLMN.
3. The method of claim 1 ,
wherein the first S-NSSAI includes a first slice/service type (SST),
wherein the second S-NSSAI includes a second SST, and
wherein the second mapped S-NSSAI includes a mapped home PLMN (HPLMN) SST.
4. The method of claim 3 ,
wherein the first S-NSSAI further includes a first slice differentiator (SD), and
wherein the second mapped S-NSSAI further includes a mapped HPLMN SD.
5. The method of claim 1 ,
wherein the first S-NSSAI associated with the PDU session is updated to the second S-NSSAI in case a first HPLMN SST of the first S-NSSAI matched to a mapped HPLMN SST of the second mapped S-NSSAI.
6. The method of claim 1 ,
wherein the first S-NSSAI associated with the PDU session is updated to the second S-NSSAI in case a first slice differentiator (SD) of the first S-NSSAI matched to a second mapped HPLMN SD of the second mapped S-NSSAI.
7. The method of claim 1 ,
wherein the PDU session established in the first PLMN is used in the second PLMN by locally updating the first S-NSSAI to the second S-NSSAI, and
wherein after the UE moves to the second PLMN from the first PLMN the PDU session is used continuously and not released.
8. A method performed by an access and mobility management function (AMF) entity in a wireless communication system, the method comprising:
receiving, from a user equipment (UE), a registration request message for a second public land mobile network (PLMN); and
transmitting, to the UE, a registration accept message including allowed network slice selection assistance information (NSSAI), wherein the allowed NSSAI includes second mapped single-network slice selection assistance information (S-NSSAI) and second S-NSSAI, and wherein the second S-NSSAI corresponds to the second mapped S-NSSAI,
wherein a first single-network slice selection assistance information (S-NSSAI) is associated with a protocol data unit (PDU) session for a first PLMN, and
wherein the first S-NSSAI associated with the PDU session is updated to the second S-NSSAI in case that the first S-NSSAI matches to the second mapped S-NSSAI.
9. The method of claim 8 ,
wherein the PDU session is established in the first PLMN.
10. The method of claim 8 ,
wherein the first S-NSSAI includes a first slice/service type (SST),
wherein the second S-NSSAI includes a second SST, and
wherein the second mapped S-NSSAI includes a mapped home PLMN (HPLMN) SST.
11. The method of claim 10 ,
wherein the first S-NSSAI further includes a first slice differentiator (SD), and
wherein the second mapped S-NSSAI further includes a mapped HPLMN SD.
12. The method of claim 8 ,
wherein the first S-NSSAI associated with the PDU session is updated to the second S-NSSAI in case a first HPLMN SST of the first S-NSSAI matched to a mapped HPLMN SST of the second mapped S-NSSAI.
13. The method of claim 8 ,
wherein the first S-NSSAI associated with the PDU session is updated to the second S-NSSAI in case a first slice differentiator (SD) of the first S-NSSAI matched to a second mapped HPLMN SD of the second mapped S-NSSAI.
14. The method of claim 8 ,
wherein the PDU session established in the first PLMN is used in the second PLMN by locally updating the first S-NSSAI to the second S-NSSAI, and
wherein after the UE moves to the second PLMN from the first PLMN the PDU session is used continuously and not released.
15. A user equipment (UE) in a wireless communication system, the UE comprising:
a transceiver; and
at least one processor operably connected with the transceiver, the at least one processor configured to:
identify a first single-network slice selection assistance information (S-NSSAI) associated with a protocol data unit (PDU) session for a first public land mobile network (PLMN),
transmit, to an access and mobility management function (AMF) entity, a registration request message for a second PLMN,
receive, from the AMF entity, a registration accept message including allowed network slice selection assistance information (NSSAI), wherein the allowed NSSAI includes second mapped S-NSSAI and second S-NSSAI, and wherein the second S-NSSAI corresponds to the second mapped S-NSSAI,
identify whether the first S-NSSAI associated with the PDU session matches to the second mapped S-NSSAI, and
update the first S-NSSAI associated with the PDU session to the second S-NSSAI in case that the first S-NSSAI matches to the second mapped S-NSSAI.
16. The UE of claim 15 ,
wherein the first S-NSSAI includes a first slice/service type (SST),
wherein the second S-NSSAI includes a second SST, and
wherein the second mapped S-NSSAI includes a mapped home PLMN (HPLMN) SST.
17. The UE of claim 16 ,
wherein the first S-NSSAI further includes a first slice differentiator (SD), and
wherein the second mapped S-NSSAI further includes a mapped HPLMN SD.
18. The UE of claim 15 ,
wherein the first S-NSSAI associated with the PDU session is updated to the second S-NSSAI in case a first HPLMN SST of the first S-NSSAI matched to a mapped HPLMN SST of the second mapped S-NSSAI.
19. The UE of claim 15 ,
wherein the first S-NSSAI associated with the PDU session is updated to the second S-NSSAI in case a first slice differentiator (SD) of the first S-NSSAI matched to a second mapped HPLMN SD of the second mapped S-NSSAI.
20. The UE of claim 15 ,
wherein the PDU session established in the first PLMN is used in the second PLMN by locally updating the first S-NSSAI to the second S-NSSAI, and
wherein after the UE moves to the second PLMN from the first PLMN the PDU session is used continuously and not released.