Reregistration to slices with mapped S-NSSAIS alone in 5G system
A method of registering to slices with mapped S-NSSAI alone in a 5GS is described. The method can include, upon a UE entering a VPLMN, the UE having a first PDN connection or a first PDU session that is to be transferred to the VPLMN and associated with a first HPLMN S-NSSAI, determining whether the UE has a first VPLMN S-NSSAI applicable in the VPLMN corresponding to the first HPLMN S-NSSAI. If not, a registration request message can be transmitted to the VPLMN. The registration request message can include the first HPLMN S-NSSAI as a first mapped S-NSSAI for indicating a slice of the VPLMN to which the UE intends to register.
1. A method, comprising:
upon a user equipment (UE) entering a visited public land mobile network (VPLMN), the UE having a first protocol data unit (PDU) session that is associated with a first home public land mobile network (HPLMN) single network slice selection assistance information (S-NSSAI), determining whether the UE has a first VPLMN S-NSSAI applicable in the VPLMN corresponding to the first HPLMN S-NSSAI; and
in response to the UE not having the first VPLMN S-NSSAI applicable in the VPLMN corresponding to the first HPLMN S-NSSAI, transmitting a registration request message to the VPLMN, the registration request message including the first HPLMN S-NSSAI as a first mapped S-NSSAI for indicating a slice of the VPLMN to which the UE intends to register.
2. The method of claim 1 , wherein the first HPLMN S-NSSAI is included in a requested mapped network slice selection assistance information (NSSAI) information element (IE).
3. The method of claim 1 , wherein for the first PDU session that is associated with the first HPLMN S-NSSAI, the UE is performing mobility from N1 mode to N1 mode from another VPLMN to the VPLMN.
4. The method of claim 1 , wherein for the first PDU session that is associated with the first HPLMN S-NSSAI, the UE is performing mobility from N1 mode to N1 mode from the HPLMN to the VPLMN.
5. The method of claim 1 , wherein in response to the UE not having any S-NSSAI applicable in the VPLMN, a requested mapped NSSAI IE in the registration request message does not include any S-NSSAIs.
6. The method of claim 1 , wherein in response to the UE has a second VPLMN S-NSSAI applicable in the VPLMN for a second PDU session that is associated with a second HPLMN S-NSSAI, the registration request message further includes a requested NSSAI IE that includes (1) the second VPLMN S-NSSAI applicable in the VPLMN for indicating a slice to which the UE intends to register for transferring the second PDU session, and (2) the second HPLMN S-NSSAI as a second mapped S-NSSAI corresponding to the second VPLMN S-NSSAI applicable in the VPLMN.
7. The method of claim 1 , further comprising:
receiving a registration accept message including an allowed NSSAI IE that includes an allowed S-NSSAI for the slice of the VPLMN to which the UE intends to register and the first mapped S-NSSAI corresponding to the allowed S-NSSAI; and
associating the allowed S-NSSAI and the first mapped S-NSSAI with a PDU session that is established in the VPLMN and corresponds to the first PDU session.
8. An apparatus, comprising circuitry configured to:
upon a user equipment (UE) entering a visited public land mobile network (VPLMN), the UE having a first protocol data unit (PDU) session that is associated with a first home public land mobile network (HPLMN) single network slice selection assistance information (S-NSSAI), determine whether the UE has a first VPLMN S-NSSAI applicable in the VPLMN corresponding to the first HPLMN S-NSSAI; and
in response to the UE not having the first VPLMN S-NSSAI applicable in the VPLMN corresponding to the first HPLMN S-NSSAI, transmit a registration request message to the VPLMN, the registration request message including the first HPLMN S-NSSAI as a first mapped S-NSSAI for indicating a slice of the VPLMN to which the UE intends to register.
9. The apparatus of claim 8 , wherein the first HPLMN S-NSSAI is included in a requested mapped network slice selection assistance information (NSSAI) information element (IE).
10. The apparatus of claim 8 , wherein for the first PDU session that is associated with the first HPLMN S-NSSAI, the UE is performing mobility from N1 mode to N1 mode from another VPLMN to the VPLMN, or from the HPLMN to the VPLMN.
11. The apparatus of claim 8 , wherein in response to the UE not having any S-NSSAI applicable in the VPLMN, a requested mapped NSSAI IE in the registration request message does not include any S-NSSAIs.
12. The apparatus of claim 8 , wherein in response to the UE has a second VPLMN S-NSSAI applicable in the VPLMN for a second PDU session that is associated with a second HPLMN S-NSSAI, the registration request message further includes a requested NSSAI IE that includes (1) the second VPLMN S-NSSAI applicable in the VPLMN for indicating a slice to which the UE intends to register for transferring the second PDU session, and (2) the second HPLMN S-NSSAI as a second mapped S-NSSAI corresponding to the second VPLMN S-NSSAI applicable in the VPLMN.
13. The apparatus of claim 8 , wherein the circuitry is further configured to:
receive a registration accept message including an allowed NSSAI IE that includes an allowed S-NSSAI for the slice of the VPLMN to which the UE intends to register and the mapped S-NSSAI corresponding to the allowed S-NSSAI; and
associate the allowed S-NSSAI and first mapped S-NSSAI with a PDU session that is established in the VPLMN and corresponds to the first PDU session.
14. A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform a method, the method comprising:
upon a user equipment (UE) entering a visited public land mobile network (VPLMN), the UE having a first protocol data unit (PDU) session that is associated with a first home public land mobile network (HPLMN) single network slice selection assistance information (S-NSSAI), determining whether the UE has a first VPLMN S-NSSAI applicable in the VPLMN corresponding to the first HPLMN S-NSSAI; and
in response to the UE not having the first VPLMN S-NSSAI applicable in the VPLMN corresponding to the first HPLMN S-NSSAI, transmitting a registration request message to the VPLMN, the registration request message including the first HPLMN S-NSSAI as a first mapped S-NSSAI for indicating a slice of the VPLMN to which the UE intends to register.
15. The non-transitory computer-readable medium of claim 14 , wherein for the first PDU session that is associated with the first HPLMN S-NSSAI, the UE is performing mobility from N1 mode to N1 mode from another VPLMN to the VPLMN, or from the HPLMN to the VPLMN.
16. The non-transitory computer-readable medium of claim 14 , wherein in response to the UE not having any S-NSSAI applicable in the VPLMN, a requested mapped NSSAI IE in the registration request message does not include any S-NSSAIs.
17. The non-transitory computer-readable medium of claim 14 , wherein in response to the UE has a second VPLMN S-NSSAI applicable in the VPLMN for a second PDU session that is associated with a second HPLMN S-NSSAI, the registration request message further includes a requested NSSAI IE that includes (1) the second VPLMN S-NSSAI applicable in the VPLMN for indicating a slice to which the UE intends to register for transferring the second PDU session, and (2) the second HPLMN S-NSSAI as a second mapped S-NSSAI corresponding to the second VPLMN S-NSSAI applicable in the VPLMN.