Method for determining transmission of CIOT user data in relation to S-NSSAI

1 . A method performed by a user equipment (UE) and comprising:

receiving a registration accept message including a validity time for at least one Single Network Slice Selection Assistance Information (S-NSSAI);

establishing at least one PDU (protocol data unit) session associated with the at least one S-NSSAI, when the at least one S-NSSAI is included in an Allowed NSSAI or in a Partially Allowed NSSAI; and

when the UE is outside a Network Slice Area of Service (NS-AoS) of the at least one S-NSSAI, initiating a UE-initiated Non-Access Stratum (NAS) transport procedure carrying one of a PDU session release request message and PDU session modification request message to set a Packet Switching (PS) data off status to “deactivated”, instead of initiating a UE-initiated NAS transport procedure for sending a Cellular Internet of Things (CIoT) user data as well as a service request procedure for sending the CIoT user data,

wherein when the at least one PDU session is established for the at least one S-NSSAI included in the partially allowed NSSAI and when a current tracking area identifier (TAI) is not in a list of tracking areas (TAs) for which the at least one S-NSSAI is allowed, the UE maintains contexts for the at least one established PDU session and initiates one of a UE-requested PDU session release procedure or a UE-requested PDU session modification procedure to set the PS data off status to “deactivated”, instead of initiating the UE-initiated NAS transport procedure for sending the CIoT user data as well as the service request procedure for sending the CIoT user data, and

wherein when the validity time indicates the at least one S-NSSAI is not available, and when the at least one S-NSSAI is already part of the Allowed NSSAI or Partially Allowed NSSAI, the UE removes the at least one S-NSSAI from a locally stored Allowed NSSAI or Partially Allowed NSSAI and the UE also locally releases any PDU sessions associated with the at least one S-NSSAI.

2 . The method of claim 1 , further comprising:

initiating the UE-initiated NAS transport procedure to send the CIoT user data or the service request procedure to send the CIoT user data, if the at least one PDU session is established for the at least one S-NSSAI included in the partially allowed NSSAI and if the current TAI is in the list of TAs for which the at least one S-NSSAI is allowed.

3 . The method of claim 1 , further comprising:

entering a deregistered state implicitly when the UE does not trigger a Mobility Registration Update procedure and when the Allowed NSSAI becomes empty after expiry of the validity time.

4 . The method of claim 2 , further comprising:

transmitting a registration request message including a requested NSSAI including the at least one S-NSSAI, when the validity time indicates the at least one S-NSSAI is available.

5 . The method of claim 2 , further comprising:

not including the at least one S-NSSAI in a requested NSSAI, when the validity time indicates the at least one S-NSSAI is not available.

6 . A user equipment (UE), the UE comprising:

at least one processor; and

at least one computer memory operably connectable to the at least one processor and storing instructions that, when executed by the at least one processor, perform operations comprising:

receiving a registration accept message including a validity time for at least one Single Network Slice Selection Assistance Information (S-NSSAI);

establishing at least one PDU (protocol data unit) session associated with the at least one S-NSSAI, when the at least one S-NSSAI is included in an Allowed NSSAI or in a Partially Allowed NSSAI; and

when the UE is outside a Network Slice Area of Service (NS-AoS) of the at least one S-NSSAI, initiating a UE-initiated Non-Access Stratum (NAS) transport procedure carrying one of a PDU session release request message and PDU session modification request message to set a Packet Switching (PS) data off status to “deactivated”, instead of initiating a UE-initiated NAS transport procedure for sending a Cellular Internet of Things (CIoT) user data as well as a service request procedure for sending the CIoT user data,

wherein when the at least one PDU session is established for the at least one S-NSSAI included in the partially allowed NSSAI and when a current tracking area identifier (TAI) is not in a list of tracking areas (TAs) for which the at least one S-NSSAI is allowed, the UE maintains contexts for the at least one established PDU session and initiates one of a UE-requested PDU session release procedure or a UE-requested PDU session modification procedure to set the PS data off status to “deactivated”, instead of initiating the UE-initiated NAS transport procedure for sending the CIoT user data as well as the service request procedure for sending the CIoT user data, and

wherein when the validity time indicates the at least one S-NSSAI is not available, and when the at least one S-NSSAI is already part of the Allowed NSSAI or Partially Allowed NSSAI, the UE removes the at least one S-NSSAI from a locally stored Allowed NSSAI or Partially Allowed NSSAI and the UE also locally releases any PDU sessions associated with the at least one S-NSSAI.

7 . The UE of claim 6 , wherein the operations may further comprise:

initiating the UE-initiated NAS transport procedure to send the CIoT user data or the service request procedure to send the CIoT user data, if the at least one PDU session is established for the at least one S-NSSAI included in the partially allowed NSSAI and if the current TAI is in the list of TAs for which the at least one S-NSSAI is allowed.

8 . The UE of claim 6 , wherein the operations may further comprise:

transmitting a registration request message including a requested NSSAI including the at least one S-NSSAI, when the validity time indicates the at least one S-NSSAI is available.

9 . The UE of claim 6 , wherein the operations may further comprise:

not including the at least one S-NSSAI in a requested NSSAI, when the validity time indicates the at least one S-NSSAI is not available.

10 . The UE of claim 6 , wherein the operations may further comprise:

entering a deregistered state implicitly when the UE does not trigger a Mobility Registration Update procedure and when the Allowed NSSAI becomes empty after expiry of the validity time.

11 . A semiconductor chipset equipped into a user equipment (UE), comprising:

at least one processor; and

at least one memory capable of storing instructions and being connected electrically to the at least one processor operably,

wherein an operation, performed when the instructions are executed by the at least one processor, includes:

receiving a registration accept message including a validity time for at least one Single Network Slice Selection Assistance Information (S-NSSAI);

establishing at least one PDU (protocol data unit) session associated with the at least one S-NSSAI, when the at least one S-NSSAI is included in an Allowed NSSAI or in a Partially Allowed NSSAI; and

when the UE is outside a Network Slice Area of Service (NS-AoS) of the at least one S-NSSAI, initiating a UE-initiated Non-Access Stratum (NAS) transport procedure carrying one of a PDU session release request message and PDU session modification request message to set a Packet Switching (PS) data off status to “deactivated”, instead of initiating a UE-initiated NAS transport procedure for sending a Cellular Internet of Things (CIoT) user data as well as a service request procedure for sending the CIoT user data,

wherein when the at least one PDU session is established for the at least one S-NSSAI included in the partially allowed NSSAI and when a current tracking area identifier (TAI) is not in a list of tracking areas (TAs) for which the at least one S-NSSAI is allowed, the at least one processor maintains contexts for the at least one established PDU session and initiates one of a UE-requested PDU session release procedure or a UE-requested PDU session modification procedure to set the PS data off status to “deactivated”, instead of initiating the UE-initiated NAS transport procedure for sending the CIoT user data nor the service request procedure for sending the CIoT user data, and

wherein when the validity time indicates the at least one S-NSSAI is not available, and when the at least one S-NSSAI is already part of the Allowed NSSAI or Partially Allowed NSSAI, the UE removes the at least one S-NSSAI from a locally stored Allowed NSSAI or Partially Allowed NSSAI and the UE also locally releases any PDU sessions associated with the at least one S-NSSAI.

12 . The semiconductor chipset of claim 11 , wherein the operation may further comprise:

initiating the UE-initiated NAS transport procedure to send the CIoT user data or the service request procedure to send the CIoT user data, if the at least one PDU session is established for the at least one S-NSSAI included in the partially allowed NSSAI and if the current TAI is in the list of TAs for which the at least one S-NSSAI is allowed.

13 . The semiconductor chipset of claim 11 , wherein the operation may further comprise:

transmitting a registration request message including a requested NSSAI including the at least one S-NSSAI, when the validity time indicates the at least one S-NSSAI is available.

14 . The semiconductor chipset of claim 11 , wherein the operation may further comprise:

not including the at least one S-NSSAI in a requested NSSAI, when the validity time indicates the at least one S-NSSAI is not available.

15 . The semiconductor chipset of claim 11 , wherein the operation may further comprise:

entering a deregistered state implicitly when the UE does not trigger a Mobility Registration Update procedure and when the Allowed NSSAI becomes empty after expiry of the validity time.