Method of AMF, method of UE, AMF and UE

Abstract

A method of handling for network slice specific authentication and authorization procedure by an access and mobility management function, AMF (800) is disclosed. In an embodiment, when the network encounters radio link failure before the ongoing generic UE configuration update procedure is completed, the network should restart the generic UE configuration update procedure. In another embodiment, when the N1 NAS signaling connection is established after the radio link failure, the network sends the configuration update command message containing the allowed NSSAI.

Description

Technical Field

[0001] This invention generally relates to wireless telecommunications, and in certain embodiments, to the processing of slice authentication and authorization processes. Background Technology

[0002] The serving PLMN should perform NSAA for S-NSSAIs subject to NSAA, such as those subject to NSAA based on subscription messages, during the registration process when the registration request message includes the requested NSAA that undergoes network slice-specific authentication and authorization (hereinafter referred to as "NSSAA"). The UE should indicate in the registration request message in the UE's 5GMM core network capabilities whether the UE supports the NSAA feature. If the UE does not support the NSAA feature, and if the UE requests any of these S-NSSAIs subject to NSAA, the AMF should not trigger an NSAA procedure for the UE, and these S-NSSAIs subject to the NSAA procedure will be rejected by the PLMN. To perform NSAA for the S-NSSAI, the AMF invokes an EAP-based NSAA procedure for the S-NSSAI. When the NSSAA process begins and is in progress for an S-NSSAI, the AMF stores the S-NSSAI's NSSAA status as pending. When the NSSAA process completes, the S-NSSAI either becomes part of the allowed NSSAIs or becomes a rejected S-NSSAI, depending on the outcome of the NSSAA process. The NSSAA status of each S-NSSAI (if any) is stored and transmitted when the AMF changes it. Figure 1 The example processing related to the NSSAA procedure is shown below.

[0003] Existing technical documents

[0004] Non-patent literature

[0005] Non-patent literature 1: 3GPP TR 21.905: "Vocabulary for 3GPP Specifications" V16.0.0 (2019-06)

[0006] Non-patent document 2: 3GPP TS23.501: "System architecture for the 5G System (5GS)" V16.5.1 (2020-08)

[0007] Non-patent document 3: 3GPP TS23.502: "Procedures for the 5G System (5GS)" V16.5.1 (2020-08)

[0008] Non-patent document 4: 3GPP TS24.501: "Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3". V16.5.1 (2020-07) Summary of the Invention

[0009] The problem the invention aims to solve

[0010] When a radio link failure occurs before the general UE configuration update process is completed, the S-NSSAI status in the UE and the S-NSSAI status on the network side may not match and be out of sync, which will result in the loss of S-NSSAI-related services for the user.

[0011] Solution for solving the problem

[0012] In a first aspect of the invention, a method for an Access and Mobility Management Function (AMF) is provided, the method comprising: sending a configuration update command message, wherein the configuration update command message includes allowed network slice selection assistance information, i.e., allowed NSSAI or denied NSSAI; starting a timer upon sending the configuration update command message; and retransmitting the configuration update command message upon the expiration of the timer if a radio link-related failure is detected before a configuration update completion message is received.

[0013] In a second aspect of the invention, a method for a user equipment (UE) is provided, the method comprising: communicating with an access and mobility management function (AMF); and initiating a registration process in the event of radio coverage loss and the UE having a single NSSAI in a pending network slice selection assistance information (NSSAI).

[0014] In a third aspect of the invention, an Access and Mobility Management Function (AMF) includes: components for sending a configuration update command message, wherein the configuration update command message includes allowed network slice selection assistance information, i.e., allowed NSSAI or denied NSSAI; components for starting a timer when the configuration update command message is sent; and components for retransmitting the configuration update command message when the timer expires if a radio link-related failure is detected before a configuration update completion message is received.

[0015] In a fourth aspect of the invention, a user equipment, i.e., a UE, includes: components for communicating with an access and mobility management function, i.e., an AMF; and components for initiating a registration process in the event of radio coverage loss and the UE having a single NSSAI in a pending network slice selection assistance information, i.e., a pending NSSAI. Attached Figure Description

[0016] Figure 1 This illustrates the traditional network slicing-specific authentication and authorization process.

[0017] Figure 2 This is a signaling diagram illustrating an embodiment of restarting the general UE configuration update process.

[0018] Figure 3 This is a signaling diagram illustrating an embodiment of sending a configuration update command (CONFIGURATION UPDATE COMMAND) message containing an allowed NSSAI when establishing an N1 NAS signaling connection after a wireless link failure.

[0019] Figure 4 This is a signaling diagram illustrating an embodiment of the PDU session establishment process.

[0020] Figure 5 This is a signaling diagram illustrating an embodiment of the UE registration process.

[0021] Figure 6 This is a schematic block diagram illustrating the UE.

[0022] Figure 7 This is a schematic block diagram illustrating a RAN node.

[0023] Figure 8 This is a schematic diagram illustrating the AMF. Detailed Implementation

[0024] This invention provides an improved system and method for processing slice authentication and authorization procedures. More specifically, this invention relates to a method for transmitting permitted NSSAI to a UE in weak radio coverage during a network-specific slice authentication and authorization process.

[0025] To further illustrate the advantages and features of the present invention, the invention will be described in more detail below with reference to specific embodiments shown in the accompanying drawings. It should be understood that these drawings depict only typical embodiments of the invention and should not be considered limiting in scope.

[0026] The present invention will be illustrated and explained with the aid of the accompanying drawings through additional uniqueness and detail.

[0027] Furthermore, those skilled in the art will understand that the elements in the accompanying drawings are shown for simplicity and may not necessarily be drawn to scale. Additionally, regarding the construction of the apparatus, one or more components may have been represented by conventional symbols in the drawings, and the drawings may only show specific details relevant to understanding embodiments of the invention, so as not to obscure the drawings with details that will readily become clear to those skilled in the art from the description herein.

[0028] For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments shown in the accompanying drawings, and these embodiments will be described using specific language. However, it will be understood that this is not intended to limit the scope of the invention. Such modifications and further alterations to the illustrated systems, as well as such further applications of the principles of the invention that would normally occur to those skilled in the art, will be construed as being within the scope of the invention.

[0029] The terms “comprises,” “comprising,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process or method comprising a series of steps does not include only those steps, but may include other steps not expressly listed or inherent to such process or method. Similarly, the prefix “comprises…a” does not exclude the presence of other devices, subsystems, elements, structures, components, additional devices, additional subsystems, additional elements, additional structures, or additional components, unless further constraints are imposed. The phrases “in an embodiment,” “in another embodiment,” and similar language appearing throughout this specification may, but not necessarily all, refer to the same embodiment.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The systems, methods, and examples provided herein are illustrative only and are not intended to be limiting.

[0031] In the appended specification and claims, numerous terms will be referenced, which should be defined as having the following meanings. Unless the context clearly specifies otherwise, the singular forms “a,” “an,” and “the” include plural references.

[0032] As used herein, information is associated with data and knowledge because data is meaningful information and represents values ​​attributed to parameters. Further knowledge implies an understanding of abstract or concrete concepts. Note that this example system is simplified for the purpose of describing the disclosed subject matter and is not intended to limit the scope of the invention. The embodiments disclosed herein may be implemented using other means, systems, and configurations besides or instead of the system, and all such embodiments are considered to be within the scope of the invention.

[0033] Example 1 of the problem statement:

[0034] When the network receives an S-NSSAI that has undergone NSSAA from a requested NSSAI during a NAS procedure (e.g., a registration procedure), the network will perform an NSSAA procedure. After performing the NSSAA procedure, the network will transmit the result of the NSSAA procedure for the S-NSSAI to the UE. If the NSSAA procedure is successful, the network will place the S-NSSAI in the allowed NSSAIs; otherwise, it will place the S-NSSAI in the rejected NSSAIs. The AMF then initiates a general UE configuration update procedure to transmit at least one of the allowed and rejected NSSAIs (a new allowed NSSAI or a rejected NSSAI, or both) to the UE in a configuration update command message. If a radio link failure occurs before the general UE configuration update procedure is completed, the UE may be unable to receive the allowed NSSAI from the network. Therefore, the status of the S-NSSAI in the UE and the status of the S-NSSAI on the network side may not match and be out of sync, which will result in the loss of services related to the S-NSSAI for the user.

[0035] Example 2 of the problem statement:

[0036] When the network receives an NSSAI subject to NSSAA from a requested NSSAI during a NAS procedure (e.g., a registration procedure), the network performs an NSSAA procedure. After performing the NSSAA procedure, the network transmits the result of the NSSAA procedure for the S-NSSAI to the UE. If the NSSAA procedure is successful, the network places the S-NSSAI in the allowed NSSAIs; otherwise, it places the S-NSSAI in the rejected NSSAIs. The network maintains the new allowed NSSAIs and the old allowed NSSAIs and initiates a general UE configuration update procedure to transmit at least one of the new allowed NSSAIs and rejected NSSAIs (either a new allowed NSSAI or a rejected NSSAI, or both) to the UE in a configuration update command message. Upon receiving a CONFIGURATION UPDATE COMPLETE message from the UE, the network deletes the old allowed NSSAIs and maintains the new allowed NSSAIs. The difference between the new and old permitted NSSAIs lies in whether or not they include S-NSSAIs subject to NSSAA. That is, the new permitted NSSAIs include at least one S-NSSAI that contains an NSSAA-subjected S-NSSAI. The old permitted NSSAIs included at least one S-NSSAI, but did not include any NSSAA-subjected S-NSSAIs.

[0037] When a radio link failure occurs before the general UE configuration update process is completed, the network will abort the general UE configuration update process. In this case, if the network does not receive a configuration update completion message from the UE, the network maintains two lists of allowed NSSAIs: the new allowed NSSAIs and the old allowed NSSAIs. When the network receives a 5G session management message (e.g., a PDU session establishment request message) containing S-NSSAIs from the new allowed NSSAIs, the network behavior is unclear as to whether the network will execute the PDU session establishment process or reject it.

[0038] This invention describes a solution to the problem of S-NSSAI condition mismatch between the UE and the network. The mismatch may occur due to radio link failure or any other reason.

[0039] All procedures disclosed in each embodiment can be applied to S-NSSAI status management between the UE and the network for 3GPP access and non-3GPP access. All procedures disclosed in each embodiment can be applied to PLMN and S-NSSAI status management between the UE and the network for standalone non-public networks and public network integrated NPNs as described in sections 5.30.2 and 5.30.3 of 3GPP TS23.501[2].

[0040] In some embodiments, a general UE configuration update procedure is disclosed that occurs after the AMF detects a radio link failure. For example, in Embodiment 2... Figure 3 Steps 8 and 9 in the above steps. If a registration process occurs after a radio link failure, the registration process can take over the operations intended by the general UE configuration update process. The registration process can be an initial registration process, a registration process due to mobility, or a periodic registration process. For example, the allowed NSSAI to be sent in the configuration update command message is sent in the registration acceptance message. In this case, the following message name substitutions apply to all embodiments.

[0041] (1) The configuration update command message is replaced by the registration acceptance message.

[0042] (2) The configuration update complete message is replaced by the registration complete message.

[0043] First example implementation (Solution 1):

[0044] like Figure 2 As shown, if the network encounters a radio link failure before the ongoing general UE configuration update process is completed, the network should restart the general UE configuration update process.

[0045] The following details the solution.

[0046] 1. The UE sends a registration request message to the AMF containing the requested NSSAI (which includes at least one S-NSSAI).

[0047] 2. When the AMF receives a registration request message from the UE, the AMF determines whether the S-NSSAI included in the requested NSSAI is subject to NSSAA by referring to the UE's subscriber data obtained from the UDM using the Nudm_SDM_Get service.

[0048] If S-NSSAI undergoes an NSSAA process, the AMF will mark S-NSSAI as suspended.

[0049] 3. The AMF sends a registration acceptance message to the UE containing the pending NSSAI, including S-NSSAI.

[0050] 4. As described in Section 4.2.9 of 3GPP TS23.502[3], the AMF initiates the NSSAA procedure for S-NSSAI. Step 4 refers only to EAP-based network slice-specific authentication and authorization for S-NSSAI. Step 5 and thereafter describe the UE configuration update procedure that can be performed after EAP-based network slice-specific authentication and authorization.

[0051] 5. After the NSSAA procedure for S-NSSAI is successfully completed, the AMF initiates a general UE configuration update procedure by sending a configuration update command message containing the allowed NSSAI, including S-NSSAI. The AMF starts a retry timer (e.g., T3555) simultaneously with or after sending the configuration update command message.

[0052] When the NSSAA procedure fails and the AMF sends a configuration update command message containing a rejected NSSAI, including an S-NSSAI, the AMF also starts a retry timer. That is, the reason for starting the retry timer is the transmission of the configuration update command message. The allowed NSSAIs are a list of at least one of the S-NSSAIs. The rejected NSSAIs are a list of at least one of the S-NSSAIs.

[0053] 6. When the AMF detects a radio link failure (e.g., the NG-RAN indicates to the AMF via an NGAP message that the UE radio contact has been lost), the AMF does not suspend the general UE configuration update process; that is, the AMF continues to run the retry timer.

[0054] 7. When the retry timer expires, the AMF retransmits a configuration update command message containing either an allowed NSSAI (including S-NSSAI) or a rejected NSSAI (including S-NSSAI).

[0055] 8. When the UE receives the configuration update command message, the UE updates the status of S-NSSAI and transmits the configuration update complete message to the AMF.

[0056] 9. When the AMF receives the configuration update complete message from the UE, if the configuration update command message in step 7 contains S-NSSAI in the allowed NSSAIs, the AMF updates the S-NSSAI status to valid and updates the S-NSSAI status to allowed S-NSSAI. That is, S-NSSAI becomes part of the allowed NSSAIs.

[0057] If the configuration update command message in step 7 contains an S-NSSAI within a rejected NSSAI, the AMF updates the status of the S-NSSAI to that of a rejected S-NSSAI. In other words, the S-NSSAI becomes part of a rejected NSSAI. The AMF can maintain information associated with the rejected S-NSSAI because that S-NSSAI failed to pass NSSAA.

[0058] Variations of Solution 1:

[0059] In this embodiment, the AMF includes the 5G-GUTI (e.g., the new 5G-GUTI or the current 5G-GUTI) along with the allowed NSSAI or rejected NSSAI in the configuration update command message in steps 5 and 7. When a radio link failure is detected in step 6, the AMF continues to run a retry timer. When the retry timer expires, the AMF retransmits the configuration update command message.

[0060] In the embodiments, the above embodiments are also applicable to situations where, during the general UE configuration update process, the configuration update command message contains other information elements (e.g., configured NSSAI, allowed CAG information).

[0061] Second example implementation (Solution 2):

[0062] like Figure 3 As shown, when an N1 NAS signaling connection is established after a wireless link failure, the network sends a configuration update command message containing an authorized NSSAI.

[0063] The following details the solution.

[0064] 1. The UE sends a registration request message to the AMF containing the requested NSSAI (which includes at least one S-NSSAI).

[0065] 2. When the AMF receives a registration request message from the UE, the AMF determines whether the S-NSSAI included in the requested NSSAI has undergone NSSAA proceedings by referring to the UE's subscriber data obtained from the UDM using the Nudm_SDM_Get service. If the S-NSSAI has undergone NSSAA proceedings, the AMF marks the S-NSSAI as pending.

[0066] 3. The AMF sends a registration acceptance message to the UE containing the pending NSSAI, including S-NSSAI.

[0067] 4. As described in Section 4.2.9 of 3GPP TS23.502[3], the AMF initiates the NSSAA procedure for S-NSSAI. This step 4 refers only to EAP-based network slice-specific authentication and authorization for S-NSSAI. The UE configuration update procedure that can be performed after EAP-based network slice-specific authentication and authorization is described in step 5 and thereafter.

[0068] 5. After the NSSAA procedure for S-NSSAI is successfully completed, the AMF initiates a general UE configuration update procedure by sending a configuration update command message containing the allowed NSSAI, including S-NSSAI. The AMF may start a retry timer (e.g., T3555) simultaneously with or after sending the configuration update command message.

[0069] The AMF may also start a retry timer when the NSSAA process fails and the AMF sends a configuration update command message containing an NSSAI of rejection, including S-NSSAI. In other words, the reason for starting the retry timer is the transmission of the configuration update command message.

[0070] 6. When the AMF detects a radio link failure (e.g., the NG-RAN indicates to the AMF via an NGAP message that the UE has lost radio contact), the AMF aborts the general UE configuration update process, and the retry timer is stopped if it is running.

[0071] The AMF sets the UE status "Requires UCU (UE Configuration Update)" along with the message content of the configuration update command message sent in step 5 in the UE MM context or local memory within the AMF. The UE status "Requires UCU" means that a general UE configuration update process is required for the UE because the S-NSSAI status between the UE and the network may not match.

[0072] Alternatively, the AMF will set the "out-of-sync" S-NSSAI status in the UE MM context or local memory within the AMF. "Out-of-sync" S-NSSAI status means that a general UE configuration update process is required for that S-NSSAI because the S-NSSAI status between the UE and the network may not match.

[0073] For example, the AMF maintains or stores information indicating at least one of the following conditions: a UE condition requiring UCU and an S-NSSAI condition indicating "out of sync".

[0074] If an AMF relocation is performed while the AMF is maintaining at least one of the UE conditions “requires UCU” and S-NSSAI conditions “out of sync”, then as described in Section 5.2.2.2.2 of 3GPP TS23.502[3], the Namf_Communication_UEContextTransfer service is required to transfer at least one of the UE conditions “requires UCU” (along with associated information) and S-NSSAI conditions “out of sync” from the old AMF to the new AMF.

[0075] 7. Establish a new N1 NAS signaling connection with the UE. For example, when the UE returns to 3GPP coverage and sends a registration request message to the AMF. A new N1 NAS signaling connection is established through a registration process that includes sending the registration request message.

[0076] 8. If the AMF manages (or stores) a UE state as "requires UCU" or an S-NSSAI state as "out of sync," the AMF retransmits a configuration update command message containing either an allowed NSSAI (including S-NSSAI) or a rejected NSSAI (including S-NSSAI). When the UE receives the configuration update command message, the UE updates the S-NSSAI state.

[0077] 9. The UE sends a configuration update complete message to the AMF.

[0078] 10. When the AMF receives the configuration update complete message from the UE, if the configuration update command message in step 8 contains S-NSSAI in the allowed NSSAIs, the AMF updates the S-NSSAI status to valid and updates the S-NSSAI status to allowed S-NSSAIs. That is, S-NSSAI becomes part of the allowed NSSAIs.

[0079] If the configuration update command message in step 8 contains a rejected NSSAI, the AMF updates the status of the S-NSSAI to a rejected S-NSSAI. That is, the S-NSSAI becomes part of a rejected NSSAI. The AMF can maintain information associated with the rejected S-NSSAI because that S-NSSAI failed to pass the NSSAA.

[0080] Variations of Solution 2:

[0081] In this embodiment, when a new N1 NAS signaling connection is established with the UE in step 7 and the AMF maintains the S-NSSAI status as "out of sync," the AMF can initiate an NSSAA procedure for the S-NSSAI. Then, if the NSSAA procedure completes successfully, the AMF uses the general UE configuration update procedure to transmit the allowed NSSAI, including the S-NSSAI, to the UE. After the NSSAA procedure completes successfully, the AMF can delete or reset the UE status "requires UCU" or the S-NSSAI status "out of sync."

[0082] In another embodiment, if the AMF receives a registration request message as a new N1NAS signaling connection in step 7 and maintains the S-NSSAI status as "out of sync," instead of initiating a general UE configuration update procedure, the AMF may send a registration acceptance message to the UE containing an allowed NSSAI, including the S-NSSAI. The AMF should maintain the new allowed NSSAI marked as invalid and the old allowed NSSAI marked as valid, or only maintain the new allowed NSSAI. When the UE receives a registration acceptance message with "allowed NSSAI," the UE should send a registration completion message to confirm receipt of the latest allowed NSSAI. When the AMF receives the registration completion message, the AMF should mark the new allowed NSSAI as valid and the old allowed NSSAI as invalid.

[0083] Third example implementation (Solution 3):

[0084] like Figure 4 As shown, when the AMF receives a request to activate a PDU session containing a new allowed NSSAI in the S-NSSAI, the AMF should allow the PDU session establishment process.

[0085] The following details the solution.

[0086] 1. The UE sends a registration request message to the AMF containing the requested NSSAI, which includes at least one S-NSSAI.

[0087] 2. When the AMF receives a registration request message from the UE, the AMF determines whether the S-NSSAI included in the requested NSSAI is subject to NSSAA by referring to the UE's subscriber data obtained from the UDM using the Nudm_SDM_Get service.

[0088] If S-NSSAI undergoes an NSSAA process, the AMF will mark S-NSSAI as suspended.

[0089] 3. The AMF sends a registration acceptance message to the UE containing the pending NSSAI, including S-NSSAI.

[0090] 4. As described in Section 4.2.9 of 3GPP TS23.502[3], the AMF initiates the NSSAA procedure for S-NSSAI. This step 4 refers only to EAP-based network slice-specific authentication and authorization for S-NSSAI. The UE configuration update procedure that can be performed after EAP-based network slice-specific authentication and authorization is described in step 5 and thereafter.

[0091] 5. After the NSSAA procedure for the S-NSSAI is successfully completed, the AMF initiates a general UE configuration update procedure by sending a configuration update command message containing a new allowed NSSAI, including the S-NSSAI. The AMF may start a retry timer (e.g., T3555) simultaneously with or after sending the configuration update command message. The AMF maintains (or stores) both the new allowed NSSAI and the old allowed NSSAI. The old allowed NSSAI does not include the S-NSSAI that underwent the NSSAA procedure in step 4.

[0092] The AMF may also start a retry timer when the NSSAA process fails and the AMF sends a configuration update command message containing an NSSAI of rejection, including S-NSSAI. In other words, the reason for starting the retry timer is the transmission of the configuration update command message.

[0093] 6. The UE updates the status of allowed or denied NSSAIs based on the content of the configuration update command message. If the configuration update command message includes S-NSSAIs among the allowed NSSAIs, the UE interprets the configuration update command message as indicating that S-NSSAIs are available.

[0094] 7. The UE sends a configuration update complete message to the AMF. However, due to a radio link failure, this message cannot reach the AMF.

[0095] 8. When the AMF detects a radio link failure (e.g., the NG-RAN indicates to the AMF via an NGAP message that the UE has lost radio contact), the AMF aborts the general UE configuration update process, and the retry timer is stopped if it is running.

[0096] 9. The UE sends a UL NAS TRANSPORT message to the AMF to establish a PDU session. The UL NAS TRANSPORT message includes an S-NSSAI and a payload container, which contains a PDU SESSIONESTABLISHMENT REQUEST message.

[0097] 10. The AMF receives the UL NAS transport message. The AMF verifies or determines whether the S-NSSAI included in the UL NAS transport message exists in the new allowed NSSAI. If the S-NSSAI exists in the new allowed NSSAI, then as described in 4.3.2 of 3GPP TS23.502[3], the AMF allows the establishment of a PDU session and transmits the PDU session establishment request message to the SMF, and continues the PDU session establishment process.

[0098] The AMF marks (or stores or maintains) the new allowed NSSAI as valid and deletes the old allowed NSSAI. The AMF can forward the new allowed NSSAI to the NG-RAN in an NGAP message. The AMF can also forward the new allowed NSSAI to the SMF.

[0099] In one example, if the S-NSSAI exists in the new allowed NSSAIs but not in the old allowed NSSAIs in the AMF, the AMF understands that the UE has received the latest configuration update command message, and makes the new allowed NSSAIs valid and deletes the old allowed NSSAIs. From this point on, the AMF only maintains the new allowed NSSAIs.

[0100] In one example, the UE determines whether S-NSSAI exists in the new list of allowed NSSAIs or the old list of NSSAIs, or both. The AMF treats S-NSSAI as allowed and transmits the PDU session establishment request message to the SMF.

[0101] Fourth example implementation (Solution 4):

[0102] like Figure 5 As shown, when the AMF receives a request to activate a PDU session containing an S-NSSAI that is not in the old list of allowed NSSAIs, the AMF rejects the PDU session establishment procedure. After this, the UE initiates the registration procedure by sending a registration request message containing the requested S-NSSAI from the NSSAI list.

[0103] The following details the solution.

[0104] 1. The UE sends a registration request message to the AMF containing the requested NSSAI, which includes at least one S-NSSAI.

[0105] 2. When the AMF receives a registration request message from the UE, the AMF determines whether the S-NSSAI included in the requested NSSAI has undergone NSSAA proceedings by referring to the UE's subscriber data obtained from the UDM using the Nudm_SDM_Get service. If the S-NSSAI has undergone NSSAA proceedings, the AMF marks the S-NSSAI as pending.

[0106] 3. The AMF sends a registration acceptance message to the UE containing the pending NSSAI, including S-NSSAI.

[0107] 4. As described in Section 4.2.9 of 3GPP TS23.502[3], the AMF initiates the NSSAA procedure for S-NSSAI. This step 4 refers only to EAP-based network slice-specific authentication and authorization for S-NSSAI. The UE configuration update procedure that can be performed after EAP-based network slice-specific authentication and authorization is described in step 5 and thereafter.

[0108] 5. After the NSSAA procedure for S-NSSAI is successfully completed, the AMF initiates a general UE configuration update procedure by sending a configuration update command message containing the new allowed NSSAI, including S-NSSAI. The AMF may start a retry timer (e.g., T3555) simultaneously with or after sending the configuration update command message. The AMF maintains both the new and old allowed NSSAIs.

[0109] The AMF may also start a retry timer when the NSSAA process fails and the AMF sends a configuration update command message containing an NSSAI of rejection, including S-NSSAI. In other words, the reason for starting the retry timer is the transmission of the configuration update command message.

[0110] 6. The UE updates the status of allowed or denied NSSAIs based on the content of the configuration update command message. If the configuration update command message includes S-NSSAIs among the allowed NSSAIs, the UE interprets the configuration update command message as indicating that S-NSSAIs are available.

[0111] 7. The UE sends a configuration update complete message to the AMF. However, due to a radio link failure, this message cannot reach the AMF.

[0112] 8. When the AMF detects a radio link failure (e.g., the NG-RAN indicates to the AMF via an NGAP message that the UE has lost radio contact), the AMF aborts the general UE configuration update process, and the retry timer is stopped if it is running.

[0113] 9. The UE sends a UL NAS transport message to the AMF to establish a PDU session. The UL NAS transport message includes an S-NSSAI and a payload container, which contains a PDU session establishment request message.

[0114] 10. When the AMF receives an uplink (UL) NAS transport message containing S-NSSAI, and the S-NSSAI included in the UL NAS transport message in the AMF does not exist in the old allowed NSSAIs, the AMF rejects the UL NAS transport message. In other words, the AMF rejects the establishment of the PDU session.

[0115] 11. The AMF sends a Downlink (DL) NAS Transport message to the UE, indicating that the Uplink (UL) NAS Transport message in step 10 was rejected by the AMF. This message may contain a new 5G MM reason: "Incompatible S-NSSAI", or "Re-registration required due to incompatible S-NSSAI", or "Network-specific slice authentication and authorization process required", or any other reason value that indicates to the UE that the S-NSSAI status between the UE and the network may be mismatched, and therefore a registration process should be performed to synchronize. When the UE receives the Downlink (DL) NAS Transport message, the UE removes the S-NSSAI from the allowed NSSAIs in the UE.

[0116] 12. Based on the information in the downlink (DL) NAS transmission message, the UE can initiate the registration process by sending a registration request message that includes the requested NSSAI, which may include S-NSSAI.

[0117] If the AMF determines that the S-NSSAI in the requested NSSAI will be included in the new allowed NSSAI in the registration acceptance message, the AMF sends a registration acceptance message to the UE containing the new 5G-GUTI and the new allowed NSSAI, which includes the S-NSSAI.

[0118] If the S-NSSAI in the requested NSSAI undergoes an NSSAA process, and the AMF decides to perform an NSSAA process for the S-NSSAI, then the UE and network perform an NSSAA process for the S-NSSAI and a general UE configuration update process. After the NSSAA process and the general UE configuration update process are completed, followed by the registration process, the allowed NSSAI status is synchronized between the UE and the network, and the AMF makes the new allowed NSSAI valid and invalidates the old allowed NSSAI, and uses the new allowed NSSAI in subsequent NAS processes or any other processes.

[0119] The following bullet points illustrate some examples of details related to the permitted NSSAI status synchronization between the UE and the network.

[0120] (1) After receiving a registration acceptance message containing a new allowed NSSAI including S-NSSAI in response to a registration request message, the UE makes the new allowed NSSAI valid and invalidates the old allowed NSSAI.

[0121] (2) After the UE sends a registration completion message to the AMF in response to the registration acceptance message, it makes the new allowed NSSAI valid and invalidates the old allowed NSSAI.

[0122] (3) After receiving a registration completion message in response to a registration acceptance message containing a new allowed NSSAI including S-NSSAI, AMF makes the new allowed NSSAI valid and invalidates the old allowed NSSAI.

[0123] (4) After receiving a configuration update command message containing a new allowed NSSAI including S-NSSAI, the UE makes the new allowed NSSAI valid and invalidates the old allowed NSSAI.

[0124] (5) After the UE sends a configuration update complete message to the AMF in response to the configuration update command message, it makes the new allowed NSSAI valid and invalidates the old allowed NSSAI.

[0125] (6) After receiving a configuration update completion message in response to a configuration update command message containing a new allowed NSSAI including S-NSSAI, AMF makes the new allowed NSSAI valid and invalidates the old allowed NSSAI.

[0126] In another embodiment, when the UE performs the registration process after receiving the DL NAS transmission message from the AMF, if the previous NSSAA process in step 4 was successful, the AMF can notify the UE of the S-NSSAI in the allowed NSSAI, instead of placing the S-NSSAI in the pending NSSAI.

[0127] Similar to the above embodiments, when the UE performs the registration process after receiving the DL NAS transmission message from the AMF, if the previous NSSAA process in step 4 fails to authenticate and authorize the use of S-NSSAI, the AMF can notify the UE of the rejected S-NSSAI instead of placing the S-NSSAI in the pending NSSAI.

[0128] In the embodiment of step 5, the AMF may include the 5G-GUTI in the configuration update command. If the network receives the 5G-GUTI sent in the configuration update command message in a NAS message (e.g., a service request message), the AMF makes the new allowed NSSAI valid and removes the old allowed NSSAI. The AMF will then begin using the new allowed NSSAI in subsequent NAS procedures or other UE-related procedures.

[0129] Variations of Solution 4:

[0130] When the AMF receives a UL NAS transmission message in step 9 and discovers a potential mismatch between the UE and the network related to the S-NSSAI status, the AMF may initiate an NSSAA procedure for the S-NSSAI indicated in the UL NAS transmission message in step 9. Alternatively, the AMF may initiate an NSSAA procedure for all pending S-NSSAIs or for all S-NSSAIs in the context of the UE's MM within the AMF.

[0131] Following the NSSAA procedure, the UE sends a PDU session establishment request message containing the S-NSSAI that has been successfully authenticated and authorized for use.

[0132] Variations of the embodiments:

[0133] If the UE moves to a 5GMM-IDLE state before, during, or after the NSSAA procedure (step 4), or during the UE configuration update procedure (steps 5 through 8) (e.g., the N1 signaling connection is released due to radio link failure, the RRC connection is released by the NG-RAN, or radio coverage is lost), the UE can initiate a registration procedure, a service request procedure, or any other NAS procedure to establish an N1 NAS signaling connection, allowing the AMF to take appropriate action to complete the NSSAA procedure. The following bullet points illustrate the actions the AMF will take in each period when the UE moves to the 5GMM-IDLE state.

[0134] (1) Time period 1: The UE receives the registration acceptance message in step 3, but has not yet initiated the NSAA procedure in step 4.

[0135] (1-1) When an N1 NAS signaling connection is established during time period 1, the AMF will initiate an NSSAA procedure for all S-NSSAIs in the pending NSSAI.

[0136] (2) Time period 2: During the NSSAA process in step 4.

[0137] (2-1) When an N1 NAS signaling connection is established during time period 2, the AMF shall take the following actions: The AMF shall initiate an NSAA procedure for all S-NSSAIs in the suspended NSSAIs, or the AMF shall initiate an NSAA procedure only for the S-NSSAIs in the suspended NSSAIs that have not yet undergone the NSAA procedure.

[0138] (3) Time period 3: After the NSAA process in step 4 is completed, but the general UE configuration update process has not yet been completed.

[0139] (3-1) When an N1 NAS signaling connection is established during time period 3, the AMF shall take the following action: The AMF shall initiate a general UE configuration update process.

[0140] Based on the variation of solution 2 Figure 3 The above treatment applies when the NSAA procedure is performed after step 7. Figure 3 The NSAA process following step 7.

[0141] The invention may be described as shown in Section 5.4.4.6.

[0142] 5.4.4.6 Network-side anomalies

[0143] The following anomalies can be identified:

[0144] a) Timer T3555 expired.

[0145] The network should retransmit the configuration update command message when timer T3555 expires for the first time, and should reset and start timer T3555. This retransmission is repeated four times, and the process should be terminated when timer T3555 expires for the fifth time. Additionally, if the configuration update command message includes 5G-GUTI IE, the network should behave as described in cases b)-1) below.

[0146] b) Lower layer failed.

[0147] If a lower-level failure is detected before the configuration update completion message is received, and:

[0148] 1) If the configuration update command message includes a 5G-GUTI IE, both the old and new 5G-GUTIs should be considered valid until the old 5G-GUTI can be considered invalid by the AMF. If a new TAI list is provided in the configuration update command message, both the old and new TAI lists should also be considered valid until the old TAI list can be considered invalid by the AMF.

[0149] During this period, AMF:

[0150] i) Initially, the old 5G-S-TMSI from the old 5G-GUTI can be used to perform the paging attempt related to the network-originating transaction within the area defined by the old TAI list. If a new TAI list is provided in the configuration update command message, this new TAI list should also be used for paging. Based on the response from the UE, the AMF can re-initiate the configuration update command. If a response is received from the tracking area within both the old and new TAI lists, the network should re-initiate the configuration update command message. If no response is received for the paging attempt, the network can use the new 5G-S-TMSI from the new 5G-GUTI to perform the paging attempt related to the transaction. In this case, if the new TAI list and the new 5G-GUTI are provided together in the configuration update command message, the new TAI list should be used instead of the old TAI list. Based on the response from the UE, the AMF should treat the new 5G-GUTI as valid and the old 5G-GUTI as invalid.

[0151] ii) The new 5G-GUTI should be considered valid if it is used by the UE, and additionally, the new TAI list should be considered valid if it is provided together with the new TAI list in the configuration update command message; and

[0152] iii) If the UE is using an older 5G-GUTI, an identification process can be used, followed by a new universal UE configuration update process; or

[0153] 2) If the configuration update command message contains an allowed NSSAI IE, the AMF shall treat the new allowed NSSAI IE as valid. When the AMF receives a UL NAS transport message containing an S-NSSAI present in the new allowed NSSAI, the AMF shall treat the S-NSSAI as allowed and take the action specified in sub-clause 5.4.5.3. If the configuration update command message does not contain a 5G-GUTI IE and an allowed NSSAI IE, the network shall abort the process.

[0154] c) Conflict between general UE configuration update and UE-initiated deregistration process.

[0155] If the network receives a deregistration request message before the ongoing general UE configuration update process is completed, the network should abort the general UE configuration update process and allow the deregistration process to proceed.

[0156] d) Conflicts between general UE configuration updates and mobility-specific registration processes, as well as periodic registration updates.

[0157] If the network receives a registration request message before the ongoing general UE configuration update process is completed, the network should suspend the general UE configuration update process and allow the mobility-specific registration process and the periodic registration update process to proceed.

[0158] e) Conflict between general UE configuration update and service request process

[0159] If the network receives a service request message before the ongoing general UE configuration update process is completed, both processes should proceed.

[0160] Figure 6 This is a block diagram showing the main components of the UE (600). As shown, the UE (600) includes transceiver circuitry (602) operable to transmit signals to and receive signals from connected (one or more) nodes via one or more antennas (601). Although not necessarily in Figure 6 As shown, the UE will of course have all the common functions of a traditional mobile device (such as a user interface), and this can be provided appropriately by any one or any combination of hardware, software, and firmware. For example, software may be pre-installed in memory and / or can be downloaded via a telecommunications network or from a removable data storage device (RMD).

[0161] The controller (604) controls the operation of the UE based on software stored in the memory (605). This software includes an operating system and a communication control module, which at least has a transceiver control module. The communication control module (using its transceiver control submodule) is responsible for processing (generating / transmitting / receiving) signaling and uplink / downlink data packets between the UE and other nodes (such as base stations / (R)AN nodes, MME, AMF (and other core network nodes)). Such signaling may include, for example, appropriately formatted signaling messages related to connection establishment and maintenance (e.g., RRC connection establishment and other RRC messages), periodic location update-related messages (e.g., tracking area update, paging area update, location area update), etc. Such signaling may also include, for example, broadcast information in the reception situation (e.g., master information and system information).

[0162] Figure 7 This is a block diagram illustrating the main components of an exemplary (R)AN node (700) (e.g., a base station ("eNB" in LTE, "gNB" in 5G)). As shown, the (R)AN node includes transceiver circuitry (702) operable to transmit and receive signals from connected (one or more) UEs via one or more antennas (701), and to transmit and receive signals from other network nodes (directly or indirectly) via a network interface (703). A controller (704) controls the operation of the (R)AN node based on software stored in a memory (705). For example, the software may be pre-installed in the memory and / or downloadable via a telecommunications network or from a removable data storage device (RMD). The software includes an operating system and a communication control module, including at least a transceiver control module.

[0163] The communication control module (using its transceiver control submodule) is responsible for (e.g., directly or indirectly) processing (generating / transmitting / receiving) signaling between the (R)AN node and other nodes (such as the UE, MME, AMF, etc.). Signaling may include, for example, appropriately formatted signaling messages related to (for a specific UE) radio connection and positioning procedures, and particularly to connection establishment and maintenance (e.g., RRC connection establishment and other RRC messages), periodic location update-related messages (e.g., tracking area update, paging area update, location area update), S1 AP messages, and NG AP messages (i.e., messages via the N2 reference point), etc. Such signaling may also include, for example, broadcast information in transmission situations (e.g., master information and system information).

[0164] The controller (704) is also configured (by software or hardware) to handle related tasks, such as UE mobility estimation and / or movement trajectory estimation when implemented.

[0165] Figure 8 This is a block diagram showing the main components of the AMF (800). The AMF (800) is included in the 5GC. As shown, the AMF (800) includes transceiver circuitry (801) operable to transmit signals to and receive signals from other nodes (including the UE) via a network interface (804). A controller (802) controls the operation of the AMF (800) based on software stored in a memory (803). For example, the software may be pre-installed in the memory (803) and / or may be downloaded via a telecommunications network or from a removable data storage device (RMD). This software includes an operating system and a communication control module, at least including a transceiver control module.

[0166] The communication control module (using its transceiver control submodule) is responsible for (directly or indirectly) processing (generating / sending / receiving) signaling between the AMF and other nodes (such as the UE, base station / (R)AN node (e.g., "gNB" or "eNB")). Such signaling may include, for example, appropriately formatted signaling messages related to the procedures described herein, such as NG AP messages (i.e., messages via the N2 reference point) for transmitting NAS messages from the UE and to the UE.

[0167] In this invention, a user equipment (or “UE”, “mobile station”, “mobile device”, or “wireless device”) is an entity connected to a network via a wireless interface. It should be noted that the UE in this specification is not limited to dedicated communication devices, and as explained in the following paragraphs, can be applied to any device having the communication functions of a UE as described in this specification.

[0168] The terms “User Equipment” or “UE” (as used by 3GPP), “Mobile Station,” “Mobile Device,” and “Radio Device” are generally intended to be synonymous with each other and include standalone mobile stations such as terminals, mobile phones, smartphones, tablets, cellular IoT devices, IoT devices, and machines. It should be understood that the terms “UE” and “Radio Device” also encompass devices that remain stationary for extended periods of time.

[0169] UE can be, for example, a transport device (e.g., transport devices such as: rolling stock; motorized vehicles; motorcycles; bicycles; trains; buses; trolleys; rickshaws; ships and other water transport vehicles; airplanes; rockets; satellites; drones; balloons; etc.). UE can also be, for example, an information and communication device (e.g., information and communication devices such as: electronic computers and related equipment; communication and related equipment; electronic components; etc.).

[0170] UE can be, for example, a refrigeration unit, a refrigeration unit application product, a trade and / or service industry equipment, a vending machine, an automated service machine, office machinery or equipment, consumer electronics and electronic equipment (e.g., consumer electronic equipment such as: audio equipment; video equipment; speakers; radios; televisions; microwave ovens; rice cookers; coffee machines; dishwashers; washing machines; dryers; electric fans or related equipment; vacuum cleaners; etc.).

[0171] UE can be, for example, an electrical application system or device (e.g., electrical application systems or devices such as: x-ray systems; particle accelerators; radioisotope devices; acoustic devices; electromagnetic application devices; electronic power application devices; etc.).

[0172] UE can be, for example, a personal digital assistant or related device of a wireless equipment (such as a wireless card or module designed to be attached to or inserted into another electronic device (e.g., a personal computer, an electrical measuring machine).

[0173] The UE can be part of a device or system that uses various wired and / or wireless communication technologies to provide applications, services, and solutions related to the “Internet of Things (IoT)” described below. IoT devices (or “things”) can be equipped with suitable electronics, software, sensors, network connectivity, and / or the like, enabling these devices to collect and exchange data with each other and with other communicating devices. IoT devices can include automated equipment that follows software instructions stored in internal memory. IoT devices can operate without human supervision or interaction. IoT devices can also remain stationary and / or inactive for extended periods. IoT devices can be implemented as part of (typically) stationary devices. IoT devices can also be embedded in non-stationary devices (e.g., vehicles) or attached to animals or people to be monitored / tracked.

[0174] It should be understood that IoT technology can be implemented on any communication device that can connect to a communication network used for sending / receiving data, regardless of whether such communication device is controlled by human input or by software instructions stored in memory.

[0175] It should be understood that IoT devices are sometimes also referred to as machine-type communication (MTC) devices, machine-to-machine (M2M) communication devices, or narrowband IoT UEs (NB-IoT UEs). It should be understood that a UE can support one or more IoT or MTC applications. Some examples of MTC applications are listed in Table 3 (source: 3GPP TS 22.368, Appendix B, the contents of which are incorporated herein by reference). This list is not exhaustive and is intended to indicate some examples of machine-type communication applications.

[0176] Table 1: Examples of Machine Type Communication Applications

[0177]

[0178]

[0179] Applications, services, and solutions can include MVNO (Mobile Virtual Network Operator) services, emergency radio communication systems, PBX (Private Branch Exchange) systems, PHS / digital cordless telecommunications systems, POS (Point of Sale) systems, advertising call systems, MBMS (Multimedia Broadcast and Multicast Services), V2X (Vehicle-to-Everything) systems, train radio systems, location-related services, disaster / emergency wireless communication services, community services, video streaming services, femtocell application services, VoLTE (Voice over LTE) services, billing services, radio on demand services, roaming services, activity monitoring services, carrier / network selection services, feature limitation services, PoC (Proof of Concept) services, personal information management services, ad-hoc network / DTN (Delay Tolerant Network) services, etc.

[0180] Furthermore, the UE categories described above are merely examples of the application of the technical ideas and exemplary embodiments described in this document. Needless to say, these technical ideas and embodiments are not limited to the UEs described above, and various modifications can be made to them.

[0181] Other embodiments of this aspect include corresponding computer systems, devices, and computer programs, each configured to perform actions of the method, recorded on one or more computer storage devices. One or more computer systems may be configured to perform specific operations or actions by installing software, firmware, hardware, or combinations thereof on the system, which, upon operation, causes the system to perform these actions. One or more computer programs may be configured to perform specific operations or actions by including instructions that, when executed by a data processing device, cause the device to perform these actions.

[0182] Furthermore, skilled programmers can, for example, write such computer programs or identify suitable hardware circuits to implement the disclosed invention without difficulty, based on the flowcharts and related descriptions in the application text. Therefore, disclosing a specific set of program code instructions or detailed hardware arrangements is not considered necessary for a full understanding of how to make and use the invention. The inventive function of the claimed computer-implemented processing will be described in more detail in the following description in conjunction with the remaining diagrams illustrating other processing flows. Furthermore, certain steps in the processes or processing flows described in all the following logic flowcharts must naturally precede other steps for the invention to function as described. However, the invention is not limited to the order of the steps if such an order or sequence does not alter the function of the invention. That is, it is recognized that some steps may be performed before, after, or in parallel with other steps without departing from the scope of the invention.

[0183] abbreviation

[0184] For the purposes of this document, the abbreviations given in 3GPP TR 21.905[1] and below shall apply. The abbreviations defined in this document take precedence over the definitions of the same abbreviations (if any) in 3GPP TR 21.905[1].

[0185] 5GC 5G Core Network

[0186] 5G LAN 5G Local Area Network

[0187] 5GS 5G system

[0188] 5G-AN 5G Access Network

[0189] 5G-AN PDB 5G Access Network Packet Delay Budget

[0190] 5G-EIR 5G Device Identifier Register

[0191] 5G-GUTI 5G Globally Unique Temporary Identifier

[0192] 5G-BRG 5G Broadband Home Gateway

[0193] 5G-CRG 5G Cable Home Gateway

[0194] 5G GM 5G Master Clock

[0195] 5G-RG 5G Home Gateway

[0196] 5G-S-TMSI 5G S-Temporary Mobile Subscription Identifier

[0197] 5G VN (5G Virtual Network)

[0198] 5QI 5G QoS identifier

[0199] AF application functions

[0200] AMF access and mobility management functions

[0201] AS Access Layer

[0202] ATSSS access service guidance, switching, and splitting

[0203] ATSSS-LL ATSSS Low Level

[0204] AUSF Authentication Server Functionality

[0205] BMCA Best Master Clock Algorithm

[0206] BSF Binding Support Functionality

[0207] CAG Closed Access Group

[0208] CAPIF, a general API framework for 3GPP northbound APIs.

[0209] CHF Billing Function

[0210] CN PDB Core Network Packet Delay Budget

[0211] CP control plane

[0212] DAPS Dual Activation Protocol Stack

[0213] DL downlink

[0214] DN Data Network

[0215] DNAIDN Access Identifier

[0216] DNN data network name

[0217] DRX discontinuous reception

[0218] DS-TT device-side TSN converter

[0219] ePDG Evolution Packet Data Gateway

[0220] EBI EPS Carrying Marker

[0221] EUI Extended Unique Identifier

[0222] FAR forwarding action rules

[0223] FN-BRG Fixed-line Broadband Home Gateway

[0224] FN-CRG Fixed-line Cable Home Gateway

[0225] FN-RG Fixed-line Home Gateway

[0226] FQDN (Fully Qualified Domain Name)

[0227] GFBR guarantees stream bit rate

[0228] GMLC Gateway Mobile Location Center

[0229] GPSI General Public Subscription Identifier

[0230] GUAMI Globally Unique AMF Identifier

[0231] HR Home Route (Roaming)

[0232] IAB Integration Access and Backhaul

[0233] IMEI / TAC IMEI type allocation code

[0234] IPUPS PLMN Inter-UP Security

[0235] I-SMF Intermediate SMF

[0236] I-UPF intermediate UPF

[0237] LADN Local Area Data Network

[0238] LBO Local Offloading (Roaming)

[0239] LMF location management function

[0240] LoA automation level

[0241] LPP LTE positioning protocol

[0242] LRF location retrieval function

[0243] MCX Mission-Critical Services

[0244] MDBV Maximum Data Burst

[0245] MFBR Maximum Stream Bit Rate

[0246] MICO only initiates connections from mobile devices.

[0247] MPS Multimedia Priority Service

[0248] MPTCP Multipath TCP Protocol

[0249] N3IWF Non-3GPP Interoperability Function

[0250] The N5CW WLAN side does not have 5G capability.

[0251] NAI Network Access Identifier

[0252] NEF Network Open Functions

[0253] NF Network Functions

[0254] NGAP Next Generation Application Protocol

[0255] NID Network Identifier

[0256] NPN (Non-Public Network)

[0257] NR New Radio

[0258] NRF network storage function

[0259] NSI ID (Network Slice Instance Identifier)

[0260] NSSAA Network Slicing-Specific Authentication and Authorization

[0261] NSSAAF network slicing-specific authentication and authorization functions

[0262] NSSAI Network Slice Selection Auxiliary Information

[0263] NSSF Network Slice Selection Function

[0264] NSSP Network Slice Selection Strategy

[0265] NW-TT Network Side TSN Converter

[0266] NWDAF network data analysis function

[0267] PCF strategy control function

[0268] PDB group delay budget

[0269] PDR Grouping Detection Rules

[0270] PDU Protocol Data Unit

[0271] PEI Permanent Device Identifier

[0272] PER error rate

[0273] PFD packet flow description

[0274] PNI-NPN public network integration non-public network

[0275] PPD paging strategy differential

[0276] PPF paging process marker

[0277] PPI Paging Strategy Indicator

[0278] PSA PDU Session Anchor

[0279] PTP Precision Time Protocol

[0280] QFI QoS Stream Identifier

[0281] QoE experience quality

[0282] RACS wireless capability signaling optimization

[0283] (R)AN (Wireless) Access Network

[0284] RG Home Gateway

[0285] RIM Remote Interference Management

[0286] RQA Reflection QoS Attributes

[0287] RQI reflection QoS indication

[0288] RSN Redundant Serial Number

[0289] SA NR Independent New Radio

[0290] SBA service-based architecture

[0291] SBI Service-Based Interface

[0292] SCP Service Communication Agent

[0293] SD slice differentiation markings

[0294] SEAF safety anchor function

[0295] SEPP Secure Edge Protection Agent

[0296] SMF Session Management Function

[0297] SMSF Short Message Service Function

[0298] SN serial number

[0299] SNPN Independent Non-Public Network

[0300] S-NSSAI Single Network Slice Selection Auxiliary Information

[0301] SSC Session and Service Continuity

[0302] SSCMSP Session and Service Continuity Mode Selection Strategy

[0303] SST Slicing / Service Type

[0304] SUCI subscription hidden identifier

[0305] SUPI subscription permanent identifier

[0306] SV software version

[0307] TNAN Trusted Non-3GPP Access Network

[0308] TNAP Trusted Non-3GPP Access Point

[0309] TNGF Trusted Non-3GPP Gateway Function

[0310] TNL Transport Network Layer

[0311] TNLA Transport Network Layer Association

[0312] TSC Time-Sensitive Communication

[0313] TSCAI TSC Auxiliary Information

[0314] TSN Time-Sensitive Network

[0315] TSN GM TSN Master Clock

[0316] TSP Traffic Guidance Strategy

[0317] TT TSN Converter

[0318] TWIF Trusted WLAN Interconnection Function

[0319] UCMF UE Wireless Capability Management Function

[0320] UDM Unified Data Management

[0321] UDR Unified Data Storage

[0322] UDSF Unstructured Data Storage Function

[0323] UL uplink

[0324] UL CL uplink classifier

[0325] UPF User Face Functions

[0326] URLLC Ultra-Reliable Low-Latency Communication

[0327] UE reachability request parameters for URRP-AMF AMF

[0328] URSP UE routing policy

[0329] VID VLAN identifier

[0330] VLAN Virtual Local Area Network

[0331] W-5GAN wired 5G access network

[0332] W-5GBAN wired BBF access network

[0333] W-5GCAN wired 5G cable access to the network

[0334] W-AGF Wireless Access Gateway Function

[0335] definition

[0336] For the purposes of this document, the terms and definitions given in 3GPP TR 21.905[1] and below shall apply. The terms defined in this document take precedence over the definitions of the same terms in 3GPP TR 21.905[1], if any.

[0337] This application is based on and claims priority to Indian Patent Application 202011042823, filed on 1 October 2020, the disclosure of which is incorporated herein by reference in its entirety.

[0338] [List of reference numerals]

[0339] 600UE

[0340] 601 antenna

[0341] 602 transceiver circuit

[0342] 603 User Interface

[0343] 604 controller

[0344] 605 memory

[0345] 700(R)AN nodes

[0346] 701 antenna

[0347] 702 transceiver circuit

[0348] 703 Network Interface

[0349] 704 controller

[0350] 705 memory

[0351] 800AMF

[0352] 801 transceiver circuit

[0353] 802 controller

[0354] 803 memory

[0355] 804 network interface

Claims

1. A method performed by an Access and Mobility Management Function (AMF), the method comprising: Send a configuration update command message, wherein the configuration update command message includes network slice selection assistance information, i.e., allowed NSSAI or denied NSSAI; Upon sending the configuration update command message, start the timer; When the timer expires, the configuration update command message is retransmitted, and the timer is reset and restarted; and If a failure related to the wireless link is detected before the configuration update completion message is received, the retransmission will be repeated a predetermined number of times.

2. The method according to claim 1, wherein If the configuration update command message includes an allowed NSSAI or a rejected NSSAI, the configuration update command message will be retransmitted.

3. The method according to claim 1 or 2, further comprising: Receive a registration request message from the user equipment (UE), wherein the registration request message includes the requested NSSAI; as well as The network slice-specific authentication and authorization (NSSAA) process is performed, wherein the configuration update command message is sent during the general UE configuration update process following the NSAA process.

4. An Access and Mobility Management Function (AMF), comprising: A component for sending configuration update command messages, wherein the configuration update command messages include network slice selection assistance information, i.e., allowed NSSAI or denied NSSAI; A component for starting a timer when the configuration update command message is sent; Components for retransmitting the configuration update command message when the timer expires, and for resetting and restarting the timer; and A component for retransmitting a predetermined number of times if a wireless link-related failure is detected before a configuration update completion message is received.

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