User device, communication device, method for user device, and method for communication device

Abstract

An example aspect of the present disclosure includes a method in a user equipment (UE), the method including communicating with a communications device, the method including transmitting a first S-NSSAI included in a Pending NSSAI to the communications device.

Description

Technical Field

[0001] The present disclosure relates to a method of a user equipment (UE), a method of a communication device, a UE, and a communication device.

Background Art

[0002] The Network Slice-Specific Authentication and Authorization (NSSAA) procedure was introduced in 3GPP (registered trademark) Release 16. This procedure enables the execution of network slice-specific authentication and authorization by an AAA server (the AAA server may be located in an external network).

[0003] When a UE requests access to one or more S-NSSAIs, the serving PLMN executes the NSSAA procedure for one or more S-NSSAIs of the HPLMN that are subject to the NSSAA procedure based on the subscription information. When the UE transmits a Registration Request message including one or more S-NSSAIs within the Requested NSSAI that are subject to the NSSAA procedure, the AMF transmits a Registration Accept message including a list of Pending NSSAIs (or the Pending NSSAI) including one or more network slices (e.g., one or more S-NSSAIs) that are subject to the NSSAA procedure. After the completion of the UE registration procedure, the AMF starts the NSSAA procedure for one or more S-NSSAIs within the Pending NSSAI. If the NSSAA procedure is successful, the AMF notifies the UE that one or more S-NSSAIs within the Pending NSSAI are currently available, causes the UE to delete those one or more S-NSSAIs from the storage of the Pending NSSAI within the UE, and causes them to be placed in the storage of the Allowed NSSAI within the UE.

[0004] One or more 3GPP specifications further define a mechanism that allows a UE to initiate a registration procedure while an NSSAA procedure is in progress. In this case, according to 3GPP TS24.501[5], the UE does not include one or more S-NSSAIs stored by the UE in the Pending NSSAI in the Requested NSSAI.

[0005] 3GPP Release 17 introduced the Network Slice Based Cell Reselection feature. This feature allows a UE to perform cell reselection based on one or more network slices managed in the NAS layer within the UE. Because support for one or more S-NSSAIs for each cell may be limited, the UE may use the Network Slice Based Cell Reselection feature to tune to the correct cell based on the S-NSSAIs of interest to the UE. When the NAS layer within the UE decides to perform Network Slice Based Cell Reselection, it notifies the AS layer in the UE of one or more Network Slice Access Stratum (AS) Groups (one or more NSAGs) and their priorities. The AS layer in the UE may then perform cell reselection by referencing the supported NSAGs of one or more neighboring cells on the SIB that the UE can receive, based on the NSAGs and their priorities received from the NAS layer.

[0006] Basically, there are two ways in which the NAS layer within the UE selects one or more NSAGs: -Based on one or more S-NSSAIs within an Allowed NSSAI. This is when the UE seeks the best cell to best support one or more S-NSSAIs within an Allowed NSSAI. - Based on a new set of one or more S-NSSAIs. This occurs when the UE is attempting to register for a new set of one or more S-NSSAIs that have a different Requested NSSAI than the current Allowed NSSAI. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] 3GPP TR 21.905:“Vocabulary for 3GPP Specifications”.V17.1.0(2021-12)

[0008] [Non-Patent Document 2] 3GPP TS 23.501: “System architecture for the 5G System(5GS)”.V17.5.0(2022-06)

[0009] [Non-Patent Document 3] 3GPP TS 23.502:“Procedures for the 5G System(5GS)”.V17.5.0(2022-06)

[0010] [Non-Patent Document 4] 3GPP TS 23.503:“Policy and charging control framework for the 5G System(5GS)Stage 2”.V17.5.0(2022-06)

[0011] [Non-Patent Document 5] 3GPP TS 24.501:“Non-Access-Stratum(NAS)protocol for 5G System(5GS)Stage 3”.V17.7.1(2022-06)

[0012] [Non-Patent Document 6] 3GPP TS 37.340:“Evolved Universal Terrestrial Radio Access(E-UTRA)and NR Multi-connectivity stage 2”.V17.1.0(2022-06)

[0013] [Non-Patent Document 7] 3GPP TS 38.423: “NG-RAN Xn Application Protocol (XnAP)” V17.1.0 (2022-06) [Overview of the project] [Problems that the invention aims to solve]

[0014] The current 3GPP specification has one or more ambiguities. For example, the current 3GPP specification has one or more ambiguities regarding network slice-based cell reselection and NSAG.

[0015] For example, if the UE's NAS layer initiates a network slice-based cell reselection function based on one or more new sets of S-NSSAI, the new set of one or more S-NSSAI will be included in the Requested NSSAI in the Registration Request message when the UE initiates the registration procedure after the network slice-based cell reselection.

[0016] However, if an NSSAA procedure is in progress on one or more network slices (or one or more S-NSSAIs) from a Pending NSSAI, and the UE is no longer interested in one or more S-NSSAIs within the Pending NSSAI, there is no way for the UE to indicate to the AMF that it is no longer interested in one or more S-NSSAIs within the Pending NSSAI and wishes to withdraw the Pending NSSAI. An NSSAA procedure on one or more S-NSSAIs of a Pending NSSAI that the UE is no longer interested in is meaningless and can cause network load. Furthermore, this can lead to inefficient use of network resources. Network resources for one or more S-NSSAIs of a Pending NSSAI may be unnecessarily maintained within the network without being used.

[0017] In addition, there are basically two examples of how the UE behaves in the above situation under one or more 3GPP specifications. Regardless of the UE's intentions, while the UE has one or more S-NSSAIs pending NSSAI, a new set of one or more S-NSSAIs must be requested by the UE. Even if the UE wishes not to include one or more S-NSSAIs of the Pending NSSAI in the Allowed NSSAI, the UE has to wait for the NSSAA procedure to complete and may start a new registration procedure without including one or more S-NSSAIs from the Pending NSSAI in the Requested NSSAI after cell reselection based on the network slice. For example, one or more UE S-NSSAIs within the Requested NSSAI of the new registration procedure and one or more S-NSSAIs within the Pending NSSAI do not share at least one common NSSRG value, and the UE has to wait until the NSSAA procedure for the Pending NSSAI is completed, and there are cases where the UE starts a new registration procedure without including one or more S-NSSAIs from the Pending NSSAI in the Requested NSSAI after cell reselection based on the network slice.

[0018] In the first case, this may result in inefficient use of network resources. Network resources for one or more S-NSSAIs from the Pending NSSAI are unnecessarily maintained in the network without being used.

[0019] In the second case, this may cause a delay in service activation and thus may cause an unnecessary service degradation for all services using the new set of one or more S-NSSAIs.

[0020] For example, when the UE moves from the current Registration Area (RA), the UE may not be able to use the cell reselection function based on the network slice even though one or more candidate new cells support the cell reselection function based on the network slice.

[0021] According to 3GPP TS 23.501 [2], the AMF provides the UE with NSAG information only for the TAs of the RA. As a result, the UE may not know the NSAG information for one or more cells located outside the RA.

[0022] As a result, although the cell reselection function based on network slices is fully deployed in the operator network, the UE may have no choice but to use the existing cell selection mechanism when traversing the RA boundary.

[0023] This may cause unnecessary service termination for all services that use one or more S-NSSAIs within the Allowed NSSAI because when the UE traverses the RA boundary, the UE cannot select a cell suitable for one or more S-NSSAIs within the Allowed NSSAI based on the cell reselection function based on network slices.

Means for Solving the Problem

[0024] A method of a user equipment (UE) according to an exemplary aspect of the present disclosure includes communicating with a communication device. The method includes transmitting a first Single NSSAI (S-NSSAI) included in the Pending Network Slice Selection Assistance Information (NSSAI) to the communication device.

[0025] A method of a user equipment (UE) according to an exemplary aspect of the present disclosure includes communicating with a communication device. The method includes transmitting information indicating that the UE is not interested in the S-NSSAI included in the Pending NSSAI to the communication device.

[0026] A method of a communication device according to an exemplary aspect of the present disclosure includes receiving a first S-NSSAI included in the Pending NSSAI. The method includes aborting the NSSAA procedure for the first S-NSSAI.

[0027] An exemplary user device (UE) in this disclosure includes memory and at least one hardware processor coupled to the memory. The at least one hardware processor is configured to communicate with a communication device. The at least one hardware processor is configured to transmit a first S-NSSAI contained in Pending NSSAI to the communication device.

[0028] An exemplary user device (UE) in this disclosure includes memory and at least one hardware processor coupled to the memory. The at least one hardware processor is configured to communicate with a communication device. The at least one hardware processor is configured to send information to the communication device indicating that the UE is not interested in the S-NSSAI included in the Pending NSSAI.

[0029] A communication device according to an exemplary aspect of the present disclosure includes a memory and at least one hardware processor coupled to the memory. The at least one hardware processor is configured to receive a first S-NSSAI contained in a Pending NSSAI. The at least one hardware processor is configured to abort the NSSAA procedure of the first S-NSSAI. [Brief explanation of the drawing]

[0030] [Figure 1] This is a signaling diagram of a first example of an exemplary first embodiment. [Figure 2] This is a signaling diagram of a second example of the first exemplary embodiment. [Figure 3] This is a signaling diagram of the first example of an exemplary second embodiment. [Figure 4] This diagram shows the system overview. [Figure 5] This is the UE Block. [Figure 6] (R)AN node block. [Figure 7]This figure shows a system overview of an (R)AN node based on the O-RAN architecture. [Figure 8] RU is a block letter. [Figure 9] DU branch office. [Figure 10] This is the CU (Clinical Union) branch office. [Figure 11] This is a block diagram of the AMF. [Figure 12] PCF block. [Figure 13] AUSF is a block diagram. [Figure 14] UDM cylinder. [Figure 15] This is a block diagram of NSSF. [Modes for carrying out the invention]

[0031] Abbreviation For the purposes of this document, 3GPP TR 21.905[1] and the following abbreviations apply. If an abbreviation defined in this document exists in 3GPP TR 21.905[1], the definition of that abbreviation takes precedence over that definition. 4G-GUTI (4G Globally Unique Temporary UE Identity) 5GC 5G Core Network 5G LAN (5G Local Area Network) 5GS 5G System 5G-AN 5G Access Network 5G-AN PDB (5G Access Network Packet Delay Budget) 5G-EIR (5G Equipment Identity Register) 5G-GUTI: 5G Globally Unique Temporary Identifier 5G-BRG 5G Broadband Residential Gateway 5G-CRG 5G Cable Residential Gateway 5G GM (5G Grand Master) 5G-RG 5G Residential Gateway 5G-S-TMSI 5G S - Temporary Mobile Subscription Identifier 5G VN (5G Virtual Network) 5QI 5G QoS Identifier AF Application Function AMF (Access and Mobility Management Function) AMF-G Geographically selected access and mobility management function AMF-NG Non-Geographically Selected Access and Mobility Management Function ANDSF Access Network Discovery and Selection Function ARFCN: Absolute radio-frequency channel number AS Access Layer ATSSS (Access Traffic Steering, Switching, Splitting) ATSSS-LL (ATSSS Low-Layer) AUSF Authentication Server Function AUTN Authentication token BCCH Broadcast Control Channel BMCA Best Master Clock Algorithm BSF Binding Support Function CAG (Closed Access Group) CAPIF Common API Framework for 3GPP northbound APIs CHF Charging Function CN PDB Core Network Packet Delay Budget CP Control Plane DAPS (Dual Active Protocol Stacks) DL Downlink DN Data Network DNAI DN Access Identifier DNN (Data Network Name) DRX (Discontinuous Reception) DS-TT Device-side TSN translator ePDG: Evolved Packet Data Gateway EBI (Episodic Business Identity) EPS Bearer Identity EPS (Evolved Packet System) EUI (Extended Unique Identifier) FAR Forwarding Action Rule FN-BRG Fixed Network Broadband RG FN-CRG Fixed Network Cable RG FN-RG Fixed Network RG FQDN: Fully Qualified Domain Name GFBR Guaranteed Flow Bit Rate GMLC Gateway Mobile Location Center GPSI Generic Public Subscription Identifier GUAMI Globally Unique AMF Identifier GUTI (Globally Unique Temporary UE Identity) HPLMN (Home Public Land Mobile Network) HR Home Routed (Roaming) IAB Integrated access and backhaul IMEI / TAC IMEI Type Allocation Code IPUPS Inter-PLMN UP Security I-SMF Intermediate SMF I-UPF Intermediate UPF LADN (Local Area Data Network) LBO (Local Breakout (Roaming)) LMF Location Management Function Level of Automation (LoA) LPP LTE Positioning Protocol LRF Location Retrieval Function MCC Mobile Country Code MCX Mission Critical Service MDBV Maximum Data Burst Volume MFBR Maximum Flow Bit Rate MICO Mobile Initiated Connection Only Man-in-the-Middle (MITM) attack MNC (Mobile Network Code) MPS (Multimedia Priority Service) MPTCP (Multi-Path TCP Protocol) N3IWF Non-3GPP Interworking Function N3GPP Non-3GPP access N5CW Non-5G-Capable over WLAN NAI (Network Access Identifier) NAS Non-Access Stratum NEF Network Exposure Function NF Network Function NGAP Next Generation Application Protocol NID (Network Identifier) NPN (Non-Public Network) NR New Radio NSAG (Network Slice Access Layer Group) NRF Network Repository Function NSI ID: Network Slice Instance Identifier NSSAA (Network Slice-Specific Authentication and Authorization) NSSAAF Network Slice-Specific Authentication and Authorization Function (NSSAA Function) NSSAI Network Slice Selection Assistance Information NSSF Network Slice Selection Function NSSP Network Slice Selection Policy NSSRG (Network Slice Simultaneous Registration Group) NW-TT (Network-side TSN translator) NWDAF (Network Data Analytics Function) PCF Policy Control Function PCO Protocol Configuration Options PDB (Packet Delay Budget) PDR Packet Detection Rule PDU (Protocol Data Unit) PEI (Permanent Equipment Identifier) PER (Packet Error Rate) PFD Packet Flow Description PLMN (Public Land Mobile Network) PNI-NPN (Public Network Integrated NPN) PPD Paging Policy Differentiation PPF Paging Proceed Flag PPI (Paging Policy Indicator) PSA PDU Session Anchor PTP (Precision Time Protocol) QFI QoS Flow Identifier QoE (Quality of Experience) RACS Radio Capabilities Signaling Optimization (R)AN (Radio) Access Network RAT (Radio Access Technology) RG Residential Gateway RIM (Remote Interference Management) RQA Reflective QoS Attribute RQI Reflective QoS Indication RSN (Redundancy Sequence Number) SA NR: A new standalone radio (Standalone NR) SBA (Service-Based Architecture) SBI Service-Based Interface SCP Service Communication Proxy SD Slice Differentiator SEAF Security Anchor Functionality SEPP Security Edge Protection Proxy SIB (System Information Block) SMF Session Management Function SMSF Short Message Service Function SN Sequence Number SN (Serving Network Name) SNPN Standalone Non-Public Network (SNPN) S-NSSAI Single Network Slice Selection Support Information (Single NSSAI) SSC (Session and Service Continuity) SSCMSP Session and Service Continuity Mode Selection Policy (SSC Mode Selection Policy) SST Slice / Service Type SUCI (Subscription Concealed Identifier) SUPI (Subscription Permanent Identifier) SV Software Version TMSI: Temporary Mobile Subscriber Identity TNAN: Trusted Non-3GPP Access Network TNAP: Trusted Non-3GPP Access Point TNGF (Trusted Non-3GPP Gateway Function) TNL (Transport Network Layer) TNLA Transport Network Layer Association TSC Time Sensitive Communication TSCAI TSC Assistance Information TSN (Time Sensitive Networking) TSN GM (TSN Grand Master) TSP (Traffic Steering Policy) TT TSN Translator (TSN Translator) TWIF (Trusted WLAN Interworking Function) UCMF UE Radio Capability Management Function UDM (Unified Data Management) UDR (Unified Data Repository) UDSF (Unstructured Data Storage Function) UE User Equipment UL Uplink UL CL Uplink Classifier UPF User Plane Function UPSI UE Policy Section Identifier URLLC (Ultra Reliable Low Latency Communication) URRP-AMF UE Reachability Request Parameter for AMF URSP UE Route Selection Policy VID VLAN Identifier VLAN (Virtual Local Area Network) Visited Public Land Mobile Communications Network (VPLMN) W-5GAN Wireline 5G Access Network W-5GBAN Wireline BBF Access Network W-5GCAN Wireline 5G Cable Access Network W-AGF Wireline Access Gateway Function

[0032] definition For the purposes of this document, the terms and definitions set forth in 3GPP TR 21.905 [1] and below shall apply. Any terms defined in this document shall take precedence over any definitions of the same terms in 3GPP TR 21.905 [1].

[0033] general Those skilled in the art will understand that elements in the drawings are shown for simplification and may not necessarily be drawn to scale. Furthermore, with respect to the configuration of a device, one or more components of the device may be represented in the drawings by conventional symbols, and the drawings may show only certain details relevant to understanding aspects of this disclosure so as not to obscure the drawings with details that would be readily apparent to those skilled in the art who benefit from the description herein.

[0034] For the purpose of facilitating understanding of the principles of this disclosure, the embodiments shown in the figures will be referenced and specific terminology will be used to describe them. However, it will be understood that this is not intended to limit the scope of this disclosure. Such modifications and further alterations to the illustrated systems, as well as such further applications of the principles of this disclosure as would ordinarily conceivable to those skilled in the art, should be construed as being within the scope of this disclosure.

[0035] The terms “includes,” “inclusion,” or any other variation thereof are intended to encompass non-exclusive inclusion, so that a process or method including a list of steps may include other steps that are not explicitly listed or are not specific to such process or method, rather than including only those steps. Similarly, one or more devices or entities or subsystems or elements or structures or components preceded by “...includes” does not, without further constraint, exclude the existence of other devices, subsystems, elements, structures, components, additional devices, additional subsystems, additional elements, additional structures, or additional components. Throughout this specification, occurrences of the phrases “in another aspect,” “in a different aspect,” and similar wording may all, though not necessarily, refer to the same aspect.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this disclosure pertains. The systems, methods, and examples provided herein are illustrative and not intended to limit the scope of this disclosure.

[0037] In the following specification and claims, several terms that may be defined as follows are used for reference: the singular forms ("a", "an") and "the foregoing" include plural references unless otherwise explicitly indicated by the context.

[0038] Where used herein, data is meaningful information and represents values ​​resulting from parameters; therefore, information is associated with data and knowledge. Further knowledge means an understanding of abstract or concrete concepts. Note that this exemplary system is simplified for the sake of facilitating the explanation of the disclosed subject matter and is not intended to limit the scope of this disclosure. Exemplary embodiments of the disclosure disclosed herein can be carried out using other devices, systems, and configurations in addition to, or instead of, the System, and all such embodiments are considered to be within the scope of this disclosure.

[0039] Each of the exemplary embodiments described below, and each of the elements contained in each exemplary embodiment, may be implemented independently or in combination with others. These exemplary embodiments contain novel features that are distinct from one another. Thus, these exemplary embodiments contribute to achieving different objectives or solving different problems and to obtaining different advantages.

[0040] An exemplary object of this disclosure is to provide a method and apparatus that can solve the above-mentioned problems.

[0041] The following list explains the intended meaning of the terms used in this disclosure. -Subscribed S-NSSAI, multiple Subscribed S-NSSAI, or one or more Subscribed S-NSSAI: This may be equivalent to a list of S-NSSAI within a Subscribed NSSAI. -Allowed S-NSSAI, multiple Allowed S-NSSAI, or one or more Allowed S-NSSAI: May be equivalent to a list of S-NSSAI within an Allowed S-NSSAI. -Configured S-NSSAI, Configured multiple S-NSSAI, or one or more Configured S-NSSAI: A Configured S-NSSAI can be equal to a list of S-NSSAIs within a Configured NSSAI. -Rejected S-NSSAI, multiple Rejected S-NSSAI, or one or more Rejected S-NSSAI: This may be equal to a list of S-NSSAI within a Rejected NSSAI. -Pending S-NSSAI, multiple Pending S-NSSAI, or one or more Pending S-NSSAI: may be equivalent to a list of S-NSSAI within a Pending NSSAI.

[0042] Network slice-based cell reselection can be expressed as Network Slice based cell reselection.

[0043] Exemplary first embodiment When the UE3 NAS layer (UE NAS301) initiates a network slice-based cell reselection function based on one or more S-NSSAIs within the Allowed NSSAI, one or more NSAGs and their priorities are selected based on both the one or more S-NSSAIs within the Allowed NSSAI and the one or more S-NSSAIs within the Pending NSSAI.

[0044] A first example of the first exemplary embodiment: A first example of an exemplary first embodiment discloses a method by which UE NAS301 selects one or more NSAGs and NSAG priorities (or one or more NSAG priorities) based on both Allowed NSSAI and Pending NSSAI for cell reselection based on network slices, and transmits the selected one or more NSAGs and NSAG priorities (or NSAG priorities) to the UE's AS layer (UE AS302).

[0045] After the NSSAA procedure is complete, UE NAS301 checks the Allowed NSSAI. If there is a difference from before the NSSAA procedure, UE NAS301 selects an NSAG and NSAG priority based on the Allowed NSSAI, since there are no Pending NSSAI at this time. UE NAS301 then sends the selected NSAG and NSAG priority to the UE's AS layer (UE AS302).

[0046] The detailed processing of the first example of the first embodiment described below will be explained with reference to Figure 1.

[0047] Step 1. UE NAS301 sends a Registration Request message to AMF70, including S-NSSAI#1 and S-NSSAI#2 in the Requested NSSAI.

[0048] Step 2. The AMF70 sends a Registration Accept message to the UE NAS301, including Configured NSSAI, Allowed NSSAI, Pending NSSAI, and NSAG priority.

[0049] A configured NSSAI includes S-NSSAI#1 with associated NSAG#1, S-NSSAI#2 with associated NSAG#2, and S-NSSAI#3 with associated NSAG#3. Since S-NSSAI#1 is a network slice that UE3 is permitted to use, Allowed NSSAI includes S-NSSAI#1.

[0050] Here, the NSAG information in the Registration Accept message may include relationships between S-NSSAI and NSAGs (i.e., S-NSSAI#1 having related NSAG#1, S-NSSAI#2 having related NSAG#2, and S-NSSAI#3 having related NSAG#3).

[0051] Pending NSSAI includes S-NSSAI#2 because S-NSSAI#2 is subject to NSSAA procedures based on subscriber data within the home network (HPLMN).

[0052] NSAG priority indicates the priority between NSAGs. For example, NSAG priority may indicate that NSAG#2 has a higher priority than NSAG#1.

[0053] Step 3. Upon receiving the Registration Accept message in Step 2, the UE NAS301 selects an NSAG and NSAG priority based on both one or more S-NSSAIs in the Allowed NSSAI and one or more S-NSSAIs in the Pending NSSAI. That is, the UE NAS301 assumes that the NSSAA procedures for all one or more S-NSSAIs in the Pending NSSAI will be completed successfully. For example, the UE NAS301 may select NSAG#1 and NSAG#2 as NSAGs based on the Allowed NSSAI and Pending NSSAI. For example, the UE NAS301 may select or decide that NSAG#2 has a higher priority than NSAG#1 as the NSAG priority based on at least one of the Allowed NSSAI, Pending NSSAI, and NSAG priority.

[0054] Step 4. The UE NAS301 sends a Registration Complete message to the AMF70, including the Chosen NSAG and Chosen NSAG priority.

[0055] A Chosen NSAG includes one or more NSAGs selected in step 3. A Chosen NSAG priority includes the NSAG priority determined in step 3. A Chosen NSAG can be expressed as a selected NSAG or a derived NSAG. A Chosen NSAG priority can be expressed as a selected NSAG priority, a derived NSAG priority, or a determined NSAG priority.

[0056] For example, a Chosen NSAG may include NSAG#1 and NSAG#2. For example, a Chosen NSAG priority may include an NSAG priority indicating that NSAG#2 has a higher priority than NSAG#1.

[0057] Upon receiving the Registration Complete message, the AMF70 stores the Chosen NSAG and Chosen NSAG priority in the AMF70's UE context. The AMF70 (for example, the AMF70 as the initial AMF) may send the Chosen NSAG and Chosen NSAG priority to the target AMF during the Registration with AMF re-allocation procedure, in accordance with 3GPP TS 23.502 [3].

[0058] AMF70 may notify RAN5 (e.g., the RAN node) of the Chosen NSAG and Chosen NSAG priority each time AMF70 is associated with RAN5. For example, Initial Context Setup request messages, UE Context Modification Request messages, Connection Establishment Indication messages, AMF CP Relocation Indication messages, UE Information Transfer messages, UE Context Suspend Response messages, UE Context Resume Response messages, Handover Command messages, Handover Request messages, Path Switch Acknowledge messages, Downlink RAN ​​Status Transfer messages, Handover Success messages, Downlink RAN ​​Early Status Transfer messages, Paging messages, or any other existing or new NGAP messages include the Chosen NSAG and Chosen NSAG priority and forward them from AMF70 to RAN5. AMF70 may also activate or deactivate network slice support and priority-based handover in RAN5 by including new parameters or flags in the above messages between AMF70 and RAN5, for the purpose of activating or deactivating RAN5's consideration of network slice support and priority in connected mode mobility, i.e., in the selection of handover to a target cell or the selection of RRC connection release by redirection to a target cell. RAN5 may then use Chosen NSAG and Chosen NSAG priority to select one or more candidate cells for the handover procedure.One or more candidate cells for handover may be selected based on at least one combination of the support of one or more NSAGs in one or more candidate cells and the measured signal intensity measured and reported by UE3. For example, if RAN5 performs a handover, it may hand over UE3 to one or more selected candidate cells. For example, if a Chosen NSAG includes NSAG#1 and NSAG#2, RAN5 may select one or more candidate cells that support at least one of NSAG#1 and NSAG#2 (for example, RAN5 may select one or more candidate cells that support at least one of S-NSSAI#1 associated with NSAG#1 and S-NSSAI#2 associated with NSAG#2).

[0059] Furthermore, consider a scenario where, for example, a Chosen NSAG includes NSAG#1 and NSAG#2, and the measured signal intensity of one cell supporting NSAG#1 (e.g., one cell supporting S-NSSAI#1 associated with NSAG#1) is higher than the measured signal intensity of another cell supporting NSAG#2 (e.g., another cell supporting S-NSSAI#2 associated with NSAG#2). In this case, RAN5 may select one or more candidate cells, specifically the one supporting NSAG#1.

[0060] Furthermore, when RAN5 selects one or more candidate cells, RAN5 may also consider Chosen NSAG priority. For example, suppose the Chosen NSAG priority indicates that NSAG#2 has a higher priority than NSAG#1. In this case, if RAN5 finds one or more candidate cells that support NSAG#1 (e.g., one cell that supports S-NSSAI#1 related to NSAG#1) and another cell that supports NSAG#2 (e.g., another cell that supports S-NSSAI#2 related to NSAG#2), RAN5 may select the other cell.

[0061] Source RAN5 (for example, RAN5 that receives Chosen NSAG and Chosen NSAG priority from AMF70 and performs the handover procedure) may notify target RAN5 of the Chosen NSAG and Chosen NSAG priority. For example, Handover Request messages, SN Status Transfer messages, RAN Paging messages and Early Status Transfer messages, or any other existing or new XnAP messages include the Chosen NSAG and Chosen NSAG priority and forward them from source RAN5 to target RAN5.

[0062] For example, target RAN5 may use Chosen NSAG and Chosen NSAG priority to select one or more candidate cells for the handover procedure in the same manner as described above.

[0063] The target AMF that receives the Chosen NSAG and Chosen NSAG priority may perform one or more processes in the same manner as the AMF70 described above.

[0064] Step 5. UE NAS301 notifies UE AS302 of the selected NSAGs (e.g., NSAG#1 and NSAG#2) and NSAG priorities (e.g., NSAG priority indicating that NSAG#2 has a higher priority than NSAG#1).

[0065] Step 6. UE AS302 may perform cell reselection based on network slices, based on the selected NSAGs (e.g., NSAG#1 and NSAG#2) and NSAG priorities received in Step 5.

[0066] For example, UE3 applies a network slice-based cell reselection procedure when UE3 transitions to CM-IDLE mode (for example, when the network (e.g., AMF70) explicitly releases the current N1 signaling connection by initiating signaling within the network, or when an RLF is detected within UE3 or the network and UE3 or the network locally releases the N1 signaling connection). UE3 may also apply the same procedure defined herein when UE3 transitions to the RRC-INACTIVE state. The NAS layer within the UE (e.g., UE NAS301) may initiate a network slice-based cell reselection function (or network slice-based cell reselection) at any time.

[0067] Step 7. The NSSAA procedure is performed between UE NAS301 and AAA 201 for S-NSSAI#2. Step 7 may be performed after Step 4 and before Step 5. Furthermore, the order of Step 7 and the set of Steps 4 and 5 may be swapped. AAA may be referred to as AAA Server.

[0068] Step 8. After the NSSAA procedure is complete, UE NAS301 may re-select (or choose) an NSAG and determine the NSAG priority based on the Allowed NSSAI only if the NSSAA procedure in Step 7 has failed, i.e., if one or more S-NSSAIs from the Pending NSSAI have failed in the NSSAA procedure. If the NSSAA procedure in Step 7 has succeeded for all one or more S-NSSAIs from the Pending NSSAI, and all one or more S-NSSAIs from the Pending NSSAI have been added to the Allowed NSSAI of UE3 by the network (e.g., AMF70), UE NAS301 will not perform the NSAG and NSAG priority selection again, as there is no difference in the input for NSAG selection performed in Step 3.

[0069] Step 9. The UE NAS301 may send a NAS message to the AMF70 that includes the Chosen NSAG and Chosen NSAG priority. The Chosen NSAG includes one or more NSAGs selected in Step 8. The Chosen NSAG priority includes the NSAG priority determined in Step 8. For example, the NAS message could be a Registration Request message, a Registration Complete message, an Authentication response message, a UL NAS transport message, a Service request message, a Configuration update complete message, an Identity response message, a Notification response message, a Security mode complete message, a Network slice-specific authentication complete message, or any other existing or new NAS message that communicates the Chosen NSAG and Chosen NSAG priority to the AMF70.

[0070] For example, upon receiving a NAS message in step 9, the AMF70 may notify the RAN5 of the Chosen NSAG and Chosen NSAG priority, similar to step 4.

[0071] For example, RAN5 may use Chosen NSAG and Chosen NSAG priority to select one or more candidate cells for the handover procedure, similar to step 4.

[0072] For example, source RAN5 (e.g., RAN5 that receives Chosen NSAG and Chosen NSAG priority from AMF70 and performs the handover procedure) may notify target RAN5 of the Chosen NSAG and Chosen NSAG priority in the same manner as in step 4.

[0073] For example, if the AMF70 receives a NAS message, the AMF70 may execute one or more processes similar to those in step 4.

[0074] Step 10. UE NAS301 may notify UE AS302 of the selected NSAG (e.g., NSAG#1, including the Chosen NSAG determined in Step 8), meaning that in this example, the NSSAA procedure for S-NSSAI#2 has failed.

[0075] NSAG priority (for example, the Chosen NSAG priority determined in step 8) can also be notified to the UE AS302. For example, even if only one NSAG is notified, the NSAG priority can still be notified to the UE AS302.

[0076] Step 11. UE AS302 may perform cell reselection based on the network slice based on the NSAG received in Step 10 (e.g., NSAG#1).

[0077] Modification 1 of the first example of the first embodiment: If UE3 roams to a visited PLMN (VPLMN) and UE3 holds a Configured NSSAI for the VPLMN, UE3 performs network slice-based cell reselection based on one or more S-NSSAIs (e.g., one or more S-NSSAIs included in the Configured NSSAI for the VPLMN) that it intends to set in the Requested NSSAI for the Registration Request message.

[0078] Modification 2 of the first example of the first embodiment: In step 1, once an RRC connection is established, or has been established, the current RAN501 (e.g., a RAN node that has established or is in the process of establishing an RRC connection with UE3) may notify UE AS302 of one or more supporting NSAGs supported by one or more current cells using an RRCSetup message, an RRCReestablishment message, an RRCReject message, or any existing or new RRC message. One or more supporting NSAGs may indicate one or more NSAGs supported by one or more current cells. The current cell may be controlled by the current RAN501. The current RAN501 may be a RAN or RAN node serving UE3.

[0079] When UE AS302 receives one or more support NSAGs, it notifies UE NAS301 of this.

[0080] If UE NAS301 selects one or more NSAGs and NSAG priorities, it refers to one or more supported NSAGs in step 3. If the one or more Chosen NSAGs in step 3 are included in the one or more supported NSAGs received from the current RAN501, UE NAS301 does not activate cell reselection based on network slices by not sending any NSAGs and their priorities to UE AS302.

[0081] Modification 3 of the first example of the first embodiment: In one example, UE NAS301 sends a Pending NSSAI with 3GPP access only (one or more S-NSSAIs subject to NSSAA procedures are requested via 3GPP access) to UE AS302 for cell reselection based on network slice.

[0082] For example, UE AS302 may use the Pending NSSAI with 3GPP access along with the selected NSAG and NSAG priority received in step 5 for cell reselection based on network slice. For example, in step 6, UE AS302 may reselect one or more cells that support one or more S-NSSAI in the Pending NSSAI with 3GPP access.

[0083] For example, in step 5, UE NAS301 may notify UE AS302 of the selected NSAG and NSAG priority for 3GPP access.

[0084] For example, in step 3, UE NAS301 may select an NSAG and NSAG priority based on both one or more S-NSSAIs in the Allowed NSSAI for 3GPP access and one or more S-NSSAIs in the Pending NSSAI for 3GPP access (for example, UE NAS301 may select an NSAG for 3GPP access and an NSAG priority for 3GPP access). Then, in step 5, UE NAS301 may notify UE AS302 of the selected NSAG and NSAG priority for 3GPP access. UE AS302 may perform cell reselection based on the network slice based on the NSAG for 3GPP access and the NSAG priority for 3GPP access.

[0085] In one example, UE NAS301 sends a Pending NSSAI with 3GPP access (one or more S-NSSAIs subject to NSSAA procedures are requested via 3GPP access) and a Pending NSSAI without 3GPP access (one or more S-NSSAIs subject to NSSAA procedures are requested via non-3GPP access) to UE AS302 for cell reselection based on network slices.

[0086] For example, UE AS302 may use the 3GPP-accessed Pending NSSAI and the non-3GPP-accessed Pending NSSAI, along with the selected NSAG and NSAG priority received in step 5, for cell reselection based on network slices. For example, in step 6, UE AS302 may reselect one or more cells that support at least one of the one or more S-NSSAIs in the 3GPP-accessed Pending NSSAI and one or more S-NSSAIs in the non-3GPP-accessed Pending NSSAI.

[0087] For example, in step 5, UE NAS301 may notify UE AS302 of the selected NSAG and NSAG priority for at least one of 3GPP access and non-3GPP access.

[0088] For example, in step 3, UE NAS301 may select an NSAG and NSAG priority by considering at least one of the following: one or more S-NSSAIs in the Allowed NSSAI for 3GPP access, one or more S-NSSAIs in the Pending NSSAI for 3GPP access, one or more S-NSSAIs in the Allowed NSSAI for non-3GPP access, and one or more S-NSSAIs in the Pending NSSAI for non-3GPP access (for example, UE NAS301 may select at least one of the following: NSAG for 3GPP access, NSAG priority for 3GPP access, NSAG for non-3GPP access, and NSAG priority for non-3GPP access). Then, in step 5, UE NAS301 may notify UE AS302 of at least one of the following: NSAG for 3GPP access, NSAG priority for 3GPP access, NSAG for non-3GPP access, and NSAG priority for non-3GPP access. UE AS302 may perform cell reselection based on network slices based on at least one of the following: NSAG for 3GPP access, NSAG priority for 3GPP access, NSAG for non-3GPP access, and NSAG priority for non-3GPP access.

[0089] Modification 4 of the first example of the first embodiment: In step 2 of Registration Accept, or in step 7 of the UE Configuration Update procedure, if one or more S-NSSAIs from a Requested NSSAI or Pending NSSAI are rejected for Network Slice Admission Control (NSAC) reasons, i.e., because the network slice allocation has been reached or exceeded, the UE NAS301 still considers such one or more S-NSSAIs for cell reselection based on network slices, and in step 5 or step 10, the UE NAS301 selects an NSAG and NSAG priority and provides the NSAG and NSAG priority for such one or more S-NSSAIs to the UE AS302. The UE NAS301 may receive information from one or more network nodes (e.g., AMF70 or SMF) indicating information regarding NSAC (e.g., the network slice allocation has been reached or exceeded (i.e., S-NSSAIs are unavailable because the maximum number of UEs has been reached)). For example, even if one or more S-NSSAIs in a Requested NSSAI or Pending NSSAI are rejected for reasons of NSAC, UE NAS301 may still consider such one or more S-NSSAIs for cell reselection based on network slices, and UE NAS301 may select an NSAG and NSAG priority in step 3 or step 8 and provide the NSAG and NSAG priority for such one or more S-NSSAIs to UE AS302 in step 5 or step 10.

[0090] Modification 5 of the first example of the first embodiment: After the NSAG and NSAG priority are selected in step 3 or step 8, the UE AS302 may send the NSAG and NSAG priority as Chosen NSAG and Chosen NSAG priority to the newly selected RAN5 via an RRC message.

[0091] For information on how the new RAN5 uses Chosen NSAG and Chosen NSAG priorities, please refer to Step 4.

[0092] For example, UE AS302 includes the Chosen NSAG and Chosen NSAG priority in an RRCSetup Request message, RRCSetup Completete message, RRCReconfiguration message, or any other existing or new RRC message, and sends at least one of these messages to the newly selected RAN5.

[0093] Modification 6 of the first example of the first embodiment: If cell reselection based on network slice is performed by UE AS302 in steps 6 and 11, UE AS302 may scan or monitor NSAG information transmitted by SIB (e.g., SIB16) and / or dedicated signaling in the current cell and in one or more neighboring cells. If a cell is configured as a Master Node (MN) for multi connectivity, as defined in 3GPP TS 37.340 [6], the MN may transmit (i.e., broadcast) NSAG information supported by one or more Secondary Nodes (one or more SNs) associated for multi connectivity, in addition to NSAG information supported by the MN. NSAG information may indicate one or more NSAGs, or information related to one or more NSAGs. NSAG information supported by one or more associated SNs may indicate at least one of their priorities related to one or more NSAGs and SNs. When the MN broadcasts NSAG information supported by one or more SNs, the MN may broadcast the NSAG information together with information indicating the one or more associated SNs. The information indicating one or more related SNs may be a frequency band, physical cell identification information, or ARFCN.

[0094] UE3 may remain in the current cell because UE AS302 receives NSAG information (e.g., one or more NSAGs) via dedicated signaling for the current cell, configured as an SIB (e.g., SIB16) and / or MN, and the NSAGs supported by one or more SNs (e.g., one or more NSAGs may be indicated by the NSAG information) best match the one or more NSAGs received from UE NAS301, then UE3 may remain in the current cell because, when a PDU session associated with one or more S-NSSAIs is established, the multi-connection with one or more SNs can provision one or more S-NSSAIs (or services associated with one or more S-NSSAIs) associated with one or more NSAGs supported by one or more SNs.

[0095] For example, if UE AS302 receives NSAG information (e.g., one or more NSAGs) through the SIB (e.g., SIB16) and / or dedicated signaling of neighboring cells, and one or more NSAGs supported by the MN or SN with respect to one or more neighboring cells (e.g., one or more NSAGs may be indicated by the NSAG information of one or more neighboring cells) best matches one or more NSAGs received from UE NAS301, then UE3 may re-select one or more neighboring cells, since S-NSSAI (one or more services associated with S-NSSAI) associated with the NSAGs supported by the MN or one or more SNs with respect to one or more neighboring cells can be provisioned by multi-connection with the MN and one or more SNs once a PDU session for S-NSSAI is established.

[0096] For example, UE AS302 may perform network slice-based cell reselection based on NSAG information for one or more broadcasted SNs.

[0097] An MN may obtain NSAG information for one or more related SNs from local configuration or by the XnAP protocol defined in 3GPP TS 38.423[7], or it may broadcast NSAG information for one or more related SNs. The NSAG information for one or more related SNs may include one or more NSAGs supported by the one or more related SNs, NSAG priorities associated with the one or more supported NSAGs, and other relevant information.

[0098] For example, an SN may send an Xn Setup message, an Xn Setup Response message, an NG-RAN node Configuration Update message, an NG-RAN node Configuration Update Acknowledge message, a Mobility Change request message, a Mobility Change Acknowledge message message, or any other existing or new XnAP message to an MN, which includes one or more NSAGs supported by the SN, the NSAG priority associated with the one or more supported NSAGs, and other relevant information.

[0099] Modification 7 of the first example of the first embodiment: For example, AMF70 sends an indicator to UE3 in an existing NAS message or a new NAS message (e.g., a Registration Accept message during an initial registration procedure or a periodic and mobility registration procedure) during an existing NAS procedure indicating whether the NSAG procedure is applicable to one or more S-NSSAIs within the Pending NSSAI. If the indicator indicates that the NSAG procedure is not applicable to one or more S-NSSAIs within the Pending NSSAI, UE NAS301 does not send one or more S-NSSAIs within the Pending NSSAI (or an NSAG associated with one or more S-NSSAIs within the Pending NSSAI) to UE AS302 for a slice-based cell reselection procedure. For example, if the indicator indicates that the NSAG procedure is not applicable to S-NSSAI#2 in Pending NSSAI, UE NAS301 does not have to send at least one of the Pending NSSAI and S-NSSAI#2 associated with NSAG#2 to UE AS302 in step 5 (or UE NAS301 may send at least one of NSAG#1 and NSAG priority associated with NSAG#1 to UE AS302 in step 5). For example, if the indicator indicates that the NSAG procedure is applicable to S-NSSAI#2 in Pending NSSAI, UE NAS301 may send at least one of the Pending NSSAI and S-NSSAI#2 associated with NSAG#2 to UE AS302 in step 5 (for example, UE NAS301 may send at least one of NSAG#1 and NSAG#2, and NSAG priority associated with at least one of NSAG#1 and NSAG#2 to UE AS302 in step 5). For example, UE AS302 may use Pending NSSAI, similar to Modification 3 of the first example of the Exemplary First Embodiment.

[0100] In one example, AMF70 sends an indicator for each S-NSSAI in Pending NSSAI. UE3 executes an NSAG procedure as the indicator for each S-NSSAI, as defined above in this variant. For example, if Pending NSSAI includes S-NSSAI#4 and S-NSSAI#5, the indicator may indicate that the NSAG procedure is not applicable to S-NSSAI#4 and is applicable to S-NSSAI#5. AMF70 may configure the indicator based on operator policy or local settings within AMF70. If the indicator indicates that the NSAG procedure is not applicable to S-NSSAI#4 and is applicable to S-NSSAI#5, UE NAS301 may send at least one of the NSAG associated with S-NSSAI#5 and the NSAG priority associated with S-NSSAI#5 to UE AS302. Next, UE AS302 may perform a slice-based cell reselection procedure based on at least one of the NSAG associated with S-NSSAI#5 and the NSAG priority associated with S-NSSAI#5.

[0101] The above modifications may be applied to a second example of the first exemplary embodiment.

[0102] The above problems can be solved by the first example of the exemplary first embodiment and the modification of the first example of the exemplary first embodiment.

[0103] For example, the first example of the first exemplary embodiment and the first variation of the first exemplary embodiment can resolve the issue of one or more ambiguous situations in the current 3GPP specification.

[0104] For example, the first example of the Exemplary First Embodiment and the first variation of the Exemplary First Embodiment can solve the problem of one or more ambiguous situations with respect to network slice-based cell reselection functions and NSAG, etc.

[0105] For example, the first example of the exemplary first embodiment and the first example of the exemplary first embodiment can solve the problem of uncertainty as to how one or more S-NSSAIs in the UE's Pending NSSAI should be used when the UE initiates a cell reselection function based on network slices.

[0106] In addition, for example, the first example of the Exemplary First Embodiment and the first variation of the Exemplary First Embodiment can solve the problem of uncertainty regarding how the source RAN selects candidate cells for handover.

[0107] For example, the first example of the exemplary first embodiment and the first example of the exemplary first embodiment can solve the problem of uncertainty as to how source RAN5 selects one or more candidate cells for handover by RAN selecting one or more candidate cells considering NSAG and NSAG priority.

[0108] A second example of the first exemplary embodiment: A second example of the exemplary first embodiment discloses a method by which UE NAS301 first selects NSAGs and NSAG priorities based on Allowed NSSAIs for network slice-based cell reselection, even though UE NAS301 has Pending NSSAIs on UE storage.

[0109] After all one or more NSSAA procedures are completed, UE NAS301 re-selects the NSAG and NSAG priority based on Allowed NSSAI if one or more S-NSSAIs from Pending NSSAI have succeeded with respect to one or more NSSAA procedures, and then UE NAS301 sends the selected NSAG and NSAG priority to the UE's AS layer (UE AS302).

[0110] The detailed processing of the second example of the first embodiment described below will be explained with reference to Figure 2.

[0111] Steps 1 and 2 are the same as steps 1 and 2 in Figure 1 for a first example of the exemplary first embodiment.

[0112] Step 3. Upon receiving the Registration Accept message in Step 2, the UE NAS301 selects an NSAG and NSAG priority based on one or more S-NSSAIs within the Allowed NSSAI. For example, the UE NAS301 may select NSAG#1 as the NSAG. For example, the UE NAS301 may select or decide that NSAG#2 has a higher priority than NSAG#1 as the NSAG priority. For example, the UE NAS301 may select an NSAG and NSAG priority based on one or more S-NSSAIs within the Allowed NSSAI before the NSSAA procedure for one or more S-NSSAIs within the Pending NSSAI is completed. For example, the UE NAS301 may select an NSAG and NSAG priority based on one or more S-NSSAIs within the Allowed NSSAI before the NSSAA procedure for S-NSSAI#2 within the Pending NSSAI is completed. For example, UE NAS301 may select an NSAG and NSAG priority based on one or more S-NSSAIs in Allowed NSSAI after the NSSAA procedure for one or more S-NSSAIs in Pending NSSAI has successfully completed. For example, UE NAS301 may select an NSAG and NSAG priority based on one or more S-NSSAIs in Allowed NSSAI after the NSSAA procedure for S-NSSAI#2 in Pending NSSAI has successfully completed.

[0113] Step 4 is the same as Step 4 in Figure 1 for a first example of the exemplary first embodiment. For example, UE NAS301 may send a Registration Complete message to AMF70 including the Chosen NSAG and Chosen NSAG priority.

[0114] The Chosen NSAG includes one or more NSAGs selected in step 3. The Chosen NSAG priority includes the NSAG priority determined in step 3.

[0115] For example, a Chosen NSAG may include NSAG#1. For example, a Chosen NSAG priority may include an NSAG priority indicating that NSAG#2 has a higher priority than NSAG#1.

[0116] AMF70 may execute one or more processes as shown in Figure 1.

[0117] Step 5. UE NAS301 notifies UE AS302 of the selected NSAG (e.g., NSAG#1).

[0118] NSAG priority may also be notified to the UE AS302. For example, even if only one NSAG is notified, the NSAG priority may still be notified to the UE AS302.

[0119] Step 6. UE AS302 may perform cell reselection based on the network slice based on the selected NSAG received in Step 5 (e.g., NSAG#1).

[0120] Step 7. The NSSAA procedure is performed between UE NAS301 and AAA 201 for S-NSSAI#2. Step 7 may be performed after Step 4 and before Step 5. Furthermore, the order of Step 7 and the set of Steps 4 and 5 may be swapped.

[0121] Step 8. After the NSSAA procedure is completed, UE NAS301 may re-select (or choose) the NSAG and NSAG priority based on the Allowed NSSAI (e.g., at least one of S-NSSAI#1 and S-NSSAI#2) if the NSSAA procedure in Step 7 was successful. If all one or more NSSAA procedures in Step 7 fail, UE NAS301 does not perform the NSAG and NSAG priority selection again, as there is no difference in the inputs for NSAG selection performed in Step 3. For example, UE NAS301 may select NSAG#1 and NSAG#2 as NSAGs. For example, UE NAS301 may choose or decide that NSAG#2 has a higher priority than NSAG#1 as an NSAG priority. The Allowed NSSAI in Step 8 may include at least S-NSSAI#2, since the NSSAA procedure for S-NSSAI#2 was successfully completed. The Allowed NSSAI in Step 8 may include at least S-NSSAI#1 and S-NSSAI#2, since the NSSAA procedure for S-NSSAI#2 was successfully completed.

[0122] Step 9 is the same as Step 9 in Figure 1 for a first example of an exemplary first embodiment. For example, Chosen NSAG may include NSAG#1 and NSAG#2. For example, Chosen NSAG priority may include NSAG priority indicating that NSAG#2 has a higher priority than NSAG#1.

[0123] Step 10. UE NAS301 may notify UE AS302 of the selected NSAGs (e.g., NSAG#1 and NSAG#2) and NSAG priorities (e.g., NSAG priorities indicating that NSAG#2 has a higher priority than NSAG#1).

[0124] Step 11. UE AS302 may perform cell reselection based on network slices based on the NSAGs (e.g., NSAG#1 and NSAG#2) and NSAG priorities (e.g., NSAG priorities indicating that NSAG#2 has a higher priority than NSAG#1) received in Step 10.

[0125] Modification 1 of the second example of the first exemplary embodiment: In step 8, if one or more NSSAA procedures are successfully executed for one or more S-NSSAIs, and UE NAS301 recognizes that the newly added S-NSSAIs are not supported by the current cell, then in step 11, cell reselection based on network slices is performed, and UE NAS301 suppresses all services on the newly added S-NSSAIs until UE3 confirms that the newly selected cell supports the NSAG of the newly added S-NSSAIs.

[0126] Based on the information received from the current cell (e.g., system information) and the information contained in the Registration Accept message in step 2, the UE NAS301 may recognize that one or more S-NSSAIs newly added to Allowed NSSAIs are not supported by the current cell. For example, suppose UE NAS301 receives a Registration Accept message in step 2, and UE3 receives system information from the current cell (e.g., the current RAN) that includes information related to NSAG#1 (e.g., this information indicates that the current cell supports NSAG#1 or supports S-NSSAI#1 related to NSAG#1).

[0127] In this case, if the execution of the NSSAA procedure for S-NSSAI#2 included in the Pending NSSAI is successful, UE3 will receive an Allowed NSSAI which includes at least S-NSSAI#2.

[0128] In this case, UE3 recognizes, based on system information, that the current cell does not support NSAG#2 or S-NSSAI#2 associated with NSAG#2.

[0129] Next, UE NAS301 may suppress all services on S-NSSAI#2 until cell reselection based on network slices is performed in step 11 and UE3 confirms that the newly selected cell supports NSAG for S-NSSAI#2. For example, UE3 may perform cell reselection based on network slices for a cell that supports NSAG for S-NSSAI#2, and then UE3 may start using one or more services on S-NSSAI#2.

[0130] The above problems can be solved by the second example of the exemplary first embodiment and the modified example of the second example of the exemplary first embodiment.

[0131] For example, the first example of the first exemplary embodiment and the first variation of the first exemplary embodiment can resolve the issue of one or more ambiguous situations in the current 3GPP specification.

[0132] For example, a second example of the exemplary first embodiment and a variation of the second example of the exemplary first embodiment can solve the problem of one or more ambiguous situations with respect to the cell reselection function based on network slices and with respect to NSAG.

[0133] For example, a second example of the exemplary first embodiment and a variation of the second example of the exemplary first embodiment can solve the problem of uncertainty as to how one or more S-NSSAIs in the UE's Pending NSSAI should be used when the UE initiates a cell reselection function based on network slices.

[0134] In addition, for example, a second example of the exemplary first embodiment and a variation of the second example of the exemplary first embodiment can solve the problem of uncertainty as to how the source RAN selects one or more candidate cells for handover.

[0135] For example, a second example of the exemplary first embodiment and a variation of the second example of the first embodiment can solve the problem of uncertainty as to how the source RAN selects one or more candidate cells for handover by having the RAN select one or more candidate cells taking into account the NSAG and the priority of the NSAG.

[0136] Exemplary second embodiment When the UE3 NAS layer (UE NAS301) initiates the network slice-based cell reselection function based on one or more new sets of S-NSSAI, the new sets of S-NSSAI are included in the Requested NSSAI in the Registration Request message when the UE initiates the registration procedure after the network slice-based cell reselection.

[0137] This exemplary embodiment discloses how UE3 can trigger the withdrawal of one or more S-NSSAIs from a Pending NSSAI in a network, for example, AMF 70.

[0138] A first example of the second exemplary embodiment: A first example of an exemplary second embodiment discloses a method for UE3 to cancel one or more S-NSSAIs within a Pending NSSAI.

[0139] If the NSSAA procedure is in progress and UE3 is no longer interested in one or more S-NSSAIs in Pending NSSAI, UE NAS301 sends a Registration Request message to AMF70 containing one or more S-NSSAIs in Withdrawing NSSAI. Withdrawing NSSAI indicates to AMF70 that UE3 is no longer interested in one or more such S-NSSAIs in Withdrawing NSSAI.

[0140] A detailed description of the first example of the second exemplary embodiment will be provided later with reference to Figure 3.

[0141] Steps 1 and 2 are the same as steps 1 and 2 in Figure 1 for a first example of the exemplary first embodiment.

[0142] Step 3. The NSSAA procedure is performed between UE NAS301 and AAA 201 for S-NSSAI#2 in Pending NSSAI.

[0143] Step 4. The UE NAS301 selects an NSAG and NSAG priority based on one or more new sets of S-NSSAI. In this example, S-NSSAI#3 is referred to as the new set of one or more S-NSSAI. For example, an application in the UE3 associated with S-NSSAI#3 is activated, and user data is buffered within the UE3 to be sent to the associated application server in the external network. The UE NAS301 may then select an NSAG and NSAG priority based on S-NSSAI#3. S-NSSAI#3 may be associated with NSAG#3. The UE NAS301 may then select an NSAG#3 and an NSAG priority for NSAG#3. For example, while the UE3 has a Pending NSSAI including S-NSSAI#2, the UE3 may perform one or more processes in Step 4. For example, the UE3 may perform one or more processes in Step 4 if the NSSAA procedure for S-NSSAI#2 is in progress.

[0144] Step 5. UE NAS301 notifies UE AS302 of the selected NSAG (e.g., NSAG#3).

[0145] Even if only one NSAG is notified, the NSAG priority (for example, the NSAG priority for NSAG#3) can also be notified to the UE AS302.

[0146] Step 6. UE AS302 may perform cell reselection based on the network slice based on the selected NSAG received in Step 5 (e.g., NSAG#3).

[0147] Step 7. Once cell reselection based on network slices is complete in Step 6, UE NAS301 sends a Registration Request message to AMF70 containing S-NSSAI#3 in the Requested NSSAI and S-NSSAI#2 in the Withdrawing NSSAI. For example, if UE3 has a Pending NSSAI containing S-NSSAI#2 (or if an NSSAA procedure for S-NSSAI#2 is in progress), UE NAS301 may send a Registration Request message to AMF70 containing S-NSSAI#3 in the Requested NSSAI and S-NSSAI#2 in the Withdrawing NSSAI. For example, UE NAS301 may perform one or more processes in Step 7 to cancel a Pending NSSAI containing S-NSSAI#2 (or release resources for a Pending NSSAI in the network) (for example, UE NAS301 may send a Withdrawing NSSAI containing S-NSSAI#2).

[0148] For example, UE NAS301 may perform one or more processes in step 7 without waiting for the completion of the NSSAA procedure for S-NSSAI#2 (for example, UE NAS301 may send a Withdrawing NSSAI containing S-NSSAI#2).

[0149] For example, according to one or more current 3GPP standards, there is no way to indicate that a Pending NSSAI has been revoked. For example, even if UE3 (or a user of UE3) is no longer interested in a Pending NSSAI (for example, UE3 is interested in a different service on one or more S-NSSAIs that are different from one or more S-NSSAIs in a Pending NSSAI), there is no way to indicate that the Pending NSSAI has been revoked (or that UE3 is no longer interested in a Pending NSSAI).

[0150] Therefore, maintaining one or more resources and NSSAA procedures for Pending NSSAI, which UE3 is not interested in, is meaningless or wasteful and can result in inefficient use of network resources.

[0151] Furthermore, we assume that UE3 is interested in S-NSSAI#3 and no longer interested in S-NSSAI#2 within Pending NSSAI, and that S-NSSAI#2 and S-NSSAI#3 do not share at least one common NSSRG value.

[0152] In this case, UE3 may not be able to send a Requested NSSAI containing S-NSSAI#3, even if it is no longer interested in S-NSSAI#2, because S-NSSAI#2 and S-NSSAI#3 do not share at least one common NSSRG value (or UE3 does not need to determine whether S-NSSAI#2 and S-NSSAI#3 share at least one common NSSRG value or determine the contents of the Requested NSSAI while S-NSSAI#2 is in a Pending NSSAI or before the NSSAA procedure for S-NSSAI#2 is successfully completed). Therefore, this may cause unnecessary service degradation by resulting in a delay in service activation for all services using S-NSSAI#3.

[0153] According to step 7 of this exemplary embodiment, UE NAS301 sends a Withdrawing NSSAI containing S-NSSAI#2 to indicate the cancellation of S-NSSAI#2 or Pending NSSAI (or to indicate that UE3 is no longer interested in S-NSSAI#2 or Pending NSSAI). In addition, UE NAS301 sends a Requested NSSAI containing S-NSSAI#3.

[0154] For example, UE NAS301 may perform one or more processes in step 7 without checking whether one or more S-NSSAIs in the Withdrawing NSSAI and one or more S-NSSAIs in the Requested NSSAI in step 7 share at least one common NSRG value (for example, without checking whether S-NSSAI#2 and S-NSSAI#3 share at least one common NSRG value) (for example, UE NAS301 may send a Withdrawing NSSAI containing S-NSSAI#2).

[0155] A Withdrawing NSSAI includes one or more S-NSSAIs that are in a Pending NSSAI in UE storage but that the UE wishes to remove from the Pending NSSAI. A Withdrawing NSSAI may also include one or more S-NSSAIs that are in a Pending NSSAI in UE storage but that the UE is not interested in.

[0156] For example, UE3 may delete a Pending NSSAI after sending a Withdrawing NSSAI (or if UE3 sends a Withdrawing NSSAI). For example, UE3 may abort the NSSAA procedure after sending a Withdrawing NSSAI (or if UE3 sends a Withdrawing NSSAI). For example, UE3 may abort the NSSAA procedure for S-NSSAI#2 after sending a Withdrawing NSSAI (or if UE3 sends a Withdrawing NSSAI). For example, if UE3 sends a Withdrawing NSSAI containing S-NSSAI#2, UE3 may delete the Pending NSSAI containing S-NSSAI#2, or delete S-NSSAI#2 from the Pending NSSAI. For example, UE NAS301 may send a Registration Request message containing a Withdrawing NSSAI whenever UE NAS301 can send a Registration Request message. For example, UE NAS301 may send a Registration Request message containing a Withdrawing NSSAI at any time. For example, UE NAS301 may send a Registration Request message containing a Withdrawing NSSAI whenever UE3 has a Pending NSSAI.

[0157] When AMF70 receives a Registration Request message that includes a Withdrawing NSSAI, AMF70 aborts the NSSAA procedure for one or more S-NSSAIs configured in Withdrawing NSSAI.

[0158] For example, consider a case where Withdrawing NSSAI includes S-NSSAI#2. In this case, AMF70 may abort the NSSAA procedure for S-NSSAI#2. For example, suppose AMF70 receives a Registration Request message containing a Withdrawing NSSAI, and assumes that the Withdrawing NSSAI contains S-NSSAI#2. In this case, AMF70 may abort the NSSAA procedure for S-NSSAI#2 if the NSSAA procedure for S-NSSAI#2 is in progress. In this case, AMF70 may abort the NSSAA procedure for S-NSSAI#2 if AMF70 determines that the NSSAA procedure for S-NSSAI#2 is in progress.

[0159] If AMF70 receives a Registration Request message containing a Withdrawing NSSAI and the NSSAA procedure has successfully completed for one or more S-NSSAIs configured within the Withdrawing NSSAI, AMF70 removes one or more S-NSSAIs from the Allowed NSSAI. For example, consider a scenario where the Withdrawing NSSAI includes S-NSSAI#2 and the NSSAA procedure for S-NSSAI#2 has been successfully completed (or where AMF70 receives a Withdrawing NSSAI containing S-NSSAI#2, and the NSSAA procedure for S-NSSAI#2 has been successfully completed when AMF received the Withdrawing NSSAI). In this case, AMF70 may remove S-NSSAI#2 from the Allowed NSSAI in AMF70, or AMF70 may not add S-NSSAI#2 to the Allowed NSSAI in AMF70. For example, AMF70 may send the Allowed NSSAI to UE3 without S-NSSAI#2, and UE3 may update the Allowed NSSAI in UE3 based on the Allowed NSSAI received without S-NSSAI#2.

[0160] If AMF70 receives a Registration Request message containing a Withdrawing NSSAI and the NSSAA procedure completes with failure for one or more S-NSSAIs set within the Withdrawing NSSAI, AMF70 may retain one or more S-NSSAIs in the Rejected NSSAI (for example, AMF70 may include one or more S-NSSAIs in the Rejected NSSAI, or move one or more S-NSSAIs from the Pending NSSAI to the Rejected NSSAI), or maintain the status of the NSSAA procedure for the Withdrawing NSSAI. For example, AMF70 may send the Rejected NSSAI to UE3. For example, suppose a Withdrawing NSSAI includes S-NSSAI#2, and the NSSAA procedure for S-NSSAI#2 fails. In this case, AMF70 may either keep S-NSSAI#2 in the Rejected NSSAI category, or maintain the status of the NSSAA procedure for the Withdrawing NSSAI (for example, AMF70 may maintain information as a status indicating that the NSSAA procedure for S-NSSAI#2 failed).

[0161] UE3 does not consider one or more S-NSSAIs in the Withdrawing NSSAI for the NSSRG procedure; that is, UE3 does not check whether one or more S-NSSAIs in the Withdrawing NSSAI share at least one common NSSRG value (or at least one common NSSRG group) with one or more S-NSSAIs in the Requested NSSAI in the Registration Request message. UE3 may check whether one or more S-NSSAIs in the Withdrawing NSSAI share at least one common NSSRG value with one or more S-NSSAIs in the Requested NSSAI in the Registration Request message.

[0162] Note that Withdrawing NSSAI may be expressed in other ways. For example, Withdrawing NSSAI may be expressed as any other notation for an NSSAI that includes one or more S-NSSAIs that are part of abandoned NSSAI, abandoned NSSAI, unrequested NSSAI, or pending NSSAI, but which UE3 is no longer interested in. For example, Withdrawing NSSAI may be expressed as any other notation for an NSSAI that includes one or more S-NSSAIs that are not added to Allowed NSSAI for UE3 after the NSSAA procedure is successful with respect to one or more S-NSSAIs.

[0163] Step 8. AMF70 sends a Registration Accept message to UE NAS301, including Configured NSSAI, Allowed NSSAI, Pending NSSAI, and NSAG priority. A configured NSSAI includes S-NSSAI#1 with associated NSAG#1, S-NSSAI#2 with associated NSAG#2, and S-NSSAI#3 with associated NSAG#3.

[0164] Here, the NSAG information in the Registration Accept message may include relationships between S-NSSAI and NSAGs (i.e., S-NSSAI#1 having related NSAG#1, S-NSSAI#2 having related NSAG#2, and S-NSSAI#3 having related NSAG#3).

[0165] Allowed NSSAIs include S-NSSAI#3.

[0166] NSAG priority indicates the priority between NSAGs.

[0167] After the successful registration procedure in steps 7 and 8, UE3 can only have S-NSSAI#3 in the Allowed NSSAI within UE3's storage.

[0168] For example, if UE3 receives a Registration Accept message, UE3 may delete the Pending NSSAI. For example, if UE3 receives a Registration Accept message, UE3 may delete the Pending NSSAI that contains S-NSSAI#2, or it may delete S-NSSAI#2 from the Pending NSSAI.

[0169] For example, AMF70 may send a request to delete a Pending NSSAI, or a request to remove one or more S-NSSAIs contained in a Withdrawing NSSAI from the Pending NSSAI. For example, AMF70 may send a request when it receives a Withdrawing NSSAI from UE3. The request may be included in a Registration Accept message or any other NAS message. If UE3 receives a request to delete a Pending NSSAI containing S-NSSAI#2, or a request to remove S-NSSAI#2 from a Pending NSSAI, UE3 may delete the Pending NSSAI or remove S-NSSAI#2 from the Pending NSSAI.

[0170] When AMF70 applies the NSRG procedure to an Allowed NSSAI, AMF70 does not check one or more S-NSSAIs in the Withdrawing NSSAI. That is, AMF70 does not check whether one or more S-NSSAIs in the Withdrawing NSSAI share at least one common NSRG group (or at least one common NSRG value) with one or more S-NSSAIs in the Allowed NSSAI. For example, AMF70 does not need to consider the NSRG values ​​of one or more S-NSSAIs in the Withdrawing NSSAI in order to determine the contents of the Allowed NSSAI (i.e., one or more S-NSSAIs in the Allowed NSSAI and one or more S-NSSAIs in the Withdrawing NSSAI of the Registration Request message in step 8 may or may not share at least one common NSRG value).

[0171] If AMF70 successfully increases the UE count by performing a NumOfUEsUpdate service operation for one or more S-NSSAIs in Withdrawing NSSAI (for example, if AMF70 successfully increases the UE count by performing a NumOfUEsUpdate service operation for S-NSSAI#2), AMF70 may start a NumOfUEsUpdate service operation for each of the one or more S-NSSAIs in Withdrawing NSSAI to decrease the UE count in NSACF (for example, AMF70 may start a NumOfUEsUpdate service operation for S-NSSAI#2 to decrease the UE count in NSACF).

[0172] Modification 1 of the first example in the second exemplary embodiment: For example, Withdrawing NSSAI can be sent from UE3 to AMF70 by another NAS message, such as a Registration complete message, Identity Response message, Authentication response message, UL NAS TRANSPORT message, De-registration request message, Configuration update complete message, Network slice-specific authentication complete message, or other existing NAS messages, or a new NAS message defined to revoke Pending NSSAI. In this case, AMF70 sends a response with any existing or new NAS message. For example, UE NAS301 may send the above message containing Withdrawing NSSAI whenever UE NAS301 is capable of sending such messages. For example, UE NAS301 may send the above message containing Withdrawing NSSAI at any time. For example, UE NAS301 may send the above message containing Withdrawing NSSAI whenever UE3 has Pending NSSAI.

[0173] Modification 2 of the first example in the second exemplary embodiment: In another example, in step 7, instead of UE3 indicating in the Withdrawing NSSAI that it is no longer interested in one or more S-NSSAIs from the Pending NSSAI, UE3 may use a new parameter, for example called "pending off," or any other notation for the parameter, in the NAS message to AMF70 to indicate that UE3 is no longer interested in one or more S-NSSAIs from the Pending NSSAI, so that AMF70 does not include the S-NSSAI in the Allowed NSSAI for UE if the NSSAA procedure for one or more S-NSSAIs is successful. This example is applicable when UE3 is no longer interested in all one or more S-NSSAIs from the Pending NSSAI. In such a case, UE3 may use a single flag in the NAS message to AMF70 instead of listing all one or more S-NSSAIs from the Pending NSSAI in the Withdrawing NSSAI.

[0174] For example, if AMF70 receives the "pending off" parameter, AMF70 may perform one or more of the same processes as in step 7.

[0175] For example, if AMF70 receives the "pending off" parameter, AMF70 may abort the NSSAA procedure for at least one or more S-NSSAIs within the Pending NSSAI.

[0176] For example, if AMF70 receives the "pending off" parameter and the NSSAA procedure has successfully completed for one or more S-NSSAIs in the Pending NSSAI, AMF70 may remove one or more S-NSSAIs from Allowed NSSAI.

[0177] For example, if AMF70 receives a “pending off” parameter and an NSSAA procedure fails for one or more S-NSSAIs in a Pending NSSAI, AMF70 may retain one or more S-NSSAIs in a Rejected NSSAI (for example, AMF70 may include one or more S-NSSAIs in a Rejected NSSAI, or move one or more S-NSSAIs from a Pending NSSAI to a Rejected NSSAI), or maintain the status of the NSSAA procedure for one or more S-NSSAIs.

[0178] Modification 3 of the first example in the second exemplary embodiment: For example, during an existing NAS procedure, AMF70 sends an indicator to UE3 in an existing or new NAS message (for example, in the Registration Accept message during the initial registration procedure or periodic and mobility registration procedures) indicating whether the NSSRG procedure is applicable to the Pending NSSAI. If the indicator indicates that the NSSRG procedure is not applicable to one or more S-NSSAIs in the Pending NSSAI, UE NAS301 does not check whether one or more S-NSSAIs in the Pending NSSAI share a common NSSRG value with one or more S-NSSAIs in the Requested NSSAI or Allowed NSSAI, i.e., it does not check whether the NSSRG procedure is applicable to one or more S-NSSAIs in the Pending NSSAI and one or more S-NSSAIs in the Requested NSSAI or Allowed NSSAI. If the indicator shows that the NSSRG procedure is applicable to the Pending NSSAI, UE NAS301 also applies the NSSRG procedure to one or more S-NSSAIs in the Pending NSSAI; that is, UE3 checks whether one or more S-NSSAIs in the Requested NSSAI or Allowed NSSAI and one or more S-NSSAIs in the Pending NSSAI share at least one common NSSRG value. The indicator may show that the NSSRG procedure is applicable to each S-NSSAI in the Pending NSSAI.

[0179] If the indicator shows that the NSSRG procedure is not applicable to S-NSSAI#2 in the Pending NSSAI, the UE NAS301 does not need to check whether S-NSSAI#2 and one or more S-NSSAIs in the Requested NSSAI or Allowed NSSAI share at least one common NSSRG value.

[0180] For example, in this case, even if S-NSSAI#2 and one or more of the Requested NSSAI or Allowed NSSAI do not share at least one common NSSRG value, the UE NAS301 may include S-NSSAI#2 and one or more of the Requested NSSAI or Allowed NSSAI in any NAS message.

[0181] A Withdrawing NSSAI may include at least one of the one or more S-NSSAIs of the Pending NSSAI.

[0182] Furthermore, if the indicator shows that the NSSRG procedure cannot be applied to S-NSSAI#2 in the Pending NSSAI, and UE NAS301 wants to include S-NSSAI#2 in the Withdrawing NSSAI (for example, UE3 is no longer interested in S-NSSAI#2 in the Pending NSSAI), UE NAS301 does not need to check whether S-NSSAI#2 and one or more S-NSSAIs in the Requested NSSAI or Allowed NSSAI share at least one common NSSRG value.

[0183] Therefore, if the indicator shows that the NSSRG procedure is not applicable to S-NSSAI#2 in Pending NSSAI, in step 7, UE NAS301 may send a Registration Request message including a Requested NSSAI containing S-NSSAI#3 and a Withdrawing NSSAI containing S-NSSAI#2, even if S-NSSAI#2 and S-NSSAI#3 do not share at least one common NSSRG value.

[0184] Modification 4 of the first example in the second exemplary embodiment: In step 2 or 8, if one or more neighboring TAs configure one or more NSAGs for one or more S-NSSAIs in the Configured NSSAI, AMF70 may include in the Registration Accept message one or more NSAGs (for example, one or more NSAGs associated with one or more neighboring TAs) and the TACs of one or more neighboring TAs located outside the current RA. For example, AMF70 may include in the Registration Accept message or any NAS message one or more combinations of one or more TACs of one or more neighboring TAs located outside the current RA and one or more NSAGs associated with one or more neighboring TAs. AMF70 may send the Registration Accept message or any NAS message to the UE NAS301. One or more combinations may be represented as NSAG information for one or more neighboring TAs, or NSAG information for one or more neighboring TAs located near the RA but not inside the RA. The AMF70 may obtain one or more combinations from other network nodes (e.g., another AMF). The AMF70 may store one or more combinations. The AMF70 may determine one or more combinations based on local configuration or operator policy. The NSAG information of one or more neighboring TAs may include NSAG priorities associated with one or more NSAGs related to one or more neighboring TAs. In other words, AMF70 may include NSAG information (e.g., one or more NSAGs) of one or more TAs located near the RA but not within the RA in the Registration Accept message, and one or more NSAGs may be associated with one or more TAs. The NSAG information of one or more TAs in the immediate vicinity outside the current RA is used by UE3 to select or reselect cells based on the network slice-based cell reselection function when UE3 moves away from the RA. For example, UE NAS301 may send the NSAG information of one or more neighboring TAs to UE AS302, and UE AS302 may use the NSAG information of one or more neighboring TAs to select or reselect cells based on the network slice-based cell reselection function.

[0185] If UE3 has moved from the current RA and UE3 (e.g., UE AS302) can scan for one or more candidate cells that transmit or broadcast one or more NSAGs and associated TACs via SIB (e.g., SIB16) and / or dedicated signaling, UE AS302 may check whether the broadcasted NSAGs and associated TACs match one or more NSAGs and NSAG priorities provided by UE NAS301. If at least one of the one or more NSAGs and NSAG priorities matches, UE3 may tune into that cell (e.g., UE AS302 may select or re-select that cell) and initiate the registration procedure (e.g., UE NAS301 may initiate the registration procedure in that cell).

[0186] For example, UE3 may determine that it can scan for one or more candidate cells that transmit or broadcast one or more NSAGs and associated TACs based on the NSAG information of one or more neighboring TAs.

[0187] If the NSAGs and their priorities do not match, UE3 selects a cell based on the existing cell selection mechanism and initiates the registration process.

[0188] The above modifications may be applied to the first exemplary embodiment.

[0189] The above problems can be solved by the first example of the second exemplary embodiment and the modified example of the first example of the second exemplary embodiment.

[0190] For example, the first example of the first exemplary embodiment and the first variation of the first exemplary embodiment can resolve the issue of one or more ambiguous situations in the current 3GPP specification.

[0191] For example, the first example of the exemplary second embodiment and the modifications of the first example of the exemplary second embodiment can solve the problem of one or more ambiguous situations with respect to network slice-based cell reselection functions and NSAG, etc.

[0192] For example, the first example of the exemplary second embodiment and the modifications of the first example of the exemplary second embodiment can solve the problem that the NSSAA procedure of one or more S-NSSAIs of Pending NSSAIs that the UE is no longer interested in may be meaningless.

[0193] For example, the first example of the exemplary second embodiment and variations of the first example of the exemplary second embodiment can solve the problem that the NSSAA procedure of one or more S-NSSAIs of Pending NSSAIs that the UE is no longer interested in may place a load on the network.

[0194] For example, the first example of the exemplary second embodiment and variations of the first example of the exemplary second embodiment can solve the problem that NSSAA procedures for one or more S-NSSAIs of a Pending NSSAI that the UE is no longer interested in may cause inefficient use of network resources. For example, the first example of the exemplary second embodiment and variations of the first example of the exemplary second embodiment can solve the problem that network resources for one or more S-NSSAIs of a Pending NSSAI may be unnecessarily maintained in the network without being used.

[0195] For example, the first example of the second exemplary embodiment and the modifications of the first example of the second exemplary embodiment can solve the problem that can cause delays in service activation and can cause unwanted service degradation for all services using one or more new sets of S-NSSAI.

[0196] For example, the first example of the second exemplary embodiment and the modifications of the first example of the second exemplary embodiment can solve the problem that when a UE crosses an RA boundary, the UE cannot select a suitable cell for one or more S-NSSAIs within the Allowed NSSAI based on the network slice-based cell reselection function, which could cause unnecessary service termination for all services using one or more S-NSSAIs within the Allowed NSSAI.

[0197] System Overview Figure 4 schematically shows a mobile (cellular or wireless) telecommunications system 1 to which the above exemplary embodiments can be applied.

[0198] Telecommunication system 1 represents a system overview capable of end-to-end communication. For example, UE3 (or user equipment, "mobile device", 3) communicates with other UE3 or service servers in the data network 20 via their respective (R)AN nodes 5 and core network 7.

[0199] (R)AN Node 5 supports any radio access, including 5G radio access technology (RAT), E-UTRA radio access technology, beyond 5G RAT, 6G RAT, and non-3GPP RAT, including wireless local area network (WLAN) technology as defined by Electrical and Electronics Engineers (IEEE).

[0200] (R)AN node 5 can be divided into a Radio Unit (RU), a Distributed Unit (DU), and a Centralized Unit (CU). In some exemplary embodiments, each of the units is connected to one another, and (R)AN node 5 can be constructed by adopting an architecture defined by the Open RAN (O-RAN) Alliance, where the above units are called O-RU, O-DU, and O-CU, respectively.

[0201] (R)AN node 5 may be divided into control plane functions and user plane functions. Furthermore, multiple user plane functions may be assigned to support communications. In some exemplary embodiments, user traffic may be distributed across multiple user plane functions, and user traffic on each user plane function is aggregated at both UE3 and (R)AN node 5. This divided architecture is sometimes referred to as "dual connectivity" or "multi-connectivity".

[0202] (R)AN node 5 can also support communications using satellite access. In some exemplary embodiments, (R)AN node 5 can support satellite access and ground access.

[0203] Furthermore, (R)AN node 5 can also be considered an access node for non-wireless access. Non-wireless access includes fixed-line access as defined by the Broadband Forum (BBF) and optical access as defined by the Innovative Optical and Wireless Network (IOWN).

[0204] The core network 7 may include logical nodes (or "functions") for supporting communication in the telecommunications system 1. For example, the core network 7 may be a 5GC including control plane functions and user plane functions, among many other functions. Each function within a logical node can be considered a network function. Network functions may be provided to other nodes by adapting SBAs.

[0205] Network functions can be deployed in a distributed, redundant, stateless, and scalable manner, providing services from several locations and several running instances at each location, by adapting network virtualization techniques defined by the European Telecommunications Standards Institute, Network Functions Virtualization (ETSI NFV). Core network 7 can support NPN. NPN can be SNPN or Public Network Integrated NPN (PNI-NPN).

[0206] As is well known, UE3 can enter and exit the area (i.e., radio cell) served by (R)AN node 5 when UE3 is moving within the geographical area covered by the telecommunication system 1. To track UE3 and facilitate movement between different (R)AN nodes 5, the core network 7 includes at least one AMF70. AMF70 communicates with (R)AN node 5 connected to the core network 7. In some core networks, instead of AMF70, a mobility management entity (MME) or a mobility management node for beyond 5G or a mobility management node for 6G can be used.

[0207] The core network 7 also includes, in particular, SMF71, UPF72, PCF73, AUSF74, UDM75, and NSSF76. When UE3 is roaming in a visited PLMN (VPLMN), the home PLMN (HPLMN) of UE3 provides UDM75 and at least a part of the functions of SMF71, UPF72, and PCF73 to the roaming UE3.

[0208] UE3 is connected to each serving (R)AN node 5 via an appropriate air interface (e.g., the so-called "Uu" interface, etc.). The neighboring (R)AN nodes 5 are connected to each other via an appropriate (R)AN node 5 and (R)AN node interface (the so-called "Xn" interface, etc.). Each (R)AN node 5 is also connected to a node (the so-called core network node, etc.) in the core network 7 via an appropriate interface (the so-called one or more "N2" / "N3" interfaces, etc.). A connection to the data network 20 is also provided from the core network 7. The data network 20 can be a PLMN's Internet, a public network, an external network, a private network, or an internal network. When the data network 20 is provided by a PLMN operator or a Mobile Virtual Network Operator (MVNO), the IP Multimedia Subsystem (IMS) service may be provided by that data network 20. UE3 can connect to the data network 20 using IPv4, IPv6, IPv4v6, Ethernet, or an unstructured data type. The data network may include AAA 201.

[0209] The "Uu" interface may include the control plane of the Uu interface and the user plane of the Uu interface.

[0210] The user plane of the Uu interface is responsible for transmitting user traffic between UE3 and the serving (R)AN node 5. The user plane of the Uu interface may have a hierarchical structure with SDAP, PDCP, RLC, and MAC sublayers on the physical connection.

[0211] The Uu interface control plane is responsible for establishing, modifying, and releasing connections between UE3 and Serving(R)AN node 5. The Uu interface control plane may have a hierarchical structure with RRC, PDCP, RLC, and MAC sublayers via physical connections.

[0212] For example, the following message is communicated via the RRC layer to support AS signaling. - RRC Setup Request message: This message is sent from UE3 to (R)AN node 5. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be included together in the RRC Setup Request message. -EstablishmentCause and ue-Identity: ue-Identity may have the value of ng-5G-S-TMSI-Part1 or randomValue. -RRC Setup message: This message is sent from (R)AN node 5 to UE3. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be included together in the RRC Setup message. -masterCellGroup and radioBearerConfig RRC setup complete message: This message is sent from UE3 to (R)AN node 5. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be included together in the RRC setup complete message. -guami-Type, iab-NodeIndication, idleMeasAvailable, mobilityState, ng-5G-S-TMSI-Part2, registeredAMF, selectedPLMN-Identity.

[0213] The UE3 and AMF70 are connected via an appropriate interface (e.g., the so-called N1 interface). The N1 interface is responsible for providing communication between the UE3 and AMF70 to support NAS signaling. The N1 interface can be established via 3GPP access and non-3GPP access. For example, the following messages are communicated via the N1 interface. -Registration request message: This message is sent from UE3 to AMF70. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be included together in the registration request message. -5GS registration type, ngKSI, 5GS mobile identification information, non-current native NAS keyset identifier, 5GMM capability, UE security capability, Requested NSSAI, Last Visit Registered TAI, S1 UE network capability, uplink data status, PDU session status, MICO instruction, UE status, additional GUTI, authorized PDU session status, UE usage settings, requested DRX parameters, EPS NAS message container, LADN instruction, payload container type, payload container, network slicing instruction, 5GS update type, mobile station class mark 2, supported codecs, NAS message container, EPS bearer context status, requested extended DRX parameters, T3324 value, UE radio capability ID, requested mapped NSSAI, requested information, requested WUS assistance information, N5GC instruction and requested NB-N1 mode DRX parameters. -Registration accept message: This message is sent from AMF70 to UE3. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be included together in the registration accept message. -5GS registration result, 5G-GUTI, equivalent PLMN, TAI list Allowed NSSAI, Rejected NSSAI, Configured NSSAI, 5GS network function support, PDU session status, PDU session reactivation result, PDU session reactivation result error cause, LADN information, MICO instruction, network slicing instruction, service area list, T3512 value, non-3GPP registration timer value, T3502 value, emergency number list, extended emergency number list, SOR transparent container, EAP message, NSSAI inclusion mode, operator defined access category definition, negotiate DRX parameters, non-3GPP NW policy, EPS bearer context status, negotiate extended DRX parameters, T3447 value, T3448 value, T3324 value, UE radio capability ID, UE radio capability ID deletion instruction, Pending NSSAI, encryption key data, CAG information list, truncated 5G-S-TMSI settings, negotiated WUS support information, negotiated NB-N1 mode DRX parameters, and extended rejected NSSAI. -Registration Complete message: This message is sent from UE3 to AMF70. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be included together in the Registration Complete message. - SOR transparent container -Authentication Request message: This message is sent from AMF70 to UE3. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be included together in the Authentication Request message. -ngKSI, ABBA, authentication parameter RAND (5G authentication challenge), authentication parameter AUTN (5G authentication challenge), and EAP message. -Authentication Response message: This message is sent from UE3 to AMF70. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be entered together with the Authentication Response message. -Authentication Response message identifier, Authentication Response parameters, and EAP message. -Authentication Result message: This message is sent from AMF70 to UE3. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be entered together with the Authentication Result message. -ngKSI, EAP messages, and ABBA. -Authentication Failure Message: This message is sent from UE3 to AMF70. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be entered together with the Authentication Failure message. -Authentication Failure message identification information, 5GMM cause, and Authentication Failure parameters. -Authentication Reject message: This message is sent from AMF70 to UE3. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be entered together with the Authentication Reject message. -EAP message -Service Request message: This message is sent from UE3 to AMF70. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be entered together with the Service Request message. -ngKSI, service type, 5G-S-TMSI, uplink data status, PDU session status, authorized PDU session status, NAS message container. -Service Accept message: This message is sent from AMF70 to UE3. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be entered together with the Service Accept message. - PDU session status, PDU session reactivation result, PDU session reactivation result error cause, EAP message, and T3448 value. -Service Reject message: This message is sent from AMF70 to UE3. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be entered together with the Service Reject message. -5GMM cause, PDU session status, T3346 value, EAP message, T3448 value, and CAG information list. -Configuration Update Command message: This message is sent from AMF70 to UE3. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be entered together with the Configuration Update Command message. - Configuration update instructions, 5G-GUTI, TAI list, Allowed NSSAI, Service Area list, Network full name, Network short name, Local time zone, Universal time and local time zone, Network Daylight Saving Time, LADN information, MICO instructions, Network slicing instructions, Configured NSSAI, Rejected NSSAI, Operator-defined access category definition, SMS instructions, T3447 value, CAG information list, UE radio capability ID, UE radio capability ID deletion instructions, 5GS registration results, Truncated 5G-S-TMSI settings, Additional configuration instructions and extended rejected NSSAI. -Configuration Update Complete message: This message is sent from UE3 to AMF70. In addition to the parameters disclosed in exemplary embodiments of this disclosure, the following parameters may be included in the Configuration Update Complete message: -Configuration Update Complete message identifier

[0214] User Equipment (UE) Figure 5 is a block diagram showing the main components of UE3 (Mobile Device 3). As shown, UE3 includes a transceiver circuit 31 capable of transmitting signals to and receiving signals from one or more nodes connected via one or more antennas 32. Furthermore, UE3 may include a user interface 34 for inputting or outputting information from the outside. Although not necessarily shown in the figure, UE3 may have all the usual functions of a conventional mobile device, which may be provided by one or any combination of hardware, software, and firmware, as needed. The software may be pre-installed in memory and / or downloaded, for example, via a telecommunications network or from a removable data storage device (RMD). The control unit 33 controls the operation of UE3 according to the software stored in memory 36. The software may include, among others, an operating system 361 and a communication control module 362 having at least a transceiver control module 3621. The communication control module 362 (using its transceiver control module 3621) is responsible for processing (generating / transmitting / receiving) signaling and uplink / downlink data packets between the UE3 and other nodes such as the (R)AN node 5 and AMF70. Such signaling may include, for example, appropriately formatted signaling messages relating to access and mobility management procedures (for the UE3) (e.g., registration request messages and associated response messages). The control unit 33 interacts with one or more Universal Subscriber Identity Modules (USIMs) 35. If multiple USIMs 35 are installed, the control unit 33 may activate just one USIM 35 or multiple USIMs 35 simultaneously.

[0215] UE3 may support NPN, for example, and NPN may be SNPN or PNI-NPN.

[0216] UE3 may be, for example, an item of equipment for production or manufacturing and / or energy-related machinery (such as boilers, engines, turbines, solar panels, wind turbines, hydroelectric generators, thermal power plants, nuclear power generators, batteries, nuclear systems and / or related equipment, heavy electrical machinery, pumps including vacuum pumps, compressors, fans, blowers, hydraulic equipment, pneumatic equipment, metalworking machinery, manipulators, robots and / or their application systems, tools, dies or molds, rolls, conveying devices, elevators, material handling devices, textile machinery, sewing equipment, printing and / or related machinery, paper processing equipment, chemical machinery, mining machinery and / or construction machinery and / or related facilities, machinery and / or appliances for agriculture, forestry and / or fisheries, safety and / or environmental protection equipment, tractors, precision bearings, chains, gears, power transmission devices, lubrication devices, valves, pipe joints, and / or application systems for any of the aforementioned equipment or machinery, etc.).

[0217] UE3 may be, for example, an item of transportation equipment (such as transportation equipment like rolled materials, automobiles, motorcycles, bicycles, trains, buses, carts, human-powered vehicles, ships and other vessels, aircraft, rockets, satellites, drones, balloons, etc.).

[0218] UE3 may be, for example, an item of information and communication equipment (such as information and communication equipment like electronic computers and related equipment, communication and related equipment, electronic components, etc.).

[0219] UE3 may be, for example, an item of refrigerators, refrigerator application products, goods and / or service industry equipment, vending machines, self-service machines, office machines or equipment, consumer electronics and electronic devices (such as consumer electronics like audio devices, video devices, speakers, radios, TVs, microwave ovens, rice cookers, coffee machines, dishwashers, washing machines, dryers, electric fans or related equipment, vacuum cleaners, etc.).

[0220] UE3 may be, for example, an electrical application system or device (e.g., an X-ray system, particle accelerator, radioisotope device, sound wave device, electromagnetic application device, electronic power application device, etc.).

[0221] UE3 may include, for example, electronic lamps, lighting fixtures, measuring instruments, analyzers, testers, or surveying or sensing equipment (e.g., surveying or sensing equipment such as smoke detectors, motion sensors, wireless tags, etc.), wristwatches or clocks, inspection equipment, optical devices, medical equipment and / or systems, weapons, tableware items, hand tools, etc.

[0222] UE3 may be, for example, a wireless-equipped portable information terminal or related equipment (for example, a wireless card or module designed to be attached to or inserted into another electronic device (for example, a personal computer, an electrical measuring instrument)).

[0223] UE3 may be part of a device or system that uses various wired and / or wireless communication technologies to provide the applications, services, and solutions described below with respect to the Internet of Things (IoT).

[0224] Internet of Things (IoT) devices (or "Things") may comprise appropriate electronics, software, sensors, network connectivity, etc., that enable these devices to collect and exchange data with each other and with other communication devices. IoT devices may comprise automated devices that follow software instructions stored in internal memory. IoT devices may operate without requiring human supervision or interaction. IoT devices may also remain stationary and / or inactive for extended periods. IoT devices may be implemented as part of (generally) stationary devices. IoT devices may also be embedded in non-stationary devices (e.g., vehicles) or attached to animals or people being monitored / tracked.

[0225] It will be understood that IoT technology may be implemented on any communication device that can connect to a communication network to send / receive data, regardless of whether such communication device is controlled by human input or software instructions stored in memory.

[0226] It should be understood that IoT devices are sometimes called Machine-Type Communication (MTC) devices, Machine-to-Machine (M2M) communication devices, or Narrow Band-IoT UE (NB-IoT UE). It should be understood that UE3 can support one or more IoT or MTC applications.

[0227] UE3 can be a smartphone or a wearable device (e.g., smart glasses, smartwatch, smart ring, or hearable device).

[0228] UE3 may be an automobile, connected car, autonomous vehicle, vehicle device, motorcycle, or V2X (Vehicle to Everything) communication module (e.g., a vehicle-to-vehicle communication module, a vehicle-to-infrastructure communication module, a vehicle-to-people communication module, and a vehicle-to-network communication module).

[0229] (R)AN node Figure 6 is a block diagram showing the main components of an exemplary (R)AN node 5, for example, a base station (eNB in ​​LTE, gNB in ​​5G, a 5G beyond base station, a 6G base station). As shown in the diagram, the (R)AN node 5 includes a transceiver circuit 51 that is capable of transmitting and receiving signals from one or more UE3 connected via one or more antennas 52, and transmitting and receiving signals from other network nodes (directly or indirectly) via a network interface 53. A control unit 54 controls the operation of the (R)AN node 5 according to software stored in memory 55. The software may be pre-installed in memory and / or downloaded, for example, via a telecommunications network or from a removable data storage device (RMD). The software may include, among other things, an operating system 551 and a communication control module 552 having at least a transceiver control module 5521.

[0230] The communication control module 552 (using its transceiver control submodule) is responsible for processing (generating / transmitting / receiving) signaling between (R)AN node 5 and other nodes such as UE3, another (R)AN node 5, AMF70, and UPF72 (e.g., directly or indirectly). The signaling may include, for example, appropriately formatted signaling messages related to radio connectivity and connection with the core network 7 (for a particular UE3), particularly connection establishment and maintenance (e.g., RRC connection establishment and other RRC messages), NG Application Protocol (NGAP) messages (i.e., messages from the N2 reference point) and Xn application protocol (XnAP) messages (i.e., messages from the Xn reference point). Such signaling may also include, for example, broadcast information (e.g., master information and system information) when transmitted.

[0231] The control unit 54, once implemented, is also configured (by software or hardware) to handle related tasks such as UE mobility estimation and / or movement trajectory estimation.

[0232] (R) AN node 5 may support NPN, and the NPN may be SNPN or PNI-NPN.

[0233] The current RAN501 and candidate RAN502 may have the same components as (R)AN node 5. (R)AN node 5 may also be referred to as RAN node, RAN, (R)AN, etc.

[0234] System Overview of (R)AN Node 5 Based on O-RAN Architecture Figure 7 schematically shows (R)AN node 5 based on an O-RAN architecture to which the (R)AN node 5 configuration can be applied.

[0235] A (R)AN node 5 based on the O-RAN architecture represents a system overview in which the (R)AN node is divided into a radio unit (RU) 60, a distributed unit (DU) 61, and a central unit (CU) 62. In some exemplary embodiments, each unit can be combined. For example, RU 60 may be integrated / coupled with DU 61 as an integration / coupled unit, and DU 61 may be integrated / coupled with CU 62 as another integration / coupled unit. Any function in the description of a unit (e.g., one of RU 60, DU 61, and CU 62) may be implemented in the above integration / coupled unit. Furthermore, CU 62 can be separated into two functional units, such as a CU control plane (CP) and a CU user plane (UP). The CU CP has the control plane function in (R)AN node 5. The CU UP has the user plane function in (R)AN node 5. Each CU CP is connected to the CU UP via an appropriate interface "E1".

[0236] UE3 and each serving RU60 are connected via the appropriate air interface "Uu". Each RU60 is connected to DU61 via the appropriate interface (e.g., so-called "fronthaul", "open fronthaul", "F1" interface, etc.). Each DU61 is connected to CU62 via the appropriate interface (e.g., so-called "midhaul", "open midhaul", "E2" interface, etc.). Each CU62 is also connected to a node in the core network 7 (e.g., so-called core network node) via the appropriate interface (e.g., so-called "backhaul", "open backhaul", one or more "N2" / "N3" interfaces, etc.). Furthermore, the user plane portion of DU61 may also be connected to the core network node 7 via one or more appropriate interfaces "N3".

[0237] Depending on the functions divided among RU60, DU61, and CU62, each unit provides a portion of the functions provided by (R)AN node 5. For example, RU60 can provide the function for communicating with UE3 via the air interface, DU61 can provide the function for supporting the MAC layer and RLC layer, and CU62 can provide the function for supporting the PDCP layer, SDAP layer, and RRC layer.

[0238] Wireless Unit (RU) Figure 8 is a block diagram showing the main components of the RU portion of an exemplary RU60, for example, a base station (eNB in ​​LTE, gNB in ​​5G, a 5G beyond base station, a 6G base station). As shown in the diagram, the RU60 includes a transceiver circuit 601 that is capable of transmitting and receiving signals from one or more UE3 connected via one or more antennas 602, and transmitting and receiving signals from other network nodes or network units (directly or indirectly) via a network interface 603. The control unit 604 controls the operation of the RU60 according to software stored in memory 605. The software may be pre-installed in memory and / or downloaded, for example, via a telecommunications network or from a removable data storage device (RMD). The software may include, among many, an operating system 6051 and a communication control module 6052 having at least a transceiver control module 60521.

[0239] The communication control module 6052 is responsible for processing (generating / transmitting / receiving) signaling between RU60 and other nodes or units such as UE3, another RU60, and DU61 (e.g., directly or indirectly). The signaling may include, for example, appropriately formatted signaling messages regarding radio connectivity and connections with RU60 (for a particular UE3), particularly concerning the MAC and RLC layers.

[0240] The control unit 604, once implemented, is also configured (by software or hardware) to handle related tasks such as UE mobility estimation and / or movement trajectory estimation.

[0241] The RU60 may support NPN, which may be Stand-alone Non-Public (SNPN) or PNI-NPN.

[0242] As described above, RU60 may be integrated / coupled with DU61 as an integration / coupling unit. Any functions described in the description of RU60 may be implemented in the above integration / coupling unit.

[0243] Distribution Unit (DU) Figure 9 is a block diagram showing the main components of the DU section of an exemplary DU61, for example, a base station (eNB in ​​LTE, gNB in ​​5G, a 5G beyond base station, a 6G base station). As shown in the figure, the device includes a transceiver circuit 611 that is operable to transmit signals to and receive signals from other nodes or units (including RU60) via a network interface 612. A control unit 613 controls the operation of the DU61 according to software stored in memory 614. The software may be pre-installed in memory 614 and / or downloaded, for example, via a telecommunications network or from a removable data storage device (RMD). The software may include, among many, an operating system 6141 and a communication control module 6142 having at least a transceiver control module 61421. The communication control module 6142 (using its transceiver control module 61421) is responsible for handling (generating / transmitting / receiving) signaling between DU61 and other nodes or units, such as RU60 and other nodes and units.

[0244] DU61 may support NPN, which may be SNPN or PNI-NPN.

[0245] As described above, RU60 may be integrated / coupled with DU61 or CU62 as an integration / coupling unit. Any function described in the description of DU61 may be performed by one of the above integration / coupling units.

[0246] Central Unit (CU) Figure 10 is a block diagram showing the main components of the CU portion of an exemplary CU62, for example, a base station (eNB in ​​LTE, gNB in ​​5G, a 5G beyond base station, a 6G base station). As shown in the figure, the device includes a transceiver circuit 621 that is operable to transmit signals to and receive signals from other nodes or units (including DU61) via a network interface 622. A control unit 623 controls the operation of the CU62 according to software stored in memory 624. The software may be pre-installed in memory 624 and / or downloaded, for example, via a telecommunications network or from a removable data storage device (RMD). The software includes, among many, an operating system 6241 and a communication control module 6242 having at least a transceiver control module 62421. The communication control module 6242 (using its transceiver control module 62421) is responsible for handling (generating / transmitting / receiving) signaling between CU62 and DU61 and other nodes or units such as other nodes and units.

[0247] CU62 may support NPN, which may be SNPN or PNI-NPN.

[0248] As described above, CU62 may be integrated / coupled with DU61 as an integration / coupling unit. Any functions described in the description of CU62 may be implemented in the above integration / coupling unit.

[0249] AMF Figure 11 is a block diagram showing the main components of the AMF70. As shown, the device includes a transceiver circuit 701 that can operate to transmit signals to and receive signals from other nodes (including UE3 and NSSF76) via a network interface 702. The control unit 703 controls the operation of the AMF70 according to software stored in memory 704. The software may be pre-installed in memory 704 and / or downloaded, for example, via a telecommunications network or from a removable data storage device (RMD). The software includes, among other things, an operating system 7041 and a communication control module 7042 having at least a transceiver control module 70421. The communication control module 7042 (using its transceiver control module 70421) is responsible for processing (generating / transmitting / receiving) signaling between the AMF 70 and other nodes, such as UE3 (e.g., via (R)AN node 5) and other core network nodes (including core network nodes in UE3's HPLMN when UE3 is roaming). Such signaling may include, for example, appropriately formatted signaling messages relating to access and mobility management procedures (for UE3) (e.g., registration request messages and associated response messages).

[0250] AMF70 may support NPN, which may be SNPN or PNI-NPN. AMF7001 and AMF7002 may have the same components as AMF70.

[0251] PCF Figure 12 is a block diagram showing the main components of the PCF 73. As shown, the device includes a transceiver circuit 731 that is capable of transmitting signals to and receiving signals from other nodes (including the AMF 70) via a network interface 732. The control unit 733 controls the operation of the PCF 73 according to software stored in memory 734. The software may be pre-installed in memory 734 and / or downloaded, for example, via a telecommunications network or from a removable data storage device (e.g., a removable data storage device (RMD)). The software includes, among many, an operating system 7341 and a communication control module 7342 having at least a transceiver control module 73421. The communication control module 7342 (using its transceiver control module 73421) is responsible for handling (generating / sending / receiving) signaling between PCF73 and other nodes, such as AMF70 and other core network nodes (including core network nodes in UE3's HPLMN when UE3 is roaming). Such signaling may include, for example, well-formatted signaling messages related to policy management procedures (for UE3) (e.g., a convenient HTTP method based on a service-based interface).

[0252] PCF73 may support NPN, which may be SNPN or PNI-NPN. PCF7301 and PCF7302 may have the same components as PCF73.

[0253] AUSF Figure 13 is a block diagram showing the main components of the AUSF 74. As shown, the device includes a transceiver circuit 741 that is capable of transmitting signals to and receiving signals from other nodes (including UDM 75) via a network interface 742. A control unit 743 controls the operation of the AUSF 74 according to software stored in memory 744. The software may be pre-installed in memory 744 and / or downloaded, for example, via a telecommunications network or from a removable data storage device (e.g., a removable data storage device (RMD)). The software includes, among many, an operating system 7441 and a communication control module 7442 having at least a transceiver control module 74421. The communication control module 7442 (using its transceiver control module 74421) is responsible for handling (generating / sending / receiving) signaling between AUSF74 and other nodes, such as AMF70 and other core network nodes (including core network nodes in UE3's HPLMN when UE3 is roaming). Such signaling may include, for example, well-formatted signaling messages related to policy management procedures (for UE3) (e.g., a convenient HTTP method based on a service-based interface).

[0254] AUSF74 may support NPN, which may be SNPN or PNI-NPN.

[0255] UDM Figure 14 is a block diagram showing the main components of the UDM 75. As shown, the device includes a transceiver circuit 751 that is capable of transmitting signals to and receiving signals from other nodes (including AMF 70) via a network interface 752. A control unit 753 controls the operation of the UDM 75 according to software stored in memory 754. The software may be pre-installed in memory 754 and / or downloaded, for example, via a telecommunications network or from a removable data storage device (RMD). The software includes, among other things, an operating system 7541 and a communication control module 7542 having at least a transceiver control module 75421. The communication control module 7542 (using its transceiver control module 75421) is responsible for handling (generating / transmitting / receiving) signaling between the UDM 75 and other nodes, for example, AMF 70 and other core network nodes (including core network nodes in the VPLMN of UE3 when UE3 is roaming). Such signaling could include, for example, well-formatted signaling messages related to mobility management procedures (for UE3) (e.g., a convenient HTTP method based on a service-based interface).

[0256] The UDM75 may support NPN, which may be SNPN or PNI-NPN.

[0257] NSSF Figure 15 is a block diagram showing the main components of NSSF76. As shown, the device includes a transceiver circuit 761 that is capable of transmitting signals to and receiving signals from other nodes (including AMF70) via a network interface 762. A controller 763 controls the operation of NSSF76 according to software stored in memory 764. The software may be pre-installed in memory 764 and / or downloaded, for example, via a telecommunications network or from a removable data storage device (RMD). The software includes, among other things, an operating system 7641 and a communications control module 7642 having at least a transceiver control module 76421. The communications control module 7642 (using its transceiver control module 76421) is responsible for handling (generating / transmitting / receiving) signaling between NSSF76 and other nodes, such as AMF70 and other core network nodes (including core network nodes in the VPLMN of UE3 when UE3 is roaming). Such signaling could include, for example, well-formatted signaling messages related to mobility management procedures (for UE3) (e.g., a convenient HTTP method based on a service-based interface).

[0258] NSSF76 may support NPN, which may be SNPN or PNI-NPN.

[0259] The exemplary embodiments disclosed above, in whole or in part, may be described as follows, but are not limited thereto.

[0260] 5.3.4.3.4 Cell reselection based on network slice If one or more S-NSSAIs are associated with one or more NSAGs, the UE can perform cell reselection based on network slices, as described in TS38.300

[27] , TS38.304

[50] , TS38.331

[28] , and TS24.501

[47] .

[0261] When providing NSAG information to the UE, the AMF must also provide NSAG priority information for the NSAGs provided in the NSAG information. The AMF will determine the NSAG priority information based on the operator's policy. If the UE receives NSAG priority information from the AMF, the UE shall use the NSAG priority information provided by the AMF for cell reselection, as described below. If the UE does not receive any NSAG priority information from the AMF, the UE shall not use cell reselection based on network slices at all.

[0262] The UE NAS provides the UE AS with the NSAGs and their priorities received from the AMF for S-NSSAIs in Allowed NSSAIs and Pending NSSAIs with 3GPP access, as input for cell reselection. If the UE NAS provides the UE AS with the NSAGs and their priorities for one or more S-NSSAIs from Pending NSSAIs and one or more S-NSSAIs from Pending NSSAIs, but one or more S-NSSAIs are rejected, the UE NAS updates the UE AS again with the NSAGs and their priorities for Allowed NSSAIs only. Unless the UE intends to register a new set of S-NSSAIs with a Requested NSSAI that is different from the current Allowed NSSAI, in which case the UE NAS provides the UE AS layer with the NSAGs and their priorities received from the AMF for S-NSSAIs in Requested NSSAIs and pending NSSAIs with 3GPP access, if stored in the UE, thereby triggering cell reselection before sending a Registration Request containing the new Requested NSSAI.

[0263] Note: How the UE NAS provides NSAG priority to the UE AS is based on the internal UE interface and is not specified.

[0264] 4.6 Network Slices 4.6.1 General 5GS supports network slicing as described in 3GPP TS23.501[8]. Within a PLMN or SNPN, a network slice is identified by an S-NSSAI consisting of a slice / service type (SST) and a slice differentiator (SD). Inclusion of an SD in an S-NSSAI is optional. A set of one or more S-NSSAIs is called an NSSAI. The following NSSAIs are defined in 3GPP TS 23.501[8]. a) configured NSSAI b) requested NSSAI c) Allowed NSSAI d) Subscribed S-NSSAIs e) pending NSSAI, and f) Abandon NSSAI

[0265] In this document, the following NSSAIs are defined: a) Rejected NSSAI of current PLMN or SNPN b) Rejected NSSAI in the current registration area c) Rejected NSSAIs of failed or expired NSSAAs, and d) Maximum number of rejected NSSAI reached UE

[0266] In a roaming scenario, a rejected NSSAI for the current PLMN or SNPN, or a rejected NSSAI for the current registration area, or a rejected NSSAI for the maximum number of UEs reached, includes one or more S-NSSAIs for the current PLMN, and, if available, a set of one or more mapped S-NSSAIs. S-NSSAIs included in a rejected NSSAI for a failed or expired NSSAA are HPLMN S-NSSAIs.

[0267] In the case of PLMNs, a serving PLMN can configure the UE using a configured NSSAI for each PLMN, and using NSRG information if the UE indicates that it supports subscription-based limits on simultaneous registration of network slice functionality. In addition, an HPLMN can configure the UE using a single default configured NSSAI, and in PLMNs where the UE does not have a configured NSSAI or an allowed NSSAI, the default configured NSSAI can be considered valid.

[0268] Note 1: The one or more values ​​used in the default configured NSSAI are expected to be determined by all roaming partners, such as values ​​standardized by 3GPP or other organizations. In the case of an SNPN, the SNPN may configure the UE using a configured NSSAI applicable to the SNPN, and, if the UE is neither currently enrolled nor already enrolled in the onboarding service within the SNPN, using NSRG information if the UE indicates that it supports subscription-based limits on simultaneous enrollment of network slice functionality. In addition, the credential holder may set a single default configured NSSAI associated with the "List of Subscriber Data" or selected entries in a PLMN subscription, and that default configured NSSAI may be considered valid in an SNPN where the UE has neither a configured NSSAI nor an allowed NSSAI. If the UE is currently enrolled in or already enrolled in the onboarding service within the SNPN, the serving SNPN shall not provide the UE with a configured NSSAI.

[0269] The allowed and rejected NSSAIs for a current registration area are managed independently for each access type, i.e., for each 3GPP access or non-3GPP access, and are applicable to the registration area. If a UE does not have a valid registration area, the rejected NSSAIs for the current registration area are applicable to the tracking area from which they were received. If a registration area contains TAIs belonging to different PLMNs that are equivalent PLMNs, the allowed and rejected NSSAIs for the current registration area are applicable to those PLMNs within this registration area.

[0270] An allowed NSSAI associated with a registration area containing a TAI belonging to a different PLMN that is equivalent to a PLMN may be used to form a Requested NSSAI for one of the equivalent PLMNs when the UE is outside the registration area that received the allowed NSSAI.

[0271] If a network slice-specific authentication and authorization procedure is initiated for one or more S-NSSAIs within a Requested NSSAI, or if a network slice-specific authentication and authorization procedure is in progress for one or more S-NSSAIs, these one or more S-NSSAIs are included in the Pending NSSAI. Once the network slice-specific authentication and authorization procedure is completed for an S-NSSAI that was in the Pending NSSAI, the S-NSSAI is moved to either the allowed NSSAI or the rejected NSSAI, depending on the outcome of the procedure. The AMF sends the updated allowed NSSAI to the UE via the same access to the requested S-NSSAI. The AMF sends the updated rejected NSSAI via either 3GPP access or non-3GPP access. Pending NSSAIs are managed regardless of the access type; that is, a Pending NSSAI is applicable to both 3GPP and non-3GPP access of the current PLMN, even if it is sent via only one of the accesses. If a registration area includes TAIs belonging to different PLMNs that are equivalent PLMNs, the Pending NSSAI is applicable to these PLMNs within this registration area. If the UE is no longer interested in the S-NSSAIs in the pending NSSAI, the UE initiates the mobility registration procedure and sends an abandoned NSSAI in the registration request message that includes one or more pending S-NSSAIs that the UE is no longer interested in.

[0272] A rejected NSSAI for the current PLMN or SNPN is applicable to the entire registered PLMN or SNPN. The AMF shall only send a rejected NSSAI to the current PLMN if the registered area consists of TAIs belonging only to the registered PLMN. If a UE receives a rejected NSSAI for the current PLMN that includes TAIs belonging to a different PLMN with a different registered area, the UE shall treat the rejected NSSAI received for the current PLMN as applicable to the entire registered PLMN.

[0273] A rejected NSSAI for a failed or expired NSSAA includes one or more S-NSSAIs that failed network slice-specific authentication and authorization, or whose authorization has expired, and is applicable to the entire registered PLMN or SNPN.

[0274] A rejected NSSAI for the maximum number of UEs reached is applicable to the entire registered PLMN or SNPN and the access type from which the rejected NSSAI was sent. The AMF shall send a rejected NSSAI with the rejection reason "One or more S-NSSAI unavailable due to the maximum number of UEs reached" when one or more S-NSSAIs indicating that the maximum number of UEs has been reached are indicated. If the timer T3526 associated with an S-NSSAI is started when a rejected NSSAI for the maximum number of UEs reached is received, the UE may remove one or more S-NSSAIs from the rejected NSSAI, including the one or more S-NSSAI with the rejection reason "One or more S-NSSAI unavailable due to the maximum number of UEs reached," when the timer T3526 associated with one or more S-NSSAIs expires. If one or more S-NSSAIs are removed from the rejected NSSAI for the maximum number of UEs reached, the timer T3526 associated with the removed S or more S-NSSAIs shall be stopped if it is active. The UE does not stop timer T3526 if it selects an E-UTRA cell connected to the EPC.

[0275] If a UE receives rejected NSSAIs for the maximum number of UEs it has reached, the registration area shall include TAIs belonging to different PLMNs that are equivalent PLMNs, and the UE shall treat the rejected NSSAIs received for the maximum number of UEs it has reached as applicable to those equivalent PLMNs while the UE is within this registration area.

[0276] Note 2: Based on local policies, if a UE wants to register a slice identified by this S-NSSAI, the UE can remove the S-NSSAI from the rejected NSSAI of a failed or expired NSSAA.

[0277] Note 3: Based on the network local policy, if an S-NSSAI is requested by the UE based on that local policy, the network slice-specific authentication and authorization procedure may be initiated by the AMF of the S-NSSAI in the rejected NSSAI of a failed or expired NSSAA.

[0278] Note 4: To ensure that at least one PDU session can be established to access the service even if network slice-specific authentication and authorization fails, it is recommended that at least one S-NSSAI within the default Configured NSSAI or at least one default S-NSSAI be exempt from network slice-specific authentication and authorization.

[0279] Note 5: To ensure that at least one PDU session can be established to access the service, it is recommended that at least one S-NSSAI within a subscribed S-NSSAI marked as a default configured NSSAI or default S-NSSAI be exempt from network slice admission control.

[0280] Note 6: Rejected NSSAI may be provided by the network via either a rejected NSSAI IE or an extended rejected NSSAI IE.

[0281] 4.6.2 Types of Mobility Management 4.6.2.1 General Upon registering with PLMN or SNPN (excluding registration procedures for periodic registration renewal, initial registration for onboarding services in SNPN, and registration procedures for mobility registration renewal when registered for onboarding services in SNPN), the UE shall send a Requested NSSAI to the AMF if the Requested NSSAI includes one or more S-NSSAIs of the PLMN or SNPN's allowed NSSAIs, or a configured NSSAI of the PLMN or SNPN, and corresponds to one or more network slices that the UE intends to register with, i.e., a) Does the UE have a configured NSSAI for the current PLMN or SNPN? b) UE has an allowed NSSAI of the current PLMN or SNPN, or c) The UE has neither an allowed NSSAI for the current PLMN or SNPN nor a configured NSSAI for the current PLMN or SNPN, but has a default configured NSSAI. In this case, the UE indicates to the AMF that the requested NSSAI was created from the default configured NSSAI.

[0282] In addition to the S-NSSAIs included in the above-mentioned NSSAI, a Requested NSSAI can be formed based on one or more S-NSSAIs available at the UE (see subsection 5.5.1.3.2 for further details). In roaming scenarios, the UE shall also provide one or more mapping S-NSSAIs for the Requested NSSAI, if available. The AMF shall verify whether the Requested NSSAI is permitted based on the subscribed S-NSSAIs in the UE subscription and optionally one or more mapping S-NSSAIs provided by the UE. If permitted, the AMF shall provide the UE with an allowed NSSAI for the PLMN or SNPN, and, if available, one or more mapping S-NSSAIs for the allowed NSSAI for the PLMN or SNPN. The AMF shall ensure that there are no more than two S-NSSAIs for an allowed NSSAI mapped to the same S-NSSAI for HPLMN or SNPN. a) If all S-NSSAIs included in the Requested NSSAI are rejected, or if the Requested NSSAI is not included by the UE, b) If one or more default S-NSSAIs do not exist, or if all subscribed S-NSSAIs marked as defaults are not permitted, and c) UE is not registered for or does not have an onboarding service with SNPN, and UE is not registered for or does not have an emergency service, AMF may reject registration requests (see subordinate sections 5.5.1.2.5 and 5.5.1.3.5 for further details).

[0283] A set of one or more network slices of a UE can be changed at any time while the UE is registered with PLMN or SNPN, and the change can be initiated by the network or the UE. In this case, the allowed NSSAI and associated registration areas may be changed during the registration procedure or the generic UE configuration update procedure. The configured NSSAI and rejected NSSAI may be changed during the registration procedure or the generic UE configuration update procedure. The default configured NSSAI may be changed by sending a UE parameter update transparent container to the UE during the NAS transport procedure. The pending NSSAI may be changed during the registration procedure. Furthermore, using the generic UE configuration update procedure, the network can trigger the registration procedure to update the allowed NSSAI. If the UE is no longer interested in the S-NSSAI in the pending NSSAI, the UE initiates the mobility registration procedure and sends an abandoned NSSAI in the registration request message that includes the one or more pending S-NSSAI that the UE is no longer interested in. If a UE needs to send a requested NSSAI to the AMF, the S-NSSAIs within the requested NSSAI must share at least one common NSSRG group. S-NSSAIs within an abandoned NSSAI are not considered in the NSSRG procedure. When the AMF receives a registration request message containing an abandoned NSSAI, the AMF removes one or more S-NSSAIs present in the abandoned NSSAI from the pending NSSAI list. The UE may abort the NSSAA procedure for one or more S-NSSAIs present in the abandoned NSSAI. The AMF sends a registration accept message containing the most recently allowed NSSAI. The newly allowed one or more S-NSSAIs must share at least one NSSRG value.If the 5GS registration type IE indicates "Mobility Registration Renewal" and the procedure to change one or more slices currently registered for the UE has not been initiated, and the UE is still within the current registration area, the UE in NB-N1 mode will not include a Requested NSSAI during the registration procedure. If the 5GS registration type IE indicates "SNPN Onboarding Registration" or the UE is registered for the onboarding service within SNPN, the UE will not include a Requested NSSAI during the registration procedure.

[0284] AMF does not include allowed NSSAI during registration procedures where 5GS registration type IE indicates "Mobility Registration Renewal," unless the allowed NSSAI has been changed for the UE. The UE considers the last allowed NSSAI it received to be valid until the UE receives a new allowed NSSAI. AMF does not include allowed NSSAI during registration procedures where 5GS registration type IE indicates "SNPN Onboarding Registration," or during registration procedures where the UE is registering for onboarding services within SNPN.

[0285] 5.5.1.3.2 Commencement of Mobility and Periodic Registration Renewal A UE in the 5GMM-REGISTERED state will initiate the registration procedure for mobility and periodic registration renewal by sending a REGISTRATION REQUEST message to the AMF in the following cases: a) If the UE detects that the current TAI is not in the list of tracking areas previously registered with the AMF, b) When the periodic registration update timer T3512 expires in 5GMM-IDLE mode, c) If the UE receives a CONFIGURATION UPDATE COMMAND message indicating "registration requested" in the registration requested bit of the configuration update command IE, as specified in subclause 5.4.4.3, d) When a UE in the state 5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE receives paging, or when a UE receives a NOTIFICATION message with an access type indicating 3GPP access on non-3GPP access for a PDU session associated with 3GPP access,

[0286] Note 1: As an implementation option, MUSIM UE may be allowed not to respond to paging based on available information in paging messages, such as voice service instructions. e) When changing between systems from S1 mode to N1 mode, if the UE previously initiated an attach procedure or tracking area update procedure while in S1 mode, f) If the UE receives a “RRC connection failed” instruction from a lower layer and does not have signaling pending (i.e., the lower layer requests NAS signaling connection recovery), g) If the UE changes its 5GMM capability or S1 UE network capability, or both, h) If the UE usage settings are changed, i) If you need to modify one or more slices that are currently registered to the UE, j) If the UE modifies the UE-specific DRX parameters, k) When a UE in the state 5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE receives a request from a higher layer to establish an emergency PDU session or perform an emergency service fallback, l) When the UE needs to register for SMS over NAS, indicate a change in the requirements for using SMS over NAS, or deregister from SMS over NAS, m) If the UE needs to show the PDU session status to the network after performing a local release of one or more PDU sessions as specified in subsections 6.4.1.5 and 6.4.3.5, n) When a UE in 5GMM-IDLE mode changes its radio capability for NG-RAN or E-UTRAN, o) When the UE receives a fallback instruction from a lower layer and is not in signaling pending state (i.e., when the lower layer requests NAS signaling connectivity recovery, see subordinate sections 5.3.1.4 and 5.3.1.2), p) Blank, q) If the UE needs to request new LADN information, r) If the UE needs to request the use of MICO mode, or needs to stop using MICO mode, or needs to request the use of a new T3324 value, s) When a UE in 5GMM-CONNECTED mode with an RRC inactive instruction belongs to an equivalent PLMN of a registered PLMN and enters a cell in the current registration area that does not belong to a registered PLMN, t) When the UE receives a SERVICE REJECT message or DL ​​NAS TRANSPORT message via 3GPP, if the 5GMM cause value is set to #28 "Restricted Service Area", u) If the UE needs to request the use of eDRX, if the changes to the eDRX usage conditions in the UE require different extended DRX parameters, or if it is necessary to stop using eDRX,

[0287] Note 2: Changes in eDRX usage in the UE may include, for example, changes in UE settings, changes in requirements from higher layers, or a decrease in the UE's battery level. v) If a UE supporting 5G-SRVCC changes from NG-RAN to UTRAN, w) If a UE in the state 5GMM-REGISTERED.ATTEMPTING-REGISTRATION-UPDATE decides to request a new network slice after being denied because there are no requested authorized network slices, or if a UE decides to request one or more S-NSSAIs that have been removed from the maximum number of rejected NSSAIs reached by the UE, x) If the UE is not in NB-N1 mode, and the UE radio capability ID applicable to the current UE radio configuration changes due to the expiration of the network-assigned UE radio capability ID via serving PLMN or SNPN, y) If UE receives a REGISTRATION REJECT message with cause values ​​#3, #6, or #7 of 5GMM without integrity protection in another access, z) If the UE needs to request a new encryption key for encrypted broadcast-assisted data, za) If, through manual CAG selection, the UE selects a CAG-ID that is not included in the "allowed CAG list of the selected PLMN" or a CAG-ID of a PLMN for which there is no entry in the "CAG information list", or if, without selecting a CAG-ID, the UE selects a PLMN for which the entry in the "CAG information list" contains the instruction that "the UE is permitted to access 5GS only through the CAG cell", zb) If it becomes necessary to initiate, suspend, or change the conditions for UE to use WUS support information or PEIPS support information, zc) If the UE changes the UE-specific DRX parameters in NB-N1 mode, zd) If a UE in 5GMM-CONNECTED mode with RRC inactive indication has a different RAT in the current TAI list, or enters a new cell that is not in the current TAI list, If, after the UE has sent a NOTIFICATION RESPONSE message via non-3GPP access in response to receiving a NOTIFICATION message via non-3GPP access as specified in subsection 5.6.3.1, the UE enters the 5GMM-REGISTERED.NORMAL-SERVICE state or the 5GMM-REGISTERED.NON-ALLOWED-SERVICE state (as described in subsection 5.3.5.2) via 3GPP access, If a UE that supports the UAS service is not registered for the UAS service and needs to register for the 5GS for the UAS service, zg) If a UE supporting MINT needs to perform mobility registration procedures and periodic registration updates in order to register with a PLMN that provides disaster roaming, zh) A MUSIM UE that supports paging timing collision control needs to request a new 5G-GUTI allocation, and the UE is not registered for emergency services.

[0288] Note 3: Depending on the implementation, MUSIM UE may request a new 5G-GUTI allocation (for example, if the lower layer requests a change in the timing of paging occasions). zi) If the network supports paging limits and the 5GMM-REGISTERED.NON-ALLOWED-SERVICE state requires a request to the network to remove the paging limit, If zj)UE changes the 5GS Preferred CIoT Network Behavior or EPS Preferred CIoT Network Behavior, If a UE in zk)5GMM-REGISTERED.NO-CELL-AVAILABLE that has one or more S-NSSAIs in pending NSSAIs finds a suitable cell in accordance with 3GPP TS38.304

[28] , zl)UE is registered for disaster roaming services and receives a request from a higher layer to establish an emergency PDU session or perform emergency service fallback, and This is the case when zm)UE is no longer interested in the S-NSSAI that is included in the pending list in which it is stored.

[0289] 8.2.6.1 Message Definition The REGISTRATION REQUEST message is sent to the AMF by the UE. See Tables 1 and 2. Message type: REGISTRATION REQUEST Enabled: Dual Direction: From UE to network [Table 1] [Table 2]

[0290] 8.2.6.31 Abandon NSSAI If S-NSSAI is stored in Pending NSSAI and the UE is no longer interested in S-NSSAI, then this UE shall include this IE.

[0291] Transformation and Substitution Detailed exemplary embodiments have been described above. As those skilled in the art will understand, several modifications and substitutions can be made to the above exemplary embodiments, but still benefit from the disclosures embodied therein. Only a few of these substitutions and modifications are described here as examples.

[0292] For the sake of clarity, the above description assumes that the UE3 and network device have several separate modules (such as a communications control module). These modules may be provided in this way for specific applications, such as existing systems being modified to implement the present disclosure, as well as for other applications, such as systems designed from the outset with the features of the present invention in mind. However, because these modules may be integrated into the overall operating system or code, they may not be identifiable as separate entities. These modules may also be implemented in software, hardware, firmware, or a combination thereof.

[0293] Each controller may include any preferred form of processing circuitry, including, but not limited to, one or more hardware-implemented computer processors, microprocessors, central processing units (CPUs), arithmetic logic units (ALUs), input / output (IO) circuits, internal memory / cache (programs and / or data), processing registers, communication buses (e.g., control, data, and / or address buses), direct memory access (DMA) functions, hardware or software-implemented counters, pointers, and / or timers. In the exemplary embodiments described above, several software modules have been described. As those skilled in the art will understand, the software modules may be provided in compiled or uncompiled form and may be supplied to the UE3 and network equipment as signals via a computer network or on a recording medium. Furthermore, the functions performed by some or all of this software may be performed using one or more dedicated hardware circuits. However, the use of software modules is preferred because it facilitates the updating of the UE3 and network equipment to update their functions.

[0294] In the exemplary embodiments described above, 3GPP wireless communication (wireless access) technology is used. However, any other wireless communication technology (e.g., WLAN, Wi-Fi, WiMAX, Bluetooth, etc.) and other fixed-line communication technologies (e.g., BBF access, cable access, optical access, etc.) may also be used in accordance with the exemplary embodiments described above.

[0295] User device items may include, for example, communication devices such as mobile phones, smartphones, user devices, personal digital assistants, laptop / tablet computers, web browsers, and e-book readers. Such mobile (or generally fixed) devices are typically operated by a user, but it is also possible to connect so-called "Internet of Things" (IoT) devices and similar machine-type communication (MTC) devices to a network. For simplicity, this application refers to mobile devices (or UEs) in the description, but it will be understood that the described technology can be implemented on any communication device (mobile and / or generally fixed) that can connect to a communication network to send and receive data, whether such communication devices are controlled by human input or software instructions stored in memory.

[0296] Various other variations are obvious to those skilled in the art and will not be described in further detail here.

[0297] As those skilled in the art will understand, this disclosure can be embodied as a method and system. Accordingly, this disclosure can take the form of entirely hardware embodiments, software embodiments, or embodiments combining software and hardware aspects.

[0298] It will be understood that each block in a block diagram can be implemented by computer program instructions. These computer program instructions may be provided to a general-purpose computer, a dedicated computer, or a processor of another programmable data processing device in order to manufacture a machine, such that instructions executed via the processor of the computer or other programmable data processing device create means for implementing the functions / operations specified in one or more blocks of the flowchart and / or block diagram. The general-purpose processor may be a microprocessor, but instead, the processor may be any conventional processor, control unit, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, e.g., multiple microprocessors, one or more microprocessors, or any other such configuration.

[0299] Methods or algorithms described in relation to the examples disclosed herein may be embodied in hardware, software modules executed by a processor, or a combination of the two. The software modules may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the art. The storage medium may be coupled to the processor so that the processor can read information from and write information to the storage medium. Alternatively, the storage medium may be integrated with the processor. The processor and storage medium may reside within an ASIC.

[0300] The above-mentioned descriptions of the disclosed examples are provided to enable those skilled in the art to create or use this disclosure. Various modifications to these examples will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other examples without departing from the spirit or scope of this disclosure. Accordingly, this disclosure is not intended to be limited to the examples shown herein, but should be given the broadest scope consistent with the principles and novel features disclosed herein.

[0301] This disclosure is shown and described in particular with reference to its exemplary embodiments, but is not limited to these embodiments. Those skilled in the art will understand that various modifications of form and detail can be made without departing from the spirit and scope of this disclosure as defined herein. For example, the above exemplary embodiments are not limited to 5GS and are applicable to other communication systems (e.g., 6G systems, 5G beyond systems).

[0302] Note All or part of the exemplary embodiments disclosed above may be described as follows, but are not limited to:

[0303] Note 1 A method for user equipment (UE), To communicate with AMF, Based on Allowed NSSAI and Pending NSSAI, select a first NSAG and a first NSAG priority, Methods that include...

[0304] Note 2 The first NSAG and the first NSAG priority are selected at the NAS layer of the UE. The method described in Appendix 1.

[0305] Note 3 Perform a first cell reselection based on the first NSAG and the first NSAG priority. The method described in Appendix 1 or Appendix 2, further including the method described in Appendix 1 or Appendix 2.

[0306] Note 4 Performing the first cell reselection includes performing the first cell reselection based on a first NSAG, a first NSAG priority, and at least one Pending NSSAI among 3GPP access and non-3GPP access. The method described in Appendix 3.

[0307] Note 5 Receiving information about the NSAG supported by the cell, If the NSAG indicated by the information includes the first NSAG, do not perform the first cell reselection. The method described in Appendix 3 or Appendix 4, further including the method described in Appendix 4.

[0308] Note 6 The first cell reselection is performed in the AS of the UE. The method described in any one of the items in Appendix 3 to Appendix 5.

[0309] Appendix 7 Send the first NSAG and the first NSAG priority to the AMF. The method described in any one of the appendices 1 to 6, further including the method described in any one of the appendices 1 to 6.

[0310] Note 8 The first NSAG and the first NSAG priority are sent to another AMF. The method described in Appendix 7.

[0311] Note 9 The first NSAG and the first NSAG priority are sent to the Radio Access Network (RAN) node. The method described in any one of the items in Appendix 1 to Appendix 8.

[0312] Note 10 At least one of the first NSAG and the first NSAG priority is used to select a cell for handover. The method described in any one of the appendices 1 to 9.

[0313] Note 11 If the NSSAA procedure of the S-NSSAI included in the Pending NSSAI fails, a second NSAG and a second NSAG priority will be selected based on the Allowed NSSAI. To transmit the second NSAG and the second NSAG priority to AMF, The method described in any one of the appendices 1 to 10, further including the method described in any one of the appendices 1 to 10.

[0314] Note 12 The second NSAG and the second NSAG priority are selected at the NAS layer of the UE. The method described in Appendix 11.

[0315] Note 13 Perform a second cell reselection based on the second NSAG and the second NSAG priority. The method described in Appendix 11 or Appendix 12, further including the method described in Appendix 11 or Appendix 12.

[0316] Note 14 The second cell reselection is performed in the AS of the UE. The method described in Appendix 13.

[0317] Note 15 The second NSAG and the second NSAG priority are sent to another AMF. The method described in any one of the items in Appendix 11 to Appendix 14.

[0318] Note 16 The second NSAG and the second NSAG priority are sent to the RAN node. The method described in any one of the items in Appendix 11 to Appendix 15.

[0319] Note 17 The second NSAG and at least one of the second NSAG priorities are used to select a cell for handover. The method described in any one of the items in Appendix 11 to Appendix 16.

[0320] Note 18 When the UE roams to the VPLMN, a third cell reselection is performed based on the S-NSSAI included in the Configured NSSAI for the VPLMN. The method described in any one of the appendices 1 to 17, further including the method described in any one of the appendices 1 to 17.

[0321] Note 19 The first NSAG and the first NSAG priority are selected regardless of the NSAC status. The method described in any one of the items in Appendix 1 to Appendix 18.

[0322] Note 20 A method for user equipment (UE), To communicate with AMF, After the NSSAA procedure for the S-NSSAI included in the Pending NSSAI is successfully completed, the first NSAG and the first NSAG priority are selected based on the first Allowed NSSAI, Includes, The first Allowed NSSAI includes S-NSSAI. method.

[0323] Note 21 Before selecting the first NSAG and first NSAG priority, select the second NSAG and second NSAG priority based on the second Allowed NSSAI. Furthermore, the second Allowed NSSAI does not include S-NSSAI. The method described in Appendix 20.

[0324] Note 22 The second NSAG and the second NSAG priority are selected at the NAS layer of the UE. The method described in Appendix 21.

[0325] Note 23 Perform a second cell reselection based on the second NSAG and the second NSAG priority. The method described in Appendix 21 or Appendix 22, further including the method described in Appendix 21 or Appendix 22.

[0326] Note 24 The second cell reselection is performed in the AS of the UE. The method described in Appendix 23.

[0327] Note 25 Send the second NSAG and the second NSAG priority to the AMF. The method described in any one of the appendices 21 to 24, further including the method described in any one of the appendices 21 to 24.

[0328] Note 26 The second NSAG and the second NSAG priority are sent to another AMF. The method described in Appendix 25.

[0329] Note 27 The second NSAG and the second NSAG priority are sent to the RAN node. The method described in any one of the items in Appendix 21 to Appendix 26.

[0330] Note 28 The second NSAG and at least one of the second NSAG priorities are used to select a cell for handover. The method described in any one of the items in Appendix 21 to Appendix 27.

[0331] Note 29 The first NSAG and the first NSAG priority are selected at the NAS layer of the UE. The method described in any one of the items in Appendix 20 to Appendix 28.

[0332] Note 30 Perform a first cell reselection based on the first NSAG and the first NSAG priority. The method described in any one of the appendices 20 to 29, further including the method described in any one of the appendices 20 to 29.

[0333] Note 31 Performing the first cell reselection includes performing the first cell reselection based on a first NSAG, a first NSAG priority, and at least one Pending NSSAI among 3GPP access and non-3GPP access. The method described in Appendix 30.

[0334] Note 32 Receiving information about the NSAG supported by the cell, If the NSAG indicated by the information includes the first NSAG, do not perform the first cell reselection, The method described in Appendix 30 or Appendix 31, further including the method described in Appendix 31.

[0335] Note 33 The first cell reselection is performed in the AS of the UE. The method described in any one of the items in Appendix 30 to Appendix 32.

[0336] Note 34 Send the first NSAG and the first NSAG priority to the AMF. The method described in any one of the appendices 20 to 33, further including the method described in any one of the appendices 20 to 33.

[0337] Note 35 The first NSAG and the first NSAG priority are sent to another AMF. The method described in any one of the items in Appendix 20 to Appendix 34.

[0338] Note 36 The first NSAG and the first NSAG priority are sent to the RAN node. The method described in any one of the items in Appendix 20 to Appendix 35.

[0339] Note 37 At least one of the first NSAG and the first NSAG priority is used to select a cell for handover. The method described in any one of the items in Appendix 20 to Appendix 36.

[0340] Note 38 When the UE roams to VPLMN, a third cell reselection is performed based on the S-NSSAI included in the Configured NSSAI for VPLMN, The method described in any one of the appendices 20 to 37, further including the method described in any one of the appendices 20 to 37.

[0341] Note 39 The first NSAG and the first NSAG priority are selected regardless of the NSAC status. The method described in any one of the items in Appendix 20 to Appendix 38.

[0342] Note 40 A method for communication devices, Receiving the first NSAG and the first NSAG priority, To transmit the first NSAG and the first NSAG priority. Methods that include...

[0343] Note 41 Transmitting the first NSAG and the first NSAG priority includes transmitting the first NSAG and the first NSAG priority to another communication device. The method described in Appendix 40.

[0344] Note 42 Transmitting the first NSAG and the first NSAG priority includes transmitting the first NSAG and the first NSAG priority to the RAN node. The method described in Appendix 40.

[0345] Note 43 The first NSAG and at least one of the first NSAGs are used to select a cell for handover. The method described in any one of the items in Appendix 40 to Appendix 42.

[0346] Note 44 Receiving the second NSAG and the second NSAG priority, To transmit the second NSAG and the second NSAG priority, The method described in any one of the appendices 40 to 43, further including the method described in any one of the appendices 40 to 43.

[0347] Note 45 Transmitting the second NSAG and the second NSAG priority includes transmitting the second NSAG and the second NSAG priority to another communication device. The method described in Appendix 44.

[0348] Note 46 Transmitting the second NSAG and the second NSAG priority includes transmitting the second NSAG and the second NSAG priority to the RAN node. The method described in Appendix 45.

[0349] Note 47 A second NSAG and at least one of the second NSAGs are used to select a cell for handover. The method described in any one of the items in Appendix 44 to Appendix 46.

[0350] Note 48 This is the method for RAN nodes, Receiving the first NSAG and the first NSAG priority, Selecting cells for handover based on the first NSAG and the first NSAG priority, Methods that include...

[0351] Note 49 Perform a handover to the cell. The method described in Appendix 48, further including the method described in Appendix 48.

[0352] Note 50 User equipment (UE), Communication devices and means for communication, A means for selecting a first NSAG and a first NSAG priority based on Allowed NSSAI and Pending NSSAI, A user-defined equipment (UE) equipped with such equipment.

[0353] Note 51 The first NSAG and the first NSAG priority are selected at the NAS layer of the UE. UE as described in Appendix 50.

[0354] Note 52 Means for performing a first cell reselection based on a first NSAG and a first NSAG priority. The UE described in Appendix 50 or Appendix 51, further comprising the above.

[0355] Note 53 Means for performing a first cell reselection based on a first NSAG, a first NSAG priority, and at least one Pending NSSAI among 3GPP access and non-3GPP access. The UE further includes the features described in Appendix 52.

[0356] Note 54 A means for receiving information about NSAGs supported by a cell, If the NSAG indicated by the information includes the first NSAG, there is a means to avoid performing the first cell reselection, The UE described in Appendix 52 or Appendix 53, further comprising the above.

[0357] Note 55 The first cell reselection is performed in the AS of the UE. The UE described in any one of the items in Appendix 52 to Appendix 54.

[0358] Note 56 Means for transmitting the first NSAG and the first NSAG priority to a communication device A UE as described in any one of the appendices 50 to 55, further comprising the above.

[0359] Note 57 The first NSAG and the first NSAG priority are transmitted to another communication device. UE as described in Appendix 56.

[0360] Note 58 The first NSAG and the first NSAG priority are transmitted to the RAN node by the UE described in any one of the appendices 50 to 57.

[0361] Note 59 At least one of the first NSAG and the first NSAG priority is used to select a cell for handover. The UE described in any one of the items in Appendix 50 to Appendix 58.

[0362] Note 60 If the NSSAA procedure of the S-NSSAI included in the Pending NSSAI fails, a means for selecting a second NSAG and a second NSAG priority based on the Allowed NSSAI, Means for transmitting a second NSAG and a second NSAG priority to a communication device, The UE described in Appendix 50 or Appendix 59, further comprising the above.

[0363] Note 61 The second NSAG and the second NSAG priority are selected at the NAS layer of the UE. UE as described in Appendix 60.

[0364] Note 62 Means for performing a second cell reselection based on a second NSAG and a second NSAG priority. The UE described in Appendix 60 or Appendix 61, further comprising the above.

[0365] Note 63 The second cell reselection is performed in the AS of the UE. UE as described in Appendix 62.

[0366] Note 64 The second NSAG and the second NSAG priority are transmitted to another communication device. The UE described in any one of the items in Appendix 60 to Appendix 63.

[0367] Note 65 The second NSAG and the second NSAG priority are sent to the RAN node. The UE described in any one of the items in Appendix 60 to Appendix 64.

[0368] Note 66 The second NSAG and at least one of the second NSAG priorities are used to select a cell for handover. The UE described in any one of the appendices 60 to 65.

[0369] Note 67 When the UE roams to the VPLMN, means for performing a third cell reselection based on the S-NSSAI included in the Configured NSSAI for the VPLMN. A UE as described in any one of the appendices 50 to 66, further comprising the above.

[0370] Note 68 The first NSAG and the first NSAG priority are selected regardless of the NSAC status. The UE described in any one of the items in Appendix 50 to Appendix 67.

[0371] Note 69 User equipment (UE), Communication devices and means for communication, A means for selecting a first NSAG and a first NSAG priority based on a first Allowed NSSAI after the NSSAA procedure of the S-NSSAI included in the Pending NSSAI has been successfully completed, Equipped with, The first Allowed NSSAI includes S-NSSAI. User equipment (UE).

[0372] Note 70 Means for selecting a second NSAG and a second NSAG priority based on a second Allowed NSSAI before selecting a first NSAG and a first NSAG priority. Furthermore, The second Allowed NSSAI does not include S-NSSAI. UE as described in Appendix 69.

[0373] Note 71 The second NSAG and the second NSAG priority are selected at the NAS layer of the UE. UE as described in Appendix 70.

[0374] Note 72 Means for performing a second cell reselection based on a second NSAG and a second NSAG priority. The UE described in Appendix 70 or Appendix 71, further comprising the above.

[0375] Note 73 The second cell reselection is performed in the AS of the UE. UE as described in Appendix 72.

[0376] Note 74 Means for transmitting a second NSAG and a second NSAG priority to a communication device A UE as described in any one of the appendices 70 to 73, further comprising the above.

[0377] Note 75 The second NSAG and the second NSAG priority are transmitted to another communication device. UE as described in Appendix 74.

[0378] Note 76 The second NSAG and the second NSAG priority are sent to the RAN node. The UE described in any one of the items in Appendix 70 to Appendix 75.

[0379] Note 77 The second NSAG and at least one of the second NSAG priorities are used to select a cell for handover. The UE described in any one of the items in Appendix 70 to Appendix 76.

[0380] Note 78 The first NSAG and the first NSAG priority are selected at the NAS layer of the UE. UE as described in Appendix 69 or Appendix 77.

[0381] Note 79 Means for performing a first cell reselection based on a first NSAG and a first NSAG priority. A UE as described in any one of the appendices 69 to 78, further comprising the above.

[0382] Note 80 Performing the first cell reselection includes performing the first cell reselection based on a first NSAG, a first NSAG priority, and at least one Pending NSSAI among 3GPP access and non-3GPP access. UE as described in Appendix 79.

[0383] Note 81 A means for receiving information about NSAGs supported by a cell, If the NSAG indicated by the information includes the first NSAG, there is a means to avoid performing the first cell reselection, The UE described in Appendix 79 or Appendix 80, further comprising the above.

[0384] Note 82 The first cell reselection is performed in the AS of the UE. The UE described in any one of the appendices 79 to 81.

[0385] Note 83 Means for transmitting the first NSAG and the first NSAG priority to a communication device A UE as described in any one of the appendices 69 to 82, further comprising the above.

[0386] Note 84 The first NSAG and the first NSAG priority are transmitted to another communication device. The UE described in any one of the items in Appendix 69 to Appendix 83.

[0387] Note 85 The first NSAG and the first NSAG priority are sent to the RAN node. The UE described in any one of the items in Appendix 69 to Appendix 84.

[0388] Note 86 At least one of the first NSAG and the first NSAG priority is used to select a cell for handover. The UE described in any one of the items in Appendix 69 to Appendix 85.

[0389] Note 87 When the UE roams to the VPLMN, means for performing a third cell reselection based on the S-NSSAI included in the Configured NSSAI for the VPLMN. A UE as described in any one of the appendices 69 to 86, further comprising the above.

[0390] Note 88 The first NSAG and the first NSAG priority are selected regardless of the NSAC status. The UE described in any one of the items in Appendix 69 to Appendix 87.

[0391] Note 89 A communication device, Means for receiving a first NSAG and a first NSAG priority, A communication device comprising means for transmitting a first NSAG and a first NSAG priority.

[0392] Note 90 Means for transmitting a first NSAG and a first NSAG priority to another communication device A communication device further equipped with the features described in Appendix 89.

[0393] Note 91 Means for transmitting the first NSAG and the first NSAG priority to the RAN node A communication device further equipped with the features described in Appendix 89.

[0394] Note 92 The first NSAG and at least one of the first NSAGs are used to select a cell for handover. A communication device as described in any one of the items from Appendix 89 to Appendix 91.

[0395] Note 93 Means for receiving a second NSAG and a second NSAG priority, Means for transmitting a second NSAG and a second NSAG priority, A communication device as described in any one of the appendices 89 to 92, further comprising the above.

[0396] Note 94 Transmitting the second NSAG and the second NSAG priority includes transmitting the second NSAG and the second NSAG priority to another communication device. The communication device described in Appendix 93.

[0397] Note 95 Transmitting the second NSAG and the second NSAG priority includes transmitting the second NSAG and the second NSAG priority to the RAN node. The communication device described in Appendix 94.

[0398] Note 96 A second NSAG and at least one of the second NSAGs are used to select a cell for handover. A communication device as described in any one of the items 93 to 95 of the appendix.

[0399] Note 97 It is a RAN node, Means for receiving a first NSAG and a first NSAG priority, A RAN node comprising a first NSAG and means for selecting a cell for handover based on the first NSAG priority.

[0400] Note 98 Means for performing a handover to a cell A RAN node further equipped with the features described in Appendix 97.

[0401] Note 99 A method for user equipment (UE), Communicating with a communication device, The communication device transmits the first S-NSSAI included in the Pending NSSAI, Methods that include...

[0402] Note 100 Sending the first S-NSSAI includes sending the first S-NSSAI after performing cell reselection based on network slices. The method described in Appendix 99.

[0403] Note 101 Cell reselection based on network slices is performed on the second S-NSSAI, The second S-NSSAI is different from the first S-NSSAI. The method described in Appendix 100.

[0404] Note 102 Sending the first S-NSSAI includes sending a Requested NSSAI which includes the first S-NSSAI and the second S-NSSAI. The method described in Appendix 101.

[0405] Note 103 The first S-NSSAI and Requested NSSAI are included in the registration request message. The method described in Appendix 102.

[0406] Note 104 Sending a first S-NSSAI includes sending a first S-NSSAI if the UE has a Pending NSSAI. The method described in any one of the appendices 99 to 103.

[0407] Note 105 A method for user equipment (UE), Communicating with a communication device, The communication device transmits information indicating that the UE is not interested in the S-NSSAI included in the Pending NSSAI, Includes, method.

[0408] Note 106 A method for communication devices, Receiving the first S-NSSAI included in Pending NSSAI, The NSSAA procedure for the first S-NSSAI will be terminated, Methods that include...

[0409] Note 107 The first S-NSSAI is included in the registration request message. The registration request message includes Requested NSSAI, The requested NSSAI includes the second S-NSSAI. The second S-NSSAI is different from the first S-NSSAI. The method described in Appendix 106.

[0410] Note 108 Terminating the NSSAA procedure includes, if the NSSAA procedure is in progress, terminating the NSSAA procedure. The method described in Appendix 106 or Appendix 107.

[0411] Note 109 If the NSSAA procedure is completed successfully, remove the first S-NSSAI from Allowed NSSAI. The method described in any one of the appendices 106 to 108, further including the method described in any one of the appendices 106 to 108.

[0412] Note 110 If the NSSAA procedure fails, include the first S-NSSAI in the Rejected NSSAI. The method described in any one of the appendices 106 to 109, further including the method described in any one of the appendices 106 to 109.

[0413] Note 111 User equipment (UE), Communication devices and means for communication, The communication device includes means for transmitting the first S-NSSAI included in the Pending NSSAI, A user-defined equipment (UE) equipped with such equipment.

[0414] Note 112 Means for transmitting a first S-NSSAI after performing cell reselection based on network slicing. The UE described in Appendix 111 further includes the following:

[0415] Note 113 Cell reselection based on network slices is performed on the second S-NSSAI, The second S-NSSAI is different from the first S-NSSAI. UE as described in Appendix 112.

[0416] Note 114 Means for transmitting a Requested NSSAI including a first S-NSSAI and a second S-NSSAI The UE described in Appendix 113 further includes the following:

[0417] Note 115 The first S-NSSAI and Requested NSSAI are included in the registration request message. UE as described in Appendix 114.

[0418] Note 116 If the UE has a Pending NSSAI, means for transmitting the first S-NSSAI, The UE described in any one of the appendices 111 to 115.

[0419] Note 117 User equipment (UE), Communication devices and means for communication, The communication device includes means for transmitting information indicating that the UE is not interested in the S-NSSAI included in the Pending NSSAI, A user-defined equipment (UE) equipped with such equipment.

[0420] Note 118 A communication device, Means for receiving the first S-NSSAI included in Pending NSSAI, Means for terminating the NSSAA procedure of the first S-NSSAI, A communication device equipped with the following features.

[0421] Note 119 The first S-NSSAI is included in the registration request message. The registration request message includes Requested NSSAI, The requested NSSAI includes the second S-NSSAI. The second S-NSSAI is different from the first S-NSSAI. The communication device described in Appendix 118.

[0422] Note 120 If the NSSAA procedure is in progress, what means are there to stop the NSSAA procedure? A communication device as described in Appendix 118 or Appendix 119, further comprising the above.

[0423] Note 121 If the NSSAA procedure is completed successfully, a means to remove the first S-NSSAI from the Allowed NSSAI. A communication device further comprising any one of the items in Appendix 118 to Appendix 120.

[0424] Note 122 If the NSSAA procedure fails, a means to include the first S-NSSAI in the Rejected NSSAI. A communication device as described in any one of the appendices 118 to 121, further comprising the above.

[0425] This application claims the benefit of priority under Indian Patent Application No. 202211043222, filed on 28 July 2022, the disclosure of which is incorporated herein by reference in its entirety. [Explanation of symbols]

[0426] 1 System 3 UE 5 RAN 7 Core Network 20 Data Networks

Claims

1. The communication device has a transmission means for transmitting the first Single Network Slice Selection Assistance Information (S-NSSAI) included in the Pending Network Slice Selection Assistance Information (NSSAI), The transmission means transmits the first S-NSSAI after cell reselection based on network slice. User device.

2. The cell reselection based on the aforementioned network slice is performed on the second S-NSSAI, The second S-NSSAI is different from the first S-NSSAI. The user device according to claim 1.

3. The transmission means transmits the first S-NSSAI and the Requested NSSAI, which includes the second S-NSSAI. The user device according to claim 2.

4. The transmission means transmits the first S-NSSAI when the user device is holding the Pending NSSAI. The user device according to any one of claims 1 to 3.

5. A receiving means that receives the first Single Network Slice Selection Assistance Information (S-NSSAI) contained in the Pending Network Slice Selection Assistance Information (NSSAI) after cell reselection based on network slices has been performed, A means for terminating the Network Slice-Specific Authentication and Authorization (NSSAA) procedure for the first S-NSSAI, and A communication device having the following features.

6. The first S-NSSAI mentioned above is included in the registration request message, The aforementioned registration request message includes a Requested NSSAI, The aforementioned Requested NSSAI includes a second S-NSSAI, The second S-NSSAI is different from the first S-NSSAI. The communication device according to claim 5.

7. The termination means terminates the NSSAA procedure if the NSSAA procedure is in progress. The communication device according to claim 5 or 6.

8. When the communication device applies the NSSRG procedure to Allowed NSSAI, The system has means for omitting the verification of whether one or more S-NSSAIs included in the first S-NSSAI and the Allowed NSSAI share at least one common NSSRG value or at least one common NSSRG group. The communication device according to claim 5 or 6.

9. The communication device transmits the first Single Network Slice Selection Assistance Information (S-NSSAI), which is included in the Pending Network Slice Selection Assistance Information (NSSAI), after cell reselection based on network slices. User device method.

10. The first Single Network Slice Selection Assistance Information (S-NSSAI) included in the Pending Network Slice Selection Assistance Information (NSSAI) is received after cell reselection based on network slices has been performed. The Network Slice-Specific Authentication and Authorization (NSSAA) procedure for the first S-NSSAI is terminated. Methods for communication devices.

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