Method of first communication apparatus, method of user equipment (UE), first communication apparatus and ue

Abstract

An aspect of this disclosure includes a method of a first communication apparatus. The method includes communicating with a second communication apparatus. The method includes sending Alternative Single Network Slice Selection Assistance Information (S-NSSAI).

Description

METHOD OF FIRST COMMUNICATION APPARATUS, METHOD OF USER EQUIPMENT (UE), FIRST COMMUNICATION APPARATUS AND UE

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

[0002] Since Network Slicing was standardized in 3GPP Rel-15, the final decision of the network slice selection has been left to the UE. When an Application in the UE requires a service, the UE selects a network slice based on the URSP rules provided by the network. The URSP rules define what application with what network slice are allowed to initiate service. In 3GPP Rel-18 a network slice replacement feature was introduced which allows for PDU Session to be moved to an Alternative network slice which is defined by the OAM, the PCC rules or NSSF. The network slice replacement procedure is triggered by the AMF on notifications from the OAM, PCF or NSSF.

[0003] NPL 1: 3GPP TR 21.905: "Vocabulary for 3GPP Specifications". V17.1.0 (2021-12) NPL 2: 3GPP TS 23.501: "System architecture for the 5G System (5GS)". V18.1.0 (2023-03) NPL 3: 3GPP TS 23.502: "Procedures for the 5G System (5GS)". V18.1.1 (2023-04) NPL 4: 3GPP TS 23.503: "Policy and charging control framework for the 5G System (5GS) Stage 2". V18.1.0 (2023-03) NPL 5: 3GPP SA#100 Workshop - SWS-230044 https: / / www.3gpp.org / ftp / tsg_sa / TSG_SA / Workshops / 2023-06-13_Rel-19_WorkShop / Docs / SWS-230044.zip

[0004] An Application Server (or a Service provider or an Application Function (AF)) may have a good information about the right network slice for the application based on for example, the ongoing connection monitoring, connection statistics analyses, application characteristics and service requirements (e.g. a requirement for a high speed). That is why a network slice selection and replacement by the network, based on notification by the Application Server is required. However, there is no mechanism in 3GPP standards for supporting the network slice selection and replacement by the network.

[0005] A method of a first communication apparatus includes: 　　communicating with a second communication apparatus; and 　　sending Alternative Single Network Slice Selection Assistance Information (S-NSSAI).

[0006] A method of a first communication apparatus includes: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF), and 　　wherein the second communication apparatus is a Unified Data Management (UDM).

[0007] A method of a User Equipment (UE) includes: 　　communicating with a first communication apparatus; and 　　performing procedure related to a Protocol Data Unit (PDU) Session, 　　wherein the procedure related to the PDU Session is triggered by the first communication apparatus based on Alternative Single Network Slice Selection Assistance Information (S-NSSAI), 　　wherein the Alternative S-NSSAI is sent by a second communication apparatus to the first communication apparatus, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF), and 　　wherein the second communication apparatus is a Unified Data Management (UDM).

[0008] A method of a first communication apparatus includes: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　sending the Alternative S-NSSAI to a third communication apparatus, 　　wherein the first communication apparatus is a Policy Control Function (PCF), 　　wherein the second communication apparatus is a Network Exposure Function (NEF), and 　　wherein the third communication apparatus is an Access and Mobility Management Function (AMF).

[0009] A method of a first communication apparatus includes: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　sending the Alternative S-NSSAI to a third communication apparatus, 　　wherein the first communication apparatus is a Network Slice Selection Function (NSSF), 　　wherein the second communication apparatus is a Network Exposure Function (NEF), and 　　wherein the third communication apparatus is a Session Management Function (SMF).

[0010] A method of a User Equipment (UE) includes: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a first communication apparatus; and 　　performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is a Session Management Function (SMF).

[0011] A method of a first communication apparatus includes: 　　communicating with a second communication apparatus; and 　　sending Single Network Slice Selection Assistance Information (S-NSSAI) which is replaced with Alternative S-NSSAI.

[0012] A method of a User Equipment (UE) includes: 　　sending a Registration Request message, 　　wherein the Registration Request message includes Alternative Single Network Slice Selection Assistance Information (S-NSSAI); and 　　sending a Protocol Data Unit (PDU) Session Establishment Request message, 　　wherein the PDU Session Establishment Request message includes the Alternative S-NSSAI.

[0013] A method of a first communication apparatus includes: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF).

[0014] A first communication apparatus includes: 　　means for communicating with a second communication apparatus; and 　　means for sending Alternative Single Network Slice Selection Assistance Information (S-NSSAI).

[0015] A first communication apparatus includes: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　means for performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF), and 　　wherein the second communication apparatus is a Unified Data Management (UDM).

[0016] A User Equipment (UE) includes: 　　means for communicating with a first communication apparatus; and 　　means for performing procedure related to a Protocol Data Unit (PDU) Session, 　　wherein the procedure related to the PDU Session is triggered by the first communication apparatus based on Alternative Single Network Slice Selection Assistance Information (S-NSSAI), 　　wherein the Alternative S-NSSAI is sent by a second communication apparatus to the first communication apparatus, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF), and 　　wherein the second communication apparatus is a Unified Data Management (UDM).

[0017] A first communication apparatus includes: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　means for sending the Alternative S-NSSAI to a third communication apparatus, 　　wherein the first communication apparatus is a Policy Control Function (PCF), 　　wherein the second communication apparatus is a Network Exposure Function (NEF), and 　　wherein the third communication apparatus is an Access and Mobility Management Function (AMF).

[0018] A first communication apparatus includes: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　means for sending the Alternative S-NSSAI to a third communication apparatus, 　　wherein the first communication apparatus is a Network Slice Selection Function (NSSF), 　　wherein the second communication apparatus is a Network Exposure Function (NEF), and 　　wherein the third communication apparatus is a Session Management Function (SMF).

[0019] A User Equipment (UE) includes: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a first communication apparatus; and 　　means for performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is a Session Management Function (SMF).

[0020] A first communication apparatus includes: 　　means for communicating with a second communication apparatus; and 　　means for sending Single Network Slice Selection Assistance Information (S-NSSAI) which is replaced with Alternative S-NSSAI.

[0021] A User Equipment (UE) includes: 　　means for sending a Registration Request message, 　　wherein the Registration Request message includes Alternative Single Network Slice Selection Assistance Information (S-NSSAI); and 　　means for sending a Protocol Data Unit (PDU) Session Establishment Request message, 　　wherein the PDU Session Establishment Request message includes the Alternative S-NSSAI.

[0022] A first communication apparatus includes: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　means for performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF).

[0023] Fig. 1 is a diagram illustrating Network slice selection and replacement by AF via UDM for existing PDU Session(s).Fig. 2 is a diagram illustrating Network slice selection and replacement by AF via UDM for new PDU Session(s).Fig. 3 is a diagram illustrating Network slice selection and replacement by AF via PCF.Fig. 4 is a diagram illustrating Network slice selection and replacement by AF via NSSF for existing and new PDU Session(s).Fig. 5 is a diagram illustrating Network slice selection and replacement by AF with UE assistance.Fig. 6 is a diagram illustrating Network slice selection and replacement using UE subscription information.Fig. 7 is a diagram illustrating User consent for sharing sensitive information with 3rd party AF over the NAS.Fig. 8 is a diagram illustrating User consent for sharing sensitive information with 3rd party AF over Application.Fig. 9 is a diagram illustrating User consent for sharing sensitive information with 3rd party AF from NWDAF.Fig. 10 is a diagram illustrating URSP support indication to the 5GC.Fig. 11 is a diagram illustrating a system overview.Fig. 12 is a block diagram illustrating a UE.Fig. 13 is a block diagram illustrating an (R)AN node.Fig. 14 is a diagram illustrating System overview of (R)AN node based on O-RAN architecture.Fig. 15 is a block diagram illustrating an RU.Fig. 16 is a block diagram illustrating a DU.Fig. 17 is a block diagram illustrating a CU.Fig. 18 is a block diagram illustrating an AMF.Fig. 19 is a block diagram illustrating an SMF.Fig. 20 is a block diagram illustrating an UPF.Fig. 21 is a block diagram illustrating a PCF.Fig. 22 is a block diagram illustrating an NWDAF.Fig. 23 is a block diagram illustrating a UDM.Fig. 24 is a block diagram illustrating an NSSF.Fig. 25 is a block diagram illustrating an NSACF.Fig. 26 is a block diagram illustrating an AUSF.Fig. 27 is a block diagram illustrating an AF.Fig. 28 is a block diagram illustrating a NEF.

[0024] Abbreviations For the purposes of the present document, the abbreviations given in 3GPP TR 21.905 [1] and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in 3GPP TR 21.905 [1]. 4G-GUTI　　4G Globally Unique Temporary UE Identity 5GC　　5G Core Network 5GLAN　　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 APP_ID　　Application Identity ARFCN　　Absolute radio-frequency channel number AS　　Access Stratum ASN　　Abstract Syntax Notation ATSSS　　Access Traffic Steering, Switching, Splitting ATSSS-LL　　ATSSS Low-Layer AuC　　Authentication Centre 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　　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 Centre G-PDU　　GTP encapsulated user Plane Data Unit GPS　　Global Positioning System 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) HSS　　Home Subscriber Server IAB　　Integrated access and backhaul IPsec　　Internet Protocol Security IMEI / TAC　　IMEI Type Allocation Code IMSI　　International Mobile Subscriber Identity IPUPS　　Inter PLMN UP Security I-SMF　　Intermediate SMF I-UPF　　Intermediate UPF LADN　　Local Area Data Network LBO　　Local Break Out (roaming) LMF　　Location Management Function LoA　　Level of Automation LPP　　LTE Positioning Protocol LRF　　Location Retrieval Function MCC　　Mobile country code MCX　　Mission Critical Service MDBV　　Maximum Data Burst Volume ME　　Mobile Equipment MFBR　　Maximum Flow Bit Rate MICO　　Mobile Initiated Connection Only MINT　　Minimization of service interruption MITM　　Man In the Middle MME　　Mobility Management Entity MNC　　Mobile Network Code MOCN　　Multiple Operator Core Network MPS　　Multimedia Priority Service MPTCP　　Multi-Path TCP Protocol MT　　Mobile Termination 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 NMEA　　National Marine Electronics Association NPN　　Non-Public Network NR　　New Radio NSAG　　Network Slice Access Stratum Group NRF　　Network Repository Function NSAC　　Network Slice Admission Control NSACF　　Network Slice Admission Control Function NSI ID　　Network Slice Instance Identifier NSSAA　　Network Slice-Specific Authentication and Authorization NSSAAF　　Network Slice-Specific Authentication and Authorization 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 PCRF　　Policy and Charging Rules Function 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 Non-Public Network 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 QoS　　Quality of Service RACS　　Radio Capabilities Signalling optimisation (R)AN　　(Radio) Access Network RAT　　Radio Access Technology RG　　Residential Gateway RIM　　Remote Interference Management RQA　　Reflective QoS Attribute RQI　　Reflective QoS Indication RRC　　Radio Resource Control RSN　　Redundancy Sequence Number RSRP　　Reference Signal Received Power RSRQ　　Reference Signal Received Quality RVAS　　Roaming Value Added Service SA NR　　Standalone New Radio SBA　　Service Based Architecture SBI　　Service Based Interface SCP　　Service Communication Proxy SD　　Slice Differentiator SEAF　　Security Anchor Functionality SENSE　　Signal Level Enhanced Network Selection SEPP　　Security Edge Protection Proxy SGW　　Serving Gateway SIB　　System Information Block SINR　　Signal to Interference plus Noise Ratio SMF　　Session Management Function SMSF　　Short Message Service Function SN　　Sequence Number SN name　　Serving Network Name. SNPN　　Stand-alone Non-Public Network S-NSSAI　　Single Network Slice Selection Assistance Information SOR　　Steering of Roaming SSC　　Session and Service Continuity SSCMSP　　Session and Service Continuity Mode Selection Policy SST　　Slice / Service Type SUCI　　Subscription Concealed Identifier SUPI　　Subscription Permanent Identifier SV　　Software Version TAU　　Tracking Area Update TEID　　Tunnel Endpoint Identifier 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 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 USIM　　User Services Identity Module VID　　VLAN Identifier VLAN　　Virtual Local Area Network VPLMN　　Visited Public Land Mobile Network 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

[0025] Definitions For the purposes of the present document, the terms and definitions given in 3GPP TR 21.905 [1] and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in 3GPP TR 21.905 [1].

[0026] Citation List [1] 3GPP TR 21.905: "Vocabulary for 3GPP Specifications". V17.1.0 (2021-12) [2] 3GPP TS 23.501: "System architecture for the 5G System (5GS)". V18.1.0 (2023-03) [3] 3GPP TS 23.502: "Procedures for the 5G System (5GS)". V18.1.1 (2023-04) [4] 3GPP TS 23.503: "Policy and charging control framework for the 5G System (5GS) Stage 2". V18.1.0 (2023-03) [5] 3GPP SA#100 Workshop - SWS-230044 https: / / www.3gpp.org / ftp / tsg_sa / TSG_SA / Workshops / 2023-06-13_Rel-19_WorkShop / Docs / SWS-230044.zip

[0027] General Those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the Aspects of the present disclosure so as not to obscure the figures with details that will be readily apparent to those skilled in the art having the benefit of the description herein.

[0028] For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the Aspect illustrated in the figures and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as would normally occur to those skilled in the art are to be construed as being within the scope of the present disclosure.

[0029] The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such a process or method. Similarly, one or more devices or entities or sub-systems or elements or structures or components preceded by "comprises... a" does not, without more constraints, preclude the existence of other devices, sub-systems, elements, structures, components, additional devices, additional sub-systems, additional elements, additional structures or additional components. Appearances of the phrase "in an Aspect", "in another Aspect" and similar language throughout this specification may, but not necessarily do, all refer to the same Aspect.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. The system, methods, and examples provided herein are only illustrative and not intended to be limiting.

[0031] In the following specification and the claims, reference will be made to a number of terms, which may be defined to have the following meanings. The singular forms "a", "an", and "the" include plural references unless the context clearly dictates otherwise. As used herein, information is associated with data and knowledge, as data is meaningful information and represents the values attributed to parameters. Further knowledge signifies understanding of an abstract or concrete concept. Note that this example system is simplified to facilitate description of the disclosed subject matter and is not intended to limit the scope of this disclosure. Other devices, systems, and configurations may be used to implement the Aspects disclosed herein in addition to, or instead of, a system, and all such Aspects are contemplated as within the scope of the present disclosure.

[0032] Each of Aspects and elements included in the each of Aspects described below may be implemented independently or in combination with any other. These Aspects include novel characteristics different from one another. Accordingly, these Aspects contribute to achieving objects or solving problems different from one another and contribute to obtaining advantages different from one another.

[0033] Any lists described in following aspects include at least one parameter or multiple parameters. The expression "A and / or B" in this disclosure may mean "at least one of A and B". The definition of parameter(s) in each Aspect may be referred each other. An example object of this disclosure is to provide a method and apparatus that can solve the above-mentioned problem. Each Aspects and elements may relate to one of following descriptions, combination of following descriptions, or all of following descriptions, but the each Aspects and the elements are not limited to following descriptions. Each Aspects and elements may provide solution related to one of following descriptions, combination of following descriptions, or all of following descriptions, but the each Aspects and the elements may provide solution other than the following descriptions. An Application Server (or a Service provider or an Application Function (AF)) may have a good information about the right network slice for the application based on for example, the ongoing connection monitoring, connection statistics analyses, application characteristics and service requirements (e.g. a requirement for a high speed). That is why a network slice selection and replacement by the network, based on notification by the Application Server is required. However, there is no mechanism in 3GPP standards for supporting the network slice selection and replacement by the network.

[0034] In addition, for example, without the network slice selection and replacement by the network based on notification by the Application Server, the network slice resources that are deployed based on the Service Level Agreement (SLA) between Mobile network operator and the 3rd party may not be fully utilized, and may violate the objectives of SLA.

[0035] A method of a first communication apparatus according to example aspect of this disclosure includes communicating with a second communication apparatus. The method includes sending Alternative Single Network Slice Selection Assistance Information (S-NSSAI).

[0036] A method of a first communication apparatus according to example aspect of this disclosure includes receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus. The method includes performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI. The first communication apparatus is an Access and Mobility Management Function (AMF). The second communication apparatus is a Unified Data Management (UDM).

[0037] A method of a User Equipment (UE) according to example aspect of this disclosure includes communicating with a first communication apparatus. The method includes performing procedure related to a Protocol Data Unit (PDU) Session. The procedure related to the PDU Session is triggered by the first communication apparatus based on Alternative Single Network Slice Selection Assistance Information (S-NSSAI). The Alternative S-NSSAI is sent by a second communication apparatus to the first communication apparatus. The first communication apparatus is an Access and Mobility Management Function (AMF). The second communication apparatus is a Unified Data Management (UDM).

[0038] A method of a first communication apparatus according to example aspect of this disclosure includes receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus. The method includes sending the Alternative S-NSSAI to a third communication apparatus. The first communication apparatus is a Policy Control Function (PCF). The second communication apparatus is a Network Exposure Function (NEF). The third communication apparatus is an Access and Mobility Management Function (AMF).

[0039] A method of a first communication apparatus according to example aspect of this disclosure includes receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus. The method includes sending the Alternative S-NSSAI to a third communication apparatus. The first communication apparatus is a Network Slice Selection Function (NSSF). The second communication apparatus is a Network Exposure Function (NEF). The third communication apparatus is a Session Management Function (SMF).

[0040] A method of a User Equipment (UE) according to example aspect of this disclosure includes receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a first communication apparatus. The method includes performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI. The first communication apparatus is a Session Management Function (SMF).

[0041] A method of a first communication apparatus according to example aspect of this disclosure includes communicating with a second communication apparatus. The method includes sending Single Network Slice Selection Assistance Information (S-NSSAI) which is replaced with Alternative S-NSSAI.

[0042] A method of a User Equipment (UE) according to example aspect of this disclosure includes sending a Registration Request message. The Registration Request message includes Alternative Single Network Slice Selection Assistance Information (S-NSSAI). The method includes sending a Protocol Data Unit (PDU) Session Establishment Request message. The PDU Session Establishment Request message includes the Alternative S-NSSAI.

[0043] A method of a first communication apparatus according to example aspect of this disclosure includes receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus. The method includes performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI. The first communication apparatus is an Access and Mobility Management Function (AMF).

[0044] A first communication apparatus according to example aspect of this disclosure includes at least one memory, and at least one hardware processor coupled to the at least one memory. The at least one hardware processor is configured to communicate with a second communication apparatus. The at least one hardware processor is configured to send Alternative Single Network Slice Selection Assistance Information (S-NSSAI).

[0045] A first communication apparatus according to example aspect of this disclosure includes at least one memory, and at least one hardware processor coupled to the at least one memory. The at least one hardware processor is configured to receive Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus. The at least one hardware processor is configured to perform procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI. The first communication apparatus is an Access and Mobility Management Function (AMF). The second communication apparatus is a Unified Data Management (UDM).

[0046] A User Equipment (UE) according to example aspect of this disclosure includes at least one memory, and at least one hardware processor coupled to the at least one memory. The at least one hardware processor is configured to communicate with a first communication apparatus. The at least one hardware processor is configured to perform procedure related to a Protocol Data Unit (PDU) Session. The procedure related to the PDU Session is triggered by the first communication apparatus based on Alternative Single Network Slice Selection Assistance Information (S-NSSAI). The Alternative S-NSSAI is sent by a second communication apparatus to the first communication apparatus. The first communication apparatus is an Access and Mobility Management Function (AMF). The second communication apparatus is a Unified Data Management (UDM).

[0047] A first communication apparatus according to example aspect of this disclosure includes at least one memory, and at least one hardware processor coupled to the at least one memory. The at least one hardware processor is configured to receive Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus. The at least one hardware processor is configured to send the Alternative S-NSSAI to a third communication apparatus. The first communication apparatus is a Policy Control Function (PCF). The second communication apparatus is a Network Exposure Function (NEF). The third communication apparatus is an Access and Mobility Management Function (AMF).

[0048] A first communication apparatus according to example aspect of this disclosure includes at least one memory, and at least one hardware processor coupled to the at least one memory. The at least one hardware processor is configured to receive Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus. The at least one hardware processor is configured to send the Alternative S-NSSAI to a third communication apparatus. The first communication apparatus is a Network Slice Selection Function (NSSF). The second communication apparatus is a Network Exposure Function (NEF). The third communication apparatus is a Session Management Function (SMF).

[0049] A User Equipment (UE) according to example aspect of this disclosure includes at least one memory, and at least one hardware processor coupled to the at least one memory. The at least one hardware processor is configured to receive Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a first communication apparatus. The at least one hardware processor is configured to perform procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI. The first communication apparatus is a Session Management Function (SMF).

[0050] A first communication apparatus according to example aspect of this disclosure includes at least one memory, and at least one hardware processor coupled to the at least one memory. The at least one hardware processor is configured to communicate with a second communication apparatus. The at least one hardware processor is configured to send Single Network Slice Selection Assistance Information (S-NSSAI) which is replaced with Alternative S-NSSAI.

[0051] A User Equipment (UE) according to example aspect of this disclosure includes at least one memory, and at least one hardware processor coupled to the at least one memory. The at least one hardware processor is configured to send a Registration Request message. The Registration Request message includes Alternative Single Network Slice Selection Assistance Information (S-NSSAI). The at least one hardware processor is configured to send a Protocol Data Unit (PDU) Session Establishment Request message. The PDU Session Establishment Request message includes the Alternative S-NSSAI.

[0052] A first communication apparatus according to example aspect of this disclosure includes at least one memory, and at least one hardware processor coupled to the at least one memory. The at least one hardware processor is configured to receive Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus. The at least one hardware processor is configured to perform procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI. The first communication apparatus is an Access and Mobility Management Function (AMF).

[0053] First Aspect The First Aspect includes a mechanism for network slice selection for new PDU Session(s) or network slice replacement for existing PDU Session(s) by an Application Server 201 (e.g. an AF 201) via a NEF 79 and a UDM 75.

[0054] First example of the First Aspect: The detailed processes of the First example of the First Aspect for a mechanism for network slice replacement for existing PDU Session(s) by the AF 201 via a UDM 75 are described below with reference to Fig. 1. Fig. 1: Network slice selection and replacement by AF via UDM for existing PDU Session(s)

[0055] 1.　　A PDU Session is established by a UE 3 on S-NSSAI-1.

[0056] 2.　　The Application server (e.g. the AF 201) may trigger network slice replacement and may provide an Alternative S-NSSAI for each of the UE 3 (or group of UEs) subscribed S-NSSAIs in the UDM 75 via the NEF 79 in order to move an existing or a new PDU Session to an Alternative S-NSSAI. 　　　　For example, the AF 201 may trigger the network slice replacement based on information that the AF 201 has. 　　　　For example, the AF 201 may trigger the network slice replacement based on information related to at least one of ongoing connection monitoring, connection statistics analyses, application characteristics and service requirements (e.g. a requirement for a high speed and a high quality of service).

[0057] For example, the AF 201 may trigger the network slice replacement in a case where at least one of results of ongoing connection monitoring and results of connection statistics analyses meets requirement(s) which is based on operator's policy or Application's policy. 　　　　For example, the AF 201 may trigger the network slice replacement based on at least one of application characteristics and service requirements (e.g. a requirement for a high speed and a high quality of service). 　　　　For example, the above-mentioned ongoing connection monitoring, connection statistics analyses, application characteristics and service requirements may be related to S-NSSAI(s) (or a network slice(s) indicated by the S-NSSAI(s)).

[0058] For example, the above-mentioned ongoing connection monitoring, connection statistics analyses, application characteristics and service requirements may be related to S-NSSAI-1 (or a network slice indicated by the S-NSSAI-1). 　　　　For example, in a case where the results of the connection monitoring related to S-NSSAI-1 (e.g. the results of the connection monitoring related to the PDU Session(s) on S-NSSAI-1) shows that the connection quality is bad or poor or below a predetermined threshold, the AF 201 may trigger the network slice replacement (e.g., the AF 201 may send the Alternative S-NSSAI for S-NSSAI-1 as described in Step 3). 　　　　For example, in a case where the AF 201 detects that S-NSSAI (e.g. S-NSSAI-1 or the network slice indicated by S-NSSAI-1) is unavailable or congested, the AF 201 may trigger the network slice replacement (e.g., the AF 201 may send the Alternative S-NSSAI for S-NSSAI-1 as described in Step 3).

[0059] 3.　　The AF 201 uses the Service Parameters update service and sends an Nnef_Service_Parameter_Update Request message to the NEF 79 in which the AF 201 includes at least one of: -　　Global UE_Id - The Global UE_Id defines the UE 3 for which the network slice replacement is required and may be represented in the form of GPSI. External UE Group Identity may also be used to define multiple UEs for which the network slice replacement request applies. -　　S-NSSAI-1 - the network slice to be replaced for which the AF 201 provides an Alternative S-NSSAI. The AF 201 may provide the Alternative S-NSSAI for one or more S-NSSAIs for which the UE 3 is subscribed for. S-NSSAI-1 may be S-NSSAI of the network slice to be replaced for which the AF 201 provides an Alternative S-NSSAI. S-NSSAI-1 may be S-NSSAI of the network slice to be replaced. S-NSSAI-1 may be S-NSSAI of the network slice which is replaced by the Alternative S-NSSAI. -　　Alternative S-NSSAI - this is the alternative network slice for S-NSSAI-1, i.e. the network slice with which the S-NSSAI-1 is to be replaced. The AF 201 may provide multiple alternative network slices per S-NSSAI-1. The Alternative S-NSSAI may also be a special slice under the bundle service in which the UE 3 requested application is included. The Alternative S-NSSAI may be S-NSSAI of the network slice with which the S-NSSAI-1 is to be replaced. The Alternative S-NSSAI may be S-NSSAI of the network slice which replaces S-NSSAI-1. Optionally, the AF 201 may provide at least one of: -　　Location parameter - information, which may be represented as a cell or list of cells or a TA or a list of TAs or a geographical location in the meaning that the provided Alternative S-NSSAI is valid in these locations only. The Location parameter may indicate location where the Alternative S-NSSAI (or a network slice indicated by the Alternative S-NSSAI) is valid. -　　Validity parameter - information which may be provided as a time in terms of hours, days or any other representation for time duration in the meaning that the Alternative S-NSSAI is valid during these time durations. The Validity parameter may indicate time or duration or interval or period when the Alternative S-NSSAI (or a network slice indicated by the Alternative S-NSSAI) is valid. -　　APN - the Access Point Name. -　　DNN - the Data Network Name (DNN) is equivalent to an APN in EPS. -　　User IP address - An IP address that the UE 3 is assigned. For example, the User IP address is an IP address that is assigned to the UE 3.

[0060] For example, the AF 201 may store in advance or receive from other network node(s) information indicating correspondence S-NSSAI(s) and Alternative S-NSSAI(s) for the S-NSSAI(s). For example, the AF 201 may store in advance or receive from other network node(s) information indicating that the Alternative S-NSSAI for S-NSSAI-1 is S-NSSAI-2. For example, using this information, the AF 201 may select S-NSSAI-1 and the Alternative S-NSSAI (e.g. S-NSSAI-2). For example, in a case where the AF 201 triggers network slice replacement, the AF 201 may select S-NSSAI(s) to be replaced (e.g. S-NSSAI-1), and may select the Alternative S-NSSAI(s) (e.g. S-NSSAI-2) for the selected S-NSSAI(s). Then the AF 201 may send the selected S-NSSAI(s) and the selected Alternative S-NSSAI(s) to the NEF 79. For example, the AF 201 may send the Nnef_Service_Parameter_Update Request message to trigger the network slice replacement.

[0061] 4.　　The NEF 79 may invoke Nudm_SDM_Get service operation to perform at least one of the following mappings: - Map (or convert) the GPSI in Global UE_Id into SUPI, according to information received from the UDM 75. - Map (or convert) the External UE Group Identity into Internal Group Identifier, according to information received from the UDM 75.

[0062] 5.　　The NEF 79 may need to authorize the service specific parameters provisioning request with the UDM 75 by performing an Nudm_ServiceSpecificAuthorisation_Create service operation as defined in clause 4.15.6.7a of 3GPP TS 23.502 [3].

[0063] 6. The Alternative S-NSSAI is stored or updated (if already stored) within the UE 3 subscription information in the UDM 75 against the S-NSSAI it is alternative to, e.g. S-NSSAI-1. Each UE 3 subscribed S-NSSAI may be assigned an Alternative S-NSSAI in the UE subscription information within the UDM 75. If the Location parameter and / or Validity parameter is provided for the Alternative S-NSSAI, they are also stored or updated in the UE subscription information for that Alternative S-NSSAI in the UDM 75. For example, the UDM 75 may receive, from the NEF 79, at least one of S-NSSAI-1, the Alternative S-NSSAI, Location parameter and Validity parameter during at least one of steps 4 and 5. For example, the UDM 75 may store the Alternative S-NSSAI in association with S-NSSAI-1. For example, the UDM 75 may store the Alternative S-NSSAI in association with at least one of S-NSSAI-1, the Location parameter and the Validity parameter. For example, the UDM 75 may update the stored Alternative S-NSSAI based on the received Alternative S-NSSAI.

[0064] 7. The NEF 79 responds to the AF 201 by sending an Nnef_ServiceParameter_Update Response message to confirm the parameters update.

[0065] 8. The UDM 75 triggers a Nudm_SDM_Notification to the AMF 70 in which message the UDM 75 includes at least one of the network slices to be replaced (e.g. S-NSSAI-1), the Alternative S-NSSAI which is the network slice to replace S-NSSAI-1, Location parameter, Validity parameter, APN, DNN and User IP address. For example, the UDM 75 may send an Nudm_SDM_Notification message to the AMF 70 including at least one of S-NSSAI-1, the Alternative S-NSSAI, the Location parameter, the Validity parameter, APN, DNN and User IP address. This requires any existing PDU Session on the network slice (e.g. S-NSSAI-1) to be moved to the Alternative S-NSSAI. If the Location parameter and / or Validity parameter are provided, the UDM 75 may trigger the Nudm_SDM_Notification only in the locations and time compatible with the restrictions by the Location and Validity parameters. Alternatively, the UDM 75 may provide the Location parameter and / or Validity parameter to the AMF 70.

[0066] 9. If the AMF 70 receives S-NSSAI-1 and the Alternative S-NSSAI in Step 8, the AMF 70 triggers PDU Session Modification procedure, as in step 1h in clause 4.3.3.2 of 3GPP TS23.502 [3], in order to move the PDU Session from S-NSSAI-1 to the Alternative S-NSSAI. 　　　　The AMF 70 may refer to the User IP address in Step 8 (e.g. the User IP address received in Step 8) to find a PDU Session as a subject for modifying from S-NSSAI-1 to the Alternative S-NSSAI. 　　　　The AMF 70 may refer to at least one of the APN and DNN in Step 8 (e.g. at least one of the APN and DNN received in Step 8) to find a PDU Session as a subject for modifying from S-NSSAI-1 to the Alternative S-NSSAI.

[0067] The UE 3 may indicate, to node(s) (e.g., the AMF 70), support for the slice replacement feature during any procedure (e.g., the registration procedure). For example, the UE 3 may indicate, to node(s) (e.g., the AMF 70), that the UE 3 supports the network slice replacement described in this disclosure (e.g., Fig. 1). In this case, if the UE 3 indicated support for the slice replacement feature and S-NSSAI-1 requested by the UE 3 (e.g. S-NSSAI-1 on which the PDU Session is established) needs replacement as per the notification from the UDM 75 in Step 8, the AMF 70 may trigger PDU Session Modification procedure in order to move the PDU Session from S-NSSAI-1 to the Alternative S-NSSAI. For example, the message in Step 8 may indicate or notify that S-NSSAI-1 needs to be replaced with the Alternative S-NSSAI.

[0068] In addition, if the UE 3 indicated support for the slice replacement feature and S-NSSAI-1 requested by the UE 3 needs replacement as per the notification from the UDM 75 in Step 8, the AMF 70 may trigger PDU Session Modification procedure, as in step 1h in clause 4.3.3.2 of 3GPP TS23.502 [3], in order to move the PDU Session from S-NSSAI-1 to the Alternative S-NSSAI. If the AMF 70 receives at least one of the Location parameter and Validity parameter related to the Alternative S-NSSAI, the AMF 70 may trigger the network slice replacement with the Alternative S-NSSAI only in locations and times allowed by the Location and Validity parameters.

[0069] The support for the slice replacement feature may be expressed as Network Slice Replacement support. A definition of Network Slice Replacement support in First example of the Seventh Aspect may be applied to each Aspect. For example, the UE 3 may indicate the Network Slice Replacement support in the same manner as First example of the Seventh Aspect. A manner that the UE 3 indicates the Network Slice Replacement support in First example of the Seventh Aspect may be applied to each Aspect. For example, in a case where the AMF 70 receives S-NSSAI-1 and the Alternative S-NSSAI, the AMF 70 may determine that S-NSSAI-1 requested by the UE 3 needs replacement.

[0070] For example, in a case where the AMF 70 receives S-NSSAI-1 and the Alternative S-NSSAI, the AMF 70 may determine that S-NSSAI-1 requested by the UE 3 needs replacement and may perform the PDU Session Modification procedure as in step 1h in clause 4.3.3.2 of 3GPP TS23.502 [3], in order to move the PDU Session from S-NSSAI-1 to the Alternative S-NSSAI.

[0071] 10. Continue with the network triggered PDU Session modification procedure to the Alternative S-NSSAI from step 1h as per clause 4.3.3.2 in 3GPP TS 23.502 [3].

[0072] For example, in this disclosure, S-NSSAI-1 and the Alternative S-NSSAI may be included in the Alternative NSSAI. For example, in this disclosure, instead of transmitting / receiving S-NSSAI-1 and the Alternative S-NSSAI separately, the Alternative NSSAI may be transmitted / received. The Alternative NSSAI may identify a list of mapping information between the S-NSSAI to be replaced (e.g., S-NSSAI-1) and the Alternative S-NSSAI. The Alternative NSSAI may include a list of mapping information between the S-NSSAI to be replaced (e.g., S-NSSAI-1) and the Alternative S-NSSAI.

[0073] Variant 1 of the First example of the First Aspect In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 supports Network Slice Replacement support feature. For example, the AF 201 may know that the UE 3 supports Network Slice Replacement support feature based on the procedure as disclosed by the First example of the Seventh Aspect.

[0074] Variant 2 of the First example of the First Aspect In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 supports URSP rule handling. For example, the AF 201 may know that the UE 3 supports URSP rule handling based on the procedure as disclosed by the First example of the Seventh Aspect. In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 does not support URSP rule handling. For example, the AF 201 may know whether the UE 3 supports URSP rule handling based on the procedure as disclosed by the First example of the Seventh Aspect.

[0075] Variant 3 of the First example of the First Aspect In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 does not support URSP rule handling but the UE 3 supports Network Slice Replacement support feature. For example, the AF 201 may know that the UE 3 capabilities based on the procedure as disclosed by the First example of the Seventh Aspect.

[0076] Variant 4 of the First example of the First Aspect 　　　　In Step 9, the AMF 70 may send, to the UE 3, a NAS message which includes at least one of the network slice to be replaced (e.g. S-NSSAI-1), the Alternative S-NSSAI which is the network slice to replace S-NSSAI-1, Location parameter, Validity parameter, APN, DNN and User IP address. 　　　　In a case where the UE 3 receives S-NSSAI-1 and the Alternative S-NSSAI, the UE 3 may initiate the PDU Session Modification procedure in order to move the PDU Session from S-NSSAI-1 to the Alternative S-NSSAI.

[0077] For example, based on the Location parameter and Validity parameter, the UE 3 itself may initiate the PDU Session Modification procedure in order to switch to different slice that is recommended by the AF 201. The UE 3 may refer to the User IP address to find a PDU Session as a subject for modifying from S-NSSAI-1 to the Alternative S-NSSAI. The UE 3 may refer to at least one of the APN and DNN to find a PDU Session as a subject for modifying from S-NSSAI-1 to the Alternative S-NSSAI.

[0078] Variant 5 of the first example of the first Aspect In one example, the AF 201 may determine to perform the slice replacement for a particular Access type (e.g. 3GPP access or non-3GPP access) or a RAT type of 3GPP access. In this case the AF 201 may send access type (e.g. information indicating access type (e.g. 3GPP access, non-3GPP access or the RAT type (e.g. NR, EUTRA etc.) of 3GPP access)) to the NEF 79 in Step 3 in the Nnef_ServiceParameter_Update Request message. In Step 6 the access type may be also passed to the UDM 75 or UDR, and the UDM 75 or the UDR may store the access type. In Step 8, the UDM 75 provides the access type to the AMF 70. When the AMF 70 receives the access type in the Step 8, the AMF 70 may initiate the PDU Session Modification procedure for the PDU Session activated over the access type indicated by the received access type.

[0079] Second example of the First Aspect: The detailed processes of the Second example of the First Aspect for a mechanism for network slice selection for new PDU Session(s) by the AF 201 via the UDM 75 are described below with reference to Fig. 2. Fig. 2: Network slice selection and replacement by AF via UDM for new PDU Session(s)

[0080] 1.　　The Application server (e.g. the AF 201) may trigger network slice replacement and may provide an Alternative S-NSSAI for each of the UE 3 (or group of UEs) subscribed S-NSSAIs in the UDM 75 via the NEF 79. Step 1 may be same to Step 2 in Fig. 1.

[0081] 2.　　The AF 201 uses the Service Parameters update service and sends an Nnef_Service_Parameter_Update Request message to the NEF 79 in which the AF 201 includes at least one of: -　　Global UE_Id - The Global UE_Id defines the UE 3 for which the network slice replacement is required and may be represented in the form of GPSI. External UE Group Identity may also be used to define multiple UEs for which the network slice replacement request applies. -　　S-NSSAI-1 - the network slice to be replaced for which the AF 201 provides an Alternative S-NSSAI. The AF 201 may provide the Alternative S-NSSAI for one or more S-NSSAI for which the UE 3 is subscribed for. -　　Alternative S-NSSAI - this is the alternative network slice for S-NSSAI-1, i.e. the network slice with which the S-NSSAI-1 is to be replaced. The AF 201 may provide multiple alternative network slices per S-NSSAI-1.

[0082] Optionally, the AF 201 may provide at least one of: -　　Location parameter - information, which may be represented as a cell or list of cells or a TA or list of Tas or a geographical location in the meaning that the provided Alternative S-NSSAI is valid in these locations only. -　　Validity parameter - information which may be provided as a time in terms of hours, days or any other representation for time duration in the meaning that the Alternative S-NSSAI is valid during these time durations. -　　APN - the Access Point Name. -　　DNN - the Data Network Name (DNN) is equivalent to an APN in EPS. -　　User IP address - An IP address that the UE 3 is assigned. 　　Step 2 may be same to Step 3 in Fig. 1. The definition of the Global UE_Id, S-NSSAI-1, Alternative S-NSSAI, Location parameter, Validity parameter, APN, DNN, User IP address in the First example of the First Aspect may be applied to other examples or other Aspects.

[0083] 3.　　The NEF 79 may invoke Nudm_SDM_Get service operation to perform the following mappings: - Map the GPSI in Global UE_Id into SUPI, according to information received from the UDM 75. - Map the External UE Group Identity into Internal Group Identifier, according to information received from the UDM 75. Step 3 may be same to Step 4 in Fig. 1.

[0084] 4. 　　The NEF 79 may need to authorize the service specific parameters provisioning request with the UDM 75 by performing an Nudm_ServiceSpecificAuthorisation_Create service operation as defined in clause 4.15.6.7a of 3GPP TS 23.502 [3]. Step 4 may be same to Step 5 in Fig. 1.

[0085] 5. The Alternative S-NSSAI is stored or updated (if already stored) within the UE subscription information in the UDM 75 against the S-NSSAI it is alternative to, e.g. S-NSSAI-1. Each UE 3 subscribed S-NSSAI may be assigned an Alternative S-NSSAI in the UE 3 subscription information within the UDM 75. If the Location parameter and / or Validity parameter is provided for the Alternative S-NSSAI, they are also stored or updated in the UE subscription information for that Alternative S-NSSAI in the UDM 75. Step 5 may be same to Step 6 in Fig. 1.

[0086] 6. The NEF 79 responds to the AF 201 by sending an Nnef_ServiceParameter_Update Response message to confirm the parameters update. Step 6 may be same to Step 7 in Fig. 1.

[0087] 7. The UDM 75 may trigger Nudm_SDM_Notification to the AMF 70 in which message the UDM 75 includes at least one of the network slice to be replaced (e.g. S-NSSAI-1), the Alternative S-NSSAI which is the network slice to replace S-NSSAI-1, Location parameter, Validity parameter, APN, DNN and User IP address. If the Location parameter and / or Validity parameter are provided, the UDM 75 may include in the Nudm_SDM_Notification the Location parameter and / or Validity parameter as well. The AMF 70 stores the provided Alternative S-NSSAI and the Location and Validity parameters in the UE context for UE 3. For example, the UDM 75 may send an Nudm_SDM_Notification message to the AMF 70 including at least one of UE_Id (e.g. an identity of the UE 3, SUPI of the UE 3 etc.), S-NSSAI-1, the Alternative S-NSSAI, the Location parameter and the Validity parameter. Step 7 may be same to Step 8 in Fig. 1. Upon reception of the Nudm_SDM_Notification message, the AMF 70 may send an Nudm_SDM_Notification response message to the UDM 75.

[0088] 8. At some point the UE 3 triggers a request for PDU Session establishment on S-NSSAI-1 by sending a PDU Session Establishment Request message including at least one of UE_Id, PDU_Session_Id, S-NSSAI-1 and DNN. For example, the UE 3 may perform PDU Session establishment procedure for S-NSSAI-1 by sending the PDU Session Establishment Request message.

[0089] 9. If the AMF 70 receives the PDU Session Establishment Request message, the AMF 70 sends an Nudm_SDM_Get Request message to the UDM 75 including at least one of the UE_Id, S-NSSAI-1 and an indication that the UE 3 supports the network slice replacement feature. The UE 3 may send, to node(s) (e.g., the AMF 70), the indication during any procedure (e.g., the registration procedure). For example, the indication may indicate that the UE 3 supports the network slice replacement described in this disclosure (e.g., Fig. 2). In a case where the AMF 70 receives the indication from the UE 3, the AMF 70 may include the indication in the Nudm_SDM_Get Request message.

[0090] In addition, if the UE 3 indicated support for the slice replacement feature during any procedure (e.g., the registration procedure), the AMF 70 sends an Nudm_SDM_Get Request message to the UDM 75 in which message the AMF 70 includes at least one of the UE_Id, the requested S-NSSAI-1 on which a PDU Session is required and an indication that the UE 3 supports the network slice replacement feature. The indication may be expressed as "network slice replacement supported by the UE 3". For example, the UE 3 may indicate the support for the slice replacement feature in the same manner as Step 9 in Fig. 1.

[0091] 10. If the UE 3 supports the network slice replacement feature as per the indication in the Nudm_SDM_Get Request message from the AMF 70, the UDM 75 provides the Alternative S-NSSAI. The UDM 75 may provide at least one of the Location parameter and Validity parameter to the AMF 70. For example, in a case where the UDM 75 receives the Nudm_SDM_Get Request message including S-NSSAI-1, the UDM 75 may provide the Alternative S-NSSAI. For example, in a case where the UDM 75 receives the Nudm_SDM_Get Request message including S-NSSAI-1, the UDM 75 may find the Alternative S-NSSAI for S-NSSAI-1 and may provide the Alternative S-NSSAI.

[0092] 11. The UDM 75 sends an Nudm_SDM_Get Response message to the AMF 70 in which the UDM 75 includes at least one of the S-NSSAI to be replaced i.e. the S-NSSAI-1, the Alternative S-NSSAI, Location parameter, Validity parameter, APN, DNN and User IP address. For example, the UDM 75 may send the Nudm_SDM_Get Response message to the AMF 70 including at least one of the S-NSSAI-1 and the Alternative S-NSSAI. The UDM 75 may include the Location parameter, Validity parameter, APN, DNN and User IP address in the Nudm_SDM_Get Response message.

[0093] 12. If the UE 3 indicated the support for slice replacement feature (e.g. during the registration procedure) and S-NSSAI-1 requested by the UE 3 needs replacement, the AMF 70 continues with the PDU Session establishment on the Alternative S-NSSAI instead of on the requested S-NSSAI-1 by the UE 3. 　　　　The AMF 70 may refer to at least one of the APN and DNN in Step 7a or Step 11 (e.g at least one of the APN and DNN received in Step 7a or Step 11) whether modifying from S-NSSAI-1 to the Alternative S-NSSAI is needed or not. 　　　　For example, in a case where the AMF 70 receives the Nudm_SDM_Get Response message, the AMF 70 may continue or trigger the PDU Session establishment on the Alternative S-NSSAI.

[0094] For example, in a case where the AMF 70 receives S-NSSAI-1 and the Alternative S-NSSAI, the AMF 70 may determine that S-NSSAI-1 requested by the UE 3 needs replacement. For example, in a case where the AMF 70 receives S-NSSAI-1 and the Alternative S-NSSAI, the AMF 70 may determine that S-NSSAI-1 requested by the UE 3 needs replacement and may perform or trigger the PDU Session establishment procedure for the Alternative S-NSSAI.

[0095] 13. Continue with the PDU Session establishment on the Alternative S-NSSAI from step 3 as per clause 4.3.2.2.1 in 3GPP TS 23.502 [3].

[0096] Variant 1 of the Second example of the First Aspect In one example, after Step 7 (e.g. Step 7a or 7b) the AMF 70 may page the UE 3 (if not connected) and when the UE 3 establishes a connection, the AMF 70 may provide the Alternative S-NSSAI to the UE 3 by a UE Configuration Update message as per the agreed Rel-18 Alternative S-NSSAI feature in 3GPP TS 23.502 [3]. For example, the AMF 70 may send, to the UE 3, the UE Configuration Update message including the Alternative S-NSSAI. The AMF 70 may include in the UE Configuration Update message at least one of the Location parameter and the Validity parameter related to the Alternative S-NSSAI if they are available in the UE 3 context within the AMF 70. Alternatively, the AMF 70 may provide the Alternative S-NSSAI along with at least one of the Location parameter and Validity parameter within the Registration Accept message during the Registration procedure. If provided with at least one of the Alternative S-NSSAI, the Location parameter and the Validity parameter, the UE 3 makes use of the Alternative S-NSSAI only in Locations and Times allowed from the Location and Validity parameters. The UE 3 may not trigger a PDU Session request for the Alternative S-NSSAI in locations and at times restricted by the Location and Validity information for that Alternative S-NSSAI.

[0097] For example, in a case where the UE 3 receives the Alternative S-NSSAI and the UE 3 wants to establish a PDU Session on S-NSSAI-1, the UE 3 may establish the PDU Session on the Alternative S-NSSAI instead of S-NSSAI-1. For example, in a case where the UE 3 also receives the Location parameter, the UE 3 may establish the PDU Session on the Alternative S-NSSAI instead of S-NSSAI-1, at the location indicated by the Location parameter. For example, in a case where the UE 3 also receives the Validity parameter, the UE 3 may establish the PDU Session on the Alternative S-NSSAI instead of S-NSSAI-1, at the time or duration or interval or period indicated by the Validity parameter.

[0098] Variant 2 of the Second example of the First Aspect In Step 1, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 supports Network Slice Replacement support feature. For example, the AF 201 may know that the UE 3 supports Network Slice Replacement support feature based on the procedure as disclosed by the First example of the Seventh Aspect.

[0099] Variant 3 of the Second example of the First Aspect In Step 1, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 supports URSP rule handling. For example, the AF 201 may know that the UE 3 supports URSP rule handling based on the procedure as disclosed by the First example of the Seventh Aspect. In Step 1, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 does not support URSP rule handling. For example, the AF 201 may know whether the UE 3 supports URSP rule handling based on the procedure as disclosed by the First example of the Seventh Aspect.

[0100] Variant 4 of the Second example of the First Aspect In Step 1, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 does not support URSP rule handling but the UE 3 supports Network Slice Replacement support feature. For example, the AF 201 may know that the UE 3 capabilities based on the procedure as disclosed by the First example of the Seventh Aspect.

[0101] Variant 5 of the second example of the first Aspect In one example, the AF 201 may determine to perform the slice replacement for a particular Access type (e.g. 3GPP access or non-3GPP access) or a RAT type of 3GPP access. In this case the AF 201 may send access type (e.g. information indicating access type (e.g. 3GPP access, non-3GPP access per the RAT type (e.g. NR, EUTRA etc.) of 3GPP access)) to the NEF 79 in the Step 2 in the Nnef_ServiceParameter_Update Request message. In the Step 5 the access type may be also passed to the UDM 75 or UDR, and the UDM 75 or the UDR may store the access type. In at least one of Steps 7a and 11, the UDM 75 may provide the access type to the AMF 70. When the AMF 70 receives the access type in at least one of the Steps 7a and 11, the AMF 70 may initiate the PDU Session establishment procedure over the access type indicated by the received access type.

[0102] Second Aspect The Second Aspect includes a mechanism for network slice replacement for existing PDU Session(s) by an Application Server (e.g. an AF 201) via a PCF 73.

[0103] First example of the Second Aspect: The detailed processes of the First example of the Second Aspect for a mechanism for network slice replacement for existing PDU Session(s) by the AF 201 via the PCF 73 are described below with reference to Fig. 3. Fig. 3: Network slice selection and replacement by AF via PCF

[0104] 1.　　A PDU Session is established by a UE 3 on S-NSSAI-1. Step 1 may be same to Step 1 in Fig. 1.

[0105] 2.　　The Application server (e.g. the AF 201) may trigger network slice replacement and may provide an Alternative S-NSSAI for each of the UE 3 (or group of UEs) subscribed S-NSSAIs in a UDM 75 via a NEF 79 in order to move an existing or a new PDU Session to an Alternative S-NSSAI. Step 2 may be same to Step 2 in Fig. 1.

[0106] 3.　　The AF 201 uses the Service Parameters update service and sends an Nnef_Service_Parameter_Update Request message to the NEF 79 in which the AF 201 includes at least one of : -　　Global UE_Id - The Global UE_Id defines the UE 3 for which the network slice replacement is required and may be represented in the form of GPSI. External UE Group Identity may also be used to define multiple UEs for which the network slice replacement request applies. -　　S-NSSAI-1 - the network slice to be replaced for which the AF 201 provides an Alternative S-NSSAI. The AF 201 may provide the Alternative S-NSSAI for one or more S-NSSAIs for which the UE 3 is subscribed for. -　　Alternative S-NSSAI - this is the alternative network slice for S-NSSAI-1, i.e. the network slice with which the S-NSSAI-1 is to be replaced. The AF 201 may provide multiple alternative network slices per S-NSSAI-1.

[0107] Optionally, the AF 201 may provide at least one of: -　　Location parameter - information, which may be represented as a cell or list of cells or a TA or a list of Tas or a geographical location in the meaning that the provided Alternative S-NSSAI is valid in these locations only. -　　Validity parameter - information which may be provided as a time in terms of hours, days or any other representation for time duration in the meaning that the Alternative S-NSSAI is valid during these time durations. -　　APN - the Access Point Name. -　　DNN - the Data Network Name (DNN) is equivalent to an APN in EPS. -　　User IP address - An IP address that the UE 3 is assigned. Step 3 may be same to Step 3 in Fig. 1.

[0108] 4.　　The NEF 79 may invoke Nudm_SDM_Get service operation to perform the following mappings: - Map the GPSI in Global UE_Id into SUPI, according to information received from the UDM 75. - Map the External UE Group Identity into Internal Group Identifier, according to information received from the UDM 75. Step 4 may be same to Step 4 in Fig. 1.

[0109] 5.　　The NEF 79 may need to authorize the service specific parameters provisioning request with the UDM 75 by sending a Nudm_ServiceSpecificAuthorisation_Create service operation as defined in clause 4.15.6.7a. of 3GPP TS 23.502 [3]. Step 5 may be same to Step 5 in Fig. 1.

[0110] 6. The NEF 79 responds to the AF 201 by sending an Nnef_ServiceParameter_Update Response message to confirm the parameters update. Step 6 may be same to Step 7 in Fig. 1.

[0111] 7.　　The NEF 79 provides the network slice to be replaced (e.g. S-NSSAI-1) and the Alternative S-NSSAI to the PCF 73. The NEF 79 may provide the Location parameter, Validity parameter, APN, DNN and User IP address to the PCF 73. For example, the NEF 79 may send an Nnef_ServiceParameter_Update message including at least one of the UE_Id, S-NSSAI-1, Alternative S-NSSAI, Location parameter, Validity parameter, APN, DNN and User IP address. For example, the NEF 79 may provide at least one of the UE_Id, S-NSSAI-1, Alternative S-NSSAI, Location parameter, Validity parameter, APN, DNN and User IP address via any other existing or a new service between the NEF 79 and the PCF 73.

[0112] 8.　　The PCF 73 provides at least one of the S-NSSAI-1 and the Alternative S-NSSAI to the AMF 70. The PCF 73 may provide at least one of the Location parameter, Validity parameter, APN, DNN and User IP address to the AMF 70. For example, the PCF 73 may send an Npcf_AMPolicyControl_UpdateNotify message including at least one of the UE_Id, S-NSSAI-1, Alternative S-NSSAI, Location parameter, Validity parameter, APN, DNN and User IP address.

[0113] 9. If the AMF 70 receives S-NSSAI-1 and the Alternative S-NSSAI in Step 8, the AMF 70 triggers PDU Session Modification procedure, as in step 1h in clause 4.3.3.2 of 3GPP TS23.502[3], in order to move the PDU Session from S-NSSAI-1 to the Alternative S-NSSAI. The AMF 70 may refer to the User IP address in Step 8 (e.g. the User IP address received in Step 8) to find a PDU Session as a subject for modifying from S-NSSAI-1 to the Alternative S-NSSAI. The AMF 70 may refer to the at least one of the APN and DNN in Step 8 (e.g. at least one of the APN and DNN received in Step 8) to find a PDU Session as a subject for modifying from S-NSSAI-1 to the Alternative S-NSSAI.

[0114] The UE 3 may indicate, to node(s) (e.g., the AMF 70), support for the slice replacement feature during any procedure (e.g., the registration procedure). For example, the UE 3 may indicate, to node(s) (e.g., the AMF 70), that the UE 3 supports the network slice replacement described in this disclosure (e.g., Fig. 3). In this case, if the UE 3 indicated support for the slice replacement feature and S-NSSAI-1 requested by the UE 3 needs replacement as per the notification from the UDM 75 in Step 8, the AMF 70 may trigger PDU Session Modification procedure in order to move the PDU Session from S-NSSAI-1 to the Alternative S-NSSAI.

[0115] In addition, if the UE 3 indicated support for the slice replacement feature during the registration and S-NSSAI-1 requested by the UE 3 needs replacement as per the notification from the PCF 73 in Step 8, the AMF 70 triggers PDU Session Modification procedure in order to move the PDU Session from S-NSSAI-1 to the Alternative S-NSSAI. If the AMF 70 receives at least one of the Location parameter and Validity parameter related to the Alternative S-NSSAI, the AMF 70 may trigger the network slice replacement with the Alternative S-NSSAI only in locations and times allowed by the Location and Validity parameters. For example, the UE 3 may indicate the support for the slice replacement feature in the same manner as Step 9 in Fig. 1.

[0116] The AMF 70 may also provide the Alternative S-NSSAI along with at least one of the related Location parameter and Validity parameter to the UE 3 in a UE Configuration Update message or in a Registration Accept message at the next registration procedure with the UE 3. If provided with the Alternative S-NSSAI and at least one of the Location parameter and Validity parameter, the UE 3 may make use of the Alternative S-NSSAI only in Locations and times allowed from the Location and Validity parameters. The UE 3 may not trigger a PDU Session request for the Alternative S-NSSAI in locations and at times restricted by the Location and Validity information for that Alternative S-NSSAI. For example, the AMF 70 may send, to the UE 3, the UE Configuration Update message or the Registration Accept message including the Alternative S-NSSAI (e.g., the Alternative S-NSSAI may indicate that it is for S-NSSAI-1). For example, in a case where the UE 3 receives the Alternative S-NSSAI, the UE 3 may use the Alternative S-NSSAI instead of S-NSSAI-1 for the PDU Session establishment. Step 9 may be same to Step 9 in Fig. 1.

[0117] 10. Continue with the network triggered PDU Session modification to the Alternative S-NSSAI from step 1h as per clause 4.3.3.2 in 3GPP TS 23.502 [3]. Step 10 may be same to Step 10 in Fig. 1.

[0118] Variant 1 of the First example of the Second Aspect In one example, the provided in Step 8 in Fig. 3 Alternative S-NSSAI and related Location parameter and Validity parameter to the AMF 70 may be used for network slice replacement with the Alternative S-NSSAI for new PDU Sessions establishment as well. If after Step 8 in Fig. 3 the UE 3 initiates PDU Session Establishment request on a network slice for which an Alternative S-NSSAI is provided to the AMF 70 in Step 8, the AMF 70 may decide to continue with the PDU Session establishment procedure on the Alternative S-NSSAI as per clause 5.15.19 in 3GPP TS 23.501 [2] if the Location and Validity restrictions permit, i.e. if the Alternative S-NSSAI is allowed in the UE location and the request is at a time allowed by the Validity parameter.

[0119] For example, in a case where the AMF 70 receives S-NSSAI-1 and Alternative S-NSSAI in Step 8 and the UE 3 initiates PDU Session Establishment request on S-NSSAI-1 after Step 8, the AMF 70 may decide to continue with the PDU Session establishment procedure on the Alternative S-NSSAI, instead of S-NSSAI-1, as per clause 5.15.19 in 3GPP TS 23.501 [2].

[0120] Variant 2 of the First example of the Second Aspect In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 supports Network Slice Replacement support feature. For example, the AF 201 may know that the UE 3 supports Network Slice Replacement support feature based on the procedure as disclosed by the First example of the Seventh Aspect.

[0121] Variant 3 of the First example of the Second Aspect In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 supports URSP rule handling. For example, the AF 201 may know that the UE 3 supports URSP rule handling based on the procedure as disclosed by the First example of the Seventh Aspect. In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 does not support URSP rule handling. For example, the AF 201 may know whether the UE 3 supports URSP rule handling based on the procedure as disclosed by the First example of the Seventh Aspect.

[0122] Variant 4 of the First example of the Second Aspect In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 does not support URSP rule handling but the UE 3 supports Network Slice Replacement support feature. For example, the AF 201 may know that the UE 3 capabilities based on the procedure as disclosed by the First example of the Seventh Aspect.

[0123] Third Aspect The Third Aspect includes a mechanism for network slice selection for new PDU Session(s) or network slice replacement for existing PDU Session(s) by an Application Server (e.g. an AF 201) via an NSSF 76.

[0124] First example of the Third Aspect: The detailed processes of the First example of the Third Aspect for a mechanism for network slice selection for new PDU Sessions or network slice replacement for existing PDU Sessions by the AF 201 via the NSSF 76 are described below with reference to Fig. 4. Fig. 4: Network slice selection and replacement by AF via NSSF for existing and new PDU Session(s)

[0125] 1.　　A PDU Session may be established by a UE 3 on S-NSSAI-1. Step 1 may be same to Step 1 in Fig. 1.

[0126] 2.　　The Application server (e.g. the AF 201) may trigger network slice replacement and may provide an Alternative S-NSSAI for each of the UE 3 (or group of UEs) subscribed S-NSSAIs in a UDM 75 via a NEF 79 in order to move an existing or new PDU Session to an Alternative S-NSSAI. Step 2 may be same to Step 2 in Fig. 1.

[0127] 3.　　The AF 201 uses the Service Parameters update service and sends an Nnef_Service_Parameter_Update Request message to the NEF 79 in which the AF 201 includes at least one of: -　　Global UE_Id - The Global UE_Id defines the UE 3 for which the network slice replacement is required and may be represented in the form of GPSI. External UE Group Identity may also be used to define multiple UEs for which the network slice replacement request applies. -　　S-NSSAI-1 - the network slice to be replaced for which the AF 201 provides an Alternative S-NSSAI. The AF 201 may provide the Alternative S-NSSAI for one or more S-NSSAIs for which the UE 3 is subscribed for. -　　Alternative S-NSSAI - this is the alternative network slice for S-NSSAI-1, i.e. the network slice with which the S-NSSAI-1 is to be replaced. The AF 201 may provide multiple alternative network slices per S-NSSAI-1.

[0128] Optionally, the AF 201 may provide at least one of: -　　Location parameter - an information, which may be represented as a cell or list of cells or a TA or a list of Tas or a geographical location in the meaning that the provided Alternative S-NSSAI is valid in these locations only. -　　Validity parameter - an information which may be provided as a time in terms of hours, days or any other representation for time duration in the meaning that the Alternative S-NSSAI is valid during these time durations. APN - the Access Point Name. -　　DNN - the Data Network Name (DNN) is equivalent to an APN in EPS. -　　User IP address - An IP address that the UE 3 is assigned. Step 3 may be same to Step 3 in Fig. 1.

[0129] 4.　　The NEF 79 may invoke Nudm_SDM_Get service operation to perform the following mappings: - Map the GPSI in Global UE_Id into SUPI, according to information received from the UDM 75. - Map the External UE Group Identity into Internal Group Identifier, according to information received from the UDM 75. Step 4 may be same to Step 4 in Fig. 1.

[0130] 5.　　The NEF 79 may need to authorize the service specific parameters provisioning request with the UDM 75 by sending a Nudm_ServiceSpecificAuthorisation_Create service operation as defined in clause 4.15.6.7a. of 3GPP TS 23.502 [3]. Step 5 may be same to Step 5 in Fig. 1.

[0131] 6. The NEF 79 responds to the AF 201 by sending an Nnef_ServiceParameter_Update Response message to confirm the parameters update. Step 6 may be same to Step 7 in Fig. 1.

[0132] 7.　　The NEF 79 provides the network slice to be replaced (e.g. S-NSSAI-1) and the Alternative S-NSSAI to the NSSF 76. The NEF 79 may provide at least one of the Location parameter, Validity parameter, APN, DNN and User IP address to the NSSF 76. For example, the NSSF 76 may send an Nnef_ServiceParameter_Update message including at least one of the UE_Id, S-NSSAI-1, Alternative S-NSSAI, Location parameter, Validity parameter, APN, DNN and User IP address. For example, the NSSF 76 may provide at least one of the UE_Id, S-NSSAI-1, Alternative S-NSSAI, Location parameter, Validity parameter, APN, DNN and User IP address via any other existing or a new service between the NEF 79 and the NSSF 76.

[0133] 8.　　The NSSF 76 provides at least one of the S-NSSAI-1 and the Alternative S-NSSAI to the AMF 70. The NSSF 76 may provide at least one of the Location parameter, Validity parameter, APN, DNN and User IP address to the AMF 70. For example, the NSSF 76 may send an Nnssf_NSSAIAvailability_Notify message including at least one of the UE_Id, S-NSSAI-1, Alternative S-NSSAI, Location parameter, Validity parameter, APN, DNN and User IP address.

[0134] 9.　　If the UE 3 indicated support for slice replacement during the registration and S-NSSAI-1 requested by the UE 3 needs replacement as per the notification from the NSSF 76: - For existing PDU Session(s) on S-NSSAI-1 the AMF 70 triggers PDU Session Modification procedure to the Alternative S-NSSAI as in step 1h in clause 4.3.3.2 of 3GPP TS23.502 [3]; - For new PDU Session request on S-NSSAI-1 the AMF 70 continues the PDU Session establishment on the Alternative S-NSSAI as per step 3 in clause 4.3.2.2.1 in 3GPP TS 23.502 [3].

[0135] The AMF 70 may refer to the User IP address in Step 8 (e.g. the User IP address received in Step 8) to find a PDU Session as a subject for modifying from S-NSSAI-1 to the Alternative S-NSSAI.

[0136] The AMF 70 may refer to at least one of the APN and DNN in Step 8 (e.g. at least one of the APN and DNN received in Step 8) to find a PDU Session as a subject for modifying from S-NSSAI-1 to the Alternative S-NSSAI.

[0137] For example, for existing PDU Session(s) on S-NSSAI-1 (e.g. a case where the PDU Session(s) on S-NSSAI-1 is established in step 1), if the AMF 70 receives S-NSSAI-1 and the Alternative S-NSSAI in Step 8, the AMF 70 may trigger the PDU Session Modification procedure in order to move the PDU Session(s) from S-NSSAI-1 to the Alternative S-NSSAI.

[0138] For example, for new PDU Session request on S-NSSAI-1 (e.g. a case where the PDU Session(s) on S-NSSAI-1 is not established in Step 1), the UE 3 may trigger a request for PDU Session establishment on S-NSSAI-1 by sending a PDU Session Establishment Request message including at least one of UE_Id, PDU_Session_Id, S-NSSAI-1 and DNN. If the AMF 70 receives the PDU Session Establishment Request message, the AMF 70 may continue the PDU Session establishment procedure for the Alternative S-NSSAI instead of S-NSSAI-1.

[0139] The UE 3 may indicate, to node(s) (e.g., the AMF 70), support for the slice replacement feature during any procedure (e.g., the registration procedure). For example, the UE 3 may indicate, to node(s) (e.g., the AMF 70), that the UE 3 supports the network slice replacement described in this disclosure (e.g., Fig. 4).

[0140] If the UE 3 indicated support for the slice replacement feature and S-NSSAI-1 requested by the UE 3 needs replacement as per the notification from the NSSF 76 in Step 8 (e.g., the PDU Session(s) on S-NSSAI-1 is established in Step 1 and the AMF 70 receives the Nnssf_NSSAIAvailability_Notify message from the NSSF 76), the AMF 70 may trigger the PDU Session Modification procedure in order to move the PDU Session from S-NSSAI-1 to the Alternative S-NSSAI, for existing PDU Session(s) on S-NSSAI-1.

[0141] If the UE 3 indicated support for the slice replacement feature and S-NSSAI-1 requested by the UE 3 needs replacement as per the notification from the NSSF 76 in Step 8 (e.g., the AMF 70 receives, from the UE 3, the PDU Session Establishment Request message including at least one of UE_Id, PDU_Session_Id, S-NSSAI-1 and DNN and the AMF 70 receives the Nnssf_NSSAIAvailability_Notify message from the NSSF 76), the AMF 70 may continue the PDU Session establishment procedure for the Alternative S-NSSAI instead of S-NSSAI-1, for new PDU Session request on S-NSSAI-1.

[0142] For example, the UE 3 may indicate the support for the slice replacement feature in the same manner as Step 9 in Fig. 1. For example, in a case where the AMF 70 receives S-NSSAI-1 and the Alternative S-NSSAI, the AMF 70 may determine that S-NSSAI-1 requested by the UE 3 needs replacement.

[0143] For example, in a case where the AMF 70 receives S-NSSAI-1 and the Alternative S-NSSAI, the AMF 70 may determine that S-NSSAI-1 requested by the UE 3 needs replacement and may perform the PDU Session Modification procedure for the Alternative S-NSSAI or the PDU Session establishment procedure for the Alternative S-NSSAI.

[0144] Variant 1 of the First example of the Third Aspect In one example, at Step 8 in Fig. 4 the AMF 70 may provide the Alternative S-NSSAI along with at least one of the related Location parameter and Validity parameter to the UE 3 in the UE Configuration Update message or in the Registration Accept message at the registration procedure with UE 3. If provided with the Alternative S-NSSAI and at least one of the Location parameter and Validity parameter, the UE 3 may make use of the Alternative S-NSSAI only in Locations and times allowed from the Location and Validity parameters. The UE 3 may not trigger a PDU Session request for the Alternative S-NSSAI in locations and at times restricted by the Location and Validity information for that Alternative S-NSSAI.

[0145] For example, the AMF 70 may send, to the UE 3, the UE Configuration Update message or the Registration Accept message including the Alternative S-NSSAI. For example, in a case where the UE 3 receives the Alternative S-NSSAI, the UE 3 may use the Alternative S-NSSAI instead of S-NSSAI-1 for the PDU Session establishment procedure or for the PDU Session Modification procedure. For example, in a case where the UE 3 receives the UE Configuration Update message or the Registration Accept message, the UE 3 may use the Alternative S-NSSAI instead of S-NSSAI-1 for the PDU Session establishment procedure or for the PDU Session Modification procedure.

[0146] Variant 2 of the First example of the Third Aspect In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 supports Network Slice Replacement support feature. For example, the AF 201 may know that the UE 3 supports Network Slice Replacement support feature based on the procedure as disclosed by the First example of the Seventh Aspect.

[0147] Variant 3 of the First example of the Third Aspect In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 supports URSP rule handling. For example, the AF 201 may know that the UE 3 supports URSP rule handling based on the procedure as disclosed by the First example of the Seventh Aspect. In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 does not support URSP rule handling.

[0148] Variant 4 of the First example of the Third Aspect In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 does not support URSP rule handling but the UE 3 supports Network Slice Replacement support feature. For example, the AF 201 may know that the UE 3 capabilities based on the procedure as disclosed by the First example of the Seventh Aspect.

[0149] Fourth Aspect The Fourth Aspect includes a mechanism for network slice selection and replacement by an Application Server (e.g. an AF 201) with UE assistance.

[0150] First example of the Fourth Aspect: The detailed processes of the First example of the Fourth Aspect for a mechanism for network slice selection for new PDU Session(s) and for network slice replacement for existing PDU Session(s) by the AF 201 with UE 3's assistance are described below with reference to Fig. 5. Fig. 5: Network slice selection and replacement by AF with UE assistance

[0151] 1.　　A PDU Session is established by a UE 3 on S-NSSAI-1. Step 1 may be same to Step 1 in Fig. 1.

[0152] 2.　　The Application server (e.g. the AF 201) may trigger network slice replacement and may provide an Alternative S-NSSAI for each of the UE 3 (or group of UEs) subscribed S-NSSAIs in the UDM 75 via an NEF 79 in order to move an existing or a new PDU Session to an Alternative S-NSSAI. Step 2 may be same to Step 2 in Fig. 1.

[0153] 3.　　The AF 201 uses the Service Parameters update service and sends an Nnef_Service_Parameter_Update Request message to the NEF 79 in which the AF 201 includes at least one of: -　　Global UE_Id - The Global UE_Id defines the UE 3 for which the network slice replacement is required and may be represented in the form of GPSI. External UE Group Identity may also be used to define multiple UEs for which the network slice replacement request applies. -　　S-NSSAI-1 - the network slice to be replaced for which the AF 201 provides an Alternative S-NSSAI. The AF 201 may provide the Alternative S-NSSAI for one or more S-NSSAIs for which the UE is subscribed for. -　　Alternative S-NSSAI - this is the alternative network slice for S-NSSAI-1, i.e. the network slice with which the S-NSSAI-1 is to be replaced. The AF 201 may provide multiple alternative network slices per S-NSSAI-1.

[0154] Optionally, the AF 201 may provide at least one of: -　　APN - the Access Point Name. -　　DNN - the Data Network Name (DNN) is equivalent to an APN in EPS. -　　User IP address - An IP address that the UE 3 is assigned.

[0155] 4. The NEF 79 may invoke Nudm_SDM_Get service operation to perform the mappings in the same manner as to Step 4 in Fig. 1. Step 4 may be same to Step 4 in Fig. 1. The NEF 79 may need to authorize the service specific parameters provisioning request with the UDM 75 by sending a Nudm_ServiceSpecificAuthorisation_Create service operation as defined in clause 4.15.6.7a. of TS23.502 [3]. Step 4 may be same to Step 5 in Fig. 1.

[0156] 5. The NEF 79 responds to the AF 201 by sending an Nnef_ServiceParameter_Update Response message to confirm the parameters update. Step 5 may be same to Step 7 in Fig. 1.

[0157] The NEF 79 may provide the network slice to be replaced (e.g. S-NSSAI-1) and the Alternative S-NSSAI to the NSSF 76. The NEF 79 may provide at least one of the DNN, APN and User IP address to the NSSF 76. For example, the NEF 79 may send, to the NSSF 76, an Nnef_ServiceParameter_Update message including at least one of the UE_Id, S-NSSAI-1, Alternative S-NSSAI, DNN, APN and User IP address. For example, the NEF 79 may provide at least one of the UE_Id, S-NSSAI-1, Alternative S-NSSAI, DNN, APN and User IP address via any other existing or a new service between the NEF 79 and the NSSF 76.

[0158] 6. The NSSF 76 provides at least one of the S-NSSAI-1 and the Alternative S-NSSAI to the SMF 71. The NSSF 76 may provide at least one of the DNN, APN and User IP address to the SMF 71. For example, the NSSF 76 may send an Nnssf_NSSAIAvailability_Notify message including at least one of the UE_Id, S-NSSAI-1, Alternative S-NSSAI, DNN, APN and User IP address.

[0159] 7. The SMF 71 interacts with the UE 3 via an existing NAS message or a new NAS message in which the SMF 71 includes at least one of the PDU Session ID (for example, the PDU Session ID of any ongoing PDU Session, e.g. S-NSSAI-1), the network slice to be replaced, e.g. S-NSSAI-1, with the Alternative S-NSSAI. The SMF 71 may refer to the User IP address in Step 6 (e.g. the User IP address received in Step 6) to find a PDU Session as a subject for modifying from S-NSSAI-1 to the Alternative S-NSSAI.

[0160] The SMF 71 may refer to at least one of the APN and DNN in Step 6 (e.g. at least one of the APN and DNN received in Step 6) to find a PDU Session as a subject for modifying from S-NSSAI-1 to the Alternative S-NSSAI. For example, the SMF 71 may send, to the UE 3, the existing NAS message or the new NAS message including at least one of the PDU Session ID (for example, the PDU Session ID of any ongoing PDU Session, or the PDU Session ID of ongoing PDU Session for e.g. S-NSSAI-1), S-NSSAI-1, the Alternative S-NSSAI. The SMF 71 may include at least one of the DNN and the APN in the existing NAS message or the new NAS message.

[0161] 8. If the UE 3 determines that a PDU session exists for S-NSSAI-1 (e.g., in a case where the PDU Session on S-NSSAI-1 is established in Step 1), then the UE 3 moves the data from the PDU session related to S-NSSAI-1 to the PDU session related to the Alternative S-NSSAI. For example, the UE 3 may trigger PDU Session Modification procedure, as per the UE triggered PDU Session Modification procedure from step 1a of clause 4.3.3.2 in 3GPP TS23.502 [3], in order to move the PDU Session from S-NSSAI-1 to the Alternative S-NSSAI. Otherwise (e.g. in a case where there is no PDU Session on S-NSSAI-1 (or the PDU Session on S-NSSAI-1 is not established in Step 1) and establishment of the PDU Session on S-NSSAI-1 is required), the UE 3 initiates establishment of PDU Session on the Alternative S-NSSAI, instead of S-NSSAI-1 as per the PDU Session Establishment procedure in clause 4.3.3.2.1 in 3GPP TS 23.502 [3].

[0162] Variant 1 of the First example of the Fourth Aspect In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 supports Network Slice Replacement support feature. For example, the AF 201 may know that the UE 3 supports Network Slice Replacement support feature based on the procedure as disclosed by the First example of the Seventh Aspect.

[0163] Variant 2 of the First example of the Fourth Aspect In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 supports URSP rule handling. For example, the AF 201 may know that the UE 3 supports URSP rule handling based on the procedure as disclosed by the First example of the Seventh Aspect. In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 does not support URSP rule handling. For example, the AF 201 may know whether the UE 3 supports URSP rule handling based on the procedure as disclosed by the First example of the Seventh Aspect.

[0164] Variant 3 of the First example of the Fourth Aspect In Step 2, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 does not support URSP rule handling but the UE 3 supports Network Slice Replacement support feature. For example, the AF 201 may know that the UE 3 capabilities based on the procedure as disclosed by the First example of the Seventh Aspect.

[0165] Fifth Aspect The Fifth Aspect includes a mechanism for network slice replacement for existing PDU Session(s) using a UE 3 subscription information.

[0166] First example of the Fifth Aspect The detailed processes of the First example of the Fifth Aspect for a mechanism for network slice replacement for existing PDU Session(s) using the UE 3 subscription information are described below with reference to Fig. 6. Fig. 6: Network slice selection and replacement using UE subscription information

[0167] 1.　　The UE 3 initiates, by sending a Registration Request message, registration procedure towards an AMF 70 in order to register with the network. In the Registration Request message, the UE 3 includes the Alternative S-NSSAI for each S-NSSAI included in the Requested NSSAI. For example, the S-NSSAI-2 is indicated as the Alternative S-NSSAI for S-NSSAI-1. For example, the UE 3 sends the Registration Request message including at least one of the Requested NSSAI which includes S-NSSAI-1, and S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1.

[0168] 2.　　The AMF 70 continues with the registration procedure and sends an Nudm_UECM_Registration Request message to a UDM 75 in which message the AMF 70 includes the requested network slices along with the Alternative network slices for them, if any. For example, the AMF 70 may include requested S-NSSAI-1 and Alternative S-NSSAI-2 in the Nudm_UECM_Registration Request message. For example, the AMF 70 may send, to the UDM 75, the Nudm_UECM_Registration Request message including at least one of S-NSSAI-1 and S-NSSAI-2. For example, the AMF 70 may send, to the UDM 75, the Nudm_UECM_Registration Request message including at least one of S-NSSAI-1 which is included in the Requested NSSAI and S-NSSAI-2 which is the Alternative S-NSSAI. For example, the AMF 70 may send, to the UDM 75, the Nudm_UECM_Registration Request message including at least one of the Requested NSSAI including S-NSSAI-1 and S-NSSAI-2 which is the Alternative S-NSSAI.

[0169] 3.　　The UDM 75 stores the received Alternative S-NSSAI(s) from the AMF 70 in the UE 3's subscription information within the UDM 75 (or UDR) against the network slices they are alternative to. For example, the Alternative S-NSSAI-2 is stored as the Alternative S-NSSAI to S-NSSAI-1. For example, the UDM 75 may store S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1. The UDM 75 confirms the UE 3's registration by sending an Nudm_UECM_Registrtion Response message. For example, the UDM 75 may store the Alternative S-NSSAI in association with S-NSSAI-1.

[0170] For example, the UDM 75 may update the stored Alternative S-NSSAI based on the received Alternative S-NSSAI.

[0171] 4.　　The UE 3's registration procedure completes by sending a Registration Accept message to the UE 3 by the AMF 70. For example, the UE 3 may receive the Registration Accept message from the AMF 70. The Registration Accept message may include Allowed NSSAI. The Allowed NSSAI may include S-NSSAI-1.

[0172] 5.　　At some point the UE 3 triggers PDU Session establishment request on S-NSSAI-1. The UE 3 may also indicate an alternative network slice to the requested S-NSSAI-1, for example Alternative S-NSSAI-2. For example, the UE 3 may send, to an SMF 71, a PDU Session establishment request message including at least one of S-NSSAI-1 and S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1. S-NSSAI-2 as the Alternative S-NSSAI may be expressed as Alternative S-NSSAI-2.

[0173] 6.　　The PDU Session establishment procedure continues as per 3GPP TS 23.502 [3], and the PDU Session on S-NSSAI-1 is established.

[0174] 7.　　The Application server, e.g. an AF 201 may monitor the PDU Session and may decide to move the PDU Session from S-NSSAI-1 to the Alternative S-NSSAI-2 in order to improve the quality of the connection or to mitigate congestion on S-NSSAI-1 (or on the network slice indicated by S-NSSAI-1). Step 7 may be same to Step 2 in Fig. 1.

[0175] 8.　　The AF 201 uses the Service Parameters update service and sends the Nnef_Service_Parameter_Update Request message to the NEF 79 in which the AF 201 includes at least one of: -　　Global UE_Id - The Global UE_Id defines the UE 3 for which the network slice replacement is required and may be represented in the form of GPSI. External UE Group Identity may also be used to define multiple UEs for which the network slice replacement request applies. -　　Replace S-NSSAI-1 - the network slice or S-NSSAI to be replaced with Alternative S-NSSAI if one is available in the UE 3 subscription in the UDM 75. For example, Replace S-NSSAI-1 may be expressed as Replace S-NSSAI. For example, the Replace S-NSSAI may indicate S-NSSAI-1 or may be set to S-NSSAI-1. For example, the Replace S-NSSAI may indicate S-NSSAI which is replaced with the Alternative S-NSSAI. Replace S-NSSAI-1 may indicate that S-NSSAI-1 is replaced with the Alternative S-NSSAI-2.

[0176] Optionally, the AF 201 may provide DNN or APN. -　　APN - the Access Point Name. -　　DNN - the Data Network Name (DNN) is equivalent to an APN in EPS. -　　User IP address - An IP address that the UE 3 is assigned.

[0177] 9.　　The NEF 79 may invoke Nudm_SDM_Get service operation and map the GPSI in Global UE_Id into SUPI and also the NEF 79 may need to authorize the service specific parameters provisioning request with the UDM 75. Step 9 may be same to at least one of Steps 4 and 5 in Fig. 1.

[0178] 10.　　The UDM 75 selects an alternative S-NSSAI-2 for S-NSSAI-1 based on the UE 3's subscription information and updates the UE 3's policy in the PCF 73. For example, the UDM 75 may receive the Replace S-NSSAI-1 from the NEF 79 in Step 9. For example, as the UDM 75 stores S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1 in Step 3, the UDM 75 may select S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1 in a case where the UDM 75 receives the Replace S-NSSAI-1 from the NEF 79. For example, the UDM 75 may contact with the PCF 73 to update the UE3's policy in the PCF 73. For example, the UDM 75 may send, to the PCF 73, a request to update the UE3's policy in the PCF 73. The request may include at least one of UE_Id (e.g. SUPI), S-NSSAI-1 and S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1. The request may include at least one of the DNN, APN and User IP address.

[0179] For example, in a case where the PCF 73 receives the request, the PCF 73 may update the UE3's policy. For example, the PCF 73 may update information regarding network slice(s) in the UE 3's policy. For example, the PCF 73 may update the UE 3's policy so that S-NSSAI-2 is selected by the UE 3, in preference to S-NSSAI-1. For example, the PCF 73 may update the UE 3's policy so that S-NSSAI-2 is selected by the UE 3 when the UE 3 performs the registration procedure or the PDU Session establishment procedure, in preference to S-NSSAI-1. In a case where the PCF 73 receives at least one of the DNN, APN and User IP address, the PCF 73 may update the UE 3's policy so that S-NSSAI-2 for the DNN or the APN is selected by the UE 3, in preference to S-NSSAI-1.

[0180] The PCF 73 may refer to the User IP address from the UDM 75 to find a PDU Session as a subject for modifying from S-NSSAI-1 to the Alternative S-NSSAI. The PCF 73 may refer to at least one of the APN and DNN from the UDM 75 to find a PDU Session as a subject for modifying from S-NSSAI-1 to the Alternative S-NSSAI. The PCF 73 may send the updated UE 3's policy to the UE 3.

[0181] 11.　　The PCF 73 triggers a request for network slice replacement to the AMF 70, for example a request to replace S-NSSAI-1 with the Alternative S-NSSAI-2 (or S-NSSAI-2). This means that the PDU Sessions on S-NSSAI-1 needs to be transferred on the Alternative S-NSSAI-2. For example, the PCF 73 may send, to the AMF 70, the request including at least one of the UE_Id, S-NSSAI-1 and S-NSSAI-2 as the Alternative S-NSSAI. For example, the PCF 73 may send, to the AMF 70, the request including at least one of the UE_Id, S-NSSAI-1 and S-NSSAI-2 as the Alternative S-NSSAI in a case where the PCF 73 receives the request from the UDM 75 or in a case where the PCF 73 updates the UE 3's policy. The S-NSSAI-2 as the Alternative S-NSSAI may be expressed as Alternative S-NSSAI-2.

[0182] Alternatively, the request to the AMF 70 to replace the S-NSSAI-1 with the Alternative S-NSSAI-2 may be triggered by the NSSF 76 via the Nnssf_NSSAIAvailability_Notify as per clause 5.2.16.3.3 in TS23.502 [4]. For example, the NSSF 76 may receive at least one of the UE_Id, S-NSSAI-1, S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1, DNN, APN and User IP address from other network node(s) (e.g., the UDM 75, the PCF 73 etc). In this case, the NSSF 76 may send, to the AMF 70, at least one of the UE_Id, S-NSSAI-1, S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1, DNN, APN and User IP address.

[0183] 12.　　The AMF 70 triggers PDU Session Modification procedure for slice replacement from S-NSSAI-1 to the Alternative S-NSSAI-2 as per clause 5.15.19 in 3GPP TS 23.501 [2].

[0184] 13.　　Continue with the network triggered PDU Session modification to the Alternative S-NSSAI as per step 1h of clause 4.3.3.2 in 3GPP TS 23.502 [3].

[0185] For example, in a case where the PDU Session establishment request message is sent after Step 11 and the AMF 70 receives the PDU Session establishment request message, the AMF 70 may perform the PDU Session Establishment procedure for the Alternative S-NSSAI, instead of S-NSSAI-1.

[0186] Variant 1 of the First example of the Fifth Aspect In one example, after PDU Session on S-NSSAI-1 is established i.e. after Step 6 in Fig. 6 the UE 3 and the AF 201 may exchange information over the application layer related to the quality of the connection. This information may be the basis for the decision by the AF 201 at Step 7 to trigger network slice replacement.

[0187] For example, in a case where the AF 201 receives that information indicating that the quality of the connection on S-NSSAI-1 becomes worse, the AF 201 may perform the process(es) in Step 7. For example, in a case where the AF 201 receives that information indicating that S-NSSAI-1 (or the network slice indicated by S-NSSAI-1) is congested, the AF 201 may perform the process(es) in Step 7.

[0188] Variant 2 of the First example of the Fifth Aspect In Step 7, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 supports Network Slice Replacement support feature. For example, the AF 201 may know that the UE 3 supports Network Slice Replacement support feature based on the procedure as disclosed by the First example of the Seventh Aspect.

[0189] Variant 3 of the First example of the Fifth Aspect In Step 7, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 supports URSP rule handling. For example, the AF 201 may know that the UE 3 supports URSP rule handling based on the procedure as disclosed by the First example of the Seventh Aspect. In Step 7, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 does not support URSP rule handling. For example, the AF 201 may know whether the UE 3 supports URSP rule handling based on the procedure as disclosed by the First example of the Seventh Aspect.

[0190] Variant 4 of the First example of the Fifth Aspect In Step 7, the AF 201 may trigger the AF triggered request for slice replacement procedure only if the AF 201 knows that the UE 3 does not support URSP rule handling but the UE 3 supports Network Slice Replacement support feature. For example, the AF 201 may know that the UE 3 capabilities based on the procedure as disclosed by the First example of the Seventh Aspect.

[0191] Sixth Aspect The Sixth Aspect includes a mechanism for obtaining user consent for sharing sensitive information with an AF 201 (e.g. The AF 201 in this disclosure may be a 3rd party AF 201).

[0192] First example of the Sixth Aspect: The detailed processes of the First example of the Sixth Aspect for a mechanism for obtaining user consent for sharing sensitive information with the 3rdparty AF 201 over the NAS are described below with reference to Fig. 7. Fig. 7: User consent for sharing sensitive information with 3rdparty AF over the NAS

[0193] 1.　　The AF 201 requests 5GC to share user information, e.g. user location. For example, the AF 201 triggers a request to the NEF 79 and includes, in the request, at least one of the Global UE_Id (e.g. GPSI, UE 3's GPSI) and the Application Identity (App_Id). The Global UE_Id may be expressed as UE ID. The App_Id may be an identity of the Application in a UE 3. For example, the AF 201 may send, to the NEF 79, the request including at least one of the Global UE_Id and the App_Id. The request may be expressed as a user information request.

[0194] 2.　　The NEF 79 invokes the user information request to a UDM 75 and includes the GPSI and the App_Id. For example, the NEF 79 may send, to the UDM 75, the request including at least one of the GPSI and the App_Id.

[0195] 3.　　The UDM 75 converts the Global UE_Id (e.g. GPSI) to 3GPP identity (e.g. SUPI, SUPI of the UE 3) and checks whether the AF 201 is authorized for the requested service. For example, the UDM 75 may check whether the AF 201 is authorized for performing the request. For example, the UDM 75 may store in advance or receive from other network node(s) information for checking whether the AF 201 is authorized for performing the request. For example, in a case where the UDM 75 determines that the AF 201 is authorized for performing the request, the UDM 75 may proceed to process(es) in Step 4.

[0196] 4.　　The UDM 75 checks whether the UE_Id requires user consent for information sharing with the AF 201. For example, the UDM 75 may check whether the user's consent (e.g. the user may be indicated by the UE_Id (or 3GPP identity (e.g. SUPI)) for information sharing with the AF 201 is required. For example, the UDM 75 may check whether the user's consent (e.g. the user may be indicated by the UE_Id (or 3GPP identity (e.g. SUPI)) to share information (e.g. the user's location) with the AF 201 is required. For example, the UDM 75 may store in advance or receive from other network node(s) information for checking whether the UE_Id requires user consent for information sharing with the AF 201. For example, the UDM 75 may store in advance or receive from other network node(s) information for checking whether the user's consent is required.

[0197] 5.　　If the user with UE_Id requires user consent for sharing information with the AF 201 (or the UDM 75 determines that the user's consent is required), the UDM 75 triggers a request for user consent to the AMF 70. For example, the UDM 75 may send, to the AMF 70, the request including at least one of the UE_Id and the App_Id.

[0198] 6.　　The AMF 70 forwards the request for user consent to the UE 3 over a NAS signalling.

[0199] 7.　　The user agrees to share information with the AF 201. For example, in a case where the UE 3 receives the request from the AMF 70, the UE 3 may display on a screen of the UE 3 a confirmation screen to confirm the user whether the information (e.g. user location) can be shared with the AF 201. In a case where the user confirms that the information (e.g. user location) can be shared with the AF 201 (e.g. in a case where the user pushes the displayed "Yes" button on the screen of the UE 3, it can consider that the user confirms that the information (e.g. user location) can be shared with the AF 201), the UE 3 may proceed to process(es) in Step 8.

[0200] 8.　　The UE 3 sends a user consent response to the AMF 70 in a NAS signalling in which the UE 3 includes the UE_Id and the App_Id for which the user consent is related. For example, the UE 3 may send, to the AMF 70, the user consent response including at least one of the UE_Id and the App_Id. For example, the UE 3 may send, to the AMF 70, the user consent response including at least one of the UE_Id and the App_Id which is related to the user's consent.

[0201] 9.　　The AMF 70 conveys or forwards the user consent response to the UDM 75.

[0202] 10.　　The UDM 75 stores the user consent for App_Id (or for the Application indicated by the App_Id) in the UE 3's subscription information within UDM 75.

[0203] 11.　　The UDM 75 sends the user consent response to the NEF 79.

[0204] 12.　　The NEF 79 forwards the user consent response to the AF 201.

[0205] 13.　　After obtaining the user consent response, the AF 201 may take decision for network slice selection or network slice replacing for the user indicated by the UE_Id based on the QoS for ongoing PDU Session(s) of that user. For example, after obtaining the user consent response, the AF 201 may perform the AF triggered request for slice replacement described in at least one of Figs. 1, 2, 3, 4, 5 and 6. For example, after obtaining the user consent response, the AF 201 may perform, for the user indicated by the UE_Id, the AF triggered request for slice replacement described in at least one of Figs. 1, 2, 3, 4, 5 and 6.

[0206] For example, the AF 201 may store in advance or receive from other network node(s) information regarding the QoS for ongoing PDU Session(s). For example, the AF 201 may store in advance or receive from other network node(s) information regarding the QoS for ongoing PDU Session(s) per user(s).

[0207] For example, in a case where the information indicates that QoS (or quality of the connection) for the PDU Session on S-NSSAI-1 (or on the network slice indicated by S-NSSAI-1) becomes bad, the AF 201 may decide to perform the AF triggered request for slice replacement described in at least one of Figs. 1, 2, 3, 4, 5 and 6 (e.g., may select S-NSSAI-1 to be replaced and may select S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1).

[0208] For example, in a case where the information indicates that the congestion on S-NSSAI-1 (or on the network slice indicated by S-NSSAI-1) occurs, the AF 201 may decide to perform the AF triggered request for slice replacement described in at least one of Figs. 1, 2, 3, 4, 5 and 6 (e.g., may select S-NSSAI-1 to be replaced and may select S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1). For example, in a case where the user consent is positive (e.g. in a case where the user consent indicates that the user of the UE 3 agrees the information sharing with the AF 201), the AF 201 may perform the process(es) in Step 13.

[0209] Second example of the Sixth Aspect: The detailed processes of the Second example of the Sixth Aspect for a mechanism for obtaining user consent for sharing sensitive information with 3rdparty AF 201 over the Application are described below with reference to Fig. 8. Fig. 8: User consent for sharing sensitive information with 3rdparty AF over Application

[0210] 1.　　The AF 201 triggers a request to the UE 3 for information sharing over the Application layer. For example, the AF 201 may request an Application in the UE 3 to share information, e.g. user location, signal coverage level, signal quality etc, by sending an Application layer message over the Application layer. The information requested to share may include signal strength and quality, information regarding at least one of QoS and QoE etc. For example, the AF 201 may request an Application in the UE 3 to share the information related to ongoing PDU Session(s) for the UE 3. For example, the AF 201 may request an Application in the UE 3 to share the information related to ongoing PDU Session(s) on S-NSSAI-1. For example, the AF 201 may request an Application in the UE 3 to share the information related to S-NSSAI-1.

[0211] 2.　　The Application in the UE 3 alerts a user of the UE 3 for the required consent by the AF 201. For example, the Application in the UE 3 may display on User interface (UI) (e.g. on a screen of the UE 3) an alert that a user's consent for sharing the information with the AF 201 is required.

[0212] 3.　　The user is given the choice to allow or reject the information sharing with the AF 201. For example, the Application in the UE 3 or the UE 3 may display on a screen of the UE 3 a confirmation screen to confirm the user whether the information can be shared with the AF 201.

[0213] 4.　　The users choice, e.g., given consent for information sharing is conveyed to the AF 201 on application level. For example, the Application in the UE 3 may send information indicating whether the user confirms that the information can be shared with the AF 201. In a case where the user confirms that the information can be shared with the AF 201 (e.g. in a case where the user pushes the displayed "Yes" button on the screen of the UE, it can consider that the user confirms that the information can be shared with the AF 201), the Application in the UE 3 may send, to the AF 201 over the Application layer, information indicating that the user confirms that the information can be shared with the AF 201 in Step 4.

[0214] 5.　　The user shares the information (e.g. location information, signal coverage level, signal quality etc) with the AF 201 over the Application layer. For example, in a case where the user confirms that the information can be shared with the AF 201, the Application in the UE 3 may send the information (e.g. location information, signal coverage level, signal quality and etc.) to the AF 201 over the Application layer. For example, the information which is sent may be related to ongoing PDU Session(s) for the UE 3. For example, the information which is sent may be related to ongoing PDU Session(s) on S-NSSAI-1. For example, the information which is sent may be related to S-NSSAI-1.

[0215] 6.　　After obtaining the user consent and the information (e.g. the information regarding at least one of the user location, signal coverage level, signal quality, signal strength and quality, QoS and QoE etc), the AF 201 may take decision for network slice selection or network slice replacing for the user indicated by UE_Id (e.g., the Global UE_Id (e.g. GPSI, UE 3's GPSI)) based on the obtained information for ongoing PDU Session(s) of that user. For example, based on the obtained information, the AF 201 may perform the AF triggered request for slice replacement described in at least one of Figs. 1, 2, 3, 4, 5 and 6. For example, in a case where the information indicates that QoS (or quality of the connection) for the PDU Session on S-NSSAI-1 (or on the network slice indicated by S-NSSAI-1) becomes bad, the AF 201 may decide to perform the AF triggered request for slice replacement described in at least one of Figs. 1, 2, 3, 4, 5 and 6 (e.g., may select S-NSSAI-1 to be replaced and may select S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1, and may perform the associated process(es) for replacing the network slice).

[0216] For example, in a case where the information indicates that at least one of the signal coverage level, signal quality and signal strength and quality become bad (e.g., in a case where the information indicates that at least one of the signal coverage level, signal quality and signal strength and quality become worse than predefined threshold), the AF 201 may decide to perform the AF triggered request for slice replacement described in at least one of Figs. 1, 2, 3, 4, 5 and 6 (e.g., the AF 201 may select S-NSSAI-1 to be replaced and may select S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1).

[0217] The information regarding at least one of the user location, signal coverage level, signal quality, signal strength and quality, QoS and QoE etc may be expressed as status information, communication status etc. For example, in a case where communication status meets a predetermined condition or predetermined status, the AF 201 may decide to perform the AF triggered request for slice replacement described in at least one of Figs. 1, 2, 3, 4, 5 and 6 (e.g., may select S-NSSAI-1 to be replaced and may select S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1, and may perform the associated process(es) for replacing the network slice).

[0218] Third example of the Sixth Aspect: The detailed processes of the Third example of the Sixth Aspect for a mechanism for obtaining user consent for sharing sensitive information with 3rdparty AF 201 from an NWDAF 74 are described below with reference to Fig. 9. Fig. 9: User consent for sharing sensitive information with 3rdparty AF from NWDAF

[0219] 1.　　The AF 201 requires analytics information from the NWDAF 74. The AF 201 triggers a request for information sharing to the NEF 79 in which the AF 201 includes at least one of a Global UE_Id (e.g. GPSI, UE 3's GPSI) and an Application Identity (App_Id). For example, the AF 201 may send, to the NEF 79, a request including at least one of the Global UE_Id and the App_Id. The analytics information may include information for performing the process(es) in Step 13 of Fig. 7 or the process(es) in Step 6 of Fig. 8 (e.g. at least one of the user location, signal coverage level, signal quality, signal strength and quality, QoS and QoE etc).

[0220] 2.　　The NEF 79 interacts with the UDM 75 to resolve the Global UE_Id and obtains the UE 3's 3GPP Identity (e.g. SUPI of the UE 3) and then the NEF 79 forwards the request for information sharing to the NWDAF 74 including the SUPI and the App_Id. For example, in a case where the NEF 79 receives at least one of the Global UE_Id and the App_Id, the NEF 79 may send at least one of the Global UE_Id and the App_Id to the UDM 75. For example, in a case where the UDM 75 receives at least one of the Global UE_Id and the App_Id, the UDM 75 may convert the Global UE_Id (e.g. GPSI) to 3GPP identity (e.g. SUPI, SUPI of the UE 3). In a case where the UDM 75 converts the Global UE_Id (e.g. GPSI) to the 3GPP identity (e.g. SUPI, SUPI of the UE 3), the UDM 75 may send the 3GPP identity to the NEF 79. In a case where the NEF 79 receives the 3GPP identity, the NEF 79 may send, to the NWDAF 74, the request for information sharing. The request may include at least one of the 3GPP identity (e.g. SUPI) and the App_Id.

[0221] 3.　　The NWDAF 74 checks with the UDM 75 whether the requested information sharing requires user consent.

[0222] 4.　　The NWDAF 74 sends a request for information sharing consent to the UDM 75. For example, in a case where the NWDAF 74 receives the request from the NEF 79, the NWDAF 74 may send to the UDM 75 the request for information sharing consent. For example, in a case where the NWDAF 74 receives the request from the NEF 79, the NWDAF 74 may send to the UDM 75 a request to check whether the requested information sharing requires user consent. The request sent to the UDM 75 may include at least one of UE_Id (e.g. SUPI) and the App_Id.

[0223] 5.　　If the user consent is required for the information to be shared, the UDM 75 follows the Steps 5 to 10 in Fig. 7. For example, in a case where the UDM 75 receive the request from the NWDAF 74, the UDM 75 may perform Step 5 in Fig. 7, then following process(es) (e.g. process(es) in Steps 6 to 10 in Fig. 7) may be performed.

[0224] 6.　　The UDM 75 forwards the received user consent from the UE 3 to the NWDAF 74.

[0225] 7.　　If the user consent from the UE 3 is positive (e.g. in a case where the user consent indicates that the user of the UE 3 agrees the analytics information sharing with the AF 201), the NWDAF 74 sends at least one of the requested analytics information, the related UE_Id and the App_Id to the NEF 79. The requested analytics information may include information for performing the process(es) in Step 13 of Fig. 7 or the process(es) in Step 6 of Fig. 8. The requested analytics information may include at least one of the user location, signal coverage level, signal quality, signal strength and quality, QoS and QoE etc. The requested analytics information may be expressed as communication status.

[0226] 8.　　The NEF 79 forwards the received analytics information from the NWDAF 74 to the AF 201.

[0227] 9.　　Based on the received analytics information the AF 201 decides whether to replace the network slice. For example, the AF 201 may perform the process(es) in Step 13 of Fig. 7 or the process(es) in Step 6 of Fig. 8 based on the analytics information.

[0228] Seventh Aspect The Seventh Aspect includes a mechanism for UE URSP support indication to the 5GC and to an AF 201.

[0229] First example of the Seventh Aspect: The detailed processes of the First example of the Seventh Aspect for a mechanism for UE URSP support indication to the 5GC and to the AF 201 are described below with reference to Fig. 10. Fig. 10: URSP support indication to the 5GC and to the AF

[0230] 1.　　During the UE 3's registration (e.g. during a registration procedure), a UE 3 sends a Registration Request message to an AMF 70 including at least one of User ID, Network Slice Replacement support and URSP support. The User ID indicates the identity of the UE 3, for example, 5G-GUTI or SUCI. The Network Slice Replacement support indicates the UE 3's capability indicating support of the Network Slice Replacement feature as described in 3GPP TS 23.501 [2].

[0231] The URSP support indicates that the UE 3's capability to support URSP rule handling as per 3GPP TS 23.503 [4]. The URSP support may indicate that the UE 3 is able to understand or use or handle the URSP rule. The URSP support may indicate that the UE 3 supports the URSP rule. The URSP support may indicate that the UE 3 is able to determine how to route outgoing traffic using the URSP rule. The URSP support may indicate the capability of reporting URSP rule enforcement to network. The URSP support may indicate that the UE 3 supports reporting URSP rule enforcement to network. The support of URSP rule may be coded as a negative expression, for example, URSP not supporting indicator or URSP not supported. The URSP support may indicate that the UE 3 does not support the URSP rule handling. The URSP support may indicate that the UE 3 does not support reporting URSP rule enforcement to network. The URSP support may indicate that the UE 3 is not able to understand or use or handle the URSP rule. The URSP support may indicate that the UE 3 does not support the URSP rule. The URSP support may indicate that the UE 3 is not able to determine how to route outgoing traffic using the URSP rule. The URSP rule handling may include reporting URSP rule enforcement to network, understanding or using or handling the URSP rule or determining how to route outgoing traffic using the URSP rule etc.

[0232] For example, the UE 3 may send at least one of the Network Slice Replacement support and the URSP support during any procedure other than the registration procedure. The Network Slice Replacement support may be expressed as information indicating that the UE 3 supports the Network Slice Replacement feature. For example, only the UE 3 which is able to understand or use or handle the URSP rule may include the URSP support in the Registration Request message. For example, the UE 3 which is not able to understand or use or handle the URSP rule may not include the URSP support in the Registration Request message. The URSP rule may be expressed as URSP.

[0233] 2.　　Upon reception of the Registration Request message, the AMF 70 stores the UE 3's support for the Network Slice Replacement (e.g. the Network Slice Replacement support) and the URSP feature (e.g. the URSP support) in the UE 3's context (e.g. UE context(s) for the UE 3) within the AMF 70. The AMF 70 may provide URSP updates by a UE Configuration Update message or by a Registration Accept message to the UE 3 only if the UE 3 indicated support for the URSP feature (e.g. the URSP support) at the registration procedure. The AMF 70 sends an Nudm_UECMRegistration Request message to the UDM 75 including at least one of the User ID, Network Slice Replacement support and URSP support.

[0234] 3.　　Upon reception of the Nudm_UECMRegistration Request message, the UDM 75 sends an Nudm_UECMRegistration Response message to the AMF 70.

[0235] 4.　　If a NEF 79 subscribes to the Nudm SDM service as described in 3GPP TS 23.502 [3], the UDM 75 sends an Nudm_SDM_Notification message to the NEF 79 including at least one of the User ID, Network Slice Replacement support, URSP support.

[0236] 5.　　If the AF 201 subscribes to the Nnef EventExposure service as described in 3GPP TS 23.502 [3], the NEF 79 sends an Nnef_EventExposure_Notify message to the AF 201 including at least one of the User ID, Network Slice Replacement support, URSP support. For example, based on the URSP support, the AF 201 may take decision for network slice selection or network slice replacing for the user indicated by the User ID.

[0237] For example, in a case where the URSP support indicates that the UE 3 does not support the URSP rule handling (e.g. in a case where the URSP support indicates that the UE 3 is not able to understand or use or handle the URSP rule or in a case where the AF 201 does not receive the URSP support or in a case where the AF 201 does not receive the URSP support as the UE 3 does not include the URSP support in the Registration Request message), the AF 201 may take decision for network slice selection or network slice replacing for the user indicated by the User ID (e.g. the AF 201 may perform the AF triggered request for slice replacement described in at least one of Figs. 1, 2, 3, 4, 5 and 6 (e.g., the AF 201 may select S-NSSAI-1 to be replaced and may select S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1, and may perform the associated process(es) for replacing the network slice).

[0238] For example, in a case where the URSP support indicates that the UE 3 supports the URSP rule handling (e.g. in a case where the URSP support indicates that the UE 3 is able to understand or use or handle the URSP rule), the AF 201 may take decision for network slice selection or network slice replacing for the user indicated by the User ID (e.g. the AF 201 may perform the AF triggered request for slice replacement described in at least one of Figs. 1, 2, 3, 4, 5 and 6 (e.g., the AF 201 may select S-NSSAI-1 to be replaced and may select S-NSSAI-2 as the Alternative S-NSSAI for S-NSSAI-1, and may perform the associated process(es) for replacing the network slice).

[0239] 6.　　The AMF 70 sends a Registration Accept message to the UE 3 including 5G-GUTI. For example, the AMF 70 may send the Registration Accept message in a case where the AMF 70 receives the Nudm_UECMRegistration Response message from the UDM 75.

[0240] Variant 1 of the Third example of the Seventh Aspect The Step 4 may be different Nudm service message. The message in Step 4 may be, for example, an Nudm_EventExposure_Notify message or an existing other Nudm service message or a new Ndum service message or an existing Nnef service message or a new Nnef service message.

[0241] Variant 2 of the Third example of the Seventh Aspect The Step 5 may be different Nnef service message. The message in Step 5 may be, for example, an Nnef_PFDManagement_Notify message, an Nnef_Trigger_Delivery message, an Nnef_Trigger_DeliveryNotify message, an Nnef_APISupportCapability_Notify message or an existing other Nnef service message or a new Nnef service message.

[0242] According to at least one of the above Aspects or at least one of the above Variants, for example, it can solve the above-mentioned problem(s). For example, at least one of the above Aspects or at least one of the above Variants can solve the problem that there is no mechanism in 3GPP standards for supporting the network slice selection and replacement by the network. For example, at least one of the above Aspects or at least one of the above Variants can solve the problem that there is no mechanism in 3GPP standards for supporting the network slice selection and replacement by the network, as it proposes the procedure(s) for supporting the network slice selection and replacement by the network. According to at least one of the above Aspects or at least one of the above Variants, for example, it can provide the UE with a connection on the best optimised network slice considering the application and service characteristics.

[0243] System overview Fig. 11 schematically illustrates a telecommunication system 1 for a mobile (cellular or wireless) to which the above aspects are applicable. The telecommunication system 1 represents a system overview in which an end to end communication is possible. For example, UE 3 (or user equipment, 'mobile device' 3) communicates with other UEs 3 or service servers in the data network 20 via respective (R)AN nodes 5 and a core network 7.

[0244] The (R)AN node 5 supports any radio accesses including a 5G radio access technology (RAT), an E-UTRA radio access technology, a beyond 5G RAT, a 6G RAT and non-3GPP RAT including wireless local area network (WLAN) technology as defined by the Institute of Electrical and Electronics Engineers (IEEE).

[0245] The (R)AN node 5 may split into a Radio Unit (RU), Distributed Unit (DU) and Centralized Unit (CU). In some aspects, each of the units may be connected to each other and structure the (R)AN node 5 by adopting an architecture as defined by the Open RAN (O-RAN) Alliance, where the units above are referred to as O-RU, O-DU and O-CU respectively.

[0246] The (R)AN node 5 may be split into control plane function and user plane function. Further, multiple user plane functions can be allocated to support a communication. In some aspects, user traffic may be distributed to multiple user plane functions and user traffic over each user plane functions are aggregated in both the UE 3 and the (R)AN node 5. This split architecture may be called as 'dual connectivity' or 'Multi connectivity'.

[0247] The (R)AN node 5 can also support a communication using the satellite access. In some aspects, the (R)AN node 5 may support a satellite access and a terrestrial access. In addition, the (R)AN node 5 can also be referred as an access node for a non-wireless access. The non-wireless access includes a fixed line access as defined by the Broadband Forum (BBF) and an optical access as defined by the Innovative Optical and Wireless Network (IOWN).

[0248] The core network 7 may include logical nodes (or 'functions') for supporting a communication in the telecommunication system 1. For example, the core network 7 may be 5G Core Network (5GC) that includes, amongst other functions, control plane functions and user plane functions. Each function in logical nodes can be considered as a network function. The network function may be provided to another node by adapting the Service Based Architecture (SBA). A Network Function can be deployed as distributed, redundant, stateless, and scalable that provides the services from several locations and several execution instances in each location by adapting the network virtualization technology as defined by the European Telecommunications Standards Institute, Network Functions Virtualization (ETSI NFV). The core network 7 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN).

[0249] As is well known, a UE 3 may enter and leave the areas (i.e. radio cells) served by the (R)AN node 5 as the UE 3 is moving around in the geographical area covered by the telecommunication system 1. In order to keep track of the UE 3 and to facilitate movement between the different (R)AN nodes 5, the core network 7 comprises at least one access and mobility management function (AMF) 70. The AMF 70 is in communication with the (R)AN node 5 coupled to the core network 7. In some core networks, a mobility management entity (MME) or a mobility management node for beyond 5G or a mobility management node for 6G may be used instead of the AMF 70.

[0250] The core network 7 also includes, amongst others, a Session Management Function (SMF) 71, a User Plane Function (UPF) 72, a Policy Control Function (PCF) 73, a Network Data Analytics Function (NWDAF) 74, a Unified Data Management (UDM) 75, a Network Slice Selection Function (NSSF) 76 and a Network Slice Admission Control Function (NSACF) 77. When the UE 3 is roaming to a visited Public Land Mobile Network (VPLMN), a home Public Land Mobile Network (HPLMN) of the UE 3 provides the UDM 75 and at least some of the functionalities of the SMF 71, UPF 72, PCF 73 and NSACF 77 for the roaming-out UE 3.

[0251] The UE 3 and a respective serving (R)AN node 5 are connected via an appropriate air interface (for example the so-called "Uu" interface and / or the like). Neighboring (R)AN node 5 are connected to each other via an appropriate (R)AN node 5 to (R)AN node interface (such as the so-called "Xn" interface and / or the like). Each (R)AN node 5 is also connected to nodes in the core network 7 (such as the so-called core network nodes) via an appropriate interface (such as the so-called "N2" / "N3" interface(s) and / or the like). From the core network 7, connection to a data network 20 is also provided. The data network 20 can be an internet, a public network, an external network, a private network or an internal network of the PLMN. In case that the data network 20 is provided by a PLMN operator or Mobile Virtual Network Operator (MVNO), the IP Multimedia Subsystem (IMS) service may be provided by that data network 20. The UE 3 can be connected to the data network 20 using IPv4, IPv6, IPv4v6, Ethernet or unstructured data type. The data network may include an Application Function (AF) 201.

[0252] The "Uu" interface may include a Control plane of Uu interface and User plane of Uu interface. The User plane of Uu interface is responsible to convey user traffic between the UE 3 and a serving (R)AN node 5. The User plane of Uu interface may have a layered structure with SDAP, PDCP, RLC and MAC sublayer over the physical connection. The Control plane of Uu interface is responsible to establish, modify and release a connection between the UE 3 and a serving (R)AN node 5. The Control plane of Uu interface may have a layered structure with RRC, PDCP, RLC and MAC sublayers over the physical connection. For example, the following messages are communicated over the RRC layer to support AS signaling.

[0253] RRC Setup Request message: This message is sent from the UE 3 to the (R)AN node 5. In addition to the parameters that are disclosed by Aspects in this disclosure, following parameters may be included together in the RRC Setup Request message. >　　establishmentCause and ue-Identity. The ue-Identity may have a value of ng-5G-S-TMSI-Part1 or randomValue. 　　RRC Setup message: This message is sent from the (R)AN node 5 to the UE 3. In addition to the parameters that are disclosed by Aspects in this disclosure, following parameters may be included together in the RRC Setup message. >　　masterCellGroup and radioBearerConfig 　　RRC setup complete message: This message is sent from the UE 3 to the (R)AN node 5. In addition to the parameters that are disclosed by Aspects in this disclosure, 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

[0254] The UE 3 and the AMF 70 are connected via an appropriate interface (for example the so-called N1 interface and / or the like). The N1 interface is responsible to provide a communication between the UE 3 and the AMF 70 to support NAS signaling. The N1 interface may be established over a 3GPP access and over a non-3GPP access. For example, the following messages are communicated over the N1 interface. 　　registration request message: This message is sent from the UE 3 to the AMF 70. In addition to the parameters that are disclosed by Aspects in this disclosure, following parameters may be included together in the registration request message. >　　5GS registration type, ngKSI, 5GS mobile identity, Non-current native NAS key set identifier, 5GMM capability, UE security capability, Requested NSSAI, Last visited registered TAI, S1 UE network capability, Uplink data status, PDU session status, MICO indication, UE status, Additional GUTI, Allowed PDU session status, UE's usage setting, Requested DRX parameters, EPS NAS message container, LADN indication, Payload container type, Payload container, Network slicing indication, 5GS update type, Mobile station classmark 2, Supported codecs, NAS message container, EPS bearer context status, Requested extended DRX parameters, T3324 value, UE radio capability ID, Requested mapped NSSAI, Additional information requested, Requested WUS assistance information, N5GC indication and Requested NB-N1 mode DRX parameters. 　　Registration accept message: This message is sent from the AMF 70 to the UE 3. In addition to the parameters that are disclosed by Aspects in this disclosure, following parameters may be included together in the registration accept message. >　　5GS registration result, 5G-GUTI, Equivalent PLMNs, TAI list, Allowed NSSAI, Rejected NSSAI, Configured NSSAI, 5GS network feature support, PDU session status, PDU session reactivation result, PDU session reactivation result error cause, LADN information, MICO indication, Network slicing indication, Service area list, T3512 value, Non-3GPP de-registration timer value, T3502 value, Emergency number list, Extended emergency number list, SOR transparent container, EAP message, NSSAI inclusion mode, Operator-defined access category definitions, Negotiated DRX parameters, Non-3GPP NW policies, EPS bearer context status, Negotiated extended DRX parameters, T3447 value, T3448 value, T3324 value, UE radio capability ID, UE radio capability ID deletion indication, Pending NSSAI, Ciphering key data, CAG information list, Truncated 5G-S-TMSI configuration, Negotiated WUS assistance information, Negotiated NB-N1 mode DRX parameters and Extended rejected NSSAI. 　　Registration Complete message: This message is sent from the UE 3 to the AMF 70. In addition to the parameters that are disclosed by Aspects in this disclosure, following parameters may be included together in the Registration Complete message. >　　SOR transparent container. 　　Authentication Request message: This message is sent from the AMF 70 to the UE 3. In addition to the parameters that are disclosed by Aspects in this disclosure, 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 the UE 3 to the AMF 70. In addition to the parameters that are disclosed by Aspects in this disclosure, following parameters may be populated together in the Authentication Response message. >　　Authentication response message identity, Authentication response parameter and EAP message. 　　Authentication Result message: This message is sent from the AMF 70 to the UE 3. In addition to the parameters that are disclosed by Aspects in this disclosure, following parameters may be populated together in the Authentication Result message. >　　ngKSI, EAP message and ABBA. 　　Authentication Failure message: This message is sent from the UE 3 to the AMF 70. In addition to the parameters that are disclosed by Aspects in this disclosure, following parameters may be populated together in the Authentication Failure message. >　　Authentication failure message identity, 5GMM cause and Authentication failure parameter. 　　Authentication Reject message: This message is sent from the AMF 70 to the UE 3. In addition to the parameters that are disclosed by Aspects in this disclosure, following parameters may be populated together in the Authentication Reject message. >　　EAP message. 　　Service Request message: This message is sent from the UE 3 to the AMF 70. In addition to the parameters that are disclosed by Aspects in this disclosure, following parameters may be populated together in the Service Request message. >　　ngKSI, Service type, 5G-S-TMSI, Uplink data status, PDU session status, Allowed PDU session status, NAS message container. 　　Service Accept message: This message is sent from the AMF 70 to the UE 3. In addition to the parameters that are disclosed by Aspects in this disclosure, following parameters may be populated together in 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 the AMF 70 to the UE 3. In addition to the parameters that are disclosed by Aspects in this disclosure, following parameters may be populated together in 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 the AMF 70 to the UE 3. In addition to the parameters that are disclosed by Aspects in this disclosure, following parameters may be populated together in the Configuration Update Command message. >　　Configuration update indication,5G-GUTI, TAI list, Allowed NSSAI, Service area list, Full name for network, Short name for network, Local time zone, Universal time and local time zone, Network daylight saving time, LADN information, MICO indication, Network slicing indication, Configured NSSAI, Rejected NSSAI, Operator-defined access category definitions, SMS indication, T3447 value, CAG information list, UE radio capability ID, UE radio capability ID deletion indication, 5GS registration result, Truncated 5G-S-TMSI configuration, Additional configuration indication and Extended rejected NSSAI. 　　Configuration Update Complete message: This message is sent from the UE 3 to the AMF 70. In addition to the parameters that are disclosed by Aspects in this disclosure, following parameters may be populated together in the Configuration Update Complete message. >　　Configuration update complete message identity. Fig. 11: System overview

[0255] User equipment (UE) Fig. 12 is a block diagram illustrating the main components of the UE 3 (mobile device 3). As shown, the UE 3 includes a transceiver circuit 31 which is operable to transmit signals to and to receive signals from the connected node(s) via one or more antennas 32. Further, the UE 3 may include a user interface 34 for inputting information from outside or outputting information to outside. Although not necessarily shown in the Figure, the UE 3 may have all the usual functionality of a conventional mobile device and this may be provided by any one or any combination of hardware, software and firmware, as appropriate. Software may be pre-installed in the memory and / or may be downloaded via the telecommunication network or from a removable data storage device (RMD), for example. A controller 33 controls the operation of the UE 3 in accordance with software stored in a memory 36. The software includes, among other things, an operating system 361 and a communications control module 362 having at least a transceiver control module 3621. The communications control module 362 (using its transceiver control module 3621) is responsible for handling (generating / sending / receiving) signalling and uplink / downlink data packets between the UE 3 and other nodes, such as the (R)AN node 5 and the AMF 70. Such signalling may include, for example, appropriately formatted signalling messages (e.g. a registration request message and associated response messages) relating to access and mobility management procedures (for the UE 3). The controller 33 interworks with one or more Universal Subscriber Identity Module (USIM) 35. If there are multiple USIMs 35 equipped, the controller 33 may activate only one USIM 35 or may activate multiple USIMs 35 at the same time.

[0256] The UE 3 may, for example, support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). The UE 3 may, for example, be an item of equipment for production or manufacture and / or an item of energy related machinery (for example equipment or machinery such as: boilers; engines; turbines; solar panels; wind turbines; hydroelectric generators; thermal power generators; nuclear electricity generators; batteries; nuclear systems and / or associated equipment; heavy electrical machinery; pumps including vacuum pumps; compressors; fans; blowers; oil hydraulic equipment; pneumatic equipment; metal working machinery; manipulators; robots and / or their application systems; tools; molds or dies; rolls; conveying equipment; elevating equipment; materials handling equipment; textile machinery; sewing machines; printing and / or related machinery; paper converting machinery; chemical machinery; mining and / or construction machinery and / or related equipment; machinery and / or implements for agriculture, forestry and / or fisheries; safety and / or environment preservation equipment; tractors; precision bearings; chains; gears; power transmission equipment; lubricating equipment; valves; pipe fittings; and / or application systems for any of the previously mentioned equipment or machinery etc.).

[0257] The UE 3 may, for example, be an item of transport equipment (for example transport equipment such as: rolling stocks; motor vehicles; motor cycles; bicycles; trains; buses; carts; rickshaws; ships and other watercraft; aircraft; rockets; satellites; drones; balloons etc.). The UE 3 may, for example, be an item of information and communication equipment (for example information and communication equipment such as: electronic computer and related equipment; communication and related equipment; electronic components etc.).

[0258] The UE 3 may, for example, be a refrigerating machine, a refrigerating machine applied product, an item of trade and / or service industry equipment, a vending machine, an automatic service machine, an office machine or equipment, a consumer electronic and electronic appliance (for example a consumer electronic appliance such as: audio equipment; video equipment; a loud speaker; a radio; a television; a microwave oven; a rice cooker; a coffee machine; a dishwasher; a washing machine; a dryer; an electronic fan or related appliance; a cleaner etc.). The UE 3 may, for example, be an electrical application system or equipment (for example an electrical application system or equipment such as: an x-ray system; a particle accelerator; radio isotope equipment; sonic equipment; electromagnetic application equipment; electronic power application equipment etc.).

[0259] The UE 3 may, for example, be an electronic lamp, a luminaire, a measuring instrument, an analyzer, a tester, or a surveying or sensing instrument (for example a surveying or sensing instrument such as: a smoke alarm; a human alarm sensor; a motion sensor; a wireless tag etc.), a watch or clock, a laboratory instrument, optical apparatus, medical equipment and / or system, a weapon, an item of cutlery, a hand tool, or the like.

[0260] The UE 3 may, for example, be a wireless-equipped personal digital assistant or related equipment (such as a wireless card or module designed for attachment to or for insertion into another electronic device (for example a personal computer, electrical measuring machine)). The UE 3 may be a device or a part of a system that provides applications, services, and solutions described below, as to "internet of things (IoT)", using a variety of wired and / or wireless communication technologies.

[0261] Internet of Things devices (or "things") may be equipped with appropriate electronics, software, sensors, network connectivity, and / or the like, which enable these devices to collect and exchange data with each other and with other communication devices. IoT devices may comprise automated equipment that follow software instructions stored in an internal memory. IoT devices may operate without requiring human supervision or interaction. IoT devices might also remain stationary and / or inactive for a long period of time. IoT devices may be implemented as a part of a (generally) stationary apparatus. IoT devices may also be embedded in non-stationary apparatus (e.g. vehicles) or attached to animals or persons to be monitored / tracked. It will be appreciated that IoT technology can be implemented on any communication devices that can connect to a communications network for sending / receiving data, regardless of whether such communication devices are controlled by human input or software instructions stored in memory.

[0262] It will be appreciated that IoT devices are sometimes also referred to as Machine-Type Communication (MTC) devices or Machine-to-Machine (M2M) communication devices or Narrow Band-IoT UE (NB-IoT UE). It will be appreciated that a UE 3 may support one or more IoT or MTC applications. The UE 3 may be a smart phone or a wearable device (e.g. smart glasses, a smart watch, a smart ring, or a hearable device). The UE 3 may be a car, or a connected car, or an autonomous car, or a vehicle device, or a motorcycle or V2X (Vehicle to Everything) communication module (e.g. Vehicle to Vehicle communication module, Vehicle to Infrastructure communication module, Vehicle to People communication module and Vehicle to Network communication module). Fig. 12: User equipment (UE)

[0263] (R)AN node Fig. 13 is a block diagram illustrating the main components of an exemplary (R)AN node 5, for example a base station ('eNB' in LTE, 'gNB' in 5G, a base station for 5G beyond, a base station for 6G). As shown, the (R)AN node 5 includes a transceiver circuit 51 which is operable to transmit signals to and to receive signals from connected UE(s) 3 via one or more antennas 52 and to transmit signals to and to receive signals from other network nodes (either directly or indirectly) via a network interface 53. A controller 54 controls the operation of the (R)AN node 5 in accordance with software stored in a memory 55. Software may be pre-installed in the memory and / or may be downloaded via the telecommunication network or from a removable data storage device (RMD), for example. The software includes, among other things, an operating system 551 and a communications control module 552 having at least a transceiver control module 5521.

[0264] The communications control module 552 (using its transceiver control sub-module) is responsible for handling (generating / sending / receiving) signalling between the (R)AN node 5 and other nodes, such as the UE 3, another (R)AN node 5, the AMF 70 and the UPF 72 (e.g. directly or indirectly). The signalling may include, for example, appropriately formatted signalling messages relating to a radio connection and a connection with the core network 7 (for a particular UE 3), and in particular, relating to connection establishment and maintenance (e.g. RRC connection establishment and other RRC messages), NG Application Protocol (NGAP) messages (i.e. messages by N2 reference point) and Xn application protocol (XnAP) messages (i.e. messages by Xn reference point), etc. Such signalling may also include, for example, broadcast information (e.g. Master Information and System information) in a sending case.

[0265] The controller 54 is also configured (by software or hardware) to handle related tasks such as, when implemented, UE mobility estimate and / or moving trajectory estimation. The (R)AN node 5 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). The (R)AN node 5 may be expressed as a RAN node, RAN, (R)AN etc. Fig. 13: (R)AN node

[0266] System overview of (R)AN node 5 based on O-RAN architecture Fig. 14 schematically illustrates a (R)AN node 5 based on O-RAN architecture to which the (R)AN node 5 aspects are applicable. The (R)AN node 5 based on O-RAN architecture represents a system overview in which the (R)AN node is split into a Radio Unit (RU) 60, Distributed Unit (DU) 61 and Centralized Unit (CU) 62. In some aspects, each unit may be combined. For example, the RU 60 can be integrated / combined with the DU 61 as an integrated / combined unit, the DU 61 can be integrated / combined with the CU 62 as another integrated / combined unit. Any functionality in the description for a unit (e.g. one of RU 60, DU 61 and CU 62) can be implemented in the integrated / combined unit above. Further, CU 62 can separate into two functional units such as CU Control plane (CP) and CU User plane (UP). The CU CP has a control plane functionality in the (R)AN node 5. The CU UP has a user plane functionality in the (R)AN node 5. Each CU CP is connected to the CU UP via an appropriate interface (such as the so-called "E1" interface and / or the like).

[0267] The UE 3 and a respective serving RU 60 are connected via an appropriate air interface (for example the so-called "Uu" interface and / or the like). Each RU 60 is connected to the DU 61 via an appropriate interface (such as the so-called "Front haul", "Open Front haul", "F1" interface and / or the like). Each DU 61 is connected to the CU 62 via an appropriate interface (such as the so-called "Mid haul", "Open Mid haul", "E2" interface and / or the like). Each CU 62 is also connected to nodes in the core network 7 (such as the so-called core network nodes) via an appropriate interface (such as the so-called "Back haul", "Open Back haul", "N2" / "N3" interface(s) and / or the like). In addition, a user plane part of the DU 61 can also be connected to the core network nodes via an appropriate interface (such as the so-called "N3" interface(s) and / or the like).

[0268] Depending on functionality split among the RU 60, DU 61 and CU 62, each unit provides some of the functionality that is provided by the (R)AN node 5. For example, the RU 60 may provide a functionalities to communicate with a UE 3 over air interface, the DU 61 may provide functionalities to support MAC layer and RLC layer, the CU 62 may provide functionalities to support PDCP layer, SDAP layer and RRC layer. Fig. 14: System overview of (R)AN node 5 based on O-RAN architecture

[0269] Radio Unit (RU) Fig. 15 is a block diagram illustrating the main components of an exemplary RU 60, for example a RU part of base station ('eNB' in LTE, 'gNB' in 5G, a base station for 5G beyond, a base station for 6G). As shown, the RU 60 includes a transceiver circuit 601 which is operable to transmit signals to and to receive signals from connected UE(s) 3 via one or more antennas 602 and to transmit signals to and to receive signals from other network nodes or network unit (either directly or indirectly) via a network interface 603. A controller 604 controls the operation of the RU 60 in accordance with software stored in a memory 605. Software may be pre-installed in the memory and / or may be downloaded via the telecommunication network or from a removable data storage device (RMD), for example. The software includes, among other things, an operating system 6051 and a communications control module 6052 having at least a transceiver control module 60521.

[0270] The communications control module 6052 (using its transceiver control sub-module) is responsible for handling (generating / sending / receiving) signalling between the RU 60 and other nodes or units, such as the UE 3, another RU 60 and DU 61 (e.g. directly or indirectly). The signalling may include, for example, appropriately formatted signalling messages relating to a radio connection and a connection with the RU 60 (for a particular UE 3), and in particular, relating to MAC layer and RLC layer.

[0271] The controller 604 is also configured (by software or hardware) to handle related tasks such as, when implemented, UE mobility estimate and / or moving trajectory estimation. The RU 60 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). As described above, the RU 60 can be integrated / combined with the DU 61 as an integrated / combined unit. Any functionality in the description for the RU 60 can be implemented in the integrated / combined unit above. Fig. 15: Radio Unit (RU)

[0272] Distributed Unit (DU) Fig. 16 is a block diagram illustrating the main components of an exemplary DU 61, for example a DU part of a base station ('eNB' in LTE, 'gNB' in 5G, a base station for 5G beyond, a base station for 6G). As shown, the apparatus includes a transceiver circuit 611 which is operable to transmit signals to and to receive signals from other nodes or units (including the RU 60) via a network interface 612. A controller 613 controls the operation of the DU 61 in accordance with software stored in a memory 614. Software may be pre-installed in the memory 614 and / or may be downloaded via the telecommunication network or from a removable data storage device (RMD), for example. The software includes, among other things, an operating system 6141 and a communications control module 6142 having at least a transceiver control module 61421. The communications control module 6142 (using its transceiver control module 61421 is responsible for handling (generating / sending / receiving) signalling between the DU 61 and other nodes or units, such as the RU 60 and other nodes and units.

[0273] The DU 61 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). As described above, the RU 60 can be integrated / combined with the DU 61 or CU 62 as an integrated / combined unit. Any functionality in the description for DU 61 can be implemented in one of the integrated / combined unit above. Fig. 16: Distributed Unit (DU)

[0274] Centralized Unit (CU) Fig. 17 is a block diagram illustrating the main components of an exemplary CU 62, for example a CU part of base station ('eNB' in LTE, 'gNB' in 5G, a base station for 5G beyond, a base station for 6G). As shown, the apparatus includes a transceiver circuit 621 which is operable to transmit signals to and to receive signals from other nodes or units (including the DU 61) via a network interface 622. A controller 623 controls the operation of the CU 62 in accordance with software stored in a memory 624. Software may be pre-installed in the memory 624 and / or may be downloaded via the telecommunication network or from a removable data storage device (RMD), for example. The software includes, among other things, an operating system 6241 and a communications control module 6242 having at least a transceiver control module 62421. The communications control module 6242 (using its transceiver control module 62421 is responsible for handling (generating / sending / receiving) signalling between the CU 62 and other nodes or units, such as the DU 61 and other nodes and units.

[0275] The CU 62 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). As described above, the CU 62 can be integrated / combined with the DU 61 as an integrated / combined unit. Any functionality in the description for the CU 62 can be implemented in the integrated / combined unit above. Fig. 17: Centralized Unit (CU)

[0276] AMF Fig. 18 is a block diagram illustrating the main components of the AMF 70. As shown, the apparatus includes a transceiver circuit 701 which is operable to transmit signals to and to receive signals from other nodes (including the UE 3, the NSSF 76) via a network interface 702. A controller 703 controls the operation of the AMF 70 in accordance with software stored in a memory 704. Software may be pre-installed in the memory 704 and / or may be downloaded via the telecommunication network or from a removable data storage device (RMD), for example. The software includes, among other things, an operating system 7041 and a communications control module 7042 having at least a transceiver control module 70421. The communications control module 7042 (using its transceiver control module 70421 is responsible for handling (generating / sending / receiving) signalling between the AMF 70 and other nodes, such as the UE 3 (e.g. via the (R)AN node 5) and other core network nodes (including core network nodes in the HPLMN of the UE 3 when the UE 3 is roaming-in. Such signalling may include, for example, appropriately formatted signalling messages (e.g. a registration request message and associated response messages) relating to access and mobility management procedures (for the UE 3). The AMF 70 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). Fig. 18: AMF

[0277] SMF Fig. 19 is a block diagram illustrating the main components of the SMF 71. As shown, the apparatus includes a transceiver circuit 711 which is operable to transmit signals to and to receive signals from other nodes (including the AMF 70) via a network interface 712. A controller 713 controls the operation of the SMF 71 in accordance with software stored in a memory 714. Software may be pre-installed in the memory 714 and / or may be downloaded via the telecommunication network or from a removable data storage device (e.g. a removable memory device (RMD)), for example. The software includes, among other things, an operating system 7141 and a communications control module 7142 having at least a transceiver control module 71421. The communications control module 7142 (using its transceiver control module 71421 is responsible for handling (generating / sending / receiving) signalling between the SMF 71 and other nodes, such as the AMF 70 and other core network nodes (including core network nodes in the HPLMN of the UE 3 when the UE 3 is roaming-in. Such signalling may include, for example, appropriately formatted signalling messages (e.g. a HTTP restful methods based on the service based interfaces) relating to policy management procedures (for the UE 3).

[0278] The SMF 71 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). Fig. 19: SMF

[0279] UPF Fig. 20 is a block diagram illustrating the main components of the UPF 72. As shown, the apparatus includes a transceiver circuit 721 which is operable to transmit signals to and to receive signals from other nodes (including the SMF 71) via a network interface 722. A controller 723 controls the operation of the UPF 72 in accordance with software stored in a memory 724. Software may be pre-installed in the memory 724 and / or may be downloaded via the telecommunication network or from a removable data storage device (e.g. a removable memory device (RMD)), for example. The software includes, among other things, an operating system 7241 and a communications control module 7242 having at least a transceiver control module 72421. The communications control module 7242 (using its transceiver control module 72421 is responsible for handling (generating / sending / receiving) signalling between the UPF 72 and other nodes, such as the SMF 71 and other core network nodes (including core network nodes in the HPLMN of the UE 3 when the UE 3 is roaming-in. Such signalling may include, for example, appropriately formatted signalling messages (e.g. a HTTP restful methods based on the service based interfaces) relating to policy management procedures (for the UE 3). The UPF 72 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). Fig. 20: UPF

[0280] PCF Fig. 21 is a block diagram illustrating the main components of the PCF 73. As shown, the apparatus includes a transceiver circuit 731 which is operable to transmit signals to and to receive signals from other nodes (including the AMF 70) via a network interface 732. A controller 733 controls the operation of the PCF 73 in accordance with software stored in a memory 734. Software may be pre-installed in the memory 734 and / or may be downloaded via the telecommunication network or from a removable data storage device (e.g. a removable memory device (RMD)), for example. The software includes, among other things, an operating system 7341 and a communications control module 7342 having at least a transceiver control module 73421. The communications control module 7342 (using its transceiver control module 73421 is responsible for handling (generating / sending / receiving) signalling between the PCF 73 and other nodes, such as the AMF 70 and other core network nodes (including core network nodes in the HPLMN of the UE 3 when the UE 3 is roaming-in. Such signalling may include, for example, appropriately formatted signalling messages (e.g. a HTTP restful methods based on the service based interfaces) relating to policy management procedures (for the UE 3). The PCF 73 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). Fig. 21: PCF

[0281] NWDAF Fig. 22 is a block diagram illustrating the main components of the NWDAF 74. As shown, the apparatus includes a transceiver circuit 741 which is operable to transmit signals to and to receive signals from other nodes (including the AMF 70 and the UDM 75) via a network interface 742. A controller 743 controls the operation of the NWDAF 74 in accordance with software stored in a memory 744. Software may be pre-installed in the memory 744 and / or may be downloaded via the telecommunication network or from a removable data storage device (e.g. a removable memory device (RMD)), for example. The software includes, among other things, an operating system 7441 and a communications control module 7442 having at least a transceiver control module 74421. The communications control module 7442 (using its transceiver control module 74421 is responsible for handling (generating / sending / receiving) signalling between the NWDAF 74 and other nodes, such as the AMF 70 and other core network nodes (including core network nodes in the HPLMN of the UE 3 when the UE 3 is roaming-in. Such signalling may include, for example, appropriately formatted signalling messages (e.g. a HTTP restful methods based on the service based interfaces) relating to policy management procedures (for the UE 3). The NWDAF 74 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). Fig. 22: NWDAF

[0282] UDM Fig. 23 is a block diagram illustrating the main components of the UDM 75. As shown, the apparatus includes a transceiver circuit 751 which is operable to transmit signals to and to receive signals from other nodes (including the AMF 70) via a network interface 752. A controller 753 controls the operation of the UDM 75 in accordance with software stored in a memory 754. Software may be pre-installed in the memory 754 and / or may be downloaded via the telecommunication network or from a removable data storage device (RMD), for example. The software includes, among other things, an operating system 7541 and a communications control module 7542 having at least a transceiver control module 75421. The communications control module 7542 (using its transceiver control module 75421 is responsible for handling (generating / sending / receiving) signalling between the UDM 75 and other nodes, such as the AMF 70 and other core network nodes (including core network nodes in the VPLMN of the UE 3 when the UE 3 is roaming-out. Such signalling may include, for example, appropriately formatted signalling messages (e.g. a HTTP restful methods based on the service based interfaces) relating to mobility management procedures (for the UE 3). The UDM 75 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). Fig. 23: UDM

[0283] NSSF Fig. 24 is a block diagram illustrating the main components of the NSSF 76. As shown, the apparatus includes a transceiver circuit 761 which is operable to transmit signals to and to receive signals from other nodes (including the AMF 70) via a network interface 762. A controller 763 controls the operation of the NSSF 76 in accordance with software stored in a memory 764. Software may be pre-installed in the memory 764 and / or may be downloaded via the telecommunication network or from a removable data storage device (RMD), for example. 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 / sending / receiving) signalling between the NSSF 76 and other nodes, such as the AMF 70 and other core network nodes (including core network nodes in the VPLMN of the UE 3 when the UE 3 is roaming-out. Such signalling may include, for example, appropriately formatted signaling messages (e.g. a HTTP restful methods based on the service based interfaces) relating to mobility management procedures (for the UE 3). The NSSF 76 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). Fig. 24: NSSF

[0284] NSACF Fig. 25 is a block diagram illustrating the main components of the NSACF 77. As shown, the apparatus includes a transceiver circuit 771 which is operable to transmit signals to and to receive signals from other nodes (including the AMF 70) via a network interface 772. A controller 773 controls the operation of the NSACF 77 in accordance with the software stored in a memory 774. The Software may be pre-installed in the memory 774 and / or may be downloaded via the telecommunication network or from a removable data storage device (e.g. a removable memory device (RMD)), for example. The software includes, among other things, an operating system 7741 and a communications control module 7742 having at least a transceiver control module 77421. The communications control module 7742 (using its transceiver control module 77421 is responsible for handling (generating / sending / receiving) signalling between the NSACF 77 and other nodes, such as the AMF 70 and other core network nodes (including core network nodes in the HPLMN of the UE 3 when the UE 3 is roaming-in. Such signalling may include, for example, appropriately formatted signalling messages (e.g. a HTTP restful methods based on the service based interfaces) relating to network data analytics function procedures (for the UE 3). The NSACF 77 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). Fig. 25: NSACF

[0285] AUSF Fig. 26 is a block diagram illustrating the main components of the AUSF 78. As shown, the apparatus includes a transceiver circuit 781 which is operable to transmit signals to and to receive signals from other nodes (including the AMF 70) via a network interface 782. A controller 783 controls the operation of the AUSF 78 in accordance with the software stored in a memory 784. The Software may be pre-installed in the memory 784 and / or may be downloaded via the telecommunication network or from a removable data storage device (e.g. a removable memory device (RMD)), for example. The software includes, among other things, an operating system 7841 and a communications control module 7842 having at least a transceiver control module 78421. The communications control module 7842 (using its transceiver control module 78421 is responsible for handling (generating / sending / receiving) signalling between the AUSF 78 and other nodes, such as the AMF 70 and other core network nodes (including core network nodes in the HPLMN of the UE 3 when the UE 3 is roaming-in. Such signalling may include, for example, appropriately formatted signalling messages (e.g. a HTTP restful methods based on the service based interfaces) relating to network data analytics function procedures (for the UE 3). The AUSF 78 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). Fig. 26: AUSF

[0286] AF Fig. 27 is a block diagram illustrating the main components of the AF 201. As shown, the apparatus includes a transceiver circuit 2011 which is operable to transmit signals to and to receive signals from other nodes (including the UE 3) via a network interface 2012. A controller 2013 controls the operation of the AF 201 in accordance with software stored in a memory 2014. Software may be pre-installed in the memory 2014 and / or may be downloaded via the telecommunication network or from a removable data storage device (e.g. a removable memory device (RMD)), for example. The software includes, among other things, an operating system 20141 and a communications control module 20142 having at least a transceiver control module 201421. The communications control module 20142 (using its transceiver control module 201421 is responsible for handling (generating / sending / receiving) signalling between the AF 201 and other nodes, such as the UE 3 and other core network nodes (including core network nodes in the HPLMN of the UE 3 when the UE 3 is roaming-in. Such signalling may include, for example, appropriately formatted signalling messages (e.g. a HTTP restful methods based on the service based interfaces) relating to policy management procedures (for the UE 3). The AF 201 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). Fig. 27: AF

[0287] NEF Fig. 28 is a block diagram illustrating the main components of the NEF 79. As shown, the apparatus includes a transceiver circuit 791 which is operable to transmit signals to and to receive signals from other nodes (including the AF 201, the UDM 75) via a network interface 792. A controller 793 controls the operation of the NEF 79 in accordance with software stored in a memory 794. Software may be pre-installed in the memory 794 and / or may be downloaded via the telecommunication network or from a removable data storage device (RMD), for example. The software includes, among other things, an operating system 7941 and a communications control module 7942 having at least a transceiver control module 79421. The communications control module 7942 (using its transceiver control module 79421 is responsible for handling (generating / sending / receiving) signalling between the NEF 79 and other nodes, such as the AF 201, the UDM 75 and other core network nodes (including core network nodes in the VPLMN of the UE 3 when the UE 3 is roaming-out. Such signalling may include, for example, appropriately formatted signalling messages (e.g. a HTTP restful methods based on the service based interfaces) relating to mobility management procedures (for the UE 3). The NEF 79 may support the Non-Public Network (NPN). The NPN may be a Stand-alone Non-Public Network (SNPN) or a Public Network Integrated NPN (PNI-NPN). Fig. 28: NEF

[0288] Modifications and Alternatives Detailed aspects have been described above. As those skilled in the art will appreciate, a number of modifications and alternatives can be made to the above aspects whilst still benefiting from the disclosures embodied therein. By way of illustration only a number of these alternatives and modifications will now be described.

[0289] In the above description, the UE 3 and the network apparatus are described for ease of understanding as having a number of discrete modules (such as the communication control modules). Whilst these modules may be provided in this way for certain applications, for example where an existing system has been modified to implement the disclosure, in other applications, for example in systems designed with the inventive features in mind from the outset, these modules may be built into the overall operating system or code and so these modules may not be discernible as discrete entities. These modules may also be implemented in software, hardware, firmware or a mix of these.

[0290] Each controller may comprise any suitable form of processing circuitry including (but not limited to), for example: one or more hardware implemented computer processors; microprocessors; central processing units (CPUs); arithmetic logic units (ALUs); input / output (IO) circuits; internal memories / caches (program 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; and / or the like. In the above aspects, a number of software modules were described. As those skilled in the art will appreciate, the software modules may be provided in compiled or un-compiled form and may be supplied to the UE 3 and the network apparatus as a signal over a computer network, or on a recording medium. Further, the functionality performed by part or all of this software may be performed using one or more dedicated hardware circuits. However, the use of software modules is preferred as it facilitates the updating of the UE 3 and the network apparatus in order to update their functionalities.

[0291] In the above aspects, a 3GPP radio communications (radio access) technology is used. However, any other radio communications technology (e.g. WLAN, Wi-Fi, WiMAX, Bluetooth, etc.) and other fix line communications technology (e.g. BBF Access, Cable Access, optical access, etc.) may also be used in accordance with the above aspects.

[0292] Items of user equipment might include, for example, communication devices such as mobile telephones, smartphones, user equipment, personal digital assistants, laptop / tablet computers, web browsers, e-book readers and / or the like. Such mobile (or even generally stationary) devices are typically operated by a user, although it is also possible to connect so-called 'Internet of Things' (IoT) devices and similar machine-type communication (MTC) devices to the network. For simplicity, the present application refers to mobile devices (or UEs) in the description but it will be appreciated that the technology described can be implemented on any communication devices (mobile and / or generally stationary) that can connect to a communications network for sending / receiving data, regardless of whether such communication devices are controlled by human input or software instructions stored in memory. Various other modifications will be apparent to those skilled in the art and will not be described in further detail here.

[0293] As will be appreciated by one of skill in the art, the present disclosure may be embodied as a method, and system. Accordingly, the present disclosure may take the form of an entirely hardware embodiment, a software embodiment or an embodiment combining software and hardware aspects.

[0294] It will be understood that each block of the block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general-purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a plurality of microprocessors, one or more microprocessors, or any other such configuration.

[0295] The methods or algorithms described in connection with the examples disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. A storage medium may be coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC.

[0296] The previous description of the disclosed examples is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these examples will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other examples without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the examples shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0297] While the disclosure has been particularly shown and described with reference to exemplary Aspects thereof, the disclosure is not limited to these Aspects. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by this document. For example, the Aspects above are not limited to 5GS, and the Aspects are also applicable to communication system other than 5GS (e.g., 6G system, 5G beyond system).

[0298] Supplementary notes The whole or part of the example Aspects disclosed above can be described as, but not limited to, the following supplementary notes. (Supplementary note 1) A method of a first communication apparatus comprising: 　　communicating with a second communication apparatus; and 　　sending Alternative Single Network Slice Selection Assistance Information (S-NSSAI). (Supplementary note 2) The method according to supplementary note 1, 　　wherein the Alternative S-NSSAI including is sent after receiving consent of a user for a User Equipment (UE). (Supplementary note 3) The method according to supplementary note 1, 　　wherein the Alternative S-NSSAI is sent after communication status meets a predetermined status. (Supplementary note 4) The method according to supplementary note 1, further comprising: 　　receiving information indicating that a User Equipment (UE) supports Network Slice Replacement feature, 　　wherein the Alternative S-NSSAI is sent after receiving the information. (Supplementary note 5) The method according to supplementary note 1, further comprising: 　　receiving information indicating that a User Equipment (UE) supports handling of a UE Route Selection Policy (URSP) rule, 　　wherein the Alternative S-NSSAI is sent after receiving the information. (Supplementary note 6) The method according to supplementary note 1, further comprising: 　　receiving first information indicating that a User Equipment (UE) supports Network Slice Replacement feature and second information indicating that the UE does not support handling of a UE Route Selection Policy (URSP) rule, 　　wherein the Alternative S-NSSAI is sent after receiving the first information and the second information. (Supplementary note 7) The method according to any one of supplementary notes 1 to 6, 　　wherein the first communication apparatus is an Application Function (AF). (Supplementary note 8) The method according to supplementary note 1, 　　wherein the first communication apparatus is a Unified Data Management (UDM). (Supplementary note 9) The method according to supplementary note 1, 　　wherein the first communication apparatus is a Network Exposure Function (NEF). (Supplementary note 10) A method of a first communication apparatus comprising: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF), and 　　wherein the second communication apparatus is a Unified Data Management (UDM). (Supplementary note 11) The method according to supplementary note 10, 　　wherein the procedure related to the PDU session includes PDU Session Modification procedure. (Supplementary note 12) The method according to supplementary note 11, 　　wherein the PDU Session Modification procedure is performed in a case of receiving information indicating that a User Equipment (UE) supports Network Slice Replacement feature. (Supplementary note 13) The method according to supplementary note 10, 　　wherein the procedure related to the PDU session includes PDU Session Establishment procedure. (Supplementary note 14) The method according to supplementary note 13, 　　wherein the PDU Session Establishment procedure is performed in a case of receiving information indicating that a User Equipment (UE) supports Network Slice Replacement feature. (Supplementary note 15) A method of a User Equipment (UE) comprising: 　　communicating with a first communication apparatus; and 　　performing procedure related to a Protocol Data Unit (PDU) Session, 　　wherein the procedure related to the PDU Session is triggered by the first communication apparatus based on Alternative Single Network Slice Selection Assistance Information (S-NSSAI), 　　wherein the Alternative S-NSSAI is sent by a second communication apparatus to the first communication apparatus, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF), and 　　wherein the second communication apparatus is a Unified Data Management (UDM). (Supplementary note 16) The method according to supplementary note 15, 　　wherein the procedure related to the PDU session includes PDU Session Modification procedure. (Supplementary note 17) The method according to supplementary note 16, further comprising: 　　sending information indicating that the UE supports Network Slice Replacement feature, 　　wherein the PDU Session Modification procedure is performed in a case of sending the information indicating that the UE supports Network Slice Replacement feature. (Supplementary note 18) The method according to supplementary note 16, further comprising: 　　sending information indicating that the UE supports handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Modification procedure is performed in a case of sending the information indicating that the UE supports handling of a UE Route Selection Policy (URSP) rule. (Supplementary note 19) The method according to supplementary note 16, further comprising: 　　sending first information indicating that the UE supports Network Slice Replacement feature and second information indicating that the UE does not support handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Modification procedure is performed in a case of sending the first information and the second information. (Supplementary note 20) The method according to supplementary note 15, 　　wherein the procedure related to the PDU session includes PDU Session Establishment procedure. (Supplementary note 21) The method according to supplementary note 20, further comprising: 　　sending information indicating that the UE supports Network Slice Replacement feature, 　　wherein the PDU Session Establishment procedure is performed in a case of sending the information indicating that the UE supports Network Slice Replacement feature. (Supplementary note 22) The method according to supplementary note 20, further comprising: 　　sending information indicating that the UE supports handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Establishment procedure is performed in a case of sending the information indicating that the UE supports handling of the URSP rule. (Supplementary note 23) The method according to supplementary note 20, further comprising: 　　sending first information indicating that the UE supports Network Slice Replacement feature and second information indicating that the UE does not support handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Establishment procedure is performed in a case of sending the first information and the second information. (Supplementary note 24) A method of a first communication apparatus comprising: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　sending the Alternative S-NSSAI to a third communication apparatus, 　　wherein the first communication apparatus is a Policy Control Function (PCF), 　　wherein the second communication apparatus is a Network Exposure Function (NEF), and 　　wherein the third communication apparatus is an Access and Mobility Management Function (AMF). (Supplementary note 25) A method of a first communication apparatus comprising: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　sending the Alternative S-NSSAI to a third communication apparatus, 　　wherein the first communication apparatus is a Network Slice Selection Function (NSSF), 　　wherein the second communication apparatus is a Network Exposure Function (NEF), and 　　wherein the third communication apparatus is a Session Management Function (SMF). (Supplementary note 26) A method of a User Equipment (UE) comprising: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a first communication apparatus; and 　　performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is a Session Management Function (SMF). (Supplementary note 27) The method according to supplementary note 26, 　　wherein the procedure related to the PDU session includes PDU Session Modification procedure. (Supplementary note 28) The method according to supplementary note 26, 　　wherein the procedure related to the PDU session includes PDU Session Establishment procedure. (Supplementary note 29) A method of a first communication apparatus comprising: 　　communicating with a second communication apparatus; and 　　sending Single Network Slice Selection Assistance Information (S-NSSAI) which is replaced with Alternative S-NSSAI. (Supplementary note 30) The method according to supplementary note 29, 　　wherein the first communication apparatus is an Application Function (AF). (Supplementary note 31) A method of a User Equipment (UE) comprising: 　　sending a Registration Request message, 　　wherein the Registration Request message includes Alternative Single Network Slice Selection Assistance Information (S-NSSAI); and 　　sending a Protocol Data Unit (PDU) Session Establishment Request message, 　　wherein the PDU Session Establishment Request message includes the Alternative S-NSSAI. (Supplementary note 32) A method of a first communication apparatus comprising: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF). (Supplementary note 33) The method according to supplementary note 32, 　　wherein the second communication apparatus is a Policy Control Function (PCF), and 　　wherein the procedure related to the PDU session includes PDU Session Modification procedure. (Supplementary note 34) The method according to supplementary note 32, 　　wherein the second communication apparatus is a User Equipment (UE), and 　　wherein the procedure related to the PDU session includes PDU Session Establishment procedure. (Supplementary note 35) A first communication apparatus comprising: 　　means for communicating with a second communication apparatus; and 　　means for sending Alternative Single Network Slice Selection Assistance Information (S-NSSAI). (Supplementary note 36) The first communication apparatus according to supplementary note 35, 　　wherein the Alternative S-NSSAI including is sent after receiving consent of a user for a User Equipment (UE). (Supplementary note 37) The first communication apparatus according to supplementary note 35, 　　wherein the Alternative S-NSSAI is sent after communication status meets a predetermined status. (Supplementary note 38) The first communication apparatus according to supplementary note 35, further comprising: 　　means for receiving information indicating that a User Equipment (UE) supports Network Slice Replacement feature, 　　the Alternative S-NSSAI is sent after receiving the information. (Supplementary note 39) The first communication apparatus according to supplementary note 35, further comprising: 　　means for receiving information indicating that a User Equipment (UE) supports handling of a UE Route Selection Policy (URSP) rule, 　　wherein the Alternative S-NSSAI is sent after receiving the information. (Supplementary note 40) The first communication apparatus according to supplementary note 35, further comprising: 　　means for receiving first information indicating that a User Equipment (UE) supports Network Slice Replacement feature and second information indicating that the UE does not support handling of a UE Route Selection Policy (URSP) rule, 　　wherein the Alternative S-NSSAI is sent after receiving the first information and the second information. (Supplementary note 41) The first communication apparatus according to any one of supplementary notes 35 to 40, 　　wherein the first communication apparatus is an Application Function (AF). (Supplementary note 42) The first communication apparatus according to supplementary note 35, 　　wherein the first communication apparatus is a Unified Data Management (UDM). (Supplementary note 43) The first communication apparatus according to supplementary note 35, 　　wherein the first communication apparatus is a Network Exposure Function (NEF). (Supplementary note 44) A first communication apparatus comprising: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　means for performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF), and 　　wherein the second communication apparatus is a Unified Data Management (UDM). (Supplementary note 45) The first communication apparatus according to supplementary note 44, 　　wherein the procedure related to the PDU session includes PDU Session Modification procedure. (Supplementary note 46) The first communication apparatus according to supplementary note 45, 　　wherein the PDU Session Modification procedure is performed in a case where the first communication apparatus receives information indicating that a User Equipment (UE) supports Network Slice Replacement feature. (Supplementary note 47) The first communication apparatus according to supplementary note 44, 　　wherein the procedure related to the PDU session includes PDU Session Establishment procedure. (Supplementary note 48) The first communication apparatus according to supplementary note 47, 　　wherein the PDU Session Establishment procedure is performed in a case where the first communication apparatus receives information indicating that a User Equipment (UE) supports Network Slice Replacement feature. (Supplementary note 49) A User Equipment (UE) comprising: 　　means for communicating with a first communication apparatus; and 　　means for performing procedure related to a Protocol Data Unit (PDU) Session, 　　wherein the procedure related to the PDU Session is triggered by the first communication apparatus based on Alternative Single Network Slice Selection Assistance Information (S-NSSAI), 　　wherein the Alternative S-NSSAI is sent by a second communication apparatus to the first communication apparatus, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF), and 　　wherein the second communication apparatus is a Unified Data Management (UDM). (Supplementary note 50) The UE according to supplementary note 49, 　　wherein the procedure related to the PDU session includes PDU Session Modification procedure. (Supplementary note 51) The UE according to supplementary note 50, further comprising: 　　means for sending information indicating that the UE supports Network Slice Replacement feature, 　　wherein the PDU Session Modification procedure is performed in a case where the UE sends the information indicating that the UE supports Network Slice Replacement feature. (Supplementary note 52) The UE according to supplementary note 50, further comprising: 　　means for sending information indicating that the UE supports handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Modification procedure is performed in a case where the UE sends the information indicating that the UE supports handling of a UE Route Selection Policy (URSP) rule. (Supplementary note 53) The UE according to supplementary note 50, further comprising: 　　means for sending first information indicating that the UE supports Network Slice Replacement feature and second information indicating that the UE does not support handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Modification procedure is performed in a case where the UE sends the first information and the second information. (Supplementary note 54) The UE according to supplementary note 49, 　　wherein the procedure related to the PDU session includes PDU Session Establishment procedure. (Supplementary note 55) The UE according to supplementary note 54, further comprising: 　　means for sending information indicating that the UE supports Network Slice Replacement feature, 　　wherein the PDU Session Establishment procedure is performed in a case where the UE sends the information indicating that the UE supports Network Slice Replacement feature. (Supplementary note 56) The UE according to supplementary note 54, further comprising: 　　means for sending information indicating that the UE supports handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Establishment procedure is performed in a case where the UE sends the information indicating that the UE supports handling of the URSP rule. (Supplementary note 57) The UE according to supplementary note 54, further comprising: 　　means for sending first information indicating that the UE supports Network Slice Replacement feature and second information indicating that the UE does not support handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Establishment procedure is performed in a case where the UE sends the first information and the second information. (Supplementary note 58) A first communication apparatus comprising: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　means for sending the Alternative S-NSSAI to a third communication apparatus, 　　wherein the first communication apparatus is a Policy Control Function (PCF), 　　wherein the second communication apparatus is a Network Exposure Function (NEF), and 　　wherein the third communication apparatus is an Access and Mobility Management Function (AMF). (Supplementary note 59) A first communication apparatus comprising: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　means for sending the Alternative S-NSSAI to a third communication apparatus, 　　wherein the first communication apparatus is a Network Slice Selection Function (NSSF), 　　wherein the second communication apparatus is a Network Exposure Function (NEF), and 　　wherein the third communication apparatus is a Session Management Function (SMF). (Supplementary note 60) A User Equipment (UE) comprising: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a first communication apparatus; and 　　means for performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is a Session Management Function (SMF). (Supplementary note 61) The UE according to supplementary note 60, 　　wherein the procedure related to the PDU session includes PDU Session Modification procedure. (Supplementary note 62) The UE according to supplementary note 60, 　　wherein the procedure related to the PDU session includes PDU Session Establishment procedure. (Supplementary note 63) A first communication apparatus comprising: 　　means for communicating with a second communication apparatus; and 　　means for sending Single Network Slice Selection Assistance Information (S-NSSAI) which is replaced with Alternative S-NSSAI. (Supplementary note 64) The first communication apparatus according to supplementary note 63, 　　wherein the first communication apparatus is an Application Function (AF). (Supplementary note 65) A User Equipment (UE) comprising: 　　means for sending a Registration Request message, 　　wherein the Registration Request message includes Alternative Single Network Slice Selection Assistance Information (S-NSSAI); and 　　means for sending a Protocol Data Unit (PDU) Session Establishment Request message, 　　wherein the PDU Session Establishment Request message includes the Alternative S-NSSAI. (Supplementary note 66) A first communication apparatus comprising: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　means for performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF). (Supplementary note 67) The first communication apparatus according to supplementary note 66, 　　wherein the second communication apparatus is a Policy Control Function (PCF), and 　　wherein the procedure related to the PDU session includes PDU Session Modification procedure. (Supplementary note 68) The first communication apparatus according to supplementary note 66, 　　wherein the second communication apparatus is a User Equipment (UE), and 　　wherein the procedure related to the PDU session includes PDU Session Establishment procedure.

[0299] This application is based upon and claims the benefit of priority from Indian Patent Application No. 202311048590, filed on July 19, 2023, the disclosure of which is incorporated herein in its entirety by reference.

[0300] 3　　User Equipment (UE) 5　　(R)AN node 7　　Core Network 31　　TRANSCEIVER CIRCUIT 32　　ANTENNA 33　　CONTROLLER 34　　USER INTERFACE 35　　USIM 36　　MEMORY 51　　TRANSCEIVER CIRCUIT 52　　ANTENNA 53　　NETWORK INTERFACE 54　　CONTROLLER 55　　MEMORY 60　　Radio Unit (RU) 61　　Distributed Unit (DU) 62　　Centralized Unit (CU) 70　　Access and Mobility Management Function (AMF) 71　　Session Management Function (SMF) 72　　User Plane Function (UPF) 75　　Unified Data Management (UDM) 76　　Network Slice Selection Function (NSSF) 77　　Network Slice Admission Control Function (NSACF) 79　　Network Exposure Function (NEF) 201　　Application Function (AF) 601　　TRANSCEIVER CIRCUIT 602　　ANTENNA 603　　NETWORK INTERFACE 604　　CONTROLLER 605　　MEMORY 611　　TRANSCEIVER CIRCUIT 612　　NETWORK INTERFACE 613　　CONTROLLER 614　　MEMORY 621　　TRANSCEIVER CIRCUIT 622　　NETWORK INTERFACE 623　　CONTROLLER 624　　MEMORY 711　　TRANSCEIVER CIRCUIT 712　　NETWORK INTERFACE 713　　CONTROLLER 714　　MEMORY 721　　TRANSCEIVER CIRCUIT 722　　NETWORK INTERFACE 723　　CONTROLLER 724　　MEMORY 731　　TRANSCEIVER CIRCUIT 732　　NETWORK INTERFACE 733　　CONTROLLER 734　　MEMORY 741　　TRANSCEIVER CIRCUIT 742　　NETWORK INTERFACE 743　　CONTROLLER 744　　MEMORY 751　　TRANSCEIVER CIRCUIT 752　　NETWORK INTERFACE 753　　CONTROLLER 754　　MEMORY 761　　TRANSCEIVER CIRCUIT 762　　NETWORK INTERFACE 763　　CONTROLLER 764　　MEMORY 771　　TRANSCEIVER CIRCUIT 772　　NETWORK INTERFACE 773　　CONTROLLER 774　　MEMORY 781　　TRANSCEIVER CIRCUIT 782　　NETWORK INTERFACE 783　　CONTROLLER 784　　MEMORY 791　　TRANSCEIVER CIRCUIT 792　　NETWORK INTERFACE 793　　CONTROLLER 794　　MEMORY 2011　　TRANSCEIVER CIRCUIT 2012　　NETWORK INTERFACE 2013　　CONTROLLER 2014　　MEMORY

Claims

1. A method of a first communication apparatus comprising: 　　communicating with a second communication apparatus; and 　　sending Alternative Single Network Slice Selection Assistance Information (S-NSSAI).

2. The method according to claim 1, 　　wherein the Alternative S-NSSAI is sent after receiving consent of a user for a User Equipment (UE).

3. The method according to claim 1, 　　wherein the Alternative S-NSSAI is sent after communication status meets a predetermined status.

4. The method according to claim 1, further comprising: 　　receiving information indicating that a User Equipment (UE) supports Network Slice Replacement feature, 　　wherein the Alternative S-NSSAI is sent after receiving the information.

5. The method according to claim 1, further comprising: 　　receiving information indicating that a User Equipment (UE) supports handling of a UE Route Selection Policy (URSP) rule, 　　wherein the Alternative S-NSSAI is sent after receiving the information.

6. The method according to claim 1, further comprising: 　　receiving first information indicating that a User Equipment (UE) supports Network Slice Replacement feature and second information indicating that the UE does not support handling of a UE Route Selection Policy (URSP) rule, 　　wherein the Alternative S-NSSAI is sent after receiving the first information and the second information.

7. The method according to any one of claims 1 to 6, 　　wherein the first communication apparatus is an Application Function (AF).

8. The method according to claim 1, 　　wherein the first communication apparatus is a Unified Data Management (UDM).

9. The method according to claim 1, 　　wherein the first communication apparatus is a Network Exposure Function (NEF).

10. A method of a first communication apparatus comprising: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF), and 　　wherein the second communication apparatus is a Unified Data Management (UDM).

11. The method according to claim 10, 　　wherein the procedure related to the PDU Session includes PDU Session Modification procedure.

12. The method according to claim 11, 　　wherein the PDU Session Modification procedure is performed in a case of receiving information indicating that a User Equipment (UE) supports Network Slice Replacement feature.

13. The method according to claim 10, 　　wherein the procedure related to the PDU Session includes PDU Session Establishment procedure.

14. The method according to claim 13, 　　wherein the PDU Session Establishment procedure is performed in a case of receiving information indicating that a User Equipment (UE) supports Network Slice Replacement feature.

15. A method of a User Equipment (UE) comprising: 　　communicating with a first communication apparatus; and 　　performing procedure related to a Protocol Data Unit (PDU) Session, 　　wherein the procedure related to the PDU Session is triggered by the first communication apparatus based on Alternative Single Network Slice Selection Assistance Information (S-NSSAI), 　　wherein the Alternative S-NSSAI is sent by a second communication apparatus to the first communication apparatus, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF), and 　　wherein the second communication apparatus is a Unified Data Management (UDM).

16. The method according to claim 15, 　　wherein the procedure related to the PDU Session includes PDU Session Modification procedure.

17. The method according to claim 16, further comprising: 　　sending information indicating that the UE supports Network Slice Replacement feature, 　　wherein the PDU Session Modification procedure is performed in a case of sending the information indicating that the UE supports Network Slice Replacement feature.

18. The method according to claim 16, further comprising: 　　sending information indicating that the UE supports handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Modification procedure is performed in a case of sending the information indicating that the UE supports handling of the URSP rule.

19. The method according to claim 16, further comprising: 　　sending first information indicating that the UE supports Network Slice Replacement feature and second information indicating that the UE does not support handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Modification procedure is performed in a case of sending the first information and the second information.

20. The method according to claim 15, 　　wherein the procedure related to the PDU Session includes PDU Session Establishment procedure.

21. The method according to claim 20, further comprising: 　　sending information indicating that the UE supports Network Slice Replacement feature, 　　wherein the PDU Session Establishment procedure is performed in a case of sending the information indicating that the UE supports Network Slice Replacement feature.

22. The method according to claim 20, further comprising: 　　sending information indicating that the UE supports handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Establishment procedure is performed in a case of sending the information indicating that the UE supports handling of the URSP rule.

23. The method according to claim 20, further comprising: 　　sending first information indicating that the UE supports Network Slice Replacement feature and second information indicating that the UE does not support handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Establishment procedure is performed in a case of sending the first information and the second information.

24. A method of a first communication apparatus comprising: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　sending the Alternative S-NSSAI to a third communication apparatus, 　　wherein the first communication apparatus is a Policy Control Function (PCF), 　　wherein the second communication apparatus is a Network Exposure Function (NEF), and 　　wherein the third communication apparatus is an Access and Mobility Management Function (AMF).

25. A method of a first communication apparatus comprising: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　sending the Alternative S-NSSAI to a third communication apparatus, 　　wherein the first communication apparatus is a Network Slice Selection Function (NSSF), 　　wherein the second communication apparatus is a Network Exposure Function (NEF), and 　　wherein the third communication apparatus is a Session Management Function (SMF).

26. A method of a User Equipment (UE) comprising: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a first communication apparatus; and 　　performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is a Session Management Function (SMF).

27. The method according to claim 26, 　　wherein the procedure related to the PDU Session includes PDU Session Modification procedure.

28. The method according to claim 26, 　　wherein the procedure related to the PDU Session includes PDU Session Establishment procedure.

29. A method of a first communication apparatus comprising: 　　communicating with a second communication apparatus; and 　　sending Single Network Slice Selection Assistance Information (S-NSSAI) which is replaced with Alternative S-NSSAI.

30. The method according to claim 29, 　　wherein the first communication apparatus is an Application Function (AF).

31. A method of a User Equipment (UE) comprising: 　　sending a Registration Request message, 　　wherein the Registration Request message includes Alternative Single Network Slice Selection Assistance Information (S-NSSAI); and 　　sending a Protocol Data Unit (PDU) Session Establishment Request message, 　　wherein the PDU Session Establishment Request message includes the Alternative S-NSSAI.

32. A method of a first communication apparatus comprising: 　　receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF).

33. The method according to claim 32, 　　wherein the second communication apparatus is a Policy Control Function (PCF), and 　　wherein the procedure related to the PDU Session includes PDU Session Modification procedure.

34. The method according to claim 32, 　　wherein the second communication apparatus is a User Equipment (UE), and 　　wherein the procedure related to the PDU Session includes PDU Session Establishment procedure.

35. A first communication apparatus comprising: 　　means for communicating with a second communication apparatus; and 　　means for sending Alternative Single Network Slice Selection Assistance Information (S-NSSAI).

36. The first communication apparatus according to claim 35, 　　wherein the Alternative S-NSSAI is sent after receiving consent of a user for a User Equipment (UE).

37. The first communication apparatus according to claim 35, 　　wherein the Alternative S-NSSAI is sent after communication status meets a predetermined status.

38. The first communication apparatus according to claim 35, further comprising: 　　means for receiving information indicating that a User Equipment (UE) supports Network Slice Replacement feature, 　　wherein the Alternative S-NSSAI is sent after receiving the information.

39. The first communication apparatus according to claim 35, further comprising: 　　means for receiving information indicating that a User Equipment (UE) supports handling of a UE Route Selection Policy (URSP) rule, 　　wherein the Alternative S-NSSAI is sent after receiving the information.

40. The first communication apparatus according to claim 35, further comprising: 　　means for receiving first information indicating that a User Equipment (UE) supports Network Slice Replacement feature and second information indicating that the UE does not support handling of a UE Route Selection Policy (URSP) rule, 　　wherein the Alternative S-NSSAI is sent after receiving the first information and the second information.

41. The first communication apparatus according to any one of claims 35 to 40, 　　wherein the first communication apparatus is an Application Function (AF).

42. The first communication apparatus according to claim 35, 　　wherein the first communication apparatus is a Unified Data Management (UDM).

43. The first communication apparatus according to claim 35, 　　wherein the first communication apparatus is a Network Exposure Function (NEF).

44. A first communication apparatus comprising: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　means for performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF), and 　　wherein the second communication apparatus is a Unified Data Management (UDM).

45. The first communication apparatus according to claim 44, 　　wherein the procedure related to the PDU Session includes PDU Session Modification procedure.

46. The first communication apparatus according to claim 45, 　　wherein the PDU Session Modification procedure is performed in a case where the first communication apparatus receives information indicating that a User Equipment (UE) supports Network Slice Replacement feature.

47. The first communication apparatus according to claim 44, 　　wherein the procedure related to the PDU Session includes PDU Session Establishment procedure.

48. The first communication apparatus according to claim 47, 　　wherein the PDU Session Establishment procedure is performed in a case where the first communication apparatus receives information indicating that a User Equipment (UE) supports Network Slice Replacement feature.

49. A User Equipment (UE) comprising: 　　means for communicating with a first communication apparatus; and 　　means for performing procedure related to a Protocol Data Unit (PDU) Session, 　　wherein the procedure related to the PDU Session is triggered by the first communication apparatus based on Alternative Single Network Slice Selection Assistance Information (S-NSSAI), 　　wherein the Alternative S-NSSAI is sent by a second communication apparatus to the first communication apparatus, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF), and 　　wherein the second communication apparatus is a Unified Data Management (UDM).

50. The UE according to claim 49, 　　wherein the procedure related to the PDU Session includes PDU Session Modification procedure.

51. The UE according to claim 50, further comprising: 　　means for sending information indicating that the UE supports Network Slice Replacement feature, 　　wherein the PDU Session Modification procedure is performed in a case where the UE sends the information indicating that the UE supports Network Slice Replacement feature.

52. The UE according to claim 50, further comprising: 　　means for sending information indicating that the UE supports handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Modification procedure is performed in a case where the UE sends the information indicating that the UE supports handling of the URSP rule.

53. The UE according to claim 50, further comprising: 　　means for sending first information indicating that the UE supports Network Slice Replacement feature and second information indicating that the UE does not support handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Modification procedure is performed in a case where the UE sends the first information and the second information.

54. The UE according to claim 49, 　　wherein the procedure related to the PDU Session includes PDU Session Establishment procedure.

55. The UE according to claim 54, further comprising: 　　means for sending information indicating that the UE supports Network Slice Replacement feature, 　　wherein the PDU Session Establishment procedure is performed in a case where the UE sends the information indicating that the UE supports Network Slice Replacement feature.

56. The UE according to claim 54, further comprising: 　　means for sending information indicating that the UE supports handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Establishment procedure is performed in a case where the UE sends the information indicating that the UE supports handling of the URSP rule.

57. The UE according to claim 54, further comprising: 　　means for sending first information indicating that the UE supports Network Slice Replacement feature and second information indicating that the UE does not support handling of a UE Route Selection Policy (URSP) rule, 　　wherein the PDU Session Establishment procedure is performed in a case where the UE sends the first information and the second information.

58. A first communication apparatus comprising: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　means for sending the Alternative S-NSSAI to a third communication apparatus, 　　wherein the first communication apparatus is a Policy Control Function (PCF), 　　wherein the second communication apparatus is a Network Exposure Function (NEF), and 　　wherein the third communication apparatus is an Access and Mobility Management Function (AMF).

59. A first communication apparatus comprising: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　means for sending the Alternative S-NSSAI to a third communication apparatus, 　　wherein the first communication apparatus is a Network Slice Selection Function (NSSF), 　　wherein the second communication apparatus is a Network Exposure Function (NEF), and 　　wherein the third communication apparatus is a Session Management Function (SMF).

60. A User Equipment (UE) comprising: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a first communication apparatus; and 　　means for performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is a Session Management Function (SMF).

61. The UE according to claim 60, 　　wherein the procedure related to the PDU Session includes PDU Session Modification procedure.

62. The UE according to claim 60, 　　wherein the procedure related to the PDU Session includes PDU Session Establishment procedure.

63. A first communication apparatus comprising: 　　means for communicating with a second communication apparatus; and 　　means for sending Single Network Slice Selection Assistance Information (S-NSSAI) which is replaced with Alternative S-NSSAI.

64. The first communication apparatus according to claim 63, 　　wherein the first communication apparatus is an Application Function (AF).

65. A User Equipment (UE) comprising: 　　means for sending a Registration Request message, 　　wherein the Registration Request message includes Alternative Single Network Slice Selection Assistance Information (S-NSSAI); and 　　means for sending a Protocol Data Unit (PDU) Session Establishment Request message, 　　wherein the PDU Session Establishment Request message includes the Alternative S-NSSAI.

66. A first communication apparatus comprising: 　　means for receiving Alternative Single Network Slice Selection Assistance Information (S-NSSAI) from a second communication apparatus; and 　　means for performing procedure related to a Protocol Data Unit (PDU) Session based on the Alternative S-NSSAI, 　　wherein the first communication apparatus is an Access and Mobility Management Function (AMF).

67. The first communication apparatus according to claim 66, 　　wherein the second communication apparatus is a Policy Control Function (PCF), and 　　wherein the procedure related to the PDU Session includes PDU Session Modification procedure.

68. The first communication apparatus according to claim 66, 　　wherein the second communication apparatus is a User Equipment (UE), and 　　wherein the procedure related to the PDU Session includes PDU Session Establishment procedure.

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