Method of user equipment (UE), method of access and mobility management function (AMF), UE, and amf

Abstract

An aspect of this disclosure includes a user equipment (UE). The UE includes: means for communicating with a communication apparatus; and means for receiving Access Traffic Steering, Switching, Splitting (ATSSS) rule, in a case of changing from dual access using home public land mobile network (HPLMN) and stand-alone non-public network (SNPN) to ATSSS using 3GPP access and non-3GPP access in the HPLMN.

Description

METHOD OF USER EQUIPMENT (UE), METHOD OF ACCESS AND MOBILITY MANAGEMENT FUNCTION (AMF), UE, AND AMF

[0001] The present disclosure relates to a method of a User Equipment (UE), a method of an access and mobility management function (AMF), a UE, and an AMF.

[0002] Access Traffic Steering, Switching and Splitting (ATSSS) considers multi-access scenario where UE is connected via one 3GPP access and one non-3GPP access, whereas Dual Steer (DS) considers a scenario where UE is connected via dual 3GPP accesses.

[0003] In NPL 2, different use cases and potential new requirements are captured based on DS. In this disclosure, the following use cases and its corresponding new requirements are considered: i) Dual 3GPP accesses in local premises using PLMN and SNPN networks, ii) Dual 3GPP accesses interworking with non-3GPP access across PLMN and SNPN / PLMN networks, iii) Mobility between PLMN and SNPN / PLMN networks, and iv) Switching between dual 3GPP accesses across PLMN and SNPN / PLMN networks.

[0004] NPL 1: 3GPP TR 21.905: "Vocabulary for 3GPP Specifications", V17.1.0 (2021-12) 　　NPL 2: 3GPP TS 22.841: "Study on Upper layer traffic steer, switch and split over dual 3GPP access", V1.1.0 (2023-06) 　　NPL 3: 3GPP TS 23.501: "System architecture for the 5G System (5GS)", V18.2.2 (2023-07) 　　NPL 4: 3GPP TS 23.502: "Procedures for the 5G System (5GS)", V18.2.0 (2023-06) 　　NPL 5: 3GPP TS 23.503: "Policy and charging control framework for the 5G System (5GS) Stage 2", V18.2.0 (2023-06) 　　NPL 6: 3GPP TS 33.501: "Security architecture and procedures for 5G system", V18.3.0 (2023-09) 　　NPL 7: 3GPP TS 23.003: "Numbering, addressing and identification", V18.3.0 (2023-09) 　　NPL 8: IETF RFC 5580: "Carrying Location Objects in RADIUS and Diameter", (2009-08)

[0005] Regarding iii) Mobility between PLMN and SNPN / PLMN networks 　　MNO A covers a small area and MNO B covers a larger area than MNO A. MNO A has an existing business agreement with MNO B, which allows MNO A subscribers to roam on MNO B network when MNO A subscribers are outside its own coverage footprint. As the MNO A subscriber moves in and out of the MNO A coverage, MNO A core network, needs to be able to switch traffic between the two networks based on the network availability. When the MNO A subscriber enters MNO A coverage, the traffic can be switched from MNO B to MNO A or traffic can be steered on both networks depending on the service type and subscription tier of the MNO A subscriber. In this scenario, the following problems need to be solved.

[0006] ●　　The 5G system needs to be able to support traffic steering and splitting across PLMN and SNPN networks. ●　　The 5G system needs to be able to support seamless mobility between PLMN and SNPN networks.

[0007] Regarding iv) Switching between dual 3GPP accesses across PLMN and SNPN / PLMN networks 　　In some scenarios, UE may detect the availability of more than two 3GPP access networks (e.g., non-terrestrial NR, terrestrial NR, and terrestrial E-UTRA) due to mobility or location and UE may perform dual 3GPP access switching from one network to another to satisfy the quality of service requirements. In this scenario, the following problems need to be solved.

[0008] ●　　UE-initiated dual 3GPP access switching from one network to another needs to be supported. ●　　The 5G system needs to be able to support dual 3GPP access switching from one network to another.

[0009] In a first aspect, the present disclosure provides a user equipment (UE) including: 　　means for communicating with a communication apparatus; and 　　means for receiving Access Traffic Steering, Switching, Splitting (ATSSS) rule, in a case of changing from dual access using home public land mobile network (HPLMN) and stand-alone non-public network (SNPN) to ATSSS using 3GPP access and non-3GPP access in the HPLMN.

[0010] In a second aspect, the present disclosure provides an access and mobility management function (AMF) including: 　　means for communicating with a user equipment (UE); and 　　means for sending Access Traffic Steering, Switching, Splitting (ATSSS) rule, in a case of changing from dual access using home public land mobile network (HPLMN) and stand-alone non-public network (SNPN) to ATSSS using 3GPP access and non-3GPP access in the HPLMN.

[0011] In a third aspect, the present disclosure provides a user equipment (UE) including: 　　means for communicating with a communication apparatus; and 　　means for receiving DS-ATSSS rule, in a case where the UE is in a coverage of visited public land mobile network (VPLMN) and stand-alone non-public network (SNPN) and the UE is registered to the VPLMN and the SNPN.

[0012] In a fourth aspect, the present disclosure provides a user equipment (UE) including: 　　means for communicating with a communication apparatus; and 　　means for receiving an indication that switching from dual 3GPP accesses via home public land mobile network (HPLMN) to dual 3GPP accesses via the HPLMN and stand-alone non-public network (SNPN) is allowed for the UE.

[0013] In a fifth aspect, the present disclosure provides an access and mobility management function (AMF) including: 　　means for communicating with a user equipment (UE); and 　　means for sending an indication that switching from dual 3GPP accesses via home public land mobile network (HPLMN) to dual 3GPP accesses via the HPLMN and stand-alone non-public network (SNPN) is allowed for the UE.

[0014] In a sixth aspect, the present disclosure provides a user equipment (UE) including: 　　means for communicating with a communication apparatus; and 　　means for receiving DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and home public land mobile network (HPLMN).

[0015] In a seventh aspect, the present disclosure provides an access and mobility management function (AMF) including: 　　means for communicating with a user equipment (UE); and 　　means for sending DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and home public land mobile network (HPLMN).

[0016] In an eighth aspect, the present disclosure provides a method of a user equipment (UE) including: 　　communicating with a communication apparatus; and 　　receiving Access Traffic Steering, Switching, Splitting (ATSSS) rule, in a case of changing from dual access using home public land mobile network (HPLMN) and stand-alone non-public network (SNPN) to ATSSS using 3GPP access and non-3GPP access in the HPLMN.

[0017] In a ninth aspect, the present disclosure provides a method of an access and mobility management function (AMF) including: 　　communicating with a user equipment (UE); and 　　sending Access Traffic Steering, Switching, Splitting (ATSSS) rule, in a case of changing from dual access using home public land mobile network (HPLMN) and stand-alone non-public network (SNPN) to ATSSS using 3GPP access and non-3GPP access in the HPLMN.

[0018] In a tenth aspect, the present disclosure provides a method of a user equipment (UE) including: 　　communicating with a communication apparatus; and 　　receiving DS-ATSSS rule, in a case where the UE is in a coverage of visited public land mobile network (VPLMN) and stand-alone non-public network (SNPN) and the UE is registered to the VPLMN and the SNPN.

[0019] In an eleventh aspect, the present disclosure provides a method of a user equipment (UE) including: 　　communicating with a communication apparatus; and 　　receiving an indication that switching from dual 3GPP accesses via home public land mobile network (HPLMN) to dual 3GPP accesses via the HPLMN and stand-alone non-public network (SNPN) is allowed for the UE.

[0020] In a twelve aspect, the present disclosure provides a method of an access and mobility management function (AMF) including: 　　communicating with a user equipment (UE); and 　　sending an indication that switching from dual 3GPP accesses via home public land mobile network (HPLMN) to dual 3GPP accesses via the HPLMN and stand-alone non-public network (SNPN) is allowed for the UE.

[0021] In a thirteen aspect, the present disclosure provides a method of a user equipment (UE) including: 　　communicating with a communication apparatus; and 　　receiving DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and home public land mobile network (HPLMN).

[0022] In a fourteenth aspect, the present disclosure provides a method of an access and mobility management function (AMF) including: 　　communicating with a user equipment (UE); and 　　sending DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and home public land mobile network (HPLMN).

[0023] Embodiments of the present disclosure will now be described, by way of example, with reference to the accompanying drawings.Fig. 1 is a block diagram of a First example of a First Aspect.Fig. 2 is a signaling diagram of a Second example of the First Aspect.Fig. 3 is a signaling diagram of a Third example of the First Aspect.Fig. 4 is a signaling diagram of a Fourth example of the First Aspect.Fig. 5 is a signaling diagram of a Fifth example of the First Aspect.Fig. 6 is a block diagram of a First example of a Second Aspect.Fig. 7 is a signaling diagram of a Second example of the Second Aspect.Fig. 8 is a signaling diagram of a Third example of the Second Aspect.Fig. 9A is a signaling diagram of a Fourth example of the Second Aspect.Fig. 9B is a signaling diagram of the Fourth example of the Second Aspect.Fig. 10 is a block diagram of a First example of a Third Aspect.Fig. 11 is a signaling diagram of a Second example of the Third Aspect.Fig. 12 is a signaling diagram of a Third example of the Third Aspect.Fig. 13 is a signaling diagram of a Fourth example of the Third Aspect.Fig. 14 is a block diagram of a First example of a Forth Aspect.Fig. 15 is a signaling diagram of a Second example of the Forth Aspect.Fig. 16 is a signaling diagram of a Third example of the Forth Aspect.Fig. 17 is a signaling diagram of a Fourth example of the Forth Aspect.Fig. 18 is a block diagram of a First example of a Fifth Aspect.Fig. 19 is a signaling diagram of a Second example of the Fifth Aspect.Fig. 20 is a signaling diagram of a Third example of the Fifth Aspect.Fig. 21 is a signaling diagram of a Fourth example of the Fifth Aspect.Fig. 22 is a diagram illustrating a system overview.Fig. 23 is a block diagram illustrating a UE.Fig. 24 is a block diagram illustrating an (R)AN node.Fig. 25 is a diagram illustrating System overview of (R)AN node based on O-RAN architecture.Fig. 26 is a block diagram illustrating an RU.Fig. 27 is a block diagram illustrating a DU.Fig. 28 is a block diagram illustrating a CU.Fig. 29 is a block diagram illustrating an AMF.Fig. 30 is a block diagram illustrating an SMF.Fig. 31 is a block diagram illustrating a UPF.Fig. 32 is a block diagram illustrating a PCF.Fig. 33 is a block diagram illustrating an NWDAF.Fig. 34 is a block diagram illustrating a UDM.Fig. 35 is a block diagram illustrating an NSSF.Fig. 36 is a block diagram illustrating an NSACF.Fig. 37 is a block diagram illustrating an AUSF.Fig. 38 is a block diagram illustrating an AF.Fig. 39 is a block diagram illustrating an NEF.Description of Example Embodiments

[0024] Abbreviations 　　For the purposes of the present document, the abbreviations given in NPL 1 and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in NPL 1.

[0025] 4G-GUTI　　4G Globally Unique Temporary UE Identity 5GC　　5G Core Network 5GLAN　　5G Local Area Network 5G HE AV　　5G Home Environment Authentication Vector 5G SE AV　　5G Serving Environment Authentication Vector 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 ABBA　　Anti-Bidding down Between Architectures AF　　Application Function AMF　　Access and Mobility Management Function AMF-G　　Geographically selected Access and Mobility Management Function AMF-NG　　Non-Geographically selected Access and Mobility Management Function ANDSF　　Access Network Discovery and Selection Function ARFCN　　Absolute radio-frequency channel number AS　　Access 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 MN　　Master Node 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 ProSe　　Proximity based Services PSA　　PDU Session Anchor PTP　　Precision Time Protocol QFI　　QoS Flow Identifier QoE　　Quality of Experience 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 RSC　　Relay Service Code RSD　　Route Selection Descriptor 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　　Secondary Node 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

[0026] Definitions 　　For the purposes of the present document, the terms and definitions given in NPL 1 and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in NPL 1.

[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.

[0032] 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.

[0033] 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.

[0034] Any lists described in following aspects include at least one parameter or multiple parameters.

[0035] In this disclosure, regarding listed parameters in the certain message, at least one of the listed parameters may be included in the certain message.

[0036] An example object of this disclosure is to provide a method and apparatus that can solve the at least one above-mentioned problem.

[0037] First Aspect 　　In NPL 2, different use cases and potential new requirements are captured based on DS. In this disclosure, the following use cases and its corresponding new requirements are considered: i) Dual 3GPP accesses in local premises using PLMN and SNPN networks, ii) Dual 3GPP accesses interworking with non-3GPP access across PLMN and SNPN / PLMN networks, iii) Mobility between PLMN and SNPN / PLMN networks, and iv) Switching between dual 3GPP accesses across PLMN and SNPN / PLMN networks.

[0038] Regarding i) Dual 3GPP accesses in local premises using PLMN and SNPN networks 　　A particular place (e.g., stadium, campus, enterprise, mall, factory, and other local premises) is served by Mobile Network Operator (MNO) A with ad-hoc or in-venue 5G NR deployment (e.g., SNPN) and MNO B (e.g., PLMN) with 5G terrestrial or non-terrestrial NR deployment that covers a large area. MNOs A and B have business service agreement. Thus, users of MNO B with golden subscription are also served by MNO A based on QoS or traffic type. For example, the users of MNO B with golden subscription may be users who have paid not only fee for using the service of MNO B but also fee for using the service of MNO A. In this case, UE of MNO B registers with both networks and establishes a dual connection across the two networks. In this scenario, the following problems need to be solved.

[0039] ●　　The UE needs to know the available partner SNPN networks of its HPLMN in a particular place / location such as stadium in order to select, register, and steer the service traffic across HPLMN and SNPN networks.

[0040] ●　　The 5G system needs to be able to support mechanisms to enable dual steering using two networks such as HPLMN and SNPN for PLMN users based on the subscription type, service type, traffic type, geographical location, and time.

[0041] Regarding ii) Dual 3GPP accesses interworking with non-3GPP access across PLMN and SNPN / PLMN networks 　　In certain scenarios it would be beneficial to support transition between new dual-3GPP access operation and ATSSS-based one 3GPP access and one non-3GPP access operation, e.g., when coverage of one of the two 3GPP accesses becomes poor or unavailable, while a non-3GPP access link is available. One relevant scenario is when a UE / user moves from outdoor to indoor (and vice versa), can be home, office, enterprise, shopping mall or other type of venues. In this scenario, the following problems need to be solved.

[0042] ●　　UE-initiated transition from dual 3GPP access connection to 3GPP+non-3GPP access connection (e.g. the connection using 3GPP and non-3GPP access) and vice-versa need to be supported.

[0043] ●　　The 5G system needs to be able to support the transition from dual 3GPP access to one 3GPP+one non-3GPP access (e.g. one 3GPP access and one non-3GPP access) and vice-versa.

[0044] This aspect discloses mechanisms for establishing dual connections across HPLMN and SNPN networks to support HPLMN users to access services via dual 3GPP accesses using SNPN.

[0045] First example of the First Aspect 　　Fig. 1 illustrates an example architecture in which UE 3 connects with both HPLMN and SNPN for accessing services via dual 3GPP accesses.

[0046] Fig. 1 shows an architecture in which PLMN and SNPN are connected through roaming interfaces and home-routed roaming scenario is considered to anchor the service traffic via H-UPF 7201 to UE 3 using DS. It is assumed that there is a service level agreement between PLMN and SNPN and UE 3 has dual radio capability. Two independent tunnels (e.g., N3 and N9) are created to steer the traffic via both HPLMN and SNPN. H-SMF 7101 with H-PCF 7301 generates DS rules and shares with H-UPF 7201 and V-SMF 7102 and the DS rules may be updated based on the traffic congestion and the availability or unavailability of the 3GPP access link. Similar to Inter-PLMN UP Security (IPUPS), PLMN-SNPN UP Security (PSUPS) is required for securing the communication over N9 tunnel.

[0047] It is assumed that the HPLMN subscription is used to access both networks, data traffic is anchored in the HPLMN and a proper business agreement is in place among the network operators, including specific traffic routing policies, e.g., based on geographical location, subscription, traffic type, and service type.

[0048] In Fig. 1, roaming interfaces highlighted in bold lines (e.g., N8 and N16) are new connections between HPLMN and SNPN. Currently, they do not exist as SNPN operates independently and does not have relation with PLMN. As these roaming interfaces are already defined for inter-PLMN roaming scenarios, the same functionalities can be utilized for PLMN-SNPN roaming scenario as well.

[0049] In one example the UE 3 is single radio capable i.e. it can receive or transmits data either from the SNPN or PLMN at time.

[0050] Second example of the First Aspect 　　Fig. 2 illustrates an example of provisioning an SNPN selection assistance information to UE 3 in the case that UE 3 can connect with two different 3GPP networks (e.g., HPLMN and SNPN) where the UE 3 is in the coverage of area of its home network.

[0051] The detailed processes of the Second example of the First Aspect are described below with reference to Fig. 2.

[0052] Step 0a: UE 3's HPLMN has business service agreement with SNPN networks and thus UEs 3 can use HPLMN credential to register through SNPNs.

[0053] Step 0b: UDM 75 in HPLMN maintains the updated SNPN partners list.

[0054] Step 1: UE 3 has registered to the HPLMN as in clause 4.2.2.2.2 in NPL 4. During the Registration procedure, the UE 3 indicates a Support dual access and SNPN access mode (e.g., UE 3 supporting dual access and SNPN access mode has registered to the HPLMN as in clause 4.2.2.2.2 in NPL 4), and UE 3 has been provided with a list of SNPN partners (e.g. a list of SNPN(s)) and its corresponding location (e.g., TEI or Cell ID or GPS coordinates) or time when the UE is allowed to access the SNPN (on which date or date and time, the UE can register to a SNPN) details.

[0055] Fig. 3 in Second example of the First Aspect discloses how the UE 3 indicates the Support dual access and SNPN access mode to the 5GC. 　　The network may share the SNPN partners list based on the UE 3 location. 　　The list of SNPN partners may include identifier (ID) of SNPNs.

[0056] The corresponding location may be location information of the UE. 　　UE 3 supporting dual access and SNPN access mode may be UE 3 which supports DS using at least one 3GPP access in SNPN. 　　The dual access may be expressed as DS.

[0057] Step 2: UE 3 is in a local premise area and the shared SNPN partner location information is matched. In one example the UE 3 also matches the time provided to the UE 3 for the SNPN. 　　For example, UE 3 is in a coverage area of an SNPN included in the list of SNPN(s).

[0058] Step 3: If there is a single partner SNPN, then UE 3 can select it. Otherwise, UE 3 optionally checks with the network to get the latest SNPN partner networks priority list. 　　For example, in a case where the list of SNPN(s) includes one SNPN, UE 3 may select this SNPN.

[0059] For example, the list of SNPN(s) may list SNPN(s) in priority order. In a case where the list includes SNPN 1 and SNPN 2 and SNPN 1 has the higher priority than SNPN 2, UE 3 may select SNPN 1.

[0060] For example, UE 3 may select an SNPN which is available at the location where UE 3 locates. 　　For example, in a case where UE 3 is in SNPN 1, UE 3 may select this SNPN 1.

[0061] Step 4: UE 3 may send an existing NAS request message (e.g., Registration Request message) or a new NAS message to the network via AMF 70 for getting priority list of SNPNs in that location. In the case where the UE 3 reads (scans) a system information(s) from one or multiple SNPNs, the NAS request message or new NAS message may include a list of PLMN ID and Network identifier (NID) combinations.

[0062] The latest SNPN partner networks priority list may be the priority list of SNPNs. The priority list of SNPNs may include ID of SNPNs and its priority value.

[0063] Step 5: AMF 70 may send the UE 3's request to UDM 75 via Nudm_SDM_Get_Request service message and provides in this message UE 3's location information, S-NSSAI and the list of PLMN ID and NID combinations. The S-NSSAI is an S-NSSAI that the UE 3 intends to use over the SNPN network. The S-NSSAI may be included in the message in Step 4.

[0064] Step 6: UDM 75 may send the SNPN priority list based on the UE 3 location information via Nudm_SDM_Get_Response service message. The UDM 75 may use the list of PLMN ID and NID combinations to know the UE 3 location. The UDM 75 may construct the SNPN priority list based on the received S-NSSAI.

[0065] Step 7: Upon reception of the SNPN priority list from UDM 75, AMF 70 may send it to UE 3 via an existing NAS response message (e.g. Registration accept message) or an new NAS message.

[0066] Step 8: UE 3 may use the received information for a high priority SNPN network selection by setting one radio for SNPN selection and another for PLMN selection. 　　For example, UE 3 may select one 3GPP access for DS in SNPN selected in Step 3 or 7.

[0067] For example, UE 3 may select another 3GPP access for DS in HPLMN selected by the PLMN selection. 　　For example, the UE 3 may select the SNPN based on the received information.

[0068] Variant 1 of the Second example of the First Aspect 　　In one example, the list of the partner SNPNs and their priority order may be provided to the UDM 75 by the AF via the NEF and they may be further updated by the AF based on the UE 3 location and / or based on the time.

[0069] Third example of the First Aspect 　　Fig. 3 illustrates an example of provisioning an SNPN selection assistance information to UE 3 in the case that UE 3 can connect with two different 3GPP networks (e.g., HPLMN and SNPN) where the UE 3 is in the coverage area of a visited network.

[0070] The detailed processes of the Third example of the First Aspect are described below with reference to Fig. 3.

[0071] Step 0a: UE 3's HPLMN has business service agreement with SNPN networks and thus UEs 3 can use HPLMN credential to register through SNPNs.

[0072] Step 0b: UDM 75 in HPLMN maintains the updated SNPN partners list.

[0073] Step 1: UE 3 sends Registration Request message to V-AMF 70 by indicating that it can support dual 3GPP access and SNPN access mode. This message can be an initial registration message or mobility registration update message.

[0074] For example, in the Registration Request message, the UE 3 may indicate that the UE 3 supports dual 3GPP access and SNPN access mode. 　　For example, the dual 3GPP access and SNPN access mode may be a mode or function that the UE 3 supports the DS.

[0075] For example, the dual 3GPP access and SNPN access mode may be a mode or function that the UE 3 supports the SNPN access. 　　For example, the dual 3GPP access and SNPN access mode may be a mode or function that the UE 3 supports the DS and supports that one 3GPP access in the DS is SNPN access.

[0076] For example, the dual 3GPP access and SNPN access mode may be a mode or function that the UE 3 supports the DS using at least one 3GPP access in SNPN. 　　For example, UE 3 may include information or indication indicating the dual 3GPP access and SNPN access mode in the Registration Request message.

[0077] Step 2: Upon reception of the Registration Request message, the V-AMF 70 sends an Nudm_UECM_Registration request message to UDM 75 including the indication that UE 3 supports dual 3GPP access and SNPN access mode.

[0078] Step 3: UDM 75 checks UE's subscription data and sends an Nudm_UECM_Registration response message to V-AMF 70 including the indication to allow UE 3 for dual 3GPP access and access services via SNPN.

[0079] For example, the indication to allow UE 3 for dual 3GPP access and access services via SNPN may indicate that UE 3 is allowed to use at least one 3GPP access in SNPN for DS.

[0080] For example, the indication to allow UE 3 for dual 3GPP access and access services via SNPN may indicate that UE 3 is allowed to use service(s) using 3GPP access in SNPN for DS.

[0081] Step 4: The V-AMF 70 sends an Nudm_SDM_Get request message to UDM 75 for Steering of Roaming (SoR) information. The V-AMF 70 may also request for access and mobility subscription data of UE 3.

[0082] Step 5: Upon receiving the request message from V-AMF 70, UDM 75 decides to send SNPN partners information to UE via SoR based on the UE's subscription data. The SNPN partners information may be chosen by the UDM 75 based on the AMF identifier (GUAMI) that is received from the V-AMF 70 when the V-AMF 70 registered to the UDM 75 by the Nudm_UECM_Registration service.

[0083] Step 6: UDM 75 sends an Nsoraf_SoR_Get request message to SoR-AF 201 for SNPN partners list and access technology combination list.

[0084] Step 7: Upon receiving the request from UDM 75, the SoR-AF 201 sends SNPN partners list and access technology combination list via Nsoraf_SoR_Get response message. The SNPN partner in the SNPN partners list may have an associated information. The associated information may be a list of S-NSSAIs that are provided by the SNPN partner or a list of DNNs that are provided by the SNPN partner or a list of S-NSSAI / DNN combinations that are provided by the SNPN partner. The SNPN partner information may also contain SNPN availability information in terms of geographic locations and time or any other access restrictions that the home operator may decide to impose based, for example, on the user subscription level and details.

[0085] Step 8: UDM 75 may secure SoR information with SNPN partners list by invoking Nausf_SoRProtection service operation message to the AUSF 78 as per described in clause 14.1.3 in NPL 6. For example, after the Nausf_SoRProtection service operation, the SoR information may be integrity and confidentially protected for transmitting the SoR information from the UDM 75 to the UE 3. 　　The SoR information may include information received in Step 7.

[0086] Step 9: UDM 75 sends the SoR information to V-AMF 70 via Nudm_SDM_Get response message. 　　UDM 75 may send the secured SoR information to V-AMF 70 via Nudm_SDM_Get response message.

[0087] Step 10: V-AMF 70 may subscribe to UDM 75 to receive notifications for any changes or updates in SNPN partners list. 　　For example, SoR-AF 201 may send the updated SNPN partners list to UDM 75 in a case where the SNPN partners list is changed or updated.

[0088] For example, UDM 75 may send the updated or changed SNPN partners list to V-AMF 70 in a case where UDM 75 receives the updated or changed SNPN partners list from SoR-AF 201.

[0089] For example, UDM 75 may send the updated or changed SNPN partners list to V-AMF 70 in a case where V-AMF 70 subscribes to UDM 75 to receive the notifications and UDM 75 receives the updated or changed SNPN partners list from SoR-AF f1.

[0090] Step 11: V-AMF 70 sends Registration Accept message to UE 3 including the indication to allow for dual 3GPP access and access services via SNPN, and SoR information.

[0091] Step 12: UE 3 may do SoR information security check to confirm that the received SoR information is not altered in transit by VPLMN.

[0092] Step 13: UE 3 uses the received information for a high priority SNPN network selection by setting one radio for SNPN selection and another radio for PLMN selection. 　　In Step 13, UE 3 may perform same process(es) in Step 8 of Fig. 2.

[0093] Variant of the third example of the First Aspect 　　In one example the V-AMF 70 sends the allowed NSSAI or list of S-NSSAI and DNN combination corresponding to each established PDU sessions to the UDM 75 in Step 2 or 4. In Step 6 the UDM 75 sends allowed NSSAI or the S-NSSAI and DNN list (e.g., list of the S-NSSAI and DNN combination) of each established PDU sessions. The UDM 75 provides preferred SNPN list for each S-NSSAI in the allowed NSSAI list or for each S-NSSAI and DNN combination. When the UE 3 receives the preferred SNPN list it will store it. These SNPN lists are the alternate SNPN of the S-NSSAI or S-NSSAI and DNN combination where the UE 3 can register to establish the MA PDU Session.

[0094] Fourth example of the First Aspect 　　Fig. 4 illustrates an example of selecting and registering an SNPN by UE 3 in the case that UE 3 can connect with two different 3GPP networks (e.g., HPLMN and SNPN). In this scenario, it is assumed that UE 3 already registered with HPLMN and now performs second registration through SNPN network.

[0095] The detailed processes of the Fourth example of the First Aspect are described below with reference to Fig. 4.

[0096] Step 1: UE 3 has registered with HPLMN as described in Fig. 2 or Fig. 3 and received the information about partner SNPNs (e.g., the SNPN partners list) from the network.

[0097] Step 2a: After UE 3 registered with the home network, UDM 7501 sends an Nudm_SDM_Notification message to AMF 7001 including a condition when UE 3 to use SNPN partner network 3GPP access link for dual connections. AMF 7001 stores the received condition when UE 3 to use SNPN partner network 3GPP access link for dual connections in the MM context for the UE 3 in AMF 7001.

[0098] For example, UDM 7501 may sends an Nudm_SDM_Notification message including a condition for UE 3 to use 3GPP access link of the SNPN for dual connections (or for DS).

[0099] Step 2b: AMF 7001 sends the received information from UDM 7501 to UE 3 via DL NAS Transport message or any other existing NAS message.

[0100] Step 3: UE 3 enters into a local premise area where partner SNPN networks are available for accessing services via dual 3GPP accesses (or via DS).

[0101] Step 4: UE 3 has established a PDU Session over HPLMN 3GPP access as specified in clause 4.3.2.2.2 in NPL 4.

[0102] In one example the UE 3 sends the preferred SNPN list during the PDU session establishment procedure. For example, the UE 3 may send a signaling message, during PDU session establishment procedure, including the preferred SNPN list to the AMF 7001 or the SMF 7101. For example, the UE 3 includes the preferred SNPN list in the UL NAS Transport message, PDU Session Establishment Request message or any other NAS message. The preferred SNPN list may include a SNPN that the UE 3 wishes to establish a dual access with.

[0103] The AMF 7001 or SMF 7101 may send a SNPN partners list based on the received SNPN partners list from the UDM 75 in Step 2a and provides it to the UE 3 in a message during PDU session establishment message. The SNPN partners list may be expressed as the preferred SNPN list.

[0104] When the UE 3 receives the SNPN partners list from the AMF 7001 or SMF 7101, the UE 3 may take the received SNPN partners list into account in Steps 5 and 6 for selecting a SNPN.

[0105] Step 5: The given condition (e.g., the UE received data rate is less than the network given threshold value, the overall service delay is higher than the network given range, or the packet loss rate is higher than the network given range) for UE 3 by the network to use an extra 3GPP access link from a partner SNPN network is met. 　　The condition may be indicated by the condition received in Step 2b.

[0106] Step 6: UE 3 is set to operate in SNPN access mode in one radio and selects an SNPN network using the received SNPN network selection assistance information as in Fig. 2 or Fig. 3(for example, the SNPN partners list or the SNPN priority list). UE 3 set to operate in SNPN access mode in one radio may mean that UE 3 is configured to operate in DS using at least one 3GPP access in SNPN.

[0107] Step 7: UE 3 sends Registration Request message to AMF 7002 in SNPN including UE 3's dual radio capability, SNPN ID, and UE ID, UE location, Registration Type which is set to Dual access via SNPN.

[0108] The UE registration type which is set to Dual access via SNPN may indicate that the Registration or the Registration procedure is for Dual access via SNPN or for the DS via SNPN or for DS via SNPN 3GPP access network or for DS using at least SNPN 3GPP access.

[0109] AMF 7002 in SNPN may be expressed as SNPN AMF 7002. 　　The UE 3's dual radio capability may indicate that UE 3 supports the DS. 　　The UE 3's dual radio capability may indicate that UE 3 supports the DS that one of the 3GPP accesses is via SNPN.

[0110] The UE 3's dual radio capability may indicate that UE 3 supports the DS using at least one 3GPP access in SNPN. 　　3GPP access in SNPN may be expressed as SNPN 3GPP access. 　　UE registration type which is set to Dual access via SNPN may be expressed as "UE registration type = Dual access via SNPN".

[0111] The UE registration type which is set to Dual access via SNPN may indicate that the Registration or the Registration procedure is for Dual access via SNPN or for the DS via SNPN or for DS via SNPN 3GPP access network or for DS using at least SNPN 3GPP access.

[0112] The Registration Request message may include SUCI (e.g., SUCI of UE 3) and UE location. The UE location may indicate a location where UE 3 locates.

[0113] UE Location may be a geographical location. For example, Location can be a list of Tracking Area Identity (TAI), a list of NR Cell Global Identity (NCGI) as defined in NPL 7, a list of NR Cell Identity (NCI) as defined in NPL 7, a list of E-UTRAN Cell Global Identifier (ECGI) as defined in NPL 7, a list of Global Cable Identifier (GCI) as defined in NPL 7, a general City name, zip-code, formed with GPS location or a location expressed with civic and geospatial location formats as defined in NPL 8.

[0114] UE 3 may perform the process(es) in Step 7 even if the condition in Step 5 is not met. 　　UE 3 may perform the process(es) in Step 7 even if UE 3 does not receive the message in Step 2b and the condition in Step 5 is not met.

[0115] UE 3 may perform the process(es) in Step 7 in a case where UE 3 is in a coverage area of SNPN. 　　UE 3 may perform the process(es) in Step 7 in a case where SNPN is available for UE 3.

[0116] Step 8: SNPN (e.g., at least one of AMF 7002 and UDM 7502) verifies HPLMN ID from the UE ID (e.g., SUCI) based on the Service Level Agreement (SLA) between HPLMN and SNPN.

[0117] Step 9: After verification, SNPN AMF 7002 sends an Nudm_UECM_Registration_Request message to the HPLMN UDM 7501 including the dual radio capability, the UE location, the UE registration type = Dual access via SNPN, the SNPN identity (e.g., SNPN ID) and the SUCI.

[0118] Step 10: UDM 7501 verifies the UE 3's subscription type and / or its location in order to allow UE 3 to use an SNPN 3GPP access link for dual steering.

[0119] Step 11: UDM 7501 sends an Nudm_UECM_Registration_Response message to SNPN AMF 7002 by allowing dual access via SNPN for UE 3 and indicating H-SMF ID (e.g., ID of HPLMN SMF 7101).

[0120] For example, UDM 7501 may send an Nudm_UECM_Registration_Response message to SNPN AMF 7002 including information indicating that UE 3 is allowed to use dual access via SNPN and H-SMF ID.

[0121] Step 12: Upon receiving the response from UDM 7501, SNPN AMF 7002 sends a Registration Accept message to UE 3 by indicating that dual steering via SNPN 3GPP access network is allowed.

[0122] For example, SNPN AMF 7002 sends a Registration Accept message to UE 3 including information indicating that UE 3 is allowed to use dual access via SNPN. 　　For example, SNPN AMF 7002 sends a Registration Accept message to UE 3 including information indicating that UE 3 is allowed to use dual steering via SNPN 3GPP access network. 　　After Step 12, UE 3 may be registered to HPLMN and SNPN.

[0123] Variant 1 of the Fourth example of the First Aspect 　　In one example, in Step 10, the HPLMN UDM 7501 (e.g., UDM 7501 in HPLMN) may provide the S-NSSAI for which the UE 3 can register and use services from when the UE 3 accesses the SNPN. The HPLMN UDM 7501 may provide such S-NSSAI to the UE 3 via the AMF 7002 of the SNPN within the Allowed NSSAI and also within the URSP rules provided via the HPLMN PCF 7301 (e.g., PCF 7301 in HPLMN).

[0124] Fifth example of the First Aspect 　　Fig. 5 illustrates an example for establishing dual 3GPP access connections for UE across HPLMN and SNPN networks. 　　The detailed processes of the Fifth example of the First Aspect are described below with reference to Fig. 5.

[0125] Step 1: UE 3 has registered with HPLMN over 3GPP access and established a PDU Session.

[0126] Step 2: The given condition to UE 3 by the home network has met and thus UE 3 registered with an SNPN partner network.

[0127] For example, Steps after Step 5 in Fig. 4 may be performed in Step 2 of Fig. 5. 　　For example, in Step 2, UE 3 may perform the process(es) in Step 7 of Fig. 4, and UE 3 may register with the SNPN.

[0128] Step 3: UE 3 sends a PDU Session Establishment Request message to AMF 7002 in SNPN to create an independent N9 tunnel via SNPN by including information elements such as support for dual access via SNPN, UE 3 supported DS-ATSSS functionalities and modes, Allowed S-NSSAI (e.g., S-NSSAI in Allowed NSSAI), PDU Session ID, PDU Session type, and UE ID.

[0129] The PDU Session Establishment Request message may include support for dual access via SNPN, UE 3 supported DS-ATSSS functionalities and modes, Allowed S-NSSAI, PDU Session ID, PDU Session type, and UE ID. 　　The support for dual access via SNPN may indicate that UE 3 supports the DS. 　　The support for dual access via SNPN may indicate that UE 3 supports the DS which one of the accesses is SNPN.

[0130] The support for dual access via SNPN may indicate that UE 3 supports the DS that one of the 3GPP accesses is via SNPN. 　　The support for dual access via SNPN may indicate that UE 3 supports the DS using at least one 3GPP access in SNPN.

[0131] The UE 3 supported DS-ATSSS functionalities and modes may indicate that UE 3 supports DS-ATSSS functionalities and modes. 　　The UE 3 supported DS-ATSSS functionalities and modes may indicate that UE 3 supports ATSSS functionalities and modes for the DS (e.g., for the DS via HPLMN and SNPN).

[0132] Step 4: AMF 7002 sends an Nsmf_PDUSession_SMContext message to SMF 7102 in SNPN including H-SMF ID (e.g., ID of HPLMN SMF 7101) and the information elements received from the UE 3 in Step 3 for PDU Session establishment. 　　SMF 7102 in SNPN may be expressed as SNPN SMF 7102.

[0133] Step 5: SNPN SMF 7102 sends an Nsmf_PDUSession_Create request message to SMF 7101 in HPLMN including the information elements received from AMF 7002. SMF 7101 in HPLMN may be expressed as SNPN SMF 7101.

[0134] Step 6: Upon receiving the request from SNPN SMF 7102, the HPLMN SMF 7101 verifies with UDM 7501 the allowed service type and / or traffic type for the UE 3 based on the UE 3's subscription data and the given condition (For example, examining the received Dual access via SNPN, supported DS-ATSSS functionalities and modes, Allowed S-NSSAI, PDU Session ID, PDU Session type in the Nsmf_PDUSession_Create request message in Step 5 with the UE 3's subscription data) for using an SNPN 3GPP access for dual steering.

[0135] For example, SMF 7101 may communicate with UDM 7501 for verifying UE 3. 　　For example, SMF 7101 may determine that verification for UE 3 is successfully completed in a case where the SMF 7101 receives from UDM 7501 information indicating that DS using at least one SNPN 3GPP access is allowed to UE 3.

[0136] For example, SMF 7101 may determine that verification for UE 3 is successfully completed in a case where the SMF 7101 receives from UDM 7501 information indicating that service using DS which uses an SNPN 3GPP access is allowed to UE 3.

[0137] For example, SMF 7101 may determine that verification for UE 3 is successfully completed in a case where the SMF 7101 receives from UDM 7501 information indicating that Traffic Steering Switching and Splitting using DS via an SNPN 3GPP access is allowed to UE 3.

[0138] Step 7: SMF 7101 with PCF 7301 creates DS-ATSSS rules for UE 3 and DS-N4 rules for UPF 7201 by performing SM Policy Association Establishment procedure. 　　The DS-ATSSS rules may be rule(s) for using Traffic Steering Switching and Splitting in DS.

[0139] The DS-ATSSS rules may be ATSSS rule(s) for DS. 　　The DS-N4 rules may be N4 rule(s) for DS. 　　For example, after the verification successfully completed in Step 6, Step 7 may be performed.

[0140] Step 8: SMF 7101 sends DS-N4 rules to UPF 7201 via N4 Session Establishment procedure.

[0141] Step 9: HPLMN SMF 7101 sends an Nsmf_PDUSession_Create response message to SNPN SMF 7102 including DS-ATSSS rules, H-UPF ID (e.g., ID of UPF 7201), and N9 tunnel information.

[0142] Step 10: SMF 7102 sends H-UPF ID and N9 tunnel information to UPF 7202 via N4 Session Establishment procedure. The H-UPF ID is used by the UPF 7202 to establish the N9 tunnel with the H-UPF 7201.

[0143] Step 11: SMF 7102 sends an Namf_Communication_N1N2MessageTransfer message to AMF 7002 including DS-ATSSS rules.

[0144] Step 12: Upon receiving the DS-ATSSS rules from SMF 7102, AMF 7002 sends PDU Session Establishment Accept message to UE 3 including DS-ATSSS rules.

[0145] Step 13: By executing Steps 3-12, UE 3 has established an N9 independent tunnel for MA PDU Session via SNPN and steered the traffic through dual 3GPP access based on the received DS-ATSSS rules.

[0146] For example, UE 3 may use DS-ATSSS rules for steering, switching or splitting traffic between dual 3GPP accesses (e.g., one access in HPLMN and another access in SNPN).

[0147] For example, DS-ATSSS rules may be rule(s) for steering, switching or splitting traffic between dual 3GPP accesses (e.g., one access in HPLMN and another access in SNPN).

[0148] In one example, the UE 3 establishes the second leg of MA PDU Session to the SNPN according to the DS-ATSSS rules. The UE 3 and the network establish the user plane on the second leg of the MA PDU session. The UE 3 starts transmitting user data on the user plane.

[0149] Second Aspect 　　In NPL 2, different use cases and potential new requirements are captured based on DS. In this disclosure, the following use cases and its corresponding new requirements are considered: i) Dual 3GPP accesses in local premises using PLMN and SNPN networks, ii) Dual 3GPP accesses interworking with non-3GPP access across PLMN and SNPN / PLMN networks, iii) Mobility between PLMN and SNPN / PLMN networks, and iv) Switching between dual 3GPP accesses across PLMN and SNPN / PLMN networks.

[0150] Regarding i) Dual 3GPP accesses in local premises using PLMN and SNPN networks 　　A particular place (e.g., stadium, campus, enterprise, mall, factory, and other local premises) is served by Mobile Network Operator (MNO) A with ad-hoc or in-venue 5G NR deployment (e.g., SNPN) and MNO B (e.g., PLMN) with 5G terrestrial or non-terrestrial NR deployment that covers a large area. MNOs A and B have business service agreement. Thus, users of MNO B with golden subscription are also served by MNO A based on QoS or traffic type. For example, the users of MNO B with golden subscription may be users who have paid not only fee for using the service of MNO B but also fee for using the service of MNO A. In this case, UE of MNO B registers with both networks and establishes a dual connection across the two networks. In this scenario, the following problems need to be solved.

[0151] ●　　The UE needs to know the available partner SNPN networks of its HPLMN in a particular place / location such as stadium in order to select, register, and steer the service traffic across HPLMN and SNPN networks.

[0152] ●　　The 5G system needs to be able to support mechanisms to enable dual steering using two networks such as HPLMN and SNPN for PLMN users based on the subscription type, service type, traffic type, geographical location, and time.

[0153] Regarding ii) Dual 3GPP accesses interworking with non-3GPP access across PLMN and SNPN / PLMN networks 　　In certain scenarios it would be beneficial to support transition between new dual-3GPP access operation and ATSSS-based one 3GPP access and one non-3GPP access operation, e.g., when coverage of one of the two 3GPP accesses becomes poor or unavailable, while a non-3GPP access link is available. One relevant scenario is when a UE / user moves from outdoor to indoor (and vice versa), can be home, office, enterprise, shopping mall or other type of venues. In this scenario, the following problems need to be solved.

[0154] ●　　UE-initiated transition from dual 3GPP access connection to 3GPP+non-3GPP access connection (e.g. the connection using 3GPP and non-3GPP access) and vice-versa need to be supported.

[0155] ●　　The 5G system needs to be able to support the transition from dual 3GPP access to one 3GPP+one non-3GPP access (e.g. one 3GPP access and one non-3GPP access) and vice-versa.

[0156] This aspect discloses mechanisms for establishing dual connections across VPLMN and SNPN networks to support HPLMN users to access services via dual 3GPP accesses. Here, it is assumed that SNPN is within the coverage area of VPLMN, i.e., both VPLMN and SNPN are outside the coverage area of HPLMN and they can provide services to HPLMN users via home-routed service traffic based on the subscription type, location and time, service type, and traffic type.

[0157] First example of the Second Aspect 　　Fig. 6 illustrates an example architecture in which UE 3 connects with both VPLMN and SNPN for accessing services via dual 3GPP accesses from HPLMN.

[0158] Fig. 6 shows an architecture in which VPLMN and SNPN are connected with HPLMN and UEs 3 are allowed to access services via dual 3GPP accesses using HPLMN credentials through home-routed roaming. It is assumed that UE has dual radio capability and there is a service level agreement between HPLMN and VPLMN and between HPLMN and SNPN. Two N9 independent tunnels are created to steer the traffic to UE 3 via both VPLMN and SNPN. HPLMN SMF 7101 with PCF 7301 generates DS rules and shares with HPLMN UPF 7201, SNPN SMF 7102, and VPLMN SMF 7103. The network provided DS rules may be updated based on the traffic congestion in the network and the availability or unavailability of the 3GPP access link. Similar to Inter-PLMN UP Security (IPUPS), PLMN-SNPN UP Security (PSUPS) is required for securing the communication over N9 tunnel.

[0159] It is assumed that the HPLMN subscription is used to access services via both VPLMN and SNPN networks. Service traffic is anchored by UPF 7201 in the HPLMN and a proper business agreement is in place among the network operators, including specific traffic routing policies, e.g., based on geographical location, subscription, service type, and traffic type.

[0160] Second example of the Second Aspect 　　Fig. 7 illustrates an example of initial registration or mobility registration update procedure for dual 3GPP access connections for UE 3 through VPLMN and SNPN networks.

[0161] The detailed processes of the Second example of the Second Aspect are described below with reference to Fig. 7.

[0162] Step 0: UDM 7501 in HPLMN maintains new subscription data for dual steer priority.

[0163] Step 1: UE 3 is in the coverage area of VPLMN and sends Registration Request message to VPLMN AMF 7003 including User ID, indication for UE's support for dual steer, and UE location.

[0164] The indication for UE's support for dual steer may indicate that UE 3 supports the DS. 　　The indication for UE's support for dual steer may indicate that UE 3 supports the DS which one of the accesses is SNPN.

[0165] The indication for UE's support for dual steer may indicate that UE 3 supports the DS using the VPLMN and the SNPN. 　　The indication for UE's support for dual steer may indicate that UE 3 supports the DS using a 3GPP access in the VPLMN and a 3GPP access in the SNPN. 　　The UE location may indicate a location where UE 3 locates.

[0166] Step 2: AMF 7003 sends an Nudm_UECM_Registration Request to UDM 7501 including the UE location and the indication for UE's support for dual steer.

[0167] Step 3: UDM 7501 sends an Nudm_UECM_Registration Response message to AMF 7003. For example, the response message may contain the information for which the network allows dual 3GPP access for the UE 3.

[0168] Step 4: AMF 7003 sends an Nudm_SDM_Get Request message to UDM 7501 including the UE location and the indication for UE's support for dual steer.

[0169] Step 5: Upon receiving the request from AMF 7003 in Step 4, UDM 7501 sends an Nudm_SDM_Get Response message to AMF 7003 including the dual steer priority information based on the UE's subscription data.

[0170] HPLMN provides the dual steer priority information to UE 3 and it may contain the following information. ●　　Mobility management related information: 　　　　A list of allowed PLMN and SNPN networks for dual steer in which UE 3 can register. 　　　　A list of prohibited PLMN and SNPN networks in which UE 3 is not allowed to register for dual steer. 　　　　A list of S-NSSAIs or NSSAI for which UE 3 can register for accessing services via dual steer. 　　　　NSSRG information so that the UE 3 is aware for which S-NSSAI it cannot register at the same time. 　　　　Any access and mobility restrictions based on location or time.

[0171] ●　　Session management related information: 　　　　A list of Allowed NSSAI, DNN, or S-NSSAI+DNN (e.g., combination of S-NSSAI and DNN) for which UE 3 is allowed to establish multi-access PDU Session to access services through dual steer. 　　　　A list of prohibited NSSAI, DNN, or S-NSSAI+DNN for which UE 3 is not allowed to establish multi-access PDU Session to access services through dual steer. 　　　　A list of allowed traffic type for dual steer such as IPv4, IPv6, Downlink (DL) only, URLLC, ultra-low latency, time sensitive communications and networking, time synchronization and deterministic networking.　　 　　　　A list of prohibited traffic type for which UE is not allowed for accessing services through dual steer.

[0172] The dual steer priority information may include information indicating SNPN(s) for DS in which UE 3 can register or is allowed to register. 　　The dual steer priority information may include information indicating SNPN(s) for DS in which UE 3 cannot register or is not allowed to register.

[0173] Step 6a: AMF 7003 sends Registration accept message to UE 3 if UE 3 is allowed to access services through dual steer based on its subscription data. The Registration accept message may include 5G-GUTI identity for UE 3 and the dual steer priority information.

[0174] Step 6b: AMF 7003 sends Registration reject message to UE 3 if UE 3 is not allowed to access services through dual steer based on its subscription data. The Registration reject message may include the cause for rejection (e.g., roaming is not allowed for UE for dual steer).

[0175] Step 7: UE 3 stores the dual steer priority information and refers it when the UE 3 is about to initiate (or initiates) the Registration procedure and / or PDU Session establishment procedure for accessing services through dual steer.

[0176] Third example of the Second Aspect 　　Fig. 8 illustrates an example of second registration procedure for dual 3GPP access connections for UE 3 through VPLMN and SNPN networks.

[0177] The detailed processes of the Third example of the Second Aspect are described below with reference to Fig. 8.

[0178] Step 0: UDM 7501 in HPLMN maintains new subscription data for dual steer priority.

[0179] Step 1: UE 3 refers to the dual steer priority information received during the initial / first registration procedure and initiates the second registration procedure if the UE 3 is allowed to do it. Otherwise, the UE 3 does not initiate the second registration procedure with SNPN network for dual steering.

[0180] For example, UE 3 may receive the dual steer priority information in process(es) in Fig. 7.

[0181] Step 2: If UE 3 is in the coverage area of SNPN and it is allowed for dual steering via SNPN, then UE 3 sends Registration Request message to SNPN AMF 7002 including User ID, indication for UE's support for dual steer, UE location, and registered VPLMN AMF details.

[0182] For example, it assumes that UE 3 has registered with VPLMN based on the process(es) in Fig. 7, and the dual steer priority information indicates that UE 3 can register with SNPN 1 for DS. In this case, in a case where UE 3 is in the coverage area of SNPN 1, UE 3 may send the Registration Request message to AMF 7002 in SNPN 1.

[0183] Step 3: AMF 7002 sends an Nudm_UECM_Registration Request message to UDM 7501 including the UE location and the indication for UE's support for dual steer.

[0184] Step 4: UDM 7501 sends an Nudm_UECM_Registration Response message to AMF 7002. The response may include the details of VPLMN AMF 7003 (e.g., the registered VPLMN AMF details) through which the UE 3 is registered first. The same VPLMN AMF 7003 details may be shared by UE 3 to SNPN AMF 7002 in Step 2 with Registration request message as well.

[0185] The details of VPLMN AMF 7003 may indicate information related to VPLMN AMF 7003, VPLMN AMF 7003's ID, information for communicating with VPLMN AMF 7003 etc. 　　For example, the registered VPLMN AMF details in Step 2 may include the details of VPLMN AMF 7003.

[0186] Step 5: AMF 7002 sends an Nudm_SDM_Get Request message to UDM 7501 including the UE location and the indication for UE's support for dual steer.

[0187] Step 6: Upon receiving the request from AMF 7002 in Step 5, UDM 7501 sends an Nudm_SDM_Get Response message to AMF 7002 including the updated dual steer priority information based on the UE's subscription data. UDM 7501 may send, to AMF 7002, the dual steer priority information which is same one in Step 5 in Fig. 7.

[0188] HPLMN provides the updated dual steer priority information to UE 3 and it may contain the following information. ●　　Mobility management related information: 　　　　A list of allowed PLMN and SNPN networks for dual steer in which UE 3 can register. 　　　　A list of prohibited PLMN and SNPN networks in which UE 3 is not allowed to register for dual steer. 　　　　A list of S-NSSAIs or NSSAI for which UE 3 can register for accessing services via dual steer. 　　　　NSSRG information so that the UE 3 is aware for which S-NSSAI it cannot register at the same time. 　　　　Any access and mobility restrictions based on location or time.

[0189] ●　　Session management related information: 　　　　A list of Allowed NSSAI, DNN, or S-NSSAI+DNN (e.g., combination of S-NSSAI and DNN) for which UE 3 is allowed to establish multi-access PDU Session to access services through dual steer. 　　　　A list of prohibited NSSAI, DNN, or S-NSSAI+DNN for which UE 3 is not allowed to establish multi-access PDU Session to access services through dual steer. 　　　　A list of allowed traffic type for dual steer such as IPv4, IPv6, Downlink (DL) only, URLLC, ultra-low latency, time sensitive communications and networking, time synchronization and deterministic networking. 　　　　A list of prohibited traffic type for which UE is not allowed for accessing services through dual steer.

[0190] Step 7a: AMF 7002 sends Registration accept message to UE 3 if UE 3 is allowed to access services through dual steer based on its subscription data. The Registration accept message may include 5G-GUTI identity for UE 3 and the updated dual steer priority information (e.g., the received dual steer priority information from UDM 7501).

[0191] Step 7b: AMF 7002 sends Registration reject message to UE 3 if UE 3 is not allowed to access services through dual steer based on its subscription data. The Registration reject message may include the cause for rejection (e.g., roaming is not allowed for UE for dual steer).

[0192] Step 8: SNPN AMF 7002 sends an Namf_Communication_UEContextTransfer message to VPLMN AMF 7003 based on Step 2 or Step 4. The Namf_Communication_UEContextTransfer message may include SUPI (e.g., SUPI for UE 3) and SNPN AMF 7002 details through which UE is registered. Alternatively, UDM 7501 may share SNPN AMF 7002 details to VPLMN AMF 7003.

[0193] The SNPN AMF 7002 details may indicate information related to SNPN AMF 7002, SNPN AMF 7002's ID, information for communicating with SNPN AMF 7002 etc. For example, SNPN AMF 7002 may send the Namf_Communication_UEContextTransfer message to VPLMN AMF 7003 based on the registered VPLMN AMF details.

[0194] For example, SNPN AMF 7002 may send the Namf_Communication_UEContextTransfer message to VPLMN AMF 7003 indicated by the registered VPLMN AMF details.

[0195] Step 9: VPLMN AMF 7003 sends an Namf_Communication_UEContextTransfer response message to SNPN AMF 7002, which confirms the pairing of AMFs. 　　For example, in a case where VPLMN AMF 7003 receives the message in Step 8, VPLMN AMF 7003 may recognize the paring of VPLMN AMF 7003 and SNPN AMF 7002 for DS.

[0196] For example, in a case where VPLMN AMF 7003 receives the message in Step 8, VPLMN AMF 7003 may recognize that VPLMN AMF 7003 is paired with SNPN AMF 7002 for DS.

[0197] For example, VPLMN AMF 7003 may send, to SNPN AMF 7002, information related to VPLMN AMF 7003, VPLMN AMF 7003's ID, information for communicating with VPLMN AMF 7003 etc. in Step 9. The information sent to SNPN AMF 7002 in Step 9 may be used for Target pair AMF in Fig. 9A.

[0198] Fourth example of the Second Aspect 　　Figs. 9A and 9B illustrate an example for establishing multi-access PDU Session via dual 3GPP access connections for UE through VPLMN and SNPN networks.

[0199] The detailed processes of the Fourth example of the Second Aspect are described below with reference to Figs. 9A and 9B.

[0200] Step 1: If UE 3 is allowed to register and establish PDU Session as per the received dual steer priority list (e.g., the received dual steer priority information in Fig. 7 or 8) from the home network, then the UE 3 is registered via both VPLMN and SNPN networks and it is established a PDU Session via VPLMN as specified in clause 4.3.2.2.2 in NPL 4 by indicating the support for dual 3GPP access.

[0201] For example, UE 3 may perform the process(es) in Figs. 7 and 8 to register with VPLMN and SNPN. Then UE 3 may establish a PDU Session via VPLMN.

[0202] Step 2: UE 3 is in the overlapping coverage area of both VPLMN and SNPN networks and UE 3 sends PDU Session establishment request message to SNPN AMF 7002 via UL NAS Transport message. The UL NAS Transport message may include PDU Session ID, DNN, S-NSSAI, traffic type, and NAS message. The NAS message includes PDU Session establishment request message, target pair PLMN, and target pair PDU Session ID.

[0203] The traffic type may indicate type of traffic. 　　The traffic type may indicate type of traffic that UE 3 communicates in DS. 　　The traffic type may indicate type of traffic that UE 3 communicates in DS via VPLMN and SNPN.

[0204] The target pair PLMN may indicate PLMN which the UE 3 wishes to configure DS with. The Target pair PLMN may be the VPLMN that the UE 3 has registered in Step 1.

[0205] In a case where the PDU Session Establishment Request message is for establishing MA PDU Session via VPLMN and SNPN, the target pair PLMN may indicate at least one of VPLMN and SNPN.

[0206] In a case where the PDU Session Establishment Request message is for establishing the PDU Session via SNPN in addition to the PDU Session via VPLMN, the target pair PLMN may indicate at least one of VPLMN and SNPN. 　　The target pair PLMN may indicate ID of at least one of VPLMN and PLMN.

[0207] The target pair PDU Session ID may indicate PDU Session ID that the UE 3 wishes to configure MA PDU Session with. 　　The target pair PDU Session ID may indicate PDU Session ID of the PDU Session established in Step 1. 　　The target pair PDU Session ID may indicate PDU Session ID of the PDU Session for VPLMN established in Step 1.

[0208] Step 3: SNPN AMF 7002 sends an Nsmf_PDUSession_CreateSMContext request message to SNPN SMF 7102 including the PDU Session ID, DNN, S-NSSAI, traffic type, target pair PLMN, target pair PDU Session ID, target pair AMF, and PDU Session establishment request message. SNPN SMF 7102 sends response message to SNPN AMF 7002 for the request message.

[0209] The target pair AMF may indicate AMF which is a target AMF that DS to be configured with. 　　The target pair AMF may indicate AMF 7003 in VPLMN (e.g., VPLMN AMF 7003). 　　The target pair AMF may indicate information related to VPLMN AMF 7003, VPLMN AMF 7003's ID, information for communicating with VPLMN AMF 7003.

[0210] The Target pair AMF may be generated by the SNPN AMF 7002 based on information in the MM context for the UE 3 in the SNPN AMF 7002. For example, when the UE 3 performs the Registration procedure with the SNPN AMF 7002, the SNPN AMF 7002 may obtains a candidate for the Target pair AMF in the Step 4 in Fig. 8.

[0211] Step 4: SNPN SMF 7102 sends an Nsmf_PDUSession_Create Request message to HPLMN SMF 7101 including User ID, PDU Session ID, and Dual Steer support indication.

[0212] The Dual Steer support indication may indicate that SNPN SMF 7102 supports DS. 　　The Dual Steer support indication may indicate that SNPN SMF 7102 supports DS via VPLMN and SNPN.

[0213] Step 5: Upon receiving the message from SNPN SMF 7102 in Step 4, HPLMN SMF 7101 sends an Nudm_SDM_Get Request message to UDM 75 (e.g., UDM 7501 in Fig. 7) to get the details of the UE's subscription data service information. The Nudm_SDM_Get Request message may include User ID, DNN, S-NSSAI, Dual Steer support.

[0214] Step 6: Upon receiving the message from HPLMN SMF 7101 in Step 5, UDM 75 checks UEs session management subscription data and prepares Dual Steer priority information. UDM 75 sends an Nudm_SDM_Get Response message to HPLMN SMF 7101 including Dual Steer priority information of UE 3. 　　The Dual Steer priority information in Step 6 may be same one in Fig. 7 or 8.

[0215] Step 7: HPLMN SMF 7101 checks whether the requested PDU Session service information matches with the Dual Steer priority information received from UDM 75. For example, the Dual Steer priority information from UDM 75 indicates that the SNPN where the UE 3 is accessing with is set as a low priority, the HPLMN SMF 7101 may reject to configure the MA PDU Session with the SNPN.

[0216] Step 8: If UE 3 is not allowed to access a service using dual steer through VPLMN and SNPN based on its subscription data and Dual Steer priority information received from UDM 75, then HPLMN SMF 7101 sends an Nsmf_PDUSession_CreateSMContext Reject message to SNPN SMF 7102 including the cause for rejection (e.g., dual steer is not allowed through VPLMN and SNPN networks).

[0217] Step 9: Upon receiving the rejection message from HPLMN SMF 7101, SNPN SMF 7102 sends an Namf_Communication_N1N2MessageTransfer message to SNPN AMF 7002 including the PDU Session reject cause (e.g., the cause for rejection).

[0218] Step 10: SNPN AMF 7002 sends a DL NAS Transport message to UE 3 including the PDU Session Establishment Reject message with the cause for rejection (e.g., dual steer is not allowed through VPLMN and SNPN networks).

[0219] Step 11: If UE 3 is allowed to access services using dual steer through VPLMN and SNPN networks, then HPLMN SMF 7101 sends an Npcf_SMPolicyControl_Create Request message to PCF 73 including User ID, DNN, S-NSSAI, and the indication for Dual Steer (e.g., the Dual Steer support indication).

[0220] Step 12: Upon receiving the request from SMF 7101 in Step 11, PCF 73 defines DS-ATSSS rules (e.g., dual steer DS-ATSSS rules) and N4 rules for UE 3 and UPF 7201, respectively. Then, PCF 73 sends these rules for dual steer to SMF 7101 via Npcf_SMPolicyControl_Create Response message.

[0221] Step 13: Upon receiving the dual steer DS-ATSSS and N4 rules (e.g., the DS-ATSSS rules and N4 rules) from PCF 73 in Step 12, SMF 7101 sends N4 rules to UPF 7201 through N4 Session establishment procedure.

[0222] Step 14: N4 interface related Dual Steer rules (e.g., at least one of the DS-ATSSS rules and N4 rules) are installed in UPF 7201 as provided by HPLMN SMF 7101.

[0223] Step 15: HPLMN SMF 7101 sends an Nsmf_PDUSession_CreateSMContext Response message to SNPN SMF 7102 including the DS-ATSSS rules, N9 SM information such as UPF 7201's address and UP-TEID, and Active S-NSSAI. 　　The DS-ATSSS rules may be rule(s) for using Traffic Steering Switching and Splitting in DS.

[0224] The N9 SM information indicates UPF 7201's address and UP-TEID as the PDU Session Anchor of the PDU Session. The SNPN SMF 7102 informs the N9 SM information to the SNPN UPF 7202 in Step 16 for establishing a user plane connection between SNPN UPF 7202 and the UPF 7201. 　　The Active S-NSSAI is an S-NSSAI that is associated with the PDU Session that has been established in Step 1.

[0225] Step 16: Upon receiving the response message from HPLMN SMF 7101 in Step 15, SNPN SMF 7102 sends N9 SM information (e.g., the UPF 7201's address and UP-TEID) to SNPN UPF 7202 for creating N9 tunnel between HPLMN UPF 7201 and SNPN UPF 7202 in order to steer the UP traffic via this leg.

[0226] Step 17: SNPN SMF 7102 sends an Namf_Communication_N1N2MessageTransfer message to SNPN AMF 7002 including the Dual Steer DS-ATSSS rules for UE 3 and Active S-NSSAI for the PDU Session.

[0227] Step 18: SNPN AMF 7002 sends a DL NAS Transport message to UE 3 including the PDU Session Establishment Accept message and the Dual Steer DS-ATSSS rules (e.g., DS-ATSSS rules) for UE 3. 　　The Dual Steer DS-ATSSS rules for UE 3 may be included in the PDU Session Establishment Accept message.

[0228] Step 19: Uu interface related Dual Steer rules (e.g., the DS-ATSSS rules for UE 3) are installed in UE 3 as provided by HPLMN SMF 7101.

[0229] Step 20: If the Active S-NSSAI, received in Step 17, is not in the Allowed NSSAI for the UE 3 in the SNPN AMF 7002, the SNPN AMF 7002 performs the Configuration Update Command procedure with the UE 3 to make the Active S-NSSAI to be a part of the Allowed NSSAI.

[0230] Third Aspect 　　In NPL 2, different use cases and potential new requirements are captured based on DS. In this disclosure, the following use cases and its corresponding new requirements are considered: i) Dual 3GPP accesses in local premises using PLMN and SNPN networks, ii) Dual 3GPP accesses interworking with non-3GPP access across PLMN and SNPN / PLMN networks, iii) Mobility between PLMN and SNPN / PLMN networks, and iv) Switching between dual 3GPP accesses across PLMN and SNPN / PLMN networks.

[0231] Regarding i) Dual 3GPP accesses in local premises using PLMN and SNPN networks 　　A particular place (e.g., stadium, campus, enterprise, mall, factory, and other local premises) is served by Mobile Network Operator (MNO) A with ad-hoc or in-venue 5G NR deployment (e.g., SNPN) and MNO B (e.g., PLMN) with 5G terrestrial or non-terrestrial NR deployment that covers a large area. MNOs A and B have business service agreement. Thus, users of MNO B with golden subscription are also served by MNO A based on QoS or traffic type. For example, the users of MNO B with golden subscription may be users who have paid not only fee for using the service of MNO B but also fee for using the service of MNO A. In this case, UE of MNO B registers with both networks and establishes a dual connection across the two networks. In this scenario, the following problems need to be solved.

[0232] ●　　The UE needs to know the available partner SNPN networks of its HPLMN in a particular place / location such as stadium in order to select, register, and steer the service traffic across HPLMN and SNPN networks.

[0233] ●　　The 5G system needs to be able to support mechanisms to enable dual steering using two networks such as HPLMN and SNPN for PLMN users based on the subscription type, service type, traffic type, geographical location, and time.

[0234] Regarding ii) Dual 3GPP accesses interworking with non-3GPP access across PLMN and SNPN / PLMN networks 　　In certain scenarios it would be beneficial to support transition between new dual-3GPP access operation and ATSSS-based one 3GPP access and one non-3GPP access operation, e.g., when coverage of one of the two 3GPP accesses becomes poor or unavailable, while a non-3GPP access link is available. One relevant scenario is when a UE / user moves from outdoor to indoor (and vice versa), can be home, office, enterprise, shopping mall or other type of venues. In this scenario, the following problems need to be solved.

[0235] ●　　UE-initiated transition from dual 3GPP access connection to 3GPP+non-3GPP access connection (e.g. the connection using 3GPP and non-3GPP access) and vice-versa need to be supported.

[0236] ●　　The 5G system needs to be able to support the transition from dual 3GPP access to one 3GPP+one non-3GPP access (e.g. one 3GPP access and one non-3GPP access) and vice-versa.

[0237] This aspect discloses mechanisms for interworking of dual 3GPP accesses with non-3GPP access across PLMN and SNPN / PLMN networks such that UE can switch from dual 3GPP accesses to ATSSS (one 3GPP and one non-3GPP) access and vice-versa when coverage of one access becomes poor or not available.

[0238] First example of the Third Aspect 　　Fig. 10 illustrates an example architecture in which UE 3 interworks with dual 3GPP accesses and ATSSS accesses in order to switch access connection across HPLMN and SNPN networks based on the availability of access networks.

[0239] Fig. 10 shows an architecture in which UE 3 interworks with dual 3GPP access and ATSSS (one 3GPP and one non-3GPP) access across HPLMN and SNPN networks. Initially, UE 3 has dual 3GPP access connections (one from HPLMN and other from SNPN). Later, UE 3 switches to 3GPP + non-3GPP access connections (both from HPLMN) based on the availability and signal strength of access networks.

[0240] For example, 3GPP + non-3GPP access connections may mean that connections provided by 3GPP access and non-3GPP access or connections using 3GPP access and non-3GPP access. ATSSS access may mean access(es) using 3GPP access and non-3GPP access.

[0241] For example, ATSSS access may be preferred when user is within the house or office and dual 3GPP access may be preferred when user is outside the house or office. Another example is that a certain enterprise offers to its employees both mobile and Wi-Fi subscriptions from the same mobile network operator. UEs / Users can use dual 3GPP access and / or ATSSS for high data rate connectivity (e.g., for intranet video calls, outside or inside the enterprise office buildings).

[0242] It is assumed that both 3GPP and non-3GPP access networks are managed by the same mobile network operator and data is anchored in the 5G core network of the HPLMN. 　　For example, the TNGF / TWIF 503 may be an N3IWF.

[0243] Similar to Inter-PLMN UP Security (IPUPS), PLMN-SNPN UP Security (PSUPS) is required for securing the communication over N9 tunnel. It is assumed that the HPLMN subscription is used to access both networks, data traffic is anchored in the HPLMN and a proper business agreement is in place among the two network operators, including specific traffic routing policies, e.g., based on geographical location, subscription, traffic type. In Fig. 10, roaming interfaces highlighted in bold lines (e.g., N8 and N16) are new connections between HPLMN and SNPN. Currently, they do not exist as SNPN operates independently and does not have relation with PLMN. As these roaming interfaces are already defined for inter-PLMN roaming scenarios, the same functionalities can be utilized for PLMN-SNPN roaming as well.

[0244] Variant 1 of First example of the Third Aspect 　　In Fig. 10, the visited network is considered as an SNPN for example. In another example, the visited network may be VPLMN and the inter-PLMN home-routed roaming scenario may be considered for traffic access splitting, steering, and switching over dual 3GPP access networks.

[0245] Variant 2 of First example of the Third Aspect In Fig. 10, both 3GPP access network (e.g., 5G NR) and non-3GPP access network (e.g., TNGF and Wi-Fi) is managed by the HPLMN for example. In another example, both 3GPP access network (e.g., 5G NR) and non-3GPP access network (e.g., TNGF and Wi-Fi) may be managed by the visiting network (e.g., SNPN and VPLMN).

[0246] Variant 3 of First example of the Third Aspect 　　In one example, UE may have three access network connections (e.g., two 3GPP accesses and one non-3GPP access) such that user plane traffic can be routed through three legs, i.e., via three independent user plane tunnels between UE and PSA UPF and anchored by HPLMN UPF.

[0247] Second example of the Third Aspect 　　Fig. 11 illustrates an example of interworking of dual 3GPP access and ATSSS access for UE to switch from one access to another access across HPLMN and SNPN / VPLMN networks. 　　The detailed processes of the Second example of the Third Aspect are described below with reference to Fig. 11.

[0248] Step 1: UE 3 has registered with HPLMN via 3GPP 5G NR 501 access network and established a PDU Session.

[0249] Step 2: UE 3 has also registered with SNPN / VPLMN via 3GPP 5G NR 502 access network and established multi-access PDU Session for splitting, steering, and switching service traffic through dual 3GPP access. 　　For example, UE 3 may perform process(es) in First Aspect to register with SNPN / VPLMN and to establish the multi-access PDU Session.

[0250] Step 3: UE 3 detects service degradation or low signal strength over 3GPP 5G NR 502 access link and availability of non-3GPP access with a good signal strength in HPLMN, and triggers for access switching from 3GPP 5G NR 502 access to non-3GPP access TNGF 503.

[0251] Step 4: UE 3 sends Registration Request message to a newly available non-3GPP access network 503 in HPLMN including UE dual radio capabilities, Registration type as access switch, and support for interworking of DS with ATSSS. 　　The UE dual radio capabilities may indicate that UE 3 supports the DS. 　　The UE dual radio capabilities may indicate that UE 3 supports the DS that one of the 3GPP accesses is via SNPN or VPLMN.

[0252] The UE dual radio capabilities may indicate that UE 3 supports the DS using at least one 3GPP access in SNPN or VPLMN. 　　The Registration type as access switch may indicate that the Registration or the Registration procedure is for switching dual 3GPP accesses between HPLMN and SNPN / VPLMN.

[0253] The Registration type as access switch may indicate that the Registration or the Registration procedure is for switching between one combination of one 3GPP access and another 3GPP access, and another combination of one 3GPP access and one non-3GPP access.

[0254] The support for interworking of DS with ATSSS may indicate that UE 3 supports interworking of DS using dual 3GPP access with ATSSS using one 3GPP access and one non-3GPP access.

[0255] The support for interworking of DS with ATSSS may indicate that UE 3 supports changing from DS using dual 3GPP access to ATSSS using one 3GPP access and one non-3GPP access vice-versa. 　　UE 3 may send the Registration Request message via a newly available non-3GPP access network 503.

[0256] Step 5: Upon receiving the Registration Request message in Step 4, non-3GPP access network TNGF 503 sends Registration Request message to HPLMN AMF 7001 (e.g., AMF 1 or AMF 2 in Fig. 11) including the UE dual radio capabilities, Registration type as access switch, and support for interworking of DS with ATSSS. 　　TNGF 503 may send the Registration Request message to AMF 1 in Fig. 11. In this case, AMF 1 in Fig. 11 may perform Steps 6, 8 and 9 below.

[0257] Step 6: HPLMN AMF 7001 sends an Nudm_UECM_Registration_Request message to UDM 7501 including the UE dual radio capabilities, Registration type as access switch, and support for interworking of DS with ATSSS.

[0258] Step 7: UDM 7501 verifies the UE subscription data for interworking of DS with ATSSS.

[0259] Step 8: UDM 7501 sends an Nudm_UECM_Registration Response message to AMF 7001 including the indication that DS interworking with ATSSS is allowed for UE 3. 　　The indication that DS interworking with ATSSS may indicate interworking of DS using dual 3GPP access with ATSSS using one 3GPP access and one non-3GPP access is allowed for UE 3.

[0260] The indication that DS interworking with ATSSS may indicate changing from DS using dual 3GPP access to ATSSS using one 3GPP access and one non-3GPP access is allowed for UE 3. 　　The indication that DS interworking with ATSSS may indicate changing from DS using one 3GPP access in HPLMN and another 3GPP access in SNPN / VPLMN to ATSSS using one 3GPP access and one non-3GPP access in HPLMN is allowed for UE 3.

[0261] Step 9: HPLMN AMF 7001 sends Registration accept message to UE 3 including the indication that DS interworking with ATSSS is allowed for UE 3. For example, after Step 9, UE 3 may be registered with HPLMN via non-3GPP access.

[0262] Variant 1 of Second example of the Third Aspect 　　If UE 3 and network intent to use three legs (i.e., three user plane tunnels between UE and PSA UPF) to split, steer, and switch the traffic using two 3GPP accesses and one non-3GPP access, then UE 3 may indicate the Registration type as triple access or DS+ATSSS access in the Registration procedure.

[0263] Third example of the Third Aspect 　　Fig. 12 illustrates an example for PDU Session modification for supporting UE 3 transitioning from dual 3GPP access to ATSSS access across HPLMN and SNPN / VPLMN networks. 　　The detailed processes of the Third example of the Third Aspect are described below with reference to Fig. 12.

[0264] Step 1: UE 3 has registered with HPLMN via 3GPP 5G NR 501 access network and established a PDU Session.

[0265] Step 2: UE 3 has also registered with SNPN / VPLMN via 3GPP 5G NR 502 access network and established multi-access PDU Session for splitting, steering, and switching service traffic through dual 3GPP access. 　　For example, UE 3 may perform process(es) in First Aspect to register with SNPN / VPLMN and to establish the multi-access PDU Session.

[0266] Step 3: UE 3 has detected service degradation or low signal strength over 3GPP 5G NR 502 access link in SNPN / VPLMN network and thus registered over non-3GPP access TNGF 503 in HPLMN to initiate access switching from dual 3GPP access to ATSSS access for better quality of service.

[0267] Step 3 may be same to Step 3 in Fig. 11. 　　In Step 3. the process(es) in Steps 3 to 9 in Fig. 11 may be performed.

[0268] Step 4: UE 3 sends PDU Session modification request message to HPLMN AMF 7001 (e.g., AMF 1 or AMF 2 in Fig. 12) including the support for DS interworking with ATSSS, PDU Session ID, SNPN 5G NR access ID, and indicator to keep or release the connection over the SNPN access. The SNPN 5G NR access ID indicates that UE 3 is willing to switch from the SNPN 5G NR access 502 to alternative access available for the UE 3.

[0269] The support for DS interworking with ATSSS may indicate that UE 3 supports interworking of DS using dual 3GPP access with ATSSS using one 3GPP access and one non-3GPP access.

[0270] The support for DS interworking with ATSSS may indicate that UE 3 supports changing from DS using dual 3GPP access to ATSSS using one 3GPP access and one non-3GPP access vice-versa.

[0271] The indicator to keep or release the connection over the SNPN access may indicate that UE 3's intention for keeping or releasing the connection over the SNPN access.

[0272] In a case where the indicator which is set to keep, the indicator may indicate that UE 3 requests to keep the connection over the SNPN access. 　　In a case where the indicator which is set to release, the indicator may indicate that UE 3 requests to release the connection over the SNPN access.

[0273] UE 3 may send the PDU Session modification request message to AMF 1 in Fig. 11. In this case, AMF 1 in Fig. 12 may perform Steps 5, 7, 10 and 11 below.

[0274] Step 5: HPLMN AMF 7001 (e.g., AMF 2 in Fig. 12) sends an Nsmf_PDUSession_CreateSMContext request message to SMF 7101 including the support for DS interworking with ATSSS, PDU Session ID, SNPN 5G NR access ID, and indicator to keep or release the connection over the SNPN access.

[0275] Step 6: UDM 7501 verifies the UE subscription data for interworking of DS with ATSSS.

[0276] Step 7: SMF 7101 creates SM context and responds to the AMF 7001 by providing an SM Context ID through an Nsmf_PDUSession_CreateSMContext response message. If the request is rejected, then SMF 7101 sends reject message to AMF 7001 with the cause or reason for the rejection.

[0277] Step 8: SMF 7101 with PCF 7301 creates ATSSS rules for UE 3 and N4 rules for UPF 7201 by performing SM Policy Association Establishment procedure.

[0278] The new rules are created by managing DS and ATSSS rules (While the DS rule apply to the MA PDU Session with two 3GPP accesses for Dual Steer, the ATSSS rule apply to the MA PDU Session between 3GPP access and non-3GPP access for ATSSS.) in a unified manner for supporting DS and ATSSS interworking. The DS and ATSSS rules may be managed independently or derived one from another depending on the DS and ATSSS interworking agreement. SMF 7101 with PCF 7301 can generate both DS rule and ATSSS or unified DS-ATSSS rules for interworking of non-3GPP access with dual 3GPPP access in a unified way.

[0279] For example, at least one of SMF 7101 and PCF 7301 may generate ATSSS rules for ATSSS using 3GPP access and non-3GPP access in HPLMN.

[0280] Step 9: SMF 7101 sends N4 rules to UPF 7201 via N4 Session Establishment procedure.

[0281] Step 10: SMF 7101 sends an Namf_Communication_N1N2MessageTransfer message to AMF 7001 including the updated (or created) ATSSS rules for supporting access switch or transition from dual 3GPP accesses to ATSSS access.

[0282] Step 11: Upon receiving the updated ATSSS rules from the SMF 7101, AMF 7001 sends PDU Session Modification Accept message to UE 3 including the updated ATSSS rules.

[0283] Step 12: By executing Steps 4-11, UE 3 has established an N9 independent tunnel via non-3GPP access and switched the PDU Session association from dual 3GPP access to ATSSS access for splitting, steering, and switching the service traffic based on the updated ATSSS rules.

[0284] For example, in a case where the indicator in Step 4 indicates keeping the connection over SNPN access, the connection over SNPN may be kept. 　　For example, in a case where the indicator in Step 4 indicates releasing the connection over SNPN access, the network (e.g., HPLMN or SNPN / VPLMN) or UE 3 may perform a procedure for releasing the connection over SNPN.

[0285] For example, in a case where the indicator in Step 4 indicates keeping the connection over SNPN access, the updated ATSSS rules may indicate that the connection over SNPN is kept. For example, the updated ATSSS rules may indicate rules for ATSSS using 3GPP access in HPLMN, non-3GPP access in HPLMN and 3GPP access in SNPN.

[0286] For example, in a case where the indicator in Step 4 indicates releasing the connection over SNPN access, the updated ATSSS rules may indicate that the connection over SNPN is released. For example, the updated ATSSS rules may indicate rules for ATSSS using 3GPP access in HPLMN and non-3GPP access in HPLMN.

[0287] Variant 1 of Third example of the Third Aspect If UE 3 and network intent to use three legs (i.e., three user plane tunnels between UE and PSA UPF) to split, steer, and switch the traffic using two 3GPP accesses and one non-3GPP access, then UE 3 may perform PDU Session establishment procedure instead of PDU Session modification procedure and establish two UP tunnels via dual 3GPP access and one UP tunnel via non-3GPP access. SMF 7101 and PCF 7301 can define DS-ATSSS rule for both UE and PSA UPF such that the service traffic can be routed through three legs.

[0288] Fourth example of the Third Aspect 　　Fig. 13 illustrates an example in which the 5G system supports for UE 3 transitioning from dual 3GPP access to ATSSS access by updating the UE subscription data. 　　The detailed processes of the Fourth example of the Third Aspect are described below with reference to Fig. 13.

[0289] Step 1: UE 3 has registered with HPLMN via 3GPP 5G NR 501 access network and established a PDU Session.

[0290] Step 2: UE 3 has also registered with SNPN / VPLMN via 3GPP 5G NR 502 access network and established multi-access PDU Session for splitting, steering, and switching service traffic through dual 3GPP access. 　　For example, UE 3 may perform process(es) in First Aspect to register with SNPN / VPLMN and to establish the multi-access PDU Session.

[0291] Step 3: UE 3 subscription data in UDM 7501 is updated to allow DS interworking with ATSSS by network operator via OAM.

[0292] Step 4: Based on the update, UDM 7501 sends an Nudm_SDM_Notification message to AMF 7001 including an indicator that UE 3 is allowed to interworking with DS and ATSSS.

[0293] Step 5: Upon receiving the notification message from UDM 7501, AMF 7001 sends a DL Transport NAS message to UE 3 including the indicator that UE 3 is allowed to interworking with DS and ATSSS.

[0294] Step 6: As UE 3 is allowed to interworking with DS and ATSSS, UE 3 prefers to switch to HPLMN non-3GPP access via TNGF 503 from SNPN 3GPP 5G NR 502 access to maintain the service quality.

[0295] Step 7: Steps 4-9 in Fig. 11 take place.

[0296] Step 8. After successful registration procedure with non-3GPP access in Step 7, the UE 3 performs the PDU Session modification procedure as described in Steps 4-11 in Fig. 12 take place. 　　After Step 8 is completed, the UE 3 has the ATSSS access with 3GPP 5G NR 501 access network and non-3GPP access.

[0297] Fourth Aspect 　　This aspect discloses mechanisms for splitting and steering the service traffic across PLMN and SNPN access networks, and seamless mobility between PLMN and SNPN networks.

[0298] First example of the Fourth Aspect 　　Fig. 14 illustrates an example architecture in which UE 3 is served by SNPN and UE 3 may move in and out of the service area covered by SNPN.

[0299] Fig. 14 shows an architecture in which UE 3 is served by SNPN network. SNPN covers a small area and VPLMN covers a large area than SNPN. SNPN has a business service agreement with VPLMN, which allows SNPN subscribers to roam on VPLMN network when SNPN subscribers are outside of its own coverage footprint. Also, SNPN can offer simultaneous connection to UEs 3 for specific services to get a higher data rate connection by allowing their data traffic to use an extra NR connectivity link from VPLMN. Such functionality is assumed to be supported by both SNPN and VPLMN CNs, UEs 3 (of SNPN subscribers), and is associated with a set of traffic policies and conditions in which SNPN can control and provision services for its own subscribers.

[0300] When outside the coverage footprint of SNPN (but inside the coverage footprint of VPLMN), the SNPN subscribers roam on to the VPLMN network. As the SNPN subscriber moves in and out of the SNPN coverage area, SNPN can switch traffic between the two networks based on the network availability and business service agreement. When the SNPN subscriber enters into SNPN coverage area, the traffic can be switched from VPLMN connection to SNPN connection or traffic can be steered on both networks depending on the service type and subscription tier of the SNPN subscriber. The business service agreement between SNPN and VPLMN may allow for the seamless mobility of SNPN subscribers between SNPN and VPLMN networks.

[0301] Second example of the Fourth Aspect 　　Fig. 15 illustrates an example to support service traffic splitting and steering between SNPN and VPLMN networks when UE 3 is moving inside the VPLMN service area and covered by both SNPN and VPLMN.

[0302] The detailed processes of the Second example of the Fourth Aspect are described below with reference to Fig. 15.

[0303] Step 0a: SNPN and PLMN have business service agreement to support SNPN subscribers in an overlapped service area for specific services.

[0304] Step 0b: UE 3 is moving inside the VPLMN network and covered by both SNPN and VPLMN networks. 　　For example, UE 3 is in a coverage area of SNPN and a coverage area of VPLMN.

[0305] Step 1: UE 3 has registered with both SNPN and VPLMN. 　　For example, UE 3 may perform process(es) in Second Aspect to register with SNPN and VPLMN.

[0306] Step 2: UE 3 has established a PDU Session with SNPN over 3GPP NG-RAN access network 501 as specified in clause 4.3.2.2.2.2 in NPL 4.

[0307] Step 3: UE 3 sends an PDU Session establishment request message to VPLMN AMF 7002 over VPLMN RAN 502 for establishing multi-access PDU Session. The PDU Session establishment request message may include support for dual access via SNPN, supported DS-ATSSS functionalities and modes, PDU Session ID, and UE ID. The parameters in the PDU Session establishment request messages may be expressed as PDU Session establishment request parameters.

[0308] The support for dual access via SNPN may indicate that UE 3 supports the DS. 　　The support for dual access via SNPN may indicate that UE 3 supports the DS which one of the accesses is SNPN. 　　The support for dual access via SNPN may indicate that UE 3 supports the DS that one of the 3GPP accesses is via SNPN.

[0309] The support for dual access via SNPN may indicate that UE 3 supports the DS using at least one 3GPP access in SNPN. 　　The UE 3 supported DS-ATSSS functionalities and modes may indicate that UE 3 supports DS-ATSSS functionalities and modes. 　　The UE 3 supported DS-ATSSS functionalities and modes may indicate that UE 3 supports ATSSS functionalities and modes for the DS (e.g., for the DS via VPLMN and SNPN).

[0310] Step 4: VPLMN AMF 7002 sends an Nsmf_PDUSession_Create_SMContext request message to VPLMN SMF 7102 (e.g., V-SMF 7102 in Fig. 14) including the HPLMN SMF ID (e.g., ID of SNPN SMF 7101) and PDU Session establishment request parameters received in Step 3. VPLMN SMF 7102 sends an Nsmf_PDUSession_Create_SMContext response message to AMF 7002 and may share SM context ID.

[0311] Step 5: VPLMN SMF 7102 sends an Nsmf_PDUSession_Create request message to SNPN SMF 7101 (e.g., H-SMF 7101 in Fig. 14) including the support for dual access via SNPN, supported DS-ATSSS functionalities and modes, PDU Session ID, and UE ID.

[0312] Step 6: SMF 7101 with UDM 75 verifies the UE subscription data to allow for splitting and steering the service traffic across SNPN and VPLMN networks.

[0313] Step 7: SMF 7101 with PCF 7301 (e.g., H-PCF 7301 in Fig. 14) creates DS-ATSSS rules for UE 3 and N4 rules for UPF 7201 (e.g., H-UPF 7201 in Fig. 14) by performing SM Policy Association Establishment procedure. The rules may be used to split the service traffic across SNPN and VPLMN networks.

[0314] Step 8: SMF 7101 sends DS-N4 rules (e.g., the N4 rules) to UPF 7201 via N4 Session Establishment procedure.

[0315] Step 9: SNPN SMF 7101 sends an Nsmf_PDUSession_Create response message to VPLMN SMF 7102 including DS-ATSSS rules, H-UPF ID (e.g., ID of SNPN UPF 7201), and N9 tunnel information.

[0316] Step 10: SMF 7102 sends the H-UPF ID and N9 tunnel information to UPF 7202 (e.g., V-UPF 7202 in Fig. 14) via N4 Session Establishment procedure.

[0317] Step 11: SMF 7102 sends an Namf_Communication_N1N2MessageTransfer message to AMF 7002 including the DS-ATSSS rules.

[0318] Step 12: Upon receiving the DS-ATSSS rules from SMF 7102, AMF 7002 sends PDU Session Establishment Accept message to UE 3 including the DS-ATSSS rules.

[0319] Step 13: By executing Steps 3-12, UE 3 has established an N9 independent tunnel for MA PDU Session via VPLMN for splitting and steering the traffic through dual 3GPP access based on the received DS-ATSSS rules. 　　For example, UE 3 may use the DS-ATSSS rules for ATSSS via one 3GPP access in SNPN and another 3GPP access in VPLMN.

[0320] Third example of the Fourth Aspect 　　Fig. 16 illustrates an example to support service traffic splitting and steering between SNPN and VPLMN networks when UE 3 is moving out of the SNPN service area and covered by VPLMN network. 　　The detailed processes of the Second example of the Fourth Aspect are described below with reference to Fig. 16.

[0321] Step 0a: SNPN and PLMN have business service agreement to support SNPN subscribers in an overlapped service area for specific services.

[0322] Step 0b: UE 3 is covered by both SNPN and VPLMN networks. 　　For example, UE 3 is in a coverage area of SNPN and a coverage area of VPLMN.

[0323] Step 1: UE 3 has registered with both SNPN and PLMN (e.g., VPLMN) and established MA PDU Session to split and steer the traffic through dual 3GPP access as shown in Fig. 15. 　　For example, UE 3 may perform process(es) in Fig. 15 to register with both SNPN and PLMN (e.g.., VPLMN) and to established MA PDU Session.

[0324] Step 2: After the MA PDU session is established, UE 3 performs the detection of availability or unavailability of the access networks and report them to the Performance Management Function (PMF) in H-UPF (e.g., SNPN UPF 7201) as per DS-ATSSS rules.

[0325] Step 3: UE 3 moves out of SNPN coverage area and initiates PDU Session modification procedure to perform QoS update trigger by reporting to PMF in SNPN UPF 7201 about the access availability / unavailability.

[0326] For example, UE 3 may report the access unavailability of SNPN to PMF in SNPN UPF 7201. 　　For example, UE 3 may report, via VPLMN, the access unavailability of SNPN to PMF in SNPN UPF 7201.

[0327] Step 4: UPF 7201 sends an access availability / unavailability report to SMF 7101.

[0328] Step 5: SMF 7101 with PCF 7301 creates the updated DS-ATSSS rules for UE 3 and N4 rules for UPF 7201 by performing SM Policy Association update procedure based on the received the access availability / unavailability report from UPF 7201. The rules may be used to switch the service traffic entirely from SNPN leg to VPLMN leg.

[0329] Step 6: SMF 7101 sends DS-N4 rules (e.g., the N4 rules) to UPF 7201 via N4 Session Modification procedure. For example, the DS-N4 rules indicates to the UPF 7201 to tear down the N9 connection with the UPF 7202.

[0330] Step 7: SNPN SMF 7101 sends an Nsmf_PDUSession_Update request message to VPLMN SMF 7102 including SM Release PDU Session Command message, the updated DS-ATSSS rules, H-UPF ID (e.g., ID of SNPN UPF 7201), and N9 tunnel information.

[0331] Step 8: SMF 7102 sends the H-UPF ID and N9 tunnel information to UPF 7202 via N4 Session Release procedure.

[0332] Step 9: SMF 7102 sends an Namf_Communication_N1N2MessageTransfer message to AMF 7002 including N1 SM container and the updated DS-ATSSS rules. The N1 SM container contains the PDU Session Release Command message.

[0333] Step 10: Upon receiving the Namf_Communication_N1N2MessageTransfer message from SMF 7102, AMF 7002 sends Release Command message to UE 3 including the updated DS-ATSSS rules.

[0334] Step 11: By executing Steps 3-10, UE 3 has switched from MA PDU Session via dual 3GPP access to a single VPLMN 3GPP access PDU Session due to unavailability of SNPN 3GPP access using the received DS-ATSSS rules.

[0335] For example, in a case where UE 3 reports unavailability of SNPN 3GPP access in Step 3, the DS-ATSSS rules may be updated for switching the traffic from SNPN to VPLMN. In other words, in this case, UE 3 may use the DS-ATSSS rules for handling the traffic so as to switch from SNPN to VPLMN (e.g., UE 3 may send the traffic via VPLMN by using the DS-ATSSS rules).

[0336] For example, UE 3 may report unavailability of one 3GPP access of DS (e.g., one 3GPP access in VPLMN or SNPN). In this case, the DS-ATSSS rules may be updated for switching the traffic from the one 3GPP access to another 3GPP access of DS (e.g., in a case where the one 3GPP access is in VPLMN, the another 3GPP access is in SNPN. In a case where the one 3GPP access is in SNPN, the another 3GPP access is in VPLMN).

[0337] Fourth example of the Fourth Aspect 　　Fig. 17 illustrates an example to support seamless mobility between SNPN and VPLMN networks when UE is moving in and out of the SNPN and VPLMN networks. 　　The detailed processes of the Second example of the Fourth Aspect are described below with reference to Fig. 17.

[0338] Step 0a: SNPN and PLMN have business service agreement to support SNPN subscribers in an overlapped service area for specific services.

[0339] Step 0b: UE 3 is covered by both SNPN and VPLMN networks. 　　For example, UE 3 is in a coverage area of SNPN and a coverage area of VPLMN.

[0340] Step 1: UE 3 has registered with both SNPN and PLMN (e.g., VPLMN) and established MA PDU Session to execute active-standby mode for performing seamless mobility when UE is moving in and outside of coverage of area of SNPN and VPLMN networks. Based on the business service agreement between SNPN and VPLMN networks, UE 3 connects to VPLMN when UE 3 is outside the coverage area of SNPN and UE 3 connects back to SNPN (i.e., home network) when UE is within the coverage area of SNPN.

[0341] For example, UE 3 may perform process(es) in Fig. 15 to register with both SNPN and PLMN (e.g.., VPLMN) and to established MA PDU Session.

[0342] Step 2: After the MA PDU session is established and active-standby steering mode is activated, UE 3 performs the detection of availability or unavailability of the access networks and report them to the Performance Management Function (PMF) in H-UPF (e.g., SNPN UPF 7201) as per DS-ATSSS rules.

[0343] Step 3: UE 3 may move in or out of SNPN coverage area and initiates PDU Session modification procedure to perform QoS update trigger by reporting to PMF in SNPN UPF 7201 about the access availability / unavailability.

[0344] For example, UE 3 may report, via VPLMN, the access unavailability of SNPN to PMF in SNPN UPF 7201. 　　For example, UE 3 may report, via SNPN, the access unavailability of VPLMN to PMF in SNPN UPF 7201.

[0345] Step 4: UPF 7201 sends an access availability / unavailability report to SMF 7101.

[0346] Step 5: SMF 7101 with PCF 7301 creates the updated DS-ATSSS rules for UE 3 and N4 rules for UPF 7201 by performing SM Policy Association Update procedure based on the received the access availability / unavailability report from UPF 7201. The rules may be used to switch the service traffic entirely from SNPN leg to VPLMN leg and vice-versa.

[0347] Step 6: SMF 7101 sends DS-N4 rules (e.g., the N4 rules) to UPF 7201 via N4 Session Modification procedure. 　　The DS-N4 rules (e.g., the N4 rules) may be N4 rules for DS.

[0348] Step 7: SNPN SMF 7101 sends an Nsmf_PDUSession_Update Request message to VPLMN SMF 7102 including SM PDU Session Modification Command message, the updated DS-ATSSS rules, H-UPF ID (e.g., ID of SNPN UPF 7201), and N9 tunnel information.

[0349] Step 8: SMF 7102 sends the H-UPF ID and N9 tunnel information to UPF 7202 via N4 Session Modification procedure.

[0350] Step 9: SMF 7102 sends an Namf_Communication_N1N2MessageTransfer message to AMF 7002 including N1 SM container and the updated DS-ATSSS rules. The N1 SM container contains SM PDU Session Modification Command message.

[0351] Step 10: Upon receiving the Namf_Communication_N1N2MessageTransfer message from SMF 7102, AMF 7002 sends PDU Session Modification Command message to UE 3 including the updated DS-ATSSS rules.

[0352] Step 11: By executing Steps 3-10, UE 3 has seamlessly switched the traffic from SNPN 3GPP access to VPLMN 3GPP access and vice-versa due to availability / unavailability of SNPN 3GPP access or VPLMN 3GPP access using the received DS-ATSSS rules.

[0353] For example, UE 3 may use the DS-ATSSS rules for ATSSS via one 3GPP access in VPLMN. 　　For example, UE 3 may use the DS-ATSSS rules for ATSSS using one 3GPP access in VPLMN. 　　The DS-ATSSS rules may be used for ATSSS using or via one 3GPP access in VPLMN.

[0354] In a case where UE 3 moves out of VPLMN coverage are in Step 3, UE 3 may report, via SNPN, unavailability of 3GPP access in VPLMN. In this case, the DS-ATSSS rules may be updated for switching the traffic from VPLMN to SNPN. In other words, in this case, UE 3 may use the DS-ATSSS rules for handling the traffic so as to switch from VPLMN to SNPN (e.g., UE 3 may send the traffic via SNPN by using the DS-ATSSS rules).

[0355] Fifth Aspect 　　This aspect discloses mechanisms for UE switching between dual 3GPP accesses across PLMN and SNPN networks such that UE can switch from dual 3GPP access connections from one network to another network based on the availability of 3GPP access networks. The available 3GPP access networks for dual 3GPP access switching include both terrestrial networks (e.g., NG-RAN, E-UTRAN) and non-terrestrial networks (e.g., GEO-NR, LEO-NR). The UE may also connect to more than two networks (e.g., HPLMN and 2 VPLMNs).

[0356] First example of the Fifth Aspect 　　Fig. 18 illustrates an example architecture in which UE 3 switches between dual 3GPP accesses across HPLMN and SNPN networks based on the availability of access networks.

[0357] Fig. 18 shows an architecture in which UE 3 switches between dual 3GPP accesses across HPLMN and SNPN networks. Initially, UE 3 may have dual 3GPP access connections by connecting to two networks (one from HPLMN and other from SNPN). Later, UE 3 may switch dual 3GPP access connections from two networks to a single network (both 3GPP connections from the single network (e.g., HPLMN)) based on the availability and signal strength of access networks. In addition, initially, UE 3 may have dual 3GPP access connections by connecting to single network (both 3GPP connections from the single network (e.g., HPLMN)). Later, UE 3 may switch dual 3GPP access connections from single network to two networks (one from HPLMN and other from SNPN) based on the availability and signal strength of access networks.

[0358] Similar to Inter-PLMN UP Security (IPUPS), PLMN-SNPN UP Security (PSUPS) is required for securing the communication over N9 tunnel. It is assumed that the HPLMN subscription is used to access both networks, data traffic is anchored in the HPLMN and a proper business agreement is in place among the two network operators, including specific traffic routing policies, e.g., based on geographical location, subscription, traffic type. In Fig. 18, roaming interfaces highlighted in bold lines (e.g., N8 and N16) are new connections between HPLMN and SNPN. Currently, they do not exist as SNPN operates independently and does not have relation with PLMN. As these roaming interfaces are already defined for inter-PLMN roaming scenarios, the same functionalities can be utilized for PLMN-SNPN roaming as well.

[0359] Variant 1 of First example of the Fifth Aspect 　　In Fig. 18, the visited network is considered as an SNPN for example. In another example, the visited network may be VPLMN and the inter-PLMN home-routed roaming scenario may be considered for traffic access splitting, steering, and switching between dual 3GPP accesses.

[0360] Variant 2 of First example of the Fifth Aspect 　　In Fig. 18, both 3GPP access networks (e.g., 5G NTN RAN and TN RAN) are managed by the HPLMN for example. In another example, both terrestrial and non-terrestrial 3GPP access networks may be managed by a visiting network (e.g., SNPN and VPLMN).

[0361] Variant 3 of First example of the Fifth Aspect 　　In one example, UE may have three access network connections (e.g., three 3GPP accesses) such that user plane traffic can be routed through three legs, i.e., via three independent user plane tunnels between UE and PSA UPF and anchored by HPLMN UPF.

[0362] Second example of the Fifth Aspect 　　Fig. 19 illustrates an example of interworking of dual 3GPP access and ATSSS access for UE 3 to switch from one access to another access across HPLMN and SNPN / VPLMN networks.

[0363] The detailed processes of the Second example of the Fifth Aspect are described below with reference to Fig. 19.

[0364] Step 1: UE 3 has registered with HPLMN via 3GPP NTN RAN 501 access network (e.g., via 3GPP access in the NTN) and established a PDU Session.

[0365] Step 2: UE 3 has also registered with HPLMN via 3GPP TN RAN 503 access network and established multi-access PDU Session for splitting, steering, and switching service traffic through dual 3GPP access.

[0366] Step 3: UE 3 detects service degradation or low signal strength over 3GPP TN RAN 502 access link and availability of 3GPP NG-RAN access network with a good signal strength in SNPN, and triggers for access switching between dual 3GPP accesses from a single network to two networks.

[0367] Step 4: UE 3 sends Registration Request message to AMF 7002 via a newly available 3GPP NG-RAN access network 502 in SNPN. The Registration Request message may include support for dual 3GPP access via SNPN, Registration type as access switch, and support for switching between dual 3GPP accesses.

[0368] The support for dual 3GPP access via SNPN may be expressed as support for dual access via SNPN. 　　The support for switching between dual 3GPP accesses may indicate that UE 3 supports switching between dual 3GPP accesses.

[0369] The support for switching between dual 3GPP accesses may indicate that UE 3 supports switching between combination of one 3GPP access in HPLMN and another 3GPP access in HPLMN, and combination of 3GPP access in HPLMN and 3GPP access in SNPN / VPLMN.

[0370] Step 5: SNPN AMF 7002 sends an Nudm_UECM_Registration_Request message to UDM 75 including the support for dual 3GPP access via SNPN, Registration type as access switch, and support for switching between dual 3GPP accesses.

[0371] Step 6: UDM 75 verifies the UE subscription data for switching between dual 3GPP accesses.

[0372] Step 7: UDM 75 sends an Nudm_UECM_Registration Response message to AMF 7002 including the indication that switching between dual 3GPP accesses is allowed for UE 3 and H-SMF ID (e.g., ID of HPLMN SMF 7101).

[0373] Step 8: SNPN AMF 7002 sends Registration accept message to UE 3 including the indication that switching between dual 3GPP accesses is allowed for UE 3. 　　For example, after Step 8, UE 3 may be registered with HPLMN via one 3GPP access in the NTN and with SNPN via another 3GPP access.

[0374] In a case where UE 3 detects service degradation or low signal strength over 3GPP NTN RAN 501 access link and availability of 3GPP NG-RAN access network with a good signal strength in SNPN, UE 3 may perform the process(es) in Step 4. Then, the process(es) in Steps 5 to 8, and UE 3 may be registered with HPLMN via one 3GPP access in the TN and with SNPN via another 3GPP access.

[0375] Variant 1 of Second example of the Fifth Aspect 　　If UE 3 and network intent to use three legs (i.e., three user plane tunnels between UE and PSA UPF) to split, steer, and switch the traffic using three 3GPP accesses, then UE 3 may indicate the Registration type as triple 3GPP access in the Registration procedure.

[0376] Third example of the Fifth Aspect 　　Fig. 20 illustrates an example for PDU Session modification for supporting UE 3 transitioning from dual 3GPP access to ATSSS access across HPLMN and SNPN / VPLMN networks. 　　The detailed processes of the Third example of the Fifth Aspect are described below with reference to Fig. 20.

[0377] Step 1: UE 3 has registered with both 3GPP NTN and 3GPP TN RAN in HPLMN and established a multi-access PDU Session for steering the service traffic through dual 3GPP accesses.

[0378] Step 2: UE 3 has detected service degradation or low signal strength over 3GPP TN RAN 503 access link in HPLMN network and thus registered over 3GPP 5G NR 502 in SNPN to initiate access switching between dual 3GPP accesses for better quality of service. 　　For example, UE 3 may perform the process(es) in Figure19 to register with SNPN via 3GPP access.

[0379] Step 3: UE 3 sends PDU Session modification request message to SNPN AMF 7002 including the support for dual access via SNPN, support for switching between dual 3GPP accesses, PDU Session ID, HPLMN TN RAN ID, and indicator to keep or release the connection over the HPLMN TN RAN. The HPLMN TN RAN ID indicates that UE is willing to switch from the HPLMN TN RAN access 503 to alternative access available for the UE 3.

[0380] The support for dual access via SNPN may indicate that UE 3 supports the DS. 　　The support for dual access via SNPN may indicate that UE 3 supports the DS which one of the accesses is SNPN. 　　The support for dual access via SNPN may indicate that UE 3 supports the DS that one of the 3GPP accesses is via SNPN.

[0381] The support for dual access via SNPN may indicate that UE 3 supports the DS using at least one 3GPP access in SNPN. 　　The support for switching between dual 3GPP accesses may indicate that UE 3 supports switching between dual 3GPP accesses.

[0382] The support for switching between dual 3GPP accesses may indicate that UE 3 supports switching between combination of one 3GPP access in HPLMN and another 3GPP access in HPLMN, and combination of 3GPP access in HPLMN and 3GPP access in SNPN / VPLMN.

[0383] The indicator to keep or release the connection over the HPLMN TN RAN may indicate that UE 3's intention for keeping or releasing the connection over the HPLMN TN RAN (e.g., over 3GPP access in TN of HPLMN).

[0384] In a case where the indicator which is set to keep, the indicator may indicate that UE 3 requests to keep the connection over the HPLMN TN RAN. 　　In a case where the indicator which is set to release, the indicator may indicate that UE 3 requests to release the connection over the HPLMN TN RAN. 　　The indicator is transferred to the SMF 7101 in the HPLMN via the SMF 7102 in the SNPN and reflected to the process at Step 7 in the SMF 7101 in the HPLMN.

[0385] Step 4: SNPN AMF 7002 sends an Nsmf_PDUSession_Create_SMContext request message to SNPN SMF 7102 including the HPLMN SMF ID and the information elements received from the UE 3 in Step 3 for PDU Session modification. SNPN SMF 7102 sends an Nsmf_PDUSession_Create_SMContext response message to AMF 7002 and may share SM context ID.

[0386] Step 5: SNPN SMF 7102 sends an Nsmf_PDUSession_Create request to HPLMN SMF 7101 including the information elements received from AMF 7002 in Step 4 for PDU Session modification.

[0387] Step 6: Upon receiving the request from SNPN SMF 7102, the HPLMN SMF 7101 verifies with UDM 75 whether the UE 3 is allowed for switching between dual 3GPP accesses using an SNPN 3GPP access.

[0388] Step 7: SMF 7101 with PCF 7301 creates the updated DS-ATSSS rules for UE 3 and the updated DS-N4 rules for UPF 7201 by performing SM Policy Association Update procedure. The new DS rules are created to support the switching between dual 3GPP accesses.

[0389] Step 8: SMF 7101 sends the updated DS-N4 rules to UPF 7201 via N4 Session Modification procedure.

[0390] Step 9: HPLMN SMF 7101 sends an Nsmf_PDUSession_Update Request message to SNPN SMF 7102 including SM PDU Session Modification Command message, the updated DS-ATSSS rules, H-UPF ID (e.g., ID of UPF 7201), and N9 tunnel information.

[0391] Step 10: SMF 7102 sends the H-UPF ID and N9 tunnel information to UPF 7202 via N4 Session Modification procedure.

[0392] Step 11: SMF 7102 sends an Namf_Communication_N1N2MessageTransfer message to AMF 7002 including N1 SM container and the updated DS-ATSSS rules. The N1 SM container include SM PDU Session Modification Command message.

[0393] Step 12: Upon receiving the Namf_Communication_N1N2MessageTransfer message from SMF 7102, AMF 7002 sends PDU Session Modification Command message to UE 3 including the updated DS-ATSSS rules.

[0394] Step 13: By executing Steps 3-12, UE 3 first has established an independent N9 tunnel for the MA PDU Session through 3GPP access in SNPN and then released or kept the connection over 3GPP TN RAN access in HPLMN based on the received DS-ATSSS rules.

[0395] For example, UE 3 may use the DS-ATSSS rules for ATSSS via one 3GPP access in SNPN. 　　For example, UE 3 may use the DS-ATSSS rules for ATSSS using one 3GPP access in SNPN. 　　The DS-ATSSS rules may be used for ATSSS using or via one 3GPP access in SNPN.

[0396] For example, in a case where the indicator in Step 3 indicates keeping the connection over the HPLMN TN RAN, the connection over the HPLMN TN RAN may be kept. 　　For example, in a case where the indicator in Step 3 indicates releasing the connection over the HPLMN TN RAN, the network (e.g., HPLMN or SNPN) or UE 3 may perform a procedure for releasing the connection over the HPLMN TN RAN.

[0397] For example, in a case where the indicator in Step 3 indicates keeping the connection over the HPLMN TN RAN, the DS-ATSSS rules may indicate that the connection over the HPLMN TN RAN is kept. In this case, the DS-ATSSS rules may indicate the rules for ATSSS via or using at least one of the HPLMN NTN RAN (e.g., 3GPP access in NTN of HPLMN), the HPLMN TN RAN (e.g., 3GPP access in TN of HPLMN) and the SNPN RAN (e.g., 3GPP access in SNPN).

[0398] For example, in a case where the indicator in Step 3 indicates releasing the connection over the HPLMN TN RAN, the DS-ATSSS rules may indicate that the connection over SNPN is released. In this case, the DS-ATSSS rules may indicate the rules for ATSSS via or using the HPLMN NTN RAN (e.g., 3GPP access in NTN of HPLMN) and the SNPN RAN (e.g., 3GPP access in SNPN).

[0399] Variant 1 of Third example of the Fifth Aspect 　　If UE 3 and network intent to use three legs (i.e., three user plane tunnels between UE and PSA UPF) to split, steer, and switch the traffic using two 3GPP accesses and one non-3GPP access, then UE 3 may perform PDU Session establishment procedure instead of PDU Session modification procedure and establish two UP tunnels via dual 3GPP access and one UP tunnel via non-3GPP access. SMF 7101 and PCF 7301 can define DS-ATSSS rule for both UE and PSA UPF such that the service traffic can be routed through three legs.

[0400] Fourth example of the Fifth Aspect 　　Fig. 21 illustrates an example in which the 5G system supports for UE 3 switching between 3GPP dual accesses by updating the UE 3 subscription data. 　　The detailed processes of the Fourth example of the Fifth Aspect are described below with reference to Fig. 21.

[0401] Step 1: UE 3 has registered with HPLMN via 3GPP NTN RAN 501 and established a PDU Session.

[0402] Step 2: UE 3 has also registered with HPLMN via 3GPP TN RAN 503 and established multi-access PDU Session for splitting, steering, and switching service traffic through dual 3GPP access.

[0403] Step 3: UE 3 subscription data in UDM 75 is updated to allow UE switching between dual 3GPP accesses by network operator via OAM.

[0404] Step 4: Based on the update, UDM 75 sends an Nudm_SDM_Notification message to SNPN AMF 7002 including an indicator that UE is allowed for switching between dual 3GPP accesses.

[0405] Step 5: Upon receiving the notification message from UDM 75, SNPN AMF 7002 sends a DL Transport NAS message to UE 3 by including the indicator that UE is allowed to perform switching between dual 3GPP accesses.

[0406] Step 6: As UE 3 is allowed to perform switching between dual 3GPP accesses, UE 3 prefers to switch to 3GPP 5G NR 502 access network in SNPN from 3GPP TN RAN 503 to maintain the service quality.

[0407] Step 7: Steps 4-9 in Fig. 19 take place with AMF 7001 in HPLMN (e.g., AMF 2 in Fig. 21) that is connected with the HPLMN 3GPP RAN 503 instead of AMF 7002.

[0408] Step 8. After successful registration procedure with HPLMN 3GPP RAN 503 in Step 7, the UE 3 performs the PDU Session modification procedure as described in Steps 4-11 in Fig. 12 take place with the AMF 7001 in HPLMN (e.g., AMF 2 in Fig. 21) that is connected with the HPLMN 3GPP RAN 503 instead of AMF 7002.

[0409] After Step 8 is completed, the UE 3 has the dual 3GPP accesses with 3GPP NTN RAN 501 and 3GPP TN RAN 503.

[0410] System overview 　　Fig. 22 schematically illustrates a telecommunication system 1 for a mobile (cellular or wireless) to which the above aspects are applicable.

[0411] 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.

[0412] 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).

[0413] 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.

[0414] 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'.

[0415] 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.

[0416] 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).

[0417] 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).

[0418] 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).

[0419] 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).

[0420] 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.

[0421] 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.

[0422] 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.

[0423] 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.

[0424] 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.

[0425] For example, the following messages are communicated over the RRC layer to support AS signaling. ●　　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.

[0426] ●　　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

[0427] ●　　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

[0428] 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.

[0429] ●　　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.

[0430] ●　　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.

[0431] ●　　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.

[0432] ●　　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.

[0433] ●　　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.

[0434] ●　　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.

[0435] ●　　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.

[0436] ●　　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.

[0437] ●　　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.

[0438] ●　　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.

[0439] ●　　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.

[0440] ●　　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.

[0441] ●　　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.

[0442] User equipment (UE) 　　Fig. 23 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.

[0443] 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).

[0444] 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.).

[0445] 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.).

[0446] 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.).

[0447] 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.).

[0448] 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.).

[0449] 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. 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)).

[0450] 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.

[0451] 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.

[0452] 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.

[0453] 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.

[0454] 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).

[0455] 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).

[0456] (R)AN node 　　Fig. 24 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.

[0457] 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.

[0458] 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.

[0459] 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).

[0460] The RAN in this disclosure may have same components to the (R)AN node 5. The (R)AN node 5 may be expressed as a RAN node, RAN, (R)AN etc. 　　The TNGF or TWIF may have same components to the (R)AN node 5.

[0461] System overview of (R)AN node 5 based on O-RAN architecture 　　Fig. 25 schematically illustrates a (R)AN node 5 based on O-RAN architecture to which the (R)AN node 5 aspects are applicable.

[0462] 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).

[0463] 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).

[0464] 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 (e.g., the Network Relay UE 300) 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.

[0465] Radio Unit (RU) 　　Fig. 26 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.

[0466] 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 (e.g., the Network Relay UE 300)), and in particular, relating to MAC layer and RLC layer.

[0467] 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.

[0468] 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).

[0469] 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.

[0470] Distributed Unit (DU) 　　Fig. 27 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.

[0471] 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).

[0472] 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.

[0473] Centralized Unit (CU) 　　Fig. 28 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.

[0474] 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).

[0475] 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.

[0476] AMF 　　Fig. 29 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 (e.g., the Network Relay UE 300 and 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).

[0477] 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). 　　The AMF in this disclosure may have same components to the AMF 70.

[0478] SMF 　　Fig. 30 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 (e.g., the Network Relay UE 300 and 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).

[0479] 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). 　　The SMF in this disclosure may have same components to the SMF 71.

[0480] UPF 　　Fig. 31 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 (e.g., the Network Relay UE 300 and 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).

[0481] 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). 　　The UPF in this disclosure may have same components to the UPF 72.

[0482] PCF 　　Fig. 32 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 (e.g., the Network Relay UE 300 and 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).

[0483] 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). 　　The PCF in this disclosure may have same components to the PCF 73.

[0484] NWDAF 　　Fig. 33 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).

[0485] 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).

[0486] UDM 　　Fig. 34 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 (e.g., the Network Relay UE 300 and 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).

[0487] 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).

[0488] NSSF 　　Fig. 35 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 signalling messages (e.g. a HTTP restful methods based on the service based interfaces) relating to mobility management procedures (for the UE 3).

[0489] 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). 　　NSACF 　　Fig. 36 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).

[0490] 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). 　　AUSF 　　Fig. 37 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).

[0491] 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). 　　AF 　　Fig. 38 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 (e.g., the Network Relay UE 300 and 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).

[0492] 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). 　　The AF in this disclosure may have same components to the AF 201.

[0493] NEF 　　Fig. 39 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 AMF 70) via a network interface 792. A controller 793 controls the operation of the NEF 79 in accordance with the software stored in a memory 794. The 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 (e.g. a removable memory 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 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).

[0494] 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).

[0495] 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.

[0496] 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.

[0497] 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.

[0498] 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.

[0499] 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.

[0500] 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.

[0501] 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.

[0502] 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.

[0503] 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.

[0504] 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.

[0505] 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).

[0506] This application is based upon and claims the benefit of priority from Indian Patent Application No. 202311065586, filed on September 29, 2023, the disclosure of which is incorporated herein in its entirety by reference.

[0507] Supplementary notes 　　The whole or part of the example Aspects disclosed above can be described as, but not limited to, the following supplementary notes. 　　(First Supplementary notes) 　　　　(Supplementary note A1) 　　A user equipment (UE) comprising: 　　means for communicating with a communication apparatus; and 　　means for receiving information of stand-alone non-public network (SNPN) that is allowed the UE to access, in a case where the UE supports dual access using the SNPN. 　　　　(Supplementary note A2) 　　An access and mobility management function (AMF) comprising: 　　means for communicating with a user equipment (UE); and 　　means for sending information of stand-alone non-public network (SNPN) that is allowed the UE to access, in a case where the UE supports dual access using the SNPN. 　　　　(Supplementary note A3) 　　A user equipment (UE) comprising: 　　means for communicating with a communication apparatus; and 　　means for performing Registration procedure for dual access, 　　wherein the dual access uses stand-alone non-public network (SNPN) and home public land mobile network (HPLMN). 　　　　(Supplementary note A4) 　　An access and mobility management function (AMF) comprising: 　　means for communicating with a communication apparatus; and 　　means for performing Registration procedure for dual access, 　　wherein the dual access uses stand-alone non-public network (SNPN) and home public land mobile network (HPLMN). 　　　　(Supplementary note A5) 　　A user equipment (UE) comprising: 　　means for communicating with a communication apparatus; and 　　means for performing Protocol Data Unit (PDU) Session Establishment procedure for dual access, 　　wherein the dual access uses stand-alone non-public network (SNPN) and home public land mobile network (HPLMN). 　　　　(Supplementary note A6) 　　An access and mobility management function (AMF) comprising: 　　means for communicating with a communication apparatus; and 　　means for performing Protocol Data Unit (PDU) Session Establishment procedure for dual access, 　　wherein the dual access uses stand-alone non-public network (SNPN) and home public land mobile network (HPLMN). 　　　　(Supplementary note A7) 　　A user equipment (UE) comprising: 　　means for communicating with a communication apparatus; and 　　means for performing Registration procedure for dual access, 　　wherein the dual access uses stand-alone non-public network (SNPN) and visited public land mobile network (VPLMN). 　　　　(Supplementary note A8) 　　The user equipment according to Supplementary note A7, further comprising: 　　means for communicating with a communication apparatus; and 　　means for receiving dual steer priority information during the Registration procedure, in a case where the UE supports dual access using the SNPN. 　　　　(Supplementary note A9) 　　An access and mobility management function (AMF) comprising: 　　means for communicating with a communication apparatus; and 　　means for performing Registration procedure for dual access, 　　wherein the dual access uses stand-alone non-public network (SNPN) and visited public land mobile network (VPLMN). 　　　　(Supplementary note A10) 　　The access and mobility management function according to Supplementary note A9, further comprising: 　　means for communicating with a communication apparatus; and 　　means for receiving dual steer priority information during the Registration procedure, in a case where a user equipment supports dual access using the SNPN. 　　　　(Supplementary note A11) 　　A user equipment (UE) comprising: 　　means for communicating with communication apparatus; and 　　means for receiving DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and visited public land mobile network (VPLMN). 　　　　(Supplementary note A12) 　　An access and mobility management function (AMF) comprising: 　　means for communicating with a user equipment (UE); and 　　means for sending DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and visited public land mobile network (VPLMN). 　　　　(Supplementary note A13) 　　A user equipment (UE) comprising: 　　means for communicating with a communication apparatus; and 　　means for receiving information indicating that dual steer interworking with Access Traffic Steering, Switching, Splitting (ATSSS) is allowed for the UE, in a case where the UE is registered to home public land mobile network (HPLMN) and stand-alone non-public network (SNPN). 　　　　(Supplementary note A14) 　　An access and mobility management function (AMF) comprising: 　　means for communicating with a user equipment (UE); and 　　means for sending information indicating that dual steer interworking with Access Traffic Steering, Switching, Splitting (ATSSS) is allowed for the UE, in a case where the UE supports interworking of ATSSS with Dual Steer (DS). 　　　　(Supplementary note A15) 　　A method of a user equipment (UE) comprising: 　　communicating with a communication apparatus; and 　　receiving information of stand-alone non-public network (SNPN) that is allowed the UE to access, in a case where the UE supports dual access using the SNPN. 　　　　(Supplementary note A16) 　　A method of an access and mobility management function (AMF) comprising: 　　communicating with a user equipment (UE); and 　　sending information of stand-alone non-public network (SNPN) that is allowed the UE to access, in a case where the UE supports dual access using the SNPN. 　　　　(Supplementary note A17) 　　A method of a user equipment (UE) comprising: 　　communicating with a communication apparatus; and 　　performing Registration procedure for dual access, 　　wherein the dual access uses stand-alone non-public network (SNPN) and home public land mobile network (HPLMN). 　　　　(Supplementary note A18) 　　A method of an access and mobility management function (AMF) comprising: 　　communicating with a communication apparatus; and 　　performing Registration procedure for dual access, 　　wherein the dual access uses stand-alone non-public network (SNPN) and home public land mobile network (HPLMN). 　　　　(Supplementary note A19) 　　A method of a user equipment (UE) comprising: 　　communicating with a communication apparatus; and 　　performing Protocol Data Unit (PDU) Session Establishment procedure for dual access, 　　wherein the dual access uses stand-alone non-public network (SNPN) and home public land mobile network (HPLMN). 　　　　(Supplementary note A20) 　　A method of an access and mobility management function (AMF) comprising: 　　communicating with a communication apparatus; and 　　performing Protocol Data Unit (PDU) Session Establishment procedure for dual access, 　　wherein the dual access uses stand-alone non-public network (SNPN) and home public land mobile network (HPLMN). 　　　　(Supplementary note A21) 　　A method of a user equipment (UE) comprising: 　　communicating with a communication apparatus; and 　　performing Registration procedure for dual access, 　　wherein the dual access uses stand-alone non-public network (SNPN) and visited public land mobile network (VPLMN). 　　　　(Supplementary note A22) 　　The method according to Supplementary note A21, further comprising: 　　receiving dual steer priority information during the Registration procedure, in a case where the UE supports dual access using the SNPN. 　　　　(Supplementary note A23) 　　A method of an access and mobility management function (AMF) comprising: 　　communicating with a user equipment (UE); and 　　performing Registration procedure for dual access, 　　wherein the dual access uses stand-alone non-public network (SNPN) and visited public land mobile network (VPLMN). 　　　　(Supplementary note A24) 　　The method according to Supplementary note A23, further comprising: 　　receiving dual steer priority information during the Registration procedure, in a case where the UE supports dual access using the SNPN. 　　　　(Supplementary note A25) 　　A method of a user equipment (UE) comprising: 　　communicating with a communication apparatus; and 　　receiving DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and visited public land mobile network (VPLMN). 　　　　(Supplementary note A26) 　　A method of an access and mobility management function (AMF) comprising: 　　communicating with a user equipment (UE); and 　　sending DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and visited public land mobile network (VPLMN). 　　　　(Supplementary note A27) 　　A method of a user equipment (UE) comprising: 　　communicating with a communication apparatus; and 　　receiving information indicating that dual steer interworking with Access Traffic Steering, Switching, Splitting (ATSSS) is allowed for the UE, in a case where the UE is registered to home public land mobile network (HPLMN) and stand-alone non-public network (SNPN). 　　　　(Supplementary note A28) 　　A method of an access and mobility management function (AMF) comprising: 　　communicating with a user equipment (UE); and 　　sending information indicating that dual steer interworking with Access Traffic Steering, Switching, Splitting (ATSSS) is allowed for the UE, in a case where the UE supports interworking of ATSSS with Dual Steer (DS). 　　(Second Supplementary notes) 　　　　(Supplementary note B1) 　　A user equipment (UE) comprising: 　　means for communicating with a communication apparatus; and 　　means for receiving Access Traffic Steering, Switching, Splitting (ATSSS) rule, in a case of changing from dual access using home public land mobile network (HPLMN) and stand-alone non-public network (SNPN) to ATSSS using 3GPP access and non-3GPP access in the HPLMN. 　　　　(Supplementary note B2) 　　An access and mobility management function (AMF) comprising: 　　means for communicating with a user equipment (UE); and 　　means for sending Access Traffic Steering, Switching, Splitting (ATSSS) rule, in a case of changing from dual access using home public land mobile network (HPLMN) and stand-alone non-public network (SNPN) to ATSSS using 3GPP access and non-3GPP access in the HPLMN. 　　　　(Supplementary note B3) 　　A user equipment (UE) comprising: 　　means for communicating with a communication apparatus; and 　　means for receiving DS-ATSSS rule, in a case where the UE is in a coverage of visited public land mobile network (VPLMN) and stand-alone non-public network (SNPN) and the UE is registered to the VPLMN and the SNPN. 　　　　(Supplementary note B4) 　　A user equipment (UE) comprising: 　　means for communicating with a communication apparatus; and 　　means for receiving an indication that switching from dual 3GPP accesses via home public land mobile network (HPLMN) to dual 3GPP accesses via the HPLMN and stand-alone non-public network (SNPN) is allowed for the UE. 　　　　(Supplementary note B5) 　　An access and mobility management function (AMF) comprising: 　　means for communicating with a user equipment (UE); and 　　means for sending an indication that switching from dual 3GPP accesses via home public land mobile network (HPLMN) to dual 3GPP accesses via the HPLMN and stand-alone non-public network (SNPN) is allowed for the UE. 　　　　(Supplementary note B6) 　　A user equipment (UE) comprising: 　　means for communicating with a communication apparatus; and 　　means for receiving DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and home public land mobile network (HPLMN). 　　　　(Supplementary note B7) 　　An access and mobility management function (AMF) comprising: 　　means for communicating with a user equipment (UE); and 　　means for sending DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and home public land mobile network (HPLMN). 　　　　(Supplementary note B8) 　　A method of a user equipment (UE) comprising: 　　communicating with a communication apparatus; and 　　receiving Access Traffic Steering, Switching, Splitting (ATSSS) rule, in a case of changing from dual access using home public land mobile network (HPLMN) and stand-alone non-public network (SNPN) to ATSSS using 3GPP access and non-3GPP access in the HPLMN. 　　　　(Supplementary note B9) 　　A method of an access and mobility management function (AMF) comprising: 　　communicating with a user equipment (UE); and 　　sending Access Traffic Steering, Switching, Splitting (ATSSS) rule, in a case of changing from dual access using home public land mobile network (HPLMN) and stand-alone non-public network (SNPN) to ATSSS using 3GPP access and non-3GPP access in the HPLMN. 　　　　(Supplementary note B10) 　　A method of a user equipment (UE) comprising: 　　communicating with a communication apparatus; and 　　receiving DS-ATSSS rule, in a case where the UE is in a coverage of visited public land mobile network (VPLMN) and stand-alone non-public network (SNPN) and the UE is registered to the VPLMN and the SNPN. 　　　　(Supplementary note B11) 　　A method of a user equipment (UE) comprising: 　　communicating with a communication apparatus; and 　　receiving an indication that switching from dual 3GPP accesses via home public land mobile network (HPLMN) to dual 3GPP accesses via the HPLMN and stand-alone non-public network (SNPN) is allowed for the UE. 　　　　(Supplementary note B12) 　　A method of an access and mobility management function (AMF) comprising: 　　communicating with a user equipment (UE); and 　　sending an indication that switching from dual 3GPP accesses via home public land mobile network (HPLMN) to dual 3GPP accesses via the HPLMN and stand-alone non-public network (SNPN) is allowed for the UE. 　　　　(Supplementary note B13) 　　A method of a user equipment (UE) comprising: 　　communicating with a communication apparatus; and 　　receiving DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and home public land mobile network (HPLMN). 　　　　(Supplementary note B14) 　　A method of an access and mobility management function (AMF) comprising: 　　communicating with a user equipment (UE); and 　　sending DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and home public land mobile network (HPLMN).

[0508] 1　　TELECOMMUNICATION SYSTEM 3　　USER EQUIPMENT (UE) 5, 501-503　　(R)AN NODE 60　　RADIO UNIT (RU) 61　　DISTRIBUTED UNIT (DU) 62　　CENTRALIZED UNIT (CU) 7　　CORE NETWORK 70, 7001, 7002　　ACCESS AND MOBILITY MANAGEMENT FUNCTION (AMF) 71, 7101, 7102　　SESSION MANAGEMENT FUNCTION (SMF) 72, 7201, 7202　　USER PLANE FUNCTION (UPF) 73, 7301, 7302　　POLICY CONTROL FUNCTION (PCF) 74　　NETWORK DATA ANALYTICS FUNCTION (NWDAF) 75, 7501, 7502　　UNIFIED DATA MANAGEMENT (UDM) 76　　NETWORK SLICE SELECTION FUNCTION (NSSF) 77　　NETWORK SLICE ADMISSION CONTROL FUNCTION (NSACF) 78　　AUTHENTICATION SERVER FUNCTION (AUSF) 79　　NETWORK EXPOSURE FUNCTION (NEF) 20　　DATA NETWORK 201　　APPLICATION FUNCTION (AF) 31, 51, 601, 611, 621, 701, 711, 721, 731, 741, 751, 761, 771, 781, 791, 2011　　TRANSCEIVER CIRCUIT 32, 52, 602　　ANTENNA 53, 603, 612, 622, 702, 712, 722, 732, 742, 752, 762, 772, 782, 792, 2012　　NETWORK INTERFACE 33, 54, 604, 613, 623, 703, 713, 723, 733, 743, 753, 763, 773, 783, 793, 2013　　CONTROLLER 34　　USER INTERFACE 35　　UNIVERSAL SUBSCRIBER IDENTITY MODULE (USIM) 36, 55, 605, 614, 624, 704, 714, 724, 734, 744, 754, 764, 774, 784, 794, 2014　　MEMORY 361, 551, 6051, 6141, 6241, 7041, 7141, 7241, 7341, 7441, 7541, 7641, 7741, 7841, 7941, 20141　　OPERATING SYSTEM 362, 552, 6052, 6142, 6242, 7042, 7142, 7242, 7342, 7442, 7542, 7642, 7742, 7842, 7942, 20142　　COMMUNICATIONS CONTROL MODULE 3621, 5521, 60521, 61421, 62421, 70421, 71421, 72421, 73421, 74421, 75421, 76421, 77421, 78421, 79421, 201421　　TRANSCEIVER CONTROL MODULE

Claims

1. A user equipment (UE) comprising: 　　means for communicating with a communication apparatus; and 　　means for receiving Access Traffic Steering, Switching, Splitting (ATSSS) rule, in a case of changing from dual access using home public land mobile network (HPLMN) and stand-alone non-public network (SNPN) to ATSSS using 3GPP access and non-3GPP access in the HPLMN.

2. An access and mobility management function (AMF) comprising: 　　means for communicating with a user equipment (UE); and 　　means for sending Access Traffic Steering, Switching, Splitting (ATSSS) rule, in a case of changing from dual access using home public land mobile network (HPLMN) and stand-alone non-public network (SNPN) to ATSSS using 3GPP access and non-3GPP access in the HPLMN.

3. A user equipment (UE) comprising: 　　means for communicating with a communication apparatus; and 　　means for receiving DS-ATSSS rule, in a case where the UE is in a coverage of visited public land mobile network (VPLMN) and stand-alone non-public network (SNPN) and the UE is registered to the VPLMN and the SNPN.

4. A user equipment (UE) comprising: 　　means for communicating with a communication apparatus; and 　　means for receiving an indication that switching from dual 3GPP accesses via home public land mobile network (HPLMN) to dual 3GPP accesses via the HPLMN and stand-alone non-public network (SNPN) is allowed for the UE.

5. An access and mobility management function (AMF) comprising: 　　means for communicating with a user equipment (UE); and 　　means for sending an indication that switching from dual 3GPP accesses via home public land mobile network (HPLMN) to dual 3GPP accesses via the HPLMN and stand-alone non-public network (SNPN) is allowed for the UE.

6. A user equipment (UE) comprising: 　　means for communicating with a communication apparatus; and 　　means for receiving DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and home public land mobile network (HPLMN).

7. An access and mobility management function (AMF) comprising: 　　means for communicating with a user equipment (UE); and 　　means for sending DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and home public land mobile network (HPLMN).

8. A method of a user equipment (UE) comprising: 　　communicating with a communication apparatus; and 　　receiving Access Traffic Steering, Switching, Splitting (ATSSS) rule, in a case of changing from dual access using home public land mobile network (HPLMN) and stand-alone non-public network (SNPN) to ATSSS using 3GPP access and non-3GPP access in the HPLMN.

9. A method of an access and mobility management function (AMF) comprising: 　　communicating with a user equipment (UE); and 　　sending Access Traffic Steering, Switching, Splitting (ATSSS) rule, in a case of changing from dual access using home public land mobile network (HPLMN) and stand-alone non-public network (SNPN) to ATSSS using 3GPP access and non-3GPP access in the HPLMN.

10. A method of a user equipment (UE) comprising: 　　communicating with a communication apparatus; and 　　receiving DS-ATSSS rule, in a case where the UE is in a coverage of visited public land mobile network (VPLMN) and stand-alone non-public network (SNPN) and the UE is registered to the VPLMN and the SNPN.

11. A method of a user equipment (UE) comprising: 　　communicating with a communication apparatus; and 　　receiving an indication that switching from dual 3GPP accesses via home public land mobile network (HPLMN) to dual 3GPP accesses via the HPLMN and stand-alone non-public network (SNPN) is allowed for the UE.

12. A method of an access and mobility management function (AMF) comprising: 　　communicating with a user equipment (UE); and 　　sending an indication that switching from dual 3GPP accesses via home public land mobile network (HPLMN) to dual 3GPP accesses via the HPLMN and stand-alone non-public network (SNPN) is allowed for the UE.

13. A method of a user equipment (UE) comprising: 　　communicating with a communication apparatus; and 　　receiving DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and home public land mobile network (HPLMN).

14. A method of an access and mobility management function (AMF) comprising: 　　communicating with a user equipment (UE); and 　　sending DS-ATSSS rule, wherein the DS-ATSSS rule is used for dual access using stand-alone non-public network (SNPN) and home public land mobile network (HPLMN).

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