Accessing local services via a CAG cell

Abstract

Example embodiments of the present disclosure provide solutions for accessing local services via a Closed Access Group (CAG) cell In an example method, a terminal device receives, from an Access and Mobility management Function (AMF), a message indicating mapping information between one or more Data Network Names (DNNs) and one or more CAG IDs. The terminal device determines a DNN of the one or more DNNs based on the mapping information and a CAG ID supported by a cell of a base station that the terminal device accesses. The terminal device transmits, to the AMF and via the base station of the cell, a Protocol Data Unit (PDU) session establishment request including the determined DNN as a requested DNN

Description

ACCESSING LOCAL SERVICES VIA A CAG CELLFIELD

[0001] Example embodiments of the present disclosure generally relate to the field of communication, and in particular, to a terminal device, a base station, network devices, methods, apparatuses, and computer readable media for accessing local services via a Closed Access Group (CAG) cell.BACKGROUND

[0002] A communication network can be seen as a facility that enables communications between two or more communication devices, or provides communication devices access to a data network. A mobile or wireless communication network is one example of a communication network. Such communication networks operate in accordance with standards, such as those promulgated by 3 GPP (Third Generation Partnership Project) or ETSI (European Telecommunications Standards Institute). Examples of such standards include the so-called 5G (5th Generation) standard or other standards promulgated by 3GPP.SUMMARY

[0003] In general, embodiments of the present disclosure provide solutions for accessing local services via a Closed Access Group (CAG) cell.

[0004] In a first aspect, there is provided terminal device comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to: receive, from an Access and Mobility management Function (AMF), a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); determine a DNN of the one or more DNNs based on the mapping information and a CAG ID supported by a cell of a base station that the terminal device accesses; and transmit, to the AMF and via the base station of the cell, a Protocol Data Unit (PDU) session establishment request including the determined DNN as a requested DNN.

[0005] In a second aspect, there is provided a network device comprising an Access and Mobility management Function (AMF), the network device comprising: at least oneprocessor; and at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to: transmit, to a terminal device, a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); and receive, from the terminal device and via a base station, a Protocol Data Unit (PDU) session establishment request including a requested DNN, wherein the requested DNN is determined based on the mapping information and a CAG ID supported by a cell of the base station that the terminal device accesses.

[0006] In a third aspect, there is provided method, comprising receiving, from an Access and Mobility management Function (AMF), a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); determining a DNN of the one or more DNNs based on the mapping information and a CAG ID supported by a cell of a base station which the terminal device accesses; and transmitting, to the AMF and via the base station a Protocol Data Unit (PDU) session establishment request including the determined DNN as a requested DNN.

[0007] In a fourth aspect, there is provided a method comprising: transmitting, to a terminal device, a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); and receiving, from the terminal device and via a base station, a Protocol Data Unit (PDU) session establishment request including a requested DNN, wherein the requested DNN is determined based on the mapping information and a CAG ID supported by a cell of the base station that the terminal device accesses.

[0008] In a fifth aspect, there is provided an apparatus comprising: means for receiving, from an Access and Mobility management Function (AMF), a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); means for determining a DNN of the one or more DNNs based on the mapping information and a CAG ID supported by a cell of a base station which the terminal device accesses; and means for transmitting, to the AMF, via the base station, a Protocol Data Unit (PDU) session establishment request including the determined DNN as a requested DNN.

[0009] In a sixth aspect, there is provided an apparatus comprising: means for transmitting, to a terminal device, a message indicating mapping information between one or more DataNetwork Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); and means for receiving, from the terminal device and via a base station, a Protocol Data Unit (PDU) session establishment request including a requested DNN, wherein the requested DNN is determined based on the mapping information and a CAG ID supported by a cell of the base station that the terminal device accesses.

[0010] In a seventh aspect, there is provided a computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least: means for receiving, from an Access and Mobility management Function (AMF), a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); means for determining a DNN of the one or more DNNs based on the mapping information and a CAG ID supported by a cell of a base station which the terminal device accesses; and means for transmitting, to the AMF, via the base station, a Protocol Data Unit (PDU) establishment request including the determined DNN as a requested DNN.

[0011] In an eighth aspect, there is provided a computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least: transmitting, to a terminal device, a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); and receiving, from the terminal device and via a base station, a Protocol Data Unit (PDU) session establishment request including a requested DNN, wherein the requested DNN is determined based on the mapping information and a CAG ID supported by a cell of the base station that the terminal device accesses.

[0012] In a ninth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to: receive, from an Access and Mobility management Function (AMF), a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); determine a DNN of the one or more DNNs based on the mapping information and a CAG ID supported by a cell of a base station that the terminal device accesses; and transmit, to the AMF and via the base station of the cell, a Protocol Data Unit (PDU) session establishment request including the determined DNN as a requested DNN.

[0013] In a tenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to: transmit, to a terminal device, a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); and receive, from the terminal device and via a base station, a Protocol Data Unit (PDU) session establishment request including a requested DNN, wherein the requested DNN is determined based on the mapping information and a CAG ID supported by a cell of the base station that the terminal device accesses.

[0014] In an eleventh aspect, there is provided a terminal device comprising a receiving circuitry configured to receive, from an Access and Mobility management Function (AMF), a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); a determining circuitry configured to determine a DNN of the one or more DNNs based on the mapping information and a CAG ID supported by a cell of a base station that the terminal device accesses; and a transmitting circuitry configured to transmit, to the AMF and via the base station of the cell, a Protocol Data Unit (PDU) session establishment request including the determined DNN as a requested DNN.

[0015] In a twelfth aspect, there is provided a terminal device comprising an Access and Mobility management Function (AMF), the network device comprising transmitting circuitry configured to transmit to, a terminal device, a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); and receiving circuitry configured to receive, from the terminal device and via a base station, a Protocol Data Unit (PDU) session establishment request including a requested DNN, wherein the requested DNN is determined based on the mapping information and a CAG ID supported by a cell of the base station that the terminal device accesses.

[0016] It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Some embodiments will now be described with reference to the accompanying drawings, in which:

[0018] FIG. 1 illustrates an example network environment in which some embodiments of the present disclosure can be implemented;

[0019] FIG. 2 illustrates an example of a process flow for providing relevant Closed Access Group (CAG) information using node level signaling via N4 association in accordance with some embodiments of the present disclosure;

[0020] FIG. 3 illustrates an example of a process flow for providing relevant CAG information using node level signaling via Network Repository Function (NRF) related procedure in accordance with some embodiments of the present disclosure;

[0021] FIG. 4 illustrates an example of a process flow for providing relevant CAG information and Local-User Plane Function (L-UPF) address information using UE associated signaling and local breakout (LBO) verification checking in SMF in accordance with some embodiments of the present disclosure;

[0022] FIG. 5 illustrates an example of a process flow for providing relevant CAG information and L-UPF address information using UE associated signaling and LBO verification checking in Access and Mobility management Function (AMF) in accordance with some embodiments of the present disclosure;

[0023] FIG. 6 illustrates an example of a process flow for enabling selected traffic offloading for CAG cells in accordance with some embodiments of the present disclosure;

[0024] FIG. 7 illustrates an example of a process flow for accessing local services via CAG information in accordance with some embodiments of the present disclosure;

[0025] FIG. 8 illustrates an example flowchart of a method implemented at a network device comprising a Session Management Function (SMF) according to embodiments of the present disclosure;

[0026] FIG. 9 illustrates an example flowchart of a method implemented at a network device comprising an AMF according to embodiments of the present disclosure;

[0027] FIG. 10 illustrates an example flowchart of a method implemented at a network device comprising a UPF according to embodiments of the present disclosure;

[0028] FIG. 11 illustrates an example flowchart of a method implemented at a network device comprising a base station according to embodiments of the present disclosure;

[0029] FIG. 12 illustrates an example flowchart of a method implemented at a network device comprising an SMF according to embodiments of the present disclosure;

[0030] FIG. 13 illustrates an example flowchart of a method implemented at a network device comprising an Application Function (AF) according to embodiments of the present disclosure;

[0031] FIG. 14 illustrates an example flowchart of a method implemented at a network device comprising a data repository according to embodiments of the present disclosure;

[0032] FIG. 15 illustrates an example flowchart of a method implemented at a network device comprising a Network Exposure Function (NEF) according to embodiments of the present disclosure;

[0033] FIG. 16 illustrates an example flowchart of a method implemented at a terminal device according to embodiments of the present disclosure;

[0034] FIG. 17 illustrates an example flowchart of a method implemented at a network device comprising an AMF according to embodiments of the present disclosure;

[0035] FIG. 18 illustrates an example simplified block diagram of a device that is suitable for implementing embodiments of the present disclosure; and

[0036] FIG. 19 illustrates an example block diagram of an example computer readable medium in accordance with some embodiments of the present disclosure.

[0037] Throughout the drawings, the same or similar reference numerals represent the same or similar elements.DETAILED DESCRIPTION

[0038] Principles of the present disclosure will now be described with reference to some embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

[0039] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

[0040] References in the present disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0041] It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0042] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof. As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0043] As used in this application, the term “circuitry” may refer to one or more or all of the following:(a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and(b) combinations of hardware circuits and software, such as (as applicable):(i) a combination of analog and / or digital hardware circuit(s) with software / firmware and(ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and(c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor s), that requires software (for example, firmware) for operation, but the software may not be present when it is not needed for operation.

[0044] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0045] As used herein, the term “network”, “communication network” or “data network” refers to a network following any suitable communication standards, such as long term evolution (LTE), LTE-advanced (LTE-A), wideband code division multiple access (WCDMA), high-speed packet access (HSPA), wireless fidelity (Wi-Fi), narrow band Internet of things (NB-IoT), satellite, enhanced machine-type communication (eMTC), nonterrestrial communication, terrestrial communication, and so on. Furthermore, the communications between a terminal device and a network device / element in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the fourth generation (4G), 4.5G, the fifth generation (5G), the sixth generation (6G), new radio (NR), IEEE 802.11 communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the presentdisclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0046] As used herein, the term “network device” may refer to a device comprising or performing a network function. For instance, a network device may refer to a device comprising or performing at least part of network functions, including but not limited to, Access and Mobility Management Function (AMF), Session Management Function (SMF), Application Function (AF), Network Exposure Function (NEF), Policy Control Function (PCF), Unified Data Management (UDM), Unified Data Repository (UDR), Network Repository Function (NRF), among others things.

[0047] It is understood that references in the above to various network functions (e.g., to an AMF, an SMF, UPF, etc.) may be implemented by apparatus (e.g., network apparatus) that performs at least some of the functionality associated with those network functions. Further, an apparatus configured to implement a network function may further be configured to implement a virtual network function instance of that network function.

[0048] In some embodiments, the apparatus may be or comprise a network function, such as an AMF, an SMF, a UPF, an AF, a NEF, a NRF, a UDM, a UDR, etc. In the present disclosure, an apparatus being / comprising a network function refers to an apparatus / device configured to provide / perform at least part of functionalities of that network function.

[0049] The term “network device” may refer also to a network node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) or a transmission and reception point (TRP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a NR NB (also referred to as a gNB), a Femto (also referred to as home gNB), a remote radio unit (RRU), a radio header (RH), a remote radio head (RRH), a WiFi (Wireless Fidelity) device, a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology.

[0050] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a subscriber station (SS), a portable subscriber station, a mobile station (MS), a station (STA) or station device, or an access terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, atablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (for example, remote surgery), an industrial device and applications (for example, a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. The terminal device may be a Dual Steer (DS) device which could comprise of two logical UEs or one UE with 2 Universal Subscriber Identity Modules (USIMs).

[0051] The term “transceiver” may refer to any device that may be coupled to one or more antennas or antenna ports to wirelessly transmit and / or receive communication signals. The antennas or antenna ports may be the same or different types. The antennas or antenna ports may be located in different positions of an apparatus. One or more transceivers allow the apparatus to communicate with other devices that may be wired and / or wireless. The one or more transceivers may include processors, controllers, radios, sockets, plugs, buffers, or the like circuits to form one or more communication channels to one or more radio frequency units. The one or more transceivers may be integrated in an apparatus or a system, for example a cellular communication apparatus or system, a satellite communication apparatus or system, a WLAN system, or a short ranging system for example Bluetooth system.In Release -19 a study item (SI) on additional topological enhancements for NR includes the objective for 5G as follows:Study the overall RAN architecture and required functional and procedural impacts for supporting 5G Femto deployments.Study how to define the 5G access control mechanism by (re-)using the existing GAG functionality and identify needed enhancements (if any).Clarify the access to local services from the 5G Femto via collocated local UPF and identify issues, if any.

[0052] It was concluded in the study: in order to support access to local services, NR Femto nodes reuse LADN and edge computing functionality as specified in 3GPP TS (Technical Specification) 23.501 and 3GPP TS 23.548; and the local UPF may be either stand-alone or co-located with the NR Femto node. Scalability of local UPF discovery e.g. when using mobile edge computing solutions, has been identified and may require further analysis.

[0053] In the present disclosure, 3GPP TS 23.501 refers to 3GPP TS 23.501 V19.1.0, 3GPP TS 23.502 refers to 3GPP TS 23.502 V19.1.0, 3GPP TS 23.548 refers to 3GPP TS 23.548 V19.0.0 and 3GPP TS 36.413 refers to 3GPP TS 36.413 V18.2.0.

[0054] In 5G Local Area Data Network (LADN) and edge computing (EC), the 5G Core Network function (i.e., Session Management Function (SMF)) selects a User Plane Function (UPF) close to the User Equipment (UE) and the selected UPF forwards traffic to enable local access to the Data Network (DN) via an N6 interface according to the provided traffic steering rules to the UPF. This may be based on the UE’s subscription data, UE location, the information from Application Function (AF) as defined in clause 5.6.7 of 3GPP TS 23.501, the Edge Application Server (EAS) deployment information, EAS Internet Protocol (IP) address reported from Edge Application Server Discovery Function (EASDF) (as defined in 3GPP TS 23.548), policy, or other related traffic rules. However, there is no Closed Access Group (CAG) related UPF selection taken into account in 5G EC or LADN as CAG is part of Access and Mobility (AM) subscription data in Unified Data Management (UDM), and SMF does not take into account AM subscription data for UPF selection. SMF uses Session Management (SM) Subscription data that is the data needed for Protocol Data Unit (PDU) Session management and doesn’t include CAG related information.

[0055] In 4G Local IP Access (LIPA), the Packet Data Network Gateway (PDN GW) selection function uses subscriber information provided by the Home Subscriber Server (HSS) and possibly additional criteria such as LIPA support per Access Point Name (APN) configured in Serving GPRS Support Node (SGSN) / Mobility Management Entity (MME) to select the local Gateway (GW). The PDN subscription contexts provided by the HSS contain, optionally for an APN, an indication of whether LIPA is conditional, prohibited, or only LIPA is supported for this APN. In addition, the Closed Subscriber Group (CSG) subscription data includes, for a CSG ID, the corresponding APN(s) that can be used to access specific Packet Data Networks (PDNs) via LIPA. Additionally, the Home eNodeB (HeNB) supporting the LIPA function indicates the local GW address to the MME in everySI Application Protocol (Sl-AP) INITIAL UE MESSAGE and every UPLINK Non-Access Stratum (NAS) TRANSPORT control message as specified in 3GPP TS 36.413. In order to select the appropriate Local Gateway (L-GW) for LIPA service, if permitted by the CSG subscription data, the PDN GW selection function uses the L-GW address proposed by HeNB in the SI Application Protocol (Sl-AP) message. If no L-GW address is proposed by the HeNB and the UE requested an APN with LIPA permissions set to “LIPA-only,” the request shall be rejected. However, LIPA support and corresponding APNs related to CSG ID and L-GW address are provided in UE-specific / associated signaling in the interface from HSS to MME and HeNB to MME, which introduces a lot of redundant signaling overhead over the different network interfaces.

[0056] In view of this, the present disclosure is targeted to the problem in general as identified in 3GPP study: Scalability of local UPF discovery e.g. when using mobile edge computing or LADN solutions. More specifically, the targeted problem is on how to reduce the signaling overhead for providing to SMF the necessary information for local UPF selection in order to better support to access local services via Femto or CAG cells.

[0057] In a nutshell, the embodiments of the disclosure include the node level signaling mechanism to provide to the SMF the CAG information (e.g. CAG ID) associated with the local-UPF (L-UPF). The CAG ID is a unique identifier assigned to a Closed Access Group (CAG) in mobile networks to identify specific groups of users or devices that are authorized to access certain network resources or services. It helps the network manage and restrict access effectively. UEs can be associated with one or more CAG IDs, allowing them to connect to designated network cells or services based on their permissions. The CAG ID is typically broadcasted by the network as part of the system information, allowing UEs to determine which CAG cells they can access.

[0058] In one embodiment, the CAG information associated with the L-UPF can be provided to the SMF directly from L-UPF using N4 association procedure, wherein N4 is the interface between SMF and UPF. In another embodiment, the CAG information associated with the L-UPF can be provided to NRF as part of UPF profile and then can be queried by the SMF from a Network Repository Function (NRF) using network function (NF) management procedure.

[0059] The further embodiments of the disclosure include: enhancing the UE associated signaling to include the CAG information and also the address information (e.g., IP address)of L-UPF from AMF to SMF in the PDU session management procedure; enhancing the UE associated signaling on registration procedure or UE configuration update procedure to include the Data Network Name (DNN) and CAG ID mapping information to facilitate UE to request PDU session establishment for accessing local service via the DNN associated with the corresponding CAG ID; and enhancing the Application Function (AF) traffic influence (TI) to indicate which traffic to be offloaded via the CAG ID.

[0060] Note that L-UPF is a UPF co-located with a Femto and / or a CAG cell and L-UPF and UPF are used interchangeably in this disclosure. Also note that the terms Femto Local Breakout (LBO) used in this disclosure represents access to local services via CAG cell(s) (for Femto or Public Network Integrated Non-Public Network (PNLNPN)).

[0061] FIG. 1 illustrates an example network environment in which some embodiments of the present disclosure can be implemented. As shown in FIG. 1, the communication network 100 may include a UE 110, a RAN node 120 (e.g., a base station such as gNB), and a core network including various Network Functions (NFs). The NFs include Control Plane (CP) NFs including but not limited to: an AMF 140, an SMF 150, an NRF 160, an NEF 170, a Unified data management (UDM) 180, a Unified data Repository (UDR) 185, a Policy Control Function (PCF) 190, and an Application Function (AF) 195. The NFs further include User Plane (UP) NFs including but not limited to UPF 130 and the Data Network (DN) 135. The UPF 130 may include PDU Session Anchor (PSA) UPF and / or local-UPF (L-UPF).

[0062] The AMF 140 is used for handling access and mobility management tasks related to the UE 110. This includes user registration, connection management, and mobility management as the user moves between different cells. The AMF 140 can interact with other network functions, including the UDM 180 for subscription data and the SMF 150 for session management. The AMF 140 may communicate with the RAN node 120 via N2 interface, and with the UE 110 via N1 interface using Non Access Stratum (NAS) messages.

[0063] The SMF 150 is responsible for managing user sessions in the network. It oversees the establishment, modification, and release of Protocol Data Unit (PDU) sessions, which are used for data transmission. The SMF 150 can interacts with the AMF 150 for session setup requests and with the UPFs 130 via N4 interface for data forwarding.

[0064] The NRF 160 serves to support the dynamic management and discovery of network functions (NFs) within the core network, including function registration, function discovery, dynamic management and others. The NEF 170 is used to facilitate the exposure of networkcapabilities and services to third-party applications, ensuring secure and efficient interactions. The NEF 170 can interface with various network functions, including the AF 195 for specific application-related services, and the NRF 160 for discovering available network services.

[0065] The UDM 180 is responsible for managing subscriber-related data, including user profiles, authentication information, and subscription detail. The UDM 180 may interact with the AMF 140 for user authentication and the NEF 170 for providing subscriber data. The UDR 185 may serve as a storage system for all types of subscriber data, including service-related information and other operational data. The UDR 185 may works closely with the UDM 180, providing the necessary data storage capabilities for subscriber information, while also interfacing with other network functions that need access to this data.

[0066] The PCF 190 can manage and enforce policy rules related to Quality of Service (QoS), resource allocation, and overall service delivery for users and applications. It may interact with the SMF 150 to provide QoS parameters for session establishment and management, with the UDM 180 and UDR 185 to access subscriber-related information for policy decisions, and with the NEF 170 to share policy information with external applications and services.

[0067] The UPFs 130 is responsible for handle user data traffic, enabling transmission of the flow of data between the UE 110 and the DN 135 (such as the Internet or private networks). The UPF may interface with the SMF 150 for session-related commands and control, and with the DN 135 to facilitate user data flow to external networks.

[0068] According to embodiments of the disclosure, the procedures between the different NFs described with reference to FIGS. 2 to 7 in the following can indicate which UPF can act as L-UPF for a CAG cell, and / or indicate which traffic can be offloaded via a CAG cell when a PDU session is served by the CAG cell identified by the CAG ID.

[0069] FIG. 2 illustrates an example of a process flow for providing relevant Closed Access Group (CAG) information using node level signaling via N4 association in accordance with some embodiments of the present disclosure. For ease of understanding, the process flow 200 will be described with reference to FIG.l, It would be appreciated that although the process flow 200 has been described referring to the communication network 100 of FIG. 1, the process flow 200 may be likewise applied to other similar communication scenarios.

[0070] The process flow 200 is used for establishing the PDU session to access the localservices via Femto or CAG cell. As shown, it involves at least the UE 110, the L-UPF 130, the AMF 140, the SMF 150 and the UDM 180.

[0071] At step 201, during N4 association procedure between the UPF 130 and the SMF 150, the L-UPF 130 may provide CAG information to the SMF 150 as part of the procedure, which could be an association setup and / or an association update as defined in 3GPP specification TS 23.502. For this step, either the UPF 130 may be configured with the SMFs, or with the SMF set IDs of the SMF sets which control the L-UPF 130, or the L-UPF 130 may discover the SMFs 140 from the NRF 160 based on existing procedures. Herein, the CAG information may include one or more CAG IDs that the L-UPF 130 is associated with and this can be pre-configured in the L-UPF 130 in case the L-UPF 130 is integrated with the RAN node 120 (e.g., a Femto node). The CAG information may be one CAG ID or a list of CAG IDs depending on whether L-UPF is standalone UPF or co-located UPF with the Femto node and / or the CAG ID(s) the Femto node is broadcasting.

[0072] At step 202, upon N4 association, the SMF 150 may receive or obtain the address information (e.g., IP address) of the L-UPF 130 and store the address information associated with the CAG Information that L-UPF 130 provided.

[0073] At step 203, the UE 110 requests the PDU session establishment for accessing local services associated with a given CAG ID and indicate the requested DNN corresponding to data network of the local services offered with the corresponding CAG ID in the NAS message: PDU Session Establishment Request.

[0074] At step 204, the AMF 140 may send to SMF 150 a session management (SM) create request, e.g., Nsmf PDUSession CreateSMContextRequest message that indicates the requested DNN and the CAG ID of the CAG cell from which the NAS message is received from UE 110.

[0075] At step 205 and 205b, if SM subscription data is not available in the SMF 150 for the UE 110 yet, the SMF 150 may retrieve the SM subscription data of the UE 110 from the UDM 180. The SM subscription data may include the Femto LBO information per CAG ID. The LBO information may include e.g. whether LBO is conditional allowed, prohibited or LBO-only allowed. It may also include the corresponding DNN(s) per CAG ID when LBO is allowed.

[0076] In this embodiment, the Femto LBO information is assumed to be part of SM subscription data. For this case, the existing SM subscription data can be updated to includeFemto LBO information and optional the DNNs per CAG ID. Alternatively, it may be part of access and mobility (AM) subscription data as in another embodiment related to FIG.5.

[0077] Instead of using SM subscription data from the UDM 180 to provide the LBO information, the local configuration from Operations and Maintenance (O&M) to the SMF 150 or using non-UE specific database to provide the LBO information may be used. This approach can reduce the signaling overhead as retrieving UE’s SM subscription data related to LBO information from the UDM 180 introduces redundant information from the UDM 180 to the SMF 150.

[0078] At step 206, upon Femto LBO information is available, the SMF 150 checks the requested DNN from UE’s PDU session establishment request and the Femto LBO information to determine whether LBO is allowed or not.

[0079] At step 207, if LBO is allowed, the SMF 150 selects the L-UPF 130 based on the stored address information of the L-UPF 130 that is associated with the CAG ID according to the information provided from L-UPF 130 during N4 association procedure at step 201. Afterwards, the SMF 140 may cause the selected L-UPF to serve the requested PDU session for the UE 110.

[0080] FIG. 3 illustrates an example of a process flow 300 for providing relevant CAG information using node level signaling via NRF related procedure in accordance with some embodiments of the present disclosure.

[0081] The process flow 300 is used for establishing the PDU session to access the local services via Femto or CAG cell. As shown, it involves at least the UE110, the L-UPF 130, the AMF 140, the SMF 150 and the NRF 160.

[0082] At step 301, when the L-UPF 130 registers its UPF profile to the NRF 160, the CAG information is provided among other UPF profile information such as the IP address. Herein the CAG information and the way it is made available to L-UPF 130 are the same as described in FIG. 2.

[0083] At step 302a and 302b, early discovery of L-UPF addresses is performed. When the SMF 150 discovers the UPF services available in the network via NRF 160, the NRF 160 may provide the L-UPF profile including the CAG information, IP address of L-UPF in the response message. The discovers can be based on a configuration and can be one-time or periodic request that would happen independently from any other request / trigger for theSMF 150 to keep the updated list of UPF profiles.

[0084] Accordingly, at step 303, the SMF 150 stores the IP address of the L-UPF 130 and the association with the CAG Information in the L-UPF profile.

[0085] As an alternative of steps 302a and 302b, late discovery of L-UPF address may be performed. When the SMF 150 receives the Nsmf_PDUSessionCreate message with the CAG ID in step 305 and the SMF 150 doesn’t have a UPF profile information that matches with the given CAG ID, the SMF 150 may query at step 302a’ the NRF 160 including the CAG ID in the Nnrf NFDiscovery Request, and at step 302b’, get the L-UPF address corresponding to this CAG ID in the NFDiscovery Response. The late discovery may be performed after step 305 or even 306.

[0086] At step 303-306 are the same as in FIG. 2. Therefore, in the process flow 300, the procedure between SMF 150 and UDM 180 is not illustrated in FIG. 3 for simplification reason.

[0087] At step 307, for the early discovery case, if LBO is allowed, the SMF 150 selects the L-UPF 130 based on the stored IP address of the L-UPF 130 that is associated with the CAG ID according to the information provided from NRF 160. For late discovery case, the SMF 150 selects the L-UPF 140 based on the information provided from NRF after step 305. Afterwards, the SMF 140 may cause the selected L-UPF to serve the requested PDU session for the UE 110.

[0088] FIG. 4 illustrates an example of a process flow 400 for providing relevant CAG information and L-UPF address information and LBO verification checking in SMF in accordance with some embodiments of the present disclosure.

[0089] The process flow 400 is used for establishing the PDU session to access the local services via a Femto or CAG cell. It involves at least the UE 110, the RAN node 120 (e.g., Femto node), the AMF 140, the SMF 150 and the UDM 180.

[0090] At step 401 or 403, the Femto node (i.e. HgNB) provides the IP address of L-UPF 130 and the association with CAG ID to the AMF 140.

[0091] At step 401, the information may be provided using Next Generation Application Protocol (NGAP): NG Setup or RAN Configuration Update procedure so that the information is provided using Femto node associated signaling and independent from UE associated signaling. This alternative can save the signaling overhead over N2 interfacebetween HgNB and AMF. It may be applied for the scenario that there is direct interface between HgNB and AMF without Femto gateway (GW) deployed.

[0092] At step 403, in another alternative, the information may be provided using UE associated NGAP procedure such as Initial UE message or UL NAS Transfer message. This alternative may be used when the first alternative cannot be applied e.g. when the N2 interface between HgNB and AMF is aggregated via Femto GW.

[0093] At step 402, the UE 110 requests the PDU session establishment for local service access by indicating the requested DNN.

[0094] At step 404, the AMF 140 sends to the SMF 150 the SM create request, e.g., Nsmf_PDUSession_CreateSMContextRequest message that indicates the requested DNN, the CAG ID of the CAG cell from which the NAS message is received from UE (which it received via the HgNB or Femto node) and the IP address of the L-UPF 130 associated with the CAG ID.

[0095] At steps 405 and 406, they are the same as in FIG. 2 (e.g., check of the LBO information per CAG ID with the UDM 180).

[0096] At step 407, the SMF 150 selects the L-UPF 130 based on the IP address provided from AMF 140. Afterwards, the SMF 150 may cause the selected L-UPF to serve the requested PDU session for the UE 110.

[0097] FIG. 5 illustrates an example of a process flow for providing relevant CAG information and L-UPF address information and LBO verification checking in AMF in accordance with some embodiments of the present disclosure.

[0098] The process flow 500 is used for establishing the PDU session to access the local services via a Femto or CAG cell. It involves at least the UE 110, the RAN node 120 (e.g., Femto node), the AMF 140, the SMF 150 and the UDM 180.

[0099] At step 500a and 500b, during registration, the AMF 140 retrieves the Femto LBO information per CAG ID from the UDM 180 as part of AM subscription data The Femto LBO information is included in AM subscription data instead of SM subscription data as in FIG. 2 or FIG. 4. Thus, upon receiving the NAS PDU session establishment request message and the CAG ID from HgNB or Femto node, the AMF 140 already has the AM subscription data from UDM 180 for this CAG ID.

[0100] The steps 501-503 are the same as in FIG. 4.

[0101] At step 504, based on the Femto LBO information in the AM subscription data, the AMF 140 checks the requested DNN from UE’s PDU session request to determine whether LBO for the requested DNN is allowed or not for this CAG ID.

[0102] At step 505, if LBO from Femto is allowed, the AMF 140 sends to the SMF 150 the Nsmf PDUSession CreateSMContextRequest message that indicates IP address of L- UPF 130 (also received from HgNB or Femto node) to allow the SMF 150 to select the L- UPF 130 for the established PDU session.

[0103] Otherwise, if LBO is not allowed, the AMF 140 may indicate to the SMF 150 when forwarding the PDU Session setup request to reject the PDU session using either existing cause (e.g. LADN area not allowed) or the new cause that is related to Femto LBO is not allowed (e.g. DNN / CAG ID incompatible).

[0104] The step 506 is the same as FIG. 4. After step 506, the SMF 140 may cause the selected L-UPF to serve the requested data session for the UE 110 if LBO from Femto is allowed as indicated by AMF.

[0105] FIG. 6 illustrates an example of a process flow 600 for enabling selected traffic offloading for CAG cells in accordance with some embodiments of the present disclosure.

[0106] At step 600a, the UE 110 has already established a PDU session and got an IP address from central PSA UPF. At step 600b, the SMF 150 is provided with the L-PSA UPF address and its associated CAG information based on the one of embodiments described with reference to FIGS. 2 to 5.

[0107] At steps 601 and 602, the AF 195 creates Traffic Influence (TI) request with a CAG ID or a list of CAG IDs and sends Nnef TrafficInfluence Create / Update request to the NEF 170. For this request, if only some traffic needs to get offloaded, it is controlled by AF TI where the CAG would act as a kind of data network access identifier (DNAI). Also, for this request, an 0AM entity can act as an AF as the CAG ID association to L-UPF may not be available outside the 5GC network. Hence, for this request, the target UE may be identified by SUPI X, traffic filter may be any traffic to be offloaded at the L-UPF, where to offload = CAGx associated with SUPI X, instead of DNAI. “where to offload” parameter can be considered as the extended “Potential Locations of Applications” that indicates potential locations of applications, represented by a list of DNAI(s) and / or CAG(s). Therefore, the NEF 170 may map the AF-Service-Identifier information to a list of CAG ID(s) when the AF TI request includes a CAG or a list of CAG ID(s).

[0108] At step 603a, the NEF 170 stores the AF request information in the UDR 185 including Potential Locations of Applications with a list of CAG ID(s). Then, at step 603b, the NEF 170 responds AF request.

[0109] At step 604, the PCF(s) 190 that have subscribed to modifications of AF requests receive(s) a Nudr DM Notify notification of data change from the UDR 185 related to AF TI including a list of CAG ID(s).

[0110] At step 605, the PCF(s) 190 update(s) the SMF 150 for the potentially impacted PDU sessions that are going to be routed to the L-UPF 130 that is associated with the CAG ID. This implies adding CAG ID instead of DNAI in PCC rules part about AF influence on traffic routing Enforcement Control.

[0111] At step 606, the SMF 150 utilizes the information on the CAG ID and its associated L-UPF 130 to select the appropriate L-UPF 130.

[0112] For the given procedure, the UE 110 may still have an IP address corresponding to the central PSA (UPF), but all traffic is offloaded via local access of the L-UPF 130 via the wireline residential gateway (RG), where the RG enforces network address translation (NAT) to the traffic (ensuring the DL traffic towards the UE are routed via the wireline access and not the wireless access).

[0113] For hand over (HO) cases, in some embodiments, in order for the SMF to choose a new UPF (or to trigger PDU session release in relationship with SSC mode 2 / 3 in order that the target PDU session would use a PSA UPF on the L-UPF collocated with the target CAGcell), for the embodiments in FIGS. 4 and 5, the L-UPF address is added to NGAP: HO required Ack message sent by the target HgNB or RAN node to the AMF. For embodiments in FIGS. 2 to 5, CAG ID associated with the target cell is sent from AMF to SMF to support handover.

[0114] In another solution, Area of Interest reporting feature is extended with new CAG ID input. When the SMF subscribes to AMF for UE mobility events, it provides CAG ID(s) as part of Area of Interest. The CAG ID(s) used as part of the UE mobility event subscription will be the ones that were provided or known to SMF along with L-UPF address based on the options defined above.

[0115] In some embodiments, the SMF may subscribe to the AMF for reporting mobility events of the UE in and out of an area covered by one or more CAG IDs. The SMF may receive a notification from the AMF that the UE moves into an area covered by a new CAG ID which is not part of the one or more CAG IDs associated with at least one current UPF. The SMF may trigger selection of a new UPF associated with CAG information comprising the new CAG ID.

[0116] Correspondingly, the AMF may receive, from the SMF, a subscription for reporting mobility events of the UE in and out of an area covered by one or more CAG IDs. The AMF may determine that the UE moved into an area covered by a new CAG ID which is not part of the received one or more CAG IDs from SMF for reporting mobility events of the UE. The AMF may transmit, to the SMF, a notification that UE moved into an area covered by a new CAG ID which is not part of the received one or more CAG IDs from SMF. The AMF may determine that UE moved into the area covered by the new CAG ID which is not part of the received one or more CAG IDs based on reporting of a base station or a RAN node. In addition, the AMF may configure the RAN node for reporting mobility events of the UE in and out of the area associated with the one or more CAG IDs, and receive reporting from the RAN node in response of the configuration.

[0117] FIG. 7 illustrates an example of a process flow 700 for accessing local services via Femto or CAG cell identified by CAG information in accordance with some embodiments of the present disclosure.

[0118] At step 701, UE registration to the network is performed according to e.g. the procedure defined in 3GPP TS 23.502 clause 4.2.2.2.2.

[0119] At step 702, the AMF 140 transmits a message indicating mapping informationbetween one or more DNNs and one or more CAG IDs. The mapping information may be provided to the UE 110 by the AMF 140 in NAS messages. The message may be a registration accept, registration reject or UE configuration update message. A new Information Element (IE) cagldDnnMapppinglnfo may be used to carry the mapping information as below.TS 24.501 clause 8.2.7.1 Registration Accept (used it for the illustration purpose only)TS 24.501 clause 8.2.9.1 Registration Reject (used it for the illustration purpose only)TS 24.501 clause 8.2.19.1 Configuration Update Command (used it for the illustration purpose only)

[0120] In some embodiments, each of the one or more DNNs may be mapped to one or more CAG IDs. The example of IE cagldDnnMapppinglnfo may look as below:{CAG1, DNN1},{CAG3, DNN2},{CAG4, CAG5, DNN3}{CAGn, DNNn},}

[0121] At step 703, UE 110 stores the CAG ID and DNN mapping. For all upcoming PDU session requests, the UE 110 may consider the DNN mapping / preferences for the corresponding CAG ID. Using this, the UE 110 will upfront know which DNN it uses to request PDU session establishment for accessing the local service via the CAG cell of the given CAG ID.

[0122] At step 704, the UE 110 includes the DNN as the requested DNN in PDU session establishment request message for the corresponding CAG ID to which UE is connected.

[0123] At step 705, the PDU session establishment continues as explained in 3GPP TS 23.502 clause 4.3.2.2.

[0124] The UE may use the mapping information of CAG and DNN for PDU session establishment. One user has 5G Femto (e.g. CAG ID=1) installed at home and his / her company has also 5G Femto (CAG ID=2, 3) deployed in the company premises. Both home Femto and company Femto deployment supports access to the local services e.g. local printer at home and company. The user’s UE is configured with the mapping of CAG ID and DNN, e.g. {CAG ID=1, DNN femto. home. local; CAG ID=2, 3, DNN femto.company.local}. When UE wants to access the local services via home femto cell that broadcasts CAG ID=1, the UE knows the requested DNN in the PDU session establishment request should be femto. home. local based on the mapping information configured. When UE wants to access the local services via company femto cell that broadcasts CAG ID=2 or 3, or both 2 and 3, the UE knows the requested DNN in PDU session establishment request should be femto.company.local.”

[0125] FIG. 8 illustrates a flowchart of an example method 800 implemented at an SMF in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 800 will be described from the perspective of the SMF 150 with reference to FIGS. 2 to 7.

[0126] At block 810, the SMF receives CAG information associated with a request of a terminal device for a data session from an AMF. At block 820, the SMF determines a UPF to serve the terminal device and the data session based on address information of the UPF and the CAG information associated with the request of the terminal device for the data session. For example, the SMF may determine / select the UPF from one or more UPFs supporting / having the CAG information associated with the request of the terminal device for the data session. That is, the SMF determines the UPF based on the address information of the UPF(s) (e.g., CAG information supported by the UPF(s) or associated with the address information of the UPF(s)) and the CAG information associated with the request of the terminal device for the data session.

[0127] In some embodiments, the SMF may obtain or receive address information of at least one UPF and CAG information associated with the address information of the at least one UPF. Based on the received address information, the CAG information associated with the address information and the CAG information associated with the request of the terminal device for the data session, the SMF is able to determine the UPF for the data session and / or to serve (the data session for) the terminal device.

[0128] In some embodiments, to obtain or receive the address information of the at least one UPF and the CAG information associated with address information of the at least one UPF, the SMF may receive, from the at least one UPF, the address information of the at least one UPF and the CAG information associated with the address information using an association setup or update procedure between the SMF and the UPF.

[0129] In some embodiments, to obtain or receive the address information of the at least one UPF and the CAG information associated with the address information of the at least one UPF, the SMF may transmit a request for UPF services to a Network Repository Function (NRF); and receive at least one UPF profile including the address information of the at least one UPF and the CAG information associated with the address information.

[0130] In some embodiments, to obtain or receive the address information of the at least one UPF and the CAG information associated with the address information, the SMF may, based on receiving the CAG information associated with the request of the terminal device for the data session from the AMF, transmit a request for UPF services to a NRF including the CAG information received from the AMF associated with the request of the terminal device for the data session; and receive at least one UPF profile including the addressinformation of the at least one UPF which is associated with the CAG information.

[0131] In some embodiments, the request for the UPF services is transmitted to the NRF periodically.

[0132] In some embodiments, to transmit the request for the UPF services, the SMF may determine, after reception of the CAG information associated with the request of the terminal device for the data session, whether there is a UPF profile matches the CAG information associated with the request of the terminal device for the data session; and based on a determination that no UPF profile matches the CAG information associated with the request of the terminal device for the data session, transmit the request for UPF services to the NRF.

[0133] In some embodiments, the SMF may store the CAG information associated with the address information of the at least one UPF.

[0134] In some embodiments, to receive the CAG information associated with the request of the terminal device for the data session, the SMF may receive a SM create request including the CAG information associated with the request of the terminal device for the data session and a requested DNN.

[0135] In some embodiments, the SM create request further includes the address information of the UPF(s) which is is associated with the CAG information that the terminal device has accessed. In the embodiments of the SM create request comprising the address information of multiple UPFs, the SMF may select one UPF from these UPFs, e.g., based on related policies.

[0136] In some embodiments, if the SM create request further includes the address information of the UPF(s), the CAG information may be omitted in the SM create request (see, e.g., FIG. 4 or 5).

[0137] In some embodiments, to determine the UPF to serve the terminal device and the data session, the SMF may determine whether Local Breakout (LBO) is allowed based on LBO information; and based on a determination that the LBO is allowed, select, based on address information of at least one UPF, the CAG information associated with the address information and the CAG information associated with the request of the terminal device, the UPF from at least one UPF having the address information associated with the CAG information associated with the request of the terminal device to serve the terminal device and the data session.

[0138] In some embodiments, the LBO information comprises at least one of: at least one LBO allowed indication per DNN or Single Network Slice Selection Assistance Information (S-NSSAI) in SM Subscription Data.

[0139] In some embodiments, the SMF may receive the LBO information from the AMF as part of AM subscription data of the terminal device.

[0140] In some embodiments, the network device may further obtain the LBO information from a local configuration or non-UE specific database.

[0141] In some embodiments, the CAG information comprises at least one CAG identity (ID) configured for at least one base station, and wherein the UPF is associated with the at least one base station as a local UPF.

[0142] In some embodiments, the SMF may subscribe to the AMF for reporting mobility events of the terminal device in and out of an area covered by one or more CAG IDs; receive a notification from the AMF that the terminal device moves into an area covered by a new CAG ID which is not part of the one or more CAG IDs associated with at least one current UPF; and trigger selection of a new UPF associated with CAG information comprising the new CAG ID.

[0143] FIG. 9 illustrates a flowchart of an example method 900 implemented at an AMF in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 900 will be described from the perspective of the AMF 140 with reference to FIGS. 2 to 7.

[0144] At block 910, the AMF transmits CAG information associated with a request of terminal device for a data session to an SMF.

[0145] In some embodiments, to transmit the CAG information associated with the request of the terminal device for the data session, the AMF may, in response to receiving establishment request for a PDU session from the terminal device, transmit a SM create request including the CAG information associated with the request of the terminal device for the data session and a requested DNN.

[0146] In some embodiments, the SM create request further includes address information of at least one UPF associated with the CAG information.

[0147] In some embodiments, to transmit the SM create request to the SMF, the AMF may determine whether Local Breakout (LBO) is allowed based on LBO information; and basedon a determination that the LBO is allowed, transmit the SM create request including the CAG information associated with the request of the terminal device for the data session and the address information of the at least one UPF to the SMF.

[0148] In some embodiments, the LBO information comprises at least one of: at least one LBO allowed indication per DNN; or S-NSSAI in Access and Mobility (AM) Subscription Data.

[0149] In some embodiments, based on a determination that the LBO is not allowed, the AMF may forward, to the SMF, the establishment request comprising an indication associated with rejecting the request of the terminal device for the data session.

[0150] In some embodiments, the AMF may transmit a request for AM subscription data of the terminal device to UDM; and receive the AM subscription data of the terminal device including the LBO information associated with the CAG information.

[0151] In some embodiments, the CAG information associated with the terminal device for the data session is received from the terminal device using a terminal device associated NGAP procedure.

[0152] In some embodiments, at least one of the CAG information and address information associated with at least one UPF is received from a base station using a non-terminal device associated NGAP procedure.

[0153] In some embodiments, the non-terminal device associated NGAP procedure comprises at least one of: an NGAP setup request message; an NGAP radio access network (RAN) configuration update message; a UE associated NGAP procedure; or an NGAP handover (HO) message.

[0154] In some embodiments, the CAG information comprises at least one CAG ID.

[0155] In some embodiments, the AMF may further receive, from the SMF, a subscription for reporting mobility events of the terminal device in and out of an area covered by one or more CAG IDs; determine that terminal device moved into an area covered by a new CAG ID which is not part of the received one or more CAG IDs; and transmit, to the SMF, a notification that UE moved into an area covered by a new CAG ID which is not part of the received one or more CAG IDs.

[0156] In some embodiments, the AMF may further determine that terminal device moved into the area covered by the new CAG ID which is not part of the received one or more CAGIDs from reporting of a base station.

[0157] In some embodiments, the AMF may further configure the base station for reporting mobility events of the terminal device in and out of the area associated with the one or more CAG IDs; and receive reporting of the base station in response of the configuring.

[0158] FIG. 10 illustrates a flowchart of an example method 1000 implemented at a UPF in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 1000 will be described from the perspective of the UPF 130 with reference to FIGS. 2 to 7.

[0159] At block 1010, the UPF transmits CAG information and address information of the UPF associated with the CAG information to at least one SMF or to a NRF.

[0160] In some embodiments, the CAG information comprises one or more CAG IDs configured for a base station, and wherein the UPF is associated with the base station as a local UPF.

[0161] In some embodiments, the CAG information and the address information of the UPF are transmitted to the SMF using an association setup or update procedure between the SMF and the UPF.

[0162] In some embodiments, the CAG information and the address information of the UPF are transmitted to the NRF using a network function registration procedure.

[0163] FIG. 11 illustrates a flowchart of an example method 1100 implemented at a base station in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 1100 will be described from the perspective of the RAN node 120 with reference to FIGS. 2 to 7.

[0164] At block 1110, the base station transmits CAG information and address information of at least one UPF associated with the CAG information to an AMF.

[0165] In some embodiments, the CAG information comprises at least one CAG ID configured for the base station, and wherein the at least one UPF is associated with the base station as a local UPF.

[0166] In some embodiments, the CAG information and the address information of at least one UPF are transmitted using at least one of: an NGAP setup request message; an NGAP RAN configuration update message; a UE associated NGAP procedure; or an NGAP HOmessage.

[0167] In some embodiments, the CAG information and the address information of at least one UPF are transmitted using a terminal device associated NGAP procedure.

[0168] FIG. 12 illustrates a flowchart of an example method 1200 implemented at an SMF in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 1200 will be described from the perspective of the SMF 150 with reference to FIGS. 2 to 7.

[0169] At block 1210, the SMF obtains CAG information and address information of a UPF associated with the CAG information. At block 1220, the SMF receives a SM policy control message from a PCF indicating the CAG information for traffic offloading. At block 1230, the SMF triggers, based on the session management policy control message, offloading of traffic targeted to and from a terminal device requested PDU session associated with the CAG information to the UPF.

[0170] In some embodiments, the UPF is associated with a base station serving the terminal device as a local UPF, and wherein to trigger the offloading, the SMF may apply, based on the SM policy control message, a traffic routing reconfiguration to a PDU Session Anchor (PSA) UPF.

[0171] In some embodiments, the SM policy control message further indicates at least one of the following: identity information of the terminal device; or a traffic filter comprising of a list of CAG IDs indicating traffic to be offloaded to the UPF.

[0172] In some embodiments, the CAG information includes a CAG ID or a list of CAG IDs configured for a base station, and wherein the UPF is associated with the base station as a local UPF.

[0173] FIG. 13 illustrates a flowchart of an example method 1300 implemented at an AF in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 1300 will be described from the perspective of the AF 195 with reference to FIGS. 2 to 7.

[0174] At block 1310, the AF transmits, to a NEF, a TI request indicating CAG information for traffic offloading.

[0175] In some embodiments, the CAG information includes a CAG ID or a list of CAG IDs configured for a base station, and wherein at least one UPF is associated with the basestation as a local UPF.

[0176] In some embodiments, the TI request further indicates at least one of the following: identity information of a terminal device; or a traffic filter comprising of a list of CAG IDs indicating traffic to be offloaded to the at least one UPF.

[0177] FIG. 14 illustrates a flowchart of an example method 1400 implemented at a UDR comprising a data repository in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 1400 will be described from the perspective of the UDR 185 with reference to FIGS. 2 to 7.

[0178] At block 1410, the UDR receives, from a NEF, a request to store TI information indicating CAG information for traffic offloading. At block 1420, the UDR updates TI information stored in the network device based on the CAG information for the traffic offloading. At block 1430, the UDR transmits a notification to a PCF that subscribes the TI information updates indicating the change on CAG information for traffic offloading.

[0179] FIG. 15 illustrates a flowchart of an example method 1500 implemented at a NEF in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 1500 will be described from the perspective of the NEF 170 with reference to FIGS. 2 to 7.

[0180] At block 1510, the NEF 170 receives, from an AF, a TI request indicating CAG information for traffic offloading. At block 1520, the NEF 170 transmits to a data repository, a request to store TI information indicating the CAG information for traffic offloading.

[0181] FIG. 16 illustrates a flowchart of an example method 1600 implemented at a terminal device (e.g., UE) in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 1600 will be described from the perspective of the UE 110 with reference to FIGS. 2 to 7.

[0182] At block 1610, the terminal device receives, from an AMF, a message indicating mapping information between one or more DNNs and one or more CAG IDs. At block 1620, the terminal device determines a DNN of the one or more DNNs based on the mapping information and a CAG ID supported by a cell of a base station that the terminal device accesses. At block 1630, the terminal device transmits, to the AMF and via the base station of the cell, a PDU session establishment request including the determined DNN as a requested DNN.

[0183] In some embodiments, each of the one or more DNNs is mapped to one or more CAG IDs.

[0184] In some embodiments, the terminal device may store the mapping information.

[0185] In some embodiments, the terminal device may request a PDU session to be established via a UPF associated with the base station as a local UPF by indicating the determined DNN.

[0186] In some embodiments, the message indicating the mapping information is an NAS message.

[0187] In some embodiments, the message indicating the mapping information comprises at least one of: a registration accept message; a registration reject message; or a UE configuration update message.

[0188] FIG. 17 illustrates a flowchart of an example method 1700 implemented at an AMF in accordance with some other embodiments of the present disclosure. For ease of understanding, the method 1700 will be described from the perspective of the AMF 140 with reference to FIGS. 2 to 7.

[0189] At block 1710, the AMF transmits, to a terminal device, a message indicating mapping information between one or more DNNs and one or more CAG IDs. At block 1720, the AMF receives, from the terminal device and via a base station, a PDU session establishment request including a requested DNN, wherein the requested DNN is determined based on the mapping information and a CAG ID supported by a cell of the base station that the terminal device accesses.

[0190] In some embodiments, each of the one or more DNNs is mapped to one or more CAG IDs.

[0191] In some embodiments, the AMF may transmit a message indicating the CAG ID to an SMF for selection of a UPF associated with the base station as a local UPF.

[0192] In some embodiments, the message indicating the mapping information is an NAS message.

[0193] In some embodiments, the message indicating the mapping information comprises at least one of: a registration accept message; a registration reject message; or a UE configuration update message.

[0194] In some embodiments, an apparatus capable of performing the method 800 (for example, at an SMF) may comprise means for performing the respective steps of the method 800. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0195] In some embodiments, the apparatus comprises means for receiving CAG information associated with a request of a terminal device for a data session from an AMF; and means for determining a UPF to serve the terminal device and the data session based on address information of the UPF and the CAG information associated with the request of the terminal device for the data session.

[0196] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 800. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0197] In some embodiments, an apparatus capable of performing the method 900 (for example, at an AMF) may comprise means for performing the respective steps of the method 900. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0198] In some embodiments, the apparatus comprises means for transmitting CAG information associated with a request of terminal device for a data session to an SMF.

[0199] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 900. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0200] In some embodiments, an apparatus capable of performing the method 1000 (for example, at a UPF) may comprise means for performing the respective steps of the method 1000. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0201] In some embodiments, the apparatus comprises means for transmitting CAG information and address information of a UPF associated with the CAG information to atleast one SMF or to an NRF.

[0202] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 1000. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0203] In some embodiments, an apparatus capable of performing the method 1100 (for example, at a base station) may comprise means for performing the respective steps of the method 1100. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0204] In some embodiments, the apparatus comprises means for transmitting CAG information and address information of at least one UPF associated with the CAG information to an AMF.

[0205] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 1100. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0206] In some embodiments, an apparatus capable of performing the method 1200 (for example, at an SMF) may comprise means for performing the respective steps of the method 1200. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0207] In some embodiments, the apparatus comprises means for obtaining CAG information and address information of a UPF associated with the CAG information; means for receiving an SM policy control message from a PCF indicating the CAG information for traffic offloading; and means for triggering, based on the session management policy control message, offloading of traffic targeted to and from a terminal device requested PDU session associated with the CAG information to the UPF.

[0208] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 1200. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at leastone memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0209] In some embodiments, an apparatus capable of performing the method 1300 (for example, at an AF) may comprise means for performing the respective steps of the method 1300. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0210] In some embodiments, the apparatus comprises means for transmitting, to an NEF, a TI request indicating CAG information for traffic offloading.

[0211] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 1300. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0212] In some embodiments, an apparatus capable of performing the method 1400 (for example, at UDR) may comprise means for performing the respective steps of the method 1400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0213] In some embodiments, the apparatus comprises means for receiving, from an NEF, a request to store TI information indicating CAG information for traffic offloading; means for updating TI information stored in the network device based on the CAG information for the traffic offloading; and means for transmitting a notification to a PCF that subscribes the TI information updates indicating the change on CAG information for traffic offloading.

[0214] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 1400. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0215] In some embodiments, an apparatus capable of performing the method 1500 (for example, at an NEF) may comprise means for performing the respective steps of the method 1500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0216] In some embodiments, the apparatus comprises means for receiving, from an AF, a TI request indicating CAG information for traffic offloading; and means for transmitting, to a data repository, a request to store TI information indicating the CAG information for traffic offloading.

[0217] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 1500. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0218] In some embodiments, an apparatus capable of performing the method 1600 (for example, at a terminal device) may comprise means for performing the respective steps of the method 1600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0219] In some embodiments, the apparatus comprises means for receiving, from an AMF, a message indicating mapping information between one or more DNNs and one or more CAG IDs; means for determining a DNN of the one or more DNNs based on the mapping information and a CAG ID supported by a cell of a base station that the terminal device accesses; and means for transmitting, to the AMF and via the base station of the cell, a PDU session establishment request including the determined DNN as a requested DNN.

[0220] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 1600. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0221] In some embodiments, an apparatus capable of performing the method 1700 (for example, at an AMF) may comprise means for performing the respective steps of the method 1700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

[0222] In some embodiments, the apparatus comprises means for transmitting, to a terminal device, a message indicating mapping information between one or more DNNs and one or more CAG IDs; and means for means for receiving, from the terminal device and via a base station, a PDU session establishment request including a requested DNN, wherein therequested DNN is determined based on the mapping information and a CAG ID supported by a cell of the base station that the terminal device accesses.

[0223] In some embodiments, the apparatus further comprises means for performing other steps in some embodiments of the method 1700. In some embodiments, the means comprises at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

[0224] FIG. 18 illustrates a simplified block diagram of a device 1800 that is suitable for implementing some embodiments of the present disclosure. The device 1800 may be provided to implement a communication device, for example, UEs, the network devices, base stations, or the terminal devices as shown in FIGS. 1 to 7. As shown, the device 1800 includes one or more processors 1810, one or more memories 1820 coupled to the processor 1810, and one or more communication modules 1840 coupled to the processor 1810.

[0225] The communication module 1840 is for bidirectional communications. The communication module 1840 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

[0226] The processor 1810 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 1800 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0227] The memory 1820 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 1824, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 1822 and other volatile memories that will not last in the power-down duration.

[0228] A computer program 1830 includes computer executable instructions that are executed by the associated processor 1810. The program 1830 may be stored in the ROM1824. The processor 1810 may perform any suitable actions and processing by loading the program 1830 into the RAM 1822.

[0229] The embodiments of the present disclosure may be implemented by means of the program 1830 so that the device 1800 may perform any process of the disclosure as discussed with reference to FIGS. 8 to 17. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0230] In some embodiments, the program 1830 may be tangibly contained in a computer- readable medium which may be included in the device 1800 (such as in the memory 1820) or other storage devices that are accessible by the device 1800. The device 1800 may load the program 1830 from the computer-readable medium to the RAM 1822 for execution. The computer-readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like.

[0231] FIG. 19 illustrates a block diagram of an example of a computer-readable medium 1900 in accordance with some embodiments of the present disclosure. The computer- readable medium 1900 has the program 1830 stored thereon. It is noted that although the computer-readable medium 1900 is depicted in form of CD or DVD in FIG. 13, the computer-readable medium 1900 may be in any other form suitable for carry or hold the program 1830.

[0232] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0233] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out theprocess or methods 200 to 1700 as described above with reference to FIGS. 2 to 17. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[0234] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program codes, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0235] In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer-readable medium, and the like.

[0236] The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer-readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0237] Further, while operations are depicted in a particular order, this should not beunderstood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

[0238] Although the present disclosure has been described in languages specific to structural features and / or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

WHAT IS CLAIMED IS:

1. A terminal device comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to: receive, from an Access and Mobility management Function (AMF), a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); determine a DNN of the one or more DNNs based on the mapping information and a CAG ID supported by a cell of a base station that the terminal device accesses; and transmit, to the AMF and via the base station of the cell, a Protocol Data Unit (PDU) session establishment request including the determined DNN as a requested DNN.

2. The terminal device of claim 1, wherein each of the one or more DNNs is mapped to one or more CAG IDs.

3. The terminal device of claim 1 or 2, wherein the terminal device is further caused to store the mapping information.

4. The terminal device of any of claims 1 to 3, wherein the terminal device is further caused to: request a PDU session to be established via a User Plane Function (UPF) associated with the base station as a local UPF by indicating the determined DNN.

5. The terminal device of any of claims 1 to 4, wherein the message indicating the mapping information is a Non Access Stratum (NAS) message.

6. The terminal device of any of claims 1 to 5, wherein the message indicating the mapping information comprises at least one of: a registration accept message; a registration reject message; or a UE configuration update message.

7. A network device comprising an Access and Mobility management Function (AMF), the network device comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to: transmit, to a terminal device, a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); and receive, from the terminal device and via a base station, a Protocol Data Unit (PDU) session establishment request including a requested DNN, wherein the requested DNN is determined based on the mapping information and a CAG ID supported by a cell of the base station that the terminal device accesses.

8. The network device of claim 7, wherein each of the one or more DNNs is mapped to one or more CAG IDs.

9. The network device of claim 7 or 8, wherein the network device is further caused to: transmit a message indicating the CAG ID to a Session Management Function (SMF) for selection of a User Plane Function (UPF) associated with the base station as a local UPF.

10. The network device of any of claims 7 to 9, wherein the message indicating the mapping information is a Non Access Stratum (NAS) message;11. The network device of any of claims 7 to 10, wherein the message indicating the mapping information comprises at least one of: a registration accept message; a registration reject message; or a UE configuration update message.

12. A method comprising: receiving, from an Access and Mobility management Function (AMF), a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); determining a DNN of the one or more DNNs based on the mapping information and a CAG ID supported by a cell of a base station which the terminal device accesses; and transmitting, to the AMF and via the base station a Protocol Data Unit (PDU) session establishment request including the determined DNN as a requested DNN.

13. A method comprising: transmitting, to a terminal device, a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); and receiving, from the terminal device and via a base station, a Protocol Data Unit (PDU) session establishment request including a requested DNN, wherein the requested DNN is determined based on the mapping information and a CAG ID supported by a cell of the base station that the terminal device accesses.

14. A computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least: receiving, from an Access and Mobility management Function (AMF), a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); determining a DNN of the one or more DNNs based on the mapping information and a CAG ID supported by a cell of a base station which the terminal device accesses; and transmitting, to the AMF, via the base station, a Protocol Data Unit (PDU) establishment request including the determined DNN as a requested DNN.

15. A computer readable medium comprising program instructions that, when executed by an apparatus, cause the apparatus to perform at least: transmitting, to a terminal device, a message indicating mapping information between one or more Data Network Names (DNNs) and one or more Closed Access Group (CAG) identities (IDs); and receiving, from the terminal device and via a base station, a Protocol Data Unit (PDU) session establishment request including a requested DNN, wherein the requested DNN is determined based on the mapping information and a CAG ID supported by a cell of the base station that the terminal device accesses.

Images