Method and device for message transmission

Abstract

The embodiment of the invention provides a message transmission method and device. A method performed by a first SMF may include determining first information. The first information indicates that the second SMF does not need to report at least one item to the first SMF when no other item needs to be delivered to the first SMF. The method may also include transmitting the first information to a second SMF.

Description

Technical Field

[0001] The non-limiting and exemplary embodiments of this disclosure generally relate to the field of communication technology, and more particularly to methods and apparatus for message transmission. Background Technology

[0002] This section introduces several aspects that can help in a better understanding of this disclosure. Therefore, the statements in this section should be read in this light and should not be construed as an admission of what is in or not in the prior art.

[0003] In a communication network, various sessions may exist, such as Protocol Data Unit (PDU) sessions. PDU sessions can be established in various ways. For example, a User Equipment (UE) can initiate a PDU session establishment process. The network can also trigger a PDU session establishment process. PDU sessions can be managed by the Session Management Function (SMF).

[0004] An intermediate NF can be inserted when the UE is located outside the service area of ​​a network function (NF) (e.g., SMF), or when the current NF (e.g., SMF) cannot provide the target data network access identifier (DNAI) for the service route of the local access data network (DN).

[0005] For example, an intermediate SMF (I-SMF) can be inserted between the SMF and the Access and Mobility Management Function (AMF). The I-SMF has an N11 interface with the AMF and an N16a interface with the SMF, and is responsible for controlling one or more user plane functions (one or more UPFs) that the SMF cannot directly control. The exchange of Session Management (SM) contexts and the forwarding of tunneling information (if needed) are performed directly between the two SMFs without the involvement of the AMF.

[0006] Depending on the scenario, a PDU session in non-roaming or localized scenarios can be served by a single SMF, or by both an SMF and an I-SMF. When a PDU session is served by both an SMF and an I-SMF, the SMF is an NF instance with interfaces for Policy Control Functions (PCF) and Charging Functions (CHF).

[0007] Sections 4.23.2-16 of the 3GPP Technical Specification (TS) 23.502 V18.1.1 (whose publication is incorporated herein by reference in its entirety) describe various procedures related to I-SMF, such as I-SMF insertion / change / removal procedures.

[0008] In the case of roaming for a home route PDU session, the following situations may occur:

[0009] The UE moves out of the visited SMF (V-SMF) service area in the serving public land mobile network (PLMN);

[0010] The UE moves to another (service) visit PLMN (VPLMN);

[0011] The UE moves between its home PLMN (HPLMN) and VPLMN.

[0012] In the above case, the procedure for I-SMF in Clause 4.23.2-16 of 3GPP TS 23.502 V18.1.1, by replacing I-SMF with V-SMF and SMF with H-SMF, is applicable to V-SMF insertion / change / removal.

[0013] For an established PDU session, if the UE is not in the SMF service area, an I-SMF is inserted. In this case, when the UE moves from the HPLMN to the VPLMN, the V-SMF is inserted and the I-SMF is removed. For moves from the VPLMN to the HPLMN, the I-SMF is inserted and the V-SMF is removed. The procedure in Clause 4.23.2-16 of 3GPP TS 23.502 V18.1.1 applies to this situation, namely, for moves from the HPLMN to the VPLMN, the target or new I-SMF is replaced with the V-SMF, and for moves from the VPLMN to the HPLMN, the source or old I-SMF is replaced with the V-SMF.

[0014] Various information, such as PduSessionCreateData and HsmfUpdateData, can be transferred between two NFs (e.g., SMF).

[0015] PduSessionCreateData can be sent from V-SMF or I-SMF to H-SMF or Anchor SMF (A-SMF). PduSessionCreateData can be a representation of a PDU session that will be created in H-SMF or A-SMF.

[0016] Table 1 shows an example of PDUSSessionCreateData, which is part of Table 6.1.6.2.9-1 of 3GPP TS 29.502 V18.2.0, the disclosure of which is incorporated herein by reference in its entirety. UICC stands for Universal Integrated Circuit Card. ID stands for Identifier. EPS stands for Evolved Packet System. 5GS stands for System-5. SM stands for Session Management. IE stands for Information Element. LADN stands for Local Area Data Network. SNPN stands for Standalone Non-Public Network. GUAMI stands for Globally Unique AMF Identifier.

[0017] Table 1: Definition of type PduSessionCreateData

[0018]

[0019] HsmfUpdateData can be sent from H-SMF or A-SMF to V-SMF or I-SMF. PduSessionCreateData can be a representation of an update applied to a PDU session.

[0020] Table 2 shows an example of HsmfUpdateData, which is part of Table 6.1.6.2.11-1 in 3GPP TS 29.502 V18.2.0. MAPDU stands for Multiple Access PDU. NID stands for Network Identifier. UTC stands for Coordinated Universal Time. RAT stands for Radio Access Technology.

[0021] Table 2: Definition of type HsmfUpdateData

[0022]

[0023] Policy control request triggers can be sent from PCF or CHF to H-SMF or A-SMF.

[0024] Table 3 shows an example of a policy control request trigger, which is identical to Table 5.6.3.6-1 of 3GPP TS 29.512 V18.1.0, the disclosure of which is incorporated herein by reference in its entirety.

[0025] Table 3: Enumeration of PolicyControlRequestTrigger

[0026]

[0027] Summary of the Invention

[0028] The present invention is provided in a simplified form to introduce a chosen concept, which is further described in the following detailed description. This summary is neither intended to identify key or essential features of the claimed subject matter nor to limit the scope of the claimed subject matter.

[0029] Existing information transmission solutions may have some problems, potentially introducing many unnecessary messages between two NFs. For example, they may introduce many unnecessary N16 / N16a signaling messages between two SMFs.

[0030] For a PDU session established using I-SMF / V-SMF, any of the following scenarios may occur:

[0031] PCF / CHF has not yet provided H-SMF / A-SMF with event triggers for one or more items (such as changed IEs). I-SMF / V-SMF does not need to pass these one or more items on the N16 / N16a interface, and H-SMF / A-SM will not report these one or more items (such as changes to information elements (IEs), such as uelocation, time zone, service node, PLMN changes) to FPCF / CHF.

[0032] A-SMF / H-SMF has subscribed to event reports (e.g., uelocation, time zone) for one or more items through the Event Open Service. The Event Open Service does not need to interact with I-SMF / V-SMF, so I-SMF / V-SMF does not need to pass one or more items (e.g., changed IE) on the N16 / N16a interface.

[0033] A-SMF / H-SMF does not require one or more items (e.g., security results), and I-SMF / V-SMF does not require passing one or more items (e.g., modified IE) on the N16 / N16a interface.

[0034] When the UE is mobile, one or more items (such as changed IEs (e.g., uelocation, uetimezone)) are always sent from the AMF to the I-SMF / V-SMF, which then forwards them to the A-SMF / H-SMF. For the AMF to pass these one or more items to the I-SMF / V-SMF on the N11 interface, this is a piggybacking process. However, on the N16 / N16a interface, due to 3GPP specifications (e.g., 3GPP TS 29.502 V18.2.0) (see, for example, Table 6.1.6.2.11-1: Definition of Type HsmfUpdateData), if a change exists, it should be passed on the N16 / N16a interface. Even if no other necessary IEs will be sent to the A-SMF / H-SMF, and / or the A-SMF / H-SMF does not require such information, the I-SMF / V-SMF always transmits the changed IEs (e.g., uelocation, time zone) to the H / A-SMF via messages such as the Nsmf_PDUSession_UpdateSMContext request as described in 3GPP TS 23.502 V18.1.1.

[0035] This issue has introduced a large amount of unnecessary N16 / N16a signaling, especially for UEs with frequent mobility and / or for roaming services, where such signaling is generally not required.

[0036] To overcome or mitigate at least one of the above-mentioned or other problems, embodiments of this disclosure propose an improved solution for message transmission.

[0037] In a first aspect of this disclosure, a method is provided performed by a first Session Management Function (SMF). The method may include determining first information. This first information indicates that a second SMF does not need to report at least one item to the first SMF when no other items need to be passed to the first SMF. The method may further include sending the first information to the second SMF.

[0038] In a second aspect of this disclosure, a method is provided performed by a second Session Management Function (SMF). The method may include receiving first information from a first SMF or a legacy second SMF. This first information indicates that the second SMF does not need to report at least one item to the first SMF when no other items need to be passed to the first SMF. The method may further include obtaining said at least one item.

[0039] In a third aspect of this disclosure, a first SMF is provided. The first SMF includes a processor and a memory coupled to the processor. The memory stores instructions executable by the processor. The first SMF is operable to determine first information. The first information indicates that a second SMF does not need to report at least one item to the first SMF when no other items need to be passed to the first SMF. The first SMF is further operable to send the first information to the second SMF.

[0040] In a fourth aspect of this disclosure, a second SMF is provided. The second SMF includes a processor and a memory coupled to the processor. The memory stores instructions executable by the processor. The second SMF is operable to receive first information from a first SMF or a legacy second SMF. The first information indicates that the second SMF does not need to report at least one item to the first SMF when no other item needs to be passed to the first SMF. The second SMF is further operable to receive the at least one item.

[0041] In a fifth aspect of this disclosure, a computer program product comprising instructions is provided, which, when executed by at least one processor, cause the at least one processor to perform the method according to either the first or the second aspect.

[0042] In a sixth aspect of this disclosure, a computer-readable storage medium is provided that stores instructions which, when executed by at least one processor, cause the at least one processor to perform the method according to either the first or second aspect.

[0043] The embodiments described herein can provide numerous advantages, and a non-exhaustive list of examples of these advantages is provided below. In some embodiments described herein, unnecessary messages (e.g., roaming signaling messages) can be avoided between two network nodes (e.g., two SMFs (e.g., I-SMF / V-SMF and A-SMF / H-SMF)). In some embodiments described herein, signaling bandwidth (e.g., roaming signaling) on ​​interfaces (e.g., N16 interfaces) can be saved, particularly for a large number of users (e.g., millions of UEs). In some embodiments described herein, PDU mobility processes (e.g., roaming PDU mobility processes) can be simplified by reducing the transmission of unnecessary messages (e.g., N16 signaling messages). The embodiments described herein are not limited to the features and advantages described above. Additional features and advantages will be recognized by those skilled in the art upon reading the following detailed description. Attached Figure Description

[0044] From the following detailed description with reference to the accompanying drawings, by way of example, the above and other aspects, features, and benefits of various embodiments of the present disclosure will become more fully apparent, in which similar reference numerals or letters are used to refer to similar or equivalent elements. The drawings are shown to facilitate a better understanding of embodiments of the present disclosure and are not necessarily drawn to scale, wherein:

[0045] Figure 1a The diagram schematically illustrates a 5G system roaming architecture in a home routing scenario using reference point representation according to an embodiment of the present disclosure;

[0046] Figure 1b The non-roaming architecture with I-SMF inserted into the PDU session is schematically illustrated in the reference point representation;

[0047] Figure 2a This illustrates a problem scenario of Xn-based switching within an AMF without V-SMF changes and without V-UPF changes, according to embodiments of the present disclosure;

[0048] Figure 2b This illustrates a problem scenario of N2-based switching within an AMF without V-SMF changes and without V-UPF changes, according to embodiments of the present disclosure;

[0049] Figures 3a-3b , Figures 4a-4d , Figure 5-7 A flowchart of a method according to an embodiment of this disclosure is shown;

[0050] Figure 8a This is a block diagram illustrating an apparatus suitable for implementing some embodiments of the present disclosure;

[0051] Figure 8b This is a block diagram illustrating a first SMF according to an embodiment of the present disclosure;

[0052] Figure 8c This is a block diagram illustrating a second SMF according to an embodiment of the present disclosure. Detailed Implementation

[0053] Embodiments of this disclosure are described in detail with reference to the accompanying drawings. It should be understood that these embodiments are discussed only for the purpose of enabling those skilled in the art to better understand and thus implement this disclosure, and not to suggest any limitation on the scope of this disclosure. References to features, advantages, or similar language throughout this specification do not imply that all features and advantages achievable with this disclosure should be present in or in any single embodiment of this disclosure. Rather, references to features and advantages should be understood as meaning that a particular feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of this disclosure. Furthermore, in one or more embodiments, the features, advantages, and characteristics described in this disclosure may be combined in any suitable manner. Those skilled in the art will recognize that this disclosure can be practiced without one or more specific features or advantages in a particular embodiment. In other instances, additional features and advantages may be recognized in some embodiments, and these additional features and advantages may not be present in all embodiments of this disclosure.

[0054] As used herein, the term "network" refers to a network that conforms to any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE Advanced, Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), and other wireless networks. CDMA networks can implement radio technologies such as Universal Terrestrial Radio Access (UTRA). UTRA includes other variants of WCDMA and CDMA. TDMA networks can implement radio technologies such as Global System for Mobile Communications (GSM). OFDMA networks can implement radio technologies such as Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, Ad-hoc networks, wireless sensor networks, etc. In the following description, the terms "network" and "system" are used interchangeably. Furthermore, communication between two devices in a network can be performed according to any suitable communication protocol, including but not limited to those defined by standards organizations such as 3GPP. For example, communication protocols may include first-generation (1G), 2G, 3G, 4G, 4.5G, 5G, 6G communication protocols and / or any other currently known or future-developed protocols.

[0055] The terms "network device," "network node," or "network function" refer to any suitable function that can be implemented in a (physical or virtual) network entity within a communication network. For example, a network function can be implemented as a network element on dedicated hardware, as a software instance running on dedicated hardware, or as a virtualized function instantiated on a suitable platform (e.g., on cloud infrastructure). For instance, a 5G system (5GS) can include multiple NFs such as AMF (Access and Mobility Management Function), SMF (Session Management Function), AUSF (Authentication Service Function), UDM (Unified Data Management), PCF (Policy Control Function), AF (Application Function), NEF (Network Open Function), UPF (User Plane Function), and NRF (Network Repository Function), RAN (Radio Access Network), SCP (Serving Communication Agent), NWDAF (Network Data Analysis Function), NSSF (Network Slice Selection Function), NSSAAF (Network Slice Specific Authentication and Authorization Function), etc. In other embodiments, such as depending on the specific network, network functions can include different types of NFs.

[0056] Virtualization means creating virtual versions of devices or equipment, which may include virtualized hardware platforms, storage devices, and network resources. As used herein, virtualization can be applied to provider edge nodes and relates to an implementation in which at least a portion of functionality is implemented as one or more virtual components (e.g., via one or more applications, components, functions, virtual machines, or containers executed on one or more physical processing nodes in one or more networks).

[0057] In some embodiments, some or all of the functionality described herein may be implemented as virtual components executed by one or more virtual machines, which are implemented in one or more virtual environments hosted by one or more hardware nodes. Furthermore, in embodiments where the virtual node is not a radio access node or does not require radio connectivity (e.g., a core network node), the provider edge node or PE may be fully virtualized.

[0058] This functionality can be implemented by one or more applications (which may alternatively be referred to as software instances, virtual devices, network functions, virtual nodes, virtual network functions, etc.) operable to implement some of the features, functions, and / or benefits of some embodiments disclosed herein. The application runs in a virtualized environment that provides hardware including processing circuitry and memory. The memory stores instructions executable by the processing circuitry, thereby enabling the application to provide one or more of the features, benefits, and / or functions disclosed herein.

[0059] The virtualization environment includes general-purpose or special-purpose network hardware devices, which include a collection of one or more processors or processing circuits. These can be commercial off-the-shelf (COTS) processors, application-specific integrated circuits (ASICs), or any other type of processing circuitry, including digital or analog hardware components or dedicated processors. Each hardware device may include memory, which can be non-persistent memory used for temporarily storing instructions or software executed by the processing circuitry. Each hardware device may include one or more network interface controllers (NICs), also known as network interface cards, which include physical network interfaces. Each hardware device may also include non-transient, persistent, machine-readable storage media—containing software and / or instructions executable by the processing circuitry stored therein. The software can include any type of software, including software for instantiating one or more virtualization layers (also known as hypervisors), software for executing virtual machines, and software that allows them to perform the functions, features, and / or benefits associated with some of the embodiments described herein.

[0060] Virtual machines include virtual processing, virtual memory, virtual networks or interfaces, and virtual storage, and can be run by a corresponding virtualization layer or hypervisor. Different embodiments of virtual device instances can be implemented on one or more virtual machines, and can be implemented in different ways.

[0061] During operation, the processing circuitry executes software to instantiate the hypervisor, or virtualization layer, sometimes referred to as the virtual machine monitor (VMM). The virtualization layer presents a virtual operating platform to the virtual machines that appears as network hardware.

[0062] The term "terminal device" refers to any terminal device that can access a communication network and receive services from it. By way of example and not limitation, a terminal device refers to a mobile terminal, user equipment (UE), or other suitable device. A UE can be, for example, a subscriber station (SS), a portable subscriber station, a mobile station (MS), or an access terminal (AT). Terminal devices can include, but are not limited to, portable computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback devices, mobile phones, cellular phones, smartphones, Voice over IP (VoIP) phones, wireless local loop phones, tablet computers, wearable devices, personal digital assistants (PDAs), portable computers, desktop computers, wearable terminal devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEE), laptop installed devices (LME), USB dongles, smart devices, wireless customer premises equipment (CPE), etc. In the following description, the terms "terminal device," "terminal," "user equipment," and "UE" are used interchangeably. As an example, a terminal device may represent a UE configured to communicate according to one or more communication standards published by the 3rd Generation Partnership Project (3GPP), such as 3GPP's LTE or NR standards. As used herein, a "User Equipment" or "UE" may not necessarily have a "user" in relation to a human user who owns and / or operates the associated device. In some embodiments, a terminal device may be configured to send and / or receive information without direct human interaction. For example, when triggered by an internal or external event, or in response to a request from a communication network, a terminal device may be designed to send information to the network according to a predetermined schedule. Alternatively, a UE may represent a device intended for sale to a human user or operated by a human user but which may not initially be associated with a particular human user.

[0063] As another example, in the Internet of Things (IoT) scenario, a terminal device can represent a machine or other device that performs monitoring and / or measurement, and transmits the results of such monitoring and / or measurement to another terminal device and / or network device. In this case, the terminal device can be a machine-to-machine (M2M) device, which in the 3GPP context can be referred to as a machine-type communication (MTC) device. As a specific example, a terminal device can be a UE that implements the 3GPP Narrowband Internet of Things (NB-IoT) standard. Specific examples of such machines or devices are sensors, metering devices (e.g., electricity meters), industrial machinery, or household or personal appliances such as refrigerators, televisions, personal wearable devices (e.g., watches), etc. In other scenarios, a terminal device can represent a vehicle or other device capable of monitoring and / or reporting its operating status or other functions related to its operation.

[0064] References to "an embodiment," "embodiment," "exemplary embodiment," etc., in the specification indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes that particular feature, structure, or characteristic. Furthermore, these phrases do not necessarily refer to the same embodiment. Additionally, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is claimed that, whether explicitly described or not, its influence in conjunction with other embodiments is within the knowledge of those skilled in the art.

[0065] It should be understood that while the terms “first” and “second” may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of the exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed terms.

[0066] As used herein, the phrase “at least one of A and B” or “at least one of A or B” should be understood as “A only, B only, or both A and B”. The phrase “A and / or B” should be understood as “A only, B only, or both A and B”.

[0067] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” as used herein are also intended to include the plural forms. It will be further understood that, when used herein, the terms “comprising,” “including,” “having,” “owning,” “containing,” and / or “covering” specify the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0068] Note that the terms used in this article are for ease of description and to distinguish between nodes, devices, or networks, etc. As technology evolves, other terms with similar / identical meanings may also be used.

[0069] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0070] It should be noted that some embodiments of this disclosure are described primarily with respect to SMF and N16 / N16a, which are used as non-limiting examples for certain exemplary network functions and network interfaces. Therefore, the description of the exemplary embodiments given herein specifically refers to terms directly related to them. Such terms are used only in the context of the presented non-limiting examples and embodiments and are not intended to limit this disclosure in any way. Rather, any other network functions and network interfaces can be used equivalently, provided that the exemplary embodiments described herein are applicable.

[0071] Although the subjects described herein can be implemented in any suitable type of system using any suitable components, the embodiments disclosed herein are related to conforming to... Figures 1a-1b The communication system described is based on the exemplary system architecture shown. For simplicity, Figures 1a-1b The system architecture described herein only depicts a few exemplary elements. In practice, a communication system may further include any additional elements suitable for supporting communication between terminal devices or between a wireless device and another communication device (such as a landline telephone, service provider, or any other network node or terminal device). The communication system may provide communication and various types of services to one or more terminal devices to facilitate their access to and / or use of services provided by or via the communication system.

[0072] Figure 1a The diagram schematically illustrates a 5G system roaming architecture in a home routing scenario using reference points, according to embodiments of the present disclosure. Figure 1aThe architecture is the same as that described in Figure 4.2.4-6 of 3GPP TS 23.501 V18.1.0, the contents of which are incorporated herein by reference in their entirety. Figure 1a The system architecture may include some exemplary elements such as AUSF, AMF, data network, visited NSSF (V-NSSF), home NSSF (H-NSSF), visited PCF (V-PCF), visited SMF (V-SMF), home SMF (H-SMF), UDM, UPF, AF, UE, (R)AN, NSSAAF (Network Slice Specific Authentication and Authorization Function), etc.

[0073] According to an exemplary embodiment, the UE can be accessed via, for example... Figure 1a Reference point N1, as shown, establishes a signaling connection with the AMF. This signaling connection enables NAS (Non-Access Stratum) signaling exchange between the UE and the core network, including a signaling connection between the UE and the (R)AN, and an N2 connection between the (R)AN and the AMF for the UE. The (R)AN can communicate with the UPF via reference point N3. The UE can establish a Protocol Data Unit (PDU) session to a data network (e.g., an operator's network or the Internet) via reference point N6 through the UPF.

[0074] The N38 reference point can be located between V-SMFs within the same VPLMN, or between V-SMFs in different VPLMNs (to enable mobility between PLMNs).

[0075] For the roaming scenario described above, each PLMN implements a proxy function to ensure secure interconnection and hide the topology on the interface between PLMNs.

[0076] like Figure 1a As further illustrated, it also shows several reference points, such as N1, N2, N3, N4, N6, N9, N11, N38, N16, N7, N5, N22, N15, N8, N24, N10, N58, N12, N31, N59, and N13, which can support interaction between NF services in NF. For example, these reference points can be implemented through corresponding NF service-based interfaces and by specifying some NF service consumers and providers and their interactions to execute specific system procedures.

[0077] Figure 1a The various NFs shown in the diagram can be responsible for functions such as session management, mobility management, authentication, and security. Figure 1a The various NFs shown may contain, for example, the functions defined in Clause 6.2 of 3GPP TS 23.501 V18.1.0.

[0078] Figure 1bThe diagram schematically illustrates a non-roaming architecture in the reference point representation with I-SMF inserted into the PDU session, without an uplink classifier (UL-CL) / branch point (BP), according to an embodiment of the present disclosure. Figure 1b The architecture is as described in 3GPP TS 23.501 V18.1.0. Figure 5 It is identical to .34.2.2-1, and its publication is incorporated herein by full reference. Figure 1b The system architecture may include some exemplary elements, such as AUSF, AMF, DN, NSSF, PCF, I-SMF, SMF, UDM, UPF, AF, UE, (R)AN, CHF (billing function), etc.

[0079] According to an exemplary embodiment, such as Figure 1b As shown, the UE can establish a signaling connection with the AMF via reference point N1. This signaling connection enables NAS signaling exchange between the UE and the core network, including the signaling connection between the UE and the (R)AN, and the N2 connection between the (R)AN and the AMF for the UE. The (R)AN can communicate with the UPF via reference point N3. The UE can establish a PDU session with a data network (e.g., an operator network or the Internet) via the UPF through reference point N6.

[0080] N16a is the interface between SMF and I-SMF.

[0081] N38 is the interface between I-SMF.

[0082] like Figure 1b As shown, it also illustrates several reference points, such as N1, N2, N3, N4, N6, N9, N11, N14, N16a, N7, N5, N15, N38, N22, N12, N13, N8, N10, N40, and N13, which can support interactions between NF services within an NF. For example, these reference points can be implemented through corresponding NF service-based interfaces and by specifying NF service consumers and providers and their interactions to execute specific system procedures.

[0083] Figure 1b The various NFs shown can be responsible for functions such as session management, mobility management, authentication, and security. Figure 1b The various NFs shown may contain, for example, the functions defined in Clause 6.2 of 3GPP TS 23.501 V18.1.0.

[0084] Figure 2aThis paper illustrates a problem scenario of Xn-based handover within an AMF without V-SMF or V-UPF changes, according to an embodiment of the present disclosure. The Xn interface is defined between two RAN nodes.

[0085] In the embodiments, Xn-based handover within an AMF without V-SMF changes and without V-UPF changes can be the same as or similar to Xn-based inter-NG-RAN handover as described in Clause 4.9.1.2 of 3GPP TS 23.502 V18.1.1.

[0086] Step 1. Switching preparation.

[0087] Step 2. During the handover execution, the source (S) next-generation (NG) RAN forwards data to the target (T) NG RAN.

[0088] Step 3. T-NG-RAN sends an N2 path switching request to AMF.

[0089] Step 4. AMF sends an Nsmf_PDUSession_UpdateSMContext request (toBeSwitched, ueLocation, ueTimezone, N2 path switching request transmission) to V-SMF.

[0090] Step 5. The V-SMF sends a Packet Forwarding Control Protocol (PFCP) Session Modification Request (T-NGRAN-N3-Tunnel) to the visited UPF (V-UPF).

[0091] Step 6. V-UPF sends a PFCP session modification response to V-SMF.

[0092] Step 7. V-UPF sends N3 end marker to S-NG-RAN.

[0093] Step 8a. S-NG-RAN sends N3 end marker to T-NG-RAN.

[0094] Step 8b. The V-UPF sends downlink data to the T-NG-RAN, and the T-NG-RAN sends the downlink data to the UE.

[0095] Step 9a. V-SMF sends an Nsmf_PDUSession_UpdateSMContext response (Path Switching Request Confirmation Transmission (V-UPF-N3-Tunnel, Security Indication)) to AMF.

[0096] Step 9b. The UE sends uplink data to the T-NG-RAN, and the T-NG-RAN sends the uplink data to the V-UPF. The V-UPF then sends the uplink data to the H-UPF.

[0097] Step 10. V-SMF sends a PFCP session modification request (querying the URR) to V-UPF, and V-UPF sends a PFCP session modification response to V-SMF.

[0098] Step 11. V-SMF sends an Nchf_coveredCharging_Update request to V-CHF, and V-CHF sends an Nchf_coveredCharging_Update response to V-SMF.

[0099] Step 12. V-SMF sends an Nsmf_PDUSession_Update request (ueLocation, ueTimeZone) to H-SMF.

[0100] Step 13. H-SMF sends an Nsmf_PDUSession_Update response to V-SMF.

[0101] In steps 12-13, the problem may be that I-SMF / V-SMF does not need to pass changes such as ueLocation and ueTimeZone to A-SMF / H-SMF on the N16 / N16a interface.

[0102] As a first example, since PCF / CHF does not yet provide event triggers for items or IEs such as ueLocation and timezone, I-SMF / V-SMF does not need to pass the corresponding items or IEs (e.g., modified IEs) such as ueLocation and timezone to A-SMF / H-SMF on the N16 / N16a interface.

[0103] As a second example, since A-SMF / H-SMF has already subscribed to event reports for items or IEs (such as ueLocation, timezone) from AMF through the event open service that does not require interaction with I-SMF / V-SMF, I-SMF / V-SMF does not need to pass the corresponding items or IEs (such as changed IEs) such as ueLocation and timezone to A-SMF / H-SMF on the N16 / N16a interface.

[0104] As a third example, since H-SMF does not require event reporting for items or IEs (e.g., uelocation, timezone), I-SMF / V-SMF does not need to pass the corresponding items or IEs (e.g., changed IEs) such as ueLocation and timezone to A-SMF / H-SMF on the N16 / N16a interface.

[0105] Step 14. AMF sends an N2 path switching request confirmation to T-NG-RAN.

[0106] Step 15. T-NG-RAN sends a resource release message to S-NG-RAN.

[0107] Step 16. The UE can initiate the registration process.

[0108] Figure 2a The messages, terms, or abbreviations used in this document may be identical or similar to the corresponding messages, terms, or abbreviations described in various 3GPP specifications (e.g., 3GPP TS 23.502 V18.1.1 (e.g., Clause 4.9) or 3GPP TS 32.290 V18.1.0 (e.g., Clause 6.2.3) or 3GPP TS 23.501 V18.1.0 or 3GPP TS 29.502 V18.1.0).

[0109] Figure 2b This illustrates a problem scenario of N2-based handover within an AMF without V-SMF or V-UPF changes, according to embodiments of the present disclosure. N2 is a reference point between the RAN and the AMF.

[0110] In an embodiment, an N2-based handover within an AMF without V-SMF changes and without V-UPF changes can be the same as or similar to an N2-based handover between NG-RAN nodes as described in Clause 4.9.1.3 of 3GPP TS 23.502 V18.1.1.

[0111] Step 1. S-NG-RAN makes a decision to trigger relocation via N2.

[0112] Step 2. S-NG-RAN sends a handover request message to AMF.

[0113] Step 3. AMF sends an Nsmf_PDUSession_UpdateSMContext request (targetId, hoState = Preparing, N2 handover requires transmission) to V-SMF.

[0114] Step 4. V-SMF sends an Nsmf_PDUSession_UpdateSMContext response (hoState = Preparing, N2 PDU Session Resource Establishment Request Transmission) to AMF.

[0115] Step 5. The AMF sends a handover request to the T-NG-RAN.

[0116] Step 6. T-NG-RAN sends a handover request confirmation to AMF (hoState = Ready, T-NG-N3-Tunnel).

[0117] Step 7. AMF sends an Nsmf_PDUSession_UpdateSMContext request (hoState = Ready, switch request confirms transmission) to V-SMF.

[0118] Step 8. V-SMF sends an Nsmf_PDUSession_UpdateSMContext response (hoState = Ready, N2 Switching Command Transmission) to AMF.

[0119] Step 9. The AMF sends a handover command to the S-NG-RAN.

[0120] Step 10. The S-NG-RAN sends a handover command to the UE.

[0121] Step 11. The UE synchronizes to the new cell.

[0122] Step 12. The UE sends a handover confirmation message to the T-NG-RAN.

[0123] Step 13. T-NG-RAN sends a handover notification message to AMF.

[0124] Step 14. AMF sends an Nsmf_PDUSession_UpdateSMContext request (hoState = Complete) to V-SMF.

[0125] Step 15. V-SMF sends a PFCP session modification request (T-NGAN-N3-tunnel) to V-UPF.

[0126] Step 16. V-UPF sends a PFCP session modification response to V-SMF.

[0127] Step 17. V-SMF sends an Nsmf_PDUSession_UpdateSMContext response (hoState = Complete) to AMF.

[0128] Step 18. V-SMF sends a PFCP session modification request (URR query) to V-UPF. V-UPF sends a PFCP session modification response to V-SMF.

[0129] Step 19. V-SMF sends an Nchf_coveredCharging_Update request to V-CHF. V-CHF sends an Nchf_coveredCharging_Update response to V-SMF.

[0130] Step 20. V-SMF sends an Nsmf_PDUSession_Update request (ueLocation, ueTimeZone) to H-SMF.

[0131] Step 21. H-SMF sends an Nsmf_PDUSession_Update response to V-SMF.

[0132] In steps 20-21, the problem may be that the I-SMF / V-SMF does not need to pass changes such as ueLocation and ueTimeZone to the A-SMF / H-SMF on the N16 / N16a interface.

[0133] As a first example, since PCF / CHF does not yet provide event triggers for items or IEs such as ueLocation and timezone, I-SMF / V-SMF does not need to pass the corresponding items or IEs (e.g., modified IEs) such as ueLocation and timezone to A-SMF / H-SMF on the N16 / N16a interface.

[0134] As a second example, since A-SMF / H-SMF has already subscribed to event reports for items or IEs (such as ueLocation, timezone) from AMF through the event open service that does not require interaction with I-SMF / V-SMF, I-SMF / V-SMF does not need to pass the corresponding items or IEs (such as changed IEs) such as ueLocation and timezone to A-SMF / H-SMF on the N16 / N16a interface.

[0135] As a third example, since H-SMF does not require event reporting for items or IEs (such as ueLocation, timezone), I-SMF / V-SMF does not need to pass the corresponding items or IEs (such as changed IEs) such as ueLocation and timezone to A-SMF / H-SMF on the N16 / N16a interface.

[0136] Figure 2b The messages, terms, or abbreviations used in this document may be identical or similar to the corresponding messages, terms, or abbreviations described in various 3GPP specifications, such as 3GPP TS 23.502 V18.1.1 (e.g., Clause 4.9.1.3), 3GPP TS 32.290 V18.1.0 (e.g., Clause 6.2.3), 3GPP TS 23.501 V18.1.0, or 3GPP TS 29.502 V18.1.0.

[0137] To overcome or mitigate at least one of the above-mentioned or other problems, embodiments of this disclosure propose an improved solution for message transmission.

[0138] In an embodiment, if the V / I-SMF does not need to transmit one or more items (e.g., one or more changed IEs) on the N16 / N16a interface during the PDU session establishment process or PDU session lifecycle, the A-SMF / H-SMF notifies the I-SMF / V-SMF with a new IE (e.g., "notReportForChangedItems" (e.g., ULI change, time zone change, security result)).

[0139] For example, during the PDU session establishment process or PDU session lifecycle, in at least one of the following scenarios, it is not necessary to pass at least one item (e.g., a modified IE) on the N16 / N16a interface:

[0140] The PCF / CHF has not yet provided the H-SMF / A-SMF with event triggers for one or more items. The H-SMF / A-SMF will not report one or more items (such as changed IEs) to the PCF / CHF (e.g., uelocation, time zone, service node, PLMN change, Radio Access Technology (RAT) change), and the V / I-SMF is not required to pass one or more items (such as changed IEs) to the H-SMF / A-SMF on the N16 / N16a interface.

[0141] A-SMF / H-SMF has subscribed to event reports for one or more items (e.g., changed IE) (e.g., uelocation, time zone) through an event open service that does not require interaction with I-SMF / V-SMF. V / I-SMF does not need to pass one or more items (e.g., changed IE) to H-SMF / A-SMF on the N16 / N16a interface, or

[0142] A-SMF / H-SMF does not require one or more items (e.g., modified IE) (e.g., security results), and V / I-SMF does not require passing one or more items (e.g., modified IE) to H-SMF / A-SMF on the N16 / N16a interface.

[0143] During the PDU session establishment process or the PDU session lifecycle, the A-SMF / H-SMF may use a new IE to notify the I-SMF / V-SMF that the I-SMF / V-SMF does not need to report one or more items (e.g., changed IEs) to the A-SMF / H-SMF, and / or that the one or more items (e.g., changed IEs) were not requested by the A-SMF / H-SMF. For example, the new IE could be "notReportForChangedItems" (e.g., User Location Information (ULI) change, time zone change, security outcome). The new IE may be sent in a message such as an Nsmf_PDUSession_Create response or an Nsmf_PDUSession_Update request. The I-SMF / V-SMF may store the received new IEs, such as notReportForChangedItems.

[0144] In an embodiment, the new IE (e.g., notReportForChangedItems) (e.g., ULI change, time zone change, security result) can indicate:

[0145] If an item such as a changed IE (e.g., a ULI change or a time zone change) is in a newly received IE (e.g., notReportForChangedItems), and / or there are no other necessary IEs that need to be passed to A-SMF / H-SMF, then I-SMF / V-SMF should not send a special message (e.g., an Nsmf_PDUSession_Update request) to A-SMF / H-SMF to notify of items such as changed IEs, as it is not required by A-SMF / H-SMF.

[0146] In an embodiment, if there are changes to a new IE (e.g., notReportForChangedItems), the A-SMF / H-SMF can send the updated new IE (e.g., the updated notReportForChangedItems) to the I-SMF / V-SMF to notify of the latest changes.

[0147] In an embodiment, if it is necessary to delete a new IE (e.g., notReportForChangedItems), the A-SMF / H-SMF can send a deletion message to the I-SMF / V-SMF to notify the I-SMF / V-SMF to delete the new IE (e.g., notReportForChangedItems).

[0148] In an embodiment, when, for example, due to UE mobility, it is necessary to change the old I-SMF / V-SMF used for the PDU session, the old I-SMF / V-SMF can use a new IE (e.g., notReportForChangedItems) (e.g., ULI change, time zone change, security result) to notify the new I-SMF / V-SMF. The new I-SMF / V-SMF can store the received new IE (e.g., notReportForChangedItems).

[0149] In an embodiment, when an I-SMF / V-SMF needs to be inserted for a PDU session, for example due to UE mobility, the A-SMF / H-SMF can send a message including a new IE to the inserted I-SMF / V-SMF, such as an Nsmf_PDUSession_Context response (SmContextRetrievedData\smContext\new IE, e.g., notReportForChangedItems (e.g., ULI change, time zone change, security result)). The inserted I-SMF / V-SMF can store the received new IE, e.g., notReportForChangedItems.

[0150] In an embodiment, when the I-SMF / V-SMF used for the PDU session needs to be changed, for example due to UE mobility, the old I-SMF / V-SMF (or the source I-SMF / V-SMF) can send a message including the new IE to the new I-SMF / V-SMF (or the target I-SMF / V-SMF), such as an Nsmf_PDUSession_Context response (SmContextRetrievedData\smContext\new IE, such as notReportForChangedItems (e.g., ULI change, time zone change, security result)). The new I-SMF / V-SMF can store the received new IE, such as notReportForChangedItems.

[0151] In an embodiment, when the UE performs mobility and an item such as a changed IE (e.g., ULI change or time zone change) is in a stored new IE (e.g., notReportForChangedItems (e.g., ULI change, time zone change, security result)) and / or no other necessary IEs need to be passed to the A-SMF / H-SMF, the I-SMF / V-SMF will not send a dedicated message (e.g., Nsmf_PDUSession_Update request) to the A-SMF / H-SMF to notify the item such as the changed IE, because the item is not required by the A-SMF / H-SMF.

[0152] Figure 3a A flowchart of a method according to an embodiment is shown. This method can be performed by means of a device implemented in a first session management function (SMF), or by means of a device implemented at the first SMF, or by means of a device implemented as the first SMF, or by means of a device communicatively coupled to the first SMF. Therefore, the means can provide components, modules, or circuits for completing various parts of method 300, as well as components, modules, or circuits for combining with other components to complete other processes.

[0153] In box 302, the first SMF can determine the first information.

[0154] In an embodiment, the first information may indicate that the second SMF does not need to report at least one item to the first SMF when no other items need to be passed to the first SMF.

[0155] In an embodiment, the first information may indicate that the second SMF does not need to report at least one item to the first SMF, and / or that at least one item is not required by the first SMF.

[0156] The first SMF can be any suitable network device, node, entity, or function capable of supporting session management functions. In embodiments, the first SMF can be an anchor SMF or a home SMF as described in 3GPP TS 23.501 V18.1.0 or 3GPP TS 23.502 V18.1.1. For example, an H-SMF can be an SMF located in the home network.

[0157] The second SMF can be any suitable network device, node, entity, or function capable of supporting session management functions. In embodiments, the second SMF can be an intermediate SMF or a visited SMF as described in 3GPP TS 23.501 V18.1.0 or 3GPP TS 23.502 V18.1.1. For example, because one or more UPFs belong to different SMF service areas, an I-SMF can be an SMF inserted to support a PDU session because the UE is located in an area not controlled by the original SMF. For example, because one or more UPFs belong to a visited network, a V-SMF can be an SMF inserted to support a PDU session because the UE is located in a visited network not controlled by the home SMF.

[0158] In one embodiment, the first SMF can be an A-SMF or an SMF, and the second SMF can be an I-SMF. In another embodiment, the first SMF can be an H-SMF, and the second SMF can be a V-SMF.

[0159] The first information can be any suitable information, and this disclosure is not limited thereto. For example, the first information can be a list, a bitmap, an array, etc. In an embodiment, the first information can be an array containing information indicating at least one item.

[0160] At least one item can be any suitable item or information element that can be sent from the second SMF to the first SMF. For example, the at least one item can be at least one IE of PduSessionCreateData as defined in Table 6.1.6.2.9-1 of 3GPP TS 29.502 V18.2.0, and / or at least one IE of HsmfUpdateData as defined in Table 6.1.6.2.11-1 of 3GPP TS 29.502 V18.2.0, and / or at least one IE of PolicyControlRequestTrigger as defined in Table 5.6.3.6-1 of 3GPP TS 29.512 V18.1.0.

[0161] In an embodiment, the at least one item may be, for example, an item or IE that is always sent from the second SMF to the first SMF according to various 3GPP specifications (e.g., 3GPP TS29.502 V18.2.0) or a modified IE.

[0162] In this embodiment, the at least one item may include at least one changed item. A changed item means that the item has been changed for various reasons, such as UE mobility. For example, the serving network may be changed. The RAT type may be changed. The UE time zone may be changed. The UE location may be changed.

[0163] In an embodiment, the at least one item may include at least one of the following: serving network, access network type, additional access network type, radio access technology type, user equipment location, user equipment time zone, additional user equipment location, information indicating whether the user equipment is located within or outside the local data network service area, security results associated with a PDU session, user plane security information associated with a PDU session, information indicating whether the user equipment requests to establish an always-on PDU session, information indicating whether the PDU session can be moved to Evolved Packet System and whether the N26 interface will be used during Evolved Packet System interoperation, usage data report of auxiliary radio access technology for Quality of Service flow, usage data report of auxiliary radio access technology for Quality of Service flow and / or the entire PDU session, information indicating whether the access network type associated with the PDU session is changeable, information indicating access to be released, information indicating whether the PDU session is allowed to be upgraded to a multi-access PDU session, information indicating whether a multi-access PDU session is requested, information indicating unavailable access, or information indicating the maximum integrity protection data rate supported by the user equipment for the downlink, such as 3GPP TS 29.502. As defined in Table 6.1.6.2.9-1 of V18.2.0, and / or as defined in Table 6.1.6.2.11-1 of 3GPP TS 29.502 V18.2.0, and / or as defined in Table 5.6.3.6-1 of 3GPP TS 29.512 V18.1.0.

[0164] The first SMF may determine the first information in a variety of ways, and this disclosure is not limited thereto. For example, the first SMF may determine the first information based on at least one of the following: whether the project was requested by itself and / or another NF, whether the project can be obtained from another NF other than the second SMF, or whether the other NF has subscribed to the project's event reports from the first SMF, etc.

[0165] In an embodiment, the first information may be determined at least in part based on at least one of the following: the policy and / or billing function has not provided the first SMF with event triggers for one or more items in at least one project; the first SMF has subscribed to event reporting for one or more items in at least one project using an event open service that does not require interaction with the second SMF; or the one or more items in the at least one project are not requested by the first SMF. The first SMF will not report the one or more items in the at least one project to the policy and / or billing function.

[0166] Policy and / or charging functions can be any suitable network device, node, entity, or function capable of supporting policy and / or charging functions. In an embodiment, the policy and / or charging function can be the PCF or CHF described in 3GPP TS 23.501 V18.1.0 or 3GPP TS 23.502 V18.1.1.

[0167] An event trigger can be any suitable event trigger. For example, an event trigger can be at least one of the PolicyControlRequestTriggers as defined in Table 5.6.3.6-1 of 3GPP TS29.512 V18.1.0.

[0168] The event exposure service can be any suitable event exposure service. For example, the event exposure service can be the event exposure service described in 3GPP TS 23.502 V18.1.1. For example, as described in Clause 4.15.4.2 of 3GPP TS 23.502 V18.1.1, the AMF calls Namf_EventExposure_Notify to provide mobility-related events to NF consumers who have subscribed to the event by calling Namf_EventExposure_Subscribe.

[0169] As a first option, the first information may be determined based on the fact that the policy and / or billing functions have not yet provided the first SMF with event triggers for one or more items in at least one item. For example, if the policy and / or billing functions have not yet provided the first SMF with event triggers for a first item (e.g., uelocation, time zone, service node, or PLMN change), the first SMF may determine the first information, which indicates that the second SMF does not need to report the first item (e.g., uelocation, time zone, service node, or PLMN change) to the first SMF and / or the first item is not required by the first SMF.

[0170] As a second option, the first information can be determined based on the fact that the first SMF has subscribed to event reports for one or more items in at least one project using an Event Open Service that does not require interaction with the second SMF. For example, if the first SMF has subscribed to event reports for a second project (e.g., uelocation or time zone) using the AMF Event Open Service, the first SMF can determine the first information indicating that the second SMF does not need to report the second project (e.g., uelocation or time zone) to the first SMF and / or that the second project (e.g., uelocation or time zone) is not requested by the first SMF.

[0171] As a third option, the first information can be determined based on the fact that the first SMF does not require one or more items in at least one of the items. For example, if the first SMF does not require a third item (e.g., a security outcome), the first SMF can determine the first information, which indicates that the second SMF does not need to report the third item (e.g., a security outcome) to the first SMF and / or that the third item (e.g., a security outcome) is not required by the first SMF.

[0172] In embodiments, two or more of the above options can be combined to determine the first information. For example, when the first option and the second option are combined, the first SMF can determine the first information indicating that the second SMF does not need to report the first item and the second item to the first SMF and / or the first item and the second item are not required by the first SMF. When the first option and the third option are combined, the first SMF can determine the first information indicating that the second SMF does not need to report the first item and the third item to the first SMF and / or the first item and the third item are not required by the first SMF. When the second option and the third option are combined, the first SMF can determine the first information indicating that the second SMF does not need to report the second item and the third item to the first SMF and / or the second item and the third item are not required by the first SMF. When the first option, the second option, and the third option are combined, the first SMF can determine the first information indicating that the second SMF does not need to report the first item, the second item, and the third item to the first SMF and / or the first item, the second item, and the third item are not required by the first SMF.

[0173] In box 304, the first SMF can send the first information to the second SMF.

[0174] The first information can be sent to the second SMF in various messages, such as new messages or existing messages. In an embodiment, the first information can be sent to the second SMF in at least one of the following: a Protocol Data Unit (PDU) session creation response, a PDU session update request, or a PDU session context response. The PDU session creation response, PDU session update request, or PDU session context response can be similar to the corresponding messages as described in various 3GPP specifications (e.g., 3GPP TS 23.502 V18.1.1).

[0175] The first information can be sent to the second SMF during various processes or at various points in time. In embodiments, the first information can be sent to the second SMF during at least one of the following: the PDU session establishment process, the lifecycle of the PDU session, or the user equipment mobility process with the second SMF insertion. The PDU session establishment process can be similar to the corresponding process as described in 3GPP TS 23.502 V18.1.1 (e.g., Clause 4.3.2). The lifecycle of the PDU session can include, for example, the PDU session modification or update process as described in 3GPP TS 23.502 V18.1.1 (e.g., Clause 4.3.3). The user equipment mobility process with the second SMF insertion can be similar to the I-SMF insertion or V-SMF insertion process as described in 3GPP TS 23.502 V18.1.1 (e.g., Clause 4.23).

[0176] The first information can be included in any suitable data. In embodiments, the first information can be included in at least one of the data from PDU session creation, visitor session management function update data, or session management context. For example, the data from PDU session creation can include data within the PDU session creation response. The data from PDU session creation can be similar to or equivalent to PduSessionCreatedData as described in 3GPP TS 29.502 V18.1.0. The visitor session management function update data can include data within an update request toward a second SMF (e.g., V-SMF) or from a first SMF (e.g., SMF or A-SMF) to a second SMF (e.g., I-SMF). The visitor session management function update data can be similar to or equivalent to VsmfUpdateData as described in 3GPP TS 29.502 V18.1.0. The session management context can include data within the SM context retrieval response. The session management context may be similar to or equivalent to SmContextRetrievedData as described in 3GPP TS 29.502V18.1.0.

[0177] In an embodiment, the first information can be used to suppress the transmission of the at least one item to the first SMF. For example, when the second SMF receives the first information, it can suppress the transmission of the at least one item to the first SMF.

[0178] In an embodiment, suppressing the transmission of at least one item to the first SMF may include: if there are no other necessary information elements that need to be transmitted to the first SMF, then suppressing the transmission of a dedicated message to the first SMF to notify of the at least one item, because the at least one item is not needed by the first SMF.

[0179] In an embodiment, suppressing the transmission of at least one item to the first SMF includes: if there are no other items that need to be transmitted to the first SMF, then suppressing the transmission of a dedicated message to the first SMF to notify the at least one item.

[0180] In an embodiment, the first information may further indicate that when it is necessary to send at least one other item to the first SMF, the second SMF sends a message to the first SMF including the at least one other item. This message may further include the at least one other item.

[0181] Figure 3b A flowchart of a method according to another embodiment of the present disclosure is shown, which can be performed by means implemented in a first SMF, or by means implemented at the first SMF, or by means implemented as the first SMF, or by means communicatively coupled to the first SMF. Therefore, the means can provide components, modules, or circuits for performing various parts of method 310, as well as components, modules, or circuits for combining with other components to perform other processes. For the sake of brevity, descriptions of some parts already described in the above embodiments are omitted here.

[0182] In box 312, the first SMF can send a message to the second SMF for updating at least one item (or updating the first information) or deleting the first information (or deleting at least one item).

[0183] The first SMF may send a message to the second SMF to update at least one item or delete first information for various reasons. For example, when at least one item needs to be changed, updated, or deleted, the first SMF may send a message to the second SMF to update at least one item or delete first information.

[0184] The first SMF can periodically or based on event triggers determine new first information. When the new first information changes compared to the old first information, the first SMF can send a message to the second SMF to update at least one item included in the old first information or delete the old first information.

[0185] For example, the first SMF can determine whether it needs to update at least one item included in the old first information or delete the old first information when at least one of the following occurs:

[0186] The policy and / or billing functions have provided the first SMF with project-specific event triggers.

[0187] The policy and / or billing functions have removed the event triggers for the project in the first SMF, or the event triggers for the project are invalid in the first SMF.

[0188] The first SMF has subscribed to the project's event reports using, for example, an event open service that does not require interaction with the second SMF.

[0189] The first SMF has unsubscribed from the project's event reporting using the event open service, which does not require interaction with the second SMF.

[0190] The first SMF determines that the project is required, or

[0191] The first SMF determined that the project was not needed.

[0192] If the first SMF needs to update at least one item included in the old first information or delete the old first information, the first SMF may send a message to the second SMF for updating at least one item included in the old first information or deleting the old first information.

[0193] The message can be any suitable message, such as a new message or an existing message. For example, the message can be a PDU session update request as described in 3GPP TS 23.502 V18.1.1. The message can be sent to a second SMF during the lifecycle of the PDU session.

[0194] Figure 4a A flowchart of a method according to another embodiment of the present disclosure is shown. This method can be performed by means implemented in a second SMF, or by means implemented at the second SMF, or by means implemented as the second SMF, or by means communicatively coupled to the second SMF. Therefore, the means can provide components, modules, or circuits for performing various parts of method 400, as well as components, modules, or circuits for combining with other components to perform other processes. For the sake of brevity, descriptions of some parts already described in the above embodiments are omitted here.

[0195] In box 402, the second SMF can receive the first information from the first SMF or the old second SMF.

[0196] In an embodiment, the first information may indicate that the second SMF does not need to report at least one item to the first SMF when no other items need to be passed to the first SMF.

[0197] In an embodiment, the first information may indicate that the second SMF does not need to report at least one item to the first SMF, and / or that the at least one item is not required by the first SMF.

[0198] For example, the first SMF can be Figure 3a Step 304 sends the first information to the second SMF, and then the second SMF can receive the first information.

[0199] For example, the old second SMF can receive the first information from the first SMF. When the old second SMF is changed to a second SMF (i.e., the new second SMF), the old SMF can send the first information to the second SMF.

[0200] In an embodiment, the first information may be determined at least in part based on at least one of the following: the policy and / or billing function has not yet provided the first SMF with event triggers for one or more items in at least one project; the first SMF has subscribed to event reporting for one or more items in at least one project using an event open service that does not require interaction with the second SMF; or the first SMF does not require one or more items in at least one project. The first SMF will not report one or more items in at least one project to the policy and / or billing function.

[0201] In an embodiment, the first information may be received from the first SMF in at least one of a Protocol Data Unit (PDU) session creation response, a PDU session update request, or a PDU session context response.

[0202] In an embodiment, the first information may be received from the old second SMF in a PDU session context response. For example, during a user equipment mobility process with a change in the old second SMF, the new second SMF may send a PDU session context request to the old second SMF, and the old second SMF may send a PDU session context response including the first information to the new second SMF.

[0203] In an embodiment, the first information may be received from the first SMF during at least one of the following periods: PDU session establishment process, PDU session lifecycle, or user equipment mobility process with second SMF insertion.

[0204] In an embodiment, the first information may be received from the old second SMF during a user equipment mobility process with an old second SMF change. The user equipment mobility process with an old second SMF change may be similar to a V-SMF change or I-SMF change process as described in 3GPP TS 23.502 V18.1.1 (e.g., Clause 4.23).

[0205] In an embodiment, the first information may be included in at least one of the data created by the PDU session, the visit session management function update data, or the session management context.

[0206] In an embodiment, at least one item may include at least one modified item.

[0207] In an embodiment, the at least one item may include at least one of the following: serving network, access network type, additional access network type, radio access technology type, user equipment location, user equipment time zone, additional user equipment location, information indicating whether the user equipment is located within or outside the local data network service area, security results associated with a PDU session, user plane security information associated with a PDU session, information indicating whether the user equipment requests to establish an always-on PDU session, information indicating whether the PDU session can be moved to Evolved Packet System and whether the N26 interface will be used during Evolved Packet System interoperation, usage data report of auxiliary radio access technology for Quality of Service flow, usage data report of auxiliary radio access technology for Quality of Service flow and / or the entire PDU session, information indicating whether the access network type associated with the PDU session is changeable, information indicating access to be released, information indicating whether the PDU session is allowed to be upgraded to a multi-access PDU session, information indicating whether a multi-access PDU session is requested, information indicating unavailable access, or information indicating the maximum integrity protection data rate supported by the user equipment for the downlink.

[0208] In an embodiment, the first SMF may include at least one of an anchor SMF or a home SMF.

[0209] In an embodiment, the second SMF may include at least one of an intermediate SMF or a visiting SMF.

[0210] In box 404, the second SMF can obtain the at least one item. The second SMF can obtain the at least one item in a variety of ways, and this disclosure is not limited thereto. For example, the second SMF can obtain the at least one item from the AMF or other network functions. For example, when the UE has mobility, at least one item such as the associated changed IE (e.g., uelocation, uetimezone, etc.) can always be sent from the AMF to the I-SMF / V-SMF.

[0211] In box 406, optionally, the second SMF may, based on the first information, suppress the sending of at least one item to the first SMF. For example, when the second SMF receives an item, it may check whether the item belongs to the at least one item. If the item belongs to the at least one item, the second SMF may, based on the first information, not send the item to the first SMF.

[0212] In an embodiment, if no other items need to be passed to the first SMF, the second SMF may suppress the sending of dedicated messages to the first SMF to notify the at least one item.

[0213] In this embodiment, if no other necessary information elements need to be transmitted to the first SMF, the second SMF may suppress the sending of a dedicated message to the first SMF to notify the at least one item, because the at least one item is not needed by the first SMF. The dedicated message can be any suitable message, such as a new message or an existing message.

[0214] In one embodiment, if other necessary information elements need to be passed to the first SMF, the second SMF can send a dedicated message to the first SMF to notify the other necessary information elements. In another embodiment, the dedicated message may include the at least one item. In yet another embodiment, the dedicated message may not include the at least one item, since the at least one item is not needed by the first SMF.

[0215] In box 408, optionally, when at least one other item needs to be delivered to the first SMF, the second SMF may send a message to the first SMF including the at least one item. This message further includes the at least one other item.

[0216] Figure 4b A flowchart of a method according to another embodiment of the present disclosure is shown, which can be performed by means implemented in a second SMF, or by means implemented at the second SMF, or by means implemented as the second SMF, or by means communicatively coupled to the second SMF. Therefore, the means can provide components, modules, or circuits for performing various parts of method 410, as well as components, modules, or circuits for combining with other components to perform other processes. For the sake of brevity, descriptions of some parts already described in the above embodiments are omitted here.

[0217] In box 412, the second SMF can receive messages from the first SMF for updating at least one item (or updating first information) or deleting first information (or deleting at least one item). For example, the first SMF can... Figure 3b In step 312, the message is sent to the second SMF, and then the second SMF can receive the message from the first SMF.

[0218] In box 414, the second SMF can update at least one item (or update the first information) or delete the first information (or delete at least one item). For example, an update operation can include an add operation, a modify operation, a delete operation, etc. The second SMF can update one or more items within at least one item. The second SMF can delete all items within at least one item.

[0219] Figure 4cA flowchart of a method according to another embodiment of the present disclosure is shown, which can be performed by means implemented in a second SMF, or by means implemented at the second SMF, or by means implemented as the second SMF, or by means communicatively coupled to the second SMF. Therefore, the means can provide components, modules, or circuits for performing various parts of method 420, as well as components, modules, or circuits for combining with other components to perform other processes. For the sake of brevity, descriptions of some parts already described in the above embodiments are omitted here.

[0220] In box 422, the second SMF can store the first information.

[0221] Figure 4d A flowchart of a method according to another embodiment of the present disclosure is shown, which can be performed by means implemented in a second SMF, or by means implemented at the second SMF, or by means implemented as the second SMF, or by means communicatively coupled to the second SMF. Therefore, the means can provide components, modules, or circuits for performing various parts of method 430, as well as components, modules, or circuits for combining with other components to perform other processes. For the sake of brevity, descriptions of some parts already described in the above embodiments are omitted here.

[0222] In box 432, the second SMF can send the first message to the new second SMF.

[0223] In an embodiment, the first information may be sent to the new second SMF in a PDU session context response. For example, during a user equipment mobility process with a change in the second SMF, the new second SMF may send a PDU session context request to the second SMF (i.e., the old second SMF), and the second SMF may send a PDU session context response including the first information to the new second SMF.

[0224] In an embodiment, the first information may be sent to the new second SMF during a user equipment mobility procedure with a second SMF change. The user equipment mobility procedure with a second SMF change may be similar to a V-SMF change or I-SMF change procedure as described in 3GPP TS23.502 V18.1.1 (e.g., Clause 4.23).

[0225] In an embodiment, the first information may be a notReportForChangedItems indicator, which may be sent to the I-SMF / V-SMF during the PDU session establishment process or the PDU session lifecycle.

[0226] In this embodiment, during the PDU session establishment process or lifecycle, the I-SMF / V-SMF does not need to pass at least one item or IE (e.g., a modified IE) to the A-SMF / H-SMF on the N16 / N16a interface in at least one of the following situations:

[0227] PCF / CHF has not yet provided A-SMF / H-SMF with event triggers for at least one item or IE. Therefore, A-SMF / H-SMF will not report at least one item or IE, such as changed IEs (e.g., uelocation, time zone, service node, PLMN change, RAT change). I-SMF / V-SMF does not need to pass at least one item or IE (e.g., changed IE) to H / A-SMF through the N16 / N16a interface.

[0228] A-SMF / H-SMF has subscribed to event reports for at least one item or IE (e.g., a changed IE, such as uelocation, time zone) through an event open service that does not require interaction with I-SMF / V-SMF. I-SMF / V-SMF does not need to pass at least one item or IE (e.g., a changed IE) to H / A-SMF on the N16 / N16a interface; or

[0229] A-SMF / H-SMF does not require at least one item or IE (e.g., security result), and I-SMF / V-SMF does not require at least one item or IE to be passed to H / A-SMF on the N16 / N16a interface.

[0230] In an embodiment, the A-SMF / H-SMF can notify the I-SMF / V-SMF using a new IE "notReportForChangedItems" (e.g., ULI change, time zone change, security result) in the Nsmf_PDUSession_Create response or Nsmf_PDUSession_Update request. The I-SMF / V-SMF stores the received notReportForChangedItems.

[0231] In an embodiment, new notReportForChangedItems (e.g., ULI change, time zone change, security result) can indicate:

[0232] If an item or IE (e.g., a changed IE such as a ULI change or time zone change) is in the received notReportForChangedItems and / or there are no other necessary IEs that need to be passed to A-SMF / H-SMF, then I-SMF / V-SMF should not send a special message (e.g., an Nsmf_PDUSession_Update request) to A-SMF / H-SMF to notify the item or IE (e.g., the changed IE) because it is not required by A-SMF / H-SMF.

[0233] In this embodiment, the new notReportForChangedItems may include at least one of the following IEs:

[0234] servingNetwork

[0235] anType,

[0236] additionalAnType,

[0237] ratType,

[0238] ueLocation,

[0239] ueTimeZone,

[0240] Safety outcome

[0241] addUeLocation,

[0242] alwaysOnRequested

[0243] epsInterworkingInd,

[0244] secondaryRatUsageReport

[0245] secondaryRatUsageInfo,

[0246] anTypeCanBeChanged,

[0247] maReleaseInd,

[0248] maNwUpgradeInd,

[0249] maRequestInd,

[0250] unavailableAccesslnd,

[0251] maxIntegrityProtectedDataRateUl, or

[0252] maxIntegrityProtectedDataRateDl.

[0253] Figure 5 A flowchart of a method according to another embodiment of this disclosure is shown. In this embodiment, first information (e.g., a notReportForChangedItems indicator) may be sent to the I-SMF / V-SMF during the PDU session establishment process or during the PDU session lifecycle.

[0254] notReportForChangedItems can include at least one IE as defined in Tables 6.1.6.2.9-1 and 6.1.6.2.11-1 of 3GPP TS 29.502 V18.2.0, for example, notReportForChangedItems can include at least one of the following:

[0255] servingNetwork

[0256] anType,

[0257] additionalAnType,

[0258] ratType,

[0259] ueLocation,

[0260] ueTimeZone,

[0261] Safety outcome

[0262] addUeLocation,

[0263] alwaysOnRequested

[0264] epsInterworkingInd、

[0265] secondaryRatUsageReport

[0266] secondaryRatUsageInfo,

[0267] anTypeCanBeChanged,

[0268] maReleaseInd,

[0269] maNwUpgradeInd,

[0270] maRequestInd,

[0271] unavailableAccesslnd,

[0272] maxIntegrityProtectedDataRateUl, or

[0273] maxIntegrityProtectedDataRateDl.

[0274] Notice, Figure 5 The flowchart is used for roaming PDU sessions using V / H-SMF, and for example, it is also applicable to PDU sessions using I / A-SMF by replacing the visiting NF (e.g., V-SMF) with the intermediate NF (e.g., I-SMF) and the home NF (e.g., H-SMF) with the anchor NF (e.g., A-SMF).

[0275] Step 1a: During the PDU session establishment process, the V-SMF sends an Nsmf_PDUSession_Create request to the H-SMF.

[0276] Step 2a: H-SMF sends an Nsmf_PDUSession_Create response (PduSessionCreatedData\notReportForChangedItems (e.g., ULI change, time zone change, security result)) to V-SMF in at least one of the following situations:

[0277] a) PCF / CHF has not yet provided A-SMF / H-SMF with event triggers for at least one item or IE, therefore A-SMF / H-SMF will not report at least one item or IE (e.g., changed IEs such as uelocation, time zone, service node, PLMN change, RAT change) to PCF / CHF, and I-SMF / V-SMF does not need to pass at least one item or IE (e.g., changed IEs) to H / A-SMF on the N16 / N16a interface.

[0278] b) The A-SMF / H-SMF has subscribed to event reports for at least one item or IE (e.g., a changed IE, such as uelocation, time zone) through an event open service that does not require interaction with the I-SMF / V-SMF, and the I-SMF / V-SMF does not need to pass at least one item or IE (e.g., a changed IE) to the H / A-SMF on the N16 / N16a interface; or

[0279] c) A-SMF / H-SMF does not require at least one item or IE (e.g., security result), and I-SMF / V-SMF does not require at least one item or IE to be passed to H / A-SMF on the N16 / N16a interface.

[0280] Step 1b: During the PDU session lifecycle, due to at least one of the above conditions a), b), or c) (e.g., the event trigger is unsubscribed by PCF / CHF), H-SMF sends an Nsmf_PDUSession_Update request (VsmfUpdateData\notReportForChangedItems (e.g., ULI change, time zone change, security result, etc.)) to V-SMF.

[0281] In step 1b, for example, when the Nsmf_PDUSession_Create response in step 2a does not include the original notReportForChangedItems, the Nsmf_PDUSession_Update request may include the original notReportForChangedItems. Alternatively, for example, when the Nsmf_PDUSession_Create response in step 2a includes the original notReportForChangedItems, or when the previous Nsmf_PDUSession_UpdateRequest includes the original notReportForChangedItems, the Nsmf_PDUSession_Update Request may include the updated notReportForChangedItems.

[0282] Step 2b: V-SMF sends an Nsmf_PDUSession_Update response to H-SMF.

[0283] Step 3: The UE triggers the mobility process.

[0284] Step 4: NG-RAN sends an N2 path switching request to AMF.

[0285] Step 5: AMF sends an Nsmf_PDUSession_UpdateSMContext request (toBeSwitched, ueLocation, ueTimezone, N2 path switching request transmission) to V-SMF.

[0286] Step 6: V-SMF sends a PFCP session modification request (T-NGRAN-N3-tunnel) to V-UPF.

[0287] Step 7: V-UPF sends a PFCP session modification response to V-SMF.

[0288] Step 8: V-SMF sends an Nsmf_PDUSession_UpdateSMContext response (Path Switching Request Confirmation Transmission (V-UPF-N3-Tunnel)) to AMF.

[0289] Steps 9a-9b are omitted. Since the changed IE (e.g., ULI change or timezone change) is in the stored notReportForChangedItems, and / or there are no other necessary IEs to be passed to A-SMF / H-SMF, V-SMF will not send a dedicated Nsmf_PDUSession_Update request to H-SMF to notify of the changed IE, as it is not required by H-SMF, and H-SMF will not send an Nsmf_PDUSession_Update response to V-SMF.

[0290] Step 10: AMF sends an N2 path handover request confirmation (Ack) to NG-RAN.

[0291] Figure 5 The messages, terms, or abbreviations in this document may be identical or similar to the corresponding messages, terms, or abbreviations described in various 3GPP specifications (e.g., 3GPP TS 23.502 V18.1.1 (e.g., Clause 4.3), 3GPP TS 32.290 V18.1.0 (e.g., Clause 6.2.3), 3GPP TS 23.501 V18.1.0, or 3GPP TS 29.502 V18.1.0).

[0292] Figure 6 A flowchart of a method according to another embodiment of this disclosure is shown. In this embodiment, during UE mobility with V-SMF insertion, first information (e.g., a notReportForChangedItems indicator) can be sent to the I-SMF / V-SMF.

[0293] When an I-SMF / V-SMF needs to be inserted for a PDU session due to UE mobility, the A-SMF / H-SMF sends an Nsmf_PDUSession_Context response (SmContextRetrievedData\smContext\notReportForChangedItems (e.g., ULI change, time zone change, security result)) to the inserted I-SMF / V-SMF. The inserted I-SMF / V-SMF stores the received notReportForChangedItems.

[0294] Subsequently, when the UE performs mobility, if at least one item or IE (e.g., a changed IE (e.g., ULI change or time zone change)) is in the stored notReportForChangedItems (e.g., ULI change, time zone change, security result), and / or no other necessary IE needs to be passed to A-SMF / H-SMF, then I-SMF / V-SMF will not send a dedicated message (e.g., Nsmf_PDUSession_Update request) to A-SMF / H-SMF to notify the at least one item or IE (e.g., the changed IE), because it is not required by A-SMF / H-SMF.

[0295] Please note, Figure 6 The flowchart is for roaming PDU sessions using V / H-SMF, and also applies to PDU sessions using I / A-SMF.

[0296] Step 1: The UE has established a PDU session with V-SMF and H-SMF.

[0297] Step 2: AMF is inserted into V-SMF, for example, due to UE mobility.

[0298] Step 3: The AMF sends an Nsmf_PDUSession_CreateSMContext request (PDU session ID, SM context identifier (ID)) to the inserted V-SMF.

[0299] Step 4: The inserted V-SMF sends an Nsmf_PDUSession_Context request (SmContextRetrieveData) to the H-SMF.

[0300] Step 5: Since the proposed feature / solution is enabled and at least one of the above options a), b), c) is satisfied, the H-SMF sends an Nsmf_PDUSession_Create response (SmContextRetrievedData\smContext\notReportForChangedItems (e.g., ULI change, time zone change, security result)) to the inserted V-SMF.

[0301] Step 6: Insert V-SMF storage notReportForChangedItems (e.g., ULI change, time zone change, security result).

[0302] Step 7: The ongoing mobility process is complete.

[0303] Step 8: The UE triggers the mobility process.

[0304] Step 9: NG-RAN sends an N2 path switching request to AMF.

[0305] Step 10: AMF sends an Nsmf_PDUSession_UpdateSMContext request (toBeSwitched, ueLocation, ueTimezone, N2 path switching request transmission) to V-SMF.

[0306] Step 11: The V-SMF sends a PFCP session modification request (T-NGRAN-N3-tunnel) to the visited UPF (V-UPF).

[0307] Step 12: V-UPF sends a PFCP session modification response to V-SMF.

[0308] Step 13: V-SMF sends an Nsmf_PDUSession_UpdateSMContext response (Path Switching Request Confirmation Transmission (V-UPF-N3-Tunnel)) to AMF.

[0309] Step 14: If the changed IE (e.g., ULI change or time zone change) is not in the stored reportForChangedItems, and / or there are no other necessary IEs that need to be passed to A-SMF / H-SMF, then V-SMF will not send a special message such as an Nsmf_PDUSession_Update request to H-SMF to notify the changed IE, because it is not required by H-SMF.

[0310] Step 15: AMF sends an N2 path switching request confirmation to NG-RAN.

[0311] Figure 6 The messages, terms, or abbreviations in this document may be identical or similar to the corresponding messages, terms, or abbreviations described in various 3GPP specifications such as 3GPP TS 23.502 V18.1.1 (e.g., Clause 4.9), 3GPP TS 32.290 V18.1.0 (e.g., Clause 6.2.3), 3GPP TS 23.501 V18.1.0, or 3GPP TS29.502 V18.1.0.

[0312] Figure 7 A flowchart of a method according to another embodiment of this disclosure is shown. In this embodiment, during UE mobility with I-SMF / V-SMF changes, first information (e.g., a notReportForChangedItems indicator) can be sent to the I-SMF / V-SMF.

[0313] When an I-SMF / V-SMF needs to be modified for a PDU session due to UE mobility, the old I-SMF / V-SMF sends an Nsmf_PDUSession_Context response message (SmContextRetrievedData\smContext\notReportForChangedItems (e.g., ULI change, time zone change, security outcome)) to the new I-SMF / V-SMF. The new I-SMF / V-SMF stores the received notReportForChangedItems.

[0314] Subsequently, when the UE performs mobility, if at least one item or IE (e.g., a changed IE (e.g., ULI change or time zone change)) is in the stored notReportForChangedItems (e.g., ULI change, time zone change, security result), and / or no other necessary IE needs to be passed to the A-SMF / H-SMF, then the V-SMF will not send a dedicated message (e.g., an Nsmf_PDUSession_Update request) to the A-SMF / H-SMF to notify at least one item or IE (e.g., a changed IE) because it is not required by the A-SMF / H-SMF.

[0315] Notice, Figure 7 The flowchart is for roaming PDU sessions using V / H-SMF, and also applies to PDU sessions using I / A-SMF.

[0316] Step 1: The UE has established a PDU session with the source V-SMF (SV-SMF) and H-SMF.

[0317] Step 2: AMF changes SV-SMF, for example due to UE mobility.

[0318] Step 3: The AMF sends an Nsmf_PDUSession_CreateSMContext request (PDU session ID, SM context ID) to the new target V-SMF (TV-SMF).

[0319] Step 4: The new TV-SMF sends an Nsmf_PDUSession_Context request (SmContextRetrieveData) to the old SV-SMF.

[0320] Step 5: Since the SV-SMF has stored notReportForChangedItems, the old SV-SMF sends an Nsmf_PDUSession_Create response (SmContextRetrievedData\smContext\notReportForChangedItems (e.g., ULI change, time zone change, security result)) to the new TV-SMF.

[0321] Step 6: The new TV-SMF stores notReportForChangedItems (e.g., ULI changes, time zone changes, security results).

[0322] Step 7: The ongoing mobility process is complete.

[0323] Step 8: The UE triggers the mobility process.

[0324] Step 9: NG-RAN sends an N2 path switching request to AMF.

[0325] Step 10: AMF sends an Nsmf_PDUSession_UpdateSMContext request (toBeSwitched, ueLocation, ueTimezone, N2 path switching request transmission) to V-AMF.

[0326] Step 11: V-SMF sends a PFCP session modification request (T-NGRAN-N3-tunnel) to V-UPF.

[0327] Step 12: V-UPF sends a PFCP session modification response to V-SMF.

[0328] Step 13: V-SMF sends an Nsmf_PDUSession_UpdateSMContext response (Path Switching Request Confirmation Transmission (V-UPF-N3-Tunnel)) to AMF.

[0329] Step 14: If the changed IE (e.g., ULI change or time zone change) is not in the stored reportForChangedItems, and / or there are no other necessary IEs that need to be passed to A-SMF / H-SMF, then V-SMF will not send messages such as a dedicated Nsmf_PDUSession_Update request to H-SMF to notify the changed IE, because it is not required by H-SMF.

[0330] Step 15: AMF sends an N2 path switching request confirmation to NG-RAN.

[0331] Figure 7 The messages, terms, or abbreviations used in this document may be identical or similar to the corresponding messages, terms, or abbreviations described in various 3GPP specifications, such as 3GPP TS 23.502 V18.1.1 (e.g., Clause 4.9), 3GPP TS 32.290 V18.1.0 (e.g., Clause 6.2.3), 3GPP TS 23.501 V18.1.0, or 3GPP TS 29.502 V18.1.0.

[0332] In this embodiment, the IE "notReportForChangedItems" can be added to Table 6.1.6.2.10-1 of 3GPP TS 29.502V18.1.0, as shown below. It should be noted that other IEs with similar / equal meanings can be used besides "notReportForChangedItems".

[0333] Table 6.1.6.2.10-1: Definition of type PduSessionCreatedData

[0334]

[0335] In this embodiment, the IE "notRreportForChangedItems" can be added to Table 6.1.6.2.15-1 of 3GPP TS 29.502V18.1.0, as shown below. It should be noted that other IEs with similar / equal meanings can be used besides "notRreportForChangedItems".

[0336] Table 6.1.6.2.15-1: Definition of type VsmfUpdateData

[0337]

[0338] In this embodiment, the IE "notReportForChangedItems" can be added to Table 6.1.6.2.39-1 of 3GPP TS 29.502V18.1.0, as shown below. It should be noted that other IEs with similar / equal meanings can be used besides "notReportForChangedItems".

[0339] Table 6.1.6.2.39-1: Definition of type SmContext

[0340]

[0341] In this embodiment, Table 4 shows an enumeration of notReportForChangedItem, which can be added to 3GPP TS 29.502 V18.1.0. It should be noted that other IEs with similar / identical meanings can be used in addition to those shown in Table 4. One or more new IEs can be added to Table 4. One or more IEs can be deleted from Table 4. The IEs in Table 4 can be the same as or similar to the corresponding IEs as described in 3GPP TS 29.502 V18.1.0. DTSSA represents a deployment topology with a specific SMF service area.

[0342] Table 4: Enumeration of notReportForChangedItem

[0343]

[0344]

[0345] The embodiments described herein can provide numerous advantages, and a non-exhaustive list of examples of these advantages is provided below. In some embodiments described herein, unnecessary messages (e.g., roaming signaling messages) can be avoided between two network nodes (e.g., two SMFs (e.g., I-SMF / V-SMF and A-SMF / H-SMF)). In some embodiments described herein, signaling bandwidth (e.g., roaming signaling) on ​​interfaces (e.g., N16 interfaces) can be saved, particularly for a large number of users (e.g., millions of UEs). In some embodiments described herein, PDU mobility processes (e.g., roaming PDU mobility processes) can be simplified by reducing the transmission of unnecessary messages (e.g., N16 signaling messages). The embodiments described herein are not limited to the features and advantages described above. Additional features and advantages will be recognized by those skilled in the art upon reading the following detailed description.

[0346] For example, it can avoid unnecessary roaming signaling message transmissions from V-SMF to H-SMF, saving roaming signaling bandwidth on the N16 interface, especially for a large number of users (e.g., millions of UEs). It can simplify the roaming PDU mobility process and reduce mobility process time by reducing unnecessary N16 signaling message transmissions, especially for a large number of users (e.g., millions of UEs).

[0347] For example, it can avoid unnecessary signaling message transmission from I-SMF to A-SMF, saving signaling bandwidth on the N16a interface; especially for a large number of users (e.g., millions of UEs). It can simplify the roaming PDU mobility process and reduce mobility process time by reducing unnecessary N16a signaling message transmission, especially for a large number of users (e.g., millions of UEs).

[0348] Figure 8a This is a block diagram illustrating an apparatus suitable for implementing some embodiments of the present disclosure. For example, the first SMF or the second SMF described above can be implemented as or through apparatus 800.

[0349] The device 800 includes at least one processor 821 (e.g., a digital processor (DP)) and at least one memory (MEM) 822 coupled to the processor 821. The device 800 may also include a transmitter TX and a receiver RX 823 coupled to the processor 821. The MEM 822 stores a program (PROG) 824. The PROG 824 may include instructions that, when executed on the respective processor 821, enable the device 800 to operate according to embodiments of the present disclosure. A combination of at least one processor 821 and at least one MEM 822 can form a processing element 825 suitable for implementing various embodiments of the present disclosure.

[0350] Various embodiments of this disclosure may be implemented by a computer program executed by one or more of a processor 821, software, firmware, hardware, or a combination thereof.

[0351] The MEM 822 can be of any type suitable for the local technical environment and can be implemented using any suitable data storage technology, such as, by way of non-limiting example, semiconductor-based storage devices, magnetic storage devices and systems, optical storage devices and systems, fixed memory and removable memory.

[0352] The processor 821 may be of any type suitable for the local technical environment and may include, as non-limiting examples, a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture.

[0353] In embodiments where the device is implemented as a first SMF or at the first SMF, memory 822 stores instructions executable by processor 821, thereby causing the first SMF to operate in any manner associated with the first SMF as described above.

[0354] In embodiments where the device is implemented as a second SMF or at a second SMF, memory 822 stores instructions executable by processor 821, thereby causing the second SMF to operate according to any method associated with the second SMF as described above.

[0355] Figure 8b This is a block diagram illustrating a first SMF according to an embodiment of the present disclosure. As shown, the first SMF 830 may include a determining module 831 configured to determine first information. The first information may indicate that a second SMF does not need to report at least one item to the first SMF when no other items need to be passed to the first SMF. The first SMF 830 may also include a first sending module 832 configured to send the first information to the second SMF.

[0356] In an embodiment, the first SMF 830 may further include a second sending module 833, which is configured to send a message to the second SMF for updating at least one item or deleting the first information.

[0357] Figure 8c This is a block diagram illustrating a second SMF according to an embodiment of the present disclosure. As shown, the second SMF 840 may include a first receiving module 841 configured to receive first information from a first SMF or a legacy second SMF. The first information may indicate that the second SMF does not need to report at least one item to the first SMF when no other items need to be passed to the first SMF. The second SMF 840 may also include an obtaining module 842 configured to obtain at least one item.

[0358] In an embodiment, the second SMF 840 may further include a suppression module 843 configured to suppress the transmission of at least one item to the first SMF based on the first information.

[0359] In an embodiment, the second SMF 840 may further include a second receiving module 844 configured to receive from the first SMF a message for updating at least one item or deleting first information.

[0360] In an embodiment, the second SMF 840 may further include an update module 845 configured to update at least one item.

[0361] In an embodiment, the second SMF 840 may further include a deletion module 846 configured to delete the first information.

[0362] In an embodiment, the second SMF 840 may further include a storage module 847 configured to store the first information.

[0363] In an embodiment, the second SMF 840 may further include a first transmitting module 848, which is configured to transmit first information to the new second SMF.

[0364] In an embodiment, the second SMF 840 may further include a second sending module 849 configured to send a message containing at least one item to the first SMF when at least one other item needs to be delivered to the first SMF, wherein the message further contains at least one other item.

[0365] Using functional units, the first or second SMF does not require a fixed processor or memory; any computing and storage resources can be allocated from the first or second SMF in the communication system. The introduction of virtualization and network computing technologies can improve the utilization efficiency of network resources and the flexibility of the network.

[0366] In addition, an exemplary overall communication system including terminal devices and network nodes (such as a first SMF or a second SMF) can be introduced.

[0367] The term “unit” or “module” may have a conventional meaning in the field of electronic, electrical and / or electronic equipment, and may include, for example, electrical and / or electronic circuits, devices, modules, processors, memories, logic solid-state and / or discrete devices, computer programs or instructions for performing corresponding tasks, processes, calculations, outputs and / or display functions, and so on, such as those described herein.

[0368] According to one aspect of this disclosure, a computer program product is provided, which is tangibly stored on a computer-readable storage medium and includes instructions that, when executed on at least one processor, cause the at least one processor to perform any of the methods described above.

[0369] According to one aspect of this disclosure, a computer-readable storage medium is provided that stores instructions, when executed on at least one processor, causing the at least one processor to perform any of the methods described above.

[0370] Furthermore, this disclosure may also provide a carrier containing the aforementioned computer program, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, or a computer-readable storage medium. The computer-readable storage medium may be, for example, an optical disc or an electronic storage device, such as RAM (random access memory), ROM (read-only memory), flash memory, magnetic tape, CD-ROM, DVD, Blu-ray disc, etc.

[0371] The techniques described herein can be implemented in various ways, such that the means for implementing one or more functions of the corresponding apparatus described in the embodiments includes not only prior art components, but also components for implementing one or more functions of the corresponding apparatus described in the embodiments, and may include separate components for each individual function, or components that can be configured to perform two or more functions. For example, these techniques can be implemented in hardware (one or more apparatuses), firmware (one or more apparatuses), software (one or more modules), or a combination thereof. For firmware or software, implementation can be accomplished by modules (e.g., processes, functions, etc.) that perform the functions described herein.

[0372] Exemplary embodiments of the present document have been described above with reference to block diagrams and flowcharts of methods and apparatus. It will be understood that each block of the block diagrams and flowcharts, as well as combinations of blocks in the block diagrams and flowcharts, can be implemented by various components including computer program instructions. These computer program instructions can be loaded onto a general-purpose computer, a special-purpose computer, or other programmable data processing equipment to produce a machine, such that the instructions, which execute on the computer or other programmable data processing equipment, create components for implementing the functions specified in the flowchart blocks or blocks.

[0373] Furthermore, although the operations are depicted in a specific order, this should not be construed as requiring that these operations be performed in the specific order shown or sequentially, or requiring that all illustrated operations be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, while several specific implementation details are included in the foregoing discussion, these should not be construed as limiting the scope of the subject matter described herein, but rather as descriptions of features that may be specific to particular embodiments. Certain features described in the context of a single embodiment may also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0374] While this specification contains numerous specific implementation details, these should not be construed as limiting the scope of any implementation or the scope that may be claimed, but rather as descriptions of features that may be specific to particular embodiments of a particular implementation. Some features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually in multiple embodiments or in any suitable sub-combination. Furthermore, while the features described above may be described as functioning in certain combinations, and even initially claimed in this way, in certain circumstances one or more features from the claimed combination may be removed from the combination, and the claimed combination may be for sub-combinations or variations thereof.

[0375] It will be apparent to those skilled in the art that the inventive concept can be implemented in various ways with advancements in technology. The above embodiments are given for description purposes only and not for limitation of this disclosure, and it should be understood that modifications and variations can be made without departing from the spirit and scope of this disclosure, as will be readily apparent to those skilled in the art. Such modifications and variations are considered to be within the scope of this disclosure and the appended claims. The scope of protection of this disclosure is defined by the appended claims.

Claims

1. A method (300) performed by a first session management function (SMF), comprising: Determine (302) first information, wherein the first information indicates that: when no other items need to be passed to the first SMF, the second SMF does not need to report at least one item to the first SMF; and Send (304) the first information to the second SMF.

2. The method according to claim 1, wherein, The first information is used to suppress the transmission of the at least one item to the first SMF.

3. The method according to claim 2, wherein, Suppressing the transmission of the at least one item to the first SMF includes: If no other items need to be passed to the first SMF, then the sending of dedicated messages to the first SMF to notify the at least one item is suppressed.

4. The method according to any one of claims 1-3, wherein, The first information further indicates that when at least one other item needs to be delivered to the first SMF, the second SMF sends a message to the first SMF including the at least one item, wherein the message further includes the at least one other item.

5. The method according to any one of claims 1-4, wherein, The first information is determined based at least in part on at least one of the following: The policy and / or billing function has not yet provided the first SMF with event triggers for one or more items in the at least one project, wherein the first SMF will not report the one or more items in the at least one project to the policy and / or billing function; The first SMF has already subscribed to event reports for one or more projects in the at least one project using an Event Open Service that does not require interaction with the second SMF; or The first SMF does not require one or more of the items in the at least one project.

6. The method according to any one of claims 1-5, wherein, The first information is sent to the second SMF in at least one of the following ways: Protocol Data Unit (PDU) session creation response, PDU session update request, or PDU session context response.

7. The method according to any one of claims 1-6, wherein, The first information is sent to the second SMF during at least one of the following periods: PDU session establishment process The lifecycle of a PDU session, or User equipment mobility process with the second SMF insertion.

8. The method according to any one of claims 1-7, wherein, The first information is included in at least one of the following: Data created during a PDU session The visit session management function updates data, or Session management context.

9. The method according to any one of claims 1-8, wherein, The at least one item includes at least one modified item.

10. The method according to any one of claims 1-9, wherein, The at least one item includes at least one of the following: Service network, Network access type, Additional access network types, Types of radio access technologies User equipment location. User equipment time zone Additional user equipment location, Information indicating whether the user equipment is located within or outside the local data network service area. Security outcomes associated with PDU sessions User plane security information associated with PDU sessions Information indicating whether the user equipment requests to establish an always-on PDU session. Information indicating whether a PDU session can be moved to Evolved Packet System (EPS) and whether the N26 interface should be used during EPS interoperability. Usage data report for auxiliary radio access technologies used in Quality of Service (QoS) flow Usage data reports for auxiliary radio access technologies used in Quality of Service (QoS) streams and / or the entire PDU session. Information indicating whether the access network type associated with a PDU session is changeable. Information indicating the access that will be released. Information indicating whether a PDU session is allowed to be upgraded to a multi-access PDU session. Information indicating whether a multi-access PDU session has been requested. Information indicating unavailable access, or Information indicating the maximum integrity protection data rate supported by the user equipment for the downlink.

11. The method according to any one of claims 1-10, further comprising: Send (312) a message to the second SMF for updating the at least one item or deleting the first information.

12. The method according to any one of claims 1-11, wherein, The first SMF includes at least one of the following: Anchor SMF, or Belongs to SMF.

13. The method according to any one of claims 1-12, wherein, The second SMF includes at least one of the following: Middle SMF, or Visit SMF.

14. A method (400) performed by a second session management function (SMF), comprising: Receive (402) first information from either the first SMF or the older second SMF, wherein the first information indicates that the second SMF does not need to report at least one item to the first SMF when no other items need to be passed to the first SMF; and Obtain at least one item as described in (404).

15. The method of claim 14, further comprising: Based on the first information, suppress (406) sending the at least one item to the first SMF.

16. The method according to claim 15, wherein, Based on the first information, suppressing the transmission of the at least one item to the first SMF includes: If no other items need to be passed to the first SMF, then the sending of dedicated messages to the first SMF to notify the at least one item is suppressed.

17. The method according to any one of claims 14-16, further comprising: When at least one other item needs to be delivered to the first SMF, a message including the at least one item is sent to the first SMF (408), wherein the message further includes the at least one other item.

18. The method according to any one of claims 14-17, wherein, The first information is received from the first SMF in at least one of the following: Protocol Data Unit (PDU) session creation response, PDU session update request, or PDU session context response.

19. The method according to any one of claims 14-18, wherein, The first information was received from the old second SMF in the PDU session context response.

20. The method according to any one of claims 14-19, wherein, The first information is received from the first SMF during at least one of the following periods: PDU session establishment process The lifecycle of a PDU session, or User equipment mobility process with the second SMF insertion.

21. The method according to any one of claims 14-20, wherein, The first information is received from the old second SMF during a user equipment mobility process with the old second SMF changed.

22. The method according to any one of claims 14-21, wherein, The first information is included in at least one of the following: Data created during a PDU session The visit session management function updates data, or Session management context.

23. The method according to any one of claims 14-22, wherein, The at least one item includes at least one modified item.

24. The method according to any one of claims 14-23, wherein, The at least one item includes at least one of the following: Service network, Network access type, Additional access network types, Types of radio access technologies User equipment location. User equipment time zone Additional user equipment location, Information indicating whether the user equipment is located within or outside the local data network service area. Security outcomes associated with PDU sessions User plane security information associated with PDU sessions Information indicating whether the user equipment requests to establish an always-on PDU session. Information indicating whether a PDU session can be moved to Evolved Packet System (EPS) and whether the N26 interface should be used during EPS interoperability. Usage data report for auxiliary radio access technologies used in Quality of Service (QoS) flow Usage data reports for auxiliary radio access technologies used in Quality of Service (QoS) streams and / or the entire PDU session. Information indicating whether the access network type associated with the PDU session is information that can be changed. Information indicating the access that will be released. Information indicating whether a PDU session is allowed to be upgraded to a multi-access PDU session. Information indicating whether a multi-access PDU session has been requested. Information indicating unavailable access, or Information indicating the maximum integrity protection data rate supported by the user equipment for the downlink.

25. The method according to any one of claims 14-24, further comprising: Receive (412) a message from the first SMF for updating the at least one item or deleting the first information; as well as Update (414) at least one item or delete the first information.

26. The method according to any one of claims 14-25, further comprising: Store (422) the first information.

27. The method according to any one of claims 14-26, further comprising: Send (432) the first information to the new second SMF.

28. The method according to claim 27, wherein, The first information is sent to the new second SMF during a user equipment mobility process with the second SMF change.

29. The method according to any one of claims 14-28, wherein, The first SMF includes at least one of the following: Anchor SMF, or Belongs to SMF.

30. The method according to any one of claims 14-29, wherein, The second SMF includes at least one of the following: Middle SMF, or Visit SMF.

31. A first session management function (SMF) (800), comprising: Processor (821); as well as A memory (822) coupled to the processor (821) stores instructions executable by the processor (821), thereby enabling the first SMF (800) to: The first information indicates that the second SMF does not need to report at least one item to the first SMF when no other items need to be passed to the first SMF; and Send the first information to the second SMF.

32. The first SMF according to claim 31, wherein, The first SMF is further operable to perform the method of any one of claims 2 to 13.

33. A second session management function (SMF) (800), comprising: Processor (821); as well as A memory (822) coupled to the processor (821) stores instructions executable by the processor (821), thereby enabling the second SMF (800) to: Receive first information from a first SMF or an older second SMF, wherein the first information indicates that the second SMF does not need to report at least one item to the first SMF when no other items need to be passed to the first SMF; as well as Obtain at least one of the items.

34. The second SMF according to claim 33, wherein, The second SMF is further operable to perform the method of any one of claims 15 to 30.

35. A computer-readable storage medium storing instructions, which, when executed by at least one processor, cause the at least one processor to perform the method according to any one of claims 1 to 29.

36. A computer program product comprising instructions that, when executed by at least one processor, cause the at least one processor to perform the method according to any one of claims 1 to 29.

Images