Session management function entity discovery method, electronic device, and computer-readable storage medium

Abstract

The present disclosure provides a session management functional entity (SMF) discovery method that is applied to a session creation process and includes the steps of: identifying an SMF set in response to receiving a first request message sent by an access and mobility management functional entity (AMF), where the SMF in the SMF set is an SMF to which a virtual network (VN) group of a user device (UE) requesting the session creation belongs by accessing the AMF; identifying a first candidate SMF for the VN group and sending information of the first candidate SMF to the AMF, where the first candidate SMF is one of the SMFs in the SMF set. The present disclosure further provides a network function node, an access and mobility management functional entity, an electronic device, and a computer-readable storage medium.

Description

[Technical Field]

[0001] This application claims priority from Chinese Patent Application No. 202110760119.9, filed on July 6, 2021, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to the field of communications technology, and specifically to a session management function entity discovery method, a network function node, an access and mobility management function entity, an electronic device, and a computer-readable storage medium. [Background technology]

[0003] The 3GPP (registered trademark) (3rd Generation Partnership Project) R16 version introduces services that support 5G (The 5th Generation Mobile Communications) LAN (Local Area Network), providing services similar to private communication on a local area network. Users under the same 5G LAN form a 5G VN (Virtual Network) group, and each 5G VN group is assigned a 5G VN group ID.

[0004] In the conventional 3GPP standard, the same 5G VN group can only belong to one SMF (Session Management Function). However, such a restriction reduces communication reliability. For example, if the SMF to which the 5G VN group belongs fails, users in the 5G VN group may lose communication. Therefore, to ensure the availability of 5G LAN networks, the same 5G VN group is assigned to multiple SMFs in actual deployment. However, if the same 5G VN group belongs to multiple SMFs, the UEs (User Equipment) on both sides of the communication route data through two different A-UPFs (Anchor User Plane Functions), resulting in relatively large delays and network loads. Summary of the Invention [Means for solving the problem]

[0005] In a first aspect, the disclosed embodiments are applied to a session creation process, In response to receiving a first request message sent by an access and mobility management function entity (AMF), identifying a session management function entity (SMF) set, where the SMF in the SMF set is an SMF to which a virtual network (VN) group of a user device that accesses the AMF and requests the creation of a session belongs; Identifying a first candidate SMF for the VN group, the first candidate SMF being one of the SMFs in the SMF set; Sending information of the first candidate SMF to the AMF; Contains Provides a Session Management Function Entity (SMF) discovery method.

[0006] In another aspect, the disclosed embodiments are applied to a session creation process, In response to receiving a session management function entity (SMF) discovery request message sent by an access and mobility management function entity (AMF), acquiring virtual network (VN) group information attached to the SMF discovery request message; Identifying an SMF set of the VN group based on the information of the VN group and a second mapping relationship between the information of the VN group and the information of the SMF; sending an SMF discovery response message to the AMF, the SMF set being attached, so that the AMF sends a first-candidate SMF selection request; A method for discovering SMF is further provided.

[0007] In another aspect, the disclosed examples are In response to receiving a session creation request message sent by a user device (UE), sending a first request message to a network function node (NF), the first request message being configured to instruct the NF to identify a first candidate SMF of a virtual network (VN) group where the UE is located, the first candidate SMF being one of SMFs in an SMF set, and the SMF in the SMF set being an SMF to which the VN group belongs; receiving information on the first candidate SMF sent by the NF; and sending a session creation request message to a first candidate SMF corresponding to the information of the first candidate SMF. A method for discovering SMF is further provided.

[0008] In another aspect, an embodiment of the present disclosure includes a first processing module, an SMF discovery module, and a sending module, wherein the first processing module is configured to identify a session management function entity (SMF) set in response to receiving a first request message sent by an access and mobility management function entity (AMF), and the SMF in the SMF set is an SMF belonging to a virtual network (VN) group where a user device that accesses the AMF to request the creation of a session is located; The SMF discovery module is configured to identify a first candidate SMF for the VN group, where the first candidate SMF is one of the SMFs in the SMF set; The sending module is configured to send information of the first candidate SMF to the AMF. A network function node is further provided.

[0009] In another aspect, an embodiment of the present disclosure includes a receiving module, an acquiring module, a processing module, and a sending module, wherein the receiving module is configured to receive a session management function entity (SMF) discovery request message sent by an access and mobility management function entity (AMF); The acquisition module is configured to acquire information of a virtual network (VN) group attached to the SMF discovery request message; The processing module is configured to identify an SMF set of the VN group based on information of the VN group and a second mapping relationship between information of the VN group and information of an SMF; The sending module is configured to send an SMF discovery response message accompanied by the SMF set to the AMF, so that the AMF sends a first-candidate SMF selection request. A network function node is further provided.

[0010] In another aspect, an embodiment of the present disclosure includes an SMF discovery module, the SMF discovery module being configured to send a first request message to a network function node (NF) in response to receiving a create session request message sent by a user device (UE), the first request message being configured to instruct the NF to identify a first candidate SMF of a virtual network (VN) group where the UE is located, the first candidate SMF being one of SMFs in an SMF set, the SMF in the SMF set being a member SMF of the VN group, receiving information of the first candidate SMF sent by the NF, and sending a create session request message to the first candidate SMF corresponding to the information of the first candidate SMF. An access and mobility management functional entity is further provided.

[0011] In another aspect, the disclosed examples are at least one processor; a storage device having at least one computer program stored therein; The at least one computer program, when executed by the at least one processor, causes the at least one processor to implement the SMF discovery method described above. An electronic device is further provided.

[0012] In another aspect, the disclosed embodiment includes a computer program stored therein, the computer program implementing the above-described SMF discovery method when executed by a processor. A computer-readable storage medium is also provided. [Brief explanation of the drawings]

[0013] [Figure 1] 1a to 1c are schematic diagrams of three methods of data routing and forwarding between user devices in a 5G local area network (LAN) provided by an embodiment of the present disclosure. [Figure 2]FIG. 2 is a schematic flow diagram of a session management function entity (SMF) discovery method performed by a network function node (NF) according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a flow diagram of SMF registration provided by an embodiment of the present disclosure. [Figure 4] FIG. 4 is a schematic flow diagram of an SMF discovery method performed by a group management function entity (GMF) according to an embodiment of the present disclosure. [Figure 5] FIG. 5 is a flow diagram of an SMF discovery method performed by an access and mobility management function entity (AMF) according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is a schematic flow diagram of an embodiment of the present disclosure in which the AMF resends a session creation request. [Figure 7] FIG. 7 is a schematic diagram of the signaling flow of an SMF discovery method provided by an embodiment of the present disclosure in a scenario where the GMF and the group first candidate SMF selection function entity (GPSSF) are respectively located in different NFs. [Figure 8] FIG. 8 is a schematic diagram of the signaling flow of an SMF discovery method in a scenario where the GMF and GPSSF are deployed in the same NF, provided by an embodiment of the present disclosure. [Figure 9] FIG. 9 is a schematic diagram of a signaling flow provided by an embodiment of the present disclosure, in which an SMF registers with an NF in which a GMF is located. [Figure 10] FIG. 10 is a schematic diagram of the NF provided in the present disclosure. [Figure 11] FIG. 11 is a schematic diagram of the NF provided in the present disclosure. [Figure 12] FIG. 12 is a schematic diagram of the NF provided in the present disclosure. [Figure 13] FIG. 13 is a schematic diagram of an NF (NF in which a GMF is arranged) provided by an embodiment of the present disclosure. [Figure 14] FIG. 14 is a schematic diagram of an NF (NF in which a GMF is arranged) provided by an embodiment of the present disclosure. [Figure 15]FIG. 15 is a schematic structural diagram of the AMF provided in the embodiment of the present disclosure. [Figure 16] FIG. 16 is a schematic structural diagram of the AMF provided in the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0014]

[0023] The following description of exemplary embodiments will be made more fully with reference to the accompanying drawings, but the described exemplary embodiments may be embodied in different forms, and the present disclosure should not be construed as being limited to the embodiments set forth herein. The purpose of providing these examples is to make the present disclosure more detailed and complete, and to allow those skilled in the art to fully understand the scope of the present disclosure.

[0015] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0016] The terms used herein are for the purpose of describing particular embodiments only and do not limit the disclosure. As used herein, the singular forms "a," "an," and "the" include the plural unless the surrounding text clearly indicates otherwise. Also, when used herein, the terms "comprising" and / or "formed by" indicate the presence of said feature, whole, step, operation, element, and / or component, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or groups thereof.

[0017] The embodiments described herein may be described with reference to plan views and / or cross-sectional views using idealized schematic diagrams of the present disclosure. Therefore, because exemplary drawings may be modified based on manufacturing technology and / or tolerances, the embodiments are not limited to the embodiments shown in the drawings and include layout modifications formed based on the manufacturing process. Therefore, the regions illustrated in the drawings have schematic attributes, and the shapes of the regions illustrated in the drawings exemplify the specific shapes of the regions of the components, but are not intended to be limiting.

[0018] Unless otherwise specified, the meanings of all terms (including technical and scientific terms) used herein are the same as those commonly understood by those skilled in the art. For example, terms defined in a common dictionary should be interpreted as having a meaning consistent with the meaning in the relevant art and in the context of this disclosure, and are not to be interpreted as having an idealized or overly formal meaning unless expressly so limited in the present text.

[0019] Under the same 5G (The 5th Generation Mobile Communications) VN (Virtual Network) group, communication data between users can be routed locally via an Anchor User Plane Function (A-UPF), via the N19 interface between two A-UPFs, or via the Data Network (DN) via the N6 interface between two A-UPFs. The method used depends on the relationship between the UEs (User Equipment) and the A-UPFs. As shown in Figure 1a, if both communication devices (UE1 and UE2) belong to the same A-UPF, the A-UPF directly routes and forwards data locally. As shown in Figure 1b, if both communication devices (UE1 and UE2) belong to different A-UPFs and the A-UPFs support the N19 interface, data routing and forwarding is performed based on the N19 interface. As shown in Figure 1c, if both communicating parties (UE1 and UE2) belong to different A-UPFs and the A-UPF does not support the N19 interface, data routing forwarding is performed through the DN based on the N6 interface.

[0020] As can be seen from the three types of communication data routing architectures for 5G LANs (Local Area Networks), A-UPF local routing enables data routing forwarding without the need for an extra N19 or N6 interface, resulting in the lowest transmission latency and reduced network load. Based on this feature, the 3GPP standard requires that PDU (Protocol Data Unit) sessions of users under the same 5G VN group belong to the same Session Management Function (SMF), and that the SMF selects the same A-UPF for PDU sessions of the same 5G VN group as much as possible. However, this restriction leads to reduced communication reliability. If the SMF to which the 5G VN group belongs fails, users within the 5G VN group will lose communication. Therefore, to ensure the reliability of 5G LAN networks, the same 5G VN group is assigned to multiple SMFs in actual deployments. However, the current 3GPP standard cannot guarantee that PDU sessions under the same 5G VN group select the same SMF, and therefore cannot take advantage of local routing under 5G LAN services.

[0021] The disclosed embodiment provides an SMF discovery method, and when the same 5G VN group belongs to multiple SMFs, when a user creates a PDU session under the 5G VN group, the AMF (Access and Mobility Management Function, an access and mobility management function entity) selects the same SMF access as much as possible, that is, the AMF selects the same SMF for PDU sessions of the same 5G VN group. In the disclosed embodiment, PDU session creation in a 5G scenario is described as an example.

[0022] As shown in FIG. 2, the SMF discovery method provided in the disclosed embodiment is applied to a session creation process and includes steps 11 to 13.

[0023] Step 11: In response to receiving the first request message sent by the AMF, identify an SMF set, and the SMF in the SMF set is the SMF to which the VN group of the UE that accesses the AMF to request the creation of a session belongs.

[0024] A VN group includes multiple UEs, and in order for UEs in the same VN group to perform a PDU session with each other, they must first register with the AMF. UEs in the same VN group may register with the same AMF or different AMFs. A UE can create a PDU session only after completing registration with the AMF. When a UE in a VN group attempts to communicate with other UEs in the VN group after completing registration with the AMF, it sends a PDU session creation request message to the registered AMF. After receiving the PDU session creation request message, the AMF sends a first request message to the NF (Network Function).

[0025] In this step, the NF receives the first request message sent by the AMF and identifies an SMF set based on the first request message, where the SMF set consists of at least two SMFs, each of which is the SMF to which the VN group of the UE that accesses the AMF to request the creation of a PDU session belongs.

[0026] The GMF (Group Management Function) manages information about VN groups, and the GPSSF (Group Preferred SMF Selection Function) selects a preferred SMF from a set of SMFs (i.e., an SMF set) to which a VN group belongs. The GMF and GPSSF may be independently located in different NFs, or may be located simultaneously in the same NF. The GMF and GPSSF may be a functional component of an existing NF or a new NF. The NF types and function configurations differ, and the corresponding first request message also differs. The first request message and processing flow for different NF types and function configurations will be described in detail below.

[0027] Step 12: Identify a VN group first candidate SMF, where the first candidate SMF is one of the SMFs in the SMF set.

[0028] In this step, the NF identifies a first-choice SMF for the VN group, which is one of the SMFs in the SMF set. The first-choice SMF refers to the SMF that the AMF preferentially accesses. For PDU sessions originated by UEs in the VN group, the AMF preferentially accesses the first-choice SMF and sends a PDU session creation request to the first-choice SMF. Once the first-choice SMF is identified, it usually does not change unless the first-choice SMF fails, ensuring that the AMF selects the same SMF access for PDU sessions in the same 5G VN group.

[0029] Step 13: Send the information of the first candidate SMF to the AMF.

[0030] In this step, the NF type and function configuration are different, and different messages are used to send information about the first candidate SMF identified in step 12 to the AMF, facilitating the AMF to access the first candidate SMF and create a PDU session.

[0031] The disclosed embodiments provide an SMF discovery method that is applied to a session creation process, and identifies an SMF set in response to receiving a first request message sent by an AMF, and the SMF in the SMF set accesses the AMF to identify a first candidate SMF for the VN group to which the UE requesting the session creation belongs, and sends information about the first candidate SMF to the AMF, where the first candidate SMF is one of the SMFs in the SMF set. The SMF discovery method provided by the disclosed embodiments selects a first candidate SMF from the SMF set to which the VN group to which the UE belongs, and when creating a session, the AMF accesses the first candidate SMF to send a session creation request. This ensures that all AMFs access the same SMF as much as possible, whether UEs in the VN group access the same AMF or different AMFs. That is, UEs in the same VN group can directly perform local routing forwarding via the A-UPF, reducing communication delays and network loads while ensuring network communication reliability.

[0032] In some embodiments, the SMF discovery method further includes, after receiving a first request message sent by the AMF, obtaining information about the VN group attached to the first request message before identifying the first candidate SMF for the VN group.

[0033] In some embodiments, the step of identifying a first candidate SMF for the VN group (i.e., step 12) includes a step of setting the identified first candidate SMF as the first candidate SMF for the VN group in response to identifying a first candidate SMF corresponding to the information of the VN group based on a first mapping relationship between the information of the VN group and the information of the first candidate SMF, and a step of selecting one SMF from the SMF set and setting it as the first candidate SMF for the VN group in response to not identifying a first candidate SMF corresponding to the information of the VN group based on the first mapping relationship between the information of the VN group and the information of the first candidate SMF.

[0034] The NF stores a first mapping relationship between information about the VN group and information about the first candidate SMF. If the first candidate SMF can be identified based on the first mapping relationship, it indicates that the NF has previously selected a first candidate SMF for the VN group (i.e., a first candidate SMF for the VN group already exists). If, during the PDU session creation process, it is found that the NF already has a first candidate SMF for the VN group, there is no need to identify the first candidate SMF again in step 12, and the previously identified first candidate SMF becomes the first candidate SMF for the VN group. If it is found that the NF does not have a first candidate SMF for the VN group, it identifies the first candidate SMF in step 12, i.e., selects one SMF from the SMF set and sets it as the first candidate SMF for the VN group.

[0035] In some embodiments, the step of selecting one SMF from the SMF set to be the first-choice SMF for the VN group comprises the steps of: setting a pre-specified SMF in the SMF set as the first-choice SMF for the VN group; or randomly selecting one SMF from the SMF set to be the first-choice SMF for the VN group. In other words, the first-choice SMF can be identified by a method known as static configuration, or by a method known as dynamic selection. In the static configuration method, one of the SMFs in the SMF set can be pre-specified as the first-choice SMF using a profile or configuration parameters, and in the dynamic selection method, one SMF can be randomly selected from the SMF set to be the first-choice SMF.

[0036] To ensure that the AMF selects the same SMF access for PDU sessions of the same 5G VN group, after initially identifying the first-candidate SMF for the VN group, the NF needs to record information about the first-candidate SMF. Therefore, in some embodiments, the SMF discovery method further includes the step of selecting an SMF from the SMF set as the first-candidate SMF for the VN group, and then establishing a first mapping relationship between information about the VN group and information about the first-candidate SMF. By establishing the first mapping relationship between information about the VN group and information about the first-candidate SMF, the NF can determine whether a first-candidate SMF corresponding to the VN group already exists by querying the first mapping relationship. If the first mapping relationship is successful, the NF can directly obtain information about the first-candidate SMF. If the first mapping relationship is not successful, the NF needs to reselect the first-candidate SMF for the VN group, eliminating the need to select the first-candidate SMF each time. This simplifies the processing of the NF while ensuring that the first-candidate SMF does not change.

[0037] The following describes the process of identifying the first request message and the SMF set for different NF types and function configurations.

[0038] In some embodiments, a GMF and a GPSSF are co-located in the NF, the first request message is an SMF discovery request message, and the SMF discovery method further includes, after receiving the first request message sent by the AMF, acquiring VN group information attached to the SMF discovery request message. In some embodiments, the step of identifying the SMF set includes identifying the SMF set for the VN group based on the VN group information and a second mapping relationship between the VN group information and the SMF information. Because the GMF records the VN group information and the second mapping relationship between the VN group information and the SMF information, in the process of identifying the SMF set, information on all SMFs corresponding to the VN group can be identified based on the second mapping relationship, thereby obtaining the SMF set.

[0039] In some embodiments, the SMF discovery request message may further include at least one of UE location information, a DNN (Data Network Name), and network slice information. When identifying an SMF set, the VN group information and at least one of the information included in the SMF discovery request message may be combined to identify an element of the SMF set.

[0040] In some embodiments, when a GMF and a GPSSF are co-located in an NF, the step of sending information about the first-candidate SMF to an AMF (i.e., step 13) includes sending an SMF discovery response message to the AMF, where the SMF discovery response message includes the information about the first-candidate SMF. In this step, the NF where a GMF and a GPSSF are co-located returns an SMF discovery response message to the AMF, where the information about the first-candidate SMF is included in the SMF discovery response message.

[0041] In some embodiments, the SMF discovery response message may be accompanied by an SMF set, so that if the AMF subsequently fails to send a PDU session creation request to the first-choice SMF, the AMF can select another SMF from the SMF set and send the PDU session creation request again.

[0042] In some embodiments, the GMF and the GPSSF are located in different NFs, the first request message is a VN group first candidate SMF selection request message, and the step of identifying the SMF set includes a step of obtaining an SMF set attached to the VN group first candidate SMF selection request message, where the SMF set is identified by the GMF based on a second mapping relationship between the VN group information and the SMF information and the VN group information attached to the SMF discovery request message sent by the AMF, and is sent to the AMF. In other words, in a scenario where the GMF and the GPSSF are located in different NFs, the AMF first sends an SMF discovery request message attached with the VN group information to the NF where the GMF is located (e.g., NF1), and NF1 identifies the SMF set to which the VN group information corresponds based on the second mapping relationship between the VN group information and the SMF information, and returns an SMF discovery response message attached with the SMF set to the AMF. The AMF sends a VN group first candidate SMF selection request message with the SMF set attached to the NF where the GPSSF is located (e.g., NF2), and NF2 directly obtains the SMF set from the VN group first candidate SMF selection request message.

[0043] In a scenario where the GMF and the GPSSF are respectively located in different NFs, in some embodiments, the step of sending the information of the first-candidate SMF to the AMF (i.e., step 13) includes the step of sending a VN group first-candidate SMF selection response message to the AMF, the VN group first-candidate SMF selection response message carrying the information of the first-candidate SMF. In this step, the NF2 in which the GPSSF is located returns a VN group first-candidate SMF selection response message to the AMF, and the VN group first-candidate SMF selection response message carries the information of the first-candidate SMF.

[0044] In some embodiments, the SMF discovery method further includes a step of establishing a second mapping relationship between VN group information and SMF information, where the second mapping relationship is established during SMF registration. The following describes in detail the process of establishing the second mapping relationship between VN group information and SMF information in combination with Figure 3.

[0045] As shown in FIG. 3, the step of establishing a second mapping relationship between the information of the VN group and the information of the SMF includes steps 21 and 22.

[0046] In step 21, in response to receiving the SMF registration request message sent by the SMF, the VN group information attached to the SMF registration request message is obtained.

[0047] In this step, the SMF achieves SMF registration by sending an SMF registration request message to the NF in which the GMF is located (which may be an NF in which the GMF is located alone, or an NF in which the GMF and GPSSF are located together), and the SMF registration request message is accompanied by information about the VN group corresponding to the SMF.

[0048] In step 22, a second mapping relationship between the information of the VN group and the information of the SMF is established.

[0049] In this step, for the currently registered SMF, the NF in which the GMF is deployed establishes a second mapping relationship between the VN group information and the SMF information and stores the second mapping relationship locally. Note that since each SMF needs to be registered with the NF in which the GMF is deployed, the NF in which the GMF is deployed can establish and store a second mapping relationship between the information of each SMF and the information of the corresponding VN group. In this way, when identifying an SMF set later, the information of all SMFs in the VN group can be directly found based on the VN group information and the second mapping relationship, thereby obtaining the SMF set.

[0050] In some embodiments, the SMF discovery method may further include the step of returning a registration response message to the SMF after establishing a second mapping relationship between the information of the VN group and the information of the SMF (i.e., step 22).

[0051] The disclosed embodiment further provides an SMF discovery method, as shown in Figure 4, including steps 31 to 33.

[0052] Step 31: In response to receiving the SMF discovery request message sent by the AMF, obtain the VN group information attached to the SMF discovery request message.

[0053] In this step, the NF in which the GMF is deployed receives the SMF discovery request message sent by the AMF and obtains the VN group information in the SMF discovery request message.

[0054] Step 32: Identify an SMF set of the VN group based on the information of the VN group and a second mapping relationship between the information of the VN group and the information of the SMF.

[0055] Since the NF in which the GMF is located records information about the VN group and a second mapping relationship between the VN group information and the SMF information, in this step, the information about all SMFs corresponding to the VN group can be identified based on the second mapping relationship, thereby obtaining an SMF set.

[0056] Step 33: The AMF sends an SMF discovery response message with the SMF set attached to the AMF to initiate a first-candidate SMF selection request.

[0057] The SMF discovery method provided in the disclosed embodiments is applied to a session creation flow. In response to receiving an SMF discovery request message sent by an AMF, the method obtains virtual network VN group information attached to the SMF discovery request message, identifies an SMF set for the VN group based on the VN group information and a second mapping relationship between the VN group information and the SMF information, and sends an SMF discovery response message attached to the SMF set to the AMF so that the AMF can issue a first-candidate SMF selection request. The SMF discovery method provided in the disclosed embodiments selects a first-candidate SMF from the SMF set to which the VN group where the UE is located belongs, and when creating a session, the AMF accesses the first-candidate SMF to send a session creation request. This ensures that all AMFs in the VN group access the same SMF as much as possible, regardless of whether the UEs access the same AMF or different AMFs. That is, UEs in the same VN group can be directly local-routed via the A-UPF, reducing communication delays and network loads while ensuring network communication reliability.

[0058] In some embodiments, the SMF discovery method further includes a step of establishing a second mapping relationship between information of the VN group and information of the SMF, where the second mapping relationship is established when the SMF is registered. As shown in FIG. 3, the step of establishing the second mapping relationship between information of the VN group and information of the SMF includes the following steps 21 and 22:

[0059] Step 21: In response to receiving the SMF registration request message sent by the SMF, obtain the VN group information attached to the SMF registration request message.

[0060] In this step, the SMF registers the SMF by sending an SMF registration request message to the NF where the GMF is deployed (which may be an NF where the GMF is deployed alone, or an NF where the GMF and GPSSF are deployed together). The SMF registration request message includes information about the VN group corresponding to the SMF.

[0061] Step 22: Establish a second mapping relationship between the information of the VN group and the information of the SMF.

[0062] In this step, for the currently registered SMF, the NF in which the GMF is deployed establishes a second mapping relationship between the VN group information and the SMF information and stores the second mapping relationship locally. Note that since each SMF needs to be registered with the NF in which the GMF is deployed, the NF in which the GMF is deployed can establish and store a second mapping relationship between the information of each SMF and the information of the corresponding VN group. In this way, when identifying an SMF set later, the information of all SMFs in the VN group can be directly found based on the VN group information and the second mapping relationship, thereby obtaining the SMF set.

[0063] In some embodiments, the SMF discovery method may further include the step of returning a registration response message to the SMF after establishing a second mapping relationship between the information of the VN group and the information of the SMF (i.e., step 22).

[0064] The disclosed embodiment further provides an SMF discovery method, and as shown in FIG. 5, the SMF discovery method includes steps 41 to 43.

[0065] Step 41: In response to receiving the session creation request message sent by the UE, send a first request message to the NF, where the first request message is configured to instruct the NF to identify a first candidate SMF of the VN group where the UE is located, the first candidate SMF is one of the SMFs in the SMF set, and the SMF in the SMF set is the SMF to which the VN group belongs.

[0066] A VN group includes multiple UEs, and when UEs in the same VN group want to perform a PDU session with each other, they must first register with the AMF. UEs in the same VN group may register with the same AMF or different AMFs. A UE can create a PDU session only after it has registered with the AMF. When a UE in a VN group wants to communicate with other UEs in the VN group after registering with the AMF, it sends a PDU session creation request message to the AMF to which it is registered. After receiving the PDU session creation request message, the AMF sends a first request message to the NF, allowing the NF to identify the first candidate SMF for the VN group where the UE is located. The first candidate SMF is one of the SMFs in the SMF set, and the SMF in the SMF set is the SMF to which the VN group belongs.

[0067] The first request message differs depending on the type and function configuration of the NF. The first request message and processing flow for different NF types and function configurations will be described in detail below.

[0068] Step 42: Receive the information of the first candidate SMF sent by the NF.

[0069] In this step, if the type and function configuration of the NF are different, the AMF receives the information of the first candidate SMF sent by the NF of the corresponding type and function configuration through a different message.

[0070] Step 43: Send a session creation request message to the first candidate SMF corresponding to the information of the first candidate SMF.

[0071] The SMF discovery method provided in the disclosed embodiments is applied to a session creation flow, and in response to receiving a session creation request message sent by a UE, sends a first request message to an NF, where the first request message is configured to instruct the NF to identify a first candidate SMF of a VN group where the UE is located, where the first candidate SMF is one of the SMFs in an SMF set, and the SMF in the SMF set is the SMF to which the VN group belongs, receives the information of the first candidate SMF sent by the NF, and sends a session creation request message to the first candidate SMF corresponding to the information of the first candidate SMF. The SMF discovery method provided in the disclosed embodiments selects a first candidate SMF from the set of SMFs to which the VN group in which the UE is located belongs, and when creating a session, the AMF accesses the first candidate SMF and sends a session creation request. In this way, whether the UEs in the VN group access the same AMF or different AMFs, it can be ensured that all AMFs access the same SMF as much as possible. In other words, UEs in the same VN group can directly perform local routing forwarding via A-UPF, which reduces communication delays and reduces network load while ensuring the reliability of network communication.

[0072] In some embodiments, the SMF discovery method further comprises the step of obtaining an SMF set before sending a session creation request message to the first candidate SMF corresponding to the information of the first candidate SMF (i.e., step 43).

[0073] In some embodiments, as shown in FIG. 6, after sending a session creation request message to the SMF corresponding to the information of the first candidate SMF (i.e., step 43), the SMF discovery method further includes the following steps 44 and 45:

[0074] Step 44: In response to receiving the session creation request failure message sent by the first candidate SMF, select another SMF other than the first candidate SMF from the SMF set.

[0075] If the first-choice SMF fails to create a PDU session, it returns a PDU session creation request failure message to the AMF. After receiving the PDU session creation request failure message sent by the first-choice SMF, the AMF selects another SMF (i.e., an alternative SMF) from the SMF set based on a local policy and sends a PDU session creation request to the alternative SMF. The local policy may be a pre-designated alternative SMF or a randomly selected alternative SMF. Note that the local policy may be used to define whether an alternative SMF needs to be selected after the first-choice SMF fails to create a PDU session.

[0076] Step 45: Send a session creation request message to the selected other SMFs.

[0077] In some embodiments, a GMF and a GPSSF are co-located in the NF, and the first request message is an SMF discovery request message, and the SMF discovery request message is accompanied by information about the VN group where the UE is located. The steps of receiving information about first-candidate SMFs sent by the NF (i.e., step 42) and obtaining the SMF set include receiving an SMF discovery response message sent by the NF and obtaining the information about the first-candidate SMFs and the SMF set accompanied by the SMF discovery response message, where the SMF set is identified by the NF based on the VN group information and a second mapping relationship between the VN group information and the SMF information. Since the GMF in the NF records the VN group information and the second mapping relationship between the VN group information and the SMF information, during the process of identifying the SMF set, the GMF in the NF can identify information about all SMFs corresponding to the VN group based on the second mapping relationship, thereby obtaining the SMF set.

[0078] In some embodiments, the GMF and the GPSSF are respectively located in different NFs, i.e., the NFs include a first NF (NF1) and a second NF (NF2), where the first NF is NF1 in which the GMF is located and the second NF is NF2 in which the GPSSF is located. The first request message is a VN group first candidate SMF selection request message, and the SMF discovery method further includes, before sending the first request message to the NF (step 41), sending an SMF discovery request message to the first NF, the SMF discovery request message being accompanied by information of the VN group, the SMF discovery request message being configured to instruct the first NF to identify an SMF set, and receiving an SMF discovery response message sent by the first NF and obtaining the SMF set accompanied by the SMF discovery response message.

[0079] In some embodiments, the step of sending a first request message to an NF (i.e., step 41) comprises sending a VN Group First Candidate SMF Selection Request message to a second NF, the VN Group First Candidate SMF Selection Request message being accompanied by an SMF set, the VN Group First Candidate SMF Selection Request message being configured to instruct the second NF to identify a first candidate SMF for the VN group.

[0080] In other words, in a scenario where the GMF and GPSSF are located in different NFs, the AMF first sends an SMF discovery request message accompanied by VN group information to the first NF (NF1) in which the GMF is located, the first NF (NF1) identifies an SMF set corresponding to the VN group information based on the second mapping relationship between the VN group information and the SMF information, and returns an SMF discovery response message accompanied by the SMF set to the AMF, the AMF then sends a VN group first candidate SMF selection request message accompanied by the SMF set to the second NF (NF2) in which the GPSSF is located, and the second NF (NF2) obtains the SMF set in the VN group first candidate SMF selection request message and identifies the first candidate SMF for the VN group.

[0081] In some embodiments, the VN group first candidate SMF selection request message further includes information about the VN group, which facilitates the second NF (NF2) to determine whether a first candidate SMF has previously been identified for the corresponding VN group based on the information about the VN group.

[0082] To clearly explain the technical solutions of the embodiments disclosed herein, the following describes in detail the SMF discovery process in a scenario where the GMF and GPSSF are respectively deployed in different NFs using a practical example. In this example, NF1 is an NF where the GMF is deployed alone, and NF2 is an NF where the GPSSF is deployed alone, and the SMF set corresponding to the 5G VN group where the UE is located includes SMF1 and SMF2. As shown in Figure 7, the SMF discovery flow includes steps S1 to S9.

[0083] Step S1: The UE registers with the 5G core network, i.e., the UE registers with the AMF.

[0084] Step S2: The UE triggers the establishment of a PDU session under the 5G VN group by sending a PDU session creation request message to the AMF.

[0085] Step S3: The AMF initiates the process of selecting an SMF for the PDU session of the 5G VN group by sending an SMF discovery request message containing information about the 5G VN group to NF1 (i.e., an NF where the GMF is deployed alone).

[0086] Step S4: NF1 (i.e., the NF where the GMF is deployed alone) queries the second mapping relationship between the VN group information and the SMF information, obtains the SMF set (SMF1, SMF2) corresponding to the 5G VN group, and returns an SMF discovery response message accompanied by the SMF set to the AMF.

[0087] Step S5: To send a 5G VN group first candidate SMF selection request message, the AMF sends a VN group first candidate SMF selection request message to NF2 (i.e., an NF where GPSSF is deployed alone), and the VN group first candidate SMF selection request message is accompanied by information about the 5G VN group and an SMF set.

[0088] Step S6: NF2 (i.e., an NF in which GPSSF is deployed independently) determines whether it is the first time to select a first candidate SMF for the 5G VN group based on the first mapping relationship between the information of the VN group and the information of the first candidate SMF. If NF2 is the first time to select a first candidate SMF for the 5G VN group, it selects SMF1 from the SMF set by static configuration or dynamic selection method as the first candidate SMF for the 5G VN group and locally establishes a first mapping relationship between the information of the 5G VN group and the information of SMF1. If NF2 has previously selected a first candidate SMF for the 5G VN group, it obtains the information of the first candidate SMF (i.e., SMF1) previously selected for the 5G VN group. NF2 sends a VN group first candidate SMF selection response message to the AMF, accompanied by the information of the first candidate SMF (i.e., SMF1).

[0089] Step S7: The AMF sends a PDU session creation request message to the first candidate SMF1 (i.e., the first candidate SMF of the 5G VN group).

[0090] Step S8: SMF1 returns a PDU session creation response message to AMF.

[0091] Step S9: When SMF1 returns a PDU session creation request failure message, the AMF determines based on local policies whether it is necessary to continue selecting other SMFs in the 5G VN group to continue originating the PDU session creation flow. If it is necessary to continue selecting other SMFs in the 5G VN group to continue originating the PDU session creation flow, it selects other SMFs from the SMF set to access and sends a PDU session creation request message to the other SMFs. If it is not necessary to continue selecting other SMFs in the 5G VN group to continue originating the PDU session creation flow, the PDU session is rejected.

[0092] The following describes in detail the SMF discovery process in a scenario where the GMF and GPSSF are configured in the same NF, using an example. In this example, the NF is an NF where the GMF and GPSSF are configured, and the SMF set corresponding to the 5G VN group where the UE is located includes SMF1 and SMF2. As shown in Figure 8, the SMF discovery flow includes steps S81 to S89.

[0093] Step S81: The UE registers with the 5G core network, i.e., the UE registers with the AMF.

[0094] Step S82: The UE triggers the establishment of a PDU session under the 5G VN group by sending a PDU session creation request message to the AMF.

[0095] Step S83: The AMF initiates a flow to select an SMF for the PDU session of the 5G VN group by sending an SMF discovery request message with information about the 5G VN group to the NF (i.e., the NF where the GMF and GPSSF are located).

[0096] Step S84: The NF (i.e., the NF where the GMF and GPSSF are deployed) queries the second mapping relationship between the VN group information and the SMF information, and obtains the SMF set (SMF1, SMF2) corresponding to the 5G VN group.

[0097] Step S85: The NF (i.e., the NF in which the GMF and GPSSF are configured) determines whether it is the first time to select a first candidate SMF for the 5G VN group based on the first mapping relationship between the information of the VN group and the information of the first candidate SMF. If the NF is the first time to select a first candidate SMF for the 5G VN group, it selects SMF1 from the SMF set by static configuration or dynamic selection method as the first candidate SMF for the 5G VN group, and locally establishes a first mapping relationship between the information of the 5G VN group and the information of SMF1. If the NF has previously selected a first candidate SMF for the 5G VN group, it obtains the information of the first candidate SMF (SMF1) previously selected for the 5G VN group.

[0098] Step S86: The NF (i.e., the NF where the GMF and GPSSF are located) sends an SMF discovery response message to the AMF, with the SMF set and information on SMF1 attached.

[0099] Step S87: The AMF sends a PDU session creation request message to SMF1 (i.e., the first candidate SMF).

[0100] Step S88: SMF1 returns a PDU session creation response message to AMF.

[0101] Step S89: When SMF1 returns a PDU session creation request failure message, the AMF determines based on local policies whether it is necessary to continue selecting other SMFs in the 5G VN group to continue originating the PDU session creation flow. If it is necessary to continue selecting other SMFs in the 5G VN group to continue originating the PDU session creation flow, it selects other SMFs from the SMF set to access and sends a PDU session creation request message to the other SMFs. If it is not necessary to continue selecting other SMFs in the 5G VN group to continue originating the PDU session creation flow, the PDU session is rejected.

[0102] The following describes in detail the process of an SMF registering with an NF where a GMF is deployed, using a practical example. Figure 9 is a schematic diagram of the signaling flow of SMF registration with an NF (NF1) where a GMF is deployed. As shown in Figure 9, the registration of an SMF with NF1 includes steps S10 to S30.

[0103] Step S10: The SMF sends a registration request message to the NF1, and the registration request message includes information about the 5G VN group.

[0104] Step S20: NF1 establishes a second mapping relationship between the information of the 5G VN group and the information of the SMF.

[0105] Step S30: NF1 returns a registration response message to SMF.

[0106] The SMF discovery method provided in the disclosed embodiments introduces a GMF logical entity, which is responsible for managing 5G VN group information. This logical entity may be an independent NF or a component of an existing NF. The SMF discovery method further introduces a GPSSF logical entity, which is responsible for selecting a first-candidate SMF from the set of SMFs to which the 5G VN group belongs. This logical entity may be an independent NF, a component of an existing NF, or integrated into the same NF as the GMF.

[0107] Based on the same technical idea, the disclosed embodiment further provides a network function node, which includes a first processing module 101, an SMF discovery module 102, and a sending module 103, as shown in FIG.

[0108] The first processing module 101 is configured to identify a session management function entity (SMF) set in response to receiving a first request message sent by an access and mobility management function entity (AMF), and the SMF in the SMF set is an SMF to which a virtual network (VN) group of a user device that accesses the AMF and requests the creation of a session belongs.

[0109] The SMF discovery module 102 is configured to identify a first candidate SMF of the VN group, where the first candidate SMF is one of the SMFs in the SMF set.

[0110] The sending module 103 is configured to send information of the first candidate SMF to the AMF.

[0111] In some embodiments, the first processing module 101 is further configured to, after receiving a first request message sent by an AMF, obtain information of the VN group attached to the first request message before identifying the first candidate SMF for the VN group.

[0112] In some embodiments, the SMF discovery module 102 is configured to, in response to identifying a first candidate SMF corresponding to the information of the VN group based on a first mapping relationship between the information of the VN group and the information of the first candidate SMF, set the identified first candidate SMF as the VN group first candidate SMF.

[0113] In some embodiments, the SMF discovery module 102 is configured to select one SMF from the SMF set as the first candidate SMF for the VN group in response to a first candidate SMF corresponding to the information of the VN group not being identified based on a first mapping relationship between the information of the VN group and the information of the first candidate SMF.

[0114] In some embodiments, the SMF discovery module 102 is configured to set a pre-specified SMF in the SMF set as the first candidate SMF for the VN group, or to randomly select one SMF from the SMF set as the first candidate SMF for the VN group.

[0115] In some embodiments, as shown in FIG. 11, the network function node further includes a second processing module 104, which is configured to establish a first mapping relationship between information of the VN group and information of the first candidate SMF after the SMF discovery module 102 selects one SMF from the SMF set as the first candidate SMF of the VN group.

[0116] In some embodiments, the first request message is an SMF discovery request message, and the first processing module 101 is further configured to obtain VN group information attached to the SMF discovery request message, and identify an SMF set of the VN group based on the VN group information and a second mapping relationship between the VN group information and the SMF information.

[0117] In some embodiments, the sending module 103 is configured to send an SMF discovery response message to the AMF, the SMF discovery response message being accompanied by information of the first candidate SMF.

[0118] In some embodiments, the first request message is a VN group first candidate SMF selection request message, and the first processing module 101 is configured to obtain the VN group first candidate SMF selection request message, and the SMF set is identified by a group management function entity GMF based on a second mapping relationship between VN group information and SMF information and the VN group information attached to the SMF discovery request message sent by the AMF, and sent to the AMF.

[0119] In some embodiments, the sending module 103 is configured to send a VN group first-candidate SMF selection response message to the AMF, the message carrying the information of the first-candidate SMF.

[0120] In some embodiments, as shown in FIG. 12, the network function node further includes a registration module 105, which is configured to, in response to receiving an SMF registration request message sent by an SMF, obtain information of a VN group attached to the SMF registration request message and establish a second mapping relationship between the information of the VN group and the information of the SMF.

[0121] The disclosed embodiment further provides a network function node, which includes a receiving module 201, an acquiring module 202, a processing module 203, and a sending module 204, as shown in FIG.

[0122] The receiving module 201 is configured to receive a session management function entity (SMF) discovery request message sent by an access and mobility management function entity (AMF).

[0123] The obtaining module 202 is configured to obtain information of the virtual network VN group attached to the SMF discovery request message.

[0124] The processing module 203 is configured to identify an SMF set of the VN group based on the information of the VN group and a second mapping relationship between the information of the VN group and the information of the SMF.

[0125] The sending module 204 is configured to send an SMF discovery response message accompanied by the SMF set to the AMF so that the AMF initiates a first-candidate SMF selection request.

[0126] In some embodiments, as shown in FIG. 14, the network function node further includes a registration module 205, which is configured to, in response to receiving an SMF registration request message sent by an SMF, obtain information of a VN group attached to the SMF registration request message and establish a second mapping relationship between the information of the VN group and the information of the SMF.

[0127] The disclosed embodiment further provides an access and mobility management function entity, which, as shown in FIG. 15, includes an SMF discovery module 301 configured to send a first request message to a network function node (NF) in response to receiving a session creation request message sent by a user device (UE), the first request message being configured to instruct the NF to identify a first candidate SMF of a virtual network (VN) group where the UE is located, the first candidate SMF being one of the SMFs in an SMF set, the SMF in the SMF set being the SMF to which the VN group belongs, receiving information of the first candidate SMF sent by the NF, and sending a session creation request message to the first candidate SMF corresponding to the information of the first candidate SMF.

[0128] In some embodiments, as shown in FIG. 16 , the access and mobility management function entity further includes an acquisition module 302, which is configured to acquire the SMF set before sending a session creation request message to a first candidate SMF corresponding to information of the first candidate SMF.

[0129] The access and mobility management function entity further includes an SMF rediscovery module 303, which is configured to select another SMF other than the first candidate SMF from the SMF set and send a session creation request message to the selected other SMF in response to receiving a session creation request failure message sent by the first candidate SMF after the SMF discovery module 301 sends a session creation request message to the first candidate SMF corresponding to the information of the first candidate SMF.

[0130] In some embodiments, the first request message is an SMF discovery request message, and the SMF discovery request message is accompanied by information on the VN group where the UE is located. The acquisition module 302 is configured to acquire the information on the first candidate SMF and the SMF set accompanied by the SMF discovery response message sent by the NF, and the SMF set is identified by the NF based on the information on the VN group and a second mapping relationship between the information on the VN group and the information on the SMF.

[0131] In some embodiments, the NFs include a first NF and a second NF, the first request message is a VN group first candidate SMF selection request message, and the acquisition module 302 is configured to send an SMF discovery request message to the first NF, the SMF discovery request message carrying information about the VN group, the SMF discovery request message instructing the first NF to identify an SMF set, and is further configured to receive an SMF discovery response message sent by the first NF and acquire the SMF set attached to the SMF discovery response message.

[0132] The SMF discovery module 301 is configured to send a VN group first candidate SMF selection request message accompanied by the SMF set to a second NF, wherein the VN group first candidate SMF selection request message is for instructing the second NF to identify a first candidate SMF for the VN group.

[0133] In some embodiments, the VN group first candidate SMF selection request message further includes information about the VN group.

[0134] An embodiment of the present disclosure further provides an electronic device, the electronic device including at least one processor and a storage device, wherein the storage device stores at least one computer program, and when the at least one computer program is executed by the at least one processor, the at least one processor realizes the above-mentioned SMF discovery method.

[0135] An embodiment of the present disclosure further provides a computer-readable storage medium, which stores a computer program, which, when executed by a processor, realizes the above-mentioned SMF discovery method.

[0136] Those skilled in the art will understand that all or some of the steps of the methods disclosed above and the functional modules / means of the apparatuses can be implemented as software, firmware, hardware, or a suitable combination thereof. In hardware embodiments, the division between the functional modules / means mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed jointly by several components. Some or all of the physical components may be implemented as software executed by a processor (e.g., a central processing unit, a digital signal processor, or a microprocessor), or as hardware, or as an integrated circuit such as a dedicated integrated circuit. Such software may be located on a computer-readable medium, which may include computer storage media (or non-transitory media) and communication media (or transitory media). As those skilled in the art will appreciate, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (e.g., computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium used to store the desired information and which can be accessed by a computer. Additionally, those skilled in the art will know that communication media typically include computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism and can include any information delivery media.

[0137] Although exemplary embodiments are disclosed herein and specific terms are employed, these should be used and interpreted in a general, illustrative sense only, and not for limiting purposes. It will be apparent to those skilled in the art that in some instances, unless expressly indicated otherwise, features, characteristics, and / or elements described in combination with a particular embodiment may be used alone, or features, characteristics, and / or elements described in combination with other embodiments may be used in combination. Accordingly, those skilled in the art will recognize that various changes in form and detail may be made without departing from the scope of the present disclosure as set forth in the appended claims.

Claims

1. A session management function entity (SMF) discovery method executed by a network function node, comprising: In response to receiving a first request message sent by an access and mobility management function entity (AMF), identifying a session management function entity (SMF) set, the SMF set including a plurality of SMFs, the plurality of SMFs included in the SMF set belonging to a virtual network (VN) group, the VN group including a plurality of user devices that access the AMF and request the creation of a session; Identifying a first candidate SMF for the VN group, the first candidate SMF being one of the SMFs in the SMF set; and transmitting information of the first candidate SMF to the AMF so as to enable the AMF to access the first candidate SMF and transmit the session creation request message to the first candidate SMF in response to receiving a session creation request message transmitted by one of the plurality of user devices included in the VN group, and to select another SMF from the SMF set other than the first candidate SMF in response to receiving a session creation request failure message transmitted by the first candidate SMF. Session Management Function Entity (SMF) discovery method.

2. After receiving the first request message sent by the AMF, before the step of identifying the first candidate SMF for the VN group, further includes a step of acquiring information of the VN group attached to the first request message; The step of identifying a first candidate SMF for the VN group includes: and a step of, in response to identifying a first candidate SMF corresponding to the information of the VN group based on a first mapping relationship between the information of the VN group and the information of the first candidate SMF, setting the identified first candidate SMF as the first candidate SMF of the VN group. The method of claim 1.

3. The step of identifying a first candidate SMF for the VN group includes: The method further includes a step of selecting one SMF from the SMF set as the first candidate SMF for the VN group when a first candidate SMF corresponding to the information of the VN group is not identified based on a first mapping relationship between the information of the VN group and the information of the first candidate SMF. The method of claim 2.

4. The step of selecting one SMF from the SMF set as the first candidate SMF for the VN group includes: a step of setting a pre-designated SMF in the SMF set as a first candidate SMF for the VN group, or randomly selecting one SMF from the SMF set as a first candidate SMF for the VN group. The method of claim 3.

5. The method further includes the step of selecting one SMF from the SMF set as a first candidate SMF for the VN group, and then establishing a first mapping relationship between information on the VN group and information on the first candidate SMF. The method of claim 3.

6. The first request message is an SMF discovery request message, and the SMF discovery method further includes, after receiving the first request message sent by the AMF, acquiring information of a VN group attached to the SMF discovery request message; The step of identifying the SMF set includes a step of identifying the SMF set of the VN group based on information of the VN group and a second mapping relationship between information of the VN group and information of the SMF. The method of claim 1.

7. The step of sending information of the first candidate SMF to the AMF includes: Sending an SMF discovery response message to the AMF, the SMF discovery response message including information of the first candidate SMF. The method of claim 6.

8. The first request message is a VN group first candidate SMF selection request message, and the step of identifying the SMF set includes: The step of obtaining an SMF set attached to the VN group first candidate SMF selection request message, the SMF set being identified by a group management function entity (GMF) based on a second mapping relationship between VN group information and SMF information and VN group information attached to the SMF discovery request message sent by the AMF, and being sent to the AMF. The method of claim 1.

9. The step of sending information of the first candidate SMF to the AMF includes: and sending a VN group first-candidate SMF selection response message to the AMF, the message including information about the first-candidate SMF. The method of claim 8.

10. In response to receiving an SMF registration request message sent by an SMF, acquiring VN group information attached to the SMF registration request message; and establishing a second mapping relationship between the information of the VN group and the information of the SMF. The method of claim 1.

11. A session management function entity (SMF) discovery method performed by an access and mobility management function entity, comprising: In response to receiving a session creation request message sent by one of a plurality of user devices (UEs) included in a virtual network (VN) group, sending a first request message to a network function node (NF), the first request message being configured to instruct the NF to identify a first candidate SMF of the virtual network (VN) group of the UE, the first candidate SMF being one of a plurality of SMFs included in an SMF set, and the VN group belonging to the plurality of SMFs included in the SMF set; receiving information on the first candidate SMF sent by the NF; In response to receiving a session creation request message transmitted by one of the plurality of user devices included in the VN group, transmitting a session creation request message to a first candidate SMF corresponding to the information of the first candidate SMF; In response to receiving a session creation request failure message sent by the first candidate SMF, selecting another SMF other than the first candidate SMF from the SMF set and sending a session creation request message to the other SMF. How to discover SMF.

12. and further including a step of acquiring the SMF set before the step of sending a session creation request message to a first candidate SMF corresponding to the information of the first candidate SMF. The method of claim 11.

13. The first request message is an SMF discovery request message, and the SMF discovery request message is accompanied by information of the VN group where the UE is located. The step of receiving information of the first candidate SMF sent by the NF and acquiring the SMF set includes: receiving an SMF discovery response message sent by the NF, and acquiring first candidate SMF information and an SMF set attached to the SMF discovery response message, the SMF set being identified by the NF based on the VN group information and a second mapping relationship between the VN group information and the SMF information. The method of claim 12.

14. The NF includes a first NF and a second NF, the first request message is a VN group first candidate SMF selection request message, and the SMF discovery method includes: Before sending the first request message to the NF, sending an SMF discovery request message to the first NF, the SMF discovery request message being accompanied by information about a VN group, the SMF discovery request message being configured to instruct the first NF to identify an SMF set; receiving an SMF discovery response message sent by the first NF and acquiring an SMF set attached to the SMF discovery response message; The step of sending a first request message to the NF includes: sending a VN group first candidate SMF selection request message to the second NF with the SMF set attached, the VN group first candidate SMF selection request message configured to instruct the second NF to identify a first candidate SMF for the VN group; The method of claim 11.

15. The VN group first candidate SMF selection request message further includes information of the VN group; 15. The method of claim 14.

16. at least one processor; a storage device having at least one computer program stored therein; The at least one computer program, when executed by the at least one processor, causes the at least one processor to implement the method of claim 1. Electronic devices.

17. A computer program is stored therein, The computer program, when executed by a processor, implements the method of claim 1. A computer-readable storage medium.

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