Communication method and apparatus, and computer-readable storage medium

Abstract

Provided in the present application are a communication method and apparatus, and a computer-readable storage medium. The method comprises: a user equipment determining target second information corresponding to target first information, wherein the target first information is used for identifying a data network corresponding to a first protocol data unit (PDU) session; and sending to a first access network device a first message, which comprises the target second information and a first request, wherein the first request is used for requesting the establishment of the first PDU session for the user equipment, and the target second information is used by the first access network device to determine a session management network element corresponding to the target first information. The embodiments of the present application enable an access network device to select an SMF without knowledge of selection information such as a plaintext DNN, thereby protecting user privacy.

Description

Communication method, apparatus and computer readable storage medium

[0001] The present application claims priority to the Chinese patent application No. 202411359778.1, filed on September 26, 2024, entitled "Communication method, apparatus and computer readable storage medium", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, in particular to a communication method, apparatus and computer readable storage medium. BACKGROUND

[0003] In a mobile communication system, a user equipment (UE) can register to a network, and can also initiate a protocol data unit (PDU) session establishment procedure. Currently, in the PDU session establishment procedure, the UE can provide a data network name (DNN) and other parameters for selecting a session management function (SMF) to an access and mobility management function (AMF) through a non-access stratum (NAS) message, and the AMF can select the SMF based on the DNN and other parameters.

[0004] With the evolution of network architecture, in a future network, an access network device and a core network element (such as an SMF) can be directly connected in the form of a service interface. In such an architecture, how to design the SMF selection and other related PDU session establishment procedures is a problem that technicians are concerned about. SUMMARY

[0005] Embodiments of the present application disclose a communication method, apparatus and computer readable storage medium, which can enable an access network device to select an SMF without knowing the clear text DNN and other selection information.

[0006] The first aspect discloses a communication method, which can be applied to a user equipment, a component (for example, a processor, a chip, a chip system, a circuit or a functional module) in the user equipment, and a logic module or software capable of realizing all or part of the functions of the user equipment. The communication method is described below by taking the application to the user equipment as an example, which can include: determining target second information corresponding to target first information; the target first information is used to identify a data network corresponding to a first protocol data unit (PDU) session; sending a first message to a first access network device, the first message including the target second information and a first request, the first request being used to request the first PDU session to be established for the user equipment; and the target second information is used for the first access network device to determine a session management network element corresponding to the target first information.

[0007] In the embodiments of the present application, in the session establishment process, the mapping information (target second information) corresponding to the target first information can be used to replace the target first information. The target second information is visible to the first access network device, but the first access network device cannot analyze the target first information based on the target second information. The first access network device can select a session management network element based on the target second information. In this way, the target first information can be hidden by the target second information to protect the target first information from being visible to the first access network device, thereby protecting the privacy of the user.

[0008] In combination with the first aspect, in a possible implementation, the determining the target second information corresponding to the target first information includes: determining the target second information corresponding to the target first information according to a mapping relationship between a plurality of first information and a plurality of second information; one first information in the plurality of first information corresponds to one second information or a plurality of second information.

[0009] In the embodiments of the present application, the user equipment can store the mapping relationship between the plurality of first information and the plurality of second information. For example, in the process of registering the user equipment to the network, the network can pre-configure the mapping relationship between the plurality of first information and the plurality of second information for the user equipment, thereby facilitating the user equipment to determine the target second information corresponding to the target first information. In addition, one first information can correspond to one second information or a plurality of second information, so that one second information can correspond to one first information.

[0010] In combination with the first aspect, in a possible implementation, the mapping relationship between the plurality of first information and the plurality of second information is dynamically updated.

[0011] In the embodiments of the present application, the mapping relationship between the plurality of first information and the plurality of second information can be dynamically updated, which can further improve the security and avoid analyzing the target first information based on the target second information and network-related data.

[0012] The second aspect discloses a communication method, which can be applied to a first access network device, a component (for example, a processor, a chip, a chip system, a circuit, or a functional module) in the first access network device, and a logic module or software capable of realizing all or part of the functions of the first access network device. The communication method can include: receiving a first message from a user equipment, the first message including target second information and a first request, the first request being used to request establishment of a first protocol data unit (PDU) session for the user equipment; the target second information having a mapping relationship with target first information, the target first information being used to identify a data network corresponding to the first PDU session; determining a first session management network element based on the target second information; and sending the first request to the first session management network element.

[0013] In the embodiments of the present application, the first access network device can receive a first message from a user equipment, and can determine a first session management network element based on target second information in the first message, where the target second information has a mapping relationship with target first information, and the user equipment determines a first session management network element that can support a data network corresponding to the target first information based on the target second information. In this way, the target first information can be hidden by the target second information to protect the target first information from being visible to the first access network device, thereby protecting the privacy of the user.

[0014] In combination with the second aspect, in a possible implementation, the determining of the first session management network element based on the target second information includes: sending a network element discovery request to a network storage function network element, the network element discovery request including the target second information, the network element discovery request being used to request discovery of a session management network element corresponding to the target first information; receiving a network element discovery response from the network storage function network element, the network element discovery response including configuration information of one or more session management network elements corresponding to the target first information; and determining the first session management network element from the one or more session management network elements corresponding to the target first information.

[0015] In the embodiments of the present application, the network storage function network element can store second information of each registered session management network element, or store first information of each registered session management network element and a mapping relationship between the first information and the second information. In this case, the first access network device can send a network element discovery request to the network storage function network element, and carry the target second information in the network element discovery request. The network storage function network element can determine a session management network element corresponding to the target first information based on the target second information, and can send a network element discovery response to the first access network device, and carry configuration information of one or more session management network elements corresponding to the target first information in the network element discovery response, thereby facilitating the first access network device to determine the first session management network element.

[0016] In a possible implementation of the second aspect, the network element discovery request further includes first location information of the user equipment, the first location information being associated with the first access network device; the network element discovery request is used to request discovery of a session management network element corresponding to the target first information, specifically: the network element discovery request is used to request discovery of a session management network element corresponding to the target first information and the first location information; the network element discovery response includes configuration information of one or more session management network elements corresponding to the target first information, specifically: the network element discovery response includes configuration information of one or more session management network elements corresponding to the target first information and the first location information; and the first session management network element is determined from the one or more session management network elements corresponding to the target first information, specifically: the first session management network element is determined from the one or more session management network elements corresponding to the target first information and the first location information.

[0017] In the embodiments of the present application, the first location information of the user equipment can also be included in the network element discovery request, so that the network storage function network element can return configuration information of the session management network element corresponding to the target first information and the first location information, and then the first access network device can determine the first session management network element that can support creation of the first PDU session.

[0018] The third aspect discloses a communication method, which can be applied to a network storage function network element, a component (for example, a processor, a chip, a chip system, a circuit, or a functional module) in the network storage function network element, and a logic module or software capable of realizing all or part of the functions of the network storage function network element. The communication method can include: receiving a network element discovery request, the network element discovery request including target second information, the network element discovery request being used to request discovery of a session management network element corresponding to target first information; the target second information having a mapping relationship with the target first information, the target first information being used to identify a data network corresponding to a first protocol data unit (PDU) session; and sending a network element discovery response, the network element discovery response including configuration information of one or more session management network elements corresponding to the target first information.

[0019] In the embodiments of the present application, the network storage function network element can store the second information of each registered session management network element, or store the first information of each registered session management network element and the mapping relationship between the first information and the second information. In this case, after receiving the network element discovery request from the first access network device, the network storage function network element can determine the session management network element corresponding to the target first information based on the target second information in the network element discovery request, and can send a network element discovery response to the first access network device, and carry one or more configuration information of the session management network element corresponding to the target first information in the network element discovery response, so as to facilitate the first access network device to determine the first session management network element.

[0020] For example, the network element discovery request can be the second request or the third request, and the network element discovery response can be the second response or the third response. For details, refer to the description in the following specific solutions.

[0021] In combination with the third aspect, in a possible implementation, the method further includes: receiving a registration request from one or more session management network elements, each registration request including the first information and the second information corresponding to the corresponding session management network element, the second information corresponding to the session management network element having a mapping relationship with the first information corresponding to the session management network element.

[0022] In the embodiments of the present application, the session management network element can configure the second information corresponding to the first information supported by itself, and can carry the first information and the second information corresponding to itself in the registration request sent to the network storage function network element.

[0023] In combination with the third aspect, in a possible implementation, the network storage function network element stores a mapping relationship between a plurality of first information and a plurality of second information, the plurality of first information including the target first information, and the plurality of second information including the target second information; the method further includes: receiving a registration request from one or more session management network elements, each registration request including the first information corresponding to the corresponding session management network element.

[0024] In the embodiments of the present application, the session management network element can carry the first information supported by itself in the registration request sent to the network storage function network element, and the network storage function network element can configure the second information having a mapping relationship for the first information.

[0025] In combination with the third aspect, in a possible implementation, each registration request further includes the service area of the corresponding session management network element.

[0026] In the embodiments of the present application, the registration request can further include the service area of the corresponding session management network element, so that the session management network element can be selected based on the location information of the user equipment.

[0027] In a possible implementation of the third aspect, the location information of the user equipment is associated with the first access network device; the network element discovery request is used to request discovery of a session management network element corresponding to the target first information, and specifically, the network element discovery request is used to request discovery of a session management network element corresponding to the target first information and the location information; and the network element discovery response includes configuration information of one or more session management network elements corresponding to the target first information, and specifically, the network element discovery response includes configuration information of one or more session management network elements corresponding to the target first information and the location information.

[0028] For example, the location information of the user equipment can be first location information of the user equipment or second location information of the user equipment, and details can be referred to the related description in the following specific solutions.

[0029] The fourth aspect discloses a communication method, which can be applied to a second access network device, a component (for example, a processor, a chip, a chip system, a circuit, or a functional module) in the second access network device, a logic module or software capable of realizing all or part of the functions of the second access network device. The communication method can include the following steps: in a case where it is determined that an intermediate session management network element needs to be inserted or modified for a first protocol data unit (PDU) session of a user equipment, sending a network element discovery request to a network storage function network element, the network element discovery request including target second information, the network element discovery request being used to request discovery of a session management network element corresponding to target first information; the target second information has a mapping relationship with the target first information, and the target first information is used to identify a data network corresponding to the first PDU session; receiving a network element discovery response from the network storage function network element, the network element discovery response including configuration information of one or more session management network elements corresponding to the target first information; and sending a fourth request to a first intermediate session management network element based on the configuration information of the first intermediate session management network element, the fourth request being used to request establishment of a session management context of the first PDU session of the user equipment; and the first intermediate session management network element is a session management network element determined from the one or more session management network elements corresponding to the target first information.

[0030] In the embodiments of the present application, in the handover process, when a first PDU session of a user equipment needs to be inserted or modified with an intermediate session management network element, the second access network device can send a network element discovery request to a network storage function network element, and carry target second information in the network element discovery request. The network storage function network element can determine the session management network element corresponding to the target first information based on the target second information, and can send a network element discovery response to the first access network device, and carry one or more configuration information of the session management network element corresponding to the target first information in the network element discovery response, so as to facilitate the first access network device to determine the first intermediate session management network element.

[0031] In combination with the fourth aspect, in a possible implementation, the method further includes: receiving first PDU session information of the user equipment from the first access network device, the first PDU session information including the target second information, the target second information being used to determine or redetermine the session management network element serving the first PDU session.

[0032] In the embodiments of the present application, in the handover process, the second access network device can obtain first PDU session information from the first access network device, and the first PDU session information can include target second information, so as to facilitate the second access network device to determine the first intermediate session management network element based on the target second information.

[0033] In combination with the fourth aspect, in a possible implementation, the network element discovery request further includes second location information of the user equipment, the second location information being associated with the second access network device; the network element discovery request for requesting to discover the session management network element corresponding to the target first information is specifically for requesting to discover the session management network element corresponding to the target first information and the second location information; the network element discovery response including one or more configuration information of the session management network element corresponding to the target first information is specifically for including one or more configuration information of the session management network element corresponding to the target first information and the second location information; and the first intermediate session management network element being the session management network element determined from the one or more session management network elements corresponding to the target first information is specifically for being the session management network element determined from the one or more session management network elements corresponding to the target first information and the second location information.

[0034] It should be noted that the technical solutions of the first aspect, the second aspect, the third aspect and the fourth aspect of the present application can correspond to each other, and the related beneficial effects can be referred to each other.

[0035] In a fifth aspect, a communication apparatus is disclosed. The communication apparatus can implement the functions described in the first aspect. For example, the communication apparatus can include a module or a unit to perform the method in the first aspect or any of its possible implementations. The module or unit can be implemented in software or hardware, or a combination of both.

[0036] For example, the communication apparatus in the fifth aspect can be a user equipment.

[0037] In a sixth aspect, a communication apparatus is disclosed. The communication apparatus can implement the functions described in the second aspect. For example, the communication apparatus can include a module or a unit to perform the method in the second aspect or any of its possible implementations. The module or unit can be implemented in software or hardware, or a combination of both.

[0038] For example, the communication apparatus in the sixth aspect can be a first access network device.

[0039] In a seventh aspect, a communication apparatus is disclosed. The communication apparatus can implement the functions described in the third aspect. For example, the communication apparatus can include a module or a unit to perform the method in the third aspect or any of its possible implementations. The module or unit can be implemented in software or hardware, or a combination of both.

[0040] For example, the communication apparatus in the seventh aspect can be a network storage function network element.

[0041] In an eighth aspect, a communication apparatus is disclosed. The communication apparatus can implement the functions described in the fourth aspect. For example, the communication apparatus can include a module or a unit to perform the method in the fourth aspect or any of its possible implementations. The module or unit can be implemented in software or hardware, or a combination of both.

[0042] For example, the communication apparatus in the eighth aspect can be a second access network device.

[0043] A ninth aspect discloses a communication system, comprising at least two of a user equipment, a first access network equipment, a network storage function network element and a second access network equipment, the user equipment is configured to implement the method provided in the first aspect and any possible implementation of the first aspect; the first access network equipment is configured to implement the method provided in the second aspect and any possible implementation of the second aspect; the network storage function network element is configured to implement the method provided in the second aspect and any possible implementation of the second aspect; the second access network equipment is configured to implement the method provided in the second aspect and any possible implementation of the second aspect.

[0044] A tenth aspect discloses a communication apparatus, comprising a processor and a communication interface; the communication interface is configured to receive and / or send data; the processor is configured to invoke a computer program or computer instructions stored in a memory to implement the method provided in the first aspect and any possible implementation of the first aspect, or to implement the method provided in the second aspect and any possible implementation of the second aspect, or to implement the method provided in the third aspect and any possible implementation of the third aspect, or to implement the method provided in the fourth aspect and any possible implementation of the fourth aspect.

[0045] As a possible implementation, the processor of the communication apparatus disclosed in the tenth aspect comprises one or more processors.

[0046] Optionally, the communication apparatus disclosed in the tenth aspect further comprises one or more memories.

[0047] An eleventh aspect discloses a computer readable storage medium, the computer readable storage medium stores computer programs or computer instructions, when the computer programs or computer instructions are executed, implement the method provided in the first aspect and any possible implementation of the first aspect, or implement the method provided in the second aspect and any possible implementation of the second aspect, or implement the method provided in the third aspect and any possible implementation of the third aspect, or implement the method provided in the fourth aspect and any possible implementation of the fourth aspect.

[0048] The twelfth aspect discloses a chip comprising a processor configured to execute a program stored in a memory, which when executed causes the chip to perform the method provided in the first aspect and any possible implementation of the first aspect, or perform the method provided in the second aspect and any possible implementation of the second aspect, or perform the method provided in the third aspect and any possible implementation of the third aspect, or perform the method provided in the fourth aspect and any possible implementation of the fourth aspect.

[0049] As a possible implementation, the memory is located outside the chip.

[0050] The thirteenth aspect discloses a computer program product comprising computer program code which, when executed, causes the method provided in the first aspect and any possible implementation of the first aspect to be performed, or causes the method provided in the second aspect and any possible implementation of the second aspect to be performed, or causes the method provided in the third aspect and any possible implementation of the third aspect to be performed, or causes the method provided in the fourth aspect and any possible implementation of the fourth aspect to be performed.

[0051] It should be understood that the implementation and beneficial effects of the above aspects or any possible implementation of the present application can be mutually referred to. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0053] Fig. 1 is a flow diagram of NF discovery disclosed by the embodiments of the present application;

[0054] Fig. 2 is a flow diagram of Xn handover disclosed by the embodiments of the present application;

[0055] Fig. 3 is a schematic diagram of a network architecture disclosed by the embodiments of the present application;

[0056] Fig. 4 is a flow diagram of a communication method disclosed by the embodiments of the present application;

[0057] Fig. 5 is a flow diagram of another communication method disclosed by the embodiments of the present application;

[0058] Fig. 6 is a flow diagram of CDNN update disclosed by the embodiments of the present application;

[0059] FIG. 7 is a flow diagram of another CDNN updating method disclosed by embodiments of the present application;

[0060] FIG. 8 is a flow diagram of another communication method disclosed by embodiments of the present application;

[0061] FIG. 9 is a flow diagram of another communication method disclosed by embodiments of the present application;

[0062] FIG. 10 is a structural diagram of a communication apparatus disclosed by embodiments of the present application;

[0063] FIG. 11 is a hardware structural diagram of a communication apparatus disclosed by embodiments of the present application. DETAILED DESCRIPTION

[0064] Embodiments of the present application disclose a communication method, apparatus and computer readable storage medium, which can enable an access network device to select an SMF without knowing plaintext DNN selection information. The technical solutions in embodiments of the present application will be clearly and completely described below with reference to the drawings.

[0065] In order to better understand the embodiments of the present application, the related content, terms or names involved in the present application are briefly introduced as follows.

[0066] I. Control plane interaction between UE and core network

[0067] In a 5G system, after a user equipment (UE) registers to a network, the UE can establish a secure connection of N1 interface with an access and mobility management function (AMF) to perform transmission of non-access stratum (NAS) signaling / messages. The UE can communicate with the AMF through a radio access network (RAN) node, and the AMF and the RAN node can exchange control plane (CP) information through an N2 interface. The AMF can forward a downlink NAS message of the UE to the UE through the RAN node, and the AMF can also forward an uplink NAS message of the UE to other network elements. That is, the control plane interaction between the UE and other core network network elements can be performed through the AMF. Therefore, the AMF can know the RAN node to which the UE is currently connected, and can also view the content in the NAS message as a termination point of the NAS message and perform related processing based on the content in the NAS message. For example, when the UE sends a protocol data unit (PDU) session establishment request to the AMF to request establishment of a PDU session, the AMF can select a session management function (SMF) according to the location information (such as a cell ID or a tracking area (TA)) of the UE and the PDU session related parameters (such as a data network name (DNN), slice selection information, and the like) carried in the session establishment request message, the capability and service area of the SMF can meet the corresponding requirements, that is, the SMF supports the requested DNN, slice selection information, and the like, and the service area includes the current location of the UE. After the AMF selects the SMF for the PDU session of the UE, the AMF can store the information of the SMF corresponding to the PDU session of the UE, including an SMF identifier (SMF ID) and a service area corresponding to the SMF.

[0068] Further, when the air interface connection of the UE is handed over from one RAN node to another RAN node, the source RAN node or the target RAN node can send the new location information of the UE to the AMF through the N2 interface, in which case the AMF can determine whether the new location of the UE is still within the service area of the SMF, and if not, the AMF should select a suitable intermediate SMF (I-SMF) to be inserted between the AMF and the SMF to keep the anchor SMF (source SMF) unchanged, so as to realize session continuity. For example, the I-SMF can solve the problem that in the handover scenario, the target RAN node can no longer be connected to the anchor user plane function (UPF), for example, the source RAN node and the anchor UPF are in city A, and the UE has now moved to the target RAN in city B, and the target RAN cannot be connected to the anchor UPF. In this case, a B-city I-UPF can be connected to the A-city UPF through an intermediate UPF (B-city UPF). In order to insert the B-city I-UPF (I-UPF), an I-SMF in the B city needs to provide services for the session.

[0069] It can be understood that after the UE and the AMF establish a secure connection, the NAS signaling / messages transmitted through the RAN node are protected (such as integrity protection and encryption), and the specific content of the NAS signaling / messages is invisible to the RAN node, but visible to the AMF.

[0070] II. Network function (NF) discovery

[0071] When the AMF selects the SMF, it can need to discover the eligible SMF through a network repository function (NRF). For example, the AMF can receive a session establishment request message from the UE, which can include single network slice selection assistance information (S-NSSAI), UE requested DNN (UE Requested DNN), PDU session ID, request type, N1 session management container (N1SM container), and the like. The AMF can also receive UE location information (such as a cell ID) from a RAN node sent together with the NAS message. When the AMF cannot determine the SMF corresponding to the session, the AMF can discover the eligible SMF through the NRF, as shown in FIG. 1, which can include the following steps:

[0072] 101. The AMF sends an NF discovery request to the NRF.

[0073] For example, the AMF can send an NF discovery request (Nnrf_NFDiscovery_Request) message to the NRF as an NF service consumer to discover the SMF, which can include the type of NF to be discovered (SMF), UE location information (such as TA), DNN, S-NSSAI (i.e., related parameters carried in the UE session establishment request), and the like.

[0074] 102. The NRF authorizes the NF service discovery.

[0075] After receiving the discovery request message from the AMF, the NRF can perform authorization checking, i.e., determining whether the AMF is allowed to discover the SMF corresponding to the discovery request message.

[0076] 103. The NRF sends an NF discovery request response to the AMF.

[0077] In case of authorization pass, i.e. in case the AMF is allowed to discover the SMF corresponding to the discovery request message, the NRF can determine one or a group of eligible SMFs according to the discovery request message and local policy, and then can send a NF discovery request response (Nnrf_NFDiscovery_RequestResponse) message to the AMF, which can include the NF Profile of the determined one or group of eligible SMFs. The NF Profile can include one or more of the following information: NF type (SMF), NF ID, full qualified domain name (FQDN), internet protocol address (IP) address, service area, etc.

[0078] III. Handover related session management procedures

[0079] For example, the following takes Xn handover as an example, the UE is handed over from a source RAN (source RAN) node to a target RAN (target RAN) node, and the AMF does not change before and after the handover. When the handover occurs, the UE has registered to the network and established a PDU session through the SMF, and the AMF can store the PDU session ID of the UE, the associated SMF (such as SMF ID, service area, etc.), and the session management context identifier (SM Context ID) of the session in the associated SMF. Specifically, please refer to FIG. 2, which is a schematic diagram of an Xn handover procedure disclosed by an embodiment of the present application. As shown in FIG. 2, the processing procedure can include the following steps:

[0080] For example, the UE moves into the coverage range of the target RAN node, and the UE needs to be handed over from the source RAN node to the target RAN node. The target RAN node can obtain the session related information of the UE from the source RAN node through the Xn interface, including the PDU session ID, etc. After the air interface connection of the UE is switched from the source RAN node to the target RAN node, the UE can send a radio resource control (RRC) reconfiguration complete (RRCReconfigurationComplete) message to the target RAN node, indicating that the air interface handover of the target RAN node is completed.

[0081] 201. The target RAN node sends an N2 path switch request to the AMF.

[0082] Exemplarily, after the UE switches from the source RAN node to the target RAN node, the target RAN can send an N2 path switch request to the AMF. The N2 path switch request can include a list of PDU sessions to be switched, a list of PDU sessions that fail to switch, UE location information (such as a cell id or a TA), and the like.

[0083] 202. The AMF sends a PDU session SM context update request to the SMF.

[0084] After the AMF receives the N2 path switch request from the target RAN node, the AMF can determine whether the UE is still in the service area of the corresponding SMF according to the UE location information and the service area of the SMF corresponding to each PDU session. If the UE is no longer in the service area of the corresponding SMF, a new I-SMF needs to be inserted to provide services for the PDU session. If the UE is still in the service area of the SMF, the AMF can directly send a PDU session update request, that is, a PDU session SM context update request, to the SMF to update the access side tunnel and the like. For the sessions that fail to switch or are rejected, the AMF can also directly send a PDU session update request to the SMF to trigger a PDU session release process and the like. It should be noted that the PDU session in the embodiments of the present application can also be referred to as a session.

[0085] 203a. The AMF selects an I-SMF.

[0086] For the session that needs to insert an I-SMF, the AMF needs to select an I-SMF. Exemplarily, the AMF can send the related SMF through the NRF, which can be referred to the related description above.

[0087] 203b. The AMF sends a PDU session SM context setup request to the I-SMF.

[0088] After the AMF selects the I-SMF, the AMF can send a PDU session SM context setup request to the selected I-SMF. The PDU session SM context setup request can include a user permanent identifier (SUPI) of the UE, an (anchor) SMF ID, and a session SM context identifier of the UE in the SM corresponding to the (anchor) SMF.

[0089] 204. The I-SMF sends a PDU session context request to the SMF.

[0090] After the I-SMF receives the PDU session SM context setup request from the AMF, the (anchor) SMF can be determined according to the (anchor) SMF ID, and the SM context information of the session of the UE can be obtained from the SMF according to the SM context identification.

[0091] 205a-209a. The I-SMF selects and inserts the I-UPF, obtains N3 and N9 tunnel information on the I-UPF side, and requests the SMF to modify the N9 interface information between the UPF and the I-UPF, that is, the UPF should be connected to the target RAN node through the N3 interface, and the modification is that the UPF is connected to the I-UPF through the N9 interface.

[0092] 210-211. The I-SMF sends the I-UPF information to the target RAN node to connect the target RAN node to the I-UPF.

[0093] 212. Release resources.

[0094] 213. Registration procedure.

[0095] It should be noted that, regarding the session management process related to handover, the above is only a simple example in combination with FIG. 2, and more detailed content can be referred to related technical specifications of the 3rd generation partnership project (3rd generation partnership project, 3GPP).

[0096] As can be known from the above description, the NAS message sent by the UE can pass through the RAN side to the AMF, and then the AMF can perform related processing based on the NAS message, such as selecting an SMF based on the NAS message, and sending a session establishment request to the selected SMF, and the like. In this case, the interaction between the UE and other network elements in the core network is performed through the AMF. However, with the evolution of network architecture, in the future network, the interface between the RAN node and the core network can adopt a service form, and no longer be a point-to-point interface connection. The NAS message can not pass through the AMF but be directly interacted by the RAN node and the corresponding network element, such as the UE and the SMF can directly interact the NAS message. In such an architecture, the routing function of the NAS message can be transferred from the AMF to the RAN node. For example, when the UE requests to establish a PDU session, the session establishment request sent by the UE can be routed by the RAN node to a suitable SMF, that is, the RAN node needs to determine a suitable SMF. For another example, in a handover scenario, a suitable I-SMF can be determined by the RAN node, and then interacted with the selected I-SMF, without the need for the AMF to determine. However, the parameters required for selecting the SMF include DNN and the like, and these parameters involve the privacy of the UE, and it is not desirable for the RAN node to be able to view or identify these parameters in the network architecture design. Therefore, in the scenarios of session establishment, handover, roaming and the like, how to design a related technical solution to enable the RAN node to select a suitable SMF / I-SMF / V-SMF (visited session management function) without knowing the plaintext DNN and the like is a problem to be solved.

[0097] In order to better understand the embodiments of the present application, the system architecture of the embodiments of the present application will be described first.

[0098] Please refer to FIG. 3, which is a schematic diagram of a network architecture disclosed by an embodiment of the present application. As shown in FIG. 3, the network architecture can include a user equipment (UE), a (wireless) access network (R)AN, and NFs in a core network, such as NRF, AMF, SMF, and the like. In the network architecture, the (R)AN and the NFs in the core network can be directly connected, such as through a service interface. Under such a network architecture, the UE and the NFs in the core network can interact through NAS signaling / messages, for example, the UE and the SMF can interact through NAS signaling / messages. For example, when the UE requests to establish a PDU session, the session establishment request can be sent directly to the SMF through the (R)AN without passing through the AMF. In the embodiments of the present application, the network architecture shown in FIG. 3 can also be referred to as a distributed NAS architecture.

[0099] Under the distributed NAS architecture, the (R)AN can discover the NF through the NRF when the (R)AN selects the NF. The (R)AN can also register with the NRF as a kind of NF.

[0100] The user equipment, the (R)AN, and the NF in the related core network are introduced as follows.

[0101] A user equipment, which can also be referred to as a terminal device, a terminal, a mobile station (MS), a mobile terminal (MT), a customer premise equipment (CPE), etc., is a device with wireless communication function, which can provide voice and / or data connectivity for a user. A terminal device can be a handheld device, a notebook computer, an RSU (road side unit), a subscriber unit, a cellular phone, a smart phone, a wireless data card, a personal digital assistant (PDA) computer, a tablet computer, a tag, a wireless modem, other processing devices connected to a wireless modem, a handheld device, a laptop computer, a cordless phone, or a wireless local loop (WLL) station, a machine type communication (MTC) terminal, a wearable device (such as a smart watch, a smart bracelet, a pedometer, etc.), a vehicle-mounted device (such as a car, a bicycle, an electric vehicle, an airplane, a ship, a train, a high-speed rail, etc.), a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a smart home device (such as a refrigerator, a television, an air conditioner, an electricity meter, etc.), a smart robot, a plant device, a wireless terminal in self driving, a wireless terminal in remote medical surgery, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, or a wireless terminal in smart home, a flight device (such as a smart robot, a hot air balloon, a drone, an airplane, etc.) or other devices that can access a network. A terminal device can be fixed or mobile, and can be deployed on land, including indoors or outdoors, handheld, wearable or vehicle-mounted; can also be deployed on the water surface (such as a ship, etc.); and can also be deployed in the air (such as an airplane, a balloon and a satellite, etc.).

[0102] The (wireless) access network (R)AN can be a network composed of multiple RAN nodes for implementing radio physical layer functions, resource scheduling and radio resource management, radio access control, and mobility management functions, etc. The (R)AN can be connected to a user plane function (UPF) through a user plane interface N3 for transmitting data of a terminal device. The (R)AN can also establish a control plane signaling connection with an access and AMF through a control plane interface N2 for implementing radio access bearer control, etc. It should be understood that the RAN node is also an access network device, which mainly provides access for the terminal device. The access network device can include a radio access network (RAN) device and an access node (AN) device. The RAN device is mainly a radio network device in a 3rd generation partnership project (3GPP) network, and the AN device can be an access network device not defined by 3GPP. The RAN device can include various forms of base stations, such as macro base stations, micro base stations (also referred to as small stations), relay stations, access points, balloon stations, etc. For example, the RAN device can be a next generation NodeB (gNB) in a 5th generation (5G) mobile communication system, an ng-eNB (a 4G base station accessing a 5G core network). The radio access network device can also be a radio controller in a cloud radio access network (CRAN) scenario, a base station device in a future network (such as 6G, 7G, etc.), a radio access network device in a future evolved public land mobile network (PLMN) network, a wearable device, a vehicle-mounted device, a transmission and reception point (TRP), a radio network controller (RNC), a home base station (for example, a home evolved NodeB, or a home Node B, HNB), a baseband unit (BBU), an access node (AP) in a wireless fidelity (WiFi) system, etc. In the embodiments of the present application, the RAN can be a RAN network element or a RAN node.

[0103] The AMF is mainly responsible for access and mobility management of the UE, for example, authentication and authorization of the UE, UE mobility state management, allocation of a user temporary identity, etc.

[0104] The SMF is mainly responsible for UE session management, including selection of a user plane function (UPF), quality of service (QoS) management of a session, obtaining a policy and charging control (PCC) policy, establishment, modification, and release of a bearer, and the like.

[0105] The UPF is mainly responsible for transmission of data of a user equipment, and supports all or part of the following functions: interconnection of a PDU session and a data network, packet routing and forwarding (for example, supporting uplink classification and forwarding of traffic to a data network), packet detection, packet filtering, rate control, and generation of charging information.

[0106] The NRF can be responsible for registration and discovery functions of network elements, and maintain information of the network elements, such as a network element type, an IP address, a capability of the network element, a supported service, and the like.

[0107] It should be understood that the architecture shown in FIG. 3 is only illustrative, and other devices or other NFs can also be included in the architecture shown in FIG. 3, such as a unified data management (UDM) network element, a unified data repository (UDR), a policy and control function (PCF), a network exposure function (NEF), an application function (AF), a network data analytics function (NWDAF), and the like. For more detailed descriptions of these network elements / NFs, reference can be made to the content in the relevant 3GPP standards.

[0108] It should also be understood that the above network elements or functions can be implemented in the form of hardware, computer software, or a combination of hardware and computer software. For example, the above network elements or functions can be implemented by one device, or by multiple devices together, or by one functional module in one device, and the embodiments of the present application do not make a specific limitation in this regard.

[0109] In addition, the above-mentioned "network element" can also be referred to as an entity, a device or a module, etc., and the present application does not limit this. Moreover, in order to facilitate the description, the description of "network element" is omitted in part of the following description, for example, the SMF network element is simply referred to as SMF, in this case, "SMF" should be understood as the SMF network element or the SMF entity, and similar understanding should be made for other network elements or functions. That is, the function, the functional network element and the functional entity can be equivalent, such as the AMF, the AMF network element and the AMF entity can be equivalent.

[0110] It should be understood that the technical solutions provided by the embodiments of the present application can be applied to a communication system using a distributed NAS architecture, for example, a future communication system using a distributed NAS architecture.

[0111] It should be noted that the system architecture, network architecture and service scenario (or application scenario) described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. It can be known by those skilled in the art that, with the evolution of the communication network architecture and the appearance of new service scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0112] In order to better understand the embodiments of the present application, the overall concept of the embodiments of the present application will be exemplarily described below.

[0113] From the above description, in the distributed NAS architecture, session-related messages can be directly exchanged between the UE, the RAN node, and the SMF without passing through the AMF. In this case, the RAN node can select a suitable SMF / I-SMF / V-SMF. However, the information used to select the SMF / I-SMF / V-SMF may involve user privacy and needs to be invisible to the RAN node. In the embodiments of the present application, the mapping information corresponding to the selection information can be used to replace the selection information in the session establishment process. The mapping information corresponding to the selection information is visible to the RAN, but the RAN cannot obtain the original selection information based on the mapping information. Subsequently, the SMF / I-SMF / V-SMF selection can be performed based on the mapping information corresponding to the selection information. That is, in this way, the UE does not need to send the original information used to select the SMF / I-SMF / V-SMF to the RAN node, but sends the mapping information corresponding to the information to the RAN node. The RAN node can see the mapping information and select the SMF / I-SMF / V-SMF based on the mapping information. For example, a DNN is used as an example. A mapping relationship between the DNN and the CDNN (concealed DNN) can be established in advance. The UE can carry the CDNN corresponding to the DNN in the message sent to the RAN node, without carrying the DNN. Subsequently, the RAN node can select the SMF / I-SMF / V-SMF based on the CDNN. In this case, the RAN node cannot obtain the corresponding DNN, thereby protecting the user privacy. It should be understood that the DNN information in the technical solutions provided in the embodiments of the present application can be replaced by other information that may involve user privacy in the NF selection process, and the mapping relationship between the DNN and the CDNN can be replaced in the same way. The technical solutions provided in the embodiments of the present application will be described below.

[0114] Please refer to FIG. 4 first, which is a flowchart of a communication method disclosed in the embodiments of the present application. In FIG. 4, a mapping relationship between the DNN and the CDNN can be established. Subsequently, the UE can carry the corresponding CDNN in the session establishment request sent to the RAN. After receiving the session establishment request from the UE, the RAN can send an NF discovery request to the NRF and carry the corresponding CDNN, so that the NRF can help the RAN discover a suitable SMF based on the CDNN. Specifically, as shown in FIG. 4, the method can include but is not limited to the following steps:

[0115] 401. The SMF configures the mapping relationship between the DNN and the CDNN.

[0116] For example, the SMF can configure the mapping relationship between the DNN and the CDNN. For another example, the SMF can save the mapping relationship between the DNN and the CDNN.

[0117] The CDNN can be an alias of the DNN or can be an encrypted DNN. The mapping relationship between the DNN and the CDNN can be that a plurality of CDNNs correspond to one DNN, or one-to-one, that is, one CDNN corresponds to one DNN. Further, the CDNN can be static or dynamic. The static can be understood as the CDNN corresponding to the DNN does not change, and the dynamic can be understood as the CDNN corresponding to the DNN can change / update.

[0118] 402. The SMF sends a registration request to the NRF, and the registration request includes the corresponding CDNN.

[0119] The SMF can send a registration request to the NRF, and the registration request can include the related information of the SMF, such as the corresponding CDNN. Correspondingly, the NRF can receive the registration request from the SMF, and then the NRF can store the related information of the SMF, such as the corresponding CDNN. In the embodiment of the application, the CDNN corresponding to the SMF can also be understood as the CDNN supported by the SMF. Similarly, in the embodiment of the application, the DNN corresponding to the SMF can also be understood as the DNN supported by the SMF.

[0120] It should be understood that the related information of the SMF can also include one or more of the corresponding DNN (the DNN corresponding to the SMF), the SMF ID, the SMF service area, the SMF IP address, etc., which are not limited in the embodiment of the application.

[0121] It should be understood that steps 401 and 402 are optional. For example, in some possible implementations, the SMF can not configure the mapping relationship between the DNN and the CDNN, and the registration request sent by the SMF to the NRF can carry the corresponding DNN. In this case, the mapping relationship between the DNN and the CDNN can be configured by other network elements, such as an operations, administration and maintenance (OAM) network element, etc. The OAM network element can also be referred to as a network management element, a network management system, etc. After the OAM configures the mapping relationship between the DNN and the CDNN, it can send the configured mapping relationship between the DNN and the CDNN to other network elements (such as the UE, the NRF, the PCF, etc.). Further, the NRF can also determine the mapping relationship between the DNN and the CDNN in a preconfigured manner, such as for the case of network granularity of the CDNN.

[0122] 403. The UE registers to the network.

[0123] Exemplarily, the UE can register to the network through the RAN and the AMF. In embodiments of the present application, the related procedure for the UE to register to the network is not limited, and can refer to the related content in the standard.

[0124] 404. The UE determines the CDNN.

[0125] When the UE needs to initiate session establishment, the UE can determine the CDNN, for example, according to the related information provided by the application layer. Exemplarily, in some possible embodiments, the UE can be pre-configured or dynamically configured with the mapping relationship between the DNN and the CDNN, in which case, the UE can determine the CDNN according to the mapping relationship between the DNN and the CDNN. The mapping relationship between the DNN and the CDNN can be a displayed mapping relationship (for example, a mapping relationship table), or a network policy, for example, a UE routing selection policy. Exemplarily, in some possible embodiments, the UE can obtain the mapping relationship between the DNN and the CDNN in the process of registering to the network. It should be noted that the manner in which the UE obtains the mapping relationship between the DNN and the CDNN is not limited in embodiments of the present application. For example, the UE can obtain the network policy from the PCF serving the UE, or can obtain the displayed mapping relationship between the DNN and the CDNN from other network elements configured with the mapping relationship between the DNN and the CDNN.

[0126] Exemplarily, assuming that the information provided by the application layer can include the DNN, the network device can determine the CDNN corresponding to the DNN according to the stored mapping relationship between the DNN and the CDNN. Exemplarily, taking the UE routing selection policy (URSP) enhanced with the mapping relationship between the DNN and the CDNN as an example, as shown in Table 1 and Table 2 below:

[0127] Table 1

[0128] Table 2

[0129] From Table 1 and Table 2 above, it can be seen that an enhanced URSP rule can include a TD and a RSD, the TD can include an application descriptor, and can further include a DNN, etc., and the RSD includes a CDNN. When an application on the UE triggers session establishment, the UE can evaluate the URSP to determine session parameters. For example, the UE can match the URSP rule according to the information provided by the application, i.e., find all URSP rules in which the flow descriptor matches the application descriptor provided by the application, and then determine the CDNN included in the RSD according to the RSD included in the matched URSP rule. For example, the OSID in Table 1 above can be an operation system ID (operation system ID), and the OSAppID in Table 1 above can be an operation system application ID (operation system application ID).

[0130] 405. The UE sends a session establishment request message to the RAN, the session establishment request message including the CDNN.

[0131] After the UE determines the CDNN, the UE can send a session establishment request message to the RAN, and the session establishment request message can be used to request to establish a session, i.e., to establish a PDU session for the UE. In some possible implementation manners, the session establishment request message can be an RRC message.

[0132] For example, the session establishment request message includes the CDNN, and can further include an S-NSSAI, a public land mobile network (PLMN), a network ID, a PDU session ID, an SM Container, etc. Among them, the CDNN, the S-NSSAI, the PLMN, the network ID, etc. can be used for SMF selection, i.e., SMF selection information, and these information can be visible to the RAN. It can be understood that the SMF selection information can further include more or less information, and the embodiments of the present application do not limit this.

[0133] In some possible implementation manners, the CDNN, the S-NSSAI, the PLMN, the network ID, etc. SMF selection information can be carried in AN parameters, and the SM Container, etc. can be encapsulated in a NAS message, and can be used to request to establish a PDU session to the selected SMF later.

[0134] 406. The RAN sends an NF discovery request to the NRF, the NF discovery request including the CDNN.

[0135] After receiving the session establishment request message from the UE, the RAN can send an NF discovery request to the NRF based on the session establishment request message, the NF discovery request can be used to request discovery of a corresponding SMF, the NF discovery request can include the CDNN carried in the session establishment request message.

[0136] For example, the NF discovery request can further include first location information of the UE, S-NSSAI, and the like information used for selecting the SMF. The first location information of the UE is current location information of the UE, and can be associated with the RAN. For example, the first location information of the UE can be a cell ID or a TA to which the UE currently corresponds, such as a cell ID of a cell currently residing in or a TA to which the UE belongs. The NF discovery request can further carry an NF type, and the NF type can be SMF, to indicate that the NF to be discovered is the SMF.

[0137] In some possible implementation manners, after receiving the session establishment request message from the UE, the RAN can determine whether to request the NRF to select the SMF based on the session establishment request message, and in a case where it is determined to request the NRF to select the SMF, the RAN can send the NF discovery request to the NRF, that is, step 406 is performed.

[0138] 407. The NRF selects the SMF based on the CDNN.

[0139] After receiving the NF discovery request from the RAN, the NRF can obtain the CDNN and the like information used for selecting the SMF based on the NF discovery request, and then select a SMF that meets a condition based on the CDNN. It should be understood that the condition can be understood as meeting / being consistent with the selection information carried in the NF discovery request.

[0140] For example, in some possible implementation manners, the NRF can store the CDNNs corresponding to the registered SMFs, in which case the NRF can directly determine the corresponding SMF based on the CDNN. In another possible implementation manner, the NRF can store the DNNs corresponding to the registered SMFs and a mapping relationship between the DNNs and the CDNNs, in which case the NRF can first determine the DNN based on the mapping relationship between the CDNN and the DNN, and then determine the corresponding SMF based on the DNN. It should be understood that, although the first case described above is based on the CDNN to determine the corresponding SMF, the SMF determined is essentially the SMF corresponding to the DNN corresponding to the CDNN.

[0141] It should be understood that, in the case that the NF discovery request further comprises S-NSSAI, first location information of the UE, and the like information for selecting the SMF, the NRF needs to select the corresponding SMF based on all the SMF selection information including CDNN, S-NSSAI, first location information of the UE, and the like. That is, the SMF whose service area comprises the first location information of the UE needs to be selected, and the SMF supporting the corresponding S-NSSAI needs to be selected.

[0142] 408. The NRF sends the NF discovery response to the RAN.

[0143] After the NRF selects the SMF based on the CDNN and the like, the NRF can send the NF discovery response to the RAN, and the NF discovery response can comprise information of the selected one or group of SMFs meeting the conditions, such as the profile of the selected one or group of SMFs meeting the conditions. The profile of each SMF can comprise one or more of the SMF ID, SMF FQDN / IP address, SMF service area, and the like.

[0144] It should be noted that the request in the embodiments of the present application can also be referred to as a request message, and the response can also be referred to as a response message.

[0145] 409a. The RAN sends the session establishment request to the SMF.

[0146] For example, after the RAN receives the NF discovery response from the NRF, the RAN can obtain the information of one or group of SMFs carried in the NF discovery response. The RAN can select one SMF from the one or group of SMFs, and then can send the session establishment request to the selected SMF based on the information of the selected SMF. It should be noted that the embodiments of the present application do not limit the way in which the RAN selects one SMF from the one or group of SMFs, for example, the selection can be based on the load of the SMF, and the like, and the specific selection can be referred to the relevant description in the standard.

[0147] It should be understood that, in some possible embodiments, the NF discovery request in step 406 can not carry S-NSSAI, first location information of the UE, and the like information for selecting the SMF, in which case, after the RAN receives the NF discovery response from the NRF, the RAN can further select one or more SMFs from the one or more SMFs based on S-NSSAI, first location information of the UE, and the like information for selecting the SMF, and the information of the one or more SMFs carried in the NF discovery response, and then can select a target SMF from the further selected one or more SMFs, and subsequently can send the session establishment request to the target SMF.

[0148] The session establishment request sent by the RAN to the selected SMF can include a UE ID, a PDU session ID, a RAN node identity (RAN ID), an SM container, first location information of the UE, and the like. The UE ID can be a globally unique temporary identity (GUTI) in the AMF, which can be referred to as AMF-GUTI. The UE ID can also be a subscription concealed identifier (SUCI), and the like, which is not limited in the embodiments of the present application.

[0149] It should be understood that the SMF selected by the RAN in the session establishment process can be an anchor SMF.

[0150] 409b. Other session establishment procedures.

[0151] It should be understood that after the RAN sends the session establishment request to the SMF, there are other related session establishment procedures, such as the SMF selecting a UPF, the SMF returning a session establishment response to the RAN, and the like. It should be noted that in the embodiments of the present application, the related procedures for establishing a session after the RAN selects an SMF are not limited, and can be referred to the description in the related standards. Among them, the main difference can be that the interaction with the AMF can be changed to the interaction with the RAN.

[0152] After the session establishment is completed, the RAN can store one or more of the PDU session ID corresponding to the PDU session of the UE, the SMF ID, the SM context ID allocated by the SMF, the SMF service area, the CDNN, the slice selection information (such as S-NNSAI), and the like. For example, the above information can be stored in the UE context, and the UE context can also store the UE ID and the related information of other PDU sessions of the UE.

[0153] In the above processing procedure, in the session establishment process, the UE can send a CDNN to the RAN, and the RAN can obtain the information of the related SMF based on the CDNN. In this way, the problem of SMF selection of the RAN under the distributed NAS architecture can be solved, and the DNN can be hidden through the CDNN to protect the DNN from being visible to the RAN.

[0154] The selection of SMF is exemplarily introduced in FIG. 4 above, and the selection of I-SMF in the handover process is explained below in combination with FIG. 5. Referring to FIG. 5, which is a flowchart of another communication method disclosed in the embodiments of the present application. In FIG. 5, the target RAN (T-RAN) can determine whether the session of the UE needs to insert / modify an I-SMF, and in the case of determining that the I-SMF needs to be inserted / modified, the T-RAN can send an NF discovery request to the NRF, and carry selection information such as CDNN, so that the NRF can help the T-RAN discover a suitable I-SMF based on the selection information such as CDNN. Specifically, as shown in FIG. 5, the method can include but is not limited to the following steps:

[0155] 501. Session establishment.

[0156] The UE, the source RAN (S-RAN), the AMF, the NRF, the SMF, the UPF and other related network elements can interact to establish a session.

[0157] It should be noted that the embodiments of the present application do not limit the session establishment process. For example, the session establishment process can refer to the related description in FIG. 4 above, which will not be repeated here.

[0158] 502. UE handover process.

[0159] The UE moves from the S-RAN to the coverage area of the T-RAN, and the UE can be handed over from the S-RAN to the T-RAN, that is, the handover of the air interface connection. In the handover process, the S-RAN can send the context of the UE to the T-RAN, and the context of the UE can include the PDU session ID corresponding to the PDU session of the UE, the SMF ID, the SM context ID allocated by the SMF, the SMF service area, and the selection information such as CDNN.

[0160] 503. T-RAN determines that the I-SMF needs to be inserted / modified.

[0161] In the case of UE handover of the air interface connection, the T-RAN can be triggered to determine whether each session (including the deactivated session) of the UE needs to insert / modify the I-SMF. Exemplarily, the UE sends the RRCReconfigurationComplete message to the T-RAN to indicate that the air interface handover is completed, which can trigger the T-RAN to determine whether each session of the UE needs to insert / modify the I-SMF, or the S-RAN sends the handover request related to the UE to the T-RAN, which can trigger the T-RAN to determine whether each session of the UE needs to insert / modify the I-SMF.

[0162] In some possible implementation, the T-RAN can determine whether the I-SMF needs to be inserted / modified for each session of the UE based on the service area of the SMF and / or the I-SMF corresponding to each session of the UE and the second location information of the UE. The second location information of the UE can be the current location information of the UE and can be associated with the T-RAN. For example, the second location information of the UE can be the cell ID or the TA to which the UE currently corresponds, for example, the cell ID of the cell currently camped on or the TA to which the cell belongs.

[0163] For example, for each session of the UE, the T-RAN can determine whether the UE is still in the service area of the SMF corresponding to the session according to the second location information of the UE and the service area of the SMF, and if not, it can be determined that the I-SMF needs to be added, otherwise, it can be determined that the I-SMF does not need to be added. Further, in the case that the session of the UE already includes the corresponding I-SMF, the T-RAN can determine whether the UE is still in the service area of the I-SMF according to the second location information of the UE and the service area of the I-SMF corresponding to the session, and if not, it can be determined that the I-SMF needs to be modified, otherwise, it can be determined that the I-SMF does not need to be modified. Of course, if the UE returns to the service area of the anchor SMF from the service area of the I-SMF, the I-SMF can be removed, and the embodiments of the present application do not make detailed description here, mainly describe the two cases of insertion and modification, because the two cases involve I-SMF selection.

[0164] 504. The T-RAN sends an NF discovery request to the NRF, and the NF discovery request includes the CDNN.

[0165] In the case that the T-RAN determines that the I-SMF needs to be inserted / modified, the T-RAN needs to select the I-SMF, and the T-RAN can send an NF discovery request to the NRF, and the NF discovery request can be used to request to discover the corresponding SMF. The NF discovery request can include the CDNN in the UE context obtained from the S-RAN.

[0166] For example, the NF discovery request sent by the T-RAN to the NRF can further include the second location information of the UE, the S-NSSAI and other information used for selecting the SMF. The second location information of the UE can be the current location information of the UE and can be associated with the T-RAN. For example, the second location information of the UE can be the cell ID or the TA to which the UE currently corresponds, for example, the cell ID of the cell currently camped on or the TA to which the cell belongs. The NF discovery request can also carry the NF type, and the NF type can be SMF, to indicate that the NF to be discovered is the SMF.

[0167] 505. The NRF selects the SMF based on the CDNN.

[0168] After receiving the NF discovery request from the RAN, the NRF can obtain information such as the CDNN for selecting the SMF based on the NF discovery request, and then can select a qualified SMF based on the CDNN. It should be understood that the SMF selected here can actually be an I-SMF.

[0169] It should be understood that in the case where the NF discovery request further includes information such as the S-NSSAI and the second location information of the UE for selecting the SMF, the NRF needs to select the corresponding SMF based on all the SMF selection information such as the CDNN, the S-NSSAI, and the second location information of the UE. That is, it is necessary to select an SMF whose service area includes the second location information of the UE, and an SMF that supports the corresponding S-NSSAI.

[0170] 506. The NRF sends an NF discovery response to the T-RAN.

[0171] After the NRF selects the SMF based on the NF discovery request, the NRF can send an NF discovery response to the T-RAN, and the NF discovery response can include information of the selected one or group of qualified SMFs, such as the profile of the selected one or group of qualified SMFs.

[0172] Steps 504-506 are similar to steps 406-408 described above, and reference can be made to the relevant description in steps 406-408 described above.

[0173] 507a. The T-RAN sends an SM context setup request / path switch request to the I-SMF.

[0174] For example, after receiving the NF discovery response from the NRF, the RAN can obtain the information of one or a group of SMFs carried in the NF discovery response. The RAN can select one SMF from the one or group of SMFs as an I-SMF, and then can send an SM context setup request / path switch request to the selected I-SMF based on the information of the selected I-SMF. The SM context setup request / path switch request can include the anchor SMF ID, the SM context ID corresponding to the PDU session, etc. The SM context setup request / path switch request is mainly used to request the establishment of the SM context of the PDU session of the UE on the selected I-SMF, so as to complete the switching of the transmission path AN side endpoint of the data plane of the PDU session from the S-RAN to the T-RAN, and the name of the SM context setup request / path switch request is not limited in the embodiments of the present application, and other names such as context setup request can also be used.

[0175] It should be noted that the embodiments of the present application do not limit the manner in which the RAN selects one SMF from the one or group of SMFs, for example, the selection can be based on the load of the SMF, etc., and specific details can be referred to the related description in the standard.

[0176] It should be understood that in some possible implementations, the information for selecting the SMF, such as the S-NSSAI, the second location information of the UE, etc., can not be carried in the NF discovery request of step 504, in which case, after receiving the NF discovery response from the NRF, the RAN can further select one or more SMFs from the one or more SMFs based on the information for selecting the SMF, such as the S-NSSAI, the second location information of the UE, etc., and the information of the one or more SMFs carried in the NF discovery response, and then select one of the further selected one or more SMFs as the I-SMF, and subsequently send the SM context establishment request / path switching request to the selected I-SMF.

[0177] 507b. I-SMF insertion / modification process, etc.

[0178] It should be understood that after the T-RAN sends the SM context establishment request / path switching request to the I-SMF, there are other related I-SMF insertion / modification processes, such as I-SMF selecting I-UPF, I-SMF returning the SM context establishment request response / path switching request response to the T-RAN, I-SMF obtaining the SM context from the (anchor point) SMF, N4 / N9 modification, etc. It should be noted that in the embodiments of the present application, the related procedures for establishing a session after the T-RAN selects the I-SMF are not limited, and can be referred to the description in the related standard. Among them, the main difference can be that the interaction with the AMF can be changed to the interaction with the T-RAN.

[0179] After the I-SMF insertion / modification process, etc. is completed, the T-RAN can store the PDU session ID corresponding to the PDU session of the UE, the SMF ID, the SM context ID allocated by the SMF, the SMF service area, the I-SMF ID, the I-SMF service area, etc. For example, the above information can be stored in the UE context.

[0180] It can be understood that in the embodiments of the present application, in the case that multiple sessions of the UE all need to insert / modify the I-SMF, the related procedures of inserting / modifying the I-SMF for multiple sessions can be parallel, and the interaction with the AMF is reduced, and the handover delay can be reduced. In addition, since the related procedures of inserting / modifying the I-SMF for multiple sessions can be independent, after the procedure of inserting / modifying the I-SMF for any session in the multiple sessions is completed, the session can perform uplink and downlink data transmission, without waiting for the procedures of inserting / modifying the I-SMF for all sessions to be completed.

[0181] In the above processing procedure, in the case that the I-SMF needs to be inserted / modified in the handover process, the T-RAN can send an NF discovery request to the NRF and carry selection information such as CDNN, and the subsequent NRF can return information of the SMF meeting the condition, and the T-RAN can select one SMF from the SMF meeting the condition as the I-SMF. In this way, the SMF selection problem of the RAN in the handover process under the distributed NAS architecture can be solved, and the relevant information can be protected from being visible to the RAN.

[0182] The selection of the SMF in the session establishment process and the selection of the I-SMF in the handover process are exemplarily illustrated above by means of FIG. 4 and FIG. 5, and on the basis of the above, the case of dynamic updating of the CDNN is described below. It should be understood that through the dynamic updating of the CDNN, the security can be improved. This is because if the CDNN is static, that is, the CDNN corresponding to one DNN is unchanged, there may be certain risks, such as the corresponding DNN can be inferred according to long-term user behavior, network traffic data, etc.

[0183] A possible CDNN updating procedure is described below in combination with FIG. 6. Referring to FIG. 6, FIG. 6 is a flowchart of a CDNN updating procedure disclosed in an embodiment of the present application. In FIG. 6, the updating of the CDNN can be configured by an operations administration and maintenance (OAM) network element, and the OAM network element can also be referred to as a network management network element, a network management system, etc. Specifically, as shown in FIG. 6, the CDNN updating procedure can include but is not limited to the following steps:

[0184] 601. The UE acquires the CDNN configuration.

[0185] Exemplarily, the UE can acquire the CDNN configuration (such as a network policy) in the process of registering to the network, and can establish a PDU session based on the acquired CDNN configuration.

[0186] In some possible implementation, the OAM can configure the mapping relationship between the CDNN and the DNN to each NF in the network, or each NF in the network can subscribe to the mapping relationship between the CDNN and the DNN from the UDR. For example, the OAM can configure the mapping relationship between the CDNN and the DNN to the UE-PCF, or the UE-PCF can subscribe to the mapping relationship between the CDNN and the DNN from the UDR, and the UE-PCF can generate the network policy of the UE based on the mapping relationship between the CDNN and the DNN. It should be understood that the UE-PCF is the PCF serving the UE.

[0187] 602. The OAM updates the mapping relationship between the DNN and the CDNN.

[0188] For example, the OAM can update the mapping relationship between the DNN and the DNNC, such as periodic update.

[0189] After the OAM updates the mapping relationship between the DNN and the DNNC, the OAM can notify each NF (such as the SMF, the PCF, the NRF, etc.) in the network, such as steps 603a, 603b, etc.

[0190] 603a. The OAM sends the updated mapping relationship between the DNN and the CDNN to the SMF.

[0191] 603b. The OAM sends the updated mapping relationship between the DNN and the CDNN to the UE-PCF.

[0192] It can be understood that the step 603a and the step 603b are optional. In some possible implementation, after the OAM updates the mapping relationship between the DNN and the DNNC, the OAM can notify the UDR, and the UDR can notify other NFs (such as the SMF, the PCF, the NRF, etc.) in the network.

[0193] 604. The UE-PCF sends the updated policy, including the updated mapping relationship between the DNN and the CDNN, to the UE.

[0194] For example, after the UE-PCF obtains the updated mapping relationship between the DNN and the CDNN, the UE-PCF can trigger the UE policy update. The UE-PCF can send the updated policy, such as the updated URSP rule, to the UE through the UE configuration update process.

[0195] In some possible implementation, the UE-PCF can send the updated policy to the UE through the RAN.

[0196] 605. The UE sends a session update message, including the updated CDNN, to the RAN.

[0197] After receiving the new policy from the UE-PCF, the UE can determine which CDNNs of which sessions need to be updated based on the new policy. For the sessions whose CDNNs need to be updated, the UE can send a session update message to the RAN, which can include the updated CDNN and the corresponding PDU session ID, etc.

[0198] For example, assume that there is a session 1 for the UE, and the currently stored CDNN for the session 1 is #CDNN_1, but based on the new policy, it is determined that the CDNN for the session 1 should be #CDNN_2, that is, the mapping relationship between the DNN and the CDNN is updated. In this case, the UE can send a session update message to the RAN, which can include the updated #CDNN_2 and the ID of the corresponding session 1, etc. After receiving the session update message from the UE, the RAN can update the stored UE context, and update the currently stored #CDNN_1 of the session 1 to #CDNN_2. Since the RAN cannot determine whether the updated CDNN of the session 1 corresponds to the same DNN, the RAN can avoid associating the CDNN before and after the update.

[0199] It can be understood that step 605 is optional, and in some possible embodiments, other network elements (such as SMF) can also trigger the RAN to update the CDNN corresponding to the session, which is not limited in the embodiments of the present application. For example, taking the SMF update as an example, assume that there is a session 1 for the UE, and the currently stored CDNN for the session 1 is #CDNN_1, but based on the new policy, it is determined that the CDNN for the session 1 should be #CDNN_2, that is, the mapping relationship between the DNN and the CDNN is updated. In this case, the SMF can send a session update message to the RAN, which can include the updated #CDNN_2 and the ID of the corresponding session 1, etc. After receiving the session update message from the SMF, the RAN can update the stored UE context, and update the currently stored #CDNN_1 of the session 1 to #CDNN_2.

[0200] Another possible CDNN update process will be described below in conjunction with FIG. 7. Referring to FIG. 7, FIG. 7 is a flowchart of another CDNN update process disclosed in the embodiments of the present application. In FIG. 7, the update of the CDNN can be triggered by the SMF / PCF. Specifically, as shown in FIG. 7, the CDNN update process can include but is not limited to the following steps:

[0201] 701. The UE acquires the CDNN configuration.

[0202] Exemplarily, the UE can obtain the CDNN configuration (e.g. network policy) in the process of registering to the network, and can establish the PDU session based on the obtained CDNN configuration.

[0203] 702. The SM-PCF sends an SM policy control update notify to the SMF.

[0204] In some possible implementation, in case that the SM-PCF decides to update the mapping relationship between the DNN and the CDNN, the SM-PCF can send an SM policy control update notify to the SMF, which can trigger the SMF to update the mapping relationship between the DNN and the CDNN. It should be understood that the SM-PCF can be understood as a PCF serving the SMF.

[0205] It can be understood that the step 702 is optional. In some possible implementation, the SMF can periodically trigger to update the mapping relationship between the DNN and the CDNN. For example, the SMF can be configured with a timer, and the timer can be used to trigger to update the mapping relationship between the DNN and the CDNN.

[0206] 703. The SMF updates the mapping relationship between the DNN and the CDNN.

[0207] In case that the SMF receives the SM policy control update notify from the SM-PCF, or the timer triggers, etc., the SMF can update the mapping relationship between the DNN and the CDNN.

[0208] After the SMF updates the mapping relationship between the DNN and the CDNN, the SMF can notify each NF (e.g. UE-PCF, NRF, etc.) in the network, such as steps 704a, 704b, etc.

[0209] 704a. The SMF sends the updated mapping relationship between the DNN and the CDNN to the NRF.

[0210] 704b. The SMF sends the updated mapping relationship between the DNN and the CDNN to the UE-PCF.

[0211] Exemplarily, the SMF can send a UE policy update request to the UE-PCF directly or through the SM-PCF, which can include the updated mapping relationship between the CDNN and the DNN, the identity (e.g. SUPI) of the UE, etc. In case that the SMF sends the UE policy update request to the UE-PCF directly, the SMF can determine the UE-PCF from the UDM.

[0212] It can be understood that the step 704a and the step 704b are optional. In some possible implementation, after the SMF updates the mapping relationship between the DNN and the DNNC, the SMF can notify the UDR, and the UDR can notify other NFs (such as the UE-PCF, the NRF, and the like) in the network.

[0213] 705. The UE-PCF sends the updated policy to the UE, including the updated mapping relationship between the DNN and the CDNN.

[0214] For example, after the UE-PCF obtains the updated mapping relationship between the DNN and the CDNN, the UE-PCF can trigger the UE policy update. The UE-PCF can send the updated policy (such as the updated URSP rule) to the UE through the UE configuration update (UCU) process. It should be understood that the UE-PCF can determine the updated policy (such as the updated URSP rule) according to the updated mapping relationship between the DNN and the CDNN. In some possible implementation, the UCU process can further include the step 704b and the like.

[0215] In some possible implementation, the UE-PCF can send the updated policy to the UE through the RAN.

[0216] 706. The UE sends a session update message to the RAN, including the updated CDNN.

[0217] After receiving the new policy from the UE-PCF, the UE can determine which CDNN of which session needs to be updated based on the new policy. For the session whose CDNN needs to be updated, the UE can send a session update message to the RAN, and the session update message can include the updated CDNN and the corresponding PDU session ID and the like.

[0218] It should be noted that the session creation process shown in FIG. 4 is only a specific example, and does not limit the embodiments of the present application. The overall scheme of the SMF selection in the session establishment process of the embodiments of the present application will be introduced below in combination with FIG. 8. The related steps in FIG. 8 can be referred to the related steps in FIG. 4.

[0219] Please refer to FIG. 8, which is a flowchart of another communication method according to an embodiment of the present application. As shown in FIG. 8, the method can include but not limited to the following steps:

[0220] 801. The user equipment determines target second information corresponding to target first information, the target first information being used to identify a data network corresponding to a first protocol data unit (PDU) session.

[0221] Exemplarily, assuming that the session currently needed to be established by the user equipment is a first PDU session, the first information associated with the first PDU session can be target first information, for example, the DNN associated with the first PDU session can be a target DNN. In order to hide the DNN from the first access network device, the user equipment can determine target second information corresponding to the target first information, and can subsequently send the target second information to the first access network device. The target second information and the target first information have a mapping relationship.

[0222] In some possible implementation, the user equipment can determine the target second information corresponding to the target first information according to a mapping relationship between the plurality of first information and the plurality of second information. The mapping relationship between the plurality of first information and the plurality of second information can be preconfigured or dynamically configured, and one first information in the plurality of first information can correspond to one second information or a plurality of second information. It should be noted that the mapping relationship between the plurality of first information and the plurality of second information configured for the terminal equipment can be an explicit mapping relationship, for example, a mapping relationship table of the plurality of second information, or an implicit mapping relationship, for example, a preconfigured routing selection policy, which can explicitly or implicitly indicate the mapping relationship between the plurality of first information and the plurality of second information. The related description about determining the target second information corresponding to the target first information can also refer to the related description in the above step 404.

[0223] It should be noted that the configuration of the mapping relationship between the plurality of first information and the plurality of second information is not limited in the embodiments of the present application, which can be configured by the SMF and carried in the registration to the NRF, for example, the configured CDNN, or configured by other network elements, for example, the OAM. Exemplarily, in some possible implementation, the NRF can receive a registration request from one or more session management network elements, and each registration request can include the first information and the second information corresponding to the session management network element, and the second information corresponding to the session management network element has a mapping relationship with the first information corresponding to the session management network element. Exemplarily, in some possible implementation, the NRF can receive a registration request from one or more session management network elements, and each registration request includes the first information corresponding to the session management network element. In this case, the NRF can also receive the mapping relationship between the plurality of first information and the plurality of second information from other network elements, and can store the mapping relationship.

[0224] It should be understood that the registration request sent by the session management network element to the NRF can also include the service area of the corresponding session management network element, and the ID of the session management network element, etc., which is not limited in the embodiments of the present application.

[0225] In some possible implementation, the user equipment can obtain the mapping relationship between the first information and the second information in the process of registering to the network.

[0226] In some possible implementation, the mapping relationship between the first information and the second information is dynamically updated. The specific process of dynamically updating the mapping relationship can refer to the processes shown in FIG. 6 and FIG. 7.

[0227] It should be noted that in some possible implementation, the first information can also be other information for selecting an NF (such as SMF). That is, for information that needs to be kept secret, the mapping method can be used to make the access network device invisible.

[0228] 802. The user equipment sends a first message to the first access network device, the first message including target second information and a first request, the first request being used to request establishing a first PDU session for the user equipment, and the target second information being used for the first access network device to determine a session management network element corresponding to the target first information.

[0229] After the user equipment determines the target second information corresponding to the target first information, the user equipment can send a first message to the first access network device. Correspondingly, the first access network device can receive the first message from the user equipment, the first message including target second information and a first request, the first request being used to request establishing a first PDU session for the user equipment, and the target second information being used for the first access network device to determine a session management network element corresponding to the target first information. For example, the first request can be an encapsulated NAS message, which can be used to send the first request to the first session management network element after the first access network device determines the first session management network element. The first message can also refer to the session establishment request message in step 405 of FIG. 4.

[0230] 803. The first access network device determines the first session management network element based on the target second information.

[0231] After the first access network device receives the first message from the user equipment, the first access network device can determine the first session management network element based on the target second information in the first message.

[0232] In a possible implementation, the first access network device determines the first session management network element based on the target second information in the first message, which can be specifically requesting the NRF to determine. For example, the first access network device can send a second request to the NRF, the second request can include the target second information, and the second request can be used to request to discover the session management network element corresponding to the target first information. It should be understood that the second request can also be understood as being used to request to discover the session management network element corresponding to the target second information, but the session management network element corresponding to the target second information is actually the session management network element corresponding to the target first information. After receiving the second request from the first access network device, the NRF can determine the session management network element corresponding to the target first information based on the target second information carried in the second request. For example, the NRF knows the mapping relationship between the first information and the second information, and the NRF knows the first information corresponding to each registered session management network element, and can first determine the target first information based on the target second information, and then determine the session management network element corresponding to the target first information. For another example, the NRF knows the second information of each registered session management network element, and can directly determine the session management network element corresponding to the target second information based on the target second information, but the session management network element corresponding to the target second information is actually the session management network element corresponding to the target first information. After determining the session management network element corresponding to the target first information, the NRF can send a second response to the first access network device, and the second response can include the configuration information of one or more session management network elements corresponding to the target first information determined by the NRF. Accordingly, the first access network device can receive the second response from the NRF, and then determine the first session management network element from the one or more session management network elements corresponding to the target first information.

[0233] It can be understood that in addition to the target second information, the information used to select the SMF can also include slice information, location information, and the like. For example, the second request can also carry more information used to select the SMF, or the first access network device can further select the relevant SMF found in the second response based on other selection information after receiving the second response. For example, the first access network device can determine the first session management network element from the one or more session management network elements corresponding to the target first information based on the first location information of the user equipment. For example, the second request can also include the first location information of the user equipment, and the first location information is associated with the first access network device. In this case, the second request can be used to request to discover the session management network element corresponding to the target first information and the first location information, and the second response can include the configuration information of one or more session management network elements corresponding to the target first information and the first location information. Accordingly, the first access network device can determine the first session management network element from the one or more session management network elements corresponding to the target first information and the first location information.

[0234] It should be noted that the above two requests can be a network element discovery request / NF discovery request, and the second response can be a network element discovery response / NF discovery response.

[0235] The process of the first access network device requesting the NRF to discover the session management network element related to the first access network device can also refer to the related description in steps 406-408.

[0236] 804. The first access network device sends a first request to the first session management network element.

[0237] After the first access network device determines the first session management network element, the first access network device can send a first request to the first session management network element to request the establishment of a first PDU session for the user equipment.

[0238] The first request can refer to the session establishment request in step 409a. It should be understood that after the first access network device sends the first request to the first session management network element, there are still other session-related establishment processes, which are not limited by the embodiments of the present application, and can refer to step 409b and the related description in the standard. Wherein, the main difference may be that the interaction with the AMF can be changed to the interaction with the first access network device.

[0239] It should be noted that the related process of I-SMF selection in the handover process shown in FIG. 5 is only a specific example and does not limit the embodiments of the present application. The overall scheme of I-SMF selection in the handover process of the embodiments of the present application will be introduced below in combination with FIG. 9. The related steps in FIG. 9 can refer to the related steps in FIG. 5.

[0240] Please refer to FIG. 9, which is a flowchart of another communication method according to an embodiment of the present application. As shown in FIG. 9, the method can include but is not limited to the following steps:

[0241] 901. The second access network device sends a third request to the NRF in a case where it is determined that an intermediate session management network element needs to be inserted or modified for the first PDU session of the user equipment, the third request including target second information, the third request being used to request to discover a session management network element corresponding to the target first information, the target second information having a mapping relationship with the target first information, the target first information being used to identify a data network corresponding to the first PDU session.

[0242] For example, in the case of handover, the second access network device can determine whether the first PDU session of the user equipment needs to insert or modify the intermediate session management network element, and in the case where it is determined that an intermediate session management network element needs to be inserted or modified for the first PDU session of the user equipment, the second access network device can send a third request to the NRF. Correspondingly, the NRF can receive the third request from the second access network device.

[0243] It should be understood that the second access network device can be a target access network device for the handover of the user equipment. For example, the user equipment can be handed over from the first access network device to the second access network device.

[0244] In some possible implementation, during the handover, the second access network device can receive the first PDU session information of the user equipment from the first access network device, and the first PDU session information can include target second information, which is used to determine or redetermine a session management network element serving the first PDU session. For example, the second access network device can determine whether the first PDU session of the user equipment needs to insert or modify an intermediate session management network element based on the first PDU session information.

[0245] 902. The NRF sends a third response to the second access network device, and the third response includes configuration information of one or more session management network elements corresponding to the target first information.

[0246] After the NRF receives the third request from the second access network device, the NRF can determine the session management network element corresponding to the target first information based on the target second information carried in the third request. For example, the NRF knows the mapping relationship between the first information and the second information, and the NRF knows the first information corresponding to each registered session management network element, so the NRF can first determine the target first information based on the target second information, and then determine the session management network element corresponding to the target first information. For another example, the NRF knows the second information of each registered session management network element, so the NRF can directly determine the session management network element corresponding to the target second information based on the target second information, which is actually the session management network element corresponding to the target first information. After the NRF determines the session management network element corresponding to the target first information, the NRF can send a third response to the first access network device, and the third response can include the configuration information of one or more session management network elements corresponding to the target first information determined by the NRF. Correspondingly, the first access network device can receive the third response from the NRF.

[0247] It should be noted that the above three requests can be network element discovery requests / NF discovery requests, and the third response can be a network element discovery response / NF discovery response.

[0248] The process that the second access network device requests the NRF to discover the related session management network element can also refer to the related description in steps 504-506.

[0249] 903. The second access network device sends a fourth request to the first intermediate session management network element based on the configuration information of the first intermediate session management network element, and the fourth request is used to request to establish a session management context of the first PDU session of the user equipment, and the first intermediate session management network element is a session management network element determined from one or more session management network elements corresponding to the target first information.

[0250] After receiving the third response from the NRF, the second access network device can determine the first intermediate session management network element from one or more session management network elements corresponding to the target first information, and then send a fourth request to the first intermediate session management network element. Correspondingly, the first intermediate session management network element can receive the fourth request from the second access network device, and the fourth request can be used to request establishment of a session management context of the first PDU session of the user equipment, and the first intermediate session management network element can be determined from one or more session management network elements corresponding to the target first information. For example, the fourth request can refer to the SM context establishment request / path switching request in step 507a described above.

[0251] It can be understood that, in addition to the target second information, the information used to select the SMF can also include slice information, location information, etc. For example, the third request can also carry more information used to select the SMF, or the second access network device can further select the relevant SMF based on other selection information after receiving the third response, such as the second access network device can determine the first intermediate session management network element from one or more session management network elements corresponding to the target first information based on the second location information of the user equipment. For example, the third request can also include the second location information of the user equipment, and the second location information is associated with the second access network device. In this case, the third request can be used to request discovery of the session management network element corresponding to the target first information and the second location information, and the third response can include configuration information of one or more session management network elements corresponding to the target first information and the second location information. Correspondingly, the second access network device can determine the first intermediate session management network element from one or more session management network elements corresponding to the target first information and the second location information.

[0252] It should be understood that, after the second access network device sends the fourth request to the first intermediate session management network element, other I-SMF insertion / modification processes are also included, which are not limited by the embodiments of the present application, and can be referred to the related description in step 507b and the standard. Wherein, the main difference can be that the interaction with the AMF can be changed to the interaction with the second access network device.

[0253] It can be understood that the process of selecting the V-SMF and the home session management function (H-SMF) is similar to the process of selecting the I-SMF and the anchor SMF described above. That is, the I-SMF corresponds to the V-SMF, and the anchor SMF corresponds to the H-SMF. The specific description can be referred to the related description in the method embodiments described above, and will not be repeated here.

[0254] It should be noted that the related information (i.e., the same information or similar information) and the related description in the above different embodiments can be mutually referred to.

[0255] The above mainly introduces the communication provided by the embodiments of the present application. It can be understood that the above user equipment, first access network equipment, network storage function network element, second access network equipment and the like can contain the hardware structure and / or software module for executing the corresponding functions. The units and steps of the examples described in combination with the embodiments disclosed herein can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is implemented in hardware or computer software driven hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered beyond the scope of the embodiments of the present application.

[0256] The embodiments of the present application can divide the user equipment, first access network equipment, network storage function network element, second access network equipment and the like into functional modules according to the above method examples, for example, each functional module can be divided according to each function, or two or more functions can be integrated into one module. The above integrated module can be realized in the form of hardware or in the form of a software functional module. It should be noted that the division of the modules by the embodiments of the present application is illustrative, and is only a logical functional division. There can be another division manner when actually implemented.

[0257] In the case of dividing each functional module according to each function, FIG. 10 shows a possible structural schematic diagram of a communication apparatus 1000. The communication apparatus 1000 can include a processing unit 1001 and a communication unit 1002. Optionally, the communication unit 1002 can also be referred to as a transceiver unit, an output unit, or an interface unit, etc. In a possible implementation manner, the communication unit 1002 includes at least one of a sending unit or a receiving unit. The sending unit and the receiving unit can be integrated together, or two independent units, etc. In a possible design, the communication apparatus 1000 can be the above user equipment, or can be a component (for example, a processor, a chip, a chip system, a circuit or a functional module) in the user equipment, or can be a processing system in the user equipment, etc.

[0258] When the communication apparatus 1000 is used for the function of the user equipment in the embodiment shown in FIG. 8, specifically:

[0259] The processing unit 1001 is configured to determine target second information corresponding to target first information; the target first information is used to identify a data network corresponding to a first protocol data unit (PDU) session.

[0260] The communication unit 1002 is configured to send, to a first access network device, a first message including target second information and a first request, the first request being used to request establishment of a first protocol data unit (PDU) session for the user equipment, and the target second information being used for the first access network device to determine a session management network element corresponding to the target first information.

[0261] In a possible implementation, the processing unit 1001 is specifically configured to determine target second information corresponding to target first information according to a mapping relationship between a plurality of first information and a pluralityity of second information, one first information in the plurality of first information corresponding to one second information or a plurality of second information.

[0262] In a possible implementation, the mapping relationship between the plurality of first information and the plurality of second information is dynamically updated.

[0263] The specific operations of each unit in the communication apparatus 1000 can refer to the descriptions of the user equipment in the above-described embodiment shown in FIG. 8, which will not be repeated here.

[0264] In a possible design, the communication apparatus 1000 can be the first access network device, or can be a component (for example, a processor, a chip, a chip system, a circuit, or a functional module) in the first access network device, or can be a processing system in the first access network device, and the like.

[0265] When the communication apparatus 1000 is configured to perform the functions of the first access network device in the above-described embodiment shown in FIG. 8, specifically:

[0266] The communication unit 1002 is configured to receive a first message from a user equipment, the first message including target second information and a first request, the first request being used to request establishment of a first protocol data unit (PDU) session for the user equipment, and the target second information having a mapping relationship with target first information, the target first information being used to identify a data network corresponding to the first PDU session.

[0267] The processing unit 1001 is configured to determine a first session management network element based on the target second information.

[0268] The communication unit 1002 is further configured to send, to the first session management network element, the first request.

[0269] In a possible implementation, the processing unit 1001 determines the first session management network element based on the target second information, including:

[0270] The processing unit 1001 sends, to a network storage function network element through the communication unit 1002, a network element discovery request including the target second information, the network element discovery request being used to request discovery of a session management network element corresponding to the target first information.

[0271] The processing unit 1001 receives, through the communication unit 1002, a network element discovery response from the network storage function network element, the network element discovery response including one or more pieces of configuration information of session management network elements corresponding to the target first information;

[0272] The processing unit 1001 determines a first session management network element from the one or more pieces of configuration information of session management network elements corresponding to the target first information.

[0273] In a possible implementation, the network element discovery request further includes first location information of the user equipment, the first location information being associated with the first access network device; the network element discovery request is used to request discovery of a session management network element corresponding to the target first information, and specifically, the network element discovery request is used to request discovery of a session management network element corresponding to the target first information and the first location information; the network element discovery response includes one or more pieces of configuration information of session management network elements corresponding to the target first information, and specifically, the network element discovery response includes one or more pieces of configuration information of session management network elements corresponding to the target first information and the first location information;

[0274] The processing unit 1001 determines a first session management network element from the one or more pieces of configuration information of session management network elements corresponding to the target first information includes:

[0275] determining a first session management network element from the one or more pieces of configuration information of session management network elements corresponding to the target first information and the first location information.

[0276] The specific operations of each unit in the communication apparatus 1000 described above can refer to the description of the first access network device in the embodiment shown in FIG. 8, which will not be repeated here.

[0277] In a possible design, the communication apparatus 1000 can be the network storage function network element, or can be a component (for example, a processor, a chip, a chip system, a circuit, or a functional module) in the network storage function network element, or can be a processing system in the network storage function network element, and the like.

[0278] When the communication apparatus 1000 is used for the function of the network storage function network element in the embodiment shown in FIG. 8 or FIG. 9, specifically:

[0279] The communication unit 1002 receives a network element discovery request, the network element discovery request including target second information, the network element discovery request being used to request discovery of a session management network element corresponding to target first information; the target second information has a mapping relationship with the target first information, and the target first information is used to identify a data network corresponding to a first protocol data unit (PDU) session;

[0280] The communication unit 1002 is further configured to send a network element discovery response, the network element discovery response comprising one or more pieces of configuration information of the session management network element corresponding to the target first information.

[0281] In a possible implementation, the communication unit 1002 is further configured to receive a registration request from one or more session management network elements, each registration request comprising corresponding first information and second information of a corresponding session management network element, the second information of the corresponding session management network element being in a mapping relationship with the first information of the corresponding session management network element.

[0282] In a possible implementation, the communication apparatus 1000 stores a mapping relationship between a plurality of first information and a plurality of second information, the plurality of first information comprising the target first information, and the plurality of second information comprising the target second information; and the communication unit 1002 is further configured to receive a registration request from one or more session management network elements, each registration request comprising corresponding first information of a corresponding session management network element.

[0283] In a possible implementation, each registration request further comprises a service area of the corresponding session management network element.

[0284] In a possible implementation, the network element discovery request further comprises location information of the user equipment, the location information being associated with the first access network device; the network element discovery request is used to request discovery of a session management network element corresponding to the target first information, and specifically, the network element discovery request is used to request discovery of a session management network element corresponding to the target first information and the location information; and the network element discovery response comprises one or more pieces of configuration information of the session management network element corresponding to the target first information and the location information.

[0285] The specific operations of each unit in the communication apparatus 1000 described above can refer to the descriptions of the network storage function network element in the embodiments of FIG. 8 or FIG. 9 described above, which will not be repeated here.

[0286] In a possible design, the communication apparatus 1000 can be the second access network device described above, or can be a component (for example, a processor, a chip, a chip system, a circuit, or a functional module) in the second access network device, or can be a processing system in the second access network device, and the like.

[0287] When the communication apparatus 1000 is configured to perform the functions of the second access network device in the embodiment of FIG. 9 described above, specifically:

[0288] The communication unit 1002 is configured to, in a case where it is determined that an intermediate session management network element needs to be inserted or modified for a first protocol data unit (PDU) session of a user equipment, send a network element discovery request to a network storage function network element, the network element discovery request comprising target second information, the network element discovery request being used to request discovery of a session management network element corresponding to target first information; the target second information has a mapping relationship with the target first information, and the target first information is used to identify a data network corresponding to the first PDU session.

[0289] The communication unit 1002 is further configured to receive a network element discovery response from the network storage function network element, the network element discovery response comprising configuration information of one or more session management network elements corresponding to the target first information.

[0290] The communication unit 1002 is further configured to send a fourth request to a first intermediate session management network element based on the configuration information of the first intermediate session management network element, the fourth request being used to request establishment of a session management context of the first PDU session of the user equipment; and the first intermediate session management network element is a session management network element determined from the one or more session management network elements corresponding to the target first information.

[0291] In a possible implementation, the communication unit 1002 is further configured to receive first PDU session information of the user equipment from a first access network device, the first PDU session information comprising the target second information, and the target second information being used to determine or redetermine a session management network element serving the first PDU session.

[0292] In a possible implementation, the network element discovery request further comprises second location information of the user equipment, the second location information being associated with the second access network device; the network element discovery request is used to request discovery of a session management network element corresponding to the target first information, and specifically, the network element discovery request is used to request discovery of a session management network element corresponding to the target first information and the second location information; the network element discovery response comprises configuration information of one or more session management network elements corresponding to the target first information, and specifically, the network element discovery response comprises configuration information of one or more session management network elements corresponding to the target first information and the second location information; and the first intermediate session management network element is a session management network element determined from the one or more session management network elements corresponding to the target first information and the second location information.

[0293] The specific operations of each unit in the communication apparatus 1000 described above can refer to the description of the second access network device in the embodiment shown in FIG. 9, which will not be repeated here.

[0294] In a possible implementation, in the communication apparatus shown in FIG. 10, the processing unit can be one or more processors / logic circuits, and the communication unit can be a transceiver, or the communication unit can also be a sending unit and a receiving unit, the sending unit can be a transmitter, and the receiving unit can be a receiver, and the sending unit and the receiving unit are integrated in one device, for example, a transceiver. In the embodiments of the present application, the processor and the transceiver can be coupled, and the connection manner between the processor and the transceiver is not limited in the embodiments of the present application. In the process of executing the above method, the process of sending information (for example, sending the first message) in the above method can be understood as the process of outputting the above information by the processor. When the above information is outputted, the processor outputs the above information to the transceiver, so that the transceiver transmits. After the above information is outputted by the processor, the above information can also need to be processed further, and then reaches the transceiver. Similarly, the process of receiving information (for example, receiving the first message) in the above method can be understood as the process of receiving the inputted above information by the processor. When the processor receives the inputted information, the transceiver receives the above information and inputs it to the processor. Furthermore, after the transceiver receives the above information, the above information can need to be processed further, and then is inputted to the processor.

[0295] In another possible implementation, in the communication apparatus shown in FIG. 10, the processing unit can be one or more processors / logic circuits. The communication unit can be an input / output interface, or the communication unit can also be an input interface and an output interface. The input / output interface can also be referred to as a communication interface, or an interface circuit, or an interface, and the like.

[0296] FIG. 11 shows a possible hardware structure schematic diagram of the communication apparatus 1100 provided by the embodiments of the present application. The communication apparatus 1100 can include a communication interface 1104 and at least one processor 1102. Optionally, a bus 1103 can also be included. Further optionally, at least one memory 1101 can also be included, wherein the memory 1101, the processor 1102 and the communication interface 1104 can be connected through the bus 1103.

[0297] The memory 1101 is used to provide storage space, and the storage space can store data such as operating systems and computer programs. The memory 1101 can be one or a combination of a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), or a compact disc read-only memory (CD-ROM), and the like.

[0298] The processor 1102 is a module for performing arithmetic operations and / or logical operations, and can be one or a combination of a central processing unit (CPU), a graphics processing unit (GPU), a microprocessor unit (MPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a complex programmable logic device (CPLD), a co-processor (assisting the central processor to complete the corresponding processing and application), a microcontroller unit (MCU), etc. For example, the processor 1102 can be used to process communication protocols and communication data.

[0299] The communication interface 1104 is used to receive data sent by an external device and / or send data to an external device. Optionally, the communication interface 1104 can also include a transmitter (such as a radio frequency transmitter, an antenna, etc.) and / or a receiver coupled to the interface, etc. For example, the communication interface 1104 can include a control circuit and an antenna, and the control circuit is mainly used for conversion between baseband signals and radio frequency signals and processing of the radio frequency signals. The antenna is mainly used for transmitting and receiving radio frequency signals in the form of electromagnetic waves. When data needs to be transmitted wirelessly, the processor 1102 performs baseband processing on the data to be transmitted, and outputs the baseband signal to the control circuit. The control circuit performs radio frequency processing on the baseband signal and transmits the radio frequency signal in the form of electromagnetic waves through the antenna. When data is sent to the communication device, the control circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor 1102. The processor 1102 converts the baseband signal into data and processes the data.

[0300] In one possible implementation, the control circuit and the antenna can be arranged independently of the processor performing baseband processing, for example, in a distributed scenario, the control circuit and the antenna can be arranged remotely from the communication device.

[0301] In one design, the communication device 1100 can be used to perform the functions of the user equipment in the embodiments shown in FIGS. 4-9. For details, please refer to the related description of the user equipment in FIGS. 4-9, which will not be described in detail here.

[0302] In another design, the communication device 1100 can be configured to perform the functions of the first access network device in the embodiments described above with reference to FIGS. 4-9. For details, refer to the related description of the first access network device in FIGS. 4-9, which will not be repeated here.

[0303] In yet another design, the communication device 1100 can be configured to perform the functions of the network storage function network element in the embodiments described above with reference to FIGS. 4-9. For details, refer to the related description of the network storage function network element in FIGS. 4-9, which will not be repeated here.

[0304] In yet another design, the communication device 1100 can be configured to perform the functions of the second access network device in the embodiments described above with reference to FIGS. 4-9. For details, refer to the related description of the second access network device in FIGS. 4-9, which will not be repeated here.

[0305] In one possible design, the memory 1101 can store instructions, which can be a computer program, to cause the communication device 1100 to perform operations of the user equipment, or the first access network device, or the network storage function network element, or the second access network device, in any of the method embodiments described above, when the instructions are run on the processor 1102. For details, refer to the related description in FIGS. 4-9, which will not be repeated here.

[0306] It is noted that the communication device 1100 shown in FIG. 11 is merely an implementation manner of the embodiments of the present application, and in actual applications, the communication device 1100 can also include more or fewer components, which is not limited here.

[0307] It should be understood that the sending in the embodiments of the present application can be direct sending or indirect sending. Direct sending means that one device or module sends information / data directly to a corresponding device or module, and indirect sending means that one device or module sends information / data to a corresponding device or module through other devices or modules.

[0308] Obviously, the embodiments described above are only some embodiments of this application, and not all embodiments. The term "embodiment" as used herein means that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily indicate the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will understand, explicitly and implicitly, that the embodiments described herein can be combined with other embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application. The terms "first," "second," "third," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects and are not used to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, it may include a series of steps or units, or optionally, steps or units not listed, or optionally other steps or units inherent to these processes, methods, products, or devices. It is also understandable that, for an architecture with multiple devices or modules, if one device or module generates a piece of information and another device or module uses that information, there are multiple ways for the other device to obtain that information. For example, the device or module that generated the information may send the information directly to the device or module that used the information (equivalent to direct sending), or the device or module that generated the information may send the information to the device or module that used the information through other devices or modules (equivalent to indirect sending).

[0309] It is understood that the accompanying drawings show only the parts relevant to this application and not all of them. It should be understood that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but may also have additional steps not included in the drawings. The process can correspond to a method, function, procedure, subroutine, subroutine, etc.

[0310] The terms "component," "module," "system," "unit," and the like are used in the present specification to represent a computer-related entity, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a unit can be, but is not limited to, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and / or a computer. Also, the units can be executed from various computer-readable media having various data structures stored thereon. For example, the units can be communicated by local and / or remote processes according to signals having one or more data packets (e.g., from the second unit interacting with the local system, a distributed system, and / or another unit of the network, e.g., via the Internet, by way of signals). For example, the units can be communicated by local and / or remote processes according to signals having one or more data packets (e.g., from the second unit interacting with the local system, a distributed system, and / or another unit of the network, e.g., via the Internet, by way of signals).

[0311] The above detailed description has been made for the purpose of explaining the present application, technical solutions, and beneficial effects. It should be understood that the above description is only a specific implementation of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made on the basis of the technical solutions of the present application shall be included in the protection scope of the present application.

Claims

1. A communication method characterized by comprising: The method applied to a user equipment comprises: determining target second information corresponding to target first information; the target first information is used to identify a data network corresponding to a first protocol data unit (PDU) session; sending a first message to a first access network device, the first message comprising the target second information and a first request, the first request being used to request establishment of the first PDU session for the user equipment; the target second information is used for the first access network device to determine a session management network element corresponding to the target first information.

2. The method of claim 1, wherein, The determining of the target second information corresponding to the target first information comprises: determining the target second information corresponding to the target first information according to a mapping relationship between a plurality of first information and a plurality of second information; one first information in the plurality of first information corresponds to one second information or a plurality of second information.

3. The method of claim 2, wherein, The mapping relationship between the plurality of first information and the plurality of second information is dynamically updated.

4. A communication method characterized by comprising: The method applied to a first access network device comprises: receiving a first message from a user equipment, the first message comprising target second information and a first request, the first request being used to request establishment of a first protocol data unit (PDU) session for the user equipment; the target second information has a mapping relationship with target first information, the target first information being used to identify a data network corresponding to the first PDU session; determining a first session management network element based on the target second information; sending the first request to the first session management network element.

5. The method of claim 4, wherein, The determining of the first session management network element based on the target second information comprises: sending a network element discovery request to a network storage function network element, the network element discovery request comprising the target second information, the network element discovery request being used to request discovery of a session management network element corresponding to the target first information; receiving a network element discovery response from the network storage function network element, the network element discovery response comprising configuration information of one or more session management network elements corresponding to the target first information; determining the first session management network element from the one or more session management network elements corresponding to the target first information.

6. The method of claim 5, wherein, The network element discovery request further comprises first location information of the user equipment, the first location information being associated with the first access network device; the network element discovery request being used to request discovery of a session management network element corresponding to the target first information specifically comprises: the network element discovery request being used to request discovery of a session management network element corresponding to the target first information and the first location information; the network element discovery response comprising configuration information of one or more session management network elements corresponding to the target first information specifically comprises: the network element discovery response comprising configuration information of one or more session management network elements corresponding to the target first information and the first location information; The determining of the first session management network element from the one or more session management network elements corresponding to the target first information comprises: determining the first session management network element from the one or more session management network elements corresponding to the target first information and the first location information.

7. A communication method characterized by comprising: The method applied to a network storage function network element comprises: receiving a network element discovery request, the network element discovery request comprising target second information, the network element discovery request being used to request discovery of a session management network element corresponding to target first information, the target second information having a mapping relationship with the target first information, the target first information being used to identify a data network corresponding to a first protocol data unit (PDU) session; sending a network element discovery response, the network element discovery response comprising configuration information of one or more session management network elements corresponding to the target first information.

8. The method of claim 7, wherein, The method further comprises: receiving a registration request from one or more session management network elements, each registration request comprising first information corresponding to a corresponding session management network element and second information corresponding to the corresponding session management network element, the second information corresponding to the corresponding session management network element having a mapping relationship with the first information corresponding to the corresponding session management network element.

9. The method of claim 7, wherein, The network storage function network element stores a mapping relationship between a plurality of first information and a plurality of second information, the plurality of first information comprising the target first information, and the plurality of second information comprising the target second information. The method further comprises: receiving a registration request from one or more session management network elements, each registration request comprising first information corresponding to a corresponding session management network element.

10. The method according to claim 8 or 9, characterized in that, Each registration request further comprises a service area of the corresponding session management network element.

11. The method of claim 10, wherein, The network element discovery request further comprises location information of the user equipment; the network element discovery request used to request discovery of a session management network element corresponding to the target first information is specifically used to request discovery of a session management network element corresponding to the target first information and the location information; the network element discovery response comprising configuration information of one or more session management network elements corresponding to the target first information is specifically the network element discovery response comprising configuration information of one or more session management network elements corresponding to the target first information and the location information.

12. A communication method characterized by comprising: Applied to a second access network device, the method comprises: In a case where it is determined that an intermediate session management network element needs to be inserted or modified for a first protocol data unit (PDU) session of a user equipment, a network element discovery request is sent to a network storage function network element, the network element discovery request comprising target second information, the network element discovery request being used to request discovery of a session management network element corresponding to target first information, the target second information having a mapping relationship with the target first information, the target first information being used to identify a data network corresponding to the first PDU session; a network element discovery response is received from the network storage function network element, the network element discovery response comprising configuration information of one or more session management network elements corresponding to the target first information; a fourth request is sent to a first intermediate session management network element based on configuration information of the first intermediate session management network element, the fourth request being used to request establishment of a session management context of the first PDU session of the user equipment, the first intermediate session management network element being a session management network element determined from the one or more session management network elements corresponding to the target first information.

13. The method of claim 12, wherein, The method further comprises: receiving, from a first access network device, information of a first PDU session of the user equipment, the information of the first PDU session comprising the target second information, the target second information being used for determining or re-determining a session management network element serving the first PDU session.

14. The method according to claim 12 or 13, characterized in that, The network element discovery request further comprises second location information of the user equipment, the second location information being associated with the second access network device; the network element discovery request is used for requesting to discover a session management network element corresponding to the target first information specifically: the network element discovery request is used for requesting to discover a session management network element corresponding to the target first information and the second location information; the network element discovery response comprises one or more configuration information of session management network elements corresponding to the target first information specifically: the network element discovery response comprises one or more configuration information of session management network elements corresponding to the target first information and the second location information; the first intermediate session management network element is a session management network element determined from the one or more session management network elements corresponding to the target first information specifically: the first intermediate session management network element is a session management network element determined from the one or more session management network elements corresponding to the target first information and the second location information.

15. A communication system, characterized by The system comprises at least two of a user equipment, a first access device, a network storage function network element and a second access network device, the user equipment is used to implement the method of any one of claims 1-3, the first access device is used to implement the method of any one of claims 4-6, the network storage function network element is used to implement the method of any one of claims 7-11, and the second access network device is used to implement the method of any one of claims 12-14.

16. A communications device, characterized by The system comprises a module for implementing the method of any one of claims 1-14.

17. A communications device, characterized by The system comprises a processor and a transceiver, the transceiver is used for transmitting and receiving information, and the processor is used for enabling the communication device to implement the method of any one of claims 1-14.

18. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer programs or computer instructions, and the computer programs or computer instructions are executed by a processor to implement the method of any one of claims 1-14.

19. A computer program product, characterised in that, The computer program product comprises computer program codes or computer instructions, and when the computer program codes or computer instructions are executed, the method of any one of claims 1-14 is implemented.

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