Indication information transmission method, device, system, and storage medium

Abstract

To provide an indication information sending method, an apparatus and a system, and a storage medium.SOLUTION: Provided are an indication information sending method, an apparatus and a system, a storage medium, and an electronic device, where the indication information sending method includes a step of sending, by a first access and mobility management function (AMF), first indication information to a first target network element, where the first indication information is used for indicating whether a packet data unit (PDU) session is capable of interworking with a target network system.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This application claims priority to Chinese Patent Application No. 201810912161.6, filed with the China Intellectual Property Office (CNIPA) on August 10, 2018, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present application relates to the field of communications, and in particular to an indication information transmitting method, device and system, and storage medium. [Background technology]

[0003] There is a one-to-one mapping relationship between an access point name (APN) in a fourth generation (4G) system and a data network name (DNN) in a fifth generation (5G) system.

[0004] When a packet data network connection (PDN connection) is established in a 4G system, there is a restriction that the mobility management entity (MME) must select the same PDN gateway (PGW) for multiple PDN connections established using the same APN.

[0005] However, in a 5G system, such a restriction does not exist. That is, for multiple packet data unit (PDU) sessions established using the same DNN, different session management function (SMF) entities may be selected by a mobility management (AMF) entity. Because the SMF and the PDN gateway control plane (PGW-C) are combined within one network element, the selection of different SMF+PGW-C in a 5G system means that after a session is migrated to a 4G system, multiple different PDN connections under the same APN have different PGWs, which is contrary to the principles of the 4G system. Therefore, interworking cannot be implemented from a 5G system to a 4G system.

[0006] In view of the problem that interworking across network systems for user equipment (UE) cannot be implemented in the related technical field, no reasonable solution has yet been proposed. Summary of the Invention [Problem to be solved by the invention]

[0007] Embodiments of the present disclosure provide an indication information transmission method, an apparatus and system, a storage medium, and an electronic device for solving the problem that at least interworking across network systems for user equipment (UE) cannot be implemented in the related technical field. [Means for solving the problem]

[0008] According to an aspect of an embodiment of the present disclosure, there is provided an indication information sending method, including: sending, by a first AMF, first indication information to a first target network element, the first indication information being used to indicate whether a PDU session is capable of interworking with a target network system.

[0009] Optionally, the step of the first AMF sending first indication information to the first target network element includes a step of the first AMF sending a PDU session setup request to the SMF in response to the first AMF receiving a request message requesting that the UE set up a PDU session, wherein the PDU session setup request carries first indication information, and the first indication information is used to indicate whether the PDU session is capable of interworking with the target network system.

[0010] Optionally, the step of the first AMF sending first indication information to the first target network element includes a step of, in response to the first AMF determining that a status parameter of the PDU session has changed, sending a PDU session modification request to the SMF by the first AMF, wherein the PDU session modification request carries the first indication information, and the first indication information is used to indicate whether the PDU session is capable of interworking with the target network system.

[0011] Optionally, the step of the first AMF sending first indication information to the first target network element includes a step of sending first indication information to the second AMF by the first AMF in response to an inter-AMF mobility event occurring in which the UE is migrated from the first AMF to the second AMF, wherein the first indication information is used to indicate whether the PDU session of the UE under the first AMF is capable of interworking with the target network system.

[0012] Optionally, the step of the first AMF sending the indication information to the second AMF includes a step of sending a UE context message to the second AMF by the first AMF, wherein the UE context message carries the first indication information.

[0013] Optionally, the step of the first AMF sending first indication information to the first target network element includes the step of sending the first indication information to the SMF by the first AMF, where the first indication information is used to indicate whether a PDU session under the SMF is capable of interworking with the target network system, and the step of sending a message by the SMF to the second AMF in response to an inter-AMF mobility event occurring in which the UE is migrated from the first AMF to the second AMF, where the message is used to indicate whether a PDU session under the SMF is capable of interworking with the target network system.

[0014] According to another aspect of an embodiment of the present disclosure, there is further provided an indication information sending method, which includes: sending, by a first AMF, second indication information to a second target network element, where the second indication information is used to indicate that the second target network element stores DNN interworking information.

[0015] Optionally, the step of the first AMF sending second indication information to the second target network element includes a step of sending, by the first AMF, the second indication information to a unified data management (UDM) or a home subscription server (HSS), wherein the second indication information is used to indicate that the UDM or HSS has stored DNN interworking information, and the DNN interworking information includes the DNN information and at least one of an SMF address or a PGW address.

[0016] Optionally, for each DNN, the UDM or HSS stores one piece of DNN interworking information corresponding to the DNN.

[0017] Optionally, the step of the first AMF sending second indication information to the second target network element includes a step of sending second indication information by the first AMF to the second AMF in response to an inter-AMF mobility event occurring in which the UE is migrated from the first AMF to the second AMF, wherein the second indication information is used to indicate that DNN interworking information is stored, and the DNN interworking information includes the DNN information and at least one of an SMF address or a PGW address.

[0018] Optionally, the inter-AMF mobility event includes at least one of a connected state handover process or an idle state mobility process.

[0019] Optionally, the target network system is a 4G network system.

[0020] According to another aspect of an embodiment of the present disclosure, there is further provided an indication information sending device, the indication information sending device including: a first sending module applied to a first AMF and configured to send first indication information to a target network element, the first indication information being used to indicate whether a PDU session is capable of interworking with a target network system.

[0021] Optionally, the first transmitting module includes a first transmitting unit configured to send a PDU session establishment request to the SMF in response to the first AMF receiving a message requesting that the UE establish a PDU session, the PDU session establishment request carrying first indication information, the first indication information being used to indicate whether the PDU session is capable of interworking with the target network system.

[0022] Optionally, the first transmitting module further includes a second transmitting unit configured to transmit a PDU session modification request to the SMF in response to the first AMF determining that a status parameter of the PDU session has changed, the PDU session modification request carrying first indication information, the first indication information being used to indicate whether the PDU session is capable of interworking with the target network system.

[0023] Optionally, the first transmitting module further includes a third transmitting unit configured to transmit first indication information to the second AMF in response to an inter-AMF mobility event occurring in which the UE is transitioned from the first AMF to the second AMF, wherein the first indication information is used to indicate whether a PDU session of the UE under the first AMF is capable of interworking with a target network system.

[0024] According to another aspect of an embodiment of the present disclosure, there is further provided an indication information sending device, the indication information sending device including: a second sending module applied to a first AMF and configured to send second indication information to a second target network element, where the second indication information is used to indicate that the second target network element stores DNN interworking information.

[0025] Optionally, the second sending module includes a fourth sending unit configured to send second indication information to the UDM or the HSS, where the second indication information is used to indicate that the UDM or the HSS has stored DNN interworking information, and the DNN interworking information includes the DNN information and at least one of an SMF address or a PGW address.

[0026] Optionally, for each DNN, the UDM or HSS correspondingly stores one DNN interworking information.

[0027] Optionally, the second transmitting module further includes a fifth transmitting unit configured to transmit second indication information to the second AMF in response to an inter-AMF mobility event occurring in which the UE is transitioned from the first AMF to the second AMF, wherein the second indication information is used to indicate that DNN interworking information has been stored, and the DNN interworking information includes the DNN information and at least one of an SMF address or a PGW address.

[0028] According to another aspect of an embodiment of the present disclosure, there is further provided an indication information sending system, including: a first AMF configured to send first indication information to a target network element; and a target network element configured to determine, according to the first indication information, whether a PDU session can interwork with a target network system.

[0029] Optionally, the target network element includes an SMF, and in response to the first AMF receiving a message requesting that the UE establish a PDU session, the first AMF is further configured to send a PDU session establishment request to the SMF, the PDU session establishment request carrying first indication information, and the SMF is configured to determine whether the PDU session is capable of interworking with the target network system according to the first indication information carried in the PDU session establishment request.

[0030] Optionally, in response to the first AMF determining that a status parameter of the PDU session has changed, the first AMF is further configured to send a PDU session modification request to the SMF, the PDU session modification request carrying first indication information, and the SMF is configured to determine, according to the first indication information carried in the PDU session modification request, whether the PDU session whose status parameter has changed is capable of interworking with the target network system.

[0031] Optionally, the system includes a second AMF, and in response to an inter-AMF mobility event occurring in which the UE is migrated from the first AMF to the second AMF, the first AMF is further configured to send first indication information to the second AMF, and the second AMF is configured to determine, according to the first indication information, whether a PDU session under the first AMF is capable of interworking with a target network system.

[0032] According to another aspect of an embodiment of the present disclosure, there is further provided an indication information sending system, including: a first AMF configured to send second indication information to a second target network element, where the second indication information carries DNN interworking information; and the second target network element configured to store the DNN interworking information according to the second indication information.

[0033] Optionally, the second target network element includes a UDM or an HSS, and the UDM or the HSS is configured to store DNN interworking information according to the second indication information, and the DNN interworking information includes the DNN information and at least one of an SMF address or a PGW address.

[0034] Optionally, the second target network element includes a second AMF, and in response to an inter-AMF mobility event occurring in which the UE is transitioned from the first AMF to the second AMF, the first AMF is further configured to send second indication information to the second AMF, the second indication information carries DNN interworking information, and the second AMF is configured to store the DNN interworking information according to the second indication information, and the DNN interworking information includes the DNN information and at least one of an SMF address or a PGW address.

[0035] According to another aspect of an embodiment of the present disclosure, there is also provided a storage medium storing a computer program that, when executed, is configured to perform the steps of any one of the aforementioned method embodiments.

[0036] According to another aspect of an embodiment of the present disclosure, there is further provided an electronic device, the electronic device including a memory and a processor, the memory storing a computer program, the processor configured to execute the computer program and to perform the steps of any one of the aforementioned method embodiments.

[0037] Through the solution provided in the embodiment of the present disclosure, a first AMF sends first indication information to a first target network element, and the first indication information is used to indicate whether a PDU session is capable of interworking with a target network system, so that the first target network element can grasp the PDU session that is capable of interworking with the target network system, and thus select a corresponding PDU session, thereby solving the problem that interworking across network systems for UEs cannot be implemented in the related technical field, and implementing inter-network system interworking for UEs between different network systems.

[0038] The drawings described herein are used to provide further understanding of the present application and form a part of the present application. The exemplary embodiments and the description thereof are used to explain the present application and are not intended to limit the present application in any inappropriate manner. The present invention provides, for example, the following. (Item 1) An indication information transmission method, Sending first indication information to a first target network element by a first access and mobility management function (AMF), the first indication information being used to indicate whether a packet data unit (PDU) session is capable of interworking with the target network system; A method comprising: (Item 2) Sending the first indication information to the first target network element by the first AMF includes: In response to the first AMF receiving a request message requesting that a user equipment (UE) establish the PDU session, the first AMF sends a PDU session establishment request to a session management function (SMF), wherein the PDU session establishment request carries the first indication information, and the first indication information is used to indicate whether the PDU session is capable of interworking with the target network system. The method according to item 1, comprising: (Item 3) Sending the first indication information to the first target network element by the first AMF includes: In response to the first AMF determining that a status parameter of the PDU session has changed, the first AMF sends a PDU session modification request to the SMF, wherein the PDU session modification request carries the first indication information, and the first indication information is used to indicate whether the PDU session is capable of interworking with the target network system. 3. The method according to item 1 or 2, comprising: (Item 4) Sending the first indication information to the first target network element by the first AMF includes: In response to an inter-AMF mobility event occurring in which a UE is transitioned from the first AMF to a second AMF, the first AMF sends the first indication information to the second AMF, and the first indication information is used to indicate whether a PDU session of the UE under the first AMF is capable of interworking with the target network system. The method according to item 1, comprising: (Item 5) The sending of the first indication information to the second AMF by the first AMF includes: Sending a UE context message to the second AMF by the first AMF, where the UE context message carries the first indication information. Item 5. The method according to item 4, comprising: (Item 6) Sending the first indication information to the first target network element by the first AMF includes: Sending the first indication information to an SMF by the first AMF, wherein the first indication information is used to indicate whether the PDU session under the SMF is capable of interworking with the target network system; and In response to an inter-AMF mobility event occurring in which a UE is migrated from the first AMF to a second AMF, sending a message by the SMF to the second AMF, the message being used to indicate whether the PDU session under the SMF is capable of interworking with the target network system; The method according to item 1, comprising: (Item 7) The inter-AMF mobility event is At least one of a connected state handover process or an idle state mobility process 5. The method according to any one of items 1 to 4, comprising: (Item 8) 5. The method of claim 1, wherein the target network system is a fourth generation (4G) network system. (Item 9) An indication information transmission method, Sending second indication information to a second target network element by a first access and mobility management function (AMF), the second indication information being used to indicate whether the second target network element stores data network name (DNN) interworking information; A method comprising: (Item 10) sending, by the first AMF, the second indication information to the second target network element; Sending the second indication information by the first AMF to a Unified Data Management (UDM) or a Home Subscription Server (HSS), the second indication information being used to indicate that the UDM or the HSS stores the DNN interworking information, the DNN interworking information including DNN information and at least one of a Session Management Function (SMF) address or a Packet Data Unit (PDU) Gateway (PGW) address. Item 10. The method according to item 9, comprising: (Item 11) Item 11. The method of item 9 or 10, wherein for each DNN, the UDM or the HSS stores one piece of DNN interworking information corresponding to the DNN. (Item 12) sending, by the first AMF, the second indication information to the second target network element; In response to an inter-AMF mobility event occurring in which a user equipment (UE) is transitioned from the first AMF to a second AMF, the first AMF sends the second indication information to the second AMF, the second indication information being used to indicate that the DNN interworking information has been stored, and the DNN interworking information includes DNN information and at least one of an SMF address or a PGW address. Item 10. The method according to item 9, comprising: (Item 13) The inter-AMF mobility event is Item 11. The method of item 10, including at least one of a connected state handover process or an idle state mobility process. (Item 14) An indication information transmitting device applied to a first access and mobility management function (AMF), a first transmitting module configured to transmit first indication information to a target network element, the first indication information being used to indicate whether a packet data unit (PDU) session is capable of interworking with the target network system; An apparatus comprising: (Item 15) The first transmitting module: a first transmitting unit configured to transmit a PDU session establishment request to a session management function (SMF) in response to the first AMF receiving a PDU session request message from a user equipment (UE) for establishing the PDU session, the PDU session establishment request carrying the first indication information, the first indication information being used to indicate whether the PDU session is capable of interworking with the target network system; Item 15. The device according to item 14, comprising: (Item 16) The first transmitting module further comprises: a second transmitting unit configured to transmit a PDU session modification request to an SMF in response to the first AMF determining that a status parameter of the PDU session has changed, the PDU session modification request carrying the first indication information, the first indication information being used to indicate whether the PDU session is capable of interworking with the target network system; Item 16. The device according to item 14 or 15, comprising: (Item 17) The first transmitting module: a third transmitting unit configured to transmit the first indication information to the second AMF in response to an occurrence of an inter-AMF mobility event in which a UE is transitioned from the first AMF to a second AMF, the first indication information being used to indicate whether a PDU session of the UE under the first AMF is capable of interworking with the target network system; Item 15. The device according to item 14, comprising: (Item 18) An indication information transmitting device applied to a first access and mobility management function (AMF), a second sending module configured to send second indication information to a second target network element, the second indication information being used to indicate that the second target network element stores data network name (DNN) interworking information; The present device comprises: (Item 19) The second transmitting module: a fourth sending unit configured to send the second indication information to a Unified Data Management (UDM) or a Home Subscription Server (HSS), the second indication information being used to indicate that the UDM or the HSS has stored the DNN interworking information, the DNN interworking information including DNN information and at least one of a Session Management Function (SMF) address or a Packet Data Unit (PDU) Gateway (PGW) address. Item 19. The device according to item 18, comprising: (Item 20) 20. The device of item 18 or 19, wherein for each DNN, the UDM or the HSS stores one piece of DNN interworking information corresponding to the DNN. (Item 21) The second transmitting module: a fifth sending unit configured to send the second indication information to the second AMF in response to an occurrence of an inter-AMF mobility event in which the UE is transitioned from the first AMF to a second AMF, the second indication information being used to store the DNN interworking information, the DNN interworking information including DNN information and at least one of an SMF address or a PGW address. Item 19. The device according to item 18, comprising: (Item 22) An indication information transmission system, a first Access and Mobility Management Function (AMF) configured to send first indication information to the target network element; a target network element configured to determine whether a packet data unit (PDU) session is capable of interworking with a target network system according to the first indication information; A system comprising: (Item 23) the target network element comprises a Session Management Function (SMF); The first AMF is configured to send a PDU session setup request to the SMF in response to receiving a PDU session setup request message from a user equipment (UE), the PDU session setup request carrying the first indication information; The SMF is configured to determine whether the PDU session can interwork with the target network system according to the first indication information carried in the PDU session establishment request. Item 23. The system according to item 22. (Item 24) The first AMF is further configured to, in response to determining that a status parameter of the PDU session has changed, send a PDU session modification request to the SMF, the PDU session modification request carrying the first indication information; The SMF is further configured to determine, according to the first indication information carried in the PDU session modification request, whether the PDU session whose status parameter has changed can interwork with the target network system. 24. The system according to item 22 or 23. (Item 25) the target network element comprises a second AMF; The first AMF is configured to send the first indication information to the second AMF in response to an inter-AMF mobility event occurring in which the UE is transitioned from the first AMF to the second AMF; The second AMF is configured to determine, according to the first indication information, whether the PDU session under the first AMF can interwork with the target network system; Item 23. The system according to item 22. (Item 26) An indication information transmission system, a first Access and Mobility Management Function (AMF) configured to send second indication information to a second target network element, the second indication information carrying Data Network Name (DNN) interworking information; Equipped with The second target network element is configured to store the DNN interworking information according to the second indication information. (Item 27) 27. The system of claim 26, wherein the second target network element comprises a unified data management (UDM) or a home subscription server (HSS), and the UDM or the HSS is configured to store the DNN interworking information according to the second indication information, and the DNN interworking information includes DNN information and at least one of a session management function (SMF) address or a packet data unit (PDU) gateway (PGW) address. (Item 28) the second target network element comprises a second AMF; The first AMF is configured to send the second indication information to the second AMF in response to an inter-AMF mobility event occurring in which a user equipment (UE) is transitioned from the first AMF to the second AMF, wherein the second indication information carries the DNN interworking information; The second AMF is configured to store the DNN interworking information according to the second indication information, and the DNN interworking information includes DNN information and at least one of an SMF address or a PGW address; Item 27. The system according to item 26. (Item 29) 14. A storage medium storing a computer program, the computer program being configured, when executed, to perform the method according to any one of items 1-13. (Item 30) 14. An electronic device comprising a memory and a processor, wherein the memory is configured to store a computer program, and the processor is configured to execute the computer program and to implement the method according to any one of items 1-13. [Brief explanation of the drawings]

[0039] [Figure 1] FIG. 1 illustrates a network architecture in the related art that satisfies bidirectional interworking between 4G and 5G. [Figure 2] FIG. 2 is a block diagram illustrating a hardware structure of a mobile terminal for an indication information sending method according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a flowchart of an indication information transmitting method according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a flowchart of an indication information transmitting method according to an embodiment of the present disclosure. [Figure 5]FIG. 5 is a structural block diagram of an indication information sending device according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is a structural block diagram of an indication information sending device according to an embodiment of the present disclosure. [Figure 7] FIG. 7 is a structural block diagram of an indication information sending system according to an embodiment of the present disclosure. [Figure 8] FIG. 8 is a structural block diagram of an indication information sending system according to an embodiment of the present disclosure. [Figure 9] FIG. 9 is a flowchart of a PDU session setting method according to a first embodiment of the present disclosure. [Figure 10] FIG. 10 is a flowchart of a PDU session modification method according to a first embodiment of the present disclosure. [Figure 11] FIG. 11 is a flowchart of an inter-AMF mobility process according to a second embodiment of the present disclosure. [Figure 12] FIG. 12 is a flowchart of an inter-AMF mobility process according to a third embodiment of the present disclosure. [Figure 13] FIG. 13 is a flowchart illustrating an interworking information transmission process according to a fourth embodiment of the present disclosure. [Figure 14] FIG. 14 is a flowchart illustrating an interworking information transmission process according to a fifth embodiment of the present disclosure. [Figure 15] FIG. 15 is a flowchart illustrating an interworking information transmission process according to a sixth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0040] Hereinafter, the present application will be described in detail in conjunction with the embodiments with reference to the drawings. It should be noted that, if not contradictory, the embodiments in the present application and the features therein may be combined with each other.

[0041] It should be noted that terms such as "first" and "second" in the description, claims, and drawings of this application are used to distinguish between similar objects and are not necessarily used to describe a particular order or sequence.

[0042] Figure 1 illustrates a network architecture that satisfies bidirectional interworking between 4G and 5G in the related art. One important feature is that the architecture is compatible with both 4G and 5G architectures. Another important feature is that the PGW-C and SMF are co-located, the PDN Gateway User Plane (PGW-U) and User Plane Function (UPF) are co-located, the Policy Control Function (PCF) and Policy and Charging Control Function (PCRF) are co-located, and the UE user plane is always anchored on the UPF or PGW-U. The N26 interface may or may not be deployed between the AMF and MME. The system has different flows to handle the cases where the N26 interface is deployed and where the N26 interface is not deployed.

[0043] The network elements in the architecture are illustrated below.

[0044] User Equipment (UE): The UE mainly accesses a 4G or 5G network and obtains services through the wireless air interface, and the UE performs information interaction with a base station through the air interface and through a non-access stratum (NAS) signaling and management entity of the core network (when the UE accesses a 4G network, the UE interacts with the MME, while when the UE accesses a 5G network, the UE interacts with the AMF and SMF).

[0045] 4G Base Station (Radio Access Network (RAN), E-NodeB (eNB)): The 4G base station is responsible for air interface resource scheduling and air interface connection management of the network to which the UE has access.

[0046] 5G Base Station (Next Generation Radio Access Network (NG RAN), Radio Access Network): A 5G base station is responsible for air interface resource scheduling and air interface connection management of the network to which the UE accesses. An NG RAN base station may employ New Radio (NR) Access Technology (gNB) or enhanced Long Term Evolution (eLTE) technology.

[0047] Mobility Management Entity (MME): The MME is a 4G core network control plane entity, mainly responsible for user authentication, authorization and subscription check, user mobility management, PDN connection and bearer maintenance, and paging trigger in user idle state.

[0048] Serving Gateway (GW): The serving GW is a 4G core network user plane functional entity, which is mainly responsible for interaction with the PDN GW in the case of roaming.

[0049] Packet Data Network Gateway (PDN GW): The PDN GW is a 4G core network user plane functional entity through which a UE accesses the PDN network. The access point is responsible for user Internet Protocol (IP) address allocation, network-triggered bearer setup, modification, and deletion, and QoS control and charging. In the 3rd Generation Partnership Project (3GPP) system, it is the user anchor point where IP addresses are ensured to remain unchanged and service continuity is ensured. In the control and forwarding separated architecture, the P-GW is further divided into two parts: a control entity PGW-C and a user plane entity PGW-U, where the PGW-C is responsible for signaling control and the PGW-U is responsible for IP forwarding.

[0050] Home Subscription Server (HSS): The HSS stores the user's subscription information. Policy and Charging Control Function (PCRF): The PCRF is responsible for formulating policy and charging rules, and provides network control rules based on service data flows, including service data flow detection, gating control, Quality of Service (QoS) control, data flow-based charging rules, and the like, and sends the policy and charging rules formulated by the PCRF itself to the P-GW for execution.

[0051] The control functions of a 5G network are illustrated below.

[0052] Session Management Function (SMF): The SMF interacts with the UE and is mainly responsible for handling user PDU session establishment, modification, and deletion requests, selecting a User Plane Function (UPF), setting up a user plane connection between the UE and the UPF, and determining the QoS parameters of the session with the PCF.

[0053] Access and Mobility Control Function (AMF): The AMF is a common control plane function in the core network; a user has only one AMF, which is responsible for user mobility management, including user authentication, authorization, and subscription checks to ensure that the user is a legitimate user, location registration and temporary identity allocation, selecting an appropriate SMF when the user initiates a PDU connection setup request, forwarding NAS signaling between the UE and the SMF, and forwarding Access Stratum (AS) signaling between the base station and the SMF.

[0054] User Plane Function (UPF): The UPF provides user plane processing functions, including data forwarding and QoS enforcement, and also provides a user plane anchor point to ensure service continuity when users move.

[0055] Policy Control Function (PCF): The PCF provides resource authorization functionality and is very similar to the PCRF in the 4G era.

[0056] Unified Data Manager (UDM): The UDM stores user subscription data and is similar to the HSS in the 4G era.

[0057] In order to ensure the continuity of the UE handover between the 4G and 5G systems, when the UE establishes a PDU session in the 5G system and the UE moves to the 4G system, a corresponding PDN connection is created.When the UE establishes a PDU session in the 4G system and the UE moves to the 5G system, a corresponding PDN connection is also created.

[0058] When a UE requests to set up a PDU session in a 5G system, the UE carries a DNN parameter to indicate the data network to which the PDU session is connected, while the UE allocates a unique PDU session identifier (ID) within the UE and sends the unique PDU session ID to the network. When a UE sets up a PDU connection in a 4G system, the UE carries an APN parameter to indicate the data network to which the PDU connection is connected. To ensure interworking for UEs between 4G and 5G, there is a mapping relationship between the APN and the PDN.

[0059] To implement seamless mobility (ie, the IP address remains unchanged), two different scenarios exist.

[0060] In a scenario where the N26 interface exists, when a UE sets up or modifies a PDU session in a 5G system, the network generates session parameters corresponding to the 4GPDN connection and sends the session parameters to the UE. When a UE sets up or modifies a PDU connection in a 4G system, the UE generates a corresponding PDU session ID and sends the PDU session ID to the SMF+PGW-C, and the SMF+PGW-C also generates session parameters corresponding to the 5G PDU session and sends the session parameters to the UE.

[0061] When a mobility process (handover or idle state mobility) between the 4G and 5G systems occurs for a UE, the target system generates a corresponding PDN connection / PDU session in the target system according to the session information created by the source system.

[0062] In a scenario where the N26 interface does not exist, when a UE establishes a PDU session in a 5G system, the SMF+PGW-C stores the DNN and PGW-C identification information (e.g., the PGW-C fully qualified domain name (FQDN)) corresponding to this PDU session in the context of this session of the UE in the UDM or HSS. When the UE moves to a 4G system, the UE requests to re-establish a PDN connection, indicating that this session is an existing session and carrying PDU session ID information. The MME obtains the APN (mapped from the DNN) and the PGW-C identification information from the UDM or HSS, matches the APN and PGW-C identification information with the APN received from the UE, and sends a session establishment request to the PGW corresponding to the PGW-C identification information (through the S-GW). After receiving the session establishment request, the SMF+PGW-C finds the corresponding session according to the PDU session ID in this request and completes the re-establishment on the 4G side.

[0063] When the UE establishes a PDU connection in the 4G system, the SMF+PGW-C stores the APN corresponding to this PDU connection and the PGW-C identification information (such as the PGW-C FQDN) in the UDM or HSS. When the UE moves to the 5G system, the UE requests to re-establish the PDU session, and the principle is similar to that of the restoration process on the 4G side.

[0064] Because the SMF and PGW-C are co-located in a network element, selecting different SMF+PGW-C in the 5G system means that after the session is migrated to the 4G system, multiple different PDN connections under the same APN will have different PGWs, which goes against the principle of the 4G system.

[0065] In the above scenario, to ensure the uniqueness of the PGW in the 4G system, the 5G system must determine that a PDU session under one SMF can interwork with the 4G system, while a PDU session under another SMF cannot interwork with the 4G system.

[0066] Therefore, two problems exist. The first problem is how the SMF knows whether a PDU session established by a UE on this SMF can perform interworking with a 4G system. When a network is deployed using an N26 interface, the SMF can determine whether a PDU session can perform interworking through whether the AMF allocates an EBI, but when a network is not deployed using an N26 interface, the SMF cannot know about it. After moving to a 4G system, when the SMF / PGW receives a re-establishment request sent by the MME, it does not know whether it supports interworking, and the SMF / PGW will probably refuse to set up the PDU connection.

[0067] The second problem is how the UDM or HSS handles the PGW identity. For example, in a 5G system, a UE establishes two PDU sessions by using DNN1. The SMF of PDU session 1 is SMF_A+PGW-C_A, and the SMF of PDU session 2 is SMF_B+PGW-C_B. When the UE moves to a 4G system, when the UDM or HSS sends subscription data to the MME, only one PGW identity is sent for APN1 mapped by DNN1. In this case, the UDM or HSS cannot determine the PGW identity to send to the MME to let the MME know the PGW to which the PDN connection can be established.

[0068] To solve the above problems, the embodiments of the present disclosure provide the following specific implementations.

[0069] Embodiment 1 The method embodiment provided in Embodiment 1 of the present application can be implemented in a mobile terminal, a computer terminal, or other similar computing device. This embodiment will be described by using an example in which the method is executed in a mobile terminal. FIG. 2 is a block diagram showing a hardware structure of a mobile terminal for an indication information transmission method according to an embodiment of the present disclosure. As shown in FIG. 2, the mobile terminal 10 may include one or more (only one is shown in FIG. 2) processors 102 (the processors 102 may include, but are not limited to, microprocessors such as microcontroller units (MCUs), programmable logic devices such as field programmable gate arrays (FPGAs), and other processing devices) and a memory 104 used to store data. Optionally, the mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. It should be understood by those skilled in the art that the structure shown in FIG. 2 is merely illustrative and is not intended to limit the structure of the mobile terminal. For example, the mobile terminal 10 may further include more or fewer components than those shown in FIG. 2, or may have a different configuration than that shown in FIG.

[0070] The memory 104 may be configured to store computer programs, such as software programs and modules of application software, e.g., a computer program corresponding to the indication information transmission method in an embodiment of the present disclosure. The processor 102 executes the computer programs stored in the memory 104 to perform various functional applications and data processing, i.e., to implement the methods described above. The memory 104 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some embodiments, the memory 104 may also include memory located remotely from the processor 102. These remote memories may be connected to the mobile terminal 10 via a network. Examples of such networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0071] The transmission device 106 is configured to receive or transmit data over a network. A specific example of such a network may include a wireless network provided by the mobile terminal 10's communications provider. In one embodiment, the transmission device 106 includes a network interface controller (NIC) that may be connected to other network devices via a base station and thus communicate with the Internet. In one embodiment, the transmission device 106 may be a radio frequency (RF) module configured to communicate with the Internet in a wireless manner.

[0072] To solve the first problem described above, an embodiment of the present disclosure provides an indication information transmission method. Figure 3 is a flowchart of the indication information transmission method according to an embodiment of the present disclosure. As shown in Figure 3, the method includes the steps described below.

[0073] In step S301, the first AMF sends first indication information to the first target network element, and the first indication information is used to indicate whether the PDU session can perform interworking within the target network system.

[0074] Through the above method, the first AMF sends first indication information to the first target network element, and the first indication information is used to indicate whether the PDU session can perform interworking with the target network system, so that the first target network element can know which PDU session can perform interworking with the target network system, and thus selects the corresponding PDU session, thereby solving the problem that the SMF or PGW does not know whether it can support interworking, and therefore cross-network system interworking for a UE is implemented in the related technical field and cannot be implemented.

[0075] It should be noted that the target network system in this specification may be a 4G system, a 3G system, or a 5G system, or may be any other network system that needs to implement cross-network interworking, which is not limited in the embodiments of the present disclosure.

[0076] Optionally, the above step S301 may be implemented in the following manner: in response to the first AMF receiving a message requesting that the UE establish a PDU session, the first AMF sends a PDU session establishment request to the SMF, the PDU session establishment request carries first indication information, and the first indication information is used to indicate whether the PDU session can perform interworking within the target network system.

[0077] It should be noted that the configuration request message is sent from the first AMF to the SMF, and in the PDU session configuration process, the first indication information carried in the configuration request message can be used to indicate whether the currently established PDU session can perform interworking within the target network system.

[0078] Optionally, the above step S301 may be implemented in the following manner: in response to the first AMF determining that a status parameter of the PDU session has changed, the first AMF sends a PDU session modification request to the SMF, the PDU session modification request carries first indication information, and the first indication information is used to indicate whether the PDU session can perform interworking within the target network system.

[0079] It should be noted that the modification request message is sent from the first AMF to the SMF, and in the PDU session modification process, the first indication information carried in the modification request message may be used to indicate whether the currently modified PDU session can perform interworking in the target network system. "The status parameter has changed" may mean that the state of the current PDU session has changed from a state in which interworking can be performed in the target network system to a state in which interworking cannot be performed in the target network system, or that the state of the current PDU session has changed from a state in which interworking cannot be performed in the target network system to a state in which interworking can be performed in the target network system.

[0080] Optionally, the above step S301 may further be implemented in the following manner: in response to an inter-AMF mobility event occurring in which a UE is migrated from a first AMF to a second AMF, the first AMF sends first indication information to the second AMF, and the first indication information is used to indicate whether a PDU session of the UE under the first AMF can perform interworking within the target network system.

[0081] It should be noted that the inter-AMF mobility event in this specification includes at least one of a connected state handover process or an idle state mobility process. In this case, the message carried in the first indication information may be whether some or all of the PDU sessions belonging to the same UE under the first AMF can perform interworking in the target network system.

[0082] Optionally, the step of the first AMF sending the first indication information to the second AMF may be implemented in the following manner: the first AMF sends a UE context message to the second AMF, and the UE context message carries the first indication information.

[0083] Optionally, the above step S301 may be further implemented in the following manner: the first AMF sends first indication information to the SMF, and the first indication information is used to indicate whether a PDU session under the SMF can perform interworking within the target network system; and in response to an inter-AMF mobility event occurring in which the UE is migrated from the first AMF to the second AMF, the SMF sends a message to the second AMF, and the message is used to indicate whether a PDU session under the SMF can perform interworking within the target network system.

[0084] It should be noted that the process herein can be understood as follows: when a mobility event occurs, the first AMF does not directly send the first indication information to the second AMF, but sends the first indication information to the SMF, and the SMF can indicate whether the PDU session under the current SMF can perform interworking within the target network system by sending a message to the second AMF.

[0085] To solve the second problem described above, an embodiment of the present disclosure provides an indication information transmission method. Figure 4 is a flowchart of the indication information transmission method according to an embodiment of the present disclosure. As shown in Figure 4, the method includes the steps described below.

[0086] In step S401, the first AMF sends second indication information to the second target network element.

[0087] Through the above method, the first AMF sends second indication information to the second target network element, and the second indication information is used to indicate that the second target network element has stored the DNN interworking information, thereby preventing the UDM or HSS from determining what to send to the MME to let the MME know the PGW to which the PDU connection can be re-established, thus solving the problem that cross-network system interworking for the UE is implemented in the related technical field and cannot be implemented between different network systems.

[0088] Optionally, step S401 may be implemented in the following manner: the first AMF sends second indication information to the UDM or HSS, and the second indication information is used to indicate that the UDM or HSS has stored DNN interworking information, and the DNN interworking information includes the DNN information and at least one of the SMF address or the PGW address.

[0089] Optionally, for each DNN, the UDM or HSS stores one DNN interworking information corresponding to the DNN. In the above, it can be understood that each DNN has an independent message for storing corresponding interworking information, for example, DNN1 corresponds to multiple SMF / PGWs, but only SMF1 and / or PGW1 may support interworking across network systems, in which case the stored DNN interworking information may include (DNN1, SMF1) or (DNN1, PGW1) or (DNN1, SMF1, PGW1).

[0090] Optionally, the above step S401 may be implemented in the following manner: in response to an inter-AMF mobility event occurring in which a UE is migrated from a first AMF to a second AMF, the first AMF sends second indication information to the second AMF, the second indication information is used to indicate that DNN interworking information has been stored, and the DNN interworking information includes the DNN information and at least one of an SMF address or a PGW address.

[0091] Similarly, the inter-AMF mobility event in this specification includes at least one of a connected state handover process or an idle state mobility process. In this case, the DNN interworking information carried in the second indication information may be part or all of the DNN interworking information belonging to the same UE under the first AMF.

[0092] Optionally, the step of the first AMF sending the second indication information to the second AMF may be implemented in the following manner: the first AMF sends a UE context message to the second AMF, and the UE context message carries the second indication information.

[0093] Embodiment 2 In this embodiment, an indication information transmitting device is further provided. The device is configured to implement the above-described embodiments and preferred implementations. The contents described will not be repeated. As used below, the term "module" may refer to software, hardware, or a combination thereof capable of implementing a predetermined function. Although the device described below in this embodiment is implemented by software, implementation by hardware or a combination of software and hardware is also possible and conceivable.

[0094] According to another aspect of an embodiment of the present disclosure, there is further provided an indication information sending device, which is applied to a first AMF and configured to implement the above method. Figure 5 is a structural block diagram of the indication information sending device according to an embodiment of the present disclosure. As shown in Figure 5, the device includes a first sending module 50 configured to send first indication information to a target network element, where the first indication information is used to indicate whether a PDU session can perform interworking within the target network system.

[0095] Through the above device, the problem that the SMF or PGW does not know whether it can support interworking, and therefore interworking across network systems for UEs cannot be implemented in the related technical field can be solved, and cross-network system interworking for UEs between different network systems can be implemented.

[0096] Optionally, the first sending module 50 includes a first sending unit configured to send a PDU session setup request to the SMF in response to the first AMF receiving a message requesting that the UE set up a PDU session, the PDU session setup request carrying first indication information, which is used to indicate whether the PDU session can perform interworking within the target network system.

[0097] Optionally, the first transmitting module 50 further includes a second transmitting unit configured to transmit a PDU session modification request to the SMF in response to the first AMF determining that a status parameter of the PDU session has changed, the PDU session modification request carrying first indication information, which is used to indicate whether the PDU session can perform interworking within the target network system.

[0098] Optionally, the first transmitting module 50 further includes a third transmitting unit configured to transmit first indication information to the second AMF in response to an inter-AMF mobility event occurring in which the UE is transitioned from the first AMF to the second AMF, and the first indication information is used to indicate whether a PDU session of the UE under the first AMF can perform interworking within the target network system.

[0099] According to another aspect of an embodiment of the present disclosure, an indication information sending device is further provided. The device is applied to a first AMF and configured to implement the above method. Figure 6 is a structural block diagram of the indication information sending device according to an embodiment of the present disclosure. As shown in Figure 6, the device includes a second sending module 60 configured to send second indication information to a second target network element, where the second indication information is used to indicate that the second target network element has stored DNN interworking information.

[0100] Through the above device, the first AMF sends second indication information to the second target network element, and the second indication information is used to indicate that the second target network element has stored the DNN interworking information, thereby solving the problem that the UDM or HSS cannot determine what to send to the MME to let the MME know the PGW to which the PDN connection can be re-established, and therefore cross-network system interworking for the UE is implemented in the related technical field and cannot implement cross-network system interworking for the UE between different network systems.

[0101] Optionally, the second sending module 60 includes a fourth sending unit configured to send second indication information to the UDM or the HSS, where the second indication information is used to indicate that the UDM or the HSS has stored DNN interworking information, and the DNN interworking information includes the DNN information and at least one of the SMF address or the PGW address.

[0102] Optionally, for each DNN, the UDM or HSS stores one piece of DNN interworking information corresponding to the DNN.

[0103] Optionally, the second sending module 60 further includes a fifth sending unit configured to send second indication information to the second AMF in response to an inter-AMF mobility event occurring in which the UE is transitioned from the first AMF to the second AMF, the second indication information being used to indicate that DNN interworking information has been stored, and the DNN interworking information includes the DNN information and at least one of an SMF address or a PGW address.

[0104] According to another aspect of an embodiment of the present disclosure, there is further provided an indication information transmission system. The system includes the above-described apparatus and is used to implement the above-described method. Figure 7 is a structural block diagram of the indication information transmission system according to an embodiment of the present disclosure. As shown in Figure 7, the system includes a first AMF 70 configured to transmit first indication information to a target network element, and a first target network element 72 configured to determine whether a PDU session can perform interworking within the target network system according to the first indication information.

[0105] Through the above system, the problem that the SMF or PGW does not know whether it can support interworking, and therefore interworking across network systems for a UE cannot be implemented in the related technical field, can be solved, and cross-network system interworking for a UE between different network systems can be implemented.

[0106] Optionally, the first target network element 72 includes an SMF, and in response to the first AMF receiving a message requesting that the UE establish a PDU session, the first AMF is further configured to send a PDU session establishment request to the SMF, the PDU session establishment request carrying first indication information, and the SMF is configured to determine, according to the first indication information, whether the PDU session can perform interworking within the target network system.

[0107] Optionally, in response to the first AMF determining that a status parameter of the PDU session has changed, the first AMF is further configured to send a PDU session modification request to the SMF, the PDU session modification request carrying first indication information, and the SMF is configured to determine whether the PDU session whose status parameter has changed can perform interworking within the target network system.

[0108] Optionally, the first target network element 72 further includes a second AMF, and in response to an inter-AMF mobility event occurring in which the UE is migrated from the first AMF to the second AMF, the first AMF is further configured to send second indication information to the second AMF, and the second AMF is configured to determine, according to the first indication information, whether a PDU session under the first AMF can perform interworking within the target network system.

[0109] According to another aspect of an embodiment of the present disclosure, an indication information transmission system is further provided. The system includes the above-described device and is used to implement the above-described method. Figure 8 is a structural block diagram of the indication information transmission system according to an embodiment of the present disclosure. As shown in Figure 8, the system includes: a first AMF 70 configured to transmit second indication information to a second target network element, where the second indication information carries DNN interworking information; and a second target network element 80 configured to store the DNN interworking information according to the second indication information.

[0110] Through the above system, the first AMF sends second indication information to the second target network element, and the second indication information is used to indicate that the second target network element has stored the DNN interworking information, thereby preventing the UDM or HSS from determining what to send to the MME to let the MME know the PGW to which the PDN connection can be re-established, thus solving the problem that cross-network system interworking for the UE cannot be implemented between different network systems, which is implemented in the related technical field.

[0111] Optionally, the second target network element includes a UDM or an HSS, and the UDM or the HSS is configured to store DNN interworking information according to the second indication information, and the DNN interworking information includes the DNN information and at least one of an SMF address or a PGW address.

[0112] Optionally, the second target network element includes a second AMF, and in response to an inter-AMF mobility event occurring in which the UE is transitioned from the first AMF to the second AMF, the first AMF is further configured to send second indication information to the second AMF, the second indication information carries DNN interworking information, and the second AMF is configured to store the DNN interworking information according to the second indication information, and the DNN interworking information includes the DNN information and at least one of an SMF address or a PGW address.

[0113] Embodiment 3 To better understand the solutions in the above embodiments, the embodiments of the present disclosure provide the following examples to illustrate a specific application scenario by using an example in which a UE moves from a 5G system to a 4G system.

[0114] Example 1 This embodiment proposes a situation in which the AMF informs the SMF whether the UE's PDU session on this SMF can perform interworking with the 4G system during the PDU session establishment and modification process.

[0115] 9 is a flowchart of a PDU session setting method according to the first embodiment of the present disclosure. As shown in FIG. 9, the setting process includes the steps described below.

[0116] In step 200, the UE requests to set up a PDU session.

[0117] In step 201, the AMF sends a PDU session establishment request to the SMF, and the PDU session establishment request carries indication information indicating whether the PDU session can perform interworking with a 4G system.

[0118] In step 202, the PDU session setup process is completed.

[0119] 10 is a flowchart of a PDU session modification method according to the first embodiment of the present disclosure. As shown in FIG. 10, the modification process includes the steps described below.

[0120] In step 300, the UE sets up a PDU session, and the status of the PDU session can be such that the PDU session can perform interworking with the 4G system or such that the PDU session cannot perform interworking.

[0121] In step 301, the AMF determines that the status of the PDU session's interworking with 4G has changed.

[0122] In step 302, the AMF sends a PDU session modification request to the SMF, where the PDU session modification request carries indication information indicating whether the PDU session can perform interworking with the 4G system, for example, the PDU session could not perform interworking, the status of the PDU session is currently in a state where the PDU session can perform interworking, or the PDU session could perform interworking, but the status of the PDU session is currently in a state where the PDU session cannot perform interworking.

[0123] In step 303, the PDU session modification process is completed.

[0124] The above processes may be combined in various ways.

[0125] In mode 1, when a PDU session is set up, the SMF and AMF always support interworking by default, and when the interworking status changes, the SMF needs to be notified (i.e., only the steps in Figure 10 need to be performed).

[0126] In Mode 2, when a PDU session is set up, interworking is not supported by default, and the SMF needs to be notified when the interworking status changes (i.e., only the steps in Figure 10 need to be performed).

[0127] In format 3, whether interworking is supported is explicitly indicated whenever a PDU session is set up, and the SMF needs to be notified when the interworking status changes (i.e., only the steps in Figures 9 and 10 need to be performed).

[0128] Example 2 In response to the occurrence of an inter-AMF mobility process, such as a connected state handover or idle state mobility process, the source AMF (which may correspond to the first AMF in the above embodiment) needs to send an indication to the target AMF (which may correspond to the second AMF in the above embodiment) indicating whether the PDU session supports interworking with 4G.

[0129] 11 is a flowchart of an inter-AMF mobility process according to a second embodiment of the present disclosure. As shown in FIG. 11, the mobility process includes the following steps:

[0130] In step 400, the UE sets up a PDU session, and the status of the PDU session can be such that the PDU session can perform interworking with the 4G system or such that the PDU session cannot perform interworking.

[0131] In step 401, the UE is in an inter-AMF mobility process, such as a connected state handover or idle state mobility process.

[0132] In step 402, the UE context sent by the source AMF to the target AMF carries an indication indicating whether the PDU session supports interworking with 4G, or carries an indication indicating whether the PDU session under a certain SMF supports interworking with 4G.

[0133] In step 403, the inter-AMF mobility process is completed.

[0134] Example 3 In response to the occurrence of an inter-AMF mobility process, such as a connected state handover or idle state mobility process, the SMF sends an indication to the target AMF indicating whether the PDU session supports interworking with 4G.

[0135] 12 is a flowchart of an inter-AMF mobility process according to a third embodiment of the present disclosure. As shown in FIG. 12, the mobility process includes the following steps:

[0136] In step 500, the UE establishes a PDU session, and the status of the PDU session can be such that the PDU session can perform interworking with the 4G system or such that the PDU session cannot perform interworking.

[0137] In step 501, the UE is in an inter-AMF mobility process, such as a connected state handover or idle state mobility process.

[0138] In step 502, the target AMF sends a PDU session update to the SMF.

[0139] In step 503, the SMF sends a PDU session update response to the target AMF, where the PDU session update response carries an indication of whether the PDU session supports interworking with 4G.

[0140] In step 504, the inter-AMF mobility process is completed.

[0141] Example 4 For each DNN for which a PDU session is established with the UE, the AMF stores interworking information in the UDM or HSS, modifies the interworking information, or deletes the interworking information from the UDM or HSS. The information includes the DNN, PGW identification information and / or SMF identification information, and may also include the corresponding access type. The information is not stored in each PDU session context on each UDM or HSS; independent 4G-5G interworking information exists for each DNN for the UE. When the UE moves to 4G, the UDM or HSS sends the APN and PGW identification information to the MME.

[0142] 13 is a flowchart illustrating an interworking information sending process according to Example 4 of the present disclosure. As shown in FIG. 13, the method includes the steps described below.

[0143] In step 600, a PDU session is established or modified for the UE.

[0144] In step 601, the AMF stores 4G-5G interworking information in a UDM or HSS, where the information includes a DNN, a corresponding PGW-C identity and / or an SMF identity and / or a corresponding access type (e.g., 3GPP access or non-3GPP access). When there is no PDU session supporting interworking, the AMF may delete the above-mentioned 4G-5G interworking information stored in the UDM or HSS. The information is not stored in each PDU session context of the UE in the UDM or HSS, and 4G-5G interworking information exists per DNN for the UE. When the UE has PUD sessions on multiple DNNs, the 4G-5G interworking information is stored in each DNN.

[0145] Example 5 In response to an inter-AMF mobility process, such as a connected state handover or idle state mobility process, the source AMF needs to send 4G-5G interworking information to the target AMF. The information includes the DNN, the corresponding PGW-C identity information and / or SMF identity information and / or the corresponding access type (e.g., 3GPP access or non-3GPP access).

[0146] 14 is a flowchart illustrating an interworking information sending process according to Example 5 of the present disclosure. As shown in FIG. 14, the method includes the steps described below.

[0147] In step 700, the UE establishes a PDU session, and the status of the PDU session can be such that the PDU session can perform interworking with a 4G system or such that the PDU session cannot perform interworking with 4G.

[0148] In step 701, the UE is in an inter-AMF mobility process, such as a connected state handover or idle state mobility process.

[0149] In step 702, the UE context sent by the source AMF to the target AMF carries 4G-5G interworking information. The information includes a DNN, a corresponding PGW-C identification information and / or an SMF identification information and / or a corresponding access type (e.g., 3GPP access or non-3GPP access).

[0150] In step 703, the inter-AMF mobility process is completed.

[0151] Example 6 The SMF stores the interworking information in the UDM or HSS, and the information includes the DNN, the PGW identity and / or the SMF identity, and may also include the corresponding access type. The information is not stored in the PDU session context in the UDM or HSS, and 4G-5G interworking information exists per DNN for the UE. When the UE moves to 4G, the UDM or HSS sends the APN and PGW identity to the MME.

[0152] 15 is a flowchart illustrating an interworking information sending process according to Example 6 of the present disclosure. As shown in FIG. 15, the method includes the steps described below.

[0153] In step 800, a PDU session is established or modified for a UE.

[0154] In step 801, the SMF stores 4G-5G interworking information in the UDM or HSS, where the information includes a DNN and corresponding PGW-C identification information and / or SMF identification information and / or corresponding access type (e.g., 3GPP access or non-3GPP access). The information is not stored in a PDU session context in the UDM or HSS, and independent 4G-5G interworking information exists for the DNN of the PDU session for the UE. When the UE has PUD sessions on multiple DNNs, the 4G-5G interworking information is stored in each DNN.

[0155] Embodiment 4 An embodiment of the present application further provides a storage medium, which stores a computer program configured, when executed, to perform the steps of any one of the method embodiments described above.

[0156] Optionally, in this embodiment, the storage medium may be configured to store a computer program for performing the following steps: S1, a step in which a first AMF sends first indication information to a first target network element, where the first indication information is used to indicate whether the PDU session can perform interworking within the target network system.

[0157] Optionally, the storage medium is further configured to store a computer program for performing the following steps: in response to the first AMF receiving a message requesting that the UE set up a PDU session, the first AMF sends a PDU session setup request to the SMF, the PDU session setup request carrying first indication information, and the first indication information is used to indicate whether the PDU session can perform interworking within the target network system.

[0158] Optionally, the storage medium is further configured to store a computer program for performing the following step: in response to the first AMF determining that a status parameter of the PDU session has changed, the first AMF sends a PDU session modification request to the SMF, wherein the PDU session modification request carries first indication information, and the first indication information is used to indicate whether the PDU session can perform interworking within the target network system.

[0159] Optionally, the storage medium is further configured to store a computer program for performing the following steps: in response to an inter-AMF mobility event occurring in which the UE is migrated from the first AMF to the second AMF, the first AMF sends first indication information to the second AMF, wherein the first indication information is used to indicate whether a PDU session of the UE under the first AMF can perform interworking within the target network system.

[0160] Optionally, in this embodiment, the storage medium may be configured to store a computer program for performing the following steps: S1, the first AMF sending second indication information to the second target network element, where the second indication information is used to indicate that the second target network element stores DNN interworking information.

[0161] Optionally, the storage medium is further configured to store a computer program for performing the following steps: the first AMF sending second indication information to the UDM or HSS, where the second indication information is used to indicate that the UDM or HSS has stored DNN interworking information, and the DNN interworking information includes the DNN information and at least one of an SMF address or a PGW address.

[0162] Optionally, the storage medium is further configured to store a computer program for performing the following steps: in response to an inter-AMF mobility event occurring in which the UE is migrated from the first AMF to the second AMF, the first AMF sends second indication information to the second AMF, the second indication information is used to indicate that the UDM or the HSS has stored DNN interworking information, and the DNN interworking information includes the DNN information and at least one of an SMF address or a PGW address.

[0163] Optionally, in this embodiment, the storage medium may include, but is not limited to, a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk, an optical disk, or another medium capable of storing a computer program.

[0164] An embodiment of the present application further provides an electronic device, the electronic device including a memory and a processor, the memory storing a computer program, the processor configured to execute the computer program and to perform the steps of any one of the aforementioned method embodiments.

[0165] Optionally, the electronic device may further include a transmission device and an input / output device, both of which are connected to the processor.

[0166] Optionally, in this embodiment, the processor may be configured through a computer program to perform the following steps:

[0167] In S1, the first AMF sends first indication information to the target network element, and the first indication information is used to indicate whether the PDU session can perform interworking within the target network system.

[0168] Optionally, the processor is further configured through the computer program to perform the following steps:

[0169] In response to the first AMF receiving a message requesting that the UE establish a PDU session, the first AMF sends a PDU session establishment request to the SMF, where the PDU session establishment request carries first indication information, and the first indication information is used to indicate whether the PDU session can perform interworking within the target network system.

[0170] Optionally, the processor is further configured through the computer program to perform the following steps:

[0171] In response to the first AMF determining that a status parameter of the PDU session has changed, the first AMF sends a PDU session modification request to the SMF, where the PDU session modification request carries first indication information, and the first indication information is used to indicate whether the PDU session can perform interworking within the target network system.

[0172] Optionally, the processor is further configured to perform the following steps through the computer program: in response to an inter-AMF mobility event occurring in which the UE is migrated from the first AMF to the second AMF, the first AMF sends first indication information to the second AMF, wherein the first indication information is used to indicate whether a PDU session of the UE under the first AMF can perform interworking within the target network system.

[0173] Optionally, in this embodiment, the processor is further configured to perform the following steps through a computer program: S1, the first AMF sending second indication information to a second target network element, wherein the second indication information is used to indicate that the second target network element stores DNN interworking information.

[0174] Optionally, the processor is further configured to perform the following steps through the computer program: the first AMF sending second indication information to the UDM or HSS, where the second indication information is used to indicate that the UDM or HSS has stored DNN interworking information, and the DNN interworking information includes the DNN information and at least one of an SMF address or a PGW address.

[0175] Optionally, the processor is further configured to perform the following steps through the computer program: in response to an inter-AMF mobility event occurring in which the UE is migrated from the first AMF to the second AMF, the first AMF sends second indication information to the second AMF, wherein the second indication information is used to indicate that the UDM or the HSS has stored DNN interworking information, and the DNN interworking information includes the DNN information and at least one of an SMF address or a PGW address.

[0176] Optionally, for specific examples in this embodiment, reference may be made to the examples described in the preceding embodiments and optional embodiments, but these examples will not be repeated in this embodiment.

[0177] It should be clear to those skilled in the art that each of the modules or steps of the present application may be implemented by a general-purpose computing device, centralized on a single computing device, or distributed over a network formed by multiple computing devices. Optionally, these modules or steps may be implemented by program code executable by a computing device. Thus, these modules or steps may be stored in a storage device and executed by a computing device. Furthermore, in some cases, the steps illustrated or described may be executed in a sequence different from that described herein. Alternatively, these modules or steps may be implemented by being separately fabricated into integrated circuit modules, or multiple modules or steps may be implemented by being fabricated into a single integrated circuit module. Thus, the present application is not limited to any specific combination of hardware and software.

[0178] The above is only an embodiment of the present application, and is not intended to limit the present application, and those skilled in the art may have various modifications and variations of the present application. Any modifications, equivalent substitutions, improvements, and equivalents made within the principle of the present application should fall within the scope of the present application.

Claims

1. An indication information transmission method, The indication information sending method includes: a first access and mobility management function (AMF) directly sending first indication information to a unified data management (UDM); The first indication information is used to cause the UDM to store data network name (DNN) interworking information, the DNN interworking information being associated with a data session of a user equipment (UE) interworking between accessing at least two different wireless systems; the DNN interworking information includes DNN information and at least one of an address of a Session Management Function (SMF) or an address of a Protocol Data Unit (PDU) Gateway (PGW), the SMF or the PGW in the DNN interworking information is selected as only one SMF or PGW for interworking between the at least two different wireless systems among a plurality of SMFs or a plurality of PGWs associated with the DNN, and when the UE moves from a first wireless system to a second wireless system among the at least two different wireless systems, the second wireless system uses the SMF or the PGW for each Access Point Name (APN) or each DNN to maintain continuity of the session between the first wireless system and the second wireless system.

2. The method of claim 1 , wherein for each DNN, the UDM stores one DNN interworking information corresponding to the DNN.

3. The indication information sending method further includes, in response to an occurrence of an inter-AMF mobility event in which the UE transitions from the first AMF for accessing the first radio system to a second AMF for accessing the second radio system, the first AMF sending the first indication information to the second AMF; 2. The indication information transmission method according to claim 1, wherein the first indication information is used to cause the second AMF to store the DNN interworking information.

4. The indication information sending method according to claim 3, wherein the inter-AMF mobility event includes at least one of a connected state handover process or an idle state mobility process.

5. The indication information sending method further includes: the first AMF sending second indication information to a first target network element for establishing the data session as a Protocol Data Unit (PDU) session in the first radio system; and 2. The indication information transmission method according to claim 1, wherein the second indication information is used to indicate whether the PDU session is capable of interworking with the second wireless system.

6. the first target network element is the SMF; The first AMF sending the second indication information to the first target network element includes, in response to the first AMF receiving a request message requesting that the UE establish the PDU session, the first AMF sending a PDU session establishment request to the SMF; The indication information transmission method according to claim 5, wherein the PDU session setup request carries the second indication information.

7. The method according to claim 1, wherein the first target network element is the SMF; The first AMF sending the second indication information to the first target network element includes, in response to the first AMF determining that a status parameter of the PDU session has changed, the first AMF sending a PDU session modification request to the SMF; The indication information transmission method according to claim 5 , wherein the PDU session modification request carries the second indication information.

8. The indication information transmitting method includes: In response to the first AMF receiving a request message requesting that the UE set up the data session as a Protocol Data Unit (PDU) session in the first radio system, the first AMF sends a PDU session setup request to a Session Management Function (SMF), where the PDU session setup request carries second indication information; In response to the first AMF determining that a status parameter of the PDU session has changed, the first AMF sends a PDU session modification request to the SMF. further comprising 2. The indication information transmission method according to claim 1, wherein the PDU session modification request carries the second indication information, and the second indication information is used to indicate whether the PDU session is capable of interworking with the second radio system.

9. The indication information sending method further includes, in response to an occurrence of an inter-AMF mobility event in which the UE transitions from the first AMF for accessing the first radio system to a second AMF for accessing the second radio system, the SMF sending a message to the second AMF; The indication information transmission method according to claim 8, wherein the message is used to indicate whether the PDU session under the SMF is capable of interworking with the second radio system.

10. The indication information transmission method described in Claim 8, wherein the second wireless system includes a fourth generation (4G) network system.

11. The indication information sending method further includes, in response to an occurrence of an inter-AMF mobility event in which the UE transitions from the first AMF for accessing the first radio system to a second AMF for accessing the second radio system, the first AMF sending second indication information to the second AMF; 2. The method of claim 1, wherein the second indication information is used to indicate to the second AMF whether the data session established as a Protocol Data Unit (PDU) session of the UE under the first AMF for accessing the first radio system is capable of interworking with the second radio system.

12. The first AMF sending the second indication information to the second AMF includes the first AMF sending a UE context message to the second AMF; and The indication information transmission method according to claim 11 , wherein the UE context message carries the second indication information.

13. The indication information sending method according to claim 11, wherein the inter-AMF mobility event includes at least one of a connected state handover process or an idle state mobility process.

14. A storage medium storing a computer program, the computer program being configured to, when executed, perform the method of transmitting indication information according to claim 1.

15. 1. An electronic device comprising: the electronic device comprises at least one memory and at least one processor; the at least one memory is configured to store a computer program; The at least one processor is configured to execute the computer program to perform a step including a first access and mobility management function (AMF) directly sending first indication information to a unified data management (UDM); The first indication information is used to cause the UDM to store data network name (DNN) interworking information, the DNN interworking information being associated with a data session of a user equipment (UE) interworking between accessing at least two different wireless systems; the DNN interworking information includes DNN information and at least one of an address of a session management function (SMF) or an address of a protocol data unit (PDU) gateway (PGW), the SMF or the PGW in the DNN interworking information is selected as a single SMF or PGW for interworking between the at least two different wireless systems among a plurality of SMFs or a plurality of PGWs associated with the DNN, and when the UE moves from a first wireless system to a second wireless system among the at least two different wireless systems, the second wireless system uses the SMF or the PGW for each access point name (APN) or each DNN to maintain continuity of the session between the first wireless system and the second wireless system.

16. 16. The electronic device of claim 15, wherein for each DNN, the UDM stores one DNN interworking information corresponding to the DNN.

17. The at least one processor is further configured to execute the computer program to perform a step including: in response to an inter-AMF mobility event occurring in which the UE transitions from the first AMF for accessing the first radio system to a second AMF for accessing the second radio system, the first AMF sending the first indication information to the second AMF; 16. The electronic device of claim 15, wherein the first indication information is used to cause the second AMF to store the DNN interworking information.

18. The electronic device of claim 17 , wherein the inter-AMF mobility event includes at least one of a connected state handover process or an idle state mobility process.

19. The at least one processor is further configured to execute the computer program to perform a step including the first AMF sending second indication information to a first target network element for establishing the data session as a protocol data unit (PDU) session in the first radio system; and 16. The electronic device of claim 15, wherein the second indication information is used to indicate whether the PDU session is capable of interworking with the second wireless system.

20. The method according to claim 1, wherein the first target network element is the SMF; The at least one processor is configured to, in response to the first AMF receiving a request message requesting that the UE establish the PDU session, the first AMF send the second indication information to the first target network element by sending a PDU session establishment request to the SMF; 20. The electronic device of claim 19, wherein the PDU session setup request carries the second indication information.

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