Wireless communication method, terminal device, and core network device

Abstract

Provided are a wireless communication method, a terminal device, and a core network device. The method comprises: a first terminal device sends a first session establishment request to a first network element of a core network, the first session establishment request being used for requesting to establish a first session, the first session establishment request comprising first information, and the first information being used for switching between the first session and a session established by a second terminal device.

Description

Wireless communication method, terminal device and core network device Technical Field

[0001] The present application relates to the field of communication technology, and more specifically, to a wireless communication method, terminal equipment, and core network equipment. Background Art

[0002] In some scenarios, a terminal device needs to access multiple 3rd Generation Partnership Project (3GPP) networks simultaneously to ensure service continuity. To support multiple access technologies, a dual registration mechanism has been introduced. However, this dual registration and corresponding handover mechanism can only be implemented in specific scenarios and is not applicable to a wide range of terminal device applications.

[0003] Summary of the Invention

[0004] The present application provides a wireless communication method, terminal equipment, and core network equipment. The following introduces various aspects involved in the present application.

[0005] In a first aspect, a wireless communication method is provided, comprising: a first terminal device sending a first session establishment request to a first network element of a core network, wherein the first session establishment request is used to request establishment of a first session, and the first session establishment request includes first information, and the first information is used to switch between the first session and a session established by a second terminal device.

[0006] According to a second aspect, a wireless communication method is provided, including: a first network element of a core network receives a first session establishment request sent by a first terminal device, the first session establishment request is used to request establishment of a first session, the first session establishment request includes first information, and the first information is used to switch between the first session and a session established by a second terminal device.

[0007] According to a third aspect, a wireless communication method is provided, including: a second network element of a core network receives a first session establishment request sent by a first network element of the core network, wherein the first session establishment request is used to request establishment of a first session for a first terminal device, and the first session establishment request includes first information, and the first information is used to switch between the first session and the session established by the second terminal device.

[0008] In a fourth aspect, a terminal device is provided, which includes a first terminal device, and the terminal device includes: a first sending unit, used to send a first session establishment request to a first network element of a core network, the first session establishment request is used to request to establish a first session, the first session establishment request includes first information, and the first information is used to switch between the first session and the session established by the second terminal device.

[0009] In the fifth aspect, a core network device is provided, which is the first network element of the core network, and the core network device includes: a receiving unit, used to receive a first session establishment request sent by a first terminal device, the first session establishment request is used to request to establish a first session, the first session establishment request includes first information, and the first information is used to switch between the first session and the session established by the second terminal device.

[0010] In the sixth aspect, a core network device is provided, which is the second network element of the core network and includes: the second network element of the core network receives a first session establishment request sent by the first network element of the core network, the first session establishment request is used to request to establish a first session for a first terminal device, the first session establishment request includes first information, and the first information is used to switch between the first session and the session established by the second terminal device.

[0011] In the seventh aspect, a terminal device is provided, comprising a processor, a memory, and a communication interface, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the terminal device executes part or all of the steps in the method of the first aspect.

[0012] In the eighth aspect, a core network device is provided, comprising a processor, a memory, and a transceiver, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the network device executes part or all of the steps in the method of the second aspect or the third aspect.

[0013] In a ninth aspect, an embodiment of the present application provides a communication system, which includes the above-mentioned terminal device and / or core network device. In another possible design, the system may also include other devices that interact with the terminal device or core network device in the solution provided in the embodiment of the present application.

[0014] In the tenth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program, and the computer program enables a communication device (for example, a terminal device or a core network device) to execute some or all of the steps in the methods of the above aspects.

[0015] In an eleventh aspect, embodiments of the present application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, wherein the computer program is operable to cause a communication device (e.g., a terminal device or a core network device) to perform some or all of the steps of the methods described in each of the above aspects. In some implementations, the computer program product may be a software installation package.

[0016] In the twelfth aspect, an embodiment of the present application provides a chip, which includes a memory and a processor. The processor can call and run a computer program from the memory to implement some or all of the steps described in the methods of the above aspects.

[0017] In an embodiment of the present application, the terminal device can implement switching between the first session of the first terminal device and the second session of the second terminal device based on the first information in the first session establishment request, which helps to ensure service coverage and continuity in more scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG1 is a diagram illustrating an example of a system architecture of a wireless communication system to which an embodiment of the present application may be applied.

[0019] FIG2 is a system architecture diagram of a fifth generation (5G) communication system.

[0020] FIG3 is a schematic diagram of the dual registration process.

[0021] FIG4 is a flow chart of a wireless communication method according to an embodiment of the present application.

[0022] FIG5 is a flowchart of a possible implementation of the method shown in FIG4 .

[0023] FIG6 is a flowchart of another possible implementation of the method shown in FIG4 .

[0024] FIG7 is a schematic diagram of the structure of the terminal device provided in an embodiment of the present application.

[0025] FIG8 is a schematic structural diagram of a core network device provided in an embodiment of the present application.

[0026] FIG9 is a schematic structural diagram of another core network device provided in an embodiment of the present application.

[0027] FIG10 is a schematic structural diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] The technical solution in this application will be described below with reference to the accompanying drawings.

[0029] Wireless communication systems

[0030] Figure 1 is a diagram illustrating an example of the system architecture of a wireless communication system 100 to which an embodiment of the present application may be applied. The wireless communication system 100 may include a network device 110 and a terminal device 120. The network device 110 may be a device that communicates with the terminal device 120. The network device 110 may provide network coverage for a specific geographical area and may communicate with the terminal device 120 located within the coverage area. The terminal device 120 may access a network (e.g., a wireless network) through the network device 110. Optionally, the wireless communication system 100 may also include other network entities such as a network controller and a mobility management entity, which is not limited in the embodiments of the present application.

[0031] It should be understood that the technical solutions of the embodiments of the present application can be applied to various communication systems, such as: fifth generation (5G) system or new radio (NR), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), etc. The technical solutions provided in this application can also be applied to future communication systems, such as the sixth generation mobile communication system, satellite communication system, etc.

[0032] The terminal device in the embodiments of the present application may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent, or user device. The terminal device in the embodiments of the present application may refer to a device that provides voice and / or data connectivity to a user and can be used to connect people, objects, and machines, such as a handheld device with wireless connection function, a vehicle-mounted device, etc. The terminal device in the embodiments of the present application can be a mobile phone, a tablet computer, a laptop computer, a PDA, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. Optionally, the terminal device can be used to act as a base station. For example, the terminal device can act as a scheduling entity that provides sidelink signals between terminal devices in vehicle to everything (V2X) or device to device (D2D). For example, a cellular phone and a car communicate with each other using sidelink signals. The cellular phone and smart home devices communicate without relaying the communication signal through a base station.

[0033] The network device in the embodiment of the present application may be a device for communicating with a terminal device. The network device may be, for example, an access network device or a wireless access network device. For example, the network device may be a base station. The base station may broadly cover the following various names, or be replaced with the following names: NodeB, evolved NodeB (eNB), next generation NodeB (gNB), relay station, access point, transmission point (TRP), transmitting point (TP), home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, base band unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. The base station may be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof.

[0034] Terminal devices can communicate with each other via sidelinks. Sidelink communication can also be called proximity services (ProSe) communication, unilateral communication, sidelink communication, or D2D communication.

[0035] 5G network system architecture

[0036] Figure 2 is a system architecture diagram of a 5G network applicable to an embodiment of the present application. As shown in Figure 2, the 5G system or NR network architecture released by the 3GPP standard group includes: a terminal device (also known as a UE) 201, an access network device 202 supporting 3GPP technology (including a radio access network (RAN) or access network (AN)), an access and mobility management function (AMF) network element 203, a session management function (SMF) network element 204, a user plane function (UPF) network element 205, a policy control function (PCF) network element 206, an application function (AF) network element 209, a data network (DN) 208, a network slice selection function (NSSF) 211, an authentication server function (AUSF) 210, and a unified data management function (UDM) 207.

[0037] It should be noted that the network architecture shown in Figure 2 does not constitute a limitation on the 5G network architecture. In specific implementations, the 5G network architecture may include more or fewer network elements than shown, or may combine certain network elements. In addition, in Figure 2, the AN or RAN is represented in the form of (R)AN.

[0038] The terminal device 201 can be any terminal device in FIG1 , and will not be described in detail here.

[0039] The access network device 202 is an access device that the terminal device uses to access the network architecture wirelessly. It is mainly responsible for radio resource management, quality of service (QoS) management, data compression and encryption, etc. on the air interface side. For example: NodeB, eNodeB, base station in 5G mobile communication system or NR communication system, base station in future mobile communication system, etc.

[0040] UPF network element 205, AMF network element 203, SMF network element 204, and PCF network element 206 are network elements of the 3GPP core network (referred to as core network elements). UPF network element 205 can be called a user plane function network element, which is mainly responsible for the transmission of user data. Other network elements can be called control plane function network elements, which are mainly responsible for authentication, authorization, registration management, session management, mobility management, and policy control to ensure reliable and stable transmission of user data.

[0041] The UPF network element 205 (or simply "UPF") can be used to forward and receive data from the terminal. For example, the UPF network element can receive service data from the data network and transmit it to the terminal through the access network device. The UPF network element can also receive user data from the terminal through the access network device and forward it to the data network. The transmission resources allocated and scheduled by the UPF network element for the terminal are managed and controlled by the SMF network element. The bearer between the terminal and the UPF network element may include: a user plane connection between the UPF network element and the access network device, and a channel established between the access network device and the terminal. The user plane connection is a quality of service (QoS) flow that can be established between the UPF network element and the access network device to transmit data.

[0042] The AMF network element 203 (or "AMF" for short) can be used to manage terminal access to the core network, such as terminal location update, network registration, access control, terminal mobility management, terminal attachment and detachment, etc. The AMF network element can also provide control plane storage resources for the session when providing services for the terminal session to store the session identifier, the SMF network element identifier associated with the session identifier, etc.

[0043] The SMF network element 204 (or "SMF" for short) can be used to select a user plane network element for the terminal, redirect the user plane network element for the terminal, allocate an Internet Protocol (IP) address to the terminal, establish a bearer (also called a session) between the terminal and the UPF network element, modify and release the session, and control QoS.

[0044] The PCF network element 206 (or simply "PCF") is used to provide policies, such as QoS policy and slice selection policy, to the AMF network element 203 and the SMF network element 204. The PCF is responsible for formulating policies related to mobility management, session management, and billing for terminal devices.

[0045] The AF network element 209 (or simply "AF") is used to interact with the 3GPP core network elements to support application-affected data routing, access network exposure functions, and interact with the PCF network elements for policy control.

[0046] DN 208 can provide data services to users on networks such as IP Multimedia Service (IMS) and the Internet. DN 208 can contain multiple application servers (ASs) that provide different application services, such as carrier services, Internet access, or third-party services. Application servers can implement the functions of AF network elements.

[0047] NSSF 211 is used for network slice selection and supports the following functions: selecting a set of network slice instances to serve the UE; determining the allowed network slice selection assistance information (NSSAI) and, when necessary, determining the mapping to the contracted single-network slice selection assistance information (S-NSSAI); determining the configured NSSAI and, when necessary, determining the mapping to the contracted S-NSSAI; determining the set of AMFs that may be used to query the UE, or determining a list of candidate AMFs based on the configuration.

[0048] AUSF 210 is used to receive the request from AMF 203 to authenticate the terminal, request a key from UDM 207, and then forward the issued key to AMF 203 for authentication processing.

[0049] UDM 207 includes functions such as generation and storage of user contract data, management of authentication data, and supports interaction with external third-party servers.

[0050] As shown in Figure 2, a terminal device establishes an access layer connection with the AN via the Uu interface, exchanging access layer messages and wireless data transmission. The terminal device also establishes a non-access stratum (NAS) connection with the AMF network element via the N1 interface, exchanging NAS messages. In addition to managing terminal device mobility, the AMF network element is also responsible for forwarding session management-related messages between the terminal device and the SMF network element. The UPF network element communicates with the external data network via the N6 interface and with the AN via the N3 interface.

[0051] It should be understood that each network element in Figure 2 can be a network element in a hardware device, a software function running on dedicated hardware, or a virtualized function instantiated on a platform (e.g., a cloud platform). It should be noted that the network architecture shown in the above figure is only an example of the network elements included in the entire network architecture. In the embodiments of the present application, the network elements included in the entire network architecture are not limited.

[0052] Dual Registration

[0053] To ensure service coverage and continuity, increase capacity, and other requirements, a terminal device may need to access multiple 3GPP networks simultaneously and perform traffic switching and traffic diversion between the two access networks. For example, a terminal device can access both a 4G network and a 5G network simultaneously. For example, a terminal device can access two 5G networks of public land mobile networks (PLMNs) simultaneously.

[0054] Taking the example of a terminal device accessing two networks at the same time, the basic requirement in this scenario is to allow the terminal device to register in the two access networks at the same time and maintain a dual registration state.

[0055] To implement dual registration, 5G and LTE system compatibility technologies provide support. Specifically, a single terminal device can be registered in both 5G and LTE access networks simultaneously, allowing for mobility-induced network switching. The dual registration process is schematically illustrated below with reference to Figure 3.

[0056] Figure 3 illustrates the interaction between multiple devices. In addition to some of the devices shown in Figure 2, these devices also include the evolved UMTS terrestrial radio access network (E-UTRAN), the next generation RAN (NG-RAN), the evolved packet core (EPC), the packet data network gateway-control plane (PGW-C), and the home subscriber server (HSS).

[0057] Referring to Figure 3, in step S301, a UE attaches and registers to the EPC (LTE) access network. The EPC assigns the UE a 4G globally unique temporary UE identity (GUTI), or 4G-GUTI. This identity is a temporary UE ID assigned by the Mobile Management Entity (MME) and can be used to identify the MME and UE.

[0058] In step S302, the UE sends a registration request to the NG-RAN.

[0059] In step S303, the NG-RAN performs AMF selection.

[0060] In step S304, the NG-RAN sends a registration request to the new AMF.

[0061] In step S305, a registration procedure is performed.

[0062] Through steps S302 to S305, the UE accesses the 5G network and sends a registration request to the 5G core network. The UE uses the 5G-GUTI converted from the 4G-GUTI as its temporary identifier and reports it to the 5G core network.

[0063] In step S306, the AMF registers the UE information with the UDM+HSS and notifies the network element not to cancel the UE's LTE registration. The UE's LTE registration is implemented through the MME.

[0064] Through steps S307 to S309, the UE completes the registration process on the 5G access network. In step S380, the UE receives the registration accept message sent by the new AMF; in step S390, the UE sends a registration complete message to the AMF.

[0065] In step S310, the UE requests a protocol data unit (PDU) session establishment procedure (UE requested PDU session establishment procedure) to establish a PDU session (5G access network).

[0066] In step S311, the PGW-C+SMF network element initiates release of transferred packet data network (PDN) connection to release the PDN connection (LTE access network).

[0067] As can be seen above, the process shown in Figure 3 applies to dual registration mode for a single UE. Furthermore, the core network requires the UE to report associated access network information during registration in order to interact with other network elements. For example, the GUTI information reported by the UE can include information about the MME. The network element receiving the registration information, when interacting with the unified management network element (UDM+HSS), can simultaneously obtain information about both access networks.

[0068] In addition, the same SMF / PGW-C network element can be used in step S310. This session control network element can allocate the same Internet Protocol (IP) address for the two connected sessions based on the association between the two access networks, ensuring service continuity. This technology relies on the same UE, and GUTI information can be associated between the two access networks, requiring the two access networks to be operated by the same operator.

[0069] In some implementations, in order to reduce the impact on the existing network, some operators recommend using two subscriber identity modules (SIM) cards to access two networks, which can also be regarded as two associated UEs accessing the two networks simultaneously.

[0070] For example, with the introduction of Multi-Universal Subscriber Identity Module (Multi-USIM) technology, a single mobile terminal can be equipped with multiple (usually two) USIM cards. The two USIM cards can independently register with the access network, establish corresponding sessions, and conduct their own independent services. It should be noted that there is no association between the two USIM cards; from the network's perspective, they appear to be two independent UEs.

[0071] The main dual registration process is described above, combined with Figure 3. This dual registration and handover mechanism supports IP preservation, ensuring that the IP address remains unchanged before and after handover, thereby ensuring service continuity. However, this mechanism is only applicable to scenarios where a single SIM card is handing over between the EPC and the 5G core (5GC), and only supports handovers triggered by mobility.

[0072] In summary, the dual registration process in related technologies has many application scenarios and cannot be applied to a wide range of scenarios, resulting in poor flexibility. For example, the dual registration process cannot be applied to the more universal handover between 5GCs or support business continuity when switching between dual SIM cards.

[0073] Based on this, an embodiment of the present application provides a wireless communication method. In this method, a first terminal device may send a first session establishment request to a first network element of a core network to request establishment of a first session. The first session request may include first information used to switch between the first session and a session established by a second terminal device. The first information in the first session request can be used to switch between the session established by the first terminal device and the session established by the second terminal device, meeting the switching requirements in more scenarios and ensuring service continuity.

[0074] The following describes a wireless communication method according to an embodiment of the present application in conjunction with Figure 4. Figure 4 describes the interaction between a first terminal device and a first network element of a core network.

[0075] In step S410, the first terminal device sends a first session establishment request to a first network element of the core network.

[0076] In some implementations, the first terminal device or the second terminal device may be a communication device connected to multiple access networks. Alternatively, the first terminal device or the second terminal device may be a communication device that accesses multiple networks through multiple access network devices. For example, the first terminal device or the second terminal device may be a device with multiple SIM cards.

[0077] In some implementations, the first terminal device may be one of multiple associated terminal devices connected to multiple access networks. That is, the terminal device may be associated with multiple terminal devices connected to multiple access networks, with the first terminal device being one of the multiple terminal devices. For example, if the terminal device has multiple SIM cards, the first terminal device may be a terminal device represented by one of the SIM cards.

[0078] In some scenarios, the terminal device associated with the first terminal device is a dual SIM card device, and one card of the dual SIM card corresponds to the first terminal device.

[0079] In some scenarios, the terminal device associated with the first terminal device may be provided with multiple USIM cards, and the device may access multiple access networks through different USIM cards in the multiple USIM cards. For example, the terminal device may be provided with USIM1 and USIM2, and accordingly, access the first access network through USIM1 and access the second access network through USIM2.

[0080] In the embodiment of the present application, the second terminal device may be a terminal device corresponding to another SIM card or USIM card on the terminal device where the SIM card or USIM card corresponding to the first terminal device is located. In other words, the first terminal device and the second terminal device may be terminal devices corresponding to different SIM cards or USIM cards on the same terminal device. For example, on the same terminal device, the first terminal device and the second terminal device may correspond to different access networks.

[0081] In some implementations, the first network element of the core network is a registration management network element in the core network. As an example, the first network element may be an AMF or MME. Of course, in the embodiments of the present application, the first network element may also be another core network element in a future communication system having similar functions to an AMF or MME.

[0082] The first session establishment request is used to request establishment of a first session. The first session establishment request includes first information used to switch between the first session and the session established by the second terminal device. The first session can be established by the first terminal device due to specific business needs, etc.

[0083] In some implementations, before sending the first session establishment request, the first terminal device may first register.

[0084] In some implementations, before the second terminal device establishes the second session, the second terminal device may also first register.

[0085] In some implementations, the first terminal device and the second terminal device can both register through a first network element. The first network element registered by the first terminal device and the network element registered by the second terminal device can be the same or different.

[0086] This application does not impose any specific limitation on the timing of the first terminal device registering, as long as the first terminal device registers earlier than before the first terminal device sends the first session establishment request.

[0087] As an example, the first terminal device may register earlier than the second terminal device or establish the second session earlier than the second terminal device. In other words, the timing of the first terminal device's registration may be irrelevant to the second terminal device's service, and the first terminal device only needs to register on its own.

[0088] As another example, the first terminal device registers after the second terminal device establishes the second session. In this case, the first terminal device registers after the second terminal device establishes the session first and then registers the first terminal device because a handover needs to be triggered.

[0089] In some implementations, the first information is used to switch between the first session and a session already established by the second terminal device.

[0090] In some implementations, the second terminal device has already established a session before the first device sends the first session request, and the session is referred to as the second session. The second terminal device has an IP address assigned in the session, and the session has session identification information Session ID.

[0091] In some implementations, the first information is used to indicate that the second session has been established by the second terminal device. The first information can also be understood as a kind of association information.

[0092] The embodiment of the present application does not specifically limit the first information, as long as the first information can indicate that the second terminal has established a second session. For example, the first information includes one or more of the following information: relevant information of the second terminal device; relevant information of the second session.

[0093] In some implementations, the relevant information of the second terminal device may include one or more of the following: an identifier of the second terminal device (UE ID); an association identifier (association ID) of the first terminal device and the second terminal device.

[0094] In some implementations, the relevant information of the second session includes one or more of the following: an identifier (Session ID) of the second session; a data network name (DNN) corresponding to the second session; single network slice selection assistance information (S-NSSAI) corresponding to the second session; and IP address information corresponding to the second session.

[0095] As an example, the first information may include one or more of the identification UE ID of the second terminal device, the association ID of the first terminal device and the second terminal device, the Session ID of the second session, the DNN of the second session, the S-NSSAI information of the second session, and the corresponding IP address information of the second session.

[0096] In the embodiment of the present application, the association ID between the first terminal device and the second terminal device is ID information used to associate the first terminal device with the second terminal device. In some implementations, the association ID between the first terminal device and the second terminal device may be assigned by the AMF.

[0097] For example, the first information may be the UE ID of the second terminal device and the Session ID of the second session established by the second terminal device;

[0098] For another example, the first information may also be the UE ID of the second terminal device, the DNN of the second session, and the S-NSSAI information of the second session;

[0099] For another example, the first information may also be an association ID between the first terminal device and the second terminal device, a DNN of the second session, and S-NSSAI information of the second session;

[0100] For example, the first information may also be the UE ID information of the second terminal device and the corresponding IP address information of the second session.

[0101] In some implementations, the first session establishment request further includes second information, where the second information is used to indicate switching from the second session to the first session.

[0102] For example, the second information may be DualSteer switching indication information. The DualSteer switching indication information is used to indicate that the first session is a session for switching. That is, the first session is a session for DualSteer switching.

[0103] In some implementations, the wireless communication method further includes: the first terminal device receiving a response message to the first session establishment request, wherein the response message includes an IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

[0104] In some implementations, the first terminal device may receive a response message to the first session establishment request sent by the first network element.

[0105] In some implementations, the response message to the first session establishment request may be received by the first network element from the second network element and forwarded to the first terminal device.

[0106] For example, the first network element may send a first session establishment request to the second network element of the core network, and the first network element receives a response message to the first session establishment request based on the first session request.

[0107] The embodiment of the present application does not specifically limit the second network element. The second network element may be a network element in the core network that has a session management function. For example, the second network element may be an SMF network element.

[0108] In some implementations, the first session request sent by the first network element is the same as the first session request sent by the first terminal device to the first network element.

[0109] In some other embodiments, the first session request sent by the first network element is different from the first session request sent by the first terminal device to the first network element.

[0110] In this embodiment of the present application, when a first terminal device sends a first session request, the first information in the first session request indicates the second session that has been established by the second terminal device. This can support the allocation of the same IP address to the first session (the newly established session) and the second session (the already established session) when the first terminal device is switched in DualSteer. This method is mainly implemented by the switched UE (the first terminal device) sending relevant instructions and does not have any enhanced requirements for the switching UE (the second terminal device).

[0111] In some other implementations, the first information is used to switch between the first session and a session that may be established by the second terminal device.

[0112] In some implementations, the first information indicates one or more of the following: information related to the second terminal device; information related to the first session. The first information can be understood as association information. The association information indicates the associated second terminal device and information related to the first session.

[0113] The relevant information of the second terminal device can be understood as indicating the relevant information of the second terminal device. In some implementations, the relevant information of the second device includes one or more of the following: an identifier of the second terminal device (UE ID); an association identifier (association ID) between the first terminal device and the second terminal device.

[0114] In some implementations, the relevant information of the first session includes one or more of the following: a DNN corresponding to the first session; and an S-NSSAI corresponding to the first session.

[0115] As an example, the first information may include an identifier of the second terminal device (UE ID) and the S-NSSAI corresponding to the first session.

[0116] As another example, the first information may include a possible association ID, a DNN corresponding to the first session, and an S-NSSAI corresponding to the first session.

[0117] In some implementations, the first session establishment request further includes third information, where the third information is used to indicate that the first session is available for session handover.

[0118] For example, the third information may be DualSteer switching indication information. The DualSteer switching indication information is used to indicate that the first session may be a session for switching. In other words, the first session may be a session for DualSteer switching.

[0119] In some implementations, during the first session establishment process, the first session has a session identifier Session ID.

[0120] In some implementations, the first terminal device may receive a response message to the first session establishment request from the first network element. The response message to the first session establishment request includes the IP address allocated for the first session.

[0121] In some implementations, after the first terminal device sends a first session establishment request to the first network element of the core network, the wireless communication method further includes: the second terminal device sends a second session establishment request to the first network element, where the second session establishment request is used to request establishment of a second session.

[0122] In some implementations, the second session establishment request may be triggered by the second terminal device based on specific service requirements, etc.

[0123] In some implementations, the second session establishment request includes relevant information of the second session, and the relevant information of the second session is the same as the relevant information of the first session.

[0124] As an example, the relevant information of the second session includes one or more of the following: a DNN corresponding to the second session; and an S-NSSAI corresponding to the second session. The DNN corresponding to the second session is the same as the DNN corresponding to the first session. The S-NSSAI corresponding to the second session is the same as the S-NSSAI corresponding to the first session.

[0125] In some implementations, the wireless communication further includes: the second terminal device receiving a response message to the second session establishment request, the response message including an IP address corresponding to the second session, and the IP address corresponding to the second session is the same as the IP address corresponding to the first session.

[0126] In some implementations, the second terminal device may receive a response message to the second session establishment request sent by the first network element.

[0127] In some implementations, the response message to the second session establishment request may be received by the first network element from the second network element and forwarded to the second terminal device.

[0128] In the embodiment of the present application, when the first terminal device establishes the first session, the first session is designated as a session that may require DualSteer switching. When switching occurs, the second terminal device can automatically allocate the same address as the first session without any enhancement.

[0129] The above describes the method for the first terminal device to perform session switching according to the first session establishment request in conjunction with Figure 4. The following describes the method for performing session switching according to the first session establishment request from the perspective of multiple network elements in the core network.

[0130] As described above, the first network element may send a first session establishment request to the second network element of the core network, and the first network element receives a response message to the first session establishment request sent by the second network element based on the first session request. This is described in detail below.

[0131] In some implementations, the first network element sends a first session establishment request to the second network element.

[0132] As an example, the first session request sent by the first network element to the second network element is the same as the first session request sent by the first terminal device to the first network element. In this case, the first session request sent by the first network element can refer to the first session request described above and will not be repeated here.

[0133] As another example, the first session request sent by the first network element to the second network element is different from the first session request sent by the first terminal device to the first network element.

[0134] For example, the first session request sent by the first network element to the second network element includes one or more of the following information: second information indicating a switch from the second session to the first session; and fourth information indicating the second session. The second information can be described above. The fourth information can be, for example, information transformed by the first network element based on the first information described above.

[0135] As an example, if the first information in the previous text is the association ID, the DNN of the second session and the S-NSSAI information of the second session, the fourth information can be the identification UE ID of the second terminal device determined according to the transformation of the first information and the Session ID of the second session corresponding to the second terminal device.

[0136] In some implementations, the first network element receives a response message to the first session establishment request sent by the second network element, where the response message to the first session establishment request includes an IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

[0137] In some implementations, the response message to the first session establishment request may be a first message sent by the second network element to a third network element of the core network in response to the first session establishment request message and obtained from the third network element based on the first message. The first message is used to instruct the third network element to allocate the same IP address for the first session as that for the second session.

[0138] The embodiment of the present application does not make any specific limitation on the third network element. The third network element may be a network element of the core network that can allocate IP addresses, for example, the third network element may be a UPF network element.

[0139] In some implementations, the first message includes one or more of the following: an identifier of the second session; and an IP address corresponding to the second session.

[0140] In some embodiments, the wireless communication method further includes: the third network element feeding back a response message to the first message to the second network element, wherein the response message to the first message includes the same IP address as that of the second session.

[0141] In some embodiments, the second network element sends a response message to the first network element for the first session establishment request based on the response message to the first message, and the response message to the first session establishment request includes the IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

[0142] As mentioned above, the response message to the second session establishment request may be received by the first network element from the second network element and forwarded to the second terminal device.

[0143] In some implementations, the first network element may send a second session establishment request to the second network element of the core network, where the second session establishment request includes relevant information of the second session, and the relevant information of the second session is the same as the relevant information of the first session.

[0144] In some implementations, the response message to the second session establishment request may be a message received from a third network element of the core network based on a first message sent by the second network element to the third network element in response to the second session establishment request message. The first message is used to instruct the third network element to allocate the same IP address to the second session as that used for the first session.

[0145] In some implementations, the first message includes one or more of the following: an identifier of the first session; and an IP address corresponding to the first session.

[0146] In some implementations, the wireless communication method further includes: the first network element receiving a response message to the second session establishment request sent by the second network element, the response message to the second session establishment request including an IP address corresponding to the second session, and the IP address corresponding to the second session is the same as the IP address corresponding to the first session.

[0147] In some implementations, the first message is a message sent by the second network element to the third network element via a corresponding interface. For example, when the second network element is an SMF and the third network element is a UPF, the first message can be sent to the UPF via the N4 interface.

[0148] The following describes the embodiments of the present application in more detail with reference to the specific examples of Figures 5 and 6. It should be noted that the examples of Figures 5 and 6 are merely intended to help those skilled in the art understand the embodiments of the present application, and are not intended to limit the embodiments of the present application to the specific numerical values ​​or specific scenarios illustrated. It is obvious that those skilled in the art can make various equivalent modifications or changes based on the examples of Figures 5 and 6, and such modifications or changes also fall within the scope of the embodiments of the present application.

[0149] Figure 5 is a flowchart of a possible implementation of an embodiment of the present application. In the example of Figure 5, the first terminal device is UE2, the second terminal device is UE1, the first network element of the core network is the AMF, the second network element is the SMF, and the third network element is the UPF. UE1 and UE2 are associated with each other.

[0150] For the embodiment of Figure 5, the overall inventive concept is: UE1 first establishes a session. When triggering a switch to UE2, UE2 initiates a session establishment request and carries association information indicating the UE1 session in the request. After receiving the request, the SMF allocates the same UPF and the same IP address to the session requested by UE2.

[0151] 5 , the wireless communication method may include steps S51 a - S58 .

[0152] In step S51a, UE1 registers.

[0153] In step S51b, UE2 registers.

[0154] The AMF that registers UE1 and UE2 can be the same or different. FIG5 takes the same AMF as an example.

[0155] The embodiment of the present application does not specifically limit the timing of generating S51b.

[0156] For example, step S51b may occur after step S52 and before step S53, that is, after the session of UE1 is established, the registration of UE2 is performed because a handover needs to be triggered.

[0157] For another example, step S51b may occur before step S52 or S51a, that is, step S51b has nothing to do with the service of UE1 and performs the registration of UE2 independently. However, the registration of UE2 must occur before UE2 makes a session establishment request.

[0158] In step S52, UE1 establishes session 1, where it is assumed that the address allocated to UE1 in the session is IP1 and the identification information of the session is Session ID1. Session 1 is the second session established by the second terminal mentioned above.

[0159] In step S53, UE2 sends a first session establishment request to AMF2.

[0160] For example, the first session establishment request may be that UE2 decides to establish a session for DualSteer switching due to specific service requirements.

[0161] The first session request may include association information 1 and may also include DualSteer handover indication information. Association information 1 indicates session 1. The DualSteer handover indication information indicates that the current session is the session to be handed over. Association information 1 may be the first information described above. The DualSteer handover indication information may be the second information described above.

[0162] Association information 1 includes one or more of UE1's ID information, association ID, Session ID 1, DNN S-NSSAI information for Session 1, and address information IP 1 corresponding to Session 1. The association ID is used to associate the ID information of UE1 and UE2. In some embodiments, the association ID may be allocated by the AMF.

[0163] As an example, the association information 1 may be the ID information of UE1 and the session Session ID1 of UE1.

[0164] As another example, the association information 1 may be the ID information of UE1 and the DNN S-NSSAI information.

[0165] As another example, the association information 1 may be an association ID, DNN S-NSSAI information.

[0166] As another example, the association information 1 may be the ID information of UE1, the IP address information of session 1, and the like.

[0167] In the embodiment of the present application, the AMF used for registration and the AMF used to receive the session establishment request can be the same or different. Figure 5 takes different examples as an example. As shown in Figure 5, the AMF used for registration is AMF1, and the AMF used to receive the session establishment request is AMF2.

[0168] In step S54, AMF2 sends a first session establishment request to SMF.

[0169] The first session establishment request may include the association information 2 and may also include DualSteer switching indication information.

[0170] In some embodiments, the associated information 2 may be the same as the associated information 1. That is, the associated information 2 is the first information mentioned above.

[0171] In other embodiments, the association information 2 may be different from the association information 1. For example, the association information 2 may be obtained by transforming the association information 1. In this case, the association information is equivalent to the fourth information described above.

[0172] As an example, association information 1 may be association ID, DNN S-NSSAI information, and AMF transforms association information 1 into association information 2. Association information 2 may include the ID information of UE1 and the Session ID1 corresponding to UE1.

[0173] In step S55, the SMF sends an N4 request to the UPF.

[0174] The N4 request is used to instruct the UPF to allocate the same IP address for the current UE2 session as that for UE1 session 1. The N4 request may be the first message mentioned above, wherein the N4 request includes the session ID of UE1 and / or the address IP1 corresponding to UE1 session 1.

[0175] In step S56, the UPF feeds back the N4 response to the SMF.

[0176] The N4 response includes the same IP address as that of UE1 session 1. The N4 response may be a response message to the first message mentioned above.

[0177] In step S57, SMF sends a response message of the first session establishment request to AMF2.

[0178] The response message to the first session establishment request includes the IP address allocated for the current session, which is the same as IP1 of session 1 of UE1.

[0179] In step S58, AMF2 feeds back a response message of the first session establishment request to UE2.

[0180] In the embodiment of FIG. 5 , when UE2 sends the session establishment request, it also sends the association information associated with the handover session, which may also carry DualSteer handover indication information.

[0181] In addition, the SMF determines the associated session based on the association information and allocates the same IP address as the associated session to the current session.

[0182] This embodiment can support allocating the same IP address to the newly established session when DualSteer UE switching is performed. This is mainly achieved by sending relevant instructions between the switched UE and the access network of the switched UE. There are no enhanced requirements for the access network of the switching UE.

[0183] Figure 6 is a flowchart of another possible implementation of an embodiment of the present application. In the example of Figure 6, the first terminal device is UE1, the second terminal device is UE2, the first network element of the core network is the AMF, the second network element is the SMF, and the third network element is the UPF. UE1 and UE2 are associated with each other.

[0184] For the embodiment of Figure 6, the overall inventive concept is: when establishing a session, UE1 specifies the current session as a session that may require dualsteer switching, and carries relevant indication messages. When DualSteer switching is triggered, UE2 sends a session establishment request normally, and SMF allocates the same UPF and IP address to UE2 based on the previous configuration information.

[0185] 6 , the wireless communication method may include steps S61 a - S68 .

[0186] In step S61a, UE1 registers.

[0187] In step S61b, UE2 registers.

[0188] The AMF that registers UE1 and UE2 can be the same or different. FIG6 takes the same AMF as an example.

[0189] The embodiment of the present application does not impose any specific limitation on the timing of generating S61b.

[0190] For example, step S61b may occur after step S62 and before step S63, that is, after the session of UE1 is established, the registration of UE2 is performed because a handover needs to be triggered.

[0191] For another example, step S61b may occur before step S62 or S61a, that is, step S61b has nothing to do with the service of UE1 and performs the registration of UE2 independently. However, the registration of UE2 must occur before UE2 makes a session establishment request.

[0192] In step S62, UE1 sends a first session establishment request to AMF1.

[0193] For example, the first session establishment request may be that UE1 decides to establish a session that may be used for DualSteer switching due to specific service requirements.

[0194] The first session request may include association information 1 and DNN1S-NSSAI1 information; it may also include DualSteer handover indication information. Association information 1 indicates the associated UE 2 and information related to the current session. The DualSteer handover indication information indicates that the current session is a session that may be used for DualSteer handover. Association information 1 may be the first information described above. The DualSteer handover indication information may be the second information described above.

[0195] The association information 1 includes the ID information of UE2 and one or more association IDs. The association ID is used to associate the ID information of UE1 and UE2. In some embodiments, the association ID may be allocated by the AMF.

[0196] For example, the association information 1 may be the ID information of UE2 and the DNN S-NSSAI information.

[0197] For another example, the association information 1 may be the association ID, DNN1S-NSSAI1 information.

[0198] In step S63, AMF1 sends a first session establishment request to SMF.

[0199] The first session establishment request includes the association information 2 and may also include DualSteer switching indication information.

[0200] In some embodiments, the associated information 2 may be the same as the associated information 1. That is, the associated information 2 is the first information mentioned above.

[0201] In other embodiments, the association information 2 may be different from the association information 1. For example, the association information 2 may be obtained by transforming the association information 1. In this case, the association information is equivalent to the fourth information described above.

[0202] As an example, association information 1 may be association ID, DNN1S-NSSAI1 information, and AMF transforms association information 1 into association information 2, where association information 2 includes UE2's ID information and DNN1S-NSSAI1 information.

[0203] In step S64, UE1 establishes a session process.

[0204] It is assumed that the session ID is Session ID1 and the assigned address is IP1.

[0205] In step S65, UE2 sends a second session establishment request to AMF2.

[0206] It should be understood that the receiver of the second session establishment request may be the AMF1 mentioned above, or the AMF2 in FIG6 . This embodiment of the present application does not specifically limit this.

[0207] For example, the second session establishment request may be that UE2 decides to establish a session due to specific service requirements.

[0208] The second session establishment request may include relevant information about the second session. The second relevant information may be, for example, UE2 ID, DNN1, and S-NSSAI1. The second relevant information is the same as the DNN and S-NSSAI corresponding to session 1. This is equivalent to switching UE1's session 1 to this session.

[0209] In step S66, AMF2 sends a second session establishment request to SMF.

[0210] The second session establishment request carries DNN1, S-NSSAI1, and UE2ID. The SMF can determine whether the current session is initiated by UE2 based on the received second session establishment request. If so, step S67 can be executed.

[0211] In step S67, SMF sends an N4 request to UPF. Since DNN1 and S-NSSAI1 are dedicated to DualSteer service, and UE1 has previously transmitted its associated UE2, when SMF receives the session establishment request sent by UE2, it can know that this session is used for DualSteer switching. Accordingly, SMF can know the associated UE1 and the corresponding session 1. Therefore, the N4 request sent by SMF may contain the session ID of UE1 and / or the address IP1 corresponding to UE1 session 1, instructing UPF to allocate the same address as UE1 session 1 to the current UE2 session. The N4 request can be the first message mentioned above.

[0212] In step S68, the UPF feeds back the N4 response to the SMF.

[0213] The N4 response includes the same IP address as that of UE1 session 1. The N4 response may be a response message to the first message mentioned above.

[0214] In step S69, SMF sends a response message of the second session establishment request to AMF2.

[0215] The response message to the second session establishment request includes the IP address allocated for the current session (ie, the same IP1 as that for session 1 of UE1).

[0216] In step S691, AMF2 feeds back a response message of the second session establishment request to UE2.

[0217] In the embodiment of Figure 6, when UE1 sends a session establishment request, it also sends the UE2 ID information that may be associated with it, and uses a specific DNN and S-NSSAI dedicated to the DualSteer service. The SMF stores the associated information context.

[0218] In addition, UE2 uses a specific DNN and S-NSSAI dedicated to the DualSteer service when establishing a session. When the SMF receives a request from UE2 to establish a session using the DNN S-NSSAI, it looks up the associated UE ID1 and the corresponding session 1 and assigns the same IP address to UE2's current session as to UE1's session 1.

[0219] Compared with the embodiment in FIG. 5 , the embodiment in FIG. 6 can specify the current session as a session that may require DualSteer switching when establishing the session. When switching occurs, UE2 can automatically allocate the same address without any enhancement.

[0220] The method embodiment of the present application is described in detail above in conjunction with Figures 1 to 6 . The device embodiment of the present application is described in detail below in conjunction with Figures 7 to 10 . It should be understood that the description of the method embodiment corresponds to the description of the device embodiment. Therefore, for parts not described in detail, reference can be made to the above method embodiment.

[0221] FIG7 is a schematic diagram of a terminal device according to an embodiment of the present application. The terminal device 700 shown in FIG7 includes a first terminal device. As shown in FIG7 , the terminal device 700 includes a first sending unit 710 .

[0222] The first sending unit 710 is used to send a first session establishment request to a first network element of the core network, where the first session establishment request is used to request establishment of a first session, and the first session establishment request includes first information, which is used to switch between the first session and the session established by the second terminal device.

[0223] Optionally, the first information is used to indicate a second session that has been established by the second terminal device.

[0224] Optionally, the first information includes one or more of the following information: relevant information of the second terminal device; relevant information of the second session.

[0225] Optionally, the relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; and an association identifier between the first terminal device and the second terminal device.

[0226] Optionally, the relevant information of the second session includes one or more of the following: an identifier of the second session; a DNN corresponding to the second session; an S-NSSAI corresponding to the second session; or an IP address corresponding to the second session.

[0227] Optionally, the first session establishment request further includes second information, where the second information is used to indicate switching from the second session to the first session.

[0228] Optionally, the terminal device further includes: a first receiving unit, configured to receive a response message to the first session establishment request, wherein the response message includes an IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

[0229] Optionally, the first information is used to indicate one or more of the following: relevant information of the second terminal device; relevant information of the first session.

[0230] Optionally, the relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; and an association identifier between the first terminal device and the second terminal device.

[0231] Optionally, the relevant information of the first session includes one or more of the following: the DNN corresponding to the first session; the S-NSSAI corresponding to the first session.

[0232] Optionally, the first session establishment request further includes third information, where the third information is used to indicate that the first session can be used for session switching.

[0233] Optionally, the terminal device also includes a second terminal device, and the second terminal device also includes: a second sending unit, used to send a second session establishment request to the first network element of the core network after the first terminal device sends the first session establishment request to the first network element of the core network, and the second session establishment request is used to request to establish a second session.

[0234] Optionally, the second session establishment request includes relevant information of the second session, and the relevant information of the second session is the same as the relevant information of the first session.

[0235] Optionally, the second terminal device further includes: a second receiving unit, configured to receive a response message to the second session establishment request, the response message including an IP address corresponding to the second session, and the IP address corresponding to the second session is the same as the IP address corresponding to the first session.

[0236] Optionally, the first network element is AMF.

[0237] Figure 8 is a schematic diagram of a core network device according to an embodiment of the present application. The core network device 800 shown in Figure 8 is a first network element of the core network. As shown in Figure 8 , the core network device 800 includes a receiving unit 810 .

[0238] The receiving unit 810 is used to receive a first session establishment request sent by a first terminal device, where the first session establishment request is used to request establishment of a first session. The first session establishment request includes first information, and the first information is used to switch between the first session and a session established by a second terminal device.

[0239] Optionally, the first information is used to indicate a second session that has been established by the second terminal device.

[0240] Optionally, the first information includes one or more of the following information: relevant information of the second terminal device; relevant information of the second session.

[0241] Optionally, the relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; and an association identifier between the first terminal device and the second terminal device.

[0242] Optionally, the relevant information of the second session includes one or more of the following: an identifier of the second session; a DNN corresponding to the second session; an S-NSSAI corresponding to the second session; or an IP address corresponding to the second session.

[0243] Optionally, the first session establishment request further includes second information, where the second information is used to indicate switching from the second session to the first session.

[0244] Optionally, the core network device also includes: a sending unit, used to send a response message of the first session establishment request to the first terminal device, the response message including the IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

[0245] Optionally, the sending unit is also used to: send the first session establishment request to the second network element of the core network, the first session establishment request including one or more of the following information: second information used to indicate switching from the second session to the first session; fourth information used to indicate the second session.

[0246] Optionally, the receiving unit is further configured to: receive a response message to the first session establishment request, where the response message to the first session establishment request includes an IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

[0247] Optionally, the second network element is an SMF.

[0248] Optionally, the first information is used to indicate one or more of the following: relevant information of the second terminal device; relevant information of the first session.

[0249] Optionally, the relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; and an association identifier between the first terminal device and the second terminal device.

[0250] Optionally, the relevant information of the first session includes one or more of the following: the DNN corresponding to the first session; the S-NSSAI corresponding to the first session.

[0251] Optionally, the first session establishment request further includes third information, where the third information is used to indicate that the first session can be used for session switching.

[0252] Optionally, after the first network element of the core network receives the first session establishment request sent by the first terminal device, the receiving unit is further used to: receive a second session establishment request sent by the second terminal device, where the second session establishment request is used to request establishment of a second session.

[0253] Optionally, the second session establishment request includes relevant information of the second session, and the relevant information of the second session is the same as the relevant information of the first session.

[0254] Optionally, the sending unit is further used to: send a response message to the second session establishment request to the second terminal device, the response message including the IP address corresponding to the second session, and the IP address corresponding to the second session is the same as the IP address corresponding to the first session.

[0255] Optionally, the sending unit is further configured to send the second session establishment request to a second network element in the core network, where the second session establishment request includes relevant information of the second session, and the relevant information of the second session is the same as the relevant information of the first session.

[0256] Optionally, the receiving unit is further configured to: receive a response message to the second session establishment request, where the response message to the second session establishment request includes an IP address corresponding to the second session, and the IP address corresponding to the second session is the same as the IP address corresponding to the first session.

[0257] Optionally, the second network element is an SMF.

[0258] Optionally, the first network element is AMF.

[0259] Figure 9 is a schematic diagram of a core network device according to an embodiment of the present application. The core network device 900 shown in Figure 9 is a second network element of the core network. As shown in Figure 9 , the core network device 900 includes a receiving unit 910 .

[0260] The receiving unit 910 is used to receive a first session establishment request sent by a first network element of the core network, where the first session establishment request is used to request establishment of a first session for a first terminal device. The first session establishment request includes first information, and the first information is used to switch between the first session and the session established with the second terminal device.

[0261] Optionally, the first information is used to indicate a second session that has been established by the second terminal device.

[0262] Optionally, the first information includes one or more of the following information: relevant information of the second terminal device; relevant information of the second session.

[0263] Optionally, the relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; and an association identifier between the first terminal device and the second terminal device.

[0264] Optionally, the relevant information of the second session includes one or more of the following: an identifier of the second session; a DNN corresponding to the second session; an S-NSSAI corresponding to the second session; or an IP address corresponding to the second session.

[0265] Optionally, the first session establishment request further includes second information, where the second information is used to indicate switching from the second session to the first session.

[0266] Optionally, the core network device also includes: a sending unit, used to send a response message of the first session establishment request to the first network element, the response message of the first session establishment request includes the IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

[0267] Optionally, the sending unit is further configured to: in response to the first session establishment request message, send a first message to a third network element of the core network, wherein the first message is configured to instruct the third network element to allocate the same IP address as the second session to the first session.

[0268] Optionally, the first message includes one or more of the following: an identifier of the second session; and an IP address corresponding to the second session.

[0269] Optionally, the third network element is a UPF.

[0270] Optionally, the first information is used to indicate one or more of the following: relevant information of the second terminal device; relevant information of the first session.

[0271] Optionally, the relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; and an association identifier between the first terminal device and the second terminal device.

[0272] Optionally, the relevant information of the first session includes one or more of the following: the DNN corresponding to the first session; the S-NSSAI corresponding to the first session.

[0273] Optionally, the first session establishment request further includes third information, where the third information is used to indicate that the first session can be used for session switching.

[0274] Optionally, the receiving unit is further used to: after receiving the first session establishment request sent by the first network element of the core network, receive a second session establishment request sent by the first network element, where the second session establishment request is used to request establishment of a second session for the second terminal device.

[0275] Optionally, the second session establishment request includes relevant information of the second session, and the relevant information of the second session is the same as the relevant information of the first session.

[0276] Optionally, the sending unit is further used to: send a response message of the second session establishment request to the first network element, the response message including the IP address corresponding to the second session, and the IP address corresponding to the second session is the same as the IP address corresponding to the first session.

[0277] Optionally, the sending unit is further used to: in response to the second session establishment request message, send a first message to a third network element of the core network, where the first message is used to instruct the third network element to allocate the same IP address as the first session to the second session.

[0278] Optionally, the first message includes one or more of the following: an identifier of the first session; and an IP address corresponding to the first session.

[0279] Optionally, the third network element is a UPF.

[0280] Optionally, the second network element is an SMF.

[0281] Optionally, the first network element is AMF.

[0282] Figure 10 is a schematic block diagram of a communication device according to an embodiment of the present application. The dashed lines in Figure 10 indicate that the unit or module is optional. The device 1000 may be used to implement the method described in the above method embodiment. The device 1000 may be a chip, a terminal device, or a network device.

[0283] The device 1000 may include one or more processors 1010. The processor 1010 may support the device 1000 to implement the method described in the method embodiment above. The processor 1010 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0284] The apparatus 1000 may further include one or more memories 1020. The memories 1020 store programs that can be executed by the processor 1010, causing the processor 1010 to perform the methods described in the above method embodiments. The memories 1020 may be independent of the processor 1010 or integrated into the processor 1010.

[0285] The apparatus 1000 may further include a transceiver 1030. The processor 1010 may communicate with other devices or chips via the transceiver 1030. For example, the processor 1010 may transmit and receive data with other devices or chips via the transceiver 1030.

[0286] The present application also provides a computer-readable storage medium for storing a program. The computer-readable storage medium can be applied to a terminal or network device provided in the present application, and the program enables a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0287] The present application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to a terminal or network device provided in the present application, and the program causes a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0288] The embodiments of the present application also provide a computer program. The computer program can be applied to the terminal or network device provided in the embodiments of the present application, and the computer program enables a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0289] It should be understood that the terms used in this application are intended only to explain the specific embodiments of this application and are not intended to limit this application. The terms "first," "second," and so on in the specification, claims, and accompanying drawings of this application are used to distinguish between different objects, not to describe a specific order. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0290] In the embodiments of this application, the term "indication" may refer to a direct indication, an indirect indication, or an indication of an association. For example, "A indicates B" may refer to a direct indication of B, e.g., B can obtain information through A; it may refer to an indirect indication of B, e.g., A indicates C, e.g., B can obtain information through C; or it may refer to an association between A and B.

[0291] In the embodiment of the present application, "B corresponding to A" means that B is associated with A and B can be determined based on A. However, it should be understood that determining B based on A does not mean determining B based solely on A, but B can also be determined based on A and / or other information.

[0292] In the embodiments of the present application, the term "corresponding" may indicate a direct or indirect correspondence between the two, or an association relationship between the two, or a relationship between indication and indication, configuration and configuration, etc.

[0293] In the embodiments of the present application, "pre-definition" or "pre-configuration" may be implemented by pre-storing corresponding codes, tables, or other methods that can be used to indicate relevant information in a device (e.g., a terminal device and a network device). The present application does not limit the specific implementation method. For example, pre-definition may refer to information defined in a protocol.

[0294] In the embodiments of the present application, the “protocol” may refer to a standard protocol in the communications field, for example, it may include an LTE protocol, an NR protocol, and related protocols used in future communication systems, and the present application does not limit this.

[0295] In the embodiments of this application, the term "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0296] In various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0297] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0298] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0299] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0300] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be read by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital versatile disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0301] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A wireless communication method, characterized in that: include: The first terminal device sends a first session establishment request to the first network element of the core network, where the first session establishment request is used to request establishment of a first session. The first session establishment request includes first information, where the first information is used to switch between the first session and a session established by the second terminal device.

2. The method according to claim 1, characterized in that The first information is used to indicate a second session that has been established by the second terminal device.

3. The method according to claim 2, characterized in that The first information includes one or more of the following information: relevant information of the second terminal device; Related information of the second session.

4. The method according to claim 3, characterized in that The relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; The association identifier of the first terminal device and the second terminal device.

5. The method according to claim 3 or 4, characterized in that The relevant information of the second session includes one or more of the following: an identifier of the second session; The DNN corresponding to the second session; The S-NSSAI corresponding to the second session; The IP address corresponding to the second session.

6. The method according to any one of claims 2 to 5, characterized in that The first session establishment request further includes second information, where the second information is used to indicate switching from the second session to the first session.

7. The method according to any one of claims 2 to 6, characterized in that The method further comprises: The first terminal device receives a response message to the first session establishment request, where the response message includes an IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

8. The method according to claim 1, characterized in that The first information is used to indicate one or more of the following: relevant information of the second terminal device; Related information of the first session.

9. The method according to claim 8, characterized in that The relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; The association identifier of the first terminal device and the second terminal device.

10. The method according to claim 8 or 9, characterized in that The relevant information of the first session includes one or more of the following: The DNN corresponding to the first session; The S-NSSAI corresponding to the first session.

11. The method according to any one of claims 8 to 10, characterized in that The first session establishment request further includes third information, where the third information is used to indicate that the first session can be used for session switching.

12. The method according to any one of claims 8 to 11, characterized in that After the first terminal device sends the first session establishment request to the first network element of the core network, the method further includes: The second terminal device sends a second session establishment request to the first network element, where the second session establishment request is used to request establishment of a second session.

13. The method according to claim 12, characterized in that The second session establishment request includes relevant information of the second session, and the relevant information of the second session is the same as the relevant information of the first session.

14. The method according to claim 12 or 13, characterized in that The method further comprises: The second terminal device receives a response message to the second session establishment request, where the response message includes an IP address corresponding to the second session, and the IP address corresponding to the second session is the same as the IP address corresponding to the first session.

15. The method according to any one of claims 1 to 14, characterized in that The first network element is AMF.

16. A wireless communication method, characterized in that: include: The first network element of the core network receives a first session establishment request sent by a first terminal device, where the first session establishment request is used to request establishment of a first session, and the first session establishment request includes first information, where the first information is used to switch between the first session and a session established by a second terminal device.

17. The method according to claim 16, characterized in that The first information is used to indicate a second session that has been established by the second terminal device.

18. The method according to claim 17, characterized in that The first information includes one or more of the following information: relevant information of the second terminal device; Related information of the second session.

19. The method according to claim 18, characterized in that The relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; The association identifier of the first terminal device and the second terminal device.

20. The method according to claim 18 or 19, characterized in that The relevant information of the second session includes one or more of the following: an identifier of the second session; The DNN corresponding to the second session; The S-NSSAI corresponding to the second session; The IP address corresponding to the second session.

21. The method according to any one of claims 17 to 20, characterized in that The first session establishment request further includes second information, where the second information is used to indicate switching from the second session to the first session.

22. The method according to any one of claims 17 to 21, characterized in that The method further comprises: The first network element sends a response message to the first session establishment request to the first terminal device, where the response message includes an IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

23. The method according to any one of claims 17 to 22, characterized in that The method further comprises: The first network element sends the first session establishment request to the second network element of the core network, where the first session establishment request includes one or more of the following information: second information, used to indicate switching from the second session to the first session; The fourth information is used to indicate the second session.

24. The method according to claim 23, wherein The method further comprises: The first network element receives a response message to the first session establishment request, where the response message to the first session establishment request includes an IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

25. The method according to claim 23 or 24, characterized in that The second network element is SMF.

26. The method according to claim 16, wherein The first information is used to indicate one or more of the following: relevant information of the second terminal device; Related information of the first session.

27. The method according to claim 26, characterized in that The relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; The association identifier of the first terminal device and the second terminal device.

28. The method according to claim 26 or 27, characterized in that The relevant information of the first session includes one or more of the following: The DNN corresponding to the first session; The S-NSSAI corresponding to the first session.

29. The method according to any one of claims 26 to 28, characterized in that The first session establishment request further includes third information, where the third information is used to indicate that the first session can be used for session switching.

30. The method according to any one of claims 11 to 14, characterized in that After the first network element of the core network receives the first session establishment request sent by the first terminal device, the method further includes: The first network element receives a second session establishment request sent by the second terminal device, where the second session establishment request is used to request establishment of a second session.

31. The method according to claim 30, wherein The second session establishment request includes relevant information of the second session, and the relevant information of the second session is the same as the relevant information of the first session.

32. The method according to claim 30 or 31, characterized in that The method further comprises: The first network element sends a response message to the second session establishment request to the second terminal device, where the response message includes an IP address corresponding to the second session, and the IP address corresponding to the second session is the same as the IP address corresponding to the first session.

33. The method according to any one of claims 30 to 32, characterized in that The method further comprises: The first network element sends the second session establishment request to the second network element in the core network, where the second session establishment request includes relevant information of the second session, and the relevant information of the second session is the same as the relevant information of the first session.

34. The method according to claim 33, wherein The method further comprises: The first network element receives a response message to the second session establishment request, where the response message to the second session establishment request includes an IP address corresponding to the second session, and the IP address corresponding to the second session is the same as the IP address corresponding to the first session.

35. The method according to claim 33 or 34, characterized in that The second network element is SMF.

36. The method according to any one of claims 16 to 35, characterized in that The first network element is AMF.

37. A wireless communication method, characterized in that: include: The second network element of the core network receives a first session establishment request sent by the first network element of the core network, where the first session establishment request is used to request establishment of a first session for a first terminal device, and the first session establishment request includes first information, which is used to switch between the first session and the session established with the second terminal device.

38. The method according to claim 37, wherein The first information is used to indicate a second session that has been established by the second terminal device.

39. The method according to claim 38, characterized in that The first information includes one or more of the following information: relevant information of the second terminal device; Related information of the second session.

40. The method according to claim 39, wherein The relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; The association identifier of the first terminal device and the second terminal device.

41. The method according to claim 39 or 40, characterized in that The relevant information of the second session includes one or more of the following: an identifier of the second session; The DNN corresponding to the second session; The S-NSSAI corresponding to the second session; The IP address corresponding to the second session.

42. The method according to any one of claims 38 to 41, characterized in that The first session establishment request further includes second information, where the second information is used to indicate switching from the second session to the first session.

43. The method according to any one of claims 38 to 42, characterized in that The method further comprises: The second network element sends a response message to the first session establishment request to the first network element, where the response message to the first session establishment request includes an IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

44. The method according to any one of claims 38 to 43, characterized in that The method further comprises: In response to the first session establishment request message, the second network element sends a first message to a third network element of the core network, where the first message is used to instruct the third network element to allocate the same IP address as the second session to the first session.

45. The method according to claim 44, wherein The first message includes one or more of the following: an identifier of the second session; The IP address corresponding to the second session.

46. The method according to claim 44 or 45, characterized in that The third network element is UPF.

47. The method according to claim 37, wherein The first information is used to indicate one or more of the following: relevant information of the second terminal device; Related information of the first session.

48. The method according to claim 47, wherein The relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; The association identifier of the first terminal device and the second terminal device.

49. The method according to claim 47 or 48, characterized in that The relevant information of the first session includes one or more of the following: The DNN corresponding to the first session; The S-NSSAI corresponding to the first session.

50. The method according to any one of claims 47 to 49, characterized in that The first session establishment request further includes third information, where the third information is used to indicate that the first session can be used for session switching.

51. The method according to any one of claims 47 to 50, characterized in that After the second network element of the core network receives the first session establishment request sent by the first network element of the core network, the method further includes: The second network element receives a second session establishment request sent by the first network element, where the second session establishment request is used to request establishment of a second session for the second terminal device.

52. The method according to claim 51, characterized in that The second session establishment request includes relevant information of the second session, and the relevant information of the second session is the same as the relevant information of the first session.

53. The method according to claim 51 or 52, characterized in that The method further comprises: The second network element sends a response message to the second session establishment request to the first network element, where the response message includes an IP address corresponding to the second session, and the IP address corresponding to the second session is the same as the IP address corresponding to the first session.

54. The method according to any one of claims 51 to 53, characterized in that The method further comprises: In response to the second session establishment request message, the second network element sends a first message to a third network element of the core network, where the first message is used to instruct the third network element to allocate the same IP address as the first session to the second session.

55. The method according to claim 54, characterized in that The first message includes one or more of the following: an identifier of the first session; The IP address corresponding to the first session.

56. The method according to claim 54 or 55, characterized in that The third network element is UPF.

57. The method according to any one of claims 37 to 56, characterized in that The second network element is SMF.

58. The method according to any one of claims 37 to 57, characterized in that The first network element is AMF.

59. A terminal device, characterized in that: The terminal device includes a first terminal device, and the terminal device includes: A first sending unit is used to send a first session establishment request to a first network element of a core network, where the first session establishment request is used to request establishment of a first session, and the first session establishment request includes first information, where the first information is used to switch between the first session and a session established with a second terminal device.

60. The terminal device according to claim 59, characterized in that The first information is used to indicate a second session that has been established by the second terminal device.

61. The terminal device according to claim 60, characterized in that The first information includes one or more of the following information: relevant information of the second terminal device; Related information of the second session.

62. The terminal device according to claim 61, characterized in that The relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; The association identifier of the first terminal device and the second terminal device.

63. The terminal device according to claim 61 or 62, characterized in that: The relevant information of the second session includes one or more of the following: an identifier of the second session; The DNN corresponding to the second session; The S-NSSAI corresponding to the second session; The IP address corresponding to the second session.

64. The terminal device according to any one of claims 60 to 63, characterized in that: The first session establishment request further includes second information, where the second information is used to indicate switching from the second session to the first session.

65. The terminal device according to any one of claims 60 to 64, characterized in that The terminal device further includes: The first receiving unit is configured to receive a response message to the first session establishment request, where the response message includes an IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

66. The terminal device according to claim 59, characterized in that The first information is used to indicate one or more of the following: relevant information of the second terminal device; Related information of the first session.

67. The terminal device according to claim 66, characterized in that The relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; The association identifier of the first terminal device and the second terminal device.

68. The terminal device according to claim 66 or 67, characterized in that: The relevant information of the first session includes one or more of the following: The DNN corresponding to the first session; The S-NSSAI corresponding to the first session.

69. The terminal device according to any one of claims 66 to 68, characterized in that The first session establishment request further includes third information, where the third information is used to indicate that the first session can be used for session switching.

70. The terminal device according to any one of claims 66 to 69, characterized in that: The terminal device further includes a second terminal device, and the second terminal device further includes: The second sending unit is used to send a second session establishment request to the first network element of the core network after the first terminal device sends the first session establishment request to the first network element of the core network, where the second session establishment request is used to request to establish a second session.

71. The terminal device according to claim 70, characterized in that The second session establishment request includes relevant information of the second session, and the relevant information of the second session is the same as the relevant information of the first session.

72. The terminal device according to claim 70 or 71, characterized in that: The second terminal device further includes: The second receiving unit is configured to receive a response message to the second session establishment request, where the response message includes an IP address corresponding to the second session, and the IP address corresponding to the second session is the same as the IP address corresponding to the first session.

73. The terminal device according to any one of claims 59 to 72, characterized in that The first network element is AMF.

74. A core network device, characterized in that: The core network device is a first network element of the core network, and the core network device includes: A receiving unit is configured to receive a first session establishment request sent by a first terminal device, where the first session establishment request is used to request establishment of a first session, and the first session establishment request includes first information, where the first information is used to switch between the first session and a session established by a second terminal device.

75. The core network device according to claim 74, characterized in that: The first information is used to indicate a second session that has been established by the second terminal device.

76. The core network device according to claim 75, characterized in that The first information includes one or more of the following information: relevant information of the second terminal device; Related information of the second session.

77. The core network device according to claim 76, characterized in that The relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; The association identifier of the first terminal device and the second terminal device.

78. The core network device according to claim 76 or 77, characterized in that: The relevant information of the second session includes one or more of the following: an identifier of the second session; The DNN corresponding to the second session; The S-NSSAI corresponding to the second session; The IP address corresponding to the second session.

79. The core network device according to any one of claims 75 to 78, characterized in that: The first session establishment request further includes second information, where the second information is used to indicate switching from the second session to the first session.

80. The core network device according to any one of claims 75 to 79, characterized in that: The core network equipment further includes: A sending unit is used to send a response message of the first session establishment request to the first terminal device, where the response message includes an IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

81. The core network device according to any one of claims 75 to 80, characterized in that: The sending unit is further configured to: Send the first session establishment request to the second network element of the core network, where the first session establishment request includes one or more of the following information: second information, used to indicate switching from the second session to the first session; The fourth information is used to indicate the second session.

82. The core network device according to claim 81, characterized in that: The receiving unit is further configured to: A response message to the first session establishment request is received, where the response message to the first session establishment request includes an IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

83. The core network device according to claim 81 or 82, characterized in that: The second network element is SMF.

84. The core network device according to claim 74, characterized in that The first information is used to indicate one or more of the following: relevant information of the second terminal device; Related information of the first session.

85. The core network device according to claim 84, characterized in that: The relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; The association identifier of the first terminal device and the second terminal device.

86. The core network device according to claim 84 or 85, characterized in that: The relevant information of the first session includes one or more of the following: The DNN corresponding to the first session; The S-NSSAI corresponding to the first session.

87. The core network device according to any one of claims 84 to 86, characterized in that: The first session establishment request further includes third information, where the third information is used to indicate that the first session can be used for session switching.

88. The core network device according to any one of claims 84 to 87, characterized in that: After the first network element of the core network receives the first session establishment request sent by the first terminal device, the receiving unit is further configured to: A second session establishment request sent by the second terminal device is received, where the second session establishment request is used to request establishment of a second session.

89. The core network device according to claim 88, characterized in that The second session establishment request includes relevant information of the second session, and the relevant information of the second session is the same as the relevant information of the first session.

90. The core network device according to claim 88 or 89, characterized in that: The sending unit is further configured to: A response message of the second session establishment request is sent to the second terminal device, where the response message includes an IP address corresponding to the second session, and the IP address corresponding to the second session is the same as the IP address corresponding to the first session.

91. The core network device according to any one of claims 88 to 90, characterized in that: The sending unit is further configured to: The second session establishment request is sent to a second network element in the core network, where the second session establishment request includes relevant information of the second session, and the relevant information of the second session is the same as the relevant information of the first session.

92. The core network device according to claim 91, characterized in that The receiving unit is further configured to: Receive a response message to the second session establishment request, where the response message to the second session establishment request includes the second session pair. The IP address corresponding to the second session is the same as the IP address corresponding to the first session.

93. The core network device according to claim 91 or 92, characterized in that: The second network element is SMF.

94. The core network device according to any one of claims 74 to 93, characterized in that: The first network element is AMF.

95. A core network device, characterized in that: The core network device is a second network element of the core network, and the core network device includes: A receiving unit is used to receive a first session establishment request sent by a first network element of a core network, where the first session establishment request is used to request establishment of a first session for a first terminal device, and the first session establishment request includes first information, where the first information is used to switch between the first session and a session established with a second terminal device.

96. The core network device according to claim 95, characterized in that The first information is used to indicate a second session that has been established by the second terminal device.

97. The core network device according to claim 96, characterized in that The first information includes one or more of the following information: relevant information of the second terminal device; Related information of the second session.

98. The core network device according to claim 97, characterized in that: The relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; The association identifier of the first terminal device and the second terminal device.

99. The core network device according to claim 97 or 98, characterized in that: The relevant information of the second session includes one or more of the following: an identifier of the second session; The DNN corresponding to the second session; The S-NSSAI corresponding to the second session; The IP address corresponding to the second session.

100. The core network device according to any one of claims 96 to 99, characterized in that: The first session establishment request further includes second information, where the second information is used to indicate switching from the second session to the first session.

101. The core network device according to any one of claims 96 to 100, characterized in that: The core network equipment further includes: A sending unit is used to send a response message to the first session establishment request to the first network element, where the response message to the first session establishment request includes an IP address corresponding to the first session, and the IP address corresponding to the first session is the same as the IP address corresponding to the second session.

102. The core network device according to any one of claims 96 to 101, characterized in that: The sending unit is further configured to: In response to the first session establishment request message, a first message is sent to a third network element of the core network, where the first message is used to instruct the third network element to allocate the same IP address as the second session to the first session.

103. The core network device according to claim 102, characterized in that: The first message includes one or more of the following: an identifier of the second session; The IP address corresponding to the second session.

104. The core network device according to claim 102 or 103, characterized in that: The third network element is UPF.

105. The core network device according to claim 95, characterized in that: The first information is used to indicate one or more of the following: relevant information of the second terminal device; Related information of the first session.

106. The core network device according to claim 105, characterized in that: The relevant information of the second terminal device includes one or more of the following: an identifier of the second terminal device; The association identifier of the first terminal device and the second terminal device.

107. The core network device according to claim 105 or 106, characterized in that: The relevant information of the first session includes one or more of the following: The DNN corresponding to the first session; The S-NSSAI corresponding to the first session.

108. The core network device according to any one of claims 105 to 107, characterized in that: The first session establishment request further includes third information, where the third information is used to indicate that the first session can be used for session switching.

109. The core network device according to any one of claims 105 to 108, characterized in that: The receiving unit is further configured to: after receiving the first session establishment request sent by the first network element of the core network, receive a second session establishment request sent by the first network element, where the second session establishment request is used to request establishment of a second session for the second terminal device.

110. The core network device according to claim 109, characterized in that: The second session establishment request includes relevant information of the second session, and the relevant information of the second session is the same as the relevant information of the first session.

111. The core network device according to claim 109 or 110, characterized in that: The sending unit is further configured to: Sending a response message to the second session establishment request to the first network element, where the response message includes an IP address corresponding to the second session, and the IP address corresponding to the second session is the same as the IP address corresponding to the first session.

112. The core network device according to any one of claims 109 to 111, characterized in that: The sending unit is further configured to: In response to the second session establishment request message, a first message is sent to a third network element of the core network, where the first message is used to instruct the third network element to allocate the same IP address as the first session to the second session.

113. The core network device according to claim 112, characterized in that: The first message includes one or more of the following: an identifier of the first session; The IP address corresponding to the first session.

114. The core network device according to claim 112 or 113, characterized in that: The third network element is UPF.

115. The core network device according to any one of claims 95 to 114, characterized in that: The second network element is SMF.

116. The core network device according to any one of claims 95 to 115, characterized in that: The first network element is AMF.

117. A terminal device, characterized in that: The terminal device comprises a transceiver, a memory and a processor, wherein the memory is used to store a program, and the processor is used to call the program in the memory and control the transceiver to receive or send a signal so that the terminal device executes the method according to any one of claims 1 to 15.

118. A core network device, characterized in that: It includes a transceiver, a memory and a processor, the memory is used to store programs, the processor is used to call the programs in the memory and control the transceiver to receive or send signals so that the core network device executes the method as described in any one of claims 16-58.

119. A device, characterized in that The device comprises a processor configured to call a program from a memory so as to cause the device to execute the method according to any one of claims 1 to 58.

120. A chip, characterized in that: The device comprises a processor configured to call a program from a memory so that a device equipped with the chip executes the method according to any one of claims 1 to 58.

121. A computer-readable storage medium, characterized in that A program is stored thereon, the program causing a computer to execute the method according to any one of claims 1 to 58.

122. A computer program product, characterized in that The method comprises a program for causing a computer to execute the method according to any one of claims 1 to 58.

123. A computer program, characterized in that The computer program causes a computer to execute the method according to any one of claims 1 to 58.

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