Session management method and communication device

Abstract

The invention provides a session management method and a communication device, relates to the field of communication, and is used for ensuring normal proceeding of a session switching process, improving the flexibility of session switching and the integrity of a management process after an AMF (Advanced Media Function) is changed. The method comprises the following steps: receiving first information, wherein the first information is used for indicating whether a first access and mobility management function network element supports dual orientation; a first authorization result is obtained according to the first information, the first authorization result is used for indicating whether switching from a first session to a second session is allowed or not, the first session is a session between the first terminal and a network, the second session is a session between the second terminal and the network, and the bi-directional device comprises the first terminal and the second terminal; and the first access and mobility management function network element is used for managing the second terminal.

Description

Technical Field

[0001] This application relates to the field of communications, and more particularly to a session management method and a communication device. Background Technology

[0002] With the rapid development of communication technology, devices that support multiple subscriber identity module (SIM) cards or include two terminal devices have emerged, such as DualSteer Devices. DualSteer Devices are devices that support user data switching across two 3rd generation partnership project (3GPP) access networks. These devices may include two or more terminal devices. The following description uses DualSteer Devices as an example to illustrate this type of device.

[0003] In dual-directional devices, the terminal devices are connected to the same session management function (SMF) network element on the control plane, allowing user data to be switched between different terminal devices.

[0004] Under the influence of factors such as location changes or network limitations, the access and mobility management function (AMF) of the dual-direction device may change. Considering that the changed AMF may not have the relevant capabilities to support dual-direction DualSteer, causing the dual-direction device to be unable to implement session-related functions (such as session handover), how to implement the session management process of the dual-direction device after the AMF change is a problem that needs to be explored. Summary of the Invention

[0005] This application provides a session management method and communication device that enables dual-directional devices to implement session management processes (including session handover processes) after changing the access AMF.

[0006] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0007] Firstly, a session management method is provided. This method can be applied to a first communication device, which may be a terminal device (such as a dual-directional device) or a network element. For example, the first communication device may be an Access and Mobility Management Function (AMF) network element (specifically, the first communication device may be an AMF supporting dual-directionality) or a Session Management Function (SMF) network element. The method can also be applied to components within the first communication device, such as chips or processors in the dual-directional device, the AMF network element, or the session management function network element. The method can also be implemented by logical nodes, logical modules, or software capable of implementing all or part of the first communication device. For ease of description, the following description assumes the method is executed by the first communication device. The session management method includes:

[0008] The first communication device receives first information, which is used to indicate whether the first access and mobility management function network element supports dual-direction;

[0009] The first communication device obtains a first authorization result based on the first information, wherein the first authorization result is used to indicate whether to allow a switch from a first session to a second session, the first session being a session between a first terminal and the network, the second session being a session between a second terminal and the network, the dual-directional device including a first terminal and a second terminal, and the first access and mobility management function network element being used to manage the second terminal.

[0010] In this embodiment, the second terminal accesses the first access and mobility management function (MLM) network element, and the first terminal accesses the second access and mobility management function (MLM) network element. The first access and mobility management function (MLM) network element is the access and mobility management function network element that the second terminal (or a dual-directional device including the first terminal) replaces due to location changes or network factors.

[0011] In the session-related process of dual-direction devices, considering that the modified first access and mobility management function network element may not have the relevant capabilities to support dual-direction (or session handover), the method provided in this application embodiment establishes a relevant channel for the first communication device (exemplarily, if the first communication device is an AMF, it can be a second access and mobility management function network element) to understand whether the first access and mobility management function network element supports dual-direction capability, thereby realizing the session management process (including the session handover management process).

[0012] Furthermore, the session management process is illustrated below using the session handover management process as an example. The first communication device receives first information regarding whether the first access and mobility management function network element supports session handover, and determines whether the session handover process should continue. This helps the first communication device or subsequent devices related to the process to adjust the session and related policies in a timely manner according to the characteristics of the first access and mobility management function network element. This avoids the situation where the session handover service process cannot proceed normally due to the first access and mobility management function network element not supporting session handover, and enables the dual-directional device to implement the session management process (including the session handover process) after changing the access AMF.

[0013] In one optional implementation, the first information includes first capability information or a second authorization result of the first access and mobility management function network element, wherein the first capability information is used to indicate whether the first access and mobility management function network element supports dual-direction DualSteer, and the second authorization result includes the result that the first access and mobility management function network element supports dual-direction or the result that the first access and mobility management function network element does not support dual-direction.

[0014] In this embodiment, the first capability information indicates whether the first access and mobility management function network element supports dual-direction, representing whether the first access and mobility management function network element has the relevant function to implement dual-direction or whether it has the capability to implement dual-direction. Therefore, by refining the content of the first information in different scenarios, the receiver can more accurately understand the capability or authorization status of the first access and mobility management function network element. This helps the receiver (such as the first communication device) to more accurately judge the feasibility of the session management process (e.g., session handover), thereby making more reasonable decisions and improving the efficiency and accuracy of session management.

[0015] In one alternative implementation, if the first information indicates that the first access and mobility management function network element supports dual-direction, the first authorization result includes allowing a handover from the first session to the second session;

[0016] If the first information indicates that the first access and mobility management function network element does not support dual-direction, then the first authorization result includes not allowing a handover from the first session to the second session.

[0017] The first communication device is enabled to determine whether the first access and mobility management function network element supports dual-direction capability, so as to avoid the situation where the session handover process cannot proceed normally because the first access and mobility management function network element does not support dual-direction.

[0018] In one optional implementation, the method further includes:

[0019] Send the first authorization result to the dual-directional device.

[0020] In an optional implementation, the first authorization result includes disallowing a switch from the first session to the second session, and the method further includes:

[0021] Update the first session to a non-bidirectional session.

[0022] It is understood that "non-dual-direction session" refers to a session other than a dual-direction session, such as a session without a dual-direction identifier. In this embodiment, by updating the first session to a non-dual-direction session, the session handover process can proceed normally when the first access and mobility management function network element does not support dual-direction capability.

[0023] In one alternative implementation, updating the first session to a non-bidirectional session includes:

[0024] Send a second message, which indicates that the first session should be updated to a non-bidirectional session.

[0025] In an alternative implementation, the first authorization result includes allowing a switch from the first session to the second session, and the method further includes:

[0026] Send a third message, which indicates that the first session should be switched to the second session.

[0027] In this embodiment, the feasibility of session switching can be comprehensively assessed based on the establishment status of the first session and network capability information. This comprehensive evaluation mechanism ensures the scientific and accurate nature of the decision-making process, avoiding errors caused by insufficient or incorrect information. Simultaneously, it provides a reliable basis for subsequent network resource allocation and session management, contributing to the optimization of network resource utilization efficiency.

[0028] In one optional implementation, obtaining the first authorization result based on the first information includes:

[0029] The first authorization result is obtained based on the establishment of the first session and the first information.

[0030] The first communication device is enabled to combine the first information with its own trigger point to determine whether to perform a session switch. In this embodiment, the trigger point is the establishment status of the first session; it should be understood that the establishment status of the first session includes both established and not established.

[0031] Secondly, a session management method is provided. This method can be applied to unified data management (UDM) network elements or access and mobility management function (UAM) network elements; it can also be applied to components within unified data management or UAM network elements, such as chips or processors; and it can also be implemented by logical nodes, logical modules, or software capable of implementing all or part of the unified data management or UAM network elements. The session management method includes:

[0032] Obtain first information, which is used to indicate whether the first access and mobility management function network element supports dual-direction, the dual-direction device includes a second terminal, and the first access and mobility management function network element is used to manage the second terminal;

[0033] Send the first message.

[0034] Considering that the modified first access and mobility management function network element may not have the relevant capabilities to support dual-direction (DualSteer), for example, the relevant capabilities may specifically refer to the ability of the first access and mobility management function network element to participate in the session handover process in the dual-direction device. The method provided in this application establishes a channel through which a unified data management function network element or an access and mobility management function network element (such as the second access and mobility management function network element mentioned above) understands whether the first access and mobility management function network element supports dual-direction capabilities, thereby establishing a session pipeline.

[0035] In one optional implementation, obtaining the first information includes:

[0036] The fourth information is received, which includes the second capability information of the first access and mobility management function network element or the identifier of the first access and mobility management function network element. The second capability information is used to indicate that the first access and mobility management function network element supports dual-direction. The identifier of the first access and mobility management function network element is used to determine the first capability information of the first access and mobility management function network element. The first capability information is used to indicate whether the first access and mobility management function network element supports dual-direction.

[0037] The first information is determined based on the fourth information.

[0038] By receiving and processing fourth information (such as second capability information or identifiers of first access and mobility management function network elements), network elements such as UDM can gain a more comprehensive understanding of the network status, thereby generating first information more accurately. This indirect acquisition method increases the diversity and reliability of information, helping to improve the accuracy and flexibility of network decision-making.

[0039] In one alternative implementation, the registration request message includes fourth information, which is used to request the registration of the first access and mobility management function network element to the unified data management function network element.

[0040] Embedding the fourth piece of information into the registration request message combines the network element registration process with the capability information reporting process. This integration simplifies network management procedures, reduces additional signaling overhead, and improves the utilization efficiency of network resources.

[0041] In one optional implementation, the first information includes first capability information or a second authorization result of the first access and mobility management function network element, wherein the first capability information is used to indicate whether the first access and mobility management function network element supports dual redirection, and the second authorization result includes the result that the first access and mobility management function network element supports dual redirection or the result that the first access and mobility management function network element does not support dual redirection.

[0042] In one optional implementation, the method further includes:

[0043] The second authorization result is determined based on the first capability information or the second capability information of the first access and mobility management function network element.

[0044] In this embodiment, the unified data management function network element is used as one of the management nodes for session handover. The unified data management function network element is enabled to determine the second authorization result by combining the characteristics of whether the first access and mobility management function network elements support dual-direction.

[0045] In an optional embodiment, the dual-directional device further includes a first terminal, and the method further includes:

[0046] The second access and mobility management function network element for managing the first terminal is determined based on the first identifier, which includes the user's permanent identifier for the first terminal.

[0047] The second aspect enables the implementing entity to clearly define the participants in the session-related process, thereby realizing the session management process related to dual-directional devices.

[0048] In one optional implementation, the method further includes:

[0049] The first session management function network element is determined based on the first identifier, which includes the permanent user identifier of the first terminal, and the first session is a session between the first terminal and the network.

[0050] In one optional implementation, the method further includes:

[0051] The fifth information is received. The fifth information is used to request the identifier of the first session management function network element. The fifth information includes a first identifier and a second identifier. The second identifier includes the session identifier of the first session. The first session management function network element is associated with the first session.

[0052] Send the sixth message, which includes the identifier of the first session management function network element.

[0053] In one optional implementation, obtaining the first information includes:

[0054] Receive the first message.

[0055] Thirdly, a session management method is provided. This method can be applied to an access and mobility management function (AMU) network element (this AMU network element may not be the same as the aforementioned AMU network element; for example, the AMU network element applied in this method can specifically be a first AMU network element, which can be a network element that manages the second terminal in a dual-directional device); the method can also be applied to components within the AMU network element, such as chips or processors; the method can also be implemented by logical nodes, logical modules, or software capable of implementing all or part of the AMU network element. The session management method includes:

[0056] Send the second capability information of the first access and mobility management function network element, the second capability information being used to indicate that the first access and mobility management function network element supports dual-direction;

[0057] The third information is received, which is used to instruct the initiation of switching the first session to the second session. The first session is a session between the first terminal and the network, and the second session is a session between the second terminal and the network. The dual-directional device includes the first terminal and the second terminal. The first access and mobility management function network element is used to manage the second terminal.

[0058] By proactively sending second capability information, the first access and mobility management function network element can demonstrate its capabilities to other elements in the network, thereby promoting the optimal allocation of network resources. Simultaneously, receiving third information and initiating session handover accordingly enables the network to respond more flexibly to changes in service demands, improving network response speed and adaptability.

[0059] In one alternative implementation, the method further includes:

[0060] Send a fifth message, which is used to request the identifier of the first session management function network element. The fifth message includes a first identifier and a second identifier. The second identifier includes the session identifier of the first session. The first session management function network element is associated with the first session.

[0061] Receive the sixth information, which includes the identifier of the first session management function network element.

[0062] By requesting and receiving identification information from session management function network elements, the first access and mobility management function network elements can more accurately locate and manage relevant session resources. This identification management mechanism helps to achieve refined management and efficient utilization of session resources, improving the overall performance and reliability of the network.

[0063] In one alternative implementation, the method further includes:

[0064] Based on the identifier of the first session management function network element, the seventh information is sent to the first session management function network element. The seventh information is used to indicate a session handover. The seventh information includes the first identifier, the second identifier, the third identifier, and the fourth identifier. The third identifier includes the permanent user identifier of the second terminal, and the fourth identifier includes the session identifier of the second session.

[0065] Fourthly, a communication device is provided for implementing the various methods described above. This communication device can be a first communication device in any of the above aspects or any implementation thereof, or a device including the first communication device, or a device included in the first communication device, such as a chip; or, the communication device can be a unified data management function network element in any of the above aspects or any implementation thereof, or a device including the unified data management function network element, or a device included in the unified data management function network element, such as a chip; or, the communication device can be an access and mobility management function network element in any of the above aspects or any implementation thereof, or a device including the access and mobility management function network element, or a device included in the access and mobility management function network element, such as a chip. The communication device includes modules, units, or means corresponding to the above methods, which can be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

[0066] In some possible designs, the communication device may include a processing module and a transceiver module. The transceiver module, also referred to as a transceiver unit, is used to implement the transmission and / or reception functions in any of the above aspects and their possible implementations. The transceiver module may consist of transceiver circuits, transceivers, transceivers, or communication interfaces. The processing module can be used to implement the processing functions in any of the above aspects and their possible implementations.

[0067] In some possible designs, the transceiver module includes a sending module and a receiving module, which are used to implement the sending and receiving functions in any of the above aspects and any possible implementation methods.

[0068] Fifthly, a communication device is provided, comprising: at least one processor; said processor being configured to execute a computer program or instructions to cause the communication device to perform the method described in any of the preceding aspects.

[0069] In one possible implementation, the communication device further includes the memory. Optionally, the memory is coupled to the processor; the memory may be integrated with the processor, or it may be independent of the processor. Optionally, the processor is used to execute computer programs or instructions stored in the memory.

[0070] In one possible implementation, the memory is independent of the communication device.

[0071] In one possible implementation, the communication device further includes a communication interface for communicating with modules outside the communication device.

[0072] The communication device can be a first communication device in any of the above aspects or any implementation thereof, or a device including the first communication device, or a device included in the first communication device, such as a chip; or, the communication device can be a unified data management function network element in any of the above aspects or any implementation thereof, or a device including the unified data management function network element, or a device included in the unified data management function network element, such as a chip; or, the communication device can be an access and mobility management function network element in any of the above aspects or any implementation thereof, or a device including the access and mobility management function network element, or a device included in the access and mobility management function network element, such as a chip.

[0073] In a sixth aspect, a computer-readable storage medium is provided, which stores a computer program or instructions that, when executed on a communication device, enable the communication device to perform the methods described in any of the above aspects or any implementation thereof.

[0074] In a seventh aspect, a computer program product containing instructions is provided, which, when run on a communication device, enables the communication device to perform the methods described in any of the foregoing aspects or any implementation thereof.

[0075] Eighthly, a communication device (e.g., a chip or chip system) is provided, the communication device including a processor for implementing the functions involved in any of the above aspects or any implementation thereof.

[0076] In some possible designs, the communication device includes a memory for storing necessary program instructions and data.

[0077] In some possible designs, when the device is a chip system, it can be composed of chips or contain chips and other discrete components.

[0078] Ninth aspect, a communication system is provided, the communication system comprising: a terminal device (such as a dual-directional device), a unified data management (UDM) network element, an SMF, and an AMF, as described in any of the above aspects or any implementation thereof.

[0079] It is understood that when the communication device provided by any of the fourth to ninth aspects is a chip, the aforementioned sending action / function can be understood as an output, and the aforementioned receiving action / function can be understood as an input.

[0080] The technical effects of any of the design methods in aspects four through nine can be found in the technical effects of the different design methods in aspects one, two, and three above, and will not be repeated here. Attached Figure Description

[0081] Figure 1 This is a schematic diagram of a 5GS architecture provided in an embodiment of this application;

[0082] Figure 2 A schematic diagram illustrating a session switching method provided in an embodiment of this application;

[0083] Figure 3 This is a schematic diagram of the structure of a dual-orientation device provided in an embodiment of this application;

[0084] Figure 4A A schematic diagram illustrating a session switching scenario provided in an embodiment of this application;

[0085] Figure 4B A schematic diagram illustrating yet another session switching scenario provided in an embodiment of this application;

[0086] Figure 4C A schematic diagram illustrating yet another session switching scenario provided in an embodiment of this application;

[0087] Figure 4D A schematic diagram illustrating yet another session switching scenario provided in an embodiment of this application;

[0088] Figure 5 This is a schematic diagram of a communication system architecture provided in an embodiment of this application;

[0089] Figure 6 A flowchart illustrating a session switching method provided in an embodiment of this application;

[0090] Figure 7A flowchart illustrating another session switching method provided in an embodiment of this application;

[0091] Figure 8 A flowchart illustrating another session switching method provided in an embodiment of this application;

[0092] Figure 9 A flowchart illustrating another session switching method provided in an embodiment of this application;

[0093] Figure 10 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0094] Figure 11 This is a schematic diagram of another communication device provided in an embodiment of this application. Detailed Implementation

[0095] The technical solutions of this application embodiment can be applied to various communication systems, such as Wi-Fi wireless network systems, vehicle-to-everything (V2X) communication systems, device-to-device (D2D) communication systems, vehicle-to-everything (V2X) communication systems, fourth-generation (4G) mobile communication systems, such as long-term evolution (LTE) systems, worldwide interoperability for microwave access (WiMAX) communication systems, fifth-generation (5G) mobile communication systems, such as new radio (NR) systems, and future communication systems, such as 5.5G and sixth-generation (6G) mobile communication systems.

[0096] To facilitate understanding of the technical solutions provided in the embodiments of this application, a brief introduction to the relevant technical terms is given first. The brief introduction is as follows:

[0097] First, the 5G system (5GS):

[0098] Figure 1 This is a schematic diagram of a 5GS architecture provided in an embodiment of this application. For example... Figure 1 As shown, 5GS includes: access network (AN) and core network (CN), and may also include: terminals.

[0099] The aforementioned terminal can be a terminal with transceiver capabilities, or a chip or chip system that can be installed on the terminal. This terminal can also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station (MS), mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent, or user apparatus. The terminals in the embodiments of this application may be mobile phones, cellular phones, smartphones, tablets, wireless data cards, personal digital assistants (PDAs), wireless modems, handsets, laptop computers, machine-type communication (MTC) terminals, computers with wireless transceiver capabilities, virtual reality (VR) terminals, augmented reality (AR) terminals, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical care, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, vehicle-mounted terminals, roadside units (RSUs) with terminal functions, etc. The terminal of this application may also be an on-board module, on-board unit, on-board component, on-board chip or on-board unit that is built into a vehicle as one or more components or units.

[0100] The aforementioned AN is used to implement access-related functions, providing network access capabilities for authorized users and determining transmission links of different quality levels to transmit user data based on user level, service requirements, etc. The AN forwards control signals and user data between the terminal and the CN. The AN may include access network equipment, also known as radio access network (RAN) equipment.

[0101] The Network Center (CN) is primarily responsible for maintaining the subscription data of the mobile network and providing terminals with functions such as session management, mobility management, policy management, and security authentication. The CN mainly includes all or some of the following functions: User Plane Function (UPF), Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Session Management Function (SMF), Network Slice Selection Function (NSSF), Network Exposure Function (NEF), Network Repository Function (NRF), Policy Control Function (PCF), Unified Data Management (UDM), Unified Data Repository (UDR), and Application Function (AF).

[0102] like Figure 1 As shown, the UE accesses the 5G network through the RAN device. The UE communicates with the AMF through the N1 interface (N1 for short); the RAN communicates with the AMF through the N2 interface (N2 for short); the RAN communicates with the UPF through the N3 interface (N3 for short); the SMF communicates with the UPF through the N4 interface (N4 for short); and the UPF accesses the data network (DN) through the N6 interface (N6 for short). Furthermore, Figure 1 The control plane functions shown, such as AUSF, AMF, SMF, NSSF, NEF, NRF, PCF, UDM, UDR, or AF, interact using service-oriented interfaces. For example, the service-oriented interface provided by AUSF is Nausf; AMF is Namf; SMF is Nsmf; NSSF is Nnssf; NEF is Nnef; NRF is Nnrf; PCF is Npcf; UDM is Nudm; UDR is Nudr; and AF is Naf.

[0103] RAN equipment can be a device that provides access to terminals. For example, RAN equipment may include: access network equipment for next-generation mobile communication systems, such as 6G, such as 6G base stations, or in next-generation mobile communication systems, the network equipment may also have other naming conventions, all of which are covered within the protection scope of the embodiments of this application, and this application does not limit them in any way. Alternatively, RAN equipment may also include 5G, such as gNB in ​​a new radio (NR) system, or one or a group of antenna panels (including multiple antenna panels) of a base station in 5G, or it may be a network node constituting a gNB, transmission and reception point (TRP or transmission point (TP)) or transmission measurement function (TMF), such as a building base band unit (BBU), or a centralized unit (CU) or distributed unit (DU), an RSU with base station function, or a wired access gateway, or the core network of 5G. Alternatively, RAN equipment may also include access points (APs) in wireless fidelity (WiFi) systems, wireless relay nodes, wireless backhaul nodes, various forms of macro base stations, micro base stations (also known as small stations), relay stations, access points, wearable devices, vehicle-mounted equipment, and so on.

[0104] The User-Defined Processing (UPP) is primarily responsible for user data processing (forwarding, receiving, billing, etc.). For example, a UPF can receive user data from a data network (DN) and forward it to the terminal through access network equipment. Alternatively, a UPF can receive user data from the terminal through access network equipment and forward it to the DN. A DN refers to the operator's network that provides data transmission services to users. Examples include Internet Protocol (IP) multimedia services (IMS) and the Internet. A DN can be an external network of the operator or a network controlled by the operator, used to provide services to the terminal. In a Protocol Data Unit (PDU) session, the UPF directly connected to the DN via N6 is also called the Protocol Data Unit Session Anchor (PSA).

[0105] AUSF is primarily used to perform security authentication for terminals.

[0106] The AMF (Access Window) is primarily responsible for signaling processing, such as access control, mobility management, attach and detach, and gateway selection. When an AMF network element provides services to a session in a terminal device, it provides control plane storage resources for that session to store the session identifier and the associated SMF network element identifier. In this embodiment, at least two AMFs exist, hereinafter referred to as AMF1 and AMF2. Compared to existing AMFs, the AMFs in this embodiment have some enhancements, the results of which are listed below:

[0107] (1) AMF1 and AMF2 are able to know that SUPI1 and SUPI2 are authorized by DualSteer.

[0108] (2) AMF1 can select an SMF that supports DualSteer based on the indication information of the session establishment request of the UE (such as DualSteer Device).

[0109] (3) AMF2 can select the same SMF based on the SMF information of the peer.

[0110] SMF is primarily responsible for user plane network element selection, user plane network element redirection, IP address allocation, bearer establishment, modification and release, and QoS control.

[0111] The PCF primarily supports providing a unified policy framework to control network behavior, delivering policy rules to control-layer network functions, and acquiring user subscription information related to policy decisions. The PCF can provide policies to the AMF and SMF, such as Quality of Service (QoS) policies and slice selection policies.

[0112] NSSF is primarily used to select network slices for terminals.

[0113] NEF is primarily used to support the opening of capabilities and events.

[0114] UDM is primarily responsible for managing UE subscription data, including the storage and management of UE identifiers and UE access authorization.

[0115] UDR is primarily used to store structured data, including contract data, policy data, externally exposed structured data, and application-related data.

[0116] AF primarily supports interaction with CN to provide services, such as influencing data routing decisions, policy control functions, or providing third-party services to the network side.

[0117] It is understood that the functions mentioned in the embodiments of this application can also refer to functional network elements or functional entities. For example, UPF can be referred to as UPF network element, AMF can be referred to as AMF network element, SMF can be referred to as SMF network element, PCF can be referred to as PCF network element, and so on, without limitation.

[0118] In addition, the terms "function" and "functional network element" are used interchangeably in the following text. For example, "PCF" and "PCF network element" have the same meaning. This will be explained uniformly here and will not be repeated below.

[0119] Second, session switching (DualSteer traffic switching):

[0120] Session switching refers to the ability of a DualSteer Device to switch a session on one set of subscription data to another set of subscription data, such as... Figure 2 As shown, Figure 2 This diagram illustrates a session handover embodiment provided in this application. The specific implementation is as follows: A DualSteer Device connects to the same UPF (User Provider Function) via the same operator in the user plane and to the same SMF (Supporting Management Function) in the control plane. The first and second terminals in the DualSteer Device are assigned the same IP address. Therefore, the session handover process does not affect the connection between the UPF and the Internet, thereby minimizing service interruption.

[0121] And session switching in Figure 2 Specifically, this could refer to switching from the first session to the second session. Figure 2 In the diagram, the first session is the solid curve portion between the first terminal and RAN#1 and UPF, and the second session is the dashed curve portion between the second terminal and RAN#2 and UPF.

[0122] Considering that the second session may not have been established or may be in a deactivated state before the session switch is performed, therefore... Figure 2 The second session is connected by the dashed line.

[0123] Third, DualSteer Device:

[0124] A dual-directional device can be understood as a device that supports user data switching across two 3GPP access networks, or as a device with multiple subscription permanent identifiers (SUPIs) that can share the same operator's subscription configuration. For example, ... Figure 3 As shown, Figure 3This is a schematic diagram of a dual-directional device provided in an embodiment of this application. The dual-directional device may include two subscription information or SUPIs, and there is an association between the two subscription data or SUPIs corresponding to the two subscription information. The two subscription data or the two SUPIs can be associated with the same user. In addition, the dual-directional device can be a UE with multiple subscriber identity module (SIM) cards, or it can be a device integrating multiple UEs, wherein each UE has a SIM card module and a communication module, and can establish a connection with the network.

[0125] It is understood that a dual-directional device can have two SIM cards, which can achieve dual-SIM dual-pass functionality, meaning that both SIM cards can simultaneously send and receive data. Alternatively, a dual-directional device can include two independent UEs (e.g., Figure 3 The dual-directional device can be encapsulated in the same device (i.e., a dual-directional device), or UE1 and UE2 can be connected together in other ways. Alternatively, the dual-directional device may logically include a management layer that can control UE1 and UE2. The specific product form of the dual-directional device is not limited in the embodiments of this application.

[0126] In addition, the name "dual-directional device" is just an example and can also be other names, such as dual-connection device, dual-steering device, multi-directional device, etc. This application does not specifically limit this.

[0127] Fourth, AMF switching:

[0128] Dual-directional devices implement switching session management based on enhanced AMF#1 and AMF#2. If the AMF#2 supporting DualSteer that the second terminal accesses changes due to factors such as mobility or network restrictions, considering the randomness of AMF, the newly accessed AMF#3 of the second terminal may or may not support DualSteer. The following analysis mainly focuses on the case where AMF#3 does not support DualSteer.

[0129] Furthermore, considering that the sessions established by the first terminal and the second terminal can be established in two scenarios—one where the session is established only on one side, and the other where sessions are established on both sides—the AMF handover occurs in different terminals in these two scenarios, and the process for implementing the session handover differs. These can be further subdivided into four scenarios, please refer to [link to relevant documentation]. Figures 4A-4D The following is a detailed explanation of these four scenarios:

[0130] Scenario 1: A session is established only on the first terminal side, and the AMF accessed by the second terminal changes.

[0131] exist Figure 4A In this scenario, although the second terminal switches from AMF#2 (which supports DualSteer, or DS) to AMF#3 (which does not support DualSteer), the first terminal's session is still managed by AMF#1 (which supports DualSteer). At this point, because AMF#3 does not support DualSteer, it cannot recognize the relevant indication information or the associated DualSteer session information after receiving the session establishment request. If AMF#3 treats this request as an initial request, it will reselect an SMF and send a session establishment request to the SMF with an indication that the request is an initial request. After the SMF completes the session establishment, because it is an initial session establishment and there is no session information from the other side, the SMF will not assign the same IP address, causing the second terminal's IP address to change after the switch, resulting in service interruption. Therefore, the first session (PDU Session ID#1) cannot be authorized for DualSteer Switching. Based on this result, the solution in this application embodiment will make a more granular judgment on scenario A.

[0132] Scenario 2: The session is established only on the second terminal side, and the AMF accessed by the second terminal changes.

[0133] exist Figure 4B In this scenario, the second terminal switches from AMF#2, which supports DualSteer, to AMF#3, which does not. The second terminal's session is then managed by AMF#3. Although the moved AMF#3 does not support DualSteer, since the second session (PDU Session ID#2) has already been established, AMF#3 can obtain the second terminal's context (SMF ID) through AMF#2. Furthermore, since AMF#1 supports DualSteer, AMF#1 can obtain the same SMF ID as AMF#3 through UDM. Therefore, the second session (PDU Session ID#2) can be authorized for DualSteer switching.

[0134] Scenario 3: A connection session is established between the first terminal and the second terminal (where the user plane on the first terminal is activated and the user plane on the second terminal is deactivated), and the AMF accessed by the second terminal changes.

[0135] exist Figure 4CIn this scenario, the second terminal switches from AMF#2, which supports DualSteer, to AMF#3, which does not support DualSteer. The session on the active side (the first session) is managed by AMF#1, which supports DualSteer. Although the moved AMF#3 does not support DualSteer, because an associated session has been established between the two sides (PDU Session ID#2 has been pre-established), AMF#3, which does not support DualSteer, can obtain the context (SMF ID) of the second terminal through AMF#2. Therefore, the first session (PDU Session ID#1) can be authorized for DualSteer switching.

[0136] Scenario 4: The first terminal establishes a connection session with the second terminal (where the user plane on the second terminal is activated and the user plane on the first terminal is deactivated), and the AMF accessed by the second terminal changes.

[0137] exist Figure 4D In this scenario, the second terminal switches from AMF#2, which supports DualSteer, to AMF#3, which does not. The session on the active side is managed by AMF#3, which does not support DualSteer. Although the moved AMF#3 does not support DualSteer, since the PDU Session ID#2 session has already been established, AMF#3 can obtain the context (SMFID) of the second terminal through AMF#2. Because AMF#1 supports DualSteer and associated sessions have been established on both sides (PDU Session ID#1 session has been pre-established), the second session (PDU Session ID#2) can be authorized to perform DualSteer switching.

[0138] It should be understood that the first terminal and the second terminal mentioned above are only illustrative. They may correspond to different terminal devices within the dual-directional device, or to different terminal devices separately set up within the dual-directional device. This application does not limit them in this regard.

[0139] In summary, due to factors such as location changes or network limitations, dual-directional devices may experience changes in the access and mobility management function network elements. Considering that the changed AMF may not have the relevant capabilities to support dual-directional DualSteer, the dual-directional device may be unable to perform session-related functions (such as session handover).

[0140] Furthermore, based on the descriptions of the four scenarios above, in scenario 1 (a session is established only on the first terminal side, and the AMF accessed by the second terminal changes), if the newly accessed AMF does not support DualSteer, then during the session switching process, the two sessions may be unable to access the same IP address, resulting in service interruption and other problems.

[0141] To address the aforementioned technical problems, the embodiments of this application propose the following technical solutions.

[0142] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0143] In the embodiments of this application, "instruction" can include direct and indirect instructions, as well as explicit and implicit instructions. The information indicated by a certain piece of information is called the information to be instructed. In the specific implementation process, there are many ways to instruct the information to be instructed, such as, but not limited to, directly instructing the information to be instructed, such as the information to be instructed itself or its index. It can also indirectly instruct the information to be instructed by instructing other information, where there is a relationship between the other information and the information to be instructed. It can also instruct only a part of the information to be instructed, while the other parts are known or pre-agreed upon. For example, the instruction of specific information can be achieved by using a pre-agreed (e.g., protocol-defined) arrangement of various pieces of information, thereby reducing instruction overhead to some extent. At the same time, common parts of various pieces of information can be identified and uniformly indicated to reduce the instruction overhead caused by individually indicating the same information.

[0144] Furthermore, the specific indication method can also be any existing indication method, such as, but not limited to, the above-mentioned indication methods and their various combinations. Specific details of various indication methods can be found in existing technologies, and will not be repeated here. As described above, for example, when multiple pieces of information of the same type need to be indicated, the indication methods for different pieces of information may differ. In the specific implementation process, the required indication method can be selected according to specific needs. This application embodiment does not limit the selected indication method; therefore, the indication methods involved in this application embodiment should be understood to cover various methods that enable the party to be indicated to obtain the information to be indicated.

[0145] It should be understood that the information to be indicated can be sent as a whole or divided into multiple sub-information messages sent separately, and the sending period and / or timing of these sub-information messages can be the same or different. The specific sending method is not limited in this application embodiment. The sending period and / or timing of these sub-information messages can be predefined, for example, according to a protocol, or configured by the sending device by sending configuration information to the receiving device.

[0146] In this application, "sending information" can be understood as one device sending information to another device, or it can also be understood as one logical module within a device sending information to another logical module. For example, "network device sending information" can be understood as a network device sending information to another device (such as a terminal or other network device), or it can be understood as logical module 1 in the network device sending information to logical module 2 in the network device.

[0147] In this application, "receiving information" can be understood as one device receiving information from another device, or it can also be understood as a logical module within a device receiving information from another logical module. For example, "network device receiving information" can be understood as a network device receiving information from another device (such as a terminal or other network device), or it can be understood as logical module 1 in the network device receiving information from logical module 2 in the network device.

[0148] In this application, phrases such as "sending information to... (e.g., a terminal)" or related illustrations in the accompanying drawings can be understood as indicating that the destination of the information is a terminal. This can include sending information directly or indirectly to a terminal. Similarly, phrases such as "receiving information from... (e.g., a terminal)," "receiving information from... (e.g., a terminal)," or "receiving information sent by (e.g., a terminal)," or related illustrations in the accompanying drawings, can be understood as indicating that the source of the information is a terminal. This can include receiving information directly or indirectly from a terminal. Information may undergo necessary processing between the source and destination, such as format changes, but the destination can understand the valid information from the source. Similar expressions in this application can be interpreted similarly and will not be elaborated further here.

[0149] "Predefined" or "pre-configured" can be achieved by pre-saving corresponding codes, tables, or other means that can be used to indicate relevant information in the device. This application does not limit the specific implementation method. "Saving" can refer to saving in one or more memories. These memories can be separate installations or integrated into the encoder, decoder, processor, or communication device. Alternatively, some memories can be separately installed, while others are integrated into the decoder, processor, or communication device. The type of memory can be any form of storage medium, and this application does not limit this.

[0150] The “protocol” mentioned in the embodiments of this application may refer to a protocol family in the field of communication, a standard protocol with a similar protocol family frame structure, or a related protocol applied to future communication systems. The embodiments of this application do not specifically limit this.

[0151] In the embodiments of this application, descriptions such as "when," "under the circumstances," "if," and "if" all refer to the device making corresponding processing under certain objective circumstances, and are not limited to a specific time. They do not require the device to make a judgment action during implementation, nor do they imply any other limitations.

[0152] In the description of the embodiments of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can represent A or B. "And / or" in the embodiments of this application is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone, where A and B can be singular or plural. Furthermore, in the description of the embodiments of this application, unless otherwise stated, "multiple" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple. Additionally, to facilitate a clear description of the technical solutions of the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first," "second," etc., do not limit the quantity or order of execution, and that "first," "second," etc., are not necessarily different. Furthermore, in the embodiments of this application, words such as "exemplary" or "for example" are used to indicate that something is being used as an example, illustration, or description. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner for ease of understanding.

[0153] The network architecture and business scenarios described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0154] To facilitate understanding of the embodiments of this application, a communication system will be used as an example to describe in detail the communication system applicable to the embodiments of this application.

[0155] Figure 5 This is a schematic diagram of a communication system architecture provided in an embodiment of this application. Figure 5As shown, the communication system includes: dual-directional equipment, one or more access and mobility management function network elements, unified data management function network elements, and session management function network elements.

[0156] A dual-directional device can be a device that includes multiple terminal devices. For example, the dual-directional device includes a first terminal and a second terminal. The terminal device can refer to the terminal itself or the SIM card within the terminal. For further details regarding the dual-directional device, please refer to the relevant description in the preamble section "Dual-directional Device" of the specific implementation method; it will not be repeated here.

[0157] One or more access and mobility management function network elements can be network elements used by multiple terminal devices in a dual-directional device to perform functions such as access control, mobility management, attach and detach, and gateway selection (e.g. Figure 1 (AMF in the network). For example, when the first terminal and the second terminal access the same network, the access and mobility management function network elements registered by the two terminals are different access and mobility management function network elements.

[0158] A unified data management function network element can be an access and mobility management function network element used to store the subscription data and policy information corresponding to multiple terminal devices included in a dual-directional device, for example... Figure 1 In the context of UDM, it can be understood that during the session handover process of a terminal device, the unified data management function network element can respond to the session handover request applied for by the access and mobility management function network element corresponding to the terminal device.

[0159] It should be understood that the contracted data may include service information subscribed to by the terminal device. This service information may include information about one or more services, billing information, or slicing information, etc. For example, the service information of a service may include the service's application ID, transmission requirements (such as bandwidth requirements), data network name (DNN), or IP address, etc.

[0160] Billing methods may include the traffic billing method agreed upon at the time of signing the contract. For example, the traffic billing method for service A or business A is k / GB (gigabits), and the traffic billing method for service B or business B is m / GB.

[0161] Slicing information can include the service type corresponding to the terminal device. For example, the contract may stipulate that the terminal device is used for entertainment services. Or, the contract may stipulate that the terminal device is used for work-related services.

[0162] The session management function network element is mainly responsible for user plane network element selection, user plane network element redirection, IP address allocation, bearer establishment, modification and release, and QoS control, such as... Figure 1SMF in the middle.

[0163] It should be noted that the terminal device, dual-directional device, and core network device carrying the above-mentioned functional network elements in the embodiments of this application can all be one or more chips, or they can be system on chip (SOC), etc. Figure 5 The figures are merely illustrative and the number of devices or equipment they include is not limited. Figure 5 The names of various devices, equipment, or network elements, and the naming of various links, are unrestricted, except... Figure 5 In addition to the names shown, various devices, equipment, network elements, or links may be named using other names without restriction. Furthermore, Figure 5 The communication links between the various devices, equipment, or network elements are unrestricted; for example, Figure 5 The devices, equipment, or network elements mentioned can be referred to Figure 1 The devices, equipment, or network elements communicate via communication links.

[0164] In addition Figure 5 In addition to the devices or network elements shown, the communication system may also include other devices or network elements, such as Figure 1 The RAN, UPF, or DN shown are not restricted.

[0165] It should be understood that with the evolution of the network, Figure 5 The communication system shown can also support or include other network functions, such as AI or sensing-related functions. Additionally, Figure 5 The network element names shown may also change in future network evolution, and this application embodiment does not specifically limit this.

[0166] The interaction process between various network elements / devices in the above-described communication system will be specifically described below through method embodiments. The communication method provided in this application embodiment can be applied to the above-described communication system and specifically applied to various scenarios mentioned in the above-described communication system, which will be described in detail below.

[0167] The execution entities of this method are a first communication device and a second communication device. The first communication device may be a terminal device (dual-directional device), an access and mobility management function network element (such as the AMF mentioned above), or a session management function network element (such as the SMF mentioned above). Correspondingly, the second communication device is a device that sends information (such as first information) to the first communication device. The second communication device may be an access and mobility management function network element or a unified data management function network element (such as the UDM mentioned above).

[0168] In different implementation scenarios, the first communication device and the second communication device may differ.

[0169] For example, if the first communication device is an access and mobility management function (AMU) network element, then the second communication device can be a unified data management function (UDM) network element; if the first communication device is a terminal device, then the second communication device can be an AMU network element (it should be understood that this AMU network element may not be the same AMU network element as the previous AMU network element F); if the first communication device is a session management function (SMG) network element, then the second communication device can be a UDM network element.

[0170] The key steps in the general scenario are explained below. Please see below for details. Figure 6 , Figure 6 A flowchart illustrating a session switching method provided in an embodiment of this application; Figure 6 The method shown can be applied to the above. Figure 1 or Figure 5 The system architecture shown is illustrated. Of course, this method can also be applied to other architectures, and this application does not limit it. Figure 6 The method shown can be applied to Figure 4A In the scenario shown, specifically, the method includes:

[0171] Step S601: The first communication device receives first information from the second communication device.

[0172] Correspondingly, the second communication device sends the first information to the first communication device.

[0173] The first information is used to indicate whether the first access and mobility management function network element supports dual-direction.

[0174] In this embodiment, the first access and mobility management function network element is the network element newly accessed by the second terminal. That is, after the access and mobility management function network element accessed by the second terminal is switched due to factors such as mobility or network restrictions, the newly accessed access and mobility management function network element becomes the new access and mobility management function network element. Considering the randomness of the newly accessed access and mobility management function network element, the first access and mobility management function network element newly accessed by the second terminal may or may not support dual-direction.

[0175] However, it should be noted that the access and mobility management function network element accessed by the second terminal before the first access and mobility management function network element supports dual-direction. This is in conjunction with scenario 1 above. Figure 4A According to the relevant content, if the first access and mobility management function network element does not support dual-direction, the transmission of the first information can solve the problem that the device / network element participating in the session-related process cannot perceive whether the first access and mobility management function network element newly accessed by the second terminal supports dual-direction.

[0176] Furthermore, the dual-directional device includes a first terminal and a second terminal.

[0177] Optionally, the aforementioned first access and mobility management function network element is used to manage the second terminal. Correspondingly, the second access and mobility management function network element is used to manage the first terminal.

[0178] It should be understood that the first terminal and the second terminal can also be other devices, such as multi-directional devices; the term "dual-directional device" here is for illustrative purposes only. Furthermore, the first terminal and the second terminal are related.

[0179] It should be understood that if the first access and mobility management function network element supports dual-direction, it means that the first access and mobility management function network element can participate in the session-related processes of the dual-direction device, or that the first access and mobility management function network element can implement the session-related processes of the dual-direction device. For example, the session-related processes of the dual-direction device include processes such as session handover and session routing. In this embodiment, session handover is used as an example to illustrate the session-related processes of the dual-direction device.

[0180] Specifically, if the first access and mobility management function network element supports dual-direction, it means that the first access and mobility management function network element can participate in the handover from the first session to the second session. Otherwise, it cannot.

[0181] Optionally, the first session is a session between the first terminal and the network, and the second session is a session between the second terminal and the network. It should be understood that the first and second sessions can refer to the communication process between a user terminal (UE) and a data network (DN). Once a PDU session is established, a data transmission channel is actually established between the UE and the DN. This process is similar to the PDP context in 2G / 3G and the bearer context in 4G, and can also be the data flow process between the terminal device and base stations or network elements in the network; here, it is simply referred to as a session between the terminal and the network.

[0182] It should be understood that switching from the first session to the second session here specifically refers to switching a session on one set of subscription data to another set of subscription data, thereby minimizing service interruption. In the embodiments of this application, the first session / second session can be a PDU session. For example, the first session can be represented by PDU Session ID#1, and the second session can be represented by PDU Session ID#2.

[0183] The first session mentioned above is a session associated with the first terminal, and the second session mentioned above is a session associated with the second terminal. To resolve the above... Figure 4ARegarding the corresponding scenario, in this embodiment of the application, the second session has not yet been established, or the second session has not been pre-established. It should be noted that although the second session has not yet been established, the session switching process can still proceed normally. If the first information includes support for switching from the first session to the second session, the subsequent process can initiate the establishment of the second session and realize the transfer of relevant data from the first session to the second session for continued transmission.

[0184] In one optional implementation, the first information includes first capability information or a second authorization result of the first access and mobility management function (AMU) network element. The first capability information indicates whether the first AMU network element supports DualSteer, and the second authorization result includes whether the first AMU network element supports DualSteer or not. Optionally, in the session handover process, the second authorization result can be either authorizing or denying session handover.

[0185] In one optional implementation, the first information includes first capability information of the first access and mobility management function (AM) network element. This first capability information may be sent by the first AM network element to indicate that it supports dual-direction capabilities. The second communication device or the unified data management function (UDM) network element receives the first capability information and forwards it to the first communication device. It should be understood that in scenarios where the second communication device is not a DFM network element, the second communication device will receive the first capability information forwarded by the DFM network element.

[0186] Considering that in some scenarios, the first access and mobility management function network element does not send capability information, in order to reduce the network element load and the consumption caused by signaling transmission, the second communication device or the unified data management function network element is enabled to make a judgment on the situation where the first access and mobility management function network element does not send capability information. That is, when the first access and mobility management function network element does not send capability information, the second communication device or the unified data management function network element can obtain the result that the first access and mobility management function network element does not support dual-direction.

[0187] It should be understood that if the first capability information is used to indicate that the first access and mobility management function network element supports dual-direction DualSteer, then the first information is used to indicate that the first access and mobility management function network element supports dual-direction; if the first capability information is used to indicate that the first access and mobility management function network element does not support dual-direction, then the first information is used to indicate that the first access and mobility management function network element does not support dual-direction.

[0188] It should also be understood that, during the session handover process, if the second authorization result includes the result that the first access and mobility management function network element supports dual redirection, the first information can also be used to instruct the first access and mobility management function network element to support switching the first session to the second session; if the second authorization result includes the result that the first access and mobility management function network element does not support dual redirection, the first information can also be used to instruct the first access and mobility management function network element not to support switching the first session to the second session.

[0189] Optionally, the second authorization result can be generated and sent by the unified data management function network element.

[0190] Step S602: The first communication device obtains the first authorization result based on the first information.

[0191] The first authorization result is used to indicate whether switching from the first session to the second session is allowed.

[0192] In an optional implementation, if the first information indicates that the first access and mobility management function network element supports dual-direction, then the first authorization result includes allowing a handover from the first session to the second session. It should be understood that the inclusion here may represent information other than "allowing a handover from the first session to the second session," or it may simply represent information indicating that the first authorization result allows a handover from the first session to the second session.

[0193] Furthermore, "allowing a switch from the first session to the second session" can also be understood as "allowing a session switch" or "authorizing subsequent devices to continue the session switch." This application does not limit the subject and description of the session switch.

[0194] In one alternative implementation, if the first information indicates that the first access and mobility management function network element does not support dual-direction, then the first authorization result includes not allowing a switch from the first session to the second session.

[0195] Similarly, the first authorization result can also be that switching from the first session to the second session is not allowed, which will not be elaborated here.

[0196] In an optional implementation, if the first authorization result includes disallowing switching from the first session to the second session, the first communication device updates the first session to a non-dual-direction session. Optionally, the first session / second session is a session with a dual-direction session tag attached; correspondingly, a non-dual-direction session can refer to a session without a dual-direction session tag attached. Accordingly, the update process is a common session update process in the prior art, and will not be described in detail here.

[0197] It should be noted that the process of updating the first session to a non-dual-directional session varies depending on the implementation scenario. For example, if the first communication device is an AMF (e.g., a second access and mobility management function network element), the session update process may involve the first communication device initiating a session update request to the session management function network element. If the first communication device is a terminal device (e.g., a dual-directional device), the session update process may involve the terminal device initiating a session update request or directly canceling the session handover process of the first session.

[0198] Optionally, the aforementioned first authorization result is specifically used to indicate whether the first access and mobility management function network element supports or does not support the dual-direction related procedure. Further, the aforementioned first authorization result may include the result that the first access and mobility management function network element supports the dual-direction related procedure or the result that the first access and mobility management function network element does not support the dual-direction related procedure.

[0199] In this embodiment of the application, the dual-directional device is enabled to implement the session management process after changing the access AMF.

[0200] During the session handover process, when the first communication device enables the second access and mobility management function network element to support the DualSteer feature or when the UDM authorizes the second terminal to perform DualSteer switching session handover, it notifies or enables the second access and mobility management function network element and the first terminal to allow the first session PDU Session ID#1 to switch normally. When the first access and mobility management function network element does not support the DualSteer feature or the UDM does not support the second terminal to perform DualSteer switching session handover, the first communication device can promptly adjust its own policy and the established PDU Session ID#1.

[0201] Considering that the execution entities of the above method are a first communication device and a second communication device, the first communication device may be a terminal device (dual-directional device), an access and mobility management function network element or a session management function network element, and the second communication device may be an access and mobility management function network element or a unified data management function network element.

[0202] The following explanation addresses the scenario where the first communication device and the second communication device are different entities.

[0203] First, an exemplary embodiment will be described where the first communication device is an access and mobility management function network element, and the second communication device is a unified data management function network element. Please refer to [link to previous text]. Figure 7 , Figure 7 This is a flowchart illustrating another session switching method provided in an embodiment of this application. This method can be applied to... Figure 5The system architecture is shown below. In this architecture, the first terminal in the terminal equipment (dual-directional device) connects to the second access and mobility management function network element, while the second terminal, due to mobility or network restrictions, connects to the first access and mobility management function network element. The second communication device is a unified data management function network element. Figure 7 In the corresponding method flow, steps S701 to S703 and steps S706 to S711 are optional steps. Figure 7 The dashed lines used in the diagram illustrate the process. Subsequent embodiments will apply the same treatment to optional steps (using dashed lines for illustration), and this application will not repeat the details. The specific flow of this method is as follows:

[0204] Step S701: The first access and mobility management function network element sends the fourth information to the unified data management function network element.

[0205] Correspondingly, the unified data management function network element receives the fourth information sent from the first access and mobility management function network element.

[0206] The fourth information includes the second capability information of the first access and mobility management function network element or the identifier of the first access and mobility management function network element. The second capability information is used to indicate that the first access and mobility management function network element supports dual-direction. The identifier of the first access and mobility management function network element is used by the unified data management function network element to determine the first capability information of the first access and mobility management function network element. The first capability information is used to indicate whether the first access and mobility management function network element supports dual-direction.

[0207] It should be understood that the second capability information can be information sent by the first access and mobility management function network element to the unified data management function network element when it supports dual-direction.

[0208] If the first access and mobility management function (MLM) network element does not support dual-direction, it will not send the second capability information. Correspondingly, the unified data management function (UDM) network element can determine the first capability information of the first MLM network element based on whether it sends the second capability information. In an optional implementation, the fourth information also includes capability information where the result is empty.

[0209] Optionally, the identifier of the aforementioned first access and mobility management function network element may specifically be a Network Function Identifier (NF ID).

[0210] Optionally, the unified data management function network element is pre-configured with capability information (including first capability information) of one or more access and mobility management function network elements. The unified data management function network element can determine the first capability information of the first access and mobility management function network element from the capability information of the one or more access and mobility management function network elements mentioned above, based on the identifier of the first access and mobility management function network element.

[0211] In this embodiment, before step S701, the first session PDU Session ID#1 of the first terminal has been established. The dual-direction device initiates a mobility registration request to the first access and mobility management function network element and reports its own dual-direction capabilities. Optionally, the dual-direction device sends mobility registration request information to the first access and mobility management function network element. This request information includes the dual-direction device's own capability information, which is used to indicate the dual-direction capabilities of the dual-direction device. For example, this mobility registration request information may specifically be sent by the second terminal in the dual-direction device.

[0212] Step S702: The unified data management function network element determines the first information based on the fourth information.

[0213] The first information is used to indicate whether the first access and mobility management function network element supports dual-direction. Furthermore, implementation methods related to the first information can be found in [link to relevant documentation]. Figure 6 The relevant descriptions in step S601 are not repeated here.

[0214] In an optional implementation, if the fourth information includes the second capability information of the first access and mobility management function network element, then the first information is used to indicate that the first access and mobility management function network element supports switching the first session to the second session.

[0215] In an optional implementation, if the fourth information includes an identifier of the first access and mobility management function (MLM) network element, then the unified data management function (UDF) network element determines the first capability information of the first MLM network element from the pre-configured capability information based on the identifier. If the first capability information is used to indicate that the first MLM network element supports dual-direction, then the aforementioned first information is used to indicate that the first MLM network element supports dual-direction. Conversely, if the first capability information is used to indicate that the first MLM network element does not support dual-direction, then the aforementioned first information is used to indicate that the first MLM network element does not support dual-direction.

[0216] To save signaling overhead, in one optional implementation, the registration request message includes fourth information. This registration request message is used to request the registration of the first access and mobility management function network element with the unified data management function network element. By carrying the fourth information in the registration request message, communication overhead is saved.

[0217] In one optional implementation, the first information includes first capability information or a second authorization result of the first access and mobility management function network element, wherein the first capability information is used to indicate whether the first access and mobility management function network element supports dual-direction, and the second authorization result includes the result that the first access and mobility management function network element supports dual-direction or the result that the first access and mobility management function network element does not support dual-direction.

[0218] Considering that the unified data management function network element may need to consider the session establishment status and whether it has received information related to triggering handover, the unified data management function network element can manage whether the first access and mobility management function network element supports dual-direction. In an optional implementation, if the first information includes the first capability information of the first access and mobility management function network element, the unified data management function network element can determine the second authorization result based on the first capability information (or second capability information) of the first access and mobility management function network element. The second authorization result includes either the first access and mobility management function network element supporting dual-direction or the first access and mobility management function network element not supporting dual-direction. Generally, in the session handover process, the first capability information of the first access and mobility management function network element is used to indicate that the first access and mobility management function network element supports dual-direction, and the second authorization result includes authorizing session handover; conversely, the first capability information of the first access and mobility management function network element is used to indicate that the first access and mobility management function network element does not support dual-direction, and the second authorization result includes refusing session handover. This application uses a session switching process as an example to illustrate the session-related processes of a dual-directional device. Therefore, the descriptions of "session switching" and "switching the first session to the second session" in this application's embodiments may vary in different session-related processes. For example, in a session splitting scenario, the second authorization result may include authorizing session splitting or refusing session splitting. This application does not limit this.

[0219] In an optional implementation, when the first access and mobility management function network element does not send the second capability information or identifier to the unified data management function network element, steps S701 and S702 are optional steps, and steps S701 and S702 can be replaced by "the unified data management function network element determines the first information".

[0220] Step S703: The unified data management function network element determines the second access and mobility management function network element that manages the first terminal based on the first identifier.

[0221] The first identifier includes the user permanent identifier SUPI of the first terminal.

[0222] In one alternative implementation, the unified data management function network element determines the first identifier of the first terminal based on the subscription data of the second terminal.

[0223] Step S704: The unified data management function network element sends the first information to the second access and mobility management function network element.

[0224] Correspondingly, the first access and mobility management function network element receives the first information sent from the unified data management function network element.

[0225] Step S705: The second access and mobility management function network element obtains the first authorization result based on the first information.

[0226] Possible implementations corresponding to steps S704 and S705 can be found in [reference needed]. Figure 6 The description of the relevant implementation methods is omitted here.

[0227] Step S706: The second access and mobility management function network element sends the first authorization result to the dual-direction device.

[0228] Correspondingly, the dual-directional device receives the first authorization result sent by the second access and mobility management function network element.

[0229] The first authorization result is used to indicate whether switching from the first session to the second session is allowed.

[0230] Optionally, if the first authorization result includes allowing a switch from the first session to the second session, then proceed to step S707.

[0231] Optionally, if the first authorization result includes disallowing a handover from the first session to the second session, the second access and mobility management function network element will update the first session to a non-dual-direction session. It should be understood that the specific procedure for the second access and mobility management function network element to update the first session to a non-dual-direction session may be that the second access and mobility management function network element notifies the dual-direction device to update the session, or notifies the session management function network element managing the first session to update the session.

[0232] Step S707: Associating dual-directional device session information.

[0233] The aforementioned session information includes relevant information from the first session and relevant information from the second session. For example, associated session information can specifically refer to the first terminal sending relevant information from the first session and its own context to the second terminal, and the second terminal also sending the aforementioned content back to the first terminal.

[0234] If the first authorization result mentioned above includes disallowing a switch from the first session to the second session, the dual-direction device will determine not to perform a session switch, and the process will be aborted, unless the second access and mobility management function network element updates the first session to a non-dual-direction session.

[0235] Step S708: The dual-directional device sends third information to the first access and mobility management function network element.

[0236] Correspondingly, the first access and mobility management function network element receives third information from the dual-directional device.

[0237] The third message is used to indicate whether to switch from the first session to the second session.

[0238] Step S709: The first access and mobility management function network element sends the fifth information to the unified data management function network element.

[0239] Correspondingly, the unified data management function network element receives the fifth information from the first access and mobility management function network element.

[0240] The fifth information is used to request the identifier of the first session management function network element. The fifth information includes a first identifier and a second identifier. The second identifier includes the session identifier of the first session, and the first session management function network element is associated with the first session. It should be understood that the second identifier is used to indicate the relevant identifier of the first session. For example, it is indicated here that this identifier can be the session identifier of the first session. The inclusion here is used to indicate that the second identifier includes other identifiers used to indicate the first session besides the "session identifier of the first session." Of course, it can also be a session identifier used to indicate that the second identifier is the session identifier of the first session.

[0241] Step S710: The unified data management function network element sends the sixth information to the first access and mobility management function network element.

[0242] Correspondingly, the first access and mobility management function network element receives the sixth information from the unified data management function network element.

[0243] The sixth piece of information includes the identifier of the first session management function network element.

[0244] Step S711: The first access and mobility management function network element sends the seventh information to the first session management function network element according to the identifier of the first session management function network element.

[0245] Correspondingly, the first session management function network element receives the seventh information from the first access and mobility management function.

[0246] The seventh piece of information is used to indicate a session switch.

[0247] Optionally, the seventh information includes a first identifier, a second identifier, a third identifier, and a fourth identifier, wherein the third identifier includes the user's permanent identifier for the second terminal, and the fourth identifier includes the session identifier for the second session.

[0248] It should be understood that the third identifier is used to indicate the relevant identifier of the second terminal. For example, it is indicated here that the identifier may be the user permanent identifier (SUPI) of the second terminal. The inclusion here of the third identifier may include other identifiers used to indicate the second terminal in addition to "the SUPI of the second terminal". Of course, it may also be the SUPI of the second terminal used to indicate that the third identifier is the SUPI of the second terminal.

[0249] Optionally, the seventh information may also include a third information, which indicates that the first session should be switched to the second session.

[0250] In one optional implementation, the first session management function network element can perform PDU session association and handover processing based on the seventh information.

[0251] This application embodiment enhances the access and mobility management function network element, enabling the access and mobility management function network element to report capability information to the unified data management function network element; the enhanced access and mobility management function network element can process the capability information of the peer's access and mobility management function network element, and update the already established first session PDU Session ID#1 according to the capability information of the peer's access and mobility management function network element or the authorization result of the second terminal's session handover (second authorization result / first authorization result); the enhanced access and mobility management function network element sends the peer's access and mobility management function network element capability information and the authorization result of the second terminal's session handover to the dual-directional device.

[0252] The method provided in this application reports the status of the peer (first access and mobility management function) to the source AMF (second access and mobility management function network element), allowing the source AMF and source UE (first terminal) to understand the peer's status. When the peer AMF supports the DualSteer feature or the UDM authorizes the peer UE#2 (second terminal) to perform DualSteerSwitching session switching, the source AMF and source UE allow PDU Session ID#1 to switch normally. When the peer AMF does not support the DualSteer feature or the UDM does not support the peer UE#2 performing DualSteer Switching session switching, the source AMF and source UE can promptly adjust their own policies and the established PDU Session ID#1. After the AMF changes, session flow management is achieved. Furthermore, this avoids service interruptions caused by the peer AMF not supporting the DualSteer feature or the UDM not supporting the peer UE#2 performing DualSteer Switching sessions.

[0253] Secondly, an exemplary embodiment is provided where the first communication device is a dual-directional device and the second communication device is a second access and mobility management function network element. Please refer to [link to example]. Figure 8 , Figure 8 This is a flowchart illustrating another session switching method provided in an embodiment of this application. This method can be applied to... Figure 5 The system architecture is shown below. In this architecture, the first terminal in the terminal equipment (dual-directional equipment) connects to the second access and mobility management function network element, while the second terminal, due to mobility or network restrictions, connects to the first access and mobility management function network element. The specific process of this method is as follows:

[0254] Step S801: The first access and mobility management function network element sends the fourth information to the unified data management function network element.

[0255] Correspondingly, the unified data management function network element receives the fourth information sent from the first access and mobility management function network element.

[0256] It should be noted that possible implementations of the fourth information involved in this embodiment can be found in [reference needed]. Figure 7 The relevant possible implementations described in the text are not repeated here. Furthermore, the remaining steps in this embodiment involve... Figure 6 or Figure 7 Information, devices, network elements, equipment, etc., with the same names in the corresponding method embodiments can be found in [reference needed]. Figure 6 or Figure 7 Description of possible implementations in the corresponding method embodiments.

[0257] Step S802: The unified data management function network element determines the first information based on the fourth information.

[0258] The first information is used to indicate whether the first access and mobility management function network element supports dual-direction.

[0259] Step S803: The unified data management function network element determines the second access and mobility management function network element that manages the first terminal based on the first identifier.

[0260] Step S804: The unified data management function network element sends the first information to the second access and mobility management function network element.

[0261] Correspondingly, the second access and mobility management function network element receives the first information sent from the unified data management function network element.

[0262] Step S805: The second access and mobility management function network element sends the first information to the dual-directional device.

[0263] Correspondingly, the dual-directional device receives the first information from the second access and mobility management function network element.

[0264] Step S806: The dual-directional device obtains the first authorization result based on the first information.

[0265] In one alternative implementation, the dual-directional device obtains a first authorization result based on the establishment status of the first session and first information. For example, the establishment status of the first session includes whether the first session has been established or not.

[0266] In one optional implementation, the dual-directional device also needs to determine the first authorization result by considering factors such as system conditions, whether there is a handover requirement, or whether a session handover procedure has been triggered. In the session handover procedure, generally, the first information is used to indicate that the first access and mobility management function network element supports dual-directionality, and the first authorization result includes allowing session handover; the first information is used to indicate that the first access and mobility management function network element does not support switching the first session to the second session, and the first authorization result includes refusing session handover. However, if other factors are considered, such as the establishment status of the first session, system conditions, or whether a session handover procedure has been triggered, the first authorization result may not correspond to the first information, i.e., it may not conform to general conditions.

[0267] If the first authorization result includes allowing session handover, the dual-directional device associates the session information and proceeds to step S807. If the first authorization result includes denying session handover, the dual-directional device stops executing the session handover procedure.

[0268] Step S807: The dual-directional device sends the third information to the first access and mobility management function network element.

[0269] Correspondingly, the first access and mobility management function network element receives third information from the dual-directional device.

[0270] Step S808: The first access and mobility management function network element sends the fifth information to the unified data management function network element.

[0271] Correspondingly, the unified data management function network element receives the fifth information from the first access and mobility management function network element.

[0272] Step S809: The unified data management function network element sends the sixth information to the first access and mobility management function network element.

[0273] Correspondingly, the first access and mobility management function network element receives the sixth information from the unified data management function network element.

[0274] Step S810: The first access and mobility management function network element sends the seventh information to the first session management function network element according to the identifier of the first session management function network element.

[0275] Correspondingly, the first session management function network element receives the seventh information from the first access and mobility management function.

[0276] In one optional implementation, the first session management function network element can perform PDU session association and handover processing based on the seventh information.

[0277] This application embodiment enhances the dual-directional device by first enhancing its processing of access and mobility management function network element capability information at both ends and the authorization result of the second terminal performing session handover; and enhancing the dual-directional device to determine whether to associate a session and initiate session handover based on the session establishment status and the access and mobility management function network element capabilities at both ends.

[0278] Secondly, regarding the first communication device being a first session management function network element (in this embodiment, the first session management function network element may specifically be...) Figure 1 The first session management function (SMF) is a unified data management function network element (in this embodiment, the first session management function network element may specifically be...). Figure 1 The UDM in the example is illustrated below. Please refer to [link to UDM]. Figure 9 , Figure 9 This is a flowchart illustrating another session switching method provided in an embodiment of this application. This method can be applied to... Figure 5The system architecture is shown below. In this architecture, the first terminal in the terminal device (dual-directional device) connects to the second access and mobility management function network element, while the second terminal, due to mobility or network restrictions, connects to the first access and mobility management function network element. The first session management function network element manages the first session. The specific flow of this method is as follows:

[0279] Step S901: The first access and mobility management function network element sends the fourth information to the unified data management function network element.

[0280] Correspondingly, the unified data management function network element receives the fourth information sent from the first access and mobility management function network element.

[0281] It should be noted that possible implementations of the fourth information involved in this embodiment can be found in [reference needed]. Figure 7 The relevant possible implementations described in the text are not repeated here. Furthermore, the remaining steps in this embodiment involve... Figure 6 or Figure 7 Information, devices, network elements, equipment, etc., with the same names in the corresponding method embodiments can be found in [reference needed]. Figure 6 or Figure 7 Description of possible implementations in the corresponding method embodiments.

[0282] Step S902: The unified data management function network element determines the first information based on the fourth information.

[0283] Step S903: The unified data management function network element determines the first session management function network element that manages the first session based on the first identifier.

[0284] The first identifier includes the user's permanent identifier for the first terminal.

[0285] In one optional implementation, the unified data management function network element queries the first identifier and the first session (or the session identifier of the first session) based on the subscription data of the dual-directional device (specifically, the second terminal in the dual-directional device), and determines the first session management function network element that manages the first session based on the query results.

[0286] Step S904: The unified data management function network element sends the first information to the first session management function network element.

[0287] Correspondingly, the first session management function network element receives the first information sent from the unified data management function network element.

[0288] Step S905: The first session management function network element obtains the first authorization result based on the first information.

[0289] If the first authorization result includes permission to perform a session switch, the dual-directional device associates session information and proceeds to step S807.

[0290] Optionally, if the first authorization result includes disallowing switching from the first session to the second session, the first session management function network element updates the first session to a non-dualSteer session. For example, when the first access and mobility management function network element does not support the dualSteer feature, the first session management function network element sends an instruction to the second access and mobility management function network element to update the first session PDU Session ID#1 session to a non-dualSteer session. Optionally, the first session management function network element sends second information to the second access and mobility management function network element, the second information indicating that the first session be updated to a non-dualSteer session. Further, the second access and mobility management function network element notifies the dual-steer terminal that the second terminal is not authorized to perform a DualSteer Switching session handover, and the dual-steer device does not perform a session handover.

[0291] Step S906: The first session management function network element sends the first authorization result to the second access and mobility management function network element.

[0292] Correspondingly, the second access and mobility management function network element receives the first authorization result from the first session management function network element.

[0293] Step S907: The second access and mobility management function network element sends the first authorization result to the dual-direction device.

[0294] Correspondingly, the dual-directional device receives the first authorization result from the second access and mobility management function network element.

[0295] If the first authorization result includes permission to perform a session handover, the dual-directional device associates the session information and proceeds to step S908.

[0296] Step S908: The dual-directional device sends the third information to the first access and mobility management function network element.

[0297] Correspondingly, the first access and mobility management function network element receives third information from the dual-directional device.

[0298] Step S909: The first access and mobility management function network element sends the fifth information to the unified data management function network element.

[0299] Correspondingly, the unified data management function network element receives the fifth information from the first access and mobility management function network element.

[0300] Step S910: The unified data management function network element sends the sixth information to the first access and mobility management function network element.

[0301] Correspondingly, the first access and mobility management function network element receives the sixth information from the unified data management function network element.

[0302] Step S911: The first access and mobility management function network element sends the seventh information to the first session management function network element according to the identifier of the first session management function network element.

[0303] Correspondingly, the first session management function network element receives the seventh information from the first access and mobility management function.

[0304] This application embodiment enhances the session management function network element. First, it enhances the session management function network element's ability information for processing the access and mobility management function network elements at both ends. Second, it enhances the session management function network element's ability information for the peer's access and mobility management function network element, or the authorization result of the second terminal's session handover, to determine whether to allow the second terminal to perform a session handover. Third, it enhances the session management function network element's ability to send the authorization result of the second terminal's session handover to the source's access and mobility management function network element.

[0305] The above mainly describes the solutions provided by the embodiments of this application from the perspective of interaction between various network elements. Correspondingly, the embodiments of this application also provide a communication device for implementing the various methods described above. This communication device can be the first or second communication device in the above method embodiments, or a device or apparatus containing the first or second communication device, or a component within the device; the communication device can be a dual-directional device in the above method embodiments, or a device containing the dual-directional device, or a component usable in a dual-directional device; or, the communication device can be an access and mobility management function network element in the above method embodiments, or a device containing the access and mobility management function network element, or a component usable in an access and mobility management function network element. Alternatively, the communication device can be a unified data management function network element in the above method embodiments, or a device containing the unified data management function network element, or a component usable in a unified data management function network element. Alternatively, the communication device can be a session management function network element in the above method embodiments, or a device containing the session management function network element, or a component usable in a session management function network element.

[0306] It is understood that, in order to achieve the aforementioned functions, the communication device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0307] This application embodiment can divide the communication device into functional modules according to the above method embodiment. For example, each function can be divided into a separate functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0308] Taking the communication device as an example, which is a dual-directional device, an access and mobility management function network element, a unified data management function network element, or a session management function network element in the above method embodiments, Figure 10 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application. Figure 10 As shown, the communication device 1000 includes a processing module 1001 and a transceiver module 1002. The processing module 1001 is used to execute the processing functions of the dual-directional device, or the access and mobility management function network element, or the unified data management function network element in the above method embodiments. The transceiver module 1002 is used to execute the transceiver functions of the dual-directional device, or the access and mobility management function network element, or the unified data management function network element in the above method embodiments.

[0309] All relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0310] Since the communication device 1000 provided in this embodiment can execute the above-described communication method, the technical effects it can achieve can be referred to the above-described method embodiments, and will not be repeated here.

[0311] In one possible design, the transceiver module 1002 may include a receiving module and a transmitting module. Figure 10 (Not shown in the image). The transceiver module is used to implement the sending and receiving functions of the communication device 1000.

[0312] In one possible design, the communication device 1000 may further include a storage module. Figure 10 (Not shown in the image), this storage module stores programs or instructions. When the processing module 1001 executes the program or instructions, it enables the communication device 1000 to perform operations. Figures 6-9 The functions of the dual-directional device, or access and mobility management function network element, or unified data management function network element, or session management function network element in any of the methods shown.

[0313] It should be understood that the processing module 1001 involved in the communication device 1000 can be implemented by a processor or processor-related circuit components, and can be a processor or processing unit; the transceiver module 1002 can be implemented by a transceiver or transceiver-related circuit components, and can be a transceiver or transceiver unit.

[0314] For example, Figure 11 This is a schematic diagram of another communication device provided in an embodiment of this application. The communication device can be a dual-directional device, an access and mobility management function network element, or a unified data management function network element; it can also be a chip (system) or other component or assembly that can be disposed within a dual-directional device, an access and mobility management function network element, or a unified data management function network element. For example... Figure 11 As shown, the communication device 1100 may include a processor 1101. In one possible design, the communication device 1100 may also include a memory 1102 and / or a transceiver 1103. The processor 1101 is coupled to the memory 1102 and the transceiver 1103, for example, they may be connected via a communication bus.

[0315] The following is combined Figure 11 A detailed description of each component of the communication device 1100 is provided below:

[0316] The processor 1101 is the control center of the communication device 1100. It can be a single processor or a collective term for multiple processing elements. For example, the processor 1101 can be one or more central processing units (CPUs), application-specific integrated circuits (ASICs), or one or more integrated circuits configured to implement the embodiments of this application, such as one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs).

[0317] In one possible design, the processor 1101 can perform various functions of the communication device 1100 by running or executing software programs stored in the memory 1102 and calling data stored in the memory 1102.

[0318] In a specific implementation, as one example, the processor 1101 may include one or more CPUs, for example... Figure 11 CPU0 and CPU1 are shown in the diagram.

[0319] In a specific implementation, as one example, the communication device 1100 may also include multiple processors, for example... Figure 11 The processors 1101 and 1104 shown are illustrated. Each of these processors can be a single-core processor (CPU) or a multi-core processor (CPU). Here, "processor" can refer to one or more devices, circuits, and / or processing cores used to process data (e.g., computer program instructions).

[0320] The memory 1102 is used to store the software program that executes the solution of this application, and is controlled by the processor 1101 to execute it. The specific implementation method can be referred to the above method embodiment, and will not be repeated here.

[0321] In one possible design, the memory 1102 can be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or it can be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto. The memory 1102 can be integrated with the processor 1101 or exist independently and coupled to the processor 1101; this application embodiment does not specifically limit this.

[0322] Transceiver 1103 is used for communication with other communication devices. For example, if communication device 1100 is a dual-directional device, transceiver 1103 can be used to communicate with access and mobility management function network elements, or access management network elements, etc. As another example, if communication device 1100 is an access and mobility management function network element, transceiver 1103 can be used to communicate with dual-directional devices.

[0323] In one possible design, transceiver 1103 may include a receiver and a transmitter. Figure 11 (Not shown separately). The receiver is used to implement the receiving function, and the transmitter is used to implement the sending function.

[0324] In one possible design, transceiver 1103 can be an input / output interface or interface circuit for inputting and / or outputting signals.

[0325] In one possible design, the transceiver 1103 can be integrated with the processor 1101, or it can exist independently and be coupled to the processor 1101. This application embodiment does not specifically limit this.

[0326] It should be noted that, Figure 11 The structure of the communication device 1100 shown does not constitute a limitation on the communication device. Actual communication devices may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0327] Furthermore, the communication device 1100 can execute the above-described communication method, and therefore the technical effects it can achieve can be referred to the above-described method embodiments, which will not be repeated here.

[0328] In an optional embodiment, this application also provides a computer-readable storage medium storing a computer program or instructions that, when executed by a computer, implement the functions of the above-described method embodiments.

[0329] In an optional embodiment, this application also provides a computer program product that, when executed by a computer, implements the functions of the above-described method embodiments.

[0330] In an optional implementation, this application also provides a communication system, which includes the terminal device (such as a dual-directional device) described in the above method embodiments, a unified data management function (UDM) network element, SMF, and AMF.

[0331] In an optional implementation, this application also provides a communication method, which includes the method described in any of the above-described method embodiments or any implementation thereof.

[0332] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software programs, implementation can be, in whole or in part, in the form of a computer program product. This computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. 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. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device including one or more servers, data centers, etc., that can be integrated with the medium. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium, or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0333] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0334] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0335] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0336] The units described as separate components may or may not be physically separate. 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 the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0337] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0338] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0339] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, the disclosure, and the appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0340] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the scope of this application. Accordingly, this specification and drawings are merely illustrative examples of the application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of the claims and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. A session management method, characterized in that, The method includes: Receive first information, the first information being used to indicate whether the first access and mobility management function network element supports dual-direction; A first authorization result is obtained based on the first information, wherein the first authorization result is used to indicate whether to allow switching from the first session to the second session, the first session is a session between the first terminal and the network, the second session is a session between the second terminal and the network, the dual-directional device includes the first terminal and the second terminal, and the first access and mobility management function network element is used to manage the second terminal.

2. The method according to claim 1, characterized in that, The first information includes first capability information or second authorization result of the first access and mobility management function network element, wherein the first capability information is used to indicate whether the first access and mobility management function network element supports dual redirection, and the second authorization result includes the result that the first access and mobility management function network element supports dual redirection or the result that the first access and mobility management function network element does not support dual redirection.

3. The method according to claim 1 or 2, characterized in that, If the first information indicates that the first access and mobility management function network element supports dual-direction, then the first authorization result includes allowing a switch from the first session to the second session; If the first information indicates that the first access and mobility management function network element does not support dual-direction, then the first authorization result includes not allowing a switch from the first session to the second session.

4. The method according to any one of claims 1-3, characterized in that, The method further includes: Send the first authorization result to the dual-directional device.

5. The method according to any one of claims 1-4, characterized in that, The first authorization result includes disallowing switching from the first session to the second session, and the method further includes: Update the first session to a non-bidirectional session.

6. The method according to claim 5, characterized in that, Updating the first session to a non-bidirectional session includes: Send a second message, which indicates that the first session be updated to a non-bidirectional session.

7. The method according to any one of claims 1-3, characterized in that, The first authorization result includes allowing a switch from the first session to the second session, and the method further includes: Send a third message, which indicates that the first session be switched to the second session.

8. The method according to any one of claims 1-3 and 7, characterized in that, The step of obtaining the first authorization result based on the first information includes: The first authorization result is obtained based on the establishment status of the first session and the first information.

9. A session management method, characterized in that, The method includes: Obtain first information, which is used to indicate whether the first access and mobility management function network element supports dual-direction, the dual-direction device includes a second terminal, and the first access and mobility management function network element is used to manage the second terminal; Send the first message.

10. The method according to claim 9, characterized in that, The acquisition of the first information includes: Receive fourth information, the fourth information including second capability information of the first access and mobility management function network element or the identifier of the first access and mobility management function network element, the second capability information is used to indicate that the first access and mobility management function network element supports dual-direction, the identifier of the first access and mobility management function network element is used to determine the first capability information of the first access and mobility management function network element, and the first capability information is used to indicate whether the first access and mobility management function network element supports dual-direction; The first information is determined based on the fourth information.

11. The method according to claim 10, characterized in that, The registration request message includes the fourth information, and the registration request message is used to request the first access and mobility management function network element to register with the unified data management function network element.

12. The method according to any one of claims 9-11, characterized in that, The first information includes first capability information or second authorization result of the first access and mobility management function network element, wherein the first capability information is used to indicate whether the first access and mobility management function network element supports dual redirection, and the second authorization result includes the result that the first access and mobility management function network element supports dual redirection or the result that the first access and mobility management function network element does not support dual redirection.

13. The method according to any one of claims 10-12, characterized in that, The method further includes: The second authorization result is determined based on the first capability information or the second capability information of the first access and mobility management function network element.

14. The method according to any one of claims 9-13, characterized in that, The dual-directional device further includes a first terminal, and the method further includes: The second access and mobility management function network element for managing the first terminal is determined based on the first identifier, wherein the first identifier includes the user permanent identifier of the first terminal.

15. The method according to any one of claims 9-13, characterized in that, The method further includes: The first session management function network element that manages the first session is determined based on the first identifier, wherein the first identifier includes the user permanent identifier of the first terminal, and the first session is a session between the first terminal and the network.

16. The method according to any one of claims 9-15, characterized in that, The method further includes: The system receives a fifth piece of information, which is used to request the identifier of the first session management function network element. The fifth piece of information includes a first identifier and a second identifier. The second identifier includes the session identifier of the first session. The first session management function network element is associated with the first session. Send a sixth message, wherein the sixth message includes the identifier of the first session management function network element.

17. The method according to any one of claims 9-16, characterized in that, The acquisition of the first information includes: Receive the first information.

18. A session management method, characterized in that, The method includes: Send second capability information of the first access and mobility management function network element, wherein the second capability information is used to indicate that the first access and mobility management function network element supports dual-direction; The system receives third information, which is used to instruct the initiation of switching the first session to the second session. The first session is a session between the first terminal and the network, and the second session is a session between the second terminal and the network. The dual-directional device includes the first terminal and the second terminal, and the first access and mobility management function network element is used to manage the second terminal.

19. The method according to claim 18, characterized in that, The method further includes: Send a fifth message, which is used to request the identifier of the first session management function network element. The fifth message includes a first identifier and a second identifier. The second identifier includes the session identifier of the first session. The first session management function network element is associated with the first session. Receive the sixth information, wherein the sixth information includes the identifier of the first session management function network element.

20. The method according to claim 19, characterized in that, The method further includes: Based on the identifier of the first session management function network element, a seventh message is sent to the first session management function network element. The seventh message is used to indicate a session handover. The seventh message includes the first identifier, the second identifier, the third identifier, and the fourth identifier. The third identifier includes the permanent user identifier of the second terminal, and the fourth identifier includes the session identifier of the second session.

21. A communication device, characterized in that, Includes modules for implementing the method as described in any one of claims 1-20.

22. A communication device, characterized in that, include: Processor, the processor being coupled to memory; The processor is configured to execute a computer program stored in the memory, so that the communication device performs the method as described in any one of claims 1 to 20.

23. A chip, characterized in that, include: A processor for retrieving and running a computer program from memory, causing a communication device on which the chip is mounted to perform the method as described in any one of claims 1 to 20.

24. A computer-readable storage medium, characterized in that, include: The computer-readable storage medium stores a computer program that, when executed, causes the computer to perform the method as described in any one of claims 1 to 20.

25. A computer program product, characterized in that, When the computer program product is executed by the communication device, it causes the communication device to implement the method as described in any one of claims 1 to 20.

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