Information transmission method and apparatus, terminal device, network element, and storage medium

Abstract

Embodiments of the present application provide an information transmission method, comprising: an access network element sending a first message to a first user plane network element, wherein the first message is determined on the basis of a first NAS message, and the first NAS message is a NAS message sent by a terminal device to a target network element; and / or the access network element receiving a second message sent by the first user plane network element, wherein the second message is determined on the basis of a second NAS message, and the second NAS message is a NAS message sent by the target network element to the terminal device. The embodiments of the present application further provide an information transmission apparatus, a device, a network element, and a storage medium.

Description

Information transmission methods and devices, terminal equipment, network elements and storage media Technical Field

[0001] This application relates to the field of communication technology, and in particular to an information transmission method and apparatus, terminal equipment, network element and storage medium. Background Technology

[0002] In practical applications, any interaction between terminal devices and the core network needs to be conducted through Non-Access Stratum (NAS) messages, meaning they all need to be forwarded through Access and Mobility Management Function (AMF) network elements. However, with the evolution of communication technologies and the increasing volume of signaling data from Artificial Intelligence (AI) and sensing technologies, the AMF may become a bottleneck in signaling transmission. Summary of the Invention

[0003] This application provides an information transmission method and apparatus, a terminal device, a network element, and a storage medium.

[0004] Firstly, an information transmission method is provided, applied to an access network element, the method comprising:

[0005] The access network element sends a first message to the first user plane network element, and the first message is determined based on the first NAS message; the first NAS message is the NAS message sent by the terminal device to the target network element;

[0006] And / or,

[0007] The access network element receives a second message sent by the first user plane network element. The second message is determined based on a second NAS message, which is a NAS message sent by the target network element to the terminal device.

[0008] Secondly, a method for transmitting information is provided, applied to a first user plane network element, the method comprising:

[0009] The first user plane network element receives a first message sent by the access network element, the first message being determined based on a first NAS message; the first NAS message is a NAS message sent by the terminal device to the target network element;

[0010] And / or,

[0011] The first user plane network element sends a second message to the access network element. The second message is determined based on the second NAS message, which is the NAS message sent by the target network element to the terminal device.

[0012] Thirdly, an information transmission method is provided, applied to a target network element, the method comprising:

[0013] The target network element receives a first message sent by the first user plane network element; the first message is determined based on a first NAS message; the first NAS message is a NAS message sent by the first terminal device to the target network element;

[0014] And / or,

[0015] The target network element sends a second message or a third message to the first user plane network element. The second message is determined based on a second NAS message. The third message includes a second NAS message and second indication information. The second indication information is used to determine the second message. The second NAS message is a NAS message sent by the target network element to the first terminal device.

[0016] Fourthly, an information transmission method is provided, applied to a terminal device, the method comprising:

[0017] The terminal device sends a first NAS message and a first indication information to the access network element. The first NAS message is a NAS message sent by the terminal device to the target network element, and the first indication information is used to determine the target network element.

[0018] And / or,

[0019] The terminal device receives the second NAS message sent by the access network element.

[0020] Fifthly, an information transmission method is provided, applied to a terminal device, the method comprising:

[0021] The terminal device sends a fourth message to the access network element. The fourth message carries a third NAS message, which is carried by a third IP data packet. The third NAS message is a NAS message sent by the terminal device to the target network element.

[0022] And / or,

[0023] The terminal device receives a fifth message sent by an access network element. The fifth message carries a fourth NAS message, which is carried by a fourth IP data packet. The fourth NAS message is a NAS message sent by the target network element to the terminal device.

[0024] Sixthly, an information transmission method is provided, applied to an access network element, the method comprising:

[0025] The access network element sends a third IP data packet to the target network element. The third IP data packet is used to carry a third NAS message, which is a NAS message sent by the terminal device to the target network element.

[0026] And / or,

[0027] The access network element receives a fourth IP data packet sent by the target network element. The fourth IP data packet is used to carry a fourth NAS message, which is a NAS message sent by the target network element to the terminal device.

[0028] Seventhly, an information transmission method is provided, applied to a target network element, the method comprising:

[0029] The target network element receives a third IP data packet sent by the access network element. The third IP data packet is used to carry a third NAS message, which is a NAS message sent by the terminal device to the target network element.

[0030] And / or,

[0031] The target network element sends a fourth IP data packet to the access network element. The fourth IP data packet is used to carry a fourth NAS message, which is a NAS message sent by the target network element to the terminal device.

[0032] Eighthly, an information transmission device is provided, applied to an access network element, the device comprising:

[0033] The first sending unit is configured to send a first message to a first user plane network element, wherein the first message is determined based on a first NAS message; the first NAS message is a NAS message sent by the terminal device to the target network element.

[0034] And / or,

[0035] The first receiving unit is configured to receive a second message sent by a first user plane network element. The second message is determined based on a second NAS message, which is a NAS message sent by the target network element to the terminal device.

[0036] Ninthly, an information transmission device is provided, applied to a first user plane network element, the device comprising:

[0037] The second receiving unit is configured to receive a first message sent by an access network element, wherein the first message is determined based on a first NAS message; the first NAS message is a NAS message sent by a first terminal device to a target network element.

[0038] And / or,

[0039] The second sending unit is configured to send a second message to an access network element. The second message is determined based on a second NAS message, which is a NAS message sent by the target network element to the first terminal device.

[0040] Tenthly, an information transmission device is provided, applied to a target network element, the device comprising:

[0041] The third receiving unit is configured to receive a first message sent by a first user plane network element; the first message is determined based on a first NAS message; the first NAS message is a NAS message sent by a first terminal device to the target network element;

[0042] And / or,

[0043] The third sending unit is configured to send a second message or a third message to the first user plane network element. The second message is determined based on a second NAS message. The third message includes a second NAS message and second indication information. The second indication information is used to determine the second message. The second NAS message is a NAS message sent by the target network element to the first terminal device.

[0044] Eleventhly, an information transmission device is provided, applied to a terminal device, the device comprising:

[0045] The fourth sending unit is configured to send a first NAS message and a first indication information to an access network element. The first NAS message is a NAS message sent by the terminal device to the target network element, and the first indication information is used to determine the target network element.

[0046] And / or,

[0047] The fourth receiving unit is configured to receive the second NAS message sent by the access network element.

[0048] In a twelfth aspect, an information transmission device is provided, applied to a terminal device, the device comprising:

[0049] The fifth sending unit is configured to send a fourth message to the access network element. The fourth message carries a third NAS message, which is carried by a third IP data packet. The third NAS message is a NAS message sent by the terminal device to the target network element.

[0050] And / or,

[0051] The fifth receiving unit is configured to receive a fifth message sent by an access network element. The fifth message carries a fourth NAS message, which is carried by a fourth IP data packet. The fourth NAS message is a NAS message sent by the target network element to the terminal device.

[0052] In a thirteenth aspect, an information transmission device is provided, applied to an access network element, the device comprising:

[0053] The sixth sending unit is configured to send a third IP data packet to the target network element. The third IP data packet is used to carry a third NAS message, which is a NAS message sent by the terminal device to the target network element.

[0054] And / or,

[0055] The sixth receiving unit is configured to receive a fourth IP data packet sent by the target network element. The fourth IP data packet is used to carry a fourth NAS message, which is a NAS message sent by the target network element to the terminal device.

[0056] Fourteenth aspect, a kind of information transmission device is provided, applied to a target network element, the device comprising:

[0057] The seventh receiving unit is configured to receive a third IP data packet sent by an access network element. The third IP data packet is used to carry a third NAS message, which is a NAS message sent by a terminal device to a target network element.

[0058] And / or,

[0059] The seventh sending unit is configured to send a fourth IP data packet to the access network element. The fourth IP data packet is used to carry a fourth NAS message, which is a NAS message sent by the target network element to the terminal device.

[0060] In a fifteenth aspect, a communication device is provided, the communication device comprising: a memory, a transceiver, a processor, and a bus system;

[0061] The memory is used to store programs and instructions;

[0062] The transceiver is used to receive or send information under the control of the processor;

[0063] The processor is used to execute programs in the memory;

[0064] The bus system is used to connect the memory, the transceiver, and the processor to enable communication between the memory, the transceiver, and the processor;

[0065] The processor is used to call program instructions in the memory to execute the information transmission method described above.

[0066] The chip provided in this application embodiment is used to implement the above-described information transmission method.

[0067] Specifically, the chip includes a processor for retrieving and running a computer program from memory, causing a device equipped with the chip to perform the aforementioned information transmission method.

[0068] The computer-readable storage medium provided in this application embodiment is used to store a computer program that causes a computer to execute the above-described information transmission method.

[0069] The computer program product provided in this application includes computer program instructions that cause a computer to execute the above-described information transmission method.

[0070] The computer program provided in this application embodiment, when run on a computer, causes the computer to execute the above-described information transmission method.

[0071] In the information transmission method provided in this application embodiment, an access network element can send a first message to a first user plane network element, the first message being determined based on a first NAS message; the first NAS message is a NAS message sent by a terminal device to a target network element; and / or, the access network element receives a second message sent by the first user plane network element, the second message being determined based on a second NAS message, the second NAS message being a NAS message sent by the target network element to the terminal device. In other words, this application embodiment can forward NAS messages between the target network element and the terminal device through the user plane network element, thereby reducing the signaling transmission load pressure of the AMF and improving data transmission efficiency. Attached Figure Description

[0072] Figure 1 is a schematic diagram of a system architecture provided in an embodiment of this application;

[0073] Figure 2 is a schematic diagram of a control plane protocol stack structure provided in an embodiment of this application;

[0074] Figure 3 is a flowchart illustrating an information transmission method according to an embodiment of this application;

[0075] Figures 4A and 4B are schematic diagrams of a transmission protocol frame structure provided in an embodiment of this application;

[0076] Figure 5 is a schematic flowchart of an information transmission method provided in an embodiment of this application;

[0077] Figure 6 is a schematic flowchart of an information transmission method provided in an embodiment of this application;

[0078] Figure 7 is a schematic flowchart of an information transmission method provided in an embodiment of this application;

[0079] Figure 8 is a schematic diagram of another transmission protocol frame structure provided in an embodiment of this application;

[0080] Figure 9 is a flowchart illustrating an information transmission method according to an embodiment of this application.

[0081] Figure 10 is a flowchart illustrating an information transmission method according to an embodiment of this application.

[0082] Figure 11 is a schematic flowchart of an information transmission method provided in an embodiment of this application;

[0083] Figure 12 is a schematic diagram of another system architecture provided in an embodiment of this application;

[0084] Figure 13 is a structural schematic diagram of an information transmission device 1300 provided in an embodiment of this application;

[0085] Figure 14 is a structural schematic diagram of an information transmission device 1400 provided in an embodiment of this application;

[0086] Figure 15 is a structural schematic diagram of an information transmission device 1500 provided in an embodiment of this application;

[0087] Figure 16 is a structural schematic diagram of an information transmission device 1600 provided in an embodiment of this application;

[0088] Figure 17 is a structural schematic diagram of an information transmission device 1700 provided in an embodiment of this application;

[0089] Figure 18 is a structural schematic diagram of an information transmission device 1800 provided in an embodiment of this application;

[0090] Figure 19 is a schematic diagram of the structure of an information transmission device 1900 provided in an embodiment of this application. Detailed Implementation

[0091] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings. The accompanying drawings are for reference only and are not intended to limit the embodiments of this invention.

[0092] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0093] It should be noted that this application applies to mobile networks, especially future-oriented mobile networks such as 6G networks.

[0094] Figure 1 illustrates a schematic diagram of a system architecture provided in this application. As shown in Figure 1, the system architecture includes Access and Mobility Management Function (AMF) network elements, Session Management Function (SMF) network elements, Policy Control Function (PCF) network elements, Authentication Server Function (AUSF) network elements, Unified Data Management (UDM) network elements, Application Function (AF) network elements, User Plane Function (UPF) network elements, Network Slice Selection Function (NSSF) network elements, Network Exposure Function (NEF) network elements, and Network Repository Function (NRF) network elements.

[0095] Furthermore, the communication system architecture also includes Wireless Access Network (R)AN elements, User Equipment (UE) and Data Network (DN) elements.

[0096] The AMF network element is mainly used for terminal registration, mobility management, and tracking area update processes in mobile networks. The mobility management network element can receive Non-Access Stratum (NAS) messages, complete registration management, connection management, and reachability management, allocate tracking area lists, and perform mobility management, and also transparently transmit session management messages to the SMF network element.

[0097] SMF network elements are primarily used for session management in mobile networks, such as session creation, modification, and release. Specific functions include assigning Internet Protocol (IP) addresses to users and selecting user plane network elements that provide packet forwarding capabilities.

[0098] In addition, the PCF network element includes user subscription data management, policy control, billing policy control, and Quality of Service (QoS) control. The AUSF network element is primarily used to authenticate service functions using an extensible authentication protocol (EAP) and store keys to achieve user authentication and authorization. The UDM network element is mainly used to store user data, such as subscription information and authentication / authorization information.

[0099] UPF network elements are primarily used for user plane service processing, such as service routing, packet forwarding, anchoring functions, Quality of Service (QoS) mapping and enforcement, uplink identification and routing to the data network, downlink packet buffering and downlink data arrival notification triggering, and connection to external data networks. NSSF network elements are primarily used to select the network slice serving the UE, determine the Network Slice Selection Assistance Information (NSSAI) configured for the UE, and determine the NSSAI allowed by the UE.

[0100] (R)AN network elements are devices that provide wireless communication functions for UEs. Access network devices include, but are not limited to: base stations (xNodeB, xNB) in future mobile networks, next-generation base stations (gNodeB, gNB) in 5G, evolved Node B (eNB), Radio Network Controller (RNC), Node B (NB), Base Station Controller (BSC), Base Transceiver Station (BTS), femtocell, Base Band Unit (BBU), Transmitting and Receiving Point (TRP), Transmitting Point (TP), mobile switching center, etc.

[0101] The UE in this application embodiment is a device with wireless transceiver capabilities, which can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on water; and it can also be deployed in the air (e.g., on airplanes, balloons, and satellites). The UE can be a mobile phone, tablet computer, computer with wireless transceiver capabilities, VR device, AR device, wireless device in autonomous driving, wireless device in telemedicine, device in smart grid, wireless device in transportation safety, wireless device in smart city, etc.

[0102] DN network elements are mainly used to provide services to users, such as operator services, Internet access services, and third-party services.

[0103] It should be noted that the aforementioned network elements can be network components within hardware devices, software functions running on dedicated hardware, or virtualized functions instantiated on a platform (e.g., a cloud platform). These network elements can be divided into one or more services; furthermore, services that exist independently of network functions may also exist.

[0104] Referring to Figure 1, the UE can connect to the AMF network element through the N1 interface, and the (R)AN network element can connect to the AMF network element through the N2 interface. The UE connects to the (R)AN network element through the Uu interface. N3 is the connection interface between the RAN equipment and the UPF network element. N4 is the connection interface between the SMF network element and the UPF, used to transmit control signaling between the SMF network element and the UPF network element. N6 is the connection interface between the UPF network element and the DN network element.

[0105] It should be noted that the system architecture shown in Figure 1 draws on the successful experience of IT system service-oriented and microservice architectures. It achieves decoupling and integration between network functions through modularization. The decoupled network functions can be independently expanded, evolved, and deployed on demand. The interaction between all network functions (NFs) in the control plane adopts service-oriented interfaces. The same service can be called by multiple NFs, reducing the coupling of interface definitions between NFs. Ultimately, it realizes the on-demand customization of the entire network function and flexibly supports different business scenarios and requirements.

[0106] Referring to Figure 1, Nausf is the service-based interface displayed by AUSF, Namf is the service-based interface displayed by AMF, Nsmf is the service-based interface displayed by SMF, Nnef is the service-based interface displayed by NEF, Nnrf is the service-based interface displayed by NRF, Npcf is the service-based interface displayed by PCF, Nudm is the service-based interface displayed by UDM, and Naf is the service-based interface displayed by AF.

[0107] As shown in Figure 1, some interactions between core network elements support service-oriented interfaces. However, the N1 interface between the UE and AMF, the N2 interface between (R)AN and AMF, and the N4 interface between SMF and UPF still use traditional reference points for interaction. The service-oriented architecture evolution is not yet complete. Currently, the design for (R)AN and UPF to interact with other core network elements through service-oriented interfaces is under discussion.

[0108] In related technologies, when a UE interacts with an NF network element, it still needs to reach the corresponding NF network element through the N1 interface and then through the AMF. For example, referring to Figure 2, when a UE interacts with an NR, the RAN and AMF can act as relays to forward messages. Specifically, the control plane protocol stack, from top to bottom, consists of: Non-Access Stratum (NAS), Radio Resource Control (RRC) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, Medium Access Control (MAC) layer, and Physical (PHY) layer. It should be understood that the NAS layer is not located on the RAN, but rather on the AMF.

[0109] It should be noted that in some embodiments, the PHY layer may also be referred to as Layer 1 (L1).

[0110] It should be noted that in some embodiments, the PDCP layer, RLC layer, and MAC layer can be understood as data link layers and can be collectively referred to as Layer 2 (L2).

[0111] Referring to Figure 2, the protocol stack for communication between the RAN and AMF, from top to bottom, is as follows: Next Generation Application Protocol (NGAP) layer, Stream Control Transmission Protocol (SCTP) layer, Internet Protocol (IP) layer, L2, and L1. The protocol stack for communication between the AMF and NF network elements, from top to bottom, is as follows: Hypertext Transfer Protocol 2.0 (HTTP / 2) layer, Transport Layer Security (TLS) layer, Transmission Control Protocol (TCP) layer, IP layer, L2, and L1.

[0112] It is evident that the dedicated interface design between the UE and AMF remains complex. Any interaction between the UE and the core network requires NAS layer messages, which means they all need to be forwarded through the AMF. With the increasing volume of signaling data from artificial intelligence (AI) and sensing technologies, the AMF may become a bottleneck in signaling transmission.

[0113] Based on this, the embodiments of this application provide an information transmission method that can solve the problem that NAS messages are all transmitted through AMF in the prior art, reduce the signaling transmission load pressure of AMF, and improve the efficiency of data transmission.

[0114] In one embodiment of this application, NAS messages can be forwarded through a first user plane network element. In this way, NAS messages do not need to be forwarded through the AMF, which can reduce the signaling transmission load of the AMF and improve the efficiency of data transmission.

[0115] It should be noted that the first user plane network element can be a network element responsible for processing and forwarding user data. For example, the first user plane network element can be a UPF or a Packet Data Network Gateway User Plane Function (PGW-U). The first user plane network element can also be a network element with user data processing and forwarding functions, such as a next-generation network element with UPF or PGW-U functions. This application does not limit the first user plane network element.

[0116] It should be noted that the target network function (Target NF) can be any network element in the core network other than the first user plane network element. For example, the target NF can be SMF, PCF, UDM, AF, NRF, NEF, NSSF, etc. The target NF can also be a network element newly introduced in future communication technologies.

[0117] In addition, the target network element can also be a Virtual UE Function (VUEF) network element set up in the core network. It should be understood that the UE and VUEF exchange NAS messages via IP packet payloads. The VUEF establishes a corresponding virtual UE instance for the UE. The virtual UE instance represents the actual UE and interacts with other network elements such as mobility management elements and session management elements through service-oriented interfaces. The VUEF receives IP data from the UE, obtains the NAS message from it, and then sends the NAS message to the corresponding network element on behalf of the UE through the service-oriented interface. Because the interaction with core network elements is performed by the VUEF on behalf of the UE, the VUEF can also shield ordinary UEs from the network element information deployed in the network, that is, it can shield the UE from network topology information, which is beneficial to the security of the operator's network.

[0118] It should also be noted that the information transmission method provided in this embodiment includes uplink information transmission and / or downlink information transmission, which will be described in detail below.

[0119] First, let's introduce the uplink information transmission process.

[0120] Referring to Figure 3, which shows a flowchart of an information transmission method, the information transmission method provided in this application embodiment may include the following:

[0121] S310, the terminal device sends a first NAS message and a first indication information, and correspondingly, the access network element receives the first NAS message and the first indication information; the first NAS message is a NAS message sent by the terminal device to the target network element, and the first indication information is used to determine the target network element.

[0122] S320. The access network element sends a first message to the first user plane network element, or in other words, the first user plane network element receives the first message sent by the access network element; wherein, the first message is determined according to the first NAS message.

[0123] S330, The first user plane network element sends a first message to the target network element, or in other words, the target network element receives the first message sent by the first user plane network element.

[0124] It should be understood that the first NAS message is an uplink NAS message. "Uplink" indicates that the transmission direction of the signal or data is from the terminal device in the cell to the core network element. In other words, the first NAS message can be a NAS message sent by the terminal device to the core network target NF.

[0125] In this embodiment of the application, the first NAS message and the first indication information sent by the terminal device to the access network element in step S310 can be carried by an RRC message. That is, the terminal device can send an RRC message to send the first NAS message and the first indication information to the access network element.

[0126] It should be noted that RRC messages can be RRC setup complete messages, RRC reconstruction complete messages, RRC setup request messages, uplink information transfer messages, etc., or they can be access layer messages newly defined in 6G networks. This application embodiment does not limit the type of RRC messages.

[0127] It should also be noted that the first NAS message and the first indication information can be carried through the same RRC message or through different RRC messages; this application embodiment does not impose any restrictions on this. For example, the terminal device carries the first indication information through RRCSetupRequest and the first NAS message through RRCSetupComplete.

[0128] In this embodiment of the application, the first indication information can be used to determine the receiving end of the first NAS message, i.e., the target network element.

[0129] In some embodiments, the first indication information may include one or more of the following:

[0130] Identification information of the target network element;

[0131] IP address information of the target network element;

[0132] The message type of the first NAS message;

[0133] Network element selection auxiliary information.

[0134] It should be understood that when the terminal device locally stores relevant information about the target network element receiving the first NAS message, the terminal device can directly indicate the identification information and / or IP address information of the target network element of the first NAS message to the access network element.

[0135] It should also be understood that if the terminal device does not store relevant information about the target network element locally, the terminal device may indicate the message type of the first NAS message and / or the network element selection auxiliary information to the access network element, so that the access network element can determine the receiving end of the first NAS message based on the message type of the first NAS message and / or the network element selection auxiliary information.

[0136] It should be noted that the terminal device can indicate the message type of the first NAS message through an RRC message. There are several ways for the terminal device to indicate the NAS message type in the RRC message.

[0137] In one possible implementation, the terminal device can carry the first NAS message in a NAS container within an RRC message, and carry the NAS message type in the RRC message, such as mobility management type, session management type, registration, deregistration, session establishment, session modification, session release, etc.

[0138] In another possible implementation, the terminal device can carry the first NAS message in a different type of NAS container in the RRC message. For example, set the NAS-MM container to carry NAS messages of mobility management type, set the NAS-SM container to carry NAS messages of session management type, and set the NAS-SF container to carry NAS messages of awareness related type.

[0139] It should be understood that access network elements cannot parse NAS messages carried by terminal devices in RRC messages via NAS containers. By indicating the message type of the first NAS message in the RRC message, access network elements can determine the target network element of the first NAS message.

[0140] In some embodiments, network element selection assistance information includes one or more of the following:

[0141] Business information, such as business type information;

[0142] Target network element selection instructions, such as instructions for selecting distributed network elements or instructions for selecting centralized network elements;

[0143] Data Network Name (DNN);

[0144] Slice information.

[0145] It should be understood that multiple network elements may exist in the core network to perform the same function, and different network elements may handle different services. When terminal devices report service information (such as service type) to access network elements, it can help the access network elements determine the specific target NF.

[0146] Furthermore, network elements in the core network can be deployed centrally in the core network or distributed close to the access network elements. Access network elements need to determine whether to select a distributed or centralized target NF. Access network elements can determine this based on the target network element selection instruction.

[0147] It should also be understood that different core network elements correspond to different DNNs, and access network elements can select the Target NF that matches the DNN based on the DNN reported by the terminal device.

[0148] In addition, different core network elements process different slices, and access network elements can select the Target NF that matches the slice information based on the slice information reported by the terminal device.

[0149] In this embodiment of the application, after the access network element receives the first NAS message and the first indication information sent by the terminal device, the access network element can determine the target network element of the first NAS message. Specifically, the access network element can determine the target network element based on the first NAS message and / or the first indication information.

[0150] In one possible implementation, if the first indication information indicates the identification information of the target network element and / or the IP address information of the target network element, the access network element can directly determine the target network element of the first NAS message.

[0151] In another possible implementation, when the first indication information indicates the message type of the first NAS message, and / or the network element selects auxiliary information, the relevant information of the target network element of the first NAS message is obtained from the data storage network element. The access network element obtains the relevant information of the target network element from the data storage network element through the following steps:

[0152] The access network element sends a first network element query request to the data storage network element; the first network element query request includes the first indication information and / or the location information of the terminal device.

[0153] The access network element receives information about one or more candidate network elements sent by the data storage network element; the one or more candidate network elements include the target network element.

[0154] It should be noted that the location information of the terminal device can be location tracking area information, cell information, etc., and this application embodiment does not limit it.

[0155] It should also be noted that the relevant information of the network element (including the target network element and / or candidate network element) may include the identification information of the network element and / or the IP address information of the network element.

[0156] It should be understood that an access network element can send a first network element query request to a data storage network element. The request may include one or more of the following: the message type of the first NAS message, network element selection auxiliary information, and location information.

[0157] It should also be understood that the data storage network element can select candidate network elements based on the received network element selection auxiliary information. The candidate network elements returned by the data storage network element can be network elements centrally deployed in the operator's core network or distributed network elements.

[0158] For example, the first network element query request indicates that the message type of the first NAS message is session management, the network element selection auxiliary information indicates the selection of a distributed network element, and the location information is tracking area TA1. Accordingly, the data storage network element can return relevant information about the distributed SMFs deployed near TA1 that serve TA1.

[0159] It should be noted that when the data storage network element returns multiple candidate network elements, the access network element can select one of the multiple candidate network elements as the target network element. For example, the access network element can randomly select one of the multiple candidate network elements as the target network element, or the access network element can select one candidate network element as the target network element according to a preset rule (e.g., select the candidate network element closest to the terminal device as the target network element). This application embodiment does not limit this.

[0160] It should also be noted that access network elements can also select target network elements that match the message type, network element auxiliary information, and terminal device location information based on the configuration of relevant network elements already stored locally.

[0161] In another possible implementation, the relevant information of the target network element in the first NAS message (the identification information of the target network element, and / or the IP address information of the target network element) can be pre-stored in the local storage space of the access network element, for example, through Operation Administration and Maintenance (OAM) management. That is, after receiving the first NAS message, the access network element can obtain the relevant information of the target network element from its local storage space without interacting with the data storage network element.

[0162] In some embodiments, after receiving the first NAS message, the access network element also needs to determine whether the first NAS message can be forwarded through the first user plane network element. In this embodiment, the access network element can determine the type of the target network element. If the type of the target network element is a first type, the access network element determines to send the first NAS message to the target network element through the first user plane network element.

[0163] It should be noted that the first type can be predefined or configured in the core network, and this application embodiment does not limit this.

[0164] It should be understood that access network elements can classify uplink NAS messages. When the destination network element of an uplink NAS message is a first-type network element, the access network element determines that the uplink NAS message can be forwarded through the first user plane network element. When the destination network element of a NAS message is not a first-type network element, the access network element determines that the uplink NAS message should be sent using the traditional method, i.e., forwarded via AMF. In this way, the load on the network elements forwarding NAS messages can be balanced, improving the transmission efficiency of NAS messages.

[0165] In this embodiment of the application, after determining that the first NAS message is forwarded through the first user plane network element, the access network element can send the first message to the first user plane network element (i.e., S320).

[0166] It should be noted that the first message can be determined based on the first NAS message, or in other words, the first message can be obtained based on the first NAS message.

[0167] It should be understood that after the access network element determines that the first NAS message needs to be forwarded through the first user plane, the access network element can process the first NAS message sent by the terminal device to obtain the first message, so that the processed first message can conform to the transmission protocol between the access network element and the first user plane element, and / or conform to the transmission protocol between the first user plane element and the target network element.

[0168] For example, taking the first user plane network element as UPF, referring to the transport protocol stacks shown in Figures 4A and 4B, the transport protocol stack between the access network element and the UPF, from top to bottom, is as follows: IP layer, User Plane General Packet Radio Service Tunneling Protocol User Plane (CTP-U) layer, User Datagram Protocol (UDP) / IP layer, L2, L1. In Figure 4A, the transport protocol stack between the UPF and the Target NF, from top to bottom, is as follows: IP layer, L2, and L1. In Figure 4B, the transport protocol stack between the UPF and the Target NF, from top to bottom, is as follows: HTTP (e.g., HTTP / 2+TCP, or HTTP / 3+QUIC), IP, L2, and L1.

[0169] It should be noted that the transmission protocol between the terminal device and the access network element is the same as that in Figure 2, and will not be repeated here for the sake of simplicity.

[0170] As can be seen from the examples shown in Figures 4A and 4B, the transmission protocols between the access network element and the UPF, as well as between the UPF and the Target NF, both include the IP protocol. Therefore, the first message can be a data packet conforming to the IP protocol. In this embodiment, the first message can also be referred to as the first IP data packet.

[0171] It should be understood that the payload of the first IP packet is the first NAS message. The header of the first IP packet can be referred to as the first IP header. The destination address information in the first IP header is the IP address information of the target network element.

[0172] In one possible implementation, the source address information in the first IP header is the IP address information of the terminal device.

[0173] For example, Table 1 shows the format of the first message provided by this implementation.

[0174] Table 1

[0175] In another possible implementation, the source address information of the first IP header is the IP address information of the access network element.

[0176] For example, Table 2 shows the format of the first message provided by this implementation.

[0177] Table 2

[0178] It should be understood that after determining that the first NAS message needs to be forwarded through the first user plane network element, the access network element processes the first NAS message to obtain the first message. This can be done by the access network element adding a first IP header to the first NAS message based on the relevant information of the target network element to obtain the first message.

[0179] In this way, the first message conforms to the transmission protocol between the access network element and the first user plane network element, and / or conforms to the transmission protocol between the first user plane network element and the target network element. Thus, the first user plane network element can send the first NAS message to the target NF via IP routing.

[0180] It should also be noted that the transmission protocol between the access network element and the first user plane network element can also be other protocols, such as NGAP, SCTP, etc. Correspondingly, the first message can be a data packet carrying the first NAS message and conforming to other protocols.

[0181] In some embodiments, the sending of a first message from the access network element to the first user plane network element in S320 can be achieved by the access network element sending the first message to the first user plane network element through a first tunnel. Correspondingly, the first user plane network element can receive the first message sent by the access network element, wherein the first user plane network element receives the first message sent by the access network element through the first tunnel.

[0182] It should be noted that the first tunnel is a dedicated tunnel between the terminal equipment and the first user plane network element.

[0183] For example, taking the first user plane network element as a UPF, a dedicated GTP-U tunnel can be established between the terminal device and the UPF. Referring to Figures 4A and 4B, the first tunnel can be a dedicated GTP-U tunnel for the terminal device. It should be understood that GTP-U is a data transmission channel at the terminal device level, capable of distinguishing different terminal devices.

[0184] It should be noted that there are multiple ways in which the first user plane network element in S330 can send the first message to the target network element.

[0185] In one possible implementation, the first user plane network element sends a first message to the target network element via IP routing.

[0186] It should be understood that the first user plane network element can send the first message to the target NF corresponding to the destination address information through IP routing based on the destination address information in the first IP header.

[0187] For example, when the first user plane network element is a UPF, the UPF can send the first message to the Target NF through the N6 interface.

[0188] In another possible implementation, the first user plane network element sends a first message to the target network element through a first service interface.

[0189] It should be understood that the first user plane network element calls the services provided by the Target NF through the service-oriented interface, such as defining the Nnf_request service provided by the Target NF, and sends the first NAS message by calling this service.

[0190] Therefore, the uplink NAS message transmission method provided in this application embodiment can forward uplink NAS messages to the target network element through the first user plane network element. In this way, the uplink NAS messages do not need to be forwarded through the AMF, which can reduce the signaling transmission load pressure of the AMF and improve the efficiency of data transmission.

[0191] The following describes the downlink information transmission process.

[0192] Referring to the flowchart of an information transmission method shown in Figure 5, the information transmission method provided in this application embodiment may include the following:

[0193] S510. The target network element sends a second message or a third message to the first user plane network element. The third message includes a second NAS message and a second indication information. The second indication information is used to determine the second message. The second NAS message is a NAS message sent by the target network element to the first terminal device.

[0194] S520. The first user plane network element sends a second message to the access network element. The second message is determined according to the second NAS message. The second NAS message is the NAS message sent by the target network element to the first terminal device.

[0195] S530, the access network element sends a second NAS message to the terminal device.

[0196] It should be understood that the second NAS message is a downlink NAS message. Downlink indicates that the transmission direction of the signal or data is from the core network element to the terminal equipment in the cell. In other words, the second NAS message can be a NAS message sent from the core network target NF to the terminal equipment.

[0197] It should be noted that the target network element can forward the second NAS message sent to the terminal device through the first user plane network element. It should be understood that the forwarding of downlink NAS messages by the target network element through the first user plane network element can be predefined, configured by the core network for the target network element, or determined by the target network element according to preset rules (for example, if the target network element is of type 1, the target network element forwards the downlink NAS message through the first user plane network element; otherwise, it forwards the downlink NAS message through the traditional method, i.e., through the AMF). This application embodiment does not impose any restrictions on this.

[0198] It should be understood that after generating the second NAS message, the target network element can send the second NAS message to the first user plane network element. There are several ways in which the target network element can send the second NAS message to the first user plane network element.

[0199] In one possible implementation (denoted as Method 1), the target network element can send a second message to the first user plane network element. The second message is determined based on a second NAS message, or in other words, the second message is obtained based on a second NAS message.

[0200] It should be noted that if the target network element determines that the second NAS message needs to be forwarded through the first user plane network element, the target network element can process the second NAS message to obtain the second message, so that the processed second message can conform to the transmission protocol between the target network element and the first user plane network element, and / or the transmission protocol between the first user plane network element and the access network element.

[0201] For example, taking the first user plane network element as UPF, referring to the transmission protocol stack shown in Figures 4A and 4B, it can be seen that the transmission protocol between the Target NF and UPF, as well as the transmission protocol between UPF and access network element, both include the IP protocol. Therefore, the second message can be a data packet conforming to the IP protocol.

[0202] In this embodiment of the application, the second message can also be referred to as the second IP data packet. The payload of the second IP data packet is the second NAS message, and the IP header of the second IP data packet can be referred to as the second IP header.

[0203] The source address information in the second IP header is the IP address information of the target network element.

[0204] In one implementation, the destination address information in the second IP header is the IP address information of the access network element.

[0205] For example, Table 3 shows the format of the second message provided by this embodiment.

[0206] Table 3

[0207] In one implementation, the destination address information in the second IP header is the IP address information of the terminal device.

[0208] For example, Table 4 shows the format of the second message provided by this embodiment.

[0209] Table 4

[0210] It should be understood that in the above method 1, the target network element processes the second NAS message to obtain the second message, which can be: the target network element adds a second IP header to the second NAS message to obtain the second message.

[0211] It should also be understood that the target network element can add a second IP header to the second NAS message based on the second indication information to obtain the second message. The second indication information includes one or more of the following:

[0212] Identification information of the terminal device;

[0213] IP address information of the terminal device;

[0214] Identification information of access network elements;

[0215] IP address information of access network elements.

[0216] It should be noted that the target network element may locally store one or more of the following: the terminal device's identification information, the terminal device's IP address information, the identification information of the access network element where the terminal device resides, and the IP address information of the access network element where the terminal device resides. For example, the target network element can determine the above information from the uplink NAS message sent to it by the terminal device. Furthermore, if the target network element does not locally store the above information, it can send a query request to the data storage network element and receive the above information fed back by the data storage network element. This application embodiment does not limit the method of obtaining the second indication information.

[0217] It should also be noted that, in Method 1 above, when the destination address information in the second IP header is the IP address information of the access network element, the target network element also needs to send the terminal device's identification information and / or the terminal device's IP address information to the first user plane network element. The specific reason is that the second IP header does not contain the terminal device's IP address; therefore, it is necessary to additionally send the terminal device's identification information and / or IP address information to inform the first user plane network element of the target terminal device of the second NAS message.

[0218] In another possible implementation (denoted as mode 2), the target network element can send a third message to the first user plane network element. The third message includes a second NAS message and a second indication information, which is used to determine the second message.

[0219] It should be understood that the target network element may not process the second NAS message, but instead send the second NAS message and the second indication information directly to the first user plane network element. The first user plane network element then processes the second NAS message based on the second indication information to obtain a second message that conforms to the transmission protocol between the first user plane network element and the access network element.

[0220] It should be noted that the transmission protocol between the first user plane network element and the access network element can also be other types of protocols, such as NGAP, SCTP, etc. Correspondingly, the second message can be a data packet carrying the second NAS message and conforming to other protocols.

[0221] In this embodiment of the application, the method by which the target network element sends a second message or a third message to the first access network element in step S510 includes a variety of methods.

[0222] In one implementation, the target network element sends a second message or a third message to the first user plane network element via IP routing. That is, the target network element can send the second message or the third message to the first user plane network element via IP routing. For example, when the first user plane network element is a UPF, the target network element can send the second message or the third message to the UPF through the N6 interface.

[0223] In another implementation, the target network element sends a second message or a third message to the first user plane network element through a second service-oriented interface. That is, the target network element invokes the services provided by the first user plane network element through the service-oriented interface to send the second message or the third message.

[0224] In the above method 1, after the first user plane network element receives the second message sent by the target network element, the first user plane network element may further forward the second message to the access network element.

[0225] In the above method 2, after the first user plane network element receives the third message (including the second NSA message and the second indication information) sent by the target network element, the first user plane network element can generate a second message based on the second NSA message and the second indication information. Furthermore, the first user plane network element can send the obtained second message to the access network element.

[0226] It should be understood that the second message can be a second NAS message with a second IP header added. Based on this, the first user plane network element generates the second message based on the second NSA message and the second indication information. This can be achieved by the first user plane network element adding a second IP header to the second NAS message based on the second indication information to obtain the second message.

[0227] It should be noted that the method by which the first user plane network element adds a second IP header to the second NAS message is the same as the method by which the target network element adds a second IP header to the geothermal NAS message. For the sake of brevity, it will not be described again here.

[0228] In some embodiments, the first user plane network element sending a second message to the access network element can be achieved by the first user plane network element sending the second message to the access network element through a first tunnel. Correspondingly, the access network element receiving the second message sent by the first user plane network element can be achieved by the access network element receiving the second message sent by the first user plane network element through a first tunnel.

[0229] It should be noted that the first tunnel is a dedicated tunnel between the terminal device and the first user plane network element.

[0230] For example, taking the first user plane network element as a UPF, a dedicated GTP-U tunnel can be established between the terminal device and the UPF. Referring to Figures 4A and 4B, the first tunnel can be a dedicated GTP-U tunnel for the terminal device. It should be understood that GTP-U is a data transmission channel at the terminal device level, capable of distinguishing different terminal devices.

[0231] It should be understood that after receiving the second message, the access network element can obtain the second NAS message from the second message.

[0232] For example, taking the first user plane network element as UPF, the access network element obtains the second NAS message from the second message, including: the access network device removes the second IP header from the second message to obtain the second NAS message.

[0233] Furthermore, the access network element can send the second NAS message to the terminal device corresponding to the second NAS message.

[0234] It should be noted that access network elements can carry second NAS messages through RRC messages. For example, RRC messages, such as RRCSetup, RRCResume, RRCRelease, RRCReconfiguration, DLInformationTransfer, etc., can also be access layer messages newly defined in 6G networks.

[0235] For the second message shown in Table 3, the destination address in the second IP header is the IP address of the access network element. In this scenario, the access network element can determine the terminal device receiving the second NAS message (i.e., the target UE of the second NAS message) through the first tunnel for receiving the second or third message, i.e., the dedicated tunnel between the terminal device and the first user plane network element. Further, the access network element sends the second NAS message to the terminal device corresponding to the first tunnel.

[0236] For example, taking the first user plane network element as the UPF, the access network element can determine the terminal device (i.e., the target UE) corresponding to the second NAS message through the terminal device's dedicated GTP-U tunnel. Specifically, through the destination address information in the second IP header, the xNB can know that it received a NAS message from the UPF and that it needs to be sent to the UE via a control plane RRC message. For instance, in the IP header of normal downlink user plane data (DL UP data), the destination address (dst addr) cannot be the IP address of the access network element, so the access network element can know that this is a NAS message; correspondingly, the access network element knows from the source address (src addr) that this is a NAS message from the target NF.

[0237] For the second message shown in Table 4, the destination address in the second IP header is the IP address of the terminal device. The access network element can determine the terminal device (i.e., the target UE of the second NAS message) corresponding to the second NAS message through the destination address information in the second IP header. Then, the access network element sends the second NAS message to the corresponding terminal device.

[0238] For example, taking the first user plane network element as a UPF, the access network element can determine the target UE of the second NAS message through the terminal device's dedicated GTP-U tunnel and the destination address in the second IP header. Specifically, through the IP header information, the access network element knows that this is a NAS message and originates from the target NF based on the source address.

[0239] Therefore, in the downlink information transmission method provided in this application embodiment, downlink NAS messages can be forwarded through the first user plane network element. In this way, downlink NAS messages do not need to be forwarded through the AMF, which can reduce the signaling transmission load pressure of the AMF and improve the efficiency of data transmission.

[0240] It should be noted that the uplink and downlink information transmissions described above can be implemented independently, meaning that the uplink and downlink information transmission processes do not affect each other. Alternatively, the uplink and downlink information transmissions described above can be implemented in combination. In one example, referring to Figure 6, the uplink information transmission process (steps S310-S330) can be executed first, followed by the downlink information transmission process (steps S510-S530). In this case, the destination address information in the second IP header of the second message in steps S510 and S520 can be determined based on the source address information in the first IP header of the first message. In another example, the method provided in this application embodiment can also execute the downlink information transmission process (steps S510-S530) first, followed by the uplink information transmission process (steps S310-S330). In this case, the destination address information in the first IP header of the first message in steps S310 and S320 can be determined based on the source address information in the second IP header of the second message.

[0241] In summary, in the information transmission method provided by the embodiments of this application, both uplink NAS messages and downlink NSA messages can be forwarded through the first user plane network element without going through the AMF. This solves the problem in the prior art that NAS messages are transmitted through the AMF, reduces the signaling transmission load of the AMF, and improves the efficiency of data transmission.

[0242] In another embodiment of this application, NAS messages can be sent to the target network element via the IP routing of the access network element. That is, in this embodiment, NAS messages can be sent directly to the target network element through the access network element without being forwarded by the first user plane network element. This can reduce the signaling transmission load of the AMF and improve the efficiency of data transmission.

[0243] It should be noted that the information transmission method provided in this embodiment also includes uplink information transmission and / or downlink information transmission. The uplink information transmission and downlink information transmission will be separated and described separately below.

[0244] First, let's introduce the uplink information transmission process.

[0245] Referring to the flowchart of an information transmission method shown in Figure 7, the information transmission method provided in this application embodiment may include the following:

[0246] S710. The terminal device sends a fourth message to the access network element, or in other words, the access network element receives the fourth message sent by the terminal device; wherein, the fourth message carries a third NAS message, the third NAS message is carried by a third IP data packet, and the third NAS message is a NAS message sent by the terminal device to the target network element.

[0247] S720: The access network element sends a third IP data packet to the target network element, or in other words, the target network element receives a third IP data packet sent by the access network element.

[0248] It should be understood that the third NAS message is an uplink NAS message. Uplink indicates that the transmission direction of the signal or data is from the terminal equipment in the cell to the core network element. In other words, the third NAS message can be a NAS message sent by the terminal equipment to the core network target NF.

[0249] In this embodiment, the access network element can directly send uplink NAS messages to the target network element. Referring to Figure 8, the transmission protocols between the access network element and the target network element, from top to bottom, are: IP layer, L2, and L1. It can be seen that data transmission between the access network element and the target network element is conducted via IP.

[0250] Based on this, in this embodiment of the application, the terminal device can encapsulate the third NAS message into an IP data packet (referred to as the third IP data packet in this embodiment of the application) and send it to the access network element. Then, the access network element sends the third NAS message to the target network element through IP routing.

[0251] In this embodiment of the application, referring to Table 5, the third IP data packet includes a third IP header and a third payload. The third payload includes the third NAS message. The destination address information of the third IP header is the IP address information of the target network element, and the source address information of the third IP header is the IP address information of the terminal device.

[0252] Table 5

[0253] It should be noted that the fourth message in S710 can be an AS message. For example, the fourth message can be an RRC message or other types of AS messages, and this application embodiment does not limit this.

[0254] In this embodiment of the application, an IP layer container can be introduced in the fourth message. The message format of the fourth message can be: {IP layer container[third IP packet header (IP address of terminal device, IP address of target network element), payload of IP packet is [third NAS message]}.

[0255] For example, when the fourth message is an RRC message, the structure of the RRC message carrying the third NAS message is: RRC message{IP layer container[IP packet header (IP address of terminal device, IP address of target network element), payload of IP packet is [third NAS message]}.

[0256] It should be noted that IP packets are not visible to the underlying processing units, and the payload of IP packets is not visible to the access network devices.

[0257] It should also be noted that in some embodiments, there may be protocols such as TCP / HTTP2 between the third NAS message and the IP layer.

[0258] In this embodiment of the application, before the terminal device sends the third NAS message through the fourth message, it also needs to obtain relevant information of the target network element of the third NAS message (such as the identification information and / or IP address information of the target network element).

[0259] In one implementation, if the terminal device locally stores relevant information about the target network element, the terminal device can directly encapsulate the third NAS message into a third IP data packet based on the relevant information about the target network element.

[0260] In another possible implementation, the terminal device can obtain information about the target network element of the third NAS message in the following way:

[0261] The terminal device sends a second network element query request to the access network element;

[0262] The terminal device receives information about one or more candidate network elements sent by the access network element; the one or more candidate network elements include the target network element.

[0263] It should be noted that the relevant information of the candidate network element includes the IP address information of the candidate network element, and / or the identification information of the candidate network element.

[0264] In some embodiments, the second network element query request includes one or more of the following:

[0265] Network element type;

[0266] Network element selection auxiliary information;

[0267] Device information for the terminal equipment;

[0268] Location information of the terminal device.

[0269] The network element type may include session management type, mobility management type, registration / deregistration type, session modification, session release, etc., and this application embodiment does not limit this.

[0270] Network element selection auxiliary information includes one or more of the following:

[0271] Business information;

[0272] Target network element selection instruction;

[0273] Data network name;

[0274] Slice information.

[0275] It should be noted that the relevant content of the auxiliary information for network element selection can be found in the relevant descriptions in the above embodiments, and will not be repeated here for the sake of brevity.

[0276] In addition, the location information of the terminal device may include location tracking area information and cell information (such as the identification information of the access network element and / or the IP address information of the access network element). The device information of the terminal device may include the identification information of the terminal device and / or the IP address information of the terminal device.

[0277] It should be understood that in some embodiments, if the access network element has already stored the relevant information of the target network element corresponding to the third NAS message locally, the access network element can directly return the relevant information of one or more candidate network elements. For example, the identification information and / or IP address information of one or more target network elements.

[0278] In other embodiments, if the access network element does not locally store the relevant information of the target network element corresponding to the third NAS message, the access network element can determine the relevant information of the target network element in the following ways:

[0279] The access network element sends a second network element query request to the data storage network element;

[0280] Access network elements receive information about one or more candidate network elements sent by data storage network elements.

[0281] In other words, if the access network element does not have local storage of the relevant information of the target network element corresponding to the third NAS message, the access network element can send a second network element query request to the data storage network element.

[0282] It should be noted that the information carried in the second network element request can be referred to the description in the above embodiments, and will not be repeated here for the sake of brevity.

[0283] It should also be noted that in some embodiments, the access network element can request relevant information of the target network element in batches, for example, by indicating the device information of multiple terminal devices or by indicating multiple network element types, to request relevant information of multiple target network elements in batches.

[0284] In this embodiment of the application, the data storage network element can return relevant information of one or more candidate network elements to the access network element, such as the identification information and / or IP address information of one or more target network elements.

[0285] It should be noted that the one or more candidate network elements returned by the access network element to the terminal device, and the candidate network elements returned by the data storage network element to the access network element, can be network elements centrally deployed in the operator's core network or distributed network elements. For example, if the second network element query request indicates that the network element type is a session management network element, the network element selection auxiliary information indicates the selection of a distributed network element, and the location information is tracking area TA1, the data storage network element can return relevant information of a distributed session management network element serving TA1 and deployed near TA1.

[0286] It should also be noted that in some embodiments, the data storage network element can return relevant information of candidate network elements to the access network element in batches, such as multiple target network elements for a terminal device, or a target network element for multiple terminal devices, etc. This application embodiment does not limit this.

[0287] In this embodiment, the terminal device can determine the target network element corresponding to the third NAS message based on the relevant information of one or more candidate network elements returned by the access network element. For example, when the access network element returns the relevant information of multiple candidate network elements, the terminal device can randomly select one of them as the target network element of the third NAS message, or the terminal device can select one candidate network element as the target network element according to a preset rule (e.g., select the candidate network element closest to the terminal device as the target network element). This embodiment does not limit this.

[0288] It should be noted that, in this embodiment of the application, when the terminal device performs cell handover, it is also necessary to update the IP address information of the terminal device.

[0289] It should be understood that in this embodiment, the access network element uses IP routing to send third NAS messages. Therefore, when a cell handover occurs, the terminal device's IP address needs to be updated. Specifically, when the terminal device switches from the source access network element to the target access network element, the target access network element needs to reallocate an IP address for the terminal device. Therefore, the terminal device needs to obtain new IP address information from the target access network element.

[0290] It should be noted that terminal devices can obtain updated IP address information from access network elements. For example, terminal devices can obtain updated IP address information from the target access network element, such as from the RRC message sent by the target access network element after handover, such as RRCReconfiguration, or from the IP address information in the handover command of the source access network element.

[0291] It should also be noted that the target network element or data storage network element also needs to know the updated IP address information of the terminal device. Specifically, access network elements (including source access network elements or target access network elements) can send the updated IP address information of the terminal device to the target network element or data storage network element.

[0292] In this embodiment of the application, after receiving the fourth message and obtaining the third IP data packet through the fourth message, the access network element can send the third IP data packet to the target network element. The access network element can send the third IP data packet to the target network element in various ways.

[0293] In one possible implementation, the access network element sends the third IP data packet to the target network element via IP routing.

[0294] It should be understood that access network elements can perform functions similar to UPF. Access network elements can send third NAS messages to the target network element indicated by the destination address information through IP routing, based on the destination address information in the third IP header.

[0295] In another possible implementation, the access network element sends the third IP data packet to the target network element through a third service interface.

[0296] It should be understood that access network elements can call the services provided by the Target NF through service-oriented interfaces. For example, they can define the Nnf_request service provided by the Target NF and send third-party IP packets by calling this service.

[0297] Therefore, in the uplink NAS message transmission method provided in this application embodiment, the terminal device can encapsulate the uplink NAS message into an IP data packet and send it to the access network element. In this way, the access network element can send the IP data packet to the corresponding target network element. Thus, the uplink NAS message does not need to be forwarded through the AMF, which can reduce the signaling transmission load pressure of the AMF and improve the data transmission efficiency.

[0298] The following describes the downlink information transmission process.

[0299] Referring to Figure 9, which shows a flowchart of an information transmission method, the information transmission method provided in this application embodiment may include the following:

[0300] S910, The target network element sends a fourth IP data packet to the access network element, or in other words, the access network element receives the fourth IP data packet sent by the target network element; wherein, the fourth IP data packet is used to carry a fourth NAS message, and the fourth NAS message is a NAS message sent by the target network element to the terminal device;

[0301] S920. The access network element sends a fifth message to the terminal device. The fifth message carries a fourth NAS message, which is carried by a fourth IP data packet. The fourth NAS message is a NAS message sent by the target network element to the terminal device.

[0302] It should be understood that the fourth NAS message is a downlink NAS message. Downlink indicates that the transmission direction of the signal or data is from the core network element to the terminal equipment in the cell. In other words, the fourth NAS message can be a NAS message sent from the core network target NF to the terminal equipment.

[0303] As shown in Figure 8, data transmission between the access network element and the target network element can be performed via IP. Based on this, in this embodiment, the target network element can directly send downlink NAS messages to the access network element. Specifically, the target network element can encapsulate the fourth NAS message into an IP data packet (referred to as the fourth IP data packet in this embodiment) and send it to the access network element. Then, the access network element sends the fourth NAS message to the terminal device.

[0304] In this embodiment of the application, referring to Table 6, the fourth IP data packet includes a fourth IP header and a fourth payload, wherein the fourth payload includes a fourth NSA message, the destination address information of the fourth IP header is the IP address information of the terminal device, and the source address information of the fourth IP header is the IP address information of the terminal device.

[0305] Table 6

[0306] It should be noted that the fourth IP packet is not visible to the underlying processing unit, and the payload of the fourth IP packet is not visible to the access network equipment.

[0307] It should also be noted that in some embodiments, there may be protocols such as TCP / HTTP2 between the fourth NAS message and the IP layer.

[0308] In this embodiment of the application, before the target network element in S910 sends the fourth IP data packet to the access network element, the target network element also needs to obtain the terminal device corresponding to the fourth NAS message.

[0309] In one implementation, if the target network element locally stores information about the terminal device corresponding to the fourth NAS message, the target network element can directly encapsulate the fourth NAS message into a fourth IP data packet based on the relevant information of the terminal device. For example, the target network element can obtain and store the relevant information of the terminal device from the third IP header of the third IP data packet sent by the terminal device.

[0310] In another possible implementation, the target network element can obtain relevant information about the terminal device that receives the fourth NAS message in the following way:

[0311] The target network element sends a device query request to the data storage network element;

[0312] The target network element receives device information sent by the data storage network element. The device information includes one or more of the following:

[0313] IP address information of the terminal device;

[0314] IP address information of access network elements.

[0315] In other words, the target network element can query the data storage network element for relevant information about the terminal device, and / or relevant information about the access network element to which the terminal device is connected.

[0316] In this embodiment of the application, the target network element encapsulates the fourth NAS message to obtain the fourth IP data packet, and then sends the fourth IP data packet to the access network element. The methods by which the target network element sends the fourth IP data packet to the access network element include various methods.

[0317] In one possible implementation, the target network element sends the fourth IP data packet to the access network element via IP routing.

[0318] In another possible implementation, the target network element sends the fourth IP data packet to the access network element through the fourth service interface.

[0319] In this embodiment of the application, after the access network element receives the fourth IP data packet, it can send a fifth message to the terminal device to carry the fourth IP data packet.

[0320] It should be noted that in S920, the fifth message can be an AS message. For example, the fourth message can be an RRC message or other types of AS messages, and this application embodiment does not limit this.

[0321] In this embodiment of the application, an IP layer container can be introduced in the fifth message. The message format of the fifth message can be: {IP layer container[fourth IP packet header (IP address of the target network element, IP address of the terminal device), the payload of the IP packet is [fourth NAS message]}.

[0322] For example, when the fifth message is an RRC message, the structure of the RRC message carrying the fourth NAS message is: RRC message{IP layer container[IP packet header (IP address of the target network element, IP address of the terminal device), the payload of the IP packet is [fourth NAS message]}.

[0323] Therefore, in the downlink NAS message transmission method provided in this application embodiment, the target network element can encapsulate the downlink NAS message into an IP data packet and send it to the access network element. In this way, the access network element can send the downlink NAS message carried by the IP data packet to the corresponding terminal device. Thus, the downlink NAS message does not need to be forwarded through the AMF, which can reduce the signaling transmission load pressure of the AMF and improve the efficiency of data transmission.

[0324] It should be noted that the uplink and downlink information transmissions described above can be implemented independently, meaning that the uplink and downlink information transmission processes do not affect each other. Alternatively, the uplink and downlink information transmissions described above can be implemented in combination. In one example, referring to Figure 10, the uplink information transmission process (steps S710-S720) can be executed first, followed by the downlink information transmission process (steps S910-S920). In step S910, the destination address information in the fourth IP header of the fourth IP data packet can be determined based on the source address information in the third IP header. In another example, the method provided in this application embodiment can also execute the downlink information transmission process (steps S910-S920) first, followed by the uplink information transmission process (steps S710-S720). In step S310, the destination address information in the third IP header can be determined based on the source address information in the fourth IP header.

[0325] In summary, in the information transmission method provided by this application embodiment, uplink NAS messages and downlink NSA messages can be encapsulated into IP data packets and directly forwarded through access network elements. This eliminates the need for NAS messages to pass through the AMF, solving the problem in existing technologies where all NAS messages are transmitted through the AMF, reducing the signaling transmission load on the AMF, and improving data transmission efficiency.

[0326] The methods provided in the embodiments of this application will be described in detail below with reference to specific application scenarios.

[0327] It should be understood that in traditional technologies, NAS messages must be cross-AMF. This application provides the following optional solutions for how the UE can send signals directly to the NF without having to go through a single network element node (such as the AMF in a 5G system).

[0328] Option 1: The UE sends an uplink NAS message to the xNB without carrying the IP layer. The xNB adds the IP layer to the NAS message based on the information indicated by the UE in the RRC layer and sends it to the UPF.

[0329] It should be understood that the transmission from the UE to the xNB still goes through the CP, carrying NAS messages and related information via the RRC, thus having a minimal impact on the UE. Furthermore, the transmission from the xNB to the NF is handled by the UP, with the NAS messages forwarded by the UPF.

[0330] It should be noted that N1 and N2 do not have to be SBI, which has little impact on UE and xNB.

[0331] Option 2: The UE encapsulates the uplink NAS message into an IP packet, the xNB acts as an IP router, and forwards it to the target NF without TCP / HTTP2. Alternatively, the target NF encapsulates the downlink NAS message into an IP packet and sends it directly to the xNB, which then forwards it to the UE.

[0332] The two optional schemes described above are explained in detail below through Examples 1 (including Examples 1a and 1b) and Example 2, respectively. It should be noted that Example 1 corresponds to optional scheme 1, where NAS signaling is forwarded via UPF. Example 2 corresponds to optional scheme 2, where NAS signaling is directly forwarded via the xNB's IP routing.

[0333] Example 1a

[0334] Referring to Figure 11, the specific implementation process of Example 1a includes the following steps.

[0335] Step 1: The UE sends an RRC message to the xNB, which carries a first NAS message and indicates the NAS message type.

[0336] It should be noted that the RRC messages, such as RRCSetupComplete, RRCResumeComplete, RRCSetupRequest, ULInformationTransfer, etc., can also be access layer messages newly defined in 6G networks.

[0337] It should be noted that there are two implementation methods for indicating the NAS message type in the RRC message.

[0338] In one implementation, the first NAS message is carried in the NAS container of the RRC message, and the NAS message type is carried in the RRC message, such as mobility management type, session management type, registration, deregistration, session establishment, session modification, session release, etc.

[0339] In another implementation, the first NAS message is carried in different types of NAS containers within the RRC message. For example, a NAS-MM container is set to carry NAS messages of mobility management type, a NAS-SM container is set to carry NAS messages of session management type, and a NAS-SF container is set to carry NAS messages of awareness-related type.

[0340] It should be understood that the xNB cannot parse NAS messages carried by the UE in RRC messages via the NAS container. The xNB can determine the Target NF of the NAS message through these methods that indicate the NAS message type in the RRC message.

[0341] Optionally, in some embodiments, the UE may also carry first network element selection assistance information when sending the RRC message to the xNB.

[0342] The first network element selection assistance information is network element selection assistance information provided by the UE, including one or more of the following:

[0343] Business information, such as business type;

[0344] Target network element selection instructions, such as instructions for selecting distributed network elements or instructions for selecting centralized network elements;

[0345] DNN;

[0346] Slice information.

[0347] It should be understood that the xNB can determine the control plane network element that receives the NAS message based on the type of the NAS message: for example, AMF, SMF, or other types of control plane network elements, such as PCF, etc.

[0348] It should be noted that control plane network elements can be centrally deployed in the core network or distributed and located close to the access network. The xNB needs to determine whether to select a distributed or centralized target NF. The xNB can determine this based on the first network element selection auxiliary information.

[0349] Step 2: The xNB obtains the Target NF information of the first NAS message based on the NAS message type carried by the RRC and / or the auxiliary information selected by the first network element, and adds the IP header.

[0350] It should be noted that the xNB determines the Target NF type for receiving the first NAS message based on the NAS message type indicated by the RRC and / or the first network element selection auxiliary information, and determines that the first NAS message needs to be forwarded through the UPF. In other words, the xNB needs to know which NAS message types can be sent to the UPF for forwarding via GTU-U.

[0351] Optionally, the xNB further obtains the Target NF information of the first NAS message based on the NAS message type and / or the first network element selection auxiliary information.

[0352] Optionally, in one possible implementation, the following steps are specifically included:

[0353] Step 2-1: The xNB sends a Target NF information query request to the data storage network element. The request includes the network element type, network element selection auxiliary information, and location information such as location tracking area information and cell information.

[0354] Step 2-2: The data storage network element returns information about one or more Target NFs, such as the identifier of the Target NF and the IP address of the Target NF.

[0355] It should be noted that, based on the received network element selection auxiliary information, the Target NF information returned by the data storage network element can be either a Target NF centrally deployed in the operator's core network or a distributed Target NF. For example, in step 2-1, the network element type is a session management network element, the network element selection auxiliary information indicates the selection of a distributed network element, the location information is tracking area TA1, and the data storage network element returns information about distributed session management network elements serving TA1 and deployed near TA1.

[0356] Steps 2-3: The xNB determines the Target NF information based on the information returned by the data storage network element.

[0357] It should be noted that if the data storage network element returns information for multiple Target NFs, the xNB can select one of them as the Target NF.

[0358] It should also be noted that xNB can omit steps 2-1 to 2-3 based on the configuration already stored locally.

[0359] It should be understood that in this embodiment of the application, the xNB needs to know the information of the Target NF in order to complete the addition of the IP header.

[0360] Alternatively, in another possible implementation, the Target NF information of the first NAS message can be pre-stored locally on the xNB, for example, via OAM.

[0361] In this embodiment, the xNB adds an IP header based on the Target NF information of the first NAS message. The specific encapsulation results are shown in Table 7.

[0362] Table 7

[0363] Understandably, the xNB adds an IP header based on the Target NF information of the first NAS message, which can be used by the UPF to route NAS messages to the Target NF via IP.

[0364] Step 3: The xNB sends the first NAS message to the UPF via GTP-U.

[0365] It should be understood that the xNB sends the first NAS message with the added IP header in Step 2 to the UPF via the UE-specific GTP-U tunnel. That is, through the N3 interface between the RAN and the UPF.

[0366] It should also be understood that GTP-U is a UE-level data transmission channel that can distinguish between different UEs.

[0367] Step 4: The UPF sends the first NAS message to the Target NF via IP routing.

[0368] Specifically, the UPF sends the first NAS message to the Target NF via IP routing based on the IP address of the Target NF in the destination address of the IP header. For example, it sends the message to the Target NF via the N6 interface.

[0369] Optionally, the UPF calls the services provided by the Target NF through a service-oriented interface, such as defining the Nnf_request service provided by the Target NF, and sends the first NAS message by calling this service.

[0370] Step 5: The Target NF returns the second NAS message that needs to be sent to the UE to the UPF.

[0371] It should be noted that the Target NF sends the second NAS message and the corresponding UE identification information and / or the UE's IP address and / or the xNB's IP address to the UPF via the N6 interface.

[0372] The xNB's IP address is obtained from the source address in the IP header of the first NAS message.

[0373] Optionally, the Target NF can add an IP header to the second NAS message and send the second NAS message with the added IP header to the UPF. Referring to Table 8, the second NAS message is encapsulated with an IP header by the Target NF.

[0374] Table 8

[0375] Optionally, the IP header can be added by the UPF. The target NF can directly send a second NAS message to the UPF, along with information used to determine the IP header, such as UE identification information and / or UE address and / or xNB address, etc.

[0376] It should be noted that the IP header does not contain the UE's IP address, therefore additional UE identification information and / or UE address and / or xNB address are required to inform the UPF of the UE in the second NAS message.

[0377] Optionally, the Target NF returns a second NAS message to the UPF through a service-oriented interface, such as defining the Nnf_response service provided by the Target NF.

[0378] Step 6: The UPF returns the second NAS message with the IP header to the xNB via GTP-U.

[0379] It should be understood that the UPF will send the second NAS message with an IP header to the xNB through the UE-dedicated GTP-U tunnel, i.e., through the N3 interface between the RAN and the UPF, based on the UE identification information and / or UE address and / or xNB address.

[0380] In this embodiment of the application, the xNB can know the target UE of the second NAS message through the UE-specific GTP-U tunnel.

[0381] Optionally, the IP header of the second NAS message can also be added by UPF.

[0382] It should be understood that, based on the information in the IP header, the xNB can know that it has received a NAS message from the UPF and that it needs to be sent to the UE via a control plane RRC message.

[0383] Step 7 / 8: The xNB removes the IP header and returns the second NAS message to the UE via an RRC message.

[0384] It should be understood that the xNB returns the second NAS message to the UE via an RRC message based on the UE-specific GTP-U tunnel and IP header information.

[0385] It should be noted that the RRC messages, such as RRCSetup, RRCResume, RRCRelease, RRCReconfiguration, DLInformationTransfer, etc., can also be access layer messages newly defined in 6G networks. This application embodiment does not limit them.

[0386] Specifically, through the UE-dedicated GTP-U tunnel, the xNB can identify the target UE of the second NAS message. Secondly, through the IP header information, the xNB can determine that the message received from the UPF is a NAS message and needs to be sent to the UE via a control plane RRC message. For example, in the IP header of normal DL UP data, the destination address (dst addr) cannot be the xNB's IP address, allowing the xNB to identify it as a NAS message. Similarly, the xNB can determine that the second NAS message originates from the target NF based on the source address (src addr).

[0387] Example 1b

[0388] It should be noted that the difference between Embodiment 1b and Embodiment 1a is that when the xNB sends UL NAS signaling to the UPF, the source address in the IP header added by the xNB is filled with the UE's IP address; when the NF sends DL NAS signaling to the UPF, the destination address in the IP header added by the NF is filled with the UE's IP address. In this case, the xNB needs to know the UE's IP address, for example, the xNB determines the UE's IP address through the mapping relationship between the UE ID and the UE's IP address.

[0389] Specifically, referring to Figure 11, the specific implementation process of Example 1b includes the following steps.

[0390] Step 1: The UE sends an RRC message to the access network device xNB. The RRC message carries a first NAS message and indicates the NAS message type. It may also carry first network element selection auxiliary information.

[0391] It should be noted that the relevant content of Step 1 in Embodiment 1b can be referred to the description in Embodiment 1a above. For the sake of brevity, it will not be repeated here.

[0392] Step 2: The xNB obtains the Target NF information of the first NAS message based on the NAS message type carried by the RRC and / or the auxiliary information selected by the first network element, and adds the IP header.

[0393] It should be noted that the xNB determines the Target NF type for receiving the first NAS message based on the NAS message type indicated by the RRC and / or the first network element selection auxiliary information, and determines that the first NAS message should be forwarded through the UPF based on the Target NF type of the first NAS message.

[0394] In other words, the xNB needs to know which NAS message types it can send to the UPF for forwarding via GTU-U.

[0395] In this embodiment, the xNB adds an IP header based on the Target NF information of the first NAS message. The specific encapsulation results are shown in Table 9.

[0396] Table 9

[0397] It should be noted that the difference from Example 1a is that here the xNB fills in the UE's IP address in the IP header.

[0398] In this embodiment of the application, the xNB determines the UE's IP address based on the UE ID, including one or more of the following:

[0399] The xNB needs to know the mapping relationship between the UE ID and the UE's IP address, for example, based on the information stored by the xNB;

[0400] Query data storage network elements, UPF, AMF, and other core network elements using UE ID;

[0401] When the UE sends an RRC message carrying the first NAS message, it includes the UE's IP address in the RRC message.

[0402] It should be understood that NAS signaling is transmitted between the xNB and the UE via the traditional RRC method. The xNB does not have the UE's IP address by default, so it needs to obtain it separately.

[0403] Step 3: The xNB sends the first NAS message to the UPF via GTP-U.

[0404] Step 4: The UPF sends the first NAS message to the Target NF via IP routing.

[0405] Step 5: The Target NF returns the second NAS message that needs to be sent to the UE to the UPF.

[0406] Specifically, the Target NF sends the second NAS message to the UPF via the N6 interface. The UE's IP address can be obtained from the source address in the IP header of the first NAS message.

[0407] Optionally, the Target NF can add an IP header to the second NAS message and send the second NAS message with the added IP header to the UPF. As shown in Table 10, the second NAS message is encapsulated with an IP header by the Target NF.

[0408] Table 10

[0409] Optionally, the IP header can be added by the UPF. The target NF can directly send a second NAS message to the UPF, along with information used to determine the IP header, such as UE identification information and / or UE address and / or xNB address, etc.

[0410] It should be understood that by adding the UE's IP address to the IP header, the UPF can directly locate the UE's dedicated GTP-U tunnel based on the UE's IP address.

[0411] Optionally, the Target NF returns a second NAS message to the UPF through a service-oriented interface, such as defining the Nnf_response service provided by the Target NF.

[0412] Step 6: The UPF returns the second NAS message with the IP header to the xNB via GTP-U.

[0413] It should be understood that the UPF can know the UE's IP address based on the information in the IP header, and will send the second NAS message with the IP header to the xNB through the UE's dedicated GTP-U tunnel, that is, through the N3 interface between the RAN and the UPF.

[0414] In this embodiment of the application, the xNB can know the target UE of the second NAS message through the UE-specific GTP-U tunnel.

[0415] Optionally, the IP header of the second NAS message can also be added by UPF.

[0416] It should be understood that through the information in the IP header, the xNB can know that it has received a NAS message from the UPF and that it needs to be sent to the UE by the control plane RRC message. In addition, it can also know the IP address of the target UE and further know the UE ID based on the mapping relationship between the UE ID and the UE's IP address (or through the UE's dedicated GTP-U tunnel).

[0417] Step 7 / 8: The xNB removes the IP header and returns the second NAS message to the UE via an RRC message.

[0418] In this embodiment, the xNB returns the second NAS message to the UE via an RRC message based on the UE-specific GTP-U tunnel and IP header information.

[0419] It should be noted that the RRC messages, such as RRCSetup, RRCResume, RRCRelease, RRCReconfiguration, DLInformationTransfer, etc., can also be access layer messages newly defined in 6G networks. This application embodiment does not limit them.

[0420] It should be understood that the xNB can identify the target UE of the second NAS message through the UE-specific GTP-U tunnel and the destination address in the IP header information. Additionally, based on the source address in the IP header information, the xNB knows that this is a NAS message and originates from the target NF.

[0421] Example 2

[0422] In Example 2, uplink NAS signaling bypasses the UPF and is directly sent to the NF / VUEF (SBI-N1+SBI-N2) via the xNB's IP routing. Downlink NAS signaling also bypasses the UPF; the NF / VUEF sends the downlink NAS signaling to the xNB via IP routing. In other words, the UE encapsulates the NAS message into an IP packet, which can optionally be further carried via TCP / HTTP2. The xNB forwards the NAS message to the NF / VUEF via IP routing.

[0423] It should be noted that the target network element in Example 2 can be an NF or a VUEF. Referring to Figure 12, the core network sets up a virtual UE function (VUEF). The UE and VUEF exchange NAS messages via IP packet payloads. The VUEF establishes a corresponding virtual UE instance for the UE. The virtual UE instance represents the actual UE and interacts with other network elements, such as mobility management elements and session management elements, through service-oriented interfaces. The VUEF receives IP data from the UE, obtains the NAS message, and then sends the NAS message to the corresponding network element on behalf of the UE through the service-oriented interface. Because the interaction with core network elements is performed by the VUEF on behalf of the UE, the VUEF can also shield ordinary UEs from the network element information deployed in the network, that is, it can shield the UE from network topology information, which is beneficial to the security of the operator's network.

[0424] The specific implementation process of Example 2 is as follows (the UE sends a third NAS message to the NF / VUEF, and / or the NF / VUEF sends a fourth NAS message to the UE):

[0425] Step 1: The UE sends an AS layer message, such as an RRC message, to the access network device xNB. The AS layer message carries a third NAS message, which is carried by IP packets. The method of carrying the third NAS message by IP packets is shown in Table 11.

[0426] Table 11

[0427] Specifically, an IP layer container can be introduced into the RRC message. Correspondingly, the structure of the RRC message carrying the third NAS message is: RRC message {IP layer container [IP packet header (address of the terminal device, address of the target NF), IP packet payload [third NAS message]}. Here, the IP packet header is not visible to the underlying processing unit, and the IP packet payload is not visible to the access network device. Optionally, protocols such as TCP / HTTP2 can also be used between the third NAS message and the IP layer.

[0428] Step 2: The xNB forwards the NAS message to the NF / VUEF via IP routing. Specifically, the xNB performs a function similar to a UPF. Based on the IP address of the target NF in the destination address in the IP header, the xNB sends the third NAS message to the target NF via IP routing. For example, it can send it to the target NF through a service interface.

[0429] It should be noted that in Embodiment 2, when the UE switches from the source xNB to the target xNB, the UE's IP address needs to be updated, and the UE needs to obtain a new IP address from the xNB. Optionally, the UE can obtain it from the target xNB (for example, from an RRC message sent by the target xNB after the handover is completed, such as RRCReconfiguration), or it can be indicated in the handover command of the source xNB. The NF, VUEF, or data storage network element needs to know the UE's updated IP address. Optionally, the source xNB or target xNB sends the UE's new IP address to the NF, VUEF, or data storage network element.

[0430] It should also be noted that before the UE sends the third NAS message in Step 1, the UE needs to obtain the IP address information of the target NF of the third NAS message. The UE can obtain the IP address information of the target NF of the third NAS message in the following way.

[0431] Step 0-1: The UE sends a Target NF information query request to the xNB and / or data storage network element. The request includes the network element type, network element selection assistance information, location information such as location tracking area information, cell information (xNB identification information and / or xNB address), and UE information (such as UE identification information and / or UE address).

[0432] Optionally, the UE can first send a Target NF information query request to the xNB, which then sends the request to the data storage network element. For example, if the xNB already stores the Target NF information locally, it directly returns information for one or more Target NFs. If the xNB does not store the Target NF information locally, it sends a Target NF information query request to the data storage network element, including the network element type, network element selection assistance information, location information such as location tracking area information, cell information (xNB identification information and / or xNB address), and UE information (e.g., UE identification information and / or UE address). Optionally, the xNB can request Target NF information in batches, for example, by indicating multiple UE information or multiple network element types.

[0433] Steps 0-2: The xNB and / or data storage network element returns information about one or more Target NFs, such as the Target NF identifier and Target NF IP address. Based on the received network element selection auxiliary information, the Target NF information returned by the data storage network element can be a Target NF centrally deployed in the operator's core network or a distributed Target NF. For example, in Step 1, if the network element type is a session management network element, the network element selection auxiliary information indicates the selection of a distributed network element, and the location information is tracking area TA1, the data storage network element returns information about a distributed session management network element serving TA1 and deployed near TA1.

[0434] Optionally, the data storage network element can return Target NF information to the xNB in ​​batches, such as multiple Target NFs for a single UE, or a single Target NF for multiple UEs.

[0435] Steps 0-3: The UE determines the Target NF information based on the information returned by the data storage network element. For example, if there is information on multiple Target NFs, the UE selects one of them as the Target NF.

[0436] Step 3: NF / VUEF sends a fourth NAS message to xNB, which is carried by an IP packet.

[0437] The third NAS message is carried by IP packets as shown in Table 12.

[0438] Table 12

[0439] It should be noted that the IP packet header is not visible to the underlying processing unit, and the IP packet payload is not visible to the access network device. Optionally, there may be protocols such as TCP / HTTP2 between the fourth NAS message and the IP layer.

[0440] Optionally, before the NF / VUEF sends the fourth NAS message in Step 3, the NF / VUEF needs to obtain the UE's IP address information and / or the UE's xNB IP address information for the fourth NAS message. For example, this can be done by querying the data storage network element. Alternatively, the NF / VUEF can query the UE's xNB information by further sending an xNB information query request to the data storage network element.

[0441] Step 4: The xNB sends an AS layer message to the UE, such as an RRC message. The AS layer message carries a fourth NAS message, which is carried by an IP packet (as shown in Table 12).

[0442] Specifically, an IP layer container can be introduced into the RRC message. Correspondingly, the structure of the RRC message carrying the fourth NAS message is: RRC message{IP layer container[IP packet header (address of terminal device, address of Target NF), payload of IP packet is [fourth NAS message]}.

[0443] The information transmission method provided in this application can solve the problem that NAS messages are all transmitted through AMF in the prior art, reduce the signaling transmission load of AMF, and improve the efficiency of data transmission.

[0444] One embodiment of this application provides an information transmission device, which can be applied to the access network element provided in the above embodiment. As shown in FIG13, the information transmission device 1300 provided in this embodiment may include:

[0445] The first sending unit 1310 is configured to send a first message to a first user plane network element, wherein the first message is determined based on a first NAS message; the first NAS message is a NAS message sent by the terminal device to the target network element.

[0446] And / or,

[0447] The first receiving unit 1320 is configured to receive a second message sent by a first user plane network element. The second message is determined based on a second NAS message, which is a NAS message sent by the target network element to the terminal device.

[0448] In some embodiments, the first message is a first NSA message with a first IP header added, wherein the destination address information of the first IP header is the IP address information of the target network element.

[0449] In some embodiments, the source address information of the first IP header is the IP address information of the terminal device or the IP address information of the access network element.

[0450] In some embodiments, the first receiving unit 1320 is further configured to receive the first NAS message and first indication information sent by the terminal device, wherein the first indication information is used to determine the target network element.

[0451] In some embodiments, the first indication information includes one or more of the following:

[0452] The identification information of the target network element;

[0453] The IP address information of the target network element;

[0454] The message type of the first NAS message;

[0455] Network element selection auxiliary information.

[0456] In some embodiments, the network element selection assistance information includes one or more of the following:

[0457] Business information;

[0458] Target network element selection instruction;

[0459] Data network name;

[0460] Slice information.

[0461] In some embodiments, the information transmission device 1300 further includes a first processing unit configured to determine the target network element based on the first indication information.

[0462] In some embodiments, the first sending unit 1310 is further configured to send a first network element query request to a data storage network element; the first network element query request includes the first indication information and / or the location information of the terminal device;

[0463] The first receiving unit 1320 is further configured to receive information related to one or more candidate network elements sent by the data storage network element; the one or more candidate network elements include the target network element.

[0464] In some embodiments, the first processing unit is further configured to determine, when the type of the target network element is a first type, to send the first NAS message to the target network element through the first user plane network element.

[0465] In some embodiments, the first processing unit is further configured to add a first IP header to the first NAS message based on the target network element to obtain the first message.

[0466] In some embodiments, the first sending unit 1310 is further configured to send the first message to the first user plane network element through a first tunnel; the first tunnel is a dedicated tunnel between the terminal device and the first user plane network element.

[0467] In some embodiments, the second message is a second NAS message with a second IP header added; the source address information of the second IP header is the IP address information of the target network element.

[0468] In some embodiments, the destination address information of the second IP header is the IP address information of the access network element or the IP address information of the terminal device.

[0469] In some embodiments, the first receiving unit 1320 is further configured to receive the second message sent by the first user plane network element through a first tunnel; the first tunnel is a dedicated tunnel between the terminal device and the first user plane network element.

[0470] In some embodiments, the first processing unit is further configured to remove the second IP header from the second message to obtain the second NAS message;

[0471] The first sending unit 1310 is further configured to send the second NAS message to the terminal device.

[0472] In some embodiments, the terminal device determines the first tunnel based on the destination address information in the second IP header and / or the first tunnel; the first tunnel is a dedicated tunnel between the first terminal device and the first user plane network element.

[0473] One embodiment of this application provides an information transmission device, which can be applied to the first user plane network element provided in the above embodiment. As shown in FIG14, the information transmission device 1400 provided in this embodiment may include:

[0474] The second receiving unit 1410 is configured to receive a first message sent by an access network element, wherein the first message is determined based on a first NAS message; the first NAS message is a NAS message sent by a first terminal device to a target network element.

[0475] And / or,

[0476] The second sending unit 1420 is configured to send a second message to an access network element. The second message is determined based on a second NAS message, which is a NAS message sent by the target network element to the first terminal device.

[0477] In some embodiments, the first message is a first NAS message with a first IP header added, wherein the destination address information in the first IP header is the IP address information of the target network element.

[0478] In some embodiments, the source address information of the first IP header is the IP address information of the terminal device or the IP address information of the access network element.

[0479] In some embodiments, the second receiving unit 1410 is further configured to receive the first message sent by the access network element through a first tunnel; the first tunnel is a dedicated tunnel between the terminal device and the first user plane network element.

[0480] In some embodiments, the second sending unit 1420 is further configured to send the first message to the target network element.

[0481] In some embodiments, the second sending unit 1420 is further configured to send the first message to the target network element via IP routing.

[0482] In some embodiments, the second sending unit 1420 is further configured to send the first message to the target network element through a first service interface.

[0483] In some embodiments, the second message is a second NAS message with a second IP header added; the source address information of the second IP header is the IP address information of the target network element.

[0484] In some embodiments, the destination address information of the second IP header is the IP address information of the access network element or the IP address information of the first terminal device.

[0485] In some embodiments, the second receiving unit 1410 is further configured to receive a second message sent by the target network element.

[0486] In some embodiments, the second receiving unit 1410 is further configured to receive a third message sent by the target network element, the third message including a second NAS message and second indication information, the second indication information being used to determine the second message.

[0487] In some embodiments, the second indication information includes one or more of the following:

[0488] The identification information of the terminal device;

[0489] The IP address information of the terminal device;

[0490] The identification information of the access network element;

[0491] The IP address information of the access network element.

[0492] In some embodiments, the information transmission device 1400 further includes a second processing unit configured to add a second IP header to the second NAS message based on the second indication information to obtain the second message.

[0493] In some embodiments, the second sending unit 1420 further includes sending the second message to the access network element through a first tunnel; the first tunnel is a dedicated tunnel between the terminal device and the first user plane network element.

[0494] One embodiment of this application provides an information transmission device, which can be applied to the target network element provided in the above embodiment. As shown in FIG15, the information transmission device 1500 provided in this embodiment may include:

[0495] The third receiving unit 1510 is configured to receive a first message sent by a first user plane network element; the first message is determined based on a first NAS message; the first NAS message is a NAS message sent by a first terminal device to the target network element;

[0496] And / or,

[0497] The third sending unit 1520 is configured to send a second message or a third message to a first user plane network element. The second message is determined based on a second NAS message. The third message includes a second NAS message and second indication information. The second indication information is used to determine the second message. The second NAS message is a NAS message sent by the target network element to the first terminal device.

[0498] In some embodiments, the first message is a first NAS message with a first IP header added, wherein the destination address of the first IP header is the IP address of the target network element.

[0499] In some embodiments, the source address information of the first IP header is the IP address information of the terminal device or the IP address information of the access network element.

[0500] In some embodiments, the second message is a second NAS message with a second IP header added; the source address information of the second IP header is the IP address information of the target network element.

[0501] In some embodiments, the destination address information of the second IP header is the IP address information of the access network element or the IP address information of the first terminal device.

[0502] In some embodiments, the information transmission device 1500 further includes a third processing unit configured to add a second IP header to the second NAS message based on the second indication information to obtain a second message.

[0503] In some embodiments, the second indication information includes one or more of the following:

[0504] The identification information of the terminal device;

[0505] The IP address information of the terminal device;

[0506] The identification information of the access network element;

[0507] The IP address information of the access network element.

[0508] In some embodiments, the third sending unit 1520 is further configured to send the second message or the third message to the first user plane network element via IP routing.

[0509] In some embodiments, the third sending unit 1520 is further configured to send the second message or the third message to the first user plane network element through the second service interface.

[0510] One embodiment of this application provides an information transmission device, which can be applied to the terminal device provided in the above embodiment. As shown in FIG16, the information transmission device 1600 provided in this embodiment may include:

[0511] The fourth sending unit 1610 is configured to send a first NAS message and a first indication information to an access network element. The first NAS message is a NAS message sent by the terminal device to the target network element, and the first indication information is used to determine the target network element.

[0512] And / or,

[0513] The fourth receiving unit 1620 is configured to receive the second NAS message sent by the access network element.

[0514] In some embodiments, the first indication information includes one or more of the following:

[0515] The identification information of the target network element;

[0516] The IP address information of the target network element;

[0517] The message type of the first NAS message;

[0518] Network element selection auxiliary information.

[0519] In some embodiments, the network element selection assistance information includes one or more of the following:

[0520] Business information;

[0521] Target network element selection instruction;

[0522] Data network name;

[0523] Slice information.

[0524] One embodiment of this application provides an information transmission device, which can be applied to the terminal device provided in the above embodiment. As shown in FIG17, the information transmission device 1700 provided in this embodiment may include:

[0525] The fifth sending unit 1710 is configured to send a fourth message to an access network element. The fourth message carries a third NAS message, which is carried by a third IP data packet. The third NAS message is a NAS message sent by the terminal device to the target network element.

[0526] And / or,

[0527] The fifth receiving unit 1720 is configured to receive a fifth message sent by an access network element. The fifth message carries a fourth NAS message, which is carried by a fourth IP data packet. The fourth NAS message is a NAS message sent by the target network element to the terminal device.

[0528] In some embodiments, the third IP packet includes a third IP header and a third payload, the third payload including the third NAS message, the destination address information of the third IP header being the IP address information of the target network element, and the source address information of the third IP header being the IP address information of the terminal device.

[0529] In some embodiments, the fourth IP packet includes a fourth IP header and a fourth payload, the fourth payload including the fourth NSA message, the destination address information of the fourth IP header being the IP address information of the terminal device, and the source address information of the fourth IP header being the IP address information of the terminal device.

[0530] In some embodiments, the information transmission device 1700 further includes a fifth processing unit configured to update the IP address information of the terminal device when the terminal device performs cell handover.

[0531] In some embodiments, the fifth sending unit 1710 is further configured to send a second network element query request to the access network element;

[0532] The fifth receiving unit 1720 is further configured to receive information related to one or more candidate network elements sent by the access network element; the one or more candidate network elements include the target network element.

[0533] In some embodiments, the second network element query request includes one or more of the following:

[0534] Network element type;

[0535] Network element selection auxiliary information;

[0536] The location information of the terminal device.

[0537] In some embodiments, the network element selection assistance information includes one or more of the following:

[0538] Business information;

[0539] Target network element selection instruction;

[0540] Data network name;

[0541] Slice information.

[0542] In some embodiments, the relevant information of the candidate network element includes the IP address information of the candidate network element and / or the identification information of the candidate network element.

[0543] One embodiment of this application provides an information transmission device, which can be applied to the terminal device provided in the above embodiment. As shown in FIG18, the information transmission device 1800 provided in this embodiment may include:

[0544] The sixth sending unit 1810 is configured to send a third IP data packet to the target network element. The third IP data packet is used to carry a third NAS message, which is a NAS message sent by the terminal device to the target network element.

[0545] And / or,

[0546] The sixth receiving unit 1820 is configured to receive a fourth IP data packet sent by the target network element. The fourth IP data packet is used to carry a fourth NAS message, which is a NAS message sent by the target network element to the terminal device.

[0547] In some embodiments, the sixth receiving unit 1820 is further configured to receive a fourth message sent by a terminal device, the fourth message carrying a third NAS message, the third NAS message being carried by a third IP data packet.

[0548] In some embodiments, the third IP packet includes a third IP header and a third payload, the third payload including the third NAS message, the destination address information of the third IP header being the IP address information of the target network element, and the source address information of the third IP header being the IP address information of the terminal device.

[0549] In some embodiments, the sixth sending unit 1810 is further configured to send a fifth message to the terminal device, the fifth message carrying a fourth NAS message, the fourth NAS message being carried by a fourth IP data packet.

[0550] In some embodiments, the fourth IP packet includes a fourth IP header and a fourth payload, the fourth payload including the fourth NSA message, the destination address information of the fourth IP header being the IP address information of the terminal device, and the source address information of the fourth IP header being the IP address information of the terminal device.

[0551] In some embodiments, the information transmission device 1800 further includes a sixth processing unit configured to update the IP address information of the terminal device when the terminal device performs cell handover.

[0552] In some embodiments, the sixth receiving unit 1820 is further configured to receive a second network element query request sent by the terminal device;

[0553] The sixth sending unit 1810 is further configured to send information related to one or more candidate network elements to the terminal device; the one or more candidate network elements include the target network element.

[0554] In some embodiments, the sixth sending unit 1810 is further configured to send the second network element query request to the data storage network element;

[0555] The sixth receiving unit 1820 is further configured to receive information related to one or more candidate network elements sent by the data storage network element.

[0556] In some embodiments, the second network element query request includes one or more of the following:

[0557] Network element type;

[0558] Network element selection auxiliary information;

[0559] The location information of the terminal device.

[0560] In some embodiments, the network element selection assistance information includes one or more of the following:

[0561] Business information;

[0562] Target network element selection instruction;

[0563] Data network name;

[0564] Slice information.

[0565] In some embodiments, the relevant information of the candidate network element includes the IP address information of the candidate network element and / or the identification information of the candidate network element.

[0566] In some embodiments, the sixth sending unit 1810 is further configured to send the third IP data packet to the target network element via IP routing.

[0567] In some embodiments, the sixth sending unit 1810 is further configured to send the third IP data packet to the target network element through a third service interface.

[0568] One embodiment of this application provides an information transmission device, which can be applied to the terminal device provided in the above embodiment. As shown in FIG19, the information transmission device 1900 provided in this embodiment may include:

[0569] The seventh receiving unit 1910 is configured to receive a third IP data packet sent by an access network element. The third IP data packet is used to carry a third NAS message, which is a NAS message sent by a terminal device to a target network element.

[0570] And / or,

[0571] The seventh sending unit 1920 is configured to send a fourth IP data packet to the access network element. The fourth IP data packet is used to carry a fourth NAS message, which is a NAS message sent by the target network element to the terminal device.

[0572] In some embodiments, the third IP packet includes a third IP header and a third payload, the third payload including the third NAS message, the destination address information of the third IP header being the IP address information of the target network element, and the source address information of the third IP header being the IP address information of the terminal device.

[0573] In some embodiments, the fourth IP packet includes a fourth IP header and a fourth payload, the fourth payload including the fourth NSA message, the destination address information of the fourth IP header being the IP address information of the terminal device, and the source address information of the fourth IP header being the IP address information of the terminal device.

[0574] In some embodiments, the seventh sending unit 1920 is further configured to send a device query request to the data storage network element;

[0575] The seventh receiving unit 1910 is further configured to receive device information sent by the data storage network element, the device information including one or more of the following:

[0576] The IP address information of the terminal device;

[0577] The IP address information of the access network element.

[0578] In some embodiments, the seventh sending unit 1920 is further configured to send the fourth IP data packet to the access network element via IP routing.

[0579] In some embodiments, the seventh sending unit 1920 is further configured to send the fourth IP data packet to the access network element through the fourth service interface.

[0580] It should be noted that the functional units in the above embodiments can be integrated into one processing module, or each unit can exist physically separately, or two or more units can be integrated into one module. The integrated module can be implemented in hardware or as a software functional module.

[0581] If an integrated module is implemented as a software functional module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment, in essence, or the part that contributes to the prior art, or all or part 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.) or processor to execute all or part of the steps of the method of this embodiment. 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.

[0582] In the embodiments provided in this application, the processor can be at least one of the following: Application Specific Integrated Circuit (ASIC), Digital Signal Processor (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), Central Processing Unit (CPU), and controller. It is understood that for different devices, the electronic device used to implement the above processor function can also be other types, and the embodiments in this application do not specifically limit it.

[0583] In practical applications, the memory can be volatile memory, such as RAM; or non-volatile memory, such as ROM, flash memory, hard disk drive (HDD) or solid-state drive (SSD); or a combination of the above types of memory, and provide instructions and data to the processor 1101.

[0584] This application also provides a computer storage medium, specifically a computer-readable storage medium. It stores computer instructions, which, when executed by a processor, implement any step of the information transmission method described in this application when the computer storage medium is a network device or terminal.

[0585] This application also provides a computer program product, including computer program instructions.

[0586] When the computer program instructions are run on the computer, the computer executes the corresponding processes implemented by the terminal device or network element in the various methods of the embodiments of this application. For the sake of brevity, they will not be described in detail here.

[0587] The aforementioned computer storage media / memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic random access memory (FRAM), flash memory, magnetic surface memory, optical disc, or compact disc read-only memory (CD-ROM), etc.; or it can be various terminals that include one or any combination of the above-mentioned memories, such as mobile phones, computers, tablet devices, personal digital assistants, etc.

[0588] It should be understood that the terms "an embodiment," "an embodiment," "an embodiment of this application," "the foregoing embodiments," or "some embodiments" mentioned throughout the specification mean that the target features, structures, or characteristics related to the embodiment are included in at least one embodiment of this application. Therefore, the phrases "an embodiment," "an embodiment," "an embodiment of this application," "the foregoing embodiments," or "some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these target features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. The sequence numbers of the above-described embodiments of this application are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0589] Unless otherwise specified, any step in the embodiments of this application performed by the detection device may be executed by the processor of the detection device. Unless otherwise specified, the embodiments of this application do not limit the order in which the detection device performs the following steps. Furthermore, the methods used to process data in different embodiments may be the same or different methods. It should also be noted that any step in the embodiments of this application can be executed independently by the detection device; that is, when the detection device performs any step in the above embodiments, it may not depend on the execution of other steps.

[0590] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0591] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0592] In addition, each functional unit in the various embodiments of this application can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0593] The methods disclosed in the several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0594] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0595] The features disclosed in the several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method or device embodiments.

[0596] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.

[0597] Alternatively, if the integrated units described above are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, or the parts that contribute to related technologies, 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, testing equipment, or network device, etc.) to execute all or part 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 mobile storage devices, ROMs, magnetic disks, or optical disks.

[0598] In the embodiments of this application, descriptions of the same steps and content in different embodiments can be referred to each other. In the embodiments of this application, the term "and" does not affect the order of steps.

[0599] The above description is merely an embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An information transmission method applied to an access network element, the method comprising: The access network element sends a first message to the first user plane network element, and the first message is determined based on the first NAS message; The first NAS message is a NAS message sent by the terminal device to the target network element; And / or, The access network element receives a second message sent by the first user plane network element. The second message is determined based on a second NAS message, which is a NAS message sent by the target network element to the terminal device.

2. The method according to claim 1, wherein, The first message is a first NSA message with a first IP header added, and the destination address information of the first IP header is the IP address information of the target network element.

3. The method according to claim 2, wherein, The source address information in the first IP header is either the IP address information of the terminal device or the IP address information of the access network element.

4. The method according to any one of claims 1-3, wherein, Also includes: The access network element receives the first NAS message and the first indication information sent by the terminal device, wherein the first indication information is used to determine the target network element.

5. The method according to claim 4, wherein, The first indication information includes one or more of the following: The identification information of the target network element; The IP address information of the target network element; The message type of the first NAS message; Network element selection auxiliary information.

6. The method according to claim 5, wherein, The network element selection auxiliary information includes one or more of the following: Business information; Target network element selection instruction; Data network name; Slice information.

7. The method according to any one of claims 4-6, wherein, Also includes: The access network element determines the target network element based on the first indication information.

8. The method according to claim 7, wherein, Also includes: The access network element sends a first network element query request to the data storage network element; The first network element query request includes the first indication information and / or the location information of the terminal device; The access network element receives information about one or more candidate network elements sent by the data storage network element; The one or more candidate network elements include the target network element.

9. The method according to any one of claims 4-8, wherein, Also includes: If the target network element is of type 1, the access network element determines to send the first NAS message to the target network element through the first user plane network element.

10. The method according to any one of claims 4-9, wherein, Also includes: The access network element adds a first IP header to the first NAS message based on the target network element to obtain the first message.

11. The method according to any one of claims 1-10, wherein, The access network element sends a first message to the first user plane network element, including: The access network element sends the first message to the first user plane network element through the first tunnel; the first tunnel is a dedicated tunnel between the terminal device and the first user plane network element.

12. The method according to any one of claims 1-11, wherein, The second message is a second NAS message with a second IP header added; the source address information of the second IP header is the IP address information of the target network element.

13. The method according to claim 12, wherein, The destination address information in the second IP header is either the IP address information of the access network element or the IP address information of the terminal device.

14. The method according to any one of claims 1-13, wherein, The access network element receives a second message sent by the first user plane network element, including: The access network element receives the second message sent by the first user plane network element through the first tunnel; the first tunnel is a dedicated tunnel between the terminal device and the first user plane network element.

15. The method according to any one of claims 1-14, wherein, Also includes: The access network device removes the second IP header from the second message to obtain the second NAS message; The access network element sends the second NAS message to the terminal device.

16. The method according to claim 15, wherein, The terminal device determines the first tunnel based on the destination address information in the second IP header and / or the first tunnel; the first tunnel is a dedicated tunnel between the first terminal device and the first user plane network element.

17. An information transmission method, the method comprising: The first user plane network element receives a first message sent by the access network element, and the first message is determined based on the first NAS message; The first NAS message is a NAS message sent by the terminal device to the target network element; And / or, The first user plane network element sends a second message to the access network element. The second message is determined based on the second NAS message, which is the NAS message sent by the target network element to the terminal device.

18. The method according to claim 17, wherein, The first message is a first NAS message with a first IP header added, and the destination address information in the first IP header is the IP address information of the target network element.

19. The method according to claim 18, wherein, The source address information in the first IP header is either the IP address information of the terminal device or the IP address information of the access network element.

20. The method according to any one of claims 17-19, wherein, The first user plane network element receives a first message sent by the access network element, including: The first user plane network element receives the first message sent by the access network element through the first tunnel; the first tunnel is a dedicated tunnel between the terminal device and the first user plane network element.

21. The method according to any one of claims 17-20, wherein, Also includes: The first user plane network element sends the first message to the target network element.

22. The method according to claim 21, wherein, The first user plane network element sends the first message to the target network element via IP routing.

23. The method according to claim 21, wherein, The first user plane network element sends the first message to the target network element through the first service interface.

24. The method according to any one of claims 17-23, wherein, The second message is a second NAS message with a second IP header added; the source address information of the second IP header is the IP address information of the target network element.

25. The method according to claim 24, wherein, The destination address information in the second IP header is either the IP address information of the access network element or the IP address information of the first terminal device.

26. The method according to any one of claims 17-25, wherein, Also includes: The first user plane network element receives the second message sent by the target network element.

27. The method according to any one of claims 17-25, wherein, The first user plane network element receives a third message sent by the target network element. The third message includes a second NAS message and second indication information, the second indication information being used to determine the second message.

28. The method according to claim 27, wherein, The second indication information includes one or more of the following: The identification information of the terminal device; The IP address information of the terminal device; The identification information of the access network element; The IP address information of the access network element.

29. The method according to claim 27 or 28, wherein, Also includes: The first user plane network element adds a second IP header to the second NAS message based on the second indication information to obtain the second message.

30. The method according to any one of claims 17-29, wherein, The first user plane network element sends a second message to the access network element, including: The first user plane network element sends the second message to the access network element through the first tunnel; the first tunnel is a dedicated tunnel between the terminal device and the first user plane network element.

31. An information transmission method, the method comprising: The target network element receives the first message sent by the first user plane network element; The first message is determined based on the first NAS message; The first NAS message is a NAS message sent by the first terminal device to the target network element; And / or, The target network element sends a second message or a third message to the first user plane network element. The second message is determined based on a second NAS message. The third message includes a second NAS message and second indication information. The second indication information is used to determine the second message. The second NAS message is a NAS message sent by the target network element to the first terminal device.

32. The method of claim 31, wherein, The first message is a first NAS message with a first IP header added, and the destination address of the first IP header is the IP address of the target network element.

33. The method of claim 32, wherein, The source address information in the first IP header is either the IP address information of the terminal device or the IP address information of the access network element.

34. The method of any one of claims 31-33, wherein, The second message is a second NAS message with a second IP header added; the source address information of the second IP header is the IP address information of the target network element.

35. The method of claim 34, wherein, The destination address information in the second IP header is either the IP address information of the access network element or the IP address information of the first terminal device.

36. The method of claim 34 or 35, wherein, Also includes: The target network element adds a second IP header to the second NAS message based on the second indication information to obtain the second message.

37. The method of any one of claims 31-36, wherein, The second indication information includes one or more of the following: The identification information of the terminal device; The IP address information of the terminal device; The identification information of the access network element; The IP address information of the access network element.

38. The method according to any one of claims 31-37, wherein, The target network element sends the second message or the third message to the first user plane network element via IP routing.

39. The method according to any one of claims 31-37, wherein, The target network element sends the second message or the third message to the first user plane network element through the second service interface.

40. An information transmission method, the method comprising: The terminal device sends a first NAS message and a first indication information to the access network element. The first NAS message is a NAS message sent by the terminal device to the target network element, and the first indication information is used to determine the target network element. And / or, The terminal device receives the second NAS message sent by the access network element.

41. The method according to claim 40, wherein, The first indication information includes one or more of the following: The identification information of the target network element; The IP address information of the target network element; The message type of the first NAS message; Network element selection auxiliary information.

42. The method according to claim 41, wherein, The network element selection auxiliary information includes one or more of the following: Business information; Target network element selection instruction; Data network name; Slice information.

43. An information transmission method, the method comprising: The terminal device sends a fourth message to the access network element. The fourth message carries a third NAS message, which is carried by a third IP data packet. The third NAS message is a NAS message sent by the terminal device to the target network element. And / or, The terminal device receives a fifth message sent by an access network element. The fifth message carries a fourth NAS message, which is carried by a fourth IP data packet. The fourth NAS message is a NAS message sent by the target network element to the terminal device.

44. The method according to claim 43, wherein, The third IP data packet includes a third IP header and a third payload. The third payload includes the third NAS message. The destination address information of the third IP header is the IP address information of the target network element, and the source address information of the third IP header is the IP address information of the terminal device.

45. The method according to claim 43 or 44, wherein, The fourth IP packet includes a fourth IP header and a fourth payload. The fourth payload includes the fourth NSA message. The destination address information of the fourth IP header is the IP address information of the terminal device, and the source address information of the fourth IP header is the IP address information of the terminal device.

46. ​​The method according to claim 44 or 45, wherein, When the terminal device performs a cell handover, update the IP address information of the terminal device.

47. The method according to any one of claims 43-46, wherein, The terminal device sends a second network element query request to the access network element; The terminal device receives information about one or more candidate network elements sent by the access network element; The one or more candidate network elements include the target network element.

48. The method according to claim 47, wherein, The second network element query request includes one or more of the following: Network element type; Network element selection auxiliary information; The location information of the terminal device.

49. The method according to claim 48, wherein, The network element selection auxiliary information includes one or more of the following: Business information; Target network element selection instruction; Data network name; Slice information.

50. The method according to any one of claims 47-49, wherein, The relevant information of the candidate network element includes the IP address information of the candidate network element, and / or the identification information of the candidate network element.

51. An information transmission method, the method comprising: The access network element sends a third IP data packet to the target network element. The third IP data packet is used to carry a third NAS message, which is a NAS message sent by the terminal device to the target network element. And / or, The access network element receives a fourth IP data packet sent by the target network element. The fourth IP data packet is used to carry a fourth NAS message, which is a NAS message sent by the target network element to the terminal device.

52. The method according to claim 51, wherein, Also includes: The access network element receives a fourth message sent by the terminal device. The fourth message carries a third NAS message, which is carried by a third IP data packet.

53. The method according to claim 51 or 52, wherein, The third IP data packet includes a third IP header and a third payload. The third payload includes the third NAS message. The destination address information of the third IP header is the IP address information of the target network element, and the source address information of the third IP header is the IP address information of the terminal device.

54. The method according to any one of claims 51-53, wherein, Also includes: The access network element sends a fifth message to the terminal device. The fifth message carries a fourth NAS message, which is carried by a fourth IP data packet.

55. The method according to any one of claims 51-54, wherein, The fourth IP packet includes a fourth IP header and a fourth payload. The fourth payload includes the fourth NSA message. The destination address information of the fourth IP header is the IP address information of the terminal device, and the source address information of the fourth IP header is the IP address information of the terminal device.

56. The method according to any one of claims 51-55, wherein, When the terminal device performs a cell handover, update the IP address information of the terminal device.

57. The method according to any one of claims 51-56, wherein, Also includes: The access network element receives a second network element query request sent by the terminal device; The access network element sends information about one or more candidate network elements to the terminal device; The one or more candidate network elements include the target network element.

58. The method according to claim 57, wherein, Also includes: The access network element sends the second network element query request to the data storage network element; The access network element receives information about one or more candidate network elements sent by the data storage network element.

59. The method according to claim 57 or 58, wherein, The second network element query request includes one or more of the following: Network element type; Network element selection auxiliary information; The location information of the terminal device.

60. The method according to claim 59, wherein, The network element selection auxiliary information includes one or more of the following: Business information; Target network element selection instruction; Data network name; Slice information.

61. The method according to any one of claims 57-60, wherein, The relevant information of the candidate network element includes the IP address information of the candidate network element, and / or the identification information of the candidate network element.

62. The method according to any one of claims 51-61, wherein, The access network element sends the third IP data packet to the target network element via IP routing.

63. The method according to any one of claims 51-61, wherein, The access network element sends the third IP data packet to the target network element through the third service interface.

64. An information transmission method, the method comprising: The target network element receives a third IP data packet sent by the access network element. The third IP data packet is used to carry a third NAS message, which is a NAS message sent by the terminal device to the target network element. And / or, The target network element sends a fourth IP data packet to the access network element. The fourth IP data packet is used to carry a fourth NAS message, which is a NAS message sent by the target network element to the terminal device.

65. The method according to claim 64, wherein, The third IP data packet includes a third IP header and a third payload. The third payload includes the third NAS message. The destination address information of the third IP header is the IP address information of the target network element, and the source address information of the third IP header is the IP address information of the terminal device.

66. The method according to claim 64 or 65, wherein, The fourth IP packet includes a fourth IP header and a fourth payload. The fourth payload includes the fourth NSA message. The destination address information of the fourth IP header is the IP address information of the terminal device, and the source address information of the fourth IP header is the IP address information of the terminal device.

67. The method according to any one of claims 64-66, wherein, The target network element sends a device query request to the data storage network element; The target network element receives device information sent by the data storage network element, wherein the device information includes one or more of the following: The IP address information of the terminal device; The IP address information of the access network element.

68. The method according to any one of claims 64-67, wherein, The target network element sends the fourth IP data packet to the access network element via IP routing.

69. The method according to any one of claims 64-68, wherein, The target network element sends the fourth IP data packet to the access network element through the fourth service interface.

70. An information transmission device applied to an access network element, the device comprising: The first sending unit is configured to send a first message to a first user plane network element, wherein the first message is determined based on a first NAS message. The first NAS message is a NAS message sent by the terminal device to the target network element; And / or, The first receiving unit is configured to receive a second message sent by a first user plane network element. The second message is determined based on a second NAS message, which is a NAS message sent by the target network element to the terminal device.

71. An information transmission device applied to a first network element, the device comprising: The second receiving unit is configured to receive a first message sent by an access network element, wherein the first message is determined based on a first NAS message. The first NAS message is a NAS message sent by the first terminal device to the target network element; And / or, The second sending unit is configured to send a second message to an access network element. The second message is determined based on a second NAS message, which is a NAS message sent by the target network element to the first terminal device.

72. An information transmission device applied to a target network element, the device comprising: The third receiving unit is configured to receive the first message sent by the first user plane network element; The first message is determined based on the first NAS message; The first NAS message is a NAS message sent by the first terminal device to the target network element; And / or, The third sending unit is configured to send a second message or a third message to the first user plane network element. The second message is determined based on a second NAS message. The third message includes a second NAS message and second indication information. The second indication information is used to determine the second message. The second NAS message is a NAS message sent by the target network element to the first terminal device.

73. An information transmission device applied to a terminal device, the device comprising: The fourth sending unit is configured to send a first NAS message and a first indication information to an access network element. The first NAS message is a NAS message sent by the terminal device to the target network element, and the first indication information is used to determine the target network element. And / or, The fourth receiving unit is configured to receive the second NAS message sent by the access network element.

74. An information transmission device applied to a terminal device, the device comprising: The fifth sending unit is configured to send a fourth message to the access network element. The fourth message carries a third NAS message, which is carried by a third IP data packet. The third NAS message is a NAS message sent by the terminal device to the target network element. And / or, The fifth receiving unit is configured to receive a fifth message sent by an access network element. The fifth message carries a fourth NAS message, which is carried by a fourth IP data packet. The fourth NAS message is a NAS message sent by the target network element to the terminal device.

75. An information transmission device applied to an access network element, the device comprising: The sixth sending unit is configured to send a third IP data packet to the target network element. The third IP data packet is used to carry a third NAS message, which is a NAS message sent by the terminal device to the target network element. And / or, The sixth receiving unit is configured to receive a fourth IP data packet sent by the target network element. The fourth IP data packet is used to carry a fourth NAS message, which is a NAS message sent by the target network element to the terminal device.

76. An information transmission device applied to a target network element, the device comprising: The seventh receiving unit is configured to receive a third IP data packet sent by an access network element. The third IP data packet is used to carry a third NAS message, which is a NAS message sent by a terminal device to a target network element. And / or, The seventh sending unit is configured to send a fourth IP data packet to the access network element. The fourth IP data packet is used to carry a fourth NAS message, which is a NAS message sent by the target network element to the terminal device.

77. A network device, the network device comprising: Memory, transceiver, processor, and bus system; The memory is used to store programs and instructions; The transceiver is used to receive or send information under the control of the processor; The processor is used to execute programs in the memory; The bus system is used to connect the memory, the transceiver, and the processor to enable communication between the memory, the transceiver, and the processor; The processor is configured to invoke program instructions in the memory to execute the method as described in any one of claims 1 to 16, or claims 17 to 30, or claims 31 to 39, or claims 51 to 63, or claims 64 to 69.

78. A terminal, the terminal comprising: Memory, transceiver, processor, and bus system; The memory is used to store programs and instructions; The transceiver is used to receive or send information under the control of the processor; The processor is used to execute programs in the memory; The bus system is used to connect the memory, the transceiver, and the processor to enable communication between the memory, the transceiver, and the processor; The processor is used to invoke program instructions in the memory to execute the method as described in any one of claims 40 to 42, or claims 43 to 50.

79. A computer storage medium storing one or more programs, said one or more programs being executable by one or more processors to implement the method of any one of claims 1 to 16, or claims 17 to 30, or claims 31 to 39, or claims 40 to 42, or claims 43 to 50, or claims 51 to 63, or claims 64 to 69.

80. A chip, comprising: A processor for retrieving and running a computer program from memory, causing a device having the chip mounted to perform the method as described in any one of claims 1 to 16, or claims 17 to 30, or claims 31 to 39, or claims 40 to 42, or claims 43 to 50, or claims 51 to 63, or claims 64 to 69.

81. A computer program product comprising a computer storage medium storing a computer program, the computer program comprising instructions executable by at least one processor, wherein the instructions, when executed by the at least one processor, implement the method of any one of claims 1 to 16, or claims 17 to 30, or claims 31 to 39, or claims 40 to 42, or claims 43 to 50, or claims 51 to 63, or claims 64 to 69.

82. A computer program that causes a computer to perform the method as described in any one of claims 1 to 16, or claims 17 to 30, or claims 31 to 39, or claims 40 to 42, or claims 43 to 50, or claims 51 to 63, or claims 64 to 69.

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