A communication method and apparatus

Abstract

This application relates to the field of communication technology, and in particular to a communication method and apparatus, aiming to decouple message routing functions from access and mobility management function network elements, thereby avoiding the impact on routing between terminal devices and RAN nodes and the core network, as well as the access management and mobility management functions of access and mobility management function network elements, when new features are introduced into the network. The method can be executed by a third network element, and includes: receiving first information from a terminal device, the first information being used to request a first service; determining a first identifier associated with a first network element, the first network element serving the first service; sending the first information and the first identifier to the first network element; and sending the first identifier to the terminal device, wherein the first identifier is used for routing to the first network element.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0002] In 5th generation (5G) networks, radio access network (RAN) nodes establish connections with access and mobility management function (AMF) network elements in the core network. When RAN nodes need to transmit messages from terminal devices or messages generated by RAN nodes to other network function (NF) network elements in the core network, they need to use AMF network elements as intermediate forwarding nodes.

[0003] However, when new features are added to the network, the message routing function of the AMF network element may need to be upgraded accordingly to identify the information cells corresponding to the new feature and determine how to perform the operations related to the new feature. Since the AMF network element is also responsible for the access and mobility management of terminal devices, when the aforementioned new feature is not directly related to access and mobility management, the upgrade of the message routing function may unnecessarily affect the access and mobility management functions of the AMF network element, as well as the connection between the core network and the RAN node. For example, if upgrading the AMF network element requires restarting the AMF network element, the connection between the RAN node and the AMF network element interface (N2) may be interrupted, and the connection between the terminal device and the AMF network element interface (N1) may also be interrupted.

[0004] Therefore, how to decouple message routing functions from access and mobility management functions, and avoid the introduction of new features from causing unnecessary impacts on message routing, access management and mobility management functions, as well as the connection between the RAN and the core network, is a problem that needs to be solved. Summary of the Invention

[0005] This application provides a communication method and apparatus to decouple message routing functions from access and mobility management functions, thereby avoiding the impact on message routing between terminal devices and RAN nodes and the core network, the connection between RAN nodes and the core network, and the access management and mobility management functions of AMF network elements when new features are introduced into the network.

[0006] In a first aspect, embodiments of this application provide a communication method that can be applied to a third network element. The method includes: receiving first information from a terminal device, the first information being used to request a first service; determining a first identifier associated with a first network element, the first network element serving the first service; sending the first information and the first identifier to the first network element; and sending the first identifier to the terminal device, wherein the first identifier is used for routing to the first network element.

[0007] In this embodiment, the third network element can refer to a network element that has message routing (i.e., non-access stratum (NAS) message routing) functionality between the terminal device and the core network. Additionally, the third network element may also have message routing functionality between the RAN node and the core network.

[0008] The first network element can be an AMF network element or another NF network element. For example: when the first service is access and mobility management service, the first network element can be an AMF network element; when the first service is session management service, the first network element can be a session management function (SMF) network element.

[0009] Using the above method, the third network element can determine the first identifier associated with the first network element, and route the information or messages sent by the terminal device or RAN node to the first network element according to the first identifier. This avoids parsing and routing based on the information elements in the NAS message, decoupling the message routing function from the AMF network element. This prevents the introduction of new features into the network from affecting the message routing and connection between the terminal device and RAN node and the core network, as well as the access management and mobility management functions of the AMF network element.

[0010] In one possible design, the method further includes sending a first identifier to the RAN node of the serving terminal device.

[0011] Through the above design, the third network element can send the first identifier to the RAN node (i.e., access network equipment) of the serving terminal equipment, so that the RAN node of the serving terminal equipment can also send the first service-related message to the first network element through the first identifier.

[0012] In one possible design, the method further includes: receiving a first message from a terminal device, the first message including second information and a first identifier; and sending the second information to the first network element, or sending the second information and the first identifier to the first network element according to the association relationship between the first identifier and the first network element.

[0013] Through the above design, the third network element can route messages to the corresponding first network element based on the saved association between the first identifier and the first network element, which helps to ensure the accuracy of message routing, and the third network element does not need to parse the content of the second information.

[0014] In one possible design, before determining the first identifier associated with the first network element, the method further includes at least one of the following: determining that the message carrying the first information does not contain an identifier associated with the network element; determining that the message type carrying the first information is an initial terminal device message; determining that the message carrying the first information contains network element selection information; or determining that the message type carrying the first information indicates a request to establish a first service.

[0015] The above design ensures that different identifiers are assigned to different services of the terminal device, avoiding the situation where multiple associated identifiers are assigned to network elements serving the same service, or multiple identifiers are associated with the same network element. This helps improve the accuracy and efficiency of routing and shields the terminal device from the impact of changes in the network topology of the core network and the network elements serving the first service.

[0016] In one possible design, before sending the first identifier to the terminal device, the method further includes: receiving third information from a first network element, the third information including the first identifier; sending the first identifier to the terminal device, including: sending the third information to the terminal device.

[0017] The above design enables the first network element to send a first identifier associated with the first network element to the terminal device.

[0018] In one possible design, before sending the first identifier to the terminal device, the method further includes: receiving fourth information from a first network element, the fourth information not including the first identifier; sending the first identifier to the terminal device, including: sending the fourth information and the first identifier to the terminal device.

[0019] The above design enables a third network element to send a first identifier associated with the first network element to a terminal device.

[0020] In one possible design, determining the first identifier associated with the first network element includes: sending a first request message to the first network element, the first request message being used to request the allocation of an identifier for the terminal device; and receiving a first response message from the first network element, the first response message including the first identifier.

[0021] In one possible design, determining the first identifier associated with the first network element includes: sending a first request message to the first network element, the first request message including first information, the first request message being used to establish a first service, and the first request message instructing the first network element to allocate a first identifier; and receiving a first response message from the first network element, the first response message including the first identifier.

[0022] The above design allows the first identifier associated with a network element (i.e., NF network element) to be determined by the first network element.

[0023] In one possible design, the method further includes: receiving fifth information from a terminal device, the fifth information being used to request a second service; determining a second identifier associated with a second network element, the second network element serving the second service; sending the fifth information to the second network element; and sending the second identifier to the terminal device, wherein the second identifier is used for routing to the second network element.

[0024] The above design enables third-party network elements to provide routing services for multiple services of terminal devices simultaneously.

[0025] In one possible design, the method further includes: receiving a second message from a terminal device, the second message including sixth information, seventh information, a first identifier, and a second identifier, wherein the sixth information is associated with the first identifier and the seventh information is associated with the second identifier; sending the sixth information to the first network element according to the association relationship between the first identifier and the first network element; and sending the seventh information to the second network element according to the association relationship between the second identifier and the second network element.

[0026] The above design enables terminal devices to send information to multiple NF network elements through the same message, which improves information transmission efficiency. At the same time, the third network element can send the sixth and seventh messages in parallel, reducing the latency of terminal devices requesting services.

[0027] In one possible design, the terminal device is in an idle state, and the method further includes: receiving a second message from the terminal device, the second message including sixth information, seventh information, a first identifier, and a second identifier, wherein the sixth information is associated with the first identifier and the seventh information is associated with the second identifier; if the first network element is an access and mobility management function network element, sending the sixth information to the first network element according to the association relationship between the first identifier and the first network element; receiving a response from the first network element to the sixth information, and sending the seventh information to the second network element according to the association relationship between the second identifier and the second network element.

[0028] Through the above design, information sent by terminal devices to multiple NF network elements can be sent through the same message, which can improve information transmission efficiency. At the same time, when the terminal device is in an idle state, for information sent to access and mobility management function network elements (such as AMF network elements), the third network element can send it first, so that the terminal device can first restore to the connected state, and then other NF network elements can process the service requests of the terminal device. This avoids other NF network elements being affected by the terminal device not being in the connected state or not updating its status information, thus preventing other NF network elements from being affected in processing information from the terminal device.

[0029] In one possible design, with the terminal device in an idle state, the method further includes: receiving a second message from the terminal device, the second message including sixth information, seventh information, a first identifier, and a second identifier, wherein the sixth information is associated with the first identifier and the seventh information is associated with the second identifier, and the sixth information is the first information carried in the second message for requesting services; sending the sixth information to the first network element according to the association relationship between the first identifier and the first network element, wherein when the terminal device is in an idle state, the first information carried in the second message for requesting services is the information of the corresponding access and mobility management function network element; receiving a response from the first network element to the sixth information, and sending the seventh information to the second network element according to the association relationship between the second identifier and the second network element.

[0030] Through the above design, information sent by terminal devices to multiple NF network elements can be sent through the same message, which can improve information transmission efficiency. At the same time, when the terminal device is in an idle state, for information sent to access and mobility management function network elements, the third network element does not need to identify which identifier corresponds to the network element type of access and mobility management network element. The third network element can send the information first, so that the terminal device can first restore to the connected state, and then other NF network elements can process the service requests of the terminal device. This avoids other NF network elements being affected by the terminal device not being in the connected state or not updating its state information, thus affecting the processing of information from the terminal device.

[0031] In one possible design, the terminal device is in an idle state, and the method further includes: determining the identifier of the terminal device (such as a subscription permanent identifier (SUPI)) based on the first identifier; and saving the association between the identifier of the terminal device and the RAN node serving the terminal device.

[0032] With the above design, when the terminal device sends information to the NF network element in the idle state and switches to the connected state, a new connection corresponding to the terminal device will be established between the third network element and the RAN node serving the terminal device. The third network element can save the association between the identifier of the terminal device and the RAN node (such as the identifier of the RAN node, and / or the next generation application protocol (NGAP) ID assigned by the RAN node to the terminal device, etc.) in order to identify the terminal device corresponding to the connection established with the RAN.

[0033] In one possible design, the first network element is an access and mobility management function network element, and the method further includes: sending the identifier of the terminal device, the identifier of the third network element, and / or the address to the unified data management network element; or, the first network element sends the identifier of the terminal device, the identifier of the third network element, and / or the address to the unified data management network element.

[0034] With the above design, when a terminal device registers with an access and mobility management function network element, it can send the terminal device's identifier, the identifier of the third network element, and / or the address to the unified data management network element. This allows other network elements to obtain the identifier of the third network element serving the terminal device from the unified data management network element based on the terminal device's identifier, and then send downlink messages to the terminal device through the third network element serving the terminal device.

[0035] In one possible design, the method further includes: determining that the first identifier is updated to a third identifier, and sending a third request message to the terminal device, the third request message including the first identifier and the third identifier; wherein the third identifier is associated with the first network element and is used for routing to the first network element.

[0036] With the above design, when the third network element reassigns the associated identifier to the first network element, the identifier associated with the first network element stored on the terminal device side can be updated, ensuring the accuracy of routing.

[0037] In one possible design, the first network element is an access and mobility management function network element, and the first identifier includes a first routing identifier and the identifier of the third network element; the second network element is a non-access and mobility management function network element, and the second identifier includes a second routing identifier.

[0038] With the above design, when the first network element is an access and mobility management function network element, the first identifier can include not only the identifier used for routing, but also the identifier of the third network element. This avoids the terminal device entering an idle state and the RAN node being unable to determine the third network element that previously served the terminal device after releasing the context of the terminal device.

[0039] Secondly, embodiments of this application provide a communication method that can be applied to a terminal device. The terminal device can refer to the terminal device itself or to a component (e.g., a processor, module, chip, or chip system) within the terminal device that implements the method. The method includes: sending first information to a third network element, the first information being used to request a first service; and receiving a first identifier from either the third network element or a first network element, wherein the first network element serves the first service, and the first identifier is associated with the first network element or the first service, used for routing to the first network element.

[0040] In one possible design, the method further includes: sending a first message to a third network element, the first message including second information and a first identifier, wherein the second information is information corresponding to the first service.

[0041] In one possible design, the method further includes: saving the association between the first identifier and the business identifier and / or business type of the first service.

[0042] In one possible design, the method further includes: sending a fifth message, the fifth request being used to request a second service; receiving a second identifier from a third network element or a second network element, wherein the second network element serves the second service, and the second identifier is associated with the second network element for routing to the second network element.

[0043] In one possible design, the terminal device is in an idle state, and the method further includes: sending a second message to a third network element, the second message including sixth information, seventh information, a first identifier, and a second identifier, wherein the sixth information is associated with the first identifier and the seventh information is associated with the second identifier.

[0044] In one possible design, the first service is of the type of access and / or mobility management, and the sixth information is the first piece of information carried in the second message for requesting the service, such as a service request message for access and mobility management.

[0045] Thirdly, embodiments of this application provide a communication method that can be applied to an RAN node (also known as an access network device). Here, the RAN node can refer to the RAN node itself or to a component within the RAN node that implements the method (e.g., a processor, module, chip, or chip system). The method includes: receiving first information from a terminal device, the first information being used to request a first service; sending the first information to a third network element; and receiving a first identifier from the third network element, wherein the first network element serves the first service, and the first identifier is associated with the first network element and used for routing to the first network element.

[0046] Fourthly, embodiments of this application provide a communication device that has the function of implementing the methods described in the first, second, or third aspects above. The function can be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions, such as an interface unit and a processing unit.

[0047] In one possible design, the device can be a chip or an integrated circuit.

[0048] In one possible design, the device includes a memory and a processor, the memory being used to store instructions executed by the processor, and when the instructions are executed by the processor, the device can perform the first, second, or third aspect of the method.

[0049] Fifthly, embodiments of this application provide a communication device including an interface circuit and a processor, wherein the processor and the interface circuit are coupled to each other. The interface circuit is used for inputting and / or outputting signals, and the processor uses logic circuits or executing instructions to implement the methods described in the first, second, or third aspects above. It is understood that the interface circuit can be a transceiver, a transceiver device, or an input / output interface.

[0050] Optionally, the communication device may also include a memory for storing instructions executed by the processor, or storing input data required by the processor to execute instructions, or storing data generated after the processor executes instructions. The memory may be a physically independent unit, or it may be coupled to the processor, or the processor may include the memory (i.e., the processor and the memory are integrated together).

[0051] In one possible implementation, the communication device is a chip or chip system.

[0052] In a sixth aspect, embodiments of this application provide a communication system, which includes a third network element and a terminal device. The third network element is used to implement the method described in the first aspect; the terminal device is used to implement the method described in the second aspect.

[0053] In one possible design, the system also includes RAN nodes, which are used to implement the method described in the third aspect above.

[0054] In a seventh aspect, embodiments of this application provide a computer-readable storage medium storing a computer program or instructions that, when executed by a processor, can implement the methods described in the first, second, or third aspects.

[0055] Eighthly, embodiments of this application also provide a computer program product, including a computer program or instructions, which, when executed by a processor, can implement the methods described in the first, second, or third aspects above.

[0056] Ninthly, embodiments of this application also provide a chip system including a processor, the processor being coupled to a memory, the memory being used to store programs or instructions, and when the program or instructions are executed by the processor, the methods of the first, second, or third aspects described above can be implemented.

[0057] The technical effects achievable by aspects two through nine above are similar to those achievable by aspect one above, and will not be repeated here. Attached Figure Description

[0058] Figure 1 A schematic diagram of the architecture of the communication network provided in the embodiments of this application;

[0059] Figure 2 This is a schematic diagram of the terminal device registration process provided in an embodiment of this application;

[0060] Figure 3 This is a schematic diagram of the 5G-GUTI structure provided in an embodiment of this application;

[0061] Figure 4 A schematic diagram of the session establishment process provided in the embodiments of this application;

[0062] Figure 5 This is a schematic diagram illustrating the process of AMF network element routing uplink NAS messages provided in an embodiment of this application;

[0063] Figure 6 This is a schematic diagram of the service request process provided in the embodiments of this application;

[0064] Figure 7 and Figure 8 This is a schematic diagram of the routing architecture provided in an embodiment of this application;

[0065] Figure 9 , Figure 11A , Figure 11B , Figure 12 , Figure 14 This is a schematic diagram of a communication method provided in an embodiment of this application;

[0066] Figure 10 , Figure 13 A structural schematic diagram of the identifier provided in the embodiments of this application;

[0067] Figure 15 This is a schematic diagram of the message service request process provided in the embodiments of this application;

[0068] Figure 16 This is a schematic diagram of the identifier update process provided in an embodiment of this application;

[0069] Figure 17 and Figure 18 This is a schematic diagram of the structure of the communication device provided in the embodiments of this application. Detailed Implementation

[0070] This application provides a communication method and apparatus. The method and apparatus are based on the same inventive concept. Since the principles by which the method and apparatus solve the problem are similar, their implementations can be mutually referenced, and repeated details will not be elaborated further.

[0071] Figure 1 A schematic diagram of a possible, non-limiting communication network is shown. (e.g.) Figure 1As shown, the communication network 10 includes a radio access network (RAN) 100 and a core network (CN) 200. RAN 100 includes at least one RAN node (e.g., ...). Figure 1 110a and 110b (collectively referred to as RAN node 110) and at least one terminal device (such as Figure 1 120a-120j in RAN 100 are collectively referred to as terminal equipment 120. RAN 100 may also include other RAN nodes, such as wireless relay equipment and / or wireless backhaul equipment. Figure 1 (Not shown in the image). Terminal device 120 is connected to RAN node 110 wirelessly. RAN node 110 is connected to core network 200 wirelessly or via wired connection. The core network equipment in core network 200 and RAN node 110 in RAN 100 can be different physical devices, or they can be the same physical device integrating core network logical functions and radio access network logical functions.

[0072] RAN 100 can be a cellular network related to the 3rd Generation Partnership Project (3GPP), such as 4G, 5G mobile communication networks, or future communication networks. RAN 100 can also be an open access network (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) network. RAN 100 can also be a communication network that integrates two or more of the above systems.

[0073] Understandable Figure 1 This application only illustrates one possible communication network that can be applied to an embodiment of this application. In other possible scenarios, the communication network may also include other devices.

[0074] RAN node 110, sometimes also referred to as access network equipment, RAN entity, access node, network equipment, etc., constitutes part of the communication network and is used to help terminal devices achieve wireless access. Multiple RAN nodes 110 in the communication network 10 can be of the same type or different types. In some scenarios, the roles of RAN node 110 and terminal device 120 are relative, for example, Figure 1Network element 120i can be a helicopter or a drone, and it can be configured as a mobile base station. For terminal devices 120j that access RAN 100 through network element 120i, network element 120i is a base station; however, for base station 110a, network element 120i is a terminal device. RAN node 110 and terminal device 120 are sometimes referred to as communication devices, for example... Figure 1 Network elements 110a and 110b can be understood as communication devices with base station functions, while network elements 120a-120j can be understood as communication devices with terminal equipment functions.

[0075] In one possible scenario, a RAN node can be a base station (BS), an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a base station in a future communication network, or an access node in a WiFi network, etc. A RAN node can also be a macro base station (such as...). Figure 1 110a), micro base stations or indoor stations (such as Figure 1 The RAN node can be a relay node or donor node (as described in section 110b), or a wireless controller in a CRAN scenario. Optionally, the RAN node can also be a server, wearable device, vehicle, or in-vehicle equipment. For example, the RAN node in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). All or part of the functions of the RAN node in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform). The RAN node in this application can also be a logical node, logical module, or software capable of implementing all or part of the RAN node functions.

[0076] In another possible scenario, multiple RAN nodes collaborate to assist terminal devices in achieving wireless access, with different RAN nodes each implementing a portion of the base station's functions. For example, RAN nodes can be central units (CUs), distributed units (DUs), CU-control plane (CPs), CU-user plane (UPs), or radio units (RUs), etc. CUs and DUs can be set up separately or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio frequency equipment or radio frequency units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0077] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an O-RAN system, CU can also be called O-CU (Open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules.

[0078] Terminal devices, also known as terminals, user equipment (UE), mobile stations, mobile terminals, etc., are devices used to provide voice or data connectivity to users, and can also be Internet of Things (IoT) devices. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, and smart cities. Terminal devices can be: mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), wearable devices (such as smartwatches, smart bracelets, pedometers, smart glasses, etc.), in-vehicle equipment (such as cars, bicycles, electric vehicles, airplanes, ships, trains, high-speed trains, etc.), satellite terminals, virtual reality (VR) devices, augmented reality (AR) devices, smart point of sale (POS) machines, customer-premises equipment (CPE), light user equipment (UE), reduced capability user equipment (REDCAP UE), wireless terminals in industrial control, smart home devices (such as refrigerators, televisions, air conditioners, electricity meters, etc.), smart robots, robotic arms, workshop equipment, wireless terminals in autonomous driving, wireless terminals in telemedicine, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, or wireless terminals in smart homes, and flying equipment (such as smart robots, hot air balloons, drones, airplanes), etc. The terminal device can also be a vehicle device, such as a complete vehicle device, an in-vehicle module, an in-vehicle chip, an onboard unit (OBU), or a telematics box (T-BOX). The terminal device can also be other devices with terminal functions; for example, it can be a device that functions as a terminal in D2D communication. The embodiments of this application do not limit the form of the terminal device.

[0079] Communication between RAN nodes and terminal devices, as well as between terminal devices, can be conducted using licensed spectrum, unlicensed spectrum, or both simultaneously. Communication between RAN nodes and terminal devices, as well as between terminal devices, can also be conducted using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used between RAN nodes and terminal devices.

[0080] A Network Function (CN) can include multiple network function (NF) network elements, such as access and mobility management (AMF) network elements, unified data management (UDM) network elements, session management (SMF) network elements, location management (LMF) network elements, and network repository (NRF) network elements. NF network elements can also be referred to as NF; for example, an AMF network element can also be referred to as AMF, and an SMF network element can also be referred to as SMF.

[0081] To facilitate understanding by those skilled in the art, some terms used in this application are explained below.

[0082] 1) Terminal device (UE) registration process.

[0083] Figure 2 This is a schematic diagram of a possible terminal device registration process provided in an embodiment of this application, wherein... Figure 2 The focus is on how AMF network elements route NAS messages (such as messages between AMF network elements and UEs) and N2 messages (messages between AMF network elements and RANs). This process includes:

[0084] Step 1: The UE sends a registration request message to the RAN node.

[0085] For example: The UE and the RAN node can establish a connection via an air interface (also referred to as the air interface). The RAN node stores the UE's temporary identifier on the air interface (such as a radio network temporary identity (RNTI)). When the UE initiates registration, it can send a first registration request message to the RAN node. The first registration request message may include a NAS message (such as a registration request message sent by the UE to the AMF network element, which may include the UE's subscription concealed identifier (SUCI)). The first registration request message may also include access network (AN) parameters, the UE's temporary identifier on the air interface, etc.

[0086] Step 2: Select AMF network elements for RAN nodes.

[0087] The RAN node can select an AMF network element that has already established a next-generation application protocol (NGAP) connection with the RAN node, based on the radio access technology (RAT) information currently accessed by the UE and the UE slice information in the AN parameters.

[0088] Step 3: The RAN node sends an initial UE message to the AMF network element.

[0089] The initial UE message may include the RAN UE NGAP ID (i.e., the NGAP identifier (identity, ID) assigned to the UE by the RAN node) and the UE registration request message (i.e., the NAS message, which includes the UE's SUCI).

[0090] In some implementations, the following steps can also be performed: the AMF network element (i.e., the new AMF network element) sends a communication UE context transfer request (namf_communication_UEcontextTransfer request) to the AMF network element (i.e., the old AMF network element) previously accessed by the UE; the AMF network element (i.e., the new AMF network element) receives a communication UE context transfer response (namf_communication_UE contextTransferresponse) sent by the AMF network element (i.e., the old AMF network element) previously accessed by the UE; and the AMF network element performs AUSF network element selection.

[0091] Step X: The AMF network element sends an initial context setup request message to the RAN node.

[0092] Where X is an integer greater than 3, the initial context establishment request message may include the RAN UE NGAP ID, the AMF UE NGAP ID (i.e., the NGAP identifier assigned to the UE by the AMF network element), and a NAS message sent to the UE (e.g., a registration accept message, including the 5G-globalunique temporary UE identity (GUTI) assigned to the UE by the AMF network element, i.e., 5G-GUTI). The AMF network element can send the NAS message (e.g., the registration accept message) to the UE.

[0093] Among them, the structure of 5G GUTI can be as follows: Figure 3 As shown, this includes the Mobile Country Code (MCC), Mobile Network Code (MNC), AMF Region ID, AMF Set ID, AMF Pointer, and 5G Temporary Mobile Subscriber Identity (TMSI). The MCC and MNC constitute the Public Land Mobile Network (PLMN) identifier, which can be used to represent the PLMN identifier of the PLMN where the AMF network element resides or the PLMN identifier of the PLMN the UE accesses. The AMF Region ID, AMF Set ID, and AMF Pointer constitute the AMF ID. The 5G-TMSI is a temporary identifier assigned to the UE. The MCC, MNC, and AMF ID constitute the Globally Unique AMF Identifier (GUAMI), and the AMF Set ID, AMF Pointer, and 5G-TMSI constitute the 5G Short-Temporary Mobile Subscriber Identity (5G-S-TMSI).

[0094] At this point, the RAN node stores the UE's air interface identifier (such as RNTI), the UE's identifier on the NGAP connection (i.e., AMF UE NGAP ID and RAN UE NGAP ID), and information about the AMF serving the UE (address or ID, etc.). These are all in the UE context and are interconnected. The AMF network element stores the UE's subscription permanent identifier (SUPI), the UE's identifier on the NGAP connection (i.e., AMF UE NGAP ID and RAN UE NGAP ID), and information about the RAN node serving the UE (address, ID, etc.). These are all in the UE context and are also interconnected. The SUPI can be obtained by decrypting the UE's SUCI. The AMF UE NGAP ID and the RAN UE NGAP ID can be called an NGAP ID pair.

[0095] In the subsequent process: (1) Other NF network elements can send messages to the UE through the AMF network element. They can request the AMF network element's Communication_N1N2 Message Transfer service and use SUPI to specify the target UE. The AMF network element determines the RAN node serving the UE and the NGAP ID pair based on the SUPI, and then routes the message down. (2) Other NF network elements can send messages to the RAN node serving the UE through the AMF network element. They can also request the AMF network element's Communication_N1N2 Message Transfer service and use SUPI to specify the target UE. The AMF network element determines the RAN node serving the UE based on the SUPI, and then routes the message down.

[0096] 2) Session establishment process.

[0097] Figure 4 This application provides a schematic diagram of a possible session establishment process, wherein... Figure 4 In addition to potentially sending uplink messages to AMF network elements, it is also necessary to send them to NF network elements such as SMF network elements. This process includes:

[0098] Step 1: The UE sends a Protocol Data Unit (PDU) session establishment request message to the AMF network element through the RAN node.

[0099] For example: After a UE registers with the network, it can send a NAS PDU to the AMF network element through the RAN node. After receiving the NAS PDU from the UE, the RAN node can send an uplink NAS TRANSPORT message to the AMF network element, which includes information such as the RAN UE NGAP ID, AMF UE NGAP ID, UE location, and the NAS PDU.

[0100] The NAS PDU may include parameters such as PDU session ID, data network name (DNN) and slice information, as well as an N1 session management (SM) container. The N1SM container may encapsulate NAS messages (such as PDU session establishment request messages) sent by the UE to the SMF network element.

[0101] Step 2: Select SMF network element from AMF network element.

[0102] For example: AMF network elements can select SMF network elements based on parameters such as "DNN and slice information" and determine the address or ID of the SMF network element.

[0103] Step 3: The AMF network element sends a session management context creation request (Nsmf_PDU session_create SM context request) to the SMF network element.

[0104] The request to create a session management context may include information such as the N1 SM container, the UE's SUPI, AMFID, and / or address.

[0105] The AMF network element can store the PDU session ID and the corresponding SMF network element information (such as SMFID and / or address) in the UE context. The SMF network element stores the UE's SUPI, PDU session ID, and AMF network element information (such as ID and / or address).

[0106] It is understandable that the session establishment process may also include other steps, such as the SMF network element sending a request response to the AMF network element to create a session management context (Nsmf_PDU session_create SM context response), etc.

[0107] In subsequent processes, when the UE sends a NAS message (also known as a NAS PDU) to the SMF network element, the NAS message (the NAS type of this message is SM) includes the PDU session ID. The AMF network element can then determine which SMF network element to send the NAS message to based on the PDU session ID.

[0108] Reference Figure 5 The diagram illustrates the process of an AMF (Agency Management Function) network element routing uplink NAS messages. For a NAS message, the AMF network element first determines the routing method based on the NAS type field in the message header. For example, if it's an SM (Mobile Management) type NAS message, the AMF network element can send the NAS message to the SMF network element associated with the PDU session ID carried in the NAS message. If it's a mobility management (MM) type NAS message, the AMF network element then determines whether the NAS message is intended for itself based on the message type field (usually 8 bits) in the message header. For example, the message type field indicates that the NAS message is a registration request, service request, etc., and is sent to the AMF network element itself.

[0109] If the message type field indicates that the NAS message is an uplink (UL) NAS transport, then the NAS message may be sent to other NF network elements. For cases where the message type field indicates that the NAS message is a UL NAS transport, the AMF network element can open the NAS message payload and view the payload container type field. If the payload container type field is 0010, indicating a Short Messaging Service (SMS) type, the payload contains an encapsulated SMS-related message. The AMF (Advanced Management Function) network element routes the content of the NAS message to the SMS-related NF (Network Function) network element (such as a Short Message Service Function (SMSF) network element). If it is 0101, indicating a UE policy container type, it means routing to a Policy Control Function (PCF) network element is required. Since the AMF network element stores the identifier or address of the UE's PCF network element in the UE context, it can use this information to route the content of the NAS message to the PCF network element. If it is 0111, indicating a Location Service (LCS) message container type, it means routing to an LMF (Location Service) network element is required. The AMF network element does not know which LMF network element to route to, so it needs to parse the payload again and check the routing identifier information element in the payload. This information element indicates the ID / address of the LMF, and the AMF network element routes the content of the NAS message to that LMF network element.

[0110] It's important to note that a NAS message sent to an SMF network element can be understood as an MM-type NAS message containing an SM-type NAS message. The message type of this MM NAS message is also UL NAS transport. If the payload container type field is 0001, i.e., N1 SM information type, then the payload contains an encapsulated SM NAS message. The AMF network element routes the content of the NAS message to the corresponding SMF network element based on the PDUsession ID in the header of this encapsulated SM NAS message.

[0111] 3) Service request process.

[0112] Figure 6This is a schematic diagram of a possible service request process provided in an embodiment of this application, wherein... Figure 6 This section focuses on how the RAN node routes messages to the AMF network elements that previously served the UE after the UE enters the idle state. This process includes:

[0113] Step 1: The UE sends a radio resource control (RRC) message to the RAN node.

[0114] After the UE registers with the network, the AMF network element stores the UE's context. Then the UE enters the idle state, and the RAN node releases the UE's context, including the UE's temporary air interface identifier and the NGAP identifier on the N2 interface.

[0115] When a UE wishes to return from idle to connected mode, it can send an RRC message to the RAN node, including AN parameters and a NAS PDU (service request message sent to the AMF network element). The AN parameters include the UE's 5G-S-TMSI.

[0116] Step 2: The RAN node sends an N2 message to the AMF network element.

[0117] For example: The RAN node can determine the AMF network element based on the 5G-S-TMSI (the S-TMSI includes the AMF Set and AMFpointer). The RAN node can send an N2 message to the AMF network element that previously served the UE, which includes the RAN UE NGAPID and NAS PDU (UE service request message) newly allocated by the RAN node.

[0118] In this way, during the service request process, the RAN node can determine the AMF network element based on the 5G-S-TMSI and perform uplink routing to the AMF network element.

[0119] Understandably, the service request process may also include other steps, such as the AMF network element authenticating the UE through the authentication server function (AUSF) network element, etc.

[0120] 4) In the description of this application, terms such as "first" and "second" are used only to distinguish multiple objects and are not used to limit the size, content, order, sequence, priority, or importance of multiple objects. For example, "first information" and "second information" do not indicate a difference in priority or importance between the two pieces of information.

[0121] 5) In the embodiments of this application, the number of nouns, unless otherwise specified, refers to "singular nouns or plural nouns," that is, "one or more." "At least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. For example, A / B means: A or B. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c means: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0122] 6) In this application, "sending information" can be understood as one device sending information to another device, or it can also be understood as one logic module within a device sending information to another logic module. For example, "device A sending information" can be understood as device A sending information to another device (device B), or it can be understood as logic module 1 in device A sending information to logic module 2 in device A. In this application, "receiving information" can be understood as one device receiving information from another device, or it can also be understood as one logic module within a device receiving information from another logic module. For example, "device A receiving information" can be understood as device A receiving information from another device (such as device B), or it can be understood as logic module 1 in device A receiving information from logic module 2 in device A. In this application, "sending information to… (e.g., device B)" or the relevant illustrations in the accompanying drawings can be understood as the destination of the information being device B. This can include sending information directly or indirectly to device B. The phrases "receiving information from... (e.g., device A)," "receiving information from... (e.g., device A)," or "receiving information sent by (e.g., device A)," or the relevant illustrations in the accompanying drawings, can be understood as indicating that the source of the information is device A, which may include receiving information directly or indirectly from device A. The information may undergo necessary processing between the source and destination, such as format changes, but the destination can understand the valid information from the source. Similar expressions in this application can be interpreted similarly and will not be repeated here.

[0123] With the increase in network characteristics and service functions, AMF network elements not only need to route messages to SMF network elements, but also need to route messages to other NF network elements. When the NAS type is SM, in addition to selecting SMF network elements based on information such as DNN / slice, it is also necessary to identify new service-related parameters (such as control plane CIoT 5GS optimization, old PDU session ID, etc.) to select SMF network elements. When the NAS type is UL NAS transport, it is necessary to determine the NF network element to be routed to based on the payload container type and the specific content of the optional payload.

[0124] This results in the coupling of access management (AM) / MM functions and routing functions within the AMF network element. When new features or functions are introduced into the network, the AMF network element needs to identify relevant parameters to correctly route related service messages between terminal devices and network elements serving the new features or functions. Therefore, the introduction of new features or functions will affect the AMF network element, requiring upgrades and updates, even if the feature / function is essentially unrelated to the AMF network element. This design may affect AM / MM functions unrelated to the new features or functions, and may also affect the connection between the RAN node and the CN, posing operational risks such as connection interruptions to the access network and access network configuration changes, resulting in insufficient flexibility. For example, upgrading an AMF network element requires restarting it, which may interrupt the N2 interface connection between the RAN node and the core network, and the N1 interface connection between the terminal device and the core network.

[0125] Based on this, embodiments of this application provide a communication method and apparatus to decouple message routing functions from AMF network elements, thereby avoiding the impact on message routing between terminal devices and RAN nodes and the core network, as well as the access management and mobility management functions of AMF network elements, when new features are introduced into the network. The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0126] Figure 7 For message routing architecture based on AMF network elements, by Figure 7 It can be seen that messages between the UE or RAN node and NF network elements such as LMF network element and SMF network element in CN are all routed through AMF network element. Figure 8The message routing architecture based on the signaling routing function (SRF) network element provided in this application embodiment is composed of... Figure 8 It can be seen that, in Figure 8 In the illustrated message routing architecture, the message routing function can be decoupled from the AMF network element and treated as a separate network element, namely the SRF network element. The SRF network element includes, but is not limited to, routing functions. Other NF network elements (including AMF / SMF / LMF, etc.) remain transparent to the UE and RAN nodes regardless of their state or whether they have been replaced. This ensures that when new features (or new services) are introduced, the replacement, upgrade, or reconfiguration of NF network elements does not affect unrelated NF network elements, terminal devices, and RAN nodes. It is understood that the name and function of the SRF network element are not limited in this embodiment. For example, the SRF network element can also be called a Core Network Portal Function (CPF) network element, and the SRF network element can also possess functions other than routing.

[0127] The communication method provided in this application can be executed by a third network element. This third network element has routing capabilities, such as message routing (NAS message routing) between terminal devices and the core network, and message routing between RAN nodes and the core network. Furthermore, this application does not limit the deployment location or specific name of the third network element. For example, logically, the third network element can be deployed independently, integrated with RAN nodes, or integrated with other NF network elements in the CN, etc.; physically, the third network element can be deployed as a separate device, on the same device as RAN nodes, or on the same device as other NF network elements in the CN, etc. Taking the SRF network element as an example, refer to... Figure 8 As shown, SRF network elements can be deployed independently to provide signaling routing functions for terminal devices (such as UE1, UE2), RAN nodes (such as RAN1, RAN2), and AMF and SMF network elements in the CN.

[0128] Furthermore, in this application's embodiments, taking the Access and Mobility Management Function (AMF) network element, the Session Management Function (SMF) network element, the Unified Data Management (UDM) network element, the Network Storage Function (NRF) network element, and the Network Function Selection Function (NFSF) network element as examples, it is understood that this application does not exclude the possibility of using other names for AMF, SMF, UDM, NRF, and NFSF network elements in 5G mobile communication networks and other future communication networks. For example, in future communication networks, some or all of the aforementioned core network elements may use the terminology from 5G networks, or they may use other names.

[0129] In this embodiment, the interface between the terminal device and the NF network element (such as AMF or SMF network element) in the core network is described as interface Nx1, and the interface between the RAN node and the NF network element in the core network is described as interface Nx2. Interface Nx1 can be used to transmit control plane information between the terminal device and the NF network element in the core network, and interface Nx2 can be used to transmit control plane information between the RAN node and the NF network element in the core network. It is understood that the above-mentioned interfaces Nx1 and Nx2 are merely examples. This application does not limit the interface names between the terminal device and the NF network element in the core network, nor does it exclude the possibility that other names may be used for the interfaces (such as the above-mentioned interfaces Nx1 and Nx2) in 5G mobile communication networks and other future communication networks. For example, in future communication networks, some or all of the above-mentioned interfaces may use other names.

[0130] Figure 9 This is one of the schematic diagrams of a communication method provided in an embodiment of this application. The method includes:

[0131] S901: The terminal device sends the first information to the third network element, and the third network element receives the first information accordingly. The first information is used to request the first service.

[0132] In this embodiment, the first information may refer to information or messages sent by the terminal device to the core network to request a certain service. For example, the first information may be information for requesting registration, information for requesting a session, or information for requesting location, etc. The terminal device can request services such as registration (i.e., access and mobility management related services), session establishment (i.e., session management related services), or location services from the core network by sending the first information.

[0133] For the first information, the terminal device can send the first information to the third network element through the RAN node serving the terminal device (or the RAN node to which the terminal device is connected).

[0134] Taking the first information used for registration requests as an example, a terminal device can send a registration request message to the RAN node serving the terminal device. This registration request message can carry the first information, as well as access network parameters. The first information may include the terminal device's subscription concealed identifier (SUCI) and registration type, while the AN parameters may include slice information. After receiving the registration request message, the RAN node can select a third network element to establish a connection with the RAN node (such as an NGAP connection) and send an initial terminal device message (which can also be called an initial UE message when the terminal device is a UE) to the third network element. This initial terminal device message can carry the first information, the NGIPD1 assigned to the terminal device by the RAN node, and Nx2 parameters (such as the terminal device's location information and the RAN node's identifier).

[0135] It is understandable that when a RAN node selects a third network element, it can select one from at least one third network element with an established connection according to a set strategy (such as random, minimum load, etc.), or it can select a third network element based on AN parameters, such as selecting a third network element that is related to the slice information included in the AN, etc. This application does not limit the way the RAN node selects a third network element.

[0136] Taking the first information as the information used to request a session as an example, before the terminal device sends the first information for requesting a session, the terminal device has already registered with the network, and the RAN node and the third network element have established a connection for the terminal device. For example, the RAN node assigns NGAP ID1 to the terminal device, and the third network element assigns NGAP ID2 to the terminal device. The terminal device can send a PDU session establishment request message to the RAN node. The PDU session establishment request message can include the first information, and can also include AN parameters (such as slice information). The first information can include PDU session ID, DNN, single slice selection parameters, etc. After receiving the PDU session establishment request message including the first information, the RAN node can send an uplink NAS transmission message to the third network element. This message can include the first information, the NGAP ID1 assigned by the RAN node to the terminal device, the NGAP ID2 assigned by the third network element to the terminal device, etc.

[0137] S902: The third network element determines the first identifier associated with the first network element, wherein the first network element serves the first service.

[0138] In one possible implementation, the first network element serving the first service can be determined by the third network element.

[0139] For example: if the first information includes NAS type MM or the message carrying the first information includes NAS type MM, the third network element can determine that the first service is an access and mobility management related service, which requires an AMF network element to provide services for the first service. The third network element can select one AMF network element from at least one AMF network element that has established a connection with the third network element according to a set strategy (such as random, minimum load, etc.) as the first network element to serve the first service; or, if the first information includes PDU session ID and DNN, the third network element can determine that the first service is a session management service, which requires an SMF network element to provide services for the first service. The third network element can select the SMF network element associated with the DNN as the first network element to serve the first service.

[0140] In another possible implementation, the first network element serving the first service can also be determined by a third network element through an NRF network element or an NFSF network element, etc.

[0141] For example: After receiving the first information, the third network element can send at least one of the parameters, such as the NAS type and DNN, of the first network element used to select the service provider for the first service to the NRF network element. After the NRF network element determines the first network element, it sends the identifier and / or address of the first network element to the third network element. Alternatively, after receiving the first information, the third network element can send the NF selection container of the network element used to select the service provider for the first service to the NRF network element. After the NRF network element determines the first network element, it sends the identifier and / or address of the first network element to the third network element. The NF selection container can come from the terminal device, and the NF selection container can include at least one of the parameters, such as the NAS type and DNN, of the first network element used to select the service provider for the first service.

[0142] After selecting the first network element serving the first service, the third network element can assign a first identifier associated with the first network element to the terminal device. The association between the first identifier and the first network element can mean that the first identifier is associated with the identifier and / or address of the first network element. Through the first identifier, the third network element can uniquely identify a first network element associated with the first identifier.

[0143] It is understood that the identifier (such as the first identifier) ​​associated with the NF network element (such as the first network element) can be a sequence, a random number, etc. The association of the identifier (such as the first identifier) ​​with the NF network element (such as the first network element) can mean that part or all of the content of the identifier is associated with the NF network element. This application does not limit the structure of the identifier associated with the NF network element or the way the identifier is associated with the NF network element.

[0144] For example: the identifier associated with an NF network element may include a routing identifier portion and other portions, wherein the other portions are optional. Figure 10This is a schematic diagram of a possible identifier structure associated with an NF network element provided in an embodiment of this application. The identifier associated with the NF network element is called SRF-GUTI or terminal device global temporary identifier. SRF-GUTI may include a temporary routing identifier (TRID). In addition, SRF-GUTI may also include one or more of MCC, MNC, SRFID, NF ID, etc. Among them, TRID is a unique identifier assigned to the third network element (unique at the third network element), NF ID is the identifier of the NF network element associated with SRF-GUTI, SRFID is the identifier of the third network element, MCC and MNC can uniquely identify the PLMN to which the third network element belongs or which the terminal device is connected to, MCC, MNC and SRFID can constitute a globally unique SRFID (globally unique SRF identifier, GUSRI), SRFID (if included in SRF-GUTI), NF ID (if included in SRF-GUTI) and TRID constitute an SRF short TRID (SRF-short-temporary routing identifier, SRF-S-TRID).

[0145] In some embodiments, before allocating the first identifier associated with the first network element, the third network element may further determine that the message carrying the first information satisfies at least one of the following conditions: the message carrying the first information does not contain an identifier associated with a network element (such as an NF network element); the message type carrying the first information is an initial terminal device message; the message carrying the first information contains network element selection information (such as DNN, or NF selection container); or the message type carrying the first information indicates a request to establish a first service. Based on these conditions, the third network element can determine that the first service requested by the first information is a new service or a new service session of an existing service type, and has not sent the first identifier associated with the first network element serving the first service to the terminal device, thereby avoiding the situation where the third network element repeatedly allocates identifiers associated with the same network element, resulting in multiple identifiers being associated with the same network element and affecting routing.

[0146] If the message carrying the first information includes an identifier associated with a network element, it indicates that the first information is not used to request a new service, and the third network element does not need to allocate an identifier associated with the network element serving the new service. The third network element can obtain the identifier included in the message and, based on the stored association relationship between the identifier and the network element, send the first information to the network element associated with that identifier.

[0147] As an example: When a third network element receives a message carrying first information, if the message does not include routing information, or includes routing information but does not contain an identifier associated with the network element, the third network element can determine that the first information is for requesting a new service, and can allocate a first identifier associated with the first network element. If the message carrying first information includes an identifier associated with the network element, it indicates that the first information is information that needs to be routed to the network element associated with that identifier, rather than for requesting a new service, and the third network element can send the first information to the network element associated with that identifier.

[0148] It should be noted that if the message carrying the first information includes an identifier associated with a network element, the third network element can obtain the identifier associated with the network element carried in the message through the field (such as the routing field) used to carry the identifier associated with the network element. However, since the third network element has already assigned an identifier associated with the network element receiving the first information, there is no need to reassign the identifier. Instead, the first information is sent to the network element associated with the identifier based on the association between the identifier and the network element.

[0149] In one possible implementation, if the first service is a registration service (i.e., access and mobility management related services) and the first network element is an AMF network element, the first identifier may include the identifier of the third network element, so that after the terminal device accesses and registers to the network, after entering the idle state (e.g., RRC connected state) from the connected state (e.g., RRC idle state), the RAN node selects the third network element according to the identifier of the third network element during the service request process.

[0150] In one possible implementation, if the first service is a session management related service and the first network element is an SMF network element, the identifier of the third network element may not be included in the first identifier, thereby saving air interface overhead. Furthermore, after the terminal device enters the idle state (such as the RRC connected state) from the connected state (such as the RRC idle state), it must first request access and mobility management related services (such as service requests or registration requests) so that the network can perform access control before it can request other types of services.

[0151] S903: The third network element sends the first information and the first identifier to the first network element, and the first network element receives the first information and the first identifier accordingly.

[0152] After the third network element determines the first identifier associated with the first network element, it can send the first information and the first identifier to the first network element.

[0153] As an example: A third network element can send an Nx1Nx2 handling request message to a first network element. The Nx1Nx2 handling request message may include first information and a first identifier, and may also include the identifier of the third network element and Nx2 parameters (such as the location information of the terminal device).

[0154] After receiving the first information, the first network element can process the first information and the first identifier, and can send the response information that needs to be sent to the terminal device to the first network element.

[0155] Taking the first information as the information used to request registration, and the first network element as the AMF network element as an example, after receiving the first information and the first identifier, the AMF network element can process the first information and save the first identifier, for example, by saving the first identifier in the context of the terminal device. After the terminal device successfully registers, it can send an Nx1Nx2 handling response message to the third network element. The Nx1Nx2 handling response message can include response information that needs to be sent to the terminal device (such as registration acceptance information), and can also include the terminal device's identifier (such as SUPI or generic public subscription identifier, GPSI), the first identifier, etc.

[0156] In this design, the first network element (such as an AMF or SMF network element) is a network element in the core network. The first information sent by the terminal device to the first network element is NAS information. The first network element carries the terminal device's identifier in the processing response message sent to the third network element. This allows the third network element to obtain the terminal device's identifier even if it lacks the ability to parse (or encode / decode) the NAS information content and cannot obtain the terminal device's identifier by parsing the first information content. This allows the third network element to associate the terminal device's identifier with the RAN node serving the terminal device for routing downlink messages sent to the terminal device. This design simplifies the design of the third network element, as it does not require the third network element to have NAS information content parsing capabilities.

[0157] It is understood that the first network element may include or exclude the first identifier associated with the first network element in the response information (such as registration acceptance information) sent to the terminal device, and this application does not limit this.

[0158] It is understandable that the message sent by the first network element to the third network element can also be an Nx1Nx2 transmission request message. This application does not limit the name of the message. The message can carry a first identifier so that the third network element can identify the terminal device associated with the message when the identifier of the terminal device is not determined.

[0159] S904: The third network element sends a first identifier to the terminal device, and the terminal device receives the first identifier accordingly, wherein the first identifier is used for routing to the first network element.

[0160] In one possible implementation, the first identifier can be sent to the terminal device by the first network element.

[0161] As an example: the third information sent by the first network element to the third network element may include the first identifier. The third information may be a response to the first information or other information sent by the first network element to the terminal device. In the case where the first network element terminates the non-access stratum, the third information is non-access stratum information or a message (or NAS PDU). After receiving the third information, the third network element can send the third information to the terminal device through the RAN node, so that the terminal device can obtain the first identifier associated with the first network element.

[0162] In another possible implementation, the first identifier can be sent to the terminal device by a third network element.

[0163] As an example: After determining the first identifier, the third network element can send the first identifier to the RAN node through the Nx2 interface with the RAN node, and the RAN node will send the first identifier to the terminal device through an RRC message.

[0164] As another example: the third network element possesses non-access stratum security termination and encoding / decoding capabilities. The fourth information sent by the first network element to the third network element may not include the first identifier. The fourth information can be a response to the first information or other information sent by the first network element to the terminal device. After receiving the fourth information, the third network element can perform non-access stratum encoding on the fourth information and the first identifier, and then send the non-access stratum encoded fourth information and the first identifier (i.e., non-access stratum information) to the terminal device through the RAN node, enabling the terminal device to obtain the first identifier associated with the first network element.

[0165] It is understood that the first identifier can be sent in the same message as the response information of the first network element to the first information, or it can be sent in different messages. This application does not limit this.

[0166] In one possible implementation, if the first information is for requesting registration, the third network element can also assign an NGAP ID2 to the terminal device and send the NGAP ID1 assigned by the RAN node to the terminal device and the NGAP ID2 assigned by the third network element to the terminal device to the RAN node, so as to establish a connection with the RAN node corresponding to the terminal device.

[0167] After receiving the first identifier, the terminal device can save the association between the first identifier and the service identifier and / or service type of the first service. If the terminal device subsequently needs to send information (or messages) corresponding to this service identifier and / or service type, it can use the first identifier. For example, the terminal device can send the information and the first identifier in the same message, or carry the first identifier in the message to be sent.

[0168] For example: The first information is used to request registration services. The service type corresponding to the registration service is Access and Mobility Management (i.e., NAS type is MM). After receiving the first identifier, the terminal device can store the association between the first identifier and the service type Access and Mobility Management. When the terminal device sends information or messages corresponding to the service type Access and Mobility Management (e.g., periodic registration update request message, mobility registration update request message), it can use the first identifier.

[0169] Alternatively, the first information is used to request PDU session services. After receiving the first identifier, the terminal device can store the association between the first identifier and the PDU session ID of the PDU session. When the terminal device sends session management service related information or messages (such as session modification request messages or session release request messages) related to the PDU session, it can use the first identifier.

[0170] After receiving a message including the first identifier from the terminal device, the third network element can route the message or the information carried in the message to the first network element according to the association between the first identifier and the first network element (such as the identifier and / or address of the first network element).

[0171] Taking the terminal device sending a second message containing second information and a first identifier to a third network element as an example, after receiving the second message, the third network element can send the second information (or the second information and the first identifier) ​​to the first network element according to the association between the first identifier and the first network element.

[0172] In some embodiments, the third network element may also send a first identifier associated with the first service to the RAN node of the serving terminal equipment. After receiving the first identifier, the RAN node may also store the association between the first identifier and the service identifier and / or service type of the first service. Subsequently, when the RAN node has information (or messages) corresponding to the service identifier and / or service type that needs to be sent, it can also use the first identifier. For example, the RAN node can send the information and the first identifier in the same message, or carry the first identifier in the message that needs to be sent.

[0173] As an example: The first information is used to request registration of services. The service type corresponding to the registration service is Access and Mobility Management. After receiving the first identifier, the RAN node can store the association between the first identifier and the service type Access and Mobility Management (i.e., NAS type is MM). When the RAN node sends information or messages corresponding to the service type Access and Mobility Management (e.g., handover request messages), it can use the first identifier.

[0174] Alternatively, the first information is used to request PDU session services. After receiving the first identifier, the RAN can store the association between the first identifier and the PDU session ID of the PDU session. When the RAN node sends session management service related information or messages (such as session release request messages or handover request messages) related to the PDU session, it can use the first identifier.

[0175] The following example uses the registration service as the first service, the AMF network element as the first network element, the SRF network element as the third network element, and the SRF-GUTI-1 as the first identifier. Figure 11A Specific embodiments, for the above Figure 9 The embodiments are described below. Figure 11A This is a second schematic diagram of a communication method provided in an embodiment of this application. The method includes:

[0176] S1101: The terminal device sends a registration request message to the RAN node, and the RAN node receives the registration request message accordingly.

[0177] The registration request message may include first information for requesting registration services, the air interface identifier of the terminal device (such as RNTI), and AN parameters (such as slice information). The first information can be NAS information or a message (also called a NAS PDU), and may include information such as the terminal device's SUCI and / or NAS type MM.

[0178] S1102: RAN node selects SRF network element.

[0179] For example, when a RAN node selects an SRF network element, it can select one from at least one SRF network element with an established connection according to a set strategy (such as random, minimum load, etc.), or it can select an SRF network element based on AN parameters, such as selecting an SRF network element that is related to the slice information included in the AN, etc. This application does not limit the way the RAN node selects an SRF network element.

[0180] S1103: The RAN node sends an initial terminal device message to the SRF network element, and the SRF network element receives the initial terminal device message accordingly.

[0181] The initial terminal device message includes first information, and may also include RAN UE NGAP ID (a temporary identifier for the terminal device assigned by the RAN node for communication between the RAN node and the SRF), Nx2 parameters (such as RAN ID (the identifier of the RAN node), location information of the terminal device, etc.).

[0182] S1104: The SRF network element determines the SRF-GUTI-1 associated with the AMF network element, where the AMF network element serves the registration service.

[0183] After receiving the initial terminal device message containing the first information, the SRF network element can select the AMF network element that serves the registered service.

[0184] For example, the SRF network element can send information such as NAS type MM and terminal device location information to the NRF network element, which then selects the AMF network element based on the NAS type MM and terminal device location information. The implementation of the SRF network element selecting the AMF network element for the service registration can refer to the implementation of the third network element determining the first network element described above, and will not be elaborated further.

[0185] In addition, the SRF network element can determine that the first information is for requesting new services based on the fact that the initial terminal device message does not contain an identifier associated with the network element (such as not containing routing information, or containing routing information but not containing an identifier associated with the network element). It can then assign an SRF-GUTI-1 associated with the AMF network element to the terminal device.

[0186] S1105: The SRF network element sends an Nx1Nx2 processing request message to the AMF network element, and the AMF network element receives the Nx1Nx2 processing request message accordingly.

[0187] The Nx1Nx2 processing request message may include SRF-GUTI-1, first information, and may also include SRFID (i.e., the identifier of the SRF network element), Nx2 parameters (such as the location of the terminal device), and other information.

[0188] S1106: The AMF network element performs authentication and other operations on terminal devices.

[0189] After receiving the processing request message, the AMF network element can perform operations such as authenticating the terminal device, obtaining the subscription (i.e., obtaining the subscription information of the terminal device), and determining the mobility management policy of the terminal device.

[0190] S1107: The AMF network element sends an Nx1Nx2 processing request response message / Nx1Nx2 transport request message to the SRF network element, and the SRF network element receives the Nx1Nx2 processing request response message / Nx1Nx2 transport request message accordingly.

[0191] In one possible implementation, after the terminal device successfully registers, the AMF network element can respond to the Nx1Nx2 processing request message from the SRF network element by sending an Nx1Nx2 processing request response message to the SRF network element. The Nx1Nx2 processing request response message may include third information (including SRF-GUTI-1) sent to the terminal device, and optionally include the terminal device's SUPI.

[0192] After receiving the Nx1Nx2 processing request response message, the SRF network element can determine the SRF UE NGAP ID (a temporary identifier for terminal equipment allocated by the SRF network element for communication between the RAN node and the SRF) and update the routing table.

[0193] As an example, the routing table can be shown in Table 1A and Table 1B below. Table 1A is the uplink (UL) routing table, which includes the association between SRF-GUTI-1 and AMF ID (the identifier of the AMF network element); Table 1B is the downlink (DL) routing table, which includes the association between the SUPI of the terminal device and the RAN ID and NGPID pair (i.e., RAN UE NGAP ID and SRF UE NGAP ID).

[0194] It is understandable that if SRF-GUTI-1 includes TRID-1, and also includes at least one of SRFID, AMF ID, MCC, MNC, etc., then TRID-1 in SRF-GUTI-1 can be associated with AMF ID, and the association between TRID-1 and AMF ID can also be stored in the uplink routing table. Furthermore, for registration services (or in cases where the first network element is an AMF network element), TRID-1 or SRF ID+TRID-1, besides being used for routing information or messages from the SRF network element to the AMF network element, can also be used to identify terminal devices for paging. TRID-1 or SRFID+TRID-1 can also be referred to as a temporary identifier for the terminal device.

[0195] Table 1A

[0196]

[0197] Table 1B

[0198]

[0199] In another possible implementation, after successful registration of the terminal device, the AMF network element can also send an Nx1Nx2 transmission request message to the SRF network element. The Nx1Nx2 request response message can include third information (including SRF-GUTI-1) sent to the terminal device, optionally including the terminal device's SUPI. Furthermore, the third information can be a NAS message or information. The SRF network element may not be aware of the content of the third information (e.g., transparently transmitting the third information between the AMF network element and the terminal device). The Nx1Nx2 transmission request message can also include SRF-GUTI-1, which is used by the SRF network element to determine the terminal device corresponding to the message.

[0200] After receiving the Nx1Nx2 transmission request message, the SRF network element can determine the SRF UE NGAP ID (a temporary identifier for terminal equipment allocated by the SRF network element for communication between the RAN node and the SRF) and update the routing table, such as updating tables 1A and 1B mentioned above.

[0201] It is understandable that SRF network elements may not maintain routing tables. SRF-GUTI-1, AMF ID or address, SUPI, RAN ID, NGAP ID pair, and other information can be stored in the context of the terminal device stored by the SRF network element. This information is stored in the context of the same terminal device and is related to each other.

[0202] S1108: The SRF network element sends an initial context setup request message to the RAN node, and the RAN node receives the initial context setup request message accordingly.

[0203] The initial context establishment request message may include third-party information (including SRF-GUTI-1), SRFUE NGAP ID, and RAN UE NGAP ID. The RAN node can determine the terminal device based on the SRF UE NGAP ID (i.e., the NGAP ID assigned to the terminal device by the RAN node) and send the third-party information to the terminal device.

[0204] After receiving the Initial Context Establishment Request message, the RAN node can also store the SRF UE NGAP ID, RAN UENGAP ID, air interface identifier of the terminal device (such as RNTI), SRF UE NGAP ID, RAN UE NGAP ID, and SRFID or address in the context of the terminal device.

[0205] In some embodiments, the initial context establishment request message may further include SRF-GUTI-1, and the RAN node may also store the association between SRF-GUTI-1 and the service type of Access and Mobility Management (i.e., NAS type MM). Subsequently, when the RAN node sends terminal equipment-related messages (such as handover request messages) to the AMF network element, it may carry SRF-GUTI-1 in the message.

[0206] S1109: The RAN node sends third information (including SRF-GUTI-1) to the terminal device, and the terminal device receives the third information accordingly.

[0207] After receiving the third-party information, the terminal device can save the association between SRF-GUTI-1 and the service type of access and mobility management.

[0208] After saving the association between SRF-GUTI-1 and the service type access and mobility management, if there is information or message with the service type access and mobility management (taking the second information as an example), the terminal device sends the second information and SRF-GUTI-1 (or TRID-1 in SRF-GUTI-1) to the RAN node. After receiving the second information and SRF-GUTI-1 (or TRID-1), the RAN node can send an NGAP message to the SRF. The NGAP message can include the second information, SRF-GUTI-1 (or TRID-1), the RAN UE NGAP ID and SRF UE NGAP ID corresponding to the terminal device, and can also include Nx2 parameters (such as the location of the terminal device). When the SRF network element receives the NGAP message, it can send the second information, Nx2 parameters (if they exist), etc. to the AMF network element according to the association between SRF-GUTI-1 (or TRID-1) and the AMF network element. The RAN UENGAP ID and SRF UE NGAP ID corresponding to the terminal device can also be referred to as the UE NGAP ID pair corresponding to the terminal device. That is, the UE NGAP ID pair corresponding to the terminal device includes the RAN UE NGAP ID and SRF UE NGAP ID corresponding to the terminal device.

[0209] In one possible implementation, the SRF network element can also send the identifier of the terminal device and the identifier and / or address of the SRF network element serving the terminal device to the UDM network element. Alternatively, the AMF network element can also send the identifier of the terminal device and the identifier and / or address of the SRF network element serving the terminal device to the UDM network element. The UDM network element can also store the association between the identifier of the terminal device and the identifier and / or address of the SRF network element serving the terminal device. If other NF network elements have downlink information or messages that need to be sent to the terminal device, they can obtain the identifier and / or address of the SRF network element serving the terminal device from the UDM network element based on the identifier of the terminal device, and send an Nx1Nx2 transmission request message to that SRF network element. The Nx1Nx2 transmission request message includes the identifier of the terminal device and the information or message that needs to be sent to the terminal device. The SRF network element then performs downlink routing based on the identifier of the terminal device.

[0210] The terminal device identifier can be used to identify the terminal device between SRF network elements and other NF network elements. This identifier can be the terminal device's SUPI or GPSI, etc. Taking the terminal device's SUPI as an example, refer to... Figure 11A As shown, an SRF network element can send a registration message containing the SUPI and SRFID (identifier of the SRF network element) of the terminal device to a UDM network element, or an AMF network element can send a registration message containing the SUPI and SRFID of the terminal device to a UDM network element. The UDM network element can store the association between the SUPI and SRFID of the terminal device. Other NF network elements can request the identifier of the SRF network element serving the terminal device, i.e., the SRFID, from the UDM network element through the SUPI of the terminal device, thereby identifying the SRF network element serving the terminal device.

[0211] Subsequently, AMF network elements or other NF network elements can send downlink information or messages to the terminal device, including SUPI and other information or messages that need to be sent to the terminal device, to the SRF network element. Figure 11A Taking NAS PDU as an example, when the SRF network element receives the Nx1Nx2 transmission request message, it can determine the RAN ID and NGAP ID pair based on SUPI, and send an NGAP message including the NGAP ID pair and NAS PDU to the RAN node corresponding to the RAN ID. The RAN node then determines the terminal device based on the NGAP ID pair and sends the NAS PDU to the terminal device.

[0212] In some implementations, if the SRF network element context stores the terminal device's SUPI, UE NGAP ID pair, and SRF-GUTI-1 / TRID-1, the information or messages sent by the AMF network element to the terminal device can also be routed downlink by SRF-GUTI-1 / TRID-1 instead of SUPI. The SRF network element can also determine the RAN ID and NGAP ID pair based on SRF-GUTI-1 / TRID-1 for downlink routing.

[0213] pass Figure 11A As can be seen from the communication method shown, the message routing function can be completed by the SRF network element. Even if the AMF network element serving the terminal device is changed, or the AMF entity enters a stateless state, the SRF can update the mapping relationship between the SRF-GUTI-1 (or TRID-1) and the identifier or address of the AMF network element. The RAN node and the terminal device are unaware of this and it will not affect the connection between the RAN node, the terminal device and the AMF network element, or the transmission of information or messages.

[0214] The above Figure 11A This example illustrates how SRF-GUTI-1 is sent from the SRF network element to the AMF network element, and then the AMF network element includes SRF-GUTI-1 in the third information sent to the terminal device. The AMF network element then sends SRF-GUTI-1 to the terminal device using this third information. In some embodiments, the SRF network element can also send SRF-GUTI-1 to the terminal device. For example, the SRF network element can send SRF-GUTI-1 to the RAN node via the Nx2 interface with the RAN node, and the RAN node can then send SRF-GUTI-1 to the terminal device via RRC messages, etc.

[0215] For example: Figure 11B This is the third schematic diagram of the communication method provided in the embodiments of this application, wherein... Figure 11B The implementation of each step can be referred to Figure 11A The implementation of each step is repeated here and will not be elaborated upon again. Figure 11A The difference lies in the following: In step S1107, the third information in the message sent by the AMF network element to the SRF network element does not include SRF-GUTI-1; in step S1108, the message sent by the SRF network element to the RAN node includes both the third information and SRF-GUTI-1; and in step S1109, the RAN node sends SRF-GUTI-1 in addition to the third information to the terminal device. Among these, in... Figure 11B The information that does not include SRF-GUTI-1 can also be called the fourth information.

[0216] The above example illustrates how the first identifier associated with the first network element is assigned by the third network element. It can be understood that the first identifier can also be assigned by other network elements, for example, the first identifier can be assigned by the first network element.

[0217] As an example: A third network element can send a first request message to a first network element to request the allocation of an identifier for a terminal device. Upon receiving the first request message, the first network element can allocate a first identifier and reply to the third network element with a first response message including the first identifier, thereby allocating the first identifier associated with the first network element.

[0218] Understandably, if the first identifier is allocated by the first network element, the third network element may not need to send the first identifier to the first network element to save signaling overhead. For example, the first network element may carry the first information in the first request message. After obtaining the first identifier from the first network element, the third network element may not need to perform the step of sending the first information and the first identifier to the first network element to save signaling overhead.

[0219] The following example will be used to illustrate the concept of the first service being the registration service, the first network element being the AMF network element, the third network element being the SRF network element, and the first identifier being SRF-GUTI-1. Figure 12 This is a fourth schematic diagram of a communication method provided in an embodiment of this application. The method includes:

[0220] S1201: The terminal device sends a registration request message to the RAN node, and the RAN node receives the registration request message accordingly.

[0221] The registration request message may include first information for requesting registration services, the air interface identifier of the terminal device (such as RNTI), and AN parameters (such as slice information). The first information can be NAS information or a message (also called a NAS PDU), and may include information such as the terminal device's SUCI and / or NAS type MM.

[0222] S1202: RAN node selects SRF network element.

[0223] For example, when a RAN node selects an SRF network element, it can select one from at least one SRF network element with an established connection according to a set strategy (such as random, minimum load, etc.), or it can select an SRF network element based on AN parameters, such as selecting an SRF network element that is related to the slice information included in the AN, etc. This application does not limit the way the RAN node selects an SRF network element.

[0224] S1203: The RAN node sends an initial terminal device message to the SRF network element, and the SRF network element receives the initial terminal device message accordingly.

[0225] The initial terminal device message includes first information, and may also include RAN UE NGAP ID (a temporary identifier for the terminal device assigned by the RAN node for communication between the RAN node and the SRF), Nx2 parameters (such as RAN ID (the identifier of the RAN node), location information of the terminal device, etc.).

[0226] S1204: The SRF network element is selected as the AMF network element, where the AMF network element serves the registration service.

[0227] After receiving the initial terminal device message containing the first information, the SRF network element can select the AMF network element that serves the registered service.

[0228] For example, the NAS type (MM) and the location information of the terminal device can be sent to the NRF network element. The NRF network element then selects the AMF network element based on the NAS type (MM) and the location information of the terminal device. The implementation of the SRF network element selecting the AMF network element for the service registration can refer to the implementation of determining the first network element using the third network element described above, and will not be elaborated further.

[0229] S1205: The SRF network element sends an Nx1Nx2 processing request message to the AMF network element, and the AMF network element receives the Nx1Nx2 processing request message accordingly.

[0230] The Nx1Nx2 processing request message may include first information, as well as SRFID (i.e., the identifier of the SRF network element), Nx2 parameters (such as the location of the terminal device), and other information.

[0231] S1206: The AMF network element performs authentication and other operations on terminal devices.

[0232] After receiving a processing request message, the AMF network element can perform operations such as authenticating the terminal device, retrieving the subscription (i.e., obtaining the terminal device's subscription information), and determining the terminal device's mobility management policy. Additionally, the AMF network element can assign an SRF-GUTI-1 to the terminal device.

[0233] The SRF-GUTI structure allocated to any NF network element can be as follows: Figure 13As shown, the SRF-GUTI includes a TRID, and may also include one or more of MCC, MNC, SRFID, etc. The TRID is a unique identifier assigned to the NF network element; the MCC and MNC can uniquely identify the PLMN to which the third network element belongs or to which the terminal equipment is connected; and the SRFID is the identifier of the third network element. Additionally, the SRF-GUTI may also include an NF ID and / or NAS type. The NF ID is the identifier of the NF, and the NAS type corresponds to the type of NAS connection or the type of the NF network element, used to avoid duplicate TRIDs assigned between different NF network elements.

[0234] SRF-GUTI-1 can include TRID-1, and can also include one or more of the following: MCC, MNC, SRFID, MM (i.e., NAStype).

[0235] S1207: The AMF network element sends an Nx1Nx2 processing request response message to the SRF network element, and the SRF network element receives the Nx1Nx2 processing request response message accordingly.

[0236] In one possible implementation, after the terminal device successfully registers, the AMF network element can respond to the Nx1Nx2 processing request message from the SRF network element by sending an Nx1Nx2 processing request response message to the SRF network element. The Nx1Nx2 processing request response message may include third information sent to the terminal device (including SRF-GUTI-1), SRF-GUTI-1, and may also include AMFID (i.e., the identifier of the AMF network element) and the SUPI of the terminal device.

[0237] It is understandable that the third information is the third information sent by the AMF network element to the terminal device. If the SRF network element is unaware of the content of the third information (for example, when the third information is transparently transmitted between the AMF network element and the terminal device), then the SRF-GUTI-1 needs to be carried in the request-response message processed by Nx1Nx2 so that the SRF network element can obtain the SRF-GUTI-1 allocated by the AMF network element. If the SRF network element is aware of the content of the third information, it can obtain the SRF-GUTI-1 allocated by the AMF network element through the third information. In this case, the SRF-GUTI-1 allocated by the AMF network element can be omitted in the request-response message processed by Nx1Nx2 to save signaling overhead.

[0238] After receiving the Nx1Nx2 processing request response message, the SRF network element can determine the SRF UE NGAP ID (a temporary identifier for terminal equipment allocated by the SRF network element for communication between the RAN node and the SRF) and update the routing table.

[0239] As an example: SRF network elements can store the association between SRF-GUTI-1 and AMF ID (the identifier of the AMF network element) in the uplink routing table (wherein, if SRF-GUTI-1 includes AMF ID, this association may not be stored); the downlink routing table stores the association between RAN ID, NFAP ID pair (i.e., RAN UE NGAP ID and SRF UE NGAP ID) and SRF-GUTI-1 (or terminal device SUPI).

[0240] It is understandable that if SRF-GUTI-1 includes TRID-1, and also includes at least one of SRFID, AMF ID, MNC, etc., then TRID-1 in SRF-GUTI-1 can be associated with AMF ID, and the association between TRID-1 and AMF ID can also be stored in the uplink routing table.

[0241] In addition, for registration services (i.e., when the first network element is an AMF network element), TRID-1 or SRFID+TRID-1 can be used not only for routing information or messages from SRF network elements to AMF network elements, but also for identifying terminal devices and for paging terminal devices. TRID-1 or SRFID+TRID-1 can also be called a temporary identifier for terminal devices, a routing identifier, or a global temporary identifier for terminal devices, etc.

[0242] It is understandable that SRF network elements may not maintain routing tables. SRF-GUTI-1, AMF ID or address, SUPI, RAN ID, NGAP ID pair, and other information can be stored in the context of the terminal device stored by the SRF network element. This information is stored in the context of the same terminal device and is related to each other.

[0243] S1208: The SRF network element sends an initial context setup request message to the RAN node, and the RAN node receives the initial context setup request message accordingly.

[0244] The initial context establishment request message may include third-party information (including SRF-GUTI-1), SRFUE NGAP ID, and RAN UE NGAP ID.

[0245] After receiving the Initial Context Establishment Request message, the RAN node can store the SRF UE NGAP ID, RAN UENGAP ID, air interface identifier (such as RNTI) of the terminal device, and SRFID or address in the context of the terminal device.

[0246] In some embodiments, the initial context establishment request message may further include SRF-GUTI-1, and the RAN node may also store the association between SRF-GUTI-1 and the service type of Access and Mobility Management (i.e., NAS type MM). Subsequently, when the RAN node sends terminal equipment-related messages (such as handover request messages) to the AMF network element, it may carry SRF-GUTI-1 in the message.

[0247] S1209: The RAN node sends third information (including SRF-GUTI-1) to the terminal device, and the terminal device receives the third information accordingly.

[0248] After receiving the third-party information, the terminal device can save the association between SRF-GUTI-1 and service type access and mobility management, and use it for sending information or messages of that service type.

[0249] It is understandable that a terminal device can initiate multiple services. For example, after initiating the first service, the terminal device can also initiate the second service.

[0250] For example: After receiving the first identifier and establishing a connection with the first network element serving the first service, the terminal device can also send fifth information to the third network element to request the second service. Upon receiving the fifth information, the third network element can determine the second identifier associated with the second network element, send the fifth information (or the fifth information and the second identifier) ​​to the second network element serving the second service, and send the second identifier to the terminal device. Upon receiving the second identifier, the terminal device can save the second identifier for routing information or messages of the second service to the second network element. The implementation of the third network element determining the second identifier associated with the second network element and sending the second identifier to the terminal device can refer to the implementation of the third network element determining the first identifier associated with the first network element and sending the first identifier to the terminal device, and will not be elaborated further.

[0251] The following explanation uses the example of a second service being PDU session service, a second network element being an SMF network element, a third network element being an SRF network element, and a second identifier being TRID-2 (or SRF-GUTI-2). Figure 14 The fifth schematic diagram of the communication method provided in the embodiments of this application includes:

[0252] S1401: The terminal device sends a PDU session establishment request message to the RAN node, and the RAN node receives the PDU session establishment request message accordingly.

[0253] The PDU session establishment request message may include the fifth piece of information for requesting the PDU session, the air interface identifier of the terminal device (such as RNTI1), and AN parameters (such as slice information). The first piece of information can be NAS information or a message (also called a NAS PDU), and may include information such as the terminal device's SUCI, PDU session ID, and DNN.

[0254] S1402: The RAN node sends an uplink NAS transfer (UL NASTRANSPORT) message to the SRF network element serving the terminal equipment, and the SRF network element receives the uplink NAS transfer message accordingly.

[0255] The uplink NAS transmission message may include the fifth piece of information, the UE NGAP ID pair corresponding to the terminal device, and Nx2 parameters (such as the location information of the terminal device).

[0256] S1403: The SRF network element determines the TRID-2 (or SRF-GUTI-2) associated with the SMF network element, wherein the SMF network element serves the PDU session service.

[0257] For example, an SRF network element can send the DNN and other information to an NRF network element, which then selects an SMF network element based on the DNN and other information. The implementation of the SRF network element selecting the SMF network element to serve the PDU session service can refer to the implementation of the third network element determining the first network element, and will not be elaborated further.

[0258] In addition, the SRF network element can determine that the fifth information is information used to request new services based on the fact that the uplink NAS transmission message does not contain an identifier associated with the network element (such as not containing routing information, or containing routing information but not containing an identifier associated with the network element). It can then allocate a TRID-2 (or SRF-GUTI-2) associated with the SMF network element serving the PDU session service to the terminal device.

[0259] S1404: The SRF network element sends an Nx1Nx2 processing request message to the SMF network element, and the SMF network element receives the Nx1Nx2 processing request message accordingly.

[0260] The Nx1Nx2 processing request message may include TRID-2 (or SRF-GUTI-2), fifth information, and may also include SRFID (i.e., the identifier of the SRF network element), Nx2 parameters (such as the location of the terminal device), and other information.

[0261] S1405: SMF network elements perform operations such as UPF network element selection.

[0262] S1406: The SMF network element sends an Nx1Nx2 processing request response message to the SRF network element, and the SRF network element receives the Nx1Nx2 processing request response message accordingly.

[0263] The Nx1Nx2 processing request response message may include the terminal device's SUPI, the eighth information sent by the SMF network element to the terminal device, and the Nx2 SM info. The eighth information may be NAS information or message (also known as NASPDU), and may include the PDU session ID and the Nx1 SM container. The Nx1 SM container may include TRID-2 (or SRF-GUTI-2). The Nx2 SM info may include the SMF ID or TRID-2 and the tunnel identifier on the UPF network element side.

[0264] After receiving the Nx1Nx2 processing request response message, the SRF network element can update the routing table.

[0265] As an example: the updated uplink routing table can be as shown in Table 2A below, including the association between TRID-2 (or SRF-GUTI-2) and SMF ID (i.e., the identifier of the SMF network element).

[0266] Table 2A

[0267]

[0268] It is understandable that SRF network elements may not maintain routing tables and instead store information such as TRID-2 (or SRF-GUTI-2), SMF ID or address, and PDU session ID in the context of the terminal device. This information is stored in the context of the same terminal device and is interconnected.

[0269] S1407: The SRF network element sends a PDU session resourcesetup request message to the RAN node, and the RAN node receives the PDU session resourcesetup request message accordingly.

[0270] The PDU session resource establishment request message may include the eighth information (including TRID-2 (or SRF-GUTI-2)), UE NGAP ID pair, and Nx2 SM info.

[0271] In some embodiments, the PDU session resource establishment request message may also include TRID-2 (or SRF-GUTI-2). After receiving TRID-2 (or SRF-GUTI-2), the RAN node may store TRID-2 (or SRF-GUTI-2) with the PDU session ID, or store the association between TRID-2 (or SRF-GUTI-2) and the PDU session ID and the NAS type SM. Subsequently, when the RAN node sends session management service related messages (such as session release request messages, handover request messages) of the terminal device's PDU session to the SMF network element, it may carry TRID-2 (or SRF-GUTI-2) in the message.

[0272] S1408: The RAN node sends the eighth message to the terminal device, and the terminal device receives the eighth message accordingly.

[0273] S1409: The terminal device stores the association between TRID-2 (or SRF-GUTI-2) and PDU session ID.

[0274] For example, the terminal device may store the association between TRID-2 (or SRF-GUTI-2) and PDU session ID, or the association between TRID-2 (or SRF-GUTI-2) and PDU session ID and the service type is session management.

[0275] In addition, the RAN node can also send a PDU session resource establishment request response message to the SRF network element, which may include the UENGAP ID pair, the Nx2 SM info sent by the RAN node to the SMF network element (such as the tunnel identifier on the RAN node side), and may also include the SMF ID or TRID-2. The SRF network element can also send the Nx2 SM info and the SUPI of the terminal device to the SMF network element for the establishment of the PDU session.

[0276] Subsequently, if there are uplink messages related to this PDU session, the terminal device can carry TRID-2 (or SRF-GUTI-2) in the uplink message. The SRF network element can send the uplink message or the information included in the uplink message to the SMF network element according to the association between TRID-2 (or SRF-GUTI-2) and the SMF network element.

[0277] For downlink messages of SMF network elements, the downlink message may carry TRID-2 (or SRF-GUTI-2) or SUPI of the terminal device. The SRF network element can determine the RAN ID and NGAP ID pair corresponding to the terminal device based on TRID-2 (or SRF-GUTI-2) or SUPI of the terminal device, and then route the downlink message or the information included in the downlink message to the terminal device through the RAN node serving the terminal device.

[0278] Understandably, in some implementations, the SRF network element may not send TRID-2 to the SMF network element (for example, TRID-2 is not included in step S1404). TRID-2 can be sent directly to the terminal device by the SRF network element to save signaling overhead.

[0279] In one possible implementation, to improve transmission efficiency, information sent by a terminal device to multiple NF network elements can be sent through the same message.

[0280] As an example: The terminal device stores a first identifier associated with a first network element serving a first service and a second identifier associated with a second network element serving a second service. If the terminal device needs to send a sixth message to the first network element and a seventh message to the second network element, the terminal device can send a second message including the sixth message, the seventh message, the first identifier, and the second identifier to the third network element through the RAN node. The sixth message is associated with the first identifier, and the seventh message is associated with the second identifier. The third network element can send the sixth message to the first network element based on the association between the first identifier and the first network element, and send the seventh message to the second network element based on the association between the second identifier and the second network element.

[0281] In some embodiments, after the terminal device enters the idle state, the third network element may not release the context of the terminal device or the routing table corresponding to the terminal device. If the terminal device needs to resume a certain service after entering the idle state (or needs to resume the connection with the NF network element serving a certain service), the message sent by the terminal device to the third network element may include information sent to the NF network element serving the service and an identifier associated with the NF network element. The third network element can route the information sent by the terminal device to the NF network element serving the service to the NF network element according to the identifier associated with the NF network element.

[0282] Understandably, if a terminal device needs to resume multiple services (or resume connections with multiple NF network elements serving multiple services) after entering an idle state, the multiple messages sent by the terminal device to the multiple NF network elements serving multiple services can also be sent to a third network element in the same message to improve transmission efficiency.

[0283] The following example illustrates how a terminal device can restore the first and second services (or restore the connection with the first and second network elements) after entering an idle state, using the following example: the first service is the registration service, the first network element is the AMF network element, the first identifier is TRID-1, the second service is the PDU session service, the second network element is the SMF network element, the second identifier is TRID-2, and the second message is the service request message.

[0284] Figure 15 This is a sixth schematic diagram of a communication method provided in an embodiment of this application. The method includes:

[0285] S1501: The terminal device sends an RRC message to the RAN node, and the RAN node receives the RRC message accordingly, wherein the RRC message includes a service request message.

[0286] As an example: The terminal device registers with the network through the registration service, obtains TRID-1 associated with the AMF network element, and establishes a connection with the AMF network element (such as a NAS connection). Additionally, the terminal device establishes PDU session 1, obtains TRID-2 associated with the SMF network element serving PDU session 1, and establishes a connection with the SMF network element (such as a NAS connection). The terminal device then enters an idle state, and the RAN node releases the terminal device's context (including stored resources such as the RAN UE NGAP ID).

[0287] When the terminal device determines that it needs to restore the connection with the AMF network element and explicitly activate PDU session 1, the service request message may include the sixth information sent to the AMF network element, the TRID-1 associated with the sixth information, and the seventh information sent to the SMF network element, the TRID-2 associated with the seventh information.

[0288] The terminal device's determination to restore the connection with the AMF network element and explicitly activate PDU session 1 can be triggered by paging from the network or by other means, and this application does not limit this.

[0289] Additionally, the RRC message can also include AN parameters, such as SRFID (i.e., the identifier of the SRF network element). The specific form of the SRF ID can be SRFID or information that includes SRFID, such as including the SRF ID in SRF-GUTI-1 or SRF-S-TRID-1. The AN parameters can include SRF-GUTI-1 or SRF-S-TRID-1. The RAN node can determine the SRFID based on SRF-GUTI-1 or SRF-S-TRID-1.

[0290] S1502: RAN nodes determine SRF network elements.

[0291] RAN nodes can determine SRF network elements based on SRFID in the AN parameters.

[0292] S1503: The RAN node sends an initial terminal device message to the SRF network element, and the SRF network element receives the initial terminal device message accordingly.

[0293] The initial terminal device message includes the RAN UE NGAP ID newly assigned to the terminal device by the RAN node, a service request message (or the sixth information, the TRID-1 associated with the sixth information, and the seventh information and the TRID-2 associated with the seventh information included in the service request message), and may also include Nx2 parameters (such as the location information of the terminal device).

[0294] S1504: The SRF network element sends a first Nx1Nx2 processing request message to the AMF network element according to the association relationship between TRID-1 and the AMF network element, and the AMF network element receives the first Nx1Nx2 processing request message accordingly.

[0295] The first Nx1Nx2 processing request message includes the sixth information, and may also include the SUPI of the terminal device, Nx2 parameters (such as the location information of the terminal device), etc.

[0296] S1505: The SRF network element sends a second Nx1Nx2 processing request message to the SMF network element according to the association relationship between TRID-2 and the SMF network element. Correspondingly, the SMF network element receives the second Nx1Nx2 processing request message.

[0297] The second Nx1Nx2 processing request message includes the seventh information, and may also include the SUPI of the terminal device, Nx2 parameters (such as the location information of the terminal device), etc.

[0298] It is understood that in the embodiments of this application, the order of steps S1504 and S1505 is not limited. Step S1504 can be executed first and then step S1505 can be executed, or steps S1504 and S1505 can be executed simultaneously, or step S1505 can be executed first and then step S1504 can be executed.

[0299] In some embodiments, the terminal device may first send the sixth information to the AMF network element, and then send the seventh information to the SMF network element after receiving the response from the AMF network element to the sixth information. This avoids the SMF network element affecting the processing of the seventh information from the terminal device because the terminal device is not in a connected state or has not updated its state information.

[0300] Regarding how the SRF network element determines that the sixth information is sent to the AMF network element, one possible implementation is that the SRF network element can save the information of the AMF network element (NF type) in the context of the terminal device when initiating the registration service before the AMF network element. Alternatively, the terminal device can use the sixth information sent to the AMF network element (i.e., the sixth information corresponding to the access and mobility management service type) as the first information carried in the service request message for the service request. In other words, the SRF network element can use the sixth information sent to the AMF network element as the first NAS PDU, the first NAS payload, etc., in the service request message. For the first information carried in the service request message for the service request (i.e., the sixth information), the SRF network element can determine that this information needs to be sent to the AMF network element.

[0301] Additionally, it is understandable that if the RAN node accessed by the terminal device changes, the RAN UE NGAP ID assigned to the terminal device by the RAN node changes, or the SRF network element reassigns the SRF UE NGAPID to the terminal device, the SRF network element can also update the RAN ID and NGAP ID pair in the routing table or the stored terminal device context.

[0302] In some embodiments, when the RAN node is replaced or the terminal device is paging, the third network element can also update the identifier associated with the NF network element. The terminal device and / or the NF network element can update the identifier associated with the NF network element by sending the identifier before the update and the identifier after the update to the terminal device and / or the NF network element.

[0303] The following example demonstrates how to update the first identifier associated with the first network element. Figure 16 This application provides a schematic diagram of an identifier update process, which includes:

[0304] S1601: The third network element determines the third identifier associated with the first network element.

[0305] For example, in situations such as RAN node replacement or paging of terminal equipment, the first identifier associated with the first network element may be at risk of leakage. For instance, the first identifier might be broadcast for paging terminal equipment. Therefore, in such cases, the third network element can update the first identifier associated with the first network element and determine a new third identifier associated with the first network element to prevent the first identifier associated with the first network element from being leaked.

[0306] S1602: The third network element sends a second request message to the first network element, and the first network element receives the second request message accordingly.

[0307] The second request message may include a first identifier and a third identifier, and may also include the identifier of the terminal device (such as SUPI). After receiving the second request message, the first network element may update the first identifier to the third identifier.

[0308] In some implementations, after receiving the second request message, the first network element can also send a second response message to the third network element. The second response message may include a third identifier, as well as the identifier of the terminal device, the first identifier, etc., which can be used to indicate that the first network element has received the second request message or updated the identifier associated with the first network element.

[0309] S1603: The third network element sends a third request message to the terminal device, and the terminal device receives the third request message accordingly.

[0310] The third request message may include the first identifier and the third identifier, and may also include the identifier of the terminal device (such as SUPI). The third network element can send the third request message to the terminal device through the RAN node. After receiving the third request message, the terminal device can update the first identifier to the third identifier.

[0311] In some implementations, after receiving the third request message, the terminal device can also send a third response message to the third network element. The third response message may include a third identifier, as well as the identifier of the terminal device, a first identifier, etc., which can be used to indicate that the terminal device has received the third request message or updated the identifier associated with the terminal device.

[0312] It is understood that in the embodiments of this application, the order of steps S1602 and S1603 is not limited. Step S1602 can be executed first and then step S1603 can be executed, or steps S1602 and S1603 can be executed simultaneously, or step S1603 can be executed first and then step S1602 can be executed.

[0313] Furthermore, in this embodiment, the protocol used for the connection (or Nx2 interface) between the RAN node and the third network element (such as the SRF network element) is NGAP, and the (temporary) identifier assigned to the terminal device by the RAN node and the third network element is NGIPD, such as RAN UE NGAP ID (the (temporary) identifier assigned to the terminal device by the RAN node) or SRF UE NGAP ID (the (temporary) identifier assigned to the terminal device by the third network element (such as the SRF network element)). It is understood that NGAP is merely an example, and this application does not limit the protocol used for the connection (or Nx2 interface) between the RAN node and the third network element (such as the SRF network element), nor does it exclude the possibility of using other naming conventions for the protocols used in 5G mobile communication networks and other future communication networks. For example, the protocol used for the connection (or Nx2 interface) between the RAN node and the third network element (such as the SRF network element) could also be XX, in which case the (temporary) identifier assigned to the terminal device by the RAN node and the third network element could be XX ID, such as RAN UE XX ID, SRF UE XX ID, etc.

[0314] The communication device provided in the embodiments of this application will now be described. Please refer to... Figure 17 , Figure 17 This is a schematic diagram of a communication device according to an embodiment of this application. The communication device may include units or modules corresponding to all or part of the steps in the above method embodiments, and can be used to execute the steps executed by the third network element, terminal device, or RAN node in the above embodiments. Please refer to the relevant descriptions in the above method embodiments for details.

[0315] like Figure 17 As shown, the communication device 1700 includes a processing unit 1710 and an interface unit 1720, wherein the processing unit 1710 may be a processor or a processing circuit, and the interface unit 1720 may be a transceiver unit or an input / output interface. The communication device 1700 can be used to implement the steps executed by the third network element, terminal equipment, or RAN node in the above embodiments.

[0316] When the communication device 1700 is used to implement the steps performed by the third network element in the above embodiments:

[0317] Interface unit 1720 is used to receive first information from terminal device, the first information being used to request first service;

[0318] Processing unit 1710 is used to determine a first identifier associated with a first network element, the first network element serving a first service;

[0319] The interface unit 1720 is also used to send first information and a first identifier to the first network element; and to send the first identifier to the terminal device, wherein the first identifier is used for routing to the first network element.

[0320] In one possible design, the interface unit 1720 is also used to send a first identifier to the access network device of the serving terminal device.

[0321] In one possible design, the interface unit 1720 is also used to receive a first message from the terminal device, the first message including second information and a first identifier; and to send the second information to the first network element, or to send the second information and the first identifier to the first network element according to the association relationship between the first identifier and the first network element.

[0322] In one possible design, before the processing unit 1710 determines the first identifier associated with the first network element, it is further configured to determine that the message carrying the first information does not contain an identifier associated with the network element; determine that the message type carrying the first information is an initial terminal device message; determine that the message carrying the first information contains network element selection information; or determine that the message type carrying the first information indicates a request to establish a first service, at least one of these.

[0323] In one possible design, the interface unit 1720 is also used to receive third information from the first network element, the third information including a first identifier; when the interface unit 1720 sends the first identifier to the terminal device, it is specifically used to send the third information to the terminal device.

[0324] In one possible design, the interface unit 1720 is also used to receive fourth information from the first network element; when the interface unit 1720 sends the first identifier to the terminal device, it is specifically used to send the fourth information and the first identifier to the terminal device.

[0325] In one possible design, when the processing unit 1710 determines the first identifier associated with the first network element, it is specifically used to send a first request message to the first network element through the interface unit 1720. The first request message is used to request the allocation of an identifier for the terminal device; and to receive a first response message from the first network element, the first response message including the first identifier.

[0326] In one possible design, the interface unit 1720 is further configured to receive fifth information from the terminal device, the fifth information being used to request a second service; the processing unit 1710 is further configured to determine a second identifier associated with the second network element, the second network element serving the second service; the interface unit 1720 is further configured to send the fifth information to the second network element; and to send the second identifier to the terminal device, wherein the second identifier is used for routing to the second network element.

[0327] In one possible design, the terminal device is in an idle state. The interface unit 1720 is also used to receive a second message from the terminal device. The second message includes sixth information, seventh information, a first identifier, and a second identifier, wherein the sixth information is associated with the first identifier and the seventh information is associated with the second identifier. If the first network element is an access and mobility management function network element, the sixth information is sent to the first network element according to the association between the first identifier and the first network element. Upon receiving the response from the first network element to the sixth information, the seventh information is sent to the second network element according to the association between the second identifier and the second network element.

[0328] In one possible design, the terminal device is in an idle state. Interface unit 1720 is also used to receive a second message from the terminal device. The second message includes sixth information, seventh information, a first identifier, and a second identifier. The sixth information is associated with the first identifier, and the seventh information is associated with the second identifier. The sixth information is the first information for requesting services carried in the fourth message. Based on the association between the first identifier and the first network element, the sixth information is sent to the first network element. When the terminal device is in an idle state, the first information for requesting services carried in the second message is the information of the corresponding access and mobility management function network element. Upon receiving the response from the first network element to the sixth information, the seventh information is sent to the second network element based on the association between the second identifier and the second network element.

[0329] In one possible design, when the terminal device is in an idle state, the processing unit 1710 is further configured to determine the identifier of the terminal device based on the first identifier; and to store the association between the identifier of the terminal device and the access network device serving the terminal device.

[0330] In one possible design, the first network element is an access and mobility management function network element, and the interface unit 1720 is also used to send the identifier of the terminal device, the identifier of the third network element, and / or the address to the unified data management network element.

[0331] In one possible design, the first network element is an access and mobility management function network element, and the first network element is also used to send the identifier of the terminal device, the identifier of the third network element and / or the address to the unified data management network element.

[0332] When the communication device 1700 is used to implement the steps performed by the terminal device in the above embodiments:

[0333] Interface unit 1720 is used to send first information to a third network element, the first information being used to request a first service; and to receive a first identifier from a third network element or a first network element, wherein the first network element serves the first service, and the first identifier is associated with the first network element for routing to the first network element;

[0334] The processing unit 1710 is used to store the association between the first identifier and the service identifier and / or service type of the first service.

[0335] In one possible design, the interface unit 1720 is also used to send a first message to a third network element. The first message includes second information and a first identifier, wherein the first message is a message corresponding to the first service.

[0336] In one possible design, interface unit 1720 is also used to send fifth information, which is used to request a second service; and to receive a second identifier from a third network element or a second network element, wherein the second network element serves the second service, and the second identifier is associated with the second network element for routing to the second network element.

[0337] In one possible design, the terminal device is in an idle state, and the interface unit 1720 is also used to send a second message to the third network element. The second message includes a sixth message, a seventh message, a first identifier, and a second identifier, wherein the sixth message is associated with the first identifier and the seventh message is associated with the second identifier.

[0338] In one possible design, the first service is of the type of access and / or mobility management, and the sixth information is the first piece of information carried in the second message for requesting the service.

[0339] When the communication device 1700 is used to implement the steps performed by the RAN node in the above embodiments:

[0340] Interface unit 1720 is used to receive first information from terminal device, the first information being used to request a first service; send the first information to a third network element; and receive a first identifier from the third network element, wherein the first network element serves the first service, and the first identifier is associated with the first network element for routing to the first network element; processing unit 1710 is also used to store the association relationship between the identifier of the terminal device and the first identifier.

[0341] like Figure 18 As shown, this application also provides a communication device 1800, including a processor 1810 and potentially a communication interface 1820. The processor 1810 and the communication interface 1820 are coupled to each other. It is understood that the communication interface 1820 can be a transceiver, input / output interface, input interface, output interface, interface circuit, etc. Optionally, the communication device 1800 may further include a memory 1830 for storing instructions executed by the processor 1810, or storing input data required by the processor 1810 to execute instructions, or storing data generated after the processor 1810 executes instructions. The memory 1830 can be a physically independent unit, or it can be coupled to the processor 1810, or the processor 1810 may include the memory 1830.

[0342] When the communication device 1800 is used to implement the steps executed by the third network element, terminal device or RAN node in the above embodiments, the processor 1810 can be used to implement the function of the processing unit 1710, and the communication interface 1820 can be used to implement the function of the interface unit 1720.

[0343] In this application embodiment, the processor (e.g., processor 1810) can be one or more central processing units (CPUs). If the processor is a CPU, it can be a single-core CPU or a multi-core CPU. The processor can also be one or a combination of several of the following: CPU, general-purpose processor, application-specific integrated circuit (ASIC), digital signal processor (DSP), microprocessor unit (MPU), microcontroller unit (MCU), graphics processing unit (GPU), field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, artificial intelligence processor (AI processor), or neural processing unit (NPU). The processor can implement or execute the methods, steps, and logic block diagrams disclosed in this application embodiment. The steps of the methods disclosed in this application embodiment can be directly manifested as being executed by a hardware processor, or executed by a combination of hardware and software modules within the processor.

[0344] In this embodiment, the memory (e.g., memory 1830) may include, but is not limited to, cache, read-only memory (ROM), random access memory (RAM), synchronous dynamic random access memory (SDRAM), hard disk drive (HDD) or solid-state drive (SSD), erasable programmable read-only memory (EPROM), or compact disc read-only memory (CD-ROM), etc. Memory is any other medium capable of carrying or storing desired program code having an instruction or data structure form and accessible by a computer, but is not limited thereto. The memory in this embodiment may also be a circuit or any other device capable of implementing storage functions for storing computer programs or instructions, and / or data.

[0345] It is understood that the method steps in the embodiments of this application can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium well known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Additionally, the ASIC can reside in a network device or a terminal device. Alternatively, the processor and storage medium can exist as discrete components in the network device or terminal device.

[0346] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one network device, terminal, computer, server, or data center to another network device, terminal, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0347] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0348] Additionally, it should be understood that in the embodiments of this application, the term "exemplary" is used to indicate that it is an example, illustration, or description. Any embodiment or design scheme described as "exemplary" in this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the term "exemplary" is intended to present the concept in a concrete manner.

[0349] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

Claims

1. A communication method, characterized in that, Applied to third-party network elements, including: Receive first information from the terminal device, the first information being used to request a first service; A first identifier is determined to be associated with the first network element, and the first network element serves the first service; Send the first information and the first identifier to the first network element; The first identifier is sent to the terminal device, wherein the first identifier is used for routing to the first network element.

2. The method as described in claim 1, characterized in that, The method further includes: The first identifier is sent to the access network device serving the terminal device.

3. The method as described in claim 1 or 2, characterized in that, The method further includes: Receive a first message from the terminal device, the first message including second information and the first identifier; Based on the association between the first identifier and the first network element, the second information is sent to the first network element, or the second information and the first identifier are sent to the first network element.

4. The method according to any one of claims 1-3, characterized in that, Before determining the first identifier associated with the first network element, the method further includes at least one of the following: It is determined that the message carrying the first information does not contain an identifier associated with a network element; The message type carrying the first information is determined to be an initial terminal device message; It is determined that the message carrying the first information contains network element selection information; or... The message type carrying the first information is determined to indicate a request to establish the first service.

5. The method according to any one of claims 1-4, characterized in that, Before sending the first identifier to the terminal device, the method further includes: Receive third information from the first network element, the third information including the first identifier; Sending the first identifier to the terminal device includes: The third information is sent to the terminal device.

6. The method according to any one of claims 1-4, characterized in that, Before sending the first identifier to the terminal device, the method further includes: Receive the fourth information from the first network element; Sending the first identifier to the terminal device includes: The fourth information and the first identifier are sent to the terminal device.

7. The method according to any one of claims 1-6, characterized in that, The first identifier associated with the first network element is determined, including: Send a first request message to the first network element, the first request message being used to request the allocation of an identifier for the terminal device; Receive a first response message from the first network element, the first response message including the first identifier.

8. The method according to any one of claims 1-7, characterized in that, The method further includes: Receive fifth information from the terminal device, the fifth information being used to request a second service; A second identifier is determined to be associated with the second network element, which serves the second service; Send the fifth information to the second network element; The second identifier is sent to the terminal device, wherein the second identifier is used for routing to the second network element.

9. The method as described in claim 8, characterized in that, The terminal device is in an idle state, and the method further includes: Receive a second message from the terminal device, the second message including sixth information, seventh information, the first identifier, and the second identifier, wherein the sixth information is associated with the first identifier and the seventh information is associated with the second identifier; When the first network element is an access and mobility management function network element, the sixth information is sent to the first network element according to the association between the first identifier and the first network element; Upon receiving the response from the first network element to the sixth information, the seventh information is sent to the second network element based on the association between the second identifier and the second network element.

10. The method as described in claim 8, characterized in that, The terminal device is in an idle state, and the method further includes: A second message is received from the terminal device. The second message includes sixth information, seventh information, the first identifier, and the second identifier. The sixth information is associated with the first identifier, and the seventh information is associated with the second identifier. The sixth information is the first information for requesting services carried in the fourth message. Based on the association between the first identifier and the first network element, the sixth information is sent to the first network element, wherein when the terminal device is in an idle state, the first information carried in the second message for requesting services is the information of the corresponding access and mobility management function network element; Upon receiving the response from the first network element to the sixth information, the seventh information is sent to the second network element based on the association between the second identifier and the second network element.

11. The method as described in claim 3, 9, or 10, characterized in that, The terminal device is in an idle state, and the method further includes: The identifier of the terminal device is determined based on the first identifier; The association between the identifier of the terminal device and the access network device serving the terminal device is stored.

12. The method according to any one of claims 1-11, characterized in that, The first network element is an access and mobility management function network element, and the method further includes: Send the identifier of the terminal device, the identifier of the third network element, and / or the address to the unified data management network element.

13. The method according to any one of claims 1-12, characterized in that, The first network element is an access and mobility management function network element, and the method further includes: The first network element sends the identifier of the terminal device, the identifier of the third network element, and / or the address to the unified data management network element.

14. A communication method, characterized in that, Applied to terminal devices, including: Send first information to the third network element, the first information being used to request the first service; Receive a first identifier from the third network element or the first network element, wherein the first network element serves the first service, and the first identifier is associated with the first network element for routing to the first network element.

15. The method as described in claim 14, characterized in that, The method further includes: Send a first message to the third network element. The first message includes second information and the first identifier, wherein the second information is information corresponding to the first service.

16. The method as described in claim 14 or 15, characterized in that, The method further includes: Save the association between the first identifier and the service identifier and / or service type of the first service.

17. The method according to any one of claims 11-16, characterized in that, The method further includes: Send a fifth message, which is used to request a second service; Receive a second identifier from the third network element or the second network element, wherein the second network element serves the second service, and the second identifier is associated with the second network element for routing to the second network element.

18. The method as described in claim 17, characterized in that, The terminal device is in an idle state, and the method further includes: A second message is sent to the third network element. The second message includes sixth information, seventh information, the first identifier, and the second identifier, wherein the sixth information is associated with the first identifier and the seventh information is associated with the second identifier.

19. The method as described in claim 18, characterized in that, The service type of the first service is access and / or mobility management, and the sixth information is the first piece of information carried in the second message for requesting the service.

20. A communication method, characterized in that, Applied to access network equipment, including: Receive first information from the terminal device, the first information being used to request a first service; Send the first information to the third network element; Receive a first identifier from the third network element, wherein the first network element serves the first service, and the first identifier is associated with the first network element for routing to the first network element.

21. A communication device, characterized in that, It includes modules or units for performing the method as described in any one of claims 1-13; or, it includes modules or units for performing the method as described in any one of claims 14-19, or it includes modules or units for performing the method as described in claim 20.

22. A communication device, characterized in that, The method includes a processor and an interface circuit, the interface circuit being used to input and / or output signals, and the processor being used to implement the method as described in any one of claims 1-13 via logic circuits or execution instructions; or to implement the method as described in any one of claims 14-19; or to implement the method as described in claim 20.

23. A computer program product, characterized in that, It includes a computer program or instructions that, when executed by a processor, cause the method of any one of claims 1-13 to be implemented; or cause the method of any one of claims 14-19 to be implemented; or cause the method of claim 20 to be implemented.

24. A chip system, characterized in that, The chip system includes a processor, which is coupled to a memory for storing computer programs or instructions that, when executed by the processor, implement the method as described in any one of claims 1-13; or, implement the method as described in any one of claims 14-19; or, implement the method as described in claim 20.

25. A computer-readable storage medium, characterized in that, The storage medium stores a computer program or instructions that, when executed by a processor, cause the method as described in any one of claims 1-13 to be implemented; or cause the method as described in any one of claims 14-19 to be implemented; or cause the method as described in claim 20 to be implemented.

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