A communication method and apparatus

Abstract

This application relates to the field of communication technology, and more particularly to a communication method and apparatus, aimed at supporting the selection of NF network elements without affecting network elements with routing functions when new features are introduced into the network. The method can be executed by a fourth network element, and includes: receiving a first message, the first message including first information and a first container, the first information being used by a terminal device to request a first service, and the first container being used to determine the network element serving the first service; sending a first request to the NF selection function network element, the first request including the first container; receiving a first response from the NF selection function network element, the first response including the identifier and / or address of the first network element; and sending a second message to the first network element, the second message including the first information.

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, network elements with routing capabilities (such as AMF network elements) may need to be upgraded accordingly to identify the NF network elements corresponding to the new features. Upgrading network elements with routing capabilities may require operations such as restarting, which may interrupt the connection with RAN nodes and the connection between terminal devices, thus affecting the routing function.

[0004] Therefore, how to support the selection of NF network elements when introducing new network features without affecting network elements with routing functions is a problem that needs to be considered. Summary of the Invention

[0005] This application provides a communication method and apparatus to support the selection of NF network elements when new features are introduced into the network, without affecting network elements with routing functions.

[0006] In a first aspect, embodiments of this application provide a communication method applicable to a fourth network element. The method includes: receiving a first message, the first message including first information and a first container, the first information being used by a terminal device to request a first service, and the first container being used to determine a network element serving the first service; sending a first request to an NF selection function network element, the first request including the first container; receiving a first response from the NF selection function network element, the first response including the identifier and / or address of the first network element; and sending a second message to the first network element, the second message including the first information.

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

[0008] Through the above design, message routing and NF selection functions can be decoupled. The fourth network element can directly send the first container to the NF selection function network element instead of resolving the first container used to determine the network element serving the first service. The NF selection function network element then determines the first network element serving the first service based on the first container. This ensures that the parameters of new features (or new services) do not affect the routing function of the fourth network element, eliminating the need for routing function upgrades. It also supports the selection of NF network elements when new features are introduced into the network without affecting the fourth network element, reducing the complexity of the routing function and improving network flexibility.

[0009] In one possible design, the method further includes: determining a first network element based on a first response.

[0010] In one possible design, the second message also includes the first container.

[0011] Through the above design, the first container can also be sent to the first network element serving the first service. This allows the first network element to select another NF network element serving the terminal device when it no longer serves the terminal device (e.g., when the terminal device leaves the service area of ​​the first network element), thus ensuring the continuity of service to the terminal device. Alternatively, it can be used by the first network element to determine the parameters of the first service, avoiding duplicate service parameters in the first container and the first information in the first message, thereby saving air interface overhead.

[0012] In one possible design, the method further includes: sending a first identifier associated with the first network element to the terminal device; and / or sending the first identifier associated with the first network element to the access network device (i.e., RAN node) serving the terminal device; wherein the first identifier is used for routing to the first network element.

[0013] Using the above method, the fourth network element can determine the first identifier associated with the first network element, and route the information sent by the terminal device or access network device to the first network element according to the first identifier. This avoids parsing and routing based on the information elements in the 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 access network device and the core network, as well as the access management and mobility management functions of the AMF network element.

[0014] In one possible design, before sending the first request to the NF selection function network element, the method further includes: determining that the first message satisfies at least one of the following: the first message includes a first container; the content of the routing information in the first message is empty; the first message does not include routing information; the routing information in the first message is associated with the NF selection function network element; or, the first message includes first indication information, the first indication information indicating NF selection.

[0015] Through the above design, the fourth network element can determine whether the first service requested by the first information request is a new service or a new service session of an existing service type, and has not determined the first network element serving the first service, thereby avoiding the problem of repeatedly determining the NF network element serving the same service and responding to the service execution.

[0016] In one possible implementation, the first container includes at least one of the following: the NF type corresponding to the first service, the data network name (DNN) corresponding to the first service, the network slice information corresponding to the first service, the request type corresponding to the first service, the feature identifier corresponding to the first service, the capability information corresponding to the first service, or the name of the first service.

[0017] Through the above design, the terminal device can encapsulate the parameters used to select the NF network element in the first container, so that the fourth network element can extract the parameters used to select the NF network element without parsing the specific content of the message from the terminal device, which helps to simplify the logic of the fourth network element.

[0018] In one possible implementation, the first request may further include at least one of the following: the radio access technology (RAT) type corresponding to the terminal device, the access type corresponding to the terminal device, the identifier of the terminal device, the location information of the terminal device, or the subscription information of the terminal device.

[0019] The above information helps the NF select function network element to more accurately determine the first network element serving the first service.

[0020] In one possible implementation, the first response further includes the identifier and / or address of at least one second network element, which is used to process the service data corresponding to the terminal device after the first network element. Optionally, the second message also includes the identifier and / or address of at least one second network element.

[0021] Based on the above information, the NF selection function network element can also determine the identifier and / or address of at least one second network element used to process the service data corresponding to the terminal device after the first network element. The second message sent by the fourth network element to the first network element can also include the identifier and / or address of at least one second network element, which is beneficial for the first network element to quickly determine the network element that will subsequently process the service data corresponding to the terminal device.

[0022] In one possible implementation, the first message is a session establishment request message, the first network element is the visited session management function network element of the terminal device, and at least one second network element includes the home session management function network element of the terminal device.

[0023] The above design facilitates the addressing of the home session management function network element of the terminal device when the terminal device is in a home routed (HR) roaming scenario, and the home session management function network element of the terminal device can then perform session establishment operations on the terminal device.

[0024] Secondly, embodiments of this application provide a communication method applicable to a fourth network element. The method includes: receiving an NF discovery request from a terminal device, the NF discovery request including a first container, the first container being used to determine a network element serving a first service; sending a first request to an NF selection function network element, the first request including the first container; receiving a first response from the NF selection function network element, the first response including an identifier and / or address of the first network element; sending an NF discovery response to the terminal device, the NF discovery response including at least one of a first identifier associated with the first network element, an identifier of the first network element, or an address of the first network element, wherein the first identifier is used for routing to the first network element; receiving a third message from the terminal device, the third message including first information, and at least one of a first identifier, an identifier of the first network element, or an address of the first network element, the first information being used to request the first service; and sending the first information to the first network element according to at least one of the first identifier, the identifier of the first network element, or the address of the first network element.

[0025] In this embodiment, the fourth network element can refer to a network element that has message routing (i.e., non-access stratum (NAS) message routing) functionality between the terminal and the core network. Additionally, the fourth network element may also have message routing functionality between the access network device and the core network.

[0026] With the above design, the fourth network element can first discover the first network element serving the first service based on the NF discovery request from the terminal device, and then route the first information sent by the terminal device to the first network element. This simplifies the logic of the fourth network element and avoids the fourth network element caching the first information to be routed.

[0027] In one possible design, the method further includes sending a first identifier to the access network device of the serving terminal device.

[0028] Through the above design, the fourth network element can send the first identifier to the access network equipment of the terminal equipment, so that the terminal equipment of the serving terminal equipment can also send the first service-related message to the first network element through the first identifier.

[0029] In one possible design, the NF discovery request further includes at least one of the following: the identifier of the NF selection function network element, the address of the NF selection network element, or a second identifier associated with the NF selection network element; sending a first request to the NF selection function network element includes: sending a first request to the NF selection function network element based on at least one of the following: the identifier of the NF selection function network element, the address of the NF selection network element, or the second identifier.

[0030] The above design facilitates the selection of NF selection function network elements by the fourth network element.

[0031] In one possible design, the first container includes at least one of the following: the request type corresponding to the first service, the NF type corresponding to the first service, the DNN corresponding to the first service, the network slice information corresponding to the first service, the feature identifier corresponding to the first service, the capability information corresponding to the first service, or the name of the first service.

[0032] Through the above design, the terminal device can encapsulate the parameters used to select the NF network element in the first container, so that the fourth network element can extract the parameters used to select the NF network element without parsing the specific content of the message from the terminal device, which helps to simplify the logic of the fourth network element.

[0033] In one possible implementation, the first request may also include at least one of the following: the RAT type corresponding to the terminal device, the access type corresponding to the terminal device, the identifier of the terminal device, the location information of the terminal device, or the subscription information of the terminal device.

[0034] The above information helps the NF select function network element to more accurately determine the first network element serving the first service.

[0035] In one possible implementation, the NF selection response further includes the identifier and / or address of at least one second network element, which is used to process the service data corresponding to the terminal device after the first network element; sending first information to the first network element includes: sending the first information and the identifier and / or address of at least one second network element to the first network element.

[0036] Based on the above information, the NF selection function network element can also determine the identifier and / or address of at least one second network element used to process the service data corresponding to the terminal device after the first network element. The fourth network element can also send the identifier and / or address of at least one second network element to the first network element, which is beneficial for the first network element to quickly determine the network element that will subsequently process the service data corresponding to the terminal device.

[0037] Thirdly, embodiments of this application provide a communication method that can be applied to a terminal device. Here, 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: determining a first container, the first container being used to determine a network element serving a first service; and sending the first container and first information to a fourth network element, the first information being used to request the first service.

[0038] In one possible implementation, the method further includes: receiving a first identifier from a fourth network element, wherein the first identifier is associated with a first network element and is used for routing to the first network element, the first network element serving a first service.

[0039] In one possible implementation, the first container includes at least one of the following: the NF type corresponding to the first service, the DNN corresponding to the first service, the network slice information corresponding to the first service, the request type corresponding to the first service, the feature identifier corresponding to the first service, the capability information corresponding to the first service, or the name of the first service.

[0040] Fourthly, embodiments of this application provide a communication method that can be applied to a terminal device. Here, 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 a Network Function (NF) discovery request to a fourth network element, the NF discovery request including a first container used to determine a network element serving a first service; receiving an NF discovery response from the fourth network element, the NF discovery response including at least one of a first identifier, an identifier of the first network element, or an address of the first network element, wherein the first network element serves the first service, the first identifier is associated with the first network element, and is used for routing to the first network element; and sending a third message to the fourth network element, the third message including first information, and at least one of the first identifier, the identifier of the first network element, or the address of the first network element, the first information used to request the first service.

[0041] In one possible implementation, the NF discovery request may also include at least one of the following: the identifier of the NF selection function element, the address of the NF selection element, or a second identifier associated with the NF selection element.

[0042] In one possible implementation, the first container includes at least one of the following: the request type corresponding to the first service, the NF type corresponding to the first service, the DNN corresponding to the first service, the network slice information corresponding to the first service, the feature identifier corresponding to the first service, the capability information corresponding to the first service, or the name of the first service.

[0043] Fifthly, embodiments of this application provide a communication method that can be applied to a first network element. The method includes: receiving a second message from a fourth network element, the second message including first information and a first container, the first information being used by a terminal device to request a first service; sending a second request to an NF selection function network element, the second request including the first container; receiving a second response from the NF selection function network element, the second response including the identifier and / or address of a third network element; and sending context information of the terminal device to the third network element.

[0044] In one possible implementation, the first container includes at least one of the following: the NF type corresponding to the first service, the DNN corresponding to the first service, the network slice information corresponding to the first service, the request type corresponding to the first service, the feature identifier corresponding to the first service, the capability information corresponding to the first service, or the name of the first service.

[0045] In one possible implementation, the second request may further include at least one of the following: the RAT type corresponding to the terminal device, the access type corresponding to the terminal device, the identifier of the terminal device, the location information of the terminal device, or the subscription information of the terminal device.

[0046] Sixthly, embodiments of this application provide a communication device that has the function of implementing the methods of any one of the first to fifth aspects described 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 methods of any one of the first to fifth aspects.

[0049] In a seventh aspect, 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 of any one of the first to fifth aspects described 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] Eighthly, embodiments of this application provide a communication system, which includes a fourth network element and a terminal device. The fourth 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 third aspect.

[0053] In one possible design, the system also includes a first network element, which is used to implement the method described in the fifth aspect above.

[0054] Ninthly, embodiments of this application provide a communication system, which includes a fourth network element and a terminal device. The fourth network element is used to implement the method of the second aspect described above; the terminal device is used to implement the method of the fourth aspect described above.

[0055] In a tenth 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 of any one of the first to fifth aspects described above.

[0056] Eleventhly, 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 of any one of the first to fifth aspects described above.

[0057] In a twelfth aspect, 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 any one of the first to fifth aspects described above can be implemented.

[0058] The technical effects that can be achieved by the third to twelfth aspects mentioned above should be referred to the technical effects that can be achieved by the first or second aspects mentioned above, and will not be repeated here. Attached Figure Description

[0059] Figure 1 A schematic diagram of the architecture of the communication network provided in the embodiments of this application;

[0060] Figure 2 This is a schematic diagram of the terminal device registration process provided in an embodiment of this application;

[0061] Figure 3 A schematic diagram of the session establishment process provided in the embodiments of this application;

[0062] Figure 4 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 5 and Figure 6 This is a schematic diagram of the routing architecture provided in an embodiment of this application;

[0064] Figure 7 , Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 This is a schematic diagram of a communication method provided in an embodiment of this application;

[0065] Figure 13 and Figure 14 This is a schematic diagram of the structure of the communication device provided in the embodiments of this application. Detailed Implementation

[0066] 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 problems are similar, their implementations can be mutually referenced, and repeated details will not be repeated.

[0067] Figure 1 A schematic diagram of a possible, non-limiting communication network is shown. (e.g.) Figure 1 As 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.

[0068] 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.

[0069] 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.

[0070] 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 1 Network 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.

[0071] 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 1The 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.

[0072] 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).

[0073] 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.

[0074] 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.

[0075] 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.

[0076] A CN can include multiple network function (NF) network elements, such as access and mobility management function (AMF) network elements, unified data management (UDM) network elements, session management function (SMF) network elements, location management function (LMF) network elements, and network repository function (NRF) network elements. NF network elements can also be simply referred to as NF; for example, an AMF network element can also be called an AMF, and an SMF network element can also be called an SMF. NF network elements can also be abbreviated as "network element." Additionally, a CN can also include network function selection function (NFSF) network elements. An NFSF network element is a network element with NF selection functionality. An NFSF network element can be a new NF network element or an NRF network element, etc., and this application does not limit this.

[0077] To facilitate understanding by those skilled in the art, some terms used in this application are explained below.

[0078] 1) Terminal device (UE) registration process.

[0079] 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:

[0080] Step 1: The UE sends a registration request message to the RAN node.

[0081] 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, etc.

[0082] Step 2: Select AMF network elements for RAN nodes.

[0083] 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.

[0084] Step 3: The RAN node sends an initial UE message to the AMF network element.

[0085] 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).

[0086] 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 previously accessed by the UE (i.e., the old AMF network element); 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 previously accessed by the UE (i.e., the old AMF network element); and the AMF network element performs the authentication server function (AUSF) network element selection.

[0087] Step X: The AMF network element sends an initial context setup request message to the RAN node.

[0088] 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.

[0089] 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 also in the UE context and are interconnected. The SUPI can be obtained by decrypting the UE's SUCI. The AMF UE NGAP ID and RAN UE NGAP ID can be called an NGAP ID pair.

[0090] 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.

[0091] 2) Session establishment process.

[0092] Figure 3 This application provides a schematic diagram of a possible session establishment process, wherein... Figure 3 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:

[0093] Step 1: The UE sends a Protocol Data Unit (PDU) session establishment request message to the AMF network element through the RAN node.

[0094] 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.

[0095] 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.

[0096] Step 2: Select SMF network element from AMF network element.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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).

[0101] 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.

[0102] 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.

[0103] Reference Figure 4 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.

[0104] 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.

[0105] 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.

[0106] 3) 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, timing, priority, or importance of the multiple objects. For example, "first network element" and "second network element" do not indicate a difference in priority or importance between the two network elements.

[0107] 4) 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.

[0108] 5) 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.

[0109] From the above Figure 2 , Figure 3 and Figure 4 As network characteristics and service functions increase, AMF network elements, in addition to routing messages to SMF network elements, also need to route messages to other NF network elements. 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 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 AMF 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 RAN nodes and 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. This necessitates decoupling the message routing function from the AMF network element to prevent the introduction of new network features from affecting message routing between terminal devices and RAN nodes and the core network, as well as the access management and mobility management functions of the AMF network element.

[0110] Reference Figure 5 As shown, this is a message routing architecture based on AMF network elements, consisting of... Figure 5 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 6 The message routing architecture based on the signaling routing function (SRF) network element provided in this application embodiment is composed of... Figure 6 It can be seen that, in Figure 6In 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.

[0111] However, when new features are added to the network, network elements with routing capabilities (such as AMF or SRF network elements) may need to be upgraded accordingly to identify the NF network elements corresponding to the new features. Upgrading network elements with routing capabilities may require operations such as restarting, which may interrupt connections with RAN nodes and connections between terminal devices, thus affecting routing functionality.

[0112] Taking the selection of SMF network elements related to new features as an example: AMF network elements must identify NF selection-related parameters in the request sent by the terminal device, such as DNN and NAS type, in order to determine the corresponding SMF capability and thus make the correct SMF network element selection. This means that even if a certain parameter / feature is essentially unrelated to the AMF network element, the AMF network element must still identify it in order to make the SMF network element selection, which fails to achieve sufficient decoupling.

[0113] Therefore, how to support the selection of NF network elements when introducing new network features without affecting network elements with routing functions is a problem that needs to be considered.

[0114] Based on this, embodiments of this application provide a communication method and apparatus to support the selection of NF network elements without affecting network elements with routing functions when new features are introduced into the network.

[0115] The communication method provided in this application embodiment can be executed by a fourth network element. This fourth network element has routing capabilities, such as message routing (i.e., Nx1 / NAS message routing) between the terminal and the core network, and message routing (i.e., Nx2 message routing) between the RAN node and the core network. Furthermore, this application does not limit the deployment location or specific name of the fourth network element. For example, logically, the fourth network element can be deployed independently, integrated with the RAN node, or integrated with other NF network elements in the CN, etc.; physically, the fourth network element can be deployed as a separate device, on the same device as the RAN node, or on the same device as other NF network elements in the CN, etc. Taking the fourth network element as an SRF network element as an example, refer to... Figure 6 As shown, the SRF network element 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. It is understandable that the fourth network element can also be an AMF network element with routing capabilities, or a RAN node, etc.

[0116] Furthermore, in this embodiment of the application, taking the access and mobility management function network element as AMF, the session management function network element as SMF, the unified data management network element as UDM, the network storage function network element as NRF, and the network function selection network element as NFSF as an example, it is understood that this application does not exclude the possibility of using other names for each network element in 5G mobile communication networks and other future communication networks. For example, in future communication networks, some or all of the above-mentioned core network network elements may use the terminology from 5G networks, or they may use other names.

[0117] 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.

[0118] Figure 7 This is one of the schematic diagrams of a communication method provided in an embodiment of this application. The method includes:

[0119] S701: The terminal device sends the first message, and correspondingly, the fourth network element receives the first message.

[0120] The first message includes first information and a first container. The first information is used by the terminal device to request the first service, and the first container is used to determine the network element serving the first service.

[0121] In this embodiment, the first information may refer to information 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 session establishment, or information for requesting location services, etc. The terminal device can request services such as registration, session establishment, or location services from the core network by sending the first information; the first message may be a registration request message, a PDU session establishment request message, a location service request message, etc.

[0122] The first container, also known as the NF selection container, can include (or encapsulate) one or more parameters used for determining (or selecting) NF network elements. The terminal device can encapsulate the parameters used to determine the network element serving the first service within the first container.

[0123] The first container may include one or more of the following information: the NF type corresponding to the first service, the DNN corresponding to the first service, the network slice information corresponding to the first service, the request type corresponding to the first service, the feature identifier corresponding to the first service, the capability information corresponding to the first service, and the name of the first service. The request type, also known as the NAS type, indicates the function of the first service, i.e., what process or service the terminal device requests. This can be the functional type of the process or service, or the specific type of process or service, such as access and mobility management, session management, or requests for registration, session establishment, session modification, establishing location services, establishing sensing services, establishing artificial intelligence services, etc. The feature identifier identifies the features that the selected or determined network element should support, such as processing features based on PDU sets, redundant transmission features, dual-direction features, etc. The capability information can be used to identify the capabilities that the selected NF network element should possess.

[0124] For example: the first information is used to request a session establishment service. The NF type corresponding to the session establishment service is SMF and the DNN is DNN1. Then the first container can include information with NF type SMF and DNN1.

[0125] Alternatively, if the first information is used to request registration services, and the NF type corresponding to the registration service is AMF, and the request type is registration service or access and mobility management, then the first container can include NF type AMF, request type registration service or mobility management.

[0126] For a first message that includes first information and a first container, the terminal device can send it to the fourth network element through the RAN node serving the terminal device (or the RAN node to which the terminal device is connected). It is understandable that when the first message is sent to the fourth network element through the RAN node, the first message may undergo necessary processing at the RAN node, such as format changes.

[0127] For example: After receiving the first message, the RAN node can send an Nx2 message to the fourth network element through the Nx2 interface between the RAN node and the fourth network element. The Nx2 message can carry the first message. Alternatively, after receiving the first message, the RAN node can send an Nx2 message to the fourth network element through the Nx2 interface between the RAN node and the fourth network element. The Nx2 message can carry the content of the first message, such as: the first information and the first container.

[0128] S702: The fourth network element sends a first request to the NF selection function network element. Correspondingly, the NF selection function network element receives the first request, which includes the first container.

[0129] S703: The NF selection function network element sends a first response to the fourth network element, and the fourth network element receives the first response accordingly. The first response includes the identifier and / or address of the first network element.

[0130] In this embodiment, the NF selection function network element can be a network element with NF selection function, such as an NRF network element, an NFSF network element, or an AMF network element. The NF selection function network element can store information about multiple NF network elements, such as one or more of the following: identifier (e.g., ID), address (e.g., Internet Protocol (IP) address), type, capability information, and characteristic information of multiple NF network elements.

[0131] Specifically, information about NF network elements can be reported by the NF network element to the NF selection function network element when the NF network element joins the network. For example, when an NF network element joins the network, it can send a registration message to the NF selection function network element. This registration message can include one or more of the following information: the NF network element's identifier, address, type, capability information, and characteristic information. Alternatively, the NF selection function network element can request the NF network element to report its identifier, address, type, capability information, and characteristic information by sending a registration message to the NF network element. This application does not limit the method by which the NF selection function network element obtains information from the NF network element.

[0132] After receiving the first message, the fourth network element can send a first request, including the first container, directly to the NF selection function network element without parsing the contents of the first container. After receiving the first request, the NRF network element can determine the first network element serving the first service based on the first container.

[0133] As an example: The first container includes an NF of type AMF and a request type of access and mobility management. The NF selection function network element can determine that the first service is an access and mobility management related service (such as a registration service), select an AMF network element, and reply to the fourth network element with a first response including the identifier and / or address of the AMF network element.

[0134] As another example: The first container includes DNN1 and slice information 1. The NF selection function network element can determine that the first service is a session management related service (such as session establishment), and can select the SMF network element associated with the DNN and slice information 1, and reply to the fourth network element with a first response including the identifier and / or address of the SMF network element.

[0135] In some implementations, the first request may also include general NF selection parameters, which can be obtained by the fourth network element from the RAN node of the serving terminal device. These general NF selection parameters may include at least one of the following: the radio access technology (RAT) type corresponding to the terminal device (e.g., 4G or 5G), the access type corresponding to the terminal device (e.g., 3GPP access and non-3GPP access), the identifier of the terminal device, or the location information of the terminal device. The NF selection function network element can also select a first network element serving the first service based on the first container and the general NF selection parameters.

[0136] As an example: the first container includes DNN1, and the first request also includes the location of the terminal device. An SMF network element associated with the DNN1 can be selected. If multiple SMF network elements are associated with the DNN1, the NF selection function network element can select an SMF network element whose location meets certain conditions (such as being the closest or having a distance less than a set distance threshold) from the terminal device's location, and reply to the fourth network element with a first response including the identifier and / or address of the SMF network element. This application does not limit the method by which the NF selection function network element determines the first network element serving the first service based on the first container (or the first container and general NF selection parameters).

[0137] In some implementations, before the fourth network element sends the first request to the NF selection function network element, it can also determine that the first message meets at least one of the following conditions: the first message includes a first container; the routing information in the first message is empty; the first message does not include routing information; the routing information in the first message is associated with the NF selection function network element (e.g., including the NF selection function network element identifier or address); or the first message includes first indication information, which indicates that NF selection should be performed. If the first message meets at least one of the above conditions, the fourth network element can determine that the first service is a new service or a new service session of an existing service type, and has not previously determined the first network element serving the first service, thereby avoiding the problem of repeatedly determining the NF network element serving the same service and responding to service execution issues.

[0138] S704: The fourth network element sends a second message to the first network element, and the first network element receives the second message accordingly. The second message includes the first information.

[0139] Upon receiving the first response from the NF selection function network element, the fourth network element can determine the first network element serving the first service based on the response. For example, the fourth network element can determine the identifier and / or address carried in the first response as the identifier and / or address of the first network element serving the first service.

[0140] After the fourth network element determines the first network element serving the first service, it can send a second message carrying the first information to the first network element. Upon receiving the second message, the first network element can perform service processing based on the first information. The second message can be an Nx1Nx2 handling request message, etc., and this application does not limit the second message.

[0141] Taking the first information as the information used to request registration services, and the first network element as the AMF network element as an example, after the fourth network element receives the first information and the first container, it can cache the first information and send a first request including the first container to the NF selection function network element. After receiving the first response message from the NF selection function network element including the identifier and / or address of the AMF network element, the fourth network element can send a second message to the AMF network element according to the identifier and / or address of the AMF network element. The second message includes the cached first information. After receiving the second message, the AMF network element can perform subsequent registration processing on the terminal device according to the first information, 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.

[0142] In some embodiments, the fourth network element may further determine a first identifier associated with the first network element, and store the association between the first identifier and the first network element (such as the identifier and / or address of the first network element), and may send the first identifier to the terminal device and / or the RAN node serving the terminal device, wherein the first identifier is used for routing to the first network element.

[0143] 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. Then, after the fourth network element receives the message containing the first identifier from the terminal device, it can route the message or the information carried in the message to the first network element based on the association between the first identifier and the first network element (such as the identifier and / or address of the first network element).

[0144] 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.

[0145] Alternatively, the first information can be used for PDU session establishment 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.

[0146] Similarly, after receiving the first identifier, the RAN node can 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 needs to send information (or messages) corresponding to this service identifier and / or service type, 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 to be sent. Then, after the fourth network element receives a message from the RAN node including the first identifier, it can route the message or the information carried in the message to the first network element based on the association between the first identifier and the first network element (such as the identifier and / or address of the first network element).

[0147] 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.

[0148] Alternatively, the first information can be used for PDU session establishment 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.

[0149] It is understood that the first identifier associated with the first network element can be assigned by the fourth network element or by other NF network elements (such as the first network element), and this application does not limit this.

[0150] In some embodiments, the fourth network element may also send a first container used to determine the network element serving the first service to the first network element. For example, the second message sent to the first network element may include not only the first information for requesting the first service, but also the first container. When the first network element no longer serves the terminal device (e.g., the terminal device leaves the service area of ​​the first network element, or the first network element needs to offload the load to other network elements), the first network element may send a second request including the first container to the NF selection function network element. The NF selection function network element, based on the first container, re-determines the third network element serving the terminal device, and obtains the identifier and / or address of the third network element through the third response from the NF selection function network element, and sends the context information of the terminal device to the third network element, so that the third network element continues to provide services to the terminal device.

[0151] The following explanation uses the following example: the first service is PDU session establishment service, the first network element is SMF network element, the fourth network element is SRF network element, the NF selection function network element is NFSF network element, and the terminal device is in a non-roaming scenario or a local breakout (LBO) roaming scenario. Figure 8 This is a second schematic diagram of a communication method provided in an embodiment of this application. The method includes:

[0152] S801: The terminal device sends the first message to the RAN node, and the RAN node receives the first message accordingly.

[0153] The first message may include first information for requesting the establishment of a PDU session (such as a PDU session establishment request) and a first container for determining the network element serving the PDU session. Optionally, the first message may also include AN parameters (such as slice information) sent by the terminal device to the RAN node.

[0154] The first information may include information such as PDU session ID, and the first container may include at least one of the following: the name of the first service, PDU session, DNN1 corresponding to the PDU session, or slice information 1 corresponding to the PDU session.

[0155] S802: The RAN node sends an uplink NAS transmission (e.g., UL NASTRANSPORT) message to the SRF network element serving the terminal equipment, and the SRF network element receives the uplink NAS transmission message accordingly.

[0156] Among them, the SRF network element serving the terminal device can be selected by the RAN node when the terminal device registers with the network. For example, the RAN node can select an SRF network element 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 according to 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 the SRF network element.

[0157] The uplink NAS transmission message may include a first message or the content of the first message, that is, it may include the first information or the first container. It may also include Nx2 parameters. The Nx2 parameters may include at least one of the general NF selection parameters, such as the location information of the terminal device.

[0158] S803: The SRF network element sends a first request to the NFSF network element, and the NFSF network element receives the first request accordingly.

[0159] The first request may be an NF selection request, etc., and this application does not limit the name of the first request. The first request includes a first container, and may also include general NF selection parameters and the identifier of the terminal device (such as SUPI).

[0160] In some embodiments, to avoid repeatedly determining the NF network element serving the same service, the SRF network element may determine, before sending the first request to the NFSF network element, that the first message satisfies at least one of the following conditions: the first message includes a first container; the routing information in the first message is empty; the first message does not include routing information; the routing information in the first message is associated with the NFSF network element (e.g., including a second identifier associated with the NFSF network element, the identifier of the NFSF network element, etc.); or the first message includes first indication information, which indicates NF selection. If the PDU session establishment request message satisfies at least one of the above conditions, the SRF network element can determine that the PDU session service is a new PDU session service and that a network element serving the PDU session service needs to be selected.

[0161] In addition, SRF network elements can also cache the first information to be routed, and optionally cache Nx2 parameters, the first container, etc.

[0162] S804: The NFSF network element sends a first response to the SRF network element, and the SRF network element receives the first response accordingly.

[0163] The first response may be an NF selection response, etc., and this application does not limit the name of the first response. The first response includes the identifier and / or address of the SMF network element.

[0164] After receiving the first request, the NFSF network element can select an SMF network element based on the first container, or the first container and the NF selection general parameters. For example, if the first container includes DNN1 and the NF selection general parameters include the location of the terminal device, the NF element can select an SMF network element associated with DNN1. If multiple SMF network elements are associated with DNN1, the NF selection function network element can select an SMF network element whose location meets certain conditions (such as being the closest or having a distance less than a set distance threshold) from the terminal device.

[0165] In one possible implementation, the NFSF network element can obtain the terminal device's subscription data from the UDM network element through the terminal device's identifier. The NFSF network element can also select the SMF network element based on the terminal device's subscription data (such as whether the terminal device uses LBO roaming, etc.), the first container, and the NF selection general parameters.

[0166] As an example: If an NFSF network element determines that a terminal device is in roaming access based on the terminal device's identifier (e.g., the identifier of the public land mobile network (PLMN) included in the terminal device's identifier is different from the identifier of the PLMN to which the NFSF network element belongs), then it uses the terminal device's identifier to request the terminal device's subscription data from the UDM network element of the terminal device's home location. Based on the terminal device's subscription information, it determines that the terminal device is using LBO roaming. Then, the NFSF network element can determine the SMF network element of the roaming location based on the first container.

[0167] It is understandable that the subscription information of the terminal device can also be obtained by the NRF network element from the UDM network element through the identifier of the terminal device and sent to the NFSF network element. For example, the subscription information of the terminal device can also be included in the first request. This application does not limit the method by which the NFSF network element obtains the subscription information of the terminal device.

[0168] S805: 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.

[0169] The Nx1Nx2 processing request message includes 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), first container and other information.

[0170] In some embodiments, the SRF network element may also determine a first identifier associated with the SMF network element (such as the identifier and / or address of the SMF network element) for routing to the SMF network element. The first identifier may also be included in the Nx1Nx2 processing request message sent by the SRF network element to the SMF network element.

[0171] S806: SMF network elements perform operations such as UPF network element selection.

[0172] For example, SMF network elements can perform PDU session establishment-related operations such as UPF network element selection.

[0173] S807: The SMF network element sends an Nx1Nx2 processing response message to the SRF network element, and the SRF network element receives the Nx1Nx2 processing response message accordingly.

[0174] The Nx1Nx2 processing response message includes second information sent by the SMF network element to the terminal device, and may also include third information. The second information may be NAS information or message (also known as NAS PDU), and may include PDU session ID and first identifier. The third information may include SMF ID or first identifier, tunnel identifier on the UPF network element side, PDU session ID, etc.

[0175] Specifically, the Nx1 and Nx2 processing response messages can include the second and third information respectively, or the Nx1 and Nx2 processing response messages can include a fourth information, which includes the second and third information, and the fourth information includes the name of the Nx2 message when the SRF network element sends the Nx2 message to the RAN network element.

[0176] The Nx1 and Nx2 response messages are used by SMF network elements to send second information to terminal devices and / or third information to RAN nodes via SRF network elements. The message name is not limited and can be replaced with Nx1 / Nx2 transmission request messages, etc.

[0177] It is understandable that the second information in the Nx1Nx2 processing response message can be a separate information element, such as an Nx1 information container, or it can be included in other information. Similarly, the third information can also be a separate information element, such as an Nx2 information container, or it can be included in other information.

[0178] As an example, the Nx1Nx2 processing response message includes an Nx1 information container, an Nx2 information container, and an Nx2 message type indicator. The SRF network element generates an Nx2 message (e.g., based on the Nx1 information container, Nx2 information container, and Nx2 message type indicator) to send to the RAN node. Figure 8 The fourth message in the Nx2 message type indicator has a name (type) that is determined by the Nx2 message type indicator.

[0179] As another example, the Nx1Nx2 processing response message includes an Nx2 information container. This Nx2 information container includes second information and may also include third information based on the needs of the first network element. The Nx2 information container can be used to instruct the SRF network element to send an Nx2 message to the RAN node (e.g., ...). Figure 8 The Nx2 message name used when sending the Nx2 message to the RAN node (i.e., the Nx2 information container itself is an Nx2 message encapsulated by the first network element that does not include the UE NGAP ID pair (such as RAN UE NGAP ID (a temporary identifier for terminal equipment between the RAN node and the SRF network element assigned by the RAN node) and SRF UE NGAP ID (a temporary identifier for terminal equipment between the RAN node and the SRF network element assigned by the SRF network element)). The SRF network element only needs to send this container and the UE NGAP ID pair to the RAN node, without needing additional logic to generate the Nx2 message. Alternatively, the Nx2 information container may also include an Nx2 message type indicator, which indicates the Nx2 message name used by the SRF network element when sending the Nx2 message to the RAN node.

[0180] S808: The SRF network element sends a fourth message to the RAN node, and the RAN node receives the fourth message accordingly.

[0181] The fourth message includes the second information, and may also include the third information, and may also include the RAN UE NGAP ID (a temporary identifier for terminal equipment assigned by the RAN node for use between the RAN node and the SRF network element) and the SRF UE NGAP ID (a temporary identifier for terminal equipment assigned by the SRF network element for use between the RAN node and the SRF network element).

[0182] In some embodiments, the third information may further include a first identifier. After receiving the first identifier, the RAN node may store the first identifier and the PDU session ID, or store the association between the first identifier 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 and handover request messages) related to the PDU session of the terminal device to the SMF network element, the first identifier may be carried in the message.

[0183] S809: The RAN node sends the second information to the terminal device, and the terminal device receives the second information accordingly.

[0184] S810: The terminal device stores the association between the first identifier and the PDU session ID.

[0185] For example, the terminal device may store the association between the first identifier and the PDU session ID, or the association between the first identifier, the PDU session ID, and the service type of session management.

[0186] Subsequently, if there are uplink messages related to the PDU session, the terminal device can carry the first identifier 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 the first identifier and the SMF network element.

[0187] In addition, the RAN node can also send a PDU session resource establishment request response message to the SRF network element. This message may include the fifth information (such as the tunnel identifier on the RAN node side) sent by the RAN node to the SMF network element, as well as the SMF ID or the first identifier. The SRF network element may also send the fifth information and the identifier of the terminal device to the SMF network element for the establishment of the PDU session.

[0188] Understandably, in some implementations, the SRF network element may not send the first identifier to the SMF network element (for example, the first identifier is not included in step S805). The first identifier can be sent directly to the terminal device by the SRF network element (for example, sent to the terminal device through the RAN node) to save signaling overhead.

[0189] In some embodiments, after the NF selection function network element receives a first request from a fourth network element including a first container, if the first service requested by the terminal device requires processing by multiple (same or different types) NF network elements, the response from the NF selection function network element to the fourth network element may include information about the multiple NF network elements, or path information. In addition to the identifier and / or address of the first network element, the information (or path info) of the multiple NF network elements may also include the identifier and / or address of at least one second network element, wherein the at least one second network element can be an NF network element used to process the first service after the first network element.

[0190] The following explanation uses the following example: the first service is PDU session establishment service, the first network element is SMF network element, the fourth network element is SRF network element, and the NF selection function network element is NFSF network element. Figure 9 This is the third schematic diagram of a communication method provided in an embodiment of this application. The method includes:

[0191] S901: The terminal device sends the first message to the RAN node, and the RAN node receives the first message accordingly.

[0192] The first message may include first information for requesting the establishment of a PDU session (such as a PDU session establishment request) and a first container for determining the network element serving the PDU session. Optionally, the first message may also include AN parameters (such as slice information) sent by the terminal device to the RAN node.

[0193] The first information may include information such as PDU session ID, and the first container may include at least one of the following: the type of the first service is requesting to establish a session, the DNN1 corresponding to the PDU session, or the slice information 1 corresponding to the PDU session.

[0194] S902: The RAN node sends an uplink NAS transmission message to the SRF network element serving the terminal equipment, and the SRF network element receives the uplink NAS transmission message accordingly.

[0195] Among them, the SRF network element serving the terminal device can be selected by the RAN node when the terminal device registers with the network. For example, the RAN node can select an SRF network element 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 according to 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 the SRF network element.

[0196] The uplink NAS transmission message may include a first message or the content of the first message, that is, it may include the first information or the first container. It may also include Nx2 parameters. The Nx2 parameters may include at least one of the general NF selection parameters, such as the location information of the terminal device.

[0197] S903: The SRF network element sends a first request to the NFSF network element, and the NFSF network element receives the first request accordingly.

[0198] The first request may be an NF selection request, etc., and this application does not limit the name of the first request. The first request includes a first container, and may also include general NF selection parameters and the identifier of the terminal device (such as SUPI).

[0199] In some embodiments, to avoid repeatedly determining the NF network element serving the same service, the SRF network element may, before sending the first request to the NFSF network element, determine that the first message satisfies at least one of the following conditions: the first message includes a first container; the routing information in the first message is empty; the first message does not include routing information; the routing information in the first message is associated with the NFSF network element (e.g., including a second identifier associated with the NFSF network element, the identifier of the NFSF network element, etc.); or the first message includes first indication information, which indicates NF selection. If the first message satisfies at least one of the above conditions, the SRF network element can determine that the PDU session service is a new PDU session service and that a network element serving the PDU session service needs to be selected.

[0200] In addition, SRF network elements can cache the first information to be routed, and optionally also cache Nx2 parameters, the first container, etc.

[0201] S904: The NFSF network element sends a first response to the SRF network element, and the SRF network element receives the first response accordingly.

[0202] The first response can be an NF selection response, etc., and this application does not limit the name of the first response. The first response includes the identifier and / or address of the SMF network element, and the identifier and / or address of at least one second network element (such as a PCF network element, a charging function (CHF) network element, etc.).

[0203] After receiving the first request, the NFSF network element can select an SMF network element and at least one second network element based on the first container, or the general parameters for selecting the first container and the NF. For example, for PDU session establishment services, after the SMF network element completes its processing, the PCF network element and CHF network element are still needed for processing. Therefore, in the first response, in addition to carrying the identifier and / or address of the SMF network element, the identifier and / or address of the PCF network element and CHF network element can also be carried.

[0204] Understandably, to facilitate the identification of the processing order of the first service by NF network elements, NFSF network elements can sort the identifiers and / or addresses of SMF network elements (i.e., the first network element) and at least one second network element in the first response according to the processing order. For example, if the identifiers of SMF network elements, PCF network elements, and CHF network elements are arranged in the order of SMF network elements, PCF network elements, and CHF network elements, then the processing order of the first service is SMF network elements, PCF network elements, and CHF network elements.

[0205] In one possible implementation, the NFSF can also obtain the terminal device's subscription data from the UDM network element through the terminal device's identifier. The NFSF network element can also select the SMF network element and at least one second network element (such as the PCF network element or CHF network element) based on the terminal device's subscription data (such as whether the terminal device uses LBO roaming), the first container, and the NF selection general parameters.

[0206] As an example: If an NFSF network element determines that a terminal device is in roaming access based on the terminal device's identifier, it will use the terminal device's identifier to request the terminal device's subscription data from the UDM network element of the terminal device's home location. Based on the terminal device's subscription information, it will determine that the terminal device is using LBO roaming. Then, the NFSF network element can determine the SMF network element, PCF network element, and CHF network element of the roaming location based on the first container.

[0207] S905: 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.

[0208] The Nx1Nx2 processing request message includes 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), first container and other information.

[0209] In addition, the Nx1Nx2 processing request message also includes path information, which includes the identifier and / or address of at least one second network element.

[0210] In some embodiments, the SRF network element may also determine a first identifier associated with the SMF network element (such as the identifier and / or address of the SMF network element) for routing to the SMF network element. The first identifier may also be included in the Nx1Nx2 processing request message sent by the SRF network element to the SMF network element.

[0211] S906: The SMF network element determines the second network element of the next hop in the PDU session flow based on the path information.

[0212] S907: The SMF network element sends a service message to the second network element of the next hop.

[0213] For example: The path information includes the identifier of the PCF network element and the identifier of the CHF network element. The SMF network element can determine that the second network element of the next hop is the PCF network element based on the identifier of the PCF network element and the identifier of the CHF network element, and continue to send service messages to the PCF network element, such as sending a session policy association request message to the PCF network element. The service message may include the above-mentioned path information.

[0214] In some embodiments, if the terminal device is in a home routed (HR) roaming scenario, the first message is a session establishment request message. The first network element determined by the NF selection function network element can be the visited SMF (V-SMF) network element of the terminal device, and at least one second network element includes the home SMF (H-SMF) network element of the terminal device, which is used for session establishment.

[0215] The following explanation uses the following scenario as an example: the first service is PDU session establishment service, the first network element is V-SMF network element, at least one second network element including H-SMF network element, the fourth network element is SRF network element, the NF selection function network element is V-NFSF network element, and the terminal device is in an HR roaming scenario. Figure 10 This is a fourth schematic diagram of a communication method provided in an embodiment of this application. The method includes:

[0216] S1001: The terminal device sends the first message to the RAN node, and the RAN node receives the first message accordingly.

[0217] The first message may include first information for requesting the establishment of a PDU session and a first container for determining the network element serving the PDU session. Optionally, the first message may also include AN parameters (such as slice information) sent by the terminal device to the RAN node.

[0218] The first information may include information such as PDU session ID, and the first container may include at least one of the following: the type of the first service is requesting to establish a session, the DNN1 corresponding to the PDU session, or the slice information 1 corresponding to the PDU session.

[0219] S1002: The RAN node sends an uplink NAS transmission message to the SRF network element serving the terminal equipment, and the SRF network element receives the uplink NAS transmission message accordingly.

[0220] Among them, the SRF network element serving the terminal device can be selected by the RAN node when the terminal device registers with the network. For example, the RAN node can select an SRF network element 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 according to 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 the SRF network element.

[0221] The uplink NAS transmission message may include a first message or the content of the first message, that is, it may include the first information or the first container. It may also include Nx2 parameters. The Nx2 parameters may include at least one of the general NF selection parameters, such as the location information of the terminal device.

[0222] S1003: The SRF network element sends a first request to the V-NFSF network element, and the V-NFSF network element receives the first request accordingly.

[0223] The first request may be an NF selection request, etc., and this application does not limit the name of the first request. The first request includes a first container, and may also include general NF selection parameters and the identifier of the terminal device (such as SUPI).

[0224] In some embodiments, to avoid repeatedly determining the NF network element serving the same service, the SRF network element may, before sending the first request to the V-NFSF network element (i.e., the visited NFSF network element of the terminal device), determine that the first message satisfies at least one of the following conditions: the first message includes a first container; the routing information in the first message is empty; the first message does not include routing information; the routing information in the first message is associated with the V-NFSF network element (e.g., including a second identifier associated with the V-NFSF network element, the identifier of the V-NFSF network element, etc.); or the first message includes first indication information, which indicates NF selection. If the first message satisfies at least one of the above conditions, the SRF network element can determine that the PDU session service is a new PDU session service and that a network element serving the PDU session service needs to be selected.

[0225] In addition, SRF network elements can cache the first information to be routed, and optionally, they can also cache Nx2 parameters, the first container, etc.

[0226] S1004: The V-NFSF network element sends a first response to the SRF network element, and the SRF network element receives the first response accordingly.

[0227] The first response can be an NF selection response, etc., and this application does not limit the name of the first response. The first response includes the identifier and / or address of the V-SMF network element and the identifier and / or address of the H-SMF network element.

[0228] In one possible implementation, the V-NFSF network element can determine whether a terminal device needs to perform HR roaming based on the terminal device's identifier and subscription data (such as whether the terminal device uses HR roaming, or supports DNNs that use HR roaming). The V-NFSF network element can determine the V-SMF network element and H-SMF network element based on the first container, or the first container and NF selection general parameters. The subscription information of the terminal device can be obtained by the V-NFSF network element from the UDM network element.

[0229] Optionally, the H-SMF network element can be determined by the V-NFSF network element requesting the home HFSF network element (i.e., the H-NFSF network element) of the terminal device. As an example: the V-NFSF network element can send a first container (or a first container and NF common selection parameters) to the H-NFSF network element. The H-NFSF network element can determine the H-SMF network element based on the first container (or the first container and NF common selection parameters) and send an NFSF container to the V-NFSF network element, containing the identifier and / or address of the H-SMF network element.

[0230] Understandably, to facilitate the identification of the processing order of the first service by NF network elements, V-NFSF network elements can sort V-SMF network elements and H-SMF network elements and / or addresses according to the processing order in the first response. For example, they can be arranged in the order of the V-SMF network element identifier and / or address, and the H-SMF network element identifier and / or address.

[0231] S1005: The SRF network element sends an Nx1Nx2 processing request message to the V-SMF network element, and the V-SMF network element receives the Nx1Nx2 processing request message accordingly.

[0232] The Nx1Nx2 processing request message includes 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), first container and other information.

[0233] In addition, the Nx1Nx2 processing request message also includes the identifier and / or address of the H-SMF network element.

[0234] In some embodiments, the SRF network element may also determine a first identifier associated with a V-SMF network element (such as the identifier and / or address of the V-SMF network element) for routing to the V-SMF network element. The first identifier may also be included in the Nx1Nx2 processing request message sent by the SRF network element to the V-SMF network element.

[0235] S1006: The V-SMF network element sends an SM context establishment or modification request message to the H-SMF network element based on the identifier and / or address of the H-SMF network element.

[0236] The SM context establishment or modification request message may include initial information, Nx2 parameters (such as the location of the terminal device), and the first container. Upon receiving the SM context establishment or modification request message, the H-SMF network element can perform PDU session establishment-related operations, such as selecting a UPF network element.

[0237] In some implementations, the terminal device can first send an NF discovery request to the fourth network element to discover the first network element serving the first service, and then send the first information to the first network element through the fourth network element, so as to simplify the logic of the fourth network element and avoid the fourth network element caching the first information to be routed.

[0238] Figure 11 The fifth schematic diagram of the communication method provided in the embodiments of this application includes:

[0239] S1101: The terminal device sends an NF discovery request, and the fourth network element receives the NF discovery request accordingly.

[0240] The NF discovery request includes a first container, which is used to identify the network element serving the first service.

[0241] S1102: The fourth network element sends a first request to the NF selection function network element, and the NF selection function network element receives the first request accordingly. The first request includes the first container.

[0242] S1103: The NF selection function network element sends a first response to the fourth network element. Correspondingly, the fourth network element receives the first response, which includes the identifier and / or address of the first network element.

[0243] S1104: The fourth network element sends an NF discovery response to the terminal device, and the terminal device receives the NF discovery response accordingly.

[0244] The NF discovery response includes routing information for the first network element, such as at least one of the following: a first identifier associated with the first network element, the identifier of the first network element, or the address of the first network element, wherein the first identifier is used for routing to the first network element.

[0245] S1105: The terminal device sends a third message to the fourth network element, and the fourth network element receives the third message accordingly.

[0246] The third message includes first information, and at least one of the following: first identifier, identifier of the first network element, or address of the first network element, used to request the first service.

[0247] S1106: The fourth network element sends first information to the first network element based on at least one of the first identifier, the identifier of the first network element, or the address of the first network element.

[0248] Figure 11 The implementation of each step can be referred to Figure 7 The implementation of each step, and Figure 7 The communication methods in them are different, in Figure 11 In the communication method shown, the terminal device can first send a first container to determine the network element serving the first service. After the fourth network element determines the first network element serving the first service through the NF selection function network element, it sends the identifier or address of the first network element, or a first identifier associated with the first network element, to the terminal device. The terminal device, in sending a third message to the fourth network element including first information for requesting the first service, can carry at least one of the identifier or address of the first network element, or a first identifier associated with the first network element, for the fourth network element to route the first information to the first network element. This avoids the fourth network element needing to determine whether it needs to determine the first network element serving the first service through the NF selection function network element, and also avoids the fourth network element caching the first information, thus simplifying the logic of the fourth network element.

[0249] The following explanation uses the example of the fourth network element being the SRF network element, the NF selection function network element being the NFSF network element, and the first service being the PDU session establishment service. Figure 12 This is a sixth schematic diagram of a communication method provided in an embodiment of this application. The method includes:

[0250] S1201: The terminal device sends an NF discovery request to the RAN node, and the RAN node receives the NF discovery request accordingly.

[0251] After a terminal device connects to the network (or registers with the network), the network (such as an AMF network element) can send configuration information (such as terminal device policies) to the terminal device. This information may include routing information of the NFSF network element, such as the identifier and / or address of the NFSF network element, or a second identifier associated with the NFSF network element. The SRF network element stores the association between the second identifier and the NFSF network element.

[0252] When a terminal device needs to establish a PDU session but does not have routing information to an SMF network element (such as the identifier or address of the SMF network element), the terminal device can send an NF discovery request to the RAN node. The NF discovery request includes a first container used to determine the network element serving the PDU session establishment service, and may also include routing information of the NFSF network element, such as at least one of the address, identifier, or second identifier of the NFSF network element.

[0253] S1202: The RAN node sends an NF discovery request to the SRF network element, and the SRF network element receives the NF discovery request accordingly.

[0254] After receiving an NF discovery request from an end device, the RAN node can forward the NF discovery request to the SRF network element. Additionally, the RAN node can also send Nx2 parameters to the SRF network element. These Nx2 parameters can include at least one of the general NF selection parameters, such as the location information of the end device.

[0255] S1203: The SRF network element sends a first request to the NFSF network element, and the NFSF network element receives the first request accordingly.

[0256] The first request may be an NF selection request, etc., and this application does not limit the name of the first request. The first request includes a first container, and may also include general NF selection parameters and the identifier of the terminal device (such as SUPI).

[0257] S1204: The NFSF network element sends a first response to the SRF network element, and the SRF network element receives the first response accordingly.

[0258] The first response may be an NF selection response, etc., and this application does not limit the name of the first response. The first response includes the identifier and / or address of the SMF network element.

[0259] After receiving the first request, the NFSF network element can select an SMF network element based on the first container, or the first container and the NF selection general parameters. For example, if the first container includes DNN1 and the NF selection general parameters include the location of the terminal device, the NF element can select an SMF network element associated with DNN1. If multiple SMF network elements are associated with DNN1, the NF selection function network element can select an SMF network element whose location meets certain conditions (such as being the closest or having a distance less than a set distance threshold) from the terminal device.

[0260] In one possible implementation, the NFSF network element can obtain the terminal device's subscription data from the UDM network element through the terminal device's identifier. The NFSF network element can also select the SMF network element based on the terminal device's subscription data (such as whether the terminal device uses LBO roaming, etc.), the first container, and the NF selection general parameters.

[0261] As an example: If an NFSF network element determines that a terminal device is in roaming access based on the terminal device's identifier, it will use the terminal device's identifier to request the terminal device's subscription data from the UDM network element of the terminal device's home location. Based on the terminal device's subscription information, it will determine that the terminal device is using LBO roaming. Then, the NFSF network element can determine the SMF network element of the roaming location based on the first container.

[0262] In some embodiments, the SRF network element may also determine a first identifier associated with the SMF network element (such as the identifier and / or address of the SMF network element) for routing to the SMF network element, and store the association between the first identifier and the SMF network element.

[0263] S1205: The SRF network element sends an NF discovery response to the terminal device, and the terminal device receives the NF discovery response accordingly.

[0264] The NF discovery response includes routing information for the SMF network element, such as at least one of the following: a first identifier associated with the SMF network element, the identifier of the SMF network element, or the address of the SMF network element, wherein the first identifier is used for routing to the SMF network element.

[0265] For example: The SRF network element can send an Nx2 message to the RAN node through the Nx2 interface between the RAN node and the RAN node. The Nx2 message includes an NF discovery response. After receiving the Nx2 message, the RAN node can send the NF discovery response to the terminal device.

[0266] S1206: The terminal device sends a third message to the SRF network element, and the SRF network element receives the third message accordingly.

[0267] For example: The terminal device can send a third message to the RAN node. Upon receiving the third message, the RAN node can send an Nx2 message to the SRF network element through the Nx2 interface with the SRF network element. The Nx2 message includes the third message or its contents. The third message may include first information for requesting the establishment of a PDU session, and at least one of the following: a first identifier associated with the SMF network element, the identifier of the SMF network element, or the address of the SMF network element.

[0268] An SRF network element can route first information to an SMF network element based on at least one of the first identifier associated with the SMF network element, the identifier of the SMF network element, or the address of the SMF network element.

[0269] Furthermore, in this embodiment, the protocol used for the connection (or Nx2 interface) between the RAN node and the fourth 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 fourth 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 fourth 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 fourth 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 fourth 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 fourth network element could be XX ID, such as RAN UE XX ID, SRF UE XX ID, etc.

[0270] The communication device provided in the embodiments of this application will be described below. Please refer to... Figure 13 , Figure 13 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 may be used to execute the steps executed by the fourth network element, terminal device, or first network element in the above embodiments. Please refer to the relevant descriptions in the above method embodiments for details.

[0271] like Figure 13 As shown, the communication device 1300 includes a processing unit 1310 and an interface unit 1320, wherein the processing unit 1310 may be a processor or a processing circuit, and the interface unit 1320 may be a transceiver unit or an input / output interface. The communication device 1300 can be used to implement the steps executed by the fourth network element, the terminal device, or the first network element in the above embodiments.

[0272] When the communication device 1300 is used to implement the steps performed by the fourth network element in the above embodiments:

[0273] Interface unit 1320 is configured to receive a first message, the first message including first information and a first container, the first information being used by a terminal device to request a first service, the first container being used to determine the network element serving the first service; send a first request to an NF selection function network element, the first request including the first container; receive a first response from an NF selection function network element, the first response including the identifier and / or address of the first network element; and send a second message to the first network element, the second message including the first information.

[0274] In one possible design, the processing unit 1310 is used to determine the first network element based on the first response.

[0275] In one possible design, the second message also includes the first container.

[0276] In one possible design, the processing unit 1310 is further configured to determine a first identifier associated with the first network element; the interface unit 1320 is further configured to send the first identifier associated with the first network element to the terminal device; and / or send the first identifier associated with the first network element to the access network device serving the terminal device; wherein the first identifier is used for routing to the first network element.

[0277] In one possible design, before sending the first request to the NF selection function network element, the processing unit 1310 is further configured to determine that the first message satisfies at least one of the following: the first message includes a first container; the content of the routing information in the first message is empty; the first message does not include routing information; the routing information in the first message is associated with the NF selection function network element; or, the first message includes first indication information, which indicates that NF selection is performed.

[0278] In one possible design, the first container includes at least one of the following: the NF type corresponding to the first service, the DNN corresponding to the first service, the network slice information corresponding to the first service, the request type corresponding to the first service, the feature identifier corresponding to the first service, the capability information corresponding to the first service, or the name of the first service.

[0279] In one possible design, the first request may also include at least one of the following: the RAT type corresponding to the terminal device, the access type corresponding to the terminal device, the identifier of the terminal device, the location information of the terminal device, or the subscription information of the terminal device.

[0280] In one possible design, the first response also includes the identifier and / or address of at least one second network element, which is used to process the service data corresponding to the terminal device after the first network element.

[0281] In one possible design, the second message also includes the identifier and / or address of at least one second network element.

[0282] In one possible design, the first message is a session establishment request message, the first network element is the visited location session management function network element of the terminal device, and at least one second network element includes the home location session management function network element of the terminal device.

[0283] Alternatively, interface unit 1320 is configured to receive a Network Function (NF) discovery request from a terminal device, the NF discovery request including a first container for determining a network element serving a first service; send a first request to an NF selection function network element, the first request including the first container; receive a first response from the NF selection function network element, the first response including an identifier and / or address of the first network element; send an NF discovery response to the terminal device, the NF discovery response including at least one of a first identifier associated with the first network element, an identifier of the first network element, or an address of the first network element, wherein the first identifier is used for routing to the first network element; receive a third message from the terminal device, the third message including first information, and at least one of a first identifier, an identifier of the first network element, or an address of the first network element, the first information being used to request the first service; and send the first information to the first network element based on at least one of the first identifier, the identifier of the first network element, or the address of the first network element.

[0284] In one possible design, the interface unit 1320 is also used to send a first identifier to the access network device of the serving terminal device.

[0285] In one possible design, the NF discovery request also includes at least one of the identifier of the NF selection function network element, the address of the NF selection network element, or a second identifier associated with the NF selection network element; when the interface unit 1320 sends the first request to the NF selection function network element, it is specifically used to send the first request to the NF selection function network element according to at least one of the identifier of the NF selection function network element, the address of the NF selection network element, or the second identifier.

[0286] In one possible design, the first container includes at least one of the following: the request type corresponding to the first service, the NF type corresponding to the first service, the DNN corresponding to the first service, the network slice information corresponding to the first service, the feature identifier corresponding to the first service, the capability information corresponding to the first service, or the name of the first service.

[0287] In one possible design, the first request may also include at least one of the following: the RAT type corresponding to the terminal device, the access type corresponding to the terminal device, the identifier of the terminal device, the location information of the terminal device, or the subscription information of the terminal device.

[0288] In one possible design, the NF selection response also includes the identifier and / or address of at least one second network element, which is used to process the service data corresponding to the terminal device after the first network element; when the interface unit 1320 sends the first information to the first network element, it is specifically used to send the first information and the identifier and / or address of at least one second network element to the first network element.

[0289] When the communication device 1300 is used to implement the steps performed by the terminal device in the above embodiments:

[0290] Processing unit 1310 is used to determine a first container, the first container being used to determine a network element serving a first service;

[0291] Interface unit 1320 is used to send a first container and first information to the fourth network element. The first information is used to request a first service.

[0292] In one possible design, interface unit 1320 is also used to receive a first identifier from a fourth network element, wherein the first identifier is associated with a first network element and is used for routing to the first network element, and the first network element serves a first service.

[0293] In one possible design, the first container includes at least one of the following: the NF type corresponding to the first service, the DNN corresponding to the first service, the network slice information corresponding to the first service, the request type corresponding to the first service, the feature identifier corresponding to the first service, the capability information corresponding to the first service, or the name of the first service.

[0294] Alternatively, processing unit 1310 is configured to determine a first container, the first container being used to determine a network element serving the first service; interface unit 1320 is configured to send a Network Function (NF) discovery request to a fourth network element, the NF discovery request including the first container; receive an NF discovery response from the fourth network element, the NF discovery response including at least one of a first identifier, an identifier of the first network element, or an address of the first network element, wherein the first network element serves the first service, the first identifier is associated with the first network element and is used for routing to the first network element; and send a third message to the fourth network element, the third message including first information, and at least one of a first identifier, an identifier of the first network element, or an address of the first network element, the first information being used to request the first service.

[0295] In one possible design, the NF discovery request may also include at least one of the following: the identifier of the NF selection function element, the address of the NF selection element, or a second identifier associated with the NF selection element.

[0296] In one possible design, the first container includes at least one of the following: the request type corresponding to the first service, the NF type corresponding to the first service, the DNN corresponding to the first service, the network slice information corresponding to the first service, the feature identifier corresponding to the first service, the capability information corresponding to the first service, or the name of the first service.

[0297] When the communication device 1300 is used to implement the steps performed by the first network element in the above embodiments:

[0298] Interface unit 1320 is configured to receive a second message from a fourth network element, the second message including first information and a first container, the first information being used by the terminal device to request a first service; send a second request to a network function (NF) selection function network element, the second request including the first container; receive a second response from the NF selection function network element, the second response including the identifier and / or address of a third network element; and send context information of the terminal device to the third network element.

[0299] In one possible design, the first container includes at least one of the following: the NF type corresponding to the first service, the DNN corresponding to the first service, the network slice information corresponding to the first service, the request type corresponding to the first service, the feature identifier corresponding to the first service, the capability information corresponding to the first service, or the name of the first service.

[0300] In one possible design, the second request may also include at least one of the following: the RAT type corresponding to the terminal device, the access type corresponding to the terminal device, the identifier of the terminal device, the location information of the terminal device, or the subscription information of the terminal device.

[0301] Figure 14 As shown, this application also provides a communication device 1400, including a processor 1410 and a communication interface 1420. The processor 1410 and the communication interface 1420 are coupled to each other. It is understood that the communication interface 1420 can be a transceiver, an input / output interface, an input interface, an output interface, an interface circuit, etc. Optionally, the communication device 1400 may further include a memory 1430 for storing instructions executed by the processor 1410, or storing input data required by the processor 1410 to execute instructions, or storing data generated after the processor 1410 executes instructions. The memory 1430 can be a physically independent unit, or it can be coupled to the processor 1410, or the processor 1410 may include the memory 1430.

[0302] When the communication device 1400 is used to implement the steps executed by the fourth network element, terminal device, or first network element in the above embodiments, the processor 1410 can be used to implement the function of the processing unit 1310, and the communication interface 1420 can be used to implement the function of the interface unit 1320.

[0303] In this application embodiment, the processor (e.g., processor 1410) 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.

[0304] In this embodiment, the memory (e.g., memory 1430) 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.

[0305] 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.

[0306] 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.

[0307] 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.

[0308] 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.

[0309] 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 the fourth network element, including: Receive a first message, the first message including first information and a first container, the first information being used by the terminal device to request a first service, and the first container being used to determine the network element serving the first service; Send a first request to the Network Function NF (NF) Select Function Network Element, wherein the first request includes the first container; Receive a first response from the NF selection function network element, the first response including the identifier and / or address of the first network element; Send a second message to the first network element, the second message including the first information.

2. The method as described in claim 1, characterized in that, The method further includes: Based on the first response, the first network element is determined.

3. The method as described in claim 1 or 2, characterized in that, The second message also includes the first container.

4. The method according to any one of claims 1-3, characterized in that, The method further includes: Send the first identifier associated with the first network element to the terminal device; and / or, Send a first identifier associated with the first network element to the access network device serving the terminal device; The first identifier is used for routing to the first network element.

5. The method according to any one of claims 1-4, characterized in that, Before sending the first request to the NF selection function network element, the method further includes: The first message is determined to satisfy at least one of the following: The first message includes a first container; The routing information in the first message is empty; The first message does not include routing information; The routing information in the first message is associated with the NF selection function network element; or, The first message includes a first instruction message, which instructs NF selection.

6. The method according to any one of claims 1-5, characterized in that, The first container includes at least one of the following: The first service's corresponding NF type, the first service's corresponding data network name (DNN), the first service's corresponding network slice information, the first service's corresponding request type, the first service's corresponding feature identifier, the first service's corresponding capability information, or the first service's name.

7. The method according to any one of claims 1-6, characterized in that, The first request also includes at least one of the following: The terminal device's corresponding wireless access technology (RAT) type, the terminal device's corresponding access type, the terminal device's identifier, the terminal device's location information, or the terminal device's subscription information.

8. The method according to any one of claims 1-7, characterized in that, The first response also includes the identifier and / or address of at least one second network element, which is used to process the service data corresponding to the terminal device after the first network element.

9. The method as described in claim 8, characterized in that, The second message also includes the identifier and / or address of the at least one second network element.

10. The method as described in claim 8 or 9, characterized in that, The first message is a session establishment request message, the first network element is the visited location session management function network element of the terminal device, and the at least one second network element includes the home location session management function network element of the terminal device.

11. A communication method, characterized in that, include: Receive a Network Function (NF) Discovery Request from a terminal device, the NF Discovery Request including a first container, the first container being used to identify network elements serving a first service; Send a first request to the NF selection function network element, the first request including the first container; Receive a first response from the NF selection function network element, the first response including the identifier and / or address of the first network element; Send an NF discovery response to the terminal device. The NF discovery response includes at least one of a first identifier associated with the first network element, an identifier of the first network element, or an address of the first network element, wherein the first identifier is used for routing to the first network element. Receive a third message from the terminal device, the third message including first information and at least one of the first identifier, the identifier of the first network element, or the address of the first network element, the first information being used to request the first service; The first information is sent to the first network element based on at least one of the first identifier, the identifier of the first network element, or the address of the first network element.

12. The method as described in claim 11, characterized in that, The method further includes: The first identifier is sent to the access network device serving the terminal device.

13. The method as described in claim 11 or 12, characterized in that, The NF discovery request also includes at least one of the following: the identifier of the NF selection function network element, the address of the NF selection network element, or a second identifier associated with the NF selection network element; Sending the first request to the NF selection function network element includes: The first request is sent to the NF selection function network element based on at least one of the identifier of the NF selection function network element, the address of the NF selection function network element, or the second identifier.

14. The method according to any one of claims 11-13, characterized in that, The first container includes at least one of the following: The request type corresponding to the first service, the NF type corresponding to the first service, the data network name (DNN) corresponding to the first service, the network slice information corresponding to the first service, the feature identifier corresponding to the first service, the capability information corresponding to the first service, or the name of the first service.

15. The method according to any one of claims 11-14, characterized in that, The first request also includes at least one of the following: The terminal device's corresponding wireless access technology (RAT) type, the terminal device's corresponding access type, the terminal device's identifier, the terminal device's location information, or the terminal device's subscription information.

16. The method according to any one of claims 11-15, characterized in that, The NF selection response also includes the identifier and / or address of at least one second network element, which is used to process the service data corresponding to the terminal device after the first network element; Sending first information to the first network element, including: Send the first information and the identifier and / or address of the at least one second network element to the first network element.

17. A communication method, characterized in that, Applied to terminal devices, including: A first container is determined, which is used to determine the network element serving the first service; The first container and the first information are sent to the fourth network element, whereby the first information is used to request the first service.

18. The method as described in claim 17, characterized in that, The method further includes: Receive a first identifier from the fourth network element, wherein the first identifier is associated with the first network element and is used for routing to the first network element, the first network element serving the first service.

19. The method as described in claim 17 or 18, characterized in that, The first container includes at least one of the following: The first service's corresponding NF type, the first service's corresponding data network name (DNN), the first service's corresponding network slice information, the first service's corresponding request type, the first service's corresponding feature identifier, the first service's corresponding capability information, or the first service's name.

20. A communication method, characterized in that, Applied to terminal devices, including: Send a Network Function (NF) Discovery Request to the fourth network element. The NF Discovery Request includes a first container, which is used to determine the network element serving the first service. Receive an NF discovery response from the fourth network element, the NF discovery response including at least one of a first identifier, an identifier of the first network element, or an address of 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; A third message is sent to the fourth network element. The third message includes first information and at least one of the first identifier, the identifier of the first network element, or the address of the first network element. The first information is used to request the first service.

21. The method as described in claim 20, characterized in that, The NF discovery request also includes at least one of the following: the identifier of the NF selection function network element, the address of the NF selection network element, or a second identifier associated with the NF selection network element.

22. The method as described in claim 20 or 21, characterized in that, The first container includes at least one of the following: The request type corresponding to the first service, the NF type corresponding to the first service, the data network name (DNN) corresponding to the first service, the network slice information corresponding to the first service, the feature identifier corresponding to the first service, the capability information corresponding to the first service, or the name of the first service.

23. A communication method, characterized in that, Applied to the first network element, including: Receive a second message from a fourth network element, the second message including first information and a first container, the first information being used by the terminal device to request a first service; Send a second request to the Network Function NF (Network Function) Select Function Network Element, the second request including the first container; Receive a second response from the NF selection function network element, the second response including the identifier and / or address of the third network element; Send the context information of the terminal device to the third network element.

24. The method as described in claim 23, characterized in that, The first container includes at least one of the following: The first service's corresponding NF type, the first service's corresponding data network name (DNN), the first service's corresponding network slice information, the first service's corresponding request type, the first service's corresponding feature identifier, the first service's corresponding capability information, or the first service's name.

25. The method as described in claim 23 or 24, characterized in that, The second request also includes at least one of the following: The terminal device's corresponding wireless access technology (RAT) type, the terminal device's corresponding access type, the terminal device's identifier, the terminal device's location information, or the terminal device's subscription information.

26. A communication device, characterized in that, Includes modules or units for performing the method as described in any one of claims 1-25.

27. A computer program product, characterized in that, It includes a computer program or instructions that, when executed by a processor, cause the method as described in any one of claims 1-25 to be implemented.

28. A chip system, characterized in that, The chip system includes a processor for coupling with a memory for storing computer programs or instructions that, when executed by the processor, implement the method as described in any one of claims 1-25.

29. 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 1-25 to be implemented.

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