Communication methods, apparatus, network side device and readable storage medium

Abstract

The present application belongs to the technical field of communications. Disclosed are communication methods, an apparatus, a network side device, and a readable storage medium. A communication method of the embodiments of the present application comprises: in the process of a terminal being switched from a first RAN to a second RAN, a first core network function receiving a first message sent by the second RAN, and determining a second core network function on the basis of the first message, wherein the first message is used for indicating that the terminal has moved to the second RAN; or, after the terminal has been switched from the first RAN to the second RAN, the first core network function receiving a second message sent by the terminal, and determining the second core network function on the basis of the second message, wherein the second message is used for mobility registration update.

Description

Communication methods, devices, network-side equipment, and readable storage media

[0001] Cross-reference of related applications

[0002] This application claims priority to Chinese Patent Application No. 202411906275.1, filed in China on December 23, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the field of communication technology, specifically relating to a communication method, apparatus, network-side device, and readable storage medium. Background Technology

[0004] In related technologies, User Equipment (UE) has two handover methods between base stations: Xn handover and N2 handover. Xn handover involves direct information exchange between two base stations; N2 handover requires information exchange via the following path: Source Radio Access Network (RAN) → Source Access and Mobility Management Function (AMF) → Target AMF → Target RAN. N2 handover requires signaling transmission between the RAN and core network functions, as well as between core network functions. Currently, only base stations configured with N2 interfaces can communicate with their AMFs; base stations without N2 interfaces cannot communicate with their AMFs, resulting in low handover efficiency and high handover latency for UEs. Summary of the Invention

[0005] This application provides a communication method, apparatus, network-side device, and readable storage medium, which can solve the problems of low UE handover efficiency and large handover latency between networks in related technologies.

[0006] In a first aspect, a communication method is provided, executed by a first core network function, the method comprising:

[0007] During the handover process from the first RAN to the second RAN, the first core network function receives a first message sent by the second RAN and determines the second core network function based on the first message, wherein the first message is used to indicate that the terminal has moved to the second RAN; or,

[0008] After the terminal switches from the first RAN to the second RAN, the first core network function receives a second message sent by the terminal and determines the second core network function based on the second message, wherein the second message is used to perform mobility registration update.

[0009] Secondly, a communication method is provided, executed by a second core network function, the method comprising:

[0010] The second core network function receives at least one of the second information sent by the first core network function and the terminal's context information;

[0011] The second information includes at least one of the following:

[0012] The base station ID of the second RAN;

[0013] The IP address of the second RAN;

[0014] FQDN of the second RAN;

[0015] The second RAN assigns a first identifier to the terminal, the first identifier being used to identify the terminal;

[0016] The first core network function assigns a second identifier to the terminal, which is used to identify the terminal.

[0017] Thirdly, a communication method is provided, executed by a second RAN, the method comprising:

[0018] During the handover process from the first RAN to the second RAN, the second RAN sends a first message to the first core network function. This first message is used to identify the second core network function and to indicate that the terminal has moved to the second RAN; or...

[0019] The second RAN obtains a first instruction from the terminal and determines a second core network function based on the first instruction, wherein the first instruction is used to indicate the selection of a new core network function.

[0020] Fourthly, a communication device is provided for first core network functions, the device comprising:

[0021] The first receiving module is used to receive a first message sent by the second RAN during the process of the terminal switching from the first RAN to the second RAN;

[0022] A first processing module is configured to determine a second core network function based on the first message, wherein the first message is used to indicate that the terminal has moved to the second RAN;

[0023] or,

[0024] The first receiving module is used to receive a second message sent by the terminal after the terminal switches from the first RAN to the second RAN;

[0025] The first processing module is used to determine the second core network function based on the second message, wherein the second message is used to perform mobility registration update.

[0026] Fifthly, a communication device is provided for second core network functions, the device comprising:

[0027] The second receiving module is used to receive at least one of the second information sent by the first core network function and the context information of the terminal;

[0028] The second information includes at least one of the following:

[0029] The base station ID of the second RAN;

[0030] The IP address of the second RAN;

[0031] FQDN of the second RAN;

[0032] The second RAN assigns a first identifier to the terminal, the first identifier being used to identify the terminal;

[0033] The first core network function assigns a second identifier to the terminal, which is used to identify the terminal.

[0034] Sixthly, a communication device is provided for a second RAN, the device comprising:

[0035] The third sending module is used to send a first message to the first core network function during the process of the terminal switching from the first RAN to the second RAN. The first message is used to identify the second core network function and to indicate that the terminal has moved to the second RAN.

[0036] Or the device may include:

[0037] The second processing module is used to obtain a first instruction from the terminal and determine a second core network function based on the first instruction, wherein the first instruction is used to indicate the selection of a new core network function.

[0038] In a seventh aspect, a communication device is provided, the device being configured to perform the steps of the method described in the first aspect, or to implement the steps of the method described in the second aspect, or to implement the steps of the method described in the third aspect.

[0039] Eighthly, a network-side device is provided, the network-side device including a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the method as described in the first aspect, or implementing the steps of the method as described in the second aspect, or implementing the steps of the method as described in the third aspect.

[0040] A ninth aspect provides a network-side device, including a processor and a communication interface, wherein, when the network-side device functions as a first core network, during the handover process of a terminal from a first radio access network (RAN) to a second RAN, the communication interface is used to receive a first message sent by the second RAN, and the processor is used to determine a second core network function based on the first message, wherein the first message is used to indicate that the terminal has moved to the second RAN; or, after the terminal has switched from the first RAN to the second RAN, the communication interface is used to receive a second message sent by the terminal, and the processor is used to determine a second core network function based on the second message, wherein the second message is used to perform a mobility registration update;

[0041] Alternatively, when the network-side device functions as a second core network, the communication interface is used to receive at least one of the second information sent by the first core network function and the terminal's context information; wherein the second information includes at least one of the following:

[0042] The base station ID of the second RAN;

[0043] The IP address of the second RAN;

[0044] FQDN of the second RAN;

[0045] The second RAN assigns a first identifier to the terminal, the first identifier being used to identify the terminal;

[0046] The first core network function assigns a second identifier to the terminal, the second identifier being used to identify the terminal;

[0047] Alternatively, when the network-side device is the second RAN, during the handover process from the first RAN to the second RAN, the communication interface is used to send a first message to the first core network function, the first message being used to identify the second core network function and to indicate that the terminal has moved to the second RAN; or...

[0048] The processor is configured to obtain a first instruction from the terminal and determine a second core network function based on the first instruction, wherein the first instruction is configured to indicate the selection of a new core network function.

[0049] In a tenth aspect, a readable storage medium is provided, on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the first aspect, or the steps of the method described in the second aspect, or the steps of the method described in the third aspect.

[0050] Eleventhly, a wireless communication system is provided, comprising: a first core network function, a second core network function, and a second RAN, wherein the first core network function is available for performing the steps of the method described in the first aspect, the second core network function is available for performing the steps of the method described in the second aspect, and the second RAN is available for performing the steps of the method described in the third aspect.

[0051] In a twelfth aspect, a chip is provided, the chip including a processor and a communication interface coupled to the processor, the processor being configured to run a program or instructions to implement the steps of the method described in the first aspect, or the steps of the method described in the second aspect, or the steps of the method described in the third aspect.

[0052] In a thirteenth aspect, a computer program / program product is provided, which is stored in a storage medium and is executed by at least one processor to implement the steps of the method as described in the first aspect, or the steps of the method as described in the second aspect, or the steps of the method as described in the third aspect.

[0053] In this embodiment, during the handover process from the first RAN to the second RAN, the first core network function determines the second core network function providing services to the terminal through a first message. This allows for base station handover first, followed by core network function handover on the core network side, effectively improving handover efficiency and reducing handover latency. Alternatively, after the terminal has switched from the first RAN to the second RAN, the first core network function determines the second core network function providing services to the terminal through a second message. This allows for core network function changes to be implemented after base station handover, further shortening handover latency and improving handover efficiency. Attached Figure Description

[0054] Figure 1 is a block diagram of a wireless communication system applicable to an embodiment of this application;

[0055] Figure 2a is a flowchart of UE handover between networks in related technologies;

[0056] Figure 2b is a schematic diagram of a network architecture applicable to an embodiment of this application;

[0057] Figure 3 is a flowchart of one of the communication methods provided in an embodiment of this application;

[0058] Figure 4 is a second flowchart of a communication method provided in an embodiment of this application;

[0059] Figure 5 is a flowchart of a communication method provided in an embodiment of this application;

[0060] Figure 6a is a flowchart of a communication method provided in an embodiment of this application;

[0061] Figure 6b is a flowchart of a communication method provided in an embodiment of this application;

[0062] Figure 6c is a flowchart of a communication method provided in an embodiment of this application;

[0063] Figure 7 is a structural diagram of a communication device provided in an embodiment of this application;

[0064] Figure 8 is a second structural diagram of a communication device provided in an embodiment of this application;

[0065] Figure 9 is a third structural diagram of a communication device provided in an embodiment of this application;

[0066] Figure 10 is a structural diagram of a communication device provided in an embodiment of this application;

[0067] Figure 11 is a structural diagram of a network-side device provided in an embodiment of this application. Detailed Implementation

[0068] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0069] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, not limited in number; for example, the first object can be one or more. Furthermore, "or" in this application indicates at least one of the connected objects. For example, the scope of protection for "A or B" covers at least three scenarios: Scenario 1: including A but not B; Scenario 2: including B but not A; Scenario 3: including both A and B. In addition, the terms "A and / or B," "at least one of A and B," and "at least one of A or B" also cover at least the above three scenarios. The character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0070] The term "instruction" in this application can be either a direct instruction (or explicit instruction) or an indirect instruction (or implicit instruction). A direct instruction can be understood as one in which the sender explicitly informs the receiver of specific information, the operation to be performed, or the requested result, etc., in the instruction sent. An indirect instruction can be understood as one in which the receiver determines the corresponding information based on the instruction sent by the sender, or makes a judgment and determines the operation to be performed or the requested result, etc., based on the judgment result.

[0071] It is worth noting that the technologies described in this application are not limited to Long Term Evolution (LTE) / LTE-Advanced (LTE-A) systems, but can also be used in other wireless communication systems, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Single-carrier Frequency-Division Multiple Access (SC-FDMA), or other systems. The terms "system" and "network" in this application are often used interchangeably, and the described technologies can be used with the systems and radio technologies mentioned above, as well as with other systems and radio technologies. The following description describes New Radio (NR) systems for illustrative purposes, and the term NR is used in most of the following description; however, these technologies can also be applied to systems other than NR systems, such as 6th generation (6G) radio systems. th Generation 6G communication system.

[0072] Figure 1 shows a block diagram of a wireless communication system applicable to an embodiment of this application. The wireless communication system includes a terminal 11 and a network-side device 12. The terminal 11 can be a mobile phone, tablet computer, laptop computer, notebook computer, personal digital assistant (PDA), handheld computer, netbook, ultra-mobile personal computer (UMPC), mobile internet device (MID), augmented reality (AR), virtual reality (VR) device, robot, wearable device, flight vehicle, vehicle user equipment (VUE), shipboard equipment, pedestrian user equipment (PUE), smart home (home devices with wireless communication capabilities, such as refrigerators, televisions, washing machines, or furniture), game console, personal computer (PC), ATM, or self-service machine, etc. Wearable devices include: smartwatches, smart bracelets, smart headphones, smart glasses, smart jewelry (smart bracelets, smart chains, smart rings, smart necklaces, smart anklets, smart anklets, etc.), smart wristbands, smart clothing, etc. Among these, in-vehicle devices can also be referred to as in-vehicle terminals, in-vehicle controllers, in-vehicle modules, in-vehicle components, in-vehicle chips, or in-vehicle units, etc. Furthermore, terminal 11 can be any of the terminals described above, or it can be a chip within a terminal, such as a modem chip, a system-on-chip (SoC), etc. It should be noted that the specific type of terminal 11 is not limited in this application embodiment. Network-side device 12 can include access network equipment or core network equipment (or core network functions), wherein access network equipment can also be referred to as Radio Access Network (RAN) equipment, radio access network functions, or radio access network units. Access network equipment can include base stations, Wireless Local Area Network (WLAN) access points (APs), or Wireless Fidelity (WiFi) nodes, etc.The term "base station" can be referred to as Node B (NB), Evolved Node B (eNB), Next Generation Node B (gNB), New Radio Node B (NR Node B), Access Point, Relay Base Station (RBS), Serving Base Station (SBS), Base Transceiver Station (BTS), Radio Base Station, Radio Transceiver, Basic Service Set (BSS), Extended Service Set (ESS), Home Node B (HNB), Home Evolved Node B, Transmit / Receive Point (TRP), or any other suitable term in the relevant field, as long as the same technical effect is achieved. The term "base station" is not limited to any specific technical terminology. It should be noted that this application embodiment only uses a base station in an NR system as an example for description and does not limit the specific type of base station.

[0073] Core network equipment, also known as core network nodes, core network functions, or core network elements, includes, but is not limited to, at least one of the following: Mobility Management Entity (MME), Access and Mobility Management Function (AMF), Session Management Function (SMF), User Plane Function (UPF), Policy Control Function (PCF), Policy and Charging Rules Function (PCRF), Edge Application Server Discovery Function (EASDF), Unified Data Management (UDM), Unified Data Repository (UDR), Home Subscriber Server (HSS), Centralized network configuration (CNC), Network Repository Function (NRF), Network Exposure Function (NEF), Local NEF (or L-NEF), and Binding Support. The core network functions include: BSF (Block Network Function), Application Function (AF), Location Management Function (LMF), Gateway Mobile Location Centre (GMLC), and Network Data Analytics Function (NWDAF). It should be noted that this application embodiment only uses core network equipment in the NR system as an example and does not limit the specific type of core network equipment. If the name of the core network equipment mentioned in this application embodiment changes in subsequent protocol versions (e.g., 6G), it will still be within the scope of protection of this application.

[0074] Optionally, the core network equipment can be implemented by one or more functional modules in a single device, or by multiple devices working together; this application does not specifically limit this. It is understood that the aforementioned functional modules can be network elements in hardware devices, software functional modules running on dedicated hardware, or virtualized functional modules instantiated on a platform (e.g., a cloud platform).

[0075] In 5G communication, there are two handover methods for UEs between base stations: Xn handover and N2 handover. Xn handover involves direct information exchange between two base stations; N2 handover requires information exchange through the following path: source RAN → source AMF → target AMF → target RAN.

[0076] Xn requires less network-side signaling and has lower handover latency. The Xn handover process, as shown in Figure 2a, includes the following steps:

[0077] 1. The UE sends a measurement report to the S-RAN according to the configuration of the source RAN (S-RAN), which includes the cell ID information of one or more candidate cells;

[0078] 2. Based on the measurement report, the S-RAN selects the target base station (target RAN, T-RAN) and sends a handover request to the T-RAN. The handover request includes the ID of the AMF serving the UE: such as the globally unique AMF Identifier (GUAMI) and the target cell ID.

[0079] 3. The T-RAN sends a handover request confirmation to the S-RAN, carrying the radio resource information allocated by the T-RAN to the UE;

[0080] 4. The T-RAN sends a handover command to the UE, carrying the radio resource information allocated to the UE by the T-RAN;

[0081] 5. The UE accesses the T-RAN based on the radio resource information allocated to it by the T-RAN and sends a handover complete message;

[0082] 6. T-RAN sends an N2 path switch request to AMF based on GUAMI information, carrying the cell ID and Tracing Area Identity (TAI) of the cell where the UE is located, as well as the resource information allocated to the UE by the RAN side;

[0083] 7. The AMF sends an update session management (SM) context request to the SMF, carrying the resource information allocated to the UE by the RAN side;

[0084] 8. The SMF sends an N4 session modify request to the UPF to send RAN-side resource information to the UPF. Please obtain the UPF-side resource information from the UPF.

[0085] 9. The SMF sends the UPF resource information to the AMF;

[0086] 10. The AMF sends the UPF's resource information to the RAN side, thereby establishing a GPRS Tunneling Protocol (GTP) tunnel between the RAN and the UPF;

[0087] 11. T-RAN instructs S-RAN to release resources.

[0088] In related technologies, Xn handover only involves base station switching and cannot switch core network functions. In N2 handover, AMF and RAN communicate based on interfaces. Only base stations with N2 interfaces configured can communicate with AMF; base stations without interfaces cannot communicate with AMF, thus only N2 handover can be performed, resulting in lower UE handover efficiency and higher handover latency.

[0089] In this embodiment of the application, the RAN is enhanced with service-based features, as shown in Figure 2b, which allows the base station to access the service-based architecture (SBA), so that the RAN can communicate with any AMF.

[0090] The communication methods, apparatus, and communication devices provided in this application will be described in detail below with reference to the accompanying drawings and through some embodiments and application scenarios.

[0091] Please refer to Figure 3, which is a flowchart of one of the communication methods provided in an embodiment of this application. The method is executed by a first core network function. As shown in Figure 3, the method includes the following steps:

[0092] Step 301: During the handover process from the first RAN to the second RAN, the first core network function receives a first message sent by the second RAN and determines the second core network function based on the first message, wherein the first message is used to indicate that the terminal has moved to the second RAN; or,

[0093] After the terminal switches from the first RAN to the second RAN, the first core network function receives a second message sent by the terminal and determines the second core network function based on the second message, wherein the second message is used to perform mobility registration update.

[0094] It should be noted that "after the terminal switches from the first RAN to the second RAN" can be understood or replaced as: when the terminal switches from the first RAN to the second RAN; or, after the terminal accesses the second RAN.

[0095] In one implementation: during the handover process from a first RAN to a second RAN, a first core network function receives a first message sent by the second RAN and determines a second core network function based on the first message, wherein the first message is used to indicate that the terminal has moved to the second RAN.

[0096] Optionally, in some implementations, the first core network function is a source AMF (S-AMF), and the second core network function is a target AMF (T-AMF). Alternatively, the first core network function can also be other network elements used for terminal access and mobility management, and the second core network function can also be other network elements used for terminal access and mobility management. For example, a Mobility Management Function (MMF) or an Access Control Function (ACF), etc.

[0097] In this embodiment of the application, the first message is used to indicate that the terminal has moved to the second RAN, which can also be understood as the first message indicating that the terminal has moved from the first RAN to the second RAN. It should be noted that "moved from the first RAN to the second RAN" can be understood or replaced as: moving from a cell in the first RAN to a cell in the second RAN, that is, the terminal moved to a cell in the second RAN; or, moving from a cell belonging to the first RAN to a cell belonging to the second RAN, that is, the terminal moved to a cell belonging to the second RAN.

[0098] Optionally, the first message may include a path switch request message.

[0099] In this embodiment, during the handover process from the first RAN to the second RAN, the first core network function receives a first message from the second RAN indicating that the terminal has moved to the second RAN, and determines the second core network function based on the first message. Thus, even when both the first RAN (base station) and the first core network function are providing services to the terminal, the handover process from the first RAN to the second RAN can be performed using an inter-base station handover method. The first core network function can then determine the second core network function providing services to the terminal, thereby enabling the UE handover process based on inter-base station handover, effectively improving handover efficiency and reducing handover latency.

[0100] Optionally, the first core network function determines the second core network function based on the first message, including:

[0101] The first core network function determines the second core network function based on the first information included in the first message, wherein the first information includes at least one of the following:

[0102] The TAI of the serving cell of the terminal;

[0103] The cell ID of the serving cell of the terminal.

[0104] For example, the first message sent by the second RAN to the first core network function (e.g., S-AMF) carries at least one of the TAI (Target Area Identifier) ​​and the cell ID of the terminal's serving cell. This allows the first core network function to determine the second core network function (e.g., T-AMF) based on the TAI and / or the cell ID of the terminal's serving cell. This enables the first core network function to select and determine the second core network function more quickly, thus improving the terminal's handover efficiency.

[0105] Optionally, the first core network function determines the second core network function based on the first message, including:

[0106] If the first core network function determines that a change in the core network function is required based on the first message, the first core network function determines the second core network function.

[0107] It should be noted that the need to change the core network function may arise in the following situations: the first core network function is not the optimal core network function for providing services to the terminal, or the first core network function is unsuitable for continuing to provide services to the terminal. If the first core network function determines that a change is needed, then the first core network function determines a second core network function.

[0108] For example, a first core network function receives a first message sent by a second RAN, the first message carrying at least one of the TAI (Target Area Identity) of the terminal's serving cell and the cell ID of the terminal's serving cell. If the first core network function determines that it will not continue to provide service to the terminal, i.e., a change in core network function is required, the first core network function can determine a second core network function based on the TAI and / or the cell ID of the terminal's serving cell.

[0109] In this application, the first core network function can determine a new core network function, namely the second core network function, when a change in the core network function is required, thereby requesting the new core network function to provide services to the terminal, so as to ensure that a more suitable core network function provides services to the terminal.

[0110] Optionally, the first core network function determines the second core network function, including:

[0111] The first core network function request NRF determines the second core network function.

[0112] For example, if the first core network function determines that a core network function needs to be changed based on the first information, the first core network function may request the NRF to determine the second core network function. Alternatively, if the first core network function receives a first message sent by the second RAN, such as a path switching message, the first core network function may request the NRF to determine the second core network function.

[0113] In this application, the first core network function can determine the second core network function based on at least one of the TAI of the serving cell of the terminal and the cell ID of the serving cell of the terminal carried in the first message, or the first core network function can request the NRF to determine the second core network function, thereby making the determination method of the second core network function more flexible.

[0114] Optionally, when the terminal is in the process of switching from the first RAN to the second RAN, the first core network function determines the second core network function based on the first message, including:

[0115] The first core network function determines the second core network function based on the information contained in the first message that indicates the second core network function.

[0116] For example, the second core network function is determined by the second RAN based on at least one of the TAI of the serving cell of the terminal and the cell ID of the serving cell of the terminal. The second RAN sends information indicating the second core network function (e.g., the second core network function ID) in the first message to the first core network function. Thus, the first core network function can know which second core network function is based on the first message, so that the first core network function can request the determined second core network function to provide services to the terminal.

[0117] Alternatively, the second core network function is determined by the first RAN based on at least one of the following: the TAI of the serving cell of the terminal, the cell ID of the serving cell of the terminal, and the base station ID of the serving base station of the terminal. After determining the second core network function, the first RAN carries information indicating the second core network function (e.g., the second core network function ID) in a handover request sent to the second RAN. The second RAN then carries the information indicating the second core network function in the first message and sends it to the first core network function, so that the first core network function can know which second core network function it is based on the first message.

[0118] In this application, the second core network function can be determined by the first RAN, the second RAN, or the first core network function, thus making the determination of the second core network function more flexible.

[0119] Furthermore, after the first core network function determines the second core network function, the method further includes:

[0120] The first core network function sends at least one of the second information and the context information of the terminal to the second core network function;

[0121] The second information includes at least one of the following:

[0122] The base station ID of the second RAN;

[0123] The Internet Protocol (IP) address of the second RAN;

[0124] The second RAN's fully qualified domain name (FQDN);

[0125] The second RAN assigns a first identifier to the terminal, which is used to identify the terminal. For example, the first identifier may be a RAN UE Next Generation Application Protocol (NGAP) ID.

[0126] The first core network function assigns a second identifier to the terminal, which is used to identify the terminal. For example, the second identifier may be the AMF UE NGAP ID.

[0127] Therefore, based on the context information of the terminal and the aforementioned second information, the second core network function can determine which terminal needs to provide services and which second RAN provides services to the terminal, thereby ensuring that the second core network function can send the resource information allocated by the UPF to the terminal to the second RAN.

[0128] In this embodiment, after receiving the terminal's context information and second information from the first core network function, the second core network function sends an update session management (SM) context request to the SMF, which carries the resource information allocated to the terminal by the second RAN. Further, the SMF sends an N4 session modify request to the UPF, which sends the resource information allocated to the terminal by the second RAN to the UPF and requests to obtain the resource information allocated to the terminal by the UPF from the UPF. The SMF then sends the resource information allocated to the terminal by the UPF to the second core network function. The second core network function sends the resource information allocated to the terminal by the UPF to the second RAN. The second RAN determines the terminal and the first RAN based on the second information and sends a release message to the first RAN to instruct the first RAN to release the resources.

[0129] In another embodiment of this application, after the terminal switches from the first RAN to the second RAN, the first core network function receives a second message sent by the terminal and determines a second core network function based on the second message, wherein the second message is used to perform mobility registration update.

[0130] Optionally, the second message is a Mobility Registration Update (MRU) message.

[0131] In this embodiment, the terminal has switched from the first RAN to the second RAN. In this case, the first core network function selects a new core network function to provide services to the terminal. For example, the terminal initiates an MRU request, that is, the terminal sends a second message to the first core network function. Optionally, the second message may be routed from the second RAN to the first core network function. The first core network function can determine the second core network function based on at least one of the terminal's serving cell's TAI and the terminal's serving cell's cell ID, in order to request the second core network function to provide services to the terminal.

[0132] Optionally, before the first core network function selects a new core network function (i.e., the second core network function), if the first core network function determines that it is not the best core network function to provide services to the terminal, for example, if the first core network function is not the best core network function to provide services to the terminal, or if the first core network function is not suitable to continue providing services to the terminal, then the first core network function can determine the second core network function based on the TAI of the terminal's serving cell and / or the cell ID of the terminal's serving cell, in order to request the second core network function to provide services to the terminal.

[0133] In this embodiment, after the terminal switches from the first RAN to the second RAN, the second core network function can be determined through the first core network function, that is, the core network function can be changed to select a new core network function to provide services to the terminal, thereby ensuring the terminal's network service.

[0134] Optionally, after the first core network function determines the second core network function, the method further includes:

[0135] The first core network function sends at least one of the second information and the context information of the terminal to the second core network function;

[0136] The second information includes at least one of the following:

[0137] The base station ID of the second RAN;

[0138] The IP address of the second RAN;

[0139] The FQDN of the second RAN;

[0140] The second RAN assigns a first identifier to the terminal, which is used to identify the terminal. For example, the first identifier may be a RAN UE NGAP ID.

[0141] The first core network function assigns a second identifier to the terminal, which is used to identify the terminal. For example, the second identifier may be the AMF UE NGAP ID.

[0142] Therefore, based on the context information of the terminal and the aforementioned second information, the second core network function can determine which terminal needs to provide services and which second RAN provides services to the terminal, thereby ensuring that the second core network function can send the resource information allocated by the UPF to the terminal to the second RAN.

[0143] Furthermore, the second core network function sends an update message to the SMF to notify the SMF that the second core network function will subsequently provide services to the terminal; the second core network function sends an update message to the second RAN based on the second information to notify the second RAN that the second core network function will subsequently provide services to the terminal.

[0144] In this application, after the terminal switches from the first RAN to the second RAN, the core network function can be changed through the MRU message, thereby further shortening the core network function switching time, reducing switching latency, and helping to improve the user experience of the terminal.

[0145] In this embodiment, during the handover process from the first RAN to the second RAN, the first core network function determines the second core network function providing services to the terminal through a first message. This allows for base station handover first, followed by core network function handover on the core network side, effectively improving handover efficiency and reducing handover latency. Alternatively, after the terminal has switched from the first RAN to the second RAN, the first core network function determines the second core network function providing services to the terminal through a second message. This allows for core network function changes to be implemented after base station handover, further shortening handover latency, improving handover efficiency, and also contributing to improved terminal communication quality and user experience.

[0146] Please refer to Figure 4, which is a flowchart of a communication method provided in an embodiment of this application. The method is executed by a second core network function. As shown in Figure 4, the method includes the following steps:

[0147] Step 401: The second core network function receives at least one of the second information sent by the first core network function and the terminal's context information.

[0148] The second information includes at least one of the following:

[0149] The base station ID of the second RAN;

[0150] The IP address of the second RAN;

[0151] FQDN of the second RAN;

[0152] The second RAN assigns a first identifier to the terminal, which is used to identify the terminal; for example, the first identifier may be a RAN UE NGAP ID.

[0153] The first core network function assigns a second identifier to the terminal, which is used to identify the terminal. For example, the second identifier may be the AMF UE NGAP ID.

[0154] In this embodiment of the application, the first core network function can be understood as the source core network function of the terminal (e.g., S-AMF), or as the core network function currently providing services to the terminal; the second core network function can be understood as the core network function that will provide services to the terminal (e.g., T-AMF).

[0155] In some implementations, the second core network function is determined by the first core network function based on a first message sent by the second RAN, the first message indicating that the terminal has moved to the second RAN; or, the second core network function is determined by the first core network function based on a second message sent by the terminal, the second message being used for mobility registration update. The specific implementation process of the first core network function determining the second core network function based on the first or second message can be referred to the description in the method embodiment shown in Figure 3 above, and will not be repeated in this embodiment.

[0156] In this embodiment of the application, after the first core network function determines the second core network function that provides services to the terminal, the first core network function sends the terminal's context information and the aforementioned second information to the second core network function. Based on the terminal's context information and the aforementioned second information, the second core network function can also know which terminal needs to provide services and which second RAN provides services to the terminal. This ensures that the second core network function can send the resource information allocated by the UPF to the terminal to the second RAN, thereby ensuring communication between the terminal, the base station, and the core network function.

[0157] Optionally, the method further includes:

[0158] The second core network function sends a third message to the second RAN;

[0159] The third message may be used to instruct the second core network function to provide services to the terminal; or, the third message may be used to establish a user plane connection between the second RAN and the third core network function; or, the third message may be used to send the context of the terminal to the second RAN.

[0160] For example, after a terminal switches from a first RAN to a second RAN, the first core network function sends the terminal's context information and the second information to the second core network function. Upon receiving the terminal's context information and the second information, the second core network function sends a fourth message to a fourth core network function (e.g., SMF). This fourth message instructs the second core network function to provide services to the terminal; that is, it notifies the fourth core network function that the second core network function will subsequently provide services to the terminal. Further, the second core network function sends a third message to the second RAN based on the second information. This third message instructs the second core network function to provide services to the terminal, thus enabling the second RAN to determine which core network function will subsequently provide services to the terminal, effectively ensuring communication between the terminal, the base station, and the core network functions.

[0161] Alternatively, during the handover process from the first RAN to the second RAN, after the first core network function sends the terminal's context information and the second information to the second core network function, the second core network function sends an update SM context request to the SMF, which carries the resource information allocated to the terminal by the second RAN. Further, the SMF sends an N4 session modify request to the UPF, which sends the resource information allocated to the terminal by the second RAN to the UPF and requests to obtain the resource information allocated to the terminal by the UPF from the UPF; the SMF sends the resource information allocated to the terminal by the UPF to the second core network function; the second core network function sends a third message to the second RAN based on the second information, which is used to establish a user plane connection between the second RAN and the third core network function (e.g., the UPF). In this case, the third message carries the resource information allocated to the terminal by the third core network function (e.g., the UPF), thereby ensuring communication between the terminal and the second RAN.

[0162] Alternatively, after the first core network function sends the terminal's context information and the second information to the second core network function, the second core network function sends a third message to the second RAN based on the second information. The third message is used to send the terminal's context to the second RAN, thereby ensuring communication between the terminal and the second RAN.

[0163] Please refer to Figure 5, which is a flowchart of a third embodiment of a communication method provided in this application. The method is executed by a second RAN. As shown in Figure 5, the method includes the following steps:

[0164] Step 501: During the handover process from the first RAN to the second RAN, the second RAN sends a first message to the first core network function. This first message is used to identify the second core network function and to indicate that the terminal has moved to the second RAN; or...

[0165] The second RAN obtains a first instruction from the terminal and determines a second core network function based on the first instruction, wherein the first instruction is used to indicate the selection of a new core network function.

[0166] In one implementation, during the handover process from a first RAN to a second RAN, the second RAN sends a first message to a first core network function, the first message being used to identify the second core network function. The handover process from the first RAN to the second RAN includes the following steps:

[0167] According to the configuration of the first RAN (e.g., source RAN, S-RAN), the terminal sends a measurement report to the first RAN, which includes the cell ID information of one or more candidate cells;

[0168] The first RAN selects the second RAN (e.g., target RAN, T-RAN) based on the measurement report and sends a handover request to the second RAN. The handover request includes the ID of the first core network function serving the terminal: such as the globally unique AMF Identifier (GUAMI) and the target cell ID.

[0169] The second RAN sends a handover request confirmation to the first RAN, carrying the radio resource information allocated by the second RAN to the terminal;

[0170] The first RAN sends a handover command to the terminal, carrying the radio resource information allocated to the terminal by the second RAN;

[0171] The terminal accesses the second RAN based on the radio resource information allocated by the second RAN and sends a handover complete message.

[0172] Furthermore, the second RAN sends a first message to the first core network function. This first message is used to determine the second core network function. For example, the first message carries at least one of the TAI of the serving cell of the terminal and the cell ID of the serving cell of the terminal, thereby enabling the first core network function to determine the second core network function based on the first message. The specific implementation process of the first core network function determining the second core network function can be referred to the description in the method embodiment described in Figure 3, and will not be repeated in this embodiment.

[0173] Optionally, in this embodiment, the method further includes:

[0174] The second RAN receives a third message sent by the second core network function, the third message being used to establish a user plane connection between the second RAN and the third core network function; or, the third message being used to send the context of the terminal to the second RAN.

[0175] It should be noted that after the first core network function determines the second core network function, the first core network function sends at least one of the following to the second core network function: second information and terminal context information. The specific content of the second information can be referred to the description in the method embodiment shown in Figure 3, and will not be repeated here. Further, the second core network function sends an update SM context request to the SMF, which carries resource information allocated to the terminal by the second RAN. Further, the SMF sends an N4 session modify request to the UPF, used to send the resource information allocated to the terminal by the second RAN to the UPF, and request to obtain the resource information allocated to the terminal by the UPF from the UPF; the SMF sends the resource information allocated to the terminal by the UPF to the second core network function; the second core network function sends a third message to the second RAN according to the second information, the third message being used to establish a user plane connection between the second RAN and the third core network function (e.g., the UPF). In this case, the third message carries the resource information allocated to the terminal by the third core network function (e.g., the UPF), thereby ensuring communication between the terminal and the second RAN.

[0176] Alternatively, after the first core network function sends the terminal's context information and the second information to the second core network function, the second core network function sends a third message to the second RAN based on the second information. The third message is used to send the terminal's context information to the second RAN, thereby ensuring communication between the terminal and the second RAN.

[0177] Alternatively, in another implementation, after the terminal switches from the first RAN to the second RAN, the terminal sends an RRC message to the second RAN. This RRC message carries a first indication, meaning the second RAN obtains the first indication from the terminal. This first indication is used to select a new core network function. The second RAN then selects and determines a second core network function based on the first indication. The second RAN determines the second core network function to provide services to the terminal based on at least one of the terminal's serving cell's TAI and the terminal's serving cell's cell ID.

[0178] In this way, after the terminal completes the handover, it can use RRC messages to indicate the selection of a new core network function, that is, to switch the core network function. This can further shorten the handover time of the core network function, reduce the handover latency, and help improve the communication quality and user experience of the terminal.

[0179] Optionally, the second RAN obtains a first instruction from the terminal, including:

[0180] The second RAN obtains the first instruction and the fifth message from the terminal;

[0181] After the second RAN determines the second core network function according to the first instruction, the method further includes:

[0182] The second RAN sends the fifth message to the second core network function;

[0183] The fifth message is used to update the mobility registration.

[0184] For example, the RRC message sent by the terminal to the second RAN carries the first indication and the fifth message, such as the fifth message being an MRU message; after the second RAN determines the second core network function according to the first indication, it sends the fifth message to the second core network function, so that the second core network function can know that the terminal needs to perform mobility registration update according to the fifth message, thereby ensuring that the second core network function can complete the mobility registration update of the terminal.

[0185] Further, the second core network function requests the terminal's context information from the first core network function based on the fifth message, and obtains the terminal's context information sent by the first core network function; the second core network function sends a third message (e.g., an update message) to the SMF, which notifies the SMF that the second core network function will subsequently provide services to the terminal. Further, the second core network function sends a response message to the fifth message (e.g., an MRU accept message) to the terminal, thereby notifying the terminal that the registration update is complete. The response message to the fifth message may be routed from the second core network function to the terminal via the second RAN.

[0186] In this embodiment of the application, after the terminal switches from the first RAN to the second RAN, the second RAN can determine the second core network function according to the first instruction obtained from the terminal. Thus, the second RAN can determine the second core network function after the switch is completed, which means that the terminal switches the core network function. This can further shorten the switch time, reduce the switch latency, and improve the terminal communication quality and user experience.

[0187] Please refer to Figure 6a, which is a flowchart of a communication method provided in an embodiment of this application. As shown in Figure 6a, the method includes the following steps:

[0188] 11. The UE sends a measurement report to the S-RAN (first RAN) according to the S-RAN configuration. The measurement report contains the cell ID information of one or more candidate cells.

[0189] 12. Based on the measurement report, the S-RAN selects the T-RAN (second RAN) and sends a handover request to the T-RAN. The handover request includes the ID of the AMF (first core network function) serving the UE: such as the globally unique AMF Identifier (GUAMI) and the target cell ID.

[0190] 13. The T-RAN sends a handover request confirmation to the S-RAN, carrying the radio resource information allocated by the T-RAN to the UE;

[0191] 14. The T-RAN sends a handover command to the UE, carrying the radio resource information allocated to the UE by the T-RAN;

[0192] 15. The UE accesses the T-RAN based on the radio resource information allocated to the UE by the T-RAN and sends a handover complete message;

[0193] 16. T-RAN sends an N2 path switch request to S-AMF based on the GUAMI information, carrying the cell ID and TAI of the cell where the UE is located, as well as the resource information allocated to the UE by the T-RAN side;

[0194] 17. The S-AMF selects the T-AMF based on at least one of the cell ID and TAI of the cell where the UE is located, carried in the N2 path Switch request;

[0195] Optionally, before selecting a T-AMF, the S-AMF determines that it will not continue to provide services to the UE, and determines the T-AMF based on at least one of the TAI and Cell ID of the cell where the UE is located;

[0196] S-AMF can choose T-AMF itself, or request NRF to make the selection.

[0197] Alternatively, step 17 may also include:

[0198] Option 1: T-RAN selects T-AMF and sends the T-AMF information to S-AMF in step 16; wherein, T-RAN selects T-AMF based on at least one of the TAI and Cell ID of the cell where the UE is located;

[0199] Option 2: S-RAN selects T-AMF and sends the T-AMF information to T-RAN in step 12. T-RAN then sends the T-AMF information to S-AMF in step 16. S-RAN selects T-AMF based on at least one of the target cell's Cell ID, base station ID, and TAI.

[0200] 18. The S-AMF sends the UE's context information and second information to the determined T-AMF, the second information including at least one of the following:

[0201] T-RAN base station ID;

[0202] T-RAN's IP address;

[0203] FQDN of T-RAN;

[0204] The ID assigned to the UE by the T-RAN, for example, RAN UE NGAP ID;

[0205] The ID assigned to the UE by S-AMF, for example, AMF UE NGAP ID.

[0206] 19. The T-AMF sends an update session management (SM) context request to the SMF, carrying the resource information allocated to the UE by the T-RAN side;

[0207] 20. The SMF sends an N4 session modify request to the UPF to send T-RAN side resource information to the UPF and requests to obtain UPF side resource information from the UPF.

[0208] 21. The SMF sends an update SM context request confirmation to the T-AMF, carrying the resource information of the UPF;

[0209] 22. The T-AMF sends the resource information allocated by the UPF to the UE to the T-RAN side;

[0210] 23. The T-RAN determines the UE and S-RAN based on the second information and sends a release message to the S-RAN to release resources.

[0211] In this embodiment, under the RAN service scenario, any RAN can communicate with any AMF. Therefore, when a UE moves between two base stations, the base station can be changed first via Xn handover, and then the AMF can be changed on the core network side, thereby accelerating the handover process, reducing handover latency, and also helping to save network resources.

[0212] Please refer to Figure 6b, which is a flowchart of a communication method provided in an embodiment of this application. As shown in Figure 6b, the method includes the following steps:

[0213] 31. The UE completes the handover process between UEs as shown in Figure 2a and remains in S-AMF;

[0214] 32. The UE sends an RRC message to the T-RAN, carrying the first indication and the MRU message;

[0215] The first instruction is used to indicate the selection of a new AMF;

[0216] The MRU message is a registration message carrying a mobility indication;

[0217] 33. The T-RAN selects the T-AMF based on the first instruction, for example, based on at least one of the TAI and Cell ID of the cell where the UE is camped;

[0218] 34. T-RAN sends an MRU message to T-AMF;

[0219] 35. The T-AMF requests the UE's context information from the S-AMF based on the MRU message and obtains the UE's context information;

[0220] 36. The T-AMF sends an Update SM Context Request message to the SMF to notify the SMF that the T-AMF will subsequently provide services to the UE;

[0221] 37. T-AMF sends an MRU accept message to the UE.

[0222] In this embodiment, the UE can change the AMF through the MRU message after completing the handover between base stations, which can further shorten the handover time, reduce the handover latency, and help improve the UE communication quality and user experience.

[0223] Please refer to Figure 6c, which is a flowchart of a communication method provided in an embodiment of this application. As shown in Figure 6c, the method includes the following steps:

[0224] 41. The UE completes the handover process between UEs as shown in Figure 2a and remains in S-AMF;

[0225] 42. The UE initiates an MRU request, which is routed to the S-AMF by the T-RAN;

[0226] 43. S-AMF selects T-AMF, for example, based on at least one of the TAI and Cell ID of the cell where the UE is located;

[0227] Optionally, if the S-AMF determines that it will not continue to provide services to the UE before selecting the T-AMF, the T-AMF is determined based on at least one of the TAI and Cell ID of the cell where the UE is located.

[0228] 44. The S-AMF sends the UE's context information and second information to the designated T-AMF;

[0229] The second information includes at least one of the following:

[0230] T-RAN base station ID,

[0231] T-RAN IP address,

[0232] FQDN of T-RAN

[0233] The ID assigned to the UE by the T-RAN, for example, RAN UE NGAP ID.

[0234] The ID assigned to the UE by S-AMF, for example, AMF UE NGAP ID;

[0235] 45. The T-AMF sends an update SM context information request to the SMF to notify the SMF that the T-AMF will subsequently provide services to the UE;

[0236] 46. ​​The T-AMF sends a UE context update message to the T-RAN based on the second information, which is used to notify the T-RAN that the T-AMF will provide services to the UE thereafter.

[0237] In this embodiment, after completing the handover between base stations, the UE can change the AMF through the MRU request message, which can further shorten the handover time, reduce the handover latency, and help improve the UE communication quality and user experience.

[0238] The communication method provided in this application can be executed by a communication device. This application uses the example of a communication device executing the communication method to illustrate the communication device provided in this application.

[0239] This application provides a communication device. As an example, the communication device may be a communication equipment or a component within a communication equipment, such as a chip. The communication equipment may be a terminal, a network-side device, or a server, etc. Exemplarily, the terminal may include, but is not limited to, the type of terminal 11 listed above, and the network-side device may include, but is not limited to, the type of network-side device 12 listed above. This application does not impose specific limitations.

[0240] The communication device includes a receiving module, a transmitting module, and a processing module. These modules can be implemented in software or hardware. When implemented in hardware, the processing module can be implemented by a processor. For example, the processor can include general-purpose processors, special-purpose processors, such as a Central Processing Unit (CPU), microprocessor, Digital Signal Processor (DSP), Artificial Intelligence (AI) processor, Graphics Processing Unit (GPU), Application Specific Integrated Circuit (ASIC), Network Processor (NP), Field Programmable Gate Array (FPGA), or other programmable logic devices, gate circuits, transistors, discrete hardware components, etc. The receiving and transmitting modules can be implemented by a communication interface, which can include one or more of the following: transceiver, pins, circuits, bus, radio frequency unit, etc.

[0241] Please refer to Figure 7, which is a structural diagram of one of the communication devices provided in an embodiment of this application. The communication device is applied to a first core network function. As shown in Figure 7, the communication device 700 includes:

[0242] The first receiving module 701 is used to receive a first message sent by the second RAN during the process of the terminal switching from the first RAN to the second RAN;

[0243] The first processing module 702 is used to determine the second core network function based on the first message, wherein the first message is used to indicate that the terminal has moved to the second RAN;

[0244] or,

[0245] The first receiving module 701 is used to receive a second message sent by the terminal after the terminal switches from the first RAN to the second RAN;

[0246] The first processing module 702 is used to determine the second core network function based on the second message, wherein the second message is used to perform mobility registration update.

[0247] Optionally, the first processing module 702 is further configured to:

[0248] The second core network function is determined based on the first information included in the first message, wherein the first information includes at least one of the following:

[0249] The TAI of the serving cell of the terminal;

[0250] The cell ID of the serving cell of the terminal.

[0251] Optionally, if it is determined from the first message that the core network function needs to be changed, the first processing module 702 is used to determine the second core network function.

[0252] Optionally, the first processing module 702 is further configured to:

[0253] The Network Request Function (NRF) determines the second core network function.

[0254] Optionally, the first message is a route switching message; or, the second message is a Mobility Registration Update (MRU) message.

[0255] Optionally, when the terminal is in the process of switching from the first RAN to the second RAN, the first processing module 702 is further configured to:

[0256] The second core network function is determined based on the information contained in the first message that indicates the second core network function.

[0257] Optionally, the device further includes:

[0258] The first sending module is used to send at least one of the second information and the context information of the terminal to the second core network function;

[0259] The second information includes at least one of the following:

[0260] The base station ID of the second RAN;

[0261] The IP address of the second RAN;

[0262] The FQDN of the second RAN;

[0263] The second RAN assigns a first identifier to the terminal, and the first identifier is used to identify the terminal;

[0264] The first core network function assigns a second identifier to the terminal, which is used to identify the terminal.

[0265] In this embodiment, during the handover process from the first RAN to the second RAN, the device determines the second core network function providing services to the terminal through a first message. This allows for base station handover first, followed by core network function handover on the core network side, effectively improving handover efficiency and reducing handover latency. Alternatively, after the terminal has switched from the first RAN to the second RAN, the device determines the second core network function providing services to the terminal through a second message. This allows for core network function change after base station handover is completed, further shortening handover latency and improving handover efficiency.

[0266] The communication device 700 provided in this application embodiment can realize the various processes of the first core network function implementation in the method embodiment of FIG3 and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0267] Please refer to Figure 8, which is a second structural diagram of a communication device provided in an embodiment of this application. The communication device is applied to a second core network function. As shown in Figure 8, the communication device 800 includes:

[0268] The second receiving module 801 is used to receive at least one of the second information sent by the first core network function and the context information of the terminal;

[0269] The second information includes at least one of the following:

[0270] The base station ID of the second RAN;

[0271] The IP address of the second RAN;

[0272] FQDN of the second RAN;

[0273] The second RAN assigns a first identifier to the terminal, the first identifier being used to identify the terminal;

[0274] The first core network function assigns a second identifier to the terminal, which is used to identify the terminal.

[0275] Optionally, the device further includes:

[0276] The second sending module is used to send a third message to the second RAN;

[0277] The third message may be used to instruct the second core network function to provide services to the terminal; or, the third message may be used to establish a user plane connection between the second RAN and the third core network function; or, the third message may be used to send the context of the terminal to the second RAN.

[0278] Optionally, when the third message is used to establish a user plane connection between the second RAN and the third core network function, the third message carries resource information allocated by the third core network function for the terminal.

[0279] Optionally, the device is further used for:

[0280] A fourth message is sent to the fourth core network function, the fourth message being used to instruct the second core network function to provide services to the terminal.

[0281] In this embodiment of the application, the device receives the context information of the terminal and the aforementioned second information, thereby knowing which terminal needs to provide services and which second RAN provides services to the terminal. This ensures that the second core network function can send the resource information allocated by the UPF to the terminal to the second RAN, thus ensuring communication between the terminal, the base station, and the core network function.

[0282] The communication device 800 provided in this application embodiment can realize the various processes of the second core network function implementation in the method embodiment of FIG4 and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0283] Please refer to Figure 9, which is a third structural diagram of a communication device provided in an embodiment of this application. The communication device is applied to a second RAN. As shown in Figure 9, the communication device 900 includes:

[0284] The third sending module 901 is used to send a first message to the first core network function during the process of the terminal switching from the first RAN to the second RAN. The first message is used to determine the second core network function and to indicate that the terminal has moved to the second RAN.

[0285] Or the device may include:

[0286] The second processing module 902 is used to obtain a first instruction from the terminal and determine a second core network function based on the first instruction, wherein the first instruction is used to indicate the selection of a new core network function.

[0287] Optionally, the second processing module 902 is further configured to:

[0288] Obtain the first instruction and the fifth message from the terminal;

[0289] The third sending module 901 is further configured to: send the fifth message to the second core network function;

[0290] The fifth message is used to update the mobility registration.

[0291] Optionally, the second processing module 902 is further configured to:

[0292] Select a new core network function according to the first instruction, and determine the second core network function as the new core network function according to at least one of the TAI and cell ID of the serving cell of the terminal.

[0293] Optionally, when the terminal is in the process of switching from the first RAN to the second RAN, the device further includes:

[0294] The third receiving module is configured to receive a third message sent by the second core network function, the third message being used to establish a user plane connection between the second RAN and the third core network function; or, the third message being used to send the context of the terminal to the second RAN.

[0295] Optionally, when the third message is used to establish a user plane connection between the second RAN and the third core network function, the third message carries resource information allocated by the third core network function for the terminal.

[0296] In this embodiment of the application, after the terminal switches from the first RAN to the second RAN, the second RAN can determine the second core network function according to the first instruction obtained from the terminal. Thus, the second RAN can determine the second core network function after the switch is completed, which means that the terminal switches the core network function. This can further shorten the switch time, reduce the switch latency, and improve the terminal communication quality and user experience.

[0297] The communication device 900 provided in this application embodiment can implement the various processes implemented by the second RAN in the method embodiment of FIG5 and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0298] As shown in Figure 10, this application embodiment also provides a communication device 1000, including a processor 1001 and a memory 1002. The memory 1002 stores programs or instructions that can run on the processor 1001. For example, when the communication device 1000 functions as a first core network, the program or instructions executed by the processor 1001 implement the various steps of the communication method embodiment described in Figure 3 above, and achieve the same technical effect. When the communication device 1000 functions as a second core network, the program or instructions executed by the processor 1001 implement the various steps of the communication method embodiment described in Figure 4 above, and achieve the same technical effect. When the communication device 1000 functions as a second RAN, the program or instructions executed by the processor 1001 implement the various steps of the communication method embodiment described in Figure 5 above, and achieve the same technical effect. To avoid repetition, these will not be described again here.

[0299] This application also provides a network-side device, including a processor and a communication interface. The communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the steps of the method embodiment shown in FIG3, FIG4, or FIG5. This network-side device embodiment corresponds to the above-described network-side device method embodiment. All implementation processes and methods of the above-described method embodiments can be applied to this network-side device embodiment and can achieve the same technical effect.

[0300] Specifically, this application also provides a network-side device. As shown in FIG11, the network-side device 1100 includes a processor 1101, a network interface 1102, and a memory 1103. The network-side device may be the communication device shown in FIG7, FIG8, or FIG9. The network interface 1102 is, for example, a Common Public Radio Interface (CPRI).

[0301] Specifically, the network-side device 1100 in this application embodiment further includes: instructions or programs stored in memory 1103 and executable on processor 1101. Processor 1101 calls the instructions or programs in memory 1103 to execute the methods executed by the modules shown in FIG7, FIG8 or FIG9 and achieve the same technical effect. To avoid repetition, it will not be described in detail here.

[0302] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described communication method embodiments and achieve the same technical effects. To avoid repetition, they will not be described again here.

[0303] The processor mentioned above is the processor in the terminal described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk. In some examples, the readable storage medium may be a non-transient readable storage medium.

[0304] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above-described communication method embodiments and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0305] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0306] This application also provides a computer program / program product, which is stored in a storage medium and executed by at least one processor to implement the various processes of the above-described communication method embodiments, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0307] This application also provides a communication system, including: a first core network function, a second core network function, and a second RAN. The first core network function can be used to perform the steps of the communication method described above, the second core network function can be used to perform the steps of the communication method described above, and the second RAN can be used to perform the steps of the communication method described above.

[0308] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0309] From the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of computer software products plus necessary general-purpose hardware platforms, and of course, they can also be implemented by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes several instructions to cause the terminal or network-side device to execute the methods described in the various embodiments of this application.

[0310] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other implementations under the guidance of this application without departing from the spirit and scope of the claims. All of these implementations are within the protection scope of this application.

Claims

1. A communication method, comprising: During the handover process from a first radio access network (RAN) to a second RAN, a first core network function receives a first message sent by the second RAN and determines a second core network function based on the first message, wherein the first message indicates that the terminal has moved to the second RAN; or, After the terminal switches from the first RAN to the second RAN, the first core network function receives a second message sent by the terminal and determines the second core network function based on the second message, wherein the second message is used to perform mobility registration update.

2. The method of claim 1, wherein, The first core network function determines the second core network function based on the first message, including: The first core network function determines the second core network function based on the first information included in the first message, wherein the first information includes at least one of the following: The tracking area identifier (TAI) of the serving cell of the terminal; The cell identifier ID of the serving cell of the terminal.

3. The method of claim 1 or 2, wherein, The first core network function determines the second core network function based on the first message, including: If the first core network function determines that a change in the core network function is required based on the first message, the first core network function determines the second core network function.

4. The method according to any one of claims 1 to 3, wherein, The first core network function determines the second core network function, including: The first core network function requests network storage function (NRF) to determine the second core network function.

5. The method of claim 1, wherein, The first message includes a path switching message; or, The second message includes a Mobility Registration Update (MRU) message.

6. The method of claim 1, wherein, When the terminal is in the process of switching from the first RAN to the second RAN, the first core network function determines the second core network function based on the first message, including: The first core network function determines the second core network function based on the information contained in the first message that indicates the second core network function.

7. The method according to any one of claims 1-6, further comprising: The first core network function sends at least one of the second information and the context information of the terminal to the second core network function; The second information includes at least one of the following: The base station ID of the second RAN; The Internet Protocol (IP) address of the second RAN; The fully qualified domain name (FQDN) of the second RAN; The second RAN assigns a first identifier to the terminal, and the first identifier is used to identify the terminal; The first core network function assigns a second identifier to the terminal, which is used to identify the terminal.

8. A communication method, comprising: The second core network function receives at least one of the second information sent by the first core network function and the terminal's context information; The second information includes at least one of the following: The base station ID of the second RAN; The IP address of the second RAN; FQDN of the second RAN; The second RAN assigns a first identifier to the terminal, the first identifier being used to identify the terminal; The first core network function assigns a second identifier to the terminal, which is used to identify the terminal.

9. The method according to claim 8, further comprising: The second core network function sends a third message to the second RAN; The third message can be used to instruct the second core network function to provide services to the terminal; or, the third message can be used to establish a user plane connection between the second RAN and the third core network function; or, the third message can be used to send the terminal's context information to the second RAN.

10. The method of claim 9, wherein, When the third message is used to establish a user plane connection between the second RAN and the third core network function, the third message carries resource information allocated by the third core network function for the terminal.

11. The method of claim 8, further comprising: The second core network function sends a fourth message to the fourth core network function, the fourth message being used to instruct the second core network function to provide services to the terminal.

12. A communication method, comprising: During the handover process from the first RAN to the second RAN, the second RAN sends a first message to the first core network function. This first message is used to identify the second core network function and to indicate that the terminal has moved to the second RAN; or... The second RAN obtains a first instruction from the terminal and determines a second core network function based on the first instruction, wherein the first instruction is used to indicate the selection of a new core network function.

13. The method according to claim 12, wherein, The second RAN obtains a first instruction from the terminal, including: The second RAN obtains the first instruction and the fifth message from the terminal; After the second RAN determines the second core network function according to the first instruction, the method further includes: The second RAN sends the fifth message to the second core network function; The fifth message is used to update the mobility registration.

14. The method according to claim 12, wherein, The second RAN determines the second core network function according to the first instruction, including: The second RAN selects a new core network function according to the first instruction, and determines the second core network function as the new core network function according to at least one of the TAI and cell ID of the serving cell of the terminal.

15. The method according to claim 12, wherein, When the terminal is in the process of switching from a first RAN to a second RAN, the method further includes: The second RAN receives a third message sent by the second core network function, the third message being used to establish a user plane connection between the second RAN and the third core network function; or, the third message being used to send the terminal's context information to the second RAN.

16. The method according to claim 15, wherein, When the third message is used to establish a user plane connection between the second RAN and the third core network function, the third message carries resource information allocated by the third core network function for the terminal.

17. A communication device applied to a first core network function, the device comprising: The first receiving module is used to receive a first message sent by the second RAN during the process of the terminal switching from the first RAN to the second RAN; A first processing module is configured to determine a second core network function based on the first message, wherein the first message is used to indicate that the terminal has moved to the second RAN; or, The first receiving module is used to receive a second message sent by the terminal after the terminal switches from the first RAN to the second RAN; The first processing module is used to determine the second core network function based on the second message, wherein the second message is used to perform mobility registration update.

18. The apparatus according to claim 17, wherein, The first processing module is also used for: The second core network function is determined based on the first information included in the first message, wherein the first information includes at least one of the following: The TAI of the serving cell of the terminal; The cell ID of the serving cell of the terminal.

19. The apparatus according to claim 17, wherein, When the terminal is in the process of switching from the first RAN to the second RAN, the first processing module is further configured to: The second core network function is determined based on the information contained in the first message that indicates the second core network function.

20. The apparatus according to any one of claims 17-19, further comprising: The first sending module is used to send at least one of the second information and the context information of the terminal to the second core network function; The second information includes at least one of the following: The base station ID of the second RAN; The IP address of the second RAN; The FQDN of the second RAN; The second RAN assigns a first identifier to the terminal, and the first identifier is used to identify the terminal; The first core network function assigns a second identifier to the terminal, which is used to identify the terminal.

21. A communication device applied to a second core network function, the device comprising: The second receiving module is used to receive at least one of the second information sent by the first core network function and the context information of the terminal; The second information includes at least one of the following: The base station ID of the second RAN; The IP address of the second RAN; FQDN of the second RAN; The second RAN assigns a first identifier to the terminal, the first identifier being used to identify the terminal; The first core network function assigns a second identifier to the terminal, which is used to identify the terminal.

22. The apparatus of claim 21, further comprising: The second sending module is used to send a third message to the second RAN; The third message can be used to instruct the second core network function to provide services to the terminal; or, the third message can be used to establish a user plane connection between the second RAN and the third core network function; or, the third message can be used to send the terminal's context information to the second RAN.

23. The apparatus according to claim 22, wherein, When the third message is used to establish a user plane connection between the second RAN and the third core network function, the third message carries resource information allocated by the third core network function for the terminal.

24. A communication device applied to a second RAN, the device comprising: The third sending module is used to send a first message to the first core network function during the process of the terminal switching from the first RAN to the second RAN. The first message is used to identify the second core network function and to indicate that the terminal has moved to the second RAN. Or the device may include: The second processing module is used to obtain a first instruction from the terminal and determine a second core network function based on the first instruction, wherein the first instruction is used to indicate the selection of a new core network function.

25. The apparatus according to claim 24, wherein, The second processing module is also used for: Obtain the first instruction and the fifth message from the terminal; The third sending module is also used to: send the fifth message to the second core network function; The fifth message is used to update the mobility registration.

26. The apparatus according to claim 24, wherein, The second processing module is also used for: Select a new core network function according to the first instruction, and determine the second core network function as the new core network function according to at least one of the TAI and cell ID of the serving cell of the terminal.

27. The apparatus according to claim 24, wherein, When the terminal is in the process of switching from the first RAN to the second RAN, the device further includes: The third receiving module is used to receive a third message sent by the second core network function, the third message being used to establish a user plane connection between the second RAN and the third core network function; or, the third message being used to send the context information of the terminal to the second RAN.

28. A network-side device, comprising a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the communication method as described in any one of claims 1-16.

29. A readable storage medium storing a program or instructions that, when executed by a processor, implement the steps of the communication method as described in any one of claims 1-16.

30. A computer program product stored in a storage medium, the computer program product being executed by at least one processor to implement the steps of the communication method as described in any one of claims 1-16.

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