Information sending method and apparatus, information receiving method and apparatus, and related device

Abstract

The present application relates to the technical field of communications, and discloses an information sending method and apparatus, an information receiving method and apparatus, and a related device. The method in embodiments of the present application comprises: a first access network device executes a first operation, the first operation comprising at least one of the following: when the first access network device satisfies a first condition, the first access network device sends a first message to a core network device, wherein the first message is used for requesting first key information, and the first key information is key information used for a terminal to perform LTM handover between CUs; and the first access network device sends a second message to the core network device, wherein the second message comprises first indication information.

Description

Information sending method, information receiving method, device and related equipment

[0001] Cross-references

[0002] This disclosure claims priority to Chinese patent application No. 2024102165661, filed on February 27, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application belongs to the field of communication technology, and specifically relates to an information sending method, an information receiving method, an apparatus and related equipment. Background Art

[0004] In related art, when a terminal performs Layer 1 or Layer 2-triggered mobility (LTM) handover between centralized units (CUs), multiple key information can be allocated to the candidate CU during the LTM preparation process to avoid Radio Resource Control (RRC) reconfiguration during the cell handover process. However, after the terminal completes an LTM handover, the terminal's new serving access network device must perform a path switch process with the core network device. The core network device then sends a Path Switch Request Acknowledge message to the serving access network device, which contains the key information for the terminal's subsequent LTM handover. This results in the terminal being unable to determine whether to use the key information in the PATH Switch Request Acknowledge message or the key information allocated during the LTM preparation process for the next LTM handover. Consequently, the terminal suffers from duplicate key allocation during the LTM handover process between CUs, making it impossible for the terminal to accurately determine the key used for authentication. This results in a high probability of failure in the LTM handover process between CUs. Summary of the Invention

[0005] The embodiments of the present application provide an information sending method, an information receiving method, an apparatus and related equipment, which can solve the problem of a high probability of failure of the LTM switching process between CUs of a terminal.

[0006] In a first aspect, a method for sending information is provided, comprising:

[0007] The first access network device performs a first operation, where the first operation includes at least one of the following:

[0008] When the first access network device meets the first condition, the first access network device sends a first message to the core network device, where the first message is used to request first key information, where the first key information is key information used by the terminal to perform LTM switching between CUs;

[0009] The first access network device sends a second message to the core network device, where the second message includes first indication information;

[0010] The first indication information is used to indicate at least one of the following:

[0011] The terminal performs LTM switching between CUs;

[0012] The second message is associated with the LTM switching process between CUs of the terminal;

[0013] The first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal;

[0014] The first access network device does not expect the core network device to allocate key information for the terminal for the next LTM handover between CUs;

[0015] The first access network device ignores the key information allocated by the core network device to the terminal for the next LTM handover between CUs;

[0016] The first access network device ignores the key information in the path switch request confirmation message.

[0017] In a second aspect, a method for receiving information is provided, comprising:

[0018] The core network device performs a second operation, where the second operation includes at least one of the following:

[0019] The core network device receives a first message sent by a first access network device, where the first message is used to request first key information, where the first key information is key information used by the terminal to perform LTM switching between CUs;

[0020] The core network device receives a second message sent by the first access network device, where the second message includes first indication information;

[0021] The first indication information is used to indicate at least one of the following:

[0022] The terminal performs LTM switching between CUs;

[0023] The second message is associated with the LTM switching process between CUs of the terminal;

[0024] The first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal;

[0025] The first access network device does not expect the core network device to allocate key information for the terminal for the next LTM handover between CUs;

[0026] The first access network device ignores the key information allocated by the core network device to the terminal for the next LTM handover between CUs;

[0027] The first access network device ignores the key information in the path switch request confirmation message.

[0028] In a third aspect, an information sending device is provided, comprising:

[0029] The execution module is configured to execute a first operation, where the first operation includes at least one of the following:

[0030] When the first access network device meets the first condition, sending a first message to the core network device, where the first message is used to request first key information, where the first key information is key information used by the terminal to perform LTM switching between CUs;

[0031] Sending a second message to the core network device, where the second message includes the first indication information;

[0032] The first indication information is used to indicate at least one of the following:

[0033] The terminal performs LTM switching between CUs;

[0034] The second message is associated with the LTM switching process between CUs of the terminal;

[0035] The first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal;

[0036] The first access network device does not expect the core network device to allocate key information for the terminal for the next LTM handover between CUs;

[0037] The first access network device ignores the key information allocated by the core network device to the terminal for the next LTM handover between CUs;

[0038] The first access network device ignores the key information in the path switch request confirmation message.

[0039] In a fourth aspect, an information receiving device is provided, comprising:

[0040] The execution module is configured to execute a second operation, where the second operation includes at least one of the following:

[0041] receiving a first message sent by a first access network device, where the first message is used to request first key information, where the first key information is key information used by the terminal to perform LTM switching between CUs;

[0042] receiving a second message sent by the first access network device, where the second message includes first indication information;

[0043] The first indication information is used to indicate at least one of the following:

[0044] The terminal performs LTM switching between CUs;

[0045] The second message is associated with the LTM switching process between CUs of the terminal;

[0046] The first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal;

[0047] The first access network device does not expect the core network device to allocate key information for the terminal for the next LTM handover between CUs;

[0048] The first access network device ignores the key information allocated by the core network device to the terminal for the next LTM handover between CUs;

[0049] The first access network device ignores the key information in the path switch request confirmation message.

[0050] In a fifth aspect, a communication device is provided, comprising a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the program or instructions are executed by the processor, the steps of the method described in the first aspect are implemented, or the steps of the method described in the second aspect are implemented.

[0051] In a sixth aspect, a first access network device is provided, including a processor and a communication interface, wherein the processor is configured to:

[0052] Perform a first operation, where the first operation includes at least one of the following:

[0053] When the first access network device meets the first condition, the first access network device sends a first message to the core network device, where the first message is used to request first key information, where the first key information is key information used by the terminal to perform LTM switching between CUs;

[0054] The first access network device sends a second message to the core network device, where the second message includes first indication information;

[0055] The first indication information is used to indicate at least one of the following:

[0056] The terminal performs LTM switching between CUs;

[0057] The second message is associated with the LTM switching process between CUs of the terminal;

[0058] The first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal;

[0059] The first access network device does not expect the core network device to allocate key information for the terminal for the next LTM handover between CUs;

[0060] The first access network device ignores the key information allocated by the core network device to the terminal for the next LTM handover between CUs;

[0061] The first access network device ignores the key information in the path switch request confirmation message.

[0062] In a seventh aspect, a core network device is provided, including a processor and a communication interface, wherein the processor is configured to:

[0063] Perform a second operation, where the second operation includes at least one of the following:

[0064] The core network device receives a first message sent by a first access network device, where the first message is used to request first key information, where the first key information is key information used by the terminal to perform LTM switching between CUs;

[0065] The core network device receives a second message sent by the first access network device, where the second message includes first indication information;

[0066] The first indication information is used to indicate at least one of the following:

[0067] The terminal performs LTM switching between CUs;

[0068] The second message is associated with the LTM switching process between CUs of the terminal;

[0069] The first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal;

[0070] The first access network device does not expect the core network device to allocate key information for the terminal for the next LTM handover between CUs;

[0071] The first access network device ignores the key information allocated by the core network device to the terminal for the next LTM handover between CUs;

[0072] The first access network device ignores the key information in the path switch request confirmation message.

[0073] In an eighth aspect, a readable storage medium is provided, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the method described in the first aspect or the steps of the method described in the second aspect are implemented.

[0074] In the ninth aspect, a chip is provided, comprising a processor and a communication interface, wherein 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 described in the first aspect, or to implement the steps of the method described in the second aspect.

[0075] In the tenth 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 described in the first aspect, or to implement the steps of the method described in the second aspect.

[0076] In the eleventh aspect, an information sending and receiving system is provided, including: a first access network device and a core network device, wherein the first access network device can be used to execute the steps of the method described in the first aspect, and the core network device can be used to execute the steps of the method described in the second aspect.

[0077] In an embodiment of the present application, when the first access network device meets the first condition, the first access network device sends a first message to the core network device, where the first message is used to request first key information, and the first key information is key information used for the terminal to perform LTM switching between CUs. Therefore, during the LTM switching process between CUs of the terminal, the core network device can determine whether to send the first key information to the first access network device based on the request of the first access network device, thereby avoiding repeated allocation of keys to the terminal and reducing the probability of failure of the LTM switching process between CUs of the terminal; or, the first access network device sends a second message to the core network device, where the second message includes first indication information, and the first access network device indicates the LTM switching between CUs to the core network device or ignores the first key information, which can support the core network device not to repeatedly allocate keys to the terminal, or support the first access network device to ignore the keys repeatedly allocated by the core network device, thereby reducing the probability of failure of the LTM switching process between CUs of the terminal. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] FIG1 is a block diagram of a wireless communication system to which embodiments of the present application may be applied;

[0079] FIG2 is a schematic diagram of an HO switching process in the related art;

[0080] FIG3 is a schematic diagram of an LTM process in the related art;

[0081] FIG4 is a schematic diagram of a path switching request in the related art;

[0082] FIG5 is a flow chart of an information receiving method provided in an embodiment of the present application;

[0083] FIG6 is a flow chart of an information sending method provided in an embodiment of the present application;

[0084] FIG7 is a schematic structural diagram of an information receiving device provided in an embodiment of the present application;

[0085] FIG8 is a schematic structural diagram of an information sending device provided in an embodiment of the present application;

[0086] FIG9 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0087] FIG10 is a schematic diagram of a structure of a network side device according to an embodiment of the present application;

[0088] FIG11 is a second structural diagram of a network-side device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0089] The following will be combined with the accompanying drawings in the embodiments of this application to clearly describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0090] The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same type, and do not limit the number of objects, for example, the first object can be one or more. In addition, "or" in this application represents at least one of the connected objects. For example, "A or B" covers three options, namely, Option 1: including A but not including B; Option 2: including B but not including A; Option 3: including both A and B. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0091] The term "indication" in this application can be either a direct indication (or explicit indication) or an indirect indication (or implicit indication). A direct indication can be understood as the sender explicitly informing the receiver of specific information, the operation to be performed, or the requested result, etc. in the instruction sent; an indirect indication can be understood as the receiver determining the corresponding information based on the instruction sent by the sender, or making a judgment and determining the operation to be performed or the requested result, etc. based on the judgment result.

[0092] It is worth noting that the technology described in the embodiments of the present application is not limited to the Long Term Evolution (LTE) / LTE-Advanced (LTE-A) system, 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 the embodiments of the present application are often used interchangeably, and the technology described can be used for the systems and radio technologies mentioned above, as well as for other systems and radio technologies. The following description describes a New Radio (NR) system for illustrative purposes, and NR terminology is used in most of the following description, but these technologies can also be applied to systems other than NR systems, such as 6th generation (6G) systems. th Generation, 6G) communication system.

[0093] FIG1 is a block diagram of a wireless communication system applicable to an embodiment of the present application. The wireless communication system includes a terminal 11 and a network-side device 12. The terminal 11 may be a mobile phone, a tablet computer (Tablet Personal Computer), a laptop computer (Laptop Computer), a notebook computer, a personal digital assistant (PDA), a handheld computer, a netbook, an ultra-mobile personal computer (UMPC), a mobile internet device (MID), an augmented reality (AR), a virtual reality (VR) device, a robot, a wearable device (Wearable Device), an aircraft (Flight Vehicle), a vehicle-mounted device (VUE), a ship-mounted device, a pedestrian user equipment (PUE), a smart home (home appliances with wireless communication capabilities, such as refrigerators, televisions, washing machines, or furniture), a game console, a personal computer (PC), an ATM, or a self-service machine, or other terminal-side devices. Wearable devices include: smart watches, smart bracelets, smart headphones, smart glasses, smart jewelry (smart bracelets, smart bracelets, smart rings, smart necklaces, smart anklets, smart anklets, etc.), smart wristbands, smart clothing, etc. Among them, the vehicle-mounted device can also be called a vehicle-mounted terminal, a vehicle-mounted controller, a vehicle-mounted module, a vehicle-mounted component, a vehicle-mounted chip or a vehicle-mounted unit, etc. It should be noted that the specific type of the terminal 11 is not limited in the embodiment of the present application. The network side device 12 may include an access network device or a core network device, wherein the access network device may also be called a radio access network (Radio Access Network, RAN) device, a radio access network function or a radio access network unit. The access network device may include a base station, a wireless local area network (WLAN) access point (AS) or a wireless fidelity (WiFi) node, etc.Among them, the base station can be referred to as Node B (NB), Evolved Node B (eNB), the 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 (home evolved Node B), Transmission Reception Point (TRP) or other appropriate terms in the relevant field. As long as the same technical effect is achieved, the base station is not limited to specific technical vocabulary. It should be noted that in the embodiment of the present application, only the base station in the NR system is used as an example for introduction, and the specific type of the base station is not limited.

[0094] The core network equipment may include but is not limited to at least one of the following: core network node, core network function, mobility management entity (MME), access mobility management function (AMF), session management function (SMF), user plane function (UPF), policy control function (PCF), policy and charging rules function unit (PCRF), edge application service discovery function (EASDF), unified data management (UDM), unified data repository (UDR), home user server (HSS), centralized network configuration (CNC), network storage function (NRF), network exposure function (NEF), local NEF (L-NEF), binding support function (BSF), application function ( It should be noted that in the embodiments of the present application, only the core network device in the NR system is introduced as an example, and the specific type of the core network device is not limited.

[0095] For ease of understanding, some terms involved in the embodiments of this application are explained below:

[0096] 1. Layer 3 (L3) Handover (HO) Handover Process

[0097] The HO handover process is shown in Figure 2 and includes the following steps:

[0098] (1) The source gNB configures the user equipment (UE) measurement reporting process, and the UE reports according to the measurement configuration.

[0099] (2) The source gNB decides to perform UE handover based on the measurement report and radio resource management (RRM) information.

[0100] (3) The source gNB sends a handover request message to the target gNB, requesting the target gNB to prepare for the UE handover.

[0101] (4) The target gNB performs access control.

[0102] (5) The target gNB prepares for handover at Layer 1 and Layer 2 and sends a handover request confirmation message to the source gNB.

[0103] (6) The source gNB sends an RRC Reconfiguration message to the UE, triggering the UE's handover. The RRC Reconfiguration message contains information about the target cell to be accessed: at least the target cell's identifier (ID), the new cell radio network temporary identifier (C-RNTI), and the target gNB's security algorithm identifier for security algorithm selection. It may also include dedicated Random Access Channel (RACH) resources, public RACH resources, and target cell system information.

[0104] (7) The source gNB sends an SN STATUS TRANSFER message to the target gNB.

[0105] (8) The UE synchronizes to the target cell and sends an RRCReconfiguration message to the target gNB to complete the handover process.

[0106] (9) The target gNB sends a PATH SWITCH REQUEST message to the AMF to trigger the 5GC to update the downlink path to the target gNB and establish an NG-C interface instance with the target gNB.

[0107] (10) The 5GC switches the downlink path to the target gNB. The UPF sends one or more “end market” packets to each PDU session / tunnel on the old path with the source gNB, and then releases the user plane / Transport Network Layer (TNL) resources between the UPF and the source gNB.

[0108] (11)AMF confirms the PATH SWITCH REQUEST message and replies with a PATH SWITCH REQUEST ACKNOWLEDGE message.

[0109] (12) Upon receiving the PATH SWITCH REQUEST ACKNOWLEDGE message from the AMF, the target gNB sends a CONTEXT RELEASE message to the source gNB to notify the source gNB of the successful handover. The source gNB then releases the radio and control plane resources associated with the UE uplink traffic.

[0110] 2. Intra-CU LTM Process

[0111] To reduce handover latency, LTM (L1 / L2-triggered mobility) was introduced. The Data Unit (DU) uses L1 / L2 signaling to instruct the terminal to switch to a suitable candidate cell based on the Layer 1 measurement results reported by the terminal. LTM only supports cell handover within the same CU. The process is shown in Figure 3.

[0112] Continuous LTM: The UE switches continuously between multiple configured candidate cells without the network having to reconfigure the configuration information of the candidate cells.

[0113] 3. Key update process

[0114] The key update process for Xn switching is as follows:

[0115] Network side:

[0116] When there is an unused {NH, NCC} pair in the source gNB / ng-eNB, vertical key derivation is performed, otherwise horizontal key derivation is performed, where NH (Next Hop) is determined by the AMF key K AMF Derivation, NCC is the link counter (Next Hop Chaining Counter) of NH; if vertical key derivation is performed, the source gNB / ng-eNB calculates K based on NH, using the PCI and frequency of the target cell as input. NG-RAN *; If horizontal key derivation is performed, the source gNB / ng-eNB uses the currently used key K gNB , using the PCI and frequency of the target cell as input to calculate K NG-RAN *;

[0117] The source gNB / ng-eNB will NG-RAN*,NCC}pair is sent to the target gNB / ng-eNB. The target gNB / ng-eNB uses K NG-RAN * As K when UE switches to the target cell gNB The target gNB / ng-eNB will use NCC and target K gNB The UE associates with the NCC and includes it in the HO Command message, transparently transmitting it to the source gNB / ng-eNB, which then sends it to the UE.

[0118] After the handover is completed, the target gNB / ng-eNB sends an NGAP PATH SWITCH REQUEST message to the AMF. After receiving the message, the AMF increases the locally saved NCC by 1 and calculates the NCC value based on K. AMF A new NH is derived, and the AMF sends the new {NH, NCC} to the target gNB / ng-eNB via NGAP PATH SWITCH REQUEST ACKNOWLEDGE for subsequent handovers, and deletes other saved {NH, NCC} pairs.

[0119] UE side:

[0120] When the UE performs a handover and applies the RRC configuration of the target cell:

[0121] (1) If the NCC value received by the UE in the handover command is the same as the K value currently used gNB / K eNB If the associated NCC is the same, the UE will use the current K gNB / K eNB , target PCI and frequency level are derived to obtain K NG-RAN *;

[0122] (2) If the NCC value received by the UE in the handover command is different from the K value currently used gNB / K eNB If the associated NCC is different, the UE first synchronizes the NCC and NH until it matches the NCC indicated by the handover command. Then the UE vertically derives K based on the synchronized NH, target PCI and frequency. NG-RAN *.

[0123] UE uses K NG-RAN *K used for communication with target gNB / ng-eNB gNB / K eNB .

[0124] The purpose of the PATH Switch Request procedure is to establish a signaling connection between the UE and the 5GC and, in certain circumstances, to request a switch of the downlink endpoint of the transport bearer between the NG-RAN node and the UPF, as shown in Figure 4.

[0125] The PATH Switch Request message is sent from the NG-RAN to the AMF to inform the AMF of the new serving NG-RAN node and to transfer some data plane downlink tunnel nodes of one or more PDU session resources to the SMF. The message contains the UE's key capabilities.

[0126] The PATH Switch Request Acknowledge message includes key uplink information, where the key context information includes relevant parameters for deriving security keys for user plane and Radio Resource Control (RRC) signaling, namely, the {Next Hop Chaining Count / NCC, Next-Hop NH} parameters.

[0127] 4. Inter-CU LTM (Inter-CU Layer 2 Triggered Mobility) Working Description

[0128] One goal of inter-CU LTM is to avoid performing RRC reconfiguration after cell handover in consecutive LTM mobility steps. This is as follows:

[0129] Specify support for subsequent LTM mobility procedures aiming to avoid RRC configuration between cell switches as per Rel-18LTM;

[0130] Coordination with SA3 needed with respect to security key handling.

[0131] One area that needs to be enhanced is key update. Currently, when an inter-CU handover occurs in L3 handover, key update is required via RRC reconfiguration. For inter-CU LTM, to avoid RRC reconfiguration after a cell handover, the AMF assigns multiple key information, such as {NH NCC} pairs, to the candidate gNB during LTM preparation.

[0132] However, after the terminal completes an LTM switch, the terminal's new service access network device (such as the target gNB) needs to execute the PATH SWITCH process to the core network device (such as the AMF). The core network device feeds back the key information used for the terminal's subsequent LTM switch to the service access network device through the PATH Switch Request Acknowledge message, resulting in the terminal being unable to determine whether to use the key information in the PATH Switch Request Acknowledge message or the key information allocated during the LTM preparation period for the next LTM switch. As a result, there is a problem of repeated key allocation for the terminal in the LTM switch process between the terminal's CUs. The terminal cannot accurately determine the key used for authentication, resulting in a high probability of failure of the LTM switch process between the terminal's CUs.

[0133] The following, in combination with the accompanying drawings, describes in detail the information sending method, information receiving method, apparatus and related equipment provided by the embodiments of the present application through some embodiments and their application scenarios.

[0134] 5 , which is a flow chart of a method for sending information provided by an embodiment of the present application. As shown in FIG5 , the method for sending information includes the following steps:

[0135] Step 101: A first access network device performs a first operation, where the first operation includes at least one of the following:

[0136] When the first access network device meets the first condition, the first access network device sends a first message to the core network device, where the first message is used to request first key information, where the first key information is key information used by the terminal to perform LTM switching between CUs;

[0137] The first access network device sends a second message to the core network device, where the second message includes first indication information;

[0138] The first indication information is used to indicate at least one of the following:

[0139] The terminal performs LTM switching between CUs;

[0140] The second message is associated with the LTM switching process between CUs of the terminal;

[0141] The first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal;

[0142] The first access network device does not expect the core network device to allocate key information for the terminal for the next LTM handover between CUs;

[0143] The first access network device ignores the key information allocated by the core network device to the terminal for the next LTM handover between CUs;

[0144] The first access network device ignores the key information in the path switch request acknowledgment (PATH SWITCH REQUEST ACK NOELEDGE) message.

[0145] The first access network device may be a CU or a gNB, for example. For example, the first access network device may be a target CU when the terminal performs LTM handover between CUs. The first key information may include NCC-related information, including the NCC; the first key information may also include a group ID.

[0146] In one embodiment, when the terminal performs LTM switching between CUs, the first access network device performs the first operation; or, when the terminal performs LTM switching between CUs, the first access network device performs the first operation.

[0147] In one implementation, the first message or the second message may be a PATH SWITCH REQUEST message.

[0148] It should be noted that when the first indication information is used to indicate the above-mentioned multiple items, at least two of the indication information instructing the terminal to perform LTM switching between CUs, the indication information instructing the second message to associate the LTM switching process between CUs of the terminal, the indication information indicating that the first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal, the indication information indicating that the first access network device does not expect the core network device to allocate key information for the next LTM switching between CUs to the terminal, the indication information instructing the first access network device to ignore the key information allocated by the core network device to the terminal for the next LTM switching between CUs, and the indication information instructing the first access network device to ignore the key information in the path switching request confirmation message can be represented by the same indication information in the second message, or can be represented by multiple indication information in the second message. This embodiment does not limit this.

[0149] In one embodiment, when the access network device receives an RRC reconfiguration complete message (RRCReconfigurationComplete message) sent by the terminal, the first access network device performs a first operation. For example, when the access network device receives an RRCReconfigurationComplete message sent by the terminal, the first access network device sends a second message to the core network device.

[0150] In one embodiment, the first indication information is used to instruct the terminal to perform LTM switching between CUs or the second message is associated with the LTM switching process between CUs of the terminal, so that the core network device can determine that the terminal performs LTM switching between CUs based on the first indication information, and the core network device may not allocate key information for the next LTM switching between CUs to the terminal, or the core network device can learn that the first access network device ignores the key information in the PATH SWITCH Response message.

[0151] In one embodiment, the first indication information is used to indicate that the first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal; or, the first indication information is used to indicate that the first access network device does not expect the core network device to allocate key information for the next LTM switching between CUs to the terminal, so that the core network device can not allocate key information for the next LTM switching between CUs to the terminal.

[0152] In one embodiment, the first indication information is used to instruct the first access network device to ignore the key information allocated by the core network device to the terminal for the next LTM switching between CUs; ​​or, the first indication information is used to instruct the first access network device to ignore the key information in the path switch request confirmation message, so that the core network device can know that the first access network device ignores the key information in the PATH SWITCH Response message.

[0153] It should be noted that when the access network device receives the RRCReconfigurationComplete message sent by the terminal, the first access network device sends a second message to the core network device, and the core network device does not allocate key information for the next LTM switching between CUs to the terminal, or the core network device learns that the first access network device ignores the key information in the path switching response message (PATH SWITCH Response message), so that the terminal can only authenticate through the key information allocated by the core network device to the candidate CU during the LTM preparation (Preparation) process, avoiding the problem that the terminal cannot determine which key to use in the next switching process.

[0154] In addition, the first access network device satisfies the first condition, which may include that the first access network device does not have key information that can be used for LTM switching between CUs of the terminal; or, the first access network device receives a request message sent by the terminal to request the first key information; or the first access network device receives a request message sent by other access network devices to request the first key information, and the other access network devices include access network devices corresponding to the source cell or access network devices corresponding to other candidate cells; etc. This embodiment does not limit this.

[0155] An embodiment of the present application proposes a method for exchanging key information between a gNB or CU and a core network device (such as an AMF) during an inter-CU LTM process. The gNB / CU indicates inter-CU switching to the AMF in a PATH SWITCH REQUEST message, or instructs the Target CU to ignore the first key information allocated by the AMF to the UE for subsequent switching; or, when the gNB or CU does not have a key for the next inter-CU LTM of the UE, it indicates to the AMF in a PATH SWITCH REQUEST message to configure a key for the inter-CU LTM associated with the CU for the UE; or, when the gNB or CU requests an inter-CU key associated with a related group ID from the AMF in a PATH SWITCH REQUEST message, the key for the inter-CU LTM associated with the related group ID is requested by the UE. The embodiment of the present application can solve the problem that when multiple {NH, NCC} pairs associated with candidate CUs are configured for inter-CU LTM during the LTM Preparation process to avoid RRC reconfiguration during cell switching, when the UE undergoes cell switching, the AMF repeatedly allocates {NH, NCC} for subsequent switching of the UE in the PATH SWITCH process.

[0156] It should be noted that after a UE performs an inter-CU handover, the new serving gNB must perform a PATH SWITCH procedure with the AMF. The PATH Switch Request Acknowledge message sent by the AMF to the new serving gNB must include key context information, namely, the {NH, NCC} pair, for subsequent handover procedures for the UE. However, in related art, for inter-CU LTM, to avoid RRC reconfiguration during cell handover, multiple {NH, NCC} pairs are allocated to the candidate CU during the LTM Preparation process. For example, when the UE performs the Xth handover to the CU, the Xth NH is used for key update. Therefore, the AMF does not need to re-allocate the {NH, NCC} pairs for the UE during the PATH SWITCH procedure after each inter-CU LTM handover. Otherwise, the AMF will perform unnecessary updates of the NCC and NH procedures, resulting in the UE having multiple keys for the next handover, making it impossible for the UE to determine which key to use during the next handover.

[0157] In an embodiment of the present application, when the first access network device meets the first condition, the first access network device sends a first message to the core network device, where the first message is used to request first key information, and the first key information is key information used for the terminal to perform LTM switching between CUs. Therefore, during the LTM switching process between CUs of the terminal, the core network device can determine whether to send the first key information to the first access network device based on the request of the first access network device, thereby avoiding repeated allocation of keys to the terminal and reducing the probability of failure of the LTM switching process between CUs of the terminal; or, the first access network device sends a second message to the core network device, where the second message includes first indication information, and the first access network device indicates the LTM switching between CUs to the core network device or ignores the first key information, which can support the core network device not to repeatedly allocate keys to the terminal, or support the first access network device to ignore the keys repeatedly allocated by the core network device, thereby reducing the probability of failure of the LTM switching process between CUs of the terminal.

[0158] Optionally, when the first access network device meets the first condition, the first access network device sending the first message to the core network device includes:

[0159] In a case where the first access network device does not have key information that can be used for LTM switching between CUs of the terminal, the first access network device sends a first message to the core network device, where the first message includes second indication information or third indication information;

[0160] The second indication information is used for at least one of the following: requesting the core network device to configure the first key information associated with the first access network device for the terminal; requesting the core network device to configure the first key information associated with the group corresponding to the first access network device for the terminal;

[0161] The third indication information is used to indicate at least one of the following: the number of the first key information associated with the first access network device configured by the core network device for the terminal; the number of the first key information associated with the group corresponding to the first access network device configured by the core network device for the terminal.

[0162] The first message may be a PATH SWITCH REQUEST message. The group corresponding to the first access network device may be the group where the first access network device is located. For example, if the first access network device is a CU, the group corresponding to the first access network device may be the CU group where the first access network device is located.

[0163] It should be noted that the core network device can configure the first key information for the terminal according to the number of the first key information indicated by the third indication information or the number of the first key information agreed upon in the protocol.

[0164] In this embodiment, when the first access network device does not have key information that can be used for LTM switching between CUs of the terminal, the first access network device sends a second indication message to the core network device, so that the core network device can configure the first key information associated with the first access network device or the first key information associated with the group corresponding to the first access network device for the terminal based on the second indication information.

[0165] In this embodiment, when the first access network device does not have key information that can be used for LTM switching between CUs of the terminal, the first access network device sends a third indication message to the core network device, so that the core network device can configure the first key information associated with the first access network device or the first key information associated with the group corresponding to the first access network device for the terminal according to the number of the first key information indicated by the third indication message.

[0166] Optionally, the number of the first key information indicated by the third indication information is N, and the method further includes:

[0167] The first access network device receives a third message sent by the core network device, where the third message includes N first key information;

[0168] The first access network device sends the N first key information to the terminal.

[0169] The third message may be a PATH SWITCH REQUEST ACKNOWLEDGE message. The N first key information may be associated with the first access network device, or associated with a group corresponding to the first access network device, for use in inter-CU LTM of the terminal.

[0170] In this embodiment, the first access network device receives a third message sent by the core network device, the third message including N pieces of first key information; and the first access network device sends the N pieces of first key information to the terminal. Thus, the core network device can configure the first key information for the terminal according to the number of first key information pieces indicated by the third indication information or the number of first key information pieces agreed upon in the protocol, and the terminal can subsequently perform LTM switching based on the obtained first key information.

[0171] Optionally, when the first access network device meets the first condition, the first access network device sending the first message to the core network device includes:

[0172] When the first access network device receives the fourth message sent by the terminal, the first access network device sends a first message to the core network device;

[0173] The fourth message includes at least one of the following:

[0174] At least one group identification ID; fourth indication information;

[0175] The fourth indication information is used for at least one of the following:

[0176] Requesting allocation of the first key information to the access network device corresponding to the at least one group ID;

[0177] Indicate the number of the first key information requested to be allocated to the access network device corresponding to the at least one group ID;

[0178] Requesting allocation of the first key information to the first access network device;

[0179] Indicate the number of the first key information requested to be allocated to the first access network device;

[0180] Indicate that the access network device corresponding to at least one group ID does not have key information that can be used for LTM switching between CUs of the terminal;

[0181] Indicates that key information of LTM switching between CUs of the terminal of the access network device corresponding to at least one group ID has been used;

[0182] Indicates that the first access network device does not have key information that can be used for LTM switching between CUs of the terminal, or that all key information of the first access network device that can be used for LTM switching between CUs of the terminal has been used.

[0183] The fourth message may be an RRCReconfigurationComplete message. The first message may be a PATH SWITCH REQUEST message. The access network device corresponding to the at least one group ID may include an access network device associated with the LTM candidate cell corresponding to the at least one group ID.

[0184] In one embodiment, after the first access network device sends the first message to the core network device, the method further includes: the first access network device receiving a fifth message sent by the core network device;

[0185] The fifth message includes the first key information corresponding to the first group ID, and the at least one group ID or the group ID corresponding to the first access network device includes the first group ID; or

[0186] The fifth message does not include the first key information corresponding to the second group ID, or the fifth message includes sixth indication information corresponding to the second group ID, the at least one group ID or the group ID corresponding to the first access network device includes the second group ID, and the sixth indication information is used to indicate the release of configuration information of the access network device associated with the second group ID; or

[0187] The fifth message does not include the first key information corresponding to the third group ID, or the fifth message includes the ninth indication information corresponding to the third group ID, the at least one group ID or the group ID corresponding to the first access network device includes the third group ID, and the ninth indication information is used to indicate the deactivation of the LTM candidate configuration information associated with the third group ID.

[0188] In this embodiment, when the first access network device receives the fourth message sent by the terminal, the first access network device sends a first message to the core network device, thereby supporting the core network device to respond to the request of the first access network device, and to feedback the first key information to the first access network device when the first access network device receives the fourth message sent by the terminal.

[0189] Optionally, the first message includes at least one of the following: the at least one group ID; fifth indication information;

[0190] The fifth indication information is used for at least one of the following:

[0191] Requesting the core network device to allocate the first key information to the access network device corresponding to the at least one group ID;

[0192] Indicate the number of the first key information that the core network device is requested to allocate to the access network device corresponding to the at least one group ID;

[0193] Requesting the core network device to allocate the first key information to the first access network device;

[0194] Indicates the number of the first key information that the core network device is requested to allocate to the first access network device.

[0195] Optionally, after the first access network device sends the first message to the core network device, the method further includes:

[0196] The first access network device receives a fifth message sent by the core network device;

[0197] In the case where the fifth message includes the first key information corresponding to the first group ID, the first access network device sends the first key information corresponding to the first group ID to the terminal, and the at least one group ID or the group ID corresponding to the first access network device includes the first group ID.

[0198] The fifth message may be a PATH SWITCH REQUEST ACKNOWLEDGE message.

[0199] The first message may include the first group ID.

[0200] In one embodiment, the fourth indication information indicates that the number of the first key information requested to be allocated to the access network device corresponding to the at least one group ID is M, and the first key information corresponding to each group ID in the first key information corresponding to the first group ID includes M first key information.

[0201] In this embodiment, the first access network device receives the fifth message sent by the core network device; when the fifth message includes the first key information corresponding to the first group ID, the first access network device sends the first key information corresponding to the first group ID to the terminal, so that the terminal can perform subsequent LTM switching based on the first key information corresponding to the first group ID obtained.

[0202] Optionally, after the first access network device sends the first message to the core network device, the method further includes:

[0203] The first access network device receives a fifth message sent by the core network device;

[0204] In a case where the fifth message does not include the first key information corresponding to the second group ID, or the fifth message includes sixth indication information corresponding to the second group ID, the first access network device sends seventh indication information to the access network device associated with the second group ID, where the at least one group ID or the group ID corresponding to the first access network device includes the second group ID;

[0205] The sixth indication information is used to instruct to release the configuration information of the access network device associated with the second group ID;

[0206] The seventh indication information is used to instruct the access network device associated with the second group ID to release the resources configured for the terminal for LTM switching between CUs.

[0207] The first message may include the second group ID.

[0208] In addition, the configuration information of the access network device associated with the second group ID may include LTM candidate configuration information of the access network device associated with the second group ID.

[0209] In this embodiment, the first access network device receives the fifth message sent by the core network device; when the fifth message does not include the first key information corresponding to the second group ID, or when the fifth message includes the sixth indication information corresponding to the second group ID, the first access network device sends the seventh indication information to the access network device associated with the second group ID, so that the first access network device can release the LTM candidate configuration information of the access network devices associated with at least part of the group ID based on the core network device's feedback on the fourth message or the first message. That is to say, for a piece of LTM candidate configuration information, when its key for inter-CU LTM is fully used, the core network device or the first access network device can instruct the access network device associated with the LTM candidate configuration information to release the LTM candidate configuration information.

[0210] Optionally, the method further includes:

[0211] The first access network device sends eighth indication information to the terminal, where the eighth indication information is used to instruct the terminal to release the LTM candidate configuration information associated with the second group ID.

[0212] The eighth indication information may be carried in an RRC message. The LTM candidate configuration information may include configuration information of an LTM candidate cell.

[0213] In this embodiment, the first access network device sends eighth indication information to the terminal, and the eighth indication information is used to instruct the terminal to release the LTM candidate configuration information associated with the second group ID. Therefore, when the core network device does not allocate key information for some or all of the group IDs requested from it or when the core network device instructs the first access network device to release the configuration information of some or all of the requested group IDs, the first access network device instructs the terminal to release the LTM candidate configuration information associated with at least some of the group IDs in accordance with the instruction of the core network device. That is, for a piece of LTM candidate configuration information, when its key for inter-CU LTM is fully used, the core network device or the first access network device can instruct the terminal to release the LTM candidate configuration information.

[0214] Optionally, after the first access network device sends the first message to the core network device, the method further includes:

[0215] The first access network device receives a fifth message sent by the core network device;

[0216] When the fifth message does not include the first key information corresponding to the third group ID, or the fifth message includes ninth indication information corresponding to the third group ID, the first access network device sends tenth indication information to the terminal, where the at least one group ID or the group ID corresponding to the first access network device includes the third group ID;

[0217] The ninth indication information is used to instruct deactivation of the LTM candidate configuration information associated with the third group ID;

[0218] The tenth indication information is used to instruct the terminal to deactivate the LTM candidate configuration information associated with the third group ID.

[0219] The tenth indication information may be carried in an RRC message.

[0220] The first message may include a third group ID.

[0221] In one implementation, after receiving the tenth indication information, the terminal no longer performs L1 measurement of the candidate cell associated with the third group ID.

[0222] In this embodiment, the first access network device receives the fifth message sent by the core network device; when the fifth message does not include the first key information corresponding to the third group ID, or when the fifth message includes the ninth indication information corresponding to the third group ID, the first access network device sends the tenth indication information to the terminal, so that the first access network device can deactivate the LTM candidate configuration information associated with at least part of the group ID based on the core network device's feedback on the fourth message or the first message. That is to say, for a piece of LTM candidate configuration information, when its key for inter-CU LTM is fully used, the core network device or the first access network device can instruct the terminal to deactivate the LTM candidate configuration information, that is, the terminal no longer considers the candidate cell associated with the LTM candidate configuration information as an available candidate cell.

[0223] 6 , which is a flow chart of an information receiving method provided in an embodiment of the present application. As shown in FIG6 , the information receiving method includes the following steps:

[0224] Step 201: The core network device performs a second operation, where the second operation includes at least one of the following:

[0225] The core network device receives a first message sent by a first access network device, where the first message is used to request first key information, where the first key information is key information used by the terminal to perform LTM switching between CUs;

[0226] The core network device receives a second message sent by the first access network device, where the second message includes first indication information;

[0227] The first indication information is used to indicate at least one of the following:

[0228] The terminal performs LTM switching between CUs;

[0229] The second message is associated with the LTM switching process between CUs of the terminal;

[0230] The first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal;

[0231] The first access network device does not expect the core network device to allocate key information for the terminal for the next LTM handover between CUs;

[0232] The first access network device ignores the key information allocated by the core network device to the terminal for the next LTM handover between CUs;

[0233] The first access network device ignores the key information in the path switch request confirmation message.

[0234] In one implementation, the core network device performs the second operation during the terminal performing LTM switching between CUs; ​​or, when the terminal performs LTM switching between CUs, the core network device performs the second operation.

[0235] Optionally, the first message includes second indication information or third indication information;

[0236] The second indication information is used for at least one of the following: requesting the core network device to configure the first key information associated with the first access network device for the terminal; requesting the core network device to configure the first key information associated with the group corresponding to the first access network device for the terminal;

[0237] The third indication information is used to indicate at least one of the following: the number of the first key information associated with the first access network device configured by the core network device for the terminal; the number of the first key information associated with the group corresponding to the first access network device configured by the core network device for the terminal.

[0238] Optionally, the number of the first key information indicated by the third indication information is N, and the method further includes:

[0239] The core network device sends a third message to the first access network device, where the third message includes N pieces of first key information.

[0240] Optionally, the first message includes at least one of the following: at least one group ID; fifth indication information;

[0241] The fifth indication information is used for at least one of the following:

[0242] Requesting the core network device to allocate the first key information to the access network device corresponding to the at least one group ID;

[0243] Indicate the number of the first key information that the core network device is requested to allocate to the access network device corresponding to the at least one group ID;

[0244] Requesting the core network device to allocate the first key information to the first access network device;

[0245] Indicates the number of the first key information that the core network device is requested to allocate to the first access network device.

[0246] Optionally, after the core network device receives the first message sent by the access network device, the method further includes:

[0247] The core network device sends a fifth message to the first access network device;

[0248] The fifth message includes the first key information corresponding to the first group ID, and the at least one group ID or the group ID corresponding to the first access network device includes the first group ID; or

[0249] The fifth message does not include the first key information corresponding to the second group ID, or the fifth message includes sixth indication information corresponding to the second group ID, the at least one group ID or the group ID corresponding to the first access network device includes the second group ID, and the sixth indication information is used to indicate the release of configuration information of the access network device associated with the second group ID; or

[0250] The fifth message does not include the first key information corresponding to the third group ID, or the fifth message includes the ninth indication information corresponding to the third group ID, the at least one group ID or the group ID corresponding to the first access network device includes the third group ID, and the ninth indication information is used to indicate the deactivation of the LTM candidate configuration information associated with the third group ID.

[0251] It should be noted that this embodiment is an implementation method of the core network device corresponding to the embodiment shown in Figure 5. Its specific implementation method can refer to the relevant description of the embodiment shown in Figure 5. To avoid repetition, this embodiment will not be repeated.

[0252] The information sending method and information receiving method of the present application are described below through several embodiments.

[0253] In the following embodiments, the first access network device is taken as Target CU and the core network device is AMF as an example for explanation.

[0254] Example 1:

[0255] In this embodiment, when the UE performs inter-CU LTM handover to the candidate CU, the candidate CU instructs the AMF to perform inter-CU LTM handover, including the following process:

[0256] (1) The UE receives an RRCReconfiguration message, which contains the following:

[0257] Configuration information of multiple candidate cells associated with inter-CU LTM, where each candidate cell's configuration information is associated with a group ID;

[0258] Key-related information, the key-related information includes: a group ID; M NCC-related information, the NCC-related information includes an NCC.

[0259] For example, the configuration information of 8 candidate cells is as follows: {cell#0,ID#A}{cell#1,ID#A}{cell#2,ID#B}{cell#3,ID#B}{cell#4,ID#C}{cell#5,ID#C},{cell#6,ID#D}{cell#7,ID#D};

[0260] The key-related information is: {ID#A, NCC=4, NCC=5}{ID#B, NCC=6, NCC=7}{ID#C, NCC=0, NCC=1}{ID#D, NCC=2, NCC=3}.

[0261] (2) The UE receives an LTM handover command, which instructs the UE to perform inter-CU LTM. The UE performs an LTM handover procedure according to the LTM handover command. During the LTM handover procedure, the UE sends an RRC Reconfiguration Complete message to the target CU.

[0262] (3) After receiving the RRCReconfigurationComplete message from the UE, the Target CU sends a PATH SWITCH REQUEST message to the AMF.

[0263] In one embodiment, the PATH SWITCH REQUEST message includes first indication information, where the first indication information is used to indicate at least one of the following:

[0264] The UE has executed inter-CU LTM, or the PATH SWITCH REQUEST is for an inter-CU LTM handover scenario;

[0265] The UE or the target CU currently has an available NCC for inter-CU LTM;

[0266] The Target CU does not expect the AMF to allocate the first key information for subsequent handover to the UE;

[0267] The Target CU ignores the first key information allocated by the AMF to the UE for subsequent switching or the first key information in the PATH SWITCH REQUEST ACK NOELEDGE message.

[0268] In another embodiment, the PATH SWITCH REQUEST message includes first target indication information and second target indication information, where the first target indication information is used to indicate any one of the following:

[0269] The UE executes inter-CU LTM or the PATH SWITCH REQUEST is for an inter-CU LTM handover scenario;

[0270] The UE or the target CU currently has an available NCC for inter-CU LTM;

[0271] The second target indication information is used to indicate any one of the following:

[0272] The Target CU does not expect the AMF to allocate the first key information for subsequent handover to the UE;

[0273] The Target CU ignores the first key information allocated by the AMF to the UE for subsequent switching or the first key information in the PATH SWITCH REQUEST ACK NOELEDGE message.

[0274] (4) The target CU receives the PATH SWITCH REQUEST ACKNOELEDGE message from AMF and ignores the first key information carried therein.

[0275] The first key information includes NH and NCC.

[0276] Through this embodiment, if multiple NCCs are configured for the candidate CU during LTM preparation, and the UE still has an available NCC for the candidate CU during the LTM switching process, the AMF is informed through the PATH SWITCH REQUEST message in the PATH SWITCH process, so that the AMF can no longer allocate a new {NH, NCC} for the UE.

[0277] Example 2:

[0278] In this embodiment, when a candidate CU does not have an available NCC, it requests the AMF to allocate an available {NH, NCC} to itself, including the following process:

[0279] (1): Same as Example 1;

[0280] (2): Same as Example 1;

[0281] (3) After receiving the RRCReconfigurationComplete message from the UE, the target CU finds that it no longer has the NCC for the UE's inter-CU LTM. That is, this LTM switch uses the last available NCC. The target CU sends a PATH SWITCH REQUEST message to the AMF. The PATH SWITCH REQUEST message contains at least one of the following:

[0282] Second indication information, where the second indication information is used to indicate: requesting the AMF to configure, for the UE, N first key information associated with the CU (i.e., the CU that sends the PATH SWITCH REQUEST) or the group corresponding to the CU;

[0283] The integer N is used to instruct the AMF to configure N first key information associated with the CU or the group corresponding to the CU for the UE.

[0284] (4) The target CU receives a PATH SWITCH REQUEST ACKNOWLEDGE message from the AMF. The PATH SWITCH REQUEST ACKNOWLEDGE message includes N first key information. The target CU sends an RRC reconfiguration message to the UE, including N first key information. The first key information includes an NCC associated with the CU for inter-CU LTM of the terminal.

[0285] Example 3:

[0286] In this embodiment, after receiving the indication information from the UE, the candidate CU requests the AMF to configure {NH, NCC} for inter-CU LTM, including the following process:

[0287] (1): Same as Example 1;

[0288] (2): Same as Example 1;

[0289] (3) After receiving the RRCReconfigurationComplete message from the UE, the target CU finds that the RRCReconfigurationComplete message contains at least one of the following:

[0290] One or more group IDs;

[0291] fourth indication information, where the fourth indication information is used to indicate that M pieces of first key information are requested for the one or more group IDs, or to indicate that no key information for inter-CU LTM is available for the one or more group IDs or that all key information for inter-CU LTM associated with the group IDs has been used;

[0292] An integer M, used to indicate that M first key information is requested for the group ID.

[0293] (4) The Target CU sends a PATH SWITCH REQUEST message to the AMF. The PATH SWITCH REQUEST message contains at least one of the following:

[0294] One or more group IDs;

[0295] Fifth indication information, where the fifth indication information is used to indicate: requesting the AMF to configure, for the UE, M first key information associated with the one or more group IDs;

[0296] The integer M is used to instruct the AMF to configure M first key information associated with the group ID for the UE.

[0297] (5) The target CU receives the PATH SWITCH REQUEST ACKNOWLEDGE message from the AMF. The PATH SWITCH REQUEST ACKNOWLEDGE message has the following situations:

[0298] The PATH SWITCH REQUEST ACKNOWLEDGE message includes key information associated with one or more group IDs, and the key information associated with each group ID includes M first key information. The target CU sends an RRC reconfiguration message to the UE, including key information associated with one or more group IDs, and the key information associated with each group ID includes M first key information; or

[0299] The PATH SWITCH REQUEST ACKNOWLEDGE message does not include key information associated with the relevant group ID or includes sixth indication information, where the sixth indication information is used to instruct the target CU to release the candidate cell configuration information associated with the one or more group IDs; the target CU sends seventh indication information (such as release signaling) to the candidate CU associated with the group ID, where the seventh indication information is used to instruct the candidate CU to release the resources configured for the inter-CU LTM switching for the UE; and the target CU sends an RRC message to the UE, where the RRC message is used to instruct the UE to release the configuration information of the candidate cell associated with the group ID; or

[0300] The PATH SWITCH REQUEST ACKNOWLEDGE message does not include the key information associated with the relevant group ID or the ninth indication information (such as deactivation information). The target CU sends an RRC message to the UE, which is used to instruct the UE to deactivate the configuration information of the candidate cell associated with the group ID. Optionally, the UE no longer performs L1 measurement of the candidate cell associated with the group ID.

[0301] The embodiment of the present application solves the problem that when multiple key information of the candidate CU has been configured during the inter-CU LTM preparation process, using the PATH SWITCH process to continue to switch the configuration key for the candidate CU will cause unnecessary RRC reconfiguration. The embodiment of the present application can avoid the AMF from performing additional key update processes.

[0302] The information sending method provided in the embodiment of the present application can be executed by an information sending device. In the embodiment of the present application, the information sending device provided in the embodiment of the present application is described by taking the information sending method executed by the information sending device as an example.

[0303] Please refer to FIG. 7 , which is a structural diagram of an information sending device provided in an embodiment of the present application. The first access network device includes the information sending device. As shown in FIG. 7 , the information sending device 300 includes:

[0304] The execution module 301 is configured to execute a first operation, where the first operation includes at least one of the following:

[0305] When the first access network device meets the first condition, sending a first message to the core network device, where the first message is used to request first key information, where the first key information is key information used by the terminal to perform LTM switching between CUs;

[0306] Sending a second message to the core network device, where the second message includes the first indication information;

[0307] The first indication information is used to indicate at least one of the following:

[0308] The terminal performs LTM switching between CUs;

[0309] The second message is associated with the LTM switching process between CUs of the terminal;

[0310] The first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal;

[0311] The first access network device does not expect the core network device to allocate key information for the terminal for the next LTM handover between CUs;

[0312] The first access network device ignores the key information allocated by the core network device to the terminal for the next LTM handover between CUs;

[0313] The first access network device ignores the key information in the path switch request confirmation message.

[0314] Optionally, the execution module is specifically configured to:

[0315] When the first access network device does not have key information that can be used for LTM switching between CUs of the terminal, sending a first message to the core network device, where the first message includes the second indication information or the third indication information;

[0316] The second indication information is used for at least one of the following: requesting the core network device to configure the first key information associated with the first access network device for the terminal; requesting the core network device to configure the first key information associated with the group corresponding to the first access network device for the terminal;

[0317] The third indication information is used to indicate at least one of the following: the number of the first key information associated with the first access network device configured by the core network device for the terminal; the number of the first key information associated with the group corresponding to the first access network device configured by the core network device for the terminal.

[0318] Optionally, the number of the first key information indicated by the third indication information is N, and the apparatus further includes:

[0319] A first receiving module, configured to receive a third message sent by the core network device, where the third message includes N first key information;

[0320] The first sending module is configured to send the N first key information to the terminal.

[0321] Optionally, the execution module is specifically configured to:

[0322] When the first access network device receives the fourth message sent by the terminal, sending the first message to the core network device;

[0323] The fourth message includes at least one of the following:

[0324] At least one group identification ID; fourth indication information;

[0325] The fourth indication information is used for at least one of the following:

[0326] Requesting allocation of the first key information to the access network device corresponding to the at least one group ID;

[0327] Indicate the number of the first key information requested to be allocated to the access network device corresponding to the at least one group ID;

[0328] Requesting allocation of the first key information to the first access network device;

[0329] Indicate the number of the first key information requested to be allocated to the first access network device;

[0330] Indicate that the access network device corresponding to at least one group ID does not have key information that can be used for LTM switching between CUs of the terminal;

[0331] Indicates that key information of LTM switching between CUs of the terminal of the access network device corresponding to at least one group ID has been used;

[0332] Indicates that the first access network device does not have key information that can be used for LTM switching between CUs of the terminal, or that all key information of the first access network device that can be used for LTM switching between CUs of the terminal has been used.

[0333] Optionally, the first message includes at least one of the following: the at least one group ID; fifth indication information;

[0334] The fifth indication information is used for at least one of the following:

[0335] Requesting the core network device to allocate the first key information to the access network device corresponding to the at least one group ID;

[0336] Indicate the number of the first key information that the core network device is requested to allocate to the access network device corresponding to the at least one group ID;

[0337] Requesting the core network device to allocate the first key information to the first access network device;

[0338] Indicates the number of the first key information that the core network device is requested to allocate to the first access network device.

[0339] Optionally, the device further comprises:

[0340] A second receiving module, configured to receive a fifth message sent by the core network device;

[0341] In the case where the fifth message includes the first key information corresponding to the first group ID, the first access network device sends the first key information corresponding to the first group ID to the terminal, and the at least one group ID or the group ID corresponding to the first access network device includes the first group ID.

[0342] Optionally, the device further comprises:

[0343] A third receiving module, configured to receive a fifth message sent by the core network device;

[0344] In a case where the fifth message does not include the first key information corresponding to the second group ID, or the fifth message includes sixth indication information corresponding to the second group ID, the first access network device sends seventh indication information to the access network device associated with the second group ID, where the at least one group ID or the group ID corresponding to the first access network device includes the second group ID;

[0345] The sixth indication information is used to instruct to release the configuration information of the access network device associated with the second group ID;

[0346] The seventh indication information is used to instruct the access network device associated with the second group ID to release the resources configured for the terminal for LTM switching between CUs.

[0347] Optionally, the device further comprises:

[0348] The second sending module is configured to send eighth indication information to the terminal, where the eighth indication information is used to instruct the terminal to release the LTM candidate configuration information associated with the second group ID.

[0349] Optionally, the device further comprises:

[0350] a fifth receiving module, configured to receive a fifth message sent by the core network device;

[0351] When the fifth message does not include the first key information corresponding to the third group ID, or the fifth message includes ninth indication information corresponding to the third group ID, the first access network device sends tenth indication information to the terminal, where the at least one group ID or the group ID corresponding to the first access network device includes the third group ID;

[0352] The ninth indication information is used to instruct deactivation of the LTM candidate configuration information associated with the third group ID;

[0353] The tenth indication information is used to instruct the terminal to deactivate the LTM candidate configuration information associated with the third group ID.

[0354] The information sending device in the embodiments of the present application can be an electronic device, such as an electronic device with an operating system, or a component in an electronic device, such as an integrated circuit or chip. The electronic device can be a terminal, or it can be other devices other than a terminal. For example, the terminal can include but is not limited to the types of terminal 11 listed above, and other devices can be servers, network attached storage (NAS), etc., which are not specifically limited in the embodiments of the present application.

[0355] The information sending device provided in the embodiment of the present application can implement the various processes implemented in the method embodiment of Figure 5 and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0356] Please refer to FIG8 , which is a structural diagram of an information receiving device provided in an embodiment of the present application. The core network device includes the information receiving device. As shown in FIG8 , the information receiving device 400 includes:

[0357] The execution module 401 is configured to execute a second operation, where the second operation includes at least one of the following:

[0358] receiving a first message sent by a first access network device, where the first message is used to request first key information, where the first key information is key information used by the terminal to perform LTM switching between CUs;

[0359] receiving a second message sent by the first access network device, where the second message includes first indication information;

[0360] The first indication information is used to indicate at least one of the following:

[0361] The terminal performs LTM switching between CUs;

[0362] The second message is associated with the LTM switching process between CUs of the terminal;

[0363] The first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal;

[0364] The first access network device does not expect the core network device to allocate key information for the terminal for the next LTM handover between CUs;

[0365] The first access network device ignores the key information allocated by the core network device to the terminal for the next LTM handover between CUs;

[0366] The first access network device ignores the key information in the path switch request confirmation message.

[0367] Optionally, the first message includes second indication information or third indication information;

[0368] The second indication information is used for at least one of the following: requesting the core network device to configure the first key information associated with the first access network device for the terminal; requesting the core network device to configure the first key information associated with the group corresponding to the first access network device for the terminal;

[0369] The third indication information is used to indicate at least one of the following: the number of the first key information associated with the first access network device configured by the core network device for the terminal; the number of the first key information associated with the group corresponding to the first access network device configured by the core network device for the terminal.

[0370] Optionally, the number of the first key information indicated by the third indication information is N, and the apparatus further includes:

[0371] The first sending module is configured to send a third message to the first access network device, where the third message includes N pieces of first key information.

[0372] Optionally, the first message includes at least one of the following: at least one group ID; fifth indication information;

[0373] The fifth indication information is used for at least one of the following:

[0374] Requesting the core network device to allocate the first key information to the access network device corresponding to the at least one group ID;

[0375] Indicate the number of the first key information that the core network device is requested to allocate to the access network device corresponding to the at least one group ID;

[0376] Requesting the core network device to allocate the first key information to the first access network device;

[0377] Indicates the number of the first key information that the core network device is requested to allocate to the first access network device.

[0378] Optionally, the device further comprises:

[0379] A second sending module, configured to send a fifth message to the first access network device;

[0380] The fifth message includes the first key information corresponding to the first group ID, and the at least one group ID or the group ID corresponding to the first access network device includes the first group ID; or

[0381] The fifth message does not include the first key information corresponding to the second group ID, or the fifth message includes sixth indication information corresponding to the second group ID, the at least one group ID or the group ID corresponding to the first access network device includes the second group ID, and the sixth indication information is used to indicate the release of configuration information of the access network device associated with the second group ID; or

[0382] The fifth message does not include the first key information corresponding to the third group ID, or the fifth message includes the ninth indication information corresponding to the third group ID, the at least one group ID or the group ID corresponding to the first access network device includes the third group ID, and the ninth indication information is used to indicate the deactivation of the LTM candidate configuration information associated with the third group ID.

[0383] The information receiving device in the embodiments of the present application can be an electronic device, such as an electronic device with an operating system, or a component in an electronic device, such as an integrated circuit or chip. The electronic device can be a terminal, or it can be other devices other than a terminal. For example, the terminal can include but is not limited to the types of terminal 11 listed above, and other devices can be servers, network attached storage (NAS), etc., which are not specifically limited in the embodiments of the present application.

[0384] The information receiving device provided in the embodiment of the present application can implement the various processes implemented in the method embodiment of Figure 6 and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0385] Optionally, as shown in Figure 9, an embodiment of the present application further provides a communication device 500, including a processor 501 and a memory 502, wherein the memory 502 stores a program or instruction that can be run on the processor 501. For example, when the communication device 500 is a first access network device, the program or instruction is executed by the processor 501 to implement the various steps of the above-mentioned information sending method embodiment applied to the first access network device, and can achieve the same technical effect. To avoid repetition, it is not repeated here. When the communication device 500 is a core network device, the program or instruction is executed by the processor 501 to implement the various steps of the above-mentioned information receiving method embodiment applied to the core network device, and can achieve the same technical effect. To avoid repetition, it is not repeated here.

[0386] The present application also provides a network-side device, including a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is configured to execute a program or instruction to implement the steps of the method embodiment shown in Figure 5 or Figure 6. This network-side device embodiment corresponds to the above-mentioned method embodiment, and each implementation process and implementation method of the above-mentioned method embodiment can be applied to this network-side device embodiment and can achieve the same technical effects.

[0387] Specifically, an embodiment of the present application further provides a network-side device. The network-side device can be a first access network device or a core network device. As shown in Figure 10, the network-side device 600 includes: an antenna 601, a radio frequency device 602, a baseband device 603, a processor 604, and a memory 605. The antenna 601 is connected to the radio frequency device 602. In the uplink direction, the radio frequency device 602 receives information via the antenna 601 and sends the received information to the baseband device 603 for processing. In the downlink direction, the baseband device 603 processes the information to be transmitted and sends it to the radio frequency device 602. The radio frequency device 602 processes the received information and sends it through the antenna 601.

[0388] The method executed by the network-side device in the above embodiment may be implemented in the baseband device 603 , which includes a baseband processor.

[0389] The baseband device 603 may include, for example, at least one baseband board, on which multiple chips are arranged, as shown in Figure 10, one of which is, for example, a baseband processor, which is connected to the memory 605 through a bus interface to call the program in the memory 605 and execute the network device operations shown in the above method embodiment.

[0390] The network side device may further include a network interface 606, which is, for example, a Common Public Radio Interface (CPRI).

[0391] Specifically, the network side device 600 of the embodiment of the present application also includes: instructions or programs stored in the memory 605 and can be run on the processor 604. The processor 604 calls the instructions or programs in the memory 605 to execute the method executed by each module shown in Figure 7 or Figure 8, and achieves the same technical effect. To avoid repetition, it will not be repeated here.

[0392] Specifically, an embodiment of the present application further provides a network-side device. The network-side device may be a first access network device or a core network device. As shown in FIG11 , the network-side device 700 includes a processor 701, a network interface 702, and a memory 703. The network interface 702 may be, for example, a common public radio interface (CPRI).

[0393] Specifically, the network side device 700 of the embodiment of the present application also includes: instructions or programs stored in the memory 703 and can be run on the processor 701. The processor 701 calls the instructions or programs in the memory 703 to execute the methods executed by each module shown in Figure 7 or Figure 8, and achieves the same technical effect. To avoid repetition, it will not be repeated here.

[0394] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the various processes of the above-mentioned information sending method or information receiving method embodiment are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0395] The processor is the processor in the terminal described in the above embodiment. The readable storage medium includes a computer-readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk. In some examples, the readable storage medium may be a non-transitory readable storage medium.

[0396] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned information sending method or information receiving method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0397] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0398] An embodiment of the present application further provides a computer program / program product, which is stored in a storage medium. The computer program / program product is executed by at least one processor to implement the various processes of the above-mentioned information sending method or information receiving method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0399] An embodiment of the present application also provides an information sending and receiving system, including: a first access network device and a core network device, wherein the first access network device can be used to execute the steps of the information sending method applied to the first access network device as described above, and the core network device can be used to execute the steps of the information receiving method applied to the core network device as described above.

[0400] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0401] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of a computer software product plus a necessary general-purpose hardware platform, or of course, by hardware. The computer software product is stored in a storage medium (such as ROM, RAM, magnetic disk, optical disk, etc.) and includes a number of instructions for enabling a terminal or network-side device to execute the methods described in each embodiment of the present application.

[0402] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms of implementation methods without departing from the purpose of this application and the scope of protection of the claims. These implementation methods are all within the protection of this application.

Claims

1. A method for sending information, comprising: The first access network device performs a first operation, where the first operation includes at least one of the following: When the first access network device meets the first condition, the first access network device sends a first message to the core network device, where the first message is used to request first key information, where the first key information is key information used for the terminal to perform layer 1 or layer 2 triggered mobility LTM handover between central units CU; The first access network device sends a second message to the core network device, where the second message includes first indication information; The first indication information is used to indicate at least one of the following: The terminal performs LTM switching between CUs; The second message is associated with the LTM switching process between CUs of the terminal; The first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal; The first access network device does not expect the core network device to allocate key information for the next LTM handover between CUs to the terminal; The first access network device ignores the key information allocated by the core network device to the terminal for the next LTM handover between CUs; The first access network device ignores the key information in the path switch request confirmation message.

2. The method according to claim 1, wherein The step of sending a first message from the first access network device to the core network device when the first access network device satisfies the first condition includes: In a case where the first access network device does not have key information that can be used for LTM switching between CUs of the terminal, the first access network device sends a first message to the core network device, where the first message includes second indication information or third indication information; The second indication information is used for at least one of the following: requesting the core network device to configure the first key information associated with the first access network device for the terminal; requesting the core network device to configure the first key information associated with the group corresponding to the first access network device for the terminal; The third indication information is used to indicate at least one of the following: the number of the first key information associated with the first access network device configured by the core network device for the terminal; the number of the first key information associated with the group corresponding to the first access network device configured by the core network device for the terminal.

3. The method according to claim 2, wherein: The number of the first key information indicated by the third indication information is N, and the method further includes: The first access network device receives a third message sent by the core network device, where the third message includes N first key information; The first access network device sends the N first key information to the terminal.

4. The method according to claim 1, wherein The step of sending a first message from the first access network device to the core network device when the first access network device satisfies the first condition includes: When the first access network device receives the fourth message sent by the terminal, the first access network device sends a first message to the core network device; The fourth message includes at least one of the following: At least one group identification ID; fourth indication information; The fourth indication information is used for at least one of the following: Requesting allocation of the first key information to the access network device corresponding to the at least one group ID; Indicate the number of the first key information requested to be allocated to the access network device corresponding to the at least one group ID; Requesting allocation of the first key information to the first access network device; Indicate the number of the first key information requested to be allocated to the first access network device; Indicate that the access network device corresponding to at least one group ID does not have key information that can be used for LTM switching between CUs of the terminal; Indicates that key information of LTM switching between CUs of the terminal of the access network device corresponding to at least one group ID has been used; Indicates that the first access network device does not have key information that can be used for LTM switching between CUs of the terminal, or that all key information of the first access network device that can be used for LTM switching between CUs of the terminal has been used.

5. The method according to claim 4, wherein The first message includes at least one of the following: the at least one group ID; fifth indication information; The fifth indication information is used for at least one of the following: Requesting the core network device to allocate the first key information to the access network device corresponding to the at least one group ID; Indicate the number of the first key information that the core network device is requested to allocate to the access network device corresponding to the at least one group ID; Requesting the core network device to allocate the first key information to the first access network device; Indicates the number of the first key information that the core network device is requested to allocate to the first access network device.

6. The method according to claim 4 or 5, wherein: After the first access network device sends the first message to the core network device, the method further includes: The first access network device receives a fifth message sent by the core network device; In the case where the fifth message includes the first key information corresponding to the first group ID, the first access network device sends the first key information corresponding to the first group ID to the terminal, and the at least one group ID or the group ID corresponding to the first access network device includes the first group ID.

7. The method according to claim 4 or 5, wherein: After the first access network device sends the first message to the core network device, the method further includes: The first access network device receives a fifth message sent by the core network device; In a case where the fifth message does not include the first key information corresponding to the second group ID, or the fifth message includes sixth indication information corresponding to the second group ID, the first access network device sends seventh indication information to the access network device associated with the second group ID, where the at least one group ID or the group ID corresponding to the first access network device includes the second group ID; The sixth indication information is used to instruct to release the configuration information of the access network device associated with the second group ID; The seventh indication information is used to instruct the access network device associated with the second group ID to release the resources configured for the terminal for LTM switching between CUs.

8. The method according to claim 7, wherein: The method further comprises: The first access network device sends eighth indication information to the terminal, where the eighth indication information is used to instruct the terminal to release the LTM candidate configuration information associated with the second group ID.

9. The method according to claim 4 or 5, wherein: After the first access network device sends the first message to the core network device, the method further includes: The first access network device receives a fifth message sent by the core network device; When the fifth message does not include the first key information corresponding to the third group ID, or the fifth message includes ninth indication information corresponding to the third group ID, the first access network device sends tenth indication information to the terminal, where the at least one group ID or the group ID corresponding to the first access network device includes the third group ID; The ninth indication information is used to instruct deactivation of the LTM candidate configuration information associated with the third group ID; The tenth indication information is used to instruct the terminal to deactivate the LTM candidate configuration information associated with the third group ID.

10. A method for receiving information, comprising: The core network device performs a second operation, where the second operation includes at least one of the following: The core network device receives a first message sent by the first access network device, where the first message is used to request first key information, where the first key information is key information used by the terminal to perform LTM switching between CUs; The core network device receives a second message sent by the first access network device, where the second message includes first indication information; The first indication information is used to indicate at least one of the following: The terminal performs LTM switching between CUs; The second message is associated with the LTM switching process between CUs of the terminal; The first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal; The first access network device does not expect the core network device to allocate key information for the next LTM handover between CUs to the terminal; The first access network device ignores the key information allocated by the core network device to the terminal for the next LTM handover between CUs; The first access network device ignores the key information in the path switch request confirmation message.

11. The method according to claim 10, wherein: The first message includes second indication information or third indication information; The second indication information is used for at least one of the following: requesting the core network device to configure the first key information associated with the first access network device for the terminal; requesting the core network device to configure the first key information associated with the group corresponding to the first access network device for the terminal; The third indication information is used to indicate at least one of the following: the number of the first key information associated with the first access network device configured by the core network device for the terminal; the number of the first key information associated with the group corresponding to the first access network device configured by the core network device for the terminal.

12. The method according to claim 11, wherein The number of the first key information indicated by the third indication information is N, and the method further includes: The core network device sends a third message to the first access network device, where the third message includes N pieces of first key information.

13. The method according to claim 10, wherein: The first message includes at least one of the following: at least one group ID; fifth indication information; The fifth indication information is used for at least one of the following: Requesting the core network device to allocate the first key information to the access network device corresponding to the at least one group ID; Indicate the number of the first key information that the core network device is requested to allocate to the access network device corresponding to the at least one group ID; Requesting the core network device to allocate the first key information to the first access network device; Indicates the number of the first key information that the core network device is requested to allocate to the first access network device.

14. The method according to claim 13, wherein After the core network device receives the first message sent by the access network device, the method further includes: The core network device sends a fifth message to the first access network device; The fifth message includes the first key information corresponding to the first group ID, and the at least one group ID or the group ID corresponding to the first access network device includes the first group ID; or The fifth message does not include the first key information corresponding to the second group ID, or the fifth message includes sixth indication information corresponding to the second group ID, the at least one group ID or the group ID corresponding to the first access network device includes the second group ID, and the sixth indication information is used to indicate the release of configuration information of the access network device associated with the second group ID; or The fifth message does not include the first key information corresponding to the third group ID, or the fifth message includes the ninth indication information corresponding to the third group ID, the at least one group ID or the group ID corresponding to the first access network device includes the third group ID, and the ninth indication information is used to indicate the deactivation of the LTM candidate configuration information associated with the third group ID.

15. An information sending device, comprising: The execution module is configured to execute a first operation, where the first operation includes at least one of the following: When the first access network device meets the first condition, sending a first message to the core network device, where the first message is used to request first key information, where the first key information is key information used by the terminal to perform LTM switching between CUs; Sending a second message to the core network device, where the second message includes the first indication information; The first indication information is used to indicate at least one of the following: The terminal performs LTM switching between CUs; The second message is associated with the LTM switching process between CUs of the terminal; The first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal; The first access network device does not expect the core network device to allocate key information for the next LTM handover between CUs to the terminal; The first access network device ignores the key information allocated by the core network device to the terminal for the next LTM handover between CUs; The first access network device ignores the key information in the path switch request confirmation message.

16. The device according to claim 15, wherein The execution module is specifically used for: When the first access network device does not have key information that can be used for LTM switching between CUs of the terminal, sending a first message to the core network device, where the first message includes the second indication information or the third indication information; The second indication information is used for at least one of the following: requesting the core network device to configure the first key information associated with the first access network device for the terminal; requesting the core network device to configure the first key information associated with the group corresponding to the first access network device for the terminal; The third indication information is used to indicate at least one of the following: the number of the first key information associated with the first access network device configured by the core network device for the terminal; the number of the first key information associated with the group corresponding to the first access network device configured by the core network device for the terminal.

17. The device according to claim 15, wherein The execution module is specifically used for: When the first access network device receives the fourth message sent by the terminal, sending the first message to the core network device; The fourth message includes at least one of the following: At least one group identification ID; fourth indication information; The fourth indication information is used for at least one of the following: Requesting allocation of the first key information to the access network device corresponding to the at least one group ID; Indicate the number of the first key information requested to be allocated to the access network device corresponding to the at least one group ID; Requesting allocation of the first key information to the first access network device; Indicate the number of the first key information requested to be allocated to the first access network device; Indicate that the access network device corresponding to at least one group ID does not have key information that can be used for LTM switching between CUs of the terminal; Indicates that key information of LTM switching between CUs of the terminal of the access network device corresponding to at least one group ID has been used; Indicates that the first access network device does not have key information that can be used for LTM switching between CUs of the terminal, or that all key information of the first access network device that can be used for LTM switching between CUs of the terminal has been used.

18. An information receiving device, comprising: The execution module is configured to execute a second operation, where the second operation includes at least one of the following: Receiving a first message sent by a first access network device, where the first message is used to request first key information, where the first key information is key information used by a terminal to perform LTM switching between CUs; receiving a second message sent by the first access network device, where the second message includes first indication information; The first indication information is used to indicate at least one of the following: The terminal performs LTM switching between CUs; The second message is associated with the LTM switching process between CUs of the terminal; The first access network device or the terminal has key information that can be used for LTM switching between CUs of the terminal; The first access network device does not expect the core network device to allocate key information for the next LTM handover between CUs to the terminal; The first access network device ignores the key information allocated by the core network device to the terminal for the next LTM handover between CUs; The first access network device ignores the key information in the path switch request confirmation message.

19. A communication device comprising a processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, it implements the steps of the information sending method according to any one of claims 1 to 9, or implements the steps of the information receiving method according to any one of claims 10 to 14.

20. A chip comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is configured to execute a program or instruction to implement the steps of the information sending method according to any one of claims 1 to 9, or to implement the steps of the information receiving method according to any one of claims 10 to 14.

21. A readable storage medium, wherein: The readable storage medium stores a program or instruction, and when the program or instruction is executed by the processor, it implements the steps of the information sending method according to any one of claims 1 to 9, or implements the steps of the information receiving method according to any one of claims 10 to 14.

22. A computer program / program product, wherein: When the computer program / program product is executed by at least one processor, the computer program / program product implements the steps of the information sending method according to any one of claims 1 to 9, or implements the steps of the information receiving method according to any one of claims 10 to 14.

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