Cell change method and apparatus, and terminal and network-side device

Abstract

The present application belongs to the technical field of communications. Disclosed are a cell change method and apparatus, and a terminal and a network-side device. The cell change method in the embodiments of the present application comprises: a terminal acquiring a first cell change message, which carries LTM candidate configuration information; and the terminal acquiring a second cell change message, which is used for instructing the terminal to apply the LTM candidate configuration information.

Description

Cell change method, device, terminal and network side equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese Patent Application No. 2024102165765 filed on February 27, 2024, and the contents of the above-mentioned Chinese patent application disclosure are hereby incorporated by reference in their entirety as a part of this application. Technical Field

[0003] The present application belongs to the field of communication technology, and specifically relates to a cell change method, apparatus, terminal and network-side equipment. Background Art

[0004] In some communication systems, different cell change methods may exist for the same terminal, such as: cell change triggered by the Medium Access Control (MAC) layer, which can also be called Layer 1 / Layer 2-triggered mobility (LTM); and cell change triggered by the Radio Resource Control (RRC) layer. In this way, the terminal may receive multiple different cell change messages. In some related technologies, each cell change message carries independent cell change configuration information. When the terminal receives multiple cell change messages, there will be two sets of configuration information for the same cell, and the terminal can only use one set of configuration information, resulting in wasteful message overhead. Summary of the Invention

[0005] The embodiments of the present application provide a cell change method, apparatus, terminal, and network-side equipment, which can solve the problem of message overhead waste.

[0006] In a first aspect, a cell change method is provided, comprising:

[0007] The terminal obtains a first cell change message, where the first cell change message carries LTM candidate configuration information;

[0008] The terminal obtains a second cell change message, where the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information.

[0009] In a second aspect, a cell change method is provided, including:

[0010] The source node sends a second cell change message to the terminal, where the second cell change message is used to instruct the terminal to apply LTM candidate configuration information, wherein the LTM candidate configuration information is the LTM candidate configuration information obtained by the terminal through the first cell change message.

[0011] In a third aspect, a cell change method is provided, including:

[0012] The target node receives the switching request or the auxiliary node adding request sent by the source node;

[0013] The target node sends a handover confirmation or a secondary node addition confirmation message to the source node, where the handover confirmation or the secondary node addition confirmation message carries at least one of the following:

[0014] a terminal identifier allocated to the terminal at the source node;

[0015] a terminal identifier allocated to the terminal at the target node;

[0016] Updated protocol data unit (PDU) session information, wherein the updated PDU session information includes at least one of the following: quality of service (QoS) flow information allowed for access and a data forwarding address;

[0017] a transparent transmission container, wherein the transparent transmission container includes handover command information or primary and secondary cell change command information for the terminal;

[0018] Fourth indication information, the fourth indication information is used to indicate whether the target node accepts the request of the source node to use the LTM candidate configuration information to perform layer 3 handover or primary and secondary cell change;

[0019] The fourth candidate configuration identifier is used to instruct the terminal to apply the candidate configuration information associated with the fourth candidate configuration identifier in this handover or primary and secondary cell change.

[0020] In a fourth aspect, a cell change device is provided, comprising:

[0021] A first acquisition module is configured to acquire a first cell change message, where the first cell change message carries layer 1 / layer 2 triggered mobility LTM candidate configuration information;

[0022] The second acquisition module is configured to acquire a second cell change message, where the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information.

[0023] In a fifth aspect, a cell change device is provided, comprising:

[0024] The first sending module is used to send a second cell change message to the terminal, where the second cell change message is used to indicate the mobility LTM candidate configuration information triggered by the terminal application layer 1 / layer 2, wherein the LTM candidate configuration information is the LTM candidate configuration information obtained by the terminal through the first cell change message.

[0025] In a sixth aspect, a cell change device is provided, including:

[0026] A receiving module, configured to receive a switching request or a secondary node adding request sent by a source node;

[0027] a sending module, configured to send a handover confirmation or a secondary node addition confirmation message to the source node, where the handover confirmation or the secondary node addition confirmation message carries at least one of the following:

[0028] a terminal identifier allocated to the terminal at the source node;

[0029] a terminal identifier allocated to the terminal at the target node;

[0030] Updated PDU session information, wherein the updated PDU session information includes at least one of the following: quality of service (QoS) flow information allowed for access, and a data forwarding address;

[0031] a transparent transmission container, wherein the transparent transmission container includes handover command information or primary and secondary cell change command information for the terminal;

[0032] Fourth indication information, the fourth indication information is used to indicate whether the target node accepts the request of the source node to use the LTM candidate configuration information to perform layer 3 handover or primary and secondary cell change;

[0033] The fourth candidate configuration identifier is used to instruct the terminal to apply the candidate configuration information associated with the fourth candidate configuration identifier in this handover or primary and secondary cell change.

[0034] In the seventh aspect, a terminal is provided, which includes 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, the steps of the cell change method on the terminal side provided in the embodiment of the present application are implemented.

[0035] In the eighth aspect, a terminal is provided, including a processor and a communication interface, wherein the communication interface is used to obtain a first cell change message, the first cell change message carries mobility LTM candidate configuration information triggered by layer 1 / layer 2; and obtain a second cell change message, the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information.

[0036] In the ninth aspect, a network side device is provided, which includes 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, the steps of the cell change method on the source node side provided in the embodiment of the present application are implemented, and when the program or instruction is executed by the processor, the steps of the cell change method on the target node side provided in the embodiment of the present application are implemented.

[0037] In the tenth aspect, a network side device is provided, including a processor and a communication interface, wherein the communication interface is used to send a second cell change message to the terminal, and the second cell change message is used to indicate the mobility LTM candidate configuration information triggered by the application layer 1 / layer 2 of the terminal, wherein the LTM candidate configuration information is the LTM candidate configuration information obtained by the terminal through the first cell change message.

[0038] On the eleventh aspect, another network side device is provided, including a processor and a communication interface, wherein the communication interface is used for the target node to receive a switching request or a secondary node adding request sent by the source node; send a switching confirmation or a secondary node adding confirmation message to the source node, and the switching confirmation or the secondary node adding confirmation message carries at least one of the following: the terminal identifier assigned to the terminal at the source node; the terminal identifier assigned to the terminal at the target node; updated protocol data unit PDU session information, and the updated PDU session information includes at least one of the following: quality of service QoS flow information and data forwarding address allowed for access; a transparent transmission container, the transparent transmission container contains switching command information or primary and secondary cell change command information for the terminal; fourth indication information, the fourth indication information is used to indicate whether the target node accepts the source node's request to use the layer 1 / layer 2 triggered mobility LTM candidate configuration information for layer 3 switching or primary and secondary cell change; a fourth candidate configuration identifier, the fourth candidate configuration identifier is used to indicate that the terminal applies the candidate configuration information associated with the fourth candidate configuration identifier in this switching or primary and secondary cell change.

[0039] In the twelfth 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 cell change method on the terminal side as provided in the embodiment of the present application are implemented, or when the program or instruction is executed by a processor, the steps of the cell change method on the source node side as provided in the embodiment of the present application are implemented, or when the program or instruction is executed by a processor, the steps of the cell change method on the target node side as provided in the embodiment of the present application are implemented.

[0040] In the thirteenth aspect, a wireless communication system is provided, including: a terminal and a source node, or a terminal, a source node and a target node, the terminal can be used to execute the steps of the cell change method on the terminal side provided in the embodiment of the present application, the source node can be used to execute the steps of the cell change method on the source node side provided in the embodiment of the present application, and the target node can be used to execute the steps of the cell change method on the target node side provided in the embodiment of the present application.

[0041] In the fourteenth aspect, a chip is provided, which includes a processor and a communication interface, the communication interface and the processor are coupled, the processor is used to run a program or instruction to implement the cell change method on the terminal side as provided in the embodiment of the present application, or the processor is used to run a program or instruction to implement the cell change method on the source node side as provided in the embodiment of the present application, or the processor is used to run a program or instruction to implement the cell change method on the target node side as provided in the embodiment of the present application.

[0042] In the fifteenth aspect, a computer program / program product is provided, which is stored in a storage medium, and the computer program / program product is executed by at least one processor to implement the steps of the cell change method on the terminal side as provided in the embodiment of the present application, or the computer program / program product is executed by at least one processor to implement the steps of the cell change method on the source node side as provided in the embodiment of the present application, or the computer program / program product is executed by at least one processor to implement the steps of the cell change method on the target node side as provided in the embodiment of the present application.

[0043] In this embodiment of the present application, a terminal receives a first cell change message that carries LTM candidate configuration information; the terminal then receives a second cell change message that instructs the terminal to apply the LTM candidate configuration information. Because the second cell change message instructs the terminal to apply the LTM candidate configuration information carried in the first cell change message, the overhead of the second cell change message carrying the cell change configuration information is reduced, thereby saving message overhead. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG1 is a block diagram of a wireless communication system to which embodiments of the present application may be applied;

[0045] FIG2 is a flow chart of a cell change method provided in an embodiment of the present application;

[0046] FIG3 is a flowchart of another cell change method provided in an embodiment of the present application;

[0047] FIG4 is a flowchart of another cell change method provided in an embodiment of the present application;

[0048] FIG5 is a structural diagram of a cell change device provided in an embodiment of the present application;

[0049] FIG6 is a structural diagram of another cell change device provided in an embodiment of the present application;

[0050] FIG7 is a structural diagram of another cell change device provided in an embodiment of the present application;

[0051] FIG8 is a structural diagram of a communication device provided in an embodiment of the present application;

[0052] FIG9 is a structural diagram of a terminal provided in an embodiment of the present application;

[0053] FIG10 is a structural diagram of a network-side device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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, vehicle-mounted controller, vehicle-mounted module, vehicle-mounted component, vehicle-mounted chip or 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.

[0059] The network-side device 12 may include an access network device or a core network device, wherein the access network device may also be referred to as a 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 (AP), or a wireless fidelity (WiFi) node. 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), CU, Distributed Unit (DU) 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.

[0060] 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.

[0061] In the following, in combination with the accompanying drawings, a cell change method, apparatus, terminal and network-side equipment provided by the embodiments of the present application are described in detail through some embodiments and their application scenarios.

[0062] Please refer to FIG2 , which is a flowchart of a cell change method provided in an embodiment of the present application. As shown in FIG2 , the method includes the following steps:

[0063] Step 201: The terminal obtains a first cell change message, where the first cell change message carries LTM candidate configuration information.

[0064] The above-mentioned first change message of the terminal may be a cell change message received by the terminal from a network side device, for example: a cell change message sent by a receiving source node, such as a cell change message sent by a receiving source CU or gNB.

[0065] In some embodiments, the first cell change message may be a first RRC reconfiguration message (RRCReconfiguration) message, which carries the LTM candidate configuration information. In other embodiments, the first cell change message may be a Medium Access Control Control Element (MAC CE) signaling.

[0066] In an embodiment of the present application, the LTM candidate configuration information may be used by a terminal to perform an LTM-based cell change and may include configuration information of one or more LTM candidate cells. In some implementations, the configuration information of the LTM candidate cells may include at least one of the following:

[0067] Random Access Channel (RACH) configuration information, which is used by the terminal to perform early synchronization;

[0068] Transmission Configuration Indicator (TCI) status configuration information;

[0069] Radio bearer configuration information;

[0070] Layer 3 (L3) measurement configuration information;

[0071] Cell group configuration information, the cell group configuration information may include: LTM channel state information (CSI) reporting configuration information.

[0072] It should be noted that the content of the LTM candidate configuration information is not limited in the embodiments of the present application. For example, it may be the content included in the LTM candidate configuration information defined by the protocol, or the content included in the LTM candidate configuration information newly defined in a subsequent protocol version.

[0073] Step 202: The terminal obtains a second cell change message, where the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information.

[0074] The second cell change message of the terminal may be a cell change message sent by a network-side device received by the terminal, for example, a cell change message sent by a source node, such as a cell change message sent by a source CU or gNB. Furthermore, the first cell change message and the second cell change message may be sent by the terminal to the same network-side device, or the first cell change message and the second cell change message may be sent by the terminal to different network-side devices. For example, the first cell change message is sent by the terminal to the source node that has performed LTM preparation, and the second cell change message is sent by the terminal to the network node associated with the terminal's serving cell. In other words, the terminal receives the second cell change message only after an LTM-based cell change occurs after receiving the first cell change message.

[0075] In some implementations, the second cell change message may be a second RRC reconfiguration message (RRCReconfiguration) message. In other implementations, the second cell change message may be MAC CE signaling.

[0076] In some embodiments, the second cell change message is a cell change message triggered by RRC signaling. The RRC-triggered cell change message may be a cell change message triggered by RRC signaling based on layer 3 measurement, such as a cell change message for handover (HO) / primary / secondary cell change (PSCell change) triggered by RRC signaling based on layer 3 measurement, or the RRC-triggered cell change message may not be a cell change message triggered by RRC signaling based on layer 3 measurement. The second cell change message and the first cell change message may be configuration information for configuring two different cell change types, for example, the first cell change message is used to configure configuration information for a cell change triggered by layer 1 / layer 2 (L1 / L2) signaling, such as configuration information for configuring inter-CU LTM (inter-CU LTM) cell change; and the second cell change message is used to configure configuration information for a cell change triggered by layer 3 signaling.

[0077] The second cell change message is used to instruct the terminal to apply the LTM candidate configuration information, which can be understood as instructing the terminal to apply the LTM candidate configuration information during the cell change process. The instruction can be an explicit or implicit instruction to the terminal to apply the LTM candidate configuration information.

[0078] The above-mentioned terminal applying the LTM candidate configuration information may be that the terminal applies the LTM candidate configuration information to perform a cell change, such as applying the LTM candidate configuration information to perform a HO or a PSCell change.

[0079] In an embodiment of the present application, the above steps can be used to enable the second cell change message to instruct the terminal to apply the LTM candidate configuration information carried by the first cell change message, thereby reducing the overhead of the second cell change message carrying the cell change configuration information, and thus saving message overhead.

[0080] For example, in the case where RRC-triggered HO / PSCell change and inter-CU LTM coexist, since the second cell change message instructs the terminal to apply the LTM candidate configuration information, the first cell change message and the second cell change message can be avoided from sending two sets of RRC configurations of the same cell to the terminal. For example, the second cell change message does not carry the RRC configuration of the L3HO / PSCell change request to save message overhead.

[0081] In addition, since the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information, the terminal can perform LTM cell change based on L1 measurement, and if the terminal needs to re-execute inter-CU LTM, it can perform cell change based on the above-mentioned LTM candidate configuration information, thereby improving the efficiency of cell change, such as improving the efficiency of switching / PSCell change.

[0082] As an optional implementation manner, the second cell change message carries at least one of the following:

[0083] a target cell identifier, wherein when the cell associated with the target cell identifier is an LTM candidate cell, the terminal applies configuration information of the LTM candidate cell;

[0084] First indication information, where the first indication information is used to instruct the terminal to perform handover to an LTM candidate cell or change a primary or secondary cell;

[0085] second indication information, where the second indication information is used to indicate configuration information of a candidate cell associated with the target cell identifier;

[0086] A first candidate configuration identifier, where the first candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the first candidate configuration identifier;

[0087] or,

[0088] The first cell change message further carries: at least one second candidate configuration identifier, where the second candidate configuration identifier is associated with configuration information of an LTM candidate cell, wherein, when the second cell change message carries the first candidate configuration identifier, the first candidate configuration identifier is a candidate configuration identifier in the at least one second candidate configuration identifier;

[0089] The LTM candidate configuration information includes configuration information of the LTM candidate cell.

[0090] The target cell identifier may be the frequency or physical cell identifier (PCI) of the target cell, or a combination of the frequency and PCI of the target cell.

[0091] The above-mentioned target cell is the target cell for the terminal to perform cell change, that is, the terminal changes from one cell to the target cell. The target cell can be a target cell selected by the terminal or the network side device from the candidate cells. The candidate cell is the candidate cell for the cell change.

[0092] The above-mentioned LTM candidate cell is a cell associated with the LTM candidate configuration information contained in the first cell change message, that is, the terminal or network side device can select a target cell from the LTM candidate cells and then change to the target cell based on the LTM cell.

[0093] The above-mentioned LTM candidate configuration information may include configuration information of one or more LTM candidate cells, and such configuration information may also be referred to as candidate cell configuration information.

[0094] Since the above-mentioned LTM candidate configuration information includes the configuration information of the LTM candidate cell and the configuration information of each LTM candidate cell includes the cell identifier and the candidate configuration identifier, it is possible to instruct the terminal to apply the configuration information of the LTM candidate cell associated with the above-mentioned target identifier or the first candidate configuration identifier in the above-mentioned LTM candidate configuration information through the above-mentioned target identifier or the first candidate configuration identifier.

[0095] The LTM candidate cell in which the terminal, as instructed by the first indication information, performs a handover to the LTM candidate cell or a primary / secondary cell change is the LTM candidate cell in the LTM candidate configuration information, i.e., the LTM candidate configuration information includes the configuration information of the LTM candidate cell. In this way, the first indication information can be used to instruct the terminal to apply the configuration information of the LTM candidate cell in the LTM candidate configuration information, i.e., to perform a handover to the LTM candidate cell or a primary / secondary cell change based on the configuration information of the LTM candidate cell.

[0096] The second indication information for indicating the application of the configuration information of the candidate cell associated with the target cell identifier may be the second indication information for indicating the application of the configuration information of the LTM candidate cell associated with the target cell identifier, because the cell associated with the target cell identifier may be an LTM candidate cell. In this way, the second indication information can be used to instruct the terminal to apply the configuration information of the LTM candidate cell associated with the target cell identifier in the LTM candidate configuration information.

[0097] It should be noted that, in the case of not carrying the above-mentioned second indication information, the terminal may directly apply the configuration information of the LTM candidate cell associated with the target cell identifier based on the above-mentioned target cell identifier.

[0098] The first candidate configuration identifier may be associated with an LTM candidate cell, so that the first candidate configuration identifier can be used to instruct the terminal to apply the configuration information of the LTM candidate cell associated with the first candidate configuration identifier in the LTM candidate configuration information.

[0099] The at least one second candidate configuration identifier may be configuration information associated with at least one LTM candidate cell in the LTM candidate configuration information.

[0100] The above-mentioned first candidate configuration identifier is a candidate configuration identifier among the at least one second candidate configuration identifier, which can be understood as follows: the first candidate configuration identifier carried by the second cell change message is one of the at least one second candidate configuration identifier carried by the first cell change message, that is, it indicates the configuration information of an LTM candidate cell. For example: the first cell change message contains LTM candidate configuration information, that is, the configuration information of one or more candidate cells, and the configuration information of each candidate cell corresponds to a candidate configuration identifier, which is indicated here by the second candidate configuration identifier. The second cell change message carries the first candidate configuration identifier, and this first candidate configuration identifier is the candidate configuration identifier associated with the configuration information of multiple candidate cells contained in the first cell change message, so that it can be associated with the configuration information of the correct candidate cell. It should be noted that, in the case where the first cell change message does not carry the second candidate configuration identifier, the candidate configuration identifier corresponding to each LTM candidate cell can also be a protocol agreement or pre-configured.

[0101] In the above implementation, it is possible to instruct the terminal to apply the LTM candidate configuration information and indicate specific LTM candidate cells in various ways, thereby improving the efficiency of cell change.

[0102] In some implementations, when the cell associated with the target cell identifier is an LTM candidate cell and the second cell change message does not carry configuration information of the cell associated with the target cell identifier, the terminal applies the configuration information of the LTM candidate cell.

[0103] In this implementation, it can be achieved that when the second cell change message carries the target cell identifier, the second cell change message does not need to carry the configuration information of the cell associated with the target cell identifier. The target cell identifier is used to instruct the terminal to apply the configuration information of the LTM candidate cell associated with the target cell identifier, so as to save the overhead of the first cell change message or the second cell change message.

[0104] In some implementations, the second cell change message further carries at least one of the following:

[0105] Key-related information, where the key-related information is used to instruct the terminal to generate a security key to be used in a target cell or after a cell change based on the key-related information;

[0106] Timing Advance (TA) information, where the TA information is used to indicate at least one of the following: a TA of the cell associated with the target cell identifier, and a TA of the LTM candidate cell associated with the first candidate configuration identifier;

[0107] Transmission Configuration Indicator (TCI) information, the TCI information being used to indicate at least one of the following: beam information used in a cell change process without a random access channel (RACH) process (i.e., a RACH-less cell change) performed in a cell associated with the target cell identifier, and beam information used in a cell change process without a RACH process performed in an LTM candidate cell associated with the first candidate configuration identifier.

[0108] The key-related information may be related information for generating a security key used in a target cell or after a cell change.

[0109] In some implementations, the key-related information may be additional key-related information, such as Next Hop Chaining Counter (NCC) information.

[0110] The security key may be an encryption key or an integrity protection key.

[0111] The key can be changed through the key-related information to improve the reliability of terminal communication.

[0112] Since the above-mentioned TA information is used to indicate at least one of the following items: the TA of the cell associated with the target cell identifier and the TA of the LTM candidate cell associated with the first candidate configuration identifier, the terminal does not need to obtain the TA when changing the cell to the cell associated with the target cell identifier or the LTM candidate cell associated with the first candidate configuration identifier, thereby saving the signaling overhead of the cell change.

[0113] Since the TCI information is used to indicate the beam information used in the cell change process without the RACH process to the cell associated with the target cell identifier, or to indicate the beam information used in the cell change process without the RACH process to the LTM candidate cell associated with the first candidate configuration identifier, the terminal performs the cell change process without the RACH process to save the signaling overhead of the cell change.

[0114] In some embodiments, the method may further include:

[0115] The terminal selects a target candidate cell based on the target cell identifier and the first candidate configuration identifier; or

[0116] The MAC layer of the terminal selects a target candidate cell.

[0117] Among them, the above-mentioned target candidate cell is a target cell selected from the LTM candidate cell, that is, in this implementation, it is possible to select the target cell from the LTM candidate cell based on the above-mentioned second cell change message, or the MAC layer of the terminal can independently select the target cell from the LTM candidate cell to support multiple target cell selection methods and support more flexible cell changes.

[0118] In some embodiments, the method further comprises at least one of the following:

[0119] The terminal performs cell switching or primary / secondary cell change based on the configuration information of the target candidate cell;

[0120] The terminal generates a security key for use in a target cell or after a cell change based on the key-related information;

[0121] The RRC layer of the terminal indicates a MAC reset to the MAC layer of the terminal;

[0122] The RRC layer of the terminal indicates a TA to the MAC layer of the terminal to instruct execution of a cell change without a RACH procedure, wherein the TA includes: a valid TA indicated by the TA information carried by the second cell change message;

[0123] When the terminal performs TA measurement for the target candidate cell selected by the terminal and maintains a valid TA of the target candidate cell at the moment of receiving the second cell change message, the terminal performs a cell change without a RACH procedure;

[0124] When the second cell change message carries TCI status information, the RRC layer of the terminal indicates the TCI status information to the MAC layer of the terminal, and the TCI status information is used to indicate the execution of a cell change without RACH and for the MAC layer to select uplink allocation resources.

[0125] The configuration information of the target candidate cell is the configuration information of the candidate cell in the LTM candidate configuration information.

[0126] The terminal may generate a security key for use in the target cell or after the cell is changed based on the key-related information, which may be a security key generated after the terminal is changed to the target candidate cell, that is, the target cell is a target candidate cell.

[0127] The RRC layer of the terminal instructs the MAC layer of the terminal to perform a MAC reset, which means that after the terminal selects the target candidate cell, it instructs the MAC layer to perform a MAC reset, so that the cell change process of the MAC layer can be executed.

[0128] The RRC layer of the terminal indicates the TA to the MAC layer of the terminal to indicate that a cell change without a RACH procedure is to be performed, which may include:

[0129] The RRC layer of the terminal indicates a TA to the MAC layer of the terminal, where the TA indicates that a cell change without a RACH procedure is to be performed; or

[0130] The RRC layer of the terminal indicates the TA to the MAC layer of the terminal, and the behavior of indicating the TA to the MAC layer indicates performing a cell change without a RACH procedure.

[0131] The above-mentioned TCI status information is used by the MAC layer to select uplink allocation resources. The TCI status information is associated with the uplink allocation resources, so that the TCI information is indicated to the MAC layer, so that the MAC layer can select the configured uplink allocation resources (configured uplink grant) used for the first uplink transmission to the target candidate cell based on the TCI information.

[0132] In the above implementation, by indicating the TA or TCI status information, the terminal can perform a cell change without a RACH procedure, thereby reducing the signaling overhead of the cell change. In addition, since the TCI status information is used by the MAC layer to select uplink allocation resources, the MAC layer can select appropriate uplink allocation resources for data transmission.

[0133] In this embodiment of the present application, a terminal receives a first cell change message that carries LTM candidate configuration information; the terminal then receives a second cell change message that instructs the terminal to apply the LTM candidate configuration information. Because the second cell change message instructs the terminal to apply the LTM candidate configuration information carried in the first cell change message, the overhead of the second cell change message carrying the cell change configuration information is reduced, thereby saving message overhead.

[0134] Please refer to FIG3 , which is a flowchart of another cell change method provided in an embodiment of the present application. As shown in FIG3 , the method includes the following steps:

[0135] Step 301: The source node sends a second cell change message to the terminal, where the second cell change message is used to instruct the terminal to apply LTM candidate configuration information, wherein the LTM candidate configuration information is the LTM candidate configuration information obtained by the terminal through the first cell change message.

[0136] In the embodiments of the present application, the node may be an access network device, such as a gNB, eNB, or an access network device corresponding to 6G. In some implementations, the node does not represent a CU or DU, but a CU and DU may exist in the node.

[0137] Among them, the above-mentioned first cell change message may be sent by the above-mentioned source node, or may not be sent by the above-mentioned source node, that is, the first cell change message and the second cell change message may be sent by the same source node; or they may be sent by different source nodes, such as the first cell change message is sent by the source node that has performed LTM preparation, and the second cell change message is sent by the network node associated with the service cell of the terminal. For example, the terminal undergoes an LTM-based cell change after receiving the first cell change message, and then receives the second cell change message. In this case, the first cell change message and the second cell change message are sent through different source nodes.

[0138] Optionally, before the source node sends the second cell change message to the terminal, the method further includes:

[0139] The source node sends the first cell change message to the terminal, where the first cell change message carries LTM candidate configuration information.

[0140] Optionally, the first cell change message is a first radio resource control RRC reconfiguration message, and the second cell change message is a second RRC reconfiguration message.

[0141] Optionally, the second cell change message is a cell change message triggered by RRC signaling.

[0142] Optionally, before the source node sends the second cell change message to the terminal, the method further includes:

[0143] When the RRC layer of the source node decides to trigger a cell change, the RRC layer of the source node sends first information to the MAC layer of the source node or the CU of the source node sends first information to the DU of the source node, where the first information includes at least one of the following:

[0144] Target cell identifier;

[0145] measurement results of one or more candidate cells;

[0146] third indication information, where the third indication information is used to instruct the MAC layer or the DU of the source node to perform an LTM-based cell change;

[0147] A third candidate configuration identifier is used to instruct the DU of the MAC layer or the source node to trigger a handover or a primary / slave cell change to the LTM candidate cell associated with the third candidate configuration identifier.

[0148] The above-mentioned RRC layer decision to trigger the cell change may be an RRC layer decision to trigger cell switching or PSCell change.

[0149] Among them, for the terminal, the above-mentioned target cell identifier is used to indicate that when the cell associated with the target cell identifier is an LTM candidate cell, the terminal applies the configuration information of the LTM candidate cell, or the above-mentioned target cell identifier is used to indicate that when the cell associated with the target cell identifier is an LTM candidate cell, the terminal applies the configuration information of the LTM candidate cell.

[0150] The measurement results of the one or more candidate cells are used by the source node to select a target candidate cell. For example, in some embodiments, when the first information includes the measurement results of the one or more candidate cells, the method further includes:

[0151] The MAC layer of the source node or the DU of the source node selects a target candidate cell based on the measurement results of the one or more candidate cells, and the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information associated with the target candidate cell.

[0152] The third indication information is used to instruct the MAC layer or the DU of the source node to perform an LTM-based cell change, which may be to instruct the MAC layer or the DU of the source node to perform an LTM-based cell change for the terminal.

[0153] The third candidate configuration identifier is used to instruct the MAC layer or the DU of the source node to trigger switching to the LTM candidate cell associated with the third candidate configuration identifier or changing the primary and secondary cells. It can be used to instruct the MAC or the DU of the source node to perform switching or changing the primary and secondary cells to the LTM candidate cell associated with the third candidate configuration identifier for the terminal.

[0154] In the above implementation, the LTM-based cell change can be indicated at the MAC layer of the source node or the DU of the source node, and the LTM-based cell change of the terminal can be triggered by the MAC layer of the source node or the DU of the source node to reduce the complexity of the terminal.

[0155] In some implementations, the source node sending the second cell change message to the terminal includes:

[0156] In a case where the first information does not include the target cell identifier and the third candidate configuration identifier, the MAC layer of the source node or the DU of the source node selects a target candidate cell and sends a second cell change message to the terminal, where the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information, including: the second cell change message is used to trigger a cell change based on the LTM candidate configuration information associated with the target candidate cell; or

[0157] In the case where the first information includes the target cell identifier or the third candidate configuration identifier, the MAC layer of the source node or the DU of the source node selects a target candidate cell based on the target cell identifier or the third candidate configuration identifier, and sends a second cell change message to the terminal, where the second cell change message is used to instruct the terminal to apply the LTM configuration information, including: the second cell change message is used to trigger a cell change based on the LTM candidate configuration information associated with the target candidate cell.

[0158] In this way, the LTM-based cell change of the terminal can be triggered by the MAC layer of the source node or the DU of the source node, thereby reducing the complexity of the terminal.

[0159] As an optional implementation manner, the second cell change message carries at least one of the following:

[0160] a target cell identifier, where, when the cell associated with the target cell identifier is an LTM candidate cell, the terminal applies the LTM candidate configuration information associated with the LTM candidate cell;

[0161] First indication information, where the first indication information is used to instruct the terminal to perform handover to an LTM candidate cell or change a primary or secondary cell;

[0162] second indication information, where the second indication information is used to indicate configuration information of a candidate cell associated with the target cell identifier;

[0163] A first candidate configuration identifier, where the first candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the first candidate configuration identifier;

[0164] or,

[0165] The first cell change message further carries: at least one second candidate configuration identifier, where the second candidate configuration identifier is associated with configuration information of an LTM candidate cell, wherein, when the second cell change message carries the first candidate configuration identifier, the first candidate configuration identifier is a candidate configuration identifier in the at least one second candidate configuration identifier;

[0166] The LTM candidate configuration information includes LTM candidate configuration information of the LTM candidate cell.

[0167] Optionally, the second cell change message further carries at least one of the following:

[0168] Key-related information, where the key-related information is used to instruct the terminal to generate a security key to be used in a target cell or after a cell change based on the key-related information;

[0169] Timing Advance (TA) information, where the TA information is used to indicate at least one of the following: a TA of the cell associated with the target cell identifier, and a TA of the LTM candidate cell associated with the first candidate configuration identifier;

[0170] Transmission configuration indication TCI information, the TCI information is used to indicate at least one of the following: the beam information used in the cell change process without the random access channel RACH process to the cell associated with the target cell identifier, and the beam information used in the cell change process without the RACH process to the LTM candidate cell associated with the first candidate configuration identifier.

[0171] Optionally, before the source node sends the second cell change message to the terminal, the method further includes:

[0172] In a case where the RRC layer of the source node or the CU of the source node decides to trigger a cell change, the source node sends a handover request or a secondary node addition request to the target node;

[0173] The source node receives a handover confirmation message or a secondary node addition confirmation message sent by the target node, where the handover confirmation message or the secondary node addition confirmation message carries at least one of the following:

[0174] a terminal identifier allocated to the terminal at the source node;

[0175] a terminal identifier allocated to the terminal at the target node;

[0176] Updated protocol data unit (PDU) session information, wherein the updated PDU session information includes at least one of the following: quality of service (QoS) flow information allowed for access and a data forwarding address;

[0177] a transparent transmission container, wherein the transparent transmission container includes handover command information or primary and secondary cell change command information for the terminal;

[0178] Fourth indication information, the fourth indication information is used to indicate whether the target node accepts the request of the source node to use the LTM candidate configuration information to perform layer 3 handover or primary and secondary cell change;

[0179] The fourth candidate configuration identifier is used to instruct the terminal to apply the candidate configuration information associated with the fourth candidate configuration identifier in this handover or primary and secondary cell change.

[0180] The fifth indication information is used to indicate the candidate configuration information of the cell associated with the target cell identifier applied by the terminal in this handover or primary / secondary cell change.

[0181] The handover request may be a handover request for a primary cell (PCell), and the secondary node addition request (SN ADDITION REQUEST) may be a secondary node addition request for a primary secondary cell (PSCell).

[0182] The terminal identifier allocated to the terminal at the source node may be an Xn interface identifier of the terminal at the source node (source NG-RAN node UE XnAP ID reference).

[0183] The terminal identifier allocated to the terminal at the target node may be an Xn interface identifier of the terminal at the source node (target NG-RAN node UE XnAP ID reference).

[0184] The above-mentioned quality of service QoS flow information and data forwarding address allowed to access are updated quality of service QoS flow information and data forwarding address allowed to access.

[0185] In some implementations, the handover command information or the primary / secondary cell change command information includes at least one of the following:

[0186] Target cell identifier;

[0187] Sixth indication information, where the sixth indication information is used to indicate the LTM candidate configuration information of the cell associated with the target cell identifier;

[0188] A fifth candidate configuration identifier, wherein the fifth candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the fifth candidate configuration identifier.

[0189] Among them, the functions of the above-mentioned target cell identifier, sixth indication information, and fifth candidate configuration identifier are the same as those of the corresponding information in the embodiment shown in Figure 2, but the objects indicated can be the same or different.

[0190] In some implementations, if the fourth indication information indicates acceptance, affirmation, or permission, the source node may ignore the transparent transmission container carried in the handover confirmation message or the secondary node addition confirmation message.

[0191] In some embodiments, if the fourth indication information indicates rejection or negation, the source node does not ignore the transparent transmission container carried by the switching confirmation or auxiliary node addition confirmation message, and the container sent to the terminal includes the switching command information or PSCell change command information for the terminal.

[0192] The candidate configuration information associated with the fourth candidate configuration identifier may be configuration information of the LTM candidate cell associated with the fourth candidate configuration identifier.

[0193] The target node may determine the candidate configuration information through the handover confirmation or secondary node addition confirmation message, so that the terminal may change the cell that better matches the target node, which is beneficial to improving the communication performance between the terminal and the target node.

[0194] In some implementations, the handover request or the secondary node addition request carries at least one of the following:

[0195] a terminal identifier allocated to the terminal at the source node;

[0196] Reasons for handover or change of primary and secondary cells;

[0197] Target cell identifier;

[0198] A sixth candidate configuration identifier, where the sixth candidate configuration identifier is used to instruct execution of a handover to the LTM candidate cell associated with the sixth candidate configuration identifier or a primary / secondary cell change;

[0199] Updated PDU session information, where the PDU session information includes information related to data forwarding;

[0200] The seventh indication information is used to indicate at least one of the following:

[0201] Switching or changing the primary or secondary cell to a candidate cell associated with LTM;

[0202] The terminal is configured with LTM candidate configuration information;

[0203] Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

[0204] The reason for the handover or change of the primary and secondary cells may include at least one of the following:

[0205] Switching or changing the primary or secondary cell to a candidate cell associated with LTM;

[0206] The terminal is configured with LTM candidate configuration information;

[0207] Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

[0208] The candidate cells associated with the above LTM are LTM candidate cells.

[0209] By carrying the target cell identifier or the sixth candidate configuration identifier in the handover request or the secondary node addition request, the source node can indicate the target cell or the LTM candidate cell, thereby reducing the complexity of the terminal cell change.

[0210] By carrying the updated PDU session information in the handover request or the secondary node adding request, the PDU session can be updated to improve the communication performance of the terminal cell handover.

[0211] Carrying the seventh indication information in the handover request or secondary node addition request enables the target node to perform a cell change based on LTM, thereby eliminating the need to configure other cell change configuration information, thereby saving message overhead.

[0212] It should be noted that this embodiment is an implementation of the source node corresponding to the embodiment shown in Figure 2. Its specific implementation can refer to the relevant description of the embodiment shown in Figure 2. In order to avoid repeated description, this embodiment will not be repeated.

[0213] Please refer to FIG4 , which is a flowchart of another cell change method provided in an embodiment of the present application. As shown in FIG4 , the method includes the following steps:

[0214] Step 401: The target node receives a handover request or a secondary node adding request sent by the source node.

[0215] Step 402: The target node sends a handover confirmation or a secondary node addition confirmation message to the source node. The handover confirmation or secondary node addition confirmation message carries at least one of the following:

[0216] a terminal identifier allocated to the terminal at the source node;

[0217] a terminal identifier allocated to the terminal at the target node;

[0218] Updated protocol data unit (PDU) session information, wherein the updated PDU session information includes at least one of the following: quality of service (QoS) flow information allowed for access and a data forwarding address;

[0219] a transparent transmission container, wherein the transparent transmission container includes handover command information or primary and secondary cell change command information for the terminal;

[0220] Fourth indication information, the fourth indication information is used to indicate whether the target node accepts the source node's request to use the layer 1 / layer 2 triggered mobility LTM candidate configuration information to perform layer 3 handover or primary and secondary cell change;

[0221] The fourth candidate configuration identifier is used to instruct the terminal to apply the candidate configuration information associated with the fourth candidate configuration identifier in this handover or primary and secondary cell change.

[0222] The fifth indication information is used to indicate the candidate configuration information of the cell associated with the target cell identifier applied by the terminal in this handover or primary / secondary cell change.

[0223] In this embodiment, the handover confirmation or the secondary node addition confirmation message enables the source node to send a second cell change message for instructing the terminal to apply the LTM candidate configuration information, thereby saving message overhead.

[0224] Optionally, the handover command information or the primary / secondary cell change command information includes at least one of the following:

[0225] Target cell identifier;

[0226] Sixth indication information, where the sixth indication information is used to indicate the LTM candidate configuration information of the cell associated with the target cell identifier;

[0227] A fifth candidate configuration identifier, wherein the fifth candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the fifth candidate configuration identifier.

[0228] Optionally, the handover request or the secondary node adding request carries at least one of the following:

[0229] a terminal identifier allocated to the terminal at the source node;

[0230] Reasons for handover or change of primary and secondary cells;

[0231] Target cell identifier;

[0232] A sixth candidate configuration identifier, where the sixth candidate configuration identifier is used to instruct execution of a handover to the LTM candidate cell associated with the sixth candidate configuration identifier or a primary / secondary cell change;

[0233] Updated protocol data unit (PDU) session information, where the PDU session information includes information related to data forwarding;

[0234] The seventh indication information is used to indicate at least one of the following:

[0235] Switching or changing the primary or secondary cell to a candidate cell associated with LTM;

[0236] The terminal is configured with LTM candidate configuration information;

[0237] Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

[0238] Optionally, the reason for the handover or the primary / secondary cell change includes at least one of the following:

[0239] Switching or changing the primary or secondary cell to a candidate cell associated with LTM;

[0240] The terminal is configured with LTM candidate configuration information;

[0241] Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

[0242] It should be noted that this embodiment is an implementation method of the target node corresponding to the embodiment shown in Figure 3. Its specific implementation method can refer to the relevant description of the embodiment shown in Figure 3. In order to avoid repeated description, this embodiment will not be repeated.

[0243] The following node takes gNB as an example to illustrate the method provided for implementation of this application:

[0244] Example 1:

[0245] This embodiment mainly describes how the RRC layer / CU on the NW side triggers the MAC layer / DU to perform LTM cell change, which specifically includes the following steps:

[0246] Step 1: The source gNB sends an RRCReconfiguration message to the UE, which carries the LTM candidate configuration information, and receives an RRCReconfigurationComplete response message from the UE.

[0247] Step 2: The RRC layer / CU of the source gNB decides to trigger a handover / PSCell change. The RRC layer / CU sends a first message to the MAC layer / DU. The first message includes one or more of the following:

[0248] Target cell identifier. Optionally, if the target cell is an LTM candidate cell of the UE and the first information does not include radio bearer configuration, cell group configuration information, measurement configuration information, etc. associated with the target cell, the UE applies the LTM candidate configuration information associated with the target cell;

[0249] measurement results of one or more candidate cells;

[0250] Third indication information, where the third indication information is used to instruct the MAC layer / DU to perform a cell change based on LTM;

[0251] The third candidate configuration identifier is used to instruct the MAC layer / DU to trigger an LTM-based cell change to the candidate cell associated with the candidate configuration identifier.

[0252] Step 3: After the MAC layer / DU receives the first information, if the first information does not include the candidate configuration identifier / target cell identifier, the MAC layer / DU selects the candidate cell by itself and sends a second cell change message (MAC CE) to the UE to trigger the UE to perform LTM cell change (also referred to as performing LTM); otherwise, the MAC layer selects the candidate cell according to the candidate configuration identifier / target cell identifier indicated by the RRC layer, and sends cell switching signaling or PSCell change signaling to the UE.

[0253] Example 2:

[0254] In this embodiment, the RRC layer / CU on the NW side triggers the UE to apply the configuration information of the LTM candidate cell and perform a cell change to the LTM candidate cell, including the following steps:

[0255] Step 1: The UE receives the RRCReconfiguration message from the source gNB, which carries the LTM candidate configuration information, and sends an RRCReconfigurationComplete response message to the source gNB.

[0256] Step 2: The UE receives an RRCReconfiguration message carrying second information, where the second information includes one or more of the following:

[0257] Target cell identifier. Optionally, if the target cell is an LTM candidate cell of the UE, and the second information does not include radio bearer configuration, cell group configuration information, measurement configuration information, etc. associated with the target cell, the UE applies the LTM candidate configuration information associated with the target cell;

[0258] First indication information, where the second indication information is used to instruct the UE to perform handover to an LTM candidate cell or a PSCell change;

[0259] A first candidate configuration identifier, used to instruct the UE to perform handover or PSCell change to the candidate cell associated with the first candidate configuration identifier;

[0260] TA information, such as a TA value, indicating the TA value of the candidate cell associated with the candidate configuration identifier / target cell identifier. If the TA value is a valid TA, the UE may perform a RACH-less based cell change.

[0261] TCI information, such as TCI state information, is used to instruct the UE to execute beam information used in a RACH-less cell change scenario based on the candidate cell associated with the candidate configuration identifier / target cell identifier, such as the UE selecting the associated uplink allocation resources (configured uplink grant), or for data transmission after the handover is completed.

[0262] Step 3: After the MAC layer of the UE receives the second information indicated by the RRC layer, if the second information does not include a candidate configuration identifier or a target cell identifier, the MAC layer of the UE selects the candidate cell by itself and indicates the candidate configuration identifier selected by the RRC layer; otherwise, the UE selects the candidate cell according to the candidate configuration identifier / target cell identifier indicated by the RRC layer.

[0263] The UE behavior may include one or more of the following:

[0264] The UE applies the configuration information of the LTM candidate cell associated with the candidate cell selected by the MAC layer or the candidate configuration identifier / target cell identifier indicated by the RRC layer (i.e., the LTM candidate configuration information of the candidate cell), and executes the associated RRC procedure for LTM cell change;

[0265] After receiving the second information, the RRC layer of the terminal instructs the MAC layer to perform a MAC reset (MAC reset) or after receiving the candidate configuration identifier indicated by the MAC layer, the RRC layer of the terminal instructs the MAC layer to perform a MAC reset;

[0266] If the second information includes a valid TA value, indicating the TA value to the physical layer; or if it is a candidate cell selected by the MAC layer and the UE performs TA measurement on the selected candidate cell, indicating the TA value to the physical layer;

[0267] If the second information includes a valid TA value, indicating the TA value to the MAC layer to instruct the UE to perform RACH-less based cell switching; or if it is a candidate cell selected by the MAC layer, and the UE performs TA measurement on the selected candidate cell, and the UE maintains a valid TA value for the selected candidate cell, performing a RACH-less based cell change;

[0268] If the second information includes TCI state information, the TCI state information is indicated to the MAC layer to instruct the UE to perform a RACH-less cell change, and for the MAC layer to select a configured uplink grant for the first uplink transmission to the candidate cell.

[0269] Example 3:

[0270] This embodiment mainly describes the enhanced process of Layer 3 HO (L3 HO) / PSCell change preparation, which includes the following steps:

[0271] Step 1: The source gNB sends an RRCReconfiguration message to the UE, which carries the LTM candidate configuration information, and receives an RRCReconfigurationComplete response message from the UE.

[0272] Step 2: The RRC layer of the source gNB decides to trigger a handover or PSCell change. The source gNB sends a HANDOVER REQUEST (for PCell) / SN ADDITION REQUEST (for PSCell) to the target gNB. The HANDOVER REQUEST / SN ADDITION REQUEST message carries at least one of the following:

[0273] UE identifier assigned at the source node (source NG-RAN node UE XnAP ID)

[0274] Handover reason / PSCell change reason, where the handover reason / PSCell change indicates any of the following: handover / PSCell change to a candidate cell associated with LTM; the UE is configured with LTM candidate configuration information; RRC or layer 3 signaling is used to trigger the UE handover / PSCell change to a candidate cell associated with LTM;

[0275] Seventh indication information, the seventh indication information is used to indicate any one of the following: handover / PSCell change to a candidate cell associated with LTM; the UE is configured with LTM candidate configuration information; RRC or layer 3 signaling is used to trigger the UE handover / PSCell change to a candidate cell associated with LTM;

[0276] Target cell identifier;

[0277] a sixth candidate configuration identifier;

[0278] Updated PDU session information, including information related to data forwarding.

[0279] Step 3: After receiving the HANDOVER REQUEST / SN ADDITION REQUEST message from the source gNB, the target gNB sends a HANDOVER REQUEST ACKNOWLEDGE / SN ADDITION REQUEST ACKNOWLEDGE message to the source gNB. The HANDOVER REQUEST ACKNOWLEDGE / SN ADDITION REQUEST ACKNOWLEDGE message contains one or more of the following:

[0280] UE identifier assigned at the source node, such as the Xn interface identifier of the terminal at the source node (source NG-RAN node UE XnAP ID reference)

[0281] UE identifier assigned at the target node, such as the terminal's Xn interface identifier at the target node (target NG-RAN node UE XnAP ID reference)

[0282] Updated PDU session resource information, including updated QoS flow information allowed to access or updated data forwarding address;

[0283] The third information includes one or more of the following:

[0284] fourth indication information, the fourth indication information being used to indicate whether the target gNB accepts the source gNB's request to use the LTM configuration for L3 HO / PSCell change; if the fourth indication information indicates acceptance, affirmation, or permission, the source gNB ignores the transparent transmission container sent by the target node to the source node in the HANOVER REQUEST ACKNOWLEDGE / SN ADDITION REQUEST ACKNOWLEDGE message, the container containing handover command information / PSCell change command information for the UE; if the fourth indication information indicates rejection or negation, the source gNB must not ignore the transparent transmission container sent by the target node to the source node in the HANOVER REQUEST ACKNOWLEDGE / SN ADDITION REQUEST ACKNOWLEDGE message, the container containing handover command information / PSCell change command information for the UE; a fourth candidate configuration identifier, the fourth candidate configuration identifier being used to instruct the source gNB to apply the candidate configuration information associated with the fourth candidate configuration identifier to the UE in this handover / PSCell change; and fifth indication information, the fifth indication information instructing the source gNB to apply the candidate configuration information associated with the target cell to the UE in this handover / PSCell change.

[0285] The target node sends a transparent transmission container to the source node, wherein the transparent transmission container includes handover command information / PSCell change command information for the UE. The handover command information / PSCell change command information includes one or more of the following:

[0286] Target cell identifier. Optionally, if the target cell is an LTM candidate cell of the UE and the handover command information does not include radio bearer configuration, cell group configuration information, measurement configuration information, etc. associated with the target cell, the UE applies the LTM candidate configuration information associated with the target cell;

[0287] The sixth indication information is used to instruct the UE to apply the candidate configuration information associated with the target cell identifier

[0288] A fifth candidate configuration identifier, where the fifth candidate configuration identifier is used to instruct the UE to apply the candidate configuration information associated with the fifth candidate configuration identifier.

[0289] Step 5: After receiving the HANDOVER REQUEST ACKNOWLEDGE / SN ADDITION REQUEST message from the target gNB, the source gNB sends a Layer 3 cell change message (RRCReconfiguration message) to the UE.

[0290] Step 6: The UE receives the RRCReconfiguration message, which carries the fourth information. The fourth information includes one or more of the following:

[0291] Target cell identifier. Optionally, if the target cell is an LTM candidate cell of the UE, and the fourth information does not include radio bearer configuration, cell group configuration information, volume configuration information, etc. associated with the target cell, the UE applies the LTM candidate configuration information associated with the target cell;

[0292] A first candidate configuration identifier, used to instruct the UE to perform handover or PSCell change to the candidate cell associated with the first candidate configuration identifier;

[0293] second indication information, where the second indication information is used to indicate configuration information of a candidate cell associated with the target cell identifier;

[0294] TA information, used to indicate the TA value of the candidate cell associated with the candidate configuration identifier / target cell identifier. If the TA value is a valid TA value, the UE can perform a RACH-less based cell change.

[0295] TCI information is used to instruct the UE to execute the beam information used in the RACH-less cell change scenario based on the candidate cell associated with the candidate configuration identifier / target cell identifier, such as the UE selecting the associated configured uplink grant, or for data transmission after the handover is completed.

[0296] Step 7: After the MAC layer of the UE receives the fourth information indicated by the RRC layer, the UE selects a target candidate cell according to the candidate configuration identifier / target cell identifier indicated by the RRC layer.

[0297] The UE behavior includes one or more of the following:

[0298] The UE applies the LTM candidate configuration information of the candidate cell associated with the candidate configuration identifier / target cell identifier indicated by the RRC layer, and executes the RRC procedure for the associated LTM cell change;

[0299] After receiving the fourth information, the RRC layer of the terminal instructs the MAC layer to reset the MAC;

[0300] If the fourth information includes a valid TA value, indicating the TA value to the physical layer;

[0301] If the fourth information includes a valid TA value, indicating the TA value to the MAC layer to instruct the UE to perform a RACH-less based cell change;

[0302] If the fourth information includes TCI state information, the TCI state information is indicated to the MAC layer to instruct the UE to perform a RACH-less cell change and for the MAC layer to select a configured uplink grant for the first uplink transmission to the candidate cell.

[0303] In the embodiment of the present application, the following can be achieved:

[0304] In the case where the UE is configured with inter-CU LTM configuration information, the UE receives layer 3 cell change signaling (including HO signaling and PSCell change signaling), and the UE releases or does not release the stored inter-CU LTM candidate configuration information.

[0305] Whether the UE releases or does not release the stored inter-CU LTM configuration information is agreed upon by the protocol.

[0306] If the UE does not release the stored inter-CU LTM configuration information, when the RRC layer on the NW side triggers an L3 cell change, if the selected target cell is a candidate cell, it triggers the UE to perform a cell change to the LTM candidate cell and instructs the UE to apply the LTM candidate cell configuration.

[0307] If the UE does not release the stored inter-CU LTM configuration information, the source gNB or target gNB performs the enhanced L3 HO preparation or SN addition / change preparation procedure.

[0308] In addition, another enhanced solution for the NW side is that when the UE is configured with inter-CU LTM configuration information, the RRC layer of the NW wants to trigger the UE to perform a cell change, then the RRC layer sends information to the MAC layer to trigger the MAC layer to send LTM cell change signaling to the UE.

[0309] Specifically, when the RRC layer of the NW wants to trigger the UE to perform a cell change, the actions of the NW may include one or more of the following:

[0310] The RRC layer sends first information to the MAC layer to trigger the MAC layer to send LTM cell change signaling to the UE.

[0311] The NW side sends RRC signaling, which carries the LTM candidate configuration identifier / LTM candidate cell identifier or indication information to trigger the UE to perform a cell change to the candidate cell and apply the candidate configuration information

[0312] The source gNB sends a request message to the target gNB and indicates to the target gNB that the UE has the LTM configuration information of the target cell. After receiving the indication message, the target gNB may not configure the configuration information of the target cell for the UE.

[0313] On the UE side, the UE behavior may include one or more of the following:

[0314] When the UE side receives the L3 cell change signaling indicating the candidate configuration identifier / candidate cell identifier, the UE applies the configuration information of the associated candidate cell.

[0315] When the UE side receives L3 cell change signaling indicating the application of LTM candidate configuration but does not carry the candidate configuration identifier / candidate cell identifier, the UE selects the candidate cell by itself and performs a cell change to the candidate cell.

[0316] The cell change method provided in the embodiment of the present application can be executed by a cell change device. In the embodiment of the present application, the cell change device provided in the embodiment of the present application is described by taking the cell change method executed by the cell change device as an example.

[0317] Please refer to FIG5 , which is a structural diagram of a cell change device provided in an embodiment of the present application. As shown in FIG5 , the cell change device 500 includes:

[0318] A first acquiring module 501 is configured to acquire a first cell change message, where the first cell change message carries layer 1 / layer 2 triggered mobility LTM candidate configuration information;

[0319] The second acquisition module 502 is configured to acquire a second cell change message, where the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information.

[0320] The second cell change message is used to instruct the terminal to apply the LTM candidate configuration information.

[0321] Optionally, the first cell change message is a first radio resource control RRC reconfiguration message, and the second cell change message is a second RRC reconfiguration message.

[0322] Optionally, the second cell change message is a cell change message triggered by RRC signaling.

[0323] Optionally, the second cell change message carries at least one of the following:

[0324] a target cell identifier, wherein when the cell associated with the target cell identifier is an LTM candidate cell, the terminal applies configuration information of the LTM candidate cell;

[0325] First indication information, where the first indication information is used to instruct the terminal to perform a handover to an LTM candidate cell or a primary / secondary cell change;

[0326] second indication information, where the second indication information is used to indicate configuration information of a candidate cell associated with the target cell identifier;

[0327] A first candidate configuration identifier, where the first candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the first candidate configuration identifier;

[0328] or,

[0329] The first cell change message further carries: at least one second candidate configuration identifier, where the second candidate configuration identifier is associated with configuration information of an LTM candidate cell, wherein, when the second cell change message carries the first candidate configuration identifier, the first candidate configuration identifier is a candidate configuration identifier in the at least one second candidate configuration identifier;

[0330] The LTM candidate configuration information includes configuration information of the LTM candidate cell.

[0331] Optionally, when the cell associated with the target cell identifier is an LTM candidate cell and the second cell change message does not carry configuration information of the cell associated with the target cell identifier, the terminal applies the configuration information of the LTM candidate cell.

[0332] Optionally, the second cell change message further carries at least one of the following:

[0333] Key-related information, where the key-related information is used to instruct the terminal to generate a security key to be used in a target cell or after a cell change based on the key-related information;

[0334] Timing Advance (TA) information, where the TA information is used to indicate at least one of the following: a TA of the cell associated with the target cell identifier, and a TA of the LTM candidate cell associated with the first candidate configuration identifier;

[0335] Transmission configuration indication TCI information, the TCI information is used to indicate at least one of the following: the beam information used in the cell change process without the random access channel RACH process to the cell associated with the target cell identifier, and the beam information used in the cell change process without the RACH process to the LTM candidate cell associated with the first candidate configuration identifier.

[0336] Optionally, the device further comprises at least one of the following:

[0337] A first execution module, configured to execute cell switching or primary / secondary cell change based on the configuration information of the target candidate cell;

[0338] A generating module, configured to generate a security key to be used in a target cell or after a cell change based on the key-related information;

[0339] A first indication module, configured for a radio resource control (RRC) layer of a terminal to indicate a MAC reset to a media access control (MAC) layer of the terminal;

[0340] A second indication module is configured to cause the RRC layer of the terminal to indicate a TA to the MAC layer of the terminal to instruct execution of a cell change without a RACH procedure, wherein the TA includes: a valid TA indicated by the TA information carried by the second cell change message;

[0341] a second execution module, configured to, when the terminal performs TA measurement on the target candidate cell selected by the terminal and maintains a valid TA of the target candidate cell at the moment of receiving the second cell change message, perform a cell change without a RACH procedure;

[0342] The third indication module is used to indicate, by the RRC layer of the terminal, the TCI status information to the MAC layer of the terminal when the second cell change message carries TCI status information, wherein the TCI status information is used to indicate the execution of a cell change without RACH, and is used by the MAC layer to select uplink allocation resources.

[0343] The above-mentioned cell change device can save message overhead.

[0344] In the embodiments of the present application, the cell change device can be an electronic device, such as an electronic device with an operating system, or a component of an electronic device, such as an integrated circuit or chip. For example, the electronic device can be a terminal, or it can be a device other than a terminal. For example, the terminal can include but is not limited to the types of terminals listed in the embodiments of the present application, and the other device can be a server, a network attached storage (NAS), etc., which is not specifically limited in the embodiments of the present application.

[0345] The cell change device provided in the embodiment of the present application can implement the various processes implemented in the method embodiment shown in Figure 2 and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0346] Please refer to FIG6 , which is a structural diagram of another cell change device provided in an embodiment of the present application. As shown in FIG6 , the cell change device 600 includes:

[0347] The first sending module 601 is used to send a second cell change message to the terminal, where the second cell change message is used to indicate the mobility LTM candidate configuration information triggered by the terminal application layer 1 / layer 2, wherein the LTM candidate configuration information is the LTM candidate configuration information obtained by the terminal through the first cell change message.

[0348] Optionally, the device further comprises:

[0349] The second sending module is configured to send the first cell change message to the terminal, where the first cell change message carries LTM candidate configuration information.

[0350] Optionally, the first cell change message is a first radio resource control RRC reconfiguration message, and the second cell change message is a second RRC reconfiguration message.

[0351] Optionally, the second cell change message is a cell change message triggered by RRC signaling.

[0352] Optionally, the device further comprises:

[0353] A third sending module is configured to, when the RRC layer of the source node decides to trigger a cell change, cause the RRC layer of the source node to send first information to the MAC layer of the source node, or the central unit CU of the source node to send first information to the distributed unit DU of the source node, where the first information includes at least one of the following:

[0354] Target cell identifier;

[0355] measurement results of one or more candidate cells;

[0356] third indication information, where the third indication information is used to instruct the MAC layer or the DU of the source node to perform an LTM-based cell change;

[0357] A third candidate configuration identifier is used to instruct the DU of the MAC layer or the source node to trigger a handover or a primary / slave cell change to the LTM candidate cell associated with the third candidate configuration identifier.

[0358] Optionally, when the first information includes measurement results of the one or more candidate cells, the apparatus further includes:

[0359] A selection module is used for the MAC layer of the source node or the DU of the source node to select a target candidate cell based on the measurement results of the one or more candidate cells, and the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information associated with the target candidate cell.

[0360] Optionally, the sending the second cell change message to the terminal includes:

[0361] In a case where the first information does not include the target cell identifier and the third candidate configuration identifier, the MAC layer of the source node or the DU of the source node selects a target candidate cell and sends a second cell change message to the terminal, where the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information, including: the second cell change message is used to trigger a cell change based on the LTM candidate configuration information associated with the target candidate cell; or

[0362] In the case where the first information includes the target cell identifier or the third candidate configuration identifier, the MAC layer of the source node or the DU of the source node selects a target candidate cell based on the target cell identifier or the third candidate configuration identifier, and sends a second cell change message to the terminal, where the second cell change message is used to instruct the terminal to apply the LTM configuration information, including: the second cell change message is used to trigger a cell change based on the LTM candidate configuration information associated with the target candidate cell.

[0363] Optionally, the second cell change message carries at least one of the following:

[0364] a target cell identifier, where, when the cell associated with the target cell identifier is an LTM candidate cell, the terminal applies the LTM candidate configuration information associated with the LTM candidate cell;

[0365] First indication information, where the first indication information is used to instruct the terminal to perform handover to an LTM candidate cell or change a primary or secondary cell;

[0366] second indication information, where the second indication information is used to indicate configuration information of a candidate cell associated with the target cell identifier;

[0367] A first candidate configuration identifier, where the first candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the first candidate configuration identifier;

[0368] or,

[0369] The first cell change message further carries: at least one second candidate configuration identifier, where the second candidate configuration identifier is associated with configuration information of an LTM candidate cell, wherein, when the second cell change message carries the first candidate configuration identifier, the first candidate configuration identifier is a candidate configuration identifier in the at least one second candidate configuration identifier;

[0370] The LTM candidate configuration information includes LTM candidate configuration information of the LTM candidate cell.

[0371] Optionally, the second cell change message further carries at least one of the following:

[0372] Key-related information, where the key-related information is used to instruct the terminal to generate a security key to be used in a target cell or after a cell change based on the key-related information;

[0373] Timing Advance (TA) information, where the TA information is used to indicate at least one of the following: a TA of the cell associated with the target cell identifier, and a TA of the LTM candidate cell associated with the first candidate configuration identifier;

[0374] Transmission configuration indication TCI information, the TCI information is used to indicate at least one of the following: the beam information used in the cell change process without the random access channel RACH process to the cell associated with the target cell identifier, and the beam information used in the cell change process without the RACH process to the LTM candidate cell associated with the first candidate configuration identifier.

[0375] Optionally, the device further comprises:

[0376] a fourth sending module, configured to send a handover request or a secondary node addition request to a target node when the RRC layer of the source node or the CU of the source node decides to trigger a cell change;

[0377] a receiving module, configured to receive a handover confirmation message or a secondary node addition confirmation message sent by the target node, wherein the handover confirmation message or the secondary node addition confirmation message carries at least one of the following:

[0378] a terminal identifier allocated to the terminal at the source node;

[0379] a terminal identifier allocated to the terminal at the target node;

[0380] Updated protocol data unit (PDU) session information, wherein the updated PDU session information includes at least one of the following: quality of service (QoS) flow information allowed for access and a data forwarding address;

[0381] a transparent transmission container, wherein the transparent transmission container includes handover command information or primary and secondary cell change command information for the terminal;

[0382] Fourth indication information, the fourth indication information is used to indicate whether the target node accepts the request of the source node to use the LTM candidate configuration information to perform layer 3 handover or primary and secondary cell change;

[0383] The fourth candidate configuration identifier is used to instruct the terminal to apply the candidate configuration information associated with the fourth candidate configuration identifier in this handover or primary and secondary cell change.

[0384] The fifth indication information is used to indicate the candidate configuration information of the cell associated with the target cell identifier applied by the terminal in this handover or primary / secondary cell change.

[0385] Optionally, the handover command information or the primary / secondary cell change command information includes at least one of the following:

[0386] Target cell identifier;

[0387] Sixth indication information, where the sixth indication information is used to indicate the LTM candidate configuration information of the cell associated with the target cell identifier;

[0388] A fifth candidate configuration identifier, wherein the fifth candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the fifth candidate configuration identifier.

[0389] Optionally, the handover request or the secondary node adding request carries at least one of the following:

[0390] a terminal identifier allocated to the terminal at the source node;

[0391] Reasons for handover or change of primary and secondary cells;

[0392] Target cell identifier;

[0393] A sixth candidate configuration identifier, where the sixth candidate configuration identifier is used to instruct execution of a handover to the LTM candidate cell associated with the sixth candidate configuration identifier or a primary / secondary cell change;

[0394] Updated PDU session information, where the PDU session information includes information related to data forwarding;

[0395] The seventh indication information is used to indicate at least one of the following:

[0396] Switching or changing the primary or secondary cell to a candidate cell associated with LTM;

[0397] The terminal is configured with LTM candidate configuration information;

[0398] Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

[0399] Optionally, the reason for the handover or the primary / secondary cell change includes at least one of the following:

[0400] Switching or changing the primary or secondary cell to a candidate cell associated with LTM;

[0401] The terminal is configured with LTM candidate configuration information;

[0402] Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

[0403] The above-mentioned cell change device can save message overhead.

[0404] The cell change device in the embodiment of the present application may be an electronic device, such as an electronic device with an operating system, or a component in the electronic device, such as an integrated circuit or a chip. The electronic device may be a terminal or a network-side device.

[0405] The cell change device provided in the embodiment of the present application can implement the various processes implemented in the method embodiment shown in Figure 3 and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0406] Please refer to FIG. 7 , which is a structural diagram of another cell change apparatus provided in an embodiment of the present application. As shown in FIG. 7 , the cell change apparatus 700 includes:

[0407] The receiving module 701 is configured to receive a switching request or a secondary node adding request sent by a source node;

[0408] The sending module 702 is configured to send a handover confirmation or a secondary node addition confirmation message to the source node, where the handover confirmation or the secondary node addition confirmation message carries at least one of the following:

[0409] a terminal identifier allocated to the terminal at the source node;

[0410] a terminal identifier allocated to the terminal at the target node;

[0411] Updated protocol data unit (PDU) session information, wherein the updated PDU session information includes at least one of the following: quality of service (QoS) flow information allowed for access and a data forwarding address;

[0412] a transparent transmission container, wherein the transparent transmission container includes handover command information or primary and secondary cell change command information for the terminal;

[0413] Fourth indication information, the fourth indication information is used to indicate whether the target node accepts the request of the source node to use the LTM candidate configuration information to perform layer 3 handover or primary and secondary cell change;

[0414] The fourth candidate configuration identifier is used to instruct the terminal to apply the candidate configuration information associated with the fourth candidate configuration identifier in this handover or primary and secondary cell change.

[0415] The fifth indication information is used to indicate the candidate configuration information of the cell associated with the target cell identifier applied by the terminal in this handover or primary / secondary cell change.

[0416] Optionally, the handover command information or the primary / secondary cell change command information includes at least one of the following:

[0417] Target cell identifier;

[0418] Sixth indication information, where the sixth indication information is used to indicate the LTM candidate configuration information of the cell associated with the target cell identifier;

[0419] A fifth candidate configuration identifier, wherein the fifth candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the fifth candidate configuration identifier.

[0420] Optionally, the handover request or the secondary node adding request carries at least one of the following:

[0421] a terminal identifier allocated to the terminal at the source node;

[0422] Reasons for handover or change of primary and secondary cells;

[0423] Target cell identifier;

[0424] A sixth candidate configuration identifier, where the sixth candidate configuration identifier is used to instruct execution of a handover to the LTM candidate cell associated with the sixth candidate configuration identifier or a primary / secondary cell change;

[0425] Updated protocol data unit (PDU) session information, where the PDU session information includes information related to data forwarding;

[0426] The seventh indication information is used to indicate at least one of the following:

[0427] Switching or changing the primary or secondary cell to a candidate cell associated with LTM;

[0428] The terminal is configured with LTM candidate configuration information;

[0429] Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

[0430] Optionally, the reason for the handover or the primary / secondary cell change includes at least one of the following:

[0431] Switching or changing the primary or secondary cell to a candidate cell associated with LTM;

[0432] The terminal is configured with LTM candidate configuration information;

[0433] Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

[0434] The above-mentioned cell change device can save message overhead.

[0435] The cell change device in the embodiment of the present application may be an electronic device, such as an electronic device with an operating system, or a component in the electronic device, such as an integrated circuit or a chip. The electronic device may be a terminal or a network-side device.

[0436] The cell change device provided in the embodiment of the present application can implement the various processes implemented by the method embodiment shown in Figure 4 and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0437] Optionally, as shown in Figure 8, an embodiment of the present application further provides a communication device 800, including a processor 801 and a memory 802, wherein the memory 802 stores a program or instruction that can be run on the processor 801. For example, when the communication device 800 is a terminal, the program or instruction is executed by the processor 801 to implement the various steps of the above-mentioned terminal-side cell change method embodiment, and can achieve the same technical effect. For example, when the communication device 800 is a network-side device, the program or instruction is executed by the processor 801 to implement the various steps of the above-mentioned source node or target node side cell change method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0438] An embodiment of the present application further provides a communications device, including a processor and a communications interface, wherein the communications interface is configured to obtain a first cell change message, the first cell change message carrying layer 1 / layer 2 triggered mobility LTM candidate configuration information; and obtain a second cell change message, the second cell change message being configured to instruct the terminal to apply the LTM candidate configuration information. This communications device embodiment corresponds to the aforementioned cell change method embodiment, and each implementation process and implementation method of the aforementioned method embodiment are applicable to this communications device embodiment and can achieve the same technical effects.

[0439] Specifically, Figure 9 is a schematic diagram of the hardware structure of a terminal implementing an embodiment of the present application. The terminal 900 includes, but is not limited to, at least some of the components including a radio frequency unit 901, a network module 902, an audio output unit 903, an input unit 904, a sensor 905, a display unit 906, a user input unit 907, an interface unit 908, a memory 909, and a processor 910.

[0440] Those skilled in the art will appreciate that the terminal 900 may further include a power supply (such as a battery) to power various components. The power supply may be logically connected to the processor 910 via a power management system, thereby enabling the power management system to manage charging, discharging, and power consumption. The device structure shown in FIG9 does not limit the device. The device may include more or fewer components than shown, or may combine certain components, or have different component arrangements, which will not be described in detail here.

[0441] It should be understood that in an embodiment of the present application, the input unit 904 may include a graphics processing unit (GPU) 9041 and a microphone 9042, and the graphics processing unit 9041 processes the image data of a static picture or video obtained by an image capture device (such as a camera) in a video capture mode or an image capture mode. The display unit 906 may include a display panel 9061, and the display panel 9061 may be configured in the form of a liquid crystal display, an organic light emitting diode, etc. The user input unit 907 includes a touch panel 9071 and at least one of other input devices 9072. The touch panel 9071 is also called a touch screen. The touch panel 9071 may include two parts: a touch detection device and a touch controller. Other input devices 9072 may include, but are not limited to, a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a trackball, a mouse, and an operating stick, which will not be repeated here.

[0442] In the embodiment of the present application, after receiving downlink data from a network-side device, the RF unit 901 may transmit the data to the processor 910 for processing. Furthermore, the RF unit 901 may send uplink data to the network-side device. Typically, the RF unit 901 includes, but is not limited to, an antenna, an amplifier, a transceiver, a coupler, a low-noise amplifier, a duplexer, and the like.

[0443] The memory 909 can be used to store software programs or instructions and various data. The memory 909 may mainly include a first storage area for storing programs or instructions and a second storage area for storing data, wherein the first storage area may store an operating system, applications or instructions required for at least one function (such as a sound playback function, an image playback function, etc.), etc. In addition, the memory 909 may include a volatile memory or a non-volatile memory, or the memory 909 may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. Volatile memory can be random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DRRAM). The memory 909 in the embodiment of the present application includes but is not limited to these and any other suitable types of memory.

[0444] Processor 910 may include one or more processing units. Optionally, processor 910 integrates an application processor and a modem processor. The application processor primarily handles operations related to the operating system, user interface, and application programs, while the modem processor primarily processes wireless communication signals, such as a baseband processor. It is understood that the modem processor may not be integrated into processor 910.

[0445] The radio frequency unit 901 is used to obtain a first cell change message, which carries the mobility LTM candidate configuration information triggered by layer 1 / layer 2; and obtain a second cell change message, which is used to instruct the terminal to apply the LTM candidate configuration information.

[0446] Optionally, the first cell change message is a first radio resource control RRC reconfiguration message, and the second cell change message is a second RRC reconfiguration message.

[0447] Optionally, the second cell change message is a cell change message triggered by RRC signaling.

[0448] Optionally, the second cell change message carries at least one of the following:

[0449] a target cell identifier, wherein when the cell associated with the target cell identifier is an LTM candidate cell, the terminal applies configuration information of the LTM candidate cell;

[0450] First indication information, where the first indication information is used to instruct the terminal to perform a handover to an LTM candidate cell or a primary / secondary cell change;

[0451] second indication information, where the second indication information is used to indicate configuration information of a candidate cell associated with the target cell identifier;

[0452] A first candidate configuration identifier, where the first candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the first candidate configuration identifier;

[0453] or,

[0454] The first cell change message further carries: at least one second candidate configuration identifier, where the second candidate configuration identifier is associated with configuration information of an LTM candidate cell, wherein, when the second cell change message carries the first candidate configuration identifier, the first candidate configuration identifier is a candidate configuration identifier in the at least one second candidate configuration identifier;

[0455] The LTM candidate configuration information includes configuration information of the LTM candidate cell.

[0456] Optionally, when the cell associated with the target cell identifier is an LTM candidate cell and the second cell change message does not carry configuration information of the cell associated with the target cell identifier, the terminal applies the configuration information of the LTM candidate cell.

[0457] Optionally, the second cell change message further carries at least one of the following:

[0458] Key-related information, where the key-related information is used to instruct the terminal to generate a security key to be used in a target cell or after a cell change based on the key-related information;

[0459] Timing Advance (TA) information, where the TA information is used to indicate at least one of the following: a TA of the cell associated with the target cell identifier, and a TA of the LTM candidate cell associated with the first candidate configuration identifier;

[0460] Transmission configuration indication TCI information, the TCI information is used to indicate at least one of the following: the beam information used in the cell change process without the random access channel RACH process to the cell associated with the target cell identifier, and the beam information used in the cell change process without the RACH process to the LTM candidate cell associated with the first candidate configuration identifier.

[0461] Optionally, the processor 910 is configured to:

[0462] Selecting a target candidate cell based on the target cell identifier and the first candidate configuration identifier; or,

[0463] The MAC layer of the terminal selects a target candidate cell.

[0464] Optionally, the processor 910 is further configured to:

[0465] Performing cell switching or primary / secondary cell change based on the configuration information of the target candidate cell;

[0466] generating a security key for use in the target cell or after the cell change based on the key-related information;

[0467] The radio resource control (RRC) layer of the terminal instructs a media access control (MAC) layer of the terminal to reset the MAC;

[0468] The RRC layer of the terminal indicates a TA to the MAC layer of the terminal to instruct execution of a cell change without a RACH procedure, wherein the TA includes: a valid TA indicated by the TA information carried by the second cell change message;

[0469] When the terminal performs TA measurement for the target candidate cell selected by the terminal and maintains a valid TA of the target candidate cell at the time of receiving the second cell change message, performing a cell change without a RACH procedure;

[0470] When the second cell change message carries TCI status information, the RRC layer of the terminal indicates the TCI status information to the MAC layer of the terminal, and the TCI status information is used to indicate the execution of a cell change without RACH and for the MAC layer to select uplink allocation resources.

[0471] The above device can save message overhead.

[0472] It can be understood that the implementation process of each implementation method mentioned in this embodiment can refer to the relevant description of the above-mentioned cell change method and achieve the same or corresponding technical effects. To avoid repetition, it will not be repeated here.

[0473] The present application also provides an embodiment of a 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 3 or 4. This device embodiment corresponds to the above-mentioned cell change method embodiment, and each implementation process and implementation method of the above-mentioned method embodiment can be applied to this device embodiment and can achieve the same technical effect.

[0474] An embodiment of the present application also provides a communication device, including a processor and a communication interface, wherein the communication interface is used to send a second cell change message to the terminal, and the second cell change message is used to indicate the mobility LTM candidate configuration information triggered by the terminal application layer 1 / layer 2, wherein the LTM candidate configuration information is the LTM candidate configuration information obtained by the terminal through the first cell change message. Alternatively, the communication interface is used for the target node to receive a handover request or a secondary node addition request sent by the source node; send a handover confirmation or a secondary node addition confirmation message to the source node, the handover confirmation or the secondary node addition confirmation message carrying at least one of the following: a terminal identifier assigned to the terminal at the source node; a terminal identifier assigned to the terminal at the target node; updated protocol data unit (PDU) session information, the updated PDU session information including at least one of the following: quality of service (QoS) flow information and data forwarding address allowed for access; a transparent transmission container, the transparent transmission container containing handover command information or primary and secondary cell change command information for the terminal; fourth indication information, the fourth indication information is used to indicate whether the target node accepts the source node's request to use layer 1 / layer 2 triggered mobility LTM candidate configuration information for layer 3 handover or primary and secondary cell change; a fourth candidate configuration identifier, the fourth candidate configuration identifier is used to indicate that the terminal should apply the candidate configuration information associated with the fourth candidate configuration identifier in this handover or primary and secondary cell change. This communication device embodiment corresponds to the above-mentioned cell change method embodiment, and each implementation process and implementation method of the above-mentioned method embodiment can be applied to this communication device embodiment and can achieve the same technical effect.

[0475] Specifically, embodiments of the present application also provide a network-side device. As shown in Figure 10, device 1000 includes an antenna 1001, a radio frequency device 1002, a baseband device 1003, a processor 1004, and a memory 1005. Antenna 1001 is connected to radio frequency device 1002. In the uplink direction, radio frequency device 1002 receives information via antenna 1001 and sends the received information to baseband device 1003 for processing. In the downlink direction, baseband device 1003 processes the information to be transmitted and sends it to radio frequency device 1002. Radio frequency device 1002 processes the received information and then sends it through antenna 1001.

[0476] The cell changing method or cell changing method in the above embodiment may be implemented in the baseband device 1003, which includes a baseband processor.

[0477] The baseband device 1003 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 1005 through a bus interface to call the program in the memory 1005 and execute the device operations shown in the above method embodiment.

[0478] The device may further include a network interface 1006 , which may be, for example, a Common Public Radio Interface (CPRI).

[0479] Specifically, the device 1000 of the embodiment of the present application also includes: instructions or programs stored in the memory 1005 and executable on the processor 1004. The processor 1004 calls the instructions or programs in the memory 1005 to execute the methods executed by the modules shown in FIG6 or 7 and achieve the same technical effect. To avoid repetition, they will not be elaborated here.

[0480] In one embodiment, the network-side device is a source node:

[0481] The radio frequency device 1002 is used to send a second cell change message to the terminal, where the second cell change message is used to indicate the mobility LTM candidate configuration information triggered by the terminal application layer 1 / layer 2, wherein the LTM candidate configuration information is the LTM candidate configuration information obtained by the terminal through the first cell change message.

[0482] Optionally, before sending the second cell change message to the terminal, the radio frequency device 1002 is further configured to:

[0483] The first cell change message is sent to the terminal, where the first cell change message carries LTM candidate configuration information.

[0484] Optionally, the first cell change message is a first radio resource control RRC reconfiguration message, and the second cell change message is a second RRC reconfiguration message.

[0485] Optionally, the second cell change message is a cell change message triggered by RRC signaling.

[0486] Optionally, before sending the second cell change message to the terminal, the processor 1004 is configured to:

[0487] When the RRC layer of the source node decides to trigger a cell change, the RRC layer of the source node sends first information to the MAC layer of the source node, or the central unit CU of the source node sends first information to the distributed unit DU of the source node, where the first information includes at least one of the following:

[0488] Target cell identifier;

[0489] measurement results of one or more candidate cells;

[0490] third indication information, where the third indication information is used to instruct the MAC layer or the DU of the source node to perform an LTM-based cell change;

[0491] A third candidate configuration identifier is used to instruct the DU of the MAC layer or the source node to trigger a handover or a primary / slave cell change to the LTM candidate cell associated with the third candidate configuration identifier.

[0492] Optionally, when the first information includes measurement results of the one or more candidate cells, the processor 1004 is configured to:

[0493] The MAC layer of the source node or the DU of the source node selects a target candidate cell based on the measurement results of the one or more candidate cells, and the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information associated with the target candidate cell.

[0494] Optionally, the sending the second cell change message to the terminal includes:

[0495] In a case where the first information does not include the target cell identifier and the third candidate configuration identifier, the MAC layer of the source node or the DU of the source node selects a target candidate cell and sends a second cell change message to the terminal, where the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information, including: the second cell change message is used to trigger a cell change based on the LTM candidate configuration information associated with the target candidate cell; or

[0496] In the case where the first information includes the target cell identifier or the third candidate configuration identifier, the MAC layer of the source node or the DU of the source node selects a target candidate cell based on the target cell identifier or the third candidate configuration identifier, and sends a second cell change message to the terminal, where the second cell change message is used to instruct the terminal to apply the LTM configuration information, including: the second cell change message is used to trigger a cell change based on the LTM candidate configuration information associated with the target candidate cell.

[0497] Optionally, the second cell change message carries at least one of the following:

[0498] a target cell identifier, where, when the cell associated with the target cell identifier is an LTM candidate cell, the terminal applies the LTM candidate configuration information associated with the LTM candidate cell;

[0499] First indication information, where the first indication information is used to instruct the terminal to perform a handover to an LTM candidate cell or a primary / secondary cell change;

[0500] second indication information, where the second indication information is used to indicate configuration information of a candidate cell associated with the target cell identifier;

[0501] A first candidate configuration identifier, where the first candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the first candidate configuration identifier;

[0502] or,

[0503] The first cell change message further carries: at least one second candidate configuration identifier, where the second candidate configuration identifier is associated with configuration information of an LTM candidate cell, wherein, when the second cell change message carries the first candidate configuration identifier, the first candidate configuration identifier is a candidate configuration identifier in the at least one second candidate configuration identifier;

[0504] The LTM candidate configuration information includes LTM candidate configuration information of the LTM candidate cell.

[0505] Optionally, the second cell change message further carries at least one of the following:

[0506] Key-related information, where the key-related information is used to instruct the terminal to generate a security key to be used in a target cell or after a cell change based on the key-related information;

[0507] Timing Advance (TA) information, where the TA information is used to indicate at least one of the following: a TA of the cell associated with the target cell identifier, and a TA of the LTM candidate cell associated with the first candidate configuration identifier;

[0508] Transmission configuration indication TCI information, the TCI information is used to indicate at least one of the following: the beam information used in the cell change process without the random access channel RACH process to the cell associated with the target cell identifier, and the beam information used in the cell change process without the RACH process to the LTM candidate cell associated with the first candidate configuration identifier.

[0509] Optionally, before sending the second cell change message to the terminal, the radio frequency device 1002 is further configured to:

[0510] When the RRC layer of the source node or the CU of the source node decides to trigger a cell change, sending a handover request or a secondary node addition request to the target node;

[0511] Receive a handover confirmation or a secondary node addition confirmation message sent by the target node, where the handover confirmation or the secondary node addition confirmation message carries at least one of the following:

[0512] a terminal identifier allocated to the terminal at the source node;

[0513] a terminal identifier allocated to the terminal at the target node;

[0514] Updated protocol data unit (PDU) session information, wherein the updated PDU session information includes at least one of the following: quality of service (QoS) flow information allowed for access and a data forwarding address;

[0515] a transparent transmission container, wherein the transparent transmission container includes handover command information or primary and secondary cell change command information for the terminal;

[0516] Fourth indication information, the fourth indication information is used to indicate whether the target node accepts the request of the source node to use the LTM candidate configuration information to perform layer 3 handover or primary and secondary cell change;

[0517] The fourth candidate configuration identifier is used to instruct the terminal to apply the candidate configuration information associated with the fourth candidate configuration identifier in this handover or primary and secondary cell change.

[0518] The fifth indication information is used to indicate the candidate configuration information of the cell associated with the target cell identifier applied by the terminal in this handover or primary / secondary cell change.

[0519] Optionally, the handover command information or the primary / secondary cell change command information includes at least one of the following:

[0520] Target cell identifier;

[0521] Sixth indication information, where the sixth indication information is used to indicate the LTM candidate configuration information of the cell associated with the target cell identifier;

[0522] A fifth candidate configuration identifier, wherein the fifth candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the fifth candidate configuration identifier.

[0523] Optionally, the handover request or the secondary node adding request carries at least one of the following:

[0524] a terminal identifier allocated to the terminal at the source node;

[0525] Reasons for handover or change of primary and secondary cells;

[0526] Target cell identifier;

[0527] A sixth candidate configuration identifier, where the sixth candidate configuration identifier is used to instruct execution of a handover to the LTM candidate cell associated with the sixth candidate configuration identifier or a primary / secondary cell change;

[0528] Updated PDU session information, where the PDU session information includes information related to data forwarding;

[0529] The seventh indication information is used to indicate at least one of the following:

[0530] Switching or changing the primary or secondary cell to a candidate cell associated with LTM;

[0531] The terminal is configured with LTM candidate configuration information;

[0532] Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

[0533] Optionally, the reason for the handover or the primary / secondary cell change includes at least one of the following:

[0534] Switching or changing the primary or secondary cell to a candidate cell associated with LTM;

[0535] The terminal is configured with LTM candidate configuration information;

[0536] Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

[0537] In one embodiment, the network-side device is a target node:

[0538] The radio frequency device 1002 is configured to receive, as a target node, a handover request or a secondary node addition request sent by a source node; and send a handover confirmation or a secondary node addition confirmation message to the source node, where the handover confirmation or the secondary node addition confirmation message carries at least one of the following:

[0539] a terminal identifier allocated to the terminal at the source node;

[0540] a terminal identifier allocated to the terminal at the target node;

[0541] Updated protocol data unit (PDU) session information, wherein the updated PDU session information includes at least one of the following: quality of service (QoS) flow information allowed for access and a data forwarding address;

[0542] a transparent transmission container, wherein the transparent transmission container includes handover command information or primary and secondary cell change command information for the terminal;

[0543] Fourth indication information, the fourth indication information is used to indicate whether the target node accepts the source node's request to use the layer 1 / layer 2 triggered mobility LTM candidate configuration information to perform layer 3 handover or primary and secondary cell change;

[0544] The fourth candidate configuration identifier is used to instruct the terminal to apply the candidate configuration information associated with the fourth candidate configuration identifier in this handover or primary and secondary cell change.

[0545] The fifth indication information is used to indicate the candidate configuration information of the cell associated with the target cell identifier applied by the terminal in this handover or primary / secondary cell change.

[0546] Optionally, the handover command information or the primary / secondary cell change command information includes at least one of the following:

[0547] Target cell identifier;

[0548] Sixth indication information, where the sixth indication information is used to indicate the LTM candidate configuration information of the cell associated with the target cell identifier;

[0549] A fifth candidate configuration identifier, wherein the fifth candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the fifth candidate configuration identifier.

[0550] Optionally, the handover request or the secondary node adding request carries at least one of the following:

[0551] a terminal identifier allocated to the terminal at the source node;

[0552] Reasons for handover or change of primary and secondary cells;

[0553] Target cell identifier;

[0554] A sixth candidate configuration identifier, where the sixth candidate configuration identifier is used to instruct execution of a handover to the LTM candidate cell associated with the sixth candidate configuration identifier or a primary / secondary cell change;

[0555] Updated protocol data unit (PDU) session information, where the PDU session information includes information related to data forwarding;

[0556] The seventh indication information is used to indicate at least one of the following:

[0557] Switching or changing the primary or secondary cell to a candidate cell associated with LTM;

[0558] The terminal is configured with LTM candidate configuration information;

[0559] Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

[0560] Optionally, the reason for the handover or the primary / secondary cell change includes at least one of the following:

[0561] Switching or changing the primary or secondary cell to a candidate cell associated with LTM;

[0562] The terminal is configured with LTM candidate configuration information;

[0563] Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

[0564] The above device can save message overhead.

[0565] It can be understood that the implementation process of each implementation method mentioned in this embodiment can refer to the relevant description of the above-mentioned method embodiment and achieve the same or corresponding technical effects. To avoid repetition, it will not be repeated here.

[0566] 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 cell change method embodiment are implemented and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0567] 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.

[0568] An embodiment of the present application further provides a wireless communication system, including: a terminal and a source node, or a terminal, a source node and a target node, wherein the terminal can be used to execute the steps of the cell change method on the terminal side provided in the embodiment of the present application, the source node can be used to execute the steps of the cell change method on the source node side provided in the embodiment of the present application, and the target node can be used to execute the steps of the cell change method on the target node side provided in the embodiment of the present application.

[0569] 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 cell change method embodiment and achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0570] 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.

[0571] 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 cell change method embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0572] 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.

[0573] 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.

[0574] 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 cell change method, comprising: The terminal obtains a first cell change message, where the first cell change message carries layer 1 / layer 2 triggered mobility LTM candidate configuration information; The terminal obtains a second cell change message, where the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information.

2. The method according to claim 1, wherein The first cell change message is a first radio resource control RRC reconfiguration message, and the second cell change message is a second RRC reconfiguration message.

3. The method according to claim 1 or 2, wherein The second cell change message is a cell change message triggered by RRC signaling.

4. The method according to any one of claims 1 to 3, wherein The second cell change message carries at least one of the following: a target cell identifier, wherein when the cell associated with the target cell identifier is an LTM candidate cell, the terminal applies configuration information of the LTM candidate cell; First indication information, where the first indication information is used to instruct the terminal to perform handover to an LTM candidate cell or change a primary or secondary cell; second indication information, where the second indication information is used to indicate configuration information of a candidate cell associated with the target cell identifier; A first candidate configuration identifier, where the first candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the first candidate configuration identifier; or, The first cell change message further carries: at least one second candidate configuration identifier, where the second candidate configuration identifier is associated with configuration information of an LTM candidate cell, wherein, when the second cell change message carries the first candidate configuration identifier, the first candidate configuration identifier is a candidate configuration identifier in the at least one second candidate configuration identifier; The LTM candidate configuration information includes configuration information of the LTM candidate cell.

5. The method according to claim 4, wherein: When the cell associated with the target cell identifier is an LTM candidate cell and the second cell change message does not carry the configuration information of the cell associated with the target cell identifier, the terminal applies the configuration information of the LTM candidate cell.

6. The method according to claim 4 or 5, wherein: The second cell change message further carries at least one of the following: Key-related information, where the key-related information is used to instruct the terminal to generate a security key to be used in a target cell or after a cell change based on the key-related information; Timing Advance (TA) information, where the TA information is used to indicate at least one of the following: a TA of the cell associated with the target cell identifier, and a TA of the LTM candidate cell associated with the first candidate configuration identifier; Transmission configuration indication TCI information, the TCI information is used to indicate at least one of the following: the beam information used in the cell change process without the random access channel RACH process to the cell associated with the target cell identifier, and the beam information used in the cell change process without the RACH process to the LTM candidate cell associated with the first candidate configuration identifier.

7. The method according to any one of claims 4 to 6, wherein The method further comprises: The terminal selects a target candidate cell based on the target cell identifier and the first candidate configuration identifier; or The MAC layer of the terminal selects a target candidate cell.

8. The method of claim 7, wherein: The method further comprises at least one of the following: The terminal performs cell switching or primary / secondary cell change based on the configuration information of the target candidate cell; The terminal generates a security key for use in a target cell or after a cell change based on the key-related information; The radio resource control (RRC) layer of the terminal instructs a media access control (MAC) layer of the terminal to reset the MAC; The RRC layer of the terminal indicates a TA to the MAC layer of the terminal to instruct execution of a cell change without a RACH procedure, wherein the TA includes: a valid TA indicated by the TA information carried by the second cell change message; When the terminal performs TA measurement for the target candidate cell selected by the terminal and maintains a valid TA of the target candidate cell at the moment of receiving the second cell change message, the terminal performs a cell change without a RACH procedure; When the second cell change message carries TCI status information, the RRC layer of the terminal indicates the TCI status information to the MAC layer of the terminal, and the TCI status information is used to indicate the execution of a cell change without RACH and for the MAC layer to select uplink allocation resources.

9. A cell change method, comprising: The source node sends a second cell change message to the terminal, where the second cell change message is used to indicate the mobility LTM candidate configuration information triggered by the terminal application layer 1 / layer 2, wherein the LTM candidate configuration information is the LTM candidate configuration information obtained by the terminal through the first cell change message.

10. The method of claim 9, wherein: Before the source node sends the second cell change message to the terminal, the method further includes: The source node sends the first cell change message to the terminal, where the first cell change message carries LTM candidate configuration information.

11. The method according to claim 10, wherein: The first cell change message is a first radio resource control RRC reconfiguration message, and the second cell change message is a second RRC reconfiguration message.

12. The method according to any one of claims 9 to 11, wherein The second cell change message is a cell change message triggered by RRC signaling.

13. The method according to claim 9 or 10, wherein: Before the source node sends the second cell change message to the terminal, the method further includes: When the RRC layer of the source node decides to trigger a cell change, the RRC layer of the source node sends first information to the MAC layer of the source node, or the central unit CU of the source node sends first information to the distributed unit DU of the source node, where the first information includes at least one of the following: Target cell identifier; measurement results of one or more candidate cells; third indication information, where the third indication information is used to instruct the MAC layer or the DU of the source node to perform an LTM-based cell change; A third candidate configuration identifier is used to instruct the DU of the MAC layer or the source node to trigger a handover or a primary / slave cell change to the LTM candidate cell associated with the third candidate configuration identifier.

14. The method of claim 13, wherein: In a case where the first information includes measurement results of the one or more candidate cells, the method further includes: The MAC layer of the source node or the DU of the source node selects a target candidate cell based on the measurement results of the one or more candidate cells, and the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information associated with the target candidate cell.

15. The method according to claim 13 or 14, wherein: The source node sending a second cell change message to the terminal includes: In a case where the first information does not include the target cell identifier and the third candidate configuration identifier, the MAC layer of the source node or the DU of the source node selects a target candidate cell and sends a second cell change message to the terminal, where the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information, including: the second cell change message is used to trigger a cell change based on the LTM candidate configuration information associated with the target candidate cell; or In the case where the first information includes the target cell identifier or the third candidate configuration identifier, the MAC layer of the source node or the DU of the source node selects a target candidate cell based on the target cell identifier or the third candidate configuration identifier, and sends a second cell change message to the terminal, where the second cell change message is used to instruct the terminal to apply the LTM configuration information, including: the second cell change message is used to trigger a cell change based on the LTM candidate configuration information associated with the target candidate cell.

16. The method according to any one of claims 9 to 12, wherein The second cell change message carries at least one of the following: a target cell identifier, wherein when the cell associated with the target cell identifier is an LTM candidate cell, the terminal applies configuration information of the LTM candidate cell; First indication information, where the first indication information is used to instruct the terminal to perform a handover to an LTM candidate cell or a primary / secondary cell change; second indication information, where the second indication information is used to indicate configuration information of a candidate cell associated with the target cell identifier; A first candidate configuration identifier, where the first candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the first candidate configuration identifier; or, The first cell change message further carries: at least one second candidate configuration identifier, where the second candidate configuration identifier is associated with configuration information of an LTM candidate cell, wherein, when the second cell change message carries the first candidate configuration identifier, the first candidate configuration identifier is a candidate configuration identifier in the at least one second candidate configuration identifier; The LTM candidate configuration information includes LTM candidate configuration information of the LTM candidate cell.

17. The method of claim 16, wherein: The second cell change message further carries at least one of the following: Key-related information, where the key-related information is used to instruct the terminal to generate a security key to be used in a target cell or after a cell change based on the key-related information; Timing Advance (TA) information, where the TA information is used to indicate at least one of the following: a TA of the cell associated with the target cell identifier, and a TA of the LTM candidate cell associated with the first candidate configuration identifier; Transmission configuration indication TCI information, the TCI information is used to indicate at least one of the following: the beam information used in the cell change process without the random access channel RACH process to the cell associated with the target cell identifier, and the beam information used in the cell change process without the RACH process to the LTM candidate cell associated with the first candidate configuration identifier.

18. The method according to claim 16 or 17, wherein Before the source node sends the second cell change message to the terminal, the method further includes: In a case where the RRC layer of the source node or the CU of the source node decides to trigger a cell change, the source node sends a handover request or a secondary node addition request to the target node; The source node receives a handover confirmation message or a secondary node addition confirmation message sent by the target node, where the handover confirmation message or the secondary node addition confirmation message carries at least one of the following: a terminal identifier allocated to the terminal at the source node; a terminal identifier allocated to the terminal at the target node; Updated protocol data unit (PDU) session information, wherein the updated PDU session information includes at least one of the following: quality of service (QoS) flow information allowed for access and a data forwarding address; a transparent transmission container, wherein the transparent transmission container includes handover command information or primary and secondary cell change command information for the terminal; Fourth indication information, the fourth indication information is used to indicate whether the target node accepts the request of the source node to use the LTM candidate configuration information to perform layer 3 handover or primary and secondary cell change; A fourth candidate configuration identifier, where the fourth candidate configuration identifier is used to indicate to the terminal in this handover or primary / secondary cell change that the terminal should apply the candidate configuration information associated with the fourth candidate configuration identifier; The fifth indication information is used to indicate the candidate configuration information of the cell associated with the target cell identifier applied by the terminal in this handover or primary / secondary cell change.

19. The method of claim 18, wherein: The handover command information or the primary and secondary cell change command information includes at least one of the following: Target cell identifier; Sixth indication information, where the sixth indication information is used to indicate the LTM candidate configuration information of the cell associated with the target cell identifier; A fifth candidate configuration identifier, wherein the fifth candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the fifth candidate configuration identifier.

20. The method according to claim 18 or 19, wherein The handover request or secondary node addition request carries at least one of the following: a terminal identifier allocated to the terminal at the source node; Reasons for handover or change of primary and secondary cells; Target cell identifier; A sixth candidate configuration identifier, where the sixth candidate configuration identifier is used to instruct execution of a handover to the LTM candidate cell associated with the sixth candidate configuration identifier or a primary / secondary cell change; Updated PDU session information, where the PDU session information includes information related to data forwarding; The seventh indication information is used to indicate at least one of the following: Switching or changing the primary or secondary cell to a candidate cell associated with LTM; The terminal is configured with LTM candidate configuration information; Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

21. The method of claim 20, wherein: The reason for the handover or the change of the primary and secondary cells includes at least one of the following: Switching or changing the primary or secondary cell to a candidate cell associated with LTM; The terminal is configured with LTM candidate configuration information; Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

22. A cell change method, comprising: The target node receives the switching request or the auxiliary node adding request sent by the source node; The target node sends a handover confirmation or a secondary node addition confirmation message to the source node, where the handover confirmation or the secondary node addition confirmation message carries at least one of the following: A terminal identifier allocated to the terminal at the source node; a terminal identifier allocated to the terminal at the target node; Updated protocol data unit (PDU) session information, wherein the updated PDU session information includes at least one of the following: quality of service (QoS) flow information allowed for access and a data forwarding address; a transparent transmission container, wherein the transparent transmission container includes handover command information or primary and secondary cell change command information for the terminal; Fourth indication information, the fourth indication information is used to indicate whether the target node accepts the source node's request to use the layer 1 / layer 2 triggered mobility LTM candidate configuration information to perform layer 3 handover or primary and secondary cell change; A fourth candidate configuration identifier, where the fourth candidate configuration identifier is used to indicate to the terminal in this handover or primary / secondary cell change that the terminal should apply the candidate configuration information associated with the fourth candidate configuration identifier; The fifth indication information is used to indicate the candidate configuration information of the cell associated with the target cell identifier applied by the terminal in this handover or primary / secondary cell change.

23. The method of claim 22, wherein: The handover command information or the primary and secondary cell change command information includes at least one of the following: Target cell identifier; Sixth indication information, where the sixth indication information is used to indicate the LTM candidate configuration information of the cell associated with the target cell identifier; A fifth candidate configuration identifier, wherein the fifth candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the fifth candidate configuration identifier.

24. The method of claim 22 or 23, wherein: The handover request or secondary node addition request carries at least one of the following: a terminal identifier allocated to the terminal at the source node; Reasons for handover or change of primary and secondary cells; Target cell identifier; A sixth candidate configuration identifier, where the sixth candidate configuration identifier is used to instruct execution of a handover to the LTM candidate cell associated with the sixth candidate configuration identifier or a primary / secondary cell change; Updated protocol data unit (PDU) session information, where the PDU session information includes information related to data forwarding; The seventh indication information is used to indicate at least one of the following: Switching or changing the primary or secondary cell to a candidate cell associated with LTM; The terminal is configured with LTM candidate configuration information; Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

25. The method of claim 24, wherein: The reason for the handover or the change of the primary and secondary cells includes at least one of the following: Switching or changing the primary or secondary cell to a candidate cell associated with LTM; The terminal is configured with LTM candidate configuration information; Use RRC signaling or layer 3 signaling to trigger terminal handover or change the primary or secondary cell to the candidate cell associated with LTM.

26. A cell change device, comprising: A first acquisition module is configured to acquire a first cell change message, where the first cell change message carries layer 1 / layer 2 triggered mobility LTM candidate configuration information; The second acquisition module is used to acquire a second cell change message, where the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information.

27. The apparatus of claim 26, wherein: The second cell change message carries at least one of the following: a target cell identifier, wherein when the cell associated with the target cell identifier is an LTM candidate cell, the terminal applies configuration information of the LTM candidate cell; First indication information, where the first indication information is used to instruct the terminal to perform handover to an LTM candidate cell or change a primary or secondary cell; second indication information, where the second indication information is used to indicate configuration information of a candidate cell associated with the target cell identifier; A first candidate configuration identifier, where the first candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the first candidate configuration identifier; or, The first cell change message further carries: at least one second candidate configuration identifier, where the second candidate configuration identifier is associated with configuration information of an LTM candidate cell, wherein, when the second cell change message carries the first candidate configuration identifier, the first candidate configuration identifier is a candidate configuration identifier in the at least one second candidate configuration identifier; The LTM candidate configuration information includes configuration information of the LTM candidate cell.

28. The apparatus of claim 27, wherein: The device further comprises: A first selection module is configured to select a target candidate cell based on the target cell identifier and the first candidate configuration identifier; or The second selection module is used for the MAC layer of the terminal to select a target candidate cell.

29. The apparatus of claim 28, wherein The device further comprises at least one of the following: A first execution module, configured to execute cell switching or primary / secondary cell change based on the configuration information of the target candidate cell; A generation module, configured to generate a security key to be used in a target cell or after a cell change based on key-related information; A first indication module, configured for a radio resource control (RRC) layer of a terminal to indicate a MAC reset to a media access control (MAC) layer of the terminal; A second indication module is configured to cause the RRC layer of the terminal to indicate a TA to the MAC layer of the terminal to instruct execution of a cell change without a RACH procedure, wherein the TA includes: a valid TA indicated by the TA information carried by the second cell change message; a second execution module, configured to, when the terminal performs TA measurement on the target candidate cell selected by the terminal and maintains a valid TA of the target candidate cell at the moment of receiving the second cell change message, perform a cell change without a RACH procedure; The third indication module is used to indicate, by the RRC layer of the terminal, the TCI status information to the MAC layer of the terminal when the second cell change message carries TCI status information, wherein the TCI status information is used to indicate the execution of a cell change without RACH, and is used by the MAC layer to select uplink allocation resources.

30. A cell change device, comprising: The first sending module is used to send a second cell change message to the terminal, where the second cell change message is used to indicate the mobility LTM candidate configuration information triggered by the terminal application layer 1 / layer 2, wherein the LTM candidate configuration information is the LTM candidate configuration information obtained by the terminal through the first cell change message.

31. The apparatus of claim 30, wherein: The device further comprises: The second sending module is configured to send the first cell change message to the terminal, where the first cell change message carries LTM candidate configuration information.

32. The apparatus of claim 30 or 31, wherein: The device further comprises: The third sending module is configured to, when the RRC layer of the source node decides to trigger a cell change, cause the RRC layer of the source node to send first information to the MAC layer of the source node, or the central unit CU of the source node to send first information to the distributed unit DU of the source node, where the first information includes at least one of the following: Target cell identifier; measurement results of one or more candidate cells; third indication information, where the third indication information is used to instruct the MAC layer or the DU of the source node to perform an LTM-based cell change; A third candidate configuration identifier is used to instruct the DU of the MAC layer or the source node to trigger a handover or a primary / slave cell change to the LTM candidate cell associated with the third candidate configuration identifier.

33. The apparatus of claim 32, wherein: In a case where the first information includes measurement results of the one or more candidate cells, the apparatus further includes: A selection module is used for the MAC layer of the source node or the DU of the source node to select a target candidate cell based on the measurement results of the one or more candidate cells, and the second cell change message is used to instruct the terminal to apply the LTM candidate configuration information associated with the target candidate cell.

34. The apparatus of claim 30 or 31, wherein: The second cell change message carries at least one of the following: a target cell identifier, where, when the cell associated with the target cell identifier is an LTM candidate cell, the terminal applies the LTM candidate configuration information associated with the LTM candidate cell; First indication information, where the first indication information is used to instruct the terminal to perform a handover to an LTM candidate cell or a primary / secondary cell change; second indication information, where the second indication information is used to indicate configuration information of a candidate cell associated with the target cell identifier; A first candidate configuration identifier, where the first candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the first candidate configuration identifier; or, The first cell change message further carries: at least one second candidate configuration identifier, where the second candidate configuration identifier is associated with configuration information of an LTM candidate cell, wherein, when the second cell change message carries the first candidate configuration identifier, the first candidate configuration identifier is a candidate configuration identifier in the at least one second candidate configuration identifier; The LTM candidate configuration information includes LTM candidate configuration information of the LTM candidate cell.

35. The apparatus of claim 34, wherein: The device further comprises: a fourth sending module, configured to send a handover request or a secondary node addition request to a target node when the RRC layer of the source node or the CU of the source node decides to trigger a cell change; a receiving module, configured to receive a handover confirmation message or a secondary node addition confirmation message sent by the target node, wherein the handover confirmation message or the secondary node addition confirmation message carries at least one of the following: a terminal identifier allocated to the terminal at the source node; a terminal identifier allocated to the terminal at the target node; Updated PDU session information, wherein the updated PDU session information includes at least one of the following: quality of service (QoS) flow information allowed for access, and a data forwarding address; a transparent transmission container, wherein the transparent transmission container includes handover command information or primary and secondary cell change command information for the terminal; Fourth indication information, the fourth indication information is used to indicate whether the target node accepts the request of the source node to use the LTM candidate configuration information to perform layer 3 handover or primary and secondary cell change; A fourth candidate configuration identifier, where the fourth candidate configuration identifier is used to indicate to the terminal in this handover or primary / secondary cell change that the terminal should apply the candidate configuration information associated with the fourth candidate configuration identifier; The fifth indication information is used to indicate the candidate configuration information of the cell associated with the target cell identifier applied by the terminal in this handover or primary / secondary cell change.

36. A cell change device, comprising: A receiving module, configured to receive a switching request or a secondary node adding request sent by a source node; a sending module, configured to send a handover confirmation or a secondary node addition confirmation message to the source node, where the handover confirmation or the secondary node addition confirmation message carries at least one of the following: a terminal identifier allocated to the terminal at the source node; a terminal identifier allocated to the terminal at the target node; Updated protocol data unit (PDU) session information, wherein the updated PDU session information includes at least one of the following: quality of service (QoS) flow information allowed for access and a data forwarding address; a transparent transmission container, wherein the transparent transmission container includes handover command information or primary and secondary cell change command information for the terminal; Fourth indication information, the fourth indication information is used to indicate whether the target node accepts the request of the source node to use the LTM candidate configuration information to perform layer 3 handover or primary and secondary cell change; A fourth candidate configuration identifier, where the fourth candidate configuration identifier is used to indicate to the terminal in this handover or primary / secondary cell change that the terminal should apply the candidate configuration information associated with the fourth candidate configuration identifier; The fifth indication information is used to indicate the candidate configuration information of the cell associated with the target cell identifier applied by the terminal in this handover or primary / secondary cell change.

37. The apparatus of claim 36, wherein: The handover command information or the primary and secondary cell change command information includes at least one of the following: Target cell identifier; Sixth indication information, where the sixth indication information is used to indicate the LTM candidate configuration information of the cell associated with the target cell identifier; A fifth candidate configuration identifier, wherein the fifth candidate configuration identifier is used to instruct the terminal to perform handover or a primary / secondary cell change to the LTM candidate cell associated with the fifth candidate configuration identifier.

38. A terminal 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, the steps of the cell change method according to any one of claims 1 to 8 are implemented.

39. A network side 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, the steps of the cell change method as described in any one of claims 9 to 21 are implemented, or when the program or instruction is executed by the processor, the steps of the cell change method as described in any one of claims 22 to 25 are implemented.

40. 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 cell change method according to any one of claims 1 to 8, or implements the steps of the cell change method according to any one of claims 9 to 21, or implements the steps of the cell change method according to any one of claims 22 to 25.

41. A computer program product, wherein The computer program product is stored in a storage medium, and the computer program product is executed by at least one processor to implement the steps of the cell change method according to any one of claims 1 to 8, or the steps of the cell change method according to any one of claims 9 to 21, or the steps of the cell change method according to any one of claims 22 to 25.

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