Methods for cell handover, terminal devices, and network devices

Abstract

The present application provides methods for cell handover, terminal devices, and network devices. A method for cell handover comprises: a terminal device receiving first configuration information sent by a first network device, the first configuration information comprising configuration information corresponding to a plurality of candidate cells, wherein the plurality of candidate cells are determined on the basis of a predicted trajectory of the terminal device, and the plurality of candidate cells are used for the terminal device to perform continuous handover.

Description

Method, terminal equipment and network equipment for cell switching Technical Field

[0001] The present application relates to the field of communication technology, and more specifically, to a method, terminal equipment, and network equipment for cell switching. Background Art

[0002] In the current conditional handover mechanism, a terminal device receives candidate cell configuration information from the network device before performing a cell handover. If the candidate cell meets the handover conditions, the terminal device can switch to the candidate cell. However, this conditional handover mechanism suffers from long handover times and high signaling volume transmitted over the air interface.

[0003] Summary of the Invention

[0004] The present application provides a method, terminal device, and network device for cell handover. Several aspects of the present application are introduced below.

[0005] In a first aspect, a method for cell switching is provided, comprising: a terminal device receiving first configuration information sent by a first network device, the first configuration information including configuration information corresponding to a plurality of candidate cells, the plurality of candidate cells being determined based on a predicted trajectory of the terminal device, and the plurality of candidate cells being used for continuous switching of the terminal device.

[0006] In a second aspect, a method for cell switching is provided, comprising: a first network device sends first configuration information to a terminal device, the first configuration information including configuration information corresponding to a plurality of candidate cells, the plurality of candidate cells being determined based on a predicted trajectory of the terminal device, and the plurality of candidate cells being used for continuous switching of the terminal device.

[0007] According to a third aspect, a terminal device is provided, comprising: a receiving unit for receiving first configuration information sent by a first network device, wherein the first configuration information includes configuration information corresponding to a plurality of candidate cells, the plurality of candidate cells being determined based on a predicted trajectory of the terminal device, and the plurality of candidate cells being used for continuous switching of the terminal device.

[0008] In a fourth aspect, a network device is provided, which is a first network device, comprising: a sending unit, used to send first configuration information to a terminal device, the first configuration information including configuration information corresponding to multiple candidate cells, the multiple candidate cells are determined based on the predicted trajectory of the terminal device, and the multiple candidate cells are used for continuous switching of the terminal device.

[0009] In a fifth aspect, a terminal device is provided, comprising a processor, a memory, and a communication interface, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the terminal device executes part or all of the steps in the method of the first aspect.

[0010] In the sixth aspect, a network device is provided, comprising a processor, a memory, and a communication interface, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the network device executes part or all of the steps in the method of the second aspect.

[0011] In a seventh aspect, an embodiment of the present application provides a communication system, which includes the above-mentioned terminal and / or network device. In another possible design, the system may also include other devices that interact with the terminal or network device in the solution provided in the embodiment of the present application.

[0012] In an eighth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program enables a terminal device to execute part or all of the steps in the method of the first aspect above.

[0013] In a ninth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and the computer program enables a network device to execute part or all of the steps in the method of the second aspect above.

[0014] In a tenth aspect, embodiments of the present application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, wherein the computer program is operable to cause a terminal to perform some or all of the steps of the method of the first aspect. In some implementations, the computer program product may be a software installation package.

[0015] In an eleventh aspect, embodiments of the present application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, wherein the computer program is operable to cause a network device to perform some or all of the steps of the method of the second aspect. In some implementations, the computer program product may be a software installation package.

[0016] In the twelfth aspect, an embodiment of the present application provides a chip, which includes a memory and a processor. The processor can call and run a computer program from the memory to implement some or all of the steps described in the method of the first or second aspect above.

[0017] In the technical solution provided by the embodiment of the present application, the network device can determine multiple candidate cells based on the predicted trajectory of the terminal device (for example, the multiple candidate cells can include multiple cells on the predicted trajectory path of the terminal device) and send the configuration information of the multiple candidate cells to the terminal device. Therefore, the terminal device can perform continuous switching on the predicted trajectory path, that is, it can achieve multi-hop switching of the terminal device, thereby avoiding the need for the network device to resend the configuration information of the candidate cells to the terminal device after each switching of the terminal device is completed. Therefore, the solution of the embodiment of the present application can reduce the amount of data transmitted over the air interface and shorten the switching time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG1 is a wireless communication system 100 used in an embodiment of the present application.

[0019] FIG2 is a traditional conditional switching flow chart.

[0020] FIG3 is a flow chart of a switching process based on LTM.

[0021] FIG4 is a schematic flowchart of a method for cell switching provided in an embodiment of the present application.

[0022] FIG5 is a schematic diagram of a candidate cell provided in an embodiment of the present application.

[0023] FIG6 is a schematic block diagram of a terminal device provided in an embodiment of the present application.

[0024] FIG7 is a schematic block diagram of a network device provided in an embodiment of the present application.

[0025] FIG8 is a schematic structural diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] The technical solution in this application will be described below with reference to the accompanying drawings.

[0027] Figure 1 illustrates a wireless communication system 100 used in an embodiment of the present application. The wireless communication system 100 may include a network device 110 and a terminal device 120. The network device 110 may be a device that communicates with the terminal device 120. The network device 110 may provide communication coverage for a specific geographic area and may communicate with the terminal device 120 within the coverage area.

[0028] FIG1 exemplarily shows a network device and two terminal devices. Optionally, the wireless communication system 100 may include multiple network devices and each network device may include another number of terminal devices within its coverage area, which is not limited in this embodiment of the present application.

[0029] Optionally, the wireless communication system 100 may further include other network entities such as a network controller and a mobility management entity, which is not limited in the embodiment of the present application.

[0030] It should be understood that the technical solutions of the embodiments of the present application can be applied to various communication systems, such as: fifth generation (5G) system or new radio (NR), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), etc. The technical solutions provided in this application can also be applied to future communication systems, such as the sixth generation mobile communication system, satellite communication system, etc.

[0031] The terminal device in the embodiments of the present application may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The terminal device in the embodiments of the present application may refer to a device that provides voice and / or data connectivity to a user and can be used to connect people, objects and machines, such as a handheld device with wireless connection function, a vehicle-mounted device, etc. The terminal device in the embodiments of the present application can be a mobile phone, a tablet computer, a laptop computer, a PDA, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. Optionally, the UE can be used to act as a base station. For example, the UE can act as a scheduling entity that provides sidelink signals between UEs in V2X or D2D, etc. For example, a cellular phone and a car communicate with each other using sidelink signals. The cellular phone and smart home devices communicate without relaying the communication signal through the base station.

[0032] The network device in the embodiments of the present application may be a device for communicating with a terminal device, and may also be referred to as an access network device or a radio access network device. For example, the network device may be a base station. The network device in the embodiments of the present application may refer to a radio access network (RAN) node (or device) that connects a terminal device to a wireless network. A base station can broadly cover various names as follows, or be replaced with the following names, such as: NodeB, evolved NodeB (eNB), next generation NodeB (gNB), relay station, transmission point (TRP), transmission point (TP), master station MeNB, secondary station SeNB, multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. A base station can be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof. A base station can also refer to a communication module, modem or chip used to be set in the aforementioned device or apparatus. The base station can also be a mobile switching center and a device that performs base station functions in device-to-device D2D, vehicle-to-everything (V2X), and machine-to-machine (M2M) communications, a network-side device in a 6G network, or a device that performs base station functions in future communication systems. The base station can support networks with the same or different access technologies. The embodiments of this application do not limit the specific technology and specific device form used by the network equipment.

[0033] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move based on the location of the mobile base station. In other examples, a helicopter or drone can be configured to act as a device that communicates with another base station.

[0034] In some deployments, the network device in the embodiments of the present application may refer to a CU or a DU, or the network device may include a CU and a DU. The gNB may also include an AAU.

[0035] The network equipment and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on the water; they can also be deployed in the air on aircraft, balloons, or satellites. The embodiments of this application do not limit the scenarios in which the network equipment and terminal devices are located.

[0036] It should be understood that all or part of the functions of the communication device in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (such as a cloud platform).

[0037] Cell switching

[0038] Cell handover (HO) aims to improve the continuity of services provided by the communication system to terminal devices. In a wireless communication system, when a terminal device moves from one cell (also known as the "source cell") to another, to maintain communication, the terminal device needs to handover to another cell (also known as the "target cell"). The cell can be a primary cell (PCell) or a primary secondary cell (PSCell). Generally, cell handover can be divided into two types: traditional handover mechanism and conditional handover mechanism.

[0039] In a traditional handover mechanism, to improve the continuity of services provided by the communication system to connected terminal devices, the network device will send a handover command to the terminal device at an appropriate time (for example, when the signal measurement result of the terminal device in the serving cell falls below a threshold) to instruct the terminal device to perform a cell handover. In some implementations, the handover command may be an RRC reconfiguration message containing synchronization reconfiguration information.

[0040] For the conditional handover (CHO) mechanism, the network device can configure the configuration of one or more candidate cells and the conditional handover events associated with one or more candidate cells to the terminal device. The conditional handover event can also be called the conditional handover trigger condition. Accordingly, the terminal device can determine whether the conditional handover event is met based on the signal measurement results of the candidate cell. If the terminal device determines that a candidate cell meets the conditional handover event, the terminal device can initiate random access to the candidate cell.

[0041] The following describes the conditional switching process in conjunction with FIG2 .

[0042] In step S202, the terminal device sends a measurement report to the serving cell.

[0043] In step S204, the serving cell determines a handover strategy based on the measurement report. If the serving cell determines that the terminal device needs to perform a cell handover, the serving cell may send a handover request to the candidate cell.

[0044] In step S206, the serving cell sends a handover request to the candidate cell.

[0045] In step S208, if the candidate cell accepts the handover request, RRC configuration may be established.

[0046] In step S210, the candidate cell sends a handover confirmation message to the serving cell. The handover confirmation message may include the RRC configuration of the candidate cell.

[0047] In step S212, after receiving the handover confirmation message, the serving cell may send a conditional handover command to the terminal device.

[0048] In step S214, the terminal device measures the candidate cell. If the candidate cell meets the switching condition, the terminal device may trigger conditional switching.

[0049] In step S216, the terminal device initiates random access to the candidate cell to synchronize with the candidate cell.

[0050] In step S218, the terminal device sends a handover confirmation message to the candidate cell.

[0051] In step S220, the candidate cell sends a handover completion message to the serving cell.

[0052] In some implementations, the conditional switching command includes configuration information associated with at least one candidate cell, wherein the configuration information associated with any one of the at least one candidate cell may include one or more of configuration parameter 1, configuration parameter 2, and configuration parameter 3.

[0053] Configuration parameter 1 includes a logical identifier ID, which is used to identify the logical number of a CHO configuration, a conditional PSCell addition (CPA) configuration, or a conditional PSCell change (CPC) configuration. In some implementations, the configuration parameter 1 may include a parameter CondReconfigId.

[0054] Configuration parameter 2 includes configuration information of the candidate cell, and the terminal device can switch to the candidate cell based on the configuration information of the candidate cell. In some implementations, the above-mentioned configuration parameter 2 may include one or more of the following configuration information: a physical layer configuration that the terminal device needs to use in the candidate cell, a media access control (MAC) layer configuration that the terminal device needs to use in the candidate cell, a radio link control (RLC) layer configuration that the terminal device needs to use in the candidate cell, a data radio bearer (DRB) related configuration that the terminal device needs to use in the candidate cell, a configuration related to the frequency band and bandwidth supported by the candidate cell, and a random access configuration.

[0055] Configuration parameter 3: Handover condition configuration. In some implementations, configuration parameter 3 may include at least one measurement ID, one measurement ID associated with a measurement object (MO) configuration and a measurement report configuration. In some implementations, the measurement report configuration may include a conditional handover event. The conditional handover event is used by the terminal device to determine whether to trigger handover to the candidate cell associated with the conditional handover event. Therefore, the conditional handover event can also be referred to as a "conditional handover triggering condition" or a "handover condition related to conditional handover."

[0056] In some implementations, the conditional switching event may include at least one of a conditional event A3, a conditional event A4, a conditional event A5, a conditional event D1, and a conditional event T1.

[0057] Conditional event A3 includes that the measurement result of the candidate cell is higher than the measurement result of the current serving cell where the terminal device is located, and the difference between the measurement result of the candidate cell and the measurement result of the current serving cell is greater than or equal to the first threshold.

[0058] Conditional event A4 includes the measurement result of the candidate cell being greater than or equal to a second threshold.

[0059] Conditional event A5 includes that the measurement result of the current serving cell where the terminal device is located is lower than the third threshold, and the measurement result of the candidate cell is higher than the fourth threshold.

[0060] The conditional event D1 includes that the distance between the terminal device and the location reference point 1 is greater than a fifth threshold, and the distance between the terminal device and the location reference point 2 is less than a sixth threshold.

[0061] Conditional event T1 includes the local time of the terminal device exceeding the configured time 1 but not exceeding the configured time 2, where the time 2 is later than the time 1.

[0062] In some embodiments, conditional event A3 and conditional event A5 can be applicable to all types of conditional handovers. Conditional event A4, conditional event D1, and conditional event T1 can be applicable to NTN and CPC scenarios. In the NTN scenario, conditional handover can be configured with one or two conditional handover events. In some embodiments, conditional event D1 and conditional event T1 need to be configured together with at least one of other events (such as conditional event A3, conditional event A4, and conditional event A5). If two conditional handover events are configured, the candidate cell will trigger the random access process of the terminal device only when both conditional handover events are met at the same time.

[0063] In some embodiments, if the network device has configured multiple candidate cells for a terminal device, and the terminal device attempts to access one of the candidate cells, if random access fails due to channel deterioration, load balancing, or other reasons, the terminal device may reselect a candidate cell to attempt access. If the terminal device fails to access the candidate cell again, the conditional handover process fails, and the terminal device needs to reestablish the connection.

[0064] Layer 1 / Layer 2-triggered mobility (LTM) process

[0065] The current conditional handover mechanism is triggered by Layer 3 measurements and implemented via RRC signaling. Layer 3-based handover requires reconfiguration of the RRC or PDCP layers, as well as resetting the MAC and / or physical layers. This increases the complexity of the handover process and delays. This led to the introduction of the LTM mechanism. LTM uses Layer 1 / Layer 2 signaling to change the serving cell of a terminal device while maintaining the higher-layer configuration. This reduces latency, overhead, and interruption time.

[0066] During the LTM execution phase, the terminal device can periodically report L1 measurement results. The network device can make LTM decisions based on these measurements and send handover commands to the terminal device. The terminal device can then leave the current serving cell and attempt to access the target LTM cell. During the LTM decision process, the terminal device retains the configuration information of the LTM candidate cell after the handover is complete to facilitate subsequent handovers.

[0067] In some embodiments, the network device may send a handover command to the terminal device in the form of a MAC CE. In other words, the handover command may be carried in the MAC CE.

[0068] The LTM process is described in detail below with reference to Figure 3. The LTM process can be roughly divided into four phases: LTM preparation (e.g., steps S302 through S308), pre-synchronization (e.g., step S310), LTM execution (e.g., steps S312 through S318), and LTM completion (e.g., step S320). Each step is described in detail below.

[0069] 3 , in step S302 , the terminal device may send a measurement report to the network device. The terminal device in the embodiment of the present application may be a terminal device in an RRC connected state.

[0070] In some embodiments, the measurement report may be obtained based on L3 measurements.

[0071] In step S304, the network device may determine whether to initiate an LTM process based on the measurement report. If the network device determines to initiate an LTM process, the network device may trigger the candidate cell to perform handover preparation.

[0072] In step S306, the network device sends an RRC reconfiguration message (i.e., an RRC reconfiguration message) to the terminal device. The RRC reconfiguration message may include configuration information for candidate cells. The number of candidate cells may be one or more. After receiving the RRC reconfiguration message, the terminal device may store the configuration information for the candidate cells in the RRC reconfiguration message.

[0073] In step S308, the terminal device sends an RRC reconfiguration completion message (ie, an RRC reconfiguration complete message) to the network device.

[0074] In step S310, the terminal device performs uplink synchronization and / or downlink synchronization with the candidate cell. The terminal device may perform uplink synchronization and / or downlink synchronization with the candidate cell in advance to reduce the interruption delay of the handover process.

[0075] In step S312, the terminal device sends a measurement report to the network device. The measurement report may be obtained for L1 measurement and may include measurement results for one or more candidate cells.

[0076] In step S314, the network device makes an LTM decision. If the network device determines that the terminal device can perform a cell handover, the process proceeds to step S316. In some embodiments, the network device may determine a target cell based on the measurement results reported by the terminal device and instruct the terminal device to hand over to the target cell. In some embodiments, the network device may instruct the terminal device to hand over to the target cell via a MAC CE.

[0077] In step S316, the network device sends a cell switch command to the terminal device. The cell switch command may be carried in a MAC CE.

[0078] In step S318, the terminal device leaves the serving cell and initiates a random access procedure to the target cell. In some embodiments, the terminal device may use the configuration information of the target cell to initiate the random access procedure to the target cell. If the terminal device does not have a valid timing advance (TA) for the target cell, the terminal device may initiate a random access procedure to the target cell after receiving a cell handover command sent by the network device.

[0079] In step S320, the terminal device and the network device complete the LTM switching process.

[0080] Currently, the candidate cells included in the handover command are all cells surrounding the current serving cell. In other words, the serving cells included in the handover command only include cells that are one hop away. A terminal device can leave the current serving cell and enter a neighboring cell, but it cannot directly handover from a neighboring cell to another cell. After each handover, the network device must resend the handover command (or conditional handover command) to configure the next accessible cell. This approach is not conducive to reducing the amount of data transmitted over the air interface and shortening handover time.

[0081] Based on this, an embodiment of the present application provides a method, terminal device and network device for cell switching. The network device can determine multiple candidate cells based on the predicted trajectory of the terminal device, and send configuration information of the multiple candidate cells to the terminal device. Since the multiple candidate cells include multiple cells on the predicted trajectory path of the terminal device, the terminal device can perform continuous switching on the predicted trajectory path, that is, it can realize multi-hop switching of the terminal device, thereby reducing the amount of data transmitted over the air interface and shortening the switching time.

[0082] The following is a detailed introduction to the method for cell switching provided in an embodiment of the present application in conjunction with Figure 4.

[0083] 4 , in step S410 , a first network device sends first configuration information to a terminal device. The first network device may be a network device corresponding to a serving cell (or current serving cell) of the terminal device.

[0084] In some embodiments, the first configuration information may also be referred to as conditional switching information.

[0085] In some embodiments, the first configuration information may be carried in a handover command. For example, the first network device may send a handover command to the terminal device, where the handover command includes the first configuration information. In other embodiments, the first configuration information may also be carried in other messages. For example, the first configuration information may be carried in a dedicated message.

[0086] In some embodiments, the switching command in the embodiments of the present application may also be referred to as a conditional switching command or a continuous conditional switching command.

[0087] In some embodiments, the handover command may be carried in a MAC CE.

[0088] In some embodiments, the configuration information of the multiple candidate cells may include reserved resources corresponding to the multiple candidate cells, and the reserved resources may be used for subsequent random access by the terminal device.

[0089] In some embodiments, the first configuration information may include configuration information corresponding to multiple candidate cells. The configuration information corresponding to multiple candidate cells can be used for continuous switching of the terminal device, or in other words, the configuration information corresponding to multiple candidate cells can be used for multi-hop switching of the terminal device. The terminal device can perform multi-hop switching based on the first configuration information. For example, the terminal device can switch from cell 1 among multiple candidate cells to cell 2 among multiple candidate cells based on the first configuration information, and then switch from cell 2 among multiple candidate cells to other cells among multiple candidate cells. The switching of the terminal device from cell 1 to cell 2 can be understood as a one-hop switching or a single switching of the terminal device. In the solution of the embodiment of the present application, the configuration information required for the terminal device to perform multi-hop switching (or multiple switching) can be sent to the terminal device by the first network device through the same information (i.e., the first configuration information).

[0090] In some embodiments, the cell switching performed by the terminal device may be a conditional switching based on L3, or may be an LTM switching, or may be a conditional LTM switching.

[0091] In some embodiments, multiple candidate cells may be determined based on the predicted trajectory of the terminal device. For example, multiple candidate cells may be determined based on the predicted trajectory path of the terminal device. The multiple candidate cells may be cells along the predicted trajectory path of the terminal device. In some embodiments, the multiple candidate cells may be some or all of the cells along the predicted trajectory path. The method for determining multiple candidate cells will be described in detail below.

[0092] In some embodiments, the predicted trajectory of the terminal device can be predicted by the first network device. There are many ways for the first network device to predict the trajectory of the terminal device, which will be described in detail below.

[0093] The embodiment of the present application predicts the trajectory of the terminal device and determines multiple candidate cells based on the predicted trajectory of the terminal device, so that the terminal device can switch continuously during movement to achieve multi-hop handover. Based on the solution provided by the embodiment of the present application, the first network device can send the configuration information of multiple candidate cells to the terminal device, which can avoid the need to resend the configuration information of the candidate cells to the terminal device after each handover of the terminal device, thereby reducing the amount of signaling transmitted on the air interface and shortening the handover time.

[0094] Taking Figure 5 as an example, the traditional conditional switching mechanism can only configure one-hop candidate cells, that is, only cell 1 can be configured as a candidate cell. If the first network device needs to configure cells 1 to 4, it needs to transmit four conditional switching commands. However, the embodiment of the present application can configure multiple-hop candidate cells through one conditional switching command, that is, cell 1, cell 2, cell 3 and cell 4 can be configured as candidate cells, so that the terminal device can achieve continuous switching on cells 1 to 4.

[0095] In some embodiments, the first configuration information may further include the configuration parameter 1 and / or configuration parameter 3 described above. For example, the first configuration information may include a logical identifier ID. For another example, the first configuration information may include a switching condition configuration, such as a conditional switching event.

[0096] In some embodiments, the first configuration information can be configured based on the levels of multiple candidate cells. In other words, the first network device can hierarchically configure the configuration information of multiple candidate cells, thereby reducing the complexity of terminal device switching. In some embodiments, the configuration information of candidate cells of the same level can be configured together. In some embodiments, the level of the candidate cell can be determined based on the number of handovers corresponding to switching to the candidate cell. The number of consecutive handovers corresponding to switching to candidate cells of different levels is different, or the number of consecutive handovers corresponding to switching to candidate cells of the same level is the same.

[0097] In some embodiments, the terminal device may perform cell switching based on the levels of the candidate cells. When performing cell switching, the terminal device may select a cell from the corresponding level instead of selecting from all candidate cells, thereby reducing switching complexity.

[0098] In some embodiments, the first network device may classify multiple candidate cells into levels. In some possible implementations, the first network device may classify candidate cells into levels based on the coverage of the candidate cells and the predicted trajectory of the terminal device. For example, on the predicted trajectory of the terminal device, the farther away the cell is from the terminal device, the higher the level corresponding to the cell, and the more switching times the terminal device needs to perform. Taking Figure 5 as an example, cell 1 is a first-level cell, cell 2 is a second-level cell, cell 3 is a third-level cell, and cell 4 is a fourth-level cell. The terminal device can switch from cell 1 to cell 2, from cell 2 to cell 3, and from cell 3 to cell 4.

[0099] In some embodiments, configuration information of all candidate cells included in the first configuration information is hierarchically configured, or configuration information of some candidate cells included in the first configuration information is hierarchically configured, and configuration information of another part of candidate cells is not hierarchically configured.

[0100] In some embodiments, the multiple candidate cells include adjacent first-level cells and second-level cells. A terminal device can be handed over from a first-level cell to a second-level cell. A first cell in the first-level cell and a second cell in the second-level cell have an associated relationship. This associated relationship can be used to indicate that the terminal device can be handed over to the second cell the next time it hands over to the first cell. In other words, there is a top-down connection relationship between the first-level cell and the second-level cell. The associated relationship in the embodiments of the present application can be a connection relationship.

[0101] For example, assuming that the first-level cells include cell 1 and cell 2, and the second-level cells include cell 3, cell 4, and cell 5, if cell 1 and cell 3 have an association relationship, the terminal device can switch to cell 3 in the next handover after switching to cell 1. If cell 1 and cell 4 have no association relationship, the terminal device cannot switch to cell 4 in the next handover after switching to cell 1.

[0102] In some embodiments, the first network device may send indication information to the terminal device, where the indication information may be used to indicate the aforementioned association relationship between the first cell and the second cell. The first network device may indicate to the terminal device which cells in the first-level cells can be switched to which cells in the second-level cells. By indicating the association relationship between cells to the terminal device, the terminal device can be more clearly informed of the cells to which it can switch, avoiding blindness in the cell switching process, thereby reducing the latency of the cell switching.

[0103] In some embodiments, whether cells are associated with each other can be determined based on the predicted trajectory of the terminal device. For example, cells on the same predicted trajectory may be associated with each other, while cells not on the same predicted trajectory may not be associated with each other.

[0104] For example, assuming that the first network device predicts that the terminal device may have two trajectory routes in the future (such as in the next 1 minute), the cell ID passed by the first route is 1-2-3, and the ID of the cell passed by the second route is 1-5-6. The first network device can determine the level of the cell based on the predicted trajectory route. For example, the first network device can set cell 1 as a level 1 cell, cell 2 as a level 1.1 cell, cell 5 as a level 1.2 cell, cell 3 as a level 1.1.1 cell, and cell 6 as a level 1.1.2 cell. The association relationship in the embodiment of the present application can be referred to as a conditional switching chain (such as 1-2-3 or 1-5-6). Among them, cell 1, cell 2 and cell 3 have an association relationship, cell 1, cell 5 and cell 6 have an association relationship, while cell 2 and cell 6 do not have an association relationship, and cell 5 and cell 3 do not have an association relationship.

[0105] After the terminal device performs the first conditional handover to cell 1, the second conditional handover can be to either cell 2 or cell 5. However, if the terminal device switches to cell 2, since cells 2 and 3 are associated but not to cell 6, although cells 3 and 6 are at the same level, the terminal device can only switch to cell 3 and not to cell 6 during the third conditional handover.

[0106] In some embodiments, cells of different levels may not have an associated relationship. In this case, after switching to any cell in a certain level, the terminal device can switch to any cell in the next level in the next handover. As an example, assuming that multiple candidate cells include adjacent level 3 and level 4 cells, the terminal device can switch to any cell in the level 4 in the next handover after switching to any cell in the level 3.

[0107] For example, assuming that the third-level cells include cell 1 and cell 2, and the fourth-level cells include cell 3, cell 4 and cell 5, if the third-level cells and the fourth-level cells have no association relationship, then regardless of whether the terminal device switches to cell 1 or cell 2 for the first time, the second conditional switch can be selected from cell 3, cell 4 and cell 5.

[0108] Release of resources

[0109] In some embodiments, if the terminal device successfully switches to one of the multiple candidate cells based on the first configuration information, the first network device may release the reserved resources corresponding to the relevant cell to reduce the resources occupied by the cell switching and avoid resource waste. The release of the reserved resources may be actively performed by the first network device, or the terminal device may request the first network device. For example, the terminal device may send a first message to the first network device, and the first message is used to request the release of the reserved resources corresponding to the candidate target cell. The candidate target cell is associated with the cell after the switching. Alternatively, the candidate target cell may be understood as a cell to which the terminal device will not subsequently switch.

[0110] In some embodiments, the reserved resources may include resources required during the random access process. For example, the reserved resources may include one or more of the following: beam, frequency, and synchronization signal block.

[0111] In some embodiments, the candidate target cell may belong to multiple candidate cells. For example, the candidate target cell may be one or more cells among the multiple candidate cells. Alternatively, the candidate target cell may be some or all cells among the multiple candidate cells.

[0112] In some embodiments, the candidate target cell may be indicated by an ID of the candidate target cell. For example, the first information may include ID information of the candidate target cell and / or an ID list of the candidate target cell.

[0113] In some embodiments, the terminal device may send a first message to the first network device after each cell handover to request the release of the reserved resources corresponding to the candidate target cell, thereby enabling the reserved resources to be released as quickly as possible. In other embodiments, the terminal device may also send a first message to the first network device after completing multiple cell handovers to request the release of the reserved resources corresponding to the candidate target cell, thereby reducing the amount of data transmitted over the air interface.

[0114] The embodiments of the present application do not specifically limit the method for determining candidate target cells. In some embodiments, candidate target cells can be determined based on the level of the candidate cells. In other embodiments, candidate target cells can be determined based on the association relationship between cells.

[0115] In some embodiments, the candidate target cells include one or more of the following cells: a first target cell and a second target cell. The first target cell may be a cell at the same level as the cell being switched. In other words, after the cell switch is complete, the terminal device can request the release of reserved resources corresponding to other cells at the same level. Since the terminal device will not switch to other cells at the same level after switching to the target cell, the terminal device can request the release of reserved resources corresponding to other cells to release these resources.

[0116] The second target cell may have an association relationship with the first target cell, and the association relationship is used to indicate that the terminal device can switch to the second target cell in the next switch after switching to the first target cell. In other words, the second target cell and the first target cell may have the connection relationship described above, and the terminal device may switch from the first target cell to the second target cell. Therefore, the second target cell does not have a connection relationship with the switched cell. After the cell switching is completed, the terminal device may apply to release the reserved resources of other cells that have no connection relationship with the switched cell. Since the terminal device will only switch to cells associated with the target cell after switching to the target cell, and will not switch to cells that are not associated with the target cell, the terminal device may apply to release the reserved resources corresponding to these unassociated cells so that these resources can be released.

[0117] In some embodiments, the candidate target cells include the first target cell. For example, if the first network device does not indicate the association relationship between cells to the terminal device, the candidate target cells include the first target cell.

[0118] For example, assuming that the first-level cells include cell 1 and cell 2, and the second-level cells include cell 3, cell 4, and cell 5, there is no obvious association relationship (or connection relationship) between the first-level cells and the second-level cells. In other words, regardless of whether the terminal device performs a first conditional handover to cell 1 or cell 2, the terminal device can select from cell 3, cell 4, and cell 5 for a second conditional handover. If the terminal device switches to cell 1, the first target cell includes cell 2. The terminal device can send a first message to the first network device to request the release of reserved resources corresponding to cell 2.

[0119] In some other embodiments, the candidate target cells may include the first target cell and the second target cell. For example, if the first network device indicates an association relationship between cells to the terminal device, the candidate target cells may include the first target cell and the second target cell.

[0120] For example, the first network device can determine two conditional switching chains based on the predicted trajectory of the terminal device. The two conditional switching chains are 1-2-3-4 and 1-5-6-7. After the terminal device performs the first conditional switching to cell 1, the second conditional switching can be switched to any one of cell 2 and cell 5. If the terminal device switches to cell 2, the first target cell includes cell 5. Since cell 6 and cell 7 are cells associated with cell 5, the second target cell includes cell 6 and cell 7. The terminal device can send a first message to the first network device to apply for the release of reserved resources corresponding to cell 5, cell 6, and cell 7.

[0121] Conditional switch event

[0122] In some embodiments, the terminal device may perform cell switching based on a first conditional switching event. The first conditional switching event may be carried in the first configuration information, that is, the first configuration information may include the first conditional switching event to reduce signaling overhead. Of course, in some embodiments, the first conditional switching event may also be carried in other messages. For example, the first conditional switching event may be carried in a dedicated message.

[0123] In some embodiments, the conditional switching event may also be referred to as a trigger condition or a switching condition.

[0124] In some embodiments, the first conditional switching event may be related to the location information of the terminal device, for example, the first conditional switching event may include conditional event D1. In some embodiments, the first conditional switching event may be related to the time information of the terminal device (such as the local time of the terminal device), for example, the first conditional switching event may include conditional event T1.

[0125] In some embodiments, the first conditional switching event may include one or more of the conditional event A3, conditional event A4, conditional event A5, conditional event D1, and conditional event T1 described above.

[0126] In some embodiments, the first network device may configure a corresponding first conditional handover event for each candidate cell. The terminal device may determine whether the candidate cell satisfies the conditional handover event based on the first conditional handover event corresponding to each candidate cell.

[0127] In some embodiments, the first network device may configure the same first conditional handover event for multiple candidate cells. In other words, multiple candidate cells may share the same conditional handover event.

[0128] In some embodiments, the reserved resources corresponding to the candidate cell can be configured based on the first conditional switching event. Taking the first conditional switching event including conditional event T1 as an example, assuming that the conditional switching event corresponding to cell 1 includes conditional event T1, cell 1 only reserves resources within the time period corresponding to conditional event T1. Beyond this time period, cell 1 can release the reserved resources. Taking the first conditional switching event including conditional event D1 as an example, assuming that the conditional switching event corresponding to cell 2 includes conditional event D1, cell 2 only reserves resources within the location range corresponding to conditional event D1. Beyond this location range, cell 2 can release the reserved resources.

[0129] Since the terminal device is in a mobile state, as time goes by, or as the terminal device moves, through conditional event T1 and / or conditional event D1, after determining that the terminal device has moved away from a certain cell, the reserved resources corresponding to the cell can be released to avoid waste of resources.

[0130] In some embodiments, the first network device may further instruct the network device corresponding to the candidate cell to cache the corresponding reserved resources. For example, the first network device may send third information to a third network device, where the third information is used to instruct the third network device to cache the reserved resources corresponding to the third network device. The third network device may include a network device corresponding to at least one candidate cell among the multiple candidate cells, or in other words, the third network device may include network devices corresponding to some or all of the multiple candidate cells. The candidate cell may cache the corresponding reserved resources based on the instruction of the first network device, thereby preventing the candidate cell from prematurely caching the reserved resources and causing resource waste. The reserved resources may be reserved resources corresponding to the third network device and the terminal device.

[0131] In some embodiments, the third information may also be indicated by the core network.

[0132] The third network device may be determined based on the predicted trajectory of the terminal device. The first network device may send third information to the third network device corresponding to the candidate cell when the terminal device is about to switch to the candidate cell.

[0133] If the candidate cells are divided into levels, the third network device may be a network device corresponding to the candidate cells of the same level.

[0134] For example, using Figure 5 as an example, the handover path of the terminal device is cell 1-cell 2-cell 3-cell 4. When the terminal device hands over to cell 1, the first network device can instruct cell 2 to cache the corresponding reserved resources. When the terminal device hands over from cell 1 to cell 2, the first network device can instruct cell 3 to cache the corresponding reserved resources. When the terminal device hands over from cell 2 to cell 3, the first network device can instruct cell 4 to cache the corresponding reserved resources.

[0135] In some embodiments, the third network device includes a network device corresponding to at least one candidate cell among a plurality of candidate cells. The number of handovers required for the terminal device to switch from the current cell to the at least one candidate cell is less than or equal to a preset threshold. The preset threshold may be 1, 2, or 3, etc. For example, the at least one candidate cell may include the cell to which the terminal device needs to switch next, or in other words, the at least one candidate cell may include the cell to which the terminal device can switch after performing one handover. For another example, the at least one candidate cell may include the cell to which the terminal device needs to switch next and the cell to which the next handover is required, or in other words, the at least one candidate cell may include the cell to which the terminal device can switch after performing one handover and two handovers.

[0136] In some embodiments, the first network device may send fourth information to the fourth network device, where the fourth information may be used to indicate a second time window, where the second time window is used for the fourth network device to cache reserved resources corresponding to the terminal device within the second time window. The fourth network device may cache corresponding reserved resources (such as reserved resources corresponding to the terminal device) within the second time window. By indicating the time window for caching reserved resources to the fourth network device, the fourth network device may cache resources within the corresponding time window, and may release cached resources outside the second time window, thereby avoiding waste of resources.

[0137] In some embodiments, the second time windows corresponding to different fourth network devices may be different. For example, the second time window corresponding to network device 1 is earlier than the time window corresponding to network device 2. Network device 1 is the network device corresponding to cell 1, and network device 2 is the network device corresponding to cell 2. The number of handovers required for the terminal device to switch from the current cell to cell 1 is less than the number of handovers required for the terminal device to switch from the current cell to cell 2.

[0138] In some embodiments, the fourth information may be used to indicate one or more of the following information: a start time of the second time window, an end time of the second time window, and a duration of the second time window.

[0139] The fourth network device may include a network device corresponding to at least one of the plurality of candidate cells. For example, the fourth network device may include a network device corresponding to some of the plurality of candidate cells, or the fourth network device may include a network device corresponding to all of the plurality of candidate cells. In some embodiments, the fourth network device may be the same as the third network device.

[0140] Update of the first configuration information

[0141] Because the first network device configures configuration information of multiple candidate cells for the terminal device, the first network device does not need to update the first configuration information for a period of time. However, in certain circumstances, the first network device needs to update the first configuration information. This embodiment of the present application studies the update conditions of the first configuration information, and the update conditions are described below.

[0142] In some embodiments, the update of the first configuration information may be triggered by a first condition related to one or more of the following information: a predicted trajectory of the terminal device; a cell handover condition of the terminal device; access conditions of multiple candidate cells; and a level of the cell after the handover.

[0143] In some embodiments, the first condition is related to the predicted trajectory of the terminal device. For example, the first condition may include a change in the predicted trajectory of the terminal device. If the predicted trajectory of the terminal device changes, such as the terminal device deviates from the original predicted trajectory, it means that the candidate cell in the first configuration information may no longer be suitable for the terminal device to perform cell switching. In this case, the first network device can update the first configuration information. For another example, the first condition may include that the predicted trajectory of the terminal device becomes longer. If the first network device predicts a longer trajectory of the terminal device, the first network device can update the first configuration information. It should be noted that the update of the configuration information is passively triggered due to changes in the mobile environment.

[0144] In some embodiments, the first condition is related to the cell switching situation of the terminal device. For example, the first condition may include a cell switching failure. If the terminal device cell switching fails, the first network device may update the first configuration information. For another example, the first condition may include a cell switching failure and the reselected cell does not belong to multiple candidate cells. After the terminal device cell switching fails, the cell can be reselected, but if the reselected cell does not belong to multiple candidate cells, it means that the original conditional switching chain has been destroyed, and the terminal device may not be able to complete the cell switching and needs to reconfigure the candidate cell. Therefore, in this case, the first network device can update the first configuration information. It should be noted that the update of the configuration information is passively triggered due to changes in the mobile environment.

[0145] In some embodiments, the first condition is related to the access status of multiple candidate cells. As an example, the first condition includes that multiple candidate cells have completed access. If the terminal device has completed access to multiple candidate cells, the first network device can update the first configuration information so that the terminal device can perform the next cell switching. Taking Figure 5 as an example, the multiple candidate cells include cell 1, cell 2, cell 3 and cell 4. If the terminal device has performed random access to cell 1, cell 2, cell 3 and cell 4, the first network device can update the first configuration information. It should be noted that the update of the configuration information is actively triggered after the original configuration information is used up.

[0146] As another example, the first condition includes that random access is completed for cells of each level in a plurality of candidate cells. If the terminal device performs random access (or cell switching) for cells of each level, it means that the terminal device has completed the last level of cell switching. In this case, the first network device can update the first configuration information so that the terminal device can perform the next cell switching. For example, assuming that a plurality of candidate cells include first-level cells and second-level cells, the first-level cells include cells 1 and 2, and the second-level cells include cells 3 and 4, if the terminal device switches from cell 1 to cell 3, it means that the terminal device has completed random access for both the first-level cells and the second-level cells, then the first network device can update the first configuration information. It should be noted that the update of the configuration information is actively triggered after the original configuration information is used up.

[0147] In some embodiments, the first condition may be related to the level of the cell after the handover. As an example, the first condition may include that the cell after the handover belongs to the last-level cell. If the cell after the handover belongs to the last-level cell, it means that the terminal device has completed the last-level cell handover. In this case, the first network device may update the first configuration information to enable the terminal device to perform the next cell handover. It should be noted that the update of this configuration information is actively triggered after the original configuration information is used up.

[0148] As another example, the first condition may include that the cell after handover belongs to a preset level cell, where the preset level may be a level close to the last level. For example, the first condition may include that the cell after handover belongs to the second-to-last level cell. After the terminal device hands over to a cell of the preset level, it indicates that the terminal device is about to hand over to the last level cell. In this case, the first network device may update the first configuration information in advance to avoid interruption of continuous handover of the terminal device.

[0149] After determining that the first configuration information needs to be updated, the first network device may send second configuration information to the terminal device. The second configuration information may be understood as the updated configuration information. In some embodiments, the second configuration information may be carried in the handover command.

[0150] The embodiments of the present application do not specifically limit the form of the second configuration information. As an example, the second configuration information can be a full configuration or a complete configuration, that is, the second configuration information can be used to replace the first configuration information. In other words, the second configuration information can be used for continuous switching of the terminal device, or the second configuration information includes all configuration information for continuous switching of the terminal device. For example, the terminal device can use the second configuration information for continuous switching. In some implementations, after receiving the second configuration information, the terminal device can use the second configuration information to replace the first configuration information and directly use the second configuration information for cell switching. This method does not require the terminal device to process the second configuration information, and can use it directly, which can reduce the amount of calculation of the terminal device.

[0151] As another example, the second configuration information is an incremental configuration, that is, the second configuration information is incremental configuration information of the first configuration information. In some embodiments, at least part of the information in the second configuration information and at least part of the information in the first configuration information are used to generate third configuration information, and the third configuration information includes all configuration information for the terminal device to perform continuous switching. The third configuration information can also be understood as the merged configuration information. For example, after receiving the second configuration information, the terminal device can merge the first configuration information and the second configuration information to obtain the third configuration information. The terminal device can perform subsequent cell switching based on the third configuration information.

[0152] In some implementations, the second configuration information includes candidate cells that need to be updated (or configuration information of candidate cells). The candidate cells that need to be updated may include newly added candidate cells and / or candidate cells that need to be replaced. In some embodiments, the second configuration information may also include candidate cells that need to be deleted in the first configuration information (or configuration information of candidate cells). After the terminal device receives the second configuration information, it can merge (or superimpose) the second configuration information with the first configuration information and perform cell switching based on the merged configuration information. In this case, the terminal device can perform cell switching based on the original switching command. Since the first network device only needs to configure incremental configuration information for the terminal device, the air interface resource overhead can be reduced.

[0153] It should be noted that, in some embodiments, the first configuration information may also be updated by other network devices. For example, the first configuration information may be updated by the network device corresponding to the cell after the handover. For example, if the terminal device hands over to cell 1, the first configuration information may be updated by the network device corresponding to cell 1.

[0154] Conflict Resolution

[0155] For the traditional conditional switching mechanism, after the terminal device completes a cell switch (such as after the terminal device switches to the target cell), the network device will resend the switching command to the terminal device to configure the candidate cell required for the next switch for the terminal device. The candidate cell configured in the traditional way may overlap with the candidate cell in the first configuration information in the embodiment of the present application, which will waste air interface resources. In addition, the traditional conditional switching process may interrupt the process of continuous conditional switching. For example, after the terminal device completes the traditional conditional switching, since the network device does not know whether the terminal device accessed through the conditional switching is accessed through the traditional conditional switching mechanism or through the continuous conditional switching mechanism (that is, the switching mechanism provided by the embodiment of the present application), the continuous conditional switching may be interrupted and the corresponding configuration information is released.

[0156] For example, the first configuration information includes configuration information corresponding to cell 1, cell 2, and cell 3. Assuming that the terminal device switches to cell 1, since the network device does not know whether the terminal device switches to cell 1 using the traditional conditional switching mechanism or the continuous conditional switching mechanism, the network device (such as the network device corresponding to cell 1) may send a switching command to the terminal device to configure candidate cells. However, the candidate cells configured by the network device may include configuration information corresponding to cell 2 and / or cell 3, which will result in a waste of air interface resources.

[0157] Taking the above example, assuming that in the traditional conditional switching mechanism, the configuration information sent by the network device to the terminal device also includes the configuration information corresponding to cell 1 and cell 2, if the terminal device switches to cell 1, the configuration information corresponding to cell 1 and cell 2 will be released. After the configuration information corresponding to cell 2 is released, the continuous conditional switching will be interrupted, and the terminal device may not be able to continue the continuous switching.

[0158] In response to the above-mentioned problem, an embodiment of the present application provides a method for cell switching, in which a terminal device sends an indication message to a network device (such as a first network device) to indicate that the first configuration information (or continuous conditional switching) has been configured, thereby avoiding the network device from sending a traditional conditional switching command to the terminal device, avoiding the waste of air interface resources, and avoiding the interruption of continuous switching.

[0159] In some embodiments, if the terminal device successfully switches to one of the multiple candidate cells based on the first configuration information, the terminal device may send a second information to the second network device, where the second information is used to indicate that the terminal device has configured the first configuration information, or in other words, the second information is used to indicate that the terminal device has configured continuous conditional switching, or the second information is used to indicate that the second network device does not need to configure the fourth configuration information. The fourth configuration information may be the configuration information corresponding to the traditional conditional switching, or in other words, the fourth configuration information is used for the terminal device to perform a one-hop switching from the current cell to the next cell to be switched. The second network device is the network device corresponding to the cell after switching. After receiving the second information sent by the terminal device, the second network device may not send a switching command to the terminal device, thereby not triggering the traditional conditional switching process.

[0160] Predicted trajectory

[0161] In some embodiments, the multiple candidate cells in the embodiments of the present application may be all cells on the predicted trajectory of the terminal device, which can enable the terminal device to switch to a suitable cell and ensure the communication quality of the terminal device. In some embodiments, the multiple candidate cells in the embodiments of the present application may be some cells on the predicted trajectory of the terminal device. Since the first network device needs to reserve resources for the candidate cells, by configuring some cells on the predicted trajectory, the resource reservation pressure on the network side can be alleviated, and the reserved resources can be reduced. The occupation of network-side resources.

[0162] In some embodiments, the number of multiple candidate cells may be a first preset value. The first network device may configure candidate cells for the terminal device based on the first preset value. Assuming that the first preset value is 5, the first network device may configure 5 candidate cells for the terminal device. In some embodiments, the maximum number of multiple candidate cells may be a second preset value. In other words, the embodiment of the present application may set the maximum number of cells that the first network device can configure. Assuming that the second preset value is 8, the maximum number of candidate cells that the first network device can configure is 8, that is, the number of candidate cells configured by the first network device for the terminal device is less than or equal to 8.

[0163] The embodiment of the present application does not specifically limit the method for determining the predicted trajectory. An example is given below to illustrate.

[0164] In some embodiments, the predicted trajectory is related to the geographic location of the terminal device. The geographic location may be geographic coordinates. In some implementations, the predicted trajectory may be determined based on the geographic location of the terminal device. The first network device may predict the trajectory of the terminal device based on the geographic location of the terminal device.

[0165] In some possible implementations, the geographic location of the terminal device may be the geographic location of the terminal device within a first time window. The geographic location may be the continuous location of the terminal device within the first time window. When performing trajectory prediction for the terminal device, the first network device may determine the geographic location of the terminal device within the first time window, thereby performing trajectory prediction for the terminal device. The first time window may be a preset time window. The embodiments of the present application do not specifically limit the start time, duration, and end time of the first time window. For example, the start time of the first time window may be the start time of the trajectory prediction, or the start time of the first time window may be after the start time of the trajectory prediction. For another example, the duration of the first time window may be a first duration, which may be a preset duration. The first duration may be a duration predefined in the protocol. For example, the first duration may be 1 minute. For another example, the end time of the first time window may be after the start time of the prediction. Alternatively, the end time of the first time window is the time after the start time of the first time window plus the first duration.

[0166] In some possible implementations, the geographic location of the terminal device may also be the geographic location of the terminal device at multiple sampling points. The multiple sampling points are located after the first moment. The first moment may be the current moment, which is the moment when trajectory prediction begins, or the moment when the prediction occurs. The multiple sampling points are time sampling points. There is a certain time interval between the multiple sampling points. The time intervals between different sampling points may be the same or different. For example, the time intervals between any two adjacent sampling points are the same, that is, the first network device may periodically sample the terminal device. The sampling period may be a preset period. Taking a sampling period of 4s as an example, the first network device may sample the geographic location of the terminal device every 4s.

[0167] In some embodiments, the predicted trajectory is related to the moving speed of the terminal device. In some implementations, the predicted trajectory can be determined based on the moving speed of the terminal device. The first network device can predict the trajectory of the terminal device based on the moving speed of the terminal device.

[0168] In some possible implementations, the movement speed of the terminal device may be the movement speed of the terminal device within a first time window. The movement speed may be the continuous speed of the terminal device within the first time window. When performing trajectory prediction for the terminal device, the first network device may determine the movement speed of the terminal device within the first time window, thereby performing trajectory prediction for the terminal device. The first time window may be a preset time window. The embodiments of the present application do not specifically limit the start time, duration, and end time of the first time window. For example, the start time of the first time window may be the start time of trajectory prediction, or the start time of the first time window may be after the start time of trajectory prediction. For another example, the duration of the first time window may be a first duration, which may be a preset duration. The first duration may be a duration predefined in the protocol. For another example, the end time of the first time window may be after the start time of prediction. Alternatively, the end time of the first time window is the time after the start time of the first time window plus the first duration.

[0169] In some possible implementations, the moving speed of the terminal device may also be the moving speed of the terminal device at multiple sampling points. The multiple sampling points are located after the first moment. The first moment may be the current moment, which is the moment when trajectory prediction begins, or the moment when the prediction occurs. The multiple sampling points are time sampling points. There is a certain time interval between the multiple sampling points. The time intervals between different sampling points may be the same or different. For example, the time intervals between any two adjacent sampling points are the same, that is, the first network device may periodically sample the terminal device. The sampling period may be a preset period. Taking a sampling period of 4 seconds as an example, the first network device may sample the moving speed of the terminal device every 4 seconds.

[0170] In some embodiments, the predicted trajectory is related to information about cells that the terminal device passes through. The passed cell information may include cell ID information. In some implementations, the predicted trajectory may be determined based on information about cells that the terminal device passes through. The first network device may predict the trajectory of the terminal device based on the information about the cells that the terminal device passes through.

[0171] In some possible implementations, the cell information passed by the terminal device may be the cell information passed by the terminal device within the first time window. When the first network device performs trajectory prediction on the terminal device, it may determine the cell information passed by the terminal device within the first time window, thereby performing trajectory prediction on the terminal device. The first time window may be a preset time window. The embodiment of the present application does not specifically limit the start time, duration, and end time of the first time window. For example, the start time of the first time window is the time when trajectory prediction starts, or the start time of the first time window may be after the time when trajectory prediction starts. For another example, the duration of the first time window may be a first duration, which may be a preset duration. The first duration may be a duration predefined in the protocol. For another example, the end time of the first time window may be after the time when prediction starts. Alternatively, the end time of the first time window is the time after the start time of the first time window plus the first duration.

[0172] In some possible implementations, the cell information passed by the terminal device may also be the cell information of the terminal device at multiple sampling points. The multiple sampling points are located after the first moment. The first moment may be the current moment, which is the moment when trajectory prediction starts, or the moment when the prediction occurs. The multiple sampling points are time sampling points. There is a certain time interval between the multiple sampling points. The time intervals between different sampling points may be the same or different. For example, the time intervals between any two adjacent sampling points are the same, that is, the first network device may periodically sample the terminal device. The sampling period may be a preset period. Taking a sampling period of 4s as an example, the first network device may sample the cell information passed by the terminal device every 4s.

[0173] In some embodiments, the predicted trajectory is related to a signal measurement result measured by the terminal device. The signal measurement result may include one or more of the following: reference signal receiving power (RSRP), reference signal receiving quality (RSRQ), and signal to interference plus noise ratio (SINR). In some implementations, the predicted trajectory may be determined based on the signal measurement result measured by the terminal device. The first network device may predict the trajectory of the terminal device based on the signal measurement result measured by the terminal device.

[0174] In some possible implementations, the signal measurement result measured by the terminal device may be the signal measurement result measured by the terminal device within a first time window. When performing trajectory prediction for the terminal device, the first network device may determine the signal measurement result measured by the terminal device within the first time window, thereby performing trajectory prediction for the terminal device. The first time window may be a preset time window. The embodiments of the present application do not specifically limit the start time, duration, and end time of the first time window. For example, the start time of the first time window may be the start time of trajectory prediction, or the start time of the first time window may be after the start time of trajectory prediction. For another example, the duration of the first time window may be a first duration, which may be a preset duration. The first duration may be a duration predefined in the protocol. For another example, the end time of the first time window may be after the start time of prediction. Alternatively, the end time of the first time window is the time after the start time of the first time window plus the first duration.

[0175] In some possible implementations, the signal measurement result measured by the terminal device may also be the signal measurement result measured by the terminal device at multiple sampling points. The multiple sampling points are located after the first moment. The first moment may be the current moment, which is the moment when trajectory prediction starts, or the moment when the prediction occurs. The multiple sampling points are time sampling points. There is a certain time interval between the multiple sampling points. The time intervals between different sampling points may be the same or different. For example, the time intervals between any two adjacent sampling points are the same, that is, the first network device may periodically sample the terminal device. The sampling period may be a preset period. Taking a sampling period of 4s as an example, the first network device may sample the signal measurement result measured by the terminal device every 4s, or in other words, the terminal device may report the signal measurement result to the first network device once every 4s.

[0176] In some embodiments, the predicted trajectory can be determined based on any one of the information described above, or based on multiple information described above, which is not specifically limited in the embodiments of the present application. For example, the predicted trajectory can be determined based on the geographical location and movement speed of the terminal device.

[0177] The embodiment of the present application does not specifically limit the manner in which the first network device performs trajectory prediction. For example, the first network device may predict the trajectory of the terminal device based on a first model. The first model may be a neural network model. For example, the first model may be an artificial intelligence (AI) model or a machine learning (ML) model. By introducing AI or ML technology into the mobility scenario, the mobile position of the terminal device may become predictable, and the network device may determine the cell that the terminal device will pass through in the future based on the predicted trajectory of the terminal device, thereby configuring multiple cells passed through to the terminal device at one time, so as to reduce the amount of data transmitted over the air interface and shorten the switching time.

[0178] It should be noted that the "first" in the first-level cell, the "second" in the second-level cell, the "third" in the third-level cell, and the "fourth" in the fourth-level cell in the embodiment of the present application do not represent the actual levels, but are used to distinguish different levels.

[0179] The method embodiment of the present application is described in detail above in conjunction with Figures 1 to 5 , and the device embodiment of the present application is described in detail below in conjunction with Figures 6 to 8 . It should be understood that the description of the method embodiment corresponds to the description of the device embodiment, and therefore, for portions not described in detail, reference can be made to the above method embodiment.

[0180] FIG6 is a schematic block diagram of a terminal device provided in an embodiment of the present application. The terminal device 600 shown in FIG6 can be any of the terminal devices described above. The terminal device 600 can include a receiving unit 610.

[0181] The receiving unit 610 is used to receive first configuration information sent by a first network device, where the first configuration information includes configuration information corresponding to multiple candidate cells, where the multiple candidate cells are determined based on the predicted trajectory of the terminal device, and the multiple candidate cells are used for continuous switching of the terminal device.

[0182] In some possible implementations, the first configuration information is configured based on levels of the multiple candidate cells, wherein switching to candidate cells of different levels corresponds to different numbers of continuous switching.

[0183] In some possible implementations, the multiple candidate cells include first-level cells and second-level cells of adjacent levels, and the first cell in the first-level cells has an association relationship with the second cell in the second-level cells, and the association relationship is used to indicate that the terminal device can switch to the second cell in the next switch after switching to the first cell.

[0184] In some possible implementations, the multiple candidate cells include third-level cells and fourth-level cells of adjacent levels, and the terminal device can switch to any one of the fourth-level cells in the next switch after switching to any one of the third-level cells.

[0185] In some possible implementations, the terminal device further includes a sending unit 620. If the terminal device successfully switches to one of the multiple candidate cells based on the first configuration information, the sending unit 620 is used to send first information to the first network device. The first information is used to apply for the release of reserved resources corresponding to the candidate target cell. The candidate target cell is associated with the cell after switching, and the candidate target cell belongs to the multiple candidate cells.

[0186] In some possible implementations, the candidate target cells include one or more of the following cells: a first target cell, which is a cell at the same level as the cell after switching; a second target cell, which has an association relationship with the first target cell, and the association relationship is used to indicate that the terminal device can switch to the second target cell in the next switch after switching to the first target cell.

[0187] In some possible implementations, the first configuration information includes a first conditional switching event, and the first conditional switching event corresponds to the first candidate cell among the multiple candidate cells. If the first candidate cell satisfies the first conditional switching event and the first candidate cell is not the cell after the switch, the candidate target cell includes the first candidate cell.

[0188] In some possible implementations, the first conditional switching event is related to location information of the terminal device and / or time information of the terminal device.

[0189] In some possible implementations, the update of the first configuration information is triggered by a first condition, and the first condition is related to one or more of the following information: the predicted trajectory of the terminal device; the cell switching status of the terminal device; the access status of the multiple candidate cells; and the level of the cell after switching.

[0190] In some possible implementations, the first condition includes one or more of the following: the predicted trajectory changes; the cell switching fails and the reselected cell does not belong to the multiple candidate cells; the multiple candidate cells have completed access; the switched cell belongs to the last level cell.

[0191] In some possible implementations, the receiving unit is further used to: receive second configuration information sent by the first network device, where the second configuration information is used for continuous switching of the terminal device, or the second configuration information is incremental configuration information of the first configuration information.

[0192] In some possible implementations, if the terminal device is successfully switched to one of the multiple candidate cells based on the first configuration information, the terminal device also includes: a sending unit for sending second information to a second network device, wherein the second information is used to indicate that the terminal device has been configured with the first configuration information, and the second network device is the network device corresponding to the cell after switching.

[0193] In some possible implementations, the multiple candidate cells are all or part of the cells on the predicted trajectory.

[0194] In some possible implementations, the predicted trajectory is related to one or more of the following information: the geographic location of the terminal device; the moving speed of the terminal device; the cell information that the terminal device will pass through; and the signal measurement results measured by the terminal device.

[0195] In some possible implementations, the predicted trajectory is determined based on one or more of the following information: the geographic location of the terminal device within the first time window; the moving speed of the terminal device within the first time window; the cell information passed by the terminal device within the first time window; the signal measurement results measured by the terminal device within the first time window; the geographic location of multiple sampling points of the terminal device after the first moment; the moving speed of the terminal device at multiple sampling points after the first moment; the cell information of the terminal device at multiple sampling points after the first moment; and the signal measurement results measured by the terminal device at multiple sampling points after the first moment.

[0196] In some possible implementations, the starting time of the first time window is the time when trajectory prediction starts, or the starting time of the first time window is after the time when trajectory prediction starts.

[0197] In some possible implementations, the first moment is the moment when trajectory prediction starts, or the first moment is after the moment when trajectory prediction starts.

[0198] FIG7 is a schematic block diagram of a network device according to an embodiment of the present application. The network device 700 shown in FIG7 can be any of the first network devices described above. The network device 700 can include a sending unit 710.

[0199] The sending unit 710 is used to send first configuration information to the terminal device, where the first configuration information includes configuration information corresponding to multiple candidate cells, where the multiple candidate cells are determined based on the predicted trajectory of the terminal device, and the multiple candidate cells are used for continuous switching of the terminal device.

[0200] In some possible implementations, the first configuration information is configured based on levels of the multiple candidate cells, wherein switching to candidate cells of different levels corresponds to different numbers of continuous switching.

[0201] In some possible implementations, the multiple candidate cells include first-level cells and second-level cells of adjacent levels, and the first cell in the first-level cells has an association relationship with the second cell in the second-level cells, and the association relationship is used to indicate that the terminal device can switch to the second cell in the next switch after switching to the first cell.

[0202] In some possible implementations, the multiple candidate cells include third-level cells and fourth-level cells of adjacent levels, and the terminal device can switch to any one of the fourth-level cells in the next switch after switching to any one of the third-level cells.

[0203] In some possible implementations, the network device also includes: a receiving unit 720, used to receive first information sent by the terminal device, the first information is used to apply for the release of reserved resources corresponding to the candidate target cell, the candidate target cell is associated with the switched cell, and the first information is sent by the terminal device when the cell switching is completed.

[0204] In some possible implementations, the candidate target cells include one or more of the following cells: a first target cell, which is a cell at the same level as the cell after switching; a second target cell, which has an association relationship with the first target cell, and the association relationship is used to indicate that the terminal device can switch to the second target cell in the next switch after switching to the first target cell.

[0205] In some possible implementations, the first configuration information includes a first conditional switching event, and the first conditional switching event corresponds to the first candidate cell among the multiple candidate cells. If the first candidate cell satisfies the first conditional switching event and the first candidate cell is not the cell after the switch, the candidate target cell includes the first candidate cell.

[0206] In some possible implementations, the first conditional switching event is related to location information of the terminal device and / or time information of the terminal device.

[0207] In some possible implementations, the update of the first configuration information is triggered by a first condition, and the first condition is related to one or more of the following information: the predicted trajectory of the terminal device; the cell switching status of the terminal device; the access status of the multiple candidate cells; and the level of the cell after switching.

[0208] In some possible implementations, the first condition includes one or more of the following: the predicted trajectory changes; the cell switching fails and the reselected cell does not belong to the multiple candidate cells; the multiple candidate cells have completed access; the switched cell belongs to the last level cell.

[0209] In some possible implementations, the sending unit is further used to: send second configuration information to the terminal device, where the second configuration information is used for continuous switching of the terminal device, or the second configuration information is incremental configuration information of the first configuration information.

[0210] In some possible implementations, the multiple candidate cells are all or part of the cells on the predicted trajectory.

[0211] In some possible implementations, the predicted trajectory is related to one or more of the following information: the geographic location of the terminal device; the moving speed of the terminal device; the cell information that the terminal device will pass through; and the signal measurement results measured by the terminal device.

[0212] In some possible implementations, the predicted trajectory is determined based on one or more of the following information: the geographic location of the terminal device within the first time window; the moving speed of the terminal device within the first time window; the cell information passed by the terminal device within the first time window; the signal measurement results measured by the terminal device within the first time window; the geographic location of multiple sampling points of the terminal device after the first moment; the moving speed of the terminal device at multiple sampling points after the first moment; the cell information of the terminal device at multiple sampling points after the first moment; and the signal measurement results measured by the terminal device at multiple sampling points after the first moment.

[0213] In some possible implementations, the starting time of the first time window is the time when trajectory prediction starts, or the starting time of the first time window is after the time when trajectory prediction starts.

[0214] In some possible implementations, the first moment is the moment when trajectory prediction starts, or the first moment is after the moment when trajectory prediction starts.

[0215] In some possible implementations, the sending unit is further used to: send third information to a third network device, where the third information is used to instruct the third network device to cache reserved resources corresponding to the terminal device, the third network device includes a network device corresponding to at least one candidate cell among the multiple candidate cells, and the number of switching times required for the terminal device to switch from the current cell to the at least one candidate cell is less than or equal to a preset threshold.

[0216] In some possible implementations, the sending unit is further used to: send fourth information to a fourth network device, where the fourth information is used to indicate a second time window, and the second time window is used for the fourth network device to cache reserved resources corresponding to the terminal device within the second time window, and the fourth network device includes a network device corresponding to at least one candidate cell among the multiple candidate cells.

[0217] Figure 8 is a schematic block diagram of a communication device according to an embodiment of the present application. The dashed lines in Figure 8 indicate that the unit or module is optional. The device 800 may be used to implement the method described in the above method embodiment. The device 800 may be a chip, a terminal device, or a network device.

[0218] The device 800 may include one or more processors 810. The processor 810 may support the device 800 to implement the method described in the method embodiment above. The processor 810 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0219] The apparatus 800 may further include one or more memories 820. The memories 820 store programs that can be executed by the processor 810, causing the processor 810 to perform the methods described in the above method embodiments. The memories 820 may be independent of the processor 810 or integrated into the processor 810.

[0220] The apparatus 800 may further include a transceiver 830. The processor 810 may communicate with other devices or chips via the transceiver 830. For example, the processor 810 may transmit and receive data with other devices or chips via the transceiver 830.

[0221] The present application also provides a computer-readable storage medium for storing a program. The computer-readable storage medium can be applied to a terminal or network device provided in the present application, and the program enables a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0222] The present application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to a terminal or network device provided in the present application, and the program causes a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0223] The embodiments of the present application also provide a computer program. The computer program can be applied to the terminal or network device provided in the embodiments of the present application, and the computer program enables a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0224] It should be understood that the terms "system" and "network" in this application can be used interchangeably. In addition, the terms used in this application are only used to explain the specific embodiments of this application and are not intended to limit this application. The terms "first", "second", "third", and "fourth" in the specification and claims of this application and the accompanying drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0225] In the embodiments of this application, the term "indication" may refer to a direct indication, an indirect indication, or an indication of an association. For example, "A indicates B" may refer to a direct indication of B, e.g., B can obtain information through A; it may refer to an indirect indication of B, e.g., A indicates C, e.g., B can obtain information through C; or it may refer to an association between A and B.

[0226] In the embodiments of this application, the term "include" can refer to direct inclusion or indirect inclusion. Alternatively, the term "include" in the embodiments of this application can be replaced with "indicates" or "is used to determine." For example, "A includes B" can be replaced with "A indicates B" or "A is used to determine B."

[0227] In the embodiment of the present application, "B corresponding to A" means that B is associated with A and B can be determined based on A. However, it should be understood that determining B based on A does not mean determining B based solely on A, but B can also be determined based on A and / or other information.

[0228] In the embodiments of the present application, the term "corresponding" may indicate a direct or indirect correspondence between the two, or an association relationship between the two, or a relationship between indication and indication, configuration and configuration, etc.

[0229] In the embodiments of the present application, "pre-definition" or "pre-configuration" may be implemented by pre-storing corresponding codes, tables, or other methods that can be used to indicate relevant information in a device (e.g., a terminal device and a network device). The present application does not limit the specific implementation method. For example, pre-definition may refer to information defined in a protocol.

[0230] In the embodiments of the present application, the “protocol” may refer to a standard protocol in the communications field, for example, it may include an LTE protocol, an NR protocol, and related protocols used in future communication systems, and the present application does not limit this.

[0231] In the embodiments of this application, the term "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0232] In various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0233] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0234] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0235] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0236] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be read by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital versatile disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0237] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for cell handover, characterized in that, comprising: A terminal device receives first configuration information sent by a first network device, where the first configuration information includes configuration information corresponding to a plurality of candidate cells, the plurality of candidate cells are determined based on the predicted trajectory of the terminal device, and the plurality of candidate cells are used for the terminal device to perform continuous handover.

2. The method according to claim 1, characterized in that, The first configuration information is configured based on the levels of the plurality of candidate cells, wherein the number of handovers for continuous handover corresponding to candidate cells of different levels is different.

3. The method according to claim 2, characterized in that, The plurality of candidate cells include a first-level cell and a second-level cell of adjacent levels, and a first cell in the first-level cell has an association relationship with a second cell in the second-level cell, and the association relationship is used to indicate that the terminal device can perform a handover to the second cell in the next handover after switching to the first cell.

4. The method according to claim 2, characterized in that, The plurality of candidate cells include a third-level cell and a fourth-level cell of adjacent levels, and the terminal device can perform a handover to any cell in the fourth-level cell in the next handover after switching to any cell in the third-level cell.

5. The method according to any one of claims 2-4, characterized in that, The method further comprises: If the terminal device successfully switches to a cell among the plurality of candidate cells based on the first configuration information, the terminal device sends first information to the first network device, where the first information is used to apply for releasing reserved resources corresponding to a candidate target cell, the candidate target cell is associated with the cell after handover, and the candidate target cell belongs to the plurality of candidate cells.

6. The method according to claim 5, characterized in that, The candidate target cell includes one or more of the following cells: A first target cell, where the first target cell is a cell at the same level as the cell after handover; A second target cell, where the second target cell has an association relationship with the first target cell, and the association relationship is used to indicate that the terminal device can perform a handover to the second target cell in the next handover after switching to the first target cell.

7. The method according to claim 5 or 6, characterized in that, The first configuration information includes a first conditional handover event, the first conditional handover event corresponds to a first candidate cell among the plurality of candidate cells, and if the first candidate cell meets the first conditional handover event and the first candidate cell is not the cell after handover, the candidate target cell includes the first candidate cell.

8. The method according to claim 7, characterized in that, The first conditional handover event is related to the location information of the terminal device and / or the time information of the terminal device.

9. The method according to any one of claims 1-8, characterized in that, The update of the first configuration information is triggered by a first condition, and the first condition is related to one or more of the following information: The predicted trajectory of the terminal device; The cell handover situation of the terminal device; The access situation of the multiple candidate cells; The level of the cell after handover.

10. The method according to claim 9, wherein, The first condition includes one or more of the following: The predicted trajectory changes; The cell handover fails and the reselected cell does not belong to the multiple candidate cells; The multiple candidate cells have completed access; The cell after handover belongs to the last-level cell.

11. The method according to claim 9 or 10, wherein, If the first configuration information needs to be updated, the method further includes: The terminal device receives second configuration information sent by a first network device; wherein, the second configuration information includes all the configuration information for the terminal device to perform continuous handovers, or at least part of the information in the first configuration information and at least part of the information in the second configuration information are used to generate third configuration information, and the third configuration information includes all the configuration information for the terminal device to perform continuous handovers.

12. The method according to any one of claims 1-11, wherein, If the terminal device successfully hands over to one of the multiple candidate cells based on the first configuration information, the method further includes: The terminal device sends second information to a second network device, and the second information is used to instruct the second network device not to configure fourth configuration information, and the fourth configuration information is used for the terminal device to perform a one-hop handover from the current cell to the cell that needs to be handed over next time, and the second network device is the network device corresponding to the cell after handover.

13. The method according to any one of claims 1-12, wherein, The multiple candidate cells are all or part of the cells on the predicted trajectory.

14. The method according to claim 13, wherein, The predicted trajectory is related to one or more of the following information: The geographical location of the terminal device; The moving speed of the terminal device; The cell information that the terminal device will pass by; The signal measurement results measured by the terminal device.

15. The method according to claim 14, wherein, The predicted trajectory is determined based on one or more of the following information: The geographical location of the terminal device within a first time window; The moving speed of the terminal device within a first time window; The cell information that the terminal device passes by within a first time window; The signal measurement results measured by the terminal device within a first time window; The geographical location of the terminal device at multiple sampling points after a first moment; The moving speed of the terminal device at multiple sampling points after a first moment; The cell information of the terminal device at multiple sampling points after a first moment; The signal measurement results measured by the terminal device at multiple sampling points after a first moment.

16. The method according to claim 15, wherein, The start time of the first time window is the time when trajectory prediction starts, or the start time of the first time window is after the time when trajectory prediction starts.

17. The method according to claim 15 or 16, wherein, the first time is the time when trajectory prediction starts, or the first time is after the time when trajectory prediction starts.

18. A method for cell handover, wherein, comprising: A first network device sends first configuration information to a terminal device, the first configuration information includes configuration information corresponding to a plurality of candidate cells, the plurality of candidate cells are determined based on the predicted trajectory of the terminal device, and the plurality of candidate cells are used for the terminal device to perform consecutive handovers.

19. The method according to claim 18, wherein, the first configuration information is configured based on the levels of the plurality of candidate cells, wherein the number of handovers for consecutive handovers corresponding to candidate cells of different levels is different.

20. The method according to claim 19, wherein, the plurality of candidate cells include a first-level cell and a second-level cell of adjacent levels, a first cell in the first-level cells has an association relationship with a second cell in the second-level cells, and the association relationship is used to indicate that the terminal device can perform a handover to the second cell in the next handover after switching to the first cell.

21. The method according to claim 19, wherein, the plurality of candidate cells include a third-level cell and a fourth-level cell of adjacent levels, and the terminal device can perform a handover to any cell in the fourth-level cells in the next handover after switching to any cell in the third-level cells.

22. The method according to any one of claims 19-21, wherein, the method further comprises: The first network device receives first information sent by the terminal device, the first information is used to apply for releasing reserved resources corresponding to a candidate target cell, the candidate target cell is associated with the handover target cell, the candidate target cell belongs to the plurality of candidate cells, and the first information is sent when the terminal device successfully switches to one of the plurality of candidate cells based on the first configuration information.

23. The method according to claim 22, wherein, the candidate target cell includes one or more of the following cells: A first target cell, the first target cell is a cell at the same level as the handover target cell; A second target cell, the second target cell has an association relationship with the first target cell, and the association relationship is used to indicate that the terminal device can perform a handover to the second target cell in the next handover after switching to the first target cell.

24. The method according to claim 22 or 23, wherein, The first configuration information includes a first conditional handover event, which corresponds to a first candidate cell among the multiple candidate cells. If the first candidate cell meets the first conditional handover event and the first candidate cell is not the handover target cell, the candidate target cell includes the first candidate cell.

25. The method according to claim 24, wherein, the first conditional handover event is related to the location information of the terminal device and / or the time information of the terminal device.

26. The method according to any one of claims 18-25, wherein, the update of the first configuration information is triggered by a first condition, and the first condition is related to one or more of the following information: the predicted trajectory of the terminal device; the cell handover situation of the terminal device; the access situation of the multiple candidate cells; the level of the handover target cell.

27. The method according to claim 26, wherein, the first condition includes one or more of the following: the predicted trajectory changes; the cell handover fails and the reselection cell does not belong to the multiple candidate cells; the multiple candidate cells have completed access; the handover target cell belongs to the last-level cell.

28. The method according to claim 26 or 27, wherein, if the first configuration information needs to be updated, the method further includes: the first network device sends second configuration information to the terminal device; wherein, the second configuration information includes all the configuration information for the terminal device to perform continuous handover, or at least part of the information in the first configuration information and at least part of the information in the second configuration information are used to generate third configuration information, and the third configuration information includes all the configuration information for the terminal device to perform continuous handover.

29. The method according to any one of claims 18-28, wherein, the multiple candidate cells are all or part of the cells on the predicted trajectory.

30. The method according to claim 29, wherein, the predicted trajectory is related to one or more of the following information: the geographical location of the terminal device; the moving speed of the terminal device; the cell information that the terminal device will pass by; the signal measurement results measured by the terminal device.

31. The method according to claim 30, wherein, the predicted trajectory is determined based on one or more of the following information: the geographical location of the terminal device within a first time window; the moving speed of the terminal device within a first time window; the cell information that the terminal device passes by within a first time window; the signal measurement results measured by the terminal device within a first time window; the geographical location of the terminal device at multiple sampling points after a first moment; the moving speed of the terminal device at multiple sampling points after a first moment; the cell information of the terminal device at multiple sampling points after a first moment; the signal measurement results measured by the terminal device at multiple sampling points after a first moment.

32. The method according to claim 31, wherein, The starting moment of the first time window is the moment when trajectory prediction starts, or the starting moment of the first time window is after the moment when trajectory prediction starts.

33. The method according to claim 31 or 32, wherein, the first moment is the moment when trajectory prediction starts, or the first moment is after the moment when trajectory prediction starts.

34. The method according to any one of claims 18-33, wherein, the method further includes: the first network device sends third information to a third network device, where the third information is used to instruct the third network device to cache reserved resources corresponding to the terminal device, the third network device includes network devices corresponding to at least one candidate cell among the multiple candidate cells, and the number of handovers required for the terminal device to hand over from the current cell to the at least one candidate cell is less than or equal to a preset threshold.

35. The method according to any one of claims 18-34, wherein, the method further includes: the first network device sends fourth information to a fourth network device, where the fourth information is used to indicate a second time window, and the second time window is used for the fourth network device to cache reserved resources corresponding to the terminal device within the second time window, and the fourth network device includes network devices corresponding to at least one candidate cell among the multiple candidate cells.

36. A terminal device, wherein, it includes: a receiving unit, configured to receive first configuration information sent by a first network device, where the first configuration information includes configuration information corresponding to multiple candidate cells, the multiple candidate cells are determined based on a predicted trajectory of the terminal device, and the multiple candidate cells are used for the terminal device to perform consecutive handovers.

37. The terminal device according to claim 36, wherein, the first configuration information is configured based on the levels of the multiple candidate cells, and among them, the number of handovers for consecutive handovers to candidate cells corresponding to different levels is different.

38. The terminal device according to claim 37, wherein, the multiple candidate cells include a first-level cell and a second-level cell of adjacent levels, and a first cell in the first-level cell and a second cell in the second-level cell have an association relationship, and the association relationship is used to indicate that the terminal device can perform a handover to the second cell in the next handover after switching to the first cell.

39. The terminal device according to claim 37, wherein, the multiple candidate cells include a third-level cell and a fourth-level cell of adjacent levels, and the terminal device can perform a handover to any cell in the fourth-level cell in the next handover after switching to any cell in the third-level cell.

40. The terminal device according to any one of claims 37-39, wherein, the terminal device further includes a sending unit If the handover to one of the multiple candidate cells is successfully performed based on the first configuration information, the sending unit is configured to send first information to the first network device, where the first information is used to apply for releasing the reserved resources corresponding to the candidate target cell, the candidate target cell is associated with the cell after handover, and the candidate target cell belongs to the multiple candidate cells.

41. The terminal device according to claim 40, wherein, the candidate target cell includes one or more of the following cells: The first target cell, where the first target cell is a cell at the same level as the cell after handover; The second target cell, where the second target cell has an association relationship with the first target cell, and the association relationship is used to indicate that the terminal device can be handed over to the second target cell in the next handover after being handed over to the first target cell.

42. The terminal device according to claim 40 or 41, wherein, the first configuration information includes a first conditional handover event, the first conditional handover event corresponds to a first candidate cell among the multiple candidate cells, and if the first candidate cell meets the first conditional handover event and the first candidate cell is not the cell after handover, the candidate target cell includes the first candidate cell.

43. The terminal device according to claim 42, wherein, the first conditional handover event is related to the location information of the terminal device and / or the time information of the terminal device.

44. The terminal device according to any one of claims 36-43, wherein, the update of the first configuration information is triggered by a first condition, and the first condition is related to one or more of the following information: the predicted trajectory of the terminal device; the cell handover situation of the terminal device; the access situation of the multiple candidate cells; the level of the cell after handover.

45. The terminal device according to claim 44, wherein, the first condition includes one or more of the following: the predicted trajectory changes; the cell handover fails and the reselection cell does not belong to the multiple candidate cells; the multiple candidate cells have completed access; the cell after handover belongs to the last-level cell.

46. The terminal device according to any one of claims 36-45, wherein, if the first configuration information needs to be updated, the receiving unit is further configured to: receive second configuration information sent by the first network device; wherein, the second configuration information includes all the configuration information for the terminal device to perform consecutive handovers, or at least part of the information in the first configuration information and at least part of the information in the second configuration information are used to generate third configuration information, and the third configuration information includes all the configuration information for the terminal device to perform consecutive handovers.

47. The terminal device according to any one of claims 36-46, wherein, if the handover to one of the multiple candidate cells is successfully performed based on the first configuration information, the terminal device further includes: A sending unit, configured to send second information to a second network device, where the second information is used to indicate that the second network device does not need to configure fourth configuration information, and the fourth configuration information is used for the terminal device to perform a one-hop handover from the current cell to the cell that needs to be handed over next time, and the second network device is the network device corresponding to the cell after handover.

48. The terminal device according to any one of claims 36-47, wherein, the multiple candidate cells are all or part of the cells on the predicted trajectory.

49. The terminal device according to claim 48, wherein, the predicted trajectory is related to one or more of the following information: the geographical location of the terminal device; the moving speed of the terminal device; the cell information that the terminal device will pass through; the signal measurement results measured by the terminal device.

50. The terminal device according to claim 49, wherein, the predicted trajectory is determined based on one or more of the following information: the geographical location of the terminal device within a first time window; the moving speed of the terminal device within a first time window; the cell information that the terminal device passes through within a first time window; the signal measurement results measured by the terminal device within a first time window; the geographical location of the terminal device at multiple sampling points after a first moment; the moving speed of the terminal device at multiple sampling points after a first moment; the cell information of the terminal device at multiple sampling points after a first moment; the signal measurement results measured by the terminal device at multiple sampling points after a first moment.

51. The terminal device according to claim 50, wherein, the start moment of the first time window is the moment when trajectory prediction starts, or the start moment of the first time window is after the moment when trajectory prediction starts.

52. The terminal device according to claim 50 or 51, wherein, the first moment is the moment when trajectory prediction starts, or the first moment is after the moment when trajectory prediction starts.

53. A network device, wherein, the network device is a first network device, and includes: a sending unit, configured to send first configuration information to a terminal device, where the first configuration information includes configuration information corresponding to multiple candidate cells, and the multiple candidate cells are determined based on the predicted trajectory of the terminal device, and the multiple candidate cells are used for the terminal device to perform continuous handovers.

54. The network device according to claim 53, wherein, the first configuration information is configured based on the levels of the multiple candidate cells, where the number of handover times for continuous handovers corresponding to candidate cells of different levels is different.

55. The network device according to claim 54, wherein, the multiple candidate cells include a first-level cell and a second-level cell of adjacent levels, and a first cell in the first-level cells has an association relationship with a second cell in the second-level cells, and the association relationship is used to indicate that the terminal device can perform a handover to the second cell in the next handover after switching to the first cell.

56. The network device according to claim 54, wherein, the multiple candidate cells include third-level cells and fourth-level cells of adjacent levels, and the next handover of the terminal device after handover to any one of the third-level cells can be to any one of the fourth-level cells.

57. The network device according to any one of claims 54-56, wherein, the network device further includes: a receiving unit, configured to receive first information sent by the terminal device, where the first information is used to apply for releasing reserved resources corresponding to a candidate target cell, the candidate target cell is associated with the cell after handover, the candidate target cell belongs to the multiple candidate cells, and the first information is sent when the terminal device successfully hands over to one of the multiple candidate cells based on the first configuration information.

58. The network device according to claim 57, wherein, the candidate target cell includes one or more of the following cells: a first target cell, which is a cell at the same level as the cell after handover; a second target cell, which has an association relationship with the first target cell, and the association relationship is used to indicate that the next handover of the terminal device after handover to the first target cell can be to the second target cell.

59. The network device according to claim 57 or 58, wherein, the first configuration information includes a first conditional handover event corresponding to a first candidate cell among the multiple candidate cells. If the first candidate cell meets the first conditional handover event and the first candidate cell is not the cell after handover, the candidate target cell includes the first candidate cell.

60. The network device according to claim 59, wherein, the first conditional handover event is related to the location information of the terminal device and / or the time information of the terminal device.

61. The network device according to any one of claims 53-60, wherein, the update of the first configuration information is triggered by a first condition, and the first condition is related to one or more of the following information: the predicted trajectory of the terminal device; the cell handover situation of the terminal device; the access situation of the multiple candidate cells; the level of the cell after handover.

62. The network device according to claim 61, wherein, the first condition includes one or more of the following: the predicted trajectory changes; the cell handover fails and the reselected cell does not belong to the multiple candidate cells; the multiple candidate cells have completed access; the cell after handover belongs to the last-level cell.

63. The network device according to any one of claims 53-62, wherein, if the first configuration information needs to be updated, the sending unit is further configured to: send second configuration information to the terminal device; wherein, the second configuration information includes all configuration information for the terminal device to perform continuous handovers, or the first At least part of the configuration information and at least part of the second configuration information are used to generate third configuration information, and the third configuration information includes all the configuration information for the terminal device to perform continuous handover.

64. The network device according to any one of claims 53-63, wherein, the multiple candidate cells are all or part of the cells on the predicted trajectory.

65. The network device according to claim 64, wherein, the predicted trajectory is related to one or more of the following information: the geographical location of the terminal device; the moving speed of the terminal device; the cell information that the terminal device will pass through; the signal measurement results measured by the terminal device.

66. The network device according to claim 65, wherein, the predicted trajectory is determined based on one or more of the following information: the geographical location of the terminal device within the first time window; the moving speed of the terminal device within the first time window; the cell information that the terminal device passes through within the first time window; the signal measurement results measured by the terminal device within the first time window; the geographical location of the terminal device at multiple sampling points after the first moment; the moving speed of the terminal device at multiple sampling points after the first moment; the cell information of the terminal device at multiple sampling points after the first moment; the signal measurement results measured by the terminal device at multiple sampling points after the first moment.

67. The network device according to claim 66, wherein, the starting moment of the first time window is the moment when the trajectory prediction starts, or the starting moment of the first time window is after the moment when the trajectory prediction starts.

68. The network device according to claim 66 or 67, wherein, the first moment is the moment when the trajectory prediction starts, or the first moment is after the moment when the trajectory prediction starts.

69. The network device according to any one of claims 53-68, wherein, the sending unit is further configured to: send third information to a third network device, where the third information is used to instruct the third network device to cache reserved resources corresponding to the terminal device, and the third network device includes the network device corresponding to at least one candidate cell among the multiple candidate cells, and the number of handovers required for the terminal device to switch from the current cell to the at least one candidate cell is less than or equal to a preset threshold.

70. The network device according to any one of claims 53-69, wherein, the sending unit is further configured to: send fourth information to a fourth network device, where the fourth information is used to indicate a second time window, and the second time window is used for the fourth network device to cache reserved resources corresponding to the terminal device within the second time window, and the fourth network device includes the network device corresponding to at least one candidate cell among the multiple candidate cells.

71. A terminal device, wherein, Comprising a memory, a processor, and a communication interface, the memory is used for storing programs, and the processor is used for calling the programs in the memory to enable the terminal device to execute the method according to any one of claims 1-17.

72. A network device, characterized in that it comprises a memory, a processor, and a communication interface, the memory is used for storing programs, and the processor is used for calling the programs in the memory to enable the network device to execute the method according to any one of claims 18-35.

73. A device, characterized in that it comprises a processor for calling a program from a memory to execute the method according to any one of claims 1-17.

74. A device, characterized in that it comprises a processor for calling a program from a memory to execute the method according to any one of claims 18-35.

75. A chip, characterized in that it comprises a processor for calling a program from a memory such that a device installed with the chip executes the method according to any one of claims 1-17.

76. A chip, characterized in that it comprises a processor for calling a program from a memory such that a device installed with the chip executes the method according to any one of claims 18-35.

77. A computer-readable storage medium, characterized in that a program is stored thereon, and the program enables a computer to execute the method according to any one of claims 1-17.

78. A computer-readable storage medium, characterized in that a program is stored thereon, and the program enables a computer to execute the method according to any one of claims 18-35.

79. A computer program product, characterized in that it comprises a program, and the program enables a computer to execute the method according to any one of claims 1-17.

80. A computer program product, characterized in that it comprises a program, and the program enables a computer to execute the method according to any one of claims 18-35.

81. A computer program, characterized in that the computer program enables a computer to execute the method according to any one of claims 1-17.

82. A computer program, characterized in that the computer program enables a computer to execute the method according to any one of claims 18-35.

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